Asymmetric-shell ignition capsule design to tune the low-mode asymmetry during the peak drive

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, Jianfa, E-mail: gu-jianfa@iapcm.ac.cn; Dai, Zhensheng, E-mail: dai-zhensheng@iapcm.ac.cn; Song, Peng

2016-08-15

The low-mode radiation flux asymmetry in the hohlraum is a main source of performance degradation in the National Ignition Facility (NIF) implosion experiments. To counteract the deleterious effects of the large positive P2 flux asymmetry during the peak drive, this paper develops a new tuning method called asymmetric-shell ignition capsule design which adopts the intentionally asymmetric CH ablator layer or deuterium-tritium (DT) ice layer. A series of two-dimensional implosion simulations have been performed, and the results show that the intentionally asymmetric DT ice layer can significantly improve the fuel ρR symmetry, hot spot shape, hot spot internal energy, and themore » final neutron yield compared to the spherical capsule. This indicates that the DT asymmetric-shell capsule design is an effective tuning method, while the CH ablator asymmetric-shell capsule could not correct the fuel ρR asymmetry, and it is not as effective as the DT asymmetric-shell capsule design.« less

Analytical model development for the prediction of the frictional resistance of a capsule endoscope inside an intestine.

PubMed

Kim, J S; Sung, I H; Kim, Y T; Kim, D E; Jang, Y H

2007-11-01

For the purpose of optimizing the design of the locomotion mechanism as well as the body shape of a self-propelled capsule endoscope, an analytical model for the prediction of frictional resistance of the capsule moving inside the small intestine was first developed. The model was developed by considering the contact geometry and viscoelasticity of the intestine, based on the experimental investigations on the material properties of the intestine and the friction of the capsule inside the small intestine. In order to verify the model and to investigate the distributions of various stress components applied to the capsule, finite element (FE) analyses were carried out. The comparison of the frictional resistance between the predicted and the experimental values suggested that the proposed model could predict the frictional force of the capsule with reasonable accuracy. Also, the FE analysis results of various stress components revealed the stress relaxation of the intestine and explained that such stress relaxation characteristics of the intestine resulted in lower frictional force as the speed of the capsule decreased. These results suggested that the frontal shape of the capsule was critical to the design of the capsule with desired frictional performance. It was shown that the proposed model can provide quantitative estimation of the frictional resistance of the capsule under various moving conditions inside the intestine. The model is expected to be useful in the design optimization of the capsule locomotion inside the intestine.

A review of parametric approaches specific to aerodynamic design process

NASA Astrophysics Data System (ADS)

Zhang, Tian-tian; Wang, Zhen-guo; Huang, Wei; Yan, Li

2018-04-01

Parametric modeling of aircrafts plays a crucial role in the aerodynamic design process. Effective parametric approaches have large design space with a few variables. Parametric methods that commonly used nowadays are summarized in this paper, and their principles have been introduced briefly. Two-dimensional parametric methods include B-Spline method, Class/Shape function transformation method, Parametric Section method, Hicks-Henne method and Singular Value Decomposition method, and all of them have wide application in the design of the airfoil. This survey made a comparison among them to find out their abilities in the design of the airfoil, and the results show that the Singular Value Decomposition method has the best parametric accuracy. The development of three-dimensional parametric methods is limited, and the most popular one is the Free-form deformation method. Those methods extended from two-dimensional parametric methods have promising prospect in aircraft modeling. Since different parametric methods differ in their characteristics, real design process needs flexible choice among them to adapt to subsequent optimization procedure.

Quantifying design trade-offs of beryllium targets on NIF

NASA Astrophysics Data System (ADS)

Yi, S. A.; Zylstra, A. B.; Kline, J. L.; Loomis, E. N.; Kyrala, G. A.; Shah, R. C.; Perry, T. S.; Kanzleiter, R. J.; Batha, S. H.; MacLaren, S. A.; Ralph, J. E.; Masse, L. P.; Salmonson, J. D.; Tipton, R. E.; Callahan, D. A.; Hurricane, O. A.

2017-10-01

An important determinant of target performance is implosion kinetic energy, which scales with the capsule size. The maximum achievable performance for a given laser is thus related to the largest capsule that can be imploded symmetrically, constrained by drive uniformity. A limiting factor for symmetric radiation drive is the ratio of hohlraum to capsule radii, or case-to-capsule ratio (CCR). For a fixed laser energy, a larger hohlraum allows for driving bigger capsules symmetrically at the cost of reduced peak radiation temperature (Tr). Beryllium ablators may thus allow for unique target design trade-offs due to their higher ablation efficiency at lower Tr. By utilizing larger hohlraum sizes than most modern NIF designs, beryllium capsules thus have the potential to operate in unique regions of the target design parameter space. We present design simulations of beryllium targets with a large CCR = 4.3 3.7 . These are scaled surrogates of large hohlraum low Tr beryllium targets, with the goal of quantifying symmetry tunability as a function of CCR. This work performed under the auspices of the U.S. DOE by LANL under contract DE-AC52- 06NA25396, and by LLNL under Contract DE-AC52-07NA27344.

Alternative hot spot formation techniques using liquid deuterium-tritium layer inertial confinement fusion capsules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olson, R. E.; Leeper, R. J.

2013-09-27

The baseline DT ice layer inertial confinement fusion (ICF) ignition capsule design requires a hot spot convergence ratio of ~34 with a hot spot that is formed from DT mass originally residing in a very thin layer at the inner DT ice surface. In the present paper, we propose alternative ICF capsule designs in which the hot spot is formed mostly or entirely from mass originating within a spherical volume of DT vapor. Simulations of the implosion and hot spot formation in two DT liquid layer ICF capsule concepts—the DT wetted hydrocarbon (CH) foam concept and the “fast formed liquid”more » (FFL) concept—are described and compared to simulations of standard DT ice layer capsules. 1D simulations are used to compare the drive requirements, the optimal shock timing, the radial dependence of hot spot specific energy gain, and the hot spot convergence ratio in low vapor pressure (DT ice) and high vapor pressure (DT liquid) capsules. 2D simulations are used to compare the relative sensitivities to low-mode x-ray flux asymmetries in the DT ice and DT liquid capsules. It is found that the overall thermonuclear yields predicted for DT liquid layer capsules are less than yields predicted for DT ice layer capsules in simulations using comparable capsule size and absorbed energy. However, the wetted foam and FFL designs allow for flexibility in hot spot convergence ratio through the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density, with a potentially improved robustness to low-mode x-ray flux asymmetry.« less

Alternative hot spot formation techniques using liquid deuterium-tritium layer inertial confinement fusion capsules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olson, R. E.; Leeper, R. J.

2013-09-15

The baseline DT ice layer inertial confinement fusion (ICF) ignition capsule design requires a hot spot convergence ratio of ∼34 with a hot spot that is formed from DT mass originally residing in a very thin layer at the inner DT ice surface. In the present paper, we propose alternative ICF capsule designs in which the hot spot is formed mostly or entirely from mass originating within a spherical volume of DT vapor. Simulations of the implosion and hot spot formation in two DT liquid layer ICF capsule concepts—the DT wetted hydrocarbon (CH) foam concept and the “fast formed liquid”more » (FFL) concept—are described and compared to simulations of standard DT ice layer capsules. 1D simulations are used to compare the drive requirements, the optimal shock timing, the radial dependence of hot spot specific energy gain, and the hot spot convergence ratio in low vapor pressure (DT ice) and high vapor pressure (DT liquid) capsules. 2D simulations are used to compare the relative sensitivities to low-mode x-ray flux asymmetries in the DT ice and DT liquid capsules. It is found that the overall thermonuclear yields predicted for DT liquid layer capsules are less than yields predicted for DT ice layer capsules in simulations using comparable capsule size and absorbed energy. However, the wetted foam and FFL designs allow for flexibility in hot spot convergence ratio through the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density, with a potentially improved robustness to low-mode x-ray flux asymmetry.« less

Capsule-odometer: a concept to improve accurate lesion localisation.

PubMed

Karargyris, Alexandros; Koulaouzidis, Anastasios

2013-09-21

In order to improve lesion localisation in small-bowel capsule endoscopy, a modified capsule design has been proposed incorporating localisation and - in theory - stabilization capabilities. The proposed design consists of a capsule fitted with protruding wheels attached to a spring-mechanism. This would act as a miniature odometer, leading to more accurate lesion localization information in relation to the onset of the investigation (spring expansion e.g., pyloric opening). Furthermore, this capsule could allow stabilization of the recorded video as any erratic, non-forward movement through the gut is minimised. Three-dimensional (3-D) printing technology was used to build a capsule prototype. Thereafter, miniature wheels were also 3-D printed and mounted on a spring which was attached to conventional capsule endoscopes for the purpose of this proof-of-concept experiment. In vitro and ex vivo experiments with porcine small-bowel are presented herein. Further experiments have been scheduled.

Capsule Escape Tests - Wallops Island

NASA Image and Video Library

1959-05-14

Caption: Off the pad abort shot at Wallops using Langley PARD designed full scale capsule with Recruit rocket and extended skirt main parachute. Shows sequential images of launch and capsule splashdown.

ARTIST CONCEPT - BIG JOE

NASA Image and Video Library

1963-09-01

S63-19317 (October 1963) --- Pen and ink views of comparative arrangements of several capsules including the existing "Big Joe" design, the compromise "Big Joe" design, and the "Little Joe". All capsule designs are labeled and include dimensions. Photo credit: NASA

COMPASS Final Report: Near Earth Asteroids Rendezvous and Sample Earth Returns (NEARER)

NASA Technical Reports Server (NTRS)

Oleson, Steven R.; McGuire, Melissa L.

2009-01-01

In this study, the Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS) team completed a design for a multi-asteroid (Nereus and 1996 FG3) sample return capable spacecraft for the NASA In-Space Propulsion Office. The objective of the study was to support technology development and assess the relative benefits of different electric propulsion systems on asteroid sample return design. The design uses a single, heritage Orion solar array (SA) (approx.6.5 kW at 1 AU) to power a single NASA Evolutionary Xenon Thruster ((NEXT) a spare NEXT is carried) to propel a lander to two near Earth asteroids. After landing and gathering science samples, the Solar Electric Propulsion (SEP) vehicle spirals back to Earth where it drops off the first sample s return capsule and performs an Earth flyby to assist the craft in rendezvousing with a second asteroid, which is then sampled. The second sample is returned in a similar fashion. The vehicle, dubbed Near Earth Asteroids Rendezvous and Sample Earth Returns (NEARER), easily fits in an Atlas 401 launcher and its cost estimates put the mission in the New Frontier s (NF's) class mission.

Fabrication of capsule assemblies, phase 3

NASA Technical Reports Server (NTRS)

Keeton, A. R.; Stemann, L. G.

1973-01-01

Thirteen capsule assemblies were fabricated for evaluation of fuel pin design concepts for a fast spectrum lithium cooled compact space power reactor. These instrumented assemblies were designed for real time test of prototype fuel pins. Uranium mononitride fuel pins were encased in AISI 304L stainless steel capsules. Fabrication procedures were fully qualified by process development and assembly qualification tests. Instrumentation reliability was achieved utilizing specially processed and closely controlled thermocouple hot zone fabrication and by thermal screening tests. Overall capsule reliability was achieved with an all electron beam welded assembly.

Modular "plug-and-play" capsules for multi-capsule environment in the gastrointestinal tract.

PubMed

Phee, S J; Ting, E K; Lin, L; Huynh, V A; Kencana, A P; Wong, K J; Tan, S L

2009-01-01

The invention of wireless capsule endoscopy has opened new ways of diagnosing and treating diseases in the gastrointestinal tract. Current wireless capsules can perform simple operations such as imaging and data collection (like temperature, pressure, and pH) in the gastrointestinal tract. Researchers are now focusing on adding more sophisticated functions such as drug delivery, surgical clips/tags deployment, and tissue samples collection. The finite on-board power on these capsules is one of the factors that limits the functionalities of these wireless capsules. Thus multiple application-specific capsules would be needed to complete an endoscopic operation. This would give rise to a multi-capsule environment. Having a modular "plug-and-play" capsule design would facilitate doctors in configuring multiple application-specific capsules, e.g. tagging capsule, for use in the gastrointestinal tract. This multi-capsule environment also has the advantage of reducing power consumption through asymmetric multi-hop communication.

Development of a High Efficiency Dry Powder Inhaler: Effects of Capsule Chamber Design and Inhaler Surface Modifications

PubMed Central

Behara, Srinivas R.B.; Farkas, Dale R.; Hindle, Michael; Longest, P. Worth

2013-01-01

Purpose The objective of this study was to explore the performance of a high efficiency dry powder inhaler (DPI) intended for excipient enhanced growth (EEG) aerosol delivery based on changes to the capsule orientation and surface modifications of the capsule and device. Methods DPIs were constructed by combining newly designed capsule chambers (CC) with a previously developed three-dimensional (3D) rod array for particle deagglomeration and a previously optimized EEG formulation. The new CCs oriented the capsule perpendicular to the incoming airflow and were analyzed for different air inlets at a constant pressure drop across the device. Modifications to the inhaler and capsule surfaces included use of metal dispersion rods and surface coatings. Aerosolization performance of the new DPIs was evaluated and compared with commercial devices. Results The proposed capsule orientation and motion pattern increased capsule vibrational frequency and reduced the aerosol MMAD compared with commercial/modified DPIs. The use of metal rods in the 3D array further improved inhaler performance. Coating the inhaler and capsule with PTFE significantly increased emitted dose (ED) from the optimized DPI. Conclusions High efficiency performance is achieved for EEG delivery with the optimized DPI device and formulation combination producing an aerosol with MMAD < 1.5 µm, FPF<5µm/ED > 90%, and ED > 80%. PMID:23949304

The effects of hematoma on implant capsules.

PubMed

Caffee, H H

1986-02-01

Hematoma surrounding an implant is one of the many factors that have been suggested as possible causes for scar capsule contracture. In this study, experiments were designed to determine the influence of hematoma on the incidence and severity of capsule contracture in rabbits. Two implants were placed in each animal, 1 with a surrounding hematoma and 1 control. Capsules were evaluated subjectively and compared objectively with measurements of deformability, surface area, and capsule thickness. No differences were found with any of the objective criteria, which suggests that hematoma may not be a noteworthy cause of implant capsule contracture.

A pilot trial of ambulatory monitoring of gastric motility using a modified magnetic capsule endoscope.

PubMed

Kim, Hee Man; Choi, Ja Sung; Cho, Jae Hee

2014-04-30

The magnetic capsule endoscope has been modified to be fixed inside the stomach and to monitor the gastric motility. This pilot trial was designed to investigate the feasibility of the magnetic capsule endoscope for monitoring gastric motility. The magnetic capsule endoscope was swallowed by the healthy volunteer and maneuvered by the external magnet on his abdomen surface inside the stomach. The magnetic capsule endoscope transmitted image of gastric peristalsis. This simple trial suggested that the real-time ambulatory monitoring of gastric motility should be feasible by using the magnetic capsule endoscope.

Design and Follow-on from 50 kJ Fusion Yield using High-Density Carbon Capsules at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Berzak Hopkins, L.; Lepape, S.; Divol, L.; Pak, A.; Goyon, C.; Dewald, E.; Ho, D. D.; Khan, S. F.; Weber, C.; Meezan, N. B.; Biener, J.; Grim, G.; Ma, T.; Milovich, J. L.; Moore, A. S.; Nikroo, A.; Ross, J. S.; Stadermann, M.; Volegov, P.; Wild, C.; Callahan, D. A.; Hurricane, O. A.; Hsing, W. W.; Town, R. P. J.; Edwards, M. J.

2017-10-01

We have demonstrated nearly 3x alpha-heating at the National Ignition Facility by using tungsten-doped High-Density Carbon (HDC) capsules in low gasfill, unlined, uranium (DU) hohlraums. Shot N170601 achieved a primary neutron yield of 1.5 x 1016 neutrons with a Deuterium-Tritium ion temperature of 4.7 keV. Predecessor experiments demonstrated high-performing, efficient performance, as noted through high neutron yield production per laser energy input. Building on these `subscale' results, follow-on experiments utilize an 8% larger target than the predecessor campaign, to increase the capsule surface area and absorbed energy. The capsule fill tube has been reduced in size from 10 to 5 micron diameter, and the laser design implements a new, ``drooping'' technique for the end of the pulse, to reduce the time between laser shut-off and capsule peak emission while still maintaining capsule mass remaining. Design of the current platform as well as avenues to potentially improve performance based on these experiments will be discussed. Work performed under the auspices of the U.S. D.O.E. by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

Design and fabrication of a magnetic propulsion system for self-propelled capsule endoscope.

PubMed

Gao, Mingyuan; Hu, Chengzhi; Chen, Zhenzhi; Zhang, Honghai; Liu, Sheng

2010-12-01

This paper investigates design, modeling, simulation, and control issues related to self-propelled endoscopic capsule navigated inside the human body through external magnetic fields. A novel magnetic propulsion system is proposed and fabricated, which has great potential of being used in the field of noninvasive gastrointestinal endoscopy. Magnetic-analysis model is established and finite-element simulations as well as orthogonal design are performed for obtaining optimized mechanical and control parameters for generating appropriate external magnetic field. Simulated intestinal tract experiments are conducted, demonstrating controllable movement of the capsule under the developed magnetic propulsion system.

Implementing Capsule Representation in a Total Hip Dislocation Finite Element Model

PubMed Central

Stewart, Kristofer J; Pedersen, Douglas R; Callaghan, John J; Brown, Thomas D

2004-01-01

Previously validated hardware-only finite element models of THA dislocation have clarified how various component design and surgical placement variables contribute to resisting the propensity for implant dislocation. This body of work has now been enhanced with the incorporation of experimentally based capsule representation, and with anatomic bone structures. The current form of this finite element model provides for large deformation multi-body contact (including capsule wrap-around on bone and/or implant), large displacement interfacial sliding, and large deformation (hyperelastic) capsule representation. In addition, the modular nature of this model now allows for rapid incorporation of current or future total hip implant designs, accepts complex multi-axial physiologic motion inputs, and outputs case-specific component/bone/soft-tissue impingement events. This soft-tissue-augmented finite element model is being used to investigate the performance of various implant designs for a range of clinically-representative soft tissue integrities and surgical techniques. Preliminary results show that capsule enhancement makes a substantial difference in stability, compared to an otherwise identical hardware-only model. This model is intended to help put implant design and surgical technique decisions on a firmer scientific basis, in terms of reducing the likelihood of dislocation. PMID:15296198

Management of the Cs/Sr Capsule Project at the Hanford Site. Technology Readiness Assessment Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

The Federal Project Director (FPD) for the U.S. Department of Energy (DOE), Richland Operations Office (RL) Waste Management and D&D Division (WMD) requested a Technology Readiness Assessment (TRA) for the Management of the Cesium/Strontium Capsule Storage Project (MCSCP) at the Waste Encapsulation and Storage Facility (WESF) on the Hanford Site in Washington State. The MCSCP CD-1 TRA was performed by a team selected in collaboration between the Office of Environmental Management (EM) Chief Engineer (EM-3.3) and RL, WMD FPD. The TRA Team included subject matter and technical experts having experience in cask storage, process engineering, and system design who weremore » independent of the MCSCP, and the team was led by the Director of Operations and Processes from the EM Chief Engineer's Office (EM-3.32). Movement of the Cs/Sr capsules to dry storage, based on information from the conceptual design, involves (1) capsule packaging, (2) capsule transfer, and (3) capsule storage. The project has developed a conceptual process, described in 30059-R-02, "NAC Conceptual Design Report for the Management of the Cesium and Strontium Capsules Project", which identifies the five major activities in the process to complete the transfer from storage pool to pad-mounted cask storage. The process, shown schematically in Figure 1, is comprised of the following process steps: (1) loading capsules into the UCS; (2) UCS processing; (3) UCS insertion into the TSC Basket; (4) cask transport from WESF to CSA and (5) extended storage at the CSA.« less

Magnetically Actuated Soft Capsule With the Multimodal Drug Release Function

PubMed Central

Yim, Sehyuk; Goyal, Kartik; Sitti, Metin

2014-01-01

In this paper, we present a magnetically actuated multimodal drug release mechanism using a tetherless soft capsule endoscope for the treatment of gastric disease. Because the designed capsule has a drug chamber between both magnetic heads, if it is compressed by the external magnetic field, the capsule could release a drug in a specific position locally. The capsule is designed to release a drug in two modes according to the situation. In the first mode, a small amount of drug is continuously released by a series of pulse type magnetic field (0.01–0.03 T). The experimental results show that the drug release can be controlled by the frequency of the external magnetic pulse. In the second mode, about 800 mm3 of drug is released by the external magnetic field of 0.07 T, which induces a stronger magnetic attraction than the critical force for capsule’s collapsing. As a result, a polymeric coating is formed around the capsule. The coated area is dependent on the drug viscosity. This paper presents simulations and various experiments to evaluate the magnetically actuated multimodal drug release capability. The proposed soft capsules could be used as minimally invasive tetherless medical devices with therapeutic capability for the next generation capsule endoscopy. PMID:25378896

Polar tent for reduced perturbation of NIF ignition capsules

NASA Astrophysics Data System (ADS)

Hammel, B. A.; Pickworth, L.; Stadermann, M.; Field, J.; Robey, H.; Scott, H. A.; Smalyuk, V.

2016-10-01

In simulations, a tent that contacts the capsule near the poles and departs tangential to the capsule surface greatly reduces the capsule perturbation, and the resulting mass injected into the hot-spot, compared to current capsule support methods. Target fabrication appears feasible with a layered tent (43-nm polyimide + 8-nm C) for increased stiffness. We are planning quantitative measurements of the resulting shell- ρR perturbation near peak implosion velocity (PV) using enhanced self-emission backlighting, achieved by adding 1% Ar to the capsule fill in Symcaps (4He + H). Layered DT implosions are also planned for an integrated test of capsule performance. We will describe the design and simulation predictions. Prepared by LLNL under Contract DE-AC52-07NA27344.

An experimental study of resistant properties of the small intestine for an active capsule endoscope.

PubMed

Wang, X; Meng, M Q-H

2010-01-01

Use of the capsule endoscope (CE) in clinical examinations is limited by its passive movement resulting from the natural peristalsis of the gastrointestinal (GI) tract. Therefore, a locomotion mechanism is desirable for the next generation of capsule endoscope. Understanding the resistant properties of the small intestine is essential for designing a wireless magnetic actuation mechanism. In this paper, in vitro experiments were carried out to investigate the resistant force of the small intestine using 15 specially designed capsule prototypes and analysed the effect of the capsule dimension and moving speed. Segments of porcine small intestine were employed as a conservative model for the human intestine. When the capsules under experiment were moving at a speed of 0.5 mm/s, a resistant force of 20 to 100 mN were measured for the capsule diameter in the range of 8 to 13 mm. The force increased with moving speed. The intrinsic cause of the resistant force of the small intestine is discussed based on an analysis of the experimental data. It is believed that the viscoelastic properties of the tissue play an important role in the resistant characteristics of the small intestine.

Augmentation of intramembranous bone in rabbit calvaria using an occlusive barrier in combination with demineralized bone matrix (DBM): a pilot study.

PubMed

Beltrán, Víctor; Engelke, Wilfried; Prieto, Ruth; Valdivia-Gandur, Iván; Navarro, Pablo; Manzanares, María Cristina; Borie, Eduardo; Fuentes, Ramón

2014-01-01

The aim of this study was to histologically evaluate the performance of demineralized bone matrix (DBM) when compared with a blood clot in addition to an occlusive barrier in the bone regeneration process for bone defects in a rabbit model. Prefabricated metallic capsules with 4.5 mm and 3.5 mm dimensions were placed in five adult rabbit skulls. At the right side, the capsule was filled with DBM, and the clot was located on the left side. The barriers were supplied with a 0.5 mm horizontal peripheral flap and a vertical edge, fitting tightly into a circular slit prepared by a trephine in the skull. After a healing period of three months, the animals were sacrificed, and the samples were prepared for histological and histomorphometric analyses after capsule removal. Trabecular and medullar bone percentages were calculated from the different areas of the newly formed bone inside the metallic barriers, and non-parametric statistical analysis was used to describe the findings. The results showed a complete filling of newly formed bone inside the capsules of both groups. Less mature bone tissue was observed in the upper third of all samples, and a higher trabecular area was observed in the samples with DBM. The use of barriers resulted in the augmentation of newly formed bone in a three-month period. However, a higher trabecular area was observed in the barriers filled with DBM. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Reentry Capsule for Sample Return from Asteroids in the Planetary Exploration Missions

NASA Astrophysics Data System (ADS)

Inatani, Yoshifumi

2018-04-01

For carrying sample from the bodies of interplanetary space, a wide range of knowledge of reentry technology is needed. HAYABUSA(MUSES-C) was an asteroid explorer returned to the earth after the 7 years of voyage, and its capsule reenters into the Earth’s atmosphere, which was a good example of reentry technology implemented to the flight vehicle. It performed a safe reentry flight and recovery. For the design of the capsule, many considerations were made due to its higher entry velocity and higher aerodynamic heating than those of normal reentry from the low earth orbit. Taking into account the required functions throughout the orbital flight, reentry flight, and descent/recovery phase, the capsule was deigned, tested, manufactured and flight demonstrated finally. The paper presents the concept of the design and qualification approach of the small space capsule of the asteroid sample and return mission. And presented are how the reentry flight was performed and a brief overview of the post flight analysis primarily for these design validation purposes and for the better understanding of the flight results.

Exploring the effects of defects on DT burn, the DIME experiment and measuring capsule zero-order hydrodynamics using Polar direct drive

NASA Astrophysics Data System (ADS)

Magelssen, G. R.; Bradley, P. A.; Tregillis, I. L.; Schmitt, M. J.; Dodd, E. S.; Wysocki, F. J.; Hsu, S. C.; Cobble, J.; Batha, S. H.; Defriend Obrey, K. A.

2010-11-01

Small capsule perturbations may impact our ability to achieve high yields on NIF. Diagnosing the hydrodynamic development and the effect of defects on burn will be difficult. Los Alamos is developing a program to better understand the hydrodynamics of defects and how they influence burn. Our first effort to study the effects of defects was on Omega. Both thin-shelled (exploding pusher) and thick-shelled capsules were shot and the results published [1]. In this work we add experimental shots done recently on Omega. These shots were to complete the study of how the width and depth of the defect affects DT yield. Our AMR code is used to predict the yield. Comparisons between capsule and experimental yields will be given. Experiments are also being designed for Polar direct drive. Our first experiments are being designed to understand the zero-order hydrodynamics with Polar direct drive. Capsules about a millimeter in radius are being designed with one to two dopants in the CH shell for radiograph and MMI usage. Also, to minimize the effect of mix on the radius versus time trajectory, some capsules will replace the DT with Xe.[0pt] [1] Magelssen G. R. et al., to be published in the 2009 IFSA proceedings.

IRRADIATION-CAPSULE STUDY OF URANIUM MONOCARBIDE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Price, R.B.; Stahl, D.; Stang, J.H.

1960-03-01

Small cylindrical specimens of enriched UC were irradiated to evaluate usefulness as a high-temperature fuel for stationary power reactors. Detailed thermal and nuclear analyses were made to arrive at an appropriate capsule design on the basis of target specimen center-line temperature ( approximately 1500 deg F), specimen surface temperature (1100 deg F), specimen composition (U--5 wt.% C), and acapsule o.d. of 1.125 in. Temperature data from thermocouples inside the capsule indicated that five of the six capsules irradiated operated at close to the design conditions. Irradiation periods for individual capsules were varied to give burnups ranging from 1,000 to 20,000more » Mwd/t of U. Preliminary evidence indicates that this range of burnups was achieved. By using temperature and heat-flux data from the actual irradiations to estimate effective in-pile specimen thermal conductivities, it was found that the conductivity did not appear to vary during the exposures. (auth)« less

Mercury Capsule Construction at the NASA Lewis Research Center

NASA Image and Video Library

1959-08-21

A NASA mechanic secures the afterbody to a Mercury capsule in the hangar at the Lewis Research Center. The capsule was one of two built at Lewis for the “Big Joe” launches scheduled for September 1959. The initial phase of Project Mercury consisted of a series of unmanned launches using the Air Force’s Redstone and Atlas boosters and the Langley-designed Little Joe boosters. The first Atlas launch, referred to as “Big Joe”, was a single attempt early in Project Mercury to use a full-scale Atlas booster to simulate the reentry of a mock-up Mercury capsule without actually placing it in orbit. The overall design of Big Joe had been completed by December 1958, and soon thereafter project manager Aleck Bond assigned NASA Lewis the task of designing the electronic instrumentation and automatic stabilization system. Lewis also constructed the capsule’s lower section, which contained a pressurized area with the electronics and two nitrogen tanks for the retrorockets. Lewis technicians were responsible for assembling the entire capsule: the General Electric heatshield, NASA Langley afterbody and recovery canister, and Lewis electronics and control systems. On June 9, 1959, the capsule was loaded on an air force transport aircraft and flown to Cape Canaveral. A team of 45 test operations personnel from Lewis followed the capsule to Florida and spent the ensuing months preparing it for launch. The launch took place in the early morning hours of September 9, 1959.

Double-balloon endoscopy as the primary method for small-bowel video capsule endoscope retrieval.

PubMed

Van Weyenberg, Stijn J B; Van Turenhout, Sietze T; Bouma, Gerd; Van Waesberghe, Jan Hein T M; Van der Peet, Donald L; Mulder, Chris J J; Jacobs, Maarten A J M

2010-03-01

Capsule retention in the small bowel is a known complication of small-bowel video capsule endoscopy. Surgery is the most frequently used method of capsule retrieval. To determine the incidence and causes of capsule retention and to describe double-balloon endoscopy (DBE) as the primary technique used for capsule retrieval. Retrospective analysis of all video capsule studies was performed at our center, and evaluation of the outcome of DBE was the first method used to retrieve entrapped video capsules. Tertiary referral center. A total of 904 patients who underwent small-bowel video capsule endoscopy. Capsule retrieval by DBE. The number of patients in whom capsule retention occurred and the number of patients in whom an entrapped capsule could be retrieved by using DBE. Capsule retention occurred in 8 patients (incidence 0.88%; 95% CI, 0.41%-1.80%) and caused acute small-bowel obstruction in 6 patients. All retained capsules were successfully removed during DBE. Five patients underwent elective surgery to treat the underlying cause of capsule retention. One patient required emergency surgery because of multiple small-bowel perforations. Retrospective design. In our series, the incidence of capsule retention was low. DBE is a reliable method for removing retained capsules and might prevent unnecessary surgery. If surgery is required, preoperative capsule retrieval allows preoperative diagnosis, adequate staging in case of malignancy, and optimal surgical planning. 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Project Mercury; Little Joe

NASA Image and Video Library

1959-07-30

Assembling the Little Joe capsules. The capsules were manufactured in-house by Langley technicians. Three capsules are shown here in various stages of assembly. The escape tower and rocket motors shown on the completed capsule would be removed before shipping and finally assembly for launching at Wallops Island. Joseph Shortal wrote (vol. 3, p. 32): Design of the Little Joe capsules began at Langley before McDonnell started on the design of the Mercury capsule and was, therefore, a separate design. Although it was not designed to carry a man, it did have to carry a monkey. It had to meet the weight and center of gravity requirements of Mercury and withstand the same aerodynamic loads during the exit trajectory. Although in comparison with the overall Mercury Project, Little Joe was a simple undertaking, the fact that an attempt was made to condense a normal two-year project into a 6-month one with in house labor turned it into a major undertaking for Langley. Project Mercury: Little Joe: Boilerplate Mercury spacecraft undergo fabrication at the shops of the Langley Research Center. They will launched atop Little Joe rockets to test the spacecraft recovery systems. -- Published in Joseph A. Shortal, History of Wallops Station: Origins and Activities Through 1949, (Wallops Island, VA: National Aeronautics and Space Administration, Wallops Station, nd), Comment Edition. L59-4947 Technicians prepare a Little Joe launch vehicle prototype for the Mercury space program, 1959. Photograph published in Winds of Change, 75th Anniversary NASA publication, page 76, by James Schultz

Integration of Low-Power ASIC and MEMS Sensors for Monitoring Gastrointestinal Tract Using a Wireless Capsule System.

PubMed

Arefin, Md Shamsul; Redoute, Jean-Michel; Yuce, Mehmet Rasit

2018-01-01

This paper presents a wireless capsule microsystem to detect and monitor the pH, pressure, and temperature of the gastrointestinal tract in real time. This research contributes to the integration of sensors (microfabricated capacitive pH, capacitive pressure, and resistive temperature sensors), frequency modulation and pulse width modulation based interface IC circuits, microcontroller, and transceiver with meandered conformal antenna for the development of a capsule system. The challenges associated with the system miniaturization, higher sensitivity and resolution of sensors, and lower power consumption of interface circuits are addressed. The layout, PCB design, and packaging of a miniaturized wireless capsule, having diameter of 13 mm and length of 28 mm, have successfully been implemented. A data receiver and recorder system is also designed to receive physiological data from the wireless capsule and to send it to a computer for real-time display and recording. Experiments are performed in vitro using a stomach model and minced pork as tissue simulating material. The real-time measurements also validate the suitability of sensors, interface circuits, and meandered antenna for wireless capsule applications.

Status Report on Irradiation Capsules Designed to Evaluate FeCrAl-UO 2 Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Field, Kevin G.; Howard, Richard H.

This status report provides the background and current status of a series of irradiation capsules that were designed and are being built to test the interactions between candidate FeCrAl cladding for enhanced accident tolerant applications and prototypical enriched commercial UO 2 fuel in a neutron radiation environment. These capsules will test the degree, if any, of fuel cladding chemical interactions (FCCI) between FeCrAl and UO 2. The capsules are to be irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory to burn-ups of 10, 30, and 50 GWd/MT with a nominal target temperature at the interfaces between themore » pellets and clad of 350°C.« less

[Design of Adjustable Magnetic Field Generating Device in the Capsule Endoscope Tracking System].

PubMed

Ruan, Chao; Guo, Xudong; Yang, Fei

2015-08-01

The capsule endoscope swallowed from the mouth into the digestive system can capture the images of important gastrointestinal tract regions. It can compensate for the blind spot of traditional endoscopic techniques. It enables inspection of the digestive system without discomfort or need for sedation. However, currently available clinical capsule endoscope has some limitations such as the diagnostic information being not able to correspond to the orientation in the body, since the doctor is unable to control the capsule motion and orientation. To solve the problem, it is significant to track the position and orientation of the capsule in the human body. This study presents an AC excitation wireless tracking method in the capsule endoscope, and the sensor embedded in the capsule can measure the magnetic field generated by excitation coil. And then the position and orientation of the capsule can be obtained by solving a magnetic field inverse problem. Since the magnetic field decays with distance dramatically, the dynamic range of the received signal spans three orders of magnitude, we designed an adjustable alternating magnetic field generating device. The device can adjust the strength of the alternating magnetic field automatically through the feedback signal from the sensor. The prototype experiment showed that the adjustable magnetic field generating device was feasible. It could realize the automatic adjustment of the magnetic field strength successfully, and improve the tracking accuracy.

Light weight escape capsule for fighter aircraft

NASA Technical Reports Server (NTRS)

Robert, James A.

1988-01-01

Emergency crew escape capabilities have been less than adequate for fighter aircraft since before WW II. From the over-the-side bailout of those days through the current ejection seat with a rocket catapult, escaping from a disabled aircraft has been risky at best. Current efforts are underway toward developing a high-tech, smart ejection seat that will give fighter pilots more room to live in the sky, but an escape capsule is needed to meet current and future fighter envelopes. Escape capsules have a bad reputation due to past examples of high weight, poor performance and great complexity. However, the advantages available demand that a capsule be developed. This capsule concept will minimize the inherent disavantages and incorporate the benefits while integrating all aspects of crew station design. The resulting design is appropriate for a crew station of the year 2010 and includes improved combat acceleration protection, chemical or biological combat capability, improved aircraft to escape system interaction, and the highest level of escape performance achievable. The capsule is compact, which can allow a reduced aircraft size and weighs only 1200 lb. The escape system weight penalty is only 120 lb higher than that for the next ejection seat and the capsule has a corresponding increase in performance.

In Vivo Characterization of a Wireless Telemetry Module for a Capsule Endoscopy System Utilizing a Conformal Antenna.

PubMed

Faerber, Julia; Cummins, Gerard; Pavuluri, Sumanth Kumar; Record, Paul; Rodriguez, Adrian R Ayastuy; Lay, Holly S; McPhillips, Rachael; Cox, Benjamin F; Connor, Ciaran; Gregson, Rachael; Clutton, Richard Eddie; Khan, Sadeque Reza; Cochran, Sandy; Desmulliez, Marc P Y

2018-02-01

This paper describes the design, fabrication, packaging, and performance characterization of a conformal helix antenna created on the outside of a capsule endoscope designed to operate at a carrier frequency of 433 MHz within human tissue. Wireless data transfer was established between the integrated capsule system and an external receiver. The telemetry system was tested within a tissue phantom and in vivo porcine models. Two different types of transmission modes were tested. The first mode, replicating normal operating conditions, used data packets at a steady power level of 0 dBm, while the capsule was being withdrawn at a steady rate from the small intestine. The second mode, replicating the worst-case clinical scenario of capsule retention within the small bowel, sent data with stepwise increasing power levels of -10, 0, 6, and 10 dBm, with the capsule fixed in position. The temperature of the tissue surrounding the external antenna was monitored at all times using thermistors embedded within the capsule shell to observe potential safety issues. The recorded data showed, for both modes of operation, a low error transmission of 10 -3 packet error rate and 10 -5 bit error rate and no temperature increase of the tissue according to IEEE standards.

A modular and programmable development platform for capsule endoscopy system.

PubMed

Khan, Tareq Hasan; Shrestha, Ravi; Wahid, Khan A

2014-06-01

The state-of-the-art capsule endoscopy (CE) technology offers painless examination for the patients and the ability to examine the interior of the gastrointestinal tract by a noninvasive procedure for the gastroenterologists. In this work, a modular and flexible CE development system platform consisting of a miniature field programmable gate array (FPGA) based electronic capsule, a microcontroller based portable data recorder unit and computer software is designed and developed. Due to the flexible and reprogrammable nature of the system, various image processing and compression algorithms can be tested in the design without requiring any hardware change. The designed capsule prototype supports various imaging modes including white light imaging (WLI) and narrow band imaging (NBI), and communicates with the data recorder in full duplex fashion, which enables configuring the image size and imaging mode in real time during examination. A low complexity image compressor based on a novel color-space is implemented inside the capsule to reduce the amount of RF transmission data. The data recorder contains graphical LCD for real time image viewing and SD cards for storing image data. Data can be uploaded to a computer or Smartphone by SD card, USB interface or by wireless Bluetooth link. Computer software is developed that decompresses and reconstructs images. The fabricated capsule PCBs have a diameter of 16 mm. An ex-vivo animal testing has also been conducted to validate the results.

Specification for strontium-90 500-watt(e) radioisotopic thermoelectric generator

NASA Astrophysics Data System (ADS)

Hammel, T.; Himes, J.; Lieberman, A.; McGrew, J. W.; Owings, D.; Schumann, F.

1983-04-01

A conceptual design for a demonstration 500-watt(e) radioisotopic thermoelectric generator (RTG) was created. The design effort was divided into two tasks, viz., create a design specification for a capsule strenth member that utilizes a standard Strontium 90 fluoride filled WESF inner liner, and create a conceptual design for a 500-watt(e) RTG. The strength member specification was designed to survive an external pressure of 24,500 psi and meet the requirements of special form radioisotope heat sources. Therefore the capsule is if desired, licensed for domestic and international transport. The design for the RTG features a radioisotopic heat source, an array of nine capsules in a tungsten biological shield, four current technology series connected thermoelectric conversion modules, low conductivity thermal insulation, and a passive finned housing radiator for waste heat dissipation. The preliminary RTG specification formulated previous to contract award was met or exceeded.

Influence and measurement of mass ablation in ICF implosions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spears, B K; Hicks, D; Velsko, C

2007-09-05

Point design ignition capsules designed for the National Ignition Facility (NIF) currently use an x-ray-driven Be(Cu) ablator to compress the DT fuel. Ignition specifications require that the mass of unablated Be(Cu), called residual mass, be known to within 1% of the initial ablator mass when the fuel reaches peak velocity. The specifications also require that the implosion bang time, a surrogate measurement for implosion velocity, be known to +/- 50 ps RMS. These specifications guard against several capsule failure modes associated with low implosion velocity or low residual mass. Experiments designed to measure and to tune experimentally the amount ofmore » residual mass are being developed as part of the National Ignition Campaign (NIC). Tuning adjustments of the residual mass and peak velocity can be achieved using capsule and laser parameters. We currently plan to measure the residual mass using streaked radiographic imaging of surrogate tuning capsules. Alternative techniques to measure residual mass using activated Cu debris collection and proton spectrometry have also been developed. These developing techniques, together with bang time measurements, will allow us to tune ignition capsules to meet NIC specs.« less

Development of thermal protection system of the MUSES-C/DASH reentry capsule

NASA Astrophysics Data System (ADS)

Yamada, Tetsuya; Inatani, Yoshifumi; Honda, Masahisa; Hirai, Ken'ich

2002-07-01

In the final phase of the MUSES-C mission, a small capsule with asteroid sample conducts reentry flight directly from the interplanetary transfer orbit at the velocity over 12 km/s. The severe heat flux, the complicated functional requirements, and small weight budget impose several engineering challenges on the designing of the thermal protection system of the capsule. The heat shield is required to function not only as ablator but also as a structural component. The cloth-layered carbon-phenolic ablator, which has higher allowable stress, is developed in newly-devised fabric method for avoiding delamination due to the high aerodynamic heating. The ablation analysis code, which takes into account of the effect of pyrolysis gas on the surface recession rate, has been developed and verified in the arc-heating tests in the facility environment of broad range of enthalpy level. The capsule was designed to be ventilated during the reentry flight up to about atmospheric pressure by the time of parachute deployment by being sealed with porous flow-restrict material. The designing of the thermal protection system, the hardware specifications, and the ground-based test programs of both MUSES-C and DASH capsule are summarized and discussed here in this paper.

Design of a video capsule endoscopy system with low-power ASIC for monitoring gastrointestinal tract.

PubMed

Liu, Gang; Yan, Guozheng; Zhu, Bingquan; Lu, Li

2016-11-01

In recent years, wireless capsule endoscopy (WCE) has been a state-of-the-art tool to examine disorders of the human gastrointestinal tract painlessly. However, system miniaturization, enhancement of the image-data transfer rate and power consumption reduction for the capsule are still key challenges. In this paper, a video capsule endoscopy system with a low-power controlling and processing application-specific integrated circuit (ASIC) is designed and fabricated. In the design, these challenges are resolved by employing a microimage sensor, a novel radio frequency transmitter with an on-off keying modulation rate of 20 Mbps, and an ASIC structure that includes a clock management module, a power-efficient image compression module and a power management unit. An ASIC-based prototype capsule, which measures Φ11 mm × 25 mm, has been developed here. Test results show that the designed ASIC consumes much less power than most of the other WCE systems and that its total power consumption per frame is the least. The image compression module can realize high near-lossless compression rate (3.69) and high image quality (46.2 dB). The proposed system supports multi-spectral imaging, including white light imaging and autofluorescence imaging, at a maximum frame rate of 24 fps and with a resolution of 400 × 400. Tests and in vivo trials in pigs have proved the feasibility of the entire system, but further improvements in capsule control and compression performance inside the ASIC are needed in the future.

A probabilistic method for determining the volume fraction of pre-embedded capsules in self-healing materials

NASA Astrophysics Data System (ADS)

Lv, Zhong; Chen, Huisu

2014-10-01

Autonomous healing of cracks using pre-embedded capsules containing healing agent is becoming a promising approach to restore the strength of damaged structures. In addition to the material properties, the size and volume fraction of capsules influence crack healing in the matrix. Understanding the crack and capsule interaction is critical in the development and design of structures made of self-healing materials. Assuming that the pre-embedded capsules are randomly dispersed we theoretically model flat ellipsoidal crack interaction with capsules and determine the probability of a crack intersecting the pre-embedded capsules i.e. the self-healing probability. We also develop a probabilistic model of a crack simultaneously meeting with capsules and catalyst carriers in two-component self-healing system matrix. Using a risk-based healing approach, we determine the volume fraction and size of the pre-embedded capsules that are required to achieve a certain self-healing probability. To understand the effect of the shape of the capsules on self-healing we theoretically modeled crack interaction with spherical and cylindrical capsules. We compared the results of our theoretical model with Monte-Carlo simulations of crack interaction with capsules. The formulae presented in this paper will provide guidelines for engineers working with self-healing structures in material selection and sustenance.

LMJ Target design with the A1040 CH-ignition capsule in a cocktail holraum

NASA Astrophysics Data System (ADS)

Malinie, G.; Boniface, C.

2008-11-01

The A1040 indirect-drive ignition capsule was originally designed for the ``Full LMJ'' 240-beam configuration. An ``Ignition milestone'' has been scheduled, when the LMJ will be only partly completed, with a 160-beam, 2-cone configuration. A first approach to meet this milestone is to scale down the capsule and hohlraum of the full LMJ design. Here we use a different approach and show the A1040 ``as is'' can still meet the milestone, provided that a suitable cocktail-walled rugby hohlraum is used to drive the capsule. This is because this kind of hohlraum has a better energetic efficiency than the gold-walled cylinder originally used. From 1D and 2D integrated simulations, we investigate the influence of various parameters of the design, such as the shape of the four steps of the laser pulse, the density of the H/He gas filling of the hohlraum, and the effect of a thin gold coating on the outer surface of the polyimid window used to contain the gas.

Design of an autofocus capsule endoscope system and the corresponding 3D reconstruction algorithm.

PubMed

Zhang, Wei; Jin, Yi-Tao; Guo, Xin; Su, Jin-Hui; You, Su-Ping

2016-10-01

A traditional capsule endoscope can only take 2D images, and most of the images are not clear enough to be used for diagnosing. A 3D capsule endoscope can help doctors make a quicker and more accurate diagnosis. However, blurred images negatively affect reconstruction accuracy. A compact, autofocus capsule endoscope system is designed in this study. Using a liquid lens, the system can be electronically controlled to autofocus, and without any moving elements. The depth of field of the system is in the 3-100 mm range and its field of view is about 110°. The images captured by this optical system are much clearer than those taken by a traditional capsule endoscope. A 3D reconstruction algorithm is presented to adapt to the zooming function of our proposed system. Simulations and experiments have shown that more feature points can be correctly matched and a higher reconstruction accuracy can be achieved by this strategy.

Engineering multifunctional capsules through the assembly of metal-phenolic networks.

PubMed

Guo, Junling; Ping, Yuan; Ejima, Hirotaka; Alt, Karen; Meissner, Mirko; Richardson, Joseph J; Yan, Yan; Peter, Karlheinz; von Elverfeldt, Dominik; Hagemeyer, Christoph E; Caruso, Frank

2014-05-26

Metal-organic coordination materials are of widespread interest because of the coupled benefits of inorganic and organic building blocks. These materials can be assembled into hollow capsules with a range of properties, which include selective permeability, enhanced mechanical/thermal stability, and stimuli-responsiveness. Previous studies have primarily focused on the assembly aspects of metal-coordination capsules; however, the engineering of metal-specific functionality for capsule design has not been explored. A library of functional metal-phenolic network (MPN) capsules prepared from a phenolic ligand (tannic acid) and a range of metals is reported. The properties of the MPN capsules are determined by the coordinated metals, allowing for control over film thickness, disassembly characteristics, and fluorescence behavior. Furthermore, the functional properties of the MPN capsules were tailored for drug delivery, positron emission tomography (PET), magnetic resonance imaging (MRI), and catalysis. The ability to incorporate multiple metals into MPN capsules demonstrates that a diverse range of functional materials can be generated. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Patency© and agile© capsules

PubMed Central

Caunedo-Álvarez, Ángel; Romero-Vazquez, Javier; Herrerias-Gutierrez, Juan M

2008-01-01

Small bowel strictures can be missed by current diagnostic methods. The Patency capsule is a new non-endoscopic dissolvable capsule which has as an objective of checking the patency of digestive tract, in a non-invasive manner. The available clinical trials have demonstrated that the Patency© capsule is a good tool for assessment of the functional patency of the small bowel, and it allows identification of those patients who can safely undergo a capsule endoscopy, despite clinical and radiographic evidence of small-bowel obstruction. Some cases of intestinal occlusion have been reported with the Patency© capsule, four of them needed surgery. So, a new capsule with two timer plugs (Agile© capsule) has been recently developed in order to minimize the risk of occlusion. This new device stars its dissolution process earlier (30 h after ingestion) and its two timer plugs have been designed to begin the disintegration even when the device is blocked in a tight stricture. PMID:18785278

A locomotion mechanism with external magnetic guidance for active capsule endoscope.

PubMed

Wang, Xiaona; Meng, Max Q H; Chen, Xijun

2010-01-01

Gastrointestinal (GI) disorder is one of the most common diseases in human body. The swallowable wireless capsule endoscopy has been proved to be a convenient, painless and effective way to examine the whole GI tract. However, lack of motion control makes the movement of the capsule substantially random, resulting in missing diagnosis. In this paper, a locomotion mechanism is developed for the next-generation active capsule endoscope. An internal actuator integrated on-board the capsule is designed to provide driving force and improve the dexterity. A small permanent magnet enclosed inside the capsule interacts with an external magnetic field to control the capsule's orientation and offer extra driving force. This mechanism avoids sophisticated and bulky control system and reduces power consumption inside the capsule. Ex-vivo experimental results showed that it can make a controllable movement inside the porcine large intestine. The mechanism also has the potential to be a platform for further development, such as devices of operations, spraying medicine, biopsy etc.

Stopping mechanism for capsule endoscope using electrical stimulus.

PubMed

Woo, Sang Hyo; Kim, Tae Wan; Cho, Jin Ho

2010-01-01

An ingestible capsule, which has the ability to stop at certain locations in the small intestine, was designed and implemented to monitor intestinal diseases. The proposed capsule can contract the small intestine by using electrical stimuli; this contraction causes the capsule to stop when the maximum static frictional force (MSFF) is larger than the force of natural peristalsis. In vitro experiments were carried out to verify the feasibility of the capsule, and the results showed that the capsule was successfully stopped in the small intestine. Various electrodes and electrical stimulus parameters were determined on the basis of the MSFF. A moderate increment of the MSFF (12.7 +/- 4.6 gf at 5 V, 10 Hz, and 5 ms) and the maximum increment of the MSFF (56.5 +/- 9.77 gf at 20 V, 10 Hz, and 5 ms) were obtained, and it is sufficient force to stop the capsule.

Wireless Insufflation of the Gastrointestinal Tract

PubMed Central

Battaglia, Santina; Smith, Byron F.; Ciuti, Gastone; Gerding, Jason; Menciassi, Arianna; Obstein, Keith L.; Valdastri, Pietro; Webster, Robert J.

2013-01-01

Despite clear patient experience advantages, low specificity rates have thus far prevented swallowable capsule endoscopes from replacing traditional endoscopy for diagnosis of colon disease. One explanation for this is that capsule endoscopes lack the ability to provide insufflation, which traditional endoscopes use to distend the intestine for a clear view of the internal wall. To provide a means of insufflation from a wireless capsule platform, in this paper we use biocompatible effervescent chemical reactions to convert liquids and powders carried onboard a capsule into gas. We experimentally evaluate the quantity of gas needed to enhance capsule visualization and locomotion, and determine how much gas can be generated from a given volume of reactants. These experiments motivate the design of a wireless insufflation capsule, which is evaluated in ex vivo experiments. These experiments illustrate the feasibility of enhancing visualization and locomotion of endoscopic capsules through wireless insufflation. PMID:23212312

Wireless communication link for capsule endoscope at 600 MHz.

PubMed

Khaleghi, A; Balasingham, I

2015-01-01

Simulation of a wireless communication link for a capsule endoscopy is presented for monitoring of small intestine in humans. The realized communication link includes the transmitting capsule antenna, the outside body receiving antenna and the model of the human body. The capsule antenna is designed for operating at the frequency band of 600 MHz with an impedance bandwidth of 10 MHz and omnidirectional radiation pattern. The quality of the communication link is improved by using directive antenna outside body inside matching layer for electromagnetic wave tuning to the body. The outside body antenna has circular polarization that guaranteeing the communication link for different orientations of the capsule inside intestine. It is shown that the path loss for the capsule in 60 mm from the abdomen surface varies between 37-47 dB in relation to the antenna orientation. This link can establish high data rate wireless communications for capsule endoscopy.

Effect of Counterflow Jet on a Supersonic Reentry Capsule

NASA Technical Reports Server (NTRS)

Chang, Chau-Lyan; Venkatachari, Balaji Shankar; Cheng, Gary C.

2006-01-01

Recent NASA initiatives for space exploration have reinvigorated research on Apollo-like capsule vehicles. Aerothermodynamic characteristics of these capsule configurations during reentry play a crucial role in the performance and safety of the planetary entry probes and the crew exploration vehicles. At issue are the forebody thermal shield protection and afterbody aeroheating predictions. Due to the lack of flight or wind tunnel measurements at hypersonic speed, design decisions on such vehicles would rely heavily on computational results. Validation of current computational tools against experimental measurement thus becomes one of the most important tasks for general hypersonic research. This paper is focused on time-accurate numerical computations of hypersonic flows over a set of capsule configurations, which employ a counterflow jet to offset the detached bow shock. The accompanying increased shock stand-off distance and modified heat transfer characteristics associated with the counterflow jet may provide guidance for future design of hypersonic reentry capsules. The newly emerged space-time conservation element solution element (CESE) method is used to perform time-accurate, unstructured mesh Navier-Stokes computations for all cases investigated. The results show good agreement between experimental and numerical Schlieren pictures. Surface heat flux and aerodynamic force predictions of the capsule configurations are discussed in detail.

Hayabusa Re-Entry: Trajectory Analysis and Observation Mission Design

NASA Technical Reports Server (NTRS)

Cassell, Alan M.; Winter, Michael W.; Allen, Gary A.; Grinstead, Jay H.; Antimisiaris, Manny E.; Albers, James; Jenniskens, Peter

2011-01-01

On June 13th, 2010, the Hayabusa sample return capsule successfully re-entered Earth s atmosphere over the Woomera Prohibited Area in southern Australia in its quest to return fragments from the asteroid 1998 SF36 Itokawa . The sample return capsule entered at a super-orbital velocity of 12.04 km/sec (inertial), making it the second fastest human-made object to traverse the atmosphere. The NASA DC-8 airborne observatory was utilized as an instrument platform to record the luminous portion of the sample return capsule re-entry (60 sec) with a variety of on-board spectroscopic imaging instruments. The predicted sample return capsule s entry state information at 200 km altitude was propagated through the atmosphere to generate aerothermodynamic and trajectory data used for initial observation flight path design and planning. The DC- 8 flight path was designed by considering safety, optimal sample return capsule viewing geometry and aircraft capabilities in concert with key aerothermodynamic events along the predicted trajectory. Subsequent entry state vector updates provided by the Deep Space Network team at NASA s Jet Propulsion Laboratory were analyzed after the planned trajectory correction maneuvers to further refine the DC-8 observation flight path. Primary and alternate observation flight paths were generated during the mission planning phase which required coordination with Australian authorities for pre-mission approval. The final observation flight path was chosen based upon trade-offs between optimal viewing requirements, ground based observer locations (to facilitate post-flight trajectory reconstruction), predicted weather in the Woomera Prohibited Area and constraints imposed by flight path filing deadlines. To facilitate sample return capsule tracking by the instrument operators, a series of two racetrack flight path patterns were performed prior to the observation leg so the instruments could be pointed towards the region in the star background where the sample return capsule was expected to become visible. An overview of the design methodologies and trade-offs used in the Hayabusa re-entry observation campaign are presented.

TAGS 85/2N RTG Power for Viking Lander Capsule

DOE R&D Accomplishments Database

1969-08-01

Results of studies performed by Isotopes, Inc., Nuclear Systems Division, to optimize and baseline a TAGS 85/2N RTG for the Viking Lander Capsule prime electrical power source are presented. These studies generally encompassed identifying the Viking RTG mission profile and design requirements, and establishing a baseline RTG design consistent with these requirements.

Basic ammonothermal GaN growth in molybdenum capsules

NASA Astrophysics Data System (ADS)

Pimputkar, S.; Speck, J. S.; Nakamura, S.

2016-12-01

Single crystal, bulk gallium nitride (GaN) crystals were grown using the basic ammonothermal method in a high purity growth environment created using a non-hermetically sealed molybdenum (Mo) capsule and compared to growths performed in a similarly designed silver (Ag) capsule and capsule-free René 41 autoclave. Secondary ion mass spectrometry (SIMS) analysis revealed transition metal free (<1×1017 cm-3) GaN crystals. Anomalously low oxygen concentrations ((2-6)×1018 cm-3) were measured in a {0001} seeded crystal boule grown using a Mo capsule, despite higher source material oxygen concentrations ((1-5)×1019 cm-3) suggesting that molybdenum (or molybdenum nitrides) may act to getter oxygen under certain conditions. Total system pressure profiles from growth runs in a Mo capsule system were comparable to those without a capsule, with pressures peaking within 2 days and slowly decaying due to hydrogen diffusional losses. Measured Mo capsule GaN growth rates were comparable to un-optimized growth rates in capsule-free systems and appreciably slower than in Ag-capsule systems. Crystal quality replicated that of the GaN seed crystals for all capsule conditions, with high quality growth occurring on the (0001) Ga-face. Optical absorption and impurity concentration characterization suggests reduced concentrations of hydrogenated gallium vacancies (VGa-Hx).

Residual mercury content and leaching of mercury and silver from used amalgam capsules.

PubMed

Stone, M E; Pederson, E D; Cohen, M E; Ragain, J C; Karaway, R S; Auxer, R A; Saluta, A R

2002-06-01

The objective of this investigation was to carry out residual mercury (Hg) determinations and toxicity characteristic leaching procedure (TCLP) analysis of used amalgam capsules. For residual Hg analysis, 25 capsules (20 capsules for one brand) from each of 10 different brands of amalgam were analyzed. Total residual Hg levels per capsule were determined using United States Environmental Protection Agency (USEPA) Method 7471. For TCLP analysis, 25 amalgam capsules for each of 10 brands were extracted using a modification of USEPA Method 1311. Hg analysis of the TCLP extracts was done with USEPA Method 7470A. Analysis of silver (Ag) concentrations in the TCLP extract was done with USEPA Method 6010B. Analysis of the residual Hg data resulted in the segregation of brands into three groups: Dispersalloy capsules, Group A, retained the most Hg (1.225 mg/capsule). These capsules were the only ones to include a pestle. Group B capsules, Valliant PhD, Optaloy II, Megalloy and Valliant Snap Set, retained the next highest amount of Hg (0.534-0.770 mg/capsule), and were characterized by a groove in the inside of the capsule. Group C, Tytin regular set double-spill, Tytin FC, Contour, Sybraloy regular set, and Tytin regular set single-spill retained the least amount of Hg (0.125-0.266 mg/capsule). TCLP analysis of the triturated capsules showed Sybraloy and Contour leached Hg at greater than the 0.2 mg/l Resource Conservation and Recovery Act (RCRA) limit. This study demonstrated that residual mercury may be related to capsule design features and that TCLP extracts from these capsules could, in some brands, exceed RCRA Hg limits, making their disposal problematic. At current RCRA limits, the leaching of Ag is not a problem.

A wideband spiral antenna for ingestible capsule endoscope systems: experimental results in a human phantom and a pig.

PubMed

Lee, Sang Heun; Lee, Jaebok; Yoon, Young Joong; Park, Sangbok; Cheon, Changyul; Kim, Kihyun; Nam, Sangwook

2011-06-01

This paper presents the design of a wideband spiral antenna for ingestible capsule endoscope systems and a comparison between the experimental results in a human phantom and a pig under general anesthesia. As wireless capsule endoscope systems transmit real-time internal biological image data at a high resolution to external receivers and because they operate in the human body, a small wideband antenna is required. To incorporate these properties, a thick-arm spiral structure is applied to the designed antenna. To make practical and efficient use of antennas inside the human body, which is composed of a high dielectric and lossy material, the resonance characteristics and radiation patterns were evaluated through a measurement setup using a liquid human phantom. The total height of the designed antenna is 5 mm and the diameter is 10 mm. The fractional bandwidth of the fabricated antenna is about 21% with a voltage standing-wave ratio of less than 2, and it has an isotropic radiation pattern. These characteristics are suitable for wideband capsule endoscope systems. Moreover, the received power level was measured using the proposed antenna, a circular polarized receiver antenna, and a pig under general anesthesia. Finally, endoscopic capsule images in the stomach and large intestine were captured using an on-off keying transceiver system.

A stepped-plate bi-frequency source for generating a difference frequency sound with a parametric array.

PubMed

Je, Yub; Lee, Haksue; Park, Jongkyu; Moon, Wonkyu

2010-06-01

An ultrasonic radiator is developed to generate a difference frequency sound from two frequencies of ultrasound in air with a parametric array. A design method is proposed for an ultrasonic radiator capable of generating highly directive, high-amplitude ultrasonic sound beams at two different frequencies in air based on a modification of the stepped-plate ultrasonic radiator. The stepped-plate ultrasonic radiator was introduced by Gallego-Juarez et al. [Ultrasonics 16, 267-271 (1978)] in their previous study and can effectively generate highly directive, large-amplitude ultrasonic sounds in air, but only at a single frequency. Because parametric array sources must be able to generate sounds at more than one frequency, a design modification is crucial to the application of a stepped-plate ultrasonic radiator as a parametric array source in air. The aforementioned method was employed to design a parametric radiator for use in air. A prototype of this design was constructed and tested to determine whether it could successfully generate a difference frequency sound with a parametric array. The results confirmed that the proposed single small-area transducer was suitable as a parametric radiator in air.

Analysing intracellular deformation of polymer capsules using structured illumination microscopy

NASA Astrophysics Data System (ADS)

Chen, Xi; Cui, Jiwei; Sun, Huanli; Müllner, Markus; Yan, Yan; Noi, Ka Fung; Ping, Yuan; Caruso, Frank

2016-06-01

Understanding the behaviour of therapeutic carriers is important in elucidating their mechanism of action and how they are processed inside cells. Herein we examine the intracellular deformation of layer-by-layer assembled polymer capsules using super-resolution structured illumination microscopy (SIM). Spherical- and cylindrical-shaped capsules were studied in three different cell lines, namely HeLa (human epithelial cell line), RAW264.7 (mouse macrophage cell line) and differentiated THP-1 (human monocyte-derived macrophage cell line). We observed that the deformation of capsules was dependent on cell line, but independent of capsule shape. This suggests that the mechanical forces, which induce capsule deformation during cell uptake, vary between cell lines, indicating that the capsules are exposed to higher mechanical forces in HeLa cells, followed by RAW264.7 and then differentiated THP-1 cells. Our study demonstrates the use of super-resolution SIM in analysing intracellular capsule deformation, offering important insights into the cellular processing of drug carriers in cells and providing fundamental knowledge of intracellular mechanobiology. Furthermore, this study may aid in the design of novel drug carriers that are sensitive to deformation for enhanced drug release properties.Understanding the behaviour of therapeutic carriers is important in elucidating their mechanism of action and how they are processed inside cells. Herein we examine the intracellular deformation of layer-by-layer assembled polymer capsules using super-resolution structured illumination microscopy (SIM). Spherical- and cylindrical-shaped capsules were studied in three different cell lines, namely HeLa (human epithelial cell line), RAW264.7 (mouse macrophage cell line) and differentiated THP-1 (human monocyte-derived macrophage cell line). We observed that the deformation of capsules was dependent on cell line, but independent of capsule shape. This suggests that the mechanical forces, which induce capsule deformation during cell uptake, vary between cell lines, indicating that the capsules are exposed to higher mechanical forces in HeLa cells, followed by RAW264.7 and then differentiated THP-1 cells. Our study demonstrates the use of super-resolution SIM in analysing intracellular capsule deformation, offering important insights into the cellular processing of drug carriers in cells and providing fundamental knowledge of intracellular mechanobiology. Furthermore, this study may aid in the design of novel drug carriers that are sensitive to deformation for enhanced drug release properties. Electronic supplementary information (ESI) available: Additional figures. See DOI: 10.1039/c6nr02151d

KSC-2012-5584

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - A model capsule seen ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

KSC-2012-5580

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - A model capsule seen ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

KSC-2012-5583

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - A model capsule seen ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

KSC-2012-5585

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - A model capsule falls during tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

KSC-2012-5587

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - A model capsule falls during tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

KSC-2012-5589

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - A model capsule following a test inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

KSC-2012-5582

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - A model capsule seen ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

KSC-2012-5586

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - A model capsule falls during tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

Robust spherical direct-drive design for NI

NASA Astrophysics Data System (ADS)

Masse, Laurent; Hurricane, O.; Michel, P.; Nora, R.; Tabak, M.; Lawrence Livermore Natl Lab Team

2016-10-01

Achieving ignition in a direct-drive or indirect-drive cryogenic implosion is a tremendous challenge. Both approaches need to deal with physic and technologic issues. During the past years, the indirect drive effort on the National Ignition Facility (NIF) has revealed unpredicted lost of performances that force to think to more robust designs and to dig into detailed physics aspects. Encouraging results have been obtained using a strong first shock during the implosion of CH ablator ignition capsules. These ``high-foot'' implosion results in a significantly lower ablation Rayleigh-Taylor instability growth than that of the NIC point design capsule. The trade-off with this design is a higher fuel adiabat that limits both fuel compression and theoretical capsule yield. The purpose of designing this capsule is to recover a more ideal one-dimensional implosion that is in closer agreement to simulation predictions. In the same spirit of spending energy on margin, at the coast of decreased performance, we are presenting here a study on ``robust'' spherical direct drive design for NIF. This 2-Shock direct drive pulse shape results in a high adiabat (>3) and low convergence (<17) implosion designed to produce a near 1D-like implosion. We take a particular attention to design a robust implosion with respect to long-wavelength non uniformity seeded by power imbalance and target offset. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

Regenerated cellulose capsules for controlled drug delivery: Part III. Developing a fabrication method and evaluating extemporaneous utility for controlled-release.

PubMed

Bhatt, Bhavik; Kumar, Vijay

2016-08-25

In this article, we describe a method to utilize cellulose dissolved in dimethyl sulfoxide and paraformaldehyde solvent system to fabricate two-piece regenerated cellulose hard shell capsules for their potential use as an oral controlled drug delivery a priori vehicle. A systematic evaluation of solution rheology as well as resulting capsule mechanical, visual and thermal analysis was performed to develop a suitable method to repeatedly fabricate RC hard shell capsule halves. Because of the viscoelastic nature of the cellulose solution, a combination of dip-coating and casting method, herein referred to as dip-casting method, was developed. The dip-casting method was formalized by utilizing two-stage 2(2) full factorial design approach in order to determine a suitable approach to fabricate capsules with minimal variability. Thermal annealing is responsible for imparting shape rigidity of the capsules. Proof-of-concept analysis for the utility of these capsules in controlled drug delivery was performed by evaluating the release of KCl from them as well as from commercially available USP equivalent formulations. Release of KCl from cellulose capsules was comparable to extended release capsule formulation. Copyright © 2016 Elsevier B.V. All rights reserved.

Determining a membrane's shear modulus, independent of its area-dilatation modulus, via capsule flow in a converging micro-capillary.

PubMed

Dimitrakopoulos, P; Kuriakose, S

2015-04-14

Determination of the elastic properties of the membrane of artificial capsules is essential for the better design of the various devices that are utilized in their engineering and biomedical applications. However this task is complicated owing to the combined effects of the shear and area-dilatation moduli on the capsule deformation. Based on computational investigation, we propose a new methodology to determine a membrane's shear modulus, independent of its area-dilatation modulus, by flowing strain-hardening capsules in a converging micro-capillary of comparable size under Stokes flow conditions, and comparing the experimental measurements of the capsule elongation overshooting with computational data. The capsule prestress, if any, can also be determined with the same methodology. The elongation overshooting is practically independent of the viscosity ratio for low and moderate viscosity ratios, and thus a wide range of capsule fluids can be employed. Our proposed experimental device can be readily produced via glass fabrication while owing to the continuous flow in the micro-capillary, the characterization of a large number of artificial capsules is possible.

