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Sample records for airborne microparticles based

  1. Tandem mass spectrometry of individual airborne microparticles

    SciTech Connect

    Reilly, P.T.A.; Gieray, R.A.; Yang, M.; Whitten, W.B.; Ramsey, J.M.

    1997-01-01

    An apparatus for real-time MS/MS analysis of individual airborne microparticles by laser ablation in an ion trap is described. The performance has been demonstrated by the detection of tributyl phosphate and bis(2-ethylhexyl) phosphate on silicon carbide and kaolin microparticles. 28 refs., 5 figs.

  2. Detection and Classification of Individual Airborne Microparticles using Laser Ablation Mass Spectroscopy and Multivariate Analysis

    SciTech Connect

    Gieray, R.A.; Lazar, A.; Parker, E.P.; Ramsey, J. M.; Reilly, P.T.A.; Rosenthal, S.E.; Trahan, M.W.; Wagner, J.S.; Whitten, W.B.

    1999-04-27

    We are developing a method for the real-time analysis of airborne microparticles based on laser ablation mass spectroscopy. Airborne particles enter an ion trap mass spectrometer through a differentially-pumped inlet, are detected by light scattered from two CW laser beams, and sampled by a 10 ns excimer laser pulse at 308 nm as they pass through the center of the ion trap electrodes. After the laser pulse, the stored ions are separated by conventional ion trap methods. In this work thousands of positive and negative ion spectra were collected for eighteen different species: six bacteria, six pollen, and six particulate samples. The data were then averaged and analyzed using the Multivariate Patch Algorithm (MPA), a variant of traditional multivariate anal ysis. The MPA correctly identified all of the positive ion spectra and 17 of the 18 negative ion spectra. In addition, when the average positive and negative spectra were combined the MPA correctly identified all 18 species. Finally, the MPA is also able to identify the components of computer synthesized mixtures of the samples studied

  3. Therapeutic Strategies Based on Polymeric Microparticles

    PubMed Central

    Vilos, C.; Velasquez, L. A.

    2012-01-01

    The development of the field of materials science, the ability to perform multidisciplinary scientific work, and the need for novel administration technologies that maximize therapeutic effects and minimize adverse reactions to readily available drugs have led to the development of delivery systems based on microencapsulation, which has taken one step closer to the target of personalized medicine. Drug delivery systems based on polymeric microparticles are generating a strong impact on preclinical and clinical drug development and have reached a broad development in different fields supporting a critical role in the near future of medical practice. This paper presents the foundations of polymeric microparticles based on their formulation, mechanisms of drug release and some of their innovative therapeutic strategies to board multiple diseases. PMID:22665988

  4. Real-Time Analysis of Individual Airborne Microparticles Using Laser Ablation Mass Spectroscopy and Genetically Trained Neural Networks

    SciTech Connect

    Parker, E.P.; Rosenthal, S.E.; Trahan, M.W.; Wagner, J.S.

    1999-01-22

    We are developing a method for analysis of airborne microparticles based on laser ablation of individual molecules in an ion trap mass spectrometer. Airborne particles enter the spectrometer through a differentially-pumped inlet, are detected by light scattered from two CW laser beams, and sampled by a pulsed excimer laser as they pass through the center of the ion trap electrodes. After the laser pulse, the stored ions are separated by conventional ion trap methods. The mass spectra are then analyzed using genetically-trained neural networks (NNs). A number of mass spectra are averaged to obtain training cases which contain a recognizable spectral signature. Averaged spectra for a bacteria and a non-bacteria are shown to the NNs, the response evaluated, and the weights of the connections between neurodes adjusted by a Genetic Algorithm (GA) such that the output from the NN ranges from 0 for non-bacteria to 1 for bacteria. This process is iterated until the population of the GA converges or satisfies predetermined stopping criteria. Using this type of bipolar training we have obtained generalizing NNs able to distinguish five new bacteria from five new non-bacteria, none of which were used in training the NN.

  5. Microparticles prepared from sulfenamide-based polymers

    PubMed Central

    D’Mello, Sheetal R.; Yoo, Jun; Bowden, Ned B.; Salem, Aliasger K.

    2015-01-01

    Polysulfenamides (PSN), with a SN linkage (RSNR2) along the polymer backbone, are a new class of biodegradable and biocompatible polymers. These polymers were unknown prior to 2012 when their synthesis and medicinally relevant properties were reported. The aim of this study was to develop microparticles as a controlled drug delivery system using polysulfenamide as the matrix material. The microparticles were prepared by a water-in-oil-in-water double emulsion solvent evaporation method. For producing drug-loaded particles, FITC-dextran was used as a model hydrophilic compound. At the optimal formulation conditions, the external morphology of the PSN microparticles was examined by scanning electron microscopy to show the formation of smooth-surfaced spherical particles with low polydispersity. The microparticles had a net negative surface charge (−23 mV) as analyzed by the zetasizer. The drug encapsulation efficiency of the particles and the drug loading were found to be dependent on the drug molecular weight, amount of FITC-dextran used in fabricating FITC-dextran loaded microparticles, concentration of PSN and surfactant, and volume of the internal and external water phases. FITC-dextran was found to be distributed throughout the PSN microparticles and was released in an initial burst followed by more continuous release over time. Confocal laser scanning microscopy was used to qualitatively observe the cellular uptake of PSN microparticles and indicated localization of the particles in both the cytoplasm and the nucleus. PMID:23862723

  6. Shape-based separation of microparticles with magnetic fields

    NASA Astrophysics Data System (ADS)

    Wang, Cheng; Zhou, Ran

    2016-11-01

    Precise manipulations, e.g., sorting and focusing, of nonspherical micro-particles in fluidic environment has important applications in the fields of biology sciences and biomedical engineering. However, non-spherical microparticles are hard to manipulate because they tumble in shear flows. Most of existing techniques, including traditional filtration and centrifugation, and recent microfluidic technology, have difficulty in separating microparticles by shape. We demonstrate a novel shape-based separation technique by combining external magnetic fields with pressure-driven flows in a microchannel. Due to the magnetic field, prolate ellipsoidal particles migrate laterally at different speeds than the spherical ones, leading to effective separation. Our experimental investigations reveal the underlying physical mechanism of the observed shape-dependent migration. We find that the magnetic field breaks the rotational symmetry of the nonspherical particles, and induces shape-dependent lift force and migration velocity.

