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Sample records for adult optical penetrating

  1. Development Of The Nuclear Optical Penetration

    NASA Astrophysics Data System (ADS)

    Inoue, K.; Koike, K.; Imada, Y.

    1984-10-01

    We have developed the nuclear optical penetration to be incorporated in the wall penetration of the shell to introduce a data transmission system using optical fibers into a nuclear power plant with a pressurized water reactor. Radiation-induced coloration in optical glass seriously affects transmission characteristics of optical fibers, whereas it has been revealed that the pure-silica core optical fiber without any dopant in the core has wide applicability in radiation fields thanks to its very low radiation-induced attenuation. The wall penetration of the shell should have airtightness and resistivity to heat, vibration, and pressure, let alone radiation, excellent enough to be invariable in data transmission efficiency even when subjected to severe environmental tests. The sealing modules of this newly developed nuclear optical penetration are hermetically sealed. The gap between the optical fiber rod (100 pm in core diameter and 5 mm in rod diameter) and stainless steel tube is sealed with lamingted glass layer. As the result of He gas leakage test, high airtightness of less than 10 cc/sec was achieved. No thermal deformation of the core was caused by sealing with laminated glass layer, nor was observed transmission loss. Then the sealiing modules were subjected to the irradiation test using 60 Co gamma ray exposure of 2 x 10 rads. Though silica glass layer supporting the fiber rod and sealing glass portion turned blackish purple, transparency of the fiber was not affected. Only less than 0.5 dB of connecting loss was observed at the connecting point with the optical fiber cable. The sealing modules were also found to have resistivity to vibration and pressure as excellent as that of existing nuclear electric penetrations. We expect the nuclear optical fiber penetration will be much effective in improving reliability of data transmission systems using optical fibers in radiation fields.

  2. Optical Monitoring of Weld Penetration

    NASA Technical Reports Server (NTRS)

    Maram, J.

    1986-01-01

    Robotic welding controlled by reliable, relatively-noise-free optoelectronic unit. Bounding off meniscus of pool of molten metal, laser beam impinges on position-sensitive photodetector. Beam diameter adjusted for width of weld. Optical filters screen out light from arc. Made from small, low-cost components and utilizing optical fibers to conduct signals, system immune to electromagnetic interference common in industrial environments. Aimed for automatic welders, robot welders in particular and also adaptable to other types of welding, including tungsten/inert-gas, laser, and electron-beam techniques.

  3. Optical penetration sensor for pulsed laser welding

    DOEpatents

    Essien, Marcelino; Keicher, David M.; Schlienger, M. Eric; Jellison, James L.

    2000-01-01

    An apparatus and method for determining the penetration of the weld pool created from pulsed laser welding and more particularly to an apparatus and method of utilizing an optical technique to monitor the weld vaporization plume velocity to determine the depth of penetration. A light source directs a beam through a vaporization plume above a weld pool, wherein the plume changes the intensity of the beam, allowing determination of the velocity of the plume. From the velocity of the plume, the depth of the weld is determined.

  4. Monitoring Weld Penetration Optically From Within Torch

    NASA Technical Reports Server (NTRS)

    Smith, Matthew A.; Gilbert, Jeffrey L.; Linsacum, Deron L.; Gutlow, David A.

    1993-01-01

    Photodetector or optical fiber leading to photodetector mounted inside gas/tungsten arc welding torch to monitor arc light reflected from oscillating surface of weld pool. Proposed optical monitoring components preserve compact profile of welding torch, maintained in fixed aim at weld-pool position at end of welding torch, and protected against bumping external objects.

  5. Deep optical penetration dynamics in photobending.

    PubMed

    Corbett, Daniel; Xuan, Chen; Warner, Mark

    2015-07-01

    We model both the photostationary state and dynamics of an illuminated, photosensitive, glassy liquid crystalline sheet. To illustrate the interplay between local tilt θ of the sheet, effective incident intensity, curvature, and dynamics, we adopt the simplest variation of local incident light intensity with angle, that is, cosθ. The tilt in the stationary state never overshoots the vertical, but maximum curvature could be seen in the middle of the sheet for intense light. In dynamics, overshoot and self-eclipsing arise, revealing how important moving fronts of light penetration are. Eclipsing is qualitatively as in the experiments of Yu et al. [Y. Yu, M. Nakano, and T. Ikeda, Nature (London) 425, 145 (2003)]. PMID:26274300

  6. Deep optical penetration dynamics in photobending

    NASA Astrophysics Data System (ADS)

    Corbett, Daniel; Xuan, Chen; Warner, Mark

    2015-07-01

    We model both the photostationary state and dynamics of an illuminated, photosensitive, glassy liquid crystalline sheet. To illustrate the interplay between local tilt θ of the sheet, effective incident intensity, curvature, and dynamics, we adopt the simplest variation of local incident light intensity with angle, that is, cosθ . The tilt in the stationary state never overshoots the vertical, but maximum curvature could be seen in the middle of the sheet for intense light. In dynamics, overshoot and self-eclipsing arise, revealing how important moving fronts of light penetration are. Eclipsing is qualitatively as in the experiments of Yu et al. [Y. Yu, M. Nakano, and T. Ikeda, Nature (London) 425, 145 (2003), 10.1038/425145a].

  7. Fiber optic penetrator for offshore oil well exploration and production

    SciTech Connect

    Collins, J.C.; Warner, C.P.; Henkener, J.A.; Glauser, R.

    1986-07-01

    A fiber optic penetrator arrangement is described for an undersea wall structure of offshore oil well production apparatus, comprising: a. a generally cylindrical housing; b. a cofferdam associated with the undersea production apparatus and defining a generally cylindrical entrance port into which the penetrator is designed to be inserted and mounted; c. a sealing means for sealing the penetrator relative to the entrance port after insertion of the penetrator therein; d. an external bulkhead; e. a second bulkhead positioned internally of the external bulkead; f. a compression spring normally retaining the second bulkhead in a sealed position with the penetrator, the compressing spring being compressed between the second bulkhead and the external bulkhead; g. a breakaway connection affixed to the external bulkhead for coupling an optical fiber transmission cable to the external bulkhead, such that if the transmission cable is snagged or pulled, the external bulkhead will sever along with the breakaway connection so that the penetrator is not pulled from the cofferdam entrance port, the second bulkhead being held in position by ambient water pressure to become the primary bulkhead after the external bulkhead is severed.

  8. Neuroimaging in adult penetrating brain injury: a guide for radiographers.

    PubMed

    Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren

    2015-06-01

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings. PMID:26229677

  9. Neuroimaging in adult penetrating brain injury: a guide for radiographers

    SciTech Connect

    Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren

    2015-06-15

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.

  10. DERMAL PENETRATION OF [14C] CAPTAN IN YOUNG AND ADULT RATS

    EPA Science Inventory

    Dermal penetration of [14C] Captan was determined in young (33 day old) and adult (82 day old) female Fischer 344 rats by an in vivo method and two in vitro methods. ermal penetration in vivo at 72 hours was about 9% of the dose in both young and adult rats. o significant differe...

  11. Skin optical clearing enhancement with penetration enhancer azone using spectroscopy and optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Xu, Xiangqun; Zhu, Qiuhong

    2008-06-01

    In order to find a non-invasive way to improve the efficacy of skin optical clearing with topically applied optical clearing agents (OCA), we evaluated the effect of azone ® (epsilon-Laurocapram) as a chemical penetration enhancer on optical clearing of intact skin in vitro. Fresh porcine skin with topical application of glycerol (G) mixed with water-soluble azone (A) was investigated using near-infrared spectroscopy and optical coherence tomography (OCT). Light transmittance at 1276 nm increased by 41% and diffuse reflectance at 1066 nm decreased by 29% at 60 min after treatment with 40%G5%A on a spectrophotometer with an internal integrating sphere. 40% glycerol with addition of azone was a more effective optical clearing agent than 40% and 80% glycerol. 60%G/5%A led to a 2-fold increase in achievable OCT imaging depth and a 2.2-fold increase in light intensity reflected off the underneath needle surface after 60 minutes in the OCT in-depth reflectance profiles. In conclusion, skin optical clearing with the topical application of glycerol was markedly enhanced by water-soluble azone. Skin permeation enhancing effect of azone accounts probably for the skin clearing enhancement.

  12. Perioperative anaesthetic management of penetrating neck injury associated with Rh blood type in a young adult

    PubMed Central

    Wang, Tao; Zhou, Yeting; Shi, Jiaohui; Wang, Zhichun

    2013-01-01

    We describe here a young adult patient with penetrating neck injuries (PNI) with an Rh negative blood type and discuss the perioperative anaesthetic management of single-stage surgical exploration under general anaesthesia and extracorporeal circulation in this patient. The patient had zone II PNI and he was in a haemodynamically progressive unstable state, and the knife penetrated the left internal jugular vein, superior thyroid artery and recurrent laryngeal nerve; the trachea and the oesophagus were swelling at a rapid rate. Eight weeks after operation, the patient was discharged from the hospital without any complications. PMID:23429024

  13. Improvement of in vivo rat skin optical clearing with chemical penetration enhancers

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Zhou, Xue; Duan, Shu; Chen, Zhongwei; Zhu, Dan

    2011-03-01

    Optical method plays an important role in clinical diagnosis and treatment, but suffers from limited penetration depth of light in turbid tissue. The optical clearing technique can improve the light delivery significantly through immersion of tissues into Optical Clearing Agents (OCAs). However, the barrier function of stratum corneum makes it difficult for optical clearing of skin by topical application of OCAs. Addition of penetration enhancers to OCAs can improve the skin clearing efficacy, but most investigations were performed on in vitro skin. Here, to evaluate the efficacy of this method on in vivo skin, direct observation and measurement of diffuse reflectance spectra were performed after topical application of different mixtures. One OCA, PEG-400, and three penetration enhancers (PEs), Thiazone, Azone and Propylene Glycol (PG), were used. The results indicated that the addition of penetration enhancers could improve the optical clearing efficacy of rat skin in vivo significantly, the dermal blood vessels could be observed directly with PEs. Among the three penetration enhancers, Thiazone induced the largest enhancement of clearing efficacy, and the enhancement induced by PG is the least. This study is very helpful for in vivo application of OCAs to enhance skin optical clearing non- invasively.

  14. Optical pacing of the adult rabbit heart.

    PubMed

    Jenkins, Michael W; Wang, Y T; Doughman, Y Q; Watanabe, M; Cheng, Y; Rollins, A M

    2013-01-01

    Optical pacing has been demonstrated to be a viable alternative to electrical pacing in embryonic hearts. In this study, the feasibility of optically pacing an adult rabbit heart was explored. Hearts from adult New Zealand White rabbits (n = 9) were excised, cannulated and perfused on a modified Langendorff apparatus. Pulsed laser light (λ = 1851 nm) was directed to either the left or right atrium through a multimode optical fiber. An ECG signal from the left ventricle and a trigger pulse from the laser were recorded simultaneously to determine when capture was achieved. Successful optical pacing was demonstrated by obtaining pacing capture, stopping, then recapturing as well as by varying the pacing frequency. Stimulation thresholds measured at various pulse durations suggested that longer pulses (8 ms) had a lower energy capture threshold. To determine whether optical pacing caused damage, two hearts were perfused with 30 µM of propidium iodide and analyzed histologically. A small number of cells near the stimulation site had compromised cell membranes, which probably limited the time duration over which pacing was maintained. Here, short-term optical pacing (few minutes duration) is demonstrated in the adult rabbit heart for the first time. Future studies will be directed to optimize optical pacing parameters to decrease stimulation thresholds and may enable longer-term pacing. PMID:24049683

  15. Efficient Cargo Delivery into Adult Brain Tissue Using Short Cell-Penetrating Peptides

    PubMed Central

    Thomas, Alvin Kuriakose; Bhattarai, Prabesh; Zhang, Yixin; Brand, Michael

    2015-01-01

    Zebrafish brains can regenerate lost neurons upon neurogenic activity of the radial glial progenitor cells (RGCs) that reside at the ventricular region. Understanding the molecular events underlying this ability is of great interest for translational studies of regenerative medicine. Therefore, functional analyses of gene function in RGCs and neurons are essential. Using cerebroventricular microinjection (CVMI), RGCs can be targeted efficiently but the penetration capacity of the injected molecules reduces dramatically in deeper parts of the brain tissue, such as the parenchymal regions that contain the neurons. In this report, we tested the penetration efficiency of five known cell-penetrating peptides (CPPs) and identified two– polyR and Trans – that efficiently penetrate the brain tissue without overt toxicity in a dose-dependent manner as determined by TUNEL staining and L-Plastin immunohistochemistry. We also found that polyR peptide can help carry plasmid DNA several cell diameters into the brain tissue after a series of coupling reactions using DBCO-PEG4-maleimide-based Michael’s addition and azide-mediated copper-free click reaction. Combined with the advantages of CVMI, such as rapidness, reproducibility, and ability to be used in adult animals, CPPs improve the applicability of the CVMI technique to deeper parts of the central nervous system tissues. PMID:25894337

  16. Penetrating radiation impact on NIF final optic components

    SciTech Connect

    Marshall, C.D.; Speth, J.A.; DeLoach, L.D.; Payne, S.A.

    1996-10-15

    Goal of the National Ignition Facility (NIF) is to achieve thermonuclear ignition in a laboratory environment in inertial confinement fusion (ICF). This will enable NIF to service the DOE stockpile stewardship management program, inertial fusion energy goals, and advance scientific frontiers. All of these applications will make use of the extreme conditions that the facility will create in the target chamber. In the case of a prospected 20 MJ yield scenario, NIF will produce 10{sup 19} neutrons with DT fusion 14 MeV energy per neutron. There will also be high-energy x rays as well as solid, liquid, and gaseous target debris produced either directly or indirectly by the inertial confinement fusion process. A critical design issue is the protection of the final optical components as well as sophisticated target diagnostics in such a harsh environment.

  17. Fiber optic microneedles for transdermal light delivery: ex vivo porcine skin penetration experiments.

    PubMed

    Kosoglu, Mehmet A; Hood, Robert L; Chen, Ye; Xu, Yong; Rylander, Marissa Nichole; Rylander, Christopher G

    2010-09-01

    Shallow light penetration in tissue has been a technical barrier to the development of light-based methods for in vivo diagnosis and treatment of epithelial carcinomas. This problem can potentially be solved by utilizing minimally invasive probes to deliver light directly to target areas. To develop this solution, fiber optic microneedles capable of delivering light for either imaging or therapy were manufactured by tapering step-index silica-based optical fibers employing a melt-drawing process. Some of the microneedles were manufactured to have sharper tips by changing the heat source during the melt-drawing process. All of the microneedles were individually inserted into ex vivo pig skin samples to demonstrate the feasibility of their application in human tissues. The force on each microneedle was measured during insertion in order to determine the effects of sharper tips on the peak force and the steadiness of the increase in force. Skin penetration experiments showed that sharp fiber optic microneedles that are 3 mm long penetrate through 2 mm of ex vivo pig skin specimens. These sharp microneedles had a minimum average diameter of 73 mum and a maximum tip diameter of 8 mum. Flat microneedles, which had larger tip diameters, required a minimum average diameter of 125 mum in order to penetrate through pig skin samples. Force versus displacement plots showed that a sharp tip on a fiber optic microneedle decreased the skin's resistance during insertion. Also, the force acting on a sharp microneedle increased more steadily compared with a microneedle with a flat tip. However, many of the sharp microneedles sustained damage during skin penetration. Two designs that did not accrue damage were identified and will provide a basis of more robust microneedles. Developing resilient microneedles with smaller diameters will lead to transformative, novel modes of transdermal imaging and treatment that are less invasive and less painful for the patient. PMID:20815648

  18. Evaluation of skin optical clearing enhancement with Azone as a penetration enhancer

    NASA Astrophysics Data System (ADS)

    Xu, Xiangqun; Zhu, Qiuhong

    2007-11-01

    In order to find a non-invasive way to improve the efficacy of skin optical clearing with topically applied optical clearing agents (OCA), we evaluated the effect of Azone as a chemical penetration enhancer on optical clearing of intact skin in vitro. Fresh porcine skin with topical application of glycerol (G) mixed with various concentrations of water-soluble Azone (A w) or propylene glycol (PG) mixed with oil-soluble Azone (A o) was investigated. We measured changes in optical transmittance and diffuse reflectance of the skin under treatment with a near-infrared spectrophotometer. Light transmittance at 1276 nm increased by 37.3% and 41.1% at 60 min after the treatment in the cases with 40%PG5%A o and 40%G5%A w, respectively. Diffuse reflectance at 1066 nm decreased by 20.6% and 29.3% at 60 min after the treatment with 40%PG5%A o and 40%G5%A w, respectively. Forty percent glycerol or propylene glycol with the addition of Azone could achieve the same optical clearing effect as 80% glycerol. The results indicated that skin optical clearing with the topical application of glycerol and propylene glycol was markedly enhanced by both water-soluble and oil-soluble Azone. Skin penetration enhancing effect of Azone accounts probably for the skin clearing enhancement. In addition, Azone itself has shown optical clearing capability.

  19. A high performance fiber optic pressure penetrator for use in the deep ocean

    NASA Astrophysics Data System (ADS)

    Cowen, S. J.

    1981-02-01

    This report describes results obtained in an FY 80 developmental program carried out at the Naval Ocean System Center, San Diego, under Independent Exploratory Development funding. The objective was to develop a robust, fully-demountable, high pressure penetrator design suitable for coupling light signals transmitted by optical fiber elements in an undersea cable operated at high ambient hydrostatic pressure into an electronics package or manned space. The feasibility of constructing such penetrators utilizing Graded Refractive Index (GRIN) rod lenses as combination pressure barriers and imaging devices has been demonstrated. Prototype realizations have exhibited excellent optical throughput performance and readily survive in excess of 10,000 psi pressure differential as well as tolerating a wide temperature range. The design lends itself to hermetic construction for applications requiring no vapor diffusion over long mission durations. Such devices exhibit excellent potential for satisfying SUBSAFE requirements for manned submarine applications.

  20. Measurement of optical penetration depth and refractive index of human tissue

    NASA Astrophysics Data System (ADS)

    Xie, Shusen; Li, Hui; Li, Buhong

    2003-01-01

    Experimental techniques for measurement of optical penetration depth and refractive index of human tissue are presented, respectively. Optical penetration depth can be obtained from the measurement of the relative fluence-depth distribution inside the target tissue. The depth of normal and carcinomatous human lung tissues irradiated with the wavelengths of 406.7, 632.8 and 674.4 nm in vitro are respectively determined. In addition, a novel simple method based on total internal reflection for measuring the refractive index of biotissue in vivo is developed, and the refractive indices of skin from people of different age, sex and skin color are measured. Their refractive indices are almost same and the average is 1.533.

  1. Highly accurate and fast optical penetration-based silkworm gender separation system

    NASA Astrophysics Data System (ADS)

    Kamtongdee, Chakkrit; Sumriddetchkajorn, Sarun; Chanhorm, Sataporn

    2015-07-01

    Based on our research work in the last five years, this paper highlights our innovative optical sensing system that can identify and separate silkworm gender highly suitable for sericulture industry. The key idea relies on our proposed optical penetration concepts and once combined with simple image processing operations leads to high accuracy in identifying of silkworm gender. Inside the system, there are electronic and mechanical parts that assist in controlling the overall system operation, processing the optical signal, and separating the female from male silkworm pupae. With current system performance, we achieve a very highly accurate more than 95% in identifying gender of silkworm pupae with an average system operational speed of 30 silkworm pupae/minute. Three of our systems are already in operation at Thailand's Queen Sirikit Sericulture Centers.

  2. Electrical stimulation with a penetrating optic nerve electrode array elicits visuotopic cortical responses in cats

    NASA Astrophysics Data System (ADS)

    Lu, Yiliang; Yan, Yan; Chai, Xinyu; Ren, Qiushi; Chen, Yao; Li, Liming

    2013-06-01

    Objective. A visual prosthesis based on penetrating electrode stimulation within the optic nerve (ON) is a potential way to restore partial functional vision for blind patients. We investigated the retinotopic organization of ON stimulation and its spatial resolution. Approach. A five-electrode array was inserted perpendicularly into the ON or a single electrode was advanced to different depths within the ON (˜1-2 mm behind the eyeball, 13 cats). A sparse noise method was used to map ON electrode position and the visual cortex. Cortical responses were recorded by a 5 × 6 array. The visuotopic correspondence between the retinotopic position of the ON electrode was compared with the visual evoked cortical map and the electrical evoked potentials elicited in response to ON stimulation. Main results. Electrical stimulation with penetrating ON electrodes elicited cortical responses in visuotopographically corresponding areas of the cortex. Stimulation of the temporal side of the ON elicited cortical responses corresponding to the central visual field. The visual field position shifted from the lower to central visual field as the electrode penetrated through the depth of the ON. A spatial resolution of ˜ 2° to 3° within a limited cortical visuotopic representation could be obtained by this approach. Significance. Visuotopic electrical stimulation with a relatively fine spatial resolution can be accomplished using penetrating electrodes implanted at multiple sites and at different depths within the ON just behind the globe. This study also provides useful experimental data for the design of electrode density and the distribution of penetrating ON electrodes for a visual prosthesis.

  3. A simulation of current focusing and steering with penetrating optic nerve electrodes

    NASA Astrophysics Data System (ADS)

    Li, Menghui; Yan, Yan; Wang, Qixin; Zhao, Honghong; Chai, Xinyu; Sui, Xiaohong; Ren, Qiushi; Li, Liming

    2013-12-01

    Objective. Current focusing and steering are both widely used to shape the electric field and increase the number of distinct perceptual channels in neural stimulation, yet neither technique has been used for an optic nerve (ON)-based visual prosthesis. In order to evaluate the effects of current focusing and steering in penetrative stimulation, we built an integrated computational model to simulate and investigate the influence of stimulating parameters on ON fibre recruitment. Approach. Finite element models with extremely fine meshes were first established to compute the 3D electric potential distribution under different stimulating parameters. Then the external electric potential was fed to randomized multi-compartment cable models to predict the distribution of fibres generating an action potential. Finally a statistical process was conducted to quantify the recruitment region. Main results. The simulation results show that a two-electrode mode is superior to a three-electrode mode in current steering. The three-electrode mode performs poorly in current focusing, albeit the localized recruitment from both configurations implies that current focusing might be unnecessary in penetrative ON stimulation. Significance. This study provides useful information for the optimized design of penetrating ON electrodes and stimulating strategies. The Monte Carlo style computation paradigm is designed to simulate neural responses of an ensemble of ON fibres, which can be immediately transferred to other similar problems.

  4. In-vivo dynamic characterization of microneedle skin penetration using optical coherence tomography.

    PubMed

    Enfield, Joey; O'Connell, Marie-Louise; Lawlor, Kate; Jonathan, Enock; O'Mahony, Conor; Leahy, Martin

    2010-01-01

    The use of microneedles as a method of circumventing the barrier properties of the stratum corneum is receiving much attention. Although skin disruption technologies and subsequent transdermal diffusion rates are being extensively studied, no accurate data on depth and closure kinetics of microneedle-induced skin pores are available, primarily due to the cumbersome techniques currently required for skin analysis. We report on the first use of optical coherence tomography technology to image microneedle penetration in real time and in vivo. We show that optical coherence tomography (OCT) can be used to painlessly measure stratum corneum and epidermis thickness, as well as microneedle penetration depth after microneedle insertion. Since OCT is a real-time, in-vivo, nondestructive technique, we also analyze skin healing characteristics and present quantitative data on micropore closure rate. Two locations (the volar forearm and dorsal aspect of the fingertip) have been assessed as suitable candidates for microneedle administration. The results illustrate the applicability of OCT analysis as a tool for microneedle-related skin characterization. PMID:20799803

  5. In-vivo dynamic characterization of microneedle skin penetration using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Enfield, Joey; O'Connell, Marie-Louise; Lawlor, Kate; Jonathan, Enock; O'Mahony, Conor; Leahy, Martin

    2010-07-01

    The use of microneedles as a method of circumventing the barrier properties of the stratum corneum is receiving much attention. Although skin disruption technologies and subsequent transdermal diffusion rates are being extensively studied, no accurate data on depth and closure kinetics of microneedle-induced skin pores are available, primarily due to the cumbersome techniques currently required for skin analysis. We report on the first use of optical coherence tomography technology to image microneedle penetration in real time and in vivo. We show that optical coherence tomography (OCT) can be used to painlessly measure stratum corneum and epidermis thickness, as well as microneedle penetration depth after microneedle insertion. Since OCT is a real-time, in-vivo, nondestructive technique, we also analyze skin healing characteristics and present quantitative data on micropore closure rate. Two locations (the volar forearm and dorsal aspect of the fingertip) have been assessed as suitable candidates for microneedle administration. The results illustrate the applicability of OCT analysis as a tool for microneedle-related skin characterization.

  6. Integrating sphere effect in whole-bladder wall photodynamic therapy: III. Fluence multiplication, optical penetration and light distribution with an eccentric source for human bladder optical properties.

    PubMed

    van Staveren, H J; Keijzer, M; Keesmaat, T; Jansen, H; Kirkel, W J; Beek, J F; Star, W M

    1996-04-01

    Whole-bladder-wall (WBW) photodynamic therapy (PDT) is performed using approximately 630 nm light emitted by an isotropic light source centered in the bladder cavity. The phenomenon of an increased fluence rate in this spherical geometry, due to light scattering, is denoted as the integrating sphere effect. The fluence rate and the optical penetration depth depend on a single tissue optical parameter, namely the reduced albedo. The optical properties of (diseased) human bladder tissue, i.e. absorption coefficient, scattering coefficient, anisotropy factor and refractive index, were determined in vitro in the wavelength range of 450-880 nm. The integrating sphere effect and optical penetration depth were calculated with diffusion theory and compared to Monte Carlo (MC) computer simulations using approximately 630 nm optical properties. With increasing albedo, the integrating sphere effect calculated with diffusion approximation is increasingly larger than that found with MC simulations. Calculated and simulated optical penetration depths are in reasonable agreement. The smaller the integrating sphere effect for a given tissue absorption, the larger the optical penetration depth into the bladder wall, as the effective attenuation coefficient decreases. Optical penetration depths up to approximately 7.5 mm (definition dependent) can be responsible for unintended tissue damage beyond the bladder tissue. MC simulations were also performed with an eccentric light source and the uniformity of the light distribution at the bladder wall was assessed. The simulations show that even for a small eccentricity, the extremes in deviation from the mean fluence rate are large. All these results indicate that WBW PDT should be performed with some kind of in situ light dosimetry. PMID:8730658

  7. Changing Polygenic Penetrance on Phenotypes in the 20(th) Century Among Adults in the US Population.

    PubMed

    Conley, Dalton; Laidley, Thomas M; Boardman, Jason D; Domingue, Benjamin W

    2016-01-01

    This study evaluates changes in genetic penetrance-defined as the association between an additive polygenic score and its associated phenotype-across birth cohorts. Situating our analysis within recent historical trends in the U.S., we show that, while height and BMI show increasing genotypic penetrance over the course of 20(th) Century, education and heart disease show declining genotypic effects. Meanwhile, we find genotypic penetrance to be historically stable with respect to depression. Our findings help inform our understanding of how the genetic and environmental landscape of American society has changed over the past century, and have implications for research which models gene-environment (GxE) interactions, as well as polygenic score calculations in consortia studies that include multiple birth cohorts. PMID:27456657

  8. In vivo and in vitro dermal penetration of 2,4,5,2 prime ,4 prime , 5 prime -hexachlorobiphenyl in young and adult rats

    SciTech Connect

    Shah, P.V.; Sumler, M.R. ); Fisher, H.L.; Hall, L.L. )

    1989-10-01

    Penetration of 2,4,5,2{prime},4{prime},5{prime}-({sup 14}C)hexachlorobiphenyl (HCB) through skin of young (33 days) and adult (82 days) female Fischer 344 rats was determined in vivo and by two in vitro methods. In vivo dermal penetration at 120 hr was 45% in young and 43% in adults. At 72 hr in vivo dermal penetration was 35% in young and 26% in adults compared to 1.5% for young and 1.0% for adult as measured with a continuous flow in vitro system and 2.9% for young and 1.9% for adults as measured with a static in vitro system. Most of the dermally absorbed HCB remained in the body as only 4.9 and 2.6% of that absorbed was excreted by young and adult rats, respectively, at the end of 120 hr. Significant differences in dermal penetration and kinetics of HCB between young and adult female rats were observed. The elimination of ECB-derived material was approximately six times higher in feces than in urine. A physiological pharmacokinetic model was fitted to the organ and tissue radioactivity distribution data. Parameters in the model determined from dermal dosing of female Fischer 344 rats were in reasonable agreement with those reported in the literature for adult male Sprague-Dawley rats (iv dose). The rate constant for dermal penetration was 0.83 {times} 10{sup {minus}4} min{sup {minus}1} for adults and 0.96 {times} 10{sup {minus}4} min{sup {minus}1} for young. The delay or lag time parameter for dermal penetration was 4.4 hr in adults and 1.1 hr in young.

  9. Towards next-generation time-domain diffuse optics for extreme depth penetration and sensitivity.

    PubMed

    Mora, Alberto Dalla; Contini, Davide; Arridge, Simon; Martelli, Fabrizio; Tosi, Alberto; Boso, Gianluca; Farina, Andrea; Durduran, Turgut; Martinenghi, Edoardo; Torricelli, Alessandro; Pifferi, Antonio

    2015-05-01

    Light is a powerful tool to non-invasively probe highly scattering media for clinical applications ranging from oncology to neurology, but also for molecular imaging, and quality assessment of food, wood and pharmaceuticals. Here we show that, for a paradigmatic case of diffuse optical imaging, ideal yet realistic time-domain systems yield more than 2-fold higher depth penetration and many decades higher contrast as compared to ideal continuous-wave systems, by adopting a dense source-detector distribution with picosecond time-gating. Towards this aim, we demonstrate the first building block made of a source-detector pair directly embedded into the probe based on a pulsed Vertical-Cavity Surface-Emitting Laser (VCSEL) to allow parallelization for dense coverage, a Silicon Photomultiplier (SiPM) to maximize light harvesting, and a Single-Photon Avalanche Diode (SPAD) to demonstrate the time-gating capability on the basic SiPM element. This paves the way to a dramatic advancement in terms of increased performances, new high impact applications, and availability of devices with orders of magnitude reduction in size and cost for widespread use, including quantitative wearable imaging. PMID:26137377

  10. Towards next-generation time-domain diffuse optics for extreme depth penetration and sensitivity

    PubMed Central

    Mora, Alberto Dalla; Contini, Davide; Arridge, Simon; Martelli, Fabrizio; Tosi, Alberto; Boso, Gianluca; Farina, Andrea; Durduran, Turgut; Martinenghi, Edoardo; Torricelli, Alessandro; Pifferi, Antonio

    2015-01-01

    Light is a powerful tool to non-invasively probe highly scattering media for clinical applications ranging from oncology to neurology, but also for molecular imaging, and quality assessment of food, wood and pharmaceuticals. Here we show that, for a paradigmatic case of diffuse optical imaging, ideal yet realistic time-domain systems yield more than 2-fold higher depth penetration and many decades higher contrast as compared to ideal continuous-wave systems, by adopting a dense source-detector distribution with picosecond time-gating. Towards this aim, we demonstrate the first building block made of a source-detector pair directly embedded into the probe based on a pulsed Vertical-Cavity Surface-Emitting Laser (VCSEL) to allow parallelization for dense coverage, a Silicon Photomultiplier (SiPM) to maximize light harvesting, and a Single-Photon Avalanche Diode (SPAD) to demonstrate the time-gating capability on the basic SiPM element. This paves the way to a dramatic advancement in terms of increased performances, new high impact applications, and availability of devices with orders of magnitude reduction in size and cost for widespread use, including quantitative wearable imaging. PMID:26137377

  11. Effects of Wind Speed on Aerosol Spray Penetration in Adult Mosquito Bioassay Cages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bioassay cages are commonly used to assess efficacy of insecticides against adult mosquitoes in the field. To properly correlate adult mortality readings to insecticidal efficacy and/or spray application parameters, it is important to know how the cage used in the bioassay interacts with the spray ...

  12. Changing Polygenic Penetrance on Phenotypes in the 20th Century Among Adults in the US Population

    PubMed Central

    Conley, Dalton; Laidley, Thomas M.; Boardman, Jason D.; Domingue, Benjamin W.

    2016-01-01

    This study evaluates changes in genetic penetrance—defined as the association between an additive polygenic score and its associated phenotype—across birth cohorts. Situating our analysis within recent historical trends in the U.S., we show that, while height and BMI show increasing genotypic penetrance over the course of 20th Century, education and heart disease show declining genotypic effects. Meanwhile, we find genotypic penetrance to be historically stable with respect to depression. Our findings help inform our understanding of how the genetic and environmental landscape of American society has changed over the past century, and have implications for research which models gene-environment (GxE) interactions, as well as polygenic score calculations in consortia studies that include multiple birth cohorts. PMID:27456657

  13. Penetration of Treosulfan and its Active Monoepoxide Transformation Product into Central Nervous System of Juvenile and Young Adult Rats.

    PubMed

    Romański, Michał; Baumgart, Joachim; Böhm, Sonja; Główka, Franciszek K

    2015-12-01

    Treosulfan (TREO) is currently investigated as an alternative treatment of busulfan in conditioning before hematopoietic stem cell transplantation. The knowledge of the blood-brain barrier penetration of the drug is still scarce. In this paper, penetration of TREO and its active monoepoxide (S,S-EBDM) and diepoxide (S,S-DEB) into the CNS was studied in juvenile (JR) and young adult rats (YAR) for the first time. CD rats of both sexes (n = 96) received an intravenous dose of TREO 500 mg/kg b.wt. Concentrations of TREO, S,S-EBDM, and S,S-DEB in rat plasma, brain, and cerebrospinal fluid (CSF, in YAR only) were determined by validated bioanalytical methods. Pharmacokinetic calculations were performed in WinNonlin using a noncompartmental analysis and statistical evaluation was done in Statistica software. In male JR, female JR, male YAR, and female YAR, the brain/plasma area under the curve (AUC) ratio for unbound TREO was 0.14, 0.17, 0.10, and 0.07 and for unbound S,S-EBDM, it was 0.52, 0.48, 0.28, and 0.22, respectively. The CSF/plasma AUC ratio in male and female YAR was 0.12 and 0.11 for TREO and 0.66 and 0.64 for S,S-EBDM, respectively. Elimination rate constants of TREO and S,S-EBDM in all the matrices were sex-independent with a tendency to be lower in the JR. No quantifiable levels of S,S-DEB were found in the studied samples. TREO and S,S-EBDM demonstrated poor and sex-independent penetration into CNS. However, the brain exposure was greater in juvenile rats, so very young children might potentially be more susceptible to high-dose TREO-related CNS exposure than young adults. PMID:26428246

  14. Near-field penetrating optical microscopy: A live cell nanoscale refractive index measurement technique for quantification of internal macromolecular density

    PubMed Central

    Strasser, Samantha Dale; Shekhawat, Gajendra; Rogers, Jeremy D.; Dravid, Vinayak P.; Taflove, Allen; Backman, Vadim

    2012-01-01

    Quantification of intracellular nanoscale macromolecular density distribution is a fundamental aspect to understanding cellular processes. We report a near-field penetrating optical microscopy (NPOM) technique to directly probe the internal nanoscale macromolecular density of biological cells through quantification of intracellular refractive index (RI). NPOM inserts a tapered optical fiber probe to successive depths into an illuminated sample. A 50 nm diameter probe-tip collects signal that exhibits a linear relationship with the sample RI at a spatial resolution of approximately 50 nm for biologically relevant measurements, one order-of-magnitude finer than the Abbe diffraction limit. Live and fixed cell data illustrate the mechanical ability of a 50 nm probe to penetrate biological samples. PMID:22344088

  15. Near-field penetrating optical microscopy: a live cell nanoscale refractive index measurement technique for quantification of internal macromolecular density.