Floating capsules containing alginate-based beads of salbutamol sulfate: In vitro-in vivo evaluations.

PubMed

Malakar, Jadupati; Datta, Prabir Kumar; Purakayastha, Saikat Das; Dey, Sanjay; Nayak, Amit Kumar

2014-03-01

The present study deals with the development and evaluations of stomach-specific floating capsules containing salbutamol sulfate-loaded oil-entrapped alginate-based beads. Salbutamol sulfate-loaded oil-entrapped beads were prepared and capsulated within hard gelatin capsules (size 1). The effects of HPMC K4M and potato starch weight masses on drug encapsulation efficiency (DEE) of beads and cumulative drug release at 10h (R10 h) from capsules was analyzed by 3(2) factorial design. The optimization results indicate increasing of DEE in the oil-entrapped beads and decreasing R10 h from capsules with increment of HPMC K4M and potato starch weight masses. The optimized formulation showed DEE of 70.02 ± 3.16% and R10 h of 56.96 ± 2.92%. These capsules showed floatation over 6h and sustained drug release over 10h in gastric pH (1.2). In vivo X-ray imaging study of optimized floating capsules in rabbits showed stomach-specific gastroretention over a prolonged period. Copyright © 2013 Elsevier B.V. All rights reserved.

Control and monitoring of oxygen fugacity in piston cylinder experiments

NASA Astrophysics Data System (ADS)

Matjuschkin, Vladimir; Brooker, Richard A.; Tattitch, Brian; Blundy, Jon D.; Stamper, Charlotte C.

2015-01-01

We present a newly developed capsule design that resolves some common problems associated with the monitoring and control of oxygen fugacity ( fO2) in high-pressure piston cylinder experiments. The new fO2 control assembly consists of an AuPd outer capsule enclosing two inner capsules: one of AuPd capsule containing the experimental charge (including some water), and the other of Pt containing a solid oxygen buffer plus water. The inner capsules are separated by crushable alumina. The outer capsule is surrounded by a Pyrex sleeve to simultaneously minimise hydrogen loss from the cell and carbon infiltration from the graphite furnace. Controlled fO2 experiments using this cell design were carried out at 1.0 GPa and 1,000 °C. We used NiPd, CoPd and (Ni, Mg)O fO2 sensors, whose pressure sensitivity is well calibrated, to monitor the redox states achieved in experiments buffered by Re-ReO2, Ni-NiO and Co-CoO, respectively. Results for the fO2 sensors are in good agreement with the intended fO2 established by the buffer, demonstrating excellent control for durations of 24-48 h, with uncertainties less than ± 0.3 log bar units of fO2.

Orbit Transfer Rocket Engine Technology Program, Advanced Engine Study Task D.6

DTIC Science & Technology

1992-02-28

l!J~iliiJl 1. Report No. 2. Government Accession No. 3 . Recipient’s Catalog No. NASA 187215 4. Title and Subtitle 5. Report Date ORBIT TRANSFER ROCKET...Engine Study, three primary subtasks were accomplished: 1) Design and Parametric Data, 2) Engine Requirement Variation Studies, and 3 ) Vehicle Study...Mixture Ratio Parametrics 18 3 . Thrust Parametrics Off-Design Mixture Ratio Scans 22 4. Expansion Area Ratio Parametrics 24 5. OTV 20 klbf Engine Off

Aerodynamics of electrically driven freight pipeline system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lundgren, T.S.; Zhao, Y.

2000-06-01

This paper examines the aerodynamic characteristics of a freight pipeline system in which freight capsules are individually propelled by electrical motors. The fundamental difference between this system and the more extensively studied pneumatic capsule pipeline is the different role played by aerodynamic forces. In a driven system the propelled capsules are resisted by aerodynamic forces and, in reaction, pump air through the tube. In contrast, in a pneumatically propelled system external blowers pump air through the tubes, and this provides the thrust for the capsules. An incompressible transient analysis is developed to study the aerodynamics of multiple capsules in amore » cross-linked two-bore pipeline. An aerodynamic friction coefficient is used as a cost parameter to compare the effects of capsule blockage and headway and to assess the merits of adits and vents. The authors conclude that optimum efficiency for off-design operation is obtained with long platoons of capsules in vented or adit connected tubes.« less

Mars Sample Return Landed with Red Dragon

NASA Technical Reports Server (NTRS)

Stoker, Carol R.; Lemke, Lawrence G.

2013-01-01

A Mars Sample Return (MSR) mission is the highest priority science mission for the next decade as recommended by the recent Decadal Survey of Planetary Science. However, an affordable program to carry this out has not been defined. This paper describes a study that examined use of emerging commercial capabilities to land the sample return elements, with the goal of reducing mission cost. A team at NASA Ames examined the feasibility of the following scenario for MSR: A Falcon Heavy launcher injects a SpaceX Dragon crew capsule and trunk onto a Trans Mars Injection trajectory. The capsule is modified to carry all the hardware needed to return samples collected on Mars including a Mars Ascent Vehicle (MAV), an Earth Return Vehicle (ERV) and Sample Collection and Storage hardware. The Dragon descends to land on the surface of Mars using SuperSonic Retro Propulsion (SSRP) as described by Braun and Manning [IEEEAC paper 0076, 2005]. Samples are acquired and deliverd to the MAV by a prelanded asset, possibly the proposed 2020 rover. After samples are obtained and stored in the ERV, the MAV launches the sample-containing ERV from the surface of Mars. We examined cases where the ERV is delivered to either low Mars orbit (LMO), C3 = 0 (Mars escape), or an intermediate energy state. The ERV then provides the rest of the energy (delta V) required to perform trans-Earth injection (TEI), cruise, and insertion into a Moon-trailing Earth Orbit (MTEO). A later mission, possibly a crewed Dragon launched by a Falcon Heavy (not part of the current study) retrieves the sample container, packages the sample, and performs a controlled Earth re-entry to prevent Mars materials from accidentally contaminating Earth. The key analysis methods used in the study employed a set of parametric mass estimating relationships (MERs) and standard aerospace analysis software codes modified for the MAV class of launch vehicle to determine the range of performance parameters that produced converged spacecraft designs capable of meeting mission requirements. Subsystems modeled in this study included structures, power system, propulsion system, nose fairing, thermal insulation, actuation devices, and GN&C. Best practice application of loads and design margins for all resources were used. Both storable and cryogenic propellant systems were examined. The landed mass and lander capsule size provide boundary conditions for the MAV design and packaging. We estimated the maximum mass the Dragon capsule is capable of landing. This and the volume capability to store the MAV was deduced from publically available data from SpaceX as well as our own engineering and aerodynamic estimates. Minimum gross-liftoff mass (GLOM) for the MAV were obtained for configurations that used pump-fed storable bi-propellant rocket engines for both the MAV and the ERV stage. The GLOM required fits within our internal estimate of the mass that Dragon can land at low elevation/optimal seasons on Mars. Based on the analysis, we show that a single Mars launch sample return mission is feasible using current commercial capabilities to deliver the return spacecraft assets.

Long-term Efficacy and Biocompatibility of Encapsulated Islet Transplantation With Chitosan-Coated Alginate Capsules in Mice and Canine Models of Diabetes.

PubMed

Yang, Hae Kyung; Ham, Dong-Sik; Park, Heon-Seok; Rhee, Marie; You, Young Hye; Kim, Min Jung; Shin, Juyoung; Kim, On-You; Khang, Gilson; Hong, Tae Ho; Kim, Ji-Won; Lee, Seung-Hwan; Cho, Jae-Hyoung; Yoon, Kun-Ho

2016-02-01

Clinical application of encapsulated islet transplantation is hindered by low biocompatibility of capsules leading to pericapsular fibrosis and decreased islet viability. To improve biocompatibility, we designed a novel chitosan-coated alginate capsules and compared them to uncoated alginate capsules. Alginate capsules were formed by crosslinking with BaCl2, then they were suspended in chitosan solution for 10 minutes at pH 4.5. Xenogeneic islet transplantation, using encapsulated porcine islets in 1,3-galactosyltransferase knockout mice, and allogeneic islet transplantation, using encapsulated canine islets in beagles, were performed without immunosuppressants. The chitosan-alginate capsules showed similar pore size, islet viability, and insulin secretory function compared to alginate capsules, in vitro. Xenogeneic transplantation of chitosan-alginate capsules demonstrated a trend toward superior graft survival (P = 0.07) with significantly less pericapsular fibrosis (cell adhesion score: 3.77 ± 0.41 vs 8.08 ± 0.05; P < 0.001) compared to that of alginate capsules up to 1 year after transplantation. Allogeneic transplantation of chitosan-alginate capsules normalized the blood glucose level up to 1 year with little evidence of pericapsular fibrotic overgrowth on graft explantation. The efficacy and biocompatibility of chitosan-alginate capsules were demonstrated in xenogeneic and allogeneic islet transplantations using small and large animal models of diabetes. This capsule might be a potential candidate applicable in the treatment of type 1 diabetes mellitus patients, and further studies in nonhuman primates are required.

Mitigating the impact of hohlraum asymmetries in National Ignition Facility implosions using capsule shims

DOE PAGES

Clark, D. S.; Weber, C. R.; Smalyuk, V. A.; ...

2016-07-22

Here, current indirect drive implosion experiments on the National Ignition Facility (NIF) are believed to be strongly impacted by long wavelength perturbations driven by asymmetries in the hohlraum x-ray flux. To address this perturbation source, active efforts are underway to develop modified hohlraum designs with reduced asymmetry imprint. An alternative strategy, however, is to modify the capsule design to be more resilient to a given amount of hohlraum asymmetry. In particular, the capsule may be deliberately misshaped, or “shimmed,” so as to counteract the expected asymmetries from the hohlraum. Here, the efficacy of capsule shimming to correct the asymmetries inmore » two recent NIF implosion experiments is assessed using two-dimensional radiation hydrodynamics simulations. Despite the highly time-dependent character of the asymmetries and the high convergence ratios of these implosions, simulations suggest that shims could be highly effective at counteracting current asymmetries and result in factors of a few enhancements in neutron yields. For higher compression designs, the yield improvement could be even greater.« less

Mitigating the impact of hohlraum asymmetries in National Ignition Facility implosions using capsule shims

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clark, D. S.; Weber, C. R.; Smalyuk, V. A.

2016-07-15

Current indirect drive implosion experiments on the National Ignition Facility (NIF) [Moses et al., Phys. Plasmas 16, 041006 (2009)] are believed to be strongly impacted by long wavelength perturbations driven by asymmetries in the hohlraum x-ray flux. To address this perturbation source, active efforts are underway to develop modified hohlraum designs with reduced asymmetry imprint. An alternative strategy, however, is to modify the capsule design to be more resilient to a given amount of hohlraum asymmetry. In particular, the capsule may be deliberately misshaped, or “shimmed,” so as to counteract the expected asymmetries from the hohlraum. Here, the efficacy ofmore » capsule shimming to correct the asymmetries in two recent NIF implosion experiments is assessed using two-dimensional radiation hydrodynamics simulations. Despite the highly time-dependent character of the asymmetries and the high convergence ratios of these implosions, simulations suggest that shims could be highly effective at counteracting current asymmetries and result in factors of a few enhancements in neutron yields. For higher compression designs, the yield improvement could be even greater.« less

Safety of capsule endoscopy using human body communication in patients with cardiac devices.

PubMed

Chung, Joo Won; Hwang, Hye Jin; Chung, Moon Jae; Park, Jeong Youp; Pak, Hui-Nam; Song, Si Young

2012-06-01

The MiroCam (IntroMedic, Ltd., Seoul, Korea) is a small-bowel capsule endoscope that uses human body communication to transmit data. The potential interactions between cardiac devices and the capsule endoscope are causes for concern, but no data are available for this matter. This clinical study was designed to evaluate the potential influence of the MiroCam capsules on cardiac devices. Patients with cardiac pacemakers or implantable cardiac defibrillators referred for evaluation of small bowel disease were prospectively enrolled in this study. Before capsule endoscopy, a cardiologist checked baseline electrocardiograms and functions of the cardiac devices. Cardiac rhythms were continuously monitored by 24-h telemetry during capsule endoscopy in the hospital. After completion of procedures, functions of the cardiac devices were checked again for interference. Images from the capsule endoscopy were reviewed and analyzed for technical problems. Six patients, three with pacemakers and three with implantable cardiac defibrillators, were included in the study. We identified no disturbances in the cardiac devices and no arrhythmias detected on telemetry monitoring during capsule endoscopy. No significant changes in the programmed parameters of the cardiac devices were noted after capsule endoscopy. There were no imaging disturbances from the cardiac devices on capsule endoscopy. Capsule endoscopy using human body communication to transmit data was safely performed in patients with cardiac pacemakers or implantable cardiac defibrillators. Images from the capsule endoscopy were not affected by cardiac devices. A further large-scale study is required to confirm the safety of capsule endoscopy with various types of cardiac devices.

Multiple internalization pathways of polyelectrolyte multilayer capsules into mammalian cells.

PubMed

Kastl, Lena; Sasse, Daniel; Wulf, Verena; Hartmann, Raimo; Mircheski, Josif; Ranke, Christiane; Carregal-Romero, Susana; Martínez-López, José Antonio; Fernández-Chacón, Rafael; Parak, Wolfgang J; Elsasser, Hans-Peter; Rivera Gil, Pilar

2013-08-27

Polyelectrolyte multilayer (PEM) capsules are carrier vehicles with great potential for biomedical applications. With the future aim of designing biocompatible, effective therapeutic delivery systems (e.g., for cancer), the pathway of internalization (uptake and fate) of PEM capsules was investigated. In particular the following experiments were performed: (i) the study of capsule co-localization with established endocytic markers, (ii) switching-off endocytotic pathways with pharmaceutical/chemical inhibitors, and (iii) characterization and quantification of capsule uptake with confocal and electron microscopy. As result, capsules co-localized with lipid rafts and with phagolysosomes, but not with other endocytic vesicles. Chemical interference of endocytosis with chemical blockers indicated that PEM capsules enter the investigated cell lines through a mechanism slightly sensitive to electrostatic interactions, independent of clathrin and caveolae, and strongly dependent on cholesterol-rich domains and organelle acidification. Microscopic characterization of cells during capsule uptake showed the formation of phagocytic cups (vesicles) to engulf the capsules, an increased number of mitochondria, and a final localization in the perinuclear cytoplasma. Combining all these indicators we conclude that PEM capsule internalization in general occurs as a combination of different sequential mechanisms. Initially, an adsorptive mechanism due to strong electrostatic interactions governs the stabilization of the capsules at the cell surface. Membrane ruffling and filopodia extensions are responsible for capsule engulfing through the formation of a phagocytic cup. Co-localization with lipid raft domains activates the cell to initiate a lipid-raft-mediated macropinocytosis. Internalization vesicles are very acidic and co-localize only with phagolysosome markers, excluding caveolin-mediated pathways and indicating that upon phagocytosis the capsules are sorted to heterophagolysosomes.

Polyelectrolyte capsules preloaded with interconnected alginate matrix: An effective capsule system for encapsulation and release of macromolecules.

PubMed

Sundaramurthy, Anandhakumar; Sundramoorthy, Ashok K

2018-02-01

In recent years, the design of stimuli-responsive hollow polymeric capsules is of tremendous interest for the scientific community because of the broad application of these capsules in the biomedical field. The use of weak polyelectrolytes as layer components for capsule fabrication is especially interesting as it results in hollow capsules that show unique release characteristics under physiological conditions. In this work, a methodology to prepare sub-micron sized alginate doped calcium carbonate (CaCO 3 ) particles through controlled precipitation in the presence of alginate is reported. Hollow capsules obtained by Layer-by-Layer (LbL) assembly of poly(allylamine hydrochloride) (PAH) and poly(methacrylic acid) (PMA) are showing an interconnected alginate matrix in the interior of the capsules. Investigations showed that the presence of alginate matrix enhances the encapsulation of cationic molecules (e.g. doxorubicin hydrochloride) manifold by charge controlled attraction mechanism. Capsule permeability investigated by confocal laser scanning microscopy revealed that the transformation from an open state to closed state is accompanied by an intermediate state where capsules are neither open nor closed. Furthermore, time dependent study indicated that the encapsulation process is linear as a function of time. The cell viability experiments demonstrated excellent biocompatibility of hollow capsules with mouse embryonic fibroblast cells. Anticancer investigations showed that DOX loaded capsules have significant anti-proliferative characteristics against HeLa cells. Such capsules have high potential for use as drug carrier for cationic drugs in cancer therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

Manned geosynchronous mission requirements and system analysis study extension. Manned Orbital Transfer Vehicle (MOTV) capabilities handbook and user guide

NASA Technical Reports Server (NTRS)

1981-01-01

The primary change in crew capsule definition is a smaller MOTV crew capsule, switching from a 3-man capsule to a 2-man capsule. A second change permitted crew accommodations for sleeping and privacy to be combined with the flight station. The current baseline DRM, ER1, requires 2 men for 3 to 4 days to repair a multi-disciplined GOE Platform and a modest amount of mission dedicated hardware. A 2-man MOTV crew capsule to be used as a design reference point for the OTV, and its interfaces between the STS and other associated equipment or facilities are described in detail. The functional capabilities of the 2-man capsule, as well as its application to a wide range of generic missions, is also presented. The MOTV turnaround is addressed and significant requirements for both space based and ground based scenarios are summarized.

Effect of Feitai Capsule () on quality of life and progression-free survival of patients with unresectable non-small cell lung cancer.

PubMed

Yu, Zong-Yang; Liu, Zhi-Zhen; Ouyang, Xue-Nong; Du, Jian; Dai, Xi-Hu; Chen, Xi; Zhao, Zhong-Quan; Wang, Wen-Wu; Li, Jie

2012-02-01

To examine the effect of a Chinese medicinal herbal formula (Feitai Capsule, ) on the quality of life (QOL) and progression-free survival (PFS) of patients with unresectable non-small cell lung cancer (NSCLC). Sixty-two patients were randomly divided into the treatment group (31 cases) and the control group (31 cases). For the treatment group, 4 capsules (1.2 g/capsule) of Feitai Capsule were administered 3 times a day after meals for 3 weeks; then no drug was administered for 1 week. This schedule was continued for at least 3 more cycles (12 weeks totally). If there were no obvious toxic reactions, the treatment was extended. The patients were evaluated at least once every 8 weeks until progressive disease (PD). For the control group, the regular follow-up and evaluation were performed at least once every 8 weeks until PD. Clinical symptoms, objective response, physical constitution and energy, QOL, and PFS were evaluated regularly. Analysis of variance (ANOVA), a non-parametric test, and analysis of covariance were used to compare clinical features, amelioration of clinical symptoms, physical constitution and energy, and QOL. Kaplan-Meier analysis was used to compare the two-group PFS. Sixty patients finished the final evaluation, with 30 patients in each group. Baseline characters between groups were not significantly different (P>0.05). The control group had a 36.7% improvement in clinical symptoms, while the treatment group had a 73.3% improvement. This difference was statistically significant (Z= -2.632, P=0.008). The control group had a 26.7% improvement in the Karnofsky performance status (KPS), while the treatment group had a 53.4% improvement. This was also significantly different (Z=-2.182, P=0.029). A comparative analysis indicated a positive correlation (r=0.917, P<0.001). Compared with the control group, QOL in the treatment group was significantly improved, except in the social/family condition and doctor-patient relationship indicators. The PFS of the treatment group and control group were 6.23 months and 4.67 months, respectively (P=0.048). Feitai Capsule, a Chinese medicinal herbal treatment could improve the QOL and extend the PFS of the unresectable NSCLC patients.

PORT II

NASA Technical Reports Server (NTRS)

Muniz, Beau

2009-01-01

One unique project that the Prototype lab worked on was PORT I (Post-landing Orion Recovery Test). PORT is designed to test and develop the system and components needed to recover the Orion capsule once it splashes down in the ocean. PORT II is designated as a follow up to PORT I that will utilize a mock up pressure vessel that is spatially compar able to the final Orion capsule.

Internalization of Red Blood Cell-Mimicking Hydrogel Capsules with pH-Triggered Shape Responses

PubMed Central

2015-01-01

We report on naturally inspired hydrogel capsules with pH-induced transitions from discoids to oblate ellipsoids and their interactions with cells. We integrate characteristics of erythrocytes such as discoidal shape, hollow structure, and elasticity with reversible pH-responsiveness of poly(methacrylic acid) (PMAA) to design a new type of drug delivery carrier to be potentially triggered by chemical stimuli in the tumor lesion. The capsules are fabricated from cross-linked PMAA multilayers using sacrificial discoid silicon templates. The degree of capsule shape transition is controlled by the pH-tuned volume change, which in turn is regulated by the capsule wall composition. The (PMAA)15 capsules undergo a dramatic 24-fold volume change, while a moderate 2.3-fold volume variation is observed for more rigid PMAA–(poly(N-vinylpyrrolidone) (PMAA–PVPON)5 capsules when solution pH is varied between 7.4 and 4. Despite that both types of capsules exhibit discoid-to-oblate ellipsoid transitions, a 3-fold greater swelling in radial dimensions is found for one-component systems due to a greater degree of the circular face bulging. We also show that (PMAA–PVPON)5 discoidal capsules interact differently with J774A.1 macrophages, HMVEC endothelial cells, and 4T1 breast cancer cells. The discoidal capsules show 60% lower internalization as compared to spherical capsules. Finally, hydrogel capsules demonstrate a 2-fold decrease in size upon internalization. These capsules represent a unique example of elastic hydrogel discoids capable of pH-induced drastic and reversible variations in aspect ratios. Considering the RBC-mimicking shape, their dimensions, and their capability to undergo pH-triggered intracellular responses, the hydrogel capsules demonstrate considerable potential as novel carriers in shape-regulated transport and cellular uptake. PMID:24848786

Design calculations for NIF convergent ablator experiments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Callahan, Debra; Leeper, Ramon Joe; Spears, B. K.

2010-11-01

Design calculations for NIF convergent ablator experiments will be described. The convergent ablator experiments measure the implosion trajectory, velocity, and ablation rate of an x-ray driven capsule and are a important component of the U. S. National Ignition Campaign at NIF. The design calculations are post-processed to provide simulations of the key diagnostics: (1) Dante measurements of hohlraum x-ray flux and spectrum, (2) streaked radiographs of the imploding ablator shell, (3) wedge range filter measurements of D-He3 proton output spectra, and (4) GXD measurements of the imploded core. The simulated diagnostics will be compared to the experimental measurements to providemore » an assessment of the accuracy of the design code predictions of hohlraum radiation temperature, capsule ablation rate, implosion velocity, shock flash areal density, and x-ray bang time. Post-shot versions of the design calculations are used to enhance the understanding of the experimental measurements and will assist in choosing parameters for subsequent shots and the path towards optimal ignition capsule tuning.« less

Aircraft conceptual design - an adaptable parametric sizing methodology

NASA Astrophysics Data System (ADS)

Coleman, Gary John, Jr.

Aerospace is a maturing industry with successful and refined baselines which work well for traditional baseline missions, markets and technologies. However, when new markets (space tourism) or new constrains (environmental) or new technologies (composite, natural laminar flow) emerge, the conventional solution is not necessarily best for the new situation. Which begs the question "how does a design team quickly screen and compare novel solutions to conventional solutions for new aerospace challenges?" The answer is rapid and flexible conceptual design Parametric Sizing. In the product design life-cycle, parametric sizing is the first step in screening the total vehicle in terms of mission, configuration and technology to quickly assess first order design and mission sensitivities. During this phase, various missions and technologies are assessed. During this phase, the designer is identifying design solutions of concepts and configurations to meet combinations of mission and technology. This research undertaking contributes the state-of-the-art in aircraft parametric sizing through (1) development of a dedicated conceptual design process and disciplinary methods library, (2) development of a novel and robust parametric sizing process based on 'best-practice' approaches found in the process and disciplinary methods library, and (3) application of the parametric sizing process to a variety of design missions (transonic, supersonic and hypersonic transports), different configurations (tail-aft, blended wing body, strut-braced wing, hypersonic blended bodies, etc.), and different technologies (composite, natural laminar flow, thrust vectored control, etc.), in order to demonstrate the robustness of the methodology and unearth first-order design sensitivities to current and future aerospace design problems. This research undertaking demonstrates the importance of this early design step in selecting the correct combination of mission, technologies and configuration to meet current aerospace challenges. Overarching goal is to avoid the reoccurring situation of optimizing an already ill-fated solution.

Tri-Center Analysis: Determining Measures of Trichotomous Central Tendency for the Parametric Analysis of Tri-Squared Test Results

ERIC Educational Resources Information Center

Osler, James Edward

2014-01-01

This monograph provides an epistemological rational for the design of a novel post hoc statistical measure called "Tri-Center Analysis". This new statistic is designed to analyze the post hoc outcomes of the Tri-Squared Test. In Tri-Center Analysis trichotomous parametric inferential parametric statistical measures are calculated from…

Non-LTE modeling for the National Ignition Facility (and beyond)

NASA Astrophysics Data System (ADS)

Scott, H. A.; Hammel, B. A.; Hansen, S. B.

2012-05-01

Considerable progress has been made in the last year in the study of laser-driven inertial confinement fusion at the National Ignition Facility (NIF). Experiments have demonstrated symmetric capsule implosions with plasma conditions approaching those required for ignition. Improvements in computational models - in large part due to advances in non-LTE modeling - have resulted in simulations that match experimental results quite well for the X-ray drive, implosion symmetry and total wall emission [1]. Non-LTE modeling is a key part of the NIF simulation effort, affecting several aspects of experimental design and diagnostics. The X-rays that drive the capsule arise from high-Z material ablated off the hohlraum wall. Current capsule designs avoid excessive preheat from high-energy X-rays by shielding the fuel with a mid-Z dopant, which affects the capsule dynamics. The dopant also mixes into the hot spot through hydrodynamic instabilities, providing diagnostic possibilities but potentially impacting the energy balance of the capsule [2]. Looking beyond the NIF, a proposed design for a fusion reactor chamber depends on lowdensity high-Z gas absorbing X-rays and particles to protect the first wall [3]. These situations encompass a large range of temperatures, densities and spatial scales. They each emphasize different aspects of atomic physics and present a variety of challenges for non-LTE modeling. We discuss the relevant issues and summarize the current state of the modeling effort for these applications.

KSC-2012-5588

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - Test operators examine a model capsule after a of test inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

KSC-2012-5581

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - Test operators prepare a model capsule ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

KSC-2012-5579

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - NASA Aerospace Engineer Jeff Hagen prepares a model capsule ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to test a rotor system landing design. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

Once-daily mesalamine granules for ulcerative colitis.

PubMed

Lawlor, Garrett; Ahmed, Awais; Moss, Alan C

2010-07-01

Mesalamine extended-release capsules (Apriso [Salix Pharmaceuticals, Raleigh, NC, USA]) are the first once-daily mesalamine preparation approved by the US FDA for the maintenance of remission of ulcerative colitis (UC). Each mesalamine extended-release capsule contains granules of a mesalamine-polymer matrix that are coated with a pH-sensitive resin. This design begins releasing mesalamine (0.375 g) once the pH is more than 6 in the ileum and colon. Two clinical trials have reported that mesalamine extended-release capsules (1.5 g/day) maintained remission in 79% of patients with UC who were in clinical remission. Reported adherence with mesalamine extended-release capsules once daily was high (>90%) in these studies. This article examines the efficacy and safety of mesalamine extended-release capsules in the maintenance of remission in patients with UC.

Magnetic control system targeted for capsule endoscopic operations in the stomach--design, fabrication, and in vitro and ex vivo evaluations.

PubMed

Lien, Gi-Shih; Liu, Chih-Wen; Jiang, Joe-Air; Chuang, Cheng-Long; Teng, Ming-Tsung

2012-07-01

This paper presents a novel solution of a hand-held external controller to a miniaturized capsule endoscope in the gastrointestinal (GI) tract. Traditional capsule endoscopes move passively by peristaltic wave generated in the GI tract and the gravity, which makes it impossible for endoscopists to manipulate the capsule endoscope to the diagnostic disease areas. In this study, the main objective is to present an endoscopic capsule and a magnetic field navigator (MFN) that allows endoscopists to remotely control the locomotion and viewing angle of an endoscopic capsule. The attractive merits of this study are that the maneuvering of the endoscopic capsule can be achieved by the external MFN with effectiveness, low cost, and operation safety, both from a theoretical and an experimental point of view. In order to study the magnetic interactions between the endoscopic capsule and the external MFN, a magnetic-analysis model is established for computer-based finite-element simulations. In addition, experiments are conducted to show the control effectiveness of the MFN to the endoscopic capsule. Finally, several prototype endoscopic capsules and a prototype MFN are fabricated, and their actual capabilities are experimentally assessed via in vitro and ex vivo tests using a stomach model and a resected porcine stomach, respectively. Both in vitro and ex vivo test results demonstrate great potential and practicability of achieving high-precision rotation and controllable movement of the capsule using the developed MFN.

Head or tail: the orientation of the small bowel capsule endoscope movement in the small bowel.

PubMed

Kopylov, Uri; Papageorgiou, Neofytos P; Nadler, Moshe; Eliakim, Rami; Ben-Horin, Shomron

2012-03-01

The diagnostic accuracy of capsule endoscopy has been suggested to be influenced by the direction of the passage in the intestine. It is currently unknown if a head-first or a tail-first orientation are equally common during the descent through the small bowel. The aim of the study was to identify the orientation of the capsule along the migration through the small bowel. Thirty capsule endoscopies were reviewed by an experienced observer. The direction of the passage through the pylorus and the ileoceccal valve was recorded for all the examinations. In addition, detailed review of the passage of the capsule in different segments of the small bowel was undertaken for all the capsules. The capsule was significantly more likely to pass the pylorus head-first compared to tail-first (25 and 5 out of 30, respectively, OR 5, 95% CI 65-94%, P < 0.001). In 28/30 studies, the capsule exited the ileoceccal valve head-first (OR-14, 95% CI 77-99%, P < 0.001). In an immersion experiment, uneven distribution of weight of the capsule body was demonstrated with the head part (camera tip) being lighter than the tail part. The capsule endoscope usually passes through the pylorus and subsequent segments of the small bowel head-first. This observation suggests that the intestinal peristaltic physiology drives symmetrical bodies with their light part first. The principle of intestinal orientation by weight distribution may bear implications for capsules' design in the future.

Parametric estimation for reinforced concrete relief shelter for Aceh cases

NASA Astrophysics Data System (ADS)

Atthaillah; Saputra, Eri; Iqbal, Muhammad

2018-05-01

This paper was a work in progress (WIP) to discover a rapid parametric framework for post-disaster permanent shelter’s materials estimation. The intended shelters were reinforced concrete construction with bricks as its wall. Inevitably, in post-disaster cases, design variations were needed to help suited victims condition. It seemed impossible to satisfy a beneficiary with a satisfactory design utilizing the conventional method. This study offered a parametric framework to overcome slow construction-materials estimation issue against design variations. Further, this work integrated parametric tool, which was Grasshopper to establish algorithms that simultaneously model, visualize, calculate and write the calculated data to a spreadsheet in a real-time. Some customized Grasshopper components were created using GHPython scripting for a more optimized algorithm. The result from this study was a partial framework that successfully performed modeling, visualization, calculation and writing the calculated data simultaneously. It meant design alterations did not escalate time needed for modeling, visualization, and material estimation. Further, the future development of the parametric framework will be made open source.

The Bigfoot Drive; Experimental Results

NASA Astrophysics Data System (ADS)

Baker, Kevin; Thomas, Cliff; Khan, Shahab; Casey, Daniel; Spears, Brian; Nora, Ryan; Munro, Davis; Eder, David; Milovich, Jose; Berger, Dick; Strozzi, David; Goyon, Clement; Turnbull, David; Ma, Tammy; Izumi, Nobuhiko; Benedetti, Robin; Millot, Marius; Celliers, Peter; Yeamans, Charles; Hatarik, Robert; Landen, Nino; Hurricane, Omar; Callahan, Debbie

2016-10-01

The Bigfoot platform was developed on the National Ignition Facility to investigate low convergence, high adiabat, high rhoR hotspot implosions. This platform was designed to be less susceptible to wall motion, LPI and CBET and to be more robust against capsule hydrodynamic instabilities. To date experimental studies have been carried out at two hohlraum scales, a 5.75 and 5.4 mm diameter hohlraum. We will present experimental results from these tuning campaigns including the shape vs. cone fraction, surrogacy comparisons of self-emission from the capsules vs. radiography of the imploding capsule and doped vs. undoped capsules. Prepared by LLNL under Contract DE-AC52-07NA27344.

Towards active capsular endoscopy: preliminary results on a legged platform.

PubMed

Menciassi, Arianna; Stefanini, Cesare; Orlandi, Giovanni; Quirini, Marco; Dario, Paolo

2006-01-01

This paper illustrates the problem of active locomotion in the gastrointestinal tract for endoscopic capsules. Authors analyze the problem of locomotion in unstructured, flexible and tubular environments and explain the reasons leading to the selection of a legged system. They present a theoretical simulation of legged capsule locomotion, which is used to define the optimal parameters for capsule design and gait selection. Finally, a legged capsule--about 3 cm3 in volume--is presented; it consists of 4 back legs whose actuation is achieved thanks to a miniaturized DC brushless motor. In vitro tests demonstrate good performance in terms of achievable speed (92 mm/min).

A wireless capsule system with ASIC for monitoring the physiological signals of the human gastrointestinal tract.

PubMed

Xu, Fei; Yan, Guozheng; Zhao, Kai; Lu, Li; Gao, Jinyang; Liu, Gang

2014-12-01

This paper presents the design of a wireless capsule system for monitoring the physiological signals of the human gastrointestinal (GI) tract. The primary components of the system include a wireless capsule, a portable data recorder, and a workstation. Temperature, pH, and pressure sensors; an RF transceiver; a controlling and processing application specific integrated circuit (ASIC); and batteries were applied in a wireless capsule. Decreasing capsule size, improving sensor precision, and reducing power needs were the primary challenges; these were resolved by employing micro sensors, optimized architecture, and an ASIC design that include power management, clock management, a programmable gain amplifier (PGA), an A/D converter (ADC), and a serial peripheral interface (SPI) communication unit. The ASIC has been fabricated in 0.18- μm CMOS technology with a die area of 5.0 mm × 5.0 mm. The wireless capsule integrating the ASIC controller measures Φ 11 mm × 26 mm. A data recorder and a workstation were developed, and 20 cases of human experiments were conducted in hospitals. Preprocessing in the workstation can significantly improve the quality of the data, and 76 original features were determined by mathematical statistics. Based on the 13 optimal features achieved in the evaluation of the features, the clustering algorithm can identify the patients who lack GI motility with a recognition rate reaching 83.3%.

Parametric pendulum based wave energy converter

NASA Astrophysics Data System (ADS)

Yurchenko, Daniil; Alevras, Panagiotis

2018-01-01

The paper investigates the dynamics of a novel wave energy converter based on the parametrically excited pendulum. The herein developed concept of the parametric pendulum allows reducing the influence of the gravity force thereby significantly improving the device performance at a regular sea state, which could not be achieved in the earlier proposed original point-absorber design. The suggested design of a wave energy converter achieves a dominant rotational motion without any additional mechanisms, like a gearbox, or any active control involvement. Presented numerical results of deterministic and stochastic modeling clearly reflect the advantage of the proposed design. A set of experimental results confirms the numerical findings and validates the new design of a parametric pendulum based wave energy converter. Power harvesting potential of the novel device is also presented.

Implosion Dynamics and Mix in Double-Shell ICF Capsule Designs

NASA Astrophysics Data System (ADS)

Gunderson, Mark; Daughton, William; Simakov, Andrei; Wilson, Douglas; Watt, Robert; Delamater, Norman; Montgomery, David

2015-11-01

From an implosion dynamics perspective, double-shell ICF capsule designs have several advantages over the single-shell NIF ICF capsule point design. Double shell designs do not require precise shock sequencing, do not rely on hot spot ignition, have lower peak implosion speed requirements, and have lower convergence ratio requirements. However, there are still hurdles that must be overcome. The timing of the two main shocks in these designs is important in achieving sufficient compression of the DT fuel. Instability of the inner gold shell due to preheat from the hohlraum environment can disrupt the implosion of the inner pill. Mix, in addition to quenching burn in the DT fuel, also decreases the transfer of energy between the beryllium ablator and the inner gold shell during collision thus decreasing the implosion speed of the inner shell along with compression of the DT fuel. Herein, we will discuss practical implications of these effects on double-shell design we carry out in preparation for the NIF double-shell campaign. Work performed under the auspices of DOE by LANL under contract DE-AC52-06NA25396.

Design and analysis of radial imaging capsule endoscope (RICE) system.

PubMed

Ou-Yang, Mang; Jeng, Wei-De

2011-02-28

In this study, a radial imaging capsule endoscope (RICE) system is designed, which differs from a conventional front imaging capsule endoscope (FICE) system. To observe the wrinkled intima of the intestine, which spreads without folding around the circumference of the capsule when a capsule endoscope with a diameter that slightly exceeds that of the intestine passes through it, the RICE uses a cone mirror, a radial window shell, and a focus optical module that comprise the radial imaging system. This concept was demonstrated in a packaged optical simulator. The RICE optical model also has been established and verified by many simulations and experiments. In minimizing the sagittal and tangential aberrations, the optical module of the RICE has achieved an F-number of 4.2, a viewing angle of 65.08°, and an RMS radius of the 4th to 6th fields of less than 17 um. A comparison of these characteristics with those of the focus optical module that is used in FICE lenses reveals that the spot size is 50% larger for each field, and the modulation transfer function (MTF) is remarkably improved from 7% to 36% at 100 lp/mm on the 5th field of the sagittal plane.

Designing Synthetic Microcapsules That Undergo Biomimetic Communication and Autonomous Motion.

PubMed

Yashin, Victor V; Kolmakov, German V; Shum, Henry; Balazs, Anna C

2015-11-10

Inspired by the collective behavior of slime molds and amoebas, we designed synthetic cell-like objects that move and self-organize in response to self-generated chemical gradients, thereby exhibiting autochemotaxis. Using computational modeling, we specifically focused on microcapsules that encompass a permeable shell and are localized on an adhesive surface in solution. Lacking any internal machinery, these spherical, fluid-filled shells might resemble the earliest protocells. Our microcapsules do, however, encase particles that can diffuse through the outer shell and into the surrounding fluid. The released particles play two important, physically realizable roles: (1) they affect the permeability of neighboring capsules and (2) they generate adhesion gradients on the underlying surface. Due to feedback mechanisms provided by the released particles, the self-generated adhesion gradients, and hydrodynamic interactions, the capsules undergo collective, self-sustained motion and even exhibit antlike tracking behavior. With the introduction of a chemically patterned stripe on the surface, a triad of capsules can be driven to pick up four-capsule cargo, transport this cargo, and drop off this payload at a designated site. We also modeled a system where the released particles give rise to a particular cycle of negative feedback loops (mimicking the "repressilator" network), which regulates the production of chemicals within the capsules and hence their release into the solution. By altering the system parameters, three capsules could be controllably driven to self-organize into a stable, close-packed triad that would either translate as a group or remain stationary. Moreover, the stationary triads could be made to switch off after assembly and thus produce minimal quantities of chemicals. Taken together, our models allow us to design a rich variety of self-propelled structures that achieve complex, cooperative behavior through fundamental physicochemical phenomena. The studies can also shed light on factors that enable individual protocells to communicate and self-assemble into larger communities.

First beryllium capsule implosions on the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kline, J. L.; Yi, S. A.; Simakov, A. N.

2016-05-15

The first indirect drive implosion experiments using Beryllium (Be) capsules at the National Ignition Facility confirm the superior ablation properties and elucidate possible Be-ablator issues such as hohlraum filling by ablator material. Since the 1990s, Be has been the preferred Inertial Confinement Fusion (ICF) ablator because of its higher mass ablation rate compared to that of carbon-based ablators. This enables ICF target designs with higher implosion velocities at lower radiation temperatures and improved hydrodynamic stability through greater ablative stabilization. Recent experiments to demonstrate the viability of Be ablator target designs measured the backscattered laser energy, capsule implosion velocity, core implosionmore » shape from self-emission, and in-flight capsule shape from backlit imaging. The laser backscatter is similar to that from comparable plastic (CH) targets under the same hohlraum conditions. Implosion velocity measurements from backlit streaked radiography show that laser energy coupling to the hohlraum wall is comparable to plastic ablators. The measured implosion shape indicates no significant reduction of laser energy from the inner laser cone beams reaching the hohlraum wall as compared with plastic and high-density carbon ablators. These results indicate that the high mass ablation rate for beryllium capsules does not significantly alter hohlraum energetics. In addition, these data, together with data for low fill-density hohlraum performance, indicate that laser power multipliers, required to reconcile simulations with experimental observations, are likely due to our limited understanding of the hohlraum rather than the capsule physics since similar multipliers are needed for both Be and CH capsules as seen in experiments.« less

First beryllium capsule implosions on the National Ignition Facility

DOE PAGES

Kline, J. L.; Yi, S. A.; Simakov, A. N.; ...

2016-05-01

The first indirect drive implosion experiments using Beryllium (Be) capsules at the National Ignition Facility confirm the superior ablation properties and elucidate possible Be-ablator issues such as hohlraum filling by ablator material. Since the 1990s, Be has been the preferred Inertial Confinement Fusion (ICF) ablator because of its higher mass ablation rate compared to that of carbon-based ablators. This enables ICF target designs with higher implosion velocities at lower radiation temperatures and improved hydrodynamic stability through greater ablative stabilization. Recent experiments to demonstrate the viability of Be ablator target designs measured the backscattered laser energy, capsule implosion velocity, core implosionmore » shape from self-emission, and in-flight capsule shape from backlit imaging. The laser backscatter is similar to that from comparable plastic (CH) targets under the same hohlraum conditions. Implosion velocity measurements from backlit streaked radiography show that laser energy coupling to the hohlraum wall is comparable to plastic ablators. The measured implosion shape indicates no significant reduction of laser energy from the inner laser cone beams reaching the hohlraum wall as compared with plastic and high-density carbon ablators. These results indicate that the high mass ablation rate for beryllium capsules does not significantly alter hohlraum energetics. In addition, these data, together with data for low fill-density hohlraum performance, indicate that laser power multipliers, required to reconcile simulations with experimental observations, are likely due to our limited understanding of the hohlraum rather than the capsule physics since similar multipliers are needed for both Be and CH capsules as seen in experiments.« less

Creating A Data Base For Design Of An Impeller

NASA Technical Reports Server (NTRS)

Prueger, George H.; Chen, Wei-Chung

1993-01-01

Report describes use of Taguchi method of parametric design to create data base facilitating optimization of design of impeller in centrifugal pump. Data base enables systematic design analysis covering all significant design parameters. Reduces time and cost of parametric optimization of design: for particular impeller considered, one can cover 4,374 designs by computational simulations of performance for only 18 cases.

Video capsule endoscopy: Perspectives of a revolutionary technique

PubMed Central

Bouchard, Simon; Ibrahim, Mostafa; Van Gossum, Andre

2014-01-01

Video capsule endoscopy (VCE) was launched in 2000 and has revolutionized direct endoscopic imaging of the gut. VCE is now a first-line procedure for exploring the small bowel in cases of obscure digestive bleeding and is also indicated in some patients with Crohn’s disease, celiac disease, and polyposis syndrome. A video capsule has also been designed for visualizing the esophagus in order to detect Barrett’s esophagus or esophageal varices. Different capsules are now available and differ with regard to dimensions, image acquisition rate, battery life, field of view, and possible optical enhancements. More recently, the use of VCE has been extended to exploring the colon. Within the last 5 years, tremendous developments have been made toward increasing the capabilities of the colon capsule. Although colon capsule cannot be proposed as a first-line colorectal cancer screening procedure, colon capsule may be used in patients with incomplete colonoscopy or in patients who are unwilling to undergo colonoscopy. In the near future, new technological developments will improve the diagnostic yield of VCE and broaden its therapeutic capabilities. PMID:25516644

Lubiprostone neither decreases gastric and small-bowel transit time nor improves visualization of small bowel for capsule endoscopy: a double-blind, placebo-controlled study.

PubMed

Hooks, S Bennett; Rutland, Travis J; Di Palma, Jack A

2009-11-01

Lubiprostone, a selective activator of type 2 chloride channels, is approved for treatment of chronic idiopathic constipation and recently constipation-predominant irritable bowel syndrome. It has been suggested that lubiprostone has a prokinetic effect. This investigation was designed to evaluate lubiprostone as a preparation and propulsive agent for small-bowel capsule endoscopy. The PillCam Small Bowel capsule endoscopy system with the PillCam SB1 capsule and Rapid 5 software platform were used. The study was designed as a double-blind, placebo-controlled trial. Forty healthy adults. Gastric transit time (GTT), small-bowel transit time (SBTT), and adequacy of small-bowel cleansing preparation. The study subjects received 24 mug lubiprostone or placebo 30 minutes before PillCam capsule ingestion. Capsule endoscopy studies were read by 2 independent investigators unaware of the study medication received, and differences in interpretation were resolved by consensus. Anatomical landmarks were identified, and GTT and SBTT were calculated. Overall preparation quality assessment of the proximal, mid, and distal small bowel was determined by using a 4-step scale. The percentage of visualized bowel was determined by review of 10-minute video segments at 1-hour intervals after the capsule passed through the pylorus. In the lubiprostone group (n = 20), 2 subjects did not pass the capsule through the pylorus in the 8-hour battery life of the capsule. An additional 3 capsules did not pass into the colon. In the placebo group (n = 20), all capsules passed into the small bowel, but 1 did not pass into the colon. The subjects in whom the capsule did not pass into the small bowel were excluded from the small-bowel analysis. In the subjects in whom the capsule did reach the colon, the SBTT could not be calculated and they were excluded from SBTT analysis. The mean GTT in the lubiprostone group was 126 minutes and 43 minutes in the placebo group (P = .0095). The mean SBTT in the lubiprostone group was 188 minutes and 219 minutes in the placebo group (P = .130). The overall preparation assessment of the small bowel was not statistically significant between the 2 groups in the proximal, mid, or distal small bowel (proximal, P = .119; mid, P = .118; distal, P = .121). There was no significant difference in lubiprostone compared with placebo in the percentage of visualized small bowel. Some capsules did not leave the stomach or reach the cecum. Lubiprostone produced a significant increase in GTT but did not result in a significant decrease in SBTT compared with placebo. The administration of lubiprostone before capsule ingestion did not result in improved overall preparation of the small bowel for capsule endoscopy or increase the percentage of visualized small bowel. (The trial was registered at www.clinicaltrials.gov, identifier NCT00746395.).

SITE TECHNOLOGY CAPSULE: NOVOCS EVALUATION AT NAS NORTH ISLAND

EPA Science Inventory

This is a SITE Technology Capsule. The MACTEC, Inc. (MACTEC), NoVOCs(TM) in-well volatile organic compounds (VOC) stripping technology is an in-situ groundwater remediation technology designed for the cleanup of groundwater contaminated with VOCs. The NoVOCs(TM) technology was ev...

Capsule symmetry sensitivity and hohlraum symmetry calculations for the z-pinch driven hohlraum high-yield concept

NASA Astrophysics Data System (ADS)

Vesey, Roger; Cuneo, M. E.; Hanson Porter, D. L., Jr.; Mehlhorn, T. A.; Ruggles, L. E.; Simpson, W. W.; Hammer, J. H.; Landen, O.

2000-10-01

Capsule radiation symmetry is a crucial issue in the design of the z-pinch driven hohlraum approach to high-yield inertial confinement fusion [1]. Capsule symmetry may be influenced by power imbalance of the two z-pinch x-ray sources, and by hohlraum effects (geometry, time-dependent albedo, wall motion). We have conducted two-dimensional radiation-hydrodynamics calculations to estimate the symmetry sensitivity of the 220 eV beryllium ablator capsule that nominally yields 400 MJ in this concept. These estimates then determine the symmetry requirements to be met by the hohlraum design (for even Legendre modes) and by the top-bottom pinch imbalance and mistiming (for odd Legendre modes). We have used a combination of 2- and 3-D radiosity ("viewfactor"), and 2-D radiation-hydrodynamics calculations to identify hohlraum geometries that meet these symmetry requirements for high-yield, and are testing these models against ongoing Z foam ball symmetry experiments. 1. J. H. Hammer et al., Phys. Plas. 6, 2129 (1999).

Designing a Poly (N-isopropylacrylamide) Nanocapsule for Magnetic Field-assisted Drug Delivery

NASA Astrophysics Data System (ADS)

Denmark, Daniel; Mukherjee, Pritish; Witanachchi, Sarath

2014-03-01

The method of synthesis and the characteristics of polymer based nanocapsules as biomedical drug delivery systems are presented. Magnetic iron oxide nanoparticles have been incorporated into these capsules for effective guidance with external magnetic fields to transport therapeutic compounds to various parts of the human body. Once they have reached their destination they can be stimulated to release the drug to the target tissue through externally applied fields. The polymeric material that constitutes the capsules is specifically designed to melt away with the external stimuli to deliver the therapeutic bio agents near the target tissue. In this work we use nebulization to create aqueous poly (N-isopropylacrylamide) nanoparticles that decompose after being heated beyond their transition temperature. Transmission Electron Microscopic imaging (TEM) and dynamic light scattering (DLS) experiments have been conducted to study the decomposition of the capsules under external stimuli. Distribution of the magnetic nanoparticles within the capsules and their role in delivering the bio agents have been investigated by the Magnetic Force Microscopy (MFM).

Mitigating the impact of hohlraum asymmetries in National Ignition Facility implosions using capsule shims

NASA Astrophysics Data System (ADS)

Clark, Daniel; Weber, Christopher; Smalyuk, Vladimir; Robey, Harry; Kritcher, Andrea; Milovich, Jose; Salmonson, Jay

2016-10-01

Current indirect drive implosion experiments on the National Ignition Facility (NIF) are believed to be strongly impacted by long wavelength perturbations driven by asymmetries in the hohlraum x-ray flux. To address this perturbation source, active efforts are underway to develop modified hohlraum designs with reduced asymmetry imprint. An alternative strategy, however, is to modify the capsule design to be more resilient to a given amount of hohlraum asymmetry. In particular, the capsule may be deliberately misshaped, or ``shimmed,'' so as to counteract the expected asymmetries from the hohlraum. Here, the efficacy of capsule shimming to correct the asymmetries in two recent NIF implosion experiments is assessed using two-dimensional radiation hydrodynamics simulations. Despite the highly time-dependent character of the asymmetries and the high convergence ratios of these implosions, simulations suggest that shims could be highly effective at counteracting current asymmetries and result in factors of a few enhancements in neutron yields. For higher compression designs, the yield improvement could be even greater. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Single-arm phase II trial design under parametric cure models.

PubMed

Wu, Jianrong

2015-01-01

The current practice of designing single-arm phase II survival trials is limited under the exponential model. Trial design under the exponential model may not be appropriate when a portion of patients are cured. There is no literature available for designing single-arm phase II trials under the parametric cure model. In this paper, a test statistic is proposed, and a sample size formula is derived for designing single-arm phase II trials under a class of parametric cure models. Extensive simulations showed that the proposed test and sample size formula perform very well under different scenarios. Copyright © 2015 John Wiley & Sons, Ltd.

Effect of Symmetry on Performance of Imploding Capsules using the Big Foot Design

NASA Astrophysics Data System (ADS)

Khan, Shahab; Casey, Daniel; Baker, Kevin; Thomas, Cliff; Nora, Ryan; Spears, Brian; Benedetti, Laura; Izumi, Nobuhiko; Ma, Tammy; Nagel, Sabrina; Pak, Arthur; National Ignition Facility Collaboration

2017-10-01

At the National Ignition Facility, several simultaneous designs are investigated for optimizing Inertial Confinement Fusion (ICF) energy gain of indirectly driven imploding fuel capsules. Relatively high neutron yield has been achieved while exhibiting a non-symmetric central core and/or shell. While developing the ``Big Foot'' design, several tuning steps were undertaken to minimize the asymmetry of both the central hot core as well as the shell. Surrogate capsules (symcaps) were utilized in the 2-D Radiography platform to assess both the shell and central core symmetry. The results of the tuning experiments are presented. In addition, a comparison of performance and shape metrics demonstrates that improving symmetry of the implosion can yield better performance. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-683471.

A Unique Capsule Locus in the Newly Designated Actinobacillus pleuropneumoniae Serovar 16 and Development of a Diagnostic PCR Assay.

PubMed

Bossé, Janine T; Li, Yanwen; Sárközi, Rita; Gottschalk, Marcelo; Angen, Øystein; Nedbalcova, Katerina; Rycroft, Andrew N; Fodor, László; Langford, Paul R

2017-03-01

Actinobacillus pleuropneumoniae causes pleuropneumonia, an economically significant lung disease of pigs. Recently, isolates of A. pleuropneumoniae that were serologically distinct from the previously characterized 15 serovars were described, and a proposal was put forward that they comprised a new serovar, serovar 16. Here we used whole-genome sequencing of the proposed serovar 16 reference strain A-85/14 to confirm the presence of a unique capsular polysaccharide biosynthetic locus. For molecular diagnostics, primers were designed from the capsule locus of strain A-85/14, and a PCR was formulated that differentiated serovar 16 isolates from all 15 known serovars and other common respiratory pathogenic/commensal bacteria of pigs. Analysis of the capsule locus of strain A-85/14 combined with the previous serological data show the existence of a sixteenth serovar-designated serovar 16-of A. pleuropneumoniae . Copyright © 2017 Bossé et al.

Designing cylindrical implosion experiments on NIF to study deceleration phase of Rayleigh-Taylor

NASA Astrophysics Data System (ADS)

Vazirani, N.; Kline, J. L.; Loomis, E.; Sauppe, J. P.; Palaniyappan, S.; Flippo, K.; Srinivasan, B.; Malka, E.; Bose, A.; Shvarts, D.

2017-10-01

The Rayleigh-Taylor (RT) hydrodynamic instability occurs when a lower density fluid pushes on a higher density fluid. This occurs in inertial confinement fusion (ICF) implosions at each of the capsule interfaces during the initial acceleration and the deceleration as it stagnates. The RT instabilities mix capsule material into the fusion fuel degrading the Deuterium-Tritium reactivity and ultimately play a key role in limiting target performance. While significant effort has focused on understanding RT at the outer capsule surface, little work has gone into understanding the inner surface RT instability growth during the deceleration phase. Direct measurements of the RT instability are difficult to make at high convergence in a spherical implosion. Here we present the design of a cylindrical implosion system for the National Ignition Facility for studying deceleration phase RT. We will discuss the experimental design, the estimated instability growth, and our outstanding concerns.

Progress on LMJ targets for ignition

NASA Astrophysics Data System (ADS)

Cherfils-Clérouin, C.; Boniface, C.; Bonnefille, M.; Dattolo, E.; Galmiche, D.; Gauthier, P.; Giorla, J.; Laffite, S.; Liberatore, S.; Loiseau, P.; Malinie, G.; Masse, L.; Masson-Laborde, P. E.; Monteil, M. C.; Poggi, F.; Seytor, P.; Wagon, F.; Willien, J. L.

2009-12-01

Targets designed to produce ignition on the Laser Megajoule (LMJ) are being simulated in order to set specifications for target fabrication. The LMJ experimental plans include the attempt of ignition and burn of an ICF capsule with 160 laser beams, delivering up to 1.4 MJ and 380 TW. New targets needing reduced laser energy with only a small decrease in robustness have then been designed for this purpose. Working specifically on the coupling efficiency parameter, i.e. the ratio of the energy absorbed by the capsule to the laser energy, has led to the design of a rugby-ball shaped cocktail hohlraum; with these improvements, a target based on the 240-beam A1040 capsule can be included in the 160-beam laser energy-power space. Robustness evaluations of these different targets shed light on critical points for ignition, which can trade off by tightening some specifications or by preliminary experimental and numerical tuning experiments.

Design Options for the High-Foot Ignition Capsule Series on NIF

NASA Astrophysics Data System (ADS)

Dittrich, T. R.; Hurricane, O. A.; Berzak Hopkins, L. F.; Callahan, D. A.; Clark, D.; Doeppner, T.; Haan, S. W.; Hammel, B. A.; Harte, J. A.; Hinkel, D. E.; Ma, T.; Pak, A. E.; Park, H.-S.; Salmonson, J. D.; Weber, C. R.; Zimmerman, G. B.; Olson, R. E.; Kline, J. L.; Leeper, R. J.

2015-11-01

Several options exist for improving implosion performance in the High-Foot series of ignition capsules on NIF. One option is to modify the fill tube used to supply DT to the capsule. Simulations indicate that a gold-coated glass tube may reduce implosion hydro effects and allow fielding a larger diameter tube capable of supporting the capsule, eliminating the need for the nominal tent support. A second option adds a fourth shock to the implosion history. According to simulation, this extra shock improves fuel confinement and capsule performance. A third option studies the feasibility of holding the DT fuel in liquid form in a foam layer inside the shell. This ``wetted foam'' concept, advanced by Olson, has existed for several years and may allow some control over the convergence of the capsule during implosion. This work was performed under the auspices of the Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

Design and testing of tubular polymeric capsules for self-healing of concrete

NASA Astrophysics Data System (ADS)

Araújo, M.; Van Tittelboom, K.; Feiteira, J.; Gruyaert, E.; Chatrabhuti, S.; Raquez, J.-M.; Šavija, B.; Alderete, N.; Schlangen, E.; De Belie, N.

2017-10-01

Polymeric healing agents have proven their efficiency to heal cracks in concrete in an autonomous way. However, the bottleneck for valorisation of self-healing concrete with polymeric healing agents is their encapsulation. In the present work, the suitability of polymeric materials such as poly(methyl methacrylate) (PMMA), polystyrene (PS) and poly(lactic acid) (PLA) as carriers for healing agents in self-healing concrete has been evaluated. The durability of the polymeric capsules in different environments (demineralized water, salt water and simulated concrete pore solution) and their compatibility with various healing agents have been assessed. Next, a numerical model was used to simulate capsule rupture when intersected by a crack in concrete and validated experimentally. Finally, two real-scale self-healing concrete beams were made, containing the selected polymeric capsules (with the best properties regarding resistance to concrete mixing and breakage upon crack formation) or glass capsules and a reference beam without capsules. The self-healing efficiency was determined after crack creation by 3-point-bending tests.

Analysis of lomustine drug content in FDA-approved and compounded lomustine capsules.

PubMed

KuKanich, Butch; Warner, Matt; Hahn, Kevin

2017-02-01

OBJECTIVE To determine the lomustine content (potency) in compounded and FDA-approved lomustine capsules. DESIGN Evaluation study. SAMPLE 2 formulations of lomustine capsules (low dose [7 to 11 mg] and high dose [40 to 48 mg]; 5 capsules/dose/source) from 3 compounders and from 1 manufacturer of FDA-approved capsules. PROCEDURES Lomustine content was measured by use of a validated high-pressure liquid chromatography method. An a priori acceptable range of 90% to 110% of the stated lomustine content was selected on the basis of US Pharmacopeia guidelines. RESULTS The measured amount of lomustine in all compounded capsules was less than the stated content (range, 59% to 95%) and was frequently outside the acceptable range (failure rate, 2/5 to 5/5). Coefficients of variation for lomustine content ranged from 4.1% to 16.7% for compounded low-dose capsules and from 1.1% to 10.8% for compounded high-dose capsules. The measured amount of lomustine in all FDA-approved capsules was slightly above the stated content (range, 104% to 110%) and consistently within the acceptable range. Coefficients of variation for lomustine content were 0.5% for low-dose and 2.3% for high-dose FDA-approved capsules. CONCLUSIONS AND CLINICAL RELEVANCE Compounded lomustine frequently did not contain the stated content of active drug and had a wider range of lomustine content variability than did the FDA-approved product. The sample size was small, and larger studies are needed to confirm these findings; however, we recommend that compounded veterinary formulations of lomustine not be used when appropriate doses can be achieved with FDA-approved capsules or combinations of FDA-approved capsules.

Coupled parametric design of flow control and duct shape

NASA Technical Reports Server (NTRS)

Florea, Razvan (Inventor); Bertuccioli, Luca (Inventor)

2009-01-01

A method for designing gas turbine engine components using a coupled parametric analysis of part geometry and flow control is disclosed. Included are the steps of parametrically defining the geometry of the duct wall shape, parametrically defining one or more flow control actuators in the duct wall, measuring a plurality of performance parameters or metrics (e.g., flow characteristics) of the duct and comparing the results of the measurement with desired or target parameters, and selecting the optimal duct geometry and flow control for at least a portion of the duct, the selection process including evaluating the plurality of performance metrics in a pareto analysis. The use of this method in the design of inter-turbine transition ducts, serpentine ducts, inlets, diffusers, and similar components provides a design which reduces pressure losses and flow profile distortions.

Changing space and sound: Parametric design and variable acoustics

NASA Astrophysics Data System (ADS)

Norton, Christopher William

This thesis examines the potential for parametric design software to create performance based design using acoustic metrics as the design criteria. A former soundstage at the University of Southern California used by the Thornton School of Music is used as a case study for a multiuse space for orchestral, percussion, master class and recital use. The criteria used for each programmatic use include reverberation time, bass ratio, and the early energy ratios of the clarity index and objective support. Using a panelized ceiling as a design element to vary the parameters of volume, panel orientation and type of absorptive material, the relationships between these parameters and the design criteria are explored. These relationships and subsequently derived equations are applied to Grasshopper parametric modeling software for Rhino 3D (a NURBS modeling software). Using the target reverberation time and bass ratio for each programmatic use as input for the parametric model, the genomic optimization function of Grasshopper - Galapagos - is run to identify the optimum ceiling geometry and material distribution.

Problems of the design of low-noise input devices. [parametric amplifiers

NASA Technical Reports Server (NTRS)

Manokhin, V. M.; Nemlikher, Y. A.; Strukov, I. A.; Sharfov, Y. A.

1974-01-01

An analysis is given of the requirements placed on the elements of parametric centimeter waveband amplifiers for achievement of minimal noise temperatures. A low-noise semiconductor parametric amplifier using germanium parametric diodes for a receiver operating in the 4 GHz band was developed and tested confirming the possibility of satisfying all requirements.

Permeation fill-tube design for inertial confinement fusion target capsules

DOE PAGES

Rice, B. S.; Ulreich, J.; Fella, C.; ...

2017-03-22

A unique approach for permeation filling of nonpermeable inertial confinement fusion target capsules with deuterium–tritium (DT) is presented. This process uses a permeable capsule coupled into the final target capsule with a 0.03-mm-diameter fill tube. Leak free permeation filling of glow-discharge polymerization (GDP) targets using this method have been successfully demonstrated, as well as ice layering of the target, yielding an inner ice surface roughness of 1-more » $$\\unicode[STIX]{x03BC}$$m rms (root mean square). Finally, the measured DT ice-thickness profile for this experiment was used to validate a thermal model’s prediction of the same thickness profile.« less

Capsule Ablator Inflight Performance Measurements Via Streaked Radiography Of ICF Implosions On The NIF*

NASA Astrophysics Data System (ADS)

Dewald, E. L.; Tommasini, R.; Mackinnon, A.; MacPhee, A.; Meezan, N.; Olson, R.; Hicks, D.; LePape, S.; Izumi, N.; Fournier, K.; Barrios, M. A.; Ross, S.; Pak, A.; Döppner, T.; Kalantar, D.; Opachich, K.; Rygg, R.; Bradley, D.; Bell, P.; Hamza, A.; Dzenitis, B.; Landen, O. L.; MacGowan, B.; LaFortune, K.; Widmayer, C.; Van Wonterghem, B.; Kilkenny, J.; Edwards, M. J.; Atherton, J.; Moses, E. I.

2016-03-01

Streaked 1-dimensional (slit imaging) radiography of 1.1 mm radius capsules in ignition hohlraums was recently introduced on the National Ignition Facility (NIF) and gives an inflight continuous record of capsule ablator implosion velocities, shell thickness and remaining mass in the last 3-5 ns before peak implosion time. The high quality data delivers good accuracy in implosion metrics that meets our requirements for ignition and agrees with recently introduced 2-dimensional pinhole radiography. Calculations match measured trajectory across various capsule designs and laser drives when the peak laser power is reduced by 20%. Furthermore, calculations matching measured trajectories give also good agreement in ablator shell thickness and remaining mass.

Design and preliminary testing of a novel skin expander for total ear reconstruction in a rabbit model.

PubMed

Xiong, Wu; Yan, Yu; Hu, Feng; Liu, Can; Wang, Shaohua; Chen, Jia; Wang, Xueqi; Zhou, Jianda

2016-01-01

Ear reconstruction is one of the most complicated and challenging techniques in plastic surgery because of the histologic and anatomic properties of the ear. Success depends on fitting the auriform cartilage scaffold into the overlying skin, but current approaches can just give results that are not lifelike and can lead to complications. A novel double-capsule, double-valve plastic ear expander was designed and implanted subcutaneously on either side of the dorsum of six New Zealand white rabbits (two expanders per rabbit). The outer capsule was expanded by injecting approximately 120 mL of physiological saline, then withdrawing the liquid on two occasions. Next, the ear-shaped inner capsule was filled with high-hardness plaster, and the external capsule was emptied such that the expanded skin flap and external capsule responded to the negative pressure and closed over the ear-shaped inner capsule. As a result, the skin flap adopted an ear shape. The ear expander was left in place for 4 wk, removed with the help of a mini-incision, and stripped of its fibrous capsule. To simulate human ear reconstruction, the expander was replaced with an auriform silicone prosthesis, and the effects of auricular reconstruction were observed dynamically. All 12 skin flaps maintained abundant blood supply, created a clear outline of the ear framework, and produced a lifelike result. No complications were observed during the 4-wk observation period. The expanded skin flaps described here can mold to the desired contours and appear lifelike, as well as maintain abundant blood supply. This may provide a simpler approach to total ear reconstruction that reduces risk of complications. Copyright © 2016 Elsevier Inc. All rights reserved.

The Use of a Parametric Feature Based CAD System to Teach Introductory Engineering Graphics.

ERIC Educational Resources Information Center

Howell, Steven K.

1995-01-01

Describes the use of a parametric-feature-based computer-aided design (CAD) System, AutoCAD Designer, in teaching concepts of three dimensional geometrical modeling and design. Allows engineering graphics to go beyond the role of documentation and communication and allows an engineer to actually build a virtual prototype of a design idea and…

Democratizing science with the aid of parametric design and additive manufacturing: Design and fabrication of a versatile and low-cost optical instrument for scattering measurement.

PubMed

Nadal-Serrano, Jose M; Nadal-Serrano, Adolfo; Lopez-Vallejo, Marisa

2017-01-01

This paper focuses on the application of rapid prototyping techniques using additive manufacturing in combination with parametric design to create low-cost, yet accurate and reliable instruments. The methodology followed makes it possible to make instruments with a degree of customization until now available only to a narrow audience, helping democratize science. The proposal discusses a holistic design-for-manufacturing approach that comprises advanced modeling techniques, open-source design strategies, and an optimization algorithm using free parametric software for both professional and educational purposes. The design and fabrication of an instrument for scattering measurement is used as a case of study to present the previous concepts.

Democratizing science with the aid of parametric design and additive manufacturing: Design and fabrication of a versatile and low-cost optical instrument for scattering measurement

PubMed Central

Lopez-Vallejo, Marisa

2017-01-01

This paper focuses on the application of rapid prototyping techniques using additive manufacturing in combination with parametric design to create low-cost, yet accurate and reliable instruments. The methodology followed makes it possible to make instruments with a degree of customization until now available only to a narrow audience, helping democratize science. The proposal discusses a holistic design-for-manufacturing approach that comprises advanced modeling techniques, open-source design strategies, and an optimization algorithm using free parametric software for both professional and educational purposes. The design and fabrication of an instrument for scattering measurement is used as a case of study to present the previous concepts. PMID:29112987

Process Development and Micro-Machining of MARBLE Foam-Cored Rexolite Hemi-Shell Ablator Capsules

DOE PAGES

Randolph, Randall Blaine; Oertel, John A.; Schmidt, Derek William; ...