  7. Diaminosulfide based polymer microparticles as cancer vaccine delivery systems.

    PubMed

    Geary, Sean M; Hu, Qiaohong; Joshi, Vijaya B; Bowden, Ned B; Salem, Aliasger K

    2015-12-28

    The aim of the research presented here was to determine the characteristics and immunostimulatory capacity, in vivo, of antigen and adjuvant co-loaded into microparticles made from a novel diaminosulfide polymer, poly(4,4'-trimethylenedipiperdyl sulfide) (PNSN), and to assess their potential as cancer vaccine vectors. PNSN microparticles co-loaded with the antigen, ovalbumin (OVA), and adjuvant, CpG 1826, (PNSN(OVA + CpG)) were fabricated and characterized for size (1.64 μm diameter; PDI=0.62), charge (-23.1 ± 0.3), and loading efficiencies of antigen (7.32 μg/mg particles) and adjuvant (0.95 μg/mg particles). The ability of PNSN(OVA + CpG) to stimulate cellular and humoral immune responses in vivo was compared with other PNSN microparticle formulations as well as with poly(lactic-co-glycolic acid)(PLGA)-based microparticles, co-loaded with OVA and CpG (PLGA(OVA + CpG)), an adenovirus encoding OVA (Ad5-OVA), and OVA delivered with incomplete Freund's adjuvant (IFA(OVA)). In vivo OVA-specific IgG1 responses, after subcutaneous prime/boosts in mice, were similar when PNSN(OVA + CpG) and PLGA(OVA + CpG) were compared and the presence of CpG 1826 within the PNSN microparticles demonstrated significantly improved responses when compared to PNSN microparticles loaded with OVA alone (PNSN(OVA)), plus or minus soluble CpG 1826. Cellular immune responses to all particle-based vaccine formulations ranged from being negligible to modest with PNSN(OVA + CpG) generating the greatest responses, displaying significantly increased levels of OVA-specific CD8+ T lymphocytes compared to controls and IFA(OVA) treated mice. Finally, it was shown that of all vaccination formulations tested PNSN(OVA + CpG) was the most protective against subsequent challenge with an OVA-expressing tumor cell line, E.G7. Thus, microparticles made from poly(diaminosulfide)-based macromolecules possess promising potential as vaccine vectors and, as demonstrated here, may have impact as cancer vaccines

  8. Multitarget sensing of glucose and cholesterol based on Janus hydrogel microparticles.

    PubMed

    Sun, Xiao-Ting; Zhang, Ying; Zheng, Dong-Hua; Yue, Shuai; Yang, Chun-Guang; Xu, Zhang-Run

    2017-06-15

    A visualized sensing method for glucose and cholesterol was developed based on the hemispheres of the same Janus hydrogel microparticles. Single-phase and Janus hydrogel microparticles were both generated using a centrifugal microfluidic chip. For glucose sensing, concanavalin A and fluorescein labeled dextran used for competitive binding assay were encapsulated in alginate microparticles, and the fluorescence of the microparticles was positively correlated with glucose concentration. For cholesterol sensing, the microparticles embedded with γ-Fe2O3 nanoparticles were used as catalyst for the oxidation of 3,3',5,5'-Tetramethylbenzidine by H2O2, an enzymatic hydrolysis product of cholesterol. And the color transition was more sensitive in the microparticles than in solutions, indicating the microparticles are more applicable for visualized determination. Furthermore, Janus microparticles were employed for multitarget sensing in the two hemespheres, and glucose and cholesterol were detected within the same microparticles without obvious interference. Besides, the particles could be manipulated by an external magnetic field. The glucose and cholesterol levels were measured in human serum utilizing the microparticles, which confirmed the potential application of the microparticles in real sample detection.

  9. Alginate-based hybrid aerogel microparticles for mucosal drug delivery.

    PubMed

    Gonçalves, V S S; Gurikov, P; Poejo, J; Matias, A A; Heinrich, S; Duarte, C M M; Smirnova, I

    2016-10-01

    The application of biopolymer aerogels as drug delivery systems (DDS) has gained increased interest during the last decade since these structures have large surface area and accessible pores allowing for high drug loadings. Being biocompatible, biodegradable and presenting low toxicity, polysaccharide-based aerogels are an attractive carrier to be applied in pharmaceutical industry. Moreover, some polysaccharides (e.g. alginate and chitosan) present mucoadhesive properties, an important feature for mucosal drug delivery. This feature allows to extend the contact of DDS with biological membranes, thereby increasing the absorption of drugs through the mucosa. Alginate-based hybrid aerogels in the form of microparticles (<50μm) were investigated in this work as carriers for mucosal administration of drugs. Low methoxyl pectin and κ-carrageenan were co-gelled with alginate and further dried with supercritical CO2 (sc-CO2). Spherical mesoporous aerogel microparticles were obtained for alginate, hybrid alginate/pectin and alginate/κ-carrageenan aerogels, presenting high specific surface area (370-548m(2)g(-1)) and mucoadhesive properties. The microparticles were loaded with ketoprofen via adsorption from its solution in sc-CO2, and with quercetin via supercritical anti-solvent precipitation. Loading of ketoprofen was in the range between 17 and 22wt% whereas quercetin demonstrated loadings of 3.1-5.4wt%. Both the drugs were present in amorphous state. Loading procedure allowed the preservation of antioxidant activity of quercetin. Release of both drugs from alginate/κ-carrageenan aerogel was slightly faster compared to alginate/pectin. The results indicate that alginate-based aerogel microparticles can be viewed as promising matrices for mucosal drug delivery applications.