    PubMed

    Strasser, Samantha Dale; Shekhawat, Gajendra; Rogers, Jeremy D; Dravid, Vinayak P; Taflove, Allen; Backman, Vadim

    2012-02-15

    Quantification of intracellular nanoscale macromolecular density distribution is a fundamental aspect to understanding cellular processes. We report a near-field penetrating optical microscopy (NPOM) technique to directly probe the internal nanoscale macromolecular density of biological cells through quantification of intracellular refractive index (RI). NPOM inserts a tapered optical fiber probe to successive depths into an illuminated sample. A 50 nm diameter probe tip collects signal that exhibits a linear relationship with the sample RI at a spatial resolution of approximately 50 nm for biologically relevant measurements, one order of magnitude finer than the Abbe diffraction limit. Live and fixed cell data illustrate the mechanical ability of a 50 nm probe to penetrate biological samples. PMID:22344088

  16. Investigation on penetration of three conventional foodstuffs packaging polymers with two different thicknesses by larvae and adults of major species of stored-product pest insects.

    PubMed

    Allahvaisi, Somayeh; Purmirza, Ali Asghar; Safaralizade, Mohamad Hasan

    2009-01-01

    Despite modern methods of packaging, stored agricultural products are still under attack by stored-insect pests. Therefore, determination of the best polymer and appropriate thickness inhibiting the penetration of the insects must be considered. In this study, we investigated the ability of penetration and the rates of contamination by nine important stored product pest insects for three conventional flexible polymers (polyethylene, cellophane and polypropylene) at two thicknesses (16.5 and 29 microm), which are used as pouches for packing of agricultural products. We used adults of T. castaneum (Coleoptera), S. granarius (Coleoptera), R. dominica (Coleoptera), C. maculates (Coleoptera), O. surinamensis (Coleoptera), and larvae of P. interpunctella (Lepidoptera), E. kuehniella (Lepidoptera), S. cerealella (Lepidoptera) and T. granarium (Coleoptera). Results showed that for most of the species penetration occurred between 4 days and 2 weeks, but there were significant differences (p < or = 0.05) in the penetration of three polymers (cellophane, polyethylene and polypropylene) by the insects. Among the polymers, polyethylene with a thickness of 16.5 microm showed the highest degree of penetration and was the most unsuitable polymer for packaging of foodstuffs. Application of this polymer led to a complete infestation of the product and a lot of punctures were created by the insects. In contrast, no penetration was observed in polypropylene polymer with a thickness of 29 microm. Furthermore, adults and larvae of all species showed a much lower penetration when there was no food present in the pouches and this was the case for all polymers tested. PMID:20222605

  17. Preparing displaced adults for the optics/photonics workforce

    NASA Astrophysics Data System (ADS)

    Hull, Darrell M.

    2000-06-01

    As the optics/photonics industry continues to grow, the demand for workers is assumed to increase proportionally. Empirical data seem to support this assumption. This increase presents a challenge to optics/photonics education, since they control and assume responsibility for a key factor in the ability of industry to further expand. At the same time, the U.S. government through the Department of Labor and the Workforce Investment Act has requested that communities enact programs for displaced adults to transition to the workplace. A program of study is provided that would assist adults in making this transition from unemployment to the optics/photonics industry, with the necessary general work skills, occupational optics/photonics skills, and ability to progress on the job with academic foundations in math and science.

  18. Penetration of Pseudomonas aeruginosa by Sodium Chloride and Its Relation to the Mechanism of Optical Effects1

    PubMed Central

    Matula, Tibor I.; Macleod, Robert A.

    1969-01-01

    When cells of Pseudomonas aeruginosa were suspended in solutions containing increasing concentrations of NaCl, the optical density (OD) of the suspensions measured within 30 sec was found to increase in proportion to the increase in salt concentration. Measurement of intracellular fluid volumes indicated that the volume of the cells decreased roughly in proportion to the increase in salt concentration. After the initial increase in optical density, there was a slow decrease at all concentrations of NaCl tested except the highest, 500 mm. Metabolic inhibitors such as sodium azide and 2,4-dinitrophenol prevented the decrease. Direct analysis showed that the Na+ and Cl− concentrations in the cells were 86 and 77%, respectively, of the concentrations of the ions in the suspending medium after 1 hr. Measurement of the 22Na space in packed cells showed that Na+ penetrated the total fluid space in the packed cells. The penetration of 22Na was not prevented by the presence of metabolic inhibitors or by 500 mm NaCl in the suspending medium. The results indicate that the OD increases produced in suspensions of P. aeruginosa by NaCl are not due to the osmotic action of the salt. The subsequent optical density decreases observed are under metabolic control. PMID:4981061

  19. Pattern of stylet penetration activity by Homalodisca vitripennis (Hemiptera: Cicadellidae) adults in relation to environmental temperature and light conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of ambient spring air temperature and light intensity on stylet penetration activities of the glassy-winged sharpshooter, Homalodisca vitripennis (Germar) were studied outdoors, at ambient light and temperatures, using an electrical penetration graph (EPG). EPG waveforms representing saliva...

  20. Sub-40 fs, 1060-nm Yb-fiber laser enhances penetration depth in nonlinear optical microscopy of human skin

    NASA Astrophysics Data System (ADS)

    Balu, Mihaela; Saytashev, Ilyas; Hou, Jue; Dantus, Marcos; Tromberg, Bruce J.

    2015-12-01

    Advancing the practical utility of nonlinear optical microscopy requires continued improvement in imaging depth and contrast. We evaluated second-harmonic generation (SHG) and third-harmonic generation images from ex vivo human skin and showed that a sub-40 fs, 1060-nm Yb-fiber laser can enhance SHG penetration depth by up to 80% compared to a >100 fs, 800 nm Ti:sapphire source. These results demonstrate the potential of fiber-based laser systems to address a key performance limitation related to nonlinear optical microscopy (NLOM) technology while providing a low-barrier-to-access alternative to Ti:sapphire sources that could help accelerate the movement of NLOM into clinical practice.

  1. Quantitative comparison of wavelength dependence on penetration depth and imaging contrast for ultrahigh-resolution optical coherence tomography using supercontinuum sources at five wavelength regions

    NASA Astrophysics Data System (ADS)

    Ishida, S.; Nishizawa, N.

    2012-01-01

    Optical coherence tomography (OCT) is a non invasive optical imaging technology for micron-scale cross-sectional imaging of biological tissue and materials. We have been investigating ultrahigh resolution optical coherence tomography (UHR-OCT) using fiber based supercontinuum sources. Although ultrahigh longitudinal resolution was achieved in several center wavelength regions, its low penetration depth is a serious limitation for other applications. To realize ultrahigh resolution and deep penetration depth simultaneously, it is necessary to choose the proper wavelength to maximize the light penetration and enhance the image contrast at deeper depths. Recently, we have demonstrated the wavelength dependence of penetration depth and imaging contrast for ultrahigh resolution OCT at 0.8 μm, 1.3 μm, and 1.7 μm wavelength ranges. In this paper, additionally we used SC sources at 1.06 μm and 1.55 μm, and we have investigated the wavelength dependence of UHR-OCT at five wavelength regions. The image contrast and penetration depth have been discussed in terms of the scattering coefficient and water absorption of samples. Almost the same optical characteristics in longitudinal and lateral resolution, sensitivity, and incident optical power at all wavelength regions were demonstrated. We confirmed the enhancement of image contrast and decreased ambiguity of deeper epithelioid structure at longer wavelength region.

  2. Applications of optically detected MRI for enhanced contrast and penetration in metal

    NASA Astrophysics Data System (ADS)

    Ruangchaithaweesuk, Songtham; Yu, Dindi S.; Garcia, Nissa C.; Yao, Li; Xu, Shoujun

    2012-10-01

    We report quantitative measurements using optically detected magnetic resonance imaging (MRI) for enhanced pH contrast and flow inside porous metals. Using a gadolinium chelate as the pH contrast agent, we show the response is 0.6 s-1 mM-1 per pH unit at the ambient magnetic field for the pH range 6-8.5. A stopped flow scheme was used to directly measure T1 relaxation time to determine the relaxivity. Flow profiles and images were obtained for a series of porous metals with different average pore sizes. The signal amplitudes and spatial distributions were compared. A clogged region in one of the samples was revealed using optically detected MRI but not optical imaging or scanning electron microscopy. These applications will significantly broaden the impact of optically detected MRI in chemical imaging and materials research.

  3. In vivo retinal optical coherence tomography at 1040 nm - enhanced penetration into the choroid

    NASA Astrophysics Data System (ADS)

    Unterhuber, Angelika; Povazay, B.; Hermann, B.; Sattmann, H.; Chavez-Pirson, A.; Drexler, W.

    2005-05-01

    For the first time in vivo retinal imaging has been performed with a new compact, low noise Yb-based ASE source operating in the 1 μm range (NP Photonics, λc = 1040 nm, Δλ = 50 nm, Pout = 30 mW) at the dispersion minimum of water with ~7 μm axial resolution. OCT tomograms acquired at 800 nm are compared to those achieved at 1040 nm showing about 200 μm deeper penetration into the choroid below the retinal pigment epithelium. Retinal OCT at longer wavelengths significantly improves the visualization of the retinal pigment epithelium/choriocapillaris/choroids interface and superficial choroidal layers as well as reduces the scattering through turbid media and therefore might provide a better diagnosis tool for early stages of retinal pathologies such as age related macular degeneration which is accompanied by choroidal neovascularization, i.e., extensive growth of new blood vessels in the choroid and retina.

  4. Calculation of optical properties of dental composites as a basis for determining color impression and penetration depth of laser light

    NASA Astrophysics Data System (ADS)

    Weniger, Kirsten K.; Muller, Gerhard J.

    2005-03-01

    In order to achieve esthetic dental restorations, there should be no visible difference between restorative material and treated teeth. This requires a match of the optical properties of both restorative material and natural teeth. These optical properties are determined by absorption and scattering of light emerging not only on the surface but also inside the material. Investigating different dental composites in several shades, a method has been developed to calculate the optical parameters absorption coefficient μa, scattering coefficient μs, anisotropy factor g and reduced scattering coefficient μs'. The method includes sample preparation and measurements of transmittance and reflectance in an integrating sphere spectrometer, followed by inverse Monte Carlo simulations. Determination of optical properties is more precise and comprehensive than with the previously used Kubelka Munk theory because scattering can be looked at separated into pure scattering with the scattering coefficient μs and its direction with the anisotropy factor g. Moreover the use of the inverse Monte Carlo simulation not only minimizes systematic errors and considers the scattering phase function, but also takes into account the measuring geometry. The compilation of a data pool of optical parameters now enables the application of further calculation models as a basis for optimization of the composition of new materials. For example, a prediction of the general color impression for multiple layers can be carried out as well as the calculation of the wavelength dependent penetration depths of light with regard to photo polymerization. Further applications are possible in the area of laser ablation.

  5. Increasing the penetration depth for ultrafast laser tissue ablation using glycerol based optical clearing

    NASA Astrophysics Data System (ADS)

    Gabay, Ilan; Subramanian, Kaushik G.; Martin, Chris; Yildirim, Murat; Tuchin, Valery V.; Ben-Yakar, Adela

    2016-03-01

    Background: Deep tissue ablation is the next challenge in ultrafast laser microsurgery. By focusing ultrafast pulses below the tissue surface one can create an ablation void confined to the focal volume. However, as the ablation depth increases in a scattering tissue, increase in the required power can trigger undesired nonlinear phenomena out of focus that restricts our ability to ablate beyond a maximum ablation depth of few scattering lengths. Optical clearing (OC) might reduce the intensity and increase the maximal ablation depth by lowering the refractive index mismatch, and therefore reducing scattering. Some efforts to ablate deeper showed out of focus damage, while others used brutal mechanical methods for clearing. Our clinical goal is to create voids in the scarred vocal folds and inject a biomaterial to bring back the tissue elasticity and restore phonation. Materials and methods: Fresh porcine vocal folds were excised and applied a biocompatible OC agent (75% glycerol). Collimated transmittance was monitored. The tissue was optically cleared and put under the microscope for ablation threshold measurements at different depths. Results: The time after which the tissue was optically cleared was roughly two hours. Fitting the threshold measurements to an exponential decay graph indicated that the scattering length of the tissue increased to 83+/-16 μm, which is more than doubling the known scattering length for normal tissue. Conclusion: Optical clearing with Glycerol increases the tissue scattering length and therefore reduces the energy for ablation and increases the maximal ablation depth. This technique can potentially improve clinical microsurgery.

  6. Influence of skin-to-muscle and muscle-to-bone thickness on depth of needle penetration in adults at the deltoid intramuscular injection site

    PubMed Central

    Shankar, Nachiket; Saxena, Deepali; Lokkur, Pooja P.; Kumar, Nikhil M.; William, Neena Chris; Vijaykumar, Nirupama

    2014-01-01

    Background The objectives of the study were to estimate the following in adults of Indian origin: a) Gender and side differences in the skin-to-muscle (SM) and muscle-to-bone thickness (MB) at the deltoid intramuscular injection site; b) Correlation of SM thickness with the BMI, age and gender; c) The prevalence of under and over-penetration assuming a standard needle length of 25 mm and following prescribed guidelines for IM injection. Methods The SM, MB and skin-to-bone (SB) thicknesses were bilaterally estimated in two hundred adult Indian subjects (100 male and 100 female) using an ultrasound probe at a pre-determined point on the upper arms of the subjects. The BMI of each subject was calculated. The unpaired sample ‘t’ test and paired ‘t’ test were used to analyse differences between groups. Pearson's correlation coefficient was used in correlation analysis and suitable linear regression equations were generated. Results Females had a significantly higher SM thickness and lower MB thickness. The SM thickness was significantly greater on the left side, while the SB and MB thickness were significantly greater on the right. Multiple linear regression equations for both the dominant and non-dominant arms had good model fit properties. Under-penetration would have occurred in 2 (1%) subjects while over-penetration would have occurred in 50% of the subjects. Conclusion Over-penetration of deltoid IM injections is likely to be more prevalent as compared to under-penetration. Therefore, the technique of IM injection needs to be modified based on the body type of the individual patient. PMID:25382907

  7. PENETRATING THE HOMUNCULUS-NEAR-INFRARED ADAPTIVE OPTICS IMAGES OF ETA CARINAE

    SciTech Connect

    Artigau, Etienne; Martin, John C.; Humphreys, Roberta M.; Davidson, Kris; Chesneau, Olivier; Smith, Nathan

    2011-06-15

    Near-infrared adaptive optics imaging with the Near-Infrared Coronagraphic Imager (NICI) and NaCO reveal what appears to be a three-winged or lobed pattern, the 'butterfly nebula', outlined by bright Br{gamma} and H{sub 2} emission and light scattered by dust. In contrast, the [Fe II] emission does not follow the outline of the wings, but shows an extended bipolar distribution which is tracing the Little Homunculus ejected in {eta} Car's second or lesser eruption in the 1890s. Proper motions measured from the combined NICI and NaCO images together with radial velocities show that the knots and filaments that define the bright rims of the butterfly were ejected at two different epochs corresponding approximately to the great eruption and the second eruption. Most of the material is spatially distributed 10{sup 0}-20{sup 0} above and below the equatorial plane apparently behind the Little Homunculus and the larger SE lobe. The equatorial debris either has a wide opening angle or the clumps were ejected at different latitudes relative to the plane. The butterfly is not a coherent physical structure or equatorial torus but spatially separate clumps and filaments ejected at different times, and now 2000-4000 AU from the star.

  8. Penetrating the Homunculus -- Near-Infrared Adaptive Optics Images of Eta Carinae

    NASA Astrophysics Data System (ADS)

    Martin, John C.; Artigau, E.; Davidson, K.; Humphreys, R. M.; Chesneau, O.; Smith, N.

    2010-01-01

    We present the extraordinary near-infrared images of Eta Carinae obtained with the Near-Infrared Coronagraphic Camera (NICI) with adaptive optics on the Gemini South telescope just after Eta Car's 2009 spectroscopic event. The K-band continuum and continuum-subtracted narrow-band Br-gamma and H2 images show a three-winged pattern outlined by bright emitting dust in the innermost region of the ejecta around the central star. This intriguing pattern was first noticed by Chesneau et al. (2005) from earlier VLT/NaCO images and was named the "butterfly nebula.” In contrast the with the Br-gamma and H2 images, the [Fe II] image does not follow the outline of the "butterfly wings,” but instead shows a much broader, bipolar distribution traced to about 2 arcsec from the star. We suggest that the [Fe II] emission is tracing the "little Homunculus" previously observed only spectroscopically, and attributed to a bipolar outflow from Eta Car's second eruption in the 1890's. The nature of the "butterfly nebula" is debated and may be due to an ouflow or to an equatorial torus. Kinematic data is needed to measure or set limits on its expansion, age and orientation within the larger Homunculus. In this poster we also report the results of our measurements of the transverse motions of the knots and filaments that outline the "butterfly."

  9. Penetrating the Homunculus—Near-Infrared Adaptive Optics Images of Eta Carinae

    NASA Astrophysics Data System (ADS)

    Artigau, Étienne; Martin, John C.; Humphreys, Roberta M.; Davidson, Kris; Chesneau, Olivier; Smith, Nathan

    2011-06-01

    Near-infrared adaptive optics imaging with the Near-Infrared Coronagraphic Imager (NICI) and NaCO reveal what appears to be a three-winged or lobed pattern, the "butterfly nebula," outlined by bright Brγ and H2 emission and light scattered by dust. In contrast, the [Fe II] emission does not follow the outline of the wings, but shows an extended bipolar distribution which is tracing the Little Homunculus ejected in η Car's second or lesser eruption in the 1890s. Proper motions measured from the combined NICI and NaCO images together with radial velocities show that the knots and filaments that define the bright rims of the butterfly were ejected at two different epochs corresponding approximately to the great eruption and the second eruption. Most of the material is spatially distributed 10°-20° above and below the equatorial plane apparently behind the Little Homunculus and the larger SE lobe. The equatorial debris either has a wide opening angle or the clumps were ejected at different latitudes relative to the plane. The butterfly is not a coherent physical structure or equatorial torus but spatially separate clumps and filaments ejected at different times, and now 2000-4000 AU from the star. Based on observations obtained at the Gemini Observatory (program ID: GS-2008B-DD-6), which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  10. Monte Carlo study of skin optical clearing to enhance light penetration in the tissue: implications for photodynamic therapy of acne vulgaris

    NASA Astrophysics Data System (ADS)

    Bashkatov, Alexey N.; Genina, Elina A.; Tuchin, Valery V.; Altshuler, Gregory B.; Yaroslavsky, Ilya V.

    2008-06-01

    Result of Monte Carlo simulations of skin optical clearing is presented. The model calculations were carried out with the aim of studying of spectral response of skin under immersion liquids action and calculation of enhancement of light penetration depth. In summary, we have shown that: 1) application of glucose, propylene glycol and glycerol produced significant decrease of light scattering in different skin layers; 2) maximal clearing effect will be obtained in case of optical clearing of skin dermis, however, absorbed light fraction in skin dermis changed insignificantly, independently on clearing agent and place it administration; 3) in contrast to it, the light absorbed fraction in skin adipose layer increased significantly in case of optical clearing of skin dermis. It is very important because it can be used for development of optical methods of obesity treatment; 4) optical clearing of superficial skin layers can be used for decreasing of power of light radiation used for treatment of acne vulgaris.

  11. On-line air-tightness and insertion loss simultaneous detection method of high air-tightness fiber optic penetration connector

    NASA Astrophysics Data System (ADS)

    Zhang, Jingchuan; Yang, Xiaoning; Wang, Jing; Jiang, Junfeng

    2015-08-01

    The high air-tightness multicore fiber optic penetration connector is a core component for the optical fiber sensing and communication technologies applied in the space environment simulator under the vacuum thermal environment. High air-tightness and insertion loss are the two key indexes of the fiber optic penetration connector. The air-tightness and insertion loss on-line synchronous detection method was proposed. First, established hardware-in-the-loop testing platform by using the vacuum pumping system, the vacuum vessel, the helium mass spectrometer leak detector and optical time-domain reflectmeter, then, described the air tightness and insertion loss on-line detection principle, finally, designed a detection test scheme and air-tightness and insertion loss were tested. Experimental results indicate that the leakage rate is lower than 1.0×10-7Pa•L/S, the minimum of which is1.0×10-10Pa•L/S and the insertion loss at wave length window 1550 nm is +/-0.07db, which is less than +/-0.1db. It can lay the data basis for the design of opto-mechanical combination and later period fine processing.

  12. Histologically benign, clinically aggressive: Progressive non-optic pathway pilocytic astrocytomas in adults with NF1.

    PubMed

    Strowd, Roy E; Rodriguez, Fausto J; McLendon, Roger E; Vredenburgh, James J; Chance, Aaron B; Jallo, George; Olivi, Alessandro; Ahn, Edward S; Blakeley, Jaishri O

    2016-06-01

    Although optic pathway gliomas are the most common brain tumors associated with neurofibromatosis type 1 (NF1), extra-optic gliomas occur and may behave more aggressively with outcomes that differ by age. A retrospective case-control study was designed to describe the clinical course of adult NF1 patients with progressive extra-optic pilocytic astrocytomas (PAs) and compare to a pediatric cohort. Data for patients treated at the Johns Hopkins Comprehensive Neurofibromatosis Center from 2003 to 2013 were reviewed to identify cases (adults, age >18) and controls (pediatric, age <18) with clinically or radiographically progressive extra-optic PAs. Demographic, clinical, histologic, and radiographic data were collected. Three adult NF1 cases and four pediatric NF1 controls were identified. Mean age was 32.3 ± 9.5 years, 66% male (cases); 12.8 ± 4.2 years, 100% male (controls). Symptomatic progression occurred in two-of-three adults (67%) while the majority of pediatric patients presented with isolated radiographic progression (n = 3, 75%). Onset tended to be more rapid in adults (4 ± 1 vs. 14 ± 8.3 months, P = 0.10). Subtotal resection was the treatment for all pediatric patients. Radiotherapy (n = 2), chemotherapy (n = 2), and targeted, biologic agents (n = 2) were administered in adults. Although all pediatric patients are living, outcomes were universally poor in adults with progression to death in all (median survival 17.1 months, range 6.6-30.3). In conclusion, despite grade I histology, all three adult NF1 patients with progressive extra-optic PAs suffered an aggressive clinical course which was not seen in pediatric patients. Clinicians should be aware of this clinico-histologic discrepancy when counseling and managing adult NF1 patients with progressive extra-optic PAs. © 2016 Wiley Periodicals, Inc. PMID:26992069

  13. Histologically Benign, Clinically Aggressive: Progressive Non-Optic Pathway Pilocytic Astrocytomas in Adults with NF1

    PubMed Central

    Strowd, Roy E.; Rodriguez, Fausto J.; McLendon, Roger E.; Vredenburgh, James J.; Chance, Aaron B.; Jallo, George; Olivi, Alessandro; Ahn, Edward S.; Blakeley, Jaishri O.

    2016-01-01

    Although optic pathway gliomas are the most common brain tumors associated with neurofibromatosis type 1 (NF1), extra-optic gliomas occur and may behave more aggressively with outcomes that differ by age. A retrospective case-control study was designed to describe the clinical course of adult NF1 patients with progressive extra-optic pilocytic astrocytomas (PAs) and compare to a pediatric cohort. Data for patients treated at the Johns Hopkins Comprehensive Neurofibromatosis Center from 2003 to 2013 were reviewed to identify cases (adults, age >18) and controls (pediatric, age <18) with clinically or radiographically progressive extra-optic PAs. Demographic, clinical, histologic, and radiographic data were collected. Three adult NF1 cases and four pediatric NF1 controls were identified. Mean age was 32.3 ± 9.5 years, 66% male (cases); 12.8±4.2 years, 100% male (controls). Symptomatic progression occurred in two-of-three adults (67%) while the majority of pediatric patients presented with isolated radiographic progression (n=3, 75%). Onset tended to be more rapid in adults (4±1 vs. 14±8.3 months, P=0.10). Subtotal resection was the treatment for all pediatric patients. Radiotherapy (n=2), chemotherapy (n=2), and targeted, biologic agents (n=2) were administered in adults. Although all pediatric patients are living, outcomes were universally poor in adults with progression to death in all (median survival 17.1 months, range 6.6–30.3). In conclusion, despite grade I histology, all three adult NF1 patients with progressive extra-optic PAs suffered an aggressive clinical course which was not seen in pediatric patients. Clinicians should be aware of this clinico-histologic discrepancy when counseling and managing adult NF1 patients with progressive extra-optic PAs. PMID:26992069

  14. High-penetration imaging of retinal and choroidal pathologies by 1 μm swept-source OCT and optical coherence angiography

    NASA Astrophysics Data System (ADS)

    Yasuno, Yoshiaki; Miura, Masahiro; Okamoto, Fumiki; Hong, Youngjoo

    2008-02-01

    Two pathologic cases are evaluated by high-penetration optical coherence tomography (HP-OCT) to demonstrate its clinical significance. The HP-OCT is based on a swept-source OCT (SS-OCT) technology with a probe wavelength of 1.06 μm. The depth resolution is 10.4 μm in tissue, and the measurement speed is 28,000 depth-scans/sec. A single case of age-related macular degeneration and a single case of Vogt-Koyanagi-Harada disease are examined by HP-OCT.

  15. Zanamivir pharmacokinetics and pulmonary penetration into epithelial lining fluid following intravenous or oral inhaled administration to healthy adult subjects.

    PubMed

    Shelton, Mark J; Lovern, Mark; Ng-Cashin, Judith; Jones, Lori; Gould, Elizabeth; Gauvin, Jennifer; Rodvold, Keith A

    2011-11-01

    Zanamivir serum and pulmonary pharmacokinetics were characterized following intravenous (i.v.) or oral inhaled administration. I.v. zanamivir was given as intermittent doses of 100 mg, 200 mg, and 600 mg every 12 h (q12h) for two doses or as a continuous infusion (6-mg loading dose followed by 3 mg/h for 12 h). Oral inhaled zanamivir (two 5-mg inhalations q12h for two doses) was evaluated as well. Each zanamivir regimen was administered to six healthy subjects with serial pharmacokinetic sampling. In addition, a single bronchoalveolar lavage (BAL) fluid sample was collected at various time points and used to calculate epithelial lining fluid (ELF) drug concentrations for each subject. For intermittent i.v. administration of 100 mg, 200 mg, and 600 mg zanamivir, the median zanamivir concentrations in ELF collected 12 h after dosing were 74, 146, and 419 ng/ml, respectively, each higher than the historic mean 50% inhibitory concentrations for the neuraminidases of wild-type strains of influenza A and B viruses. Median ELF/serum zanamivir concentration ratios ranged from 55 to 79% for intermittent i.v. administration (when sampled 12 h after the last dose) and 43 to 45% for continuous infusion (when sampled 6 to 12 h after the start of the infusion). For oral inhaled zanamivir, the median zanamivir concentrations in ELF were 891 ng/ml for the first BAL fluid collection and 326 ng/ml for subsequent BAL fluid collections (when sampled 12 h after the last dose); corresponding serum drug concentrations were undetectable. This study demonstrates zanamivir's penetration into the human pulmonary compartment and supports the doses selected for the continuing development of i.v. zanamivir in clinical studies of influenza. PMID:21896909

  16. Zanamivir Pharmacokinetics and Pulmonary Penetration into Epithelial Lining Fluid following Intravenous or Oral Inhaled Administration to Healthy Adult Subjects▿

    PubMed Central

    Shelton, Mark J.; Lovern, Mark; Ng-Cashin, Judith; Jones, Lori; Gould, Elizabeth; Gauvin, Jennifer; Rodvold, Keith A.

    2011-01-01

    Zanamivir serum and pulmonary pharmacokinetics were characterized following intravenous (i.v.) or oral inhaled administration. I.v. zanamivir was given as intermittent doses of 100 mg, 200 mg, and 600 mg every 12 h (q12h) for two doses or as a continuous infusion (6-mg loading dose followed by 3 mg/h for 12 h). Oral inhaled zanamivir (two 5-mg inhalations q12h for two doses) was evaluated as well. Each zanamivir regimen was administered to six healthy subjects with serial pharmacokinetic sampling. In addition, a single bronchoalveolar lavage (BAL) fluid sample was collected at various time points and used to calculate epithelial lining fluid (ELF) drug concentrations for each subject. For intermittent i.v. administration of 100 mg, 200 mg, and 600 mg zanamivir, the median zanamivir concentrations in ELF collected 12 h after dosing were 74, 146, and 419 ng/ml, respectively, each higher than the historic mean 50% inhibitory concentrations for the neuraminidases of wild-type strains of influenza A and B viruses. Median ELF/serum zanamivir concentration ratios ranged from 55 to 79% for intermittent i.v. administration (when sampled 12 h after the last dose) and 43 to 45% for continuous infusion (when sampled 6 to 12 h after the start of the infusion). For oral inhaled zanamivir, the median zanamivir concentrations in ELF were 891 ng/ml for the first BAL fluid collection and 326 ng/ml for subsequent BAL fluid collections (when sampled 12 h after the last dose); corresponding serum drug concentrations were undetectable. This study demonstrates zanamivir's penetration into the human pulmonary compartment and supports the doses selected for the continuing development of i.v. zanamivir in clinical studies of influenza. PMID:21896909

  17. Characterization of penetration depth as a function of optical fiber separation at various absorption and scatter coefficients for a noninvasive metabolic sensor

    NASA Astrophysics Data System (ADS)

    DeMilo, Charles; Brukilacchio, Thomas; Soller, Babs R.; Soyemi, Olusola

    2004-06-01

    A visible-near IR (500-1,000nm) fiber optic sensor is under development that is intended to non-invasively assess muscle metabolism through the measurement of tissue pH and oxygen partial pressure. These parameters are calculated from the spectra of hemoglobin and myoglobin in muscle. The sensor consists of transmit (illumination) fibers and receive (detection) fibers that are coupled to a spectrometer. Light from the probe must penetrate below the surface of the skin and into a 5-10mm thick layer of muscle. A study was conducted to quantify the relationship between transmit and receive fiber separation and sensor penetration depth below the surface of the skin. A liquid phantom was created to replicate the absorption (μa) and reduced scatter coefficient (μs') profiles typically found in human blood and tissue. The phantom consisted of a solution of Intralipid and India ink in the appropriate concentrations to achieve desired reduced scatter coefficient and absorption profiles. The reduced scatter coefficient of the liquid phantom was achieved to an accuracy of +/-10% compared to previously published data. A fixed illumination fiber and translatable detector fiber were placed in the liquid phantom, and the fiber separation was varied from 3-40mm. Values of μa and μs' varied from 0.03-0.40 cm-1 and 5.0-15.0 cm-1 respectively. Results from the experiment demonstrate a strong correlation between penetration depth and fiber separation. Additionally, it was found that penetration depth was not substantially influenced by absorption and scatter concentration. As signal-to-noise is an important parameter in many non-invasive biomedical applications, the relative signal as a function of fiber separation was determined to follow an exponential relationship.

  18. Pediatric and adult vision restoration after optic nerve sheath decompression for idiopathic intracranial hypertension.

    PubMed

    Bersani, Thomas A; Meeker, Austin R; Sismanis, Dimitrios N; Carruth, Bryant P

    2016-06-01

    To compare presentations of idiopathic intracranial hypertension and efficacy of optic nerve sheath decompression between adult and pediatric patients, a retrospective cohort study was completed All idiopathic intracranial hypertension patients undergoing optic nerve sheath decompression by one surgeon between 1991 and 2012 were included. Pre-operative and post-operative visual fields, visual acuity, color vision, and optic nerve appearance were compared between adult and pediatric (<18 years) populations. Outcome measures included percentage of patients with complications or requiring subsequent interventions. Thirty-one adults (46 eyes) and eleven pediatric patients (18 eyes) underwent optic nerve sheath decompression for vision loss from idiopathic intracranial hypertension. Mean deviation on visual field, visual acuity, color vision, and optic nerve appearance significantly improved across all subjects. Pre-operative mean deviation was significantly worse in children compared to adults (p=0.043); there was no difference in mean deviation post-operatively (p=0.838). Significantly more pediatric eyes (6) presented with light perception only or no light perception than adult eyes (0) (p=0.001). Pre-operative color vision performance in children (19%) was significantly worse than in adults (46%) (p=0.026). Percentage of patients with complications or requiring subsequent interventions did not differ between groups. The consistent improvement after surgery and low rate of complications suggest optic nerve sheath decompression is safe and effective in managing vision loss due to adult and pediatric idiopathic intracranial hypertension. Given the advanced pre-operative visual deficits seen in children, one might consider a higher index of suspicion in diagnosing, and earlier surgical intervention in treating pediatric idiopathic intracranial hypertension. PMID:27163674

  19. Development of a high power supercontinuum source in the 1.7 μm wavelength region for highly penetrative ultrahigh-resolution optical coherence tomography

    PubMed Central

    Kawagoe, H.; Ishida, S.; Aramaki, M.; Sakakibara, Y.; Omoda, E.; Kataura, H.; Nishizawa, N.