2016-06-30

For this study, machined CH hemi-shell ablator capsules have been successfully produced by the MST-7 Target Fabrication Team at Los Alamos National Laboratory. Process development and micro-machining techniques have been developed to produce capsules for both the Omega and National Ignition Facility (NIF) campaigns. These capsules are gas filled up to 10 atm and consist of a machined plastic hemi-shell outer layer that accommodates various specially engineered low-density polystyrene foam cores. Machining and assembly of the two-part, step-jointed plastic hemi-shell outer layer required development of new techniques, processes, and tooling while still meeting very aggressive shot schedules for both campaigns.more » Finally, problems encountered and process improvements will be discussed that describe this very unique, complex capsule design approach through the first Omega proof-of-concept version to the larger NIF version.« less

[Post-marketing clinical study of traditional Chinese medicine--lessons learned from comprehensive evaluation of Fufang Zaoren capsule].

PubMed

Qing, Shan; Gao, Lin; Zhang, Li; Jia, Jian-Ping; Liu, Xin-Min; Ji, Shao-Liang; Yang, Xiao-Hui

2013-11-01

By comprehensive review and analysis of post-marketing clinical research on the efficacy and safety,we concluded that Fufang Zaoren capsule has certain therapeutic effects for insomnia, although current clinical research design needs improving. The post-marketing clinical studies also showed that it causes several adverse reactions at the recommended doses, such as chills, fever, dizziness, nausea, shortness of breath, chest tightness and palpitations, whereas high doses of Fufang Zaoren capsule can cause delayed extrapyramidal symptoms. Health Canada government website also prompted the L-tetrahydropalmatine in Fufang Zaoren capsule caused liver damage in pregnant women. The authors summarized the risk points, factors and risk control in the clinical use of Fufang Zaoren capsule and also present their perspective on the research status, existing problems and corresponding countermeasures in the post-marketing clinical re-evaluation of traditional Chinese medicine.

Growth factor restriction impedes progression of wound healing following cataract surgery: identification of VEGF as a putative therapeutic target

PubMed Central

Eldred, Julie A.; McDonald, Matthew; Wilkes, Helen S.; Spalton, David J.; Wormstone, I. Michael

2016-01-01

Secondary visual loss occurs in millions of patients due to a wound-healing response, known as posterior capsule opacification (PCO), following cataract surgery. An intraocular lens (IOL) is implanted into residual lens tissue, known as the capsular bag, following cataract removal. Standard IOLs allow the anterior and posterior capsules to become physically connected. This places pressure on the IOL and improves contact with the underlying posterior capsule. New open bag IOL designs separate the anterior capsule and posterior capsules and further reduce PCO incidence. It is hypothesised that this results from reduced cytokine availability due to greater irrigation of the bag. We therefore explored the role of growth factor restriction on PCO using human lens cell and tissue culture models. We demonstrate that cytokine dilution, by increasing medium volume, significantly reduced cell coverage in both closed and open capsular bag models. This coincided with reduced cell density and myofibroblast formation. A screen of 27 cytokines identified nine candidates whose expression profile correlated with growth. In particular, VEGF was found to regulate cell survival, growth and myofibroblast formation. VEGF provides a therapeutic target to further manage PCO development and will yield best results when used in conjunction with open bag IOL designs. PMID:27076230

Subject-friendly entire gastrointestinal screening with a single capsule endoscope by magnetic navigation and the Internet.

PubMed

Ohta, Hidetoshi; Katsuki, Shinichi

2014-01-01

Ever since capsule endoscopy (CE) was introduced into clinical practice, we gastroenterologists have been dreaming of using this less invasive modality to explore the entire gastrointestinal (GI) tract. To realize this dream, we have developed a magnetic navigation system which includes real-time internet streaming of endoscopic video and some useful gadgets (position detection by means of magnetic impedance (MI) sensors and a modified capsule that is "weightless" in water). The design of the weightless capsule made it possible with 0.5T (Tesla) extracorporeal magnets to control the capsule beyond 20cm. A pair of MI sensors on the body surface could detect subtle magnetic flux generated by an intra-capsular magnet in the GI tract by utilizing the space diversity effect which eliminated the interference of terrestrial magnetism. Subjects underwent CE, during which they were free from confinement in the hospital, except for 1 hour when the capsule was manipulated in the stomach and colon. This study had a completion rate of 97.5%. The high completion rate indicates that our system (single capsule endoscopy-SCE) with further improvements could become a viable modality for screening of the entire GI tract.

An Automated Self-Learning Quantification System to Identify Visible Areas in Capsule Endoscopy Images.

PubMed

Hashimoto, Shinichi; Ogihara, Hiroyuki; Suenaga, Masato; Fujita, Yusuke; Terai, Shuji; Hamamoto, Yoshihiko; Sakaida, Isao

2017-08-01

Visibility in capsule endoscopic images is presently evaluated through intermittent analysis of frames selected by a physician. It is thus subjective and not quantitative. A method to automatically quantify the visibility on capsule endoscopic images has not been reported. Generally, when designing automated image recognition programs, physicians must provide a training image; this process is called supervised learning. We aimed to develop a novel automated self-learning quantification system to identify visible areas on capsule endoscopic images. The technique was developed using 200 capsule endoscopic images retrospectively selected from each of three patients. The rate of detection of visible areas on capsule endoscopic images between a supervised learning program, using training images labeled by a physician, and our novel automated self-learning program, using unlabeled training images without intervention by a physician, was compared. The rate of detection of visible areas was equivalent for the supervised learning program and for our automatic self-learning program. The visible areas automatically identified by self-learning program correlated to the areas identified by an experienced physician. We developed a novel self-learning automated program to identify visible areas in capsule endoscopic images.

Semipermeable Capsules Wrapping a Multifunctional and Self-regulated Co-culture Microenvironment for Osteogenic Differentiation

NASA Astrophysics Data System (ADS)

Correia, Clara R.; Pirraco, Rogério P.; Cerqueira, Mariana T.; Marques, Alexandra P.; Reis, Rui L.; Mano, João F.

2016-02-01

A new concept of semipermeable reservoirs containing co-cultures of cells and supporting microparticles is presented, inspired by the multi-phenotypic cellular environment of bone. Based on the deconstruction of the “stem cell niche”, the developed capsules are designed to drive a self-regulated osteogenesis. PLLA microparticles functionalized with collagen I, and a co-culture of adipose stem (ASCs) and endothelial (ECs) cells are immobilized in spherical liquified capsules. The capsules are coated with multilayers of poly(L-lysine), alginate, and chitosan nano-assembled through layer-by-layer. Capsules encapsulating ASCs alone or in a co-culture with ECs are cultured in endothelial medium with or without osteogenic differentiation factors. Results show that osteogenesis is enhanced by the co-encapsulation, which occurs even in the absence of differentiation factors. These findings are supported by an increased ALP activity and matrix mineralization, osteopontin detection, and the up regulation of BMP-2, RUNX2 and BSP. The liquified co-capsules also act as a VEGF and BMP-2 cytokines release system. The proposed liquified capsules might be a valuable injectable self-regulated system for bone regeneration employing highly translational cell sources.

Primate lens capsule elasticity assessed using Atomic Force Microscopy

PubMed Central

Ziebarth, Noël M.; Arrieta, Esdras; Feuer, William J.; Moy, Vincent T.; Manns, Fabrice; Parel, Jean-Marie

2011-01-01

The purpose of this project is to measure the elasticity of the human and non-human primate lens capsule at the microscopic scale using Atomic Force Microscopy (AFM). Elasticity measurements were performed using AFM on the excised anterior lens capsule from 9 cynomolgus monkey (5.9–8.0 years), 8 hamadryas baboon (2.8–10.1 years), and 18 human lenses (33–79 years). Anterior capsule specimens were obtained by performing a 5mm continuous curvilinear capsulorhexis and collecting the resulting disk of capsular tissue. To remove the lens epithelial cells the specimen was soaked in 0.1% trypsin and 0.02% EDTA for five minutes, washed, and placed on a Petri dish and immersed in DMEM. Elasticity measurements of the capsule were performed with a laboratory-built AFM system custom designed for force measurements of ophthalmic tissues. The capsular specimens were probed with an AFM cantilever tip to produce force-indentation curves for each specimen. Young’s modulus was calculated from the force-indentation curves using the model of Sneddon for a conical indenter. Young’s modulus of elasticity was 20.1–131kPa for the human lens capsule, 9.19–117kPa for the cynomolgus lens capsule, and 13.1–62.4kPa for the baboon lens capsule. Young’s modulus increased significantly with age in humans (p=0.03). The age range of the monkey and baboon samples was not sufficient to justify an analysis of age dependence. The capsule elasticity of young humans (<45 years) was not statistically different from that of the monkey and baboon. In humans, there is an increase in lens capsule stiffness at the microscale that could be responsible for an increase in lens capsule bulk stiffness. PMID:21420953

A novel diagnostic tool for detecting functional patency of the small bowel: the Given patency capsule.

PubMed

Spada, C; Spera, G; Riccioni, M; Biancone, L; Petruzziello, L; Tringali, A; Familiari, P; Marchese, M; Onder, G; Mutignani, M; Perri, V; Petruzziello, C; Pallone, F; Costamagna, G

2005-09-01

The current visualization of small-bowel strictures using traditional radiological methods is associated with high radiation doses and false-negative results. These methods do not always reveal small-bowel patency for solids. The aim is to assess the safety of the Given patency system and its ability to detect intestinal strictures in patients with strictures that are known or suspected radiologically. The Given patency capsule is composed of lactose, remains intact in the gastrointestinal tract for 40-100 hours post ingestion, and disintegrates thereafter. A total of 34 patients with small-bowel stricture were prospectively enrolled; 30 had a previous diagnosis of Crohn's disease, three had adhesion syndrome and in one ischemic enteritis was suspected. Of the patients, 15 (44.1 %) had previously undergone surgery. Following ingestion, the capsule was monitored for integrity and transit time, using a specially designed Given scanner and also radiologically. Seventeen patients had been enrolled with the intent of using the patency capsule as a preliminary test in patients with small-bowel strictures before undergoing video capsule endoscopy. 30 patients (88.2 %) retrieved the capsule in the stool; it was intact in 20 (median transit time 22 hours), and disintegrated in 10 patients (median transit time 53 hours). Six patients complained of abdominal pain which disappeared within 24 hours. The scanner successfully indicated the presence of the capsule in 94 % of cases. Ten patients underwent video capsule endoscopy following the patency capsule examination; in all of these the video capsule passed through the small-bowel stricture. This feasibility study has shown that the Given patency capsule is a safe, effective, and convenient tool for assessment of functional patency of the small bowel. It can indicate functional patency even in cases where traditional radiology indicates stricture.

Stability of dronabinol capsules when stored frozen, refrigerated, or at room temperature.

PubMed

Wempe, Michael F; Oldland, Alan; Stolpman, Nancy; Kiser, Tyree H

2016-07-15

Results of a study to determine the 90-day stability of dronabinol capsules stored under various temperature conditions are reported. High-performance liquid chromatography (HPLC) with ultraviolet (UV) detection was used to assess the stability of dronabinol capsules (synthetic delta-9-tetrahydrocannabinol [Δ9-THC] mixed with high-grade sesame oil and other inactive ingredients and encapsulated as soft gelatin capsules) that were frozen, refrigerated, or kept at room temperature for three months. The dronabinol capsules remained in the original foil-sealed blister packs until preparation for HPLC-UV assessment. The primary endpoint was the percentage of the initial Δ9-THC concentration remaining at multiple designated time points. The secondary aim was to perform forced-degradation studies under acidic conditions to demonstrate that the HPLC-UV method used was stability indicating. The appearance of the dronabinol capsules remained unaltered during frozen, cold, or room-temperature storage. Regardless of storage condition, the percentage of the initial Δ9-THC content remaining was greater than 97% for all evaluated samples at all time points over the three-month study. These experimental data indicate that the product packaging and the sesame oil used to formulate dronabinol capsules efficiently protect Δ9-THC from oxidative degradation to cannabinol; this suggests that pharmacies can store dronabinol capsules in nonrefrigerated automated dispensing systems, with a capsule expiration date of 90 days after removal from the refrigerator. Dronabinol capsules may be stored at room temperature in their original packaging for up to three months without compromising capsule appearance and with minimal reduction in Δ9-THC concentration. Copyright © 2016 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Generic delivery of payload of nanoparticles intracellularly via hybrid polymer capsules for bioimaging applications.

PubMed

Sami, Haider; Maparu, Auhin K; Kumar, Ashok; Sivakumar, Sri

2012-01-01

Towards the goal of development of a generic nanomaterial delivery system and delivery of the 'as prepared' nanoparticles without 'further surface modification' in a generic way, we have fabricated a hybrid polymer capsule as a delivery vehicle in which nanoparticles are loaded within their cavity. To this end, a generic approach to prepare nanomaterials-loaded polyelectrolyte multilayered (PEM) capsules has been reported, where polystyrene sulfonate (PSS)/polyallylamine hydrochloride (PAH) polymer capsules were employed as nano/microreactors to synthesize variety of nanomaterials (metal nanoparticles; lanthanide doped inorganic nanoparticles; gadolinium based nanoparticles, cadmium based nanoparticles; different shapes of nanoparticles; co-loading of two types of nanoparticles) in their hollow cavity. These nanoparticles-loaded capsules were employed to demonstrate generic delivery of payload of nanoparticles intracellularly (HeLa cells), without the need of individual nanoparticle surface modification. Validation of intracellular internalization of nanoparticles-loaded capsules by HeLa cells was ascertained by confocal laser scanning microscopy. The green emission from Tb(3+) was observed after internalization of LaF(3):Tb(3+)(5%) nanoparticles-loaded capsules by HeLa cells, which suggests that nanoparticles in hybrid capsules retain their functionality within the cells. In vitro cytotoxicity studies of these nanoparticles-loaded capsules showed less/no cytotoxicity in comparison to blank capsules or untreated cells, thus offering a way of evading direct contact of nanoparticles with cells because of the presence of biocompatible polymeric shell of capsules. The proposed hybrid delivery system can be potentially developed to avoid a series of biological barriers and deliver multiple cargoes (both simultaneous and individual delivery) without the need of individual cargo design/modification.

Generic Delivery of Payload of Nanoparticles Intracellularly via Hybrid Polymer Capsules for Bioimaging Applications

PubMed Central

Sami, Haider; Maparu, Auhin K.; Kumar, Ashok; Sivakumar, Sri

2012-01-01

Towards the goal of development of a generic nanomaterial delivery system and delivery of the ‘as prepared’ nanoparticles without ‘further surface modification’ in a generic way, we have fabricated a hybrid polymer capsule as a delivery vehicle in which nanoparticles are loaded within their cavity. To this end, a generic approach to prepare nanomaterials-loaded polyelectrolyte multilayered (PEM) capsules has been reported, where polystyrene sulfonate (PSS)/polyallylamine hydrochloride (PAH) polymer capsules were employed as nano/microreactors to synthesize variety of nanomaterials (metal nanoparticles; lanthanide doped inorganic nanoparticles; gadolinium based nanoparticles, cadmium based nanoparticles; different shapes of nanoparticles; co-loading of two types of nanoparticles) in their hollow cavity. These nanoparticles-loaded capsules were employed to demonstrate generic delivery of payload of nanoparticles intracellularly (HeLa cells), without the need of individual nanoparticle surface modification. Validation of intracellular internalization of nanoparticles-loaded capsules by HeLa cells was ascertained by confocal laser scanning microscopy. The green emission from Tb3+ was observed after internalization of LaF3:Tb3+(5%) nanoparticles-loaded capsules by HeLa cells, which suggests that nanoparticles in hybrid capsules retain their functionality within the cells. In vitro cytotoxicity studies of these nanoparticles-loaded capsules showed less/no cytotoxicity in comparison to blank capsules or untreated cells, thus offering a way of evading direct contact of nanoparticles with cells because of the presence of biocompatible polymeric shell of capsules. The proposed hybrid delivery system can be potentially developed to avoid a series of biological barriers and deliver multiple cargoes (both simultaneous and individual delivery) without the need of individual cargo design/modification. PMID:22649489

Oxygen fugacity and piston cylinder capsule assemblies

NASA Astrophysics Data System (ADS)

Jakobsson, S.

2011-12-01

A double capsule assembly designed to control oxygen fugacity in piston cylinder experiments has been tested at 1200 °C and 10 kbar. The assembly consists of an outer Pt-capsule containing a solid buffer (Ni-NiO or Co-CoO plus H2O) and an inner AuPd-capsule containing the sample, H2O and a Pt-wire. To prevent direct contact with the buffer phases the AuPd-capsule is embedded in finely ground Al2O3 along with some coarser, fractured Al2O3 facilitating fluid inclusion formation. No water loss is observed in the sample even after 48 hrs but a slight increase in water content is observed in longer duration runs due to oxygen and hydrogen diffusion into the AuPd-capsule. Carbon from the furnace also diffuses through the outer Pt-capsule but reacts with H2O in the outer capsule to form CO2 and never reaches the inner capsule. Oxygen fugacity of runs in equilibrium with the Ni-NiO and Co-CoO buffers was measured by analyzing the Fe content of the Pt-wire in the sample1 and by analyzing Fe dissolved in the AuPd capsule2. The second method gives values that are in good agreement with established buffer whereas results from the first method are one half to one log units higher than the established values. References 1. E. Medard, C. A. McCammon, J. A. Barr, T. L. Grove, Am. Mineral. 93, 1838 (2008). 2. J. Barr, T. Grove, Contrib. Mineral. Petrol. 160, 631 (2010)

Magnetized HDC ignition capsules for yield enhancement and implosion magnetohydrodynamics

NASA Astrophysics Data System (ADS)

Zimmerman, G.; Ho, D.; Perkins, J.; Logan, G.; Hawkins, S.; Rhodes, M.

2014-10-01

Imposing a magnetic field on capsules can turn capsules that fail, because of low 1-D margin, into igniting capsules that give yield in the MegaJoule range. The imposed magnetic field can be amplified by up to O(103) as it is being compressed by the imploding shell, e.g. if the initial field is 50 T, then the field in the hot spot of the assembled configuration can reach >104 T. (We are currently designing hardware that can provide a field in the 50 T range inside NIF hohlraums.) With this highly compressed field strength, the gyro radius of alpha particles becomes smaller than the hot spot size. Consequently, the heating of the hot spot becomes more efficient. The imposed field can also prevent hot electrons in the holhraum from reaching the capsule. We choose capsules with high-density carbon (HDC) ablators for this study. HDC capsules have good 1-D performance and also have short pulses (10 ns or less), allowing the use of low gas-filled or near-vacuum hohlraums which provide high coupling efficiency. We describe a 2-D simulation of a 3-shock HDC capsule. We will show detailed magnetohydrodynamic evolution of the implosion. HDC capsules with 2-shock pulses have low margin because of their high adiabat, and it is difficult to achieve ignition in realistic 2-D simulations. The improvement in performance for 2-shock magnetized capsules will be presented. This work was supported by LLNL Laboratory Directed Research and Development LDRD 14-ER-028 under Contract DE-AC52-07NA27344.

RERTR-12 Insertion 2 Irradiation Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

D. M. Perez; G. S. Chang; D. M. Wachs

2012-09-01

The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-12 was designed to provide comprehensive information on the performance of uranium-molybdenum (U-Mo) based monolithic fuels for research reactor applications.1 RERTR-12 insertion 2 includes the capsules irradiated during the last three irradiation cycles. These capsules include Z, Y1, Y2 and Y3 type capsules. The following report summarizes the life of the RERTR-12 insertion 2 experiment through end of irradiation, including as-run neutronic analysis results, thermal analysis results and hydraulic testing results.

Wireless endoscopy in 2020: Will it still be a capsule?

PubMed Central

Koulaouzidis, Anastasios; Iakovidis, Dimitris K; Karargyris, Alexandros; Rondonotti, Emanuele

2015-01-01

Currently, the major problem of all existing commercial capsule devices is the lack of control of movement. In the future, with an interface application, the clinician will be able to stop and direct the device into points of interest for detailed inspection/diagnosis, and therapy delivery. This editorial presents current commercially-available new designs, European projects and delivery capsule and gives an overview of the progress required and progress that will be achieved -according to the opinion of the authors- in the next 5 year leading to 2020. PMID:25954085

Posterior capsule opacification.

PubMed

Wormstone, I Michael; Wang, Lixin; Liu, Christopher S C

2009-02-01

Posterior Capsule Opacification (PCO) is the most common complication of cataract surgery. At present the only means of treating cataract is by surgical intervention, and this initially restores high visual quality. Unfortunately, PCO develops in a significant proportion of patients to such an extent that a secondary loss of vision occurs. A modern cataract operation generates a capsular bag, which comprises a proportion of the anterior and the entire posterior capsule. The bag remains in situ, partitions the aqueous and vitreous humours, and in the majority of cases, houses an intraocular lens. The production of a capsular bag following surgery permits a free passage of light along the visual axis through the transparent intraocular lens and thin acellular posterior capsule. However, on the remaining anterior capsule, lens epithelial cells stubbornly reside despite enduring the rigours of surgical trauma. This resilient group of cells then begin to re-colonise the denuded regions of the anterior capsule, encroach onto the intraocular lens surface, occupy regions of the outer anterior capsule and most importantly of all begin to colonise the previously cell-free posterior capsule. Cells continue to divide, begin to cover the posterior capsule and can ultimately encroach on the visual axis resulting in changes to the matrix and cell organization that can give rise to light scatter. This review will describe the biological mechanisms driving PCO progression and discuss the influence of IOL design, surgical techniques and putative drug therapies in regulating the rate and severity of PCO.

Design options for improved performance with high-density carbon ablators and low-gas fill hohlraum targets

NASA Astrophysics Data System (ADS)

Berzak Hopkins, L.; Divol, L.; Lepape, S.; Meezan, N. B.; Dewald, E.; Ho, D.; Khan, S.; Pak, A.; Ralph, J.; Ross, J. S.

2016-10-01

Recent simulation-based and experimental work using high-density carbon ablators in unlined uranium hohlraums with 0.3 mg/cc helium fill have demonstrated round implosions with minimal evolution of Legendre moment P2 during burn. To extend this promising work, design studies have been performed to explore potential performance improvements with larger capsules, while maintaining similar case-to-capsule target ratios. We present here the results of these design studies, which will motivate a series of upcoming experiments at the National Ignition Facility. Prepared by LLNL under Contract DE-AC52-07NA27344.

Experimental investigation into biomechanical and biotribological properties of a real intestine and their significance for design of a spiral-type robotic capsule.

PubMed

Zhou, Hao; Alici, Gursel; Than, Trung D; Li, Weihua

2014-03-01

This article reports on the results and implications of our experimental investigation into the biomechanical and biotribological properties of a real intestine for the optimal design of a spiral-type robotic capsule. Dynamic shear experiments were conducted to evaluate how the storage and loss moduli and damping factor of the small intestine change with the speed or the angular frequency. The sliding friction between differently shaped test pieces, with a topology similar to that of the spirals, and the intestine sample was experimentally determined. Our findings demonstrate that the intestine's biomechanical and biotribological properties are coupled, suggesting that the sliding friction is strongly related to the internal friction of the intestinal tissue. The significant implication of this finding is that one can predict the reaction force between the capsule with a spiral-type traction topology and the intestine directly from the intestine's biomechanical measurements rather than employing complicated three-dimensional finite element analysis or an inaccurate analytical model. Sliding friction experiments were also conducted with bar-shaped solid samples to determine the sliding friction between the samples and the small intestine. This sliding friction data will be useful in determining spiral material for an optimally designed robotic capsule.

Mercury: impact studies

NASA Image and Video Library

1958-08-05

Photographed on: 08 05 1958. -- Impact test conducted by Langley's Hydrodynamics Division. The Division conducted a series of impact studies with full scale and model capsules of the original capsule shape A. Joseph Shortal wrote (Vol. 3, p. 16): The basic design of the capsule was made by M.A. Faget and his coworkers at PARD during the winter of 1957-1958. It was natural, then, that extensive use was made of the facilities at Wallops during the development of the spacecraft. The tests at Wallops consisted of 26 full-size capsules, either launched from the ground by rocket power or dropped from airplanes at high altitude and 28 scaled models, either rocket boosted or released from balloons. Emphasis in the Wallops program was on dynamic stability and aerodynamic heating of the capsule, and effectiveness of the pilot-escape and parachute-recovery systems. The biggest part of the Wallops program was the series of full-size capsules, rocket launched with the Little Joe booster, developed especially for Mercury. -- Published in Joseph A. Shortal, History of Wallops Station: Origins and Activities Through 1949, (Wallops Island, VA: National Aeronautics and Space Administration, Wallops Station, nd), Comment Edition.

Mercury: impact studies

NASA Image and Video Library

1958-09-07

Photographed on: 08 05 1958. -- Impact test conducted by Langley's Hydrodynamics Division. The Division conducted a series of impact studies with full scale and model capsules of the original capsule shape A. Joseph Shortal wrote (Vol. 3, p. 16): The basic design of the capsule was made by M.A. Faget and his coworkers at PARD during the winter of 1957-1958. It was natural, then, that extensive use was made of the facilities at Wallops during the development of the spacecraft. The tests at Wallops consisted of 26 full-size capsules, either launched from the ground by rocket power or dropped from airplanes at high altitude and 28 scaled models, either rocket boosted or released from balloons. Emphasis in the Wallops program was on dynamic stability and aerodynamic heating of the capsule, and effectiveness of the pilot-escape and parachute-recovery systems. The biggest part of the Wallops program was the series of full-size capsules, rocket launched with the Little Joe booster, developed especially for Mercury. -- Published in Joseph A. Shortal, History of Wallops Station: Origins and Activities Through 1949, (Wallops Island, VA: National Aeronautics and Space Administration, Wallops Station, nd), Comment Edition.

What the Research Says about Alternative Teacher Certification Programs. Information Capsule. Volume 1104

ERIC Educational Resources Information Center

Blazer, Christie

2012-01-01

The shortage of qualified teachers across the U.S. has contributed to the popularity of alternative certification programs. These programs are designed to attract individuals into the teaching profession by allowing candidates to become certified without having to complete a traditional teacher education program. This Information Capsule reviewed…

Magnetic hyperthermia controlled drug release in the GI tract: solving the problem of detection.

PubMed

Bear, Joseph C; Patrick, P Stephen; Casson, Alfred; Southern, Paul; Lin, Fang-Yu; Powell, Michael J; Pankhurst, Quentin A; Kalber, Tammy; Lythgoe, Mark; Parkin, Ivan P; Mayes, Andrew G

2016-09-27

Drug delivery to the gastrointestinal (GI) tract is highly challenging due to the harsh environments any drug- delivery vehicle must experience before it releases it's drug payload. Effective targeted drug delivery systems often rely on external stimuli to effect release, therefore knowing the exact location of the capsule and when to apply an external stimulus is paramount. We present a drug delivery system for the GI tract based on coating standard gelatin drug capsules with a model eicosane- superparamagnetic iron oxide nanoparticle composite coating, which is activated using magnetic hyperthermia as an on-demand release mechanism to heat and melt the coating. We also show that the capsules can be readily detected via rapid X-ray computed tomography (CT) and magnetic resonance imaging (MRI), vital for progressing such a system towards clinical applications. This also offers the opportunity to image the dispersion of the drug payload post release. These imaging techniques also influenced capsule content and design and the delivered dosage form. The ability to easily change design demonstrates the versatility of this system, a vital advantage for modern, patient-specific medicine.

Exploring symmetry in near-vacuum hohlraums

NASA Astrophysics Data System (ADS)

Berzak Hopkins, L.; Le Pape, S.; Divol, L.; Meezan, N.; MacKinnon, A.; Ho, D. D.; Jones, O.; Khan, S.; Ma, T.; Milovich, J.; Pak, A.; Ross, J. S.; Thomas, C.; Turnbull, D.; Amendt, P.; Wilks, S.; Zylstra, A.; Rinderknecht, H.; Sio, H.; Petrasso, R.

2015-11-01

Recent experiments with near-vacuum hohlraums, which utilize a minimal but non-zero helium fill, have demonstrated performance improvements relative to conventional gas-filled (0.96 - 1.6 mg/cc helium) hohlraums: minimal backscatter, reduced capsule drive degradation, and minimal suprathermal electron generation. Because this is a low laser-plasma interaction platform, implosion symmetry is controlled via pulse-shaping adjustments to laser power balance. Extending this platform to high-yield designs with high-density carbon capsules requires achieving adequate symmetry control throughout the pulse. In simulations, laser propagation is degraded suddenly by hohlraum wall expansion interacting with ablated capsule material. Nominal radiation-hydrodynamics simulations have not yet proven predictive on symmetry of the final hotspot, and experiments show more prolate symmetry than preshot calculations. Recent efforts have focused on understanding the discrepancy between simulated and measured symmetry and on alternate designs for symmetry control through varying cone fraction, trade-offs between laser power and energy, and modifications to case-to-capsule ratio. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

Posterior Capsule Opacification After Phacoemulsification: Annual Review.

PubMed

Vasavada, Abhay R; Praveen, Mamidipudi R

2014-01-01

The purpose of this article is to provide a clinical update on posterior capsule opacification (PCO) after phacoemulsification by reviewing the literature from the last 12 months. This article is a literature review. The authors conducted a 1-year literature search in the English language on PCO using PubMed. The period used to conduct the literature search was from January 1, 2013, to January 1, 2014. The following search terms were used during the PubMed search: phacoemulsification, microcoaxial incision, posterior capsule opacification, long-term evaluation of intraocular lens (IOL) implantation, IOL edge design and material, surgical technique, anterior capsule overlap on the IOL optic, diabetes mellitus, myopia, pseudoexfoliation, retinitis pigmentosa, uveitis, and neodymium: yttrium-aluminum-garnet laser capsulotomy. This review incorporates original articles that provided fresh insights and updates on PCO. Particular attention was paid to observational, randomized, controlled clinical trials, as well as analyses of larger cohorts with a prospective and retrospective study design. Letters to the editor, unpublished works, experimental trials and abstracts were not considered. This annual review provides a brief update on PCO that might be of interest to the practicing clinical ophthalmologist.

A design study for the addition of higher order parametric discrete elements to NASTRAN

NASA Technical Reports Server (NTRS)

Stanton, E. L.

1972-01-01

The addition of discrete elements to NASTRAN poses significant interface problems with the level 15.1 assembly modules and geometry modules. Potential problems in designing new modules for higher-order parametric discrete elements are reviewed in both areas. An assembly procedure is suggested that separates grid point degrees of freedom on the basis of admissibility. New geometric input data are described that facilitate the definition of surfaces in parametric space.

A Wireless Capsule Endoscope System With Low-Power Controlling and Processing ASIC.

PubMed

Xinkai Chen; Xiaoyu Zhang; Linwei Zhang; Xiaowen Li; Nan Qi; Hanjun Jiang; Zhihua Wang

2009-02-01

This paper presents the design of a wireless capsule endoscope system. The proposed system is mainly composed of a CMOS image sensor, a RF transceiver and a low-power controlling and processing application specific integrated circuit (ASIC). Several design challenges involving system power reduction, system miniaturization and wireless wake-up method are resolved by employing optimized system architecture, integration of an area and power efficient image compression module, a power management unit (PMU) and a novel wireless wake-up subsystem with zero standby current in the ASIC design. The ASIC has been fabricated in 0.18-mum CMOS technology with a die area of 3.4 mm * 3.3 mm. The digital baseband can work under a power supply down to 0.95 V with a power dissipation of 1.3 mW. The prototype capsule based on the ASIC and a data recorder has been developed. Test result shows that proposed system architecture with local image compression lead to an average of 45% energy reduction for transmitting an image frame.

SpaceX Dragon Air Circulation System

NASA Technical Reports Server (NTRS)

Hernandez, Brenda; Piatrovich, Siarhei; Prina, Mauro

2011-01-01

The Dragon capsule is a reusable vehicle being developed by Space Exploration Technologies (SpaceX) that will provide commercial cargo transportation to the International Space Station (ISS). Dragon is designed to be a habitable module while it is berthed to ISS. As such, the Dragon Environmental Control System (ECS) consists of pressure control and pressure equalization, air sampling, fire detection, illumination, and an air circulation system. The air circulation system prevents pockets of stagnant air in Dragon that can be hazardous to the ISS crew. In addition, through the inter-module duct, the air circulation system provides fresh air from ISS into Dragon. To utilize the maximum volume of Dragon for cargo packaging, the Dragon ECS air circulation system is designed around cargo rack optimization. At the same time, the air circulation system is designed to meet the National Aeronautics Space Administration (NASA) inter-module and intra-module ventilation requirements and acoustic requirements. A flight like configuration of the Dragon capsule including the air circulation system was recently assembled for testing to assess the design for inter-module and intra-module ventilation and acoustics. The testing included the Dragon capsule, and flight configuration in the pressure section with cargo racks, lockers, all of the air circulation components, and acoustic treatment. The air circulation test was also used to verify the Computational Fluid Dynamics (CFD) model of the Dragon capsule. The CFD model included the same Dragon internal geometry that was assembled for the test. This paper will describe the Dragon air circulation system design which has been verified by testing the system and with CFD analysis.

Three-dimensional modeling of direct-drive cryogenic implosions on OMEGA

DOE PAGES

Igumenshchev, I. V.; Goncharov, V. N.; Marshall, F. J.; ...

2016-05-04

The effects of large-scale (with Legendre modes ≲10) laser-imposed nonuniformities in direct-drive cryogenic implosions on the OMEGA laser system are investigated using three-dimension hydrodynamic simulations performed using a newly developed code ASTER. Sources of these nonuniformities include an illumination pattern produced by 60 OMEGA laser beams, capsule offsets (~10 to 20 μm), and imperfect pointing, energy balance, and timing of the beams (with typical σ rms ~10 μm, 10%, and 5 ps, respectively). Two implosion designs using 26-kJ triple-picket laser pulses were studied: a nominal design, in which a 880-μm-diameter capsule is illuminated by the same-diameter beams, and a “R75”more » design using a capsule of 900 μm in diameter and beams of 75% of this diameter. Simulations found that nonuniformities because of capsule offsets and beam imbalance have the largest effect on implosion performance. These nonuniformities lead to significant distortions of implosion cores resulting in an incomplete stagnation. The shape of distorted cores is well represented by neutron images, but loosely in x-rays. Simulated neutron spectra from perturbed implosions show large directional variations and up to ~ 2 keV variation of the hot spot temperature inferred from these spectra. The R75 design is more hydrodynamically efficient because of mitigation of crossed-beam energy transfer, but also suffers more from the nonuniformities. Furthermore, simulations predict a performance advantage of this design over the nominal design when the target offset and beam imbalance σ rms are reduced to less than 5 μm and 5%, respectively.« less

Three-dimensional modeling of direct-drive cryogenic implosions on OMEGA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Igumenshchev, I. V.; Goncharov, V. N.; Marshall, F. J.

The effects of large-scale (with Legendre modes ≲10) laser-imposed nonuniformities in direct-drive cryogenic implosions on the OMEGA laser system are investigated using three-dimension hydrodynamic simulations performed using a newly developed code ASTER. Sources of these nonuniformities include an illumination pattern produced by 60 OMEGA laser beams, capsule offsets (~10 to 20 μm), and imperfect pointing, energy balance, and timing of the beams (with typical σ rms ~10 μm, 10%, and 5 ps, respectively). Two implosion designs using 26-kJ triple-picket laser pulses were studied: a nominal design, in which a 880-μm-diameter capsule is illuminated by the same-diameter beams, and a “R75”more » design using a capsule of 900 μm in diameter and beams of 75% of this diameter. Simulations found that nonuniformities because of capsule offsets and beam imbalance have the largest effect on implosion performance. These nonuniformities lead to significant distortions of implosion cores resulting in an incomplete stagnation. The shape of distorted cores is well represented by neutron images, but loosely in x-rays. Simulated neutron spectra from perturbed implosions show large directional variations and up to ~ 2 keV variation of the hot spot temperature inferred from these spectra. The R75 design is more hydrodynamically efficient because of mitigation of crossed-beam energy transfer, but also suffers more from the nonuniformities. Furthermore, simulations predict a performance advantage of this design over the nominal design when the target offset and beam imbalance σ rms are reduced to less than 5 μm and 5%, respectively.« less

Design of wormlike automated robotic endoscope: dynamic interaction between endoscopic balloon and surrounding tissues.

PubMed

Poon, Carmen C Y; Leung, Billy; Chan, Cecilia K W; Lau, James Y W; Chiu, Philip W Y

2016-02-01

The current design of capsule endoscope is limited by the inability to control the motion within gastrointestinal tract. The rising incidence of gastrointestinal cancers urged improvement in the method of screening endoscopy. This preclinical study aimed to design and develop a novel locomotive module for capsule endoscope. We investigated the feasibility and physical properties of this newly designed caterpillar-like capsule endoscope with a view to enhancing screening endoscopy. This study consisted of preclinical design and experimental testing on the feasibility of automated locomotion for a prototype caterpillar endoscope. The movement was examined first in the PVC tube and then in porcine intestine. The image captured was transmitted to handheld device to confirm the control of movement. The balloon pressure and volume as well as the contact force between the balloon and surroundings were measured when the balloon was inflated inside (1) a hard PVC tube, (2) a soft PVC tube, (3) muscular sites of porcine colons and (4) less muscular sites of porcine colons. The prototype caterpillar endoscope was able to move inward and backward within the PVC tubing and porcine intestine. Images were able to be captured from the capsule endoscope attached and being observed with a handheld device. Using the onset of a contact force as indication of the buildup of the gripping force between the balloon and the lumen walls, it is concluded from the results of this study that the rate of change in balloon pressure and volume is two good estimators to optimize the inflation of the balloon. The results of this study will facilitate further refinement in the design of caterpillar robotic endoscope to move inside the GI tract.

Capsule physics comparison of National Ignition Facility implosion designs using plastic, high density carbon, and beryllium ablators

NASA Astrophysics Data System (ADS)

Clark, D. S.; Kritcher, A. L.; Yi, S. A.; Zylstra, A. B.; Haan, S. W.; Weber, C. R.

2018-03-01

Indirect drive implosion experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] have now tested three different ablator materials: glow discharge polymer plastic, high density carbon, and beryllium. How do these different ablators compare in current and proposed implosion experiments on NIF? What are the relative advantages and disadvantages of each? This paper compares these different ablator options in capsule-only simulations of current NIF experiments and potential future designs. The simulations compare the impact of the capsule fill tube, support tent, and interface surface roughness for each case, as well as all perturbations in combination. According to the simulations, each ablator is impacted by the various perturbation sources differently, and each material poses unique challenges in the pursuit of ignition on NIF.

Influence of internal composition on physicochemical properties of alginate aqueous-core capsules.

PubMed

Ben Messaoud, Ghazi; Sánchez-González, Laura; Probst, Laurent; Desobry, Stéphane

2016-05-01

To enhance physicochemical properties of alginate aqueous-core capsules, conventional strategies were focused in literature on designing composite and coated capsules. In the present study, own effect of liquid-core composition on mechanical and release properties was investigated. Capsules were prepared by dripping a CaCl2 solution into an alginate gelling solution. Viscosity of CaCl2 solution was adjusted by adding cationic, anionic and non-ionic naturally derived polymers, respectively chitosan, xanthan gum and guar gum. In parallel, uniform alginate hydrogels were prepared by different methods (pouring, in situ forming and mixing). Mechanical stability of capsules and plane hydrogels were respectively evaluated by compression experiments and small amplitude oscillatory shear rheology and then correlated. Capsules permeability was evaluated by monitoring diffusion of encapsulated cochineal dye, riboflavin and BSA. The core-shell interactions were investigated by ATR-FTIR. Results showed that inner polymer had an impact on membrane stability and could act as an internal coating or provide mechanical reinforcement. Mechanical properties of alginate capsules were in a good agreement with rheological behavior of plane hydrogels. Release behavior of the entrapped molecules changed considerably. This study demonstrated the importance of aqueous-core composition, and gave new insights for possible adjusting of microcapsules physicochemical properties by modulating core-shell interactions. Copyright © 2016 Elsevier Inc. All rights reserved.

Capsule Performance Optimization in the National Ignition Campaign

DOE Office of Scientific and Technical Information (OSTI.GOV)

Landen, O L; MacGowan, B J; Haan, S W

2009-10-13

A capsule performance optimization campaign will be conducted at the National Ignition Facility to substantially increase the probability of ignition. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting themore » key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.« less

Capsule performance optimization in the national ignition campaign

NASA Astrophysics Data System (ADS)

Landen, O. L.; MacGowan, B. J.; Haan, S. W.; Edwards, J.

2010-08-01

A capsule performance optimization campaign will be conducted at the National Ignition Facility [1] to substantially increase the probability of ignition. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

Design, fabrication, and operation of capsules for the irradiation testing of candidate advanced space reactor fuel pins

NASA Technical Reports Server (NTRS)

Thoms, K. R.

1975-01-01

Fuel irradiation experiments were designed, built, and operated to test uranium mononitride (UN) fuel clad in tungsten-lined T-111 and uranium dioxide fuel clad in both tungsten-lined T-111 and tungsten-lined Nb-1% Zr. A total of nine fuel pins was irradiated at average cladding temperatures ranging from 931 to 1015 C. The UN experiments, capsules UN-4 and -5, operated for 10,480 and 10,037 hr, respectively, at an average linear heat generation rate of 10 kW/ft. The UO2 experiment, capsule UN-6, operated for 8333 hr at an average linear heat generation rate of approximately 5 kW/ft. Following irradiation, the nine fuel pins were removed from their capsules, externally examined, and sent to the NASA Plum Brook Facility for more detailed postirradiation examination. During visual examination, it was discovered that the cladding of the fuel pin containing dense UN in each of capsules UN-4 and -5 had failed, exposing the UN fuel to the NaK in which the pins were submerged and permitting the release of fission gas from the failed pins. A rough analysis of the fission gas seen in samples of the gas in the fuel pin region indicated fission gas release-to-birth rates from these fuel pins in the range of .00001.

Aerodynamic and engineering design of a 1.5 s high quality microgravity drop tower facility

NASA Astrophysics Data System (ADS)

Belser, Valentin; Breuninger, Jakob; Reilly, Matthew; Laufer, René; Dropmann, Michael; Herdrich, Georg; Hyde, Truell; Röser, Hans-Peter; Fasoulas, Stefanos

2016-12-01

Microgravity experiments are essential for research in space science, biology, fluid mechanics, combustion, and material sciences. One way to conduct microgravity experiments on Earth is by using drop tower facilities. These facilities combine a high quality of microgravity, adequate payload masses and have the advantage of virtually unlimited repeatability under same experimental conditions, at a low cost. In a collaboration between the Institute of Space Systems (IRS) at the University of Stuttgart and Baylor University (BU) in Waco, Texas, a new drop tower is currently under development at the Center for Astrophysics, Space Physics and Engineering Research (CASPER). The design parameters of the drop tower ask for at least 1.5 s in free fall duration while providing a quality of at least 10-5 g. Previously, this quality has only been achieved in vacuum drop tower facilities where the capsule experiences virtually zero aerodynamic drag during its free fall. Since this design comes at high costs, a different drop tower design concept, which does not require an evacuated drop shaft, was chosen. It features a dual-capsule system in which the experiment capsule is shielded from aerodynamic forces by surrounding it with a drag shield during the drop. As no other dual-capsule drop tower has been able to achieve a quality as good as or better than 10-5 g previous work optimized the design with an aerodynamic perspective by using computational fluid dynamics (CFD) simulations to determine the ideal shape and size of the outer capsule and to specify the aerodynamically crucial dimensions for the overall system. Experiments later demonstrated that the required quality of microgravity can be met with the proposed design. The main focus of this paper is the mechanical realization of the capsule as well as the development and layout of the surrounding components, such as the release mechanism, the deceleration device and the drop shaft. Because the drop tower facility is a complex system with many interdependencies between all of the components, several engineering challenges had to be addressed. For example, initial disturbances that are caused by the release mechanism are a common issue that arises at drop tower facilities. These vibrations may decrease the quality of microgravity during the initial segment of free fall. Because this would reduce the free fall time experiencing high quality microgravity, a mechanism has been developed to provide a soft release. Challenges and proposed solutions for all components are highlighted in this paper.

Explicit parametric solutions of lattice structures with proper generalized decomposition (PGD) - Applications to the design of 3D-printed architectured materials

NASA Astrophysics Data System (ADS)

Sibileau, Alberto; Auricchio, Ferdinando; Morganti, Simone; Díez, Pedro

2018-01-01

Architectured materials (or metamaterials) are constituted by a unit-cell with a complex structural design repeated periodically forming a bulk material with emergent mechanical properties. One may obtain specific macro-scale (or bulk) properties in the resulting architectured material by properly designing the unit-cell. Typically, this is stated as an optimal design problem in which the parameters describing the shape and mechanical properties of the unit-cell are selected in order to produce the desired bulk characteristics. This is especially pertinent due to the ease manufacturing of these complex structures with 3D printers. The proper generalized decomposition provides explicit parametic solutions of parametric PDEs. Here, the same ideas are used to obtain parametric solutions of the algebraic equations arising from lattice structural models. Once the explicit parametric solution is available, the optimal design problem is a simple post-process. The same strategy is applied in the numerical illustrations, first to a unit-cell (and then homogenized with periodicity conditions), and in a second phase to the complete structure of a lattice material specimen.

Extended parametric representation of compressor fans and turbines. Volume 2: Part user's manual (parametric turbine)

NASA Technical Reports Server (NTRS)

Coverse, G. L.

1984-01-01

A turbine modeling technique has been developed which will enable the user to obtain consistent and rapid off-design performance from design point input. This technique is applicable to both axial and radial flow turbine with flow sizes ranging from about one pound per second to several hundred pounds per second. The axial flow turbines may or may not include variable geometry in the first stage nozzle. A user-specified option will also permit the calculation of design point cooling flow levels and corresponding changes in efficiency for the axial flow turbines. The modeling technique has been incorporated into a time-sharing program in order to facilitate its use. Because this report contains a description of the input output data, values of typical inputs, and example cases, it is suitable as a user's manual. This report is the second of a three volume set. The titles of the three volumes are as follows: (1) Volume 1 CMGEN USER's Manual (Parametric Compressor Generator); (2) Volume 2 PART USER's Manual (Parametric Turbine); (3) Volume 3 MODFAN USER's Manual (Parametric Modulation Flow Fan).

Low Power Transmitter for Wireless Capsule Endoscope

NASA Astrophysics Data System (ADS)

Lioe, D. X.; Shafie, S.; Ramiah, H.; Sulaiman, N.; Halin, I. A.

2013-04-01

This paper presents the transmitter circuit designed for the application of wireless capsule endoscope to overcome the limitation of conventional endoscope. The design is performed using CMOS 0.13 μm technology. The transmitter is designed to operate at centre frequency of 433.92 MHz, which is one of the ISM band. Active mixer and ring oscillator made up the transmitter and it consumes 1.57 mA of current using a supply voltage of 1.2 V, brings the dc power consumption of the transmitter to be 1.88 mW. Data rate of 3.5 Mbps ensure it can transmit high quality medical imaging.

Measurement of Radiation Symmetry in Z-Pinch Driven Hohlraums

NASA Astrophysics Data System (ADS)

Hanson, David L.

2001-10-01

The z-pinch driven hohlraum (ZPDH) is a promising approach to high yield inertial confinement fusion currently being characterized in experiments on the Sandia Z accelerator [1]. In this concept [2], x rays are produced by an axial z-pinch in a primary hohlraum at each end of a secondary hohlraum. A fusion capsule in the secondary is imploded by a symmetric x-ray flux distribution, effectively smoothed by wall reemission during transport to the capsule position. Capsule radiation symmetry, a critical issue in the design of such a system, is influenced by hohlraum geometry, wall motion and time-dependent albedo, as well as power balance and pinch timing between the two z-pinch x-ray sources. In initial symmetry studies on Z, we used solid low density burnthrough spheres to diagnose highly asymmetric, single-sided-drive hohlraum geometries. We then applied this technique to the more symmetric double z-pinch geometry [3]. As a result of design improvements, radiation flux symmetry in Z double-pinch wire array experiments now exceeds the measurement sensitivity of this self-backlit foam ball symmetry diagnostic (15% max-min flux asymmetry). To diagnose radiation symmetry at the 2 - 5% level attainable with our present ZPDH designs, we are using high-energy x rays produced by the recently-completed Z-Beamlet laser backlighter for point-projection imaging of thin-wall implosion and symmetry capsules. We will present the results of polar flux symmetry measuremets on Z for several ZPDH capsule geometries together with radiosity and radiation-hydrodynamics simulations for comparison. [1] M. E. Cuneo et al., Phys. Plasmas 8,2257(2001); [2] J. H. Hammer et al., Phys. Plasmas 6,2129(1999); [3] D. L. Hanson et al., Bull. Am. Phys. Soc. 45,360(2000).

High Performance Capsule Implosions on the Omega Laser Facility with Rugby Hohlraums

NASA Astrophysics Data System (ADS)

Robey, Harry F.

2009-11-01

Rugby-shaped hohlraums have been proposed as a method for x-ray drive enhancement for indirectly-driven capsule implosions [1]. This concept has recently been tested in a series of shots on the OMEGA laser facility at the Laboratory for Laser Energetics at the University of Rochester. In this talk, experimental results are presented comparing the performance of D2-filled capsules between standard cylindrical Au hohlraums and rugby-shaped hohlraums. Not only did the rugby hohlraums demonstrate 18% more x-ray drive energy as compared with the cylinders, but the high-performance design of these implosions (both cylinder and rugby) also provided 20X more DD neutrons than any previous indirectly-driven campaign on Omega (and 3X more than ever achieved on Nova implosions driven with nearly twice the laser energy). This increase in performance enables, for the first time, a measurement of the neutron burn history of an indirectly-driven implosion. Previous DD neutron yields had been too low to register this key measurement of capsule performance and the effects of dynamic mix. A wealth of additional data on the fuel areal density from the suite of charged particle diagnostics was obtained on a subset of the shots that used D^3He rather than D2 fuel. Comparisons of the experimental results with numerical simulations are shown to be in excellent agreement. The design techniques employed in this campaign, e.g., smaller NIF-like laser entrance holes and hohlraum case-to-capsule ratios, provide added confidence in the pursuit of ignition on the National Ignition Facility. [4pt] [1] P. Amendt, C. Cerjan, D. E. Hinkel, J. L. Milovich, H.-S. Park, and H. F. Robey, ``Rugby-like hohlraum experimental designs for demonstrating x-ray drive enhancement'', Phys. Plasmas 15, 012702 (2008).

Genesis Sample Return Capsule Overview

NASA Technical Reports Server (NTRS)

Willcockson, Bill

2005-01-01

I. Simple Entry Capsule Concept: a) Spin-Stabilized/No Active Control Systems; b) Ballistic Entry for 11.04 km/sec Velocity; c) No Heatshield Separation During Entry; d) Parachute Deploy via g-Switch + Timer. II. Stardust Design Inheritance a) Forebody Shape; b) Seal Concepts; c) Parachute Deploy Control; d) Utah Landing Site (UTTR). III. TPS Systems a) Heatshield - Carbon-Carbon - First Planetary Entry; b) Backshell - SLA-561V - Flight Heritage from Pathfinder, MER; d) Forebody Structural Penetrations Aerothermal and TPS Design Process has the Same Methodology as Used for Pathfinder, MER Flight Vehicles.

New optical microbarometer

NASA Astrophysics Data System (ADS)

Olivier, Serge; Hue, Anthony; Olivier, Nathalie; Le Mallet, Serge

2015-04-01

Usually, transducers implemented in infrasound sensor (microbarometer) are mainly composed of two associated elements. The first one converts the external pressure variation into a physical linear displacement. The second one converts this motion into an electrical signal. According to this configuration, MB3, MB2000 and MB2005 microbarometers are using an aneroid capsule for the first one, and an electromagnetic transducer (Magnet-coil or LVDT) for the second one. CEA DAM (designer of MB series) and PROLANN / SEISMO WAVE (manufacturer and seller of MB3) have associated their expertise to design an optical microbarometer: However, we think that changing the electromagnetic transducer by an interferometer is an interesting solution in order to increase the dynamic and the resolution of the sensor. Currently, we are exploring this way in order to propose a future optical microbarometer which will enlarge the panel of infrasound sensors. Firstly, we will present the new transducer principles, taking into account the aneroid capsule and the interferometer using integrated optics technology. More specifically, we will explain the operation of this optical technology, and discuss on its advantages and defaults. Secondly, we will present the first part of this project in which the interferometer is positioned outside the aneroid capsule. In this configuration, interferometer mechanical adjustments are easier, but measurement is directly disturbed by environmental effects like the thermal variations. Six prototypes were manufactured with two sets of different aneroid capsules, in order to compare their performances, and also an optical digitizer specifically designed to record the four channels interferometer. Then, we will present the first sensitivity and self-noise measurement results compared to those of a MB2005 microbarometer. Finally, we will propose a new design of the optical microbarometer as a second part of our study. It will implement a new location of interferometer into the aneroid capsule under vacuum in order to protect the optical measurement from environmental effects. Manufacturing such a prototype is a huge challenge from the miniaturization point of view and the interferometer mechanical stability.

Free-form geometric modeling by integrating parametric and implicit PDEs.

PubMed

Du, Haixia; Qin, Hong

2007-01-01

Parametric PDE techniques, which use partial differential equations (PDEs) defined over a 2D or 3D parametric domain to model graphical objects and processes, can unify geometric attributes and functional constraints of the models. PDEs can also model implicit shapes defined by level sets of scalar intensity fields. In this paper, we present an approach that integrates parametric and implicit trivariate PDEs to define geometric solid models containing both geometric information and intensity distribution subject to flexible boundary conditions. The integrated formulation of second-order or fourth-order elliptic PDEs permits designers to manipulate PDE objects of complex geometry and/or arbitrary topology through direct sculpting and free-form modeling. We developed a PDE-based geometric modeling system for shape design and manipulation of PDE objects. The integration of implicit PDEs with parametric geometry offers more general and arbitrary shape blending and free-form modeling for objects with intensity attributes than pure geometric models.

Direct adaptive robust tracking control for 6 DOF industrial robot with enhanced accuracy.

PubMed

Yin, Xiuxing; Pan, Li

2018-01-01

A direct adaptive robust tracking control is proposed for trajectory tracking of 6 DOF industrial robot in the presence of parametric uncertainties, external disturbances and uncertain nonlinearities. The controller is designed based on the dynamic characteristics in the working space of the end-effector of the 6 DOF robot. The controller includes robust control term and model compensation term that is developed directly based on the input reference or desired motion trajectory. A projection-type parametric adaptation law is also designed to compensate for parametric estimation errors for the adaptive robust control. The feasibility and effectiveness of the proposed direct adaptive robust control law and the associated projection-type parametric adaptation law have been comparatively evaluated based on two 6 DOF industrial robots. The test results demonstrate that the proposed control can be employed to better maintain the desired trajectory tracking even in the presence of large parametric uncertainties and external disturbances as compared with PD controller and nonlinear controller. The parametric estimates also eventually converge to the real values along with the convergence of tracking errors, which further validate the effectiveness of the proposed parametric adaption law. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Airborne Observation of the Hayabusa Sample Return Capsule Re-Entry

NASA Technical Reports Server (NTRS)

Grinstead, Jay H.; Jenniskens, Peter; Cassell, Alan M.; Albers, James; Winter, Michael W.

2011-01-01

NASA Ames Research Center and the SETI Institute collaborated on an effort to observe the Earth re-entry of the Japan Aerospace Exploration Agency's Hayabusa sample return capsule. Hayabusa was an asteroid exploration mission that retrieved a sample from the near-Earth asteroid Itokawa. Its sample return capsule re-entered over the Woomera Prohibited Area in southern Australia on June 13, 2010. Being only the third sample return mission following NASA's Genesis and Stardust missions, Hayabusa's return was a rare opportunity to collect aerothermal data from an atmospheric entry capsule returning at superorbital speeds. NASA deployed its DC-8 airborne laboratory and a team of international researchers to Australia for the re-entry. For approximately 70 seconds, spectroscopic and radiometric imaging instruments acquired images and spectra of the capsule, its wake, and destructive re-entry of the spacecraft bus. Once calibrated, spectra of the capsule will be interpreted to yield data for comparison with and validation of high fidelity and engineering simulation tools used for design and development of future atmospheric entry system technologies. A brief summary of the Hayabusa mission, the preflight preparations and observation mission planning, mission execution, and preliminary spectral data are documented.

Synthetic quorum sensing in model microcapsule colonies

NASA Astrophysics Data System (ADS)

Shum, Henry; Balazs, Anna C.

2017-08-01

Biological quorum sensing refers to the ability of cells to gauge their population density and collectively initiate a new behavior once a critical density is reached. Designing synthetic materials systems that exhibit quorum sensing-like behavior could enable the fabrication of devices with both self-recognition and self-regulating functionality. Herein, we develop models for a colony of synthetic microcapsules that communicate by producing and releasing signaling molecules. Production of the chemicals is regulated by a biomimetic negative feedback loop, the “repressilator” network. Through theory and simulation, we show that the chemical behavior of such capsules is sensitive to both the density and number of capsules in the colony. For example, decreasing the spacing between a fixed number of capsules can trigger a transition in chemical activity from the steady, repressed state to large-amplitude oscillations in chemical production. Alternatively, for a fixed density, an increase in the number of capsules in the colony can also promote a transition into the oscillatory state. This configuration-dependent behavior of the capsule colony exemplifies quorum-sensing behavior. Using our theoretical model, we predict the transitions from the steady state to oscillatory behavior as a function of the colony size and capsule density.

A Small-Area and Low-Power SoC for Less-Invasive Pressure Sensing Capsules in Ambulatory Urodynamic Monitoring

NASA Astrophysics Data System (ADS)

Iwato, Hirofumi; Sakanushi, Keishi; Takeuchi, Yoshinori; Imai, Masaharu

To measure the detrusor pressure for diagnosing lower urinary tract symptoms, we designed a small-area and low-power System on a Chip (SoC). The SoC should be small and low power because it is encapsulated in tiny air-tight capsules which are simultaneously inserted in the urinary bladder and rectum for several days. Since the SoC is also required to be programmable, we designed an Application Specific Instruction set Processor (ASIP) for pressure measurement and wireless communication, and implemented almost required functions on the ASIP. The SoC was fabricated using a 0.18µm CMOS mixed-signal process and the chip size is 2.5×2.5mm2. Evaluation results show that the power consumption of the SoC is 93.5µW, and that it can operate the capsule for seven days with a tiny battery.

Capsule physics comparison of different ablators for NIF implosion designs

NASA Astrophysics Data System (ADS)

Clark, Daniel; Kritcher, Andrea; Yi, Austin; Zylstra, Alex; Haan, Steven; Ralph, Joseph; Weber, Christopher

2017-10-01

Indirect drive implosion experiments on the Naitonal Ignition Facility (NIF) have now tested three different ablator materials: glow discharge polymer (GDP) plastic, high density carbon (HDC), and beryllium. How do these different ablator choices compare in current and future implosion experiments on NIF? What are the relative advantages and disadvantages of each? This talk compares these different ablator options in capsule-only simulations of current NIF experiments and proposed future designs. The simulations compare the impact of the capsule fill tube, support tent, and interface surface roughness for each case, as well as all perturbations in combination. According to the simulations, each ablator is impacted by the various perturbation sources differently, and each material poses unique challenges in the pursuit of ignition. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Effect of number and position of intraocular lens haptics on anterior capsule contraction: a randomized, prospective trial.

PubMed

Choi, Mihyun; Lazo, Marjorie Z; Kang, Minji; Lee, Jeehye; Joo, Choun-Ki

2018-03-20

The present study aimed to evaluate the degree of anterior capsule contraction (capsulorhexis contraction) with three different single-piece, hydrophilic acrylic intraocular lenses (IOLs). Patients were prospectively randomized to be implanted with one of three types of IOLs during cataract surgery: the Ophtec Precizon (IOL A), the Lucid Korea Microflex (IOL B), and the Carl Zeiss Asphina (IOL C). One week, 2 weeks, and 6 months after surgery, the area of the anterior capsule opening was measured using digital retro-illumination images after dilation of the pupil. The data were then evaluated using POCOman software. The study included 236 eyes of 202 patients. The area of the anterior capsule opening reduced by 3.53 ± 3.31 mm (17.06% ± 15.99%) between 1 week and 2 months post-operatively in the IOL A group, by 0.62 ± 1.32 mm (2.87% ± 6.03%) in the IOL B group, and by 1.09 ± 1.53 mm (4.72% ± 6.10%) in the IOL C group. The IOL B group showed minimal anterior capsule contraction 2 months after surgery (p < 0.001). IOLs with a four-plate haptic design (IOL B) showed more anterior capsular stability than those with a two-loop plate haptic (IOL A) or two-plate haptic (IOL C) design. The number and position of haptics in a capsular bag may affect anterior capsule contraction. We assume that supporting the zonules evenly may play a role in anterior capsular stability. Current Controlled Trials ISRCTN76566080 , Retrospectively registered (Date of registration: 14 Feb 2018).

Acoustic attenuation design requirements established through EPNL parametric trades

NASA Technical Reports Server (NTRS)

Veldman, H. F.

1972-01-01

An optimization procedure for the provision of an acoustic lining configuration that is balanced with respect to engine performance losses and lining attenuation characteristics was established using a method which determined acoustic attenuation design requirements through parametric trade studies using the subjective noise unit of effective perceived noise level (EPNL).

Kingella kingae expresses four structurally distinct polysaccharide capsules that differ in their correlation with invasive disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Starr, Kimberly F.; Porsch, Eric A.; Seed, Patrick C.

Kingella kingae is an encapsulated gram-negative organism that is a common cause of osteoarticular infections in young children. In earlier work, we identified a glycosyltransferase gene called csaA that is necessary for synthesis of the [3)-β-GalpNAc-(1→5)-β-Kdop-(2→] polysaccharide capsule (type a) in K. kingae strain 269–492. In the current study, we analyzed a large collection of invasive and carrier isolates from Israel and found that csaA was present in only 47% of the isolates. Further examination of this collection using primers based on the sequence that flanks csaA revealed three additional gene clusters (designated the csb, csc, and csd loci), allmore » encoding predicted glycosyltransferases. The csb locus contains the csbA, csbB, and csbC genes and is associated with a capsule that is a polymer of [6)-α-GlcpNAc-(1→5)-β-(8-OAc)Kdop-(2→] (type b). The csc locus contains the cscA, cscB, and cscC genes and is associated with a capsule that is a polymer of [3)-β-Ribf-(1→2)-β-Ribf-(1→2)-β-Ribf-(1→4)-β-Kdop-(2→] (type c). The csd locus contains the csdA, csdB, and csdC genes and is associated with a capsule that is a polymer of [P-(O→3)[β-Galp-(1→4)]-β-GlcpNAc-(1→3)-α-GlcpNAc-1-] (type d). Introduction of the csa, csb, csc, and csd loci into strain KK01Δcsa, a strain 269–492 derivative that lacks the native csaA gene, was sufficient to produce the type a capsule, type b capsule, type c capsule, and type d capsule, respectively, indicating that these loci are solely responsible for determining capsule type in K. kingae. Further analysis demonstrated that 96% of the invasive isolates express either the type a or type b capsule and that a disproportionate percentage of carrier isolates express the type c or type d capsule. Lastly, these results establish that there are at least four structurally distinct K. kingae capsule types and suggest that capsule type plays an important role in promoting K. kingae invasive disease« less

Kingella kingae expresses four structurally distinct polysaccharide capsules that differ in their correlation with invasive disease

DOE PAGES

Starr, Kimberly F.; Porsch, Eric A.; Seed, Patrick C.; ...

2016-10-19

Kingella kingae is an encapsulated gram-negative organism that is a common cause of osteoarticular infections in young children. In earlier work, we identified a glycosyltransferase gene called csaA that is necessary for synthesis of the [3)-β-GalpNAc-(1→5)-β-Kdop-(2→] polysaccharide capsule (type a) in K. kingae strain 269–492. In the current study, we analyzed a large collection of invasive and carrier isolates from Israel and found that csaA was present in only 47% of the isolates. Further examination of this collection using primers based on the sequence that flanks csaA revealed three additional gene clusters (designated the csb, csc, and csd loci), allmore » encoding predicted glycosyltransferases. The csb locus contains the csbA, csbB, and csbC genes and is associated with a capsule that is a polymer of [6)-α-GlcpNAc-(1→5)-β-(8-OAc)Kdop-(2→] (type b). The csc locus contains the cscA, cscB, and cscC genes and is associated with a capsule that is a polymer of [3)-β-Ribf-(1→2)-β-Ribf-(1→2)-β-Ribf-(1→4)-β-Kdop-(2→] (type c). The csd locus contains the csdA, csdB, and csdC genes and is associated with a capsule that is a polymer of [P-(O→3)[β-Galp-(1→4)]-β-GlcpNAc-(1→3)-α-GlcpNAc-1-] (type d). Introduction of the csa, csb, csc, and csd loci into strain KK01Δcsa, a strain 269–492 derivative that lacks the native csaA gene, was sufficient to produce the type a capsule, type b capsule, type c capsule, and type d capsule, respectively, indicating that these loci are solely responsible for determining capsule type in K. kingae. Further analysis demonstrated that 96% of the invasive isolates express either the type a or type b capsule and that a disproportionate percentage of carrier isolates express the type c or type d capsule. Lastly, these results establish that there are at least four structurally distinct K. kingae capsule types and suggest that capsule type plays an important role in promoting K. kingae invasive disease« less

One-Dimensional Thermal Violence Cook-Off Test

NASA Astrophysics Data System (ADS)

Cook, Malcolm; Stennett, Christopher; University of Cranfield, Shrivenham, Swindon, SN6 8LA Team; AWE plc, Aldermaston, Reading Bershire, RG7 4PR, UK Team

2017-06-01

The One-Dimensional Thermal Violence (ODTV) test is designed to quantify and rank the violence of HE charges when heated to elevated temperatures. The test design consists of a central spherical explosive pellet encased in two aluminium barrel shaped halves, fitted with a copper sealing ring, encased by two aluminium locking rings placed over them from either end. The outer surface of the capsule is heated uniformly by placing in a pre-heated molten solder bath. This allows the time-to-explosion to be recorded for different initial bath temperatures. The ODTV capsule can hold samples up to 30mm in diameter. Diagnostics include both thermocouples and Photon Dopler Velocimetry (PDV). A series of live firings have been carried out on a range of bespoke HMX/HTPB explosives. These include HMX/HTPB mix ratios of 95/5, 92/8, 90/10, 88/12 and 85/15. These tests showed that the ODTV capsule had sufficient confinement and size that it could capture the spectrum of events expected from these formulations. It has been demonstrated that the deformation of the heater cup (that houses the molten solder) can be used as an additional violence metric along with the fragmentation and PDV wall velocities of the aluminium ODTV capsule.

Zero- vs. one-dimensional, parametric vs. non-parametric, and confidence interval vs. hypothesis testing procedures in one-dimensional biomechanical trajectory analysis.

PubMed

Pataky, Todd C; Vanrenterghem, Jos; Robinson, Mark A

2015-05-01

Biomechanical processes are often manifested as one-dimensional (1D) trajectories. It has been shown that 1D confidence intervals (CIs) are biased when based on 0D statistical procedures, and the non-parametric 1D bootstrap CI has emerged in the Biomechanics literature as a viable solution. The primary purpose of this paper was to clarify that, for 1D biomechanics datasets, the distinction between 0D and 1D methods is much more important than the distinction between parametric and non-parametric procedures. A secondary purpose was to demonstrate that a parametric equivalent to the 1D bootstrap exists in the form of a random field theory (RFT) correction for multiple comparisons. To emphasize these points we analyzed six datasets consisting of force and kinematic trajectories in one-sample, paired, two-sample and regression designs. Results showed, first, that the 1D bootstrap and other 1D non-parametric CIs were qualitatively identical to RFT CIs, and all were very different from 0D CIs. Second, 1D parametric and 1D non-parametric hypothesis testing results were qualitatively identical for all six datasets. Last, we highlight the limitations of 1D CIs by demonstrating that they are complex, design-dependent, and thus non-generalizable. These results suggest that (i) analyses of 1D data based on 0D models of randomness are generally biased unless one explicitly identifies 0D variables before the experiment, and (ii) parametric and non-parametric 1D hypothesis testing provide an unambiguous framework for analysis when one׳s hypothesis explicitly or implicitly pertains to whole 1D trajectories. Copyright © 2015 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Randolph, Randall Blaine; Oertel, John A.; Schmidt, Derek William

For this study, machined CH hemi-shell ablator capsules have been successfully produced by the MST-7 Target Fabrication Team at Los Alamos National Laboratory. Process development and micro-machining techniques have been developed to produce capsules for both the Omega and National Ignition Facility (NIF) campaigns. These capsules are gas filled up to 10 atm and consist of a machined plastic hemi-shell outer layer that accommodates various specially engineered low-density polystyrene foam cores. Machining and assembly of the two-part, step-jointed plastic hemi-shell outer layer required development of new techniques, processes, and tooling while still meeting very aggressive shot schedules for both campaigns.more » Finally, problems encountered and process improvements will be discussed that describe this very unique, complex capsule design approach through the first Omega proof-of-concept version to the larger NIF version.« less

In-to-out body path loss for wireless radio frequency capsule endoscopy in a human body.