  10. Fabrication of pseudo-ceramide-based lipid microparticles for recovery of skin barrier function.

    PubMed

    Kim, Do-Hoon; Park, Woo Ram; Kim, Jeong Hwan; Cho, Eun Chul; An, Eun Jung; Kim, Jin-Woong; Oh, Seong-Geun

    2012-06-01

    The recovery of skin barrier functions was investigated with pseudo-ceramide-based lipid microparticles. The microparticles were prepared by using a fluid bed technique where lipid components (a pseudo-ceramide, cholesterol and a fatty acid) were coated on a sugar seed, and a polymer was subsequently coated on the lipid microparticles. The microparticles contained large amount of pseudo-ceramide, and the pseudo-ceramide was in the form of lamellar structures mixed with other lipid components. In addition, the microparticles were stably dispersed in aqueous media or emulsion systems without any disruption of the microparticles' structures, thereby supplying sufficient amount of the pseudo-ceramide to skins for improving skin barrier functions such as preventing water loss. Such a role of the microparticles was proven by evaluating in vivo the efficacy of the lipid microparticles in reducing a trans-epidermal water loss (TEWL) of impaired murine skins. As a result, the novel pseudo-ceramide-based lipid microparticles for barrier recovery may potentially be applied in the field of dermatology, cosmetics and pharmaceuticals.

  11. Fabrication of starch-based microparticles by an emulsification-crosslinking method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch-based microparticles (MPs) fabricated by a water-in-water (w/w) emulsification-crosslinking method could be used as a controlled-release delivery vehicle for food bioactives. Due to the processing route without the use of toxic organic solvents, it is expected that these microparticles can be...

  12. Airborne Relay-Based Regional Positioning System

    PubMed Central

    Lee, Kyuman; Noh, Hongjun; Lim, Jaesung

    2015-01-01

    Ground-based pseudolite systems have some limitations, such as low vertical accuracy, multipath effects and near-far problems. These problems are not significant in airborne-based pseudolite systems. However, the monitoring of pseudolite positions is required because of the mobility of the platforms on which the pseudolites are mounted, and this causes performance degradation. To address these pseudolite system limitations, we propose an airborne relay-based regional positioning system that consists of a master station, reference stations, airborne relays and a user. In the proposed system, navigation signals are generated from the reference stations located on the ground and are relayed via the airborne relays. Unlike in conventional airborne-based systems, the user in the proposed system sequentially estimates both the locations of airborne relays and his/her own position. Therefore, a delay due to monitoring does not occur, and the accuracy is not affected by the movement of airborne relays. We conducted several simulations to evaluate the performance of the proposed system. Based on the simulation results, we demonstrated that the proposed system guarantees a higher accuracy than airborne-based pseudolite systems, and it is feasible despite the existence of clock offsets among reference stations. PMID:26029953

  13. Amorphous Calcium Carbonate Based-Microparticles for Peptide Pulmonary Delivery.

    PubMed

    Tewes, Frederic; Gobbo, Oliviero L; Ehrhardt, Carsten; Healy, Anne Marie

    2016-01-20

    Amorphous calcium carbonate (ACC) is known to interact with proteins, for example, in biogenic ACC, to form stable amorphous phases. The control of amorphous/crystalline and inorganic/organic ratios in inhalable calcium carbonate microparticles may enable particle properties to be adapted to suit the requirements of dry powders for pulmonary delivery by oral inhalation. For example, an amorphous phase can immobilize and stabilize polypeptides in their native structure and amorphous and crystalline phases have different mechanical properties. Therefore, inhalable composite microparticles made of inorganic (i.e., calcium carbonate and calcium formate) and organic (i.e., hyaluronan (HA)) amorphous and crystalline phases were investigated for peptide and protein pulmonary aerosol delivery. The crystalline/amorphous ratio and polymorphic form of the inorganic component was altered by changing the microparticle drying rate and by changing the ammonium carbonate and HA initial concentration. The bioactivity of the model peptide, salmon calcitonin (sCT), coprocessed with alpha-1-antitrypsin (AAT), a model protein with peptidase inhibitor activity, was maintained during processing and the microparticles had excellent aerodynamic properties, making them suitable for pulmonary aerosol delivery. The bioavailability of sCT after aerosol delivery as sCT and AAT-loaded composite microparticles to rats was 4-times higher than that of sCT solution.

  14. Gellan gum based microparticles of metoclopromide hydrochloride for intranasal delivery: development and evaluation.

    PubMed

    Mahajan, Hitendra Shaligram; Gattani, Surendra Ganeshlal

    2009-04-01

    The purpose of this study was to develop nasal microparticles of metoclopromide employing gellan gum as a polymer by spray drying method. This method of microencapsulation is particularly less dependent on the solubility characteristics of the drug and polymer and is simple, reproducible, and easy to scale up. The microparticles were evaluated for characteristics like particle size, incorporation efficiency, swelling ability, zeta potential, mucoadhesion, thermal analysis, X-ray diffraction (XRD) study and in vitro drug release. The microparticles so prepared had irregular shape and smooth but distorted surface morphology. They were negatively charged. The particle size ranged from 9.38 to 10.67 microm. Differential scanning calorimetry (DSC) studies revealed that metoclopromide was molecularly dispersed inside the microparticles. The swelling was increased with increase in amount of polymer. The release of drug from microparticles was moderately sustained without lag time and attributed to formation of hydrogel; ionically cross linked hydrogel was hypothesized. The formulation was found to be non toxic to nasal tissue. These in vitro preliminary results show that spray dried microparticles based on gellan gum could be suitable nasal delivery system for the administration of metoclopromide.