    2014-01-01

    We developed a high power supercontinuum source at a center wavelength of 1.7 μm to demonstrate highly penetrative ultrahigh-resolution optical coherence tomography (UHR-OCT). A single-wall carbon nanotube dispersed in polyimide film was used as a transparent saturable absorber in the cavity configuration and a high-repetition-rate ultrashort-pulse fiber laser was realized. The developed SC source had an output power of 60 mW, a bandwidth of 242 nm full-width at half maximum, and a repetition rate of 110 MHz. The average power and repetition rate were approximately twice as large as those of our previous SC source [20]. Using the developed SC source, UHR-OCT imaging was demonstrated. A sensitivity of 105 dB and an axial resolution of 3.2 μm in biological tissue were achieved. We compared the UHR-OCT images of some biological tissue samples measured with the developed SC source, the previous one, and one operating in the 1.3 μm wavelength region. We confirmed that the developed SC source had improved sensitivity and penetration depth for low-water-absorption samples. PMID:24688825

  20. Penetration of UV-A, UV-B, blue, and red light into leaf tissues of pecan measured by a fiber optic microprobe system

    NASA Astrophysics Data System (ADS)

    Qi, Yadong; Bai, Shuju; Vogelmann, Thomas C.; Heisler, Gordon M.

    2003-11-01

    The depth of light penetration from the adaxial surfaces of the mature leaves of pecan (Carya illinoensis) was measured using a fiber optic microprobe system at four wavelengths: UV-B (310nm), UV-A (360 nm), blue light (430nm), and red light (680nm). The average thickness of the leaf adaxial epidermal layer was 15um and the total leaf thickness was 219um. The patterns of the light attenuation by the leaf tissues exhibited strong wavelength dependence. The leaf adaxial epidermal layer was chiefly responsible for absorbing the UV-A UV-B radiation. About 98% of 310 nm light was steeply attenuated within the first 5 um of the adaxial epidermis; thus, very little UV-B radiation was transmitted to the mesophyll tissues where contain photosynthetically sensitive sites. The adaxial epidermis also attenuated 96% of the UV-A radiation. In contrast, the blue and red light penetrated much deeper and was gradually attenutated by the leaves. The mesophyll tissues attenuated 17% of the blue light and 42% of the red light, which were available for photosynthesis use. Since the epidermal layer absorbed nearly all UV-B light, it acted as an effective filter screening out the harmful radiation and protecting photosynthetically sensitive tissues from the UV-B damage. Therefore, the epidermal function of the UV-B screening effectiveness can be regarded as one of the UV-B protection mechanisms in pecan.

  1. Effect of masticatory load on crack deflection/penetration investigated with en-face optical coherence tomography in ceramic fixed partial dentures

    NASA Astrophysics Data System (ADS)

    Sinescu, Cosmin; Negrutiu, Meda Lavinia; Marsavina, Liviu; Negru, Radu; Hluscu, Mihai; Caplescu, Cristiana; Bradu, Adrian; Hughes, Michael; Rominu, Mihai; Podoleanu, Adrian Gh.

    2009-02-01

    Optical Coherence Tomography (OCT) allows a better characterization of dental prostheses. The detection of substance defects within the ceramic layers for metal-ceramic prostheses was demonstrated. The detected defects have a large volume and therefore there is a high likelihood for fracture lines to be generated in the proximal areas of the ceramic fixed partial dentures. If the detection of such defects is feasible before inserting the prosthesis into the oral cavity, then timely corrective measures are possible in order to avoid the fracture of the ceramic component later on. After noninvasive localization of cracks in ceramic fixed partial dentures, the effect of the biaxial loading on crack deflection/penetration at the ceramic interface was investigated. A biaxial loaded geometry was numerically investigated using Finite Element Analysis in order to determine the energy release rate. The obtained results could be used in conjunction with criteria at interface for estimating the path of the crack after the interface was reached.

  2. Penetration of solar radiation into the water column of the central subtropical Atlantic Ocean—optical properties and possible biological consequences

    NASA Astrophysics Data System (ADS)

    Piazena, H.; Perez-Rodrigues, E.; Häder, D.-P.; Lopez-Figueroa, F.

    The optical properties of the waters as well as the penetration of both solar ultraviolet radiation (UVR) and photosynthetically active radiation (PAR) were analyzed at different stations of the central subtropical Atlantic Ocean during the AZORES II cruise of the research vessel "Hesperides" in April 1999 to assess the impact of solar UVR on microorganisms populating highly transparent oceanic waters. The investigation was based on direct spectral measurements of the scalar and downward-solar irradiance between 290 and 750 nm at different depths using a temperature-stabilized double monochromator spectroradiometer (Optronic, type 754) with a highly sensitive 4 π sensor connected to the entrance slit by a 20-m quartz fiber cable. In addition, the Secchi depth was measured, and water samples of different depths at each station were analyzed to determine the concentration and optical properties of phytoplankton as well as attenuating substances such as seston and gelbstoff in the column. Using the spectral irradiance data at different depths as well as the vertical irradiance profiles at different wavelengths, the following parameters were calculated: the spectral attenuation coefficients, the spectral depths of penetration to 1% of the sub-surface value ("1% depths"), the 1% depths for the ranges UV-B, UV-A and PAR, as well as the water type in the Jerlov system of optical classification. The optical properties of the waters investigated can be classified into the oceanic types OI-OII in the Jerlov system, which are characterized by very small concentrations of seston and of gelbstoff, which are the main absorbers for UV radiation in natural waters. The Secchi depths varied between about 15 m (type OII) to about 45 m (type OI) showing ratios to the 1% depths of PAR of about 0.21 to about 0.31. Values of the same order were found for the depths of the maximal concentration of chlorophyll a, which varied between 45 and 100 m during midnight and between 70 and 110 m

  3. Penetrating trauma

    PubMed Central

    Kuhajda, Ivan; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Huang, Haidong; Li, Qiang; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Papaiwannou, Antonis; Lampaki, Sofia; Zaric, Bojan; Branislav, Perin; Dervelegas, Konstantinos; Porpodis, Konstantinos

    2014-01-01

    Pneumothorax occurs when air enters the pleural space. Currently there is increasing incidence of road traffic accidents, increasing awareness of healthcare leading to more advanced diagnostic procedures, and increasing number of admissions in intensive care units are responsible for traumatic (non iatrogenic and iatrogenic) pneumothorax. Pneumothorax has a clinical spectrum from asymptomatic patient to life-threatening situations. Diagnosis is usually made by clinical examination and imaging techniques. In our current work we focus on the treatment of penetrating trauma. PMID:25337403

  4. Penetrating trauma.

    PubMed

    Kuhajda, Ivan; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Huang, Haidong; Li, Qiang; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Papaiwannou, Antonis; Lampaki, Sofia; Zaric, Bojan; Branislav, Perin; Dervelegas, Konstantinos; Porpodis, Konstantinos; Zarogoulidis, Paul

    2014-10-01

    Pneumothorax occurs when air enters the pleural space. Currently there is increasing incidence of road traffic accidents, increasing awareness of healthcare leading to more advanced diagnostic procedures, and increasing number of admissions in intensive care units are responsible for traumatic (non iatrogenic and iatrogenic) pneumothorax. Pneumothorax has a clinical spectrum from asymptomatic patient to life-threatening situations. Diagnosis is usually made by clinical examination and imaging techniques. In our current work we focus on the treatment of penetrating trauma. PMID:25337403

  5. Model for estimating the penetration depth limit of the time-reversed ultrasonically encoded optical focusing technique

    PubMed Central

    Jang, Mooseok; Ruan, Haowen; Judkewitz, Benjamin; Yang, Changhuei

    2014-01-01

    The time-reversed ultrasonically encoded (TRUE) optical focusing technique is a method that is capable of focusing light deep within a scattering medium. This theoretical study aims to explore the depth limits of the TRUE technique for biological tissues in the context of two primary constraints – the safety limit of the incident light fluence and a limited TRUE’s recording time (assumed to be 1 ms), as dynamic scatterer movements in a living sample can break the time-reversal scattering symmetry. Our numerical simulation indicates that TRUE has the potential to render an optical focus with a peak-to-background ratio of ~2 at a depth of ~103 mm at wavelength of 800 nm in a phantom with tissue scattering characteristics. This study sheds light on the allocation of photon budget in each step of the TRUE technique, the impact of low signal on the phase measurement error, and the eventual impact of the phase measurement error on the strength of the TRUE optical focus. PMID:24663917

  6. Mechanical Tissue Optical Clearing Devices: Enhancement of Light Penetration in Ex-Vivo Porcine Skin and Adipose Tissue

    PubMed Central

    Milner, Thomas E.; Baranov, Stepan; Nelson, J. Stuart

    2008-01-01

    Background and Objective The complex morphological structure of tissue and associated variations in the indices of refraction of components therein, provides a highly scattering medium for visible and near-infrared wavelengths of light. Tissue optical clearing permits delivery of light deeper into tissue, potentially improving the capabilities of various light-based therapeutic techniques, such as adipose tissue removal or reshaping. Study Design/ Materials and Methods We report results of a study to evaluate effectiveness of novel mechanical tissue optical clearing devices (TOCD) using white light photography and infrared imaging radiometry (IIR). The TOCD consists of a pin array and vacuum pressure source applied directly to the skin surface. IIR images recorded light absorption and temperature increase of ex vivo porcine skin and adipose during laser irradiation (980 and 1210 nm) before and after TOCD application. Results White light photographic images of in vivo human skin demonstrated localized compression and altered visual appearance, indicative of water and blood movement in skin. White light photographic images also showed increased visible light transport through regions of ex vivo porcine skin compressed by TOCD pins. Rate of heating in sub-dermal adipose regions beneath TOCD pins was two-fold higher following TOCD application. Conclusions Results of our study suggest that mechanical optical clearing may provide a means to deliver increased light fluence to dermal and adipose tissues. PMID:19065559

  7. Morphological response of injured adult rabbit optic nerve to implants containing media conditioned by growing optic nerves.

    PubMed

    Lavie, V; Harel, A; Doron, A; Solomon, A; Lobel, D; Belkin, M; Ben-Basat, S; Sharma, S; Schwartz, M

    1987-09-01

    Adult rabbit retina can express regeneration-associated characteristics after optic nerve injury, provided it is supplied with appropriate diffusible substances originating from media conditioned by regenerating fish optic nerves or by optic nerves of a newborn rabbit [Hadani et al., Proc. Natl. Acad. Sci. U.S.A., 81 (1984) 7965; Schwartz et al., Science, 228 (1985) 600]. This was shown by applying the active substances to the injured axons in the form of 'wrap-around' implants, consisting of collagen-coated silicone tubes which had been soaked in the conditioned media (CM). The regeneration-associated response was manifested biochemically and by sprouting of nerve fibers in culture. The present work provides morphological evidence that the implantation prolongs survival of ganglion cells and optic nerve fibers and induces new growth. Light microscopic analysis (using horseradish peroxidase (HRP) for labeling the fibers) revealed, 1 week following optic nerve injury, labeled fibers and ganglion cells in both the implanted and control (injured only or injured and implanted with collagen-coated silicone tubes free of CM) nerves. However, from the second week after the injury, distinct differences in the appearance of viable ganglion cells and labeled fibers, were seen between experimental and control preparations. In sections taken through the optic nerve, at the region distal to the site of injury, HRP-labeled fibers were seen in the experimental nerves 1 week, 2 weeks and to a significantly lesser extent 1 month after injury.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3676722

  8. High resolution shallow geologic characterization of a late Pleistocene eolian environment using ground penetrating radar and optically stimulated luminescence techniques: North Carolina, USA

    USGS Publications Warehouse

    Mallinson, D.; Mahan, S.; Moore, Christine

    2008-01-01

    Geophysical surveys, sedimentology, and optically-stimulated luminescence age analyses were used to assess the geologic development of a coastal system near Swansboro, NC. This area is a significant Woodland Period Native American habitation and is designated the "Broad Reach" archaeological site. 2-d and 3-d subsurface geophysical surveys were performed using a ground penetrating radar system to define the stratigraphic framework and depositional facies. Sediment samples were collected and analyzed for grain-size to determine depositional environments. Samples were acquired and analyzed using optically stimulated luminescence techniques to derive the depositional age of the various features. The data support a low eolian to shallow subtidal coastal depositional setting for this area. Li-DAR data reveal ridge and swale topography, most likely related to beach ridges, and eolian features including low-relief, low-angle transverse and parabolic dunes, blowouts, and a low-relief eolian sand sheet. Geophysical data reveal dominantly seaward dipping units, and low-angle mounded features. Sedimentological data reveal mostly moderately-well to well-sorted fine-grained symmetrical to coarse skewed sands, suggesting initial aqueous transport and deposition, followed by eolian reworking and bioturbation. OSL data indicate initial coastal deposition prior to ca. 45,000 yBP, followed by eolian reworking and low dune stabilization at ca. 13,000 to 11,500 yBP, and again at ca. 10,000 yBP (during, and slightly after the Younger Dryas chronozone).

  9. Cell proliferation and apoptosis in optic nerve and brain integration centers of adult trout Oncorhynchus mykiss after optic nerve injury

    PubMed Central

    Pushchina, Evgeniya V.; Shukla, Sachin; Varaksin, Anatoly A.; Obukhov, Dmitry K.

    2016-01-01

    Fishes have remarkable ability to effectively rebuild the structure of nerve cells and nerve fibers after central nervous system injury. However, the underlying mechanism is poorly understood. In order to address this issue, we investigated the proliferation and apoptosis of cells in contralateral and ipsilateral optic nerves, after stab wound injury to the eye of an adult trout Oncorhynchus mykiss. Heterogenous population of proliferating cells was investigated at 1 week after injury. TUNEL labeling gave a qualitative and quantitative assessment of apoptosis in the cells of optic nerve of trout 2 days after injury. After optic nerve injury, apoptotic response was investigated, and mass patterns of cell migration were found. The maximal concentration of apoptotic bodies was detected in the areas of mass clumps of cells. It is probably indicative of massive cell death in the area of high phagocytic activity of macrophages/microglia. At 1 week after optic nerve injury, we observed nerve cell proliferation in the trout brain integration centers: the cerebellum and the optic tectum. In the optic tectum, proliferating cell nuclear antigen (PCNA)-immunopositive radial glia-like cells were identified. Proliferative activity of nerve cells was detected in the dorsal proliferative (matrix) area of the cerebellum and in parenchymal cells of the molecular and granular layers whereas local clusters of undifferentiated cells which formed neurogenic niches were observed in both the optic tectum and cerebellum after optic nerve injury. In vitro analysis of brain cells of trout showed that suspension cells compared with monolayer cells retain higher proliferative activity, as evidenced by PCNA immunolabeling. Phase contrast observation showed mitosis in individual cells and the formation of neurospheres which gradually increased during 1–4 days of culture. The present findings suggest that trout can be used as a novel model for studying neuronal regeneration. PMID:27212918

  10. Cell proliferation and apoptosis in optic nerve and brain integration centers of adult trout Oncorhynchus mykiss after optic nerve injury.

    PubMed

    Pushchina, Evgeniya V; Shukla, Sachin; Varaksin, Anatoly A; Obukhov, Dmitry K

    2016-04-01

    Fishes have remarkable ability to effectively rebuild the structure of nerve cells and nerve fibers after central nervous system injury. However, the underlying mechanism is poorly understood. In order to address this issue, we investigated the proliferation and apoptosis of cells in contralateral and ipsilateral optic nerves, after stab wound injury to the eye of an adult trout Oncorhynchus mykiss. Heterogenous population of proliferating cells was investigated at 1 week after injury. TUNEL labeling gave a qualitative and quantitative assessment of apoptosis in the cells of optic nerve of trout 2 days after injury. After optic nerve injury, apoptotic response was investigated, and mass patterns of cell migration were found. The maximal concentration of apoptotic bodies was detected in the areas of mass clumps of cells. It is probably indicative of massive cell death in the area of high phagocytic activity of macrophages/microglia. At 1 week after optic nerve injury, we observed nerve cell proliferation in the trout brain integration centers: the cerebellum and the optic tectum. In the optic tectum, proliferating cell nuclear antigen (PCNA)-immunopositive radial glia-like cells were identified. Proliferative activity of nerve cells was detected in the dorsal proliferative (matrix) area of the cerebellum and in parenchymal cells of the molecular and granular layers whereas local clusters of undifferentiated cells which formed neurogenic niches were observed in both the optic tectum and cerebellum after optic nerve injury. In vitro analysis of brain cells of trout showed that suspension cells compared with monolayer cells retain higher proliferative activity, as evidenced by PCNA immunolabeling. Phase contrast observation showed mitosis in individual cells and the formation of neurospheres which gradually increased during 1-4 days of culture. The present findings suggest that trout can be used as a novel model for studying neuronal regeneration. PMID:27212918

  11. The visual control of stability in children and adults: postural readjustments in a ground optical flow.

    PubMed

    Baumberger, Bernard; Isableu, Brice; Flückiger, Michelangelo

    2004-11-01

    The aim of this research was to analyse the development of postural reactions to approaching (AOF) and receding (ROF) ground rectilinear optical flows. Optical flows were shaped by a pattern of circular spots of light projected on the ground surface by a texture flow generator. The geometrical structure of the projected scenes corresponded to the spatial organisation of visual flows encountered in open outdoor settings. Postural readjustments of 56 children, ranging from 7 to 11 years old, and 12 adults were recorded by the changes of the centre of foot pressure (CoP) on a force platform during 44-s exposures to the moving texture. Before and after the optical flows exposure, a 24-s motionless texture served as a reference condition. Effect of ground rectilinear optical flows on postural control development was assessed by analysing sway latencies (SL), stability performances and postural orientation. The main results that emerge from this experiment show that postural responses are directionally specific to optical flow pattern and that they vary as a function of the motion onset and offset. Results showed that greater developmental changes in postural control occurred in an AOF (both at the onset and offset of the optical flow) than in an ROF. Onset of an approaching flow induced postural instability, canonical shifts in postural orientation and long latencies in children which were stronger than in the receding flow. This pattern of responses evolved with age towards an improvement in stability performances and shorter SL. The backward decreasing shift of the CoP in children evolved in adults towards forward postural tilt, i.show $132#e. in the opposite direction of the texture's motion. Offset of an AOF motion induced very short SL in children (which became longer in adult subjects), strong postural instability, but weaker shift of orientation compared to the receding one. Postural stability improved and orientation shift evolved to forward inclinations with

  12. In vivo imaging of zebrafish from embryo to adult stage with optical projection tomography

    NASA Astrophysics Data System (ADS)

    Bassi, Andrea; Fieramonti, Luca; D'Andrea, Cosimo; Valentini, Gianluca; Cubeddu, Rinaldo; De Silvestri, Sandro; Cerullo, Giulio; Foglia, Efrem; Cotelli, Franco

    2013-02-01

    Optical Projection Tomography (OPT) is a three dimensional imaging technique that is particularly suitable for studying millimeter sized biological samples and organisms. Similarly to x-ray computed tomography, OPT is based on the acquisition of a sequence of images taken through the sample at many angles (projections). Assuming the linearity of the optical absorption process, the projections are combined to reconstruct the 3-D volume of the sample, typically using a filtered back-projection algorithm. OPT has been applied to in-vivo imaging of zebrafish (Danio rerio). The instrument and the protocol for in vivo imaging of zebrafish embryos and juvenile specimens are described. Light scattering remains a challenge for in vivo OPT, especially when samples at the upper size limit, like zebrafish at the adult stage, are under study. We describe Time-Gated Optical Projection Tomography (TGOPT), a technique able to reconstruct adult zebrafish internal structures by counteracting the scattering effects through a fast time-gate. The time gating mechanism is based on non-linear optical upconversion of an infrared ultrashort laser pulse and allows the detection of quasi-ballistic photons within a 100 fs temporal gate. This results in a strong improvement in contrast and resolution with respect to conventional OPT. Artifacts in the reconstructed images are reduced as well. We show that TGOPT is suited for imaging the skeletal system and nervous structures of adult zebrafish.

  13. Clinicopathological and molecular features of malignant optic pathway glioma in an adult.

    PubMed

    Nagaishi, Masaya; Sugiura, Yoshiki; Takano, Issei; Tanaka, Yoshihiro; Suzuki, Kensuke; Yokoo, Hideaki; Hyodo, Akio

    2015-01-01

    Malignant gliomas of the optic pathway are rare, and their genetic alterations are poorly understood. We describe a 64-year-old woman with anaplastic astrocytoma originating from the optic pathway, together with the molecular features. She presented with progressive visual field loss, and a biopsy sample was obtained from the lesion in the optic chiasm. She underwent radiosurgery concomitant with temozolomide chemotherapy, and subsequently remained stable for 10 months after initial presentation. Molecular analysis indicated that the mass may have shared common molecular genetic features with conventional primary astrocytic gliomas but not pilocytic gliomas, which supported the morphologic diagnosis of anaplastic astrocytoma. Molecular analysis of malignant optic pathway gliomas in adults is useful for distinguishing between high-grade gliomas and anaplastic pilocytic astrocytomas, and for determining further therapy. PMID:25150758

  14. Penetrant-Indication-Measuring Compass

    NASA Technical Reports Server (NTRS)

    Schaefer, Lloyd

    1991-01-01

    Modified drafting compass well suited to measurement of length of crack or width of area stained by penetrant-dye-inspection method. Equipped with any of variety of standard curved or straight pointed tips. Modification consists in coating tips with dye that fluoresces light pink under same ultraviolet inspection light causing penetrant dye to fluoresce yellow green. Used in locations inaccessible to conventional fluorescent comparator. Eliminates errors of optical distortion in comparator, also eliminates errors of interpolation.

  15. Isolation of intact astrocytes from the optic nerve head of adult mice

    PubMed Central

    Choi, Hee Joo; Sun, Daniel; Jakobs, Tatjana C.

    2015-01-01

    The astrocytes of the optic nerve head are a specialized subtype of white matter astrocytes that form the direct cellular environment of the unmyelinated ganglion cell axons. Due to their potential involvement in glaucoma, these astrocytes have become a target of research. Due to the heterogeneity of the optic nerve tissue, which also contains other cell types, in some cases it may be desirable to conduct gene expression studies on small numbers of well-characterized astrocytes or even individual cells. Here, we describe a simple method to isolate individual astrocytes. This method permits obtaining astrocytes with intact morphology from the adult mouse optic nerve and reduces contamination of the isolated astrocytes by other cell types. Individual astrocytes can be recognized by their morphology and collected under microscopic control. The whole procedure can be completed in 2-3 hours. We also discuss downstream applications like multiplex single-cell PCR and quantitative PCR (qPCR). PMID:26093274

  16. Decreased thyroid hormone signaling accelerates the reinnervation of the optic tectum following optic nerve crush in adult zebrafish.

    PubMed

    Bhumika, Stitipragyan; Lemmens, Kim; Vancamp, Pieter; Moons, Lieve; Darras, Veerle M

    2015-09-01

    The regenerative capacity of the adult mammalian central nervous system (CNS) is poor and finding ways to stimulate long distance axonal regeneration in humans remains a challenge for neuroscientists. Thyroid hormones, well known for their key function in CNS development and maturation, more recently also emerged as molecules influencing regeneration. While several studies investigated their influence on peripheral nerve regeneration, in vivo studies on their role in adult CNS regeneration remain scarce. We therefore investigated the effect of lowering T3 signaling on the regeneration of the optic nerve (ON) following crush in zebrafish, a species where full recovery occurs spontaneously. Adult zebrafish were exposed to iopanoic acid (IOP), which lowered intracellular 3,5,3'-triiodothyronine (T3) availability, or to the thyroid hormone receptor β antagonist methylsulfonylnitrobenzoate (C1). Both treatments accelerated optic tectum (OT) reinnervation. At 7days post injury (7dpi) there was a clear increase in the biocytin labeled area in the OT following anterograde tracing as well as an increased immunostaining of Gap43, a protein expressed in outgrowing axons. This effect was attenuated by T3 supplementation to IOP-treated fish. ON crush induced very limited cell death and proliferation at the level of the retina in control, IOP- and C1-treated fish. The treatments also had no effect on the mRNA upregulation of the regeneration markers gap43, tub1a, and socs3b at the level of the retina at 4 and 7dpi. We did, however, find a correlation between the accelerated OT reinnervation and a more rapid resolution of microglia/macrophages in the ON and the OT of IOP-treated fish. Taken together these data indicate that lowering T3 signaling accelerates OT reinnervation following ON crush in zebrafish and that this is accompanied by a more rapid resolution of the inflammatory response. PMID:25913150

  17. Comparison of Optical Coherence Tomography Measurement Reproducibility between Children and Adults

    PubMed Central

    Chung, Ho Kyung; Han, Young Keun; Oh, Sohee; Kim, Seok Hwan

    2016-01-01

    Purpose To compare the reproducibility of SD-OCT (spectral-domain optical coherence tomography) measurements of RNFL (retinal nerve fiber layer) and macular thickness between children and adults. Methods Seventy-one eyes of 71 children and 71 eyes of 71 adults were prospectively enrolled. RNFL and macular thicknesses were measured by one operator, with a brief rest between measurements. The two measurements were obtained using the eye tracking and retest function of Spectralis SD-OCT. Reproducibility was evaluated with reference to COVs (coefficients of variation) and ICCs (intraclass correlation coefficients). The ICC values of the RNFL and macular thicknesses were compared, respectively between the two groups, by Fisher’s z-test. Results The RNFL and macular thicknesses did not differ between the two groups. The COVs of the RNFL measurements ranged from 0.945 to 4.531% in the children group and from 0.496 to 1.391% in the adults group. In most of the RNFL sectors, the ICCs of the children group (range: 0.731–0.987) were significantly lower than those of the adults group (range: 0.986–0.993). The COVs of the macular measurements ranged from 0.496 to 1.157% in the children group and from 0.275 to 0.656% in the adults group. The ICCs (range: 0.860–0.974) in the children group, significantly lower than for the adults (range: 0.989–0.995), in all of the macular sectors. Conclusions The reproducibility of SD-OCT RNFL and macular measurements for children was excellent, albeit statistically lower than that for adults. PMID:26808961

  18. Building of shore-oblique transverse dune ridges revealed by ground-penetrating radar and optical dating over the last 500 years on Tottori coast, Japan Sea

    NASA Astrophysics Data System (ADS)

    Tamura, Toru; Bateman, Mark D.; Kodama, Yoshinori; Saitoh, Yu; Watanabe, Kazuaki; Yamaguchi, Naofumi; Matsumoto, Dan

    2011-09-01

    Coastal dunes provide valuable information on the past aeolian activity. Better characterization of internal dune structures and their chronology potentially can greatly improve the interpretation of past environmental changes. Ground-penetrating radar (GPR) and optically-stimulated luminescence (OSL) dating was applied to two transverse dune ridges which are arranged obliquely to the shoreline on the Tottori coast, Japan Sea. Data shows that the inner ridge has a core of Pleistocene dune draped with Holocene sand, while the outer ridge consists only of Holocene sand. The Holocene dune is generally dominated by landward migration, but the outer ridge shows a clear seaward accretion during the 18th century AD. OSL dating showed concordant results with radar stratigraphy and topographic changes since AD 1932 revealed by maps. From this we were able to present the first detailed report of the multi-decadal- to centennial-scale dune formation for the last 500 years in East Asia, contemporaneous with the Little Ice Age, during which many European coastal and inland dunes were activated. In East Asia, it is thought that the winter monsoon plays an important role for aeolian processes. The seaward migration during the 18th century reflects a decrease in wind capacity, which restricted sand transport nearshore, being related to decline in winter monsoon revealed by Chinese historical documents. In contrast, two remarkable events of landward accretion occurred in AD 1580-1640 and around AD 1840, respectively, corresponding to periods of increased dust fall in China, which suggest enhanced winter monsoon. The zone of maximum sedimentation shifted through time from the inner to outer ridges, and also towards the seaward end of the shore-oblique dune ridge, reflecting an expansion of the dune field caused by shoreline progradation. These suggest that the effective combination of GPR and OSL dating was critical in detailed characterization of the complicated depositional

  19. Bilateral simultaneous optic neuropathy in adults: clinical, imaging, serological, and genetic studies.

    PubMed Central

    Morrissey, S P; Borruat, F X; Miller, D H; Moseley, I F; Sweeney, M G; Govan, G G; Kelly, M A; Francis, D A; Harding, A E; McDonald, W I

    1995-01-01

    To elucidate the cause(s) of acute or subacute bilateral simultaneous optic neuropathy (BSON) in adult life, a follow up study of 23 patients was performed with clinical assessment, brain MRI, HLA typing, and mitochondrial DNA analysis. The results of CSF electrophoresis were available from previous investigations in 11 patients. At follow up, five (22%) had developed clinically definite multiple sclerosis, four (17%) had mitochondrial DNA point mutations indicating a diagnosis of Leber's hereditary optic neuropathy (LHON). The remaining 14 patients (61%) still had clinically isolated BSON a mean of 50 months after the onset of visual symptoms: three of 14 (21%) had multiple MRI white matter lesions compatible with multiple sclerosis, three of 14 (21%) had the multiple sclerosis associated HLA-DR15/DQw6 haplotype, and one of seven tested had CSF oligoclonal IgG bands; in total only five (36%) had one or more of these risk factors. The low frequency of risk factors for the development of multiple sclerosis in these 14 patients suggests that few will develop multiple sclerosis with more prolonged follow up. It is concluded that: (a) about 20% of cases of BSON without affected relatives are due to LHON; (b) multiple sclerosis develops after BSON in at least 20% of cases, but the long term conversion rate is likely to be considerably less than the rate of over 70% seen after an episode of acute unilateral optic neuritis in adult life. PMID:7823072

  20. Applications of hybrid diffuse optics for clinical management of adults after brain injury

    NASA Astrophysics Data System (ADS)

    Kim, Meeri Nam

    Information about cerebral blood flow (CBF) is valuable for clinical management of patients after severe brain injury. Unfortunately, current modalities for monitoring brain are often limited by hurdles that include high cost, low throughput, exposure to ionizing radiation, probe invasiveness, and increased risk to critically ill patients when transportation out of their room or unit is required. A further limitation of current technologies is an inability to provide continuous bedside measurements that are often desirable for unstable patients. Here we explore the clinical utility of diffuse correlation spectroscopy (DCS) as an alternative approach for bedside CBF monitoring. DCS uses the rapid intensity fluctuations of near-infrared light to derive a continuous measure of changes in blood flow without ionizing radiation or invasive probing. Concurrently, we employ another optical technique, called diffuse optical spectroscopy (DOS), to derive changes in cerebral oxyhemoglobin ( HbO2) and deoxyhemoglobin (Hb) concentrations. Our clinical studies integrate DCS with DOS into a single hybrid instrument that simultaneously monitors CBF and HbO2/Hb in the injured adult brain. The first parts of this dissertation present the motivations for monitoring blood flow in injured brain, as well as the theory underlying diffuse optics technology. The next section elaborates on details of the hybrid instrumentation. The final chapters describe four human subject studies carried out with these methods. Each of these studies investigates an aspect of the potential of the hybrid monitor in clinical applications involving adult brain. The studies include: (1) validation of DCS-measured CBF against xenon-enhanced computed tomography in brain-injured adults; (2) a study of the effects of age and gender on posture-change-induced CBF variation in healthy subjects; (3) a study of the efficacy of DCS/DOS for monitoring neurocritical care patients during various medical interventions such

  1. Adult mice transplanted with embryonic retinal progenitor cells: New approach for repairing damaged optic nerves

    PubMed Central

    Cho, Jang-Hyeon; Mao, Chai-An

    2012-01-01

    Purpose Retinal ganglion cell (RGC) death and optic nerve degeneration are complex processes whose underlying molecular mechanisms are only vaguely understood. Treatments commonly used for optic nerve degeneration have little long-term value and only prolong degeneration. Recent advances in stem cell replacement therapy offer new ways to overcome RGC loss by transferring healthy cells into eyes of afflicted individuals. However, studies on stem cell replacement for optic nerve degeneration are hampered by limitations of the available animal models, especially genetic models. We have developed a mouse model in which RGCs are genetically ablated in adult mice with subsequent degeneration of the optic nerve. In the study reported here, we used this model to determine whether embryonic retinal progenitor cells (RPCs) removed from donor retinas when RPCs are committing to an RGC fate could restore lost RGCs. Methods We used the RGC-depleted model as a host for transplanting donor green fluorescent protein (GFP)–labeled RPCs from embryonic retinas that are maximally expressing Atoh7, a basic helix–loop–helix gene essential for RGC specification. Dissociated GFP-labeled RPCs were characterized in situ by immunolabeling with antibodies against proteins known to be expressed in RPCs at embryonic day (E)14.5. Dissociated retinal cells were injected into the vitreous of one eye of RGC-depleted mice at two to six months of age. The injected and non-injected retinas were analyzed for gene expression using immunolabeling, and the morphology of optic nerves was assessed visually and with histological staining at different times up to four months after injection. Results We demonstrate the successful transfer of embryonic GFP-labeled RPCs into the eyes of RGC-depleted mice. Many transplanted RPCs invaded the ganglion cell layer, but the efficiency of the invasion was low. GFP-labeled cells within the ganglion cell layer expressed genes associated with early and late stages

  2. Application of ground-penetrating radar, digital optical borehole images, and cores for characterization of porosity hydraulic conductivity and paleokarst in the Biscayne aquifer, southeastern Florida, USA

    USGS Publications Warehouse

    Cunningham, K.J.