PubMed

Vermeeren, G; Tanghe, E; Thielens, A; Martens, L; Joseph, W

2016-08-01

Physical-layer characterization is important for design of in-to-out body communication for wireless body area networks (WBANs). This paper numerically investigates the path loss of an in-to-out body radio frequency (RF) wireless link between an endoscopy capsule and a receiver outside the body using a 3D electromagnetic solver. A spiral antenna in the endoscopy capsule is tuned to operate in the Medical Implant Communication Service (MICS) band at 402 MHz, accounting for the properties of the human body. The influence of misalignment, rotation of the capsule, and human body model are investigated. Semi-empirical path loss models for various homogeneous tissues and 3D realistic human body models are provided for manufacturers to evaluate the performance of in-to-out-body WBAN systems.

Rugby-like hohlraum experimental designs for demonstrating x-ray drive enhancement

NASA Astrophysics Data System (ADS)

Amendt, Peter; Cerjan, C.; Hinkel, D. E.; Milovich, J. L.; Park, H.-S.; Robey, H. F.

2008-01-01

A suite of experimental designs for the Omega laser facility [Boehly et al., Opt. Commun. 133, 495 (1997)] using rugby and cylindrical hohlraums is proposed to confirm the energetics benefits of rugby-shaped hohlraums over cylinders under optimal implosion symmetry conditions. Postprocessed Dante x-ray drive measurements predict a 12-17eV (23%-36%) peak hohlraum temperature (x-ray flux) enhancement for a 1ns flattop laser drive history. Simulated core self-emission x-ray histories also show earlier implosion times by 200-400ps, depending on the hohlraum case-to-capsule ratio and laser-entrance-hole size. Capsules filled with 10 or 50atm of deuterium (DD) are predicted to give in excess of 1010 neutrons in two-dimensional hohlraum simulations in the absence of mix, enabling DD burn history measurements for the first time in indirect-drive on Omega. Capsule designs with 50atm of DHe3 are also proposed to make use of proton slowing for independently verifying the drive benefits of rugby hohlraums. Scale-5/4 hohlraum designs are also introduced to provide further margin to potential laser-plasma-induced backscatter and hot-electron production.

Cigarette brands with flavour capsules in the filter: trends in use and brand perceptions among smokers in the USA, Mexico and Australia, 2012–2014

PubMed Central

Thrasher, James F; Abad-Vivero, Erika N; Moodie, Crawford; O'Connor, Richard J; Hammond, David; Cummings, K Michael; Yong, Hua-Hie; Salloum, Ramzi G; Czoli, Christine; Reynales-Shigematsu, Luz Myriam

2016-01-01

Objective To describe trends, correlates of use and consumer perceptions related to the product design innovation of flavour capsules in cigarette filters. Methods Quarterly surveys from 2012 to 2014 were analysed from an online consumer panel of adult smokers aged 18–64, living in the USA (n=6865 observations; 4154 individuals); Mexico (n=5723 observations; 3366 individuals); and Australia (n=5864 observations; 2710 individuals). Preferred brand varieties were classified by price (ie, premium; discount) and flavour (ie, regular; flavoured without capsule; flavoured with capsule). Participants reported their preferred brand variety's appeal (ie, satisfaction; stylishness), taste (ie, smoothness, intensity), and harm relative to other brands and varieties. GEE models were used to determine time trends and correlates of flavour capsule use, as well as associations between preferred brand characteristics (ie, price stratum, flavour) and perceptions of relative appeal, taste and harm. Results Preference for flavour capsules increased significantly in Mexico (6% to 14%) and Australia (1% to 3%), but not in the USA (4% to 5%). 18–24 year olds were most likely to prefer capsules in the USA (10%) and Australia (4%), but not Mexico. When compared to smokers who preferred regular brands, smokers who preferred brands with capsules viewed their variety of cigarettes as having more positive appeal (all countries), better taste (all countries), and lesser risk (Mexico, USA) than other brand varieties. Conclusions Results indicate that use of cigarettes with flavour capsules is growing, is associated with misperceptions of relative harm, and differentiates brands in ways that justify regulatory action. PMID:25918129

Assessing the potential of the Woman's Condom for vaginal drug delivery

PubMed Central

Kramzer, Lindsay F.; Cohen, Jessica; Schubert, Jesse; Dezzutti, Charlene S.; Moncla, Bernard J.; Friend, David; Rohan, Lisa C.

2015-01-01

Background The Woman's Condom is a new female condom that uses a dissolvable polyvinyl alcohol (PVA) capsule to simplify vaginal insertion. This preclinical study assessed the feasibility to incorporate an antiviral drug, UC781, into the Woman's Condom capsule, offering a unique drug delivery platform. Study Design UC781 capsules were fabricated using methods from the development of the Woman's Condom capsules as well as those used in vaginal film development. Capsules were characterized to evaluate physical/chemical attributes, Lactobacillus compatibility, in vitro safety and bioactivity, and condom compatibility. Results Two UC781 capsule platforms were assessed. Capsule masses (mg; mean ± SD) for platforms 1 and 2 were 116.50 ± 18.22 and 93.80 ± 8.49, respectively. Thicknesses were 0.0034 ± 0.0004 in and 0.0033 ± 0.0004 in. Disintegration times were 11 ± 3 sec and 5 ± 1 sec. Puncture strengths were 21.72 ± 3.30 N and 4.02 ± 0.83 N. Water content measured 6.98 ± 1.17 % and 7.04 ± 1.92 %. UC781 content was 0.59 ± 0.05 mg and 0.77 ± 0.11 mg. Both platforms retained in vitro bioactivity and were non-toxic to TZM-bl cells and Lactobacillus. Short-term storage of UC781 capsules with the Woman's Condom pouch did not decrease condom mechanical integrity. Conclusions UC781 was loaded into a polymeric capsule similar to that of the Woman's Condom product. This study highlights the potential use of the Woman's Condom as a platform for vaginal delivery of drugs relevant to sexual/reproductive health, including those for short or long-acting HIV prevention. PMID:25998936

Cigarette brands with flavour capsules in the filter: trends in use and brand perceptions among smokers in the USA, Mexico and Australia, 2012-2014.

PubMed

Thrasher, James F; Abad-Vivero, Erika N; Moodie, Crawford; O'Connor, Richard J; Hammond, David; Cummings, K Michael; Yong, Hua-Hie; Salloum, Ramzi G; Czoli, Christine; Reynales-Shigematsu, Luz Myriam

2016-05-01

To describe trends, correlates of use and consumer perceptions related to the product design innovation of flavour capsules in cigarette filters. Quarterly surveys from 2012 to 2014 were analysed from an online consumer panel of adult smokers aged 18-64, living in the USA (n=6865 observations; 4154 individuals); Mexico (n=5723 observations; 3366 individuals); and Australia (n=5864 observations; 2710 individuals). Preferred brand varieties were classified by price (ie, premium; discount) and flavour (ie, regular; flavoured without capsule; flavoured with capsule). Participants reported their preferred brand variety's appeal (ie, satisfaction; stylishness), taste (ie, smoothness, intensity), and harm relative to other brands and varieties. GEE models were used to determine time trends and correlates of flavour capsule use, as well as associations between preferred brand characteristics (ie, price stratum, flavour) and perceptions of relative appeal, taste and harm. Preference for flavour capsules increased significantly in Mexico (6% to 14%) and Australia (1% to 3%), but not in the USA (4% to 5%). 18-24 year olds were most likely to prefer capsules in the USA (10%) and Australia (4%), but not Mexico. When compared to smokers who preferred regular brands, smokers who preferred brands with capsules viewed their variety of cigarettes as having more positive appeal (all countries), better taste (all countries), and lesser risk (Mexico, USA) than other brand varieties. Results indicate that use of cigarettes with flavour capsules is growing, is associated with misperceptions of relative harm, and differentiates brands in ways that justify regulatory action. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Mechanistic study of the azithromycin dosage-form-dependent food effect.

PubMed

Curatolo, William; Foulds, George; Labadie, Robert

2010-07-01

Azithromycin capsules are known to exhibit a negative food effect, manifest as a decrease in azithromycin bioavailability in the fed state. Azithromycin tablets are known to be bioequivalent to capsules in the fasted state, but do not exhibit a food effect. In the present study, the involvement of gastric degradation of azithromycin to des-cladinose azithromycin (DCA) has been investigated as a possible mechanism for the observed capsule food effect. Healthy volunteers were dosed with azithromycin tablets and capsules, fasted and fed, in a four-way randomized crossover study. Serum levels of DCA were measured as a function of time post-dose. Natural log-transformed PK parameters were statistically analyzed using an ANOVA model appropriate for the study design. When capsules were dosed to fed subjects, the systemic AUC for DCA was 243% of the value observed after fasted-state dosing, and the DCA C(max) was 270% of the value observed after fasted-state dosing. When azithromycin tablets were dosed in the fasted and fed states, there was no significant difference in systemic DCA. Gastric degradation of azithromycin to DCA is the likely mechanism for the observed negative food effect observed for azithromycin capsules. This effect is not observed for tablets. These observations suggest that azithromycin capsules exhibit slow and/or delayed disintegration in the fed stomach, resulting in extended gastric residence and degradation of a portion of the gastrically retained azithromycin.

Experimental design and analysis for irradiation of SiC/SiC composite tubes under a prototypic high heat flux

NASA Astrophysics Data System (ADS)

Petrie, Christian M.; Koyanagi, Takaaki; McDuffee, Joel L.; Deck, Christian P.; Katoh, Yutai; Terrani, Kurt A.

2017-08-01

The purpose of this work is to design an irradiation vehicle for testing silicon carbide (SiC) fiber-reinforced SiC matrix composite cladding materials under conditions representative of a light water reactor in order to validate thermo-mechanical models of stress states in these materials due to irradiation swelling and differential thermal expansion. The design allows for a constant tube outer surface temperature in the range of 300-350 °C under a representative high heat flux (∼0.66 MW/m2) during one cycle of irradiation in an un-instrumented ;rabbit; capsule in the High Flux Isotope Reactor. An engineered aluminum foil was developed to absorb the expansion of the cladding tubes, due to irradiation swelling, without changing the thermal resistance of the gap between the cladding and irradiation capsule. Finite-element analyses of the capsule were performed, and the models used to calculate thermal contact resistance were validated by out-of-pile testing and post-irradiation examination of the foils and passive SiC thermometry. Six irradiated cladding tubes (both monoliths and composites) were irradiated and subsequently disassembled in a hot cell. The calculated temperatures of passive SiC thermometry inside the capsules showed good agreement with temperatures measured post-irradiation, with two calculated temperatures falling within 10 °C of experimental measurements. The success of this design could lead to new opportunities for irradiation applications with materials that suffer from irradiation swelling, creep, or other dimensional changes that can affect the specimen temperature during irradiation.

Experimental design and analysis for irradiation of SiC/SiC composite tubes under a prototypic high heat flux

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petrie, Christian M.; Koyanagi, Takaaki; McDuffee, Joel L.

The purpose of this work is to design an irradiation vehicle for testing silicon carbide (SiC) fiber-reinforced SiC matrix composite cladding materials under conditions representative of a light water reactor in order to validate thermo-mechanical models of stress states in these materials due to irradiation swelling and differential thermal expansion. The design allows for a constant tube outer surface temperature in the range of 300–350 °C under a representative high heat flux (~0.66 MW/m 2) during one cycle of irradiation in an un-instrumented “rabbit” capsule in the High Flux Isotope Reactor. An engineered aluminum foil was developed to absorb themore » expansion of the cladding tubes, due to irradiation swelling, without changing the thermal resistance of the gap between the cladding and irradiation capsule. Finite-element analyses of the capsule were performed, and the models used to calculate thermal contact resistance were validated by out-of-pile testing and post-irradiation examination of the foils and passive SiC thermometry. Six irradiated cladding tubes (both monoliths and composites) were irradiated and subsequently disassembled in a hot cell. The calculated temperatures of passive SiC thermometry inside the capsules showed good agreement with temperatures measured post-irradiation, with two calculated temperatures falling within 10 °C of experimental measurements. Furthermore, the success of this design could lead to new opportunities for irradiation applications with materials that suffer from irradiation swelling, creep, or other dimensional changes that can affect the specimen temperature during irradiation.« less

Reentry-Vehicle Shape Optimization Using a Cartesian Adjoint Method and CAD Geometry

NASA Technical Reports Server (NTRS)

Nemec, Marian; Aftosmis, Michael J.

2006-01-01

A DJOINT solutions of the governing flow equations are becoming increasingly important for the development of efficient analysis and optimization algorithms. A well-known use of the adjoint method is gradient-based shape. Given an objective function that defines some measure of performance, such as the lift and drag functionals, its gradient is computed at a cost that is essentially independent of the number of design variables (e.g., geometric parameters that control the shape). Classic aerodynamic applications of gradient-based optimization include the design of cruise configurations for transonic and supersonic flow, as well as the design of high-lift systems. are perhaps the most promising approach for addressing the issues of flow solution automation for aerodynamic design problems. In these methods, the discretization of the wetted surface is decoupled from that of the volume mesh. This not only enables fast and robust mesh generation for geometry of arbitrary complexity, but also facilitates access to geometry modeling and manipulation using parametric computer-aided design (CAD). In previous work on Cartesian adjoint solvers, Melvin et al. developed an adjoint formulation for the TRANAIR code, which is based on the full-potential equation with viscous corrections. More recently, Dadone and Grossman presented an adjoint formulation for the two-dimensional Euler equations using a ghost-cell method to enforce the wall boundary conditions. In Refs. 18 and 19, we presented an accurate and efficient algorithm for the solution of the adjoint Euler equations discretized on Cartesian meshes with embedded, cut-cell boundaries. Novel aspects of the algorithm were the computation of surface shape sensitivities for triangulations based on parametric-CAD models and the linearization of the coupling between the surface triangulation and the cut-cells. The accuracy of the gradient computation was verified using several three-dimensional test cases, which included design variables such as the free stream parameters and the planform shape of an isolated wing. The objective of the present work is to extend our adjoint formulation to problems involving general shape changes. Factors under consideration include the computation of mesh sensitivities that provide a reliable approximation of the objective function gradient, as well as the computation of surface shape sensitivities based on a direct-CAD interface. We present detailed gradient verification studies and then focus on a shape optimization problem for an Apollo-like reentry vehicle. The goal of the optimization is to enhance the lift-to-drag ratio of the capsule by modifying the shape of its heat-shield in conjunction with a center-of-gravity (c.g.) offset. This multipoint and multi-objective optimization problem is used to demonstrate the overall effectiveness of the Cartesian adjoint method for addressing the issues of complex aerodynamic design.

Parametric Study and Design of Tab Shape for Improving Aerodynamic Performance of Rotor Blade

NASA Astrophysics Data System (ADS)

Han, Jaeseong; Kwon, Oh Joon

2018-04-01

In the present study, the parametric study was performed to analyze the effect of the tab on the aerodynamic performance and characteristics of rotor blades. Also, the tab shape was designed to improve the aerodynamic performance of rotor blades. A computational fluid dynamics solver based on three-dimensional Reynolds averaged Navier-Stokes equation using an unstructured mesh was used for the parametric study and the tab design. For airfoils, the effect of length and angle of a tab was studied on the aerodynamic characteristics of airfoils. In addition, including those parameters, the effect of a span of a tab was studied for rotor blades in hovering flight. The results of the parametric study were analyzed in terms of change of the aerodynamic performance and characteristics to understand the effect of a tab. Considering the analysis, the design of tab shape was conducted to improve the aerodynamic performance of rotor blades. The simply attached tab to trailing edge of the rotor blades increases the thrust of the rotor blades without significant changing of aerodynamic characteristics of the rotor blades in hovering and forward flight.

Design for disassembly and sustainability assessment to support aircraft end-of-life treatment

NASA Astrophysics Data System (ADS)

Savaria, Christian

Gas turbine engine design is a multidisciplinary and iterative process. Many design iterations are necessary to address the challenges among the disciplines. In the creation of a new engine architecture, the design time is crucial in capturing new business opportunities. At the detail design phase, it was proven very difficult to correct an unsatisfactory design. To overcome this difficulty, the concept of Multi-Disciplinary Optimization (MDO) at the preliminary design phase (Preliminary MDO or PMDO) is used allowing more freedom to perform changes in the design. PMDO also reduces the design time at the preliminary design phase. The concept of PMDO was used was used to create parametric models, and new correlations for high pressure gas turbine housing and shroud segments towards a new design process. First, dedicated parametric models were created because of their reusability and versatility. Their ease of use compared to non-parameterized models allows more design iterations thus reduces set up and design time. Second, geometry correlations were created to minimize the number of parameters used in turbine housing and shroud segment design. Since the turbine housing and the shroud segment geometries are required in tip clearance analyses, care was taken as to not oversimplify the parametric formulation. In addition, a user interface was developed to interact with the parametric models and improve the design time. Third, the cooling flow predictions require many engine parameters (i.e. geometric and performance parameters and air properties) and a reference shroud segments. A second correlation study was conducted to minimize the number of engine parameters required in the cooling flow predictions and to facilitate the selection of a reference shroud segment. Finally, the parametric models, the geometry correlations, and the user interface resulted in a time saving of 50% and an increase in accuracy of 56% in the new design system compared to the existing design system. Also, regarding the cooling flow correlations, the number of engine parameters was reduced by a factor of 6 to create a simplified prediction model and hence a faster shroud segment selection process. None

Fixed-Order Mixed Norm Designs for Building Vibration Control

NASA Technical Reports Server (NTRS)

Whorton, Mark S.; Calise, Anthony J.

2000-01-01

This study investigates the use of H2, mu-synthesis, and mixed H2/mu methods to construct full order controllers and optimized controllers of fixed dimensions. The benchmark problem definition is first extended to include uncertainty within the controller bandwidth in the form of parametric uncertainty representative of uncertainty in the natural frequencies of the design model. The sensitivity of H2 design to unmodeled dynamics and parametric uncertainty is evaluated for a range of controller levels of authority. Next, mu-synthesis methods are applied to design full order compensators that are robust to both unmodeled dynamics and to parametric uncertainty. Finally, a set of mixed H2/mu compensators are designed which are optimized for a fixed compensator dimension. These mixed norm designs recover the H2 design performance levels while providing the same levels of robust stability as the mu designs. It is shown that designing with the mixed norm approach permits higher levels of controller authority for which the H2 designs are destabilizing. The benchmark problem is that of an active tendon system. The controller designs are all based on the use of acceleration feedback.

KSC-2012-6433

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6444

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6434

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6442

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6441

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6440

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6432

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6443

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6431

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6437

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6435

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6436

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6439

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6438

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

Symmetry tuning of a near one-dimensional 2-shock platform for code validation at the National Ignition Facility

DOE PAGES

Khan, S. F.; MacLaren, S. A.; Salmonson, J. D.; ...

2016-04-27

Here, we introduce a new quasi 1-D implosion experimental platform at the National Ignition Facility designed to validate physics models as well as to study various Inertial Confinement Fusion aspects such as implosion symmetry, convergence, hydrodynamic instabilities, and shock timing. The platform has been developed to maintain shell sphericity throughout the compression phase and produce a round hot core at stagnation. This platform utilizes a 2-shock 1 MJ pulse with 340 TW peak power in a near-vacuum AuHohlraum and a CH ablator capsule uniformly doped with 1% Si. We also performed several inflight radiography, symmetry capsule, and shock timing experimentsmore » in order to tune the symmetry of the capsule to near round throughout several epochs of the implosion. Finally, adjusting the relative powers of the inner and outer cones of beams has allowed us to control the drive at the poles and equator of the capsule, thus providing the mechanism to achieve a spherical capsule convergence. Details and results of the tuning experiments are described.« less

Rapid Access Real-Time device and Rapid Access software: new tools in the armamentarium of capsule endoscopy.

PubMed

Spada, Cristiano; Riccioni, Maria Elena; Costamagna, Guido

2007-07-01

Small bowel capsule endoscopy represents a significant advance in the investigation of the small bowel, allowing direct visualization of this section of the gastrointestinal system. More recently, new video capsules have been released, specifically designed to investigate the esophagus and the colon. In June 2006, Given Imaging Ltd received marketing clearance from the US FDA for the Rapid Access Real-Time (RT) and Rapid Access software. The Rapid Access RT is a handheld device that enables real-time viewing during capsule endoscopy procedures. To date, the clinical benefits of this device are unknown as studies on the Rapid Access RT system have not yet been published. However, it appears that the Rapid Access RT system may reduce the examination and reading time, and may impact significantly in cases where it is important to know the precise localization of the capsule (during PillCam ESO ingestion procedures, PillCam Colon examinations or when delayed gastric transit is suspected) or in case of severe gastrointestinal bleeding (when a therapeutic procedure is required urgently).

Reactions of dipolar bio-molecules in nano-capsules--example of folding-unfolding process.

PubMed

Sanfeld, A; Sefiane, K; Steinchen, A

2011-11-14

The confinement of chemical reactions in nano-capsules can lead to a dramatic effect on the equilibrium constant of these latter. Indeed, capillary effects due to the curvature and surface energy of nano-capsules can alter in a noticeable way the evolution of reactions occurring within. Nano-encapsulation of bio-materials has attracted lately wide interest from the scientific community because of the great potential of its applications in biomedical areas and targeted therapies. The present paper focuses one's attention on alterations of conformation mechanisms due to extremely confining and interacting solvated dipolar macromolecules at their isoelectric point. As a specific example studied here, the folding-unfolding reaction of proteins (particularly RNase A and creatine kinase CK) is drastically changed when encapsulated in solid inorganic hollow nano-capsules. The effects demonstrated in this work can be extended to a wide variety of nano-encapsulation situations. The design and sizing of nano-capsules can even make use of the effects shown in the present study to achieve better and more effective encapsulation. Copyright © 2011 Elsevier B.V. All rights reserved.

Lithographic Printing Via Two-Photon Polymerization of Engineered Foams

DOE PAGES

Herman, Matthew J.; Peterson, Dominic; Henderson, Kevin; ...

2017-11-29

Understanding deuterium-tritium mix in capsules is critical to achieving fusion within inertial confined fusion experiments. One method of understanding how the mix of hydrogen fuels can be controlled is by creating various structured deuterated foams and filling the capsule with liquid tritium. Historically, these materials have been a stochastically structured gas-blown foam. Later, to improve the uniformity of this material, pore formers have been used which are then chemically removed, leaving behind a foam of monodisperse voids. However, this technique is still imperfect in that fragments of the pore templating particles may not be completely removed and the void distributionmore » may not be uniform over the size scale of the capsule. Recently, advances in three-dimensional printing suggest that it can be used to create microlattices and capsule walls in one single print. Demonstrated in this paper are proof-of-concept microlattices produced using two-photon polymerization with submicrometer resolution of various structures as well as a microlattice-containing capsule. Finally, with this technology, complete control of the mixing structure is possible, amenable to modeling and easily modified for tailored target design.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herman, Matthew J.; Peterson, Dominic; Henderson, Kevin

Understanding deuterium-tritium mix in capsules is critical to achieving fusion within inertial confined fusion experiments. One method of understanding how the mix of hydrogen fuels can be controlled is by creating various structured deuterated foams and filling the capsule with liquid tritium. Historically, these materials have been a stochastically structured gas-blown foam. Later, to improve the uniformity of this material, pore formers have been used which are then chemically removed, leaving behind a foam of monodisperse voids. However, this technique is still imperfect in that fragments of the pore templating particles may not be completely removed and the void distributionmore » may not be uniform over the size scale of the capsule. Recently, advances in three-dimensional printing suggest that it can be used to create microlattices and capsule walls in one single print. Demonstrated in this paper are proof-of-concept microlattices produced using two-photon polymerization with submicrometer resolution of various structures as well as a microlattice-containing capsule. Finally, with this technology, complete control of the mixing structure is possible, amenable to modeling and easily modified for tailored target design.« less

Demonstration of high coupling efficiency to Al capsule in rugby hohlraum on NIF

NASA Astrophysics Data System (ADS)

Ping, Y.; Smalyuk, V.; Amendt, P.; Bennett, D.; Chen, H.; Dewald, E.; Goyon, C.; Graziani, F.; Johnson, S.; Khan, S.; Landen, O.; Nikroo, A.; Pino, J.; Ralph, J.; Seugling, R.; Strozzi, D.; Tipton, R.; Tommasini, R.; Wang, M.; Loomis, E.; Merritt, E.; Montgomery, D.

2017-10-01

A new design of the double-shell approach predicts a high coupling efficiency from the hohlraum to the capsule, with 700 kJ in the capsule instead of 200kJ in the conventional low-Z single-shell scheme, improving prospects of double-shell performance. A recent experiment on NIF has evaluated a first step toward this goal of energy coupling using 0.7x subscale Al capsule, Au rugby hohlraum and 1MJ drive. A shell velocity of 150 μm/ns was measured, DANTE peak temperature of 255 eV was measured, and shell kinetic energy of 36 kJ was inferred using a rocket model, all close to predictions and consistent with 330kJ of total energy coupled to the capsule. Data analysis and more results from subsequent experiments will be presented. In the next step, an additional 2x increase of total coupled energy up to 700 kJ is projected for full-scale 2-MJ drive in U Rugby hohlraum. This work was performed under DOE contract DE-AC52-07NA27344.

A Comparison of the Irradiation Creep Behavior of Several Graphites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burchell, Timothy D; Windes, Will

2016-01-01

Graphite creep strain data from the irradiation creep capsule Advanced Graphite Creep-1 (AGC-1) are reported. This capsule was the first (prototype) of a series of five or six capsules planned as part of the AGC experiment, which was designed to fully characterize the effects of neutron irradiation and the radiation creep behavior of current nuclear graphite. The creep strain data and analysis are reported for the six graphite grades incorporated in the capsule. The AGC-1 capsule was irradiated in the Advanced Test Reactor at Idaho National Laboratory (INL) at approximately 700 C and to a peak dose of 7 dpamore » (displacements per atom). The specimen s final dose, temperature, and stress conditions have been reported by INL and were used during this analysis. The derived creep coefficients (K) were calculated for each grade and were found to compare well to literature data for the creep coefficient, even under the wide range of AGC-1 specimen temperatures. Comparisons were made between AGC-1 data and historical grade data for creep coefficients.« less

Altair Navigation During Trans-Lunar Cruise, Lunar Orbit, Descent and Landing

NASA Technical Reports Server (NTRS)

Ely, Todd A.; Heyne, Martin; Riedel, Joseph E.

2010-01-01

The Altair lunar lander navigation system is driven by a set of requirements that not only specify a need to land within 100 m of a designated spot on the Moon, but also be capable of a safe return to an orbiting Orion capsule in the event of loss of Earth ground support. These requirements lead to the need for a robust and capable on-board navigation system that works in conjunction with an Earth ground navigation system that uses primarily ground-based radiometric tracking. The resulting system relies heavily on combining a multiplicity of data types including navigation state updates from the ground based navigation system, passive optical imaging from a gimbaled camera, a stable inertial measurement unit, and a capable radar altimeter and velocimeter. The focus of this paper is on navigation performance during the trans-lunar cruise, lunar orbit, and descent/landing mission phases with the goal of characterizing knowledge and delivery errors to key mission events, bound the statistical delta V costs for executing the mission, as well as the determine the landing dispersions due to navigation. This study examines the nominal performance that can be obtained using the current best estimate of the vehicle, sensor, and environment models. Performance of the system under a variety sensor outages and parametric trades is also examined.

Capsule performance optimization in the National Ignition Campaigna)

NASA Astrophysics Data System (ADS)

Landen, O. L.; Boehly, T. R.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.; Glenzer, S. H.; Hamza, A.; Hicks, D. G.; Hoffman, N.; Izumi, N.; Jones, O. S.; Kirkwood, R. K.; Kyrala, G. A.; Michel, P.; Milovich, J.; Munro, D. H.; Nikroo, A.; Olson, R. E.; Robey, H. F.; Spears, B. K.; Thomas, C. A.; Weber, S. V.; Wilson, D. C.; Marinak, M. M.; Suter, L. J.; Hammel, B. A.; Meyerhofer, D. D.; Atherton, J.; Edwards, J.; Haan, S. W.; Lindl, J. D.; MacGowan, B. J.; Moses, E. I.

2010-05-01

A capsule performance optimization campaign will be conducted at the National Ignition Facility [G. H. Miller et al., Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition by laser-driven hohlraums [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)]. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the OMEGA facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

Near-self-imaging cavity for three-mode optoacoustic parametric amplifiers using silicon microresonators.

PubMed

Liu, Jian; Torres, F A; Ma, Yubo; Zhao, C; Ju, L; Blair, D G; Chao, S; Roch-Jeune, I; Flaminio, R; Michel, C; Liu, K-Y

2014-02-10

Three-mode optoacoustic parametric amplifiers (OAPAs), in which a pair of photon modes are strongly coupled to an acoustic mode, provide a general platform for investigating self-cooling, parametric instability and very sensitive transducers. Their realization requires an optical cavity with tunable transverse modes and a high quality-factor mirror resonator. This paper presents the design of a table-top OAPA based on a near-self-imaging cavity design, using a silicon torsional microresonator. The design achieves a tuning coefficient for the optical mode spacing of 2.46  MHz/mm. This allows tuning of the mode spacing between amplification and self-cooling regimes of the OAPA device. Based on demonstrated resonator parameters (frequencies ∼400  kHz and quality-factors ∼7.5×10(5) we predict that the OAPA can achieve parametric instability with 1.6 μW of input power and mode cooling by a factor of 1.9×10(4) with 30 mW of input power.

A micromachined device describing over a hundred orders of parametric resonance

NASA Astrophysics Data System (ADS)

Jia, Yu; Du, Sijun; Arroyo, Emmanuelle; Seshia, Ashwin A.

2018-04-01

Parametric resonance in mechanical oscillators can onset from the periodic modulation of at least one of the system parameters, and the behaviour of the principal (1st order) parametric resonance has long been well established. However, the theoretically predicted higher orders of parametric resonance, in excess of the first few orders, have mostly been experimentally elusive due to the fast diminishing instability intervals. A recent paper experimentally reported up to 28 orders in a micromachined membrane oscillator. This paper reports the design and characterisation of a micromachined membrane oscillator with a segmented proof mass topology, in an attempt to amplify the inherent nonlinearities within the membrane layer. The resultant oscillator device exhibited up to over a hundred orders of parametric resonance, thus experimentally validating these ultra-high orders as well as overlapping instability transitions between these higher orders. This research introduces design possibilities for the transducer and dynamic communities, by exploiting the behaviour of these previously elusive higher order resonant regimes.

Analysis of close-contact melting with inner wall temperature variation in a horizontal cylindrical capsule

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saitoh, T.S.; Hoshi, Akira

1997-12-31

Melting and solidification of a phase change material (PCM) in a capsule is of practical importance in latent heat thermal energy storage (LHTES) systems which are considered to be very promising to reduce a peak demand of electricity in the summer season. Two melting modes are involved in melting in capsules. One is close-contact melting between the solid bulk and the capsule wall, and another is natural convection melting in the liquid region. In recent years, close-contact melting processes for a single enclosure have been solved using several numerical methods (e.g., Saitoh and Kato (1994)). However, there is no theoreticalmore » solution considering the inner wall temperature variation within cylindrical or spherical capsules. In this report close-contact melting heat transfer characteristics including melt flow in the liquid film under inner wall temperature distribution were analyzed and simple approximate equations are presented, which facilitates designing of the practical capsule bed LHTES systems. The effects of Stefan number and variable temperature profile etc. were clarified in detail. And the melting velocity of the solid bulk under various conditions was also studied theoretically. In addition, the effects of variable inner wall temperature on molten mass fraction were investigated.« less

Wireless fluorescence capsule for endoscopy using single photon-based detection

NASA Astrophysics Data System (ADS)

Al-Rawhani, Mohammed A.; Beeley, James; Cumming, David R. S.

2015-12-01

Fluorescence Imaging (FI) is a powerful technique in biological science and clinical medicine. Current FI devices that are used either for in-vivo or in-vitro studies are expensive, bulky and consume substantial power, confining the technique to laboratories and hospital examination rooms. Here we present a miniaturised wireless fluorescence endoscope capsule with low power consumption that will pave the way for future FI systems and applications. With enhanced sensitivity compared to existing technology we have demonstrated that the capsule can be successfully used to image tissue autofluorescence and targeted fluorescence via fluorophore labelling of tissues. The capsule incorporates a state-of-the-art complementary metal oxide semiconductor single photon avalanche detector imaging array, miniaturised optical isolation, wireless technology and low power design. When in use the capsule consumes only 30.9 mW, and deploys very low-level 468 nm illumination. The device has the potential to replace highly power-hungry intrusive optical fibre based endoscopes and to extend the range of clinical examination below the duodenum. To demonstrate the performance of our capsule, we imaged fluorescence phantoms incorporating principal tissue fluorophores (flavins) and absorbers (haemoglobin). We also demonstrated the utility of marker identification by imaging a 20 μM fluorescein isothiocyanate (FITC) labelling solution on mammalian tissue.

Simulation-Aided Design of Tubular Polymeric Capsules for Self-Healing Concrete.

PubMed

Šavija, Branko; Feiteira, João; Araújo, Maria; Chatrabhuti, Sutima; Raquez, Jean-Marie; Van Tittelboom, Kim; Gruyaert, Elke; De Belie, Nele; Schlangen, Erik

2016-12-24

Polymeric capsules can have an advantage over glass capsules used up to now as proof-of-concept carriers in self-healing concrete. They allow easier processing and afford the possibility to fine tune their mechanical properties. Out of the multiple requirements for capsules used in this context, the capability of rupturing when crossed by a crack in concrete of a typical size is one of the most relevant, as without it no healing agent is released into the crack. This study assessed the fitness of five types of polymeric capsules to fulfill this requirement by using a numerical model to screen the best performing ones and verifying their fitness with experimental methods. Capsules made of a specific type of poly(methyl methacrylate) (PMMA) were considered fit for the intended application, rupturing at average crack sizes of 69 and 128 μm, respectively for a wall thickness of ~0.3 and ~0.7 mm. Thicker walls were considered unfit, as they ruptured for crack sizes much higher than 100 μm. Other types of PMMA used and polylactic acid were equally unfit for the same reason. There was overall good fitting between model output and experimental results and an elongation at break of 1.5% is recommended regarding polymers for this application.

Comparative study of antibiotic-containing polymethylmetacrylate capsules and beads.

PubMed

Borzsei, László; Mintál, Tibor; Horváth, Aranka; Koós, Zoltán; Kocsis, Béla; Nyárády, József

2006-01-01

This study aimed at making local antibiotic therapy wider in cases of chronic suppurations by administering antibiotics which previously could not be given in this way through the conventional polymethylmetacrylate (PMMA) carrier techniques. Capsules from this material were produced with a pressing machine designed and laid out by us. The characteristics of antibiotic penetration from this novel carrier were compared to those of PMMA beads. The time-dependent outflow of amikacin, clindamycin, pefloxacin, piperacillin + tazobactam, amoxicillin + clavulanic acid and cefotaxime was examined from the capsules and the beads with standard microbiological techniques using the Micrococcus luteus ATCC9341 test strain. The diameter of the inhibitory zones was measured after 24 h incubation at 37 degrees C and converted to mug/ml antibiotic concentrations. Our results revealed that all antibiotics showed longer-lasting and higher concentration outflow from the PMMA capsules than from the beads. Therefore, these capsules can provide a more promising new opportunity for specific local antimicrobial treatment in cases of chronic suppurative bone and soft tissue injuries. In these cases the polymerization has already been completed and the heat does not influence the structure of the antibiotics; therefore, it can be inserted into the capsules in powder or solution form. Copyright 2006 S. Karger AG, Basel.

Simulation-Aided Design of Tubular Polymeric Capsules for Self-Healing Concrete

PubMed Central

Šavija, Branko; Feiteira, João; Araújo, Maria; Chatrabhuti, Sutima; Raquez, Jean-Marie; Van Tittelboom, Kim; Gruyaert, Elke; De Belie, Nele; Schlangen, Erik

2016-01-01

Polymeric capsules can have an advantage over glass capsules used up to now as proof-of-concept carriers in self-healing concrete. They allow easier processing and afford the possibility to fine tune their mechanical properties. Out of the multiple requirements for capsules used in this context, the capability of rupturing when crossed by a crack in concrete of a typical size is one of the most relevant, as without it no healing agent is released into the crack. This study assessed the fitness of five types of polymeric capsules to fulfill this requirement by using a numerical model to screen the best performing ones and verifying their fitness with experimental methods. Capsules made of a specific type of poly(methyl methacrylate) (PMMA) were considered fit for the intended application, rupturing at average crack sizes of 69 and 128 μm, respectively for a wall thickness of ~0.3 and ~0.7 mm. Thicker walls were considered unfit, as they ruptured for crack sizes much higher than 100 μm. Other types of PMMA used and polylactic acid were equally unfit for the same reason. There was overall good fitting between model output and experimental results and an elongation at break of 1.5% is recommended regarding polymers for this application. PMID:28772370

Waste Encapsulation and Storage Facility (WESF) Basis for Interim Operation (BIO)

DOE Office of Scientific and Technical Information (OSTI.GOV)

COVEY, L.I.

2000-11-28

The Waste Encapsulation and Storage Facility (WESF) is located in the 200 East Area adjacent to B Plant on the Hanford Site north of Richland, Washington. The current WESF mission is to receive and store the cesium and strontium capsules that were manufactured at WESF in a safe manner and in compliance with all applicable rules and regulations. The scope of WESF operations is currently limited to receipt, inspection, decontamination, storage, and surveillance of capsules in addition to facility maintenance activities. The capsules are expected to be stored at WESF until the year 2017, at which time they will havemore » been transferred for ultimate disposition. The WESF facility was designed and constructed to process, encapsulate, and store the extracted long-lived radionuclides, {sup 90}Sr and {sup 137}Cs, from wastes generated during the chemical processing of defense fuel on the Hanford Site thus ensuring isolation of hazardous radioisotopes from the environment. The construction of WESF started in 1971 and was completed in 1973. Some of the {sup 137}Cs capsules were leased by private irradiators or transferred to other programs. All leased capsules have been returned to WESF. Capsules transferred to other programs will not be returned except for the seven powder and pellet Type W overpacks already stored at WESF.« less

Parametric Optimization of Some Critical Operating System Functions--An Alternative Approach to the Study of Operating Systems Design

ERIC Educational Resources Information Center

Sobh, Tarek M.; Tibrewal, Abhilasha

2006-01-01

Operating systems theory primarily concentrates on the optimal use of computing resources. This paper presents an alternative approach to teaching and studying operating systems design and concepts by way of parametrically optimizing critical operating system functions. Detailed examples of two critical operating systems functions using the…

The Use of Metaphors as a Parametric Design Teaching Model: A Case Study

ERIC Educational Resources Information Center

Agirbas, Asli

2018-01-01

Teaching methodologies for parametric design are being researched all over the world, since there is a growing demand for computer programming logic and its fabrication process in architectural education. The computer programming courses in architectural education are usually done in a very short period of time, and so students have no chance to…

Bifunctional ultraviolet/ultrasound responsive composite TiO2/polyelectrolyte microcapsules

NASA Astrophysics Data System (ADS)

Gao, Hui; Wen, Dongsheng; Tarakina, Nadezda V.; Liang, Jierong; Bushby, Andy J.; Sukhorukov, Gleb B.

2016-02-01

Designing and fabricating multifunctional microcapsules are of considerable interest in both academic and industrial research aspects. This work reports an innovative approach to fabricate composite capsules with high UV and ultrasound responsive functionalities that can be used as external triggers for controlled release, yet with enhanced mechanical strength that can make them survive in a harsh environment. Needle-like TiO2 nanoparticles (NPs) were produced in situ into layer-by-layer (LbL) polyelectrolyte (PE) shells through the hydrolysis of titanium butoxide (TIBO). These rigid TiO2 NPs yielded the formed capsules with excellent mechanical strength, showing a free standing structure. A possible mechanism is proposed for the special morphology formation of the TiO2 NPs and their reinforcing effects. Synergistically, their response to UV and ultrasound was visualized via SEM, with the results showing an irreversible shell rapture upon exposure to either UV or ultrasound irradiation. As expected, the release studies revealed that the dextran release from the TiO2/PE capsules was both UV-dependent and ultrasound-dependent. Besides, the biocompatibility of the capsules with the incorporation of amorphous TiO2 NPs was confirmed by an MTT assay experiment. All these pieces of evidence suggested a considerable potential medicinal application of TiO2/PE capsules for controlled drug delivery.Designing and fabricating multifunctional microcapsules are of considerable interest in both academic and industrial research aspects. This work reports an innovative approach to fabricate composite capsules with high UV and ultrasound responsive functionalities that can be used as external triggers for controlled release, yet with enhanced mechanical strength that can make them survive in a harsh environment. Needle-like TiO2 nanoparticles (NPs) were produced in situ into layer-by-layer (LbL) polyelectrolyte (PE) shells through the hydrolysis of titanium butoxide (TIBO). These rigid TiO2 NPs yielded the formed capsules with excellent mechanical strength, showing a free standing structure. A possible mechanism is proposed for the special morphology formation of the TiO2 NPs and their reinforcing effects. Synergistically, their response to UV and ultrasound was visualized via SEM, with the results showing an irreversible shell rapture upon exposure to either UV or ultrasound irradiation. As expected, the release studies revealed that the dextran release from the TiO2/PE capsules was both UV-dependent and ultrasound-dependent. Besides, the biocompatibility of the capsules with the incorporation of amorphous TiO2 NPs was confirmed by an MTT assay experiment. All these pieces of evidence suggested a considerable potential medicinal application of TiO2/PE capsules for controlled drug delivery. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06666b

Physics and Designs of Ignition Capsules Using High-Density Carbon (HDC) Ablators: Robust Designs, Stability, and Shock Mergers

NASA Astrophysics Data System (ADS)

Ho, D.; Salmonson, J.; Haan, S.; Clark, D.; Lindl, J.; Meezan, N.; Thomas, C.

2015-11-01

We present six ignition designs using W-doped HDC ablators with, respectively, 2, 3, and 4-step increases in Tr. Fuel adiabat α ranges between 1.5 and 4. The 4-step design has the lowest α of 1.5 but has the highest ablation front Rayleigh-Taylor (RT) growth. Consequently, the overall robustness of the 4-step design is inferior to the intermediate- α 3-step design, assuming typical currently measured surface roughness spectrum. As the foot level is increased further and the shocks merge inside the fuel, the fuel adiabat is raised to 4. The RT growth and mix are reduced but the 1D margin is decreased making it overall more susceptible to surface roughness. The 2-step α = 2.5 design turns out to be the most robust against surface roughness and still can deliver very high 1D yield of 14.5 MJ. Systematic evaluation of the robustness of these capsules with respect to low-mode radiation asymmetries, will also be discussed. Different paths to achieve low-convergence-ratio implosions (i.e. high velocity and high α as one option versus low velocity and low α as another option), while still giving respectable neutron yield will be presented. Finally, we discuss how the performance of these doped capsules changes; if the Au wall of the hohlraum is replaced by U. Work performed under auspices of U.S. DOE by LLNL under DE-AC52-07NA27344.

Mercury Project

NASA Image and Video Library

1958-06-24

Testing of Mercury Capsule Shape A by the Hydrodynamics Division of Langley. Joseph Shortal wrote (vol. 3, p. 19): The Hydrodynamics Division provided assistance in determining landing loads. In this connection, after PARD engineers had unofficially approached that division to make some water impact tests with the boilerplate capsule, J.B. Parkinson, Hydrodynamics Chief visited Shortal to find out if the request had his support. Finding out that it did, Parkinson said, Its your capsule. If you want us to drop it in the water, we will do it. From Shortal (Vol. 3, p. 16): The basic design of the capsule was made by M.A. Faget and his coworkers at PARD during the winter of 1957-1958. It was natural, then, that extensive use was made of the facilities at Wallops during the development of the spacecraft. The tests at Wallops consisted of 26 full-size capsules, either launched from the ground by rocket power or dropped from airplanes at high altitude and 28 scaled models, either rocket boosted or released from balloons. Emphasis in the Wallops program was on dynamic stability and aerodynamic heating of the capsule, and effectiveness of the pilot-escape and parachute-recovery systems. The biggest part of the Wallops program was the series of full-size capsules, rocket launched with the Little Joe booster, developed especially for Mercury. -- Published in Joseph A. Shortal, History of Wallops Station: Origins and Activities Through 1949, (Wallops Island, VA: National Aeronautics and Space Administration, Wallops Station, nd), Comment Edition.

Cable attachment for a radioactive brachytherapy source capsule

DOEpatents

Gross, Ian G; Pierce, Larry A

2006-07-18

In cancer brachytherapy treatment, a small californium-252 neutron source capsule is attached to a guide cable using a modified crimping technique. The guide cable has a solid cylindrical end, and the attachment employs circumferential grooves micromachined in the solid cable end. The attachment was designed and tested, and hardware fabricated for use inside a radioactive hot cell. A welding step typically required in other cable attachments is avoided.

Measuring the Ablative Richtmyer-Meshkov Growth of Isolated Defects on Plastic Capsules

NASA Astrophysics Data System (ADS)

Loomis, Eric; Braun, Dave; Batha, Steve; Sedillo, Tom; Evans, Scott; Sorce, Chuck; Landen, Otto

2010-11-01

To achieve thermonuclear ignition at Megajoule class laser systems such as the NIF using inertially confined plasmas, targets must be designed with high in-flight aspect ratios (IFAR) resulting in low shell stability. Recent simulations and experiments have shown that isolated features on the outer surface of an ignition capsule can profoundly impact capsule performance by leading to material jetting or mix into the hotspot. Unfortunately, our ability to accurately predict these effects is uncertain due to disagreement between equation of state (EOS) models. In light of this, we have begun a campaign to measure the growth of isolated defects due to ablative Richtmyer-Meshkov in CH capsules to validate these models. Face- on transmission radiography has been used to measure the evolution of Gaussian bump arrays in plastic targets. Targets were indirectly-driven using Au halfraums to radiation temperatures near 65-75 eV at the Omega laser (Laboratory for Laser Energetics, University of Rochester, NY) simultaneous with x-ray backlighting from a saran (Cl) foil. Shock speed measurements were also made to determine drive conditions in the target. The results from these experiments will aid in the design of ignition drive pulses that minimize bump amplitude at the time of shell acceleration.

KSC-2012-5576

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - Astronauts Mike Fossum and Cady Coleman look over a model capsule fit with rotor blades ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

KSC-2012-5575

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - NASA's Johnson Space Center Aerospace Engineer Jeff Hagen attaches a rotor to the top of a model capsule ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

Capsule Design for Blue Light Therapy against Helicobacter pylori.

PubMed

Li, Zhangyong; Ren, Binbin; Tan, Haiyan; Liu, Shengrong; Wang, Wei; Pang, Yu; Lin, Jinzhao; Zeng, Chen

2016-01-01

A photo-medical capsule that emits blue light for Helicobacter pylori treatment was described in this paper. The system consists of modules for pH sensing and measuring, light-emitting diode driver circuit, radio communication and microcontroller, and power management. The system can differentiate locations by monitoring the pH values of the gastrointestinal tract, and turn on and off the blue light according to the preset range of pH values. Our experimental tests show that the capsule can operate in the effective light therapy mode for more than 32 minutes and the wireless communication module can reliably transmit the measured pH value to a receiver located outside the body.

Progress on LMJ targets for ignition

NASA Astrophysics Data System (ADS)

Cherfils-Clérouin, C.; Boniface, C.; Bonnefille, M.; Fremerye, P.; Galmiche, D.; Gauthier, P.; Giorla, J.; Lambert, F.; Laffite, S.; Liberatore, S.; Loiseau, P.; Malinie, G.; Masse, L.; Masson-Laborde, P. E.; Monteil, M. C.; Poggi, F.; Seytor, P.; Wagon, F.; Willien, J. L.

2010-08-01

Targets designed to produce ignition on the Laser MegaJoule are presented. The LMJ experimental plans include the attempt of ignition and burn of an ICF capsule with 160 laser beams, delivering up to 1.4MJ and 380TW. New targets needing reduced laser energy with only a small decrease in robustness have then been designed for this purpose. Working specifically on the coupling efficiency parameter, i.e. the ratio of the energy absorbed by the capsule to the laser energy, has led to the design of a rugby-shaped cocktail hohlraum. 1D and 2D robustness evaluations of these different targets shed light on critical points for ignition, that can be traded off by tightening some specifications or by preliminary experimental and numerical tuning experiments.

Effects of sinker shapes on dissolution profiles.

PubMed

Soltero, R A; Hoover, J M; Jones, T F; Standish, M

1989-01-01

In dissolution testing, according to the U.S. Pharmacopeia, a nonreactive stainless steel wire helix is typically used to sink dosage forms that would otherwise float. The objective of this investigation was to determine if other sinker shapes will influence the rate, extent, or variability of dissolution. Criteria for the optimal sinker were defined. Various new sinker designs were fabricated, tested, and classified. Four classes of sinker shapes were defined: longitudinal, lateral, screen enclosures, and internal weights. Longitudinal sinkers contact the dosage forms on the long axis. Lateral sinkers either wrap around or contact capsule dosage forms in the middle, such as the line where the top and bottom halves of a capsule shell come together. Screen enclosures are of two types: either a wire cage, which holds the entire capsule, or a circular piece of wire screen placed on top of the capsule. Internal weights consist of two steel ball bearings, one inserted into each end of the capsule. The investigation consisted of four studies: (1) visual observation of the dissolution performance using 12 different sinkers; (2) the effect on drug release from nine classified sinkers on two different capsule formulations; (3) side-by-side comparison between the selected optimal longitudinal U clip and the wire helix lateral type sinkers; and (4) hydrodynamic effects caused by the use of the longitudinal U clip and the wire helix lateral type sinkers in the absence of capsule shells. We concluded that capsules sunk with either of the two longitudinal sinkers, the U clip or the paper clip, have faster, more complete dissolution and less variable results than did lateral type sinkers.(ABSTRACT TRUNCATED AT 250 WORDS)

SECM half-inch tethered endoscopic capsule (HITEC) for esophageal imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kang, DongKyun; Kim, Minkyu; Carruth, Robert W.; Lu, Weina; Wu, Tao; Alali, Sanaz; Do, Dukho; Soomro, Amna R.; Grant, Catriona N.; Tiernan, Aubrey R.; Rosenberg, Mireille; Nishioka, Norman S.; Tearney, Guillermo J.

2016-03-01

Spectrally encoded confocal microscopy (SECM) is a high-speed confocal endomicroscopy technology that can image extremely large regions of human tissue at cellular resolution within a short imaging time. Previously, we have developed a 7-mm-diameter SECM endoscopic capsule and successfully demonstrated imaging of human esophagus in vivo. Even though we were able to successfully capture images with the previous capsule, it suffered from two limitations: (1) the capsule had a small diameter, which provided a limited contact between SECM capsule and esophagus; and (2) speckle noise in SECM images made it challenging to appreciate cellular features. In this paper, we present a new SECM capsule, termed SECM half-inch tethered endoscopic capsule (HITEC), which addresses the two aforementioned technical challenges. With the SECM HITEC, a dual-clad fiber was used to reduce the speckle noise. Miniature GRIN optics was used to increase the NA of the fiber from 0.09 to 0.25, which made it possible to build a SECM capsule with large diameter (12.7 mm) while maintaining a short rigid length (22 mm). A water-immersion objective lens was custom designed and manufactured to provide high NA of 0.7. We have manufactured the SECM HITEC catheter and tested its optical and mechanical performance. Lateral and axial resolution was measured as 1.2 µm and 13 µm, respectively. We have imaged swine esophageal tissues ex vivo, and SECM images clearly visualized cell nuclei. Non-uniform rotational distortion (NURD) was small, less than 5%. Preliminary results suggest that SECM HITEC provides sufficient optical and mechanical performance for tissue imaging. In a future clinical study, we will test the feasibility of utilizing SECM HITEC for improved cellular imaging human of the human esophagus in vivo.

A Conserved UDP-Glucose Dehydrogenase Encoded outside the hasABC Operon Contributes to Capsule Biogenesis in Group A Streptococcus

PubMed Central

Cole, Jason N.; Aziz, Ramy K.; Kuipers, Kirsten; Timmer, Anjuli M.; Nizet, Victor

2012-01-01

Group A Streptococcus (GAS) is a human-specific bacterial pathogen responsible for serious morbidity and mortality worldwide. The hyaluronic acid (HA) capsule of GAS is a major virulence factor, contributing to bloodstream survival through resistance to neutrophil and antimicrobial peptide killing and to in vivo pathogenicity. Capsule biosynthesis has been exclusively attributed to the ubiquitous hasABC hyaluronan synthase operon, which is highly conserved across GAS serotypes. Previous reports indicate that hasA, encoding hyaluronan synthase, and hasB, encoding UDP-glucose 6-dehydrogenase, are essential for capsule production in GAS. Here, we report that precise allelic exchange mutagenesis of hasB in GAS strain 5448, a representative of the globally disseminated M1T1 serotype, did not abolish HA capsule synthesis. In silico whole-genome screening identified a putative HasB paralog, designated HasB2, with 45% amino acid identity to HasB at a distant location in the GAS chromosome. In vitro enzymatic assays demonstrated that recombinant HasB2 is a functional UDP-glucose 6-dehydrogenase enzyme. Mutagenesis of hasB2 alone slightly decreased capsule abundance; however, a ΔhasB ΔhasB2 double mutant became completely acapsular. We conclude that HasB is not essential for M1T1 GAS capsule biogenesis due to the presence of a newly identified HasB paralog, HasB2, which most likely resulted from gene duplication. The identification of redundant UDP-glucose 6-dehydrogenases underscores the importance of HA capsule expression for M1T1 GAS pathogenicity and survival in the human host. PMID:22961854

Initial experimental evaluation of wireless capsule endoscopes in the bladder: implications for capsule cystoscopy.

PubMed

Gettman, Matthew T; Swain, Paul

2009-05-01

Cystoscopy remains one of the most important diagnostic procedures for the lower urinary tract. Wireless capsule endoscopy was introduced in the 1990s but use to date is limited to gastroenterology. We evaluated the feasibility in the pig model of using wireless capsule endoscopes (WCEs) for cystoscopy. Experimental evaluation of capsule cystoscopy was performed in a 50-kg farm pig. The capsule was deployed into the bladder through a custom access sheath. Images were continuously transmitted at a rate of four frames per second to a laptop computer and processed using proprietary software. Manipulation of the WCE within the bladder was performed using a set protocol. The animal was then euthanized and gross inspection was performed. We measured the ability to deploy and manipulate the capsule within the bladder. Feasibility of capturing and retrieving images in real time was also assessed. The WCE was efficiently deployed and manipulated within the bladder passively and with the use of external magnets. The entire bladder mucosa was visualized. Real-time image transmission and capture were successful. No complications were seen during capsule cystoscopy. Minor urethral bleeding was observed after the experiment, likely related to placement of the access sheath required for deployment of the WCE. Limitations are that the evaluation of WCE was performed in the pig model, in only one female animal, using a nonsurvival approach. Furthermore, the study was not designed to differentiate normal from abnormal mucosal findings and focused solely on inspection of the bladder. This report suggests that cystoscopy with a WCE is feasible. With this device, all aspects of the bladder mucosa could be visualized, and ongoing technologic and procedural developments are warranted for this new approach.

Computer aided system for parametric design of combination die

NASA Astrophysics Data System (ADS)

Naranje, Vishal G.; Hussein, H. M. A.; Kumar, S.

2017-09-01

In this paper, a computer aided system for parametric design of combination dies is presented. The system is developed using knowledge based system technique of artificial intelligence. The system is capable to design combination dies for production of sheet metal parts having punching and cupping operations. The system is coded in Visual Basic and interfaced with AutoCAD software. The low cost of the proposed system will help die designers of small and medium scale sheet metal industries for design of combination dies for similar type of products. The proposed system is capable to reduce design time and efforts of die designers for design of combination dies.

Automated a complex computer aided design concept generated using macros programming

NASA Astrophysics Data System (ADS)

Rizal Ramly, Mohammad; Asrokin, Azharrudin; Abd Rahman, Safura; Zulkifly, Nurul Ain Md

2013-12-01

Changing a complex Computer Aided design profile such as car and aircraft surfaces has always been difficult and challenging. The capability of CAD software such as AutoCAD and CATIA show that a simple configuration of a CAD design can be easily modified without hassle, but it is not the case with complex design configuration. Design changes help users to test and explore various configurations of the design concept before the production of a model. The purpose of this study is to look into macros programming as parametric method of the commercial aircraft design. Macros programming is a method where the configurations of the design are done by recording a script of commands, editing the data value and adding a certain new command line to create an element of parametric design. The steps and the procedure to create a macro programming are discussed, besides looking into some difficulties during the process of creation and advantage of its usage. Generally, the advantages of macros programming as a method of parametric design are; allowing flexibility for design exploration, increasing the usability of the design solution, allowing proper contained by the model while restricting others and real time feedback changes.

Design options for reducing the impact of the fill-tube in ICF implosion experiments on the NIF

NASA Astrophysics Data System (ADS)

Weber, Christopher R.; Berzak Hopkins, L. F.; Casey, D. T.; Clark, D. S.; Hammel, B. A.; Le Pape, S.; Macphee, A.; Milovich, J.; Pickworth, L. A.; Robey, H. F.; Smalyuk, V. A.; Stadermann, M.; Felker, S. J.; Nikroo, A.; Thomas, C. A.; Crippen, J.; Rice, N.

2017-10-01

Inertial Confinement Fusion (ICF) capsules on the National Ignition Facility (NIF) are filled with thermonuclear fuel through a fill-tube. When the capsule implodes, perturbations caused by the fill-tube allow ablator material to mix into the hot spot and reduce fusion performance. This talk will explore several design options that attempt to reduce this damaging effect. Reducing the diameter of the fill-tube and its entrance hole is the obvious course and has been tested in experiments. Simulations also show sensitivity to the amount of glue holding the fill-tube to the capsule and suggest that careful control of this feature can limit the amount of injected mass. Finally, an off-axis fill-tube reduces the initial squirt of material into the fuel and may be a way of further optimizing this engineering feature. Work performed under the auspices of the U.S. D.O.E. by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

Manufactured solutions for the three-dimensional Euler equations with relevance to Inertial Confinement Fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waltz, J., E-mail: jwaltz@lanl.gov; Canfield, T.R.; Morgan, N.R.

2014-06-15

We present a set of manufactured solutions for the three-dimensional (3D) Euler equations. The purpose of these solutions is to allow for code verification against true 3D flows with physical relevance, as opposed to 3D simulations of lower-dimensional problems or manufactured solutions that lack physical relevance. Of particular interest are solutions with relevance to Inertial Confinement Fusion (ICF) capsules. While ICF capsules are designed for spherical symmetry, they are hypothesized to become highly 3D at late time due to phenomena such as Rayleigh–Taylor instability, drive asymmetry, and vortex decay. ICF capsules also involve highly nonlinear coupling between the fluid dynamicsmore » and other physics, such as radiation transport and thermonuclear fusion. The manufactured solutions we present are specifically designed to test the terms and couplings in the Euler equations that are relevant to these phenomena. Example numerical results generated with a 3D Finite Element hydrodynamics code are presented, including mesh convergence studies.« less

Space transfer vehicle concepts and requirements study. Volume 3, book 1: Program cost estimates

NASA Technical Reports Server (NTRS)

Peffley, Al F.

1991-01-01

The Space Transfer Vehicle (STV) Concepts and Requirements Study cost estimate and program planning analysis is presented. The cost estimating technique used to support STV system, subsystem, and component cost analysis is a mixture of parametric cost estimating and selective cost analogy approaches. The parametric cost analysis is aimed at developing cost-effective aerobrake, crew module, tank module, and lander designs with the parametric cost estimates data. This is accomplished using cost as a design parameter in an iterative process with conceptual design input information. The parametric estimating approach segregates costs by major program life cycle phase (development, production, integration, and launch support). These phases are further broken out into major hardware subsystems, software functions, and tasks according to the STV preliminary program work breakdown structure (WBS). The WBS is defined to a low enough level of detail by the study team to highlight STV system cost drivers. This level of cost visibility provided the basis for cost sensitivity analysis against various design approaches aimed at achieving a cost-effective design. The cost approach, methodology, and rationale are described. A chronological record of the interim review material relating to cost analysis is included along with a brief summary of the study contract tasks accomplished during that period of review and the key conclusions or observations identified that relate to STV program cost estimates. The STV life cycle costs are estimated on the proprietary parametric cost model (PCM) with inputs organized by a project WBS. Preliminary life cycle schedules are also included.

A Study of Fixed-Order Mixed Norm Designs for a Benchmark Problem in Structural Control

NASA Technical Reports Server (NTRS)

Whorton, Mark S.; Calise, Anthony J.; Hsu, C. C.

1998-01-01

This study investigates the use of H2, p-synthesis, and mixed H2/mu methods to construct full-order controllers and optimized controllers of fixed dimensions. The benchmark problem definition is first extended to include uncertainty within the controller bandwidth in the form of parametric uncertainty representative of uncertainty in the natural frequencies of the design model. The sensitivity of H2 design to unmodelled dynamics and parametric uncertainty is evaluated for a range of controller levels of authority. Next, mu-synthesis methods are applied to design full-order compensators that are robust to both unmodelled dynamics and to parametric uncertainty. Finally, a set of mixed H2/mu compensators are designed which are optimized for a fixed compensator dimension. These mixed norm designs recover the H, design performance levels while providing the same levels of robust stability as the u designs. It is shown that designing with the mixed norm approach permits higher levels of controller authority for which the H, designs are destabilizing. The benchmark problem is that of an active tendon system. The controller designs are all based on the use of acceleration feedback.

Calibration of Resistance Factors for Drilled Shafts for the New FHWA Design Method : Research Project Capsule

DOT National Transportation Integrated Search

2011-02-01

The Federal Highway Administration (FHWA) and American Association of State : Highway and Transportation Offi cials (AASHTO) require that all federally funded : bridges including substructures be designed using the load and resistance : factor design...

Experimental investigation of a bioartificial capsule flowing in a narrow tube

NASA Astrophysics Data System (ADS)

Risso, Frédéric; Collé-Paillot, Fabienne; Zagzoule, Mokhtar

This work is an experimental study of the motion and deformation of a bioartificial capsule flowing in a tube of 4 mm diameter. The capsules, initially designed for medical applications, are droplets of salt water surrounded by a thin polymeric membrane. They are immersed in a very viscous Newtonian silicone oil that flows through a tube in the Stokes regime. The properties of the capsules were carefully determined. Two previous experimental papers were devoted to their characterization by osmotic swelling and compression between two plates. The present work also provides a series of tests that allows an accurate definition of the experimental model under investigation. The capsules are buoyant and initially quasi-spherical. Nevertheless, buoyancy and small departures from sphericity are shown to have no significant effects, provided the flowing velocity is large enough for the viscous stress to become predominant. The capsules are also initially slightly over-inflated, but there is no mass transfer through the membrane during the present experiments. Their volume therefore remains constant. The membrane can be described as an elastic two-dimensional material, the elastic moduli of which are independent of the deformation. Far from the tube ends, the capsule reaches a steady state that depends on two parameters: the capillary number, Ca; and the ratio of the radius of the capsule to that of the tube, a/R. The capillary number, which compares the hydrodynamic stresses to the elastic tensions in the membrane, was varied between 0 and 0.125. The radius ratio, which measures the magnitude of the confinement, was varied from 0.75 to 0.95. In the range investigated, the membrane material always remains in the elastic domain. At fixed a/R, the capsule is stretched in the axial direction when Ca is increased. The process of deformation involves two main stages. At small to moderate Ca, the lateral dimension of the capsule decreases whereas its axial length increases. The capsule is rounded at both ends, but the curvature of its rear decreases as Ca increases. At large Ca, the rear buckles inward. Then, the negative rear curvature goes on decreasing whereas the lateral dimension of the capsule reaches a constant value. On the other hand, increasing a/R promotes the deformation: the process remains qualitatively the same, but the different stages are attained for smaller values of Ca. Comparisons with available numerical simulations show that the results are strongly dependent on the properties of the capsules.

Geotechnical design manual : research project capsule.

DOT National Transportation Integrated Search

2016-11-01

The Louisiana Department of Transportation and Development (DOTD), through its Pavement : and Geotechnical Design section, has developed policies and procedures over the years utilizing its own methods and those incorporated from others (AASHTO, FHWA...

The use of analysis of variance procedures in biological studies

USGS Publications Warehouse

Williams, B.K.

1987-01-01

The analysis of variance (ANOVA) is widely used in biological studies, yet there remains considerable confusion among researchers about the interpretation of hypotheses being tested. Ambiguities arise when statistical designs are unbalanced, and in particular when not all combinations of design factors are represented in the data. This paper clarifies the relationship among hypothesis testing, statistical modelling and computing procedures in ANOVA for unbalanced data. A simple two-factor fixed effects design is used to illustrate three common parametrizations for ANOVA models, and some associations among these parametrizations are developed. Biologically meaningful hypotheses for main effects and interactions are given in terms of each parametrization, and procedures for testing the hypotheses are described. The standard statistical computing procedures in ANOVA are given along with their corresponding hypotheses. Throughout the development unbalanced designs are assumed and attention is given to problems that arise with missing cells.

Chromium content in the human hip joint tissues.

PubMed

Brodziak-Dopierała, Barbara; Kwapuliński, Jerzy; Sobczyk, Krzysztof; Wiechuła, Danuta

2015-02-01

Chromium has many important functions in the human body. For the osseous tissue, its role has not been clearly defined. This study was aimed at determining chromium content in hip joint tissues. A total of 91 hip joint samples were taken in this study, including 66 from females and 25 from males. The sample tissues were separated according to their anatomical parts. The chromium content was determined by the AAS method. The statistical analysis was performed with U Mann-Whitney's non-parametric test, P≤0.05. The overall chromium content in tissues of the hip joint in the study subjects was as follows: 5.73 µg/g in the articular cartilage, 5.33 µg/g in the cortical bone, 17.86 µg/g in the cancellous bone, 5.95 µg/g in the fragment of the cancellous bone from the intertrochanteric region, and 1.28 µg/g in the joint capsule. The chromium contents were observed in 2 group patients, it was 7.04 µg/g in people with osteoarthritis and 12.59 µg/g in people with fractures. The observed chromium content was highest in the cancellous bone and the lowest in the joint capsule. Chromium content was significantly different between the people with hip joint osteoarthritis and the people with femoral neck fractures. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Controlling the Display of Capsule Endoscopy Video for Diagnostic Assistance

NASA Astrophysics Data System (ADS)

Vu, Hai; Echigo, Tomio; Sagawa, Ryusuke; Yagi, Keiko; Shiba, Masatsugu; Higuchi, Kazuhide; Arakawa, Tetsuo; Yagi, Yasushi

Interpretations by physicians of capsule endoscopy image sequences captured over periods of 7-8 hours usually require 45 to 120 minutes of extreme concentration. This paper describes a novel method to reduce diagnostic time by automatically controlling the display frame rate. Unlike existing techniques, this method displays original images with no skipping of frames. The sequence can be played at a high frame rate in stable regions to save time. Then, in regions with rough changes, the speed is decreased to more conveniently ascertain suspicious findings. To realize such a system, cue information about the disparity of consecutive frames, including color similarity and motion displacements is extracted. A decision tree utilizes these features to classify the states of the image acquisitions. For each classified state, the delay time between frames is calculated by parametric functions. A scheme selecting the optimal parameters set determined from assessments by physicians is deployed. Experiments involved clinical evaluations to investigate the effectiveness of this method compared to a standard-view using an existing system. Results from logged action based analysis show that compared with an existing system the proposed method reduced diagnostic time to around 32.5 ± minutes per full sequence while the number of abnormalities found was similar. As well, physicians needed less effort because of the systems efficient operability. The results of the evaluations should convince physicians that they can safely use this method and obtain reduced diagnostic times.