  15. Polymer-based microparticles in tissue engineering and regenerative medicine.

    PubMed

    Oliveira, Mariana B; Mano, João F

    2011-07-01

    Different types of biomaterials, processed into different shapes, have been proposed as temporary support for cells in tissue engineering (TE) strategies. The manufacturing methods used in the production of particles in drug delivery strategies have been adapted for the development of microparticles in the fields of TE and regenerative medicine (RM). Microparticles have been applied as building blocks and matrices for the delivery of soluble factors, aiming for the construction of TE scaffolds, either by fusion giving rise to porous scaffolds or as injectable systems for in situ scaffold formation, avoiding complicated surgery procedures. More recently, organ printing strategies have been developed by the fusion of hydrogel particles with encapsulated cells, aiming the production of organs in in vitro conditions. Mesoscale self-assembly of hydrogel microblocks and the use of leachable particles in three-dimensional (3D) layer-by-layer (LbL) techniques have been suggested as well in recent works. Along with innovative applications, new perspectives are open for the use of these versatile structures, and different directions can still be followed to use all the potential that such systems can bring. This review focuses on polymeric microparticle processing techniques and overviews several examples and general concepts related to the use of these systems in TE and RE applications. The use of materials in the development of microparticles from research to clinical applications is also discussed.

  16. Mucoadhesive Buccal Tablets Based on Chitosan/Gelatin Microparticles for Delivery of Propranolol Hydrochloride.

    PubMed

    Abruzzo, Angela; Cerchiara, Teresa; Bigucci, Federica; Gallucci, Maria Caterina; Luppi, Barbara

    2015-12-01

    Propranolol administration through buccal route offers some distinct advantages thanks to the easy access to the oral mucosa, fast onset of action, and avoidance of hepatic and intestinal degradation mechanisms. To overcome the effective removal existing in the buccal cavity, mucoadhesive delivery systems are considered a promising approach as they facilitate a close contact with the buccal mucosa. The aim of this study was to prepare mucoadhesive tablets based on chitosan/gelatin microparticles for buccal delivery of propranolol hydrochloride. Spray-dried microparticles were prepared with different chitosan-gelatin weight ratios and characterized in terms of yield and morphology. Microparticles were subsequently compressed with the drug to obtain loaded buccal tablets. In vitro water uptake, mucoadhesion, release, and permeation tests were performed to investigate tablet ability to hydrate, to adhere to the mucosa, and to deliver drug through buccal mucosa. Microparticles showed a different morphology based on the different chitosan-gelatin weight ratios. Moreover, buccal tablets based on the prepared microparticles showed different technological and functional characteristics in virtue of their composition. In particular, tablets with an excess of chitosan showed the best mucoadhesive properties, allowed the permeation of the greatest drug amount among all formulations, and could be promising for buccal administration of propranolol hydrochloride.

  17. Chitosan-Based Nano-Embedded Microparticles: Impact of Nanogel Composition on Physicochemical Properties

    PubMed Central

    Islam, Paromita; Water, Jorrit J.; Bohr, Adam; Rantanen, Jukka

    2016-01-01

    Chitosan-based nanogels have been widely applied as drug delivery vehicles. Spray-drying of said nanogels allows for the preparation of dry powder nano-embedded microparticles. In this work, chitosan-based nanogels composed of chitosan, alginate, and/or sodium tri-penta phosphate were investigated, particularly with respect to the impact of composition on the resulting physicochemical properties. Different compositions were obtained as nanogels with sizes ranging from 203 to 561 nm. The addition of alginate and exclusion of sodium tri-penta phosphate led to an increase in nanogel size. The nanogels were subsequently spray-dried to form nano-embedded microparticles with trehalose or mannitol as matrix excipient. The microparticles of different composition were mostly spherical with a smooth surface and a mass median aerodynamic diameter of 6–10 µm. Superior redispersibility was observed for microparticles containing amorphous trehalose. This study demonstrates the potential of nano-embedded microparticles for stabilization and delivery of nanogel-based delivery systems. PMID:28025505

  18. Chitosan-Based Nano-Embedded Microparticles: Impact of Nanogel Composition on Physicochemical Properties.

    PubMed

    Islam, Paromita; Water, Jorrit J; Bohr, Adam; Rantanen, Jukka

    2016-12-22

    Chitosan-based nanogels have been widely applied as drug delivery vehicles. Spray-drying of said nanogels allows for the preparation of dry powder nano-embedded microparticles. In this work, chitosan-based nanogels composed of chitosan, alginate, and/or sodium tri-penta phosphate were investigated, particularly with respect to the impact of composition on the resulting physicochemical properties. Different compositions were obtained as nanogels with sizes ranging from 203 to 561 nm. The addition of alginate and exclusion of sodium tri-penta phosphate led to an increase in nanogel size. The nanogels were subsequently spray-dried to form nano-embedded microparticles with trehalose or mannitol as matrix excipient. The microparticles of different composition were mostly spherical with a smooth surface and a mass median aerodynamic diameter of 6-10 µm. Superior redispersibility was observed for microparticles containing amorphous trehalose. This study demonstrates the potential of nano-embedded microparticles for stabilization and delivery of nanogel-based delivery systems.

  19. Mode-based microparticle conveyor belt in air-filled hollow-core photonic crystal fiber.

    PubMed

    Schmidt, Oliver A; Euser, Tijmen G; Russell, Philip St J

    2013-12-02

    We show how microparticles can be moved over long distances and precisely positioned in a low-loss air-filled hollow-core photonic crystal fiber using a coherent superposition of two co-propagating spatial modes, balanced by a backward-propagating fundamental mode. This creates a series of trapping positions spaced by half the beat-length between the forward-propagating modes (typically a fraction of a millimeter). The system allows a trapped microparticle to be moved along the fiber by continuously tuning the relative phase between the two forward-propagating modes. This mode-based optical conveyor belt combines long-range transport of microparticles with a positional accuracy of 1 µm. The technique also has potential uses in waveguide-based optofluidic systems.