    2004-01-01

    This paper presents examples of ground-penetrating radar (GPR) data from two study sites in southeastern Florida where karstic Pleistocene platform carbonates that comprise the unconfined Biscayne aquifer were imaged. Important features shown on resultant GPR profiles include: (1) upward and lateral qualitative interpretative distribution of porosity and hydraulic conductivity; (2) paleotopographic relief on karstic subaerial exposure surfaces; and (3) vertical stacking of chronostratigraphic high-frequency cycles (HFCs). These characteristics were verified by comparison to rock properties observed and measured in core samples, and identified in digital optical borehole images. Results demonstrate that an empirical relation exists between measured whole-core porosity and hydraulic conductivity, observed porosity on digital optical borehole images, formation conductivity, and GPR reflection amplitudes-as porosity and hydraulic conductivity determined from core and borehole images increases, formation conductivity increases, and GPR reflection amplitude decreases. This relation allows for qualitative interpretation of the vertical and lateral distribution of porosity and hydraulic conductivity within HFCs. Two subtidal HFCs in the uppermost Biscayne aquifer have significantly unique populations of whole-core porosity values and vertical hydraulic conductivity values. Porosity measurements from one cycle has a median value about two to three times greater than the values from the other HFC, and median values of vertical hydraulic-conductivity about three orders of magnitude higher than the other HFC. The HFC with the higher porosity and hydraulic conductivity values is shown as a discrete package of relatively low-amplitude reflections, whereas the HFC characterized by lower porosity and hydraulic-conductivity measurements is expressed by higher amplitude reflections. Porosity and hydraulic-conductivity values measured from whole-core samples, and vuggy porosity

  3. Optic nerve sheath diameters in healthy adults measured by computer tomography

    PubMed Central

    Vaiman, Michael; Abuita, Rani; Bekerman, Inessa

    2015-01-01

    AIM To measure optic nerve sheath diameters (ONSD) in different locations by computer tomography (CT) and to recommend the best location for cases when ONSD is used for intracranial pressure monitoring. METHODS In a prospective cohort study, CT data of 300 healthy adults were analyzed (600 eyes). In all cases, the CT investigation was performed at the Emergency Department because of the various conditions that proved not to be connected with ophthalmological or neurological pathology. The ONSD were measured at 3 mm and 8 mm distance from the globe, and 3 mm from the anterior opening of the optic canal. The correlation analysis was performed with gender, age, and ethnic background. RESULTS The right/left ONSD are 4.94±1.51/5.17±1.34 mm at 3 mm, 4.35±0.76/4.45±0.62 mm at 8 mm from the globe, and 3.55±0.82/3.65±0.7 mm at 3 mm from the optic canal. No significant differences correlated with gender of the patients, their age, and ethnic background were found. CONCLUSION In healthy persons, the ONSD varies from 5.17±1.34 mm to 3.55±0.82 mm in different locations within the intraorbital space. The most stable results with lesser standard deviation can be obtained if it is measured 8-10 mm from the globe. PMID:26682181

  4. [Tracheal intubation using Airtraq optical laryngoscope in an adult patient with Goldenhar syndrome].

    PubMed

    Sasanuma, Hiromi; Niwa, Yasunori; Shimada, Nobuhiro; Machida, Masanari; Irei, Takeshi; Hayashi, Kenji; Takeuchi, Mamoru

    2013-07-01

    A 23-year-old woman with Goldenhar syndrome and conductive deafness was scheduled for tympanoplasty. Goldenhar syndrome is a developmental disorder characterized by ear malformation, mandibular hypoplasia, and vertebral anomalies. Furthermore, she had micrognathia, trismus, and mandibular hypoplasia. Awake taracheal intubation was attempted to prevent airway obstruction, because we had anticipated her difficult airway (micrognathia, trismus, and mandibular hypoplasia). The vocal cords were visualized with a Cormac and Lehane grade I, using the Airtraq optical laryngoscope Small (Size 2), under sedation. Then, an endotracheal tube was inserted after induction of general anesthesia. This is the first case report on the successful orotracheal intubation using Airtraq in an adult with Goldenhar syndrome. PMID:23905414

  5. Penetrating abdominal trauma.

    PubMed

    Henneman, P L

    1989-08-01

    The management of patients with penetrating abdominal trauma is outlined in Figure 1. Patients with hemodynamic instability, evisceration, significant gastrointestinal bleeding, peritoneal signs, gunshot wounds with peritoneal violation, and type 2 and 3 shotgun wounds should undergo emergency laparotomy. The initial ED management of these patients includes airway management, monitoring of cardiac rhythm and vital signs, history, physical examination, and placement of intravenous lines. Blood should be obtained for initial hematocrit, type and cross-matching, electrolytes, and an alcohol level or drug screen as needed. Initial resuscitation should utilize crystalloid fluid replacement. If more than 2 liters of crystalloid are needed to stabilize an adult (less in a child), blood should be given. Group O Rh-negative packed red blood cells should be immediately available for a patient in impending arrest or massive hemorrhage. Type-specific blood should be available within 15 minutes. A patient with penetrating thoracic and high abdominal trauma should receive a portable chest x-ray, and a hemo- or pneumothorax should be treated with tube thoracostomy. An unstable patient with clinical signs consistent with a pneumothorax, however, should receive a tube thoracostomy prior to obtaining roentgenographic confirmation. If time permits, a nasogastric tube and Foley catheter should be placed, and the urine evaluated for blood (these procedures can be performed in the operating room). If kidney involvement is suspected because of hematuria or penetrating trauma in the area of a kidney or ureter in a patient requiring surgery, a single-shot IVP should be performed either in the ED or the operating room. An ECG is important in patients with possible cardiac involvement and in patients over the age of 40 going to the operating room. Tetanus status should be updated, and appropriate antibiotics covering bowel flora should be given. Operative management should rarely be delayed

  6. Penetration of concrete targets

    SciTech Connect

    Forrestal, M.J.; Cargile, J.D.; Tzou, R.D.Y.

    1993-08-01

    We developed penetration equations for ogive-nosed projectiles that penetrated concrete targets after normal impact. Our penetration equations predict axial force on the projectile nose, rigid-body motion, and final penetration depth. For target constitutive models, we conducted triaxial material experiments to confining pressures of 600 MPa and curve-fit these data with a linear pressure-volumetric strain relation and with a linear Mohr-Coulomb, shear strength-pressure relation. To verify our penetration equations, we conducted eleven penetration experiments with 0.90 kg, 26.9-mm-diameter, ogive-nosed projectiles into 1.37-m-diameter concrete targets with unconfined compressive strengths between 32-40 MPa. Predictions from our penetration equation are compared with final penetration depth measurements for striking velocities between 280--800 m/s.

  7. Fluorescent penetrant inspection

    NASA Technical Reports Server (NTRS)

    Sastri, Sankar

    1990-01-01

    The purpose of this experiment is to familiarize the student with fluorescent penetrant inspection and to relate it to classification of various defects. The penetrant method of nondestructive testing is a method for finding discontinuities open to the surface in solids and essentially nonporous bodies. The method employs a penetrating liquid which is applied over the surface and enters the discontinuity or crack. After the excess of penetrant has been cleaned from the surface, the penetrant which exudes or is drawn back out of the crack indicates the presence and location of a discontinuity. The experimental procedure is described.

  8. FAA fluorescent penetrant activities

    SciTech Connect

    Moore, D.G.; Larson, B.F.

    1997-11-01

    The Federal Aviation Administration`s Airworthiness Assurance NDI Validation Center (AANC) and the Center for Aviation Systems Reliability (CASR) are currently working to develop a liquid penetrant inspection (LPI) system evaluation capability that will support the needs of the penetrant manufacturers, commercial airline industry and the FAA. The main focus of this facility is to support the evaluation of penetrant inspection materials, penetrant systems and to apply resources to support industry needs. This paper discusses efforts to create such a facility and an initial project to produce fatigue crack specimens for evaluation of Type 1 penetrant sensitivities.

  9. Maintenance of Glia in the Optic Lamina Is Mediated by EGFR Signaling by Photoreceptors in Adult Drosophila

    PubMed Central

    Lee, Yuan-Ming; Sun, Y. Henry

    2015-01-01

    The late onset of neurodegeneration in humans indicates that the survival and function of cells in the nervous system must be maintained throughout adulthood. In the optic lamina of the adult Drosophila, the photoreceptor axons are surrounded by multiple types of glia. We demonstrated that the adult photoreceptors actively contribute to glia maintenance in their target field within the optic lamina. This effect is dependent on the epidermal growth factor receptor (EGFR) ligands produced by the R1-6 photoreceptors and transported to the optic lamina to act on EGFR in the lamina glia. EGFR signaling is necessary and sufficient to act in a cell-autonomous manner in the lamina glia. Our results suggest that EGFR signaling is required for the trafficking of the autophagosome/endosome to the lysosome. The loss of EGFR signaling results in cell degeneration most likely because of the accumulation of autophagosomes. Our findings provide in vivo evidence for the role of adult neurons in the maintenance of glia and a novel role for EGFR signaling in the autophagic flux. PMID:25909451

  10. Session: Hard Rock Penetration

    SciTech Connect

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  11. MEASURING THE IMPACTS OF EXISTING ARTIFICIAL OPTICAL RADIATION AT 3 SITES: A PILOT STUDY OF MILITARY, STUDENT, AND OLDER ADULT HOUSING COMMUNITIES

    EPA Science Inventory

    By measuring and disseminating the impacts of existing artificial optical radiation and by comparing findings to current recommendations, future sustainable lighting choices for housing of military personnel, university students, and older adults will be enabled.

  12. Optical mapping of the electrical activity of isolated adult zebrafish hearts: acute effects of temperature

    PubMed Central

    Lin, Eric; Ribeiro, Amanda; Ding, Weiguang; Hove-Madsen, Leif; Sarunic, Marinko V.; Beg, Mirza Faisal

    2014-01-01

    The zebrafish (Danio rerio) has emerged as an important model for developmental cardiovascular (CV) biology; however, little is known about the cardiac function of the adult zebrafish enabling it to be used as a model of teleost CV biology. Here, we describe electrophysiological parameters, such as heart rate (HR), action potential duration (APD), and atrioventricular (AV) delay, in the zebrafish heart over a range of physiological temperatures (18–28°C). Hearts were isolated and incubated in a potentiometric dye, RH-237, enabling electrical activity assessment in several distinct regions of the heart simultaneously. Integration of a rapid thermoelectric cooling system facilitated the investigation of acute changes in temperature on critical electrophysiological parameters in the zebrafish heart. While intrinsic HR varied considerably between fish, the ex vivo preparation exhibited impressively stable HRs and sinus rhythm for more than 5 h, with a mean HR of 158 ± 9 bpm (means ± SE; n = 20) at 28°C. Atrial and ventricular APDs at 50% repolarization (APD50) were 33 ± 1 ms and 98 ± 2 ms, respectively. Excitation originated in the atrium, and there was an AV delay of 61 ± 3 ms prior to activation of the ventricle at 28°C. APD and AV delay varied between hearts beating at unique HRs; however, APD and AV delay did not appear to be statistically dependent on intrinsic basal HR, likely due to the innate beat-to-beat variability within each heart. As hearts were cooled to 18°C (by 1°C increments), HR decreased by ∼40%, and atrial and ventricular APD50 increased by a factor of ∼3 and 2, respectively. The increase in APD with cooling was disproportionate at different levels of repolarization, indicating unique temperature sensitivities for ion currents at different phases of the action potential. The effect of temperature was more apparent at lower levels of repolarization and, as a whole, the atrial APD was the cardiac parameter most affected by acute

  13. Effects of low-energy He-Ne laser irradiation on posttraumatic degeneration of adult rabbit optic nerve

    SciTech Connect

    Schwartz, M.; Doron, A.; Erlich, M.; Lavie, V.; Benbasat, S.; Belkin, M.; Rochkind, S.

    1987-01-01

    Axons of the mammalian peripheral and central nervous systems degenerate after nerve injury. We have recently found that He-Ne laser irradiation may prevent some of the consequences of the injury in peripheral nerves of mammals. In the present study, the efficacy of the laser in treating injured neurons of the mammalian CNS was tested. Optic nerves of adult rabbits were exposed daily for 8-14 days to He-Ne laser irradiation (14 min, 15 mW) through the overlying muscles and skin. As a result of this treatment, the injured nerves maintained their histological integrity, which is invariably lost in injured mammalian CNS neurons.

  14. Deployable Wireless Camera Penetrators

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Jones, Jack; Sherrit, Stewart; Wu, Jiunn Jeng

    2008-01-01

    A lightweight, low-power camera dart has been designed and tested for context imaging of sampling sites and ground surveys from an aerobot or an orbiting spacecraft in a microgravity environment. The camera penetrators also can be used to image any line-of-sight surface, such as cliff walls, that is difficult to access. Tethered cameras to inspect the surfaces of planetary bodies use both power and signal transmission lines to operate. A tether adds the possibility of inadvertently anchoring the aerobot, and requires some form of station-keeping capability of the aerobot if extended examination time is required. The new camera penetrators are deployed without a tether, weigh less than 30 grams, and are disposable. They are designed to drop from any altitude with the boost in transmitting power currently demonstrated at approximately 100-m line-of-sight. The penetrators also can be deployed to monitor lander or rover operations from a distance, and can be used for surface surveys or for context information gathering from a touch-and-go sampling site. Thanks to wireless operation, the complexity of the sampling or survey mechanisms may be reduced. The penetrators may be battery powered for short-duration missions, or have solar panels for longer or intermittent duration missions. The imaging device is embedded in the penetrator, which is dropped or projected at the surface of a study site at 90 to the surface. Mirrors can be used in the design to image the ground or the horizon. Some of the camera features were tested using commercial "nanny" or "spy" camera components with the charge-coupled device (CCD) looking at a direction parallel to the ground. Figure 1 shows components of one camera that weighs less than 8 g and occupies a volume of 11 cm3. This camera could transmit a standard television signal, including sound, up to 100 m. Figure 2 shows the CAD models of a version of the penetrator. A low-volume array of such penetrator cameras could be deployed from an

  15. Constructing a statistical atlas of the radii of the optic nerve and cerebrospinal fluid sheath in young healthy adults

    NASA Astrophysics Data System (ADS)

    Harrigan, Robert L.; Plassard, Andrew J.; Mawn, Louise A.; Galloway, Robert L.; Smith, Seth A.; Landman, Bennett A.

    2015-03-01

    Optic neuritis is a sudden inflammation of the optic nerve (ON) and is marked by pain on eye movement, and visual symptoms such as a decrease in visual acuity, color vision, contrast and visual field defects. The ON is closely linked with multiple sclerosis (MS) and patients have a 50% chance of developing MS within 15 years. Recent advances in multi-atlas segmentation methods have omitted volumetric assessment. In the past, measuring the size of the ON has been done by hand. We utilize a new method of automatically segmenting the ON to measure the radii of both the ON and surrounding cerebrospinal fluid (CSF) sheath to develop a normative distribution of healthy young adults. We examine this distribution for any trends and find that ON and CSF sheath radii do not vary between 20-35 years of age and between sexes. We evaluate how six patients suffering from optic neuropathy compare to this distribution of controls. We find that of these six patients, five of them qualitatively differ from the normative distribution which suggests this technique could be used in the future to distinguish between optic neuritis patients and healthy controls

  16. Soil penetrometers and penetrability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil penetrometers are useful tools that measure the penetrability, or strength, of a soil. They can be as simple as a rod or shaft with a blunt or sharp end, or complicated mechanically driven instruments with digital data collection systems. Regardless of their design, soil penetrometers measure s...

  17. Single wall penetration equations

    NASA Technical Reports Server (NTRS)

    Hayashida, K. B.; Robinson, J. H.

    1991-01-01

    Five single plate penetration equations are compared for accuracy and effectiveness. These five equations are two well-known equations (Fish-Summers and Schmidt-Holsapple), two equations developed by the Apollo project (Rockwell and Johnson Space Center (JSC), and one recently revised from JSC (Cour-Palais). They were derived from test results, with velocities ranging up to 8 km/s. Microsoft Excel software was used to construct a spreadsheet to calculate the diameters and masses of projectiles for various velocities, varying the material properties of both projectile and target for the five single plate penetration equations. The results were plotted on diameter versus velocity graphs for ballistic and spallation limits using Cricket Graph software, for velocities ranging from 2 to 15 km/s defined for the orbital debris. First, these equations were compared to each other, then each equation was compared with various aluminum projectile densities. Finally, these equations were compared with test results performed at JSC for the Marshall Space Flight Center. These equations predict a wide variety of projectile diameters at a given velocity. Thus, it is very difficult to choose the 'right' prediction equation. The thickness of a single plate could have a large variation by choosing a different penetration equation. Even though all five equations are empirically developed with various materials, especially for aluminum alloys, one cannot be confident in the shield design with the predictions obtained by the penetration equations without verifying by tests.

  18. Penetration resistant barrier

    DOEpatents

    Hoover, William R.; Mead, Keith E.; Street, Henry K.

    1977-01-01

    The disclosure relates to a barrier for resisting penetration by such as hand tools and oxy-acetylene cutting torches. The barrier comprises a layer of firebrick, which is preferably epoxy impregnated sandwiched between inner and outer layers of steel. Between the firebrick and steel are layers of resilient rubber-like filler.

  19. Jet penetration in glass

    SciTech Connect

    Moran, B.; Glenn, L.A.; Kusubov, A.

    1991-05-01

    We describe a phenomenological model which accounts for the mechanical response of glass to intense impulsive loading. An important aspect of this response is the dilatancy accompanying fracture. We have also conducted a number of experiments with 38.1-mm diameter precision shaped charges to establish the performance against various targets and to allow evaluation of our model. At 3 charge diameters standoff, the data indicate that both virgin and damaged glass offer better (Bernoulli-scaled) resistance to penetration than either of 4340 steel, or 6061-T6 aluminum alloy. Time-resolved measurements indicate two distinct phases of jet penetration in glass: An initial hydrodynamic phase, and a second phase characterized by a slower penetration velocity. Our calculations show that at early time, a crater is formed around the jet and only the tip of the undisturbed jet interacts with the glass. At late time the glass has collapsed on the jet and degraded penetration continues via a disturbed and fragmented jet.

  20. Tumor-Penetrating Peptides

    PubMed Central

    Teesalu, Tambet; Sugahara, Kazuki N.; Ruoslahti, Erkki

    2013-01-01

    Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC), contains the integrin-binding RGD motif. RGD mediates tumor-homing through binding to αv integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR) motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular “zip code” of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies, and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is present in the

  1. Biomechanics of penetrating trauma.

    PubMed

    Yoganandan, N; Pintar, F A

    1997-01-01

    It is well known that injuries and deaths due to penetrating projectiles have become a national and an international epidemic in Western society. The application of biomedical engineering to solve day-to-day problems has produced considerable advances in safety and mitigation/prevention of trauma. The study of penetrating trauma has been largely in the military domain where war-time specific applications were advanced with the use of high-velocity weapons. With the velocity and weapon caliber in the civilian population at half or less compared with the military counterpart, wound ballistics is a largely different problem in today's trauma centers. The principal goal of the study of penetrating injuries in the civilian population is secondary prevention and optimized emergency care after occurrence. A thorough understanding of the dynamic biomechanics of penetrating injuries quantifies missile type, caliber, and velocity to hard and soft tissue damage. Such information leads to a comprehensive assessment of the acute and long-term treatment of patients with penetrating injuries. A review of the relevant military research applied to the civilian domain and presentation of new technology in the biomechanical study of these injuries offer foundation to this field. Relevant issues addressed in this review article include introduction of the military literature, the need for secondary prevention, environmental factors including projectile velocity and design, experimental studies with biological tissues and physical models, and mathematical simulations and analyses. Areas of advancement are identified that enables the pursuit of biomechanics research in order to arrive at better secondary prevention strategies. PMID:9719858

  2. Monitoring of Single-Cell Responses in the Optic Tectum of Adult Zebrafish with Dextran-Coupled Calcium Dyes Delivered via Local Electroporation

    PubMed Central

    Kassing, Vanessa

    2013-01-01

    The zebrafish (Danio rerio) has become one of the major animal models for in vivo examination of sensory and neuronal computation. Similar to Xenopus tadpoles neural activity in the optic tectum, the major region controlling visually guided behavior, can be examined in zebrafish larvae by optical imaging. Prerequisites of these approaches are usually the transparency of larvae up to a certain age and the use of two-photon microscopy. This principle of fluorescence excitation was necessary to suppress crosstalk between signals from individual neurons, which is a critical issue when using membrane-permeant dyes. This makes the equipment to study neuronal processing costly and limits the approach to the study of larvae. Thus there is lack of knowledge about the properties of neurons in the optic tectum of adult animals. We established a procedure to circumvent these problems, enabling in vivo calcium imaging in the optic tectum of adult zebrafish. Following local application of dextran-coupled dyes single-neuron activity of adult zebrafish can be monitored with conventional widefield microscopy, because dye labeling remains restricted to tens of neurons or less. Among the neurons characterized with our technique we found neurons that were selective for a certain pattern orientation as well as neurons that responded in a direction-selective way to visual motion. These findings are consistent with previous studies and indicate that the functional integrity of neuronal circuits in the optic tectum of adult zebrafish is preserved with our staining technique. Overall, our protocol for in vivo calcium imaging provides a useful approach to monitor visual responses of individual neurons in the optic tectum of adult zebrafish even when only widefield microscopy is available. This approach will help to obtain valuable insight into the principles of visual computation in adult vertebrates and thus complement previous work on developing visual circuits. PMID:23667529

  3. Pitfalls in penetrating trauma.

    PubMed

    van Vugt, A B

    2003-08-01

    In Western Europe the most frequent cause of multiple injuries is blunt trauma. Only few of us have experience with penetrating trauma, without exception far less than in the USA or South-Africa. In Rotterdam, the Erasmus Medical Centre is a level I trauma centre, situated directly in the town centre. All penetrating traumas are directly presented to our emergency department by a well organized ambulance service supported by a mobile medical team if necessary. The delay with scoop and run principles is very short for these cases, resulting in severely injured reaching the hospital alive in increasing frequency. Although the basic principles of trauma care according to the guidelines of the Advanced Trauma Life Support (ATLS) (1-2) are the same for blunt and penetrating trauma with regard to priorities, diagnostics and primary therapy, there are some pitfalls in the strategy of management in penetrating trauma one should be aware of. Simple algorithms can be helpful, especially in case of limited experience (3). In case of life-saving procedures, the principles of Damage Control Surgery (DCS) must be followed (4-5). This approach is somewhat different from "traditional" surgical treatment. In the Ist phase prompt interventions by emergency thoracotomy and laparotomy are carried out, with only two goals to achieve: surgical control of haemorrhage and contamination. After temporary life-saving procedures, the 2nd phase is characterized by intensive care treatment, dealing with hypothermia, metabolic acidosis and clotting disturbances. Finally in the 3rd phase, within 6-24 hours, definitive surgical care takes place. In this overview, penetrating injuries of neck, thorax, abdomen and extremities will be outlined. Penetrating cranial injuries, as a neurosurgical emergency with poor prognosis, are not discussed. History and physical examination remain the corner stones of good medical praxis. In a work-up according to ATLS principles airway, breathing and circulation

  4. Long-Term Optical Device Use by Young Adults with Low Vision

    ERIC Educational Resources Information Center

    Bachofer, Cynthia Susan

    2013-01-01

    The purpose of this study was to investigate the long-term use of optical devices by individuals who participated in a school-based comprehensive low vision program focusing on use of devices, both near and distance. Thirty-seven participants (five non-users), ages 18-28, completed phone interviews giving information on their personal…

  5. Ground-penetrating rada

    NASA Astrophysics Data System (ADS)

    Thuma, W. R.

    The theory and applications of digital Ground-Penetrating Radar were discussed at a 5-day seminar held at the China University of Geosciences in Wuhan, People's Republic of China, in April. Cohosted by the Department of Applied Geophysics and Canada-China Geoscience, more than 60 senior geophysicists, engineers, technical specialists, university professors and researchers attended.Focus of the meeting was the expanded uses of the new deep-penetrating fully digital PulseEKKO, which is gaining wide acceptance around the world. Attendees showed intense interest in this new and unique technology. Applications covered were groundwater and mineral exploration; engineering, construction and toxic waste site surveying; tunnel and underground mine probing for potential geological hazards, blind ore zones, karst cavities and solution pathways; and locating buried objects such as petroleum storage tanks, unexploded bombs and archeological remains.

  6. Penetrating extremity trauma.

    PubMed

    Ivatury, Rao R; Anand, Rahul; Ordonez, Carlos

    2015-06-01

    Penetrating extremity trauma (PET) usually becomes less important when present along with multiple truncal injuries. The middle eastern wars documented the terrible mortality and morbidity resulting from PET. Even in civilian trauma, PET can lead to significant morbidity and mortality. There are now well-established principles in the evaluation and management of vascular, bony, soft tissue, and neurologic lesions that will lead to a reduction of the poor outcomes. This review will summarize some of these recent concepts. PMID:25413177

  7. Penetrable wedge analysis

    NASA Astrophysics Data System (ADS)

    Scharstein, Robert W.; Davis, Anthony M.

    1994-07-01

    Two complementary analyses of the time-harmonic scattering by a penetrable wedge are presented. The distance from the apex (appropriately scaled by the wavenumber in the exterior region) of the exciting line source is the single length scale in this infinite-domain boundary value problem. The work summarized herein represents two mathematical approaches (among a series of candidates) to solve this important scattering problem and to visualize the wave physics.

  8. Corrosion Inhibitors as Penetrant Dyes for Radiography

    NASA Technical Reports Server (NTRS)

    Novak, Howard L.; Hall, Phillip B.

    2003-01-01

    Liquid/vapor-phase corrosion inhibitors (LVCIs) have been found to be additionally useful as penetrant dyes for neutron radiography (and perhaps also x-radiography). Enhancement of radiographic contrasts by use of LVCIs can reveal cracks, corrosion, and other defects that may be undetectable by ultrasonic inspection, that are hidden from direct optical inspection, and/or that are difficult or impossible to detect in radiographs made without dyes.

  9. Penetrating cardiac injuries.

    PubMed

    Mittal, V; McAleese, P; Young, S; Cohen, M

    1999-05-01

    Our objective was to determine the influence of several clinical factors on the survival of patients with penetrating wounds to the heart. A retrospective review of 80 consecutive penetrating cardiac injuries treated in a Level II urban trauma center from 1980 through 1994 were examined. Thirty-six patients (45%) had gunshot wounds (including 1 shotgun wound), and 44 (55%) had stab wounds. Intervention consisted of emergency room (ER) or operating room thoracotomy. We measured the effect of several clinical factors on morbidity and patient survival. Survival rate was 17 of 36 (47%) in gunshot injuries and 35 of 44 (80%) in stab injuries, with an overall survival rate of 52 of 80 patients (65%). The average age was 24 years (range, 9-53), and there were 3 female patients. Twelve patients (15%) had multiple cardiac injuries, and 63 (79%) had other associated injuries. Fourteen patients (17%) presented with no blood pressure, and 55 (69%) were hypotensive on admission. ER thoracotomy was performed on 7 of 52 survivors (13%) and 24 of 28 nonsurvivors (86%). Survival after ER thoracotomy was 7 of 31 patients (22%). A selective approach is recommended, because ER thoracotomy has a limited role in penetrating cardiac injury. A high index of suspicion, prompt resuscitation, and immediate definitive surgical management resulted in a high survival rate for these frequently lethal injuries. PMID:10231214

  10. Prediction of alumina penetration

    SciTech Connect

    Mandell, D A

    1993-02-01

    The MESA hydrocode was used to predict two-dimensional tests of L/D 10 and L/D 15 tungsten rods impacting AD 90 alumina with a steel backing. The residual penetration into the steel is the measured quantity in these experiments conducted at the Southwest Research Institute (SWR). The interface velocity as a function of time between an alumina target and a lithium fluoride window, impacted by an alumina disk at velocities between 544 m/s and 2329 m/s, was also predicted. These one-dimensional flyer plate experiments were conducted at Sandia National Laboratories using Coors AD 995 alumina. The material strength and fracture models are important in the prediction of ceramic experiments. The models used in these predictions are discussed. The penetrations in the two-dimensional tests were predicted to 11.4 percent or better. In five of the six experiments, the predicted penetration depth was deeper than the measured value. This trend is expected since the calculation is based on ideal conditions. The results show that good agreement between the 1-D flyer plate data and the MESA predictions exists at the lower impact velocities, but the maximum velocity is overpredicted as the flyer plate velocity increases. At a flyer plate velocity of 2329 m/s the code overpredicted the data by 12.3 percent.

  11. The Angiotensin II Type 2 (AT2) Receptor Promotes Axonal Regeneration in the Optic Nerve of Adult Rats

    PubMed Central

    Lucius, Ralph; Gallinat, Stefan; Rosenstiel, Philip; Herdegen, Thomas; Sievers, Jobst; Unger, Thomas

    1998-01-01

    The renin-angiotensin system (RAS) has been traditionally linked to blood pressure and volume regulation mediated through the angiotensin II (ANG II) type 1 (AT1) receptor. Here we report that ANG II via its ANG II type 2 (AT2) receptor promotes the axonal elongation of postnatal rat retinal explants (postnatal day 11) and dorsal root ganglia neurons in vitro, and, moreover, axonal regeneration of retinal ganglion cells after optic nerve crush in vivo. In retinal explants, ANG II (10−7–10−5 M) induced neurite elongation via its AT2 receptor, since the effects were mimicked by the AT2 receptor agonist CGP 42112 (10−5 M) and were entirely abolished by costimulation with the AT2 receptor antagonist PD 123177 (10−5 M), but not by the AT1 receptor antagonist losartan (10−5 M). To investigate whether ANG II is able to promote axonal regeneration in vivo, we performed optic nerve crush experiments in the adult rats. After ANG II treatment (0.6 nmol), an increased number of growth-associated protein (GAP)-43–positive fibers was detected and the regenerating fibers regularly crossed the lesion site (1.6 mm). Cotreatment with the AT2 receptor antagonist PD 123177 (6 nmol), but not with the AT1 receptor antagonist losartan (6 nmol), completely abolished the ANG II–induced axonal regeneration, providing for the first time direct evidence for receptor-specific neurotrophic action of ANG II in the central nervous system of adult mammals and revealing a hitherto unknown function of the RAS. PMID:9705948

  12. Mars penetrator: Subsurface science mission

    NASA Technical Reports Server (NTRS)

    Lumpkin, C. K.

    1974-01-01

    A penetrator system to emplace subsurface science on the planet Mars is described. The need for subsurface science is discussed, and the technologies for achieving successful atmospheric entry, Mars penetration, and data retrieval are presented.

  13. Spectral-Domain Optical Coherence Tomography as a Noninvasive Method to Assess Damaged and Regenerating Adult Zebrafish Retinas

    PubMed Central

    Bailey, Travis J.; Davis, Darin H.; Vance, Joseph E.; Hyde, David R.

    2012-01-01

    Purpose. These experiments assessed the ability of spectral-domain optical coherence tomography (SD-OCT) to accurately represent the structural organization of the adult zebrafish retina and reveal the dynamic morphologic changes during either light-induced damage and regeneration of photoreceptors or ouabain-induced inner retinal damage. Methods. Retinas of control dark-adapted adult albino zebrafish were compared with retinas subjected to 24 hours of constant intense light and recovered for up to 8 weeks or ouabain-damaged retinas that recovered for up to 3 weeks. Images were captured and the measurements of retinal morphology were made by SD-OCT, and then compared with those obtained by histology of the same eyes. Results. Measurements between SD-OCT and histology were very similar for the undamaged, damaged, and regenerating retinas. Axial measurements of SD-OCT also revealed vitreal morphology that was not readily visualized by histology. Conclusions. SD-OCT accurately represented retinal lamination and photoreceptor loss and recovery during light-induced damage and subsequent regeneration. SD-OCT was less accurate at detecting the inner nuclear layer in ouabain-damaged retinas, but accurately detected the undamaged outer nuclear layer. Thus, SD-OCT provides a noninvasive and quantitative method to assess the morphology and the extent of damage and repair in the zebrafish retina. PMID:22499984

  14. Laterality of Stance during Optic Flow Stimulation in Male and Female Young Adults

    PubMed Central

    Persiani, Michela; Piras, Alessandro; Squatrito, Salvatore; Raffi, Milena

    2015-01-01

    During self-motion, the spatial and temporal properties of the optic flow input directly influence the body sway. Men and women have anatomical and biomechanical differences that influence the postural control during visual stimulation. Given that recent findings suggest a peculiar role of each leg in the postural control of the two genders, we investigated whether the body sway during optic flow perturbances is lateralized and whether anteroposterior and mediolateral components of specific center of pressure (COP) parameters of the right and left legs differ, reexamining a previous experiment (Raffi et al. (2014)) performed with two, side-by-side, force plates. Experiments were performed on 24 right-handed and right-footed young subjects. We analyzed five measures related to the COP of each foot and global data: anteroposterior and mediolateral range of oscillation, anteroposterior and mediolateral COP velocity, and sway area. Results showed that men consistently had larger COP parameters than women. The values of the COP parameters were correlated between the two feet only in the mediolateral axis of women. These findings suggest that optic flow stimulation causes asymmetry in postural balance and different lateralization of postural controls in men and women. PMID:26539509

  15. Transorbital Orbitocranial Penetrating Injury with an Iron Rod.

    PubMed

    Agrawal, Amit; Reddy, V Umamaheswara; Kumar, S Satish; Hegde, Kishor V; Rao, G Malleswara

    2016-06-01

    Transorbital orbitocranial penetrating injuries (TOPIs) are relatively rare, can be caused by high-speed projectile foreign bodies to low-energy trauma (which is rarer), and account for 24% of penetrating head injuries in adults and approximately 45% in children. We report an uncommon nonfatal case of TOPI where a 16-year-old male child sustained injury due to accidental penetration of metal bar into the forehead. A bicoronal flap was raised to remove the metal bar. The patient recovered well, had normal vision, and doing well at follow-up. PMID:27162571

  16. Penetrating Trauma to the Ureter, Bladder, and Urethra

    PubMed Central

    Zaid, Uwais B.; Bayne, David B.; Harris, Catherine R.; Alwaal, Amjad; McAninch, Jack W.; Breyer, Benjamin N.

    2015-01-01

    We describe the epidemiology, diagnosis, and management of adult civilian penetrating trauma to the ureter, bladder, and urethra. Trauma is a significant source of death and morbidity. Genitourinary injuries are present in 10% of penetrating trauma cases. Prompt recognition and appropriate management of genitourinary injuries, which are often masked or overlooked due to concomitant injuries, is essential to minimize morbidity. Penetrating trauma most commonly results from gunshot wounds or stab wounds. Compared to blunt trauma, these typically require surgical exploration. An understanding of anatomy and a high index of suspicion are necessary for prompt recognition of genitourinary injuries. PMID:26623247

  17. Penetrating Fire Extinguisher

    NASA Technical Reports Server (NTRS)

    1985-01-01

    When Feecon Corporation, a manufacturer of fire protection systems, needed a piercing nozzle for larger aircraft, they were assisted by Kennedy Space Center who provided the company with a fire extinguisher with a hard pointed tip that had been developed in case of an orbiter crash landing. The nozzle can penetrate metal skins of aircraft, trains, etc. Feecon obtained a license and now markets its cobra ram piercing nozzle to airport firefighters. Its primary advantage is that the nozzle can be held in one spot during repeated blows of the ram. *This product has been discontinued and is no longer commercially available.

  18. Enriched Environment Protects the Optic Nerve from Early Diabetes-Induced Damage in Adult Rats

    PubMed Central

    Dorfman, Damián; Aranda, Marcos L.; Rosenstein, Ruth E.