Reaction-in-flight neutrons as a signature for shell mixing in National Ignition Facility capsules

NASA Astrophysics Data System (ADS)

Hayes, A. C.; Bradley, P. A.; Grim, G. P.; Jungman, Gerard; Wilhelmy, J. B.

2010-01-01

Analytic calculations and results from computational simulations are presented that suggest that reaction-in-flight (RIF) neutrons can be used to diagnose mixing of the ablator shell material into the fuel in deuterium-tritium (DT) capsules designed for the National Ignition Facility (NIF) [J. A. Paisner, J. D. Boyes, S. A. Kumpan, W. H. Lowdermilk, and M. S. Sorem, Laser Focus World 30, 75 (1994)]. Such mixing processes in NIF capsules are of fundamental physical interest and can have important effects on capsule performance, quenching the total thermonuclear yield. The sensitivity of RIF neutrons to hydrodynamical mixing arises through the dependence of RIF production on charged-particle stopping lengths in the mixture of DT fuel and ablator material. Since the stopping power in the plasma is a sensitive function of the electron temperature and density, it is also sensitive to mix. RIF production scales approximately inversely with the degree of mixing taking place, and the ratio of RIF to down-scattered neutrons provides a measure of the mix fraction and/or the mixing length. For sufficiently high-yield capsules, where spatially resolved RIF images may be possible, neutron imaging could be used to map RIF images into detailed mix images.

Generation of pH responsive fluorescent nano capsules through simple steps for the oral delivery of low pH susceptible drugs

NASA Astrophysics Data System (ADS)

Radhakumary, Changerath; Sreenivasan, Kunnatheeri

2016-11-01

pH responsive nano capsules are promising as it can encapsulate low pH susceptible drugs like insulin and guard them from the hostile environments in the intestinal tract. The strong acidity of the gastro-intestinal tract and the presence of proteolytic enzymes are the tumbling blocks for the design of drug delivery vehicles through oral route for drugs like insulin. Nano capsules are normally built over templates which are subsequently removed by further steps. Such processes are complex and often lead into deformed and collapsed capsules. In this study, we choose calcium carbonate (CaCO3) nano particles to serve as template. Over CaCO3 nanoparticles, silica layers were built followed by polymethacrylic acid chains to acquire pH responsiveness. During the polymerization process of the methacrylic acid, the calcium carbonate core particles were dissolved leading to the formation of nano hollow capsules having a size that ranges from 225 to 246 nm and thickness from 19 to 58 nm. The methodology is simple and devoid of additional steps. The nano shells exhibited 80% release of the loaded model drug, insulin at pH 7.4 while at pH 2.0 the capsules nearly stopped the release of the drug. Polymethacrylic acid shows pH responsive swelling behavior that it swells at intestinal pH (7.0-7.5) and shrinks at gastric pH (˜2.0) thus enabling the safe unloading of the drug from the nano capsules.

New scale-down methodology from commercial to lab scale to optimize plant-derived soft gel capsule formulations on a commercial scale.

PubMed

Oishi, Sana; Kimura, Shin-Ichiro; Noguchi, Shuji; Kondo, Mio; Kondo, Yosuke; Shimokawa, Yoshiyuki; Iwao, Yasunori; Itai, Shigeru

2018-01-15

A new scale-down methodology from commercial rotary die scale to laboratory scale was developed to optimize a plant-derived soft gel capsule formulation and eventually manufacture superior soft gel capsules on a commercial scale, in order to reduce the time and cost for formulation development. Animal-derived and plant-derived soft gel film sheets were prepared using an applicator on a laboratory scale and their physicochemical properties, such as tensile strength, Young's modulus, and adhesive strength, were evaluated. The tensile strength of the animal-derived and plant-derived soft gel film sheets was 11.7 MPa and 4.41 MPa, respectively. The Young's modulus of the animal-derived and plant-derived soft gel film sheets was 169 MPa and 17.8 MPa, respectively, and both sheets showed a similar adhesion strength of approximately 4.5-10 MPa. Using a D-optimal mixture design, plant-derived soft gel film sheets were prepared and optimized by varying their composition, including variations in the mass of κ-carrageenan, ι-carrageenan, oxidized starch and heat-treated starch. The physicochemical properties of the sheets were evaluated to determine the optimal formulation. Finally, plant-derived soft gel capsules were manufactured using the rotary die method and the prepared soft gel capsules showed equivalent or superior physical properties compared with pre-existing soft gel capsules. Therefore, we successfully developed a new scale-down methodology to optimize the formulation of plant-derived soft gel capsules on a commercial scale. Copyright © 2017 Elsevier B.V. All rights reserved.

A new design methodology of obtaining wide band high gain broadband parametric source for infrared wavelength applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maji, Partha Sona; Roy Chaudhuri, Partha

In this article, we have presented a new design methodology of obtaining wide band parametric sources based on highly nonlinear chalcogenide material of As{sub 2}S{sub 3}. The dispersion profile of the photonic crystal fiber (PCF) has been engineered wisely by reducing the diameter of the second air-hole ring to have a favorable higher order dispersion parameter. The parametric gain dependence upon fiber length, pump power, and different pumping wavelengths has been investigated in detail. Based upon the nonlinear four wave mixing phenomenon, we are able to achieve a wideband parametric amplifier with peak gain of 29 dB with FWHM of ≈2000 nmmore » around the IR wavelength by proper tailoring of the dispersion profile of the PCF with a continuous wave Erbium (Er{sup 3+})-doped ZBLAN fiber laser emitting at 2.8 μm as the pump source with an average power of 5 W. The new design methodology will unleash a new dimension to the chalcogenide material based investigation for wavelength translation around IR wavelength band.« less

Study of parametric instability in gravitational wave detectors with silicon test masses

NASA Astrophysics Data System (ADS)

Zhang, Jue; Zhao, Chunnong; Ju, Li; Blair, David

2017-03-01

Parametric instability is an intrinsic risk in high power laser interferometer gravitational wave detectors, in which the optical cavity modes interact with the acoustic modes of the mirrors, leading to exponential growth of the acoustic vibration. In this paper, we investigate the potential parametric instability for a proposed next generation gravitational wave detector, the LIGO Voyager blue design, with cooled silicon test masses of size 45 cm in diameter and 55 cm in thickness. It is shown that there would be about two unstable modes per test mass at an arm cavity power of 3 MW, with the highest parametric gain of  ∼76. While this is less than the predicted number of unstable modes for Advanced LIGO (∼40 modes with max gain of  ∼32 at the designed operating power of 830 kW), the importance of developing suitable instability suppression schemes is emphasized.

A study of microwave downcoverters operating in the K sub u band

NASA Technical Reports Server (NTRS)

Fellers, R. G.; Simpson, T. L.; Tseng, B.

1982-01-01

A computer program for parametric amplifier design is developed with special emphasis on practical design considerations for microwave integrated circuit degenerate amplifiers. Precision measurement techniques are developed to obtain a more realistic varactor equivalent circuit. The existing theory of a parametric amplifier is modified to include the equivalent circuit, and microwave properties, such as loss characteristics and circuit discontinuities are investigated.

A Comparison of Kernel Equating and Traditional Equipercentile Equating Methods and the Parametric Bootstrap Methods for Estimating Standard Errors in Equipercentile Equating

ERIC Educational Resources Information Center

Choi, Sae Il

2009-01-01

This study used simulation (a) to compare the kernel equating method to traditional equipercentile equating methods under the equivalent-groups (EG) design and the nonequivalent-groups with anchor test (NEAT) design and (b) to apply the parametric bootstrap method for estimating standard errors of equating. A two-parameter logistic item response…

[A wireless power transmission system for capsule endoscope].

PubMed

Xin, Wenhui; Yan, Guozheng; Wang, Wenxing

2010-06-01

In order to deliver power to the capsule endoscope, whose position and orientation are always changing when traveling along the alimentary tract, a wireless power transmission system based on electromagnetic coupling was proposed. The system is composed of Helmholtz transmitting coil and three-dimensional receiving coil. Helmholtz coil outside the body generates a uniform magnetic field covering the whole alimentary tract; three-dimensional coil inside retrieves stable power regardless of its position and orientation. The transmitter and receiver were designed and implemented, and the experiments validated the feasibility of the system. The results show that at least 320 mW of usable power can be transmitted to capsule endoscope when its position and orientation are changing at random and the transmitting power is 25W.

KSC-2012-5574

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - NASA's Johnson Space Center Aerospace Engineer Jeff Hagen, left, and engineering intern Emmanuel Nyangweso attach rotors to the top of a model capsule ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

Neutron-induced reactions in the hohlraum to study reaction in flight neutrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boswell, M. S.; Elliott, S. R.; Tybo, J.

2013-04-19

We are currently developing the physics necessary to measure the Reaction In Flight (RIF) neutron flux from a NIF capsule. A measurement of the RIF neutron flux from a NIF capsule could be used to deduce the stopping power in the cold fuel of the NIF capsule. A foil irradiated at the Omega laser at LLE was counted at the LANL low-background counting facility at WIPP. The estimated production rate of {sup 195}Au was just below our experimental sensitivity. We have made several improvements to our counting facility in recent months. These improvements are designed to increase our sensitivity, andmore » include installing two new low-background detectors, and taking steps to reduce noise in the signals.« less

Optimizing implosion yields using rugby-shaped hohlraums

NASA Astrophysics Data System (ADS)

Park, Hye-Sook; Robey, H.; Amendt, P.; Philippe, F.; Casner, A.; Caillaud, T.; Bourgade, J.-L.; Landoas, O.; Li, C. K.; Petrasso, R.; Seguin, F.; Rosenberg, M.; Glebov, V. Yu.

2009-11-01

We present the first experimental results on optimizing capsule implosion experiments by using rugby-shaped hohlraums [1] on the Omega laser, University of Rochester. This campaign compared D2-filled capsule performance between standard cylindrical Au hohlraums and rugby-shaped hohlraums for demonstrating the energetics advantages of the rugby geometry. Not only did the rugby-shaped hohlraums show nearly 20% more x-ray drive energy over the cylindrical hohlraums, but also the high-performance design of the capsules provided nearly 20 times more DD neutrons than in any previous Omega hohlraum campaigns, thereby enabling use of neutron temporal diagnostics. Comparison with simulations on neutron burn histories, x-ray core imaging, backscattered laser light and radiation temperature are presented. [1] P. Amendt et al., Phys. Plasmas 15, 012702 (2008)

Thermal treatment of galactose-branched polyelectrolyte microcapsules to improve drug delivery with reserved targetability.

PubMed

Zhang, Fu; Wu, Qi; Liu, Li-Jun; Chen, Zhi-Chun; Lin, Xian-Fu

2008-06-05

A novel multilayered drug delivery system by LbL assembly of galactosylated polyelectrolyte, which is possible to have the potential in hepatic targeting by the presence of galactose residues at the microcapsule's surface, is designed. Thermal treatment was performed on the capsules and a dramatic thermal shrinkage up to 60% decrease of capsule diameter above 50 degrees C was observed. This thermal behavior was then used to manipulate drug loading capacity and release rate. Heating after drug loading could seal the capsule shell, enhancing the loading capacity and reducing the release rate significantly. Excellent affinity between galactose-binding lectin and heated galactose-containing microcapsules were observed, indicating a stable targeting potential even after high temperature elevating up to 90 degrees C.

Optical parametric amplification and oscillation assisted by low-frequency stimulated emission.

PubMed

Longhi, Stefano

2016-04-15

Optical parametric amplification and oscillation provide powerful tools for coherent light generation in spectral regions inaccessible to lasers. Parametric gain is based on a frequency down-conversion process and, thus, it cannot be realized for signal waves at a frequency ω3 higher than the frequency of the pump wave ω1. In this Letter, we suggest a route toward the realization of upconversion optical parametric amplification and oscillation, i.e., amplification of the signal wave by a coherent pump wave of lower frequency, assisted by stimulated emission of the auxiliary idler wave. When the signal field is resonated in an optical cavity, parametric oscillation is obtained. Design parameters for the observation of upconversion optical parametric oscillation at λ3=465 nm are given for a periodically poled lithium-niobate (PPLN) crystal doped with Nd(3+) ions.

Novel Characterization of Capsule X-Ray Drive at the National Ignition Facility [Using ViewFactor Experiments to Measure Hohlraum X-Radiation Drive from the Capsule Point-of-View in Ignition Experiments on the National Ignition Facility

DOE PAGES

MacLaren, S. A.; Schneider, M. B.; Widmann, K.; ...

2014-03-13

Here, indirect drive experiments at the National Ignition Facility are designed to achieve fusion by imploding a fuel capsule with x rays from a laser-driven hohlraum. Previous experiments have been unable to determine whether a deficit in measured ablator implosion velocity relative to simulations is due to inadequate models of the hohlraum or ablator physics. ViewFactor experiments allow for the first time a direct measure of the x-ray drive from the capsule point of view. The experiments show a 15%–25% deficit relative to simulations and thus explain nearly all of the disagreement with the velocity data. In addition, the datamore » from this open geometry provide much greater constraints on a predictive model of laser-driven hohlraum performance than the nominal ignition target.« less

Study on Octahedral Spherical Hohlraum

NASA Astrophysics Data System (ADS)

Lan, Ke; Liu, Jie; Huo, Wenyi; Li, Zhichao; Yang, Dong; Li, Sanwei; Ren, Guoli; Chen, Yaohua; Jiang, Shaoen; He, Xian-Tu; Zhang, Weiyan

2015-11-01

In this talk, we report our recent study on octahedral spherical hohlraum which has six laser entrance holes (LEHs). First, our study shows that the octahedral hohlraums have robust high symmetry during the capsule implosion at hohlraum-to- capsule radius ratio larger than 3.7 and have potential superiority on low backscatter without supplementary technology. Second, we study the laser arrangement and constraints of the octahedral hohlraums and give their laser arrangement design for ignition facility. Third, we propose a novel octahedral hohlraum with LEH shields and cylindrical LEHs, in order to increase the laser coupling efficiency and improve the capsule symmetry and to mitigate the influence of the wall blowoff on laser transport. Fourth, we study the sensitivity of capsule symmetry inside the octahedral hohlraums to laser power balance, pointing accuracy, deviations from the optimal position and target fabrication accuracy, and compare the results with that of tradiational cylinders and rugby hohlraums. Finally, we present our recent experimental studies on the octahedral hohlraums on SGIII prototype laser facility.

Design and implementation of magnetically maneuverable capsule endoscope system with direction reference for image navigation.

PubMed

Sun, Zhen-Jun; Ye, Bo; Sun, Yi; Zhang, Hong-Hai; Liu, Sheng

2014-07-01

This article describes a novel magnetically maneuverable capsule endoscope system with direction reference for image navigation. This direction reference was employed by utilizing a specific magnet configuration between a pair of external permanent magnets and a magnetic shell coated on the external capsule endoscope surface. A pair of customized Cartesian robots, each with only 4 degrees of freedom, was built to hold the external permanent magnets as their end-effectors. These robots, together with their external permanent magnets, were placed on two opposite sides of a "patient bed." Because of the optimized configuration based on magnetic analysis between the external permanent magnets and the magnetic shell, a simplified control strategy was proposed, and only two parameters, yaw step angle and moving step, were necessary for the employed robotic system. Step-by-step experiments demonstrated that the proposed system is capable of magnetically maneuvering the capsule endoscope while providing direction reference for image navigation. © IMechE 2014.

MEMS-based liquid lens for capsule endoscope

NASA Astrophysics Data System (ADS)

Seo, S. W.; Han, S.; Seo, J. H.; Kim, Y. M.; Kang, M. S.; Min, N. G.; Choi, W. B.; Sung, M. Y.

2008-03-01

The capsule endoscope, a new application area of digital imaging, is growing rapidly but needs the versatile imaging capabilities such as auto-focusing and zoom-in to be an active diagnostic tool. The liquid lens based on MEMS technology can be a strong candidate because it is able to be small enough. In this paper, a cylinder-type liquid lens was designed based on Young-Lippmann model and then fabricated with MEMS technology combining the silicon thin-film process and the wafer bonding process. The focal length of the lens module including the fabricated liquid lens was changed reproducibly as a function of the applied voltage. With the change of 30V in the applied bias, the focal length of the constructed lens module could be tuned in the range of about 42cm. The fabricated liquid lens was also proven to be small enough to be adopted in the capsule endoscope, which means the liquid lens can be utilized for the imaging capability improvement of the capsule endoscope.

A forced titration study of the antioxidant and immunomodulatory effects of Ambrotose AO supplement

PubMed Central

2010-01-01

Background Oxidative stress plays a role in acute and chronic inflammatory disease and antioxidant supplementation has demonstrated beneficial effects in the treatment of these conditions. This study was designed to determine the optimal dose of an antioxidant supplement in healthy volunteers to inform a Phase 3 clinical trial. Methods The study was designed as a combined Phase 1 and 2 open label, forced titration dose response study in healthy volunteers (n = 21) to determine both acute safety and efficacy. Participants received a dietary supplement in a forced titration over five weeks commencing with a no treatment baseline through 1, 2, 4 and 8 capsules. The primary outcome measurement was ex vivo changes in serum oxygen radical absorbance capacity (ORAC). The secondary outcome measures were undertaken as an exploratory investigation of immune function. Results A significant increase in antioxidant activity (serum ORAC) was observed between baseline (no capsules) and the highest dose of 8 capsules per day (p = 0.040) representing a change of 36.6%. A quadratic function for dose levels was fitted in order to estimate a dose response curve for estimating the optimal dose. The quadratic component of the curve was significant (p = 0.047), with predicted serum ORAC scores increasing from the zero dose to a maximum at a predicted dose of 4.7 capsules per day and decreasing for higher doses. Among the secondary outcome measures, a significant dose effect was observed on phagocytosis of granulocytes, and a significant increase was also observed on Cox 2 expression. Conclusion This study suggests that Ambrotose AO® capsules appear to be safe and most effective at a dosage of 4 capsules/day. It is important that this study is not over interpreted; it aimed to find an optimal dose to assess the dietary supplement using a more rigorous clinical trial design. The study achieved this aim and demonstrated that the dietary supplement has the potential to increase antioxidant activity. The most significant limitation of this study was that it was open label Phase 1/Phase 2 trial and is subject to potential bias that is reduced with the use of randomization and blinding. To confirm the benefits of this dietary supplement these effects now need to be demonstrated in a Phase 3 randomised controlled trial (RCT). Trial Registration Australian and New Zealand Clinical Trials Register: ACTRN12605000258651 PMID:20433711

Relative Bioavailabilities of Lisdexamfetamine Dimesylate and d-Amphetamine in Healthy Adults in an Open-Label, Randomized, Crossover Study After Mixing Lisdexamfetamine Dimesylate With Food or Drink

PubMed Central

Ermer, James; Corcoran, Mary; Lasseter, Kenneth

2016-01-01

Background: This open-label, crossover study examined lisdexamfetamine dimesylate (LDX) and d-amphetamine pharmacokinetics in healthy adults after administration of an intact LDX capsule or after the capsule was emptied into orange juice or yogurt and the contents consumed. Methods: Healthy adult volunteers (N = 30) were administered a 70-mg LDX capsule or the contents of a 70-mg capsule mixed with yogurt or orange juice using a 3-way crossover design. Blood samples were collected serially for up to 96 hours after dose. Pharmacokinetic endpoints included maximum plasma concentration (Cmax) and area under the plasma concentration versus time curve from zero to infinity (AUC0–∞) or to last assessment (AUClast). Relative LDX and d-amphetamine bioavailabilities from the contents of a 70-mg LDX capsule mixed with orange juice or yogurt were compared with those from the intact LDX capsule using bioequivalence-testing procedures. Results: Geometric least squares mean ratios (90% confidence intervals [CIs]) for d-amphetamine (active moiety) were within the prespecified bioequivalence range (0.80–1.25) when the contents of a 70-mg LDX capsule were mixed with orange juice [Cmax: 0.971 (0.945, 0.998); AUC0–∞: 0.986 (0.955, 1.019); AUClast: 0.970 (0.937, 1.004)] or yogurt [Cmax: 0.970 (0.944, 0.997); AUC0–∞: 0.945 (0.915, 0.976); AUClast: 0.944 (0.912, 0.977)]. Geometric least squares mean ratios (90% CIs) for LDX (inactive prodrug) were below the accepted range when the contents of a 70-mg LDX capsule were mixed with orange juice [Cmax: 0.641 (0.582, 0.707); AUC0–∞: 0.716 (0.647, 0.792); AUClast: 0.708 (0.655, 0.766)]; the lower 90% CI for Cmax [0.828 (0.752, 0.912)] was below the accepted range when the contents of a 70-mg LDX capsule were mixed with yogurt. Conclusions: Relative bioavailability of d-amphetamine (the active moiety) did not differ across administrations, which suggests that emptying an LDX capsule into orange juice or yogurt and consuming it is an alternative to intact capsules. PMID:27661399

Fuel Cycle Research and Development Accident Tolerant Fuels Series 1 (ATF-1) Irradiation Testing FY 2016 Status Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Core, Gregory Matthew

This report contains a summary of irradiation testing of Fuel Cycle Research and Development (FCRD) Accident Tolerant Fuels Series 1 (ATF 1) experiments performed at Idaho National Laboratory (INL) in FY 2016. ATF 1 irradiation testing work performed in FY 2016 included design, analysis, and fabrication of ATF-1B drop in capsule ATF 1 series experiments and irradiation testing of ATF-1 capsules in the ATR.

Tethered capsule OCT endomicroscopy for upper gastrointestinal tract imaging by using ball lens probe (Conference Presentation)

NASA Astrophysics Data System (ADS)

Dong, Jing; Gora, Michalina J.; Reddy, Rohith; Trasischker, Wolfgang; Poupart, Oriane; Lu, Weina; Carruth, Robert W.; Grant, Catriona N.; Soomro, Amna R.; Tiernan, Aubrey R.; Rosenberg, Mireille; Nishioka, Norman S.; Tearney, Guillermo J.

2016-03-01

While endoscopy is the most commonly used modality for diagnosing upper GI tract disease, this procedure usually requires patient sedation that increases cost and mandates its operation in specialized settings. In addition, endoscopy only visualizes tissue superfically at the macroscopic scale, which is problematic for many diseases that manifest below the surface at a microscopic scale. Our lab has previously developed technology termed tethered capsule OCT endomicroscopy (TCE) to overcome these diagnostic limitations of endoscopy. The TCE device is a swallowable capsule that contains optomechanical components that circumferentially scan the OCT beam inside the body as the pill traverses the organ via peristalsis. While we have successfully imaged ~100 patients with the TCE device, the optics of our current device have many elements and are complex, comprising a glass ferrule, optical fiber, glass spacer, GRIN lens and prism. As we scale up manufacturing of this device for clinical translation, we must decrease the cost and improve the manufacturability of the capsule's optical configuration. In this abstract, we report on the design and development of simplificed TCE optics that replace the GRIN lens-based configuration with an angle-polished ball lens design. The new optics include a single mode optical fiber, a glass spacer and an angle polished ball lens, that are all fusion spliced together. The ball lens capsule has resolutions that are comparable with those of our previous GRIN lens configuration (30µm (lateral) × 7 µm (axial)). Results in human subjects show that OCT-based TCE using the ball lens not only provides rapid, high quality microstructural images of upper GI tract, but also makes it possible to implement this technology inexpensively and on a larger scale.

Automated Adaptive Brightness in Wireless Capsule Endoscopy Using Image Segmentation and Sigmoid Function.

PubMed

Shrestha, Ravi; Mohammed, Shahed K; Hasan, Md Mehedi; Zhang, Xuechao; Wahid, Khan A

2016-08-01

Wireless capsule endoscopy (WCE) plays an important role in the diagnosis of gastrointestinal (GI) diseases by capturing images of human small intestine. Accurate diagnosis of endoscopic images depends heavily on the quality of captured images. Along with image and frame rate, brightness of the image is an important parameter that influences the image quality which leads to the design of an efficient illumination system. Such design involves the choice and placement of proper light source and its ability to illuminate GI surface with proper brightness. Light emitting diodes (LEDs) are normally used as sources where modulated pulses are used to control LED's brightness. In practice, instances like under- and over-illumination are very common in WCE, where the former provides dark images and the later provides bright images with high power consumption. In this paper, we propose a low-power and efficient illumination system that is based on an automated brightness algorithm. The scheme is adaptive in nature, i.e., the brightness level is controlled automatically in real-time while the images are being captured. The captured images are segmented into four equal regions and the brightness level of each region is calculated. Then an adaptive sigmoid function is used to find the optimized brightness level and accordingly a new value of duty cycle of the modulated pulse is generated to capture future images. The algorithm is fully implemented in a capsule prototype and tested with endoscopic images. Commercial capsules like Pillcam and Mirocam were also used in the experiment. The results show that the proposed algorithm works well in controlling the brightness level accordingly to the environmental condition, and as a result, good quality images are captured with an average of 40% brightness level that saves power consumption of the capsule.

High performance capsule implosions on the OMEGA Laser facility with rugby hohlraumsa)

NASA Astrophysics Data System (ADS)

Robey, H. F.; Amendt, P.; Park, H.-S.; Town, R. P. J.; Milovich, J. L.; Döppner, T.; Hinkel, D. E.; Wallace, R.; Sorce, C.; Strozzi, D. J.; Philippe, F.; Casner, A.; Caillaud, T.; Landoas, O.; Liberatore, S.; Monteil, M.-C.; Séguin, F.; Rosenberg, M.; Li, C. K.; Petrasso, R.; Glebov, V.; Stoeckl, C.; Nikroo, A.; Giraldez, E.

2010-05-01

Rugby-shaped hohlraums have been proposed as a method for x-ray drive enhancement for indirectly driven capsule implosions. This concept has recently been tested in a series of shots on the OMEGA laser facility [T. R. Boehly, D. L. Brown, R. S. Craxton et al., Opt. Commun. 133, 495 (1997)]. In this paper, experimental results are presented comparing the performance of D2-filled capsules between standard cylindrical Au hohlraums and rugby-shaped hohlraums. The rugby hohlraums demonstrated 18% more x-ray drive energy as compared with the cylinders, and the high-performance design of these implosions (both cylinder and rugby) also provided ≈20× more deuterium (DD) neutrons than any previous indirectly driven campaign on OMEGA and ≈3× more than ever achieved on NOVA [E. M. Campbell, Laser Part. Beams 9, 209 (1991)] implosions driven with nearly twice the laser energy. This increase in performance enables, for the first time, a measurement of the neutron burn history and imaging of the neutron core shapes in an indirectly driven implosion. Previous DD neutron yields had been too low to register this key measurement of capsule performance and the effects of dynamic mix. A wealth of additional data on the fuel areal density from the suite of charged particle diagnostics was obtained on a subset of the shots that used D H3e rather than D2 fuel. Comparisons of the experimental results with numerical simulations are shown to be in very good agreement. The design techniques employed in this campaign, e.g., smaller laser entrance holes and hohlraum case-to-capsule ratios, provide added confidence in the pursuit of ignition on the National Ignition Facility [J. D. Lindl, P. Amendt, R. L. Berger et al., Phys. Plasmas 11, 339 (2004)].

Understanding and predicting the impact of critical dissolution variables for nifedipine immediate release capsules by multivariate data analysis.

PubMed

Mercuri, A; Pagliari, M; Baxevanis, F; Fares, R; Fotaki, N

2017-02-25

In this study the selection of in vivo predictive in vitro dissolution experimental set-ups using a multivariate analysis approach, in line with the Quality by Design (QbD) principles, is explored. The dissolution variables selected using a design of experiments (DoE) were the dissolution apparatus [USP1 apparatus (basket) and USP2 apparatus (paddle)], the rotational speed of the basket/or paddle, the operator conditions (dissolution apparatus brand and operator), the volume, the pH, and the ethanol content of the dissolution medium. The dissolution profiles of two nifedipine capsules (poorly soluble compound), under conditions mimicking the intake of the capsules with i. water, ii. orange juice and iii. an alcoholic drink (orange juice and ethanol) were analysed using multiple linear regression (MLR). Optimised dissolution set-ups, generated based on the mathematical model obtained via MLR, were used to build predicted in vitro-in vivo correlations (IVIVC). IVIVC could be achieved using physiologically relevant in vitro conditions mimicking the intake of the capsules with an alcoholic drink (orange juice and ethanol). The multivariate analysis revealed that the concentration of ethanol used in the in vitro dissolution experiments (47% v/v) can be lowered to less than 20% v/v, reflecting recently found physiological conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Solid state SPS microwave generation and transmission study. Volume 2, phase 2: Appendices

NASA Technical Reports Server (NTRS)

Maynard, O. E.

1980-01-01

The solid state sandwich concept for SPS was further defined. The design effort concentrated on the spacetenna, but did include some system analysis for parametric comparison reasons. Basic solid state microwave devices were defined and modeled. An initial conceptual subsystems and system design was performed as well as sidelobe control and system selection. The selected system concept and parametric solid state microwave power transmission system data were assessed relevant to the SPS concept. Although device efficiency was not a goal, the sensitivities to design of this efficiency were parametrically treated. Sidelobe control consisted of various single step tapers, multistep tapers and Gaussian tapers. A hybrid concept using tubes and solid state was evaluated. Thermal analyses are included with emphasis on sensitivities to waste heat radiator form factor, emissivity, absorptivity, amplifier efficiency, material and junction temperature.

Development and fabrication of S-band chip varactor parametric amplifier

NASA Technical Reports Server (NTRS)

Kramer, E.

1974-01-01

A noncryogenic, S-band parametric amplifier operating in the 2.2 to 2.3 GHz band and having an average input noise temperature of less than 30 K was built and tested. The parametric amplifier module occupies a volume of less than 1-1/4 cubic feet and weighs less than 60 pounds. The module is designed for use in various NASA ground stations to replace larger, more complex cryogenic units which require considerably more maintenance because of the cryogenic refrigeration system employed. The amplifier can be located up to 15 feet from the power supply unit. Optimum performance was achieved through the use of high-quality unpackaged (chip) varactors in the amplifier design.

PRESS-based EFOR algorithm for the dynamic parametrical modeling of nonlinear MDOF systems

NASA Astrophysics Data System (ADS)

Liu, Haopeng; Zhu, Yunpeng; Luo, Zhong; Han, Qingkai

2017-09-01

In response to the identification problem concerning multi-degree of freedom (MDOF) nonlinear systems, this study presents the extended forward orthogonal regression (EFOR) based on predicted residual sums of squares (PRESS) to construct a nonlinear dynamic parametrical model. The proposed parametrical model is based on the non-linear autoregressive with exogenous inputs (NARX) model and aims to explicitly reveal the physical design parameters of the system. The PRESS-based EFOR algorithm is proposed to identify such a model for MDOF systems. By using the algorithm, we built a common-structured model based on the fundamental concept of evaluating its generalization capability through cross-validation. The resulting model aims to prevent over-fitting with poor generalization performance caused by the average error reduction ratio (AERR)-based EFOR algorithm. Then, a functional relationship is established between the coefficients of the terms and the design parameters of the unified model. Moreover, a 5-DOF nonlinear system is taken as a case to illustrate the modeling of the proposed algorithm. Finally, a dynamic parametrical model of a cantilever beam is constructed from experimental data. Results indicate that the dynamic parametrical model of nonlinear systems, which depends on the PRESS-based EFOR, can accurately predict the output response, thus providing a theoretical basis for the optimal design of modeling methods for MDOF nonlinear systems.

The optimization of wireless power transmission: design and realization.

PubMed

Jia, Zhiwei; Yan, Guozheng; Liu, Hua; Wang, Zhiwu; Jiang, Pingping; Shi, Yu

2012-09-01

A wireless power transmission system is regarded as a practical way of solving power-shortage problems in multifunctional active capsule endoscopes. The uniformity of magnetic flux density, frequency stability and orientation stability are used to evaluate power transmission stability, taking into consideration size and safety constraints. Magnetic field safety and temperature rise are also considered. Test benches are designed to measure the relevent parameters. Finally, a mathematical programming model in which these constraints are considered is proposed to improve transmission efficiency. To verify the feasibility of the proposed method, various systems for a wireless active capsule endoscope are designed and evaluated. The optimal power transmission system has the capability to supply continuously at least 500 mW of power with a transmission efficiency of 4.08%. The example validates the feasibility of the proposed method. Introduction of novel designs enables further improvement of this method. Copyright © 2012 John Wiley & Sons, Ltd.

A polar-drive shock-ignition design for the National Ignition Facilitya)

NASA Astrophysics Data System (ADS)

Anderson, K. S.; Betti, R.; McKenty, P. W.; Collins, T. J. B.; Hohenberger, M.; Theobald, W.; Craxton, R. S.; Delettrez, J. A.; Lafon, M.; Marozas, J. A.; Nora, R.; Skupsky, S.; Shvydky, A.

2013-05-01

Shock ignition [R. Betti et al., Phys. Rev. Lett. 98, 155001 (2007)] is being pursued as a viable option to achieve ignition on the National Ignition Facility (NIF). Shock-ignition target designs use a high-intensity laser spike at the end of a low-adiabat assembly pulse to launch a spherically convergent strong shock to ignite the hot spot of an imploding capsule. A shock-ignition target design for the NIF is presented. One-dimensional simulations indicate an ignition threshold factor of 4.1 with a gain of 58. A polar-drive beam-pointing configuration for shock-ignition experiments on the NIF at 750 kJ is proposed. The capsule design is shown to be robust to the various one- and two-dimensional effects and nonuniformities anticipated on the NIF. The target is predicted to ignite with a gain of 38 when including all anticipated levels of nonuniformity and system uncertainty.

Parametric and non-parametric approach for sensory RATA (Rate-All-That-Apply) method of ledre profile attributes

NASA Astrophysics Data System (ADS)

Hastuti, S.; Harijono; Murtini, E. S.; Fibrianto, K.

2018-03-01

This current study is aimed to investigate the use of parametric and non-parametric approach for sensory RATA (Rate-All-That-Apply) method. Ledre as Bojonegoro unique local food product was used as point of interest, in which 319 panelists were involved in the study. The result showed that ledre is characterized as easy-crushed texture, sticky in mouth, stingy sensation and easy to swallow. It has also strong banana flavour with brown in colour. Compared to eggroll and semprong, ledre has more variances in terms of taste as well the roll length. As RATA questionnaire is designed to collect categorical data, non-parametric approach is the common statistical procedure. However, similar results were also obtained as parametric approach, regardless the fact of non-normal distributed data. Thus, it suggests that parametric approach can be applicable for consumer study with large number of respondents, even though it may not satisfy the assumption of ANOVA (Analysis of Variances).

Conceptual design of initial opacity experiments on the national ignition facility

NASA Astrophysics Data System (ADS)

Heeter, R. F.; Bailey, J. E.; Craxton, R. S.; Devolder, B. G.; Dodd, E. S.; Garcia, E. M.; Huffman, E. J.; Iglesias, C. A.; King, J. A.; Kline, J. L.; Liedahl, D. A.; McKenty, P. W.; Opachich, Y. P.; Rochau, G. A.; Ross, P. W.; Schneider, M. B.; Sherrill, M. E.; Wilson, B. G.; Zhang, R.; Perry, T. S.

2017-02-01

Accurate models of X-ray absorption and re-emission in partly stripped ions are necessary to calculate the structure of stars, the performance of hohlraums for inertial confinement fusion and many other systems in high-energy-density plasma physics. Despite theoretical progress, a persistent discrepancy exists with recent experiments at the Sandia Z facility studying iron in conditions characteristic of the solar radiative-convective transition region. The increased iron opacity measured at Z could help resolve a longstanding issue with the standard solar model, but requires a radical departure for opacity theory. To replicate the Z measurements, an opacity experiment has been designed for the National Facility (NIF). The design uses established techniques scaled to NIF. A laser-heated hohlraum will produce X-ray-heated uniform iron plasmas in local thermodynamic equilibrium (LTE) at temperatures eV and electron densities 21~\\text{cm}-3$ . The iron will be probed using continuum X-rays emitted in a ps, diameter source from a 2 mm diameter polystyrene (CH) capsule implosion. In this design, of the NIF beams deliver 500 kJ to the mm diameter hohlraum, and the remaining directly drive the CH capsule with 200 kJ. Calculations indicate this capsule backlighter should outshine the iron sample, delivering a point-projection transmission opacity measurement to a time-integrated X-ray spectrometer viewing down the hohlraum axis. Preliminary experiments to develop the backlighter and hohlraum are underway, informing simulated measurements to guide the final design.

Distortion improvement of capsule endoscope image

NASA Astrophysics Data System (ADS)

Mang, Ou-Yang; Huang, Shih-Wei; Chen, Yung-Lin; Lin, Chu-Hsun; Lin, Tai-Yung; Kuo, Yi-Ting

2007-02-01

Distortion exists in the present capsule endoscope image resulting from the confined space and the wide-angle requirement [8]. Based on the previous two lens works, the optimal design had obtained that the field of view was about 86 degrees , and MTF was about 18% at 100 lp/mm, but distortion would go to -26%. It's difficult to add another lens on the 7mm optical path between the dome and imaging lenses for improving distortion. In order to overcome this problem, we intend to design the optical dome as another optical lens. The original dome is transparent and has an equal thickness, namely without refracting light almost. Our objective in this paper is to design the inner curvature of the dome and associate two aspheric imaging lenses in front of the CMOS sensors to advance the distortion with maintaining field of view and MTF under the same capsule volume. Furthermore, the paper proposes the real object plane of intestine is nearly a curved surface rather than an ideal flat surface. Taking those reasons under consideration, we design three imaging lenses with curved object plane and obtain the field of view is about 86 degrees , MTF is about 26% at 100 lp/mm, and the distortion improve to -7.5%. Adding the dome lens is not only to enhance the image quality, but also to maintain the tiny volume requirement.

Numerical prediction of 3-D ejector flows

NASA Technical Reports Server (NTRS)

Roberts, D. W.; Paynter, G. C.

1979-01-01

The use of parametric flow analysis, rather than parametric scale testing, to support the design of an ejector system offers a number of potential advantages. The application of available 3-D flow analyses to the design ejectors can be subdivided into several key elements. These are numerics, turbulence modeling, data handling and display, and testing in support of analysis development. Experimental and predicted jet exhaust for the Boeing 727 aircraft are examined.

Developing Parametric Models for the Assembly of Machine Fixtures for Virtual Multiaxial CNC Machining Centers

NASA Astrophysics Data System (ADS)

Balaykin, A. V.; Bezsonov, K. A.; Nekhoroshev, M. V.; Shulepov, A. P.

2018-01-01

This paper dwells upon a variance parameterization method. Variance or dimensional parameterization is based on sketching, with various parametric links superimposed on the sketch objects and user-imposed constraints in the form of an equation system that determines the parametric dependencies. This method is fully integrated in a top-down design methodology to enable the creation of multi-variant and flexible fixture assembly models, as all the modeling operations are hierarchically linked in the built tree. In this research the authors consider a parameterization method of machine tooling used for manufacturing parts using multiaxial CNC machining centers in the real manufacturing process. The developed method allows to significantly reduce tooling design time when making changes of a part’s geometric parameters. The method can also reduce time for designing and engineering preproduction, in particular, for development of control programs for CNC equipment and control and measuring machines, automate the release of design and engineering documentation. Variance parameterization helps to optimize construction of parts as well as machine tooling using integrated CAE systems. In the framework of this study, the authors demonstrate a comprehensive approach to parametric modeling of machine tooling in the CAD package used in the real manufacturing process of aircraft engines.

A study of an orbital radar mapping mission to Venus. Volume 3: Parametric studies and subsystem comparisons

NASA Technical Reports Server (NTRS)

1973-01-01

Parametric studies and subsystem comparisons for the orbital radar mapping mission to planet Venus are presented. Launch vehicle requirements and primary orbiter propulsion system requirements are evaluated. The systems parametric analysis indicated that orbit size and orientation interrelated with almost all of the principal spacecraft systems and influenced significantly the definition of orbit insertion propulsion requirements, weight in orbit capability, radar system design, and mapping strategy.

SHERPA Electromechanical Test Bed

NASA Technical Reports Server (NTRS)

Wason, John D.

2005-01-01

SHERPA (Strap-on High-altitude Entry Reconnaissance and Precision Aeromaneuver system) is a concept for low-cost-high-accuracy Martian reentry guidance for small scout-class missions with a capsule diameter of approximately 1 meter. This system uses moving masses to change the center of gravity of the capsule in order to control the lift generated by the controlled imbalance. This project involved designing a small proof-of-concept demonstration system that can be used to test the concept through bench-top testing, hardware-in-the-loop testing, and eventually through a drop test from a helicopter. This project has focused on the Mechatronic design aspects of the system including the mechanical, electrical, computer, and low-level control of the concept demonstration system.

Multidisciplinary Design Techniques Applied to Conceptual Aerospace Vehicle Design. Ph.D. Thesis Final Technical Report

NASA Technical Reports Server (NTRS)

Olds, John Robert; Walberg, Gerald D.

1993-01-01

Multidisciplinary design optimization (MDO) is an emerging discipline within aerospace engineering. Its goal is to bring structure and efficiency to the complex design process associated with advanced aerospace launch vehicles. Aerospace vehicles generally require input from a variety of traditional aerospace disciplines - aerodynamics, structures, performance, etc. As such, traditional optimization methods cannot always be applied. Several multidisciplinary techniques and methods were proposed as potentially applicable to this class of design problem. Among the candidate options are calculus-based (or gradient-based) optimization schemes and parametric schemes based on design of experiments theory. A brief overview of several applicable multidisciplinary design optimization methods is included. Methods from the calculus-based class and the parametric class are reviewed, but the research application reported focuses on methods from the parametric class. A vehicle of current interest was chosen as a test application for this research. The rocket-based combined-cycle (RBCC) single-stage-to-orbit (SSTO) launch vehicle combines elements of rocket and airbreathing propulsion in an attempt to produce an attractive option for launching medium sized payloads into low earth orbit. The RBCC SSTO presents a particularly difficult problem for traditional one-variable-at-a-time optimization methods because of the lack of an adequate experience base and the highly coupled nature of the design variables. MDO, however, with it's structured approach to design, is well suited to this problem. The result of the application of Taguchi methods, central composite designs, and response surface methods to the design optimization of the RBCC SSTO are presented. Attention is given to the aspect of Taguchi methods that attempts to locate a 'robust' design - that is, a design that is least sensitive to uncontrollable influences on the design. Near-optimum minimum dry weight solutions are determined for the vehicle. A summary and evaluation of the various parametric MDO methods employed in the research are included. Recommendations for additional research are provided.

Cluster Development Test 2: An Assessment of a Failed Test

NASA Technical Reports Server (NTRS)

Machin, Ricardo A.; Evans, Carol T.

2009-01-01

On 31 July 2008 the National Aeronautics and Space Administration Crew Exploration Vehicle Parachute Assembly System team conducted the final planned cluster test of the first generation parachute recovery system design. The two primary test objectives were to demonstrate the operation of the complete parachute system deployed from a full scale capsule simulator and to demonstrate the test technique of separating the capsule simulator from the Low Velocity Air Drop pallet used to extract the test article from a United States Air Force C-17 aircraft. The capsule simulator was the Parachute Test Vehicle with an accurate heat shield outer mold line and forward bay compartment of the Crew Exploration Vehicle Command Module. The Parachute Test Vehicle separated cleanly from the pallet following extraction, but failed to reach test conditions resulting in the failure of the test and the loss of the test assets. No personnel were injured. This paper will discuss the design of the test and the findings of the team that investigated the test, including a discussion of what were determined to be the root causes of the failure.

Design and evaluation of self-emulsifying drug delivery systems of Rhizoma corydalis decumbentis extracts.

PubMed

Ma, Hongda; Zhao, Qingchun; Wang, Yongjun; Guo, Tao; An, Ye; Shi, Guobing

2012-10-01

To improve the dissolution and oral absorption of Rhizoma corydalis decumbentis extracts (RCDE), a famous traditional Chinese herbal medicine which contains poorly water-soluble active components, self-emulsifying drug-delivery systems (SEDDS) were designed and evaluated in vitro and in vivo for the first time. Six formulations were prepared, and pseudoternary phase diagrams were constructed to identify the efficient self-emulsication region through the modified visual test. The optimized formulation consisted of 45% Solutol, 40% ethyl oleate, and 15% Transcutol P. The mean droplet size distribution of the optimized SEDDS was less than 100 nm. The release of the active components (protopine and tetrahydropalmatine) in RCDE from SEDDS hard gelatin capsules showed a faster rate in comparison with the commercial tablets. After oral administration of RCDE SEDDS capsules or the commercial tablets to fasted rats, the relative bioavailability of SEDDS capsules for protopine and tetrahydropalmatine was 209.7% and 133.2% compared with commercial tablets, respectively. Our study indicated that SEDDS has the potential to improve the bioavailability of traditional Chinese medicines, in which many active components are hydrophobic, such as RCDE.

Design and control of 2-axis tilting actuator for endoscope using ionic polymer metal composites

NASA Astrophysics Data System (ADS)

Kim, Sung-Joo; Kim, Chul-Jin; Park, No-Cheol; Yang, Hyun-Seok; Park, Young-Pil

2009-03-01

In field of endoscopy, in order to overcome limitation in conventional endoscopy, capsule endoscope has been developed and has been recently applied in medical field in hospital. However, since capsule endoscope moves passively through GI tract by peristalsis, it is not able to control direction of head including camera. It is possible to miss symptoms of disease. Therefore, in this thesis, 2-Axis Tilting Actuator for Endoscope, based on Ionic Polymer Metal Composites (IPMC), is presented. In order to apply to capsule endoscope, the actuator material should satisfy a size, low energy consumption and low working voltage. Since IPMC is emerging material that exhibits a large bending deflection at low voltage, consume low energy and it can be fabricated in any size or any shape, IPMC are selected as an actuator. The system tilts camera module of endoscope to reduce invisible area of the intestines and a goal of tilting angle is selected to be an angle of 5 degrees for each axis. In order to control tiling angle, LQR controller and the full order observer is designed.

Capsule Performance Optimization for the National Ignition Facility

NASA Astrophysics Data System (ADS)

Landen, Otto

2009-11-01

The overall goal of the capsule performance optimization campaign is to maximize the probability of ignition by experimentally correcting for likely residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. This will be accomplished using a variety of targets that will set key laser, hohlraum and capsule parameters to maximize ignition capsule implosion velocity, while minimizing fuel adiabat, core shape asymmetry and ablator-fuel mix. The targets include high Z re-emission spheres setting foot symmetry through foot cone power balance [1], liquid Deuterium-filled ``keyhole'' targets setting shock speed and timing through the laser power profile [2], symmetry capsules setting peak cone power balance and hohlraum length [3], and streaked x-ray backlit imploding capsules setting ablator thickness [4]. We will show how results from successful tuning technique demonstration shots performed at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design meet the required sensitivity and accuracy. We will also present estimates of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors, and show that these get reduced after a number of shots and iterations to meet an acceptable level of residual uncertainty. Finally, we will present results from upcoming tuning technique validation shots performed at NIF at near full-scale. Prepared by LLNL under Contract DE-AC52-07NA27344. [4pt] [1] E. Dewald, et. al. Rev. Sci. Instrum. 79 (2008) 10E903. [0pt] [2] T.R. Boehly, et. al., Phys. Plasmas 16 (2009) 056302. [0pt] [3] G. Kyrala, et. al., BAPS 53 (2008) 247. [0pt] [4] D. Hicks, et. al., BAPS 53 (2008) 2.

Pilot Study to Evaluate Compliance and Tolerability of Cranberry Capsules in Pregnancy for the Prevention of Asymptomatic Bacteriuria

PubMed Central

Rumney, Pamela J.; Hindra, Sasha; Guzman, Lizette; Le, Jennifer; Nageotte, Michael

2015-01-01

Abstract Objectives: To evaluate the compliance with and tolerability of daily cranberry capsule ingestion for asymptomatic bacteriuria (ASB) prevention in pregnancy. Design: A total of 49 pregnant women from two sites were randomly assigned to cranberry or matching placebo, two doses daily, at gestational ages less than 16 weeks. Patients were followed monthly for urinary tract infection until delivery. Up to seven monthly visits were scheduled for each patient. Delivery data were evaluated. Results: Of 38 evaluable patients, the mean compliance rate over the study period was 82% (range, 20%–100%). This compliance rate and the 74% of patients achieving good (≥75%) compliance were similar between those who received cranberry capsules and placebo. Compliance evaluation revealed that most patients stopped capsule consumption after 34–38 weeks of participation. Multivariate logistic regression and longitudinal analysis showed a significant interaction time effect with cranberry treatment. However, cranberry consumption was not a significant predictor of gastrointestinal intolerance or study withdrawal. Although 30% of patients withdrew for various reasons, only 1 withdrew because of intolerance to the cranberry capsules. Loss to follow-up was mostly due to provider change (9 of 49 [18%]) and therapy disinterest (4 of 49 [8%]). Seven cases of ASB occurred in 5 patients: 2 of 24 (8%) in the cranberry group and 3 of 25 (12%) in the placebo group. No cases of cystitis or pyelonephritis were observed. Conclusion: One third of pregnant women could not complete the study protocol for various reasons. Compliance with and tolerability of cranberry capsule ingestion appear good; these capsules provide a potentially effective means to prevent ASB in pregnancy. Further studies with large samples are necessary to confirm the findings. PMID:26535612

Wetted foam liquid fuel ICF target experiments

DOE PAGES

Olson, R. E.; Leeper, R. J.; Yi, S. A.; ...

2016-05-26

We are developing a new NIF experimental platform that employs wetted foam liquid fuel layer ICF capsules. We will use the liquid fuel layer capsules in a NIF sub-scale experimental campaign to explore the relationship between hot spot convergence ratio (CR) and the predictability of hot spot formation. DT liquid layer ICF capsules allow for flexibility in hot spot CR via the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density. Our hypothesis is that the predictive capability of hot spot formation is robust and 1D-like for a relatively low CR hot spot (CR~15), but will becomemore » less reliable as hot spot CR is increased to CR>20. Simulations indicate that backing off on hot spot CR is an excellent way to reduce capsule instability growth and to improve robustness to low-mode x-ray flux asymmetries. In the initial experiments, we will test our hypothesis by measuring hot spot size, neutron yield, ion temperature, and burn width to infer hot spot pressure and compare to predictions for implosions with hot spot CR's in the range of 12 to 25. Larger scale experiments are also being designed, and we will advance from sub-scale to full-scale NIF experiments to determine if 1D-like behavior at low CR is retained as the scale-size is increased. The long-term objective is to develop a liquid fuel layer ICF capsule platform with robust thermonuclear burn, modest CR, and significant α-heating with burn propagation.« less

Development of Naphthalene PLIF for Visualizing Ablation Products From a Space Capsule Heat Shield

NASA Technical Reports Server (NTRS)

Combs, C. S.; Clemens, N. T.; Danehy, P. M.

2014-01-01

The Orion Multi-Purpose Crew Vehicle (MPCV) will use an ablative heat shield. To better design this heat shield and others that will undergo planetary entry, an improved understanding of the ablation process would be beneficial. Here, a technique developed at The University of Texas at Austin that uses planar laser-induced fluorescence (PLIF) of a low-temperature sublimating ablator (naphthalene) to enable visualization of the ablation products in a hypersonic flow is applied. Although high-temperature ablation is difficult and expensive to recreate in a laboratory environment, low-temperature sublimation creates a limited physics problem that can be used to explore ablation-product transport in a hypersonic flow-field. In the current work, a subscale capsule reentry vehicle model with a solid naphthalene heat shield has been tested in a Mach 5 wind tunnel. The PLIF technique provides images of the spatial distribution of sublimated naphthalene in the heat-shield boundary layer, separated shear layer, and backshell recirculation region. Visualizations of the capsule shear layer using both naphthalene PLIF and Schlieren imaging compared favorably. PLIF images have shown high concentrations of naphthalene in the capsule separated flow region, intermittent turbulent structures on the heat shield surface, and interesting details of the capsule shear layer structure. It was shown that, in general, the capsule shear layer appears to be more unsteady at lower angels of attack. The PLIF images demonstrated that during a wind tunnel run, as the model heated up, the rate of naphthalene ablation increased, since the PLIF signal increased steadily over the course of a run. Additionally, the shear layer became increasingly unsteady over the course of a wind tunnel run, likely because of increased surface roughness but also possibly because of the increased blowing. Regions with a relatively low concentration of naphthalene were also identified in the capsule backshell recirculation region and are most likely the result of cross-flow-induced vortices on the capsule afterbody.

Noncontact optical measurement of lens capsule thickness ex vivo

NASA Astrophysics Data System (ADS)

Ziebarth, Noel M.; Manns, Fabrice; Uhlhorn, Stephen; Parel, Jean-Marie

2004-07-01

Purpose: To design a non-contact optical system to measure lens capsule thickness in cadaver eyes. Methods: The optical system uses a 670nm laser beam delivered to a single-mode fiber coupler. The output of the fiber coupler is focused onto the tissue using an aspheric lens (NA=0.68) mounted on a motorized translation stage. Light reflected from the sample is collected by the fiber coupler and sent to a silicon photodiode connected to a power meter. Peaks in the power signal are detected when the focal point of the aspheric lens coincides with the capsule boundaries. The capsule thickness is proportional to the distance between successive peaks. Anterior and posterior lens capsule thickness measurements were performed on 13 human, 10 monkey, and 34 New Zealand white rabbit lenses. The cadaver eyes were prepared for optical measurements by bonding a PMMA ring on the sclera. The posterior pole was sectioned, excess vitreous was removed, and the eye was placed on a Teflon slide. The cornea and iris were then sectioned. After the experiments, the lenses were excised, placed in 10% buffered formalin, and prepared for histology. Results: Central anterior lens capsule thickness was 9.4+/-2.9μm (human), 11.2+/-6.6μm (monkey), and 10.3+/-3.6μm (rabbit) optically and 14.9+/-1.6μm (human), 17.7+/-4.9μm (monkey), and 12.6+/-2.3μm (rabbit) histologically. The values for the central posterior capsule were 9.4+/-2.9μm (human), 6.6+/-2.5μm (monkey), and 7.9+/-2.3μm (rabbit) optically and 4.6+/-1.4μm (human), 4.5+/-1.2μm (monkey), and 5.7+/-1.7μm (rabbit) histologically. Conclusions: This study demonstrates that a non-contact optical system can successfully measure lens capsule thickness in cadaver eyes.

Efficiency optimization of wireless power transmission systems for active capsule endoscopes.

PubMed

Zhiwei, Jia; Guozheng, Yan; Jiangpingping; Zhiwu, Wang; Hua, Liu

2011-10-01

Multipurpose active capsule endoscopes have drawn considerable attention in recent years, but these devices continue to suffer from energy limitations. A wireless power supply system is regarded as a practical way to overcome the power shortage problem in such devices. This paper focuses on the efficiency optimization of a wireless energy supply system with size and safety constraints. A mathematical programming model in which these constraints are considered is proposed for transmission efficiency, optimal frequency and current, and overall system effectiveness. To verify the feasibility of the proposed method, we use a wireless active capsule endoscope as an illustrative example. The achieved efficiency can be regarded as an index for evaluating the system, and the proposed approach can be used to direct the design of transmitting and receiving coils.

KSC-2012-5577

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - Astronauts Mike Fossum and Cady Coleman, both in blue flight suits, look over the model capsule fit with rotor blades ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. NASA's Johnson Space Center Aerospace Engineer Jeff Hagen, right, fields questions about the project. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

KSC-2012-5578

NASA Image and Video Library

2012-09-20

CAPE CANAVERAL, Fla. - Astronauts Mike Fossum and Cady Coleman, both in blue flight suits, listen as NASA's Johnson Space Center Aerospace Engineer Jeff Hagen explains the rotor mechanism for a model capsule ahead of tests inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The design would give a capsule the stability and control of a helicopter, but would not be powered. Instead, the wind passing over the rotors as the capsule descends would make the blades turn, a process called auto-rotation. The intent is to give real spacecraft a soft landing with enough control that they could touch down anywhere in the world, whether it be a runway or parking lot. In other words, wherever a helicopter could land, a spacecraft could land, too. Photo credit: NASA/Kim Shiflett

Novel characterization of capsule x-ray drive at the National Ignition Facility.

PubMed

MacLaren, S A; Schneider, M B; Widmann, K; Hammer, J H; Yoxall, B E; Moody, J D; Bell, P M; Benedetti, L R; Bradley, D K; Edwards, M J; Guymer, T M; Hinkel, D E; Hsing, W W; Kervin, M L; Meezan, N B; Moore, A S; Ralph, J E

2014-03-14

Indirect drive experiments at the National Ignition Facility are designed to achieve fusion by imploding a fuel capsule with x rays from a laser-driven hohlraum. Previous experiments have been unable to determine whether a deficit in measured ablator implosion velocity relative to simulations is due to inadequate models of the hohlraum or ablator physics. ViewFactor experiments allow for the first time a direct measure of the x-ray drive from the capsule point of view. The experiments show a 15%-25% deficit relative to simulations and thus explain nearly all of the disagreement with the velocity data. In addition, the data from this open geometry provide much greater constraints on a predictive model of laser-driven hohlraum performance than the nominal ignition target.

Fracture toughness and Charpy impact properties of several RAFMS before and after irradiation in HFIR

NASA Astrophysics Data System (ADS)

Sokolov, M. A.; Tanigawa, H.; Odette, G. R.; Shiba, K.; Klueh, R. L.

2007-08-01

As part of the development of candidate reduced-activation ferritic steels for fusion applications, several steels, namely F82H, 9Cr-2WVTa steels and F82H weld metal, are being investigated in the joint DOE-JAEA collaboration program. Within this program, three capsules containing a variety of specimen designs were irradiated at two design temperatures in the ORNL High Flux Isotope Reactor (HFIR). Two capsules, RB-11J and RB-12J, were irradiated in the HFIR removable beryllium positions with europium oxide (Eu 2O 3) thermal neutron shields in place. Specimens were irradiated up to 5 dpa. Capsule JP25 was irradiated in the HFIR target position to 20 dpa. The design temperatures were 300 °C and 500 °C. Precracked third-sized V-notch Charpy (3.3 × 3.3 × 25.4 mm) and 0.18 T DC(T) specimens were tested to determine transition and ductile shelf fracture toughness before and after irradiation. The master curve methodology was applied to evaluate the fracture toughness transition temperature, T0. Irradiation induced shifts of T0 and reductions of JQ were compared with Charpy V-notch impact properties. Fracture toughness and Charpy shifts were also compared to hardening results.

Beryllium Ignition Targets for Indirect Drive NIF Experiments

NASA Astrophysics Data System (ADS)

Simakov, A. N.; Wilson, D. C.; Yi, S. A.; Kline, J. L.; Salmonson, J. D.; Clark, D. S.; Milovich, J. L.; Marinak, M. M.; Callahan, D. A.

2013-10-01

Current NIF plastic capsules are under-performing, and alternate ablators are being investigated. Beryllium presents an attractive option, since it has lower opacity and therefore higher ablation rate, pressure, and velocity. Previous NIF Be designs assumed significantly better hohlraum performance than recently observed (e.g., 7.5 vs. 15-17% of back-scattered power and 1.0 vs. 0.85 main pulse's power multipliers) and employed less accurate atomic configuration models than currently used (XSN vs. DCA), and thus an updated design is required. We present a new, Rev. 6 Be ignition target design that employs the full NIF capacity (1.8 MJ, 520 TW) and uses a standard 5.75 mm gold hohlraum with 1.5 mg/cm3 of helium gas fill. The 1051 μm capsule features 180 μm of layered copper-doped (with the maximum of 3 atom-%) Be ablator and 90 μm of cryogenic deuterium-tritium fuel. The peak implosion velocity of 367 μm/ns results in 4.1 keV of no-burn ion temperature, 1.6 and 1.9 g/cm2 of fuel and total areal densities, respectively, and 20.6 MJ of fusion yield. The capsule demonstrates robust performance with surface/interface roughnesses up to 1.6 times larger that Rev. 3 specs. Work supported by the US Department of Energy.

Simulations of super-ellipse hohlraum targets as a path to high neutron yields

NASA Astrophysics Data System (ADS)

Milovich, Jose; Amendt, Peter; Storm, Erik; Robey, Harry; Haan, Steve; Landen, Otto; Meezan, Nathan; Lindl, John

2017-10-01

Recently neutron yields in excess of 1016 have been achieved at the National Ignition Facility (NIF) using a low-density gas fill hohlraum and a subscale high-density-carbon capsule. The laser power used was near the current maximum level allowed on the inner cones of the NIF laser. While more energy can be extracted from the laser to provide additional improvement on the neutron yield, a more efficient design is desired. A new effort has begun to investigate alternatives to the current cylinder-shaped hohlraum for driving larger capsules (1.1 mm outer radius). If these new hohlraums can preserve the implosion symmetry, the additional absorbed energy is expected to provide a path to high neutron yield and potential ignition. Super-ellipse hohlraums, a generalization of an earlier rugby hohlraum design, have the advantage of a larger waist diameter and reduced parasitic energy losses from the corners of cylindrical hohlraums while still being able to produce the required capsule drive at the current energy and power limits available at the NIF. We will present plausible designs of these hohlraums based on the Lamé mathematical construction, and discuss their prospects to reach high neutron gains. Prepared by LLNL under Contract DE-AC52-07NA27344.

AGR-3/4 Irradiation Test Train Disassembly and Component Metrology First Look Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stempien, John Dennis; Rice, Francine Joyce; Harp, Jason Michael

2016-03-01

The AGR-3/4 experiment was designed to study fission product transport within graphitic matrix material and nuclear-grade graphite. To this end, this experiment consisted of 12 capsules, each fueled with 4 compacts containing UCO TRISO particles as driver fuel and 20 UCO designed-to-fail (DTF) fuel particles in each compact. The DTF fuel was fabricated with a thin pyrocarbon layer which was intended to fail during irradiation and provide a source of fission products. These fission products could then migrate through the compact and into the surrounding concentric rings of graphitic matrix material and/or nuclear graphite. Through post-irradiation examination (PIE) of themore » rings (including physical sampling and gamma scanning) fission product concentration profiles within the rings can be determined. These data can be used to elucidate fission product transport parameters (e.g. diffusion coefficients within the test materials) which will be used to inform and refine models of fission product transport. After irradiation in the Advanced Test Reactor (ATR) had been completed in April 2014, the AGR-3/4 experiment was shipped to the Hot Fuel Examination Facility (HFEF) at the Materials and Fuels Complex (MFC) for inspection, disassembly, and metrology. The AGR-3/4 test train was received at MFC in two separate shipments between February and April 2015. Visual examinations of the test train exterior did not indicate dimensional distortion, and only two small discolored areas were observed at the bottom of Capsules 8 and 9. No corresponding discoloration was found on the inside of these capsules, however. Prior to disassembly, the two test train sections were subject to analysis via the Precision Gamma Scanner (PGS), which did not indicate that any gross fuel relocation had occurred. A series of specialized tools (including clamps, cutters, and drills) had been designed and fabricated in order to carry out test train disassembly and recovery of capsule components (graphite rings and fuel compacts). This equipment performed well for separating each capsule in the test train and extracting the capsule components. Only a few problems were encountered. In one case, the outermost ring (the sink ring) was cracked during removal of the capsule through tubes. Although the sink ring will be analyzed in order to obtain a mass balance of fission products in the experiment, these cracks do not pose a major concern because the sink ring will not be analyzed in detail to obtain the spatial distribution of fission products. In Capsules 4 and 5, the compacts could not be removed from the inner rings. Strategies for removing the compacts are being evaluated. Sampling the inner rings with the compacts in-place is also an option. Dimensional measurements were made on the compacts, inner rings, outer rings, and sink rings. The diameters of all compacts decreased by 0.5 to 2.0 %. Generally, the extent of diametric shrinkage increased linearly with increasing neutron fluence. Most compact lengths also decreased. Compact lengths decreased with increasing fluence, reaching maximum shrinkage of about 0.9 % at a fast fluence of 4.0x10 25 n/m 2 E > 0.18 MeV. Above this fluence, the extent of length shrinkage appeared to decrease with fluence, and two compacts from Capsule 7 were found to have slightly increased in length (< 0.1 %) after a fluence of 5.2x10 25 n/m 2.« less

AGR-3/4 Irradiation Test Train Disassembly and Component Metrology First Look Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stempien, John Dennis; Rice, Francine Joyce; Harp, Jason Michael

The AGR-3/4 experiment was designed to study fission product transport within graphitic matrix material and nuclear-grade graphite. To this end, this experiment consisted of 12 capsules, each fueled with 4 compacts containing UCO TRISO particles as driver fuel and 20 UCO designed-to-fail (DTF) fuel particles in each compact. The DTF fuel was fabricated with a thin pyrocarbon layer which was intended to fail during irradiation and provide a source of fission products. These fission products could then migrate through the compact and into the surrounding concentric rings of graphitic matrix material and/or nuclear graphite. Through post-irradiation examination (PIE) of themore » rings (including physical sampling and gamma scanning) fission product concentration profiles within the rings can be determined. These data can be used to elucidate fission product transport parameters (e.g. diffusion coefficients within the test materials) which will be used to inform and refine models of fission product transport. After irradiation in the Advanced Test Reactor (ATR) had been completed in April 2014, the AGR-3/4 experiment was shipped to the Hot Fuel Examination Facility (HFEF) at the Materials and Fuels Complex (MFC) for inspection, disassembly, and metrology. The AGR-3/4 test train was received at MFC in two separate shipments between February and April 2015. Visual examinations of the test train exterior did not indicate dimensional distortion, and only two small discolored areas were observed at the bottom of Capsules 8 and 9. No corresponding discoloration was found on the inside of these capsules, however. Prior to disassembly, the two test train sections were subject to analysis via the Precision Gamma Scanner (PGS), which did not indicate that any gross fuel relocation had occurred. A series of specialized tools (including clamps, cutters, and drills) had been designed and fabricated in order to carry out test train disassembly and recovery of capsule components (graphite rings and fuel compacts). This equipment performed well for separating each capsule in the test train and extracting the capsule components. Only a few problems were encountered. In one case, the outermost ring (the sink ring) was cracked during removal of the capsule through tubes. Although the sink ring will be analyzed in order to obtain a mass balance of fission products in the experiment, these cracks do not pose a major concern because the sink ring will not be analyzed in detail to obtain the spatial distribution of fission products. In Capsules 4 and 5, the compacts could not be removed from the inner rings. Strategies for removing the compacts are being evaluated. Sampling the inner rings with the compacts in-place is also an option. Dimensional measurements were made on the compacts, inner rings, outer rings, and sink rings. The diameters of all compacts decreased by 0.5 to 2.0 %. Generally, the extent of diametric shrinkage increased linearly with increasing neutron fluence. Most compact lengths also decreased. Compact lengths decreased with increasing fluence, reaching maximum shrinkage of about 0.9 % at a fast fluence of 4.0x1025 n/m2 E > 0.18 MeV. Above this fluence, the extent of length shrinkage appeared to decrease with fluence, and two compacts from Capsule 7 were found to have slightly increased in length (< 0.1 %) after a fluence of 5.2x1025 n/m2.« less

Reaction-in-flight neutrons as a signature for shell mixing in National Ignition Facility capsules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes, A. C.; Bradley, P. A.; Grim, G. P.

2010-01-15

Analytic calculations and results from computational simulations are presented that suggest that reaction-in-flight (RIF) neutrons can be used to diagnose mixing of the ablator shell material into the fuel in deuterium-tritium (DT) capsules designed for the National Ignition Facility (NIF) [J. A. Paisner, J. D. Boyes, S. A. Kumpan, W. H. Lowdermilk, and M. S. Sorem, Laser Focus World 30, 75 (1994)]. Such mixing processes in NIF capsules are of fundamental physical interest and can have important effects on capsule performance, quenching the total thermonuclear yield. The sensitivity of RIF neutrons to hydrodynamical mixing arises through the dependence of RIFmore » production on charged-particle stopping lengths in the mixture of DT fuel and ablator material. Since the stopping power in the plasma is a sensitive function of the electron temperature and density, it is also sensitive to mix. RIF production scales approximately inversely with the degree of mixing taking place, and the ratio of RIF to down-scattered neutrons provides a measure of the mix fraction and/or the mixing length. For sufficiently high-yield capsules, where spatially resolved RIF images may be possible, neutron imaging could be used to map RIF images into detailed mix images.« less

Influence of Excipients and Spray Drying on the Physical and Chemical Properties of Nutraceutical Capsules Containing Phytochemicals from Black Bean Extract.