  20. Biocompatibility Assessment of Si-based Nano- and Micro-particles

    PubMed Central

    Jaganathan, Hamsa; Godin, Biana

    2012-01-01

    Silicon is one of the most abundant chemical elements found on the Earth. Due to its unique chemical and physical properties, silicon based materials and their oxides (e.g. silica) have been used in several industries such as building and construction, electronics, food industry, consumer products and biomedical engineering/medicine. This review summarizes studies on effects of silicon and silica nano- and micro-particles on cells and organs following four main exposure routes, namely, intravenous, pulmonary, dermal and oral. Further, possible genotoxic effects of silica based nanoparticles are discussed. The review concludes with an outlook on improving and standardizing biocompatibility assessment for nano- and micro-particles. PMID:22634160

  1. Image Based Synthesis for Airborne Minefield Data

    DTIC Science & Technology

    2005-12-01

    applications of image synthesis include artificial texture generation [1], image repairing [2], photometric image rendering [3] and ultrasound imaging...1999. 4. M. Song, R. M. Haralick, F.H. Sheehan, " Ultrasound imaging simulation and echocardiographic image synthesis ", Proceedings of the IEEE...Night Vision and Electronic Sensors Directorate AMSRD-CER-NV-TR-246I Image Based Synthesis for Airborne Minefield Data December 2005 Approved for

  2. Production and characterization of engineered alginate-based microparticles containing ECM powder for cell/tissue engineering applications.

    PubMed

    Mazzitelli, Stefania; Luca, Giovanni; Mancuso, Francesca; Calvitti, Mario; Calafiore, Riccardo; Nastruzzi, Claudio; Johnson, Scott; Badylak, Stephen F

    2011-03-01

    A method for the production of engineered alginate-based microparticles, containing extracellular matrix and neonatal porcine Sertoli cells (SCs), is described. As a source for extracellular matrix, a powder form of isolated and purified urinary bladder matrix (UBM) was employed. We demonstrated that the incorporation of UBM does not significantly alter the morphological and dimensional characteristics of the microparticles. The alginate microparticles were used for SC encapsulation as an immunoprotective barrier for transplant purposes, while the co-entrapped UBM promoted retention of cell viability and function. These engineered microparticles could represent a novel approach to enhancing immunological acceptance and increasing the functional life-span of the entrapped cells for cell/tissue engineering applications. In this respect, it is noteworthy that isolated neonatal porcine SCs, administered alone in highly biocompatible microparticles, led to diabetes prevention and reversion in nonobese diabetic (NOD) mice.

  3. Silicon microfluidic flow focusing devices for the production of size-controlled PLGA based drug loaded microparticles.

    PubMed

    Keohane, Kieran; Brennan, Des; Galvin, Paul; Griffin, Brendan T

    2014-06-05

    The increasing realisation of the impact of size and surface properties on the bio-distribution of drug loaded colloidal particles has driven the application of micro fabrication technologies for the precise engineering of drug loaded microparticles. This paper demonstrates an alternative approach for producing size controlled drug loaded PLGA based microparticles using silicon Microfluidic Flow Focusing Devices (MFFDs). Based on the precise geometry and dimensions of the flow focusing channel, microparticle size was successfully optimised by modifying the polymer type, disperse phase (Qd) flow rate, and continuous phase (Qc) flow rate. The microparticles produced ranged in sizes from 5 to 50 μm and were highly monodisperse (coefficient of variation <5%). A comparison of Ciclosporin (CsA) loaded PLGA microparticles produced by MFFDs vs conventional production techniques was also performed. MFFDs produced microparticles with a narrower size distribution profile, relative to the conventional approaches. In-vitro release kinetics of CsA was found to be influenced by the production technique, with the MFFD approach demonstrating the slowest rate of release over 7 days (4.99 ± 0.26%). Finally, MFFDs were utilised to produce pegylated microparticles using the block co-polymer, PEG-PLGA. In contrast to the smooth microparticles produced using PLGA, PEG-PLGA microparticles displayed a highly porous surface morphology and rapid CsA release, with 85 ± 6.68% CsA released after 24h. The findings from this study demonstrate the utility of silicon MFFDs for the precise control of size and surface morphology of PLGA based microparticles with potential drug delivery applications.

  4. Surface characterization and drug release from porous microparticles based on methacrylic monomers and xanthan.

    PubMed

    Lungan, Maria-Andreea; Popa, Marcel; Racovita, Stefania; Hitruc, Gabriela; Doroftei, Florica; Desbrieres, Jacques; Vasiliu, Silvia

    2015-07-10

    Porous crosslinked microparticles based on glycidyl methacrylate and xanthan were prepared by suspension polymerization and used for loading theophylline, a bronhodilatator drug, in order to obtain new drug delivery systems. The surface morphologies observed by means of SEM and AFM analysis demonstrated that microparticles show a spherical shape and are characterized by a porous structure. The presence of xanthan in the structure of microparticles leads to a decrease of surface roughness and pore diameters as well as to an increase of hydrophilicity degree compared to the micropaticles based only on glycidyl methacrylate. To analyze the in vitro release data various mathematical models were used, such as, first order, Higuchi model, Korsmeyer-Peppas model and Baker-Lonsdale model. Based on the highest values of the correlation coefficient, the analysis of the kinetic data indicate that drug release from G1 and X1 porous microparticles fits similarly well to the first order and Higuchi models and diffusion was the dominant mechanism of drug release.

  5. Nanocrystals embedded in chitosan-based respirable swellable microparticles as dry powder for sustained pulmonary drug delivery.

    PubMed

    Ni, Rui; Zhao, Jing; Liu, Qiaoyu; Liang, Zhenglin; Muenster, Uwe; Mao, Shirui

    2017-03-01

    In this study, nanocrystals embedded in microparticles were designed to achieve sustained pulmonary drug delivery of hydrophobic drugs. Chitosan based microparticles were engineered to allow sustained drug release via swelling and mucoadhesive properties of the polymer. Taking cinaciguat as a hydrophobic model drug, drug nanocrystals were prepared by high pressure homogenization and then encapsulated in chitosan microparticles via spray drying. Through various in vitro characterizations, it was shown that drug loaded microparticles had a high drug loading with promising aerosolization characteristics (mean volume diameter (Dv50) 3-4μm, experimental mass mean aerodynamic diameter (MMADe) 4-4.5μm, fine particle fraction (FPF%) 40-45%, emitted dose (ED%) 94-95%). The microparticles showed high swelling capacity within 5min, with various sustained drug release rates depending on chitosan concentration and molecular weight. Furthermore, aerosolization performances under various inhalation conditions were investigated. It was found that both inspiratory flow rate and volume had an influence on the aerosolization of developed microparticles, indicating actual inhalation efficiency might be compromised under disease conditions. Taken together, in vitro data indicate that chitosan based swellable microparticles could potentially be useful as nanocrystal carrier to achieve sustained pulmonary delivery. To complete the feasibility assessment of this formulation principle, future in vivo safety and efficacy studies are needed.