    2015-01-01

    Diabetic retinopathy is a leading cause of reduced visual acuity and acquired blindness. Axoglial alterations of the distal (close to the chiasm) optic nerve (ON) could be the first structural change of the visual pathway in streptozotocin (STZ)-induced diabetes in rats. We analyzed the effect of environmental enrichment on axoglial alterations of the ON provoked by experimental diabetes. For this purpose, three days after vehicle or STZ injection, animals were housed in enriched environment (EE) or remained in a standard environment (SE) for 6 weeks. Anterograde transport, retinal morphology, optic nerve axons (toluidine blue staining and phosphorylated neurofilament heavy immunoreactivity), microglia/macrophages (ionized calcium binding adaptor molecule 1 (Iba-1) immunoreactivity), astrocyte reactivity (glial fibrillary acid protein-immunostaining), myelin (myelin basic protein immunoreactivity), ultrastructure, and brain derived neurotrophic factor (BDNF) levels were assessed in non-diabetic and diabetic animals housed in SE or EE. No differences in retinal morphology or retinal ganglion cell number were observed among groups. EE housing which did not affect the STZ-induced weight loss and hyperglycemia, prevented a decrease in the anterograde transport from the retina to the superior colliculus, ON axon number, and phosphorylated neurofilament heavy immunoreactivity. Moreover, EE housing prevented an increase in Iba-1 immunoreactivity, and astrocyte reactivity, as well as ultrastructural myelin alterations in the ON distal portion at early stages of diabetes. In addition, EE housing avoided a decrease in BDNF levels induced by experimental diabetes. These results suggest that EE induced neuroprotection in the diabetic visual pathway. PMID:26312758

  19. Enriched Environment Protects the Optic Nerve from Early Diabetes-Induced Damage in Adult Rats.

    PubMed

    Dorfman, Damián; Aranda, Marcos L; Rosenstein, Ruth E

    2015-01-01

    Diabetic retinopathy is a leading cause of reduced visual acuity and acquired blindness. Axoglial alterations of the distal (close to the chiasm) optic nerve (ON) could be the first structural change of the visual pathway in streptozotocin (STZ)-induced diabetes in rats. We analyzed the effect of environmental enrichment on axoglial alterations of the ON provoked by experimental diabetes. For this purpose, three days after vehicle or STZ injection, animals were housed in enriched environment (EE) or remained in a standard environment (SE) for 6 weeks. Anterograde transport, retinal morphology, optic nerve axons (toluidine blue staining and phosphorylated neurofilament heavy immunoreactivity), microglia/macrophages (ionized calcium binding adaptor molecule 1 (Iba-1) immunoreactivity), astrocyte reactivity (glial fibrillary acid protein-immunostaining), myelin (myelin basic protein immunoreactivity), ultrastructure, and brain derived neurotrophic factor (BDNF) levels were assessed in non-diabetic and diabetic animals housed in SE or EE. No differences in retinal morphology or retinal ganglion cell number were observed among groups. EE housing which did not affect the STZ-induced weight loss and hyperglycemia, prevented a decrease in the anterograde transport from the retina to the superior colliculus, ON axon number, and phosphorylated neurofilament heavy immunoreactivity. Moreover, EE housing prevented an increase in Iba-1 immunoreactivity, and astrocyte reactivity, as well as ultrastructural myelin alterations in the ON distal portion at early stages of diabetes. In addition, EE housing avoided a decrease in BDNF levels induced by experimental diabetes. These results suggest that EE induced neuroprotection in the diabetic visual pathway. PMID:26312758

  20. Penetration in GTA welding

    SciTech Connect

    Heiple, C.R.; Burgardt, P.

    1990-01-01

    The size and shape of the weld bead produced in GTA welding depends on the magnitude and distribution of the energy incident on the workpiece surfaces as well as the dissipation of that energy in the workpiece. The input energy is largely controllable through the welding parameters selected, however the dissipation of that energy in the workpiece is less subject to control. Changes in energy dissipation can produce large changes in weld shape or penetration. Heat transport away from the weld pool is almost entirely by conduction, but heat transport in the weld pool is more complicated. Heat conduction through the liquid is an important component, but heat transport by convection (mass transport) is often the dominant mechanism. Convective heat transport is directional and changes the weld pool shape from that produced by conduction alone. Surface tension gradients are often the dominant forces driving fluid flow in GTA weld pools. These gradients are sensitive functions of weld pool chemistry and the energy input distribution to the weld. Experimental and theoretical work conducted primarily in the past decade has greatly enhanced our understanding of weld pool fluid flow, the forces which drive it, and its effects on weld pool shape. This work is reviewed here. While less common, changes in energy dissipation through the unmelted portion of the workpiece can also affect fusion zone shape or penetration. These effects are also described. 41 refs., 9 figs.

  1. Monolithic ballasted penetrator

    DOEpatents

    Hickerson, Jr., James P.; Zanner, Frank J.; Baldwin, Michael D.; Maguire, Michael C.

    2001-01-01

    The present invention is a monolithic ballasted penetrator capable of delivering a working payload to a hardened target, such as reinforced concrete. The invention includes a ballast made from a dense heavy material insert and a monolithic case extending along an axis and consisting of a high-strength steel alloy. The case includes a nose end containing a hollow portion in which the ballast is nearly completely surrounded so that no movement of the ballast relative to the case is possible during impact with a hard target. The case is cast around the ballast, joining the two parts together. The ballast may contain concentric grooves or protrusions that improve joint strength between the case and ballast. The case further includes a second hollow portion; between the ballast and base, which has a payload fastened within this portion. The penetrator can be used to carry instrumentation to measure the geologic character of the earth, or properties of arctic ice, as they pass through it.

  2. Skin penetration enhancers.

    PubMed

    Lane, Majella E

    2013-04-15

    The skin has evolved to prevent excessive water loss from the internal organs and to limit the ability of xenobiotics and hazardous substances to enter the body. Notwithstanding this barrier function, a number of strategies have been developed by scientists to deliver drugs to and through the skin. The aim of this review is to consider the various types of chemical penetration enhancers (CPEs) which have been investigated in the scientific literature. Potential pathways for CPEs to exert their action are examined with reference to the physical chemistry of passive skin transport. The emphasis is on those studies which have focussed on human and porcine skin because of the limitations associated with skin permeation data collated from other species. Where known, the mechanisms of action of these compounds are also discussed. Examples of enhancers used in commercial topical and transdermal formulations are provided. It is proposed that overall the effects of CPEs on the skin barrier may best be explained by a Diffusion-Partition-Solubility theory. Finally, some of the limitations of studies in the literature are considered and the importance of monitoring the fate of the penetration enhancer as well as the active is highlighted. PMID:23462366

  3. Deep penetration of light into biotissue

    NASA Astrophysics Data System (ADS)

    Bearden, Edward D.; Wilson, James D.; Zharov, Vladimir P.; Lowery, Curtis L.

    2001-07-01

    The results of a study of deep (several centimeters) light penetration into biological tissue are presented in order to estimate its significance to potentially photosensitive structures and processes including the fetal eyes. In order to accomplish this goal, samples of various tissues (fat, muscle, and uterus) from surgical patients and autopsies were examined with a double integrating sphere arrangement to determine their optical properties. The results were implemented in a Monte Carlo modeling program. Next, optical fiber probes were inserted into the uterus and abdominal wall of patients undergoing laparoscopic procedures. The fibers were couples to a photomultiplier tube with intervening filters allowing measurements of light penetration at various wavelengths. To determine the feasibility of stimulation in utero, a xenon lamp and waveguide were used to transilluminate the abdomen of several labor patients. Light in the range of 630 to 670 nm where the eye sensitivity and penetration depth are well matched, will likely provide the best chance of visual stimulation. Fetal heart rate, fetal movement, and fetal magnetoencephalography (SQUID) and electroencephalography (EEG) were observed in different studies to determine if stimulation has occurred. Since internal organs and the fetus are completely dark adapted, the amount of light required to simulate in our opinion could be on the order of 10(superscript -8 Watts.

  4. Pressure Measurement during Penetration Experiments

    NASA Astrophysics Data System (ADS)

    Krause, C.; Demming, J.; Flecht, T.; Heller, S.

    2014-04-01

    Penetration experiments are common tools for the investigation of physical surface properties. Additionally penetration experiments will find several applications in exploration missions in the near future. A penetration test stand has been flown for the investigation of penetration force reduction under reduced gravity in the 2nd Joint European Partial-G Parabolic Flight Campaign (JEPPF-2) of ESA, CNES and DLR [1]. The main contribution to the bearing resistance of a soil is combined of shaft and base resistance. During the penetration the grains of the granular material will be squeezed into the surrounding material. The penetration will cause a change in the pressure distribution inside the surrounding soil [2],[3]. An experimental setup has been designed and built for understanding and measurement of this induced pressure distribution. In the last year the parabolic flight test stand has been further developed for the measurement of pressure during the penetration process. The main part of the experiments stayed the same with a steel rod penetration into a sample cell measuring the penetration force and recording it in relation to the depth. The sample cell is equipped with a supporting sieving mechanism for sample preparation. The pressure sensors are mounted at the sample cell. During the last test campaigns the principle of measurement has been investigated and first measurements have been performed. In the presentation the measurement principle will be shown and its implementation into the parabolic flight setup. Pressure measurement results on ground tests of different penetrator and tip configurations will be presented.

  5. Segmentation of center brains and optic lobes in 3D confocal images of adult fruit fly brains.

    PubMed

    Lam, Shing Chun Benny; Ruan, Zongcai; Zhao, Ting; Long, Fuhui; Jenett, Arnim; Simpson, Julie; Myers, Eugene W; Peng, Hanchuan

    2010-02-01

    Automatic alignment (registration) of 3D images of adult fruit fly brains is often influenced by the significant displacement of the relative locations of the two optic lobes (OLs) and the center brain (CB). In one of our ongoing efforts to produce a better image alignment pipeline of adult fruit fly brains, we consider separating CB and OLs and align them independently. This paper reports our automatic method to segregate CB and OLs, in particular under conditions where the signal to noise ratio (SNR) is low, the variation of the image intensity is big, and the relative displacement of OLs and CB is substantial. We design an algorithm to find a minimum-cost 3D surface in a 3D image stack to best separate an OL (of one side, either left or right) from CB. This surface is defined as an aggregation of the respective minimum-cost curves detected in each individual 2D image slice. Each curve is defined by a list of control points that best segregate OL and CB. To obtain the locations of these control points, we derive an energy function that includes an image energy term defined by local pixel intensities and two internal energy terms that constrain the curve's smoothness and length. Gradient descent method is used to optimize this energy function. To improve both the speed and robustness of the method, for each stack, the locations of optimized control points in a slice are taken as the initialization prior for the next slice. We have tested this approach on simulated and real 3D fly brain image stacks and demonstrated that this method can reasonably segregate OLs from CBs despite the aforementioned difficulties. PMID:19698789

  6. Water penetration study

    NASA Technical Reports Server (NTRS)

    Lockwood, H. E.

    1973-01-01

    Nine film-filter combinations have been tested for effectiveness in recording water subsurface detail when exposed from an aerial platform over a typical water body. An experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and an infrared film with selected filters were tested. Results have been tabulated to show the relative capability of each film-filter combination for: (1) image contrast in shallow water (0 to 5 feet); (2) image contrast at medium depth (5 to 10 feet); (3) image contrast in deep water (10 feet plus); (4) water penetration; maximum depth where detail was discriminated; (5) image color (the spectral range of the image); (6) vegetation visible above a water background; (7) specular reflections visible from the water surface; and (8) visual compatibility; ease of discriminating image detail. Recommendations for future recording over water bodies are included.

  7. Hydraulic well penetration apparatus

    SciTech Connect

    Schellstede, H.J.; McQueen, R.W.; Peters, A.D.

    1990-05-29

    This patent describes a well penetrator. It comprises: housing means capable of being lowered down the interior of a well casing, a work fluid input means in the housing means,a movable punch member having an inner end and an outer end and being movable between a retracted position and an extended position. The outer end of the movable punch member including casing cutting means for cutting an opening in a casing when moved forcefully outwardly toward the extended position, punch support means supporting the punch member for movement relative to the housing means between the retracted position in which the outer end of the punch member is positioned substantially within the confines of the housing means and the extended position in which the outer end of the punch member is positioned outwardly of the housing means.

  8. Transorbital Penetrating Intracranial Injury by a Chopstick

    PubMed Central

    Shin, Tae-Hee; Kim, Jong-Hoon; Kwak, Kyung-Woo

    2012-01-01

    A 38-year-old man fell from a chair with a chopstick in his hand. The chopstick penetrated his left eye. He noticed pain, swelling, and numbness around his left eye. On physical examination, a linear wound was noted at the medial aspect of the left eyelid. Noncontrast computed tomography (CT) study showed a linear hypodense structure extending from the medial aspect of the left orbit to the occipital bone, suggesting a foreign body. This foreign body was hyperdense relative to normal parenchyma. From a CT scan with 3-dimensional reconstruction, the foreign body was found to be passing through the optic canal into the cranium. The clear plastic chopstick was withdrawn without difficulty. The patient was discharged home 3 weeks after his surgery. A treatment plan for a transorbital penetrating injury should be determined by a multidisciplinary team, with input from neurosurgeons and ophthalmologists. PMID:23133735

  9. Staged Penetrating Sclerokeratoplasty and Penetrating Keratoplasty for Management of Advanced Acquired Anterior Staphyloma

    PubMed Central

    de la Torre-Gonzalez, Enrique; de León Ascencio, Carolina Ponce

    2011-01-01

    Herein we describe a staged surgical technique consisting of penetrating sclerokeratoplasty (PSKP) followed by penetrating keratoplasty (PKP) and present its clinical course and complications over two years of follow-up. A 23-year-old man presented with cosmetically unacceptable protrusion of the globe corresponding to the cornea and sclera. PSKP was performed transplanting a full-thickness beveled 13 mm corneoscleral tectonic graft. Hypotony developed subsequently and was successfully managed medically, however corneal graft failure occurred. After 15 months, a 7.5 mm PKP was performed for optical reasons, which subsequently remained clear with a healthy epithelium. In this particular case, cosmetic, tectonic, therapeutic, and optical requirements were met. PSKP is a surgical procedure which entails a high rate of complications but may be the only alternative when the main goal of intervention is restoration of the globe in complicated cases such as our patient. PMID:22454726

  10. Optic nerve atrophy

    MedlinePlus

    Optic atrophy; Optic neuropathy ... There are many causes of optic atrophy. The most common is poor blood flow. This is called ischemic optic neuropathy. The problem most often affects older adults. ...

  11. Optic nerve atrophy

    MedlinePlus

    Optic nerve atrophy is damage to the optic nerve. The optic nerve carries images of what the eye sees to ... problem most often affects older adults. The optic nerve can also be damaged by shock, toxins, radiation, ...

  12. Two-dimensional and three-dimensional viability measurements of adult stem cells with optical coherence phase microscopy

    NASA Astrophysics Data System (ADS)

    Bagnaninchi, Pierre O.; Holmes, Christina; Drummond, Nicola; Daoud, Jamal; Tabrizian, Maryam

    2011-08-01

    Cell viability assays are essential tools for cell biology. They assess healthy cells in a sample and enable the quantification of cellular responses to reagents of interest. Noninvasive and label-free assays are desirable in two-dimensional (2D) and three-dimensional (3D) cell culture to facilitate time-course viability studies. Cellular micromotion, emanating from cell to substrate distance variations, has been demonstrated as a marker of cell viability with electric cell-substrate impedance sensing (ECIS). In this study we investigated if optical coherence phase microscopy (OCPM) was able to report phase fluctuations of adult stem cells in 2D and 3D that could be associated with cellular micromotion. An OCPM has been developed around a Thorlabs engine (λo = 930 nm) and integrated in an inverted microscope with a custom scanning head. Human adipose derived stem cells (ADSCs, Invitrogen) were cultured in Mesenpro RS medium and seeded either on ECIS arrays, 2D cell culture dishes, or in 3D highly porous microplotted polymeric scaffolds. ADSC micromotion was confirmed by ECIS analysis. Live and fixed ADSCs were then investigated in 2D and 3D with OCPM. Significant differences were found in phase fluctuations between the different conditions. This study indicated that OCPM could potentially assess cell vitality in 2D and in 3D microstructures.

  13. Universal penetration test apparatus with fluid penetration sensor

    DOEpatents

    Johnson, P.W.; Stampfer, J.F.; Bradley, O.D.

    1999-02-02

    A universal penetration test apparatus is described for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material. 23 figs.

  14. Universal penetration test apparatus with fluid penetration sensor

    DOEpatents

    Johnson, Phillip W.; Stampfer, Joseph F.; Bradley, Orvil D.

    1999-01-01

    A universal penetration test apparatus for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material.

  15. Neuropsychiatric changes following penetrating head injury in children

    PubMed Central

    Badhiwala, Jetan H.; Blackham, Janet R.; Bhardwaj, Ratan D.

    2014-01-01

    Background: Penetrating head injuries demand the prompt attention of a neurosurgeon. While most neurosurgical centers are experienced in the acute management of these injuries, less is known about the long-term neuropsychiatric sequelae of penetrating head trauma. In adults, direct injury to the frontal lobe classically has been associated with mental status changes. However, there is less published data in children. Case Description: We report the case of a 12-year-old boy who suffered a penetrating head injury to the frontal lobes secondary to a self-inflicted gunshot wound, and experienced subsequent resolution of pre-existing bipolar disorder and new onset of attention deficit hyperactivity disorder. Conclusion: Children with penetrating head injury require close multidisciplinary follow-up in order to monitor, and accordingly implement management strategies, for associated sequelae, including behavioral and neuropsychiatric changes. PMID:25422782

  16. Electromagnetic Field Penetration Studies

    NASA Technical Reports Server (NTRS)

    Deshpande, M.D.

    2000-01-01

    A numerical method is presented to determine electromagnetic shielding effectiveness of rectangular enclosure with apertures on its wall used for input and output connections, control panels, visual-access windows, ventilation panels, etc. Expressing EM fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential electric and magnetic fields across the apertures. Using the Method of Moments, the integral equations are solved for unknown aperture fields. From these aperture fields, the EM field inside a rectangular enclosure due to external electromagnetic sources are determined. Numerical results on electric field shielding of a rectangular cavity with a thin rectangular slot obtained using the present method are compared with the results obtained using simple transmission line technique for code validation. The present technique is applied to determine field penetration inside a Boeing-757 by approximating its passenger cabin as a rectangular cavity filled with a homogeneous medium and its passenger windows by rectangular apertures. Preliminary results for, two windows, one on each side of fuselage were considered. Numerical results for Boeing-757 at frequencies 26 MHz, 171-175 MHz, and 428-432 MHz are presented.

  17. Top Sounder Ice Penetration

    NASA Astrophysics Data System (ADS)

    Porter, D. L.; Goemmer, S. A.; Sweeney, J. H.

    2014-12-01

    Ice draft measurements are made as part of normal operations for all US Navy submarines operating in the Arctic Ocean. The submarine ice draft data are unique in providing high resolution measurements over long transects of the ice covered ocean. The data has been used to document a multidecadal drop in ice thickness, and for validating and improving numerical sea-ice models. A submarine upward-looking sonar draft measurement is made by a sonar transducer mounted in the sail or deck of the submarine. An acoustic beam is transmitted upward through the water column, reflecting off the bottom of the sea ice and returning to the transducer. Ice thickness is estimated as the difference between the ship's depth (measured by pressure) and the acoustic range to the bottom of the ice estimated from the travel time of the sonar pulse. Digital recording systems can provide the return off the water-ice interface as well as returns that have penetrated the ice. Typically, only the first return from the ice hull is analyzed. Information regarding ice flow interstitial layers provides ice age information and may possibly be derived with the entire return signal. The approach being investigated is similar to that used in measuring bottom sediment layers and will involve measuring the echo level from the first interface, solving the reflection loss from that transmission, and employing reflection loss versus impedance mismatch to ascertain ice structure information.

  18. Endophthalmitis after penetrating keratoplasty.

    PubMed

    Guss, R B; Koenig, S; De La Pena, W; Marx, M; Kaufman, H E

    1983-05-01

    Of 445 eyes (305 of which were aphakic) that underwent penetrating keratoplasty, 11 developed endophthalmitis, three immediately after surgery, two after subsequent secondary surgery, and six after late ulceration of the transplanted cornea. The diagnosis was based clinically on the loss of the red reflex and vitreous opacification, and was confirmed by culture of vitreous aspirate. All patients who developed endophthalmitis were aphakic and had received corticosteroids at the time of infection; most had undergone previous ocular surgery. These patients differed from those previously described with this condition because neither the donor tissue nor the storage medium was the source of infection. Treatment included intracameral, systemic, and topical administration of antibiotics. When the endophthalmitis originated from a corneal ulcer in a graft, the infected tissue was replaced with a new transplant. Despite treatment, the final visual outcomes were not good. One eye had a final visual acuity of 20/200 and one eye had a final visual acuity of 20/400. Three eyes had light perception and six eyes had no light perception. One eye was eventually enucleated. PMID:6342401

  19. Ground-penetrating radar methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ground-penetrating radar geophysical methods are finding greater and greater use in agriculture. With the ground-penetrating radar (GPR) method, an electromagnetic radio energy (radar) pulse is directed into the subsurface, followed by measurement of the elapsed time taken by the radar signal as it ...

  20. Sidewall penetrator for oil wells

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1981-01-01

    Penetrator bores horizontal holes in well casing to increase trapped oil drainage. Several penetrators operated by common drive are inserted into well at once. Shaft, made from spiraling cable, rotates and thrusts simultaneously through rigid curvilinear guide tube forcing bit through casing into strata. Device pierces more deeply than armor-piercing bullets and shaped explosive charges.

  1. Skin penetration of silica microparticles.

    PubMed

    Boonen, J; Baert, B; Lambert, J; De Spiegeleer, B

    2011-06-01

    Knowledge about skin penetration of nano- and microparticles is essential for the development of particle-core drug delivery systems and toxicology. A large number of studies have been devoted to metallic particle penetration. However, little work has been published about the importance of chemical material properties of the particles and the skin penetration effect of the applied formulation. Here, we investigated the penetration of 3 microm silica particles in water and in a 65% ethanolic plant extract on ex vivo human skin using scanning electron microscopy. Contrary to most other microsphere skin studies, we observed for the first time that 3 microm silica particles can penetrate the living epidermis. Moreover, when formulated in the ethanolic medium, particles even reach the dermis. The deviating chemical properties of silica compared to previously investigated microparticles (titanium dioxide, zinc oxide) and confounding effect of the formulation in which the silica microparticles are presented, is thus demonstrated. PMID:21699089

  2. Static penetration resistance of soils

    NASA Technical Reports Server (NTRS)

    Durgunoglu, H. T.; Mitchell, J. K.

    1973-01-01

    Model test results were used to define the failure mechanism associated with the static penetration resistance of cohesionless and low-cohesion soils. Knowledge of this mechanism has permitted the development of a new analytical method for calculating the ultimate penetration resistance which explicitly accounts for penetrometer base apex angle and roughness, soil friction angle, and the ratio of penetration depth to base width. Curves relating the bearing capacity factors to the soil friction angle are presented for failure in general shear. Strength parameters and penetrometer interaction properties of a fine sand were determined and used as the basis for prediction of the penetration resistance encountered by wedge, cone, and flat-ended penetrometers of different surface roughness using the proposed analytical method. Because of the close agreement between predicted values and values measured in laboratory tests, it appears possible to deduce in-situ soil strength parameters and their variation with depth from the results of static penetration tests.

  3. An Earth Penetrating Modeling Assessment

    SciTech Connect

    Stokes, E; Yarrington, P; Glenn, L

    2005-06-21

    Documentation of a study to assess the capability of computer codes to predict lateral loads on earth penetrating projectiles under conditions of non-normal impact. Calculations simulated a set of small scale penetration tests into concrete targets with oblique faces at angles of 15 and 30 degrees to the line-of-flight. Predictive codes used by the various calculational teams cover a wide range of modeling approaches from approximate techniques, such as cavity expansion, to numerical methods, such as finite element codes. The modeling assessment was performed under the auspices of the Phenomenology Integrated Product Team (PIPT) for the Robust Nuclear Earth Penetrator Program (RNEP). Funding for the penetration experiments and modeling was provided by multiple earth penetrator programs.

  4. Exogenous Modulation of Retinoic Acid Signaling Affects Adult RGC Survival in the Frog Visual System after Optic Nerve Injury.

    PubMed

    Duprey-Díaz, Mildred V; Blagburn, Jonathan M; Blanco, Rosa E

    2016-01-01

    After lesions to the mammalian optic nerve, the great majority of retinal ganglion cells (RGCs) die before their axons have even had a chance to regenerate. Frog RGCs, on the other hand, suffer only an approximately 50% cell loss, and we have previously investigated the mechanisms by which the application of growth factors can increase their survival rate. Retinoic acid (RA) is a vitamin A-derived lipophilic molecule that plays major roles during development of the nervous system. The RA signaling pathway is also present in parts of the adult nervous system, and components of it are upregulated after injury in peripheral nerves but not in the CNS. Here we investigate whether RA signaling affects long-term RGC survival at 6 weeks after axotomy. Intraocular injection of all-trans retinoic acid (ATRA), the retinoic acid receptor (RAR) type-α agonist AM80, the RARβ agonist CD2314, or the RARγ agonist CD1530, returned axotomized RGC numbers to almost normal levels. On the other hand, inhibition of RA synthesis with disulfiram, or of RAR receptors with the pan-RAR antagonist Ro-41-5253, or the RARβ antagonist LE135E, greatly reduced the survival of the axotomized neurons. Axotomy elicited a strong activation of the MAPK, STAT3 and AKT pathways; this activation was prevented by disulfiram or by RAR antagonists. Finally, addition of exogenous ATRA stimulated the activation of the first two of these pathways. Future experiments will investigate whether these strong survival-promoting effects of RA are mediated via the upregulation of neurotrophins. PMID:27611191

  5. Projectile penetration into ballistic gelatin.

    PubMed

    Swain, M V; Kieser, D C; Shah, S; Kieser, J A

    2014-01-01

    Ballistic gelatin is frequently used as a model for soft biological tissues that experience projectile impact. In this paper we investigate the response of a number of gelatin materials to the penetration of spherical steel projectiles (7 to 11mm diameter) with a range of lower impacting velocities (<120m/s). The results of sphere penetration depth versus projectile velocity are found to be linear for all systems above a certain threshold velocity required for initiating penetration. The data for a specific material impacted with different diameter spheres were able to be condensed to a single curve when the penetration depth was normalised by the projectile diameter. When the results are compared with a number of predictive relationships available in the literature, it is found that over the range of projectiles and compositions used, the results fit a simple relationship that takes into account the projectile diameter, the threshold velocity for penetration into the gelatin and a value of the shear modulus of the gelatin estimated from the threshold velocity for penetration. The normalised depth is found to fit the elastic Froude number when this is modified to allow for a threshold impact velocity. The normalised penetration data are found to best fit this modified elastic Froude number with a slope of 1/2 instead of 1/3 as suggested by Akers and Belmonte (2006). Possible explanations for this difference are discussed. PMID:24184862

  6. Cooperative Transmembrane Penetration of Nanoparticles

    PubMed Central

    Zhang, Haizhen; Ji, Qiuju; Huang, Changjin; Zhang, Sulin; Yuan, Bing; Yang, Kai; Ma, Yu-qiang

    2015-01-01

    Physical penetration of lipid bilayer membranes presents an alternative pathway for cellular delivery of nanoparticles (NPs) besides endocytosis. NPs delivered through this pathway could reach the cytoplasm, thereby opening the possibility of organelle-specific targeting. Herein we perform dissipative particle dynamics simulations to elucidate the transmembrane penetration mechanisms of multiple NPs. Our simulations demonstrate that NPs’ translocation proceeds in a cooperative manner, where the interplay of the quantity and surface chemistry of the NPs regulates the translocation efficiency. For NPs with hydrophilic surfaces, the increase of particle quantity facilitates penetration, while for NPs with partly or totally hydrophobic surfaces, the opposite highly possibly holds. Moreover, a set of interesting cooperative ways, such as aggregation, aggregation-dispersion, and aggregation-dispersion-reaggregation of the NPs, are observed during the penetration process. We find that the penetration behaviors of multiple NPs are mostly dominated by the changes of the NP-membrane force components in the membrane plane direction, in addition to that in the penetration direction, suggesting a different interaction mechanism between the multiple NPs and the membrane compared with the one-NP case. These results provide a fundamental understanding in the underlying mechanisms of cooperative penetration of NPs, and shed light on the NP-based drug and gene delivery. PMID:26013284

  7. Inspecting the reactor vessel penetrations

    SciTech Connect

    Bodson, F.; Fleming, K.W.

    1995-08-01

    The susceptibility of Alloy 600 to Primary Water Stress Corrosion Cracking (PWSCC) continues to plague nuclear power plants. Recently, the problem of PWSCC cracking has manifested itself in Control Rod Drive Mechanism (CRDM) head penetrations in nuclear plants in Europe. Framatome has been extensively involved in the performance of both inspections and repairs of CRDM head penetrations at Electricite de France (EdF) plants. B and W Nuclear Technologies (BWNT), building on Framatome technology, has developed a fully integrated service package and robotic manipulator to inspect and repair CRDM head penetrations for US utilities. Reactor vessel bottom penetration are also made of Alloy 600 and to tackle this potential PWSCC problem at EdF plants, Framatome has been performing specific inspections in order to detect the appearance of the phenomenon. This paper describes the overall range of inspection techniques and toolings developed to address these issues.

  8. Ground Penetrating Radar, Barrow, Alaska

    SciTech Connect

    John Peterson

    2015-03-06

    This is 500 MHz Ground Penetrating Radar collected along the AB Line in Intensive Site 1 beginning in October 2012 and collected along L2 in Intensive Site 0 beginning in September 2011. Both continue to the present.

  9. Investigations into Monochloramine Biofilm Penetration

    EPA Science Inventory

    Biofilm in drinking water systems is undesirable. Free chlorine and monochloramine are commonly used as secondary drinking water disinfectants, but monochloramine is perceived to penetrate biofilm better than free chlorine. However, this hypothesis remains unconfirmed by direct b...

  10. Cement penetration after patella venting.

    PubMed

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement. PMID:19010682

  11. Adaptive plasticity of the auditory space map in the optic tectum of adult and baby barn owls in response to external ear modification.

    PubMed

    Knudsen, E I; Esterly, S D; Olsen, J F

    1994-01-01

    1. This study demonstrates the influence of experience on the establishment and maintenance of the auditory map of space in the optic tectum of the barn owl. Auditory experience was altered either by preventing the structures of the external ears (the facial ruff and preaural flaps) from appearing in baby barn owls (baby ruff-cut owls) or by removing these structures in adults (adult ruff-cut owls). These structures shape the binaural cues used for localizing sounds in both the horizontal and vertical dimensions. 2. The acoustic effects of removing the external ear structures were measured using probe tube microphones placed in the ear canals. In both baby and adult ruff-cut owls, the spatial pattern of binaural localization cues was dramatically different from normal: interaural level difference (ILD) changed with azimuth instead of with elevation, the rate of change of ILD across space was decreased relative to normal, and the rate of change of interaural time difference (ITD) across frontal space was increased relative to normal. 3. The neurophysiological representations of ITD and ILD in the optic tectum were measured before and > or = 3 mo after ruff removal in adults and beginning at 4.5 months of age in baby ruff-cut owls. Multiunit tuning to ITD and to ILD was measured using dichotic stimulation in ketamine-anesthetized owls. The tectal maps of ITD and ILD were reconstructed using visual receptive field location as a marker for recording site location in the optic tectum. 4. Adjustment of the tectal map of ITD to the altered spatial pattern of acoustic ITD was essentially complete in adults as well as in baby ruff-cut owls. This adjustment changed the magnification of ITD across the tectum, with resultant changes in ITD tuning at individual tectal sites of up to approximately 25 microseconds (approximately 5% of the physiological range) relative to normal values. 5. Adaptation of the tectal ILD map to the ruff-cut spatial pattern of acoustic ILD was

  12. Penetration through the Skin Barrier.

    PubMed

    Nielsen, Jesper Bo; Benfeldt, Eva; Holmgaard, Rikke

    2016-01-01

    The skin is a strong and flexible organ with barrier properties essential for maintaining homeostasis and thereby human life. Characterizing this barrier is the ability to prevent some chemicals from crossing the barrier while allowing others, including medicinal products, to pass at varying rates. During recent decades, the latter has received increased attention as a route for intentionally delivering drugs to patients. This has stimulated research in methods for sampling, measuring and predicting percutaneous penetration. Previous chapters have described how different endogenous, genetic and exogenous factors may affect barrier characteristics. The present chapter introduces the theory for barrier penetration (Fick's law), and describes and discusses different methods for measuring the kinetics of percutaneous penetration of chemicals, including in vitro methods (static and flow-through diffusion cells) as well as in vivo methods (microdialysis and microperfusion). Then follows a discussion with examples of how different characteristics of the skin (age, site and integrity) and of the penetrants (size, solubility, ionization, logPow and vehicles) affect the kinetics of percutaneous penetration. Finally, a short discussion of the advantages and challenges of each method is provided, which will hopefully allow the reader to improve decision making and treatment planning, as well as the evaluation of experimental studies of percutaneous penetration of chemicals. PMID:26844902

  13. Demonstration of survivable space penetrator

    NASA Astrophysics Data System (ADS)

    Church, Philip; Huntington-Thresher, William; Bruce, Alan; Penny, Nick; Smith, Alan; Gowan, Rob

    2012-03-01

    This work was performed in support of MoonLITE which is a proposed UK space mission to the moon. The basic premise is to deploy 4 instrumented penetrators, one each on the near-side, farside and at the poles of the moon, with an impact velocity of approximately 300m/s. The primary science aims are to set up a passive seismometer network, investigate the presence of water and volatiles and determine thermal gradients in the lunar soil (i.e. regolith). A key requirement is that the penetrator shell survives the impact together with the instrument payload and supporting subsystems. The material chosen for the penetrator shell was 7075 aluminium alloy, which is a good compromise between high compressive strength and low mass. The baseline penetrator design was evaluated and refined using the DYNA3D hydrocode to determine the survivability of the penetrator in sand at an impact velocity of 300m/s and an attack angle of 8°. The simulations predicted that the penetrator design would survive this severe impact condition which was confirmed by experiments on the Pendine rocket test track.