PubMed

Guajardo-Flores, Daniel; Rempel, Curtis; Gutiérrez-Uribe, Janet A; Serna-Saldívar, Sergio O

2015-12-03

Black beans (Phaseolus vulgaris L.) are a rich source of flavonoids and saponins with proven health benefits. Spray dried black bean extract powders were used in different formulations for the production of nutraceutical capsules with reduced batch-to-batch weight variability. Factorial designs were used to find an adequate maltodextrin-extract ratio for the spray-drying process to produce black bean extract powders. Several flowability properties were used to determine composite flow index of produced powders. Powder containing 6% maltodextrin had the highest yield (78.6%) and the best recovery of flavonoids and saponins (>56% and >73%, respectively). The new complexes formed by the interaction of black bean powder with maltodextrin, microcrystalline cellulose 50 and starch exhibited not only bigger particles, but also a rougher structure than using only maltodextrin and starch as excipients. A drying process prior to capsule production improved powder flowability, increasing capsule weight and reducing variability. The formulation containing 25.0% of maltodextrin, 24.1% of microcrystalline cellulose 50, 50% of starch and 0.9% of magnesium stearate produced capsules with less than 2.5% weight variability. The spray drying technique is a feasible technique to produce good flow extract powders containing valuable phytochemicals and low cost excipients to reduce the end-product variability.

A two-hop wireless power transfer system with an efficiency-enhanced power receiver for motion-free capsule endoscopy inspection.

PubMed

Sun, Tianjia; Xie, Xiang; Li, Guolin; Gu, Yingke; Deng, Yangdong; Wang, Zhihua

2012-11-01

This paper presents a wireless power transfer system for a motion-free capsule endoscopy inspection. Conventionally, a wireless power transmitter in a specifically designed jacket has to be connected to a strong power source with a long cable. To avoid the power cable and allow patients to walk freely in a room, this paper proposes a two-hop wireless power transfer system. First, power is transferred from a floor to a power relay in the patient's jacket via strong coupling. Next, power is delivered from the power relay to the capsule via loose coupling. Besides making patients much more conformable, the proposed techniques eliminate the sources of reliability issues arisen from the moving cable and connectors. In the capsule, it is critical to enhance the power conversion efficiency. This paper develops a switch-mode rectifier (rectifying efficiency of 93.6%) and a power combination circuit (enhances combining efficiency by 18%). Thanks to the two-hop transfer mechanism and the novel circuit techniques, this system is able to transfer an average power of 24 mW and a peak power of 90 mW from the floor to a 13 mm × 27 mm capsule over a distance of 1 m with the maximum dc-to-dc power efficiency of 3.04%.

Parametric fMRI of paced motor responses uncovers novel whole-brain imaging biomarkers in spinocerebellar ataxia type 3.

PubMed

Duarte, João Valente; Faustino, Ricardo; Lobo, Mercês; Cunha, Gil; Nunes, César; Ferreira, Carlos; Januário, Cristina; Castelo-Branco, Miguel

2016-10-01

Machado-Joseph Disease, inherited type 3 spinocerebellar ataxia (SCA3), is the most common form worldwide. Neuroimaging and neuropathology have consistently demonstrated cerebellar alterations. Here we aimed to discover whole-brain functional biomarkers, based on parametric performance-level-dependent signals. We assessed 13 patients with early SCA3 and 14 healthy participants. We used a combined parametric behavioral/functional neuroimaging design to investigate disease fingerprints, as a function of performance levels, coupled with structural MRI and voxel-based morphometry. Functional magnetic resonance imaging (fMRI) was designed to parametrically analyze behavior and neural responses to audio-paced bilateral thumb movements at temporal frequencies of 1, 3, and 5 Hz. Our performance-level-based design probing neuronal correlates of motor coordination enabled the discovery that neural activation and behavior show critical loss of parametric modulation specifically in SCA3, associated with frequency-dependent cortico/subcortical activation/deactivation patterns. Cerebellar/cortical rate-dependent dissociation patterns could clearly differentiate between groups irrespective of grey matter loss. Our findings suggest functional reorganization of the motor network and indicate a possible role of fMRI as a tool to monitor disease progression in SCA3. Accordingly, fMRI patterns proved to be potential biomarkers in early SCA3, as tested by receiver operating characteristic analysis of both behavior and neural activation at different frequencies. Discrimination analysis based on BOLD signal in response to the applied parametric finger-tapping task significantly often reached >80% sensitivity and specificity in single regions-of-interest.Functional fingerprints based on cerebellar and cortical BOLD performance dependent signal modulation can thus be combined as diagnostic and/or therapeutic targets in hereditary ataxia. Hum Brain Mapp 37:3656-3668, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Competing collinear and noncollinear interactions in chirped quasi-phase-matched optical parametric amplifiers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Charbonneau-Lefort, Mathieu; Afeyan, Bedros; Fejer, M. M.

Chirped quasi-phase-matched optical parametric amplifiers (chirped QPM OPAs) are investigated experimentally. The measured collinear gain is constant over a broad bandwidth, which makes these devices attractive candidates for use in femtosecond amplifier systems. The experiment also shows that chirped QPM OPAs support noncollinear gain-guided modes. These modes can dominate the desired collinear gain and generate intense parametric fluorescence. Finally, design guidelines to mitigate these parasitic processes are discussed.

Parametric Amplification For Detecting Weak Optical Signals

NASA Technical Reports Server (NTRS)

Hemmati, Hamid; Chen, Chien; Chakravarthi, Prakash

1996-01-01

Optical-communication receivers of proposed type implement high-sensitivity scheme of optical parametric amplification followed by direct detection for reception of extremely weak signals. Incorporates both optical parametric amplification and direct detection into optimized design enhancing effective signal-to-noise ratios during reception in photon-starved (photon-counting) regime. Eliminates need for complexity of heterodyne detection scheme and partly overcomes limitations imposed on older direct-detection schemes by noise generated in receivers and by limits on quantum efficiencies of photodetectors.

A Passive Earth-Entry Capsule for Mars Sample Return

NASA Technical Reports Server (NTRS)

Mitcheltree, Robert A.; Kellas, Sotiris

1999-01-01

A combination of aerodynamic analysis and testing, aerothermodynamic analysis, structural analysis and testing, impact analysis and testing, thermal analysis, ground characterization tests, configuration packaging, and trajectory simulation are employed to determine the feasibility of an entirely passive Earth entry capsule for the Mars Sample Return mission. The design circumvents the potential failure modes of a parachute terminal descent system by replacing that system with passive energy absorbing material to cushion the Mars samples during ground impact. The suggested design utilizes a spherically blunted 45-degree half-angle cone forebody with an ablative heat shield. The primary structure is a hemispherical, composite sandwich enclosing carbon foam energy absorbing material. Though no demonstration test of the entire system is included, results of the tests and analysis presented indicate that the design is a viable option for the Mars Sample Return Mission.

Ultrasonically Absorptive Coatings for Hypersonic

DTIC Science & Technology

2008-05-13

UAC and TPS functions. To aid in the design of UAC with regular microstructure to be tested the CUBRC LENS I tunnel, parametric studies of the UAC-LFC...approaching the large-scale demonstration stage in the CUBRC LENS tunnel as well as fabrication of ceramic UAC samples integrated into TPS. Summary...integrate UAC and TPS functions. To aid in the design of UAC with regular microstructure to be tested the CUBRC LENS I tunnel, parametric studies of

Solid state SPS microwave generation and transmission study. Volume 1: Phase 2

NASA Technical Reports Server (NTRS)

Maynard, O. E.

1980-01-01

The solid state sandwich concept for Solar Power Station (SPS) was investigated. The design effort concentrated on the spacetenna, but did include some system analysis for parametric comparison reasons. The study specifically included definition and math modeling of basic solid state microwave devices, an initial conceptual subsystems and system design, sidelobe control and system selection, an assessment of selected system concept and parametric solid state microwave power transmission system data relevant to the SPS concept. Although device efficiency was not a goal, the sensitivities to design of this efficiency were parametrically treated. Sidelobe control consisted of various single step tapers, multistep tapers, and Gaussian tapers. A preliminary assessment of a hybrid concept using tubes and solid state is also included. There is a considerable amount of thermal analysis provided with emphasis on sensitivities to waste heat radiator form factor, emissivity, absorptivity, amplifier efficiency, material and junction temperature.

A parametric study of golf car and personal transport vehicle braking stability and their deficiencies.

PubMed

Seluga, Kristopher J; Baker, Lowell L; Ojalvo, Irving U

2009-07-01

This paper describes research and parametric analyses of braking effectiveness and directional stability for golf cars, personal transport vehicles (PTVs) and low speed vehicles (LSVs). It is shown that current designs, which employ brakes on only the rear wheels, can lead to rollovers if the brakes are applied while traveling downhill. After summarizing the current state of existing safety standards and brake system designs, both of which appear deficient from a safety perspective, a previously developed dynamic simulation model is used to identify which parameters have the greatest influence on the vehicles' yaw stability. The simulation results are then used to parametrically quantify which combination of these factors can lead to yaw induced rollover during hard braking. Vehicle velocity, steering input, path slope and tire friction are all identified as important parameters in determining braking stability, the effects of which on rollover propensity are presented graphically. The results further show that when vehicles are equipped with front brakes or four-wheel brakes, the probability of a yaw induced rollover is almost entirely eliminated. Furthermore, the parametric charts provided may be used as an aid in developing guidelines for golf car and PTV path design if rear brake vehicles are used.

Research on AutoCAD secondary development and function expansion based on VBA technology

NASA Astrophysics Data System (ADS)

Zhang, Runmei; Gu, Yehuan

2017-06-01

AutoCAD is the most widely used drawing tool among the similar design drawing products. In the process of drawing different types of design drawings of the same product, there are a lot of repetitive and single work contents. The traditional manual method uses a drawing software AutoCAD drawing graphics with low efficiency, high error rate and high input cost shortcomings and many more. In order to solve these problems, the design of the parametric drawing system of the hot-rolled I-beam (steel beam) cross-section is completed by using the VBA secondary development tool and the Access database software with large-capacity storage data, and the analysis of the functional extension of the plane drawing and the parametric drawing design in this paper. For the secondary development of AutoCAD functions, the system drawing work will be simplified and work efficiency also has been greatly improved. This introduction of parametric design of AutoCAD drawing system to promote the industrial mass production and related industries economic growth rate similar to the standard I-beam hot-rolled products.

Parametric Covariance Model for Horizon-Based Optical Navigation

NASA Technical Reports Server (NTRS)

Hikes, Jacob; Liounis, Andrew J.; Christian, John A.

2016-01-01

This Note presents an entirely parametric version of the covariance for horizon-based optical navigation measurements. The covariance can be written as a function of only the spacecraft position, two sensor design parameters, the illumination direction, the size of the observed planet, the size of the lit arc to be used, and the total number of observed horizon points. As a result, one may now more clearly understand the sensitivity of horizon-based optical navigation performance as a function of these key design parameters, which is insight that was obscured in previous (and nonparametric) versions of the covariance. Finally, the new parametric covariance is shown to agree with both the nonparametric analytic covariance and results from a Monte Carlo analysis.

Parametric Model of an Aerospike Rocket Engine

NASA Technical Reports Server (NTRS)

Korte, J. J.

2000-01-01

A suite of computer codes was assembled to simulate the performance of an aerospike engine and to generate the engine input for the Program to Optimize Simulated Trajectories. First an engine simulator module was developed that predicts the aerospike engine performance for a given mixture ratio, power level, thrust vectoring level, and altitude. This module was then used to rapidly generate the aerospike engine performance tables for axial thrust, normal thrust, pitching moment, and specific thrust. Parametric engine geometry was defined for use with the engine simulator module. The parametric model was also integrated into the iSIGHTI multidisciplinary framework so that alternate designs could be determined. The computer codes were used to support in-house conceptual studies of reusable launch vehicle designs.

Parametric Model of an Aerospike Rocket Engine

NASA Technical Reports Server (NTRS)

Korte, J. J.

2000-01-01

A suite of computer codes was assembled to simulate the performance of an aerospike engine and to generate the engine input for the Program to Optimize Simulated Trajectories. First an engine simulator module was developed that predicts the aerospike engine performance for a given mixture ratio, power level, thrust vectoring level, and altitude. This module was then used to rapidly generate the aerospike engine performance tables for axial thrust, normal thrust, pitching moment, and specific thrust. Parametric engine geometry was defined for use with the engine simulator module. The parametric model was also integrated into the iSIGHT multidisciplinary framework so that alternate designs could be determined. The computer codes were used to support in-house conceptual studies of reusable launch vehicle designs.

Parametric Modeling for Fluid Systems

NASA Technical Reports Server (NTRS)

Pizarro, Yaritzmar Rosario; Martinez, Jonathan

2013-01-01

Fluid Systems involves different projects that require parametric modeling, which is a model that maintains consistent relationships between elements as is manipulated. One of these projects is the Neo Liquid Propellant Testbed, which is part of Rocket U. As part of Rocket U (Rocket University), engineers at NASA's Kennedy Space Center in Florida have the opportunity to develop critical flight skills as they design, build and launch high-powered rockets. To build the Neo testbed; hardware from the Space Shuttle Program was repurposed. Modeling for Neo, included: fittings, valves, frames and tubing, between others. These models help in the review process, to make sure regulations are being followed. Another fluid systems project that required modeling is Plant Habitat's TCUI test project. Plant Habitat is a plan to develop a large growth chamber to learn the effects of long-duration microgravity exposure to plants in space. Work for this project included the design and modeling of a duct vent for flow test. Parametric Modeling for these projects was done using Creo Parametric 2.0.

Brayton Power Conversion System Parametric Design Modelling for Nuclear Electric Propulsion

NASA Technical Reports Server (NTRS)

Ashe, Thomas L.; Otting, William D.

1993-01-01

The parametrically based closed Brayton cycle (CBC) computer design model was developed for inclusion into the NASA LeRC overall Nuclear Electric Propulsion (NEP) end-to-end systems model. The code is intended to provide greater depth to the NEP system modeling which is required to more accurately predict the impact of specific technology on system performance. The CBC model is parametrically based to allow for conducting detailed optimization studies and to provide for easy integration into an overall optimizer driver routine. The power conversion model includes the modeling of the turbines, alternators, compressors, ducting, and heat exchangers (hot-side heat exchanger and recuperator). The code predicts performance to significant detail. The system characteristics determined include estimates of mass, efficiency, and the characteristic dimensions of the major power conversion system components. These characteristics are parametrically modeled as a function of input parameters such as the aerodynamic configuration (axial or radial), turbine inlet temperature, cycle temperature ratio, power level, lifetime, materials, and redundancy.

Parametric Cost Models for Space Telescopes

NASA Technical Reports Server (NTRS)

Stahl, H. Philip; Henrichs, Todd; Dollinger, Courtney

2010-01-01

Multivariable parametric cost models for space telescopes provide several benefits to designers and space system project managers. They identify major architectural cost drivers and allow high-level design trades. They enable cost-benefit analysis for technology development investment. And, they provide a basis for estimating total project cost. A survey of historical models found that there is no definitive space telescope cost model. In fact, published models vary greatly [1]. Thus, there is a need for parametric space telescopes cost models. An effort is underway to develop single variable [2] and multi-variable [3] parametric space telescope cost models based on the latest available data and applying rigorous analytical techniques. Specific cost estimating relationships (CERs) have been developed which show that aperture diameter is the primary cost driver for large space telescopes; technology development as a function of time reduces cost at the rate of 50% per 17 years; it costs less per square meter of collecting aperture to build a large telescope than a small telescope; and increasing mass reduces cost.

History of Road Design Standards in LADOTD : Research Project Capsule

DOT National Transportation Integrated Search

2012-10-01

According to the Louisiana Statewide Transportation Plan, Louisianas highway : network is comprised of over 60,000 miles, of which over 16,000 miles are : maintained by the state. The roadways were designed and constructed : according to the desig...

Subsonic Dynamics of Stardust Sample Return Capsule

NASA Technical Reports Server (NTRS)

Mitcheltree, Robert A.; Fremaux, Charles M.

1997-01-01

Subsonic dynamic stability tests performed in the NASA Langley 20-Foot Vertical Spin-Tunnel on a 0.238 scale model of the Stardust Sample Return Capsule are discussed. The tests reveal that the blunted 60 degree half-angle cone capsule is dynamically unstable at low subsonic conditions due to the aft location of the center-of-gravity (0.351 body diameters back from the nose). The divergent behavior of the capsule continued when the center-of-gravity was moved to 0.337 and 0.313 body diameters back from the nose. When the center-of-gravity was moved further forward to 0.290 body diameters back from the nose, the vehicle established itself in a limit cycle with amplitude around 10 degrees. Two afterbody modifications were examined which proved unsuccessful in alleviating the instability of the original design. Finally, the addition of different sized parachutes was examined as a means to stabilize the vehicle. The parachute tests indicate that a parachute with equivalent full scale drag area of at least 2.24 ft. is necessary to assure large perturbations are damped.

Dynamics of tether-assisted reentry vehicle systems

NASA Astrophysics Data System (ADS)

Zhu, Renzhang; Misra, A. K.; Lin, Huabao

The dynamics of tether-assisted reentry of a capsule is considered in this paper. A major advantage in tethered-assisted reentry is the ability to replace a retro-rocket by a tether. In this reentry procedure, a capsule is deployed down to a design altitude near the local vertical, and at an appropriate time the capsule is disconnected from the tether and enters into a reentry trajectory. In addition to static release, swing release is also considered in this paper. Three deployment schemes appropriate for swing release are considered. A two-stage accelerated-exponential/decelerated-exponential deployment appears to be the best of the three. In comparison with static release, for the same duration of return, this swing release can lead to about 22 percent reduction in tether length at the cost of an increase in tension in the tether by only 8 to 12 percent, and thus, it could decrease the tether mass launched into space. The paper analyzes the detailed dynamics of the tethered system before release as well as the reentry dynamics of the capsule after release along with the heat generated during reentry.

Light collection optimization for composite photoanode in dye-sensitized solar cells: Towards higher efficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, X. Z.; Shen, W. Z., E-mail: wzshen@sjtu.edu.cn; Laboratory of Condensed Matter Spectroscopy and Opto-Electronic Physics, and Key Laboratory of Artificial Structures and Quantum Control

2015-06-14

Composite photoanode comprising nanoparticles and one-dimensional (1D) nanostructure is a promising alternative to conventional photoanode for dye-sensitized solar cells (DSCs). Besides fast electron transport channels, the 1D nanostructure also plays as light scattering centers. Here, we theoretically investigate the light scattering properties of capsule-shaped 1D nanostructure and their influence on the light collection of DSCs. It is found that the far-field light scattering of a single capsule depends on its volume, shape, and orientation: capsules with bigger equivalent spherical diameter, smaller aspect ratio, and horizontal orientation demonstrate stronger light scattering especially at large scattering angle. Using Monte Carlo approach, wemore » simulated and optimized the light harvesting efficiency of the cell. Two multilayer composite photoanodes containing orderly or randomly oriented capsules are proposed. DSCs composed of these two photoanodes are promising for higher efficiencies because of their efficient light collection and superior electron collection. These results will provide practical guidance to the design and optimization of the photoanodes for DSCs.« less

Lessons learned from the recovered heatshield of the USERS REV capsule

NASA Astrophysics Data System (ADS)

Yamada, Tetsuya; Matsuda, Seiji; Okuyama, Keiichi; Ishii, Nobuaki

2008-01-01

The USERS Reentry Vehicle (REV) capsule carried out reentry flight from the low earth orbit and was successfully recovered on the sea in May, 2003. This paper presents the post-flight analysis of the recovered heatshield of REV capsule and summarizes the lessons learned. REV capsule, totally about 670 kg, has the combined shape of the nose hemisphere and the rear cone part, and its size is about 1.5 m in diameter and 1.9 m in length. REV is thermally protected against the aerodynamic heating by the carbon phenolic ablator heatshield. The recovered REV heatshield was scrutinized based on the outside aspect and the cross-sections. In general, the temperature profiles of the heatshield have been compared between the flight data and the prediction. The origin of the surface shallow cracks and slight delamination observed in the heatshield have been investigated based on the flight data and taking account of the ablator internal pyrolysis gas pressure, the thermal stress, and the allowable stress. The heatshield has proven to satisfy thermal protection requirements, and the validity of the designing has been confirmed.

AGR-5/6/7 Irradiation Test Predictions using PARFUME

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skerjanc, William F.

PARFUME, (PARticle FUel ModEl) a fuel performance modeling code used for high temperature gas-cooled reactors (HTGRs), was used to model the Advanced Gas Reactor (AGR)-5/6/7 irradiation test using predicted physics and thermal hydraulics data. The AGR-5/6/7 test consists of the combined fifth, sixth, and seventh planned irradiations of the AGR Fuel Development and Qualification Program. The AGR-5/6/7 test train is a multi-capsule, instrumented experiment that is designed for irradiation in the 133.4-mm diameter north east flux trap (NEFT) position of Advanced Test Reactor (ATR). Each capsule contains compacts filled with uranium oxycarbide (UCO) unaltered fuel particles. This report documents themore » calculations performed to predict the failure probability of tristructural isotropic (TRISO)-coated fuel particles during the AGR-5/6/7 experiment. In addition, this report documents the calculated source term from the driver fuel. The calculations include modeling of the AGR-5/6/7 irradiation that is scheduled to occur from October 2017 to April 2021 over a total of 13 ATR cycles, including nine normal cycles and four Power Axial Locator Mechanism (PALM) cycle for a total between 500 – 550 effective full power days (EFPD). The irradiation conditions and material properties of the AGR-5/6/7 test predicted zero fuel particle failures in Capsules 1, 2, and 4. Fuel particle failures were predicted in Capsule 3 due to internal particle pressure. These failures were predicted in the highest temperature compacts. Capsule 5 fuel particle failures were due to inner pyrolytic carbon (IPyC) cracking causing localized stresses concentrations in the SiC layer. This capsule predicted the highest particle failures due to the lower irradiation temperature. In addition, shrinkage of the buffer and IPyC layer during irradiation resulted in formation of a buffer-IPyC gap. The two capsules at the two ends of the test train, Capsules 1 and 5 experienced the smallest buffer-IPyC gap formation due to the lower irradiation fluences and temperatures. Capsule 3 experienced the largest buffer-IPyC gap formation of just under 24 µm. The release fraction of fission products Ag, Cs, and Sr silver (Ag), cesium (Cs), and strontium (Sr) vary depending on capsule location and irradiation temperature. The maximum release fraction of Ag occurs in Capsule 3, reaching up to 84.8% for the TRISO fuel particles. The release fraction of the other two fission products, Cs and Sr are much smaller and, in most cases, less than 1%. The notable exception is again in Capsule 3, where the release fraction for Cs and Sr reach up to 9.7% and 19.1%, respectively.« less

A linear parameter-varying multiobjective control law design based on youla parametrization for a flexible blended wing body aircraft

NASA Astrophysics Data System (ADS)

Demourant, F.; Ferreres, G.

2013-12-01

This article presents a methodology for a linear parameter-varying (LPV) multiobjective flight control law design for a blended wing body (BWB) aircraft and results. So, the method is a direct design of a parametrized control law (with respect to some measured flight parameters) through a multimodel convex design to optimize a set of specifications on the full-flight domain and different mass cases. The methodology is based on the Youla parameterization which is very useful since closed loop specifications are affine with respect to Youla parameter. The LPV multiobjective design method is detailed and applied to the BWB flexible aircraft example.

Reusable Launch Vehicle Tank/Intertank Sizing Trade Study

NASA Technical Reports Server (NTRS)

Dorsey, John T.; Myers, David E.; Martin, Carl J.

2000-01-01

A tank and intertank sizing tool that includes effects of major design drivers, and which allows parametric studies to be performed, has been developed and calibrated against independent representative results. Although additional design features, such as bulkheads and field joints, are not currently included in the process, the improved level of fidelity has allowed parametric studies to be performed which have resulted in understanding of key tank and intertank design drivers, design sensitivities, and definition of preferred design spaces. The sizing results demonstrated that there were many interactions between the configuration parameters of internal/external payload, vehicle fineness ratio (half body angle), fuel arrangement (LOX-forward/LOX-aft), number of tanks, and tank shape/arrangement (number of lobes).

Numerical Study of Flow Augmented Thermal Management for Entry and Re-Entry Environments

NASA Technical Reports Server (NTRS)

Cheng, Gary C.; Neroorkar, Kshitij D.; Chen, Yen-Sen; Wang, Ten-See; Daso, Endwell O.

2007-01-01

The use of a flow augmented thermal management system for entry and re-entr environments is one method for reducing heat and drag loads. This concept relies on jet penetration from supersonic and hypersonic counterflowing jets that could significantly weaken and disperse the shock-wave system of the spacecraft flow field. The objective of this research effort is to conduct parametric studies of the supersonic flow over a 2.6% scale model of the Apollo capsule, with and without the counterflowing jet, using time-accurate and steady-state computational fluid dynamics simulations. The numerical studies, including different freestream Mach number angle of attack counterflowing jet mass flow rate, and nozzle configurations, were performed to examine their effect on the drag and beat loads and to explore the counternowing jet condition. The numerical results were compared with the test data obtained from transonic blow-down wind-tunnel experiments conducted independently at NASA MSFC.

Global, Multi-Objective Trajectory Optimization With Parametric Spreading

NASA Technical Reports Server (NTRS)

Vavrina, Matthew A.; Englander, Jacob A.; Phillips, Sean M.; Hughes, Kyle M.

2017-01-01

Mission design problems are often characterized by multiple, competing trajectory optimization objectives. Recent multi-objective trajectory optimization formulations enable generation of globally-optimal, Pareto solutions via a multi-objective genetic algorithm. A byproduct of these formulations is that clustering in design space can occur in evolving the population towards the Pareto front. This clustering can be a drawback, however, if parametric evaluations of design variables are desired. This effort addresses clustering by incorporating operators that encourage a uniform spread over specified design variables while maintaining Pareto front representation. The algorithm is demonstrated on a Neptune orbiter mission, and enhanced multidimensional visualization strategies are presented.

Parametric and Generative Design Techniques for Digitalization in Building Industry: the Case Study of Glued- Laminated-Timber Industry

NASA Astrophysics Data System (ADS)

Pasetti Monizza, G.; Matt, D. T.; Benedetti, C.

2016-11-01

According to Wortmann classification, the Building Industry (BI) can be defined as engineer-to-order (ETO) industry: the engineering-process starts only when an order is acquired. This definition implies that every final product (building) is almost unique’ and processes cannot be easily standardized or automated. Because of this, BI is one of the less efficient industries today’ mostly leaded by craftsmanship. In the last years’ several improvements in process efficiency have been made focusing on manufacturing and installation processes only. In order to improve the efficiency of design and engineering processes as well, the scientific community agrees that the most fruitful strategy should be Front-End Design (FED). Nevertheless, effective techniques and tools are missing. This paper discusses outcomes of a research activity that aims at highlighting whether Parametric and Generative Design techniques allow reducing wastes of resources and improving the overall efficiency of the BI, by pushing the Digitalization of design and engineering processes of products. Focusing on the Glued-Laminated-Timber industry, authors will show how Parametric and Generative Design techniques can be introduced in a standard supply-chain system, highlighting potentials and criticism on the supply-chain system as a whole.

Robust Control Design for Uncertain Nonlinear Dynamic Systems

NASA Technical Reports Server (NTRS)

Kenny, Sean P.; Crespo, Luis G.; Andrews, Lindsey; Giesy, Daniel P.

2012-01-01

Robustness to parametric uncertainty is fundamental to successful control system design and as such it has been at the core of many design methods developed over the decades. Despite its prominence, most of the work on robust control design has focused on linear models and uncertainties that are non-probabilistic in nature. Recently, researchers have acknowledged this disparity and have been developing theory to address a broader class of uncertainties. This paper presents an experimental application of robust control design for a hybrid class of probabilistic and non-probabilistic parametric uncertainties. The experimental apparatus is based upon the classic inverted pendulum on a cart. The physical uncertainty is realized by a known additional lumped mass at an unknown location on the pendulum. This unknown location has the effect of substantially altering the nominal frequency and controllability of the nonlinear system, and in the limit has the capability to make the system neutrally stable and uncontrollable. Another uncertainty to be considered is a direct current motor parameter. The control design objective is to design a controller that satisfies stability, tracking error, control power, and transient behavior requirements for the largest range of parametric uncertainties. This paper presents an overview of the theory behind the robust control design methodology and the experimental results.

Design and Parametric Study of the Magnetic Sensor for Position Detection in Linear Motor Based on Nonlinear Parametric Model Order Reduction

PubMed Central

Paul, Sarbajit; Chang, Junghwan

2017-01-01

This paper presents a design approach for a magnetic sensor module to detect mover position using the proper orthogonal decomposition-dynamic mode decomposition (POD-DMD)-based nonlinear parametric model order reduction (PMOR). The parameterization of the sensor module is achieved by using the multipolar moment matching method. Several geometric variables of the sensor module are considered while developing the parametric study. The operation of the sensor module is based on the principle of the airgap flux density distribution detection by the Hall Effect IC. Therefore, the design objective is to achieve a peak flux density (PFD) greater than 0.1 T and total harmonic distortion (THD) less than 3%. To fulfill the constraint conditions, the specifications for the sensor module is achieved by using POD-DMD based reduced model. The POD-DMD based reduced model provides a platform to analyze the high number of design models very fast, with less computational burden. Finally, with the final specifications, the experimental prototype is designed and tested. Two different modes, 90° and 120° modes respectively are used to obtain the position information of the linear motor mover. The position information thus obtained are compared with that of the linear scale data, used as a reference signal. The position information obtained using the 120° mode has a standard deviation of 0.10 mm from the reference linear scale signal, whereas the 90° mode position signal shows a deviation of 0.23 mm from the reference. The deviation in the output arises due to the mechanical tolerances introduced into the specification during the manufacturing process. This provides a scope for coupling the reliability based design optimization in the design process as a future extension. PMID:28671580

Design and Parametric Study of the Magnetic Sensor for Position Detection in Linear Motor Based on Nonlinear Parametric model order reduction.

PubMed

Paul, Sarbajit; Chang, Junghwan

2017-07-01

This paper presents a design approach for a magnetic sensor module to detect mover position using the proper orthogonal decomposition-dynamic mode decomposition (POD-DMD)-based nonlinear parametric model order reduction (PMOR). The parameterization of the sensor module is achieved by using the multipolar moment matching method. Several geometric variables of the sensor module are considered while developing the parametric study. The operation of the sensor module is based on the principle of the airgap flux density distribution detection by the Hall Effect IC. Therefore, the design objective is to achieve a peak flux density (PFD) greater than 0.1 T and total harmonic distortion (THD) less than 3%. To fulfill the constraint conditions, the specifications for the sensor module is achieved by using POD-DMD based reduced model. The POD-DMD based reduced model provides a platform to analyze the high number of design models very fast, with less computational burden. Finally, with the final specifications, the experimental prototype is designed and tested. Two different modes, 90° and 120° modes respectively are used to obtain the position information of the linear motor mover. The position information thus obtained are compared with that of the linear scale data, used as a reference signal. The position information obtained using the 120° mode has a standard deviation of 0.10 mm from the reference linear scale signal, whereas the 90° mode position signal shows a deviation of 0.23 mm from the reference. The deviation in the output arises due to the mechanical tolerances introduced into the specification during the manufacturing process. This provides a scope for coupling the reliability based design optimization in the design process as a future extension.

Proteinaceous Resin and Hydrophilic Encapsulation: A Self-Healing-Related Study

NASA Astrophysics Data System (ADS)

Zheng, Ting

Inspired by living organisms, self-healing materials have been designed as smart materials. Their automatic healing nature is achieved through the use of capsule in which the healing agent is encapsulated. The occurrence of cracks leads to ripping of the capsule, along with crack propagation and release of the healing agent that wets the crack surface to eventually heal (bond) the crack. Such automatic repair of the crack significantly extends the service life of the material. A vast majority of existing self-healing systems have been designed for the epoxy matrix - the most common commercially used thermoset - that possesses low crack resistance. Currently, self-healing systems have not yet been introduced for fully protein-based materials, despite their great potential to replace currently used synthesis precursors for the latter and the eco-friendly nature of self-healing materials. This has been probably due to two major obstacles: poor mechanical properties of the protein-based matrix, and extreme difficulty associated with the encapsulation of hydrophilic healing agents suitable for the protein-based matrix. This study provides possible solutions towards addressing both these obstacles. To improve the inherent mechanical properties of protein-based resin, soy protein isolate (SPI) was chosen as the model in this study. Dialdehyde carboxymethyl cellulose (DCMC) was synthesized and used as the crosslinking agent to modify the SPI film. As-synthesized DCMC - a fully bio-based material - exhibited high mechanical strength, excellent thermal stability, and reduced moisture sensitivity. Good compatibility and effective crosslinking were believed to be the key reasons for such property enhancements. However, these were accompanied by poor crack resistance, where self-healing is a pertinent solution. A novel healing system for the protein matrix was designed in this work via the use of formaldehyde as a healing agent. Subsequently, the well-acknowledged challenge, e.g. hydrophilic agent encapsulation, was addressed through the development of novel polyurethane-Poly(melamine-formaldehyde) (PU-PMF) dual-component capsules. Remarkably, the external PU insulation layer was fabricated through interfacial polymerization based on a water-in-oil-in-oil (W/O/O) emulsion template. Surface tension was identified as the main driving factor for the formation of the external oil phase. The internal PMF layer was observed to strongly influence the internal morphology of the capsule. A protocol was developed, and a typical capsule with dense and neat shell morphology with a shell/capsule diameter (around 3 %) was fabricated. This study provides solutions for the two aforementioned obstacles related to the development of the healing system for the protein-based materials.

Probing the Physics of Burning DT Capsules Using Gamma-ray Diagnostics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes-Sterbenz, Anna Catherine; Hale, Gerald M.; Jungman, Gerard

2015-02-01

The Gamma Reaction History (GRH) diagnostic developed and lead by the Los Alamos National Laboratory GRH Team is used to determine the bang time and burn width of imploded inertial confinement fusion capsules at the National Ignition Facility. The GRH team is conceptualizing and designing a new Gamma-­to-Electron Magnetic Spectrometer (GEMS), that would be capable of an energy resolution ΔE/E~3-­5%. In this whitepaper we examine the physics that could be explored by the combination of these two gamma-ray diagnostics, with an emphasis on the sensitivity needed for measurements. The main areas that we consider are hydrodynamical mixing, ablator areal densitymore » and density profile, and temporal variations of the density of the cold fuel and the ablator during the DT burn of the capsule.« less

Spallation as a dominant source of pusher-fuel and hot-spot mix in inertial confinement fusion capsules

DOE PAGES

Orth, Charles D.

2016-02-23

We suggest that a potentially dominant but previously neglected source of pusher-fuel and hot-spot “mix” may have been the main degradation mechanism for fusion energy yields of modern inertial confinement fusion (ICF) capsules designed and fielded to achieve high yields — not hydrodynamic instabilities. This potentially dominant mix source is the spallation of small chunks or “grains” of pusher material into the fuel regions whenever (1) the solid material adjacent to the fuel changes its phase by nucleation, and (2) this solid material spalls under shock loading and sudden decompression. Finally, we describe this mix mechanism, support it with simulationsmore » and experimental evidence, and explain how to eliminate it and thereby allow higher yields for ICF capsules and possibly ignition at the National Ignition Facility.« less

Catheterless Long-Term Ambulatory Urodynamic Measurement Using a Novel Three-Device System

PubMed Central

Wille, Sebastian; Schumacher, Pauline; Paas, Jenny; Tenholte, Dirk; Eminaga, Okyaz; Müller, Ute; Muthen, Noemi; Mehner, Jan; Cornely, Oliver; Engelmann, Udo

2014-01-01

Aims Long-term urodynamics are required because bladder-emptying disorders are often not clearly revealed by conventional urodynamics. Patients with severe clinical overactive bladder symptoms, for instance, often show normal results. This may be due to the short evaluation time and psychological factors that complicate conventional urodynamics. This study aimed to develop an ambulatory three-component urodynamic measurement system that is easy to operate, registers urodynamic parameters for several days, and has no negative impact on the patient. Methods We developed an intravesical capsule combined with a hand-held device to register voiding desire and micturition, and an alarm pad device that detects urine loss. Recently, the intravesical capsule and its proven function were detailed in the literature. Here, we present detailed in vitro results using a female bladder model. The flexible capsule was C-shaped to minimize the risk of expulsion from the bladder during micturition. Results of biocompatibility evaluation of the intravesical capsule, which is called Wille Capsule (WiCa) are described. Results The WiCa with an oval nose and a maximum outer diameter of 5.5 mm was easily inserted through a 25-French cystoscope. Removing the WiCa by grasping the nose using the female model with bladder was easily conducted. Expulsion of the WiCa during voiding was avoided through a novel C-shaped device design. Based on in vitro cytotoxicity studies, the capsule is a promising and safe device. Conclusion Our novel system is an innovative minimally-invasive tool for accurate long-term urodynamic measurement, and does not require inserting a transurethral catheter. PMID:24840482

[Application of in vitro bionic digestion and biomembrane extraction for metal speciation analysis, bioavailability and risk assessment in lianhua qingwen capsule].

PubMed

Lin, Lu-Xiu; Li, Shun-Xing; Zheng, Feng-Ying

2014-06-01

One of the causes of the high cost of pharmaceuticals and the major obstacles to rapidly assessing the bioavailability and risk of a chemical is the lack of experimental model systems. A new pre-treatment technology, in vitro bionic digestion was designed for metal analysis in Lianhua Qingwen capsule. The capsule was digested on 37 degrees C under the acidity of the stomach or intestine, and with the inorganic and organic compounds (including digestive enzymes) found in the stomach or intestine, and then the chyme was obtained. Being similar to the biomembrane between the gastrointestinal tract and blood vessels, monolayer liposome was used as biomembrane model Affinity-monolayer liposome metals (AMLMs) and water-soluble metals were used for metal speciation analysis in the capsule. Based on the concentration of AMLMs, the main absorption site of trace metals was proposed. The metal total contents or the concentration of AMLMs in the capsule were compared to the nutritional requirements, daily permissible dose and heavy metal total contents from the "import and export of medicinal plants and preparation of green industry state standards". The metal concentrations in the capsule were within the safety baseline levels for human consumption. After in vitro bionic digestion, most of trace metals were absorbed mainly in intestine. The concentration of As, Cd, Pb was 0.38, 0.07, 1.60 mg x kg(-1), respectively, far less than the permissible dose from the "import and export of medicinal plants and preparation of green industry state standards".

Cost-Effectiveness of Cranberry Capsules to Prevent Urinary Tract Infection in Long-Term Care Facilities: Economic Evaluation with a Randomized Controlled Trial

PubMed Central

van den Hout, Wilbert B; Caljouw, Monique A A; Putter, Hein; Cools, Herman J M; Gussekloo, Jacobijn

2014-01-01

Objectives To investigate whether the preventive use of cranberry capsules in long-term care facility (LTCF) residents is cost-effective depending on urinary tract infection (UTI) risk. Design Economic evaluation with a randomized controlled trial. Setting Long-term care facilities. Participants LTCF residents (N = 928, 703 female, median age 84), stratified according to UTI risk. Measurements UTI incidence (clinically or strictly defined), survival, quality of life, quality-adjusted life years (QALYs), and costs. Results In the weeks after a clinical UTI, participants showed a significant but moderate deterioration in quality of life, survival, care dependency, and costs. In high-UTI-risk participants, cranberry costs were estimated at €439 per year (1.00 euro = 1.37 U.S. dollar), which is €3,800 per prevented clinically defined UTI (95% confidence interval = €1,300–infinity). Using the strict UTI definition, the use of cranberry increased costs without preventing UTIs. Taking cranberry capsules had a 22% probability of being cost-effective compared with placebo (at a willingness to pay of €40,000 per QALY). In low-UTI-risk participants, use of cranberry capsules was only 3% likely to be cost-effective. Conclusion In high-UTI-risk residents, taking cranberry capsules may be effective in preventing UTIs but is not likely to be cost-effective in the investigated dosage, frequency, and setting. In low-UTI-risk LTCF residents, taking cranberry capsules twice daily is neither effective nor cost-effective. PMID:25180379

On the Application of a Response Surface Technique to Analyze Roll-over Stability of Capsules with Airbags Using LS-Dyna

NASA Technical Reports Server (NTRS)

Horta, Lucas G.; Reaves, Mercedes C.

2008-01-01

As NASA moves towards developing technologies needed to implement its new Exploration program, studies conducted for Apollo in the 1960's to understand the rollover stability of capsules landing are being revisited. Although rigid body kinematics analyses of the roll-over behavior of capsules on impact provided critical insight to the Apollo problem, extensive ground test programs were also used. For the new Orion spacecraft being developed to implement today's Exploration program, new air-bag designs have improved sufficiently for NASA to consider their use to mitigate landing loads to ensure crew safety and to enable re-usability of the capsule. Simple kinematics models provide only limited understanding of the behavior of these air bag systems, and more sophisticated tools must be used. In particular, NASA and its contractors are using the LS-Dyna nonlinear simulation code for impact response predictions of the full Orion vehicle with air bags by leveraging the extensive air bag prediction work previously done by the automotive industry. However, even in today's computational environment, these analyses are still high-dimensional, time consuming, and computationally intensive. To alleviate the computational burden, this paper presents an approach that uses deterministic sampling techniques and an adaptive response surface method to not only use existing LS-Dyna solutions but also to interpolate from LS-Dyna solutions to predict the stability boundaries for a capsule on airbags. Results for the stability boundary in terms of impact velocities, capsule attitude, impact plane orientation, and impact surface friction are discussed.

Analysis and Experimental Qualification of an Irradiation Capsule Design for Testing Pressurized Water Reactor Fuel Cladding in the High Flux Isotope Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Kurt R.; Howard, Richard H.; Daily, Charles R.

The Advanced Fuels Campaign within the Fuel Cycle Research and Development program of the Department of Energy Office of Nuclear Energy is currently investigating a number of advanced nuclear fuel cladding concepts to improve the accident tolerance of light water reactors. Alumina-forming ferritic alloys (e.g., FeCrAl) are some of the leading candidates to replace traditional zirconium alloys due to their superior oxidation resistance, provided no prohibitive irradiation-induced embrittlement occurs. Oak Ridge National Laboratory has developed experimental designs to irradiate thin-walled cladding tubes with representative pressurized water reactor geometry in the High Flux Isotope Reactor (HFIR) under relevant temperatures. These designsmore » allow for post-irradiation examination (PIE) of cladding that closely resembles expected commercially viable geometries and microstructures. The experiments were designed using relatively inexpensive rabbit capsules for the irradiation vehicle. The simplistic designs combined with the extremely high neutron flux in the HFIR allow for rapid testing of a large test matrix, thus reducing the time and cost needed to advanced cladding materials closer to commercialization. The designs are flexible in that they allow for testing FeCrAl alloys, stainless steels, Inconel alloys, and zirconium alloys (as a reference material) both with and without hydrides. This will allow a direct comparison of the irradiation performance of advanced cladding materials with traditional zirconium alloys. PIE will include studies of dimensional change, microstructure variation, mechanical performance, etc. This work describes the capsule design, neutronic and thermal analyses, and flow testing that were performed to support the qualification of this new irradiation vehicle.« less

Parametric Pedagogy: Integrating Parametric CAD in Irish Post-Primary Schools

ERIC Educational Resources Information Center

McGarr, Oliver; Seery, Niall

2011-01-01

Technology education in Irish post-primary schools is undergoing significant change. In recent years the syllabi of all technology-related subjects have been revised. A new subject, Design and Communication Graphics, has replaced the traditional Technical Drawing subject. This new subject aims to develop students' spatial awareness and graphical…

Simultaneous usage of pinhole and penumbral apertures for imaging small scale neutron sources from inertial confinement fusion experiments.

PubMed

Guler, N; Volegov, P; Danly, C R; Grim, G P; Merrill, F E; Wilde, C H

2012-10-01

Inertial confinement fusion experiments at the National Ignition Facility are designed to understand the basic principles of creating self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic capsules. The neutron imaging diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by observing neutron images in two different energy bands for primary (13-17 MeV) and down-scattered (6-12 MeV) neutrons. From this, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. These experiments provide small sources with high yield neutron flux. An aperture design that includes an array of pinholes and penumbral apertures has provided the opportunity to image the same source with two different techniques. This allows for an evaluation of these different aperture designs and reconstruction algorithms.

Optical Design with Narrow-Band Imaging for a Capsule Endoscope.

PubMed

Yen, Chih-Ta; Lai, Zong-Wei; Lin, Yu-Ting; Cheng, Hsu-Chih

2018-01-01

The study proposes narrow-band imaging (NBI) lens design of 415 nm and 540 nm of a capsule endoscope (CE). The researches show that in terms of the rate of accuracy in detecting and screening neoplastic and nonneoplastic intestinal lesions, the NBI system outperformed that of traditional endoscopes and rivaled that of chromoendoscopes. In the proposed NBI CE optical system, the simulation result shows the field of view (FOV) was 109.8°; the modulation transfer function (MTF) could achieve 12.5% at 285 lp/mm and 34.1% at 144 lp/mm. The relative illumination reaches more than 60%, and the system total length was less than 4 mm. Finally, this design provides high-quality images for a 300-megapixel 1/4 ″ CMOS image sensor with a pixel size of 1.75  μ m.

Parametric design of tri-axial nested Helmholtz coils

NASA Astrophysics Data System (ADS)

Abbott, Jake J.

2015-05-01

This paper provides an optimal parametric design for tri-axial nested Helmholtz coils, which are used to generate a uniform magnetic field with controllable magnitude and direction. Circular and square coils, both with square cross section, are considered. Practical considerations such as wire selection, wire-wrapping efficiency, wire bending radius, choice of power supply, and inductance and time response are included. Using the equations provided, a designer can quickly create an optimal set of custom coils to generate a specified field magnitude in the uniform-field region while maintaining specified accessibility to the central workspace. An example case study is included.

Parametric design of tri-axial nested Helmholtz coils.

PubMed

Abbott, Jake J

2015-05-01

This paper provides an optimal parametric design for tri-axial nested Helmholtz coils, which are used to generate a uniform magnetic field with controllable magnitude and direction. Circular and square coils, both with square cross section, are considered. Practical considerations such as wire selection, wire-wrapping efficiency, wire bending radius, choice of power supply, and inductance and time response are included. Using the equations provided, a designer can quickly create an optimal set of custom coils to generate a specified field magnitude in the uniform-field region while maintaining specified accessibility to the central workspace. An example case study is included.

Parametric design of tri-axial nested Helmholtz coils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbott, Jake J., E-mail: jake.abbott@utah.edu

This paper provides an optimal parametric design for tri-axial nested Helmholtz coils, which are used to generate a uniform magnetic field with controllable magnitude and direction. Circular and square coils, both with square cross section, are considered. Practical considerations such as wire selection, wire-wrapping efficiency, wire bending radius, choice of power supply, and inductance and time response are included. Using the equations provided, a designer can quickly create an optimal set of custom coils to generate a specified field magnitude in the uniform-field region while maintaining specified accessibility to the central workspace. An example case study is included.

Resonant dampers for parametric instabilities in gravitational wave detectors

NASA Astrophysics Data System (ADS)

Gras, S.; Fritschel, P.; Barsotti, L.; Evans, M.

2015-10-01

Advanced gravitational wave interferometric detectors will operate at their design sensitivity with nearly ˜1 MW of laser power stored in the arm cavities. Such large power may lead to the uncontrolled growth of acoustic modes in the test masses due to the transfer of optical energy to the mechanical modes of the arm cavity mirrors. These parametric instabilities have the potential to significantly compromise the detector performance and control. Here we present the design of "acoustic mode dampers" that use the piezoelectric effect to reduce the coupling of optical to mechanical energy. Experimental measurements carried on an Advanced LIGO-like test mass have shown a tenfold reduction in the amplitude of several mechanical modes, thus suggesting that this technique can greatly mitigate the impact of parametric instabilities in advanced detectors.

CPAS Parachute Testing, Model Development, & Verification

NASA Technical Reports Server (NTRS)

Romero, Leah M.

2013-01-01

Capsule Parachute Assembly System (CPAS) is the human rated parachute system for the Orion vehicle used during re-entry. Similar to Apollo parachute design. Human rating requires additional system redundancy. A Government Furnished Equipment (GFE) project responsible for: Design; Development testing; Performance modeling; Fabrication; Qualification; Delivery

Orion Versus Poseidon: Understanding How Nasa's Crewed Capsule Survives Nature's Fury

NASA Technical Reports Server (NTRS)

Barbre, Robert E., Jr.

2016-01-01

This presentation summarizes the Marshall Space Flight Center Natural Environments Terrestrial and Planetary Environments (TPE) Team support to the NASA Orion space vehicle. The Orion vehicle, part of the Multi-Purpose Crew Vehicle Program, is designed to carry astronauts beyond low-Earth orbit and is currently undergoing a series of tests including Exploration Flight Test (EFT)-1. This design must address the natural environment to which the capsule and launch vehicle are exposed during all mission phases. In addition, the design must, to the best extent possible, implement the same process and data to be utilized on launch day. The TPE utilizes meteorological data to assess the sensitivities of the vehicle due to the terrestrial environment. The presentation describes examples of TPE support for vehicle design and several tests, as well as support for EFT-1 and planning for upcoming Exploration Missions while emphasizing the importance of accounting for the natural environment's impact to the vehicle early in the vehicle's program.

Design and landing dynamic analysis of reusable landing leg for a near-space manned capsule

NASA Astrophysics Data System (ADS)

Yue, Shuai; Nie, Hong; Zhang, Ming; Wei, Xiaohui; Gan, Shengyong

2018-06-01

To improve the landing performance of a near-space manned capsule under various landing conditions, a novel landing system is designed that employs double chamber and single chamber dampers in the primary and auxiliary struts, respectively. A dynamic model of the landing system is established, and the damper parameters are determined by employing the design method. A single-leg drop test with different initial pitch angles is then conducted to compare and validate the simulation model. Based on the validated simulation model, seven critical landing conditions regarding nine crucial landing responses are found by combining the radial basis function (RBF) surrogate model and adaptive simulated annealing (ASA) optimization method. Subsequently, the adaptability of the landing system under critical landing conditions is analyzed. The results show that the simulation effectively results match the test results, which validates the accuracy of the dynamic model. In addition, all of the crucial responses under their corresponding critical landing conditions satisfy the design specifications, demonstrating the feasibility of the landing system.

Influence of capsule shell composition on the performance indicators of hypromellose capsule in comparison to hard gelatin capsules.

PubMed

Al-Tabakha, Moawia M; Arida, Adi Issam; Fahelelbom, Khairi M S; Sadek, Bassem; Saeed, Dima Ahmed; Abu Jarad, Rami A; Jawadi, Jeevani

2015-01-01

The purpose of this study was to assess the in vitro performances of "vegetable" capsules in comparison to hard gelatin capsules in terms of shell weight variation, reaction to different humidity conditions, resistance to stress in the absence of moisture, powder leakage, disintegration and dissolution. Two types of capsules made of HPMC produced with (Capsule 2) or without (Capsule 3) a gelling agent and hard gelatin capsules (Capsule 1) were assessed. Shell weight variability was relatively low for all tested capsules shells. Although Capsule 1 had the highest moisture content under different humidity conditions, all capsule types were unable to protect the encapsulated hygroscopic polyvinylpyrrolidone (PVP) powder from surrounding humidity. The initial disintegration for all Capsule 1 occurred within 3 min, but for other types of capsules within 6 min (n = 18). Dissolution of acetaminophen was better when the deionized water (DIW) temperature increased from 32 to 42 °C in case of Capsule 1, but the effect of temperature was not significant for the other types of capsules. Acetaminphen dissolution from Capsule 1 was the fastest (i.e. >90% in 10 min) and independent of the media pH or contents unlike Capsule 2 which was influenced by the pH and dissolution medium contents. It is feasible to use hypromellose capsules shells with or without gelling agent for new lines of pharmaceutical products, however, there is a window for capsule shells manufacturing companies to improve the dissolution of their hypromellose capsules to match the conventional gelatin capsule shells and eventually replace them.

A Lunar Surface Operations Simulator

NASA Technical Reports Server (NTRS)

Nayar, H.; Balaram, J.; Cameron, J.; Jain, A.; Lim, C.; Mukherjee, R.; Peters, S.; Pomerantz, M.; Reder, L.; Shakkottai, P.;

Building a polysaccharide hydrogel capsule delivery system for control release of ibuprofen.

PubMed

Chen, Zhi; Wang, Ting; Yan, Qing

2018-02-01

Development of a delivery system which can effectively carry hydrophobic drugs and have pH response is becoming necessary. Here we demonstrate that through preparation of β-cyclodextrin polymer (β-CDP), a hydrophobic drug molecule of ibuprofen (IBU) was incorporated into our prepared β-CDP inner cavities, aiming to improve the poor water solubility of IBU. A core-shell capsule structure has been designed for achieving the drug pH targeted and sustained release. This delivery system was built with polysaccharide polymer of Sodium alginate (SA), sodium carboxymethylcellulose (CMC) and hydroxyethyl cellulose (HEC) by physical cross-linking. The drug pH-response control release is this hydrogel system's chief merit, which has potential value for synthesizing enteric capsule. Besides, due to our simple preparing strategy, optimal conditions can be readily determined and the synthesis process can be accurately controlled, leading to consistent and reproducible hydrogel capsules. In addition, phase-solubility method was used to investigate the solubilization effect of IBU by β-CDP. SEM was used to prove the forming of core and shell structure. FT-IR and 1 H-NMR were also used to perform structural characteristics. By the technique of UV determination, the pH targeted and sustained release study were also performed. The results have proved that our prepared polysaccharide hydrogel capsule delivery system has potential applications as oral drugs delivery in the field of biomedical materials.

Pharmaceutical 3D printing: Design and qualification of a single step print and fill capsule.

PubMed

Smith, Derrick M; Kapoor, Yash; Klinzing, Gerard R; Procopio, Adam T

2018-06-10

Fused deposition modeling (FDM) 3D printing (3DP) has a potential to change how we envision manufacturing in the pharmaceutical industry. A more common utilization for FDM 3DP is to build upon existing hot melt extrusion (HME) technology where the drug is dispersed in the polymer matrix. However, reliable manufacturing of drug-containing filaments remains a challenge along with the limitation of active ingredients which can sustain the processing risks involved in the HME process. To circumvent this obstacle, a single step FDM 3DP process was developed to manufacture thin-walled drug-free capsules which can be filled with dry or liquid drug product formulations. Drug release from these systems is governed by the combined dissolution of the FDM capsule 'shell' and the dosage form encapsulated in these shells. To prepare the shells, the 3D printer files (extension '.gcode') were modified by creating discrete zones, so-called 'zoning process', with individual print parameters. Capsules printed without the zoning process resulted in macroscopic print defects and holes. X-ray computed tomography, finite element analysis and mechanical testing were used to guide the zoning process and printing parameters in order to manufacture consistent and robust capsule shell geometries. Additionally, dose consistencies of drug containing liquid formulations were investigated in this work. Copyright © 2018 Elsevier B.V. All rights reserved.

Nanoporous capsules of block co-polymers of [(MeO-PEG-NH)-b-(L-GluA)]-PCL for the controlled release of anticancer drugs for therapeutic applications.

PubMed

Amgoth, Chander; Dharmapuri, Gangappa; Kalle, Arunasree M; Paik, Pradip

2016-03-29

Herein, new nanoporous capsules of the block co-polymers of MeO-PEG-NH-(L-GluA)10 and polycaprolactone (PCL) have been synthesized through a surfactant-free cost-effective self-assembled soft-templating approach for the controlled release of drugs and for therapeutic applications. The nanoporous polymer capsules are designed to be biocompatible and are capable of encapsulating anticancer drugs (e.g., doxorubicin hydrochloride (DOX) and imatinib mesylate (ITM)) with a high extent (∼279 and ∼480 ng μg(-1), respectively). We have developed a nanoformulation of porous MeO-PEG-NH-(L-GluA)10-PCL capsules with DOX and ITM. The porous polymer nanoformulations have been programmed in terms of the release of anticancer drugs with a desired dose to treat the leukemia (K562) and human carcinoma cells (HepG2) in vitro and show promising IC50 values with a very high mortality of cancer cells (up to ∼96.6%). Our nanoformulation arrests the cell divisions due to 'cellular scenescence' and kills the cancer cells specifically. The present findings could enrich the effectiveness of idiosyncratic nanoporous polymer capsules for use in various other nanomedicinal and biomedical applications, such as for killing cancer cells, immune therapy, and gene delivery.

Nanoporous capsules of block co-polymers of [(MeO-PEG-NH)-b-(L-GluA)]-PCL for the controlled release of anticancer drugs for therapeutic applications

NASA Astrophysics Data System (ADS)

Amgoth, Chander; Dharmapuri, Gangappa; Kalle, Arunasree M.; Paik, Pradip

2016-03-01

Herein, new nanoporous capsules of the block co-polymers of MeO-PEG-NH-(L-GluA)10 and polycaprolactone (PCL) have been synthesized through a surfactant-free cost-effective self-assembled soft-templating approach for the controlled release of drugs and for therapeutic applications. The nanoporous polymer capsules are designed to be biocompatible and are capable of encapsulating anticancer drugs (e.g., doxorubicin hydrochloride (DOX) and imatinib mesylate (ITM)) with a high extent (˜279 and ˜480 ng μg-1, respectively). We have developed a nanoformulation of porous MeO-PEG-NH-(L-GluA)10-PCL capsules with DOX and ITM. The porous polymer nanoformulations have been programmed in terms of the release of anticancer drugs with a desired dose to treat the leukemia (K562) and human carcinoma cells (HepG2) in vitro and show promising IC50 values with a very high mortality of cancer cells (up to ˜96.6%). Our nanoformulation arrests the cell divisions due to ‘cellular scenescence’ and kills the cancer cells specifically. The present findings could enrich the effectiveness of idiosyncratic nanoporous polymer capsules for use in various other nanomedicinal and biomedical applications, such as for killing cancer cells, immune therapy, and gene delivery.

Formulation and statistical optimization of gastric floating alginate/oil/chitosan capsules loading procyanidins: in vitro and in vivo evaluations.

PubMed

Chen, Rencai; Guo, Xiaomin; Liu, Xuecong; Cui, Haiming; Wang, Rui; Han, Jing

2018-03-01

The aim of the present work was to develop gastric floating capsules containing oil-entrapped beads loading procyanidins. The floating beads were prepared by ionotropic gelation method using sodium alginate, CaCl 2 and chitosan. The effect of three independent parameters (concentration of sodium alginate, CaCl 2 and chitosan) on entrapment efficiency were analyzed by Box-Behnken design. The floating beads were evaluated for surface morphology, particle size, density, entrapment efficiency, buoyancy, release behavior in vitro and floating ability in vivo. The prepared beads were grossly spherical in shape and the mean size was approximately 1.54±0.17mm. The density was 0.97g/cm 3 . And the optimal conditions were as follows: concentration of sodium alginate, CaCl 2 and chitosan were 33.75mg/mL, 9.84mg/mL and 9.05mg/mL, respectively. The optimized formulation showed entrapment efficiency of 88.84±1.04% within small error-value (0.65). The release mechanism of floating capsules followed Korsmeyer-Peppas model (r 2 =0.9902) with non-Fickian release. The gastric floating capsules exhibited 100% floating percentage in vitro and they could float on the top of gastric juice for 5h in vivo. Therefore, the floating capsules are able to prolong the gastroretentive delivery of procyanidins. Copyright © 2017 Elsevier B.V. All rights reserved.

Virtual chromoendoscopy improves the diagnostic yield of small bowel capsule endoscopy in obscure gastrointestinal bleeding.

PubMed

Boal Carvalho, Pedro; Magalhães, Joana; Dias de Castro, Francisca; Gonçalves, Tiago Cúrdia; Rosa, Bruno; Moreira, Maria João; Cotter, José

2016-02-01

Small bowel capsule endoscopy represents the initial investigation for obscure gastrointestinal bleeding. Flexible spectral imaging colour enhancement (FICE) is a virtual chromoendoscopy technique designed to enhance mucosal lesions, available in different settings according to light wavelength-- FICE1, 2 and 3. To compare the diagnostic yield of FICE1 and white light during capsule endoscopy in patients with obscure gastrointestinal bleeding. Retrospective single-centre study including 60 consecutive patients referred for small bowel capsule endoscopy for obscure gastrointestinal bleeding. Endoscopies were independently reviewed in FICE1 and white light; findings were then reviewed by another researcher, establishing a gold standard. Diagnostic yield was defined as the presence of lesions with high bleeding potential (P2) angioectasias, ulcers or tumours. Diagnostic yield using FICE1 was significantly higher than white light (55% vs. 42%, p=0.021). A superior number of P2 lesions was detected with FICE1 (74 vs. 44, p=0.003), particularly angioectasias (54 vs. 26, p=0.002), but not ulcers or tumours. FICE1 was significantly superior to white light, resulting in a 13% improvement in diagnostic yield, and potentially bleeding lesions particularly angioectasias were more often observed. Our results support the use of FICE1 while reviewing small bowel capsule endoscopy for obscure gastrointestinal bleeding. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

A Parametric Sizing Model for Molten Regolith Electrolysis Reactors to Produce Oxygen from Lunar Regolith

NASA Technical Reports Server (NTRS)

Schreiner, Samuel S.; Dominguez, Jesus A.; Sibille, Laurent; Hoffman, Jeffrey A.

2015-01-01

We present a parametric sizing model for a Molten Electrolysis Reactor that produces oxygen and molten metals from lunar regolith. The model has a foundation of regolith material properties validated using data from Apollo samples and simulants. A multiphysics simulation of an MRE reactor is developed and leveraged to generate a vast database of reactor performance and design trends. A novel design methodology is created which utilizes this database to parametrically design an MRE reactor that 1) can sustain the required mass of molten regolith, current, and operating temperature to meet the desired oxygen production level, 2) can operate for long durations via joule heated, cold wall operation in which molten regolith does not touch the reactor side walls, 3) can support a range of electrode separations to enable operational flexibility. Mass, power, and performance estimates for an MRE reactor are presented for a range of oxygen production levels. The effects of several design variables are explored, including operating temperature, regolith type/composition, batch time, and the degree of operational flexibility.

2-Shock layered tuning campaign

NASA Astrophysics Data System (ADS)

Masse, Laurent; Dittrich, T.; Khan, S.; Kyrala, G.; Ma, T.; MacLaren, S.; Ralph, J.; Salmonson, J.; Tipton, R.; Los Alamos Natl Lab Team; Lawrence Livermore Natl Lab Team

2016-10-01

The 2-Shock platform has been developed to maintain shell sphericity throughout the compression phase of an indirect-drive target implosion and produce a stagnating hot spot in a quasi 1D-like manner. A sub-scale, 1700 _m outer diameter, and thick, 200 _m, uniformly Silicon doped, gas-filled plastic capsule is driven inside a nominal size 5750 _m diameter ignition hohlraum. The hohlraum fill is near vacuum to reduce back-scatter and improve laser/drive coupling. A two-shock pulse of about 1 MJ of laser energy drives the capsule. The thick capsule prevents ablation front feed-through to the imploded core. This platform has demonstrated its efficiency to tune a predictable and reproducible 1-D implosion with a nearly round shape. It has been shown that the high foot performance was dominated by the local defect growth due to the ablation front instability and by the hohlraum radiation asymmetries. The idea here is to take advantage of this 2-Shock platform to design a 1D-like layered implosion and eliminates the deleterious effects of radiation asymmetries and ablation front instability growth. We present the design work and our first experimental results of this near one-dimensional 2-Shock layered design. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

Advances in target design for heavy ion fusion

NASA Astrophysics Data System (ADS)

Callahan, D. A.; Tabak, M.; Bennett, G. R.; Cuneo, M. E.; Vesey, R. A.; Nikroo, A.; Czechowicz, D.; Steinman, D.

2005-12-01

Over the past few years, the emphasis in heavy ion target design has moved from the distributed radiator target to the 'hybrid' target because the hybrid target allows a larger beam focal spot than the distributed radiator (~5 mm radius rather than ~2 mm radius). The larger spot relaxes some of the requirements on the driver, but introduces some new target physics issues. Most notable is the use of shine shields and shims in the hohlraum to achieve symmetry rather than achieving symmetry by beam placement. The shim is a thin layer of material placed on or near the capsule surface to block a small amount of excess radiation. While we have been developing this technique for the heavy ion hybrid target, the technique can also be used in any indirect drive target. We have begun testing the concept of a shim to improve symmetry using a double-ended z-pinch hohlraum on the Sandia Z-machine. Experiments using shimmed thin wall capsules have shown that we can reverse the sign of a P2 asymmetry and significantly reduce the size of a P4 asymmetry. These initial experiments demonstrate the concept of a shim as another method for controlling early time asymmetries in ICF capsules.

[The research-study of pneumococci transformation in the laboratory, and the rise of bacterial genetics and molecular biology].

PubMed

Carrada-Bravo, Teodoro

2016-02-01

The virulence of pneumococci for mice depends on the production of a polysaccharide-capsule, which encloses the bacteria and protects it against phagocytosis. Capsulated pneumococci yield smooth, brilliant colonies designated S, but mutant strains arise frequently which have lost the capacity to sinthetise the capsule, are avirulent and rough designated R. F. Griffith discovery of bacterial "transformation" in 1928, is a landmark in the history of genetics, because hereditary determinants could be transferred from one bacteria to another, and laid the foundation for the subsequent recognition of deoxyribonucleic acid (DNA) as the hereditary material. A systematic analysis of the chemical nature of the "transforming principle", by O. T. Avery and his colleagues during next 10 years, culminated in a formidable weight of evidence that it possessed all properties of DNA. In 1953, J. D. Watson and F. H. C Crick by a brilliant synthesis, fitted the chemical X-ray diffraction data together into a symmetrical double-helix structure, which possessed the inherent properties of genetic material, and carries the information necessary to direct all biochemical-cellular activities and self-replications. This paper describes de early rise and development of bacterial genetics and molecular biology.

Multiple Experimental Platform Consistency at NIF

NASA Astrophysics Data System (ADS)

Benedetti, L. R.; Barrios, M. A.; Bradley, D. K.; Eder, D. C.; Khan, S. F.; Izumi, N.; Jones, O. S.; Ma, T.; Nagel, S. R.; Peterson, J. L.; Rygg, J. R.; Spears, B. K.; Town, R. P.

2013-10-01

ICF experiments at NIF utilize several platforms to assess different metrics of implosion quality. In addition to the point design-a target capsule of DT ice inside a thin plastic ablator-notable platforms include: (i) Symmetry Capsules(SymCaps), mass-adjusted CH capsules filled with DT gas for similar hydrodynamic performance without the need for a DT crystal; (ii) D:3He filled SymCaps, designed for low neutron yield implosions to accommodate a variety of x-ray and optical diagnostics; and (iii) Convergent Ablators, SymCaps coupled with x-radiography to assess in-flight velocity and symmetry of the implosion over ~1 ns before stagnation and burn. These platforms are expected to be good surrogates for one another, and their hohlraum and implosion performance variations have been simulated in detail. By comparing results of similar experiments, we isolate platform-specific variations. We focus on the symmetry, convergence, and timing of x-ray emission as observed in each platform as this can be used to infer stagnation pressure and temperature. This work performed under the auspices of the U.S. Dept. of Energy by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-640865.

Pack Density Limitations of Hybrid Parachutes

NASA Technical Reports Server (NTRS)

Zwicker, Matthew L.; Sinclair, Robert J.