  6. Lectin-Based Characterization of Vascular Cell Microparticle Glycocalyx

    PubMed Central

    Scruggs, April K.; Cioffi, Eugene A.; Cioffi, Donna L.; King, Judy A. C.; Bauer, Natalie N.

    2015-01-01

    Microparticles (MPs) are released constitutively and from activated cells. MPs play significant roles in vascular homeostasis, injury, and as biomarkers. The unique glycocalyx on the membrane of cells has frequently been exploited to identify specific cell types, however the glycocalyx of the MPs has yet to be defined. Thus, we sought to determine whether MPs, released both constitutively and during injury, from vascular cells have a glycocalyx matching those of the parental cell type to provide information on MP origin. For these studies we used rat pulmonary microvascular and artery endothelium, pulmonary smooth muscle, and aortic endothelial cells. MPs were collected from healthy or cigarette smoke injured cells and analyzed with a panel of lectins for specific glycocalyx linkages. Intriguingly, we determined that the MPs released either constitutively or stimulated by CSE injury did not express the same glycocalyx of the parent cells. Further, the glycocalyx was not unique to any of the specific cell types studied. These data suggest that MPs from both normal and healthy vascular cells do not share the parental cell glycocalyx makeup. PMID:26274589

  7. A novel viscoelastic-based ferrofluid for continuous sheathless microfluidic separation of nonmagnetic microparticles.

    PubMed

    Zhang, Jun; Yan, Sheng; Yuan, Dan; Zhao, Qianbin; Tan, Say Hwa; Nguyen, Nam-Trung; Li, Weihua

    2016-10-05

    Separation of microparticles has found broad applications in biomedicine, industry and clinical diagnosis. In a conventional aqueous ferrofluid, separation of microparticles usually employs a sheath flow or two offset magnets to confine particle streams for downstream particle sorting. This complicates the fluid control, device fabrication, and dilutes the particle sample. In this work, we propose and develop a novel viscoelastic ferrofluid by replacing the Newtonian base medium of the conventional ferrofluid with non-Newtonian poly(ethylene oxide) (PEO) aqueous solution. The properties of both viscoelastic 3D focusing and negative magnetophoresis of the viscoelastic ferrofluid were verified and investigated. By employing the both properties in a serial manner, continuous and sheathless separation of nonmagnetic particles based on particle size has been demonstrated. This novel viscoelastic ferrofluid is expected to bring more flexibility and versatility to the design and functionality in microfluidic devices.

  8. Microfluidic-based fabrication, characterization and magnetic functionalization of microparticles with novel internal anisotropic structure

    NASA Astrophysics Data System (ADS)

    Qiu, Yang; Wang, Fei; Liu, Ying-Mei; Wang, Wei; Chu, Liang-Yin; Wang, Hua-Lin

    2015-08-01

    Easy fabrication and independent control of the internal and external morphologies of core-shell microparticles still remain challenging. Core-shell microparticle comprised of a previously unknown internal anisotropic structure and a spherical shell was fabricated by microfluidic-based emulsificaiton and photopolymerization. The interfacial and spatial 3D morphology of the anisotropic structure were observed by SEM and micro-CT respectively. Meanwhile, a series of layer-by-layer scans of the anisotropic structure were obtained via the micro-CT, which enhanced the detail characterization and analysis of micro materials. The formation mechanism of the internal anisotropic structure may be attributed to solution-directed diffusion caused by the semipermeable membrane structure and chemical potential difference between inside and outside of the semipermeable membrane-like polymerized shell. The morphology evolution of the anisotropic structure was influenced and controlled by adjusting reaction parameters including polymerization degree, polymerization speed, and solute concentration difference. The potential applications of these microparticles in microrheological characterization and image enhancement were also proposed by embedding magnetic nanoparticles in the inner core.

  9. Microfluidic-based fabrication, characterization and magnetic functionalization of microparticles with novel internal anisotropic structure

    PubMed Central

    Qiu, Yang; Wang, Fei; Liu, Ying-Mei; Wang, Wei; Chu, Liang-Yin; Wang, Hua-Lin

    2015-01-01

    Easy fabrication and independent control of the internal and external morphologies of core-shell microparticles still remain challenging. Core-shell microparticle comprised of a previously unknown internal anisotropic structure and a spherical shell was fabricated by microfluidic-based emulsificaiton and photopolymerization. The interfacial and spatial 3D morphology of the anisotropic structure were observed by SEM and micro-CT respectively. Meanwhile, a series of layer-by-layer scans of the anisotropic structure were obtained via the micro-CT, which enhanced the detail characterization and analysis of micro materials. The formation mechanism of the internal anisotropic structure may be attributed to solution-directed diffusion caused by the semipermeable membrane structure and chemical potential difference between inside and outside of the semipermeable membrane-like polymerized shell. The morphology evolution of the anisotropic structure was influenced and controlled by adjusting reaction parameters including polymerization degree, polymerization speed, and solute concentration difference. The potential applications of these microparticles in microrheological characterization and image enhancement were also proposed by embedding magnetic nanoparticles in the inner core. PMID:26268148

  10. Dynamic manipulation and patterning of microparticles and cells by using TiOPc-based optoelectronic dielectrophoresis.