  14. Maps of optical differential pathlength factor of human adult forehead, somatosensory motor and occipital regions at multi-wavelengths in NIR

    NASA Astrophysics Data System (ADS)

    Zhao, Huijuan; Tanikawa, Yukari; Gao, Feng; Onodera, Yoichi; Sassaroli, Angelo; Tanaka, Kenji; Yamada, Yukio

    2002-06-01

    The optical differential pathlength factor (DPF) is an important parameter for physiological measurement using near infrared spectroscopy, but for the human adult head it has been available only for the forehead. Here we report measured DPF results for the forehead, somatosensory motor and occipital regions from measurements on 11 adult volunteers using a time-resolved optical imaging system. The optode separation was about 30 mm and the wavelengths used were 759 nm, 799 nm and 834 nm. Measured DPFs were 7.25 for the central forehead and 6.25 for the temple region at 799 nm. For the central somatosensory and occipital areas (10 mm above the inion), DPFs at 799 nm are 7.5 and 8.75, respectively. Less than 10% decreases of DPF for all these regions were observed when the wavelength increased from 759 nm to 834 nm. To compare these DPF maps with the anatomical structure of the head, a Monte Carlo simulation was carried out to calculate DPF for these regions by using a two-layered semi-infinite model and assuming the thickness of the upper layer to be the sum of the thicknesses of scalp and skull, which was measured from MRI images of a subject's head. The DPF data will be useful for quantitative monitoring of the haemodynamic changes occurring in adult heads.

  15. Penetrating trauma to the facial skeleton by pickaxe - case report.

    PubMed

    Neskoromna-Jędrzejczak, Aneta; Bogusiak, Katarzyna; Przygoński, Aleksander; Timler, Dariusz

    2016-01-01

    Number of deaths related with injuries suffered as a result of experienced traumas is increasing. Penetrating traumas of the facial skeleton occur relatively rarely and much more often concern rather children than adults. Epidemiology relating this kind of trauma differs depending on the region of the world. In Poland, gunshot injuries as well as traumas caused by explosions of firecrackers or fireworks amount only to a slight percentage among all facial skeleton traumas, and the most common reason for penetrating traumas lies in accidents or assault with the use of sharp, narrow and long objects that easily enter bones of the facial skeleton. The present study reported the case of 50-year-old man who suffered from trauma of the facial skeleton, which resulted from foreign body (pickaxe) penetration into the subtemporal area, zygomatic arch and the right orbital cavity. The surgical treatment method and final outcome was presented and discussed. PMID:27096775

  16. On the reaction of adult Rhipicephalus evertsi mimeticus and Hyalomma truncatum to horizontally incidenting optical radiation of various wavelengths ranges and different irradiances and to optical radiation of a sun-simulating wavelength spectrum.

    PubMed

    Leuterer, G; Gothe, R

    1991-01-01

    The valence of horizontally incidenting light/optical radiation for host-seeking-inclined ixodid ticks was investigated by exposing male and female adults of Rhipicephalus evertsi mimeticus and Hyalomma truncatum to narrow-band monochromatic radiation in the wavelength range of 300-801 nm at irradiances corresponding to an overcast to clear sunny day, a cloudy day and a full-moon night as well as to optical radiation of a sun-simulating wavelength spectrum of 190-2600 nm within a test chamber from which other stimuli were excluded. It was demonstrated that independent of sex, adult ticks of R. e. mimeticus and H. truncatum responded to a wide wavelength spectrum in the visible and UV range, even at irradiances corresponding to a full-moon night. Interspecific differences existed in the degree and extent of the response as well as in the spectral sensitivity. Ticks of H. truncatum consistently showed a faster and stronger response and reacted phototactically positively in higher percentages than adults of R. e. mimeticus. Independent of wavelength range and irradiance, predominantly only few R. e. mimeticus ticks were stimulated to positive phototaxis, whereas at least 33.3% (in most cases, 50%) and maximally greater than 80% of H. truncatum adults reacted phototactically positively. Spectral sensitivity maxima were demonstrated at the yellow and red light and at the UV-A waveband width for R. e. mimeticus and at the violet, blue, green and yellow light wavelength for H. truncatum. With decreasing irradiance, the spectral sensitivity shifted to the blue wavelength range.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1866424

  17. [Reparative Neurogenesis in the Brain and Changes in the Optic Nerve of Adult Trout Oncorhynchus mykiss after Mechanical Damage of the Eye].

    PubMed

    Puschina, E V; Varaksin, A A; Obukhov, D K

    2016-01-01

    Reparative proliferation and neurogenesis in the brain integrative centers after mechanical eye injury in an adult trout Oncorhynchus mykiss have been studied. We have found that proliferation and neurogenesis in proliferative brain regions, the cerebellum, and the optic tectum were significantly enhanced after the eye injury. The cerebellum showed a significant increase in the proliferative activity of the cells of the dorsal proliferative zone and parenchymal cells of the molecular and granular layers. One week after the injury, PCNA-positive radial glia cells have been identified in the tectum. We have found for the first time that the eye trauma resulted in the development of local clusters of undifferentiated cells forming so called neurogenic niches in the tectum and cerebellum. The differentiation of neuronal cells detected by labeling cells with antibodies against the protein HuC/D occurred in the proliferative zones of the telencephalon, the optic tectum, cerebellum, and medulla of a trout within 2 days after the injury. We have shown that the HuC/D expression is higher in the proliferative brain regions than in the definitive neurons of a trout. In addition, we have examined cell proliferation, migration, and apoptosis caused by the eye injury in the contra- and ipsilateral optic nerves and adjacent muscle fibers 2 days after the trauma. The qualitative and quantitative assessment of proliferation and apoptosis in the cells of the optic nerve of a trout has been made using antibodies against PCNA and the TUNEL method. PMID:27149746

  18. Mars surface penetrator: System description

    NASA Technical Reports Server (NTRS)

    Manning, L. A. (Editor)

    1977-01-01

    A point design of a penetrator system for a Mars mission is described. A strawman payload which is to conduct measurements of geophysical and meteorological parameters is included in the design. The subsystems used in the point design are delineated in terms of power, mass, volume, data, and functional modes. The prospects for survival of the rigors of emplacement are described. Data handling and communications plans are presented to allow consideration of the requirements placed by the penetrator on the orbiter and ground operations. The point design is technically feasible and the payload selection scientifically desirable.

  19. Resuscitative thoracotomy in penetrating trauma.

    PubMed

    Fairfax, Lindsay M; Hsee, Li; Civil, Ian D

    2015-06-01

    The resuscitative thoracotomy (RT) is an important procedure in the management of penetrating trauma. As it is performed only in patients with peri-arrest physiology or overt cardiac arrest, survival is low. Experience is also quite variable depending on volume of penetrating trauma in a particular region. Survival ranges from 0% to as high as 89% depending on patient selection, available resources, and location of RT (operating or emergency rooms). In this article, published guidelines are reviewed as well as outcomes. Technical considerations of RT and well as proper training, personnel, and location are also discussed. PMID:25342073

  20. Development and testing of a Europa Penetrator for Astrobiology

    NASA Astrophysics Data System (ADS)

    Vijendran, S.; Perkinson, M.-C.; Waugh, L.; Ratcliffe, A.; Kennedy, T.; Church, P.; Fielding, J.; Taylor, N.

    2014-04-01

    Two phases of Penetrator development activities have been funded by ESA. The first phase focussed on the mission and system definition of a penetrator and delivery system for a mission to Europa and the second phase provided an update of the penetrator design for a larger suite of instruments focused on astrobiology and the demonstration of key system technologies through a programme of small scale and full scale testing. The science focus for the Europa penetrator is Astrobiology while the key science goals can be achieved within the first day of operation but a longer lifetime is required for the transmission of the science data to the orbiter. The extreme temperature environment of the Europan surface drove the design to a solution of a Penetrator with two separate bays. The front bay will be a short lifetime bay which will sample the surface and complete all analysis and data transfer within 10 hours. The rear bay is a warm bay which will house EPSC Abstracts Vol. 9, EPSC2014-642, 2014 European Planetary Science Congress 2014 c Author(s) 2014 EPSC European Planetary Science Congress the penetrator support systems required to transmit all collected data to the orbiter. The scientific instruments housed by the penetrator includeds a optical microimager, a habitability package and a mass spectrometer. A drilling and sampling mechanism is used for accessing the icy material outside the Penetrator for analysis. Small scale trails have been undertaken at the University of Cambridge Cavendish Laboratory to validate the impact modelling techniques and the robustness of critical components. A range of trials have been carried out to assess survivability of key elements of the design, including the sampling mechanism, potting compounds, accelerometers, shell, batteries and Torlon suspension springs. Full scale trials have been carried out to test the overall structural integrity of the system and the penetration profile. This programme was carried out in June 2013 at the

  1. Magnetically-Guided Penetrant Applicator

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1990-01-01

    Small wheeled vehicle moved inside nonmagnetic enclosure. Miniature magnetically guided truck uses foam-rubber sponge pads to apply penetrant fluid for inspection of welds in hidden surfaces of nonmagnetic tubes. Risk of explosion less than if electric motor used to drive vehicle. Inexpensive to make and made in range of sizes.

  2. Simulation of laser penetration efficiency

    NASA Astrophysics Data System (ADS)

    Semak, V. V.; Miller, T. F.

    2013-09-01

    The results of numerical simulation of laser beam interaction with a hypothetical metallic material with properties similar to a steel alloy are reported. The numerical simulation was performed using a physical model that includes detailed consideration of surface evaporation, evaporative cooling of the surface and evaporation recoil induced melt ejection. The laser beam ‘penetration’ is considered in terms of melting through the sample or drilling through the sample due to both evaporation and recoil ejection of material. As a demonstration of the predictive capabilities of the model, the average velocity of penetration through a material with steel-like properties is numerically predicted for various laser interaction parameters such as, laser beam radius, laser pulse duration (including CW regime), laser pulse energy and pulse repetition. In particular, the average penetration velocities through a sample due to melting are compared for pulsed and CW lasers of the same power. For the sake of another demonstration of penetration simulation, the temporal dynamics of the position of melt front relative to the sample surface irradiated by a laser beam was computed for different laser pulse repetition rates and constant average laser power. An illustration of the penetration efficiency (W parameter) defined as the amount of energy per unit volume delivered into a target in order to achieve either melting of drilling through a target wall is shown in a wide range of laser pulse parameters covering regimes corresponding to domination of melting through and drilling through.

  3. Percutaneous penetration--methodological considerations.

    PubMed

    Holmgaard, Rikke; Benfeldt, Eva; Nielsen, Jesper B

    2014-07-01

    Studies on percutaneous penetration are needed to assess the hazards after unintended occupational skin exposures to industrial products as well as the efficacy after intended consumer exposure to topically applied medicinal or cosmetic products. During recent decades, a number of methods have been developed to replace methods involving experimental animals. The results obtained from these methods are decided not only by the chemical or product tested, but to a significant degree also by the experimental set-up and decisions made by the investigator during the planning phase. The present MiniReview discusses some of the existing and well-known experimental in vitro and in vivo methods for studies of percutaneous penetration together with some more recent and promising methods. After this, some considerations and recommendations about advantages and limitations of the different methods and their relevance for the prediction of percutaneous penetration are given. Which method to prefer will depend on the product to be tested and the question asked. Regulatory guidelines exist for studies on percutaneous penetration, but researchers as well as regulatory bodies need to pay specific attention to the vehicles and solvents used in donor and sampling fluids so that it reflects in-use conditions as closely as possible. Based on available experimental data, mathematical models have been developed to aid predictions of skin penetration. The authors question the general use of the present mathematical models in hazard assessment, as they seem to ignore outliers among chemicals as well as the heterogeneity of skin barrier properties and skin conditions within the exposed populations. PMID:24373389

  4. Penetration below a convective zone

    NASA Astrophysics Data System (ADS)

    Hurlburt, Neal E.; Toomre, Juri; Massaguer, Josep M.; Zahn, Jean-Paul

    1994-01-01

    Two-dimensional numerical simulations are used to investigate how fully compressible nonlinear convection penetrates into a stably stratified zone beneath a stellar convection zone. Estimates are obtained of the extent of penetration as the relative stability S of the stable to the unstable zone is varied over a broad range. The model deals with a perfect gas possessing a constant dynamic viscosity. The dynamics is dominated by downward-directed plumes which can extend far into the stable material and which can lead to the excitation of a broad spectrum of internal gravity waves in the lower stable zone. The convection is highly time dependent, with the close coupling between the lateral swaying of the plumes and the internal gravity waves they generate serving to modulate the strength of the convection. The depth of penetration delta, determined by the position where the time-averaged kinetic flux has its first zero in the stable layer, is controlled by a balance between the kinetic energy carried into the stable layer by the plumes and the buoyancy braking they experience there. A passive scalar is introduced into the unstable layer to evaluate the transport of chemical species downward. Such a tracer is effectively mixed within a few convective overturning times down to a depth of delta within the stable layer. Analytical estimates based on simple scaling laws are used to interpret the variation of delta with S, showing that it first involves an interval of adiabatic penetration if the local Peclet number of the convection exceeds unity, followed by a further thermal adjustment layer, the depths of each interval scaling in turn as S-1 and S-1/4. These estimates are in accord with the penetration results from the simulations.

  5. Near infrared laser penetration and absorption in human skin

    NASA Astrophysics Data System (ADS)

    Nasouri, Babak; Murphy, Thomas E.; Berberoglu, Halil

    2014-02-01

    For understanding the mechanisms of low level laser/light therapy (LLLT), accurate knowledge of light interaction with tissue is necessary. In this paper, we present a three dimensional, multi-layer Monte Carlo simulation tool for studying light penetration and absorption in human skin. The skin is modeled as a three-layer participating medium, namely epidermis, dermis, and subcutaneous, where its geometrical and optical properties are obtained from the literature. Both refraction and reflection are taken into account at the boundaries according to Snell's law and Fresnel relations. A forward Monte Carlo method was implemented and validated for accurately simulating light penetration and absorption in absorbing and anisotropically scattering media. Local profiles of light penetration and volumetric absorption densities were simulated for uniform as well as Gaussian profile beams with different spreads at 155 mW average power over the spectral range from 1000 nm to 1900 nm. The results show the effects of beam profiles and wavelength on the local fluence within each skin layer. Particularly, the results identify different wavelength bands for targeted deposition of power in different skin layers. Finally, we show that light penetration scales well with the transport optical thickness of skin. We expect that this tool along with the results presented will aid researchers resolve issues related to dose and targeted delivery of energy in tissues for LLLT.

  6. Akon - A Penetrator for Europa

    NASA Astrophysics Data System (ADS)

    Jones, Geraint

    2016-04-01

    Jupiter's moon Europa is one of the most intriguing objects in our Solar System. This 2000km-wide body has a geologically young solid water ice crust that is believed to cover a global ocean of liquid water. The presence of this ocean, together with a source of heating through tidal forces, make Europa a conceivable location for extraterrestrial life. The science case for exploring all aspects of this icy world is compelling. NASA has selected the Europa Mission (formerly Europa Clipper) to study Europa in detail in the 2020s through multiple flybys, and ESA's JUICE mission will perform two flybys of the body in the 2030s. The US agency has extended to the European Space Agency an invitation to provide a contribution to their mission. European scientists interested in Europa science and exploration are currently organizing themselves, in the framework of a coordinated Europa M5 Inititative to study concurrently the main options for this ESA contribution, from a simple addition of individual instruments to the NASA spacecraft, to a lander to investigate Europa's surface in situ. A high speed lander - a penetrator - is by far the most promising technology to achieve this latter option within the anticipated mass constraints, and studies of such a hard lander, many funded by ESA, are now at an advanced level. An international team to formally propose an Europa penetrator to ESA in response to the anticipated ESA M5 call is growing. The working title of this proposal is Akon (Άκων), named after the highly accurate javelin gifted to Europa by Zeus in ancient Greek mythology. We present plans for the Akon penetrator, which would impact Europa's surface at several hundred metres per second, and travel up to several metres into the moon's subsurface. To achieve this, the penetrator would be delivered to the surface by a dedicated descent module, to be destroyed on impact following release of the penetrator above the surface. It is planned that the instruments to be

  7. Weld penetration and defect control

    SciTech Connect

    Chin, B.A.

    1992-05-15

    Highly engineered designs increasingly require the use of improved materials and sophisticated manufacturing techniques. To obtain optimal performance from these engineered products, improved weld properties and joint reliability are a necessarily. This requirement for improved weld performance and reliability has led to the development of high-performance welding systems in which pre-programmed parameters are specified before any welding takes place. These automated systems however lack the ability to compensate for perturbations which arise during the welding process. Hence the need for systems which monitor and control the in-process status of the welding process. This report discusses work carried out on weld penetration indicators and the feasibility of using these indicators for on-line penetration control.

  8. [Penetrating injuries to the pelvis].

    PubMed

    Doll, D; Lenz, S; Exadaktylos, A K; Stettbacher, A; Degiannis, E; Düsel, W; Siewert, J R

    2006-09-01

    As criminality and weapon use increase, general and military surgeons are increasingly confronted with penetrating pelvic injuries both at home and on peacekeeping missions. Penetrating injuries to the iliac vascular axis are associated with considerable mortality, and thus the majority of these emergency patients arrive in a state of deep hypovolemic shock. Concomitant bowel injuries are present in one of five cases, resulting in contamination of the damaged area. Surgical options are simple lateral repair, ligation of the veins, temporary shunt insertion, and prosthetic graft interposition in the injured artery. In extremis ligation of the common or external iliac artery may be the only option to save the patient's life. Surgeons must be aware that damage control surgery and related methods may be needed early on to enable patient survival. PMID:16906417

  9. Jeeps Penetrating a Hostile Desert

    ERIC Educational Resources Information Center

    Bailey, Herb

    2009-01-01

    Several jeeps are poised at base camp on the edge of a desert aiming to escort one of them as far as possible into the desert, while the others return to camp. They all have full tanks of gas and share their fuel to maximize penetration. In a friendly desert it is best to leave caches of fuel along the way to help returning jeeps. We solve the…

  10. Penetrating eye injury in war.

    PubMed

    Biehl, J W; Valdez, J; Hemady, R K; Steidl, S M; Bourke, D L

    1999-11-01

    The percentage of penetrating eye injuries in war has increased significantly in this century compared with the total number of combat injuries. With the increasing use of fragmentation weapons and possibly laser weapons on the battle-field in the future, the rate of eye injuries may exceed the 13% of the total military injuries found in Operations Desert Storm/Shield. During the Iran-Iraq War (1980-1988), eye injuries revealed that retained foreign bodies and posterior segment injuries have an improved prognosis in future military ophthalmic surgery as a result of modern diagnostic and treatment modalities. Compared with the increasing penetrating eye injuries on the battlefield, advances in ophthalmic surgery are insignificant. Eye armor, such as visors that flip up and down and protect the eyes from laser injury, needs to be developed. Similar eye protection is being developed in civilian sportswear. Penetrating eye injury in the civilian sector is becoming much closer to the military model and is now comparable for several reasons. PMID:10578588

  11. Network Penetration Testing and Research

    NASA Technical Reports Server (NTRS)

    Murphy, Brandon F.

    2013-01-01

    This paper will focus the on research and testing done on penetrating a network for security purposes. This research will provide the IT security office new methods of attacks across and against a company's network as well as introduce them to new platforms and software that can be used to better assist with protecting against such attacks. Throughout this paper testing and research has been done on two different Linux based operating systems, for attacking and compromising a Windows based host computer. Backtrack 5 and BlackBuntu (Linux based penetration testing operating systems) are two different "attacker'' computers that will attempt to plant viruses and or NASA USRP - Internship Final Report exploits on a host Windows 7 operating system, as well as try to retrieve information from the host. On each Linux OS (Backtrack 5 and BlackBuntu) there is penetration testing software which provides the necessary tools to create exploits that can compromise a windows system as well as other operating systems. This paper will focus on two main methods of deploying exploits 1 onto a host computer in order to retrieve information from a compromised system. One method of deployment for an exploit that was tested is known as a "social engineering" exploit. This type of method requires interaction from unsuspecting user. With this user interaction, a deployed exploit may allow a malicious user to gain access to the unsuspecting user's computer as well as the network that such computer is connected to. Due to more advance security setting and antivirus protection and detection, this method is easily identified and defended against. The second method of exploit deployment is the method mainly focused upon within this paper. This method required extensive research on the best way to compromise a security enabled protected network. Once a network has been compromised, then any and all devices connected to such network has the potential to be compromised as well. With a compromised

  12. Enabling kinetic micro-penetrator technology for Solar System research

    NASA Astrophysics Data System (ADS)

    Gowen, R. A.

    2008-09-01

    , to e.g. simple fins for bodies with atmospheres Whilst a 2Kg payload may be considered to be very low mass we propose that it is sufficient to carry out a comprehensive range of scientific investigations of the highest priority, and can include a chemistry package (e.g. mass spectrometer with drill, doped optical fibres), micro-seismometers and accelerometers, together with a package of environment sensors capable of measuring temperature, heat flow, dielectric constant, radiation levels, magnetic fields, and a descent camera. Other very low mass options also include a subsurface mineralogy/astrobiology camera; simple redox and pH instruments; and a beeping transmitter to allow radio interferometery from Earth to detect surface motions whether seismic or tidally induced. At present most of these payload instruments either have good space heritage but no impact qualification; are very simple; or have been fully space qualified with the previous space hardware developments. The UK penetrator consortium is currently actively pursuing a program to provide full space qualification for most of the above instruments, of which sensor elements of the mass spectrometer, prototype drill component, micro-seismometers, magnetometer, radiation sensors have currently survived the recent (May 2008) impact test at 310ms-1with a worst case 8- 10 degrees attack angle (offset between velocity vector and normal incidence angle) where forces in excess of 10Kgee were experienced. Such a payload is capable of significant sub-surface chemical inventory identification including refactory, organic materials; seismic investigations of the interior of active bodies; sub-surface mechanical information including layering from accelerometers and mineralogy/astrobiology camera, and ground truth from orbiting experiments such as dielectric constant which is particularly relevant to orbiting ground penetrating radar measurements. A descent camera can provide both impact site geophysical context as

  13. Cell type-specific Nogo-A gene ablation promotes axonal regeneration in the injured adult optic nerve

    PubMed Central

    Vajda, F; Jordi, N; Dalkara, D; Joly, S; Christ, F; Tews, B; Schwab, M E; Pernet, V

    2015-01-01

    Nogo-A is a well-known myelin-enriched inhibitory protein for axonal growth and regeneration in the central nervous system (CNS). Besides oligodendrocytes, our previous data revealed that Nogo-A is also expressed in subpopulations of neurons including retinal ganglion cells, in which it can have a positive role in the neuronal growth response after injury, through an unclear mechanism. In the present study, we analyzed the opposite roles of glial versus neuronal Nogo-A in the injured visual system. To this aim, we created oligodendrocyte (Cnp-Cre+/−xRtn4/Nogo-Aflox/flox) and neuron-specific (Thy1-Cretg+xRtn4flox/flox) conditional Nogo-A knock-out (KO) mouse lines. Following complete intraorbital optic nerve crush, both spontaneous and inflammation-mediated axonal outgrowth was increased in the optic nerves of the glia-specific Nogo-A KO mice. In contrast, neuron-specific deletion of Nogo-A in a KO mouse line or after acute gene recombination in retinal ganglion cells mediated by adeno-associated virus serotype 2.Cre virus injection in Rtn4flox/flox animals decreased axon sprouting in the injured optic nerve. These results therefore show that selective ablation of Nogo-A in oligodendrocytes and myelin in the optic nerve is more effective at enhancing regrowth of injured axons than what has previously been observed in conventional, complete Nogo-A KO mice. Our data also suggest that neuronal Nogo-A in retinal ganglion cells could participate in enhancing axonal sprouting, possibly by cis-interaction with Nogo receptors at the cell membrane that may counteract trans-Nogo-A signaling. We propose that inactivating Nogo-A in glia while preserving neuronal Nogo-A expression may be a successful strategy to promote axonal regeneration in the CNS. PMID:25257170

  14. Cell type-specific Nogo-A gene ablation promotes axonal regeneration in the injured adult optic nerve.

    PubMed

    Vajda, F; Jordi, N; Dalkara, D; Joly, S; Christ, F; Tews, B; Schwab, M E; Pernet, V

    2015-02-01

    Nogo-A is a well-known myelin-enriched inhibitory protein for axonal growth and regeneration in the central nervous system (CNS). Besides oligodendrocytes, our previous data revealed that Nogo-A is also expressed in subpopulations of neurons including retinal ganglion cells, in which it can have a positive role in the neuronal growth response after injury, through an unclear mechanism. In the present study, we analyzed the opposite roles of glial versus neuronal Nogo-A in the injured visual system. To this aim, we created oligodendrocyte (Cnp-Cre(+/-)xRtn4/Nogo-A(flox/flox)) and neuron-specific (Thy1-Cre(tg+)xRtn4(flox/flox)) conditional Nogo-A knock-out (KO) mouse lines. Following complete intraorbital optic nerve crush, both spontaneous and inflammation-mediated axonal outgrowth was increased in the optic nerves of the glia-specific Nogo-A KO mice. In contrast, neuron-specific deletion of Nogo-A in a KO mouse line or after acute gene recombination in retinal ganglion cells mediated by adeno-associated virus serotype 2.Cre virus injection in Rtn4(flox/flox) animals decreased axon sprouting in the injured optic nerve. These results therefore show that selective ablation of Nogo-A in oligodendrocytes and myelin in the optic nerve is more effective at enhancing regrowth of injured axons than what has previously been observed in conventional, complete Nogo-A KO mice. Our data also suggest that neuronal Nogo-A in retinal ganglion cells could participate in enhancing axonal sprouting, possibly by cis-interaction with Nogo receptors at the cell membrane that may counteract trans-Nogo-A signaling. We propose that inactivating Nogo-A in glia while preserving neuronal Nogo-A expression may be a successful strategy to promote axonal regeneration in the CNS. PMID:25257170

  15. Management of penetrating brain injury

    PubMed Central

    Kazim, Syed Faraz; Shamim, Muhammad Shahzad; Tahir, Muhammad Zubair; Enam, Syed Ather; Waheed, Shahan

    2011-01-01

    Penetrating brain injury (PBI), though less prevalent than closed head trauma, carries a worse prognosis. The publication of Guidelines for the Management of Penetrating Brain Injury in 2001, attempted to standardize the management of PBI. This paper provides a precise and updated account of the medical and surgical management of these unique injuries which still present a significant challenge to practicing neurosurgeons worldwide. The management algorithms presented in this document are based on Guidelines for the Management of Penetrating Brain Injury and the recommendations are from literature published after 2001. Optimum management of PBI requires adequate comprehension of mechanism and pathophysiology of injury. Based on current evidence, we recommend computed tomography scanning as the neuroradiologic modality of choice for PBI patients. Cerebral angiography is recommended in patients with PBI, where there is a high suspicion of vascular injury. It is still debatable whether craniectomy or craniotomy is the best approach in PBI patients. The recent trend is toward a less aggressive debridement of deep-seated bone and missile fragments and a more aggressive antibiotic prophylaxis in an effort to improve outcomes. Cerebrospinal fluid (CSF) leaks are common in PBI patients and surgical correction is recommended for those which do not close spontaneously or are refractory to CSF diversion through a ventricular or lumbar drain. The risk of post-traumatic epilepsy after PBI is high, and therefore, the use of prophylactic anticonvulsants is recommended. Advanced age, suicide attempts, associated coagulopathy, Glasgow coma scale score of 3 with bilaterally fixed and dilated pupils, and high initial intracranial pressure have been correlated with worse outcomes in PBI patients. PMID:21887033

  16. Investigation of MR signal modulation due to magnetic fields from neuronal currents in the adult human optic nerve and visual cortex.

    PubMed

    Chow, Li Sze; Cook, Greg G; Whitby, Elspeth; Paley, Martyn N J

    2006-07-01

    Neuronal currents produce weak transient magnetic fields, and the hypothesis being investigated here is that the components of these parallel to the B0 field can potentially modulate the MR signal, thus providing a means of direct detection of nerve impulses. A theory for the phase and amplitude changes of the MR signal over time due to an external magnetic field has been developed to predict this modulation. Experimentally, a fast gradient-echo EPI sequence (TR = 158 ms, TE = 32.4 ms) was employed in an attempt to directly detect these neuronal currents in the adult human optic nerve and visual cortex using a 280-mm quadrature head coil at 1.5 T. A symmetrical intravoxel field distribution, which can be plausibly hypothesized for the axonal fields in the optic nerve and visual cortex, would result in phase cancellation within a voxel, and hence, only amplitude changes would be expected. On the other hand, an asymmetrical intravoxel field distribution would produce both phase and amplitude changes. The in vivo magnitude image data sets show a significant nerve firing detection rate of 56%, with zero detection using the phase image data sets. The percentage magnitude signal changes relative to the fully relaxed equilibrium signal fall within a predicted RMS field range of 1.2-2.1 nT in the optic nerve and 0.4-0.6 nT in the visual cortex, according to the hypothesis that the axonal fields create a symmetrical Lorentzian field distribution within the voxel. PMID:16824962

  17. Penetrating Cardiac Nail Gun Injury in a Child.

    PubMed

    Kulaylat, Afif N; Chesnut, Charles H; Patel, Sunil; Rocourt, Dorothy V; Clark, Joseph B

    2016-08-01

    Nail gun injuries primarily occur in the extremities of adult males as a consequence of accidental occupational trauma. Such injury involving the thorax is much less common, and penetrating cardiac injury secondary to pneumatic nail gun discharge is rare. Although potentially lethal, most cases with cardiac trauma are survivable with expedient surgical intervention. Despite improvements in engineered safety mechanisms, the incidence of nail gun injuries has risen as use of the devices has increased. The widespread availability of these tools to nonprofessional consumers exposes a broader population to the potential hazards associated with these devices. We describe the presentation and successful management of the first reported case of penetrating cardiac nail gun injury in a young child. PMID:27018525

  18. Jet penetration of high explosive

    SciTech Connect

    Poulsen, P

    1999-08-11

    It is found that a transition between two flow patterns takes place in thick HE targets. In this case, the jet will initially propagate into the HE at the same rate as into an inert material of the same density. The part of the jet that has stagnated and is flowing nearly co-axially with the incoming jet (but at a much lower speed) is being forced toward the surface of the incoming jet by the pressure of the reaction products but has not as yet made contact. After it makes contact, both axial and perpendicular momentum transfer takes place between the two jet components. After this transition, a new steady state will develop for the propagating jet, with the unperturbed front of the jet propagating at a slower rate than previously. The perturbed front of the jet is still propagating at or near the original rate, having had relatively little axial momentum exchange. However, it has acquired radial momentum and is spreading out as it is propagating; it is therefore becoming less capable of penetrating downstream targets. It is the unperturbed part of the jet that is capable of penetrating downstream targets. A calculational method for predicting this case is presented in this report.

  19. Spontaneous wound dehiscence after penetrating keratoplasty.

    PubMed

    Foroutan, Alireza; Tabatabaei, Seyed Ali; Behrouz, Mahmoud Jabbarvand; Zarei, Reza; Soleimani, Mohammad

    2014-01-01

    Spontaneous wound separation may be developed even months after suture removal especially in the context of long-term corticosteroid therapy. A 68-year-old Caucasian woman presented to our cornea clinic with spontaneous wound dehiscence after her third penetrating keratoplasty (PKP) which was performed three years ago. An Ahmed glaucoma valve (New World Medical, Ranchos Cucamonga, CA) was inserted ten months after the third PKP, which successfully controlled intraocular pressure (IOP). At the examination, the last sutures were removed eight months ago and she was using flourometholone 0.1 % (Sina Darou, Tehran, Iran) with a dose of once a day. There was one quadrant of wound dehiscence from 8 to 11 òclock associated with anterior wound gape and severe corneal edema. Resuturing was performed for the patient. At the one month examination, the corneal edema was resolved and best corrected visual acuity was 20/200 mainly due to previous glaucomatous optic neuropathy. Caution about the prolonged use of corticosteroids is necessary. Topical immunosuppressives could be a promising choice in this field. PMID:25349814

  20. Spontaneous wound dehiscence after penetrating keratoplasty

    PubMed Central

    Foroutan, Alireza; Tabatabaei, Seyed Ali; Behrouz, Mahmoud Jabbarvand; Zarei, Reza; Soleimani, Mohammad

    2014-01-01

    Spontaneous wound separation may be developed even months after suture removal especially in the context of long-term corticosteroid therapy. A 68-year-old Caucasian woman presented to our cornea clinic with spontaneous wound dehiscence after her third penetrating keratoplasty (PKP) which was performed three years ago. An Ahmed glaucoma valve (New World Medical, Ranchos Cucamonga, CA) was inserted ten months after the third PKP, which successfully controlled intraocular pressure (IOP). At the examination, the last sutures were removed eight months ago and she was using flourometholone 0.1 % (Sina Darou, Tehran, Iran) with a dose of once a day. There was one quadrant of wound dehiscence from 8 to 11 òclock associated with anterior wound gape and severe corneal edema. Resuturing was performed for the patient. At the one month examination, the corneal edema was resolved and best corrected visual acuity was 20/200 mainly due to previous glaucomatous optic neuropathy. Caution about the prolonged use of corticosteroids is necessary. Topical immunosuppressives could be a promising choice in this field. PMID:25349814

  1. Tissue Penetration of Antifungal Agents

    PubMed Central

    Felton, Timothy; Troke, Peter F.

    2014-01-01

    SUMMARY Understanding the tissue penetration of systemically administered antifungal agents is critical for a proper appreciation of their antifungal efficacy in animals and humans. Both the time course of an antifungal drug and its absolute concentrations within tissues may differ significantly from those observed in the bloodstream. In addition, tissue concentrations must also be interpreted within the context of the pathogenesis of the various invasive fungal infections, which differ significantly. There are major technical obstacles to the estimation of concentrations of antifungal agents in various tissue subcompartments, yet these agents, even those within the same class, may exhibit markedly different tissue distributions. This review explores these issues and provides a summary of tissue concentrations of 11 currently licensed systemic antifungal agents. It also explores the therapeutic implications of their distribution at various sites of infection. PMID:24396137

  2. A lightweight ground penetrating radar

    SciTech Connect

    Koppenjan, S.K.; Allen, C.M.; Gardner, D.; Wong, H.R.

    1998-12-31

    The detection of buried objects, particularly unexploded ordnance (UXO), has gained significant interest in the US in the late 1990s. The desire to remediate the thousands of sites worldwide has become an increasing humanitarian concern. The application of radar to this problem has received renewed attention. Bechtel Nevada, Special Technologies Laboratory (STL) has developed several frequency modulated, continuous wave (FM-CW) ground penetrating radar (GPR) units for the US Department of Energy since 1984. To meet these new technical requirements for high resolution data and UXO detection, STL is moving forward with advances to GPR technology, signal processing, and imaging with the development of an innovative system. The goal is to design and fabricate a lightweight, battery operated unit that does not require surface contact and can be operated by a novice user.