2013-01-01

The development and testing of the Orion crew capsule parachute system has provided a unique opportunity to study dense parachute packing techniques and limits, in order to establish a new baseline for future programs. The density of parachute packs has a significant influence on vibration loads, retention system stresses, and parachute mortar performance. Material compositions and pack densities of existing designs for space capsule recovery were compared, using the pack density of the Apollo main parachutes as the current baseline. The composition of parachutes has changed since Apollo, incorporating new materials such as Kevlar , Vectran , Teflon and Spectra . These materials have different specific densities than Nylon, so the densities of hybrid parachute packs cannot be directly compared to Nylon parachutes for determination of feasibility or volume allocation. Six parachute packs were evaluated in terms of weighted average solid density in order to achieve a non-dimensional comparison of packing density. Means of mitigating damage due to packing pressure and mortar firing were examined in light of the Capsule Parachute Assembly System (CPAS) and Apollo experience. Parachute design improvements including incorporation of modern materials and manufacturing processes serves to make CPAS the new knowledge base on which future spacecraft parachute systems will be built.

Wide-angle lens for miniature capsule endoscope

NASA Astrophysics Data System (ADS)

Ou-Yang, Mang; Chen, Yung-Lin; Lee, Hsin-Hung; LU, Shih-chieh; Wu, Hsien-Ming

2006-02-01

In recent years, using the capsule endoscope to inspect the pathological change of digestive system and intestine had a great break-through on the medical engineering. However, there are some problems needs to overcome. One is that, the field of view was not wide enough, and the other is that the image quality was not enough well. The drawbacks made medical professionals to examine digestive diseases unclearly and ambiguously. In order to solve these problems, the paper designed a novel miniature lenses which has a wide angle of field of view and a good quality of imaging. The lenses employed in the capsule endoscope consisted of a piece of plastic aspherical lens and a piece of glass lens and compacted in the 9.8mm (W) *9.8mm (L) *10.7mm (H) size. Taking the white LED light source and the 10μm pixel size of 256*256 CMOS sensor under considerations, the field of view of the lenses could be achieved to 86 degrees, and the MTF to 37% at 50lp/mm of space frequency. The experimental data proves that the design is consistent with the finished prototype.

Preliminary design study of advanced multistage axial flow core compressors

NASA Technical Reports Server (NTRS)

Wisler, D. C.; Koch, C. C.; Smith, L. H., Jr.

1977-01-01

A preliminary design study was conducted to identify an advanced core compressor for use in new high-bypass-ratio turbofan engines to be introduced into commercial service in the 1980's. An evaluation of anticipated compressor and related component 1985 state-of-the-art technology was conducted. A parametric screening study covering a large number of compressor designs was conducted to determine the influence of the major compressor design features on efficiency, weight, cost, blade life, aircraft direct operating cost, and fuel usage. The trends observed in the parametric screening study were used to develop three high-efficiency, high-economic-payoff compressor designs. These three compressors were studied in greater detail to better evaluate their aerodynamic and mechanical feasibility.

Parametric Inlet Tested in Glenn's 10- by 10-Foot Supersonic Wind Tunnel

NASA Technical Reports Server (NTRS)

Slater, John W.; Davis, David O.; Solano, Paul A.

2005-01-01

The Parametric Inlet is an innovative concept for the inlet of a gas-turbine propulsion system for supersonic aircraft. The concept approaches the performance of past inlet concepts, but with less mechanical complexity, lower weight, and greater aerodynamic stability and safety. Potential applications include supersonic cruise aircraft and missiles. The Parametric Inlet uses tailored surfaces to turn the incoming supersonic flow inward toward an axis of symmetry. The terminal shock spans the opening of the subsonic diffuser leading to the engine. The external cowl area is smaller, which reduces cowl drag. The use of only external supersonic compression avoids inlet unstart--an unsafe shock instability present in previous inlet designs that use internal supersonic compression. This eliminates the need for complex mechanical systems to control unstart, which reduces weight. The conceptual design was conceived by TechLand Research, Inc. (North Olmsted, OH), which received funding through NASA s Small-Business Innovation Research program. The Boeing Company (Seattle, WA) also participated in the conceptual design. The NASA Glenn Research Center became involved starting with the preliminary design of a model for testing in Glenn s 10- by 10-Foot Supersonic Wind Tunnel (10 10 SWT). The inlet was sized for a speed of Mach 2.35 while matching requirements of an existing cold pipe used in previous inlet tests. The parametric aspects of the model included interchangeable components for different cowl lip, throat slot, and sidewall leading-edge shapes and different vortex generator configurations. Glenn researchers used computational fluid dynamics (CFD) tools for three-dimensional, turbulent flow analysis to further refine the aerodynamic design.

Design of a terahertz parametric oscillator based on a resonant cavity in a terahertz waveguide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saito, K., E-mail: k-saito@material.tohoku.ac.jp; Oyama, Y.; Tanabe, T.

We demonstrate ns-pulsed pumping of terahertz (THz) parametric oscillations in a quasi-triply resonant cavity in a THz waveguide. The THz waves, down converted through parametric interactions between the pump and signal waves at telecom frequencies, are confined to a GaP single mode ridge waveguide. By combining the THz waveguide with a quasi-triply resonant cavity, the nonlinear interactions can be enhanced. A low threshold pump intensity for parametric oscillations can be achieved in the cavity waveguide. The THz output power can be maximized by optimizing the quality factors of the cavity so that an optical to THz photon conversion efficiency, η{submore » p}, of 0.35, which is near the quantum-limit level, can be attained. The proposed THz optical parametric oscillator can be utilized as an efficient and monochromatic THz source.« less

Visualization of Capsule Reentry Vehicle Heat Shield Ablation Using Naphthalene PLIF

NASA Technical Reports Server (NTRS)

Combs, Christopher S.; Clemens, Noel T.; Danehy, Paul M.

2014-01-01

The Orion Multi-Purpose Crew Vehicle (MPCV) will use an ablative heat shield and improved understanding of the ablation process would be beneficial for design purposes. Given that ablation is a multi-physics process involving heat and mass transfer, codes aiming to predict heat shield ablation are in need of experimental data pertaining to the turbulent transport of ablation products for validation. At The University of Texas at Austin, a technique is being developed that uses planar laser-induced fluorescence (PLIF) of a low-temperature sublimating ablator (naphthalene) to visualize the transport of ablation products in a supersonic flow. Since ablation at reentry temperatures can be difficult to recreate in a laboratory setting it is desirable to create a limited physics problem and simulate the ablation process at relatively low temperature conditions using naphthalene. A scaled Orion MPCV model with a solid naphthalene heat shield has been tested in a Mach 5 wind tunnel at various angles of attack in the current work. PLIF imaging reveals the distribution of the ablation products as they are transported into the heat-shield boundary layer and over the capsule shoulders into the separated shear layer and backshell recirculation region. Visualizations of the capsule shear layer using both naphthalene PLIF and Schlieren imaging compared favorably. High concentrations of naphthalene in the capsule separated flow region, intermittent turbulent structures on the heat shield surface, and interesting details of the capsule shear layer structure were observed using the naphthalene PLIF technique. The capsule shear layer was also shown to generally appear to be more turbulent at lower angles of attack. Furthermore, the PLIF signal increased steadily over the course of a run indicating that during a wind tunnel run the model heated up and the rate of naphthalene ablation increased. The shear layer showed increasing signs of turbulence over the course of a wind tunnel run as well, likely because of the combination of increased surface roughness and surface blowing rate. PLIF imaging also detected regions with a relatively low concentration of naphthalene in the capsule backshell recirculation region that are most likely the result of cross-flow-induced vortices on the capsule afterbody.

The Parametric Study and Fine-Tuning of Bow-Tie Slot Antenna with Loaded Stub

PubMed Central

2017-01-01

A printed Bow-Tie slot antenna with loaded stub is proposed and the effects of changing the dimensions of the slot area, the stub and load sizes are considered in this paper. These parameters have a considerable effect on the antenna characteristics as well as its performance. An in-depth parametric study of these dimensions is presented. This paper proposes the necessary conditions for initial approximation of dimensions needed to design this antenna. In order to achieve the desired performance of the antenna fine tuning of all sizes of these parameters is required. The parametric studies used in this paper provide proper trends for initiation and tuning the design. A prototype of the antenna for 1.7GHz to 2.6GHz band is fabricated. Measurements conducted verify that the designed antenna has wideband characteristics with 50% bandwidth around the center frequency of 2.1GHz. Conducted measurements for reflection coefficient (S11) and radiation pattern also validate our simulation results. PMID:28114354

The Parametric Study and Fine-Tuning of Bow-Tie Slot Antenna with Loaded Stub.

PubMed

Shafiei, M M; Moghavvemi, Mahmoud; Wan Mahadi, Wan Nor Liza

2017-01-01

A printed Bow-Tie slot antenna with loaded stub is proposed and the effects of changing the dimensions of the slot area, the stub and load sizes are considered in this paper. These parameters have a considerable effect on the antenna characteristics as well as its performance. An in-depth parametric study of these dimensions is presented. This paper proposes the necessary conditions for initial approximation of dimensions needed to design this antenna. In order to achieve the desired performance of the antenna fine tuning of all sizes of these parameters is required. The parametric studies used in this paper provide proper trends for initiation and tuning the design. A prototype of the antenna for 1.7GHz to 2.6GHz band is fabricated. Measurements conducted verify that the designed antenna has wideband characteristics with 50% bandwidth around the center frequency of 2.1GHz. Conducted measurements for reflection coefficient (S11) and radiation pattern also validate our simulation results.

Automated, Parametric Geometry Modeling and Grid Generation for Turbomachinery Applications

NASA Technical Reports Server (NTRS)

Harrand, Vincent J.; Uchitel, Vadim G.; Whitmire, John B.

2000-01-01

The objective of this Phase I project is to develop a highly automated software system for rapid geometry modeling and grid generation for turbomachinery applications. The proposed system features a graphical user interface for interactive control, a direct interface to commercial CAD/PDM systems, support for IGES geometry output, and a scripting capability for obtaining a high level of automation and end-user customization of the tool. The developed system is fully parametric and highly automated, and, therefore, significantly reduces the turnaround time for 3D geometry modeling, grid generation and model setup. This facilitates design environments in which a large number of cases need to be generated, such as for parametric analysis and design optimization of turbomachinery equipment. In Phase I we have successfully demonstrated the feasibility of the approach. The system has been tested on a wide variety of turbomachinery geometries, including several impellers and a multi stage rotor-stator combination. In Phase II, we plan to integrate the developed system with turbomachinery design software and with commercial CAD/PDM software.

A decision-making tool for incorporating sustainability measures into pavement design : research project capsule.

DOT National Transportation Integrated Search

2016-10-01

The objective of the proposed study is to conceive and develop a decision-making tool : for evaluating sustainability of pavement designs based on a cradle-to-grave analysis. : This tool will utilize EPDs to enhance the reliability of the assessment ...

An Optical Parametric Amplifier for Profiling Gases of Atmospheric Interest

NASA Technical Reports Server (NTRS)

Heaps, William (Technical Monitor); Burris, John; Richter, Dale

2004-01-01

This paper describes the development of a lidar transmitter using an optical parametric amplifier. It is designed for profiling gases of atmospheric interest at high spatial and temporal precision in the near-IR. Discussions on desirable characteristics for such a transmitter with specific reference to the case of CO, are made.

Chinese herbal medicine Kuntai capsule for treatment of menopausal syndrome: a systematic review of randomized clinical trials.

PubMed

Zhou, Quan; Tao, Jing; Song, Huamei; Chen, Aihua; Yang, Huaijie; Zuo, Manzhen; Li, Hairong

2016-12-01

Kuntai capsule has been widely used for the treatment of menopausal syndrome in China for long time. We conducted this review to assess efficacy and safety of Kuntai capsule for the treatment of menopausal syndrome. We searched studies in PubMed, ClinicalTrials, the Cochrane Library, China National Knowledge Infrastructure Database(CNKI), China Science and Technology Journal Database (VIP), Wan fang Database and Chinese Biomedical Literature Database(CBM) until November 20, 2014. Randomized trials on Kuntai capsule for menopausal syndrome, compared with placebo or hormone replacement therapy (HRT) were included. Two reviewers independently retrieved the randomized controlled trials (RCTs) and extracted the information. The Cochrane risk of bias method was used to assess the quality of the included studies, and a Meta-analysis was conducted with Review Manager 5.2 software. A total of 17 RCTs (1455 participants) were included. The studies were of low methodological quality. Meta-analysis indicated that there was no statistical difference in the Kupperman index (KI) [WMD=0.51, 95% CI (-0.04, 1.06)], the effective rate of KI [OR=1.21, 95% CI (0.72, 2.04)], E2 level [WMD=-15.18, 95% CI (-33.93, 3.56)], and FSH level [WMD=-3.46, 95% CI (-7.2, 0.28)] after treatment between Kuntai versus HRT group (P>0.05). However, Compared with HRT, Kuntai capsule could significantly reduce the total incidence of adverse events [OR=0.28, 95% CI (0.17, 0.45)]. Kuntai capsule may be effective for treating menopausal syndrome and lower risk of side effects. The studies we analyzed were of low methodological quality. Therefore, more strictly designed large-scale randomized clinical trials are needed to evaluate the efficacy of Kuntai capsule in menopausal syndrome. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sample Returns Missions in the Coming Decade

NASA Technical Reports Server (NTRS)

Desai, Prasun N.; Mitcheltree, Robert A.; Cheatwood, F. McNeil

2000-01-01

In the coming decade, several missions will attempt to return samples to Earth from varying parts of the solar system. These samples will provide invaluable insight into the conditions present during the early formation of the solar system, and possibly give clues to how life began on Earth. A description of five sample return missions is presented (Stardust, Genesis, Muses-C. Mars Sample Return, and Comet Nucleus Sample Return). An overview of each sample return mission is given, concentrating particularly on the technical challenges posed during the Earth entry, descent, and landing phase of the missions. Each mission faces unique challenges in the design of an Earth entry capsule. The design of the entry capsule must address the aerodynamic, heating, deceleration, landing, and recovery requirements for the safe return of samples to Earth.

A single capsule formulation of RHB-104 demonstrates higher anti-microbial growth potency for effective treatment of Crohn's disease associated with Mycobacterium avium subspecies paratuberculosis.

PubMed

Qasem, Ahmad; Safavikhasraghi, Mitra; Naser, Saleh A

2016-01-01

Most recently we reported that RHB‑104 triple antibiotics combination in culture is bactericidal and should be effective for treatment of Crohn's disease (CD)-associated with Mycobacterium avium subspecies paratuberculosis (MAP) (Alcedo et al. in Gut Pathog 14:32, 2016). The combination exhibited unique synergistic antimicrobial growth activity. The proprietary RHB-104 capsule formulation contains active ingredients (63.3 % Clarithromycin (CLA), 6.7 % Clofazimine (CLO) and 30 % Rifabutin (RIF)). In our earlier study, we could not dissolve the proprietary RHB-104 capsule formulation in one compatible solvent. Consequently, we re-created RHB-104 analog by adding appropriate concentrations of each of the three antibiotics into the cultures. The Minimum inhibitory concentration (MIC) for RHB-104 analog, CLA, CLO, RIF, CLA-CLO, CLA-RIF, CLO-RIF and their individual solvents were reported earlier (Alcedo et al. in Gut Pathog 14:32, 2016). In this study, we succeeded in dissolving the proprietary RHB-104 capsule formulation in a single proprietary solvent. This study is designed to compare of the MIC the proprietary RHB-104 capsule formulation to RHB-104 analog against MAP and other microorganisms. BD Bactec™ MGIT™ Para-TB medium (Sparks, MD) system was used to determine the MIC of the proprietary RHB-104 capsule formulation and RHB-104 analog and their solvents against MAP and several other microorganisms. The final concentration of solvents used to dissolve all the drugs were ≤0.5 % (v/v). The MIC for the RHB-104 proprietary solvent against MAP was consistent against all microorganisms tested in the study at 12.5 % (v/v). The MIC for the proprietary RHB-104 capsule formulation was similar to RHB-104 analog against several MAP clinical strains with MIC ≤ 0.2 μg/mL. The MIC for the proprietary RHB-104 capsule formulation was at 2.0 μg/mL against MAP strain MS 137 and M. avium strain JF7 compared to 4.0 ug/mL for RHB-104 analog. Similarly, the MIC of RHB-104 formulation capsule was significantly lower than RHB-104 analog against M. tuberculosis HR237, M. fortuitism subspecies fortuitum, M. smegmatis ATCC 27199, Staphylococcus aureus ATCC 25923 and Listeria monocytogenes ATCC 19112. The data demonstrated that the proprietary RHB-104 capsule formulation is more potent in culture against Mycobacteria and other microorganisms especially those with MIC >0.2. Formulation of multi-drugs in a single capsule results in potent synergistic anti-microbial activity far exceeds treatment the culture with multi-individually dissolved drugs. RHB-104 capsule formulation should be more effective to eradicate MAP infection in patients with CD. The study provides evidence that combining weak antibiotics in one formulation might be the new silver bullet to combat bacteria.

Parametric instability of shaft with discs

NASA Astrophysics Data System (ADS)

Wahab, A. M. Abdul; Rasid, Z. A.; Abu, A.; Rudin, N. F. Mohd Noor

2017-12-01

The occurrence of resonance is a major criterion to be considered in the design of shaft. While force resonance occurs merely when the natural frequency of the rotor system equals speed of the shaft, parametric resonance or parametric instability can occur at excitation speed that is integral or sub-multiple of the frequency of the rotor. This makes the study on parametric resonance crucial. Parametric instability of a shaft system consisting of a shaft and disks has been investigated in this study. The finite element formulation of the Mathieu-Hill equation that represents the parametric instability problem of the shaft is developed based on Timoshenko’s beam theory and Nelson’s finite element method (FEM) model that considers the effect of torsional motion on such problem. The Bolotin’s method is used to determine the regions of instability and the Strut-Ince diagram. The validation works show that the results of this study are in close agreement to past results. It is found that a larger radius of disk will cause the shaft to become more unstable compared to smaller radius although both weights are similar. Furthermore, the effect of torsional motion on the parametric instability of the shaft is significant at higher rotating speed.

In-reactor performance of LWR-type tritium target rods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lanning, D.D.; Paxton, M.M.; Crumbaugh, L.

Pacific Northwest Laboratory has conducted several 1-yr irradiation tests of light water reactor-type tritium target rods. These tests have been sponsored by the U.S. Department of Energy's Office of New Production Reactors. The first test, designated water capsule-1 (WC-1), was conducted in the Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory from November 1989 to December 1990. The test vehicle contained a single 4-ft target rod within a pressurized water capsule. The capsule maintained the rod at pressurized water reactor (PWR)-type water temperature and pressure conditions. Posttest nondestructive examinations of the WC-1 rod involved visual examinations, dimensional checks,more » gamma scanning, and neutron radiography. The results indicate that the rod maintained the integrity of its pressure seal and was otherwise unaltered both mechanically and dimensionally by its irradiation and posttest handling.« less

A sealed capsule system for biological and liquid shock-recovery experiments.

PubMed

Leighs, James A; Appleby-Thomas, Gareth J; Stennett, Chris; Hameed, Amer; Wilgeroth, James M; Hazell, Paul J

2012-11-01

This paper presents an experimental method designed to one-dimensionally shock load and subsequently recover liquid samples. Resultant loading profiles have been interrogated via hydrocode simulation as the nature of the target did not allow for direct application of the diagnostics typically employed in shock physics (e.g., manganin stress gauges or Heterodyne velocimeter (Het-V)). The target setup has been experimentally tested using aluminium flyer plates accelerated by a 50-mm bore single-stage gas-gun reaching projectile impact velocities of up to ~500 ms(-1) (corresponding to peak pressures of up to ca. 4 GPa being experienced by fluid samples). Recovered capsules survived well showing only minor signs of damage. Modelled gauge traces have been validated through the use of a (slightly modified) experiment in which a Het-V facing the rear of the inner capsule was employed. In these tests, good correlation between simulated and experimental traces was observed.

A sealed capsule system for biological and liquid shock-recovery experiments

NASA Astrophysics Data System (ADS)

Leighs, James A.; Appleby-Thomas, Gareth J.; Stennett, Chris; Hameed, Amer; Wilgeroth, James M.; Hazell, Paul J.

2012-11-01

This paper presents an experimental method designed to one-dimensionally shock load and subsequently recover liquid samples. Resultant loading profiles have been interrogated via hydrocode simulation as the nature of the target did not allow for direct application of the diagnostics typically employed in shock physics (e.g., manganin stress gauges or Heterodyne velocimeter (Het-V)). The target setup has been experimentally tested using aluminium flyer plates accelerated by a 50-mm bore single-stage gas-gun reaching projectile impact velocities of up to ˜500 ms-1 (corresponding to peak pressures of up to ca. 4 GPa being experienced by fluid samples). Recovered capsules survived well showing only minor signs of damage. Modelled gauge traces have been validated through the use of a (slightly modified) experiment in which a Het-V facing the rear of the inner capsule was employed. In these tests, good correlation between simulated and experimental traces was observed.

Ion Implantation Doping of Inertial Confinement Fusion Targets

DOE PAGES

Shin, S. J.; Lee, J. R. I.; van Buuren, T.; ...

2017-12-19

Controlled doping of inertial confinement fusion (ICF) targets is needed to enable nuclear diagnostics of implosions. Here in this study, we demonstrate that ion implantation with a custom-designed carousel holder can be used for azimuthally uniform doping of ICF fuel capsules made from a glow discharge polymer (GDP). Particular emphasis is given to the selection of the initial wall thickness of GDP capsules as well as implantation and postimplantation annealing parameters in order to minimize capsule deformation during a postimplantation thermal treatment step. In contrast to GDP, ion-implanted high-density carbon exhibits excellent thermal stability and ~100% implantation efficiency for themore » entire range of ion doses studied (2 × 10 14 to 1 × 10 16 cm -2) and for annealing temperatures up to 700°C. Lastly, we demonstrate a successful doping of planar Al targets with isotopes of Kr and Xe to doses of ~10 17 cm -2.« less

Electroformation of Janus and patchy capsules

NASA Astrophysics Data System (ADS)

Rozynek, Zbigniew; Mikkelsen, Alexander; Dommersnes, Paul; Fossum, Jon Otto

2014-05-01

Janus and patchy particles have designed heterogeneous surfaces that consist of two or several patches with different materials properties. These particles are emerging as building blocks for a new class of soft matter and functional materials. Here we introduce a route for forming heterogeneous capsules by producing highly ordered jammed colloidal shells of various shapes with domains of controlled size and composition. These structures combine the functionalities offered by Janus or patchy particles, and those given by permeable shells such as colloidosomes. The simple assembly route involves the synergetic action of electro-hydrodynamic flow and electro-coalescence. We demonstrate that the method is robust and straightforwardly extendable to production of multi-patchy capsules. This forms a starting point for producing patchy colloidosomes with domains of anisotropic chemical surface properties, permeability or mixed liquid-solid phase domains, which could be exploited to produce functional emulsions, light and hollow supra-colloidosome structures, or scaffolds.

X-ray shadow imprint of hydrodynamic instabilities on the surface of inertial confinement fusion capsules by the fuel fill tube

DOE PAGES

MacPhee, A. G.; Casey, D. T.; Clark, D. S.; ...

2017-03-30

Measurements of hydrodynamic instability growth for a high-density carbon ablator for indirectly driven inertial confinement fusion implosions on the National Ignition Facility are reported. We observe significant unexpected features on the capsule surface created by shadows of the capsule fill tube, as illuminated by laser-irradiated x-ray spots on the hohlraum wall. These shadows increase the spatial size and shape of the fill tube perturbation in a way that can significantly degrade performance in layered implosions compared to previous expectations. The measurements were performed at a convergence ratio of ~2 using in-flight x-ray radiography. The initial seed due to shadow imprintmore » is estimated to be equivalent to ~50–100 nm of solid ablator material. As a result, this discovery has prompted the need for a mitigation strategy for future inertial confinement fusion designs as proposed here.« less

First downscattered neutron images from Inertial Confinement Fusion experiments at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Guler, Nevzat; Aragonez, Robert J.; Archuleta, Thomas N.; Batha, Steven H.; Clark, David D.; Clark, Deborah J.; Danly, Chris R.; Day, Robert D.; Fatherley, Valerie E.; Finch, Joshua P.; Gallegos, Robert A.; Garcia, Felix P.; Grim, Gary; Hsu, Albert H.; Jaramillo, Steven A.; Loomis, Eric N.; Mares, Danielle; Martinson, Drew D.; Merrill, Frank E.; Morgan, George L.; Munson, Carter; Murphy, Thomas J.; Oertel, John A.; Polk, Paul J.; Schmidt, Derek W.; Tregillis, Ian L.; Valdez, Adelaida C.; Volegov, Petr L.; Wang, Tai-Sen F.; Wilde, Carl H.; Wilke, Mark D.; Wilson, Douglas C.; Atkinson, Dennis P.; Bower, Dan E.; Drury, Owen B.; Dzenitis, John M.; Felker, Brian; Fittinghoff, David N.; Frank, Matthias; Liddick, Sean N.; Moran, Michael J.; Roberson, George P.; Weiss, Paul; Buckles, Robert A.; Cradick, Jerry R.; Kaufman, Morris I.; Lutz, Steve S.; Malone, Robert M.; Traille, Albert

2013-11-01

Inertial Confinement Fusion experiments at the National Ignition Facility (NIF) are designed to understand and test the basic principles of self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic (CH) capsules. The experimental campaign is ongoing to tune the implosions and characterize the burning plasma conditions. Nuclear diagnostics play an important role in measuring the characteristics of these burning plasmas, providing feedback to improve the implosion dynamics. The Neutron Imaging (NI) diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by collecting images at two different energy bands for primary (13-15 MeV) and downscattered (10-12 MeV) neutrons. From these distributions, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. The first downscattered neutron images from imploding ICF capsules are shown in this paper.

X-ray shadow imprint of hydrodynamic instabilities on the surface of inertial confinement fusion capsules by the fuel fill tube

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacPhee, A. G.; Casey, D. T.; Clark, D. S.

Measurements of hydrodynamic instability growth for a high-density carbon ablator for indirectly driven inertial confinement fusion implosions on the National Ignition Facility are reported. We observe significant unexpected features on the capsule surface created by shadows of the capsule fill tube, as illuminated by laser-irradiated x-ray spots on the hohlraum wall. These shadows increase the spatial size and shape of the fill tube perturbation in a way that can significantly degrade performance in layered implosions compared to previous expectations. The measurements were performed at a convergence ratio of ~2 using in-flight x-ray radiography. The initial seed due to shadow imprintmore » is estimated to be equivalent to ~50–100 nm of solid ablator material. As a result, this discovery has prompted the need for a mitigation strategy for future inertial confinement fusion designs as proposed here.« less

Ion Implantation Doping of Inertial Confinement Fusion Targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shin, S. J.; Lee, J. R. I.; van Buuren, T.

Controlled doping of inertial confinement fusion (ICF) targets is needed to enable nuclear diagnostics of implosions. Here in this study, we demonstrate that ion implantation with a custom-designed carousel holder can be used for azimuthally uniform doping of ICF fuel capsules made from a glow discharge polymer (GDP). Particular emphasis is given to the selection of the initial wall thickness of GDP capsules as well as implantation and postimplantation annealing parameters in order to minimize capsule deformation during a postimplantation thermal treatment step. In contrast to GDP, ion-implanted high-density carbon exhibits excellent thermal stability and ~100% implantation efficiency for themore » entire range of ion doses studied (2 × 10 14 to 1 × 10 16 cm -2) and for annealing temperatures up to 700°C. Lastly, we demonstrate a successful doping of planar Al targets with isotopes of Kr and Xe to doses of ~10 17 cm -2.« less

Fabrication of aerogel capsule, bromine-doped capsule, and modified gold cone in modified target for the Fast Ignition Realization Experiment (FIREX) Project

NASA Astrophysics Data System (ADS)

Nagai, Keiji; Yang, H.; Norimatsu, T.; Azechi, H.; Belkada, F.; Fujimoto, Y.; Fujimura, T.; Fujioka, K.; Fujioka, S.; Homma, H.; Ito, F.; Iwamoto, A.; Jitsuno, T.; Kaneyasu, Y.; Nakai, M.; Nemoto, N.; Saika, H.; Shimoyama, T.; Suzuki, Y.; Yamanaka, K.; Mima, K.

2009-09-01

The development of target fabrication for the Fast Ignition Realization EXperiment (FIREX) Project is described in this paper. For the first stage of the FIREX Project (FIREX-I), the previously designed target has been modified by using a bromine-doped ablator and coating the inner gold cone with a low-density material. A high-quality bromine-doped capsule without vacuoles was fabricated from bromine-doped deuterated polystyrene. The gold surface was coated with a low-density material by electrochemical plating. For the cryogenic fuel target, a brand new type of aerogel material, phloroglucinol/formaldehyde (PF), was investigated and encapsulated to meet the specifications of 500 µm diameter and 20 µm thickness, with 30 nm nanopores. Polystyrene-based low-density materials were investigated and the relationship between the crosslinker content and the nanopore structure was observed.

Beryllium implosion experiments at high case-to-capsule ratio on the National Ignition Facility

NASA Astrophysics Data System (ADS)

Zylstra, Alex; Yi, Austin; Kline, John; Kyrala, George; Loomis, Eric; Perry, Ted; Shah, Rahul; Batha, Steve; MacLaren, Steve; Ralph, Joe; Salmonson, Jay; Masse, Laurent; Nikroo, Abbas; Stadermann, Michael; Callahan, Debbie; Hurricane, Omar; Rice, Neal; Huang, Haibo; Kong, Casey

2017-10-01

Using beryllium as an ablator material has several potential advantages for inertial fusion because of its low opacity and thus higher ablation rate. This could enable novel designs taking advantage of the reduced ablation-front growth rate, or operating at lower radiation temperature. To investigate the integrated performance of beryllium implosions, we conducted a tuning campaign leading into DT layered implosions using a 900um radius capsule in a 6.72mm diameter hohlraum (case-to-capsule ratio CCR=3.7); the large CCR enables direct study of the 1-D implosion performance. The tuning campaign shots demonstrate excellent control over the shock timing and implosion symmetry at this CCR. Performance data from the DT experiments will also be discussed. This work was performed under the auspices of the U.S. DoE by LANL under contract DE-AC52-06NA52396.

Capsular bag opacification after experimental implantation of a new accommodating intraocular lens in rabbit eyes.

PubMed

Werner, Liliana; Pandey, Suresh K; Izak, Andrea M; Vargas, Luis G; Trivedi, Rupal H; Apple, David J; Mamalis, Nick

2004-05-01

To evaluate the development of capsular bag opacification in rabbit eyes after implantation of an intraocular lens (IOL) designed to minimize contact between the anterior capsule and the IOL and ensure expansion of the capsular bag. David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Ten New Zealand white rabbits had a study IOL (new accommodating silicone IOL [Synchrony, Visiogen, Inc.]) implanted in 1 eye and a control IOL (1-piece plate silicone IOL with large fixation holes) implanted in the other eye. Intraocular lens position, anterior capsule opacification (ACO), and posterior capsule opacification (PCO) were qualitatively assessed using slitlamp retroillumination photographs of the dilated eyes. Anterior capsule opacification and PCO were graded on a 0 to 4 scale after the eyes were enucleated (Miyake-Apple posterior and anterior views after excision of the cornea and iris). The eyes were also evaluated histopathologically. The rate of ACO and PCO was significantly higher in the control group. Fibrosis and ACO were almost absent in the study group; the control group exhibited extensive capsulorhexis contraction, including capsulorhexis occlusion. Postoperative IOL dislocation into the anterior chamber and pupillary block syndrome were observed in some eyes in the study group. The special design features associated with the study IOL appeared to help prevent PCO. Complications in the study group were probably caused by the increased posterior vitreous pressure in rabbit eyes compared to human eyes and the relatively large size of the study IOL relative to the anterior segment of rabbit eyes.

Conceptual design of reduced energy transports

NASA Technical Reports Server (NTRS)

Ardema, M. D.; Harper, M.; Smith, C. L.; Waters, M. H.; Williams, L. J.

1975-01-01

This paper reports the results of a conceptual design study of new, near-term fuel-conservative aircraft. A parametric study was made to determine the effects of cruise Mach number and fuel cost on the 'optimum' configuration characteristics and on economic performance. Supercritical wing technology and advanced engine cycles were assumed. For each design, the wing geometry was optimized to give maximum return on investment at a particular fuel cost. Based on the results of the parametric study, a reduced energy configuration was selected. Compared with existing transport designs, the reduced energy design has a higher aspect ratio wing with lower sweep, and cruises at a lower Mach number. It yields about 30% more seat-miles/gal than current wide-body aircraft. At the higher fuel costs anticipated in the future, the reduced energy design has about the same economic performance as existing designs.

A D-Optimal designed population pharmacokinetic study of oral itraconazole in adult cystic fibrosis patients

PubMed Central

Hennig, Stefanie; Waterhouse, Timothy H; Bell, Scott C; France, Megan; Wainwright, Claire E; Miller, Hugh; Charles, Bruce G; Duffull, Stephen B

2007-01-01

What is already known about this subject • Itraconazole is a triazole antifungal used in the treatment of allergic bronchopulmonary aspergillosis in patients with cystic fibrosis (CF). • The pharmacokinetic (PK) properties of this drug and its active metabolite have been described before, mostly in healthy volunteers. • However, only sparse information from case reports were available of the PK properties of this drug in CF patients at the start of our study. What this study adds • This study reports for the first time the population pharmacokinetic properties of itraconazole and a known active metabolite, hydroxy-itraconazole in adult patients with CF. • As a result, this study offers new dosing approaches and their pharmacoeconomic impact as well as a PK model for therapeutic drug monitoring of this drug in this patient group. • Furthermore, it is an example of a successful d-optimal design application in a clinical setting. Aim The primary objective of the study was to estimate the population pharmacokinetic parameters for itraconazole and hydroxy-itraconazole, in particular, the relative oral bioavailability of the capsule compared with solution in adult cystic fibrosis patients, in order to develop new dosing guidelines. A secondary objective was to evaluate the performance of a population optimal design. Methods The blood sampling times for the population study were optimized previously using POPT v.2.0. The design was based on the administration of solution and capsules to 30 patients in a cross-over study. Prior information suggested that itraconazole is generally well described by a two-compartment disposition model with either linear or saturable elimination. The pharmacokinetics of itraconazole and the metabolite were modelled simultaneously using NONMEM. Dosing schedules were simulated to assess their ability to achieve a trough target concentration of 0.5 mg ml−1. Results Out of 241 blood samples, 94% were taken within the defined optimal sampling windows. A two-compartment model with first order absorption and elimination best described itraconazole kinetics, with first order metabolism to the hydroxy-metabolite. For itraconazole the absorption rate constants (between-subject variability) for capsule and solution were 0.0315 h−1 (91.9%) and 0.125 h−1 (106.3%), respectively, and the relative bioavailability of the capsule was 0.82 (62.3%) (confidence interval 0.36, 1.97), compared with the solution. There was no evidence of nonlinearity. Simulations from the final model showed that a dosing schedule of 500 mg twice daily for both formulations provided the highest chance of target success. Conclusion The optimal design performed well and the pharmacokinetics of itraconazole and hydroxy-itraconazole were described adequately by the model. The relative bioavailability for itraconazole capsules was 82% compared with the solution. PMID:17073891

Analytical solutions for combined close-contact and natural convection melting in horizontal cylindrical heat storage capsule

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saitoh, T.S.; Hoshi, A.

1998-07-01

Melting and solidification of a phase change material (PCM) in a capsule is of practical importance in latent heat thermal energy storage (LHTES) systems which are considered to be very promising to reduce a peak demand of electricity in the summer season and carbon dioxide (CO{sub 2}) emissions. Two melting modes are involved in melting of capsules. One is close-contact melting between the solid bulk and the capsule wall, and another is natural convection melting in the liquid region. Close-contact melting processes for a single enclosure have been solved using several numerical methods (e.g., Saitoh and Kato (1994)). In additionmore » close-contact melting heat transfer characteristics including melt flow in the liquid film under inner wall temperature distribution were analyzed and simple approximate equations were already presented by Saitoh and Hoshi (1997). The effects of Stefan number and variable temperature profile etc. were clarified in detail. And the melting velocity of the solid bulk under various conditions was also studied theoretically. In addition the effects of variable inner wall temperature on molten mass fraction were investigated. The present paper reports analytical solutions for combined close-contact and natural convection melting in horizontal cylindrical capsule. Moreover, natural convection melting in the liquid region were analyzed in this report. The upper interface shape of the solid bulk is approximated by a circular arc throughout the melting process. For the sake of verification, close-contact melting heat-transfer characteristics including natural convection in the liquid region were studied experimentally. Apparent shift of upper solid-liquid interface is good agreement with the experiment. The present simple approximate solutions will be useful to facilitate designing of the practical capsule bed LHTES systems.« less

SLI381 (Adderall XR), a two-component, extended-release formulation of mixed amphetamine salts: bioavailability of three test formulations and comparison of fasted, fed, and sprinkled administration.

PubMed

Tulloch, Simon J; Zhang, Yuxin; McLean, Angus; Wolf, Kathleen N

2002-11-01

To assess the bioavailability of three test formulations of a single dose of extended-release Adderall 20-mg capsules compared with two doses of immediate-release Adderall 10-mg tablets, and to assess the bioequivalence of a single 30-mg dose of the chosen extended-release Adderall formulation (designated as SLI381) administered in applesauce (sprinkled) and the same dose administered as an intact capsule with or without food. Randomized, open-label, crossover study. Clinical research unit. Forty-one healthy adults. Study A had four treatment sequences: three test formulations (A, B, and C) of a single dose of extended-release Adderall 20 mg, and two 10-mg doses of Adderall given 4 hours apart. Study B had three treatment sequences: a single dose of SLI381 30 mg as an intact capsule after overnight fast, an intact capsule after a high-fat breakfast, and the contents of a capsule sprinkled in 1 tablespoon of applesauce. The 20-mg test formulation A had comparable pharmacokinetic profiles and bioequivalence in rate and extent of drug absorption to Adderall 10 mg twice/day for both d- and l-amphetamine. Formulations B and C had statistically significant differences from the reference drug in some pharmacokinetic parameters. A 30-mg dose of SLI381 showed no significant differences in rate and extent of absorption of d- and l-amphetamine for fasted or sprinkled conditions compared with the high-fat meal condition. SLI381 20 mg/day is bioequivalent to Adderall 10 mg twice/day. SLI381 30 mg administered in applesauce is bioequivalent in terms of both rate and extent of absorption to the same dose administered as an intact capsule in both fasted and fed states.

Conceptual design of initial opacity experiments on the national ignition facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heeter, R.  F.; Bailey, J.  E.; Craxton, R.  S.

Accurate models of X-ray absorption and re-emission in partly stripped ions are necessary to calculate the structure of stars, the performance of hohlraums for inertial confinement fusion and many other systems in high-energy-density plasma physics. Despite theoretical progress, a persistent discrepancy exists with recent experiments at the Sandia Z facility studying iron in conditions characteristic of the solar radiative–convective transition region. The increased iron opacity measured at Z could help resolve a longstanding issue with the standard solar model, but requires a radical departure for opacity theory. To replicate the Z measurements, an opacity experiment has been designed for the National Facility (NIF). The design uses established techniques scaled to NIF. A laser-heated hohlraum will produce X-ray-heated uniform iron plasmas in local thermodynamic equilibrium (LTE) at temperaturesmore » $${\\geqslant}150$$ eV and electron densities$${\\geqslant}7\\times 10^{21}~\\text{cm}^{-3}$$. The iron will be probed using continuum X-rays emitted in a$${\\sim}200$$ ps,$${\\sim}200~\\unicode[STIX]{x03BC}\\text{m}$$diameter source from a 2 mm diameter polystyrene (CH) capsule implosion. In this design,$2/3$$of the NIF beams deliver 500 kJ to the$${\\sim}6$$ mm diameter hohlraum, and the remaining$$1/3$directly drive the CH capsule with 200 kJ. Calculations indicate this capsule backlighter should outshine the iron sample, delivering a point-projection transmission opacity measurement to a time-integrated X-ray spectrometer viewing down the hohlraum axis. Preliminary experiments to develop the backlighter and hohlraum are underway, informing simulated measurements to guide the final design.« less

Aerodynamics for the Mars Phoenix Entry Capsule

NASA Technical Reports Server (NTRS)

Edquist, Karl T.; Desai, Prasun N.; Schoenenberger, Mark

2008-01-01

Pre-flight aerodynamics data for the Mars Phoenix entry capsule are presented. The aerodynamic coefficients were generated as a function of total angle-of-attack and either Knudsen number, velocity, or Mach number, depending on the flight regime. The database was constructed using continuum flowfield computations and data from the Mars Exploration Rover and Viking programs. Hypersonic and supersonic static coefficients were derived from Navier-Stokes solutions on a pre-flight design trajectory. High-altitude data (free-molecular and transitional regimes) and dynamic pitch damping characteristics were taken from Mars Exploration Rover analysis and testing. Transonic static coefficients from Viking wind tunnel tests were used for capsule aerodynamics under the parachute. Static instabilities were predicted at two points along the reference trajectory and were verified by reconstructed flight data. During the hypersonic instability, the capsule was predicted to trim at angles as high as 2.5 deg with an on-axis center-of-gravity. Trim angles were predicted for off-nominal pitching moment (4.2 deg peak) and a 5 mm off-axis center-ofgravity (4.8 deg peak). Finally, hypersonic static coefficient sensitivities to atmospheric density were predicted to be within uncertainty bounds.

Factor structure of the Shoulder Pain and Disability Index in patients with adhesive capsulitis.

PubMed

Tveitå, Einar Kristian; Sandvik, Leiv; Ekeberg, Ole Marius; Juel, Niels Gunnar; Bautz-Holter, Erik

2008-07-17

The Shoulder Pain and Disability Index (SPADI) is a self-administered questionnaire that aims to measure pain and disability associated with shoulder disease. It consists of a pain section and a disability section with 13 items being responded to on visual analogue scales. Few researchers have investigated SPADI validity in specified diagnostic groups, although the selection of an evaluative instrument should be based on evidence of validity in the target patient group. The aim of the present study was to investigate factor structure of the SPADI in a study population of patients with adhesive capsulitis. The questionnaire was administered to 191 patients with adhesive capsulitis. Descriptive statistics for items and a comparison of scores for the two subscales were produced. Internal consistency was analyzed by use of the Cronbach alpha and a principal components analysis with varimax rotation was conducted. Study design was cross-sectional. Two factors were extracted, but the factor structure failed to support the original division of items into separate pain and disability sections. We found minimal evidence to justify the use of separate subscales for pain and disability. It is our impression that the SPADI should be viewed as essentially unidimensional in patients with adhesive capsulitis.

First shock tuning and backscatter measurements for large case-to-capsule ratio beryllium targets

NASA Astrophysics Data System (ADS)

Loomis, Eric; Yi, Austin; Kline, John; Kyrala, George; Simakov, Andrei; Wilson, Doug; Ralph, Joe; Dewald, Eduard; Strozzi, David; Celliers, Peter; Millot, Marius; Tommasini, Riccardo

2016-10-01

The current under performance of target implosions on the National Ignition Facility (NIF) has necessitated scaling back from high convergence ratio to access regimes of reduced physics uncertainties. These regimes, we expect, are more predictable by existing radiation hydrodynamics codes giving us a better starting point for isolating key physics questions. One key question is the lack of predictable in-flight and hot spot shape due to a complex hohlraum radiation environment. To achieve more predictable, shape tunable implosions we have designed and fielded a large 4.2 case-to-capsule ratio (CCR) target at the NIF using 6.72 mm diameter Au hohlraums and 1.6 mm diameter Cu-doped Be capsules. Simulations show that at these dimensions during a 10 ns 3-shock laser pulse reaching 270 eV hohlraum temperatures, the interaction between hohlraum and capsule plasma, which at lower CCR lead to beam propagation impedance by artificial plasma stagnation, are reduced. In this talk we will present measurements of early time drive symmetry using two-axis line-imaging velocimetry (VISAR) and streaked radiography measuring velocity of the imploding shell and their comparisons to post-shot calculations using the code HYDRA (Lawrence Livermore National Laboratory).

Tape Cassette Bacteria Detection System

NASA Technical Reports Server (NTRS)

1973-01-01

The design, fabrication, and testing of an automatic bacteria detection system with a zero-g capability and based on the filter-capsule approach is described. This system is intended for monitoring the sterility of regenerated water in a spacecraft. The principle of detection is based on measuring the increase in chemiluminescence produced by the action of bacterial porphyrins (i.e., catalase, cytochromes, etc.) on a luminol-hydrogen peroxide mixture. Since viable as well as nonviable organisms initiate this luminescence, viable organisms are detected by comparing the signal of an incubated water sample with an unincubated control. Higher signals for the former indicate the presence of viable organisms. System features include disposable sealed sterile capsules, each containing a filter membrane, for processing discrete water samples and a tape transport for moving these capsules through a processing sequence which involves sample concentration, nutrient addition, incubation, a 4 Molar Urea wash and reaction with luminol-hydrogen peroxide in front of a photomultiplier tube. Liquids are introduced by means of a syringe needle which pierces a rubber septum contained in the wall of the capsule. Detection thresholds obtained with this unit towards E. coli and S. marcescens assuming a 400 ml water sample are indicated.

Model-based approach for design verification and co-optimization of catastrophic and parametric-related defects due to systematic manufacturing variations

NASA Astrophysics Data System (ADS)

Perry, Dan; Nakamoto, Mark; Verghese, Nishath; Hurat, Philippe; Rouse, Rich

2007-03-01

Model-based hotspot detection and silicon-aware parametric analysis help designers optimize their chips for yield, area and performance without the high cost of applying foundries' recommended design rules. This set of DFM/ recommended rules is primarily litho-driven, but cannot guarantee a manufacturable design without imposing overly restrictive design requirements. This rule-based methodology of making design decisions based on idealized polygons that no longer represent what is on silicon needs to be replaced. Using model-based simulation of the lithography, OPC, RET and etch effects, followed by electrical evaluation of the resulting shapes, leads to a more realistic and accurate analysis. This analysis can be used to evaluate intelligent design trade-offs and identify potential failures due to systematic manufacturing defects during the design phase. The successful DFM design methodology consists of three parts: 1. Achieve a more aggressive layout through limited usage of litho-related recommended design rules. A 10% to 15% area reduction is achieved by using more aggressive design rules. DFM/recommended design rules are used only if there is no impact on cell size. 2. Identify and fix hotspots using a model-based layout printability checker. Model-based litho and etch simulation are done at the cell level to identify hotspots. Violations of recommended rules may cause additional hotspots, which are then fixed. The resulting design is ready for step 3. 3. Improve timing accuracy with a process-aware parametric analysis tool for transistors and interconnect. Contours of diffusion, poly and metal layers are used for parametric analysis. In this paper, we show the results of this physical and electrical DFM methodology at Qualcomm. We describe how Qualcomm was able to develop more aggressive cell designs that yielded a 10% to 15% area reduction using this methodology. Model-based shape simulation was employed during library development to validate architecture choices and to optimize cell layout. At the physical verification stage, the shape simulator was run at full-chip level to identify and fix residual hotspots on interconnect layers, on poly or metal 1 due to interaction between adjacent cells, or on metal 1 due to interaction between routing (via and via cover) and cell geometry. To determine an appropriate electrical DFM solution, Qualcomm developed an experiment to examine various electrical effects. After reporting the silicon results of this experiment, which showed sizeable delay variations due to lithography-related systematic effects, we also explain how contours of diffusion, poly and metal can be used for silicon-aware parametric analysis of transistors and interconnect at the cell-, block- and chip-level.

Acquisition/expulsion system for earth orbital propulsion system study. Volume 5: Earth storable design

NASA Technical Reports Server (NTRS)

1973-01-01

A comprehensive analysis and parametric design effort was conducted under the earth-storable phase of the program. Passive Acquisition/expulsion system concepts were evaluated for a reusable Orbital Maneuvering System (OMS) application. The passive surface tension technique for providing gas free liquid on demand was superior to other propellant acquisition methods. Systems using fine mesh screens can provide the requisite stability and satisfy OMS mission requirements. Both fine mesh screen liner and trap systems were given detailed consideration in the parametric design, and trap systems were selected for this particular application. These systems are compatible with the 100- to 500-manned mission reuse requirements.

Biocompatible Capsules and Methods of Making

NASA Technical Reports Server (NTRS)

Loftus, David J. (Inventor)

2017-01-01

Embodiments of the invention include capsules for containing medical implants and delivery systems for release of active biological substances into a host body. Delivery systems comprise a capsule comprising an interior enclosed by walls, and a source of active biological substances enclosed within the capsule interior, wherein the active biological substances are free to diffuse across the capsule walls. The capsule walls comprise a continuous mesh of biocompatible fibers and a seal region where two capsule walls overlap. The interior of the capsule is substantially isolated from the medium surrounding the capsule, except for diffusion of at least one species of molecule between the capsule interior and the ambient medium, and prevents cell migration into or out of the capsule. Methods for preparing and using the capsules and delivery systems are provided.

Ince-Strutt stability charts for ship parametric roll resonance in irregular waves

NASA Astrophysics Data System (ADS)

Zhang, Xiao; Yang, He-zhen; Xiao, Fei; Xu, Pei-ji

2017-08-01

Ince-Strutt stability chart of ship parametric roll resonance in irregular waves is conducted and utilized for the exploration of the parametric roll resonance in irregular waves. Ship parametric roll resonance will lead to large amplitude roll motion and even wreck. Firstly, the equation describing the parametric roll resonance in irregular waves is derived according to Grim's effective theory and the corresponding Ince-Strutt stability charts are obtained. Secondly, the differences of stability charts for the parametric roll resonance in irregular and regular waves are compared. Thirdly, wave phases and peak periods are taken into consideration to obtain a more realistic sea condition. The influence of random wave phases should be taken into consideration when the analyzed points are located near the instability boundary. Stability charts for different wave peak periods are various. Stability charts are helpful for the parameter determination in design stage to better adapt to sailing condition. Last, ship variables are analyzed according to stability charts by a statistical approach. The increase of the metacentric height will help improve ship stability.

Phase noise suppression through parametric filtering

NASA Astrophysics Data System (ADS)

Cassella, Cristian; Strachan, Scott; Shaw, Steven W.; Piazza, Gianluca

2017-02-01

In this work, we introduce and experimentally demonstrate a parametric phase noise suppression technique, which we call "parametric phase noise filtering." This technique is based on the use of a solid-state parametric amplifier operating in its instability region and included in a non-autonomous feedback loop connected at the output of a noisy oscillator. We demonstrate that such a system behaves as a parametrically driven Duffing resonator and can operate at special points where it becomes largely immune to the phase fluctuations that affect the oscillator output signal. A prototype of a parametric phase noise filter (PFIL) was designed and fabricated to operate in the very-high-frequency range. The PFIL prototype allowed us to significantly reduce the phase noise at the output of a commercial signal generator operating around 220 MHz. Noise reduction of 16 dB (40×) and 13 dB (20×) were obtained, respectively, at 1 and 10 kHz offsets from the carrier frequency. The demonstration of this phase noise suppression technique opens up scenarios in the development of passive and low-cost phase noise cancellation circuits for any application demanding high quality frequency generation.

Experiments to measure ablative Richtmyer-Meshkov growth of Gaussian bumps in plastic capsules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loomis, Eric; Batha, Steve; Sedillo, Tom

2010-06-02

Growth of hydrodynamic instabilities at the interfaces of inertial confinement fusion capsules (ICF) due to ablator and fuel non-uniformities have been of primary concern to the ICF program since its inception. To achieve thermonuclear ignition at Megajoule class laser systems such as the NIF, targets must be designed for high implosion velocities, which requires higher in-flight aspect ratios (IFAR) and diminished shell stability. Controlling capsule perturbations is thus of the utmost importance. Recent simulations have shown that features on the outer surface of an ICF capsule as small as 10 microns wide and 100's of nanometers tall such as bumps,more » divots, or even dust particles can profoundly impact capsule performance by leading to material jetting or mix into the hotspot. Recent x-ray images of implosions on the NIF may be evidence of such mixing. Unfortunately, our ability to accurately predict these effects is uncertain due to disagreement between equation of state (EOS) models. In light of this, we have begun a campaign to measure the growth of isolated defects (Gaussian bumps) due to ablative Richtmyer-Meshkov in CH capsules to validate these models. The platform that has been developed uses halfraums with radiation temperatures near 75 eV (Rev. 4 foot-level) driven by 15-20 beams from the Omega laser (Laboratory for Laser Energetics, University of Rochester, NY), which sends a ~2.5 Mbar shock into a planar CH foil. Gaussian-shaped bumps (20 microns wide, 4-7 microns tall) are deposited onto the ablation side of the target. On-axis radiography with a saran (Cl He α - 2.8 keV) backlighter is used to measure bump evolution prior to shock breakout. Shock speed measurements will also be made with Omega's active shock breakout (ASBO) and streaked optical pyrometery (SOP) diagnostics in conjunction with filtered x-ray photodiode arrays (DANTE) to determine drive conditions in the target. These data will be used to discriminate between EOS models so that one may be selected to design the shape and intensity of the foot in an ignition-level drive pulse so that bump amplitude is minimized by the time the shell begins to accelerate.« less

Visual Literacy and the Integration of Parametric Modeling in the Problem-Based Curriculum

ERIC Educational Resources Information Center

Assenmacher, Matthew Benedict

2013-01-01

This quasi-experimental study investigated the application of visual literacy skills in the form of parametric modeling software in relation to traditional forms of sketching. The study included two groups of high school technical design students. The control and experimental groups involved in the study consisted of two randomly selected groups…

Optical parametric amplifiers using chirped quasi-phase-matching gratings I: practical design formulas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Charbonneau-Lefort, Mathieu; Afeyan, Bedros; Fejer, M. M.

Optical parametric amplifiers using chirped quasi-phase-matching (QPM) gratings offer the possibility of engineering the gain and group delay spectra. We give practical formulas for the design of such amplifiers. We consider linearly chirped QPM gratings providing constant gain over a broad bandwidth, sinusoidally modulated profiles for selective frequency amplification and a pair of QPM gratings working in tandem to ensure constant gain and constant group delay at the same time across the spectrum. Finally, the analysis is carried out in the frequency domain using Wentzel–Kramers–Brillouin analysis.

Development of the prototype pneumatic transfer system for ITER neutron activation system.

PubMed

Cheon, M S; Seon, C R; Pak, S; Lee, H G; Bertalot, L

2012-10-01

The neutron activation system (NAS) measures neutron fluence at the first wall and the total neutron flux from the ITER plasma, providing evaluation of the fusion power for all operational phases. The pneumatic transfer system (PTS) is one of the key components of the NAS for the proper operation of the system, playing a role of transferring encapsulated samples between the capsule loading machine, irradiation stations, counting stations, and disposal bin. For the validation and the optimization of the design, a prototype of the PTS was developed and capsule transfer tests were performed with the developed system.

Review of high convergence implosion experiments with single and double shell targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delamater, N. D.; Watt, R. G.; Varnum, W. S.

2002-01-01

Experiments have been been performed in recent years at the Omega laser studying double shell capsules as an a1 teinative, 11011 cryogenic, path towards ignition at NTF. Double shell capsules designed to mitigate the Au M-band radiation asymmetries, were experimentally found to perform well in both spherical and cylindrical hohlraums, achieving near 1-D (-90 %) clean calculated yield at convergence comparable to that required for NIF ignition. Near-term plans include directly driven double shell experiments at Omega, which eliminates Au M-band radiation as a yield degradation m ec h an i s in.

High-density carbon (HDC) capsule designs for α-heating and for ignition

NASA Astrophysics Data System (ADS)

Ho, D.; Amendt, A.; Clark, D.; Haan, S.; Milovich, J.; Salmonson, J.; Zimmerman, G.; Berzak Hopkins, L.; Biener, J.; Meezan, N.; Thomas, C.; Benedict, L.; Le Pape, S.; MacKinnon, A.; Ross, S.

2014-10-01

We show capsule designs that have HDC ablators, using 2, 3 and 4 shocks. Their advantages and disadvantages will be discussed. Two-shock designs have the shortest pulse length but have the worst 1-D ignition margin because of the high fuel adiabat. Four-shock designs have the highest 1-D ignition margin with the lowest adiabat, but have higher RT ablation front growth. This disadvantage can be overcome by using a picket to generate the 1st shock. The picket reduces the RT growth factor while the decaying 1st shock lowers the fuel adiabat further. The picket has the additional advantage of shortening the pulse length. Dopant requirements for different hohlraums will be discussed. A 3-shock design for achieving alpha heating is described, which can use either high-gas-fill (1.6 mg/cc) or near-vacuum hohlraums. A rugby-shaped hohlraum with low gas-fill (0.5 mg/cc) has high laser coupling efficiency and provides good symmetry for a 4-shock design. Comparison of simulations for selected recent HDC shots with experimental data will be presented. Prepared by LLNL under Contract DE-AC52-07NA27344.

Effectiveness of Cranberry Capsules to Prevent Urinary Tract Infections in Vulnerable Older Persons: A Double-Blind Randomized Placebo-Controlled Trial in Long-Term Care Facilities

PubMed Central

Caljouw, Monique A A; van den Hout, Wilbert B; Putter, Hein; Achterberg, Wilco P; Cools, Herman J M; Gussekloo, Jacobijn

2014-01-01

Objectives To determine whether cranberry capsules prevent urinary tract infection (UTI) in long-term care facility (LTCF) residents. Design Double-blind randomized placebo-controlled multicenter trial. Setting Long-term care facilities (LTCFs). Participants LTCF residents (N = 928; 703 women, median age 84). Measurements Cranberry and placebo capsules were taken twice daily for 12 months. Participants were stratified according to UTI risk (risk factors included long-term catheterization, diabetes mellitus, ≥1 UTI in preceding year). Main outcomes were incidence of UTI according to a clinical definition and a strict definition. Results In participants with high UTI risk at baseline (n = 516), the incidence of clinically defined UTI was lower with cranberry capsules than with placebo (62.8 vs 84.8 per 100 person-years at risk, P = .04); the treatment effect was 0.74 (95% confidence interval (CI) = 0.57–0.97). For the strict definition, the treatment effect was 1.02 (95% CI = 0.68–1.55). No difference in UTI incidence between cranberry and placebo was found in participants with low UTI risk (n = 412). Conclusion In LTCF residents with high UTI risk at baseline, taking cranberry capsules twice daily reduces the incidence of clinically defined UTI, although it does not reduce the incidence of strictly defined UTI. No difference in incidence of UTI was found in residents with low UTI risk. PMID:25180378

Development of cubic Bezier curve and curve-plane intersection method for parametric submarine hull form design to optimize hull resistance using CFD

NASA Astrophysics Data System (ADS)

Chrismianto, Deddy; Zakki, Ahmad Fauzan; Arswendo, Berlian; Kim, Dong Joon

2015-12-01

Optimization analysis and computational fluid dynamics (CFDs) have been applied simultaneously, in which a parametric model plays an important role in finding the optimal solution. However, it is difficult to create a parametric model for a complex shape with irregular curves, such as a submarine hull form. In this study, the cubic Bezier curve and curve-plane intersection method are used to generate a solid model of a parametric submarine hull form taking three input parameters into account: nose radius, tail radius, and length-height hull ratio ( L/ H). Application program interface (API) scripting is also used to write code in the ANSYS design modeler. The results show that the submarine shape can be generated with some variation of the input parameters. An example is given that shows how the proposed method can be applied successfully to a hull resistance optimization case. The parametric design of the middle submarine type was chosen to be modified. First, the original submarine model was analyzed, in advance, using CFD. Then, using the response surface graph, some candidate optimal designs with a minimum hull resistance coefficient were obtained. Further, the optimization method in goal-driven optimization (GDO) was implemented to find the submarine hull form with the minimum hull resistance coefficient ( C t ). The minimum C t was obtained. The calculated difference in C t values between the initial submarine and the optimum submarine is around 0.26%, with the C t of the initial submarine and the optimum submarine being 0.001 508 26 and 0.001 504 29, respectively. The results show that the optimum submarine hull form shows a higher nose radius ( r n ) and higher L/ H than those of the initial submarine shape, while the radius of the tail ( r t ) is smaller than that of the initial shape.

A comparative study on liquid core formulation on the diameter on the alginate capsules

NASA Astrophysics Data System (ADS)

Ong, Hui-Yen; Lee, Boon-Beng; Radzi, AkmalHadi Ma'; Zakaria, Zarina; Chan, Eng-Seng

2015-08-01

Liquid core capsule has vast application in biotechnology related industries such as pharmaceutical, medical, agriculture and food. Formulation of different types of capsule was important to determine the performance of the capsule. Generally, the liquid core capsule with different formulations generated different size of capsule.Therefore, the aim of this project is to investigate the effect of different liquid core solution formulations on the diameter of capsule. The capsule produced by extruding liquid core solutions into sodium alginate solution. Three types of liquid core solutions (chitosan, xanthan gum, polyethylene glycol (PEG)) were investigated. The results showed that there is significant change in capsule diameter despite in different types of liquid core solution were used and a series of capsule range in diameter of 3.1 mm to 4.5 mm were produced. Alginate capsule with chitosan formulation appeared to be the largest capsule among all.

Remote magnetic manipulation of a wireless capsule endoscope in the esophagus and stomach of humans (with videos).

PubMed

Swain, Paul; Toor, Arifa; Volke, Frank; Keller, Jutta; Gerber, Jeremy; Rabinovitz, Elisha; Rothstein, Richard I

2010-06-01

Remote manipulation of wireless capsule endoscopes might improve diagnostic accuracy and facilitate therapy. To test a new capsule-manipulation system. University hospital. A first-in-human study tested a new magnetic maneuverable wireless capsule in a volunteer. A wireless capsule endoscope was modified to include neodymium-iron-boron magnets. The capsule's magnetic switch was replaced with a thermal one and turned on by placing it in hot water. One imager was removed from the PillCam colon-based capsule, and the available space was used to house the magnets. A handheld external magnet was used to manipulate this capsule in the esophagus and stomach. The capsule was initiated by placing it in a microg of hot water. The capsule was swallowed and observed in the esophagus and stomach by using a gastroscope. Capsule images were viewed on a real-time viewer. The capsule was manipulated in the esophagus for 10 minutes. It was easy to make the capsule turn somersaults and to angulate at the cardioesophageal junction. In the stomach, it was easy to move the capsule back from the pylorus to the cardioesophageal junction and hold/spin the capsule at any position in the stomach. The capsule in the esophagus and stomach did not cause discomfort. Magnetic force varies with the fourth power of distance. This study suggests that remote manipulation of a capsule in the esophagus and stomach of a human is feasible and might enhance diagnostic endoscopy as well as enable therapeutic wireless capsule endoscopy. Copyright 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Least median of squares and iteratively re-weighted least squares as robust linear regression methods for fluorimetric determination of α-lipoic acid in capsules in ideal and non-ideal cases of linearity.

PubMed

Korany, Mohamed A; Gazy, Azza A; Khamis, Essam F; Ragab, Marwa A A; Kamal, Miranda F

2018-06-01

This study outlines two robust regression approaches, namely least median of squares (LMS) and iteratively re-weighted least squares (IRLS) to investigate their application in instrument analysis of nutraceuticals (that is, fluorescence quenching of merbromin reagent upon lipoic acid addition). These robust regression methods were used to calculate calibration data from the fluorescence quenching reaction (∆F and F-ratio) under ideal or non-ideal linearity conditions. For each condition, data were treated using three regression fittings: Ordinary Least Squares (OLS), LMS and IRLS. Assessment of linearity, limits of detection (LOD) and quantitation (LOQ), accuracy and precision were carefully studied for each condition. LMS and IRLS regression line fittings showed significant improvement in correlation coefficients and all regression parameters for both methods and both conditions. In the ideal linearity condition, the intercept and slope changed insignificantly, but a dramatic change was observed for the non-ideal condition and linearity intercept. Under both linearity conditions, LOD and LOQ values after the robust regression line fitting of data were lower than those obtained before data treatment. The results obtained after statistical treatment indicated that the linearity ranges for drug determination could be expanded to lower limits of quantitation by enhancing the regression equation parameters after data treatment. Analysis results for lipoic acid in capsules, using both fluorimetric methods, treated by parametric OLS and after treatment by robust LMS and IRLS were compared for both linearity conditions. Copyright © 2018 John Wiley & Sons, Ltd.

Transit Technology Evaluation - A Literature Capsule

DOT National Transportation Integrated Search

1981-11-01

The report is designed to make the literature on transportation concerning promising new transit technology more accessible to users. The Transit Technology Evaluation Program investigates the technical, social, and economic factors involved in the p...

Capsule Endoscope Aspiration after Repeated Attempts for Ingesting a Patency Capsule

PubMed Central

Mannami, Tomohiko; Ikeda, Genyo; Seno, Satoru; Sonobe, Hiroshi; Fujiwara, Nobukiyo; Komoda, Minori; Edahiro, Satoru; Ohtawa, Yasuyuki; Fujimoto, Yoshimi; Sato, Naohiro; Kambara, Takeshi; Waku, Toshihiko

2015-01-01

Capsule endoscope aspiration into the respiratory tract is a rare complication of capsule endoscopy. Despite the potential seriousness of this complication, no accepted methods exist to accurately predict and therefore prevent it. We describe the case of an 85-year-old male who presented for evaluation of iron deficiency anemia. He complained of dysphagia while ingesting a patency capsule, with several attempts over a period of 5 min before he was successful. Five days later, he underwent capsule endoscopy, where he experienced similar symptoms in swallowing the capsule. The rest of the examination proceeded uneventfully. On reviewing the captured images, the capsule endoscope was revealed to be aspirated, remaining in the respiratory tract for approximately 220 s before images of the esophagus and stomach appeared. To our knowledge, this is the first documented case of a patient who experienced capsule endoscope aspiration after ingestion of a patency capsule. This case suggests that repeated attempts required for ingesting the patency capsule can predict capsule endoscope aspiration. We presume that paying sufficient attention to the symptoms of a patient who ingests a patency capsule could help us prevent serious complications such as aspiration of the capsule endoscope. In addition, this experience implies the potential risk for ingesting the patency capsule. We must be aware that the patency capsule could also be aspirated and there may be more unrecognized aspiration cases. PMID:26600772

Capsule Endoscope Aspiration after Repeated Attempts for Ingesting a Patency Capsule.

PubMed

Mannami, Tomohiko; Ikeda, Genyo; Seno, Satoru; Sonobe, Hiroshi; Fujiwara, Nobukiyo; Komoda, Minori; Edahiro, Satoru; Ohtawa, Yasuyuki; Fujimoto, Yoshimi; Sato, Naohiro; Kambara, Takeshi; Waku, Toshihiko

2015-01-01

Capsule endoscope aspiration into the respiratory tract is a rare complication of capsule endoscopy. Despite the potential seriousness of this complication, no accepted methods exist to accurately predict and therefore prevent it. We describe the case of an 85-year-old male who presented for evaluation of iron deficiency anemia. He complained of dysphagia while ingesting a patency capsule, with several attempts over a period of 5 min before he was successful. Five days later, he underwent capsule endoscopy, where he experienced similar symptoms in swallowing the capsule. The rest of the examination proceeded uneventfully. On reviewing the captured images, the capsule endoscope was revealed to be aspirated, remaining in the respiratory tract for approximately 220 s before images of the esophagus and stomach appeared. To our knowledge, this is the first documented case of a patient who experienced capsule endoscope aspiration after ingestion of a patency capsule. This case suggests that repeated attempts required for ingesting the patency capsule can predict capsule endoscope aspiration. We presume that paying sufficient attention to the symptoms of a patient who ingests a patency capsule could help us prevent serious complications such as aspiration of the capsule endoscope. In addition, this experience implies the potential risk for ingesting the patency capsule. We must be aware that the patency capsule could also be aspirated and there may be more unrecognized aspiration cases.

Parametric Geometry, Structured Grid Generation, and Initial Design Study for REST-Class Hypersonic Inlets

NASA Technical Reports Server (NTRS)

Ferlemann, Paul G.; Gollan, Rowan J.