    PubMed

    Yang, Shih-Mo; Yu, Tung-Ming; Huang, Hang-Ping; Ku, Meng-Yen; Hsu, Long; Liu, Cheng-Hsien

    2010-06-15

    We develop light-driven optoelectronic tweezers based on the organic photoconductive material titanium oxide phthalocyanine. These tweezers function based on negative dielectrophoresis (nDEP). The dynamic manipulation of a single microparticle and cell patterning are demonstrated by using this light-driven optoelectronic DEP chip. The adaptive light patterns that drive the optoelectronic DEP onchip are designed by using Flash software to approach appropriate dynamic manipulation. This is also the first reported demonstration, to the best of our knowledge, for successfully patterning such delicate cells from human hepatocellular liver carcinoma cell line HepG2 by using any optoelectronic tweezers.

  11. Interfacial tension based on-chip extraction of microparticles confined in microfluidic Stokes flows

    NASA Astrophysics Data System (ADS)

    Huang, Haishui; He, Xiaoming

    2014-10-01

    Microfluidics involving two immiscible fluids (oil and water) has been increasingly used to produce hydrogel microparticles with wide applications. However, it is difficult to extract the microparticles out of the microfluidic Stokes flows of oil that have a Reynolds number (the ratio of inertia to viscous force) much less than one, where the dominant viscous force tends to drive the microparticles to move together with the surrounding oil. Here, we present a passive method for extracting hydrogel microparticles in microfluidic Stokes flow from oil into aqueous extracting solution on-chip by utilizing the intrinsic interfacial tension between oil and the microparticles. We further reveal that the thickness of an "extended confining layer" of oil next to the interface between oil and aqueous extracting solution must be smaller than the radius of microparticles for effective extraction. This method uses a simple planar merging microchannel design that can be readily fabricated and further integrated into a fluidic system to extract microparticles for wide applications.

  12. Offutt Air Force Base, Looking Glass Airborne Command Post, Hydraulic ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Offutt Air Force Base, Looking Glass Airborne Command Post, Hydraulic Fluid Buildings, Northeast of Looking Glass Avenue at southwest side of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  13. Offutt Air Force Base, Looking Glass Airborne Command Post, Vehicle ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Offutt Air Force Base, Looking Glass Airborne Command Post, Vehicle Refueling Station, Northeast of AGE Storage Facility at far northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  14. Magnetic microparticle-based multiplexed DNA detection with biobarcoded quantum dot probes.

    PubMed

    Xiang, Dong-shan; Zeng, Guo-ping; He, Zhi-ke

    2011-07-15

    We have developed a new analytical method to detect multiple DNA simultaneously based on the biobarcoded CdSe/ZnS quantum dot (QD) and magnetic microparticle (MMP). It was demonstrated by using oligonucleotide sequences of 64 bases associated with human papillomavirus 16 and 18 L1 genes (HPV-16 and HPV-18) as model systems. This analytical system involves three types of probes, a MMP probe and two streptavidin-modified QD probes. The MMPs are functionalized with HPV-16 and HPV-18 captures DNA to form MMP probes. The QDs are conjugated with HPV-16 or HPV-18 probe DNA along with FAM- or Rox-labeled random DNA to form HPV-16 and HPV-18 QD probes, respectively. A one-step hybridization reaction was performed by mixing the MMP probes, HPV-16 and HPV-18 target DNA (T-16 and T-18), HPV-16 and HPV-18 QD probes. Afterwards, the hybrid-conjugated microparticles were separated by a magnet and heated to remove the MMPs. Finally, the detections of T-16 and T-18 were done by measuring fluorescence signals of FAM and Rox, respectively. Under the optimum conditions, the fluorescence intensity exhibited a good linear dependence on target DNA concentration in the range from 8 × 10⁻¹¹ to 8 × 10⁻⁹ M. The detection limit of T-16 is up to 7 × 10⁻¹¹ M (3σ), and that of T-18 is 6 × 10⁻¹¹ M. Compared with other biobarcode assay methods, the proposed method that QDs were used as the solid support has some advantages including shorter preparation time of QD probes, faster binding kinetics and shorter analytical time. Besides, it is simple and accurate.

  15. Internalization and cytotoxicity analysis of silicon-based microparticles in macrophages and embryos.

    PubMed

    Fernández-Rosas, Elisabet; Gómez, Rodrigo; Ibañez, Elena; Barrios, Lleonard; Duch, Marta; Esteve, Jaume; Plaza, José A; Nogués, Carme

    2010-06-01

    Microchips can be fabricated, using semiconductor technologies, at microscopic level to be introduced into living cells for monitoring of intracellular parameters at a single cell level. As a first step towards intracellular chips development, silicon and polysilicon microparticles of controlled shape and dimensions were fabricated and introduced into human macrophages and mouse embryos by phagocytosis and microinjection, respectively. Microparticles showed to be non-cytotoxic for macrophages and were found to be localized mainly inside early endosomes, in tight association with endosomal membrane, and more rarely in acidic compartments. Embryos with microinjected microparticles developed normally to the blastocyst stage, confirming the non-cytotoxic effect of the particles. In view of these results silicon and polysilicon microparticles can serve as the frame for future intracellular chips development and this technology opens the possibility of real complex devices to be used as sensors or actuators inside living cells.

  16. Development of β-cyclodextrin-based sustained release microparticles for oral insulin delivery.

    PubMed

    D'Souza, Bernadette; Bhowmik, Tuhin; Uddin, Mohammad Nasir; Oettinger, Carl; D'Souza, Martin

    2015-01-01

    Polymeric microparticles have been previously demonstrated to deliver various therapeutic agents efficiently to targeted regions by protecting the drug from harsh gastric milieu of the gastrointestinal tract. In this study, we investigated the hypoglycemic effect of β-cyclodextrin polymeric insulin microparticles in diabetic rats via the oral route of administration. β-cyclodextrin microparticles were prepared by a unique one-step spray-drying technique and stabilized by incorporating enteric retardant polymers in the formulation. The insulin-loaded microparticles had a mean size of 0.8 ± 0.25 μm with a zeta potential of 3.57 + 0.62 mV. As seen with the chromatographic analysis, the drug content in the microparticles was determined to be 94.9 ± 2.77%. RAW macrophage cells showed greater than 80% viability after 24 h of incubation with the insulin and blank microparticles. For the in vitro release study, the microparticles were able to protect the insulin in gastric fluid where no significant release was detected, followed by only 50% release in intestinal fluid for the first 8 h of the study. This was seen to correlate with the in vivo data where 50% glucose inhibition was seen after 8 h of oral administration in diabetic rats. This data suggest that the oral insulin microparticles were able to reduce glucose levels in disease conditions and would be a favorable route of administration to patients as an alternative to daily subcutaneous injections.