  3. Cable Braid Electromagnetic Penetration Model.

    SciTech Connect

    Warne, Larry K.; Langston, William L.; Basilio, Lorena I.; Johnson, W. A.

    2015-06-01

    The model for penetration of a wire braid is rigorously formulated. Integral formulas are developed from energy principles and reciprocity for both self and transfer immittances in terms of potentials for the fields. The detailed boundary value problem for the wire braid is also setup in a very efficient manner; the braid wires act as sources for the potentials in the form of a sequence of line multipoles with unknown coefficients that are determined by means of conditions arising from the wire surface boundary conditions. Approximations are introduced to relate the local properties of the braid wires to a simplified infinite periodic planar geometry. This is used in a simplified application of reciprocity to be able to treat nonuniform coaxial geometries including eccentric interior coaxial arrangements and an exterior ground plane.

  4. Microbial keratitis after penetrating keratoplasty.

    PubMed

    Bates, A K; Kirkness, C M; Ficker, L A; Steele, A D; Rice, N S

    1990-01-01

    Thirty cases of microbial keratitis after penetrating keratoplasty were reviewed to examine the associated risk factors, the spectrum of pathogens and the prognosis for graft survival and visual outcome. The indications for keratoplasty in this group differed markedly from those for all corneal grafts performed with a much higher incidence of previous microbial keratitis and of herpes simplex keratitis. A positive culture was obtained in 93% of cases and in contrast to microbial keratitis overall, Gram positive organisms predominated particularly streptococcus pneumoniae and staphylococcus aureus. Risk factors identified were loose or broken sutures, graft decompensation and a poor ocular surface environment. There was a poor prognosis for graft survival with only 23% of cases retaining a clear graft. Overall 53% of cases were regrafted. PMID:2323481

  5. Bodily action penetrates affective perception

    PubMed Central

    Rigutti, Sara; Gerbino, Walter

    2016-01-01

    Fantoni & Gerbino (2014) showed that subtle postural shifts associated with reaching can have a strong hedonic impact and affect how actors experience facial expressions of emotion. Using a novel Motor Action Mood Induction Procedure (MAMIP), they found consistent congruency effects in participants who performed a facial emotion identification task after a sequence of visually-guided reaches: a face perceived as neutral in a baseline condition appeared slightly happy after comfortable actions and slightly angry after uncomfortable actions. However, skeptics about the penetrability of perception (Zeimbekis & Raftopoulos, 2015) would consider such evidence insufficient to demonstrate that observer’s internal states induced by action comfort/discomfort affect perception in a top-down fashion. The action-modulated mood might have produced a back-end memory effect capable of affecting post-perceptual and decision processing, but not front-end perception. Here, we present evidence that performing a facial emotion detection (not identification) task after MAMIP exhibits systematic mood-congruent sensitivity changes, rather than response bias changes attributable to cognitive set shifts; i.e., we show that observer’s internal states induced by bodily action can modulate affective perception. The detection threshold for happiness was lower after fifty comfortable than uncomfortable reaches; while the detection threshold for anger was lower after fifty uncomfortable than comfortable reaches. Action valence induced an overall sensitivity improvement in detecting subtle variations of congruent facial expressions (happiness after positive comfortable actions, anger after negative uncomfortable actions), in the absence of significant response bias shifts. Notably, both comfortable and uncomfortable reaches impact sensitivity in an approximately symmetric way relative to a baseline inaction condition. All of these constitute compelling evidence of a genuine top-down effect on

  6. Proteomic identification of non-erythrocytic alpha-spectrin-1 down-regulation in the pre-optic area of neonatally estradiol-17β treated female adult rats.

    PubMed

    Govindaraj, Vijayakumar; Rao, Addicam Jagannadha

    2016-06-01

    It is well established that sexually dimorphic brain regions, which are critical for reproductive physiology and behavior, are organized by steroid hormones during the first 2 weeks after birth in the rodents. In our recent observation, neonatal exposure to estradiol-17β (E2) in the female rat revealed increase in cyclooxygenase 2 (COX-2) level, sexually dimorphic nucleus (SDN)-pre-optic area (POA) size and down-regulation of synaptogenesis related genes in POA in the adult stage. In the present study, using the same animal model, the protein profile of control and neonatally E2-treated POA was compared by 1D-SDS-PAGE, and the protein that shows a change in abundance was identified by LC-MS/MS analysis. Results indicated that there was a single protein band, which was down-regulation in E2-treated POA and it was identified as spectrin alpha chain, non-erythrocytic 1 (SPTAN1). Consistently, the down-regulation of SPTAN1 expression was also confirmed by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. The SPTAN1 was identified as a cytoskeletal protein that is involved in stabilization of the plasma membrane and organizes intracellular organelles, and it has been implicated in cellular functions including DNA repair and cell cycle regulation. The evidence shows that any mutation in spectrins causes impairment of synaptogenesis and other neurological disorders. Also, protein-protein interaction analysis of SPTAN1 revealed a strong association with proteins such as kirrel, actinin, alpha 4 (ACTN4) and vinculin (VCL) which are implicated in sexual behavior, masculinization and defeminization. Our results indicate that SPTAN1 expression in the developing rat brain is sexually dimorphic, and we suggest that this gene may mediate E2-17β-induced masculinization and defeminization, and disrupted reproductive function in the adult stage. PMID:27166725

  7. Magneto-optical study of flux penetration and critical current densities in [001] tilt YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thin-film bicrystals

    SciTech Connect

    Polyanskii, A.A.; Gurevich, A.; Pashitski, A.E.; Heinig, N.F.; Redwing, R.D.; Nordman, J.E.; Larbalestier, D.C.

    1996-04-01

    Magneto-optical (MO) imaging has been used to visualize and calculate magnetic flux and current distributions at temperatures {ital T} ranging from 7 to 80 K in thin-film [001] tilt YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} bicrystals with misorientation angles 3{degree}{le}{theta}{le}10{degree}. A characteristic cusp in the flux distribution {ital B}{sub {ital z}}({ital x},{ital y}) was observed for 5{degree}{le}{theta}{le}7{degree}, which is shown to indicate that the critical current density {ital J}{sub {ital b}} across the boundary is smaller than the intragrain {ital J}{sub {ital c}}. We use the Bean model for thin-film superconductors to calculate the observed features of the {ital B}{sub {ital z}}({ital x},{ital y}) distribution and to separate both the intragrain {ital J}{sub {ital c}} and intergrain {ital J}{sub {ital b}}({theta}) independently from the MO data. The study of angular and temperature dependencies of {ital J}{sub {ital b}}({ital T},{theta}) in bicrystals with different {theta} shows that {ital J}{sub {ital b}}({theta}) strongly decreases with {theta} above {theta}{approx_equal}5{degree}. The decrease of {ital J}{sub {ital b}}({ital T},{theta}) with temperature becomes weaker as the misorientation angle {theta} is increased, so the substantial difference in {ital J}{sub {ital b}} for 5{degree} and 7{degree} boundaries at low {ital T} turns out to be less pronounced at liquid-nitrogen temperatures. In addition, the ratio {ital J}{sub {ital b}}({theta},{ital T})/{ital J}{sub {ital c}}({ital T}) for low-angle grain boundaries is shown to exhibit an anomalous increase with {ital T}, thus indicating that the grain boundaries can provide additional flux pinning. This is plausibly associated with the grain boundary dislocations that accommodate the misorientation of the grains. {copyright} {ital 1996 The American Physical Society.}

  8. A rheological mechanism of penetrative wear

    NASA Technical Reports Server (NTRS)

    Bates, T. R., Jr.; Ludema, K. C.; Brainard, W. A.

    1974-01-01

    A model is proposed which explains the penetrative wear of a soft material by a harder one. Three distinct modes of penetration are present depending on the applied load. During the most severe penetration plate-like wear debris is ejected at the leading edge of the slider. A series of slip line fields is presented to approximate this debris formation process. Plastic constraint is seen to be an important factor in wear particle formation.

  9. In-place HEPA filter penetration test

    SciTech Connect

    Bergman, W.; Wilson, K.; Elliott, J.

    1997-08-01

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in-place penetration test is practical. 14 refs., 14 figs., 3 tabs.

  10. Ground Penetrating Radar in Hydrogeophysics

    SciTech Connect

    Hubbard, Susan; Lambot, S.; Binley, A.; Slob, E.; Hubbard, S.

    2008-01-15

    To meet the needs of a growing population and to provide us with a higher quality of life, increasing pressures are being placed on our environment through the development of agriculture, industry, and infrastructures. Soil erosion, groundwater depletion, salinization, and pollution have been recognized for decades as major threats to ecosystems and human health. More recently, the progressive substitution of fossil fuels by biofuels for energy production and climate change have been recognized as potential threats to our water resources and sustained agricultural productivity. The vadose zone mediates many of the processes that govern water resources and quality, such as the partition of precipitation into infiltration and runoff , groundwater recharge, contaminant transport, plant growth, evaporation, and energy exchanges between the Earth's surface and its atmosphere. It also determines soil organic carbon sequestration and carbon-cycle feedbacks, which could substantially impact climate change. The vadose zone's inherent spatial variability and inaccessibility precludes direct observation of the important subsurface processes. In a societal context where the development of sustainable and optimal environmental management strategies has become a priority, there is a strong prerequisite for the development of noninvasive characterization and monitoring techniques of the vadose zone. In particular, hydrogeophysical approaches applied at relevant scales are required to appraise dynamic subsurface phenomena and to develop optimal sustainability, exploitation, and remediation strategies. Among existing geophysical techniques, ground penetrating radar (GPR) technology is of particular interest for providing high-resolution subsurface images and specifically addressing water-related questions. Ground penetrating radar is based on the transmission and reception of VHF-UHF (30-3000 MHz) electromagnetic waves into the ground, whose propagation is determined by the soil

  11. Ultrasonic/Sonic Impacting Penetrators

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Sherrit, Stewart; Stark, Randall A.

    2008-01-01

    Ultrasonic/sonic impacting penetrators (USIPs) are recent additions to the series of apparatuses based on ultrasonic/sonic drill corers (USDCs). A USIP enables a rod probe to penetrate packed soil or another substance of similar consistency, without need to apply a large axial force that could result in buckling of the probe or in damage to some buried objects. USIPs were conceived for use in probing and analyzing soil to depths of tens of centimeters in the vicinity of buried barrels containing toxic waste, without causing rupture of the barrels. USIPs could also be used for other purposes, including, for example, searching for pipes, barrels, or other hard objects buried in soil; and detecting land mines. USDCs and other apparatuses based on USDCs have been described in numerous previous NASA Tech Briefs articles. The ones reported previously were designed, variously, for boring into, and/or acquiring samples of, rock or other hard, brittle materials of geological interest. To recapitulate: A USDC can be characterized as a lightweight, low-power, piezoelectrically driven jackhammer in which ultrasonic and sonic vibrations are generated and coupled to a tool bit. As shown in the figure, a basic USDC includes a piezoelectric stack, a backing and a horn connected to the stack, a free mass (free in the sense that it can slide axially a short distance between the horn and the shoulder of tool bit), and a tool bit, i.e., probe for USIP. The piezoelectric stack is driven at the resonance frequency of the stack/horn/backing assembly to create ultrasonic vibrations that are mechanically amplified by the horn. To prevent fracture during operation, the piezoelectric stack is held in compression by a bolt. The bouncing of the free mass between the horn and the tool bit at sonic frequencies generates hammering actions to the bit that are more effective for drilling than is the microhammering action of ultrasonic vibrations in ordinary ultrasonic drills. The hammering actions

  12. Surface keratopathy after penetrating keratoplasty.

    PubMed Central

    Feiz, V; Mannis, M J; Kandavel, G; McCarthy, M; Izquierdo, L; Eckert, M; Schwab, I R; Torabian, S; Wang, J L; Wang, W

    2001-01-01

    PURPOSE: To determine the type and prevalence of epithelial abnormalities in the intermediate postoperative period after penetrating keratoplasty and to define the donor and recipient variables that influence the status of the graft epithelium. DESIGN: Prospective cohort study. METHODS: We prospectively followed the clinical course of 80 patients after penetrating keratoplasty. We monitored the status of the corneal epithelium for 3 months after surgery using slit-lamp biomicroscopy and fluorescein staining of the epithelium. Donor characteristics, recipient preoperative and postoperative variables, and postoperative medications were recorded. Epithelial abnormalities were analyzed against these variables by using univariate and combined statistical models to determine the impact of each variable on postoperative epithelial pathology. Main outcome measures included punctate keratopathy, macro-epithelial defects, hurricane keratopathy, rim defects, and filamentary keratopathy. RESULTS: Sixty-three percent of all patient visits demonstrated punctate epithelial keratopathy (PEK). Hurricane keratopathy (51%) and filamentary keratopathy (14%) constituted the next most commonly observed abnormalities. Older recipient age and the use of topical antibiotics were associated with a higher prevalence of punctate epithelial keratopathy. The odds ratio (OR) for a 1-year increase in age is 1.0276 (95% CI, 1.1013-1.0442), and the OR for using topical antibiotics is 6.9028 (95% CI, 3.1506-15.1239). Use of topical ofloxacin and increased time after surgery were associated with lower prevalence of punctate keratopathy; ORs were 0.9806 (95% CI, 0.9736-0.9876) and 0.3662 (95% CI, 0.1688-0.7943), respectively. Decreased corneal sensation and the presence of anterior blepharitis preoperatively were associated with an increase in hurricane keratopathy; ORs were 8.8265 (CI, 2.3837-32.6835) and 3.2815 (CI, 1.7388-6.1931), respectively. Total storage time for the donor material was also

  13. A high-density EEG study of differences between three high speeds of simulated forward motion from optic flow in adult participants

    PubMed Central

    Vilhelmsen, Kenneth; van der Weel, F. R. (Ruud); van der Meer, Audrey L. H.

    2015-01-01

    A high-density EEG study was conducted to investigate evoked and oscillatory brain activity in response to high speeds of simulated forward motion. Participants were shown an optic flow pattern consisting of a virtual road with moving poles at either side of it, simulating structured forward motion at different driving speeds (25, 50, and 75 km/h) with a static control condition between each motion condition. Significant differences in N2 latencies and peak amplitudes between the three speeds of visual motion were found in parietal channels of interest P3 and P4. As motion speed increased, peak latency increased while peak amplitude decreased which might indicate that higher driving speeds are perceived as more demanding resulting in longer latencies, and as fewer neurons in the motion sensitive areas of the adult brain appear to be attuned to such high visual speeds this could explain the observed inverse relationship between speed and amplitude. In addition, significant differences between alpha de-synchronizations for forward motion and alpha synchronizations in the static condition were found in the parietal midline (PM) source. It was suggested that the alpha de-synchronizations reflect an activated state related to the visual processing of simulated forward motion, whereas the alpha synchronizations in response to the static condition reflect a deactivated resting period. PMID:26578903

  14. Instability of a penetrating blade

    NASA Astrophysics Data System (ADS)

    Bigoni, D.; Bosi, F.; Dal Corso, F.; Misseroni, D.

    2014-03-01

    Application of a dead compressive load at the free end of an elastic rod (the ‘blade') induces its penetration into a sliding sleeve ending with a linear elastic spring. Bifurcation and stability analysis of this simple elastic system shows a variety of unexpected behaviors: (i) an increase of buckling load at decreasing of elastic stiffness; (ii) a finite number of buckling loads for a system with infinite degrees of freedom (leading to a non-standard Sturm-Liouville problem); (iii) more than one bifurcation load associated to each bifurcation mode; (iv) a restabilization of the straight configuration after the second bifurcation load associated to the first instability mode; (v) the presence of an Eshelby-like (or configurational) force, deeply influencing stability. Only the first of these behaviors was previously known, the second and third ones disprove common beliefs, the fourth highlights a sort of ‘island of instability', and the last one shows surprising phenomena and effects on stability.

  15. Foliage penetrating radar imaging system

    NASA Astrophysics Data System (ADS)

    Beaudoin, Christopher J.; Gatesman, Andrew J.; Giles, Robert H.; Waldman, Jerry; Testorf, Markus E.; Fiddy, Michael A.; Nixon, William E.

    2002-12-01

    A far-field radar range has been constructed at the University of Massachusetts Lowell Submillimeter-Wave Technology Laboratory to investigate electromagnetic scattering and imagery of threat military targets located in forested terrain. The radar system, operating at X-band, uses 1/35th scale targets and scenes to acquire VHF/UHF signature data. The trees and ground planes included in the measurement scenes have been dielectrically scaled in order to properly model the target/clutter interaction. The signature libraries acquired by the system could be used to help develop automatic target recognition algorithms. The difficulty in target recognition in forested areas is due to the fact that trees can have a signature larger than that of the target. The rather long wavelengths required to penetrate the foliage canopy also complicate target recognition by limiting image resolution. The measurement system and imaging algorithm will be presented as well as a validation of the measurements obtained by comparing measured signatures with analytical predictions. Preliminary linear co-polarization (HH,VV) and cross-polarization (HV,VH) data will be presented on an M1 tank in both forested and open-field scenarios.

  16. Stepped frequency ground penetrating radar

    DOEpatents

    Vadnais, Kenneth G.; Bashforth, Michael B.; Lewallen, Tricia S.; Nammath, Sharyn R.

    1994-01-01

    A stepped frequency ground penetrating radar system is described comprising an RF signal generating section capable of producing stepped frequency signals in spaced and equal increments of time and frequency over a preselected bandwidth which serves as a common RF signal source for both a transmit portion and a receive portion of the system. In the transmit portion of the system the signal is processed into in-phase and quadrature signals which are then amplified and then transmitted toward a target. The reflected signals from the target are then received by a receive antenna and mixed with a reference signal from the common RF signal source in a mixer whose output is then fed through a low pass filter. The DC output, after amplification and demodulation, is digitized and converted into a frequency domain signal by a Fast Fourier Transform. A plot of the frequency domain signals from all of the stepped frequencies broadcast toward and received from the target yields information concerning the range (distance) and cross section (size) of the target.

  17. Penetrating Wounds of Great Vessels

    PubMed Central

    Symbas, P. N.; Kourias, E.; Tyras, D. H.; Hatcher, C. R.

    1974-01-01

    Thirty-six patients with penetrating wounds of the great vessels treated at Grady Memorial Hospital during a 7-year period were reviewed. In more than 50% of the cases, diagnosis of the injury was made at the time of emergency thoracotomy for massive bleeding. In the remaining patients the diagnosis was suspected: 1) when the pulse distal to the vascular injury was absent or weak; 2) when the patient had symptoms and signs of impaired central nervous system perfusion; 3) when the missile had traversed the mediastinum and there was roentgenographic evidence of widening of the mediastinal shadow; or, 4) when a new murmur appeared. In all suspected cases with great vessel injury, the diagnosis was confirmed arteriographically. Arteriography in such patients should be performed to define the type and site of vascular injury so that its repair can be properly planned. Twenty-nine patients recovered from their injury, 6 succumbed as a result of it and 1 required midforearm amputation following repair of a subclavian artery and vein injury. Most of these patients underwent autotransfusion which greatly contributed to their successful outcome. Local temporary shunt was used for protection of the spinal cord and/or brain when impairment of their perfusion was required for the repair of the vascular wounds. ImagesFig. 1.Fig. 3.Fig. 4. PMID:17859862

  18. Enabling kinetic micro-penetrator technology for Solar System research

    NASA Astrophysics Data System (ADS)

    Gowen, R. A.

    2008-09-01

    , to e.g. simple fins for bodies with atmospheres Whilst a 2Kg payload may be considered to be very low mass we propose that it is sufficient to carry out a comprehensive range of scientific investigations of the highest priority, and can include a chemistry package (e.g. mass spectrometer with drill, doped optical fibres), micro-seismometers and accelerometers, together with a package of environment sensors capable of measuring temperature, heat flow, dielectric constant, radiation levels, magnetic fields, and a descent camera. Other very low mass options also include a subsurface mineralogy/astrobiology camera; simple redox and pH instruments; and a beeping transmitter to allow radio interferometery from Earth to detect surface motions whether seismic or tidally induced. At present most of these payload instruments either have good space heritage but no impact qualification; are very simple; or have been fully space qualified with the previous space hardware developments. The UK penetrator consortium is currently actively pursuing a program to provide full space qualification for most of the above instruments, of which sensor elements of the mass spectrometer, prototype drill component, micro-seismometers, magnetometer, radiation sensors have currently survived the recent (May 2008) impact test at 310ms-1with a worst case 8- 10 degrees attack angle (offset between velocity vector and normal incidence angle) where forces in excess of 10Kgee were experienced. Such a payload is capable of significant sub-surface chemical inventory identification including refactory, organic materials; seismic investigations of the interior of active bodies; sub-surface mechanical information including layering from accelerometers and mineralogy/astrobiology camera, and ground truth from orbiting experiments such as dielectric constant which is particularly relevant to orbiting ground penetrating radar measurements. A descent camera can provide both impact site geophysical context as

  19. Transnasal, intracranial penetrating injury treated endoscopically.

    PubMed

    Cetinkaya, Erdem Atalay; Okan, Cinemre; Pelin, Kesapli

    2006-04-01

    Intracranial penetrating injury through the nose is uncommon. We present the case of a four-year-old girl who sustained a transnasal, intracranial penetrating injury with a sharp wooden object. We performed endoscopic removal of the foreign body and repair of the associated cerebrospinal fluid fistula. PMID:16623978

  20. Social Penetration: A Description, Research, and Evaluation.

    ERIC Educational Resources Information Center

    Allensworth, Nicole J.

    Social penetration has been described by S.W. Littlejohn (1992) as "the process of increasing disclosure and intimacy in a relationship." The phrase "social penetration" originated with I. Altman and D. Taylor, the foremost researchers in this area. From other theories, Altman and Taylor developed a unified theory which provided a stable base from…

  1. FRACTIONAL PENETRATION OF PAINT OVERSPRAY ARRESTORS

    EPA Science Inventory

    The report describes the development of fractional penetration curves for liquid droplet penetration of overspray arrestors for discrete droplet diameters from 0.3 to 10 micrometers. (NOTE: Fine particulates are particles with diameters of 10 micrometers or less.) These data poin...

  2. Fluorescent penetration enhancers for transdermal applications.

    PubMed

    Seto, Jennifer E; Polat, Baris E; VanVeller, Brett; Lopez, Renata F V; Langer, Robert; Blankschtein, Daniel

    2012-02-28

    Chemical penetration enhancers are often used to enhance transdermal drug delivery. However, the fundamental mechanisms that govern the interactions between penetration enhancers and skin are not fully understood. Therefore, the goal of this work was to identify naturally fluorescent penetration enhancers (FPEs) in order to utilize well-established fluorescence techniques to directly study the behavior of FPEs within skin. In this study, 12 fluorescent molecules with amphiphilic characteristics were evaluated as skin penetration enhancers. Eight of the molecules exhibited significant activity as skin penetration enhancers, determined using skin current enhancement ratios. In addition, to illustrate the novel, direct, and non-invasive visualization of the behavior of FPEs within skin, three case studies involving the use of two-photon fluorescence microscopy (TPM) are presented, including visualizing glycerol-mitigated and ultrasound-enhanced FPE skin penetration. Previous TPM studies have indirectly visualized the effect of penetration enhancers on the skin by using a fluorescent dye to probe the transdermal pathways of the enhancer. These effects can now be directly visualized and investigated using FPEs. Finally, future studies are proposed for generating FPE design principles. The combination of FPEs with fluorescence techniques represents a useful novel approach for obtaining physical insights on the behavior of penetration enhancers within the skin. PMID:22062691

  3. USDC based rapid penetrator of packed soil

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Sherrit, Stewart; Badescu, Mircea

    2006-01-01

    Environment protection requires more testing and analysis tools. To detect buried chemical containers or other objects embedded in soil and avoid possible damages of them, a penetrator of packed soil operated using low pushing force was developed. The design was based on a novel driving mechanism of the ultrasonic/sonic driller/corer (USDC) device developed in the NDEAA lab at JPL [Bar-Cohen et al 2001, Bao et al 2003]. In the penetrator, a small free-flying mass is energized by a piezoelectric transducer and impacts a rod probe on its shoulder at frequencies of hundreds times per second. The impacts help the probe to penetrate the packed soil rapidly. A great reduction of the needed pushing force for penetration was achieved. The details of the design of the prototype penetrator and the results of performance tests are presented.

  4. Bouncing motion and penetration dynamics in multicomponent Bose-Einstein condensates

    NASA Astrophysics Data System (ADS)

    Eto, Yujiro; Takahashi, Masahiro; Nabeta, Keita; Okada, Ryotaro; Kunimi, Masaya; Saito, Hiroki; Hirano, Takuya

    2016-03-01

    We investigate the dynamic properties of bouncing and penetration in colliding binary and ternary Bose-Einstein condensates comprised of different Zeeman or hyperfine states of 87Rb. Through the application of magnetic field gradient pulses, two- or three-component condensates in an optical trap are spatially separated and then made to collide. The subsequent evolutions are classified into two categories: repeated bouncing motion and mutual penetration after damped bounces. We experimentally observed mutual penetration for immiscible condensates, bouncing between miscible condensates, and domain formation for miscible condensates. From numerical simulations of the Gross-Pitaevskii equation, we find that the penetration time can be tuned by slightly changing the atomic interaction strengths.

  5. Closed Loop Control of Penetration Depth during CO2 Laser Lap Welding Processes

    PubMed Central

    Sibillano, Teresa; Rizzi, Domenico; Mezzapesa, Francesco P.; Lugarà, Pietro Mario; Konuk, Ali Riza; Aarts, Ronald; Veld, Bert Huis in 't; Ancona, Antonio

    2012-01-01

    In this paper we describe a novel spectroscopic closed loop control system capable of stabilizing the penetration depth during laser welding processes by controlling the laser power. Our novel approach is to analyze the optical emission from the laser generated plasma plume above the keyhole, to calculate its electron temperature as a process-monitoring signal. Laser power has been controlled by using a quantitative relationship between the penetration depth and the plasma electron temperature. The sensor is able to correlate in real time the difference between the measured electron temperature and its reference value for the requested penetration depth. Accordingly the closed loop system adjusts the power, thus maintaining the penetration depth. PMID:23112646

  6. Closed loop control of penetration depth during CO₂ laser lap welding processes.

    PubMed

    Sibillano, Teresa; Rizzi, Domenico; Mezzapesa, Francesco P; Lugarà, Pietro Mario; Konuk, Ali Riza; Aarts, Ronald; Veld, Bert Huis In 't; Ancona, Antonio

    2012-01-01

    In this paper we describe a novel spectroscopic closed loop control system capable of stabilizing the penetration depth during laser welding processes by controlling the laser power. Our novel approach is to analyze the optical emission from the laser generated plasma plume above the keyhole, to calculate its electron temperature as a process-monitoring signal. Laser power has been controlled by using a quantitative relationship between the penetration depth and the plasma electron temperature. The sensor is able to correlate in real time the difference between the measured electron temperature and its reference value for the requested penetration depth. Accordingly the closed loop system adjusts the power, thus maintaining the penetration depth. PMID:23112646

  7. Modeling pollutant penetration across building envelopes

    SciTech Connect

    Liu, De-Ling; Nazaroff, William W.

    2001-04-01

    As air infiltrates through unintentional openings in building envelopes, pollutants may interact with adjacent surfaces. Such interactions can alter human exposure to air pollutants of outdoor origin. We present modeling explorations of the proportion of particles and reactive gases (e.g., ozone) that penetrate building envelopes as air enters through cracks and wall cavities. Calculations were performed for idealized rectangular cracks, assuming regular geometry, smooth inner crack surface and steady airflow. Particles of 0.1-1.0 {micro}m diameter are predicted to have the highest penetration efficiency, nearly unity for crack heights of 0.25 mm or larger, assuming a pressure difference of 4 Pa or greater and a flow path length of 3 cm or less. Supermicron and ultrafine particles are significantly removed by means of gravitational settling and Brownian diffusion, respectively. In addition to crack geometry, ozone penetration depends on its reactivity with crack surfaces, as parameterized by the reaction probability. For reaction probabilities less than {approx}10{sup -5}, penetration is complete for cracks heights greater than 1 mm. However, penetration through mm scale cracks is small if the reaction probability is {approx}10{sup -4} or greater. For wall cavities, fiberglass insulation is an efficient particle filter, but particles would penetrate efficiently through uninsulated wall cavities or through insulated cavities with significant airflow bypass. The ozone reaction probability on fiberglass fibers was measured to be 10{sup -7} for fibers previously exposed to high ozone levels and 6 x 10{sup -6} for unexposed fibers. Over this range, ozone penetration through fiberglass insulation would vary from >90% to {approx}10-40%. Thus, under many conditions penetration is high; however, there are realistic circumstances in which building envelopes can provide substantial pollutant removal. Not enough is yet known about the detailed nature of pollutant penetration

  8. Mechanisms of imiquimod skin penetration.

    PubMed

    Telò, Isabella; Pescina, Silvia; Padula, Cristina; Santi, Patrizia; Nicoli, Sara

    2016-09-10

    Imiquimod (IMQ) ia an immunostimulating drug used for the treatment of neoplastic skin diseases, such as actinic keratosis (AK) and superficial basal cell carcinoma (sBCC), and as adjuvant for vaccination. Imiquimod formulation and skin delivery is highly challenging because of its very low solubility in most pharmaceutical excipients and poor penetration properties. Objectives of the work were: (1) to evaluate IMQ solubility in different solvents and pharmaceutical excipients; (2) to evaluate IMQ skin retention after the application of simple saturated solutions; (3) to evaluate the role of stratum corneum and solvent uptake on IMQ skin retention and (4) to formulate IMQ in microemulsions - prepared using previously investigated components - and compare them with the commercial formulation. The results show that IMQ solubility is not related to the solubility parameter of the solvents considered. The highest solubility was found with oleic acid (74mg/ml); in the case of PEGs, the solubility increased linearly with MW (PEG 200: 1.9mg/ml; PEG 400 7.3mg/ml, PEG 600 12.8mg/ml). Imiquimod skin retention from saturated solutions (Tween 80, oleic acid, propylene glycol, PEG 200, PEG 400, PEG 600, Transcutol, 2-pyrrolidone, DMSO) resulted relatively similar, being 1.6μg/cm(2) in case of oleic acid (solubility 74mg/ml) and 0.18μg/cm(2) in case of propylene glycol (solubility 0.60mg/ml). Permeation experiments on stripped skin (no stratum corneum) and isolated dermis as well as uptake experiments on isolated stratum corneum sheets demonstrated that IMQ accumulation is related to skin solvent uptake. Finally, microemulsions (MEs) prepared with the above-studied components demonstrated a very good performance. In particular, a ME composed of 10% oleic acid, 35% Transcutol, 35% Tween 80 and 20% water is able to accumulate the same amount of drug as the commercial formulation but with far more efficiency, since its concentration was 12 times lower. PMID:27452419

  9. GNOME: an earth-penetrator code

    SciTech Connect

    Davie, N.T.; Richgels, M.A.

    1983-05-01

    The earth penetrator code GNOME is described, and its capabilities are illustrated by comparisons of computed results with actual field test data. GNOME uses decoupled approximate solution techniques to calculate the rigid body response of an earth penetrator. A modular structured programming method is employed, which allows a variety of pressure generating algorithms to be used without altering the basic program modules which consist of a time integrator and output routines. GNOME calculates axial and lateral loading on a cylindrical penetrator with an ogival or conical nose, but other geometrical shapes may be easily substituted for these by utilizing the modular program structure.

  10. Pressure enhanced penetration with shaped charge perforators

    DOEpatents

    Glenn, Lewis A.

    2001-01-01

    A downhole tool, adapted to retain a shaped charge surrounded by a superatmospherically pressurized light gas, is employed in a method for perforating a casing and penetrating reservoir rock around a wellbore. Penetration of a shaped charge jet can be enhanced by at least 40% by imploding a liner in the high pressure, light gas atmosphere. The gas pressure helps confine the jet on the axis of penetration in the latter stages of formation. The light gas, such as helium or hydrogen, is employed to keep the gas density low enough so as not to inhibit liner collapse.

  11. Earthquakes induced by deep penetrating bombing?

    NASA Astrophysics Data System (ADS)

    Balassanian, Serguei Y.

    2005-11-01

    The data of M≥5 earthquakes occurred in one year before and after 4 deep penetrating bombs in the region within 500 km and 1 000 km from the shooting site are presented. The 4 bombs are those happened in 1999 Kosovo of Yugoslavia, the 1991 Baghdad of Iraq, the 2001 Tora Bora of Afghanistan, and the 2003 Kirkuk of Iraq, respectively. The data indicate that the deep penetrating bombs may have remotely triggered some earthquakes. The deep penetrating bombs in seismically active regions should be forbidden.

  12. Penetration depth measurement of near-infrared hyperspectral imaging light for milk powder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The increasingly common application of near-infrared (NIR) hyperspectral imaging technique to the analysis of food powders has led to the need for optical characterization of samples. This study was aimed at exploring the feasibility of quantifying penetration depth of NIR hyperspectral imaging ligh...

  13. Non-normal impact of earth penetrators

    SciTech Connect

    Duffey, T.A.; Macek, R.W.

    1996-12-31

    A brief literature review of the general subject of projectile penetration into soil media is presented. Particular emphasis is placed on projectiles impacting soil targets at other than normal incidence and/or at an angle of attack, for which lateral accelerations exist and can dominate the structural response. Comparisons of predicted lateral accelerations with recent earth penetrator experiments are then made using a 3 degree-of-freedom rigid-body approach developed elsewhere to determine the external penetrator loading. Agreement between experimental and calculated accelerations is favorable, but the need to include flexible-body response is indicated. Finally a scheme to incorporate a spherical-cavity-expansion analytical procedure into a detailed finite element model of the penetrator is developed to account for flexible-body response.

  14. Laser weld penetration estimation using temperature measurements

    SciTech Connect

    Lankalapalli, K.N.; Tu, J.F.; Leong, K.H.; Gartner, M.

    1997-10-01

    Penetration depth is an important factor critical to the quality of a laser weld. This paper examines the feasibility of using temperature measurements on the bottom surface of the work-piece to estimate weld penetration. A three-dimensional analytical model relating penetration depth, weld bead width and welding speed to temperature distribution at the bottom surface of the workpiece is developed. Temperatures on the bottom surface of the workpiece are measured using infrared thermocouples located behind the laser beam. Experimental results from bead-on-plate welds on low carbon steel plates of varying thickness at different levels of laser power and speeds validate the model and show that the temperature on the bottom surface is a sensitive indicator of penetration depth. The proposed model is computationally efficient and is suitable for on-line process monitoring application.