2010-01-01

Computational design and analysis of three-dimensional hypersonic inlets with shape transition has been a significant challenge due to the complex geometry and grid required for three-dimensional viscous flow calculations. Currently, the design process utilizes an inviscid design tool to produce initial inlet shapes by streamline tracing through an axisymmetric compression field. However, the shape is defined by a large number of points rather than a continuous surface and lacks important features such as blunt leading edges. Therefore, a design system has been developed to parametrically construct true CAD geometry and link the topology of a structured grid to the geometry. The Adaptive Modeling Language (AML) constitutes the underlying framework that is used to build the geometry and grid topology. Parameterization of the CAD geometry allows the inlet shapes produced by the inviscid design tool to be generated, but also allows a great deal of flexibility to modify the shape to account for three-dimensional viscous effects. By linking the grid topology to the parametric geometry, the GridPro grid generation software can be used efficiently to produce a smooth hexahedral multiblock grid. To demonstrate the new capability, a matrix of inlets were designed by varying four geometry parameters in the inviscid design tool. The goals of the initial design study were to explore inviscid design tool geometry variations with a three-dimensional analysis approach, demonstrate a solution rate which would enable the use of high-fidelity viscous three-dimensional CFD in future design efforts, process the results for important performance parameters, and perform a sample optimization.

Development of a design space and predictive statistical model for capsule filling of low-fill-weight inhalation products.

PubMed

Faulhammer, E; Llusa, M; Wahl, P R; Paudel, A; Lawrence, S; Biserni, S; Calzolari, V; Khinast, J G

2016-01-01

The objectives of this study were to develop a predictive statistical model for low-fill-weight capsule filling of inhalation products with dosator nozzles via the quality by design (QbD) approach and based on that to create refined models that include quadratic terms for significant parameters. Various controllable process parameters and uncontrolled material attributes of 12 powders were initially screened using a linear model with partial least square (PLS) regression to determine their effect on the critical quality attributes (CQA; fill weight and weight variability). After identifying critical material attributes (CMAs) and critical process parameters (CPPs) that influenced the CQA, model refinement was performed to study if interactions or quadratic terms influence the model. Based on the assessment of the effects of the CPPs and CMAs on fill weight and weight variability for low-fill-weight inhalation products, we developed an excellent linear predictive model for fill weight (R(2 )= 0.96, Q(2 )= 0.96 for powders with good flow properties and R(2 )= 0.94, Q(2 )= 0.93 for cohesive powders) and a model that provides a good approximation of the fill weight variability for each powder group. We validated the model, established a design space for the performance of different types of inhalation grade lactose on low-fill weight capsule filling and successfully used the CMAs and CPPs to predict fill weight of powders that were not included in the development set.

Application of Taguchi methods to dual mixture ratio propulsion system optimization for SSTO vehicles

NASA Technical Reports Server (NTRS)

Stanley, Douglas O.; Unal, Resit; Joyner, C. R.

1992-01-01

The application of advanced technologies to future launch vehicle designs would allow the introduction of a rocket-powered, single-stage-to-orbit (SSTO) launch system early in the next century. For a selected SSTO concept, a dual mixture ratio, staged combustion cycle engine that employs a number of innovative technologies was selected as the baseline propulsion system. A series of parametric trade studies are presented to optimize both a dual mixture ratio engine and a single mixture ratio engine of similar design and technology level. The effect of varying lift-off thrust-to-weight ratio, engine mode transition Mach number, mixture ratios, area ratios, and chamber pressure values on overall vehicle weight is examined. The sensitivity of the advanced SSTO vehicle to variations in each of these parameters is presented, taking into account the interaction of each of the parameters with each other. This parametric optimization and sensitivity study employs a Taguchi design method. The Taguchi method is an efficient approach for determining near-optimum design parameters using orthogonal matrices from design of experiments (DOE) theory. Using orthogonal matrices significantly reduces the number of experimental configurations to be studied. The effectiveness and limitations of the Taguchi method for propulsion/vehicle optimization studies as compared to traditional single-variable parametric trade studies is also discussed.

Experimental parametric study of servers cooling management in data centers buildings

NASA Astrophysics Data System (ADS)

Nada, S. A.; Elfeky, K. E.; Attia, Ali M. A.; Alshaer, W. G.

2017-06-01

A parametric study of air flow and cooling management of data centers servers is experimentally conducted for different design conditions. A physical scale model of data center accommodating one rack of four servers was designed and constructed for testing purposes. Front and rear rack and server's temperatures distributions and supply/return heat indices (SHI/RHI) are used to evaluate data center thermal performance. Experiments were conducted to parametrically study the effects of perforated tiles opening ratio, servers power load variation and rack power density. The results showed that (1) perforated tile of 25% opening ratio provides the best results among the other opening ratios, (2) optimum benefit of cold air in servers cooling is obtained at uniformly power loading of servers (3) increasing power density decrease air re-circulation but increase air bypass and servers temperature. The present results are compared with previous experimental and CFD results and fair agreement was found.

Empirical validation of statistical parametric mapping for group imaging of fast neural activity using electrical impedance tomography.

PubMed

Packham, B; Barnes, G; Dos Santos, G Sato; Aristovich, K; Gilad, O; Ghosh, A; Oh, T; Holder, D

2016-06-01

Electrical impedance tomography (EIT) allows for the reconstruction of internal conductivity from surface measurements. A change in conductivity occurs as ion channels open during neural activity, making EIT a potential tool for functional brain imaging. EIT images can have  >10 000 voxels, which means statistical analysis of such images presents a substantial multiple testing problem. One way to optimally correct for these issues and still maintain the flexibility of complicated experimental designs is to use random field theory. This parametric method estimates the distribution of peaks one would expect by chance in a smooth random field of a given size. Random field theory has been used in several other neuroimaging techniques but never validated for EIT images of fast neural activity, such validation can be achieved using non-parametric techniques. Both parametric and non-parametric techniques were used to analyze a set of 22 images collected from 8 rats. Significant group activations were detected using both techniques (corrected p  <  0.05). Both parametric and non-parametric analyses yielded similar results, although the latter was less conservative. These results demonstrate the first statistical analysis of such an image set and indicate that such an analysis is an approach for EIT images of neural activity.

Empirical validation of statistical parametric mapping for group imaging of fast neural activity using electrical impedance tomography

PubMed Central

Packham, B; Barnes, G; dos Santos, G Sato; Aristovich, K; Gilad, O; Ghosh, A; Oh, T; Holder, D

2016-01-01

Abstract Electrical impedance tomography (EIT) allows for the reconstruction of internal conductivity from surface measurements. A change in conductivity occurs as ion channels open during neural activity, making EIT a potential tool for functional brain imaging. EIT images can have  >10 000 voxels, which means statistical analysis of such images presents a substantial multiple testing problem. One way to optimally correct for these issues and still maintain the flexibility of complicated experimental designs is to use random field theory. This parametric method estimates the distribution of peaks one would expect by chance in a smooth random field of a given size. Random field theory has been used in several other neuroimaging techniques but never validated for EIT images of fast neural activity, such validation can be achieved using non-parametric techniques. Both parametric and non-parametric techniques were used to analyze a set of 22 images collected from 8 rats. Significant group activations were detected using both techniques (corrected p  <  0.05). Both parametric and non-parametric analyses yielded similar results, although the latter was less conservative. These results demonstrate the first statistical analysis of such an image set and indicate that such an analysis is an approach for EIT images of neural activity. PMID:27203477

Orion is back on This Week @NASA - December 12, 2014

NASA Image and Video Library

2014-12-12

The hugely successful first flight test on Dec. 5 of NASA’s Orion spacecraft took it farther than any spacecraft designed for astronauts has been in more than 40 years. The two-orbit, 4.5 hour trip into space was designed to test many of Orion’s systems critical to crew safety – with data collected by more than 1,200 onboard sensors. The capsule splashed down in the Pacific Ocean about 600 miles southwest of San Diego and was recovered by a team of NASA, U.S. Navy and Lockheed Martin personnel aboard the USS Anchorage. Final destination for NASA’s new deep space capsule is Kennedy Space Center in Florida – where its first journey to space began – so engineers there can evaluate the data. Orion will open the space between Earth and Mars for exploration by astronauts and testing of the capabilities and technologies needed for future human missions to Mars. Also, Curiosity’s Mount Sharp findings, New Horizons’ wake-up call and Enabling unique aircraft design!

Magnetically-driven medical robots: An analytical magnetic model for endoscopic capsules design

NASA Astrophysics Data System (ADS)

Li, Jing; Barjuei, Erfan Shojaei; Ciuti, Gastone; Hao, Yang; Zhang, Peisen; Menciassi, Arianna; Huang, Qiang; Dario, Paolo

2018-04-01

Magnetic-based approaches are highly promising to provide innovative solutions for the design of medical devices for diagnostic and therapeutic procedures, such as in the endoluminal districts. Due to the intrinsic magnetic properties (no current needed) and the high strength-to-size ratio compared with electromagnetic solutions, permanent magnets are usually embedded in medical devices. In this paper, a set of analytical formulas have been derived to model the magnetic forces and torques which are exerted by an arbitrary external magnetic field on a permanent magnetic source embedded in a medical robot. In particular, the authors modelled cylindrical permanent magnets as general solution often used and embedded in magnetically-driven medical devices. The analytical model can be applied to axially and diametrically magnetized, solid and annular cylindrical permanent magnets in the absence of the severe calculation complexity. Using a cylindrical permanent magnet as a selected solution, the model has been applied to a robotic endoscopic capsule as a pilot study in the design of magnetically-driven robots.

Thermal Protection System (Heat Shield) Development - Advanced Development Project

NASA Technical Reports Server (NTRS)

Kowal, T. John

2010-01-01

The Orion Thermal Protection System (TPS) ADP was a 3 1/2 year effort to develop ablative TPS materials for the Orion crew capsule. The ADP was motivated by the lack of available ablative TPS's. The TPS ADP pursued a competitive phased development strategy with succeeding rounds of development, testing and down selections. The Project raised the technology readiness level (TRL) of 8 different TPS materials from 5 different commercial vendors, eventual down selecting to a single material system for the Orion heat shield. In addition to providing a heat shield material and design for Orion on time and on budget, the Project accomplished the following: 1) Re-invigorated TPS industry & re-established a NASA competency to respond to future TPS needs; 2) Identified a potentially catastrophic problem with the planned MSL heat shield, and provided a viable, high TRL alternate heat shield design option; and 3) Transferred mature heat shield material and design options to the commercial space industry, including TPS technology information for the SpaceX Dragon capsule.

Aerospace Education Course Syllabus.

ERIC Educational Resources Information Center

Civil Air Patrol, Maxwell AFB, AL.

This syllabus has been designed to provide the classroom teacher with a capsulized view and understanding of a one-year course at the high school level. This course is designed to be an integral part of the existing general educational program of the school and is general and introductory in nature, rather than inclusive. This syllabus is to be…

Putting Industrial Arts on Wheels.

ERIC Educational Resources Information Center

Schwaar, Walter L.

1967-01-01

A discussion augmented by plans of a partially transportable industrial arts learning laboratory. The design calls for four laboratories, parts of which are fixed and parts of which are capsule sections which can be rotated between four junior high schools on a nine week basis. Advantages and disadvantages of the design are discussed in sections…

Design of a Modular Monolithic Implicit Solver for Multi-Physics Applications

NASA Technical Reports Server (NTRS)

Carton De Wiart, Corentin; Diosady, Laslo T.; Garai, Anirban; Burgess, Nicholas; Blonigan, Patrick; Ekelschot, Dirk; Murman, Scott M.

2018-01-01

The design of a modular multi-physics high-order space-time finite-element framework is presented together with its extension to allow monolithic coupling of different physics. One of the main objectives of the framework is to perform efficient high- fidelity simulations of capsule/parachute systems. This problem requires simulating multiple physics including, but not limited to, the compressible Navier-Stokes equations, the dynamics of a moving body with mesh deformations and adaptation, the linear shell equations, non-re effective boundary conditions and wall modeling. The solver is based on high-order space-time - finite element methods. Continuous, discontinuous and C1-discontinuous Galerkin methods are implemented, allowing one to discretize various physical models. Tangent and adjoint sensitivity analysis are also targeted in order to conduct gradient-based optimization, error estimation, mesh adaptation, and flow control, adding another layer of complexity to the framework. The decisions made to tackle these challenges are presented. The discussion focuses first on the "single-physics" solver and later on its extension to the monolithic coupling of different physics. The implementation of different physics modules, relevant to the capsule/parachute system, are also presented. Finally, examples of coupled computations are presented, paving the way to the simulation of the full capsule/parachute system.

Hohlraum design for the LMJ ignition target

NASA Astrophysics Data System (ADS)

Malinie, G.; Cherfils, C.; Gauthier, P.; Lambert, F.; Monteil, M. C.

2011-10-01

First experiments with the Laser MegaJoule (LMJ) are scheduled to be performed in 2014. The current nominal point design for ignition with 160 beams on the LMJ has been described in. It consists of an indirectly driven A943 capsule, with a plastic ablator doped with Germanium. This capsule is mounted in the center of a Rugby-shaped hohlraum, which is filled with a low density H/He gas, and has a gold-uranium cocktail wall lined with pure gold. We investigate the influence of two key parameters of the hohlraum design: the radius of the laser entrance holes (LEHs), and the thickness of the cocktail layer. Since the Rugby shape of the nominal point design is that of a half-ellipse going from the hohlraum waist to the LEH, any change in the LEH radius has a global effect on the hohlraum shape. Taking into account the current laser spot profiles of the LMJ and using 2D integrated calculations with our FCI2 radiation hydrodynamics code, we assess the flexiblility we have to reduce the LEH radius and/or the cocktail layer thickness.

Development of an acoustic filter for parametric loudspeaker using phononic crystals.

PubMed

Ji, Peifeng; Hu, Wenlin; Yang, Jun

2016-04-01

The spurious signal generated as a result of nonlinearity at the receiving system affects the measurement of the difference-frequency sound in the parametric loudspeaker, especially in the nearfield or near the beam axis. In this paper, an acoustic filter is designed using phononic crystals and its theoretical simulations are carried out by quasi-one- and two-dimensional models with Comsol Multiphysics. According to the simulated transmission loss (TL), an acoustic filter is prototyped consisting of 5×7 aluminum alloy cylinders and its performance is verified experimentally. There is good agreement with the simulation result for TL. After applying our proposed filter in the axial measurement of the parametric loudspeaker, a clear frequency dependence from parametric array effect is detected, which exhibits a good match with the well-known theory described by the Gaussian-beam expansion technique. During the directivity measurement for the parametric loudspeaker, the proposed filter has also proved to be effective and is only needed for small angles. Copyright © 2016 Elsevier B.V. All rights reserved.

Rapid reduction of MORB glass in piston cylinder experiments with graphite capsule - a XANES study

NASA Astrophysics Data System (ADS)

Ni, P.; Zhang, Y.; Fiege, A.; Newville, M.; Lanzirotti, A.

2017-12-01

Graphite capsules have been widely used in high-pressure, high-temperature experiments to prevent iron loss from iron-bearing samples. One common uncertainty with this experimental setup is the oxygen fugacity (fO2) inside the capsule imposed by the presence of graphite. As Holloway et al. (1992) pointed out, the use of graphite capsule places an upper limit on the fO2 in the experiment to be below CCO (graphite-CO-CO2 buffer). More recently, Medard et al. (2015) estimated the fO2 for their experiments using Pt-graphite or graphite-only capsules to be CCO-0.8. Despite the improved understanding on the fO2 using graphite capsule, the mechanism and kinetics of fO2 control in graphite capsule is still poorly understood. Such knowledge is especially important to understand whether equilibrium fO2 is reached in the sample when short experiment durations are needed (e.g. for kinetic experiments). In this study, MORB glasses after olivine dissolution (Chen and Zhang 2008) and plagioclase dissolution (Yu et al. 2016) experiments at 0.5 GPa and 1300 ºC with durations ranging from 10 s to 30 min are analyzed by XANES to obtain Fe3+/Fetotal profiles from their contact with the graphite capsule. The results show rapid Fe reduction away from the graphite-melt interface, causing a decrease of Fe3+/Fetotal from 12% to 3%. In a duration of 30 min, the 1200-µm-thick and 2000-µm-diameter basaltic glass reached near equilibrium in its iron oxidation state, with Fe3+/Fetotal ranging from 3% to 4% throughout the run product. The equilibrium Fe3+/Fetotal ratio corresponds to an fO2 of CCO-1.4, which is within error compared to the result in Medard et al. (2015). Even in the shortest experiment with an effective duration of only 10 s, a 60 µm long reduction profile was detected. Such a rapid fO2 change can be explained by rapid H2 diffusion in melt and its reaction with ferric iron: H2+Fe2O3=2FeO+H2O, which is also supported by the H2O concentration profiles measured along the reduction profile. Our results indicate rapid fO2 equilibration in MORB-glass-composition samples during nominally anhydrous graphite capsule experiments at 1300°C, and can be used to guide experimental designs.

Creating a Strong Foundation with Engineering Design Graphics.

ERIC Educational Resources Information Center

Newcomer, Jeffrey L.; McKell, Eric K.; Raudebaugh, Robert A.; Kelley, David S.

2001-01-01

Describes the two-course engineering design graphics sequence on introductory design and graphics topics. The first course focuses on conceptual design and the development of visualization and sketching skills while the second one concentrates on detail design and parametric modeling. (Contains 28 references.) (Author/ASK)

Design of three-dimensional nonimaging concentrators with inhomogeneous media

NASA Astrophysics Data System (ADS)

Minano, J. C.

1986-09-01

A three-dimensional nonimaging concentrator is an optical system that transforms a given four-parametric manifold of rays reaching a surface (entry aperture) into another four-parametric manifold of rays reaching the receiver. A procedure of design of such concentrators is developed. In general, the concentrators use mirrors and inhomogeneous media (i.e., gradient-index media). The concentrator has the maximum concentration allowed by the theorem of conservation of phase-space volume. This is the first known concentrator with such properties. The Welford-Winston edge-ray principle in three-dimensional geometry is proven under several assumptions. The linear compound parabolic concentrator is derived as a particular case of the procedure of design.

Conversion of Component-Based Point Definition to VSP Model and Higher Order Meshing

NASA Technical Reports Server (NTRS)

Ordaz, Irian

2011-01-01

Vehicle Sketch Pad (VSP) has become a powerful conceptual and parametric geometry tool with numerous export capabilities for third-party analysis codes as well as robust surface meshing capabilities for computational fluid dynamics (CFD) analysis. However, a capability gap currently exists for reconstructing a fully parametric VSP model of a geometry generated by third-party software. A computer code called GEO2VSP has been developed to close this gap and to allow the integration of VSP into a closed-loop geometry design process with other third-party design tools. Furthermore, the automated CFD surface meshing capability of VSP are demonstrated for component-based point definition geometries in a conceptual analysis and design framework.

Integrated Design Engineering Analysis (IDEA) Environment Automated Generation of Structured CFD Grids using Topology Methods

NASA Technical Reports Server (NTRS)

Kamhawi, Hilmi N.

2012-01-01

This report documents the work performed from March 2010 to March 2012. The Integrated Design and Engineering Analysis (IDEA) environment is a collaborative environment based on an object-oriented, multidisciplinary, distributed framework using the Adaptive Modeling Language (AML) as a framework and supporting the configuration design and parametric CFD grid generation. This report will focus on describing the work in the area of parametric CFD grid generation using novel concepts for defining the interaction between the mesh topology and the geometry in such a way as to separate the mesh topology from the geometric topology while maintaining the link between the mesh topology and the actual geometry.

Parametric design and gridding through relational geometry

NASA Technical Reports Server (NTRS)

Letcher, John S., Jr.; Shook, D. Michael

1995-01-01

Relational Geometric Synthesis (RGS) is a new logical framework for building up precise definitions of complex geometric models from points, curves, surfaces and solids. RGS achieves unprecedented design flexibility by supporting a rich variety of useful curve and surface entities. During the design process, many qualitative and quantitative relationships between elementary objects may be captured and retained in a data structure equivalent to a directed graph, such that they can be utilized for automatically updating the complete model geometry following changes in the shape or location of an underlying object. Capture of relationships enables many new possibilities for parametric variations and optimization. Examples are given of panelization applications for submarines, sailing yachts, offshore structures, and propellers.

Turbine blade profile design method based on Bezier curves

NASA Astrophysics Data System (ADS)

Alexeev, R. A.; Tishchenko, V. A.; Gribin, V. G.; Gavrilov, I. Yu.

2017-11-01

In this paper, the technique of two-dimensional parametric blade profile design is presented. Bezier curves are used to create the profile geometry. The main feature of the proposed method is an adaptive approach of curve fitting to given geometric conditions. Calculation of the profile shape is produced by multi-dimensional minimization method with a number of restrictions imposed on the blade geometry.The proposed method has been used to describe parametric geometry of known blade profile. Then the baseline geometry was modified by varying some parameters of the blade. The numerical calculation of obtained designs has been carried out. The results of calculations have shown the efficiency of chosen approach.

Design of a completely model free adaptive control in the presence of parametric, non-parametric uncertainties and random control signal delay.

PubMed

Tutsoy, Onder; Barkana, Duygun Erol; Tugal, Harun

2018-05-01

In this paper, an adaptive controller is developed for discrete time linear systems that takes into account parametric uncertainty, internal-external non-parametric random uncertainties, and time varying control signal delay. Additionally, the proposed adaptive control is designed in such a way that it is utterly model free. Even though these properties are studied separately in the literature, they are not taken into account all together in adaptive control literature. The Q-function is used to estimate long-term performance of the proposed adaptive controller. Control policy is generated based on the long-term predicted value, and this policy searches an optimal stabilizing control signal for uncertain and unstable systems. The derived control law does not require an initial stabilizing control assumption as in the ones in the recent literature. Learning error, control signal convergence, minimized Q-function, and instantaneous reward are analyzed to demonstrate the stability and effectiveness of the proposed adaptive controller in a simulation environment. Finally, key insights on parameters convergence of the learning and control signals are provided. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Capsule endoscopy

MedlinePlus

Capsule enteroscopy; Wireless capsule endoscopy; Video capsule endoscopy (VCE); Small bowel capsule endoscopy (SBCE) ... a computer and software turns them into a video. Your provider watches the video to look for ...

Characterization of Aerodynamic Interactions with the Mars Science Laboratory Reaction Control System Using Computation and Experiment

NASA Technical Reports Server (NTRS)

Schoenenberger, Mark; VanNorman, John; Rhode, Matthew; Paulson, John

2013-01-01

On August 5 , 2012, the Mars Science Laboratory (MSL) entry capsule successfully entered Mars' atmosphere and landed the Curiosity rover in Gale Crater. The capsule used a reaction control system (RCS) consisting of four pairs of hydrazine thrusters to fly a guided entry. The RCS provided bank control to fly along a flight path commanded by an onboard computer and also damped unwanted rates due to atmospheric disturbances and any dynamic instabilities of the capsule. A preliminary assessment of the MSL's flight data from entry showed that the capsule flew much as predicted. This paper will describe how the MSL aerodynamics team used engineering analyses, computational codes and wind tunnel testing in concert to develop the RCS system and certify it for flight. Over the course of MSL's development, the RCS configuration underwent a number of design iterations to accommodate mechanical constraints, aeroheating concerns and excessive aero/RCS interactions. A brief overview of the MSL RCS configuration design evolution is provided. Then, a brief description is presented of how the computational predictions of RCS jet interactions were validated. The primary work to certify that the RCS interactions were acceptable for flight was centered on validating computational predictions at hypersonic speeds. A comparison of computational fluid dynamics (CFD) predictions to wind tunnel force and moment data gathered in the NASA Langley 31-Inch Mach 10 Tunnel was the lynch pin to validating the CFD codes used to predict aero/RCS interactions. Using the CFD predictions and experimental data, an interaction model was developed for Monte Carlo analyses using 6-degree-of-freedom trajectory simulation. The interaction model used in the flight simulation is presented.

Calcium phosphate supplementation increases faecal Lactobacillus spp. in a randomised trial of young adults.

PubMed

Dahl, W J; Ford, A L; Coppola, J A; Lopez, D; Combs, W; Rohani, A; Ukhanova, M; Culpepper, T; Tompkins, T A; Christman, M; Mai, V

2016-02-01

The aim of the studies was to determine the effects of calcium carbonate and calcium phosphate supplementation on faecal Lactobacillus spp., with and without a probiotic supplement, in healthy adults. Study 1 comprised of a randomised, double-blind, crossover design; participants (n=15) received 2 capsules/d of 250 mg elemental calcium as calcium carbonate (Ca1) and calcium phosphate (Ca2) each for 2-week periods, with 2-week baseline and washout periods. Study 2 was a randomised, double-blind, crossover design; participants (n=17) received 2 capsules/d of Lactobacillus helveticus R0052 and Lactobacillus rhamnosus R0011 (probiotic) alone, the probiotic with 2 capsules/d of Ca1, and probiotic with 2 capsules/d of Ca2 each for 2-week periods with 2-week baseline and washout periods. In both studies, stools were collected during the baseline, intervention and washout periods for Lactobacillus spp. quantification and qPCR analyses. Participants completed daily questionnaires of stool frequency and compliance. In Study 1, neither calcium supplement influenced viable counts of resident Lactobacillus spp., genome equivalents of lactic acid bacteria or stool frequency. In Study 2, faecal Lactobacillus spp. counts were significantly enhanced from baseline when the probiotic was administered with Ca2 (4.83±0.30, 5.79±0.31) (P=0.02), but not with Ca1 (4.98±0.31) or with the probiotic alone (5.36±0.31, 5.55±0.29) (not significant). Detection of L. helveticus R0052 and L. rhamnosus R0011 was significantly increased with all treatments, but did not differ among treatments. There were no changes in weekly stool frequency. Calcium phosphate co-administration may increase gastrointestinal survival of orally-administered Lactobacillus spp.

Effects of food on a gastrically degraded drug: azithromycin fast-dissolving gelatin capsules and HPMC capsules.

PubMed

Curatolo, William; Liu, Ping; Johnson, Barbara A; Hausberger, Angela; Quan, Ernest; Vendola, Thomas; Vatsaraj, Neha; Foulds, George; Vincent, John; Chandra, Richa

2011-07-01

Commercial azithromycin gelatin capsules (Zithromax®) are known to be bioequivalent to commercial azithromycin tablets (Zithromax®) when dosed in the fasted state. These capsules exhibit a reduced bioavailability when dosed in the fed state, while tablets do not. This gelatin capsule negative food effect was previously proposed to be due to slow and/or delayed capsule disintegration in the fed stomach, resulting in extended exposure of the drug to gastric acid, leading to degradation to des-cladinose-azithromycin (DCA). Azithromycin gelatin capsules were formulated with "superdisintegrants" to provide fast-dissolving capsules, and HPMC capsule shells were substituted for gelatin capsule shells, in an effort to eliminate the food effect. Healthy volunteers were dosed with these dosage forms under fasted and fed conditions; pharmacokinetics were evaluated. DCA pharmacokinetics were also evaluated for the HPMC capsule subjects. In vitro disintegration of azithromycin HPMC capsules in media containing food was evaluated and compared with commercial tablets and commercial gelatin capsules. When the two fast-dissolving capsule formulations were dosed to fed subjects, the azithromycin AUC was 38.9% and 52.1% lower than after fasted-state dosing. When HPMC capsules were dosed to fed subjects, the azithromycin AUC was 65.5% lower than after fasted-state dosing. For HPMC capsules, the absolute fasting-state to fed-state decrease in azithromycin AUC (on a molar basis) was similar to the increase in DCA AUC. In vitro capsule disintegration studies revealed extended disintegration times for commercial azithromycin gelatin capsules and HPMC capsules in media containing the liquid foods milk and Ensure®. Interaction of azithromycin gelatin and HPMC capsules with food results in slowed disintegration in vitro and decreased bioavailability in vivo. Concurrent measurement of serum azithromycin and the acid-degradation product DCA demonstrates that the loss of azithromycin bioavailability in the fed state is largely (and probably entirely) due to gastric degradation to DCA. Capsules can provide a useful and elegant dosage form for almost all drugs, but may result in a negative food effect for drugs as acid-labile as azithromycin.

Design Automation Using Script Languages. High-Level CAD Templates in Non-Parametric Programs

NASA Astrophysics Data System (ADS)

Moreno, R.; Bazán, A. M.

2017-10-01

The main purpose of this work is to study the advantages offered by the application of traditional techniques of technical drawing in processes for automation of the design, with non-parametric CAD programs, provided with scripting languages. Given that an example drawing can be solved with traditional step-by-step detailed procedures, is possible to do the same with CAD applications and to generalize it later, incorporating references. In today’s modern CAD applications, there are striking absences of solutions for building engineering: oblique projections (military and cavalier), 3D modelling of complex stairs, roofs, furniture, and so on. The use of geometric references (using variables in script languages) and their incorporation into high-level CAD templates allows the automation of processes. Instead of repeatedly creating similar designs or modifying their data, users should be able to use these templates to generate future variations of the same design. This paper presents the automation process of several complex drawing examples based on CAD script files aided with parametric geometry calculation tools. The proposed method allows us to solve complex geometry designs not currently incorporated in the current CAD applications and to subsequently create other new derivatives without user intervention. Automation in the generation of complex designs not only saves time but also increases the quality of the presentations and reduces the possibility of human errors.

Associations Between Egg Capsule Morphology and Predation Among Populations of the Marine Gastropod, Nucella emarginata.

PubMed

Rawlings, T A

1990-12-01

Intraspecific variation in the morphology of egg capsules is ideal for assessing the costs and benefits of encapsulation, yet little is known about the extent of such variation among populations of a single species. In the present study, I compared capsule morphology among three populations of the intertidal gastropod, Nucella emarginata. Significant differences were found both in capsule wall thickness and capsule strength. Mean capsule wall thickness varied as much as 25% among populations, with the dry weight of capsular cases differing accordingly. Capsule strength, measured as resistance to puncturing and squeezing forces, also varied among populations, but did not directly reflect differences in capsule wall thickness. Despite extensive variation in capsule morphology within this species, the number and size of eggs contained within capsules of equal volume did not differ significantly among populations. I also compared the type of capsule-eating predators that were present at each site. Shore crabs, Hemigrapsus spp., were abundant at all three sites; however, the predatory isopods Idotea wosnesenskii were only present at sites containing relatively thick-walled capsules. Although Hemigrapsus and Idotea were able to chew through both thick- and thin-walled capsules, laboratory experiments revealed that Idotea preferentially opened thin-walled capsules. These results suggest that variation in capsule morphology among populations of N. emarginata may, at least in part, reflect selection for the protection of embryos against predation.

A novel flexible microfluidic meshwork to reduce fibrosis in glaucoma surgery.

PubMed

Amoozgar, Behzad; Wei, Xiaoling; Hui Lee, Jun; Bloomer, Michele; Zhao, Zhengtuo; Coh, Paul; He, Fei; Luan, Lan; Xie, Chong; Han, Ying

2017-01-01

Fibrosis and hence capsule formation around the glaucoma implants are the main reasons for glaucoma implant failure. To address these issues, we designed a microfluidic meshwork and tested its biocompatibility in a rabbit eye model. The amount of fibrosis elicited by the microfluidic meshwork was compared to the amount elicited by the plate of conventional glaucoma drainage device. Six eyes from 3 New Zealand albino rabbits were randomized to receive either the novel microfluidic meshwork or a plate of Ahmed glaucoma valve model PF7 (AGV PF7). The flexible microfluidic implant was made from negative photoresist SU-8 by using micro-fabrication techniques. The overall size of the meshwork was 7 mm × 7 mm with a grid period of 100 μm. Both implants were placed in the subtenon space at the supratemporal quadrant in a standard fashion. There was no communication between the implants and the anterior chamber via a tube. All animal eyes were examined for signs of infection and implant erosion on days 1, 3, 7, and 14 and then monthly. Exenterations were performed in which the entire orbital contents were removed at 3 months. Histology slides of the implant and the surrounding tissues were prepared and stained with hematoxylin-eosin. Thickness of the fibrous capsules beneath the implants were measured and compared with paired student's t-test between the two groups. The gross histological sections showed that nearly no capsule formed around the microfluidic meshwork in contrast to the thick capsule formed around the plate of AGV PF7. Thickness of the fibrotic capsules beneath the AGV PF7 plate from the 3 rabbit eyes was 90μm, 82μm, and 95 μm, respectively. The thickness at the bottom of fibrotic capsules around the new microfluidic implant were 1μm, 2μm, and 1μm, respectively. The difference in thickness of capsule between the two groups was significant (P = 0.002). No complications were noticed in the 6 eyes, and both implants were tolerated well by all rabbits. The microfluidic meshwork elicited minimal fibrosis and capsule formation after 3-months implantation in a rabbit model. This provides promising evidence to aid in future development of a new glaucoma drainage implant that will elicit minimal scar formation and provide better long-term surgical outcomes.

Effect of Oral Capsule– vs Colonoscopy-Delivered Fecal Microbiota Transplantation on Recurrent Clostridium difficile Infection

PubMed Central

Roach, Brandi; Silva, Marisela; Beck, Paul; Rioux, Kevin; Kaplan, Gilaad G.; Chang, Hsiu-Ju; Coward, Stephanie; Goodman, Karen J.; Xu, Huiping; Madsen, Karen; Mason, Andrew; Wong, Gane Ka-Shu; Jovel, Juan; Patterson, Jordan; Louie, Thomas

2017-01-01

Importance Fecal microbiota transplantation (FMT) is effective in preventing recurrent Clostridium difficile infection (RCDI). However, it is not known whether clinical efficacy differs by route of delivery. Objective To determine whether FMT by oral capsule is noninferior to colonoscopy delivery in efficacy. Design, Setting, and Participants Noninferiority, unblinded, randomized trial conducted in 3 academic centers in Alberta, Canada. A total of 116 adult patients with RCDI were enrolled between October 2014 and September 2016, with follow-up to December 2016. The noninferiority margin was 15%. Interventions Participants were randomly assigned to FMT by capsule or by colonoscopy at a 1:1 ratio. Main Outcomes and Measures The primary outcome was the proportion of patients without RCDI 12 weeks after FMT. Secondary outcomes included (1) serious and minor adverse events, (2) changes in quality of life by the 36-Item Short Form Survey on a scale of 0 (worst possible quality of life) to 100 (best quality of life), and (3) patient perception on a scale of 1 (not at all unpleasant) to 10 (extremely unpleasant) and satisfaction on a scale of 1 (best) to 10 (worst). Results Among 116 patients randomized (mean [SD] age, 58 [19] years; 79 women [68%]), 105 (91%) completed the trial, with 57 patients randomized to the capsule group and 59 to the colonoscopy group. In per-protocol analysis, prevention of RCDI after a single treatment was achieved in 96.2% in both the capsule group (51/53) and the colonoscopy group (50/52) (difference, 0%; 1-sided 95% CI, −6.1% to infinity; P < .001), meeting the criterion for noninferiority. One patient in each group died of underlying cardiopulmonary illness unrelated to FMT. Rates of minor adverse events were 5.4% for the capsule group vs 12.5% for the colonoscopy group. There was no significant between-group difference in improvement in quality of life. A significantly greater proportion of participants receiving capsules rated their experience as “not at all unpleasant” (66% vs 44%; difference, 22% [95% CI, 3%-40%]; P = .01). Conclusions and Relevance Among adults with RCDI, FMT via oral capsules was not inferior to delivery by colonoscopy for preventing recurrent infection over 12 weeks. Treatment with oral capsules may be an effective approach to treating RCDI. Trial Registration clinicaltrials.gov Identifier: NCT02254811 PMID:29183074

Quantitative representations of an exaggerated anxiety response in the brain of female spider phobics-a parametric fMRI study.

PubMed

Zilverstand, Anna; Sorger, Bettina; Kaemingk, Anita; Goebel, Rainer

2017-06-01

We employed a novel parametric spider picture set in the context of a parametric fMRI anxiety provocation study, designed to tease apart brain regions involved in threat monitoring from regions representing an exaggerated anxiety response in spider phobics. For the stimulus set, we systematically manipulated perceived proximity of threat by varying a depicted spider's context, size, and posture. All stimuli were validated in a behavioral rating study (phobics n = 20; controls n = 20; all female). An independent group participated in a subsequent fMRI anxiety provocation study (phobics n = 7; controls n = 7; all female), in which we compared a whole-brain categorical to a whole-brain parametric analysis. Results demonstrated that the parametric analysis provided a richer characterization of the functional role of the involved brain networks. In three brain regions-the mid insula, the dorsal anterior cingulate, and the ventrolateral prefrontal cortex-activation was linearly modulated by perceived proximity specifically in the spider phobia group, indicating a quantitative representation of an exaggerated anxiety response. In other regions (e.g., the amygdala), activation was linearly modulated in both groups, suggesting a functional role in threat monitoring. Prefrontal regions, such as dorsolateral prefrontal cortex, were activated during anxiety provocation but did not show a stimulus-dependent linear modulation in either group. The results confirm that brain regions involved in anxiety processing hold a quantitative representation of a pathological anxiety response and more generally suggest that parametric fMRI designs may be a very powerful tool for clinical research in the future, particularly when developing novel brain-based interventions (e.g., neurofeedback training). Hum Brain Mapp 38:3025-3038, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

AASHTO mechanistic-empirical pavement design guide parametric study.

DOT National Transportation Integrated Search

2012-03-01

This study focuses on assessing the robustness of the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG v 1.1) for rigid pavement : design projects in Wisconsin. The primary tasks conducted in this study included performing sensitivity analys...

Parametric geometric model and hydrodynamic shape optimization of a flying-wing structure underwater glider

NASA Astrophysics Data System (ADS)

Wang, Zhen-yu; Yu, Jian-cheng; Zhang, Ai-qun; Wang, Ya-xing; Zhao, Wen-tao

2017-12-01

Combining high precision numerical analysis methods with optimization algorithms to make a systematic exploration of a design space has become an important topic in the modern design methods. During the design process of an underwater glider's flying-wing structure, a surrogate model is introduced to decrease the computation time for a high precision analysis. By these means, the contradiction between precision and efficiency is solved effectively. Based on the parametric geometry modeling, mesh generation and computational fluid dynamics analysis, a surrogate model is constructed by adopting the design of experiment (DOE) theory to solve the multi-objects design optimization problem of the underwater glider. The procedure of a surrogate model construction is presented, and the Gaussian kernel function is specifically discussed. The Particle Swarm Optimization (PSO) algorithm is applied to hydrodynamic design optimization. The hydrodynamic performance of the optimized flying-wing structure underwater glider increases by 9.1%.

Design of a High Thermal Gradient Bridgman Furnace

NASA Technical Reports Server (NTRS)

LeCroy, J. E.; Popok, D. P.

1994-01-01

The Advanced Automated Directional Solidification Furnace (AADSF) is a Bridgman-Stockbarger microgravity processing facility, designed and manifested to first fly aboard the second United States Microgravity Payload (USMP-2) Space Shuttle mission. The AADSF was principally designed to produce high axial thermal gradients, and is particularly suitable for metals solidification experiments, including non-dilute alloys. To accommodate a wider range of experimental conditions, the AADSF is equipped with a reconfigurable gradient zone. The overall design of the AADSF and the relationship between gradient zone design and furnace performance are described. Parametric thermal analysis was performed and used to select gradient zone design features that fulfill the high thermal gradient requirements of the USMP-2 experiment. The thermal model and analytical procedure, and parametric results leading to the first flight gradient zone configuration, are presented. Performance for the USMP-2 flight experiment is also predicted, and analysis results are compared to test data.

Development of Parametric Mass and Volume Models for an Aerospace SOFC/Gas Turbine Hybrid System

NASA Technical Reports Server (NTRS)

Tornabene, Robert; Wang, Xiao-yen; Steffen, Christopher J., Jr.; Freeh, Joshua E.

2005-01-01

In aerospace power systems, mass and volume are key considerations to produce a viable design. The utilization of fuel cells is being studied for a commercial aircraft electrical power unit. Based on preliminary analyses, a SOFC/gas turbine system may be a potential solution. This paper describes the parametric mass and volume models that are used to assess an aerospace hybrid system design. The design tool utilizes input from the thermodynamic system model and produces component sizing, performance, and mass estimates. The software is designed such that the thermodynamic model is linked to the mass and volume model to provide immediate feedback during the design process. It allows for automating an optimization process that accounts for mass and volume in its figure of merit. Each component in the system is modeled with a combination of theoretical and empirical approaches. A description of the assumptions and design analyses is presented.

Pendulum Motion in Main Parachute Clusters

NASA Technical Reports Server (NTRS)

Ray, Eric S.; Machin, Ricardo A.

2015-01-01

The coupled dynamics of a cluster of parachutes to a payload are notoriously difficult to predict. Often the payload is designed to be insensitive to the range of attitude and rates that might occur, but spacecraft generally do not have the mass and volume budgeted for this robust of a design. The National Aeronautics and Space Administration (NASA) Orion Capsule Parachute Assembly System (CPAS) implements a cluster of three mains for landing. During testing of the Engineering Development Unit (EDU) design, it was discovered that with a cluster of two mains (a fault tolerance required for human rating) the capsule coupled to the parachute cluster could get into a limit cycle pendulum motion which would exceed the spacecraft landing capability. This pendulum phenomenon could not be predicted with the existing models and simulations. A three phased effort has been undertaken to understand the consequence of the pendulum motion observed, and explore potential design changes that would mitigate this phenomenon. This paper will review the early analysis that was performed of the pendulum motion observed during EDU testing, summarize the analysis ongoing to understand the root cause of the pendulum phenomenon, and discuss the modeling and testing that is being pursued to identify design changes that would mitigate the risk.

Parametric Amplifier and Oscillator Based on Josephson Junction Circuitry

NASA Astrophysics Data System (ADS)

Yamamoto, T.; Koshino, K.; Nakamura, Y.

While the demand for low-noise amplification is ubiquitous, applications where the quantum-limited noise performance is indispensable are not very common. Microwave parametric amplifiers with near quantum-limited noise performance were first demonstrated more than 20 years ago. However, there had been little effort until recently to improve the performance or the ease of use of these amplifiers, partly because of a lack of any urgent motivation. The emergence of the field of quantum information processing in superconducting systems has changed this situation dramatically. The need to reliably read out the state of a given qubit using a very weak microwave probe within a very short time has led to renewed interest in these quantum-limited microwave amplifiers, which are already widely used as tools in this field. Here, we describe the quantum mechanical theory for one particular parametric amplifier design, called the flux-driven Josephson parametric amplifier, which we developed in 2008. The theory predicts the performance of this parametric amplifier, including its gain, bandwidth, and noise temperature. We also present the phase detection capability of this amplifier when it is operated with a pump power that is above the threshold, i.e., as a parametric phase-locked oscillator or parametron.

The near vacuum hohlraum campaign at the NIF: A new approach

NASA Astrophysics Data System (ADS)

Le Pape, S.; Berzak Hopkins, L. F.; Divol, L.; Meezan, N.; Turnbull, D.; Mackinnon, A. J.; Ho, D.; Ross, J. S.; Khan, S.; Pak, A.; Dewald, E.; Benedetti, L. R.; Nagel, S.; Biener, J.; Callahan, D. A.; Yeamans, C.; Michel, P.; Schneider, M.; Kozioziemski, B.; Ma, T.; Macphee, A. G.; Haan, S.; Izumi, N.; Hatarik, R.; Sterne, P.; Celliers, P.; Ralph, J.; Rygg, R.; Strozzi, D.; Kilkenny, J.; Rosenberg, M.; Rinderknecht, H.; Sio, H.; Gatu-Johnson, M.; Frenje, J.; Petrasso, R.; Zylstra, A.; Town, R.; Hurricane, O.; Nikroo, A.; Edwards, M. J.

2016-05-01

The near vacuum campaign on the National Ignition Facility has concentrated its efforts over the last year on finding the optimum target geometry to drive a symmetric implosion at high convergence ratio (30×). As the hohlraum walls are not tamped with gas, the hohlraum is filling with gold plasma and the challenge resides in depositing enough energy in the hohlraum before it fills up. Hohlraum filling is believed to cause symmetry swings late in the pulse that are detrimental to the symmetry of the hot spot at high convergence. This paper describes a series of experiments carried out to examine the effect of increasing the distance between the hohlraum wall and the capsule (case to capsule ratio) on the symmetry of the hot spot. These experiments have shown that smaller Case to Capsule Ratio (CCR of 2.87 and 3.1) resulted in oblate implosions that could not be tuned round. Larger CCR (3.4) led to a prolate implosion at convergence 30× implying that inner beam propagation at large CCR is not impeded by the expanding hohlraum plasma. A Case to Capsule ratio of 3.4 is a promising geometry to design a round implosion but in a smaller hohlraum where the hohlraum losses are lower, enabling a wider cone fraction range to adjust symmetry.

Influence of experimental parameters on the microencapsulation of a photopolymerizable phase.

PubMed

Pernot, J M; Brun, H; Pouyet, B; Sergent, M; Phan-Tan-Luu, R

1993-01-01

Conditions of microencapsulation by in situ polycondensation, using melamine-formaldehyde as wall material, are influenced by the chemical nature of the core to encapsulate. In our study concerning the encapsulation of a photopolymerizable phase containing an electrically charged compound, it was necessary to modify the experimental process to obtain capsules of good quality. We used the factorial design method of screening by utilization of an asymmetric matrix, according to the collapsing principle of Addleman. The advantage of this method is that it allows determination of the simultaneous influences of the 11 experimental parameters involved in this preparation. The calculation method can be applied to more than two levels for some of the factors. The continuously varying parameters were altered between two extreme levels, chosen to allow encapsulation. For discontinuous factors, such as the molecular weight of the modifying system or nature of the aminoplast, we used the commercially available compounds, respectively three and four kinds. The results of the obtained capsules were determined by comparing microphotographic pictures. With 16 experiments we found four more factors influencing quality of capsules. We also determined the most favourable levels for the other seven parameters. The results allowed us to find optimal conditions in the experimental field. We obtained capsules of a satisfactory quality for this purpose, using only minimum experimentation.

Metal Alloy ICF Capsules Created by Electrodeposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horwood, Corie; Stadermann, Michael; Bunn, Thomas L.

Electrochemical deposition is an attractive alternative to physical vapor deposition and micromachining to produce metal capsules for inertial confinement fusion (ICF). Electrochemical deposition (also referred to as electrodeposition or plating) is expected to produce full-density metal capsules without seams or inclusions of unwanted atomic constituents, the current shortcomings of micromachine and physical vapor deposition, respectively. In this paper, we discuss new cathode designs that allow for the rapid electrodeposition of gold and copper alloys on spherical mandrels by making transient contact with the constantly moving spheres. Electrodeposition of pure gold, copper, platinum, and alloys of gold-copper and gold-silver are demonstrated,more » with nonporous coatings of >40 µm achieved in only a few hours of plating. The surface roughness of the spheres after electrodeposition is comparable to the starting mandrel, and the coatings appear to be fully dense with no inclusions. A detailed understanding of the electrodeposition conditions that result in different alloy compositions and plating rates will allow for the electrodeposition of graded alloys on spheres in the near future. Finally, this report on the electrodeposition of metals on spherical mandrels is an important first step toward the fabrication of graded-density metal capsules for ICF experiments at the National Ignition Facility.« less

Effect of Tribulus terrestris, ginger, saffron, and Cinnamomum on menopausal symptoms: a randomised, placebo-controlled clinical trial.

PubMed

Taavoni, Simin; Ekbatani, Neda Nazem; Haghani, Hamid

2017-03-01

Menopausal symptoms experienced by women vary widely, and while many women transition through menopause with manageable symptoms, others experience severe symptoms, which may impair their quality of life. The purpose of this study was to determine the effect of Tribulus terrestris , ginger, saffron, and Cinnamomum on menopausal symptoms. A randomised, triple-blind, controlled trial design was used for this study. The participants were 80 postmenopausal women aged 50-60 years. A demographic data form and the Menopause Rating Scale were used to collect data. The women were randomly divided into two groups, each of which received either an Aphrodit capsule or a placebo twice a day for four weeks. The two bottles looked exactly the same, so that the investigator and the participants were not aware of the contents of the bottles. Each Aphrodit capsule contained 40 mg of Tribulus terrestris , 12.27 mg of Zingiber officinale , 3 mg of Crocus sativus extract, and 11 mg of Cinnamomum zeylanicum , while the placebo capsules contained 50 mg of starch. Descriptive and inferential statistics were used to analyse the data. A statistically significant change was reported in the menopausal symptoms of the intervention group compared with the placebo group. The results of the study demonstrate that the Aphrodit capsule was effective in reducing menopausal symptoms.

Capsule implosion optimization during the indirect-drive National Ignition Campaign

NASA Astrophysics Data System (ADS)

Landen, O. L.; Edwards, J.; Haan, S. W.; Robey, H. F.; Milovich, J.; Spears, B. K.; Weber, S. V.; Clark, D. S.; Lindl, J. D.; MacGowan, B. J.; Moses, E. I.; Atherton, J.; Amendt, P. A.; Boehly, T. R.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.; Frenje, J. A.; Glenzer, S. H.; Hamza, A.; Hammel, B. A.; Hicks, D. G.; Hoffman, N.; Izumi, N.; Jones, O. S.; Kilkenny, J. D.; Kirkwood, R. K.; Kline, J. L.; Kyrala, G. A.; Marinak, M. M.; Meezan, N.; Meyerhofer, D. D.; Michel, P.; Munro, D. H.; Olson, R. E.; Nikroo, A.; Regan, S. P.; Suter, L. J.; Thomas, C. A.; Wilson, D. C.

2011-05-01

Capsule performance optimization campaigns will be conducted at the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition. The campaigns will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models using a variety of ignition capsule surrogates before proceeding to cryogenic-layered implosions and ignition experiments. The quantitative goals and technique options and down selections for the tuning campaigns are first explained. The computationally derived sensitivities to key laser and target parameters are compared to simple analytic models to gain further insight into the physics of the tuning techniques. The results of the validation of the tuning techniques at the OMEGA facility [J. M. Soures et al., Phys. Plasmas 3, 2108 (1996)] under scaled hohlraum and capsule conditions relevant to the ignition design are shown to meet the required sensitivity and accuracy. A roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget. Finally, we show how the tuning precision will be improved after a number of shots and iterations to meet an acceptable level of residual uncertainty.

Modeling and experimental characterization of propulsion of a spiral-type microrobot for medical use in gastrointestinal tract.

PubMed

Zhou, Hao; Alici, Gursel; Than, Trung Duc; Li, Weihua

2013-06-01

In this paper, a spiral-type medical robot based on an endoscopic capsule was propelled in a fluidic and tubular environment using electromagnetic actuation. Both modeling and experimental methods have been employed to characterize the propulsion of the robotic capsule. The experiments were performed not only in a simulated environment (vinyl tube filled with silicone oil) but also in a real small intestine. The effects of the spiral parameters including lead, spiral height, the number of spirals, and cross section of the spirals on the propulsion efficiency of the robot are investigated. Based on the transmission efficiency from rotation to translation as well as the balancing of the microrobot in operation, it is demonstrated that the robot with two spirals could provide the best propulsion performance when its lead is slightly smaller than the perimeter of the capsule. As for the spiral height, it is better to use a larger one as long as the intestine's size allows. Based on the simulation and experimental results presented, this study quantifies the influence of the spiral structure on the capsule's propulsion. It provides a helpful reference for the design and optimization of the traction topology of the microrobot navigating inside the mucus-filled small intestine.

Xuezhikang Capsule for Type 2 Diabetes with Hyperlipemia: A Systematic Review and Meta-Analysis of Randomized Clinical Trails

PubMed Central

Li, Min; He, Qingyong; Chen, Yinfeng; Li, Bo; Feng, Bo; Zhang, Zhenpeng; Wang, Jie

2015-01-01

Objective. To evaluate the efficacy and safety of Xuezhikang capsule treating type 2 diabetes with hyperlipidemia. Methods. We searched six databases to identify relevant studies published before January 2015. Two review authors independently extracted data and assessed the Cochrane risk of bias tool. We resolved disagreements with this assessment through discussion and a decision was achieved by consensus. Results. We included 21 studies (1548 participants). Treatment courses were at least 8 weeks. Overall, the risk of bias of included trials was unclear. Among them, 16 studies could conduct meta-analysis. The result showed that compared with routine group (5 studies), Xuezhikang group had more effect on decreasing TC, TG, LDL-C, and rising HDL-C. However, compared with statins group (11 studies), Xuezhikang group has less effect on decreasing TC, TG, and rising HDL-C. Meanwhile, two groups had no statistical differences of LDL-C level. Conclusion. Xuezhikang capsule may be effective for treating type 2 diabetes with hyperlipemia. Our findings should be considered cautiously due to unclear risk of bias of the included studies and low methodological quality. Therefore, more strictly designed large-scale randomized clinical trials are needed to evaluate the efficacy of Xuezhikang capsule in type 2 diabetes with hyperlipemia. PMID:26246836

Wireless powering for a self-propelled and steerable endoscopic capsule for stomach inspection.

PubMed

Carta, R; Tortora, G; Thoné, J; Lenaerts, B; Valdastri, P; Menciassi, A; Dario, P; Puers, R

2009-12-15

This paper describes the integration of an active locomotion module in a wirelessly powered endoscopic capsule. The device is a submersible capsule optimized to operate in a fluid environment in a liquid-distended stomach. A 3D inductive link is used to supply up to 400mW to the embedded electronics and a set of 4 radio-controlled motor propellers. The design takes advantage of a ferrite-core in the receiving coil-set. This approach significantly improves the coupling with the external field source with respect to earlier work by the group. It doubles the power that can be received with a coreless coil-set under identical external conditions. The upper limit of the received power was achieved complying with the strict regulations for safe exposure of biological tissue to variable magnetic fields. The wireless transferred power was proven to be sufficient to achieve the speed of 7cm/s in any directions. An optimized locomotion strategy was defined which limits the power consumption by running only 2 motors at a time. A user interface and a joystick controller allow to fully drive the capsule in an intuitive manner. The device functionalities were successfully tested in a dry and a wet environment in a laboratory set-up.

Ultrafast Electron Transfer across a Nanocapsular Wall: Coumarins as Donors, Viologen as Acceptor, and Octa Acid Capsule as the Mediator.

PubMed

Chuang, Chi-Hung; Porel, Mintu; Choudhury, Rajib; Burda, Clemens; Ramamurthy, V

2018-01-11

Results of our study on ultrafast electron transfer (eT) dynamics from coumarins (coumarin-1, coumarin-480, and coumarin-153) incarcerated within octa acid (OA) capsules as electron donors to methyl viologen dissolved in water as acceptor are presented. Upon photoexcitation, coumarin inside the OA capsule transfers an electron to the acceptor electrostatically attached to the capsule leading to a long-lived radical-ion pair separated by the OA capsular wall. This charge-separated state returns to the neutral ground state via back electron transfer on the nanosecond time scale. This system allows for ultrafast electron transfer processes through a molecular wall from the apolar capsular interior to the highly polar (aqueous) environment on the femtosecond time scale. Employing femtosecond transient absorption spectroscopy, distinct rates of both forward (1-25 ps) and backward eT (700-1200 ps) processes were measured. Further understanding of the energetics is provided using Rehm-Weller analysis for the investigated photoinduced eT reactions. The results provide the rates of the eT across a molecular wall, akin to an isotropic solution, depending on the standard free energy of the reaction. The insights from this work could be utilized in the future design of efficient electron transfer processes across interfaces separating apolar and polar environments.

Designing carboxymethyl cellulose based layer-by-layer capsules as a carrier for protein delivery.

PubMed

Tripathy, Jasaswini; Raichur, Ashok M

2013-01-01

Stable hollow microcapsules composed of sodium carboxymethyl cellulose (CMC) and poly (allylamine hydrochloride) (PAH) were produced by layer-by-layer adsorption of polyelectrolytes onto CaCO(3) microparticles. Subsequently the core was removed by addition of chelating agents for calcium ions. Zeta potential studies showed charge reversal with deposition of successive polyelectrolyte layers, indicating that the alternate electrostatic adsorption of polyelectrolytes of opposite charge was successfully achieved. The size and surface morphology of the capsules was characterized by various microscopy techniques. The pH responsive loading behavior was elucidated by confocal laser scanning microscopy (CLSM) studies using fluorescence labeled dextran (FITC-dextran) and labeled BSA (FITC-BSA). CLSM images confirmed the open (pH≤6) and closed state (pH≥7) of the capsules. A model drug bovine serum albumin (BSA) was spontaneously loaded below its isoelectric point into hollow microcapsules, where BSA is positively charged. The loading of the BSA into the microcapsules was found to be dependent on the feeding concentration and pH of the medium. 65% of the loaded BSA was released over 7h of which about 34% was released in the first hour. These findings demonstrate that (CMC/PAH)(2) hollow capsules can be further exploited as a potential drug delivery system. Copyright © 2012 Elsevier B.V. All rights reserved.

Evaluation of friction enhancement through soft polymer micro-patterns in active capsule endoscopy

NASA Astrophysics Data System (ADS)

Buselli, Elisa; Pensabene, Virginia; Castrataro, Piero; Valdastri, Pietro; Menciassi, Arianna; Dario, Paolo

2010-10-01

Capsule endoscopy is an emerging field in medical technology. Despite very promising innovations, some critical issues are yet to be addressed, such as the management and possible exploitation of the friction in the gastrointestinal environment in order to control capsule locomotion more actively. This paper presents the fabrication and testing of bio-inspired polymeric micro-patterns, which are arrays of cylindrical pillars fabricated via soft lithography. The aim of the work is to develop structures that enhance the grip between an artificial device and the intestinal tissue, without injuring the mucosa. In fact, the patterns are intended to be mounted on microfabricated legs of a capsule robot that is able to move actively in the gastrointestinal tract, thus improving the robot's traction ability. The effect of micro-patterned surfaces on the leg-slipping behaviour on colon walls was investigated by considering both different pillar dimensions and the influence of tissue morphology. Several in vitro tests on biological samples demonstrated that micro-patterns of pillars made from a soft polymer with an aspect ratio close to 1 enhanced friction by 41.7% with regard to flat surfaces. This work presents preliminary modelling of the friction and adhesion forces in the gastrointestinal environment and some design guidelines for endoscopic devices.

Wireless power and data transmission strategies for next-generation capsule endoscopes

NASA Astrophysics Data System (ADS)

Puers, R.; Carta, R.; Thoné, J.

2011-05-01

Capsular endoscopy is becoming increasingly popular as an alternative to traditional gastro-intestinal (GI) examination techniques. However, the breakthrough of these devices is hindered by the limited amount of power that can be stored in a tiny pill. Most commercial devices use two watch batteries that can only provide an average power of 25 mW for about 6 h, certainly not sufficient for advanced robotic features. A dedicated inductive powering system, operating at 1 MHz to limit the human body absorption, has been developed which was proven to support the transfer of over 300 mW. The system relies on a condensed set of orthogonal ferrite coils, embedded in the capsule, and an external unit based on a Helmholtz coil driven by a class E amplifier. Control data can be sent through the inductive link by modulating the power carrier, whereas a dedicated high data rate RF link is used to transfer the images from the capsule to the base station. Besides evaluating the compatibility with radio transmission, several demonstrators were assembled combining the wireless powering system with various locomotion strategies and LED illumination. This paper describes the design and implementation of the inductive powering system, its combination with data transmission techniques and the testing activity with other capsule-dedicated modules.

Metal Alloy ICF Capsules Created by Electrodeposition

DOE PAGES

Horwood, Corie; Stadermann, Michael; Bunn, Thomas L.

2017-12-04

Electrochemical deposition is an attractive alternative to physical vapor deposition and micromachining to produce metal capsules for inertial confinement fusion (ICF). Electrochemical deposition (also referred to as electrodeposition or plating) is expected to produce full-density metal capsules without seams or inclusions of unwanted atomic constituents, the current shortcomings of micromachine and physical vapor deposition, respectively. In this paper, we discuss new cathode designs that allow for the rapid electrodeposition of gold and copper alloys on spherical mandrels by making transient contact with the constantly moving spheres. Electrodeposition of pure gold, copper, platinum, and alloys of gold-copper and gold-silver are demonstrated,more » with nonporous coatings of >40 µm achieved in only a few hours of plating. The surface roughness of the spheres after electrodeposition is comparable to the starting mandrel, and the coatings appear to be fully dense with no inclusions. A detailed understanding of the electrodeposition conditions that result in different alloy compositions and plating rates will allow for the electrodeposition of graded alloys on spheres in the near future. Finally, this report on the electrodeposition of metals on spherical mandrels is an important first step toward the fabrication of graded-density metal capsules for ICF experiments at the National Ignition Facility.« less

Robust outer synchronization between two nonlinear complex networks with parametric disturbances and mixed time-varying delays

NASA Astrophysics Data System (ADS)

Zhang, Chuan; Wang, Xingyuan; Luo, Chao; Li, Junqiu; Wang, Chunpeng

2018-03-01

In this paper, we focus on the robust outer synchronization problem between two nonlinear complex networks with parametric disturbances and mixed time-varying delays. Firstly, a general complex network model is proposed. Besides the nonlinear couplings, the network model in this paper can possess parametric disturbances, internal time-varying delay, discrete time-varying delay and distributed time-varying delay. Then, according to the robust control strategy, linear matrix inequality and Lyapunov stability theory, several outer synchronization protocols are strictly derived. Simple linear matrix controllers are designed to driver the response network synchronize to the drive network. Additionally, our results can be applied on the complex networks without parametric disturbances. Finally, by utilizing the delayed Lorenz chaotic system as the dynamics of all nodes, simulation examples are given to demonstrate the effectiveness of our theoretical results.

Analyses of ACPL thermal/fluid conditioning system

NASA Technical Reports Server (NTRS)

Stephen, L. A.; Usher, L. H.

1976-01-01

Results of engineering analyses are reported. Initial computations were made using a modified control transfer function where the systems performance was characterized parametrically using an analytical model. The analytical model was revised to represent the latest expansion chamber fluid manifold design, and systems performance predictions were made. Parameters which were independently varied in these computations are listed. Systems predictions which were used to characterize performance are primarily transient computer plots comparing the deviation between average chamber temperature and the chamber temperature requirement. Additional computer plots were prepared. Results of parametric computations with the latest fluid manifold design are included.

Comparison of dynamic isotope power systems for distributed planet surface applications

NASA Technical Reports Server (NTRS)

Bents, David J.; Mckissock, Barbara I.; Hanlon, James C.; Schmitz, Paul C.; Rodriguez, Carlos D.; Withrow, Colleen A.

1991-01-01

Dynamic isotope power system (DIPS) alternatives were investigated and characterized for the surface mission elements associated with a lunar base and subsequent manned Mars expedition. System designs based on two convertor types were studied. These systems were characterized parametrically and compared over the steady-state electrical output power range 0.2 to 20 kWe. Three methods of thermally integrating the heat source and the Stirling heater head were considered, depending on unit size. Figures of merit were derived from the characterizations and compared over the parametric range. Design impacts of mission environmental factors are discussed and quantitatively assessed.

General analysis of group velocity effects in collinear optical parametric amplifiers and generators.

PubMed

Arisholm, Gunnar

2007-05-14

Group velocity mismatch (GVM) is a major concern in the design of optical parametric amplifiers (OPAs) and generators (OPGs) for pulses shorter than a few picoseconds. By simplifying the coupled propagation equations and exploiting their scaling properties, the number of free parameters for a collinear OPA is reduced to a level where the parameter space can be studied systematically by simulations. The resulting set of figures show the combinations of material parameters and pulse lengths for which high performance can be achieved, and they can serve as a basis for a design.

Turboprop cargo aircraft systems study

NASA Technical Reports Server (NTRS)

Muehlbauer, J. C.; Hewell, J. G., Jr.; Lindenbaum, S. P.; Randall, C. C.; Searle, N.; Stone, R. G., Jr.

1981-01-01

The effects of using advanced turboprop propulsion systems to reduce the fuel consumption and direct operating costs of cargo aircraft were studied, and the impact of these systems on aircraft noise and noise prints around a terminal area was determined. Parametric variations of aircraft and propeller characteristics were investigated to determine their effects on noiseprint areas, fuel consumption, and direct operating costs. From these results, three aircraft designs were selected and subjected to design refinements and sensitivity analyses. Three competitive turbofan aircraft were also defined from parametric studies to provide a basis for comparing the two types of propulsion.

Manganoporphyrin-Polyphenol Multilayer Capsules as Radical and Reactive Oxygen Species (ROS) Scavengers

DOE PAGES

Alford, Aaron; Kozlovskaya, Veronika; Xue, Bing; ...

2017-12-18

Local modulation of oxidative stress is crucial for a variety of biochemical events including cellular differentiation, apoptosis, and defense against pathogens. Currently employed natural and synthetic antioxidants exhibit a lack of biocompatibility, bioavailability, and chemical stability, resulting in limited capability to scavenge reactive oxygen species (ROS). To mediate these drawbacks, we have developed a synergistic manganoporphyrin-polyphenol polymeric nanothin coating and hollow microcapsules with efficient antioxidant activity and controllable ROS modulation. These materials are produced by multilayer assembly of a natural polyphenolic antioxidant, tannic acid (TA), with a synthesized copolymer of polyvinylpyrrolidone containing a manganoporphyrin modality (MnP-PVPON) which mimics the enzymaticmore » antioxidant superoxide dismutase. The redox activity of the copolymer is demonstrated to dramatically increase the antioxidant response of MnP-PVPON/TA capsules versus unmodified PVPON/TA capsules through reduction of a radical cationic dye and to significantly suppress the proliferation of superoxide via cytochrome C competition. Inclusion of MnP-PVPON as an outer layer enhances radical-scavenging activity as compared to localization of the layer in the middle or inner part of the capsule shell. In addition, we demonstrate that TA is crucial for the synergistic radical-scavenging activity of the MnP-PVPON/TA system which exhibits a combined superoxide dismutase-like ability and catalase-like activity in response to the free radical superoxide challenge. The MnP-PVPON/TA capsules exhibit a negligible, 8% loss of shell thickness upon free radical treatment, while PVPON/TA capsules lose 39% of their shell thickness due to the noncatalytic free-radical-scavenging of TA, as demonstrated by small angle neutron scattering (SANS). Finally, we have found the manganoporphyrin-polyphenol capsules to be nontoxic to splenocytes from NOD mice after 48 h incubation. In conclusion, our study illustrates the strong potential of combining catalytic activity of manganoporphyrins with natural polyphenolic antioxidants to design efficient free-radical-scavenging materials that may eventually be used in antioxidant therapies and as free radical dissipating protective carriers of biomolecules for biomedical or industrial applications.« less

Manganoporphyrin-Polyphenol Multilayer Capsules as Radical and Reactive Oxygen Species (ROS) Scavengers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alford, Aaron; Kozlovskaya, Veronika; Xue, Bing

Local modulation of oxidative stress is crucial for a variety of biochemical events including cellular differentiation, apoptosis, and defense against pathogens. Currently employed natural and synthetic antioxidants exhibit a lack of biocompatibility, bioavailability, and chemical stability, resulting in limited capability to scavenge reactive oxygen species (ROS). To mediate these drawbacks, we have developed a synergistic manganoporphyrin-polyphenol polymeric nanothin coating and hollow microcapsules with efficient antioxidant activity and controllable ROS modulation. These materials are produced by multilayer assembly of a natural polyphenolic antioxidant, tannic acid (TA), with a synthesized copolymer of polyvinylpyrrolidone containing a manganoporphyrin modality (MnP-PVPON) which mimics the enzymaticmore » antioxidant superoxide dismutase. The redox activity of the copolymer is demonstrated to dramatically increase the antioxidant response of MnP-PVPON/TA capsules versus unmodified PVPON/TA capsules through reduction of a radical cationic dye and to significantly suppress the proliferation of superoxide via cytochrome C competition. Inclusion of MnP-PVPON as an outer layer enhances radical-scavenging activity as compared to localization of the layer in the middle or inner part of the capsule shell. In addition, we demonstrate that TA is crucial for the synergistic radical-scavenging activity of the MnP-PVPON/TA system which exhibits a combined superoxide dismutase-like ability and catalase-like activity in response to the free radical superoxide challenge. The MnP-PVPON/TA capsules exhibit a negligible, 8% loss of shell thickness upon free radical treatment, while PVPON/TA capsules lose 39% of their shell thickness due to the noncatalytic free-radical-scavenging of TA, as demonstrated by small angle neutron scattering (SANS). Finally, we have found the manganoporphyrin-polyphenol capsules to be nontoxic to splenocytes from NOD mice after 48 h incubation. In conclusion, our study illustrates the strong potential of combining catalytic activity of manganoporphyrins with natural polyphenolic antioxidants to design efficient free-radical-scavenging materials that may eventually be used in antioxidant therapies and as free radical dissipating protective carriers of biomolecules for biomedical or industrial applications.« less