  15. Results of analyses performed on basalt adjacent to penetrators emplaced into volcanic rock at Amboy, California, April 1976

    NASA Technical Reports Server (NTRS)

    Blanchard, M.; Bunch, T.; Davis, A.; Shade, H.; Erlichman, J.; Polkowski, G.

    1977-01-01

    The physical and chemical modifications found in the basalt after impact of four penetrators were studied. Laboratory analyses show that mineralogical and elemental changes are produced in the powdered and crushed basalt immediately surrounding the penetrator. Optical microscopy studies of material next to the skin of the penetrator revealed a layer, 0-2 mm thick, of glass and abraded iron alloy mixed with fractured mineral grains of basalt. Elemental analysis of the 0-2 mm layer revealed increased concentrations of Fe, Cr, Ni, No, and Mn, and reduced concentrations of Mg, Al, Si, and Ca. The Fe, Cr, Ni, and Mo were in fragments abraded from the penetrator. Mineralogical changes occurring in the basalt sediment next to the penetrator include the introduction of micron-size grains of alpha-iron, magnetite, and hematite. The newly formed silicate minerals include metastable phases of silica (tridymite and cristobalite). An increased concentration of Fe, Cr, Ni, and Mo occurred in the 2-mm to 1-cm layer of penetrator no. 1, which impacted at the highest velocity. No elemental concentration increase was noted for penetrators nos. 2 and 3 in the 2-mm to 1-cm layer. Contaminants introduced by the penetrator occur up to 1 cm away from the penetrator's skin. Although volatile elements do migrate and new minerals are formed during the destruction of host minerals in the crushed rock, no changes were observed beyond the 1-cm distance.

  16. Structural response measurements to insure penetrator data integrity

    SciTech Connect

    Bateman, V.I.; Mayes, R.L.; James, G.H. III

    1993-09-01

    Measurements made by a penetrator structure penetration of some medium may not measure the penetration environment directly. In general, the measurements quantify the penetrator`s structural response to the penetrator force environment. This paper reports laboratory testing and analysis techniques that have been used to identify and/or remove highly nonlinear responses which can mask the penetration environments one desires to measure. Results for two penetrator structures are presented. For the first penetrator, shock testing was conducted to determine the cause of accelerometer failure during field tests. For a second penetrator, shock testing was conducted to assist with the interpretation of accelerometer measurements made during field tests for which the penetrator was instrumented with one axial accelerometer. Very high acceleration levels for a data bandwidth of DC to 70 kHz were recorded in these field tests. The laboratory test results for these two penetrators are presented and discussed.

  17. Low Force Penetration of Icy Regolith

    NASA Technical Reports Server (NTRS)

    Mantovani, J. G.; Galloway, G. M.; Zacny, K.

    2016-01-01

    A percussive cone penetrometer measures the strength of granular material by using percussion to deliver mechanical energy into the material. A percussive cone penetrometer was used in this study to penetrate a regolith ice mixture by breaking up ice and decompacting the regolith. As compared to a static cone penetrometer, percussion allows low reaction forces to push a penetrometer probe tip more easily into dry regolith in a low gravity environment from a planetary surface rover or a landed spacecraft. A percussive cone penetrates icy regolith at ice concentrations that a static cone cannot penetrate. In this study, the percussive penetrator was able to penetrate material under 65 N of down-force which could not be penetrated using a static cone under full body weight. This paper discusses using a percussive cone penetrometer to discern changes in the concentration of water-ice in a mixture of lunar regolith simulant and ice to a depth of one meter. The rate of penetration was found to be a function of the ice content and was not significantly affected by the down-force. The test results demonstrate that this method may be ideal for a small platform in a reduced gravity environment. However, there are some cases where the system may not be able to penetrate the icy regolith, and there is some risk of the probe tip becoming stuck so that it cannot be retracted. It is also shown that a percussive cone penetrometer could be used to prospect for water ice in regolith at concentrations as high as 8 by weight.

  18. Partial penetrance facilitates developmental evolution in bacteria

    PubMed Central

    Eldar, Avigdor; Chary, Vasant; Xenopoulos, Panagiotis; Fontes, Michelle E.; Loson, Oliver C.; Dworkin, Jonathan; Piggot, Patrick; Elowitz, Michael B.

    2009-01-01

    Development normally occurs similarly in all individuals within an isogenic population, but mutations often affect the fate of individual organisms differently1-4. This phenomenon, known as partial penetrance, has been observed in diverse developmental systems. However, it remains unclear how the underlying genetic network specifies the set of possible alternative fates and how the relative frequencies of these fates evolve5-8. Here, we identify a stochastic cell fate determination process that operates in Bacillus subtilis sporulation mutants and show how it allows genetic control of the penetrance of multiple fates. Mutations in an inter-compartmental signaling process generate a set of discrete alternative fates not observed in wild-type cells, including rare formation of two viable “twin” spores, rather than one within a single cell. By genetically modulating chromosome replication and septation, we could systematically tune the penetrance of each mutant fate. Furthermore, signaling and replication perturbations synergize to dramatically increase the penetrance of twin sporulation. These results suggest a potential pathway for developmental evolution between monosporulation and twin sporulation through states of intermediate twin penetrance. Furthermore, time-lapse microscopy of twin sporulation in wild-type Clostridium oceanicum showed a strong resemblance to twin sporulation in these B. subtilis mutants9,10. Together the results suggest that noise can facilitate developmental evolution by enabling the initial expression of discrete morphological traits at low penetrance, and allowing their stabilization by gradual adjustment of genetic parameters. PMID:19578359

  19. Penetration of Bdellovibrio bacteriovorus into Host Cells

    PubMed Central

    Abram, Dinah; e Melo, J. Castro; Chou, D.

    1974-01-01

    Electron microscopy reveals that, in Bdellovibrio infection, after the formation of a passage pore in the host cell wall, the differentiated parasite penetration pole is associated with the host protoplast. This firm contact persists throughout the parasite penetration and after this process is completed. In penetrated hosts this contact is also apparent by phase microscopy. The association between the walls of the parasite and the host at the passage pore, on the other hand, is transient. Bdellovibrio do not penetrate hosts whose protoplast and cell walls are separated by plasmolysis, or in which the membrane-wall relationship is affected by low turgor pressure. It is concluded, therefore, that for penetration to occur it is essential that the host protoplast be within reach of the parasite, so that a firm contact can be established between them. A penetration mechanism is proposed that is effected by forces generated by fluxes of water and solutes due to structural changes in the infected host envelope. These forces cause a differential expansion of the host protoplast and cell wall and their separation from each other around the entry site, while the parasite remains firmly anchored to the host protoplast. Consequently, the parasite ends up enclosed in the expanded host periplasm. The actual entry, therefore, is a passive act of the parasite. Images PMID:4208138

  20. Are cognitive outcome and recovery different in civilian penetrating versus non-penetrating brain injuries?

    PubMed

    Ylioja, Shelley; Hanks, Robin; Baird, Anne; Millis, Scott

    2010-10-01

    The present study sought to determine whether cognitive outcome and course of recovery in civilian penetrating brain injury due to gunshot can be distinguished from that of non-penetrating brain injury due to motor vehicle accident. Matched survivors of penetrating and non-penetrating brain injury were assessed with a brief neuropsychological test battery at inpatient rehabilitation, 1 year post-injury, and 2 years post-injury. The traumatic brain injury groups were found to have patterns of performance marked by reliably distinct differences in isolated areas, with different cognitive predictors of brain injury type present in early versus later recovery. The degree of recovery over the first 2 years appeared to be quite similar for penetrating and non-penetrating injuries. PMID:20924980

  1. Penetration of cefotaxime into respiratory secretions.

    PubMed Central

    Fick, R B; Alexander, M R; Prince, R A; Kasik, J E

    1987-01-01

    The objective of this study was to quantitate cefotaxime and its active metabolite, desacetyl cefotaxime, in the distal airways and to compare these levels to concentrations in plasma. Respiratory secretions were obtained from the subsegmental level in 17 adult patients undergoing fiber-optic bronchoscopy within 2 h after receiving four doses of cefotaxime (2 g intravenously every 6 h). In 11 patients, cefotaxime levels measured by high-pressure liquid chromatography in bronchial secretions were below detectable limits (less than 0.5 mg/liter); however, levels of desacetyl cefotaxime exceeded 1.5 mg/liter in 9 of these 11 patients (range, 1.6 to 10 mg/liter). Concentrations of desacetyl cefotaxime in lung secretions (6.9 +/- 0.85 [standard error] mg/liter) was 77% of mean levels of desacetyl cefotaxime in plasma (8.9 +/- 1.26 mg/liter). In summary, concentrations of desacetyl cefotaxime in bronchial secretions are markedly higher than those of cefotaxime. PMID:3606080

  2. Urokinase-controlled tumor penetrating peptide.

    PubMed

    Braun, Gary B; Sugahara, Kazuki N; Yu, Olivia M; Kotamraju, Venkata Ramana; Mölder, Tarmo; Lowy, Andrew M; Ruoslahti, Erkki; Teesalu, Tambet

    2016-06-28

    Tumor penetrating peptides contain a cryptic (R/K)XX(R/K) CendR element that must be C-terminally exposed to trigger neuropilin-1 (NRP-1) binding, cellular internalization and malignant tissue penetration. The specific proteases that are involved in processing of tumor penetrating peptides identified using phage display are not known. Here we design de novo a tumor-penetrating peptide based on consensus cleavage motif of urokinase-type plasminogen activator (uPA). We expressed the peptide, uCendR (RPARSGR↓SAGGSVA, ↓ shows cleavage site), on phage or coated it onto silver nanoparticles and showed that it is cleaved by uPA, and that the cleavage triggers binding to recombinant NRP-1 and to NPR-1-expressing cells. Upon systemic administration to mice bearing uPA-overexpressing breast tumors, FAM-labeled uCendR peptide and uCendR-coated nanoparticles preferentially accumulated in tumor tissue. We also show that uCendR phage internalization into cultured cancer cells and its penetration in explants of murine tumors and clinical tumor explants can be potentiated by combining the uCendR peptide with tumor-homing module, CRGDC. Our work demonstrates the feasibility of designing tumor-penetrating peptides that are activated by a specific tumor protease. As upregulation of protease expression is one of the hallmarks of cancer, and numerous tumor proteases have substrate specificities compatible with proteolytic unmasking of cryptic CendR motifs, the strategy described here may provide a generic approach for designing proteolytically-actuated peptides for tumor-penetrative payload delivery. PMID:27106816

  3. Enhanced chlorhexidine skin penetration with eucalyptus oil

    PubMed Central

    2010-01-01

    Background Chlorhexidine digluconate (CHG) is a widely used skin antiseptic, however it poorly penetrates the skin, limiting its efficacy against microorganisms residing beneath the surface layers of skin. The aim of the current study was to improve the delivery of chlorhexidine digluconate (CHG) when used as a skin antiseptic. Method Chlorhexidine was applied to the surface of donor skin and its penetration and retention under different conditions was evaluated. Skin penetration studies were performed on full-thickness donor human skin using a Franz diffusion cell system. Skin was exposed to 2% (w/v) CHG in various concentrations of eucalyptus oil (EO) and 70% (v/v) isopropyl alcohol (IPA). The concentration of CHG (μg/mg of skin) was determined to a skin depth of 1500 μm by high performance liquid chromatography (HPLC). Results The 2% (w/v) CHG penetration into the lower layers of skin was significantly enhanced in the presence of EO. Ten percent (v/v) EO in combination with 2% (w/v) CHG in 70% (v/v) IPA significantly increased the amount of CHG which penetrated into the skin within 2 min. Conclusion The delivery of CHG into the epidermis and dermis can be enhanced by combination with EO, which in turn may improve biocide contact with additional microorganisms present in the skin, thereby enhancing antisepsis. PMID:20860796

  4. Results of analyses performed on soil adjacent to penetrators emplaced into sediments at McCook, Nebraska, January 1976. [simulated penetration into wind-deposited sediments on Martian plains

    NASA Technical Reports Server (NTRS)

    Blanchard, M.; Bunch, T.; Davis, A.; Kyte, F.; Shade, H.; Erlichman, J.; Polkowski, G.

    1977-01-01

    During 1976 several penetrators (full and 0.58 scale) were dropped into a test site McCook, Nebraska. The McCook site was selected because it simulated penetration into wind-deposited sediments (silts and sands) on Martian plains. The physical and chemical modifications found in the sediment after the penetrators' impact are described. Laboratory analyses have shown mineralogical and elemental changes are produced in the sediment next to the penetrator. Optical microscopy studies of material next to the skin of the penetrator revealed a layer of glassy material about 75 microns thick. Elemental analysis of a 0-1-mm layer of sediment next to the penetrator revealed increased concentrations for Cr, Fe, Ni, Mo, and reduced concentrations for Mg, Al Si, P, K, and Ca. The Cr, Fe, Ni, and Mo were in fragments abraded from the penetrator. Mineralogical changes occurring in the sediment next to the penetrator included the introduction of micron-size grains of alpha iron and several hydrated iron oxide minerals. The newly formed silicate minerals include metastable phases of silica (cristobalite, lechatelierite, and opal). The glassy material was mostly opal which formed when the host minerals (mica, calcite, and clay) decomposed. In summary, contaminants introduced by the penetrator occur up to 2 mm away from the penetrator's skin. Although volatile elements do migrate and new minerals are formed during the destruction of host minerals in the sediment, no changes were observed beyond the 2-mm distance. The analyses indicate 0.58-scale penetrators do effectively simulate full-scale testing for soil modification effects.

  5. Penetrators (penetrating sondes) and new possibilities for study of the planets

    NASA Technical Reports Server (NTRS)

    Davydov, V. D.; Skuridin, G. A.

    1979-01-01

    The fields of possible use of penetrators in space research are considered. A survey of the condition of development and plans for use of penetrators abroad is presented and an analysis is given of the significance of scientific problems when probing planets.

  6. METHOD AND APPARATUS FOR EARTH PENETRATION

    DOEpatents

    Adams, W.M.

    1963-12-24

    A nuclear reactor apparatus for penetrating into the earth's crust is described. The apparatus comprises a cylindrical nuclear core operating at a temperature that is higher than the melting temperature of rock. A high-density ballast member is coupled to the nuclear core such that the overall density of the core-ballast assembly is greater than the density of molten rock. The nuclear core is thermally insulated so that its heat output is constrained to flow axially, with radial heat flow being minimized. In operation, the apparatus is placed in contact with the earth's crust at the point desired to be penetrated. The heat output of the reactor melts the underlying rock, and the apparatus sinks through the resulting magma. The fuel loading of the reactor core determines the ultimate depth of crust penetration. (AEC)

  7. Penetration drag in loosely packed granular materials

    NASA Astrophysics Data System (ADS)

    Bless, Stephan; Omidvar, Mehdi; Iskander, Magued; New York University Collaboration

    2015-03-01

    The drag coefficient for penetration of granular materials by conical-nosed penetrators was computed by assuming the particles are non-interacting and rebound elastically off of the advancing penetrator. The solution was C =4 [sin(theta)]**2, where theta is the half angle of the cone. Experiments were conducted in which the drag coefficient was measured over the range 30 to 80 m/s for four types of sand: Ottawa silica sand, crushed quartz glass, coral sand, and aragonite sand. The sands were tested at relative densities of 40 and 80%. The drag coefficients for the low density materials were in excellent agreement with this simple model. The high density material had a drag considerably larger than predicted, presumably because of particle-to-particle interactions.

  8. Sunshot Initiative High Penetration Solar Portal

    DOE Data Explorer

    The DOE SunShot Initiative is a collaborative national initiative to make solar energy cost-competitive with other forms of energy by the end of the decade. Reducing the installed cost of solar energy systems by about 75% will drive widespread large-scale adoption of this renewable energy and restore U.S. leadership in the global clean energy race. The High Penetration Solar Portal was created as a resource to aggregate the most relevant and timely information related to high penetration solar scenarios and integrating solar into the grid. The site is designed so that utilities, grant awardees, regulators, researchers, and other solar professionals can easily share data, case studies, lessons learned, and demonstration project findings. [from https://solarhighpen.energy.gov/about_the_high_penetration_solar_portal

  9. Compressibility effects in shaped charge jet penetration

    NASA Astrophysics Data System (ADS)

    Haugstad, B. S.

    1981-03-01

    Among other hypotheses, the classical theory of high-speed penetration assumes the incompressibility of both the projectile and target. Employing a simple Murnaghan equation of state, we show here that direct compressibility effects (pv-work) on penetration depth are at most on the order of 10-15% for projectile speeds as high as 104 ms-1. Our results agree closely with similar results by Coombs (private communication, Royal Air Force Research Establishment, 1978), who used a more complex five-parameter equation of state. This indicates that rather simple equations of state may adequately represent essential thermodynamic features of high-speed penetration phenomena. The equation of state employed here furthermore allows approximate analytical results to be derived for both small and large projectile velocities.

  10. Penetrative Convection and Zonal Flow on Jupiter

    PubMed

    Zhang; Schubert

    1996-08-16

    Measurements by the Galileo probe support the possibility that the zonal winds in Jupiter's atmosphere originate from convection that takes place in the deep hydrogen-helium interior. However, according to models based on recent opacity data and the probe's temperature measurements, there may be radiative and nonconvective layers in the outer part of the jovian interior, raising the question of how deep convection could extend to the surface. A theoretical model is presented to demonstrate that, because of predominant rotational effects and spherical geometry, thermal convection in the deep jovian interior can penetrate into any outer nonconvective layer. These penetrative convection rolls interact nonlinearly and efficiently in the model to generate and sustain a mean zonal wind with a larger amplitude than that of the nonaxisymmetric penetrative convective motions, a characteristic of the wind field observed at the cloud level on Jupiter. PMID:8688074

  11. Detectability of penetration depth based on weld pool geometry and process emission spectrum in laser welding of copper

    NASA Astrophysics Data System (ADS)

    Özmert, Alp; Neisser-Deiters, Paul; Drenker, Alexander

    2014-05-01

    Laser welding is a promising joining process for copper interconnections. A key criterion of quality for these welds is the penetration depth. The penetration depth is subject to intrinsic variation, i.e. by the nature of the welding process. Online detection of penetration depth enables quality assurance and furthermore welding of joint configurations with tighter tolerances via closed-loop control. Weld pool geometry and keyhole optical emission in the wavelength interval of 400-1100 nm are investigated with regard to how suitable they are for the detection of penetration depth in laser welding of copper Cu-ETP. Different penetration depths were induced by stepwise modulation of laser power in bead-on-plate welds. The welds have been monitored with illuminated high-speed videography of the work piece surface and spectrometry. Increase of the weld pool length (in direction of travel) corresponding to increase in penetration depth has been observed while no noticeable change was observed of the weld pool width (transverse to the direction of travel). No significant lines were observed in the spectrum. The radiant power in VIS-spectrum was observed to increase with increasing penetration depth as well. As future work, with increasing understanding and experimental data, online monitoring by indirectly measuring the penetration depth would be possible. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 260153 (QCOALA: Quality Control for Aluminium Laser-Welded Assemblies).

  12. Surfactant improves irrigant penetration into unoperated sinuses

    PubMed Central

    Rohrer, Joseph W.; Dion, Greg R.; Brenner, Pryor S.; Abadie, Wesley M.; McMains, Kevin C.; Thomas, Roy F.

    2012-01-01

    Background: Saline irrigations are proving to be a valuable intervention in the treatment of chronic sinusitis. The use of surfactants is a well established additive to topical treatments known to reduce surface tension and may prove to be a simple, nonoperative intervention to improve intrasinus douching penetration. Methods: Six 30-mL, flat-bottomed medicine cups with circular holes cut through the bottom center and varying in diameter from 1 to 6 mm were created with punch biopsies. Water, saline, saline/dye, and saline/dye/surfactant were compared for maximum holding pressure via these modeled ostia. Holding pressures also were determined for cups with septal mucosa fused to the bottom with holes ranging from 1 to 6 mm. In addition, analysis was carried out with blood and blood/surfactant. Finally, five thawed, fresh-frozen cadaver heads were evaluated before any sinus surgery with water/dye and water/dye/surfactant for intrasinus penetration. Results: Surfactant significantly improved the ability of all solutions to penetrate ostia in both the plastic cup and fused septal mucosa model. All nonsurfactant-containing solutions were not statistically different from one another, nor did surfactant change the ostial penetration of blood. Surfactant significantly improved the ability of sinus irrigant to penetrate unoperated sinus cavities (3.12 vs 3.5, p = .021). Conclusions: The addition of surfactant to saline irrigation improves ostial penetration in undissected and undiseased cadavers. This has practical implications for unoperated patients seeking care for sinus-related symptoms in that we have now described a method for improving topical treatment of target sinus mucosa prior to surgical intervention. PMID:22643945

  13. Evaluation of time-resolved multi-distance methods to retrieve absorption and reduced scattering coefficients of adult heads in vivo: Optical parameters dependences on geometrical structures of the models used to calculate reflectance

    NASA Astrophysics Data System (ADS)

    Tanifuji, T.

    2016-03-01

    Time-resolved multi-distance measurements are studied to retrieve absorption and reduced scattering coefficients of adult heads, which have enough depth sensitivity to determine the optical parameters in superficial tissues and brain separately. Measurements were performed by putting the injection and collection fibers on the left semi-sphere of the forehead, with the injection fiber placed toward the temporal region, and by moving the collection fiber between 10 and 60 mm from the central sulcus. It became clear that optical parameters of the forehead at all collection fibers were reasonably determined by selecting the appropriate visibility length of the geometrical head models, which is related to head surface curvature at each position.

  14. Hydraulic well penetration apparatus and method

    SciTech Connect

    Schellstede, H.J.; McQueen, R.W.; Peters, A.D.

    1988-12-13

    This patient describes a method of penetrating a well casing and surrounding earth strata comprising the steps of: positioning a punch member internally of the casing at a desired depth in alignment with strata desired to be penetrated; and forcing the punch member outwardly through the casing to an extended position to effect the provision of an aperture in the casing while simultaneously moving a jet nozzle means outwardly through the punch member while concurrently providing a high pressure liquid jet from the nozzle means to effect the application of force to the casing to weaken the casing and aid the operation of the punch in cutting the case and surrounding strata.

  15. FREEFALL: A seabed penetrator flight code

    SciTech Connect

    Hickerson, J.

    1988-01-01

    This report presents a one-dimensional model and computer program for predicting the motion of seabed penetrators. The program calculates the acceleration, velocity, and depth of a penetrator as a function of time from the moment of launch until the vehicle comes to rest in the sediment. The code is written in Pascal language for use on a small personal computer. Results are presented as printed tables and graphs. A comparison with experimental data is given which indicates that the accuracy of the code is perhaps as good as current techniques for measuring vehicle performance. 31 refs., 12 figs., 5 tabs.

  16. Explosive shaped charge penetration into tuff rock

    SciTech Connect

    Vigil, M.G.

    1988-10-01

    Analysis and data for the use of Explosive Shaped Charges (ESC) to generate holes in tuff rock formation is presented. The ESCs evaluated include Conical Shaped Charges (CSC) and Explosive Formed Projectiles (EFP). The CSCs vary in size from 0.158 to 9.1 inches inside cone diameter. The EFPs were 5.0 inches in diameter. Data for projectile impact angles of 30 and 90 degrees are presented. Analytically predicted depth of penetration data generally compared favorably with experimental data. Predicted depth of penetration versus ESC standoff data and hole profile dimensions in tuff are also presented. 24 refs., 45 figs., 6 tabs.

  17. HMO penetration: has it hurt public hospitals?

    PubMed

    Clement, J P; Grazier, K L

    2001-01-01

    The purpose of this study is to determine the extent to which health maintenance organization (HMO) penetration within the public hospitals' market area affects the financial performance and viability of these institutions, relative to private hospitals. Hospital- and market-specific measures are examined in a fully interacted model of over 2,300 hospitals in 321 metropolitan statistical areas (MSAs) in 1995. Although hospitals located in markets with higher HMO penetration have lower financial performance as reflected in revenues, expenses and operating margin, public hospitals are not more disadvantaged than other hospitals by managed care. PMID:11669291

  18. Penetrating Trauma to the Parotid Gland.

    PubMed

    Tisch, Matthias; Maier, Susanne; Maier, Heinz

    2015-08-01

    Penetrating trauma to the parotid gland may present unique challenges especially when Stensen duct, neurovascular structures, and/or collateral organs are involved. Especially ballistic injuries caused by high-velocity projectiles or fragments of grenades and improvised explosive devices are often associated with massive tissue damage and a high risk of infections and other posttraumatic complications. Because penetrating parotid trauma is not very common, only limited information on the primary treatment of such injuries is available. This article gives a short overview about actual aspects on diagnosis and treatment strategies especially focusing on ballistic parotid injuries. PMID:26372712

  19. The effect of welding parameters on penetration in GTA welds

    SciTech Connect

    Shirali, A.A. ); Mills, K.C. )

    1993-07-01

    The effect of various welding parameters on the penetration of GTA welds has been investigated. Increases in welding speed were found to reduce penetration; however, increases in welding current were observed to increase the penetration in high sulfur (HS) casts and decrease penetration in low sulfur (LS) steels. Plots of penetration as a function of increasing linear energy (the heat supplied per unit length of weld) revealed a similar trend with increased penetration in HS casts, but the penetration in LS casts was unaffected by increases in linear energy. These results support the Burgardt-Heiple proposition that changes in welding parameters on penetration can be explained in terms of their effect, sequentially, on the temperature gradient and the Marangoni forces operating in the weld pool. Increases in arc length were found to decrease weld penetration regardless of the sulfur concentration of the steel, and the effects of electrode geometry and welding position on weld penetration were also investigated.

  20. Solar radiation in Saturn's atmosphere: maximum penetration and heating rates

    NASA Astrophysics Data System (ADS)

    Pérez-Hoyos, S.; Sánchez-Lavega, A.

    2005-08-01

    We use our previous long-term study (1994-2004) of Saturn's upper clouds and hazes vertical structure (Pérez-Hoyos et al., Icarus, 176, 155, 2005), to retrieve the internal fields and penetration levels of optical radiation in the atmosphere (wavelengths from 250 nm to 950 nm). We have used a doubling adding radiative transfer code and assumed different vertical cloud structure models, as bounded by our previous photometric analysis and other works. We analyze the levels between 1 mbar to 6 bar taking into account the seasonal and ring-shadowing effects on insolation. The main result is that the expected maximum penetration level of the visual radiation on the upper hazes along Saturn's year is ˜ 0.3 bar. Maps of the temporal and latitudinal distribution of the atmospheric heating rates are also presented. Our results provide realistic constraints on the available energy and vertical extent for general circulation -shallow- models for the giant planets based on the terrestrial circulation analogy. Acknowledgments: S.P.-H and A.S.-L. are supported by MCYT AYA2003-03216, fondos FEDER, and Grupos UPV 15946/2004. S.P.-H. acknowledges a PhD fellowship from the Spanish MEC.

  1. Single And Multiple Jet Penetration Experiments Into Geologic Materials

    SciTech Connect

    Kuklo, R; Murphy, M J; Rambur, T A; Switzer, L L; Summers, M A

    2003-12-19

    This paper presents the results of experiments that investigate the effect of single and multiple jet penetration into geologic materials. In previous studies of jet penetration into concrete targets, we demonstrated that an enhanced surface crater could be created by the simultaneous penetration of multiple shaped charge jets and that an enhanced target borehole could be created by the subsequent delayed penetration of a single shaped charge jet. This paper describes an extension of the multiple jet penetration research to limestone and granite.

  2. Leber’s Hereditary Optic Neuropathy: The Mitochondrial Connection Revisited

    PubMed Central

    Abu-Amero, Khaled K.

    2011-01-01

    Our current understanding of Leber’s hereditary optic neuropathy (LHON)-mitochondrial connection falls short of comprehensive. Twenty years of intensive investigation have yielded a wealth of information about mitochondria, the mitochondrial genome, the metabolism of the optic nerve and other structures, and the phenotypic variability of classic LHON. However, we still cannot completely explain how primary LHON mutations injure the optic nerve or why the optic nerve is particularly at risk. We cannot explain the incomplete penetrance or the male predominance of LHON, the typical onset in young adult life without warning, or the synchronicity of visual loss. Moreover, primary LHON mutations clearly are not present in every family with the LHON phenotype (including multigenerational maternal inheritance), and they are present in only a minority of individuals who have the LHON optic neuropathy phenotype without a family history. All lines of evidence point to abnormalities of the mitochondria as the direct or indirect cause of LHON. Therefore, the mitochondria-LHON connection needs to be revisited and examined closely. This review will attempt to do that and provide an update on various aspects of LHON. PMID:21572729

  3. A novel backpackable ice-penetrating radar system

    NASA Astrophysics Data System (ADS)

    Matsuoka, Kenichi; Saito, Ryoji; Naruse, Renji

    We have developed a novel ice-penetrating radar system that can be carried on a backpack. Including batteries for a 3 hour continuous measurement, the total weight is 13 kg. In addition, it operates reliably down to -25°C, has a low power consumption of 24 W, and is semi-waterproof. The system has a built-in-one controller with a high-brightness display for reading data quickly, a receiver with 12-bit digitizing, and a 1 kV pulse transmitter in which the pulse amplitude varies by <0.2%. Optical communications between components provides low-noise data acquisition and allows synchronizing of the pulse transmission with sampling. Measurements with the system revealed the 300 m deep bed topography of a temperate valley glacier in the late ablation season.

  4. Penetration of diffuse ultraviolet radiation into interstellar clouds

    SciTech Connect

    Flannery, B.P.; Roberge, W.; Rybicki, G.B.

    1980-03-01

    We show that the solution of the transfer equation appropriate for models of the penetration of diffuse UV radiation into interstellar clouds, subject to attenuation by coherent, nonconservative, anisotropic scattering from grains, can be expressed analytically, with arbitrary accuracy, by means of the spherical harmonics method. Models of plane-parallel and homogeneous spherical clouds are given as functions of three parameters: tau/sub c/ the central optical depth, ..omega.. the single scattering albedo, and g the parameter in the Henyey-Greenstein phase function. These models qualitatively confirm the results of earlier Monte Carlo simulations of dust scattering, but reveal quantitative discrepancies: the earlier results overestimated the actual mean intensity, often by more than an order of magnitude.

  5. Penetration of UV Radiation in the Earth's Oceans

    NASA Technical Reports Server (NTRS)

    Mitchell, B. Greg; Lubin, Dan

    2005-01-01

    This project was a collaboration between SIO/UCSD and NASA/GSFC to develop a global estimation of the penetration of UV light into open ocean waters, and into coastal waters. We determined the ocean UV reflectance spectra seen by satellites above the atmosphere by combining existing sophisticated radiative transfer models with in situ UV Visible data sets to improve coupled radiance estimates both underwater and within the atmosphere. Results included improved estimates of surface spectral irradiance, 0.3-1.0 micron, and estimates of photosynthetic inhibition, DNA mutation, and CO production. Data sets developed under this proposal have been made publicly available via submission to the SeaWiFS Bio-Optical Archive and Storage System. Numerous peer-reviewed publications and conference proceedings and abstracts resulted from the work supported by this research award.

  6. Failure and penetration response of borosilicate glass during short-rod impact

    SciTech Connect

    Anderson, C. E. Jr.; Orphal, D. L.; Behner, Th.; Hohler, V.; Wickert, M.; Templeton, D. W.

    2007-12-12

    The failure characterization of brittle materials like glass is of fundamental importance in describing the penetration resistance against projectiles. A critical question is whether this failure front remains 'steady' after the driving stress is removed. A test series with short gold rods (D = 1 mm, L/D{approx_equal}5-11) impacting borosilicate glass at {approx}1 to 2 km/s was carried out to investigate this question. The reverse ballistic method was used for the experiments, and the impact and penetration process was observed simultaneously with five flash X-rays and a 16-frame high-speed optical camera. Very high measurement accuracy was established to ensure reliable results. Results show that the failure front induced by rod impact and penetration does arrest (ceases to propagate) after the rod is totally eroded inside the glass. The impact of a second rod after a short time delay reinitiates the failure front at about the same speed.

  7. A Quantitative Analysis of Worldwide VCR Penetration.

    ERIC Educational Resources Information Center

    Lin, Carolyn

    By examining relationships between a host of national policy, domestic economic, media system, and media infrastructure factors, a study assesses possible predictors for videotape cassette recorder (VCR) penetration across 63 countries. Overall statistical results generated through hypothesis testing indicated that these factors were relatively…

  8. Planetary penetrators: Their origins, history and future

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph D.

    2011-08-01

    Penetrators, which emplace scientific instrumentation by high-speed impact into a planetary surface, have been advocated as an alternative to soft-landers for some four decades. However, such vehicles have yet to fly successfully. This paper reviews in detail, the origins of penetrators in the military arena, and the various planetary penetrator mission concepts that have been proposed, built and flown. From the very limited data available, penetrator developments alone (without delivery to the planet) have required ˜$30M: extensive analytical instrumentation may easily double this. Because the success of emplacement and operation depends inevitably on uncontrollable aspects of the target environment, unattractive failure probabilities for individual vehicles must be tolerated that are higher than the typical '3-sigma' (99.5%) values typical for spacecraft. The two pathways to programmatic success, neither of which are likely in an austere financial environment, are a lucky flight as a 'piggyback' mission or technology demonstration, or with a substantial and unprecedented investment to launch a scientific (e.g. seismic) network mission with a large number of vehicles such that a number of terrain-induced failures can be tolerated.

  9. Computed tomographic findings in penetrating peptic ulcer

    SciTech Connect

    Madrazo, B.L.; Halpert, R.D.; Sandler, M.A.; Pearlberg, J.L.

    1984-12-01

    Four cases of peptic ulcer penetrating the head of the pancreas were diagnosed by computed tomography (CT). Findings common to 3 cases included (a) an ulcer crater, (b) a sinus tract, and (c) enlargement of the head of the pancreas. Unlike other modalities, the inherent spatial resolution of CT allows a convenient diagnosis of this important complication of peptic ulcer disease.

  10. 7 CFR 3201.14 - Penetrating lubricants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... The designation can be found in the Comprehensive Procurement Guideline, 40 CFR 247.11. ... Designated Items § 3201.14 Penetrating lubricants. (a) Definition. Products formulated to provide light... the product as a percent of the weight (mass) of the total organic carbon in the finished product....