  17. Bottle beam based optical trapping system for three-dimensional trapping of high and low index microparticles

    NASA Astrophysics Data System (ADS)

    Ahluwalia, Balpreet Singh; Yuan, Xiaocong; Tao, Shaohua

    2005-08-01

    The quest for applying optical tweezers system for novel applications has aggrandized its trapping capabilities since its inception. Researchers have proposed and applied light based micro-manipulation technique in the field of colloidal sciences, bioscience, MEMS and the count is limitless. In this paper we report the self-imaged optical bottle beam based optical tweezers system. A self-imaged bottle beam possesses three-dimensional intensity-null points along the propagation axis. The transverse intensity profile of the self-imaged bottle beam oscillates along the propagation axis, hence providing three-dimensional trapping potential for high and low indices microparticles at constructive and destructive interference points, respectively. Bottle beam based optical tweezer system adds the beneficial property of Gaussian and Bessel beam based trapping systems by providing three-dimensional trapping potential and self-reconstruction ability, respectively. As self-imaged bottle beam belong to the family of propagation-invariant beams, it can be used to trap chain of high and low indices microparticles three-dimensionally along the propagation directions, which can be used to periodically stack microparticles (of different refractive index) longitudinally.

  18. Continuous sheathless microparticle and cell patterning using CL-SSAWs (conductive liquid-based standing surface acoustic waves)

    NASA Astrophysics Data System (ADS)

    Nam, Jeonghun; Kim, Jae Young; Lim, Chae Seung

    2017-01-01

    We present continuous, sheathless microparticle patterning using conductive liquid (CL)-based standing surface acoustic waves (SSAWs). Conventional metal electrodes patterned on a piezoelectric substrate were replaced with electrode channels filled with a CL. The device performance was evaluated with 5-μm fluorescent polystyrene particles at different flow rate and via phase shifting. In addition, our device was further applied to continuous concentration of malaria parasites at the sidewalls of the fluidic channel.

  19. Pluronic-Functionalized Silica-Lipid Hybrid Microparticles: Improving the Oral Delivery of Poorly Water-Soluble Weak Bases.

    PubMed

    Rao, Shasha; Richter, Katharina; Nguyen, Tri-Hung; Boyd, Ben J; Porter, Christopher J H; Tan, Angel; Prestidge, Clive A

    2015-12-07

    A Pluronic-functionalized silica-lipid hybrid (Plu-SLH) microparticle system for the oral delivery of poorly water-soluble, weak base drugs is reported for the first time. A highly effective Plu-SLH microparticle system was composed of Labrasol as the lipid phase, Pluronic F127 as the polymeric precipitation inhibitor (PPI), and silica nanoparticles as the solid carrier. For the model drug cinnarizine (CIN), the Plu-SLH delivery system was shown to offer significant biopharmaceutical advantages in comparison with unformulated drug and drug in the silica-lipid hybrid (SLH) system. In vitro two-phase dissolution studies illustrated significantly reduced pH provoked CIN precipitation and an 8- to 14-fold improvement in the extent of dissolution in intestinal conditions. In addition, under simulated intestinal digesting conditions, the Plu-SLH provided approximately three times more drug solubilization than the SLH. Oral administration in rats resulted in superior bioavailability for Plu-SLH microparticles, i.e., 1.6- and 2.1-fold greater than the SLH and the unformulated CIN, respectively. A physical mixture of Pluronic and SLH (Plu&SLH), having the same composition as Plu-SLH, was also evaluated, but showed no significant increase in CIN absorption when compared to unmodified CIN or SLH. This work represents the first study where different methods of incorporating PPI to formulate solid-state lipid-based formulations were compared for the impact on the biopharmaceutical performance. The data suggest that the novel physicochemical properties and structure of the fabricated Plu-SLH microparticle delivery system play an important role in facilitating the synergistic advantage of Labrasol and Pluronic F127 in preventing drug precipitation, and the Plu-SLH provides efficient oral delivery of poorly water-soluble weak bases.

  20. Size based separation of micro-particles using adhesive ciliated surfaces: Mimicing the behaviour of suspension feeders

    NASA Astrophysics Data System (ADS)

    Tripathi, Anurag; Bhattacharya, Amitabh; Balazs, Anna

    2013-03-01

    Separation of different size micro-particles in microfluidic devices is important for many biomedical applications. Inspired by the selective intake of small food particles by marine suspension feeders, we propose a novel separation mechanism of micro-particles using active cilia arrays with adhesive tips. By means of Lattice Boltzmann simulations, we show that mixture of two different size particles with size ratio greater than or equal to two can be nearly completely separated by tuning adhesion strength and cilia stiffness. The proposed technique can be used even at low Reynolds number (Re << 1) where separation mechanisms based on inertial effects will be of little use. For a given cilia-particle interaction, the balance of hydrodynamic and adhesive forces favors capture of particles below a critical size, which can be predicted by a simple analytical model.

  1. Airborne Tactical Intent-Based Conflict Resolution Capability

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Vivona, Robert A.; Roscoe, David A.

    2009-01-01

    Trajectory-based operations with self-separation involve the aircraft taking the primary role in the management of its own trajectory in the presence of other traffic. In this role, the flight crew assumes the responsibility for ensuring that the aircraft remains separated from all other aircraft by at least a minimum separation standard. These operations are enabled by cooperative airborne surveillance and by airborne automation systems that provide essential monitoring and decision support functions for the flight crew. An airborne automation system developed and used by NASA for research investigations of required functionality is the Autonomous Operations Planner. It supports the flight crew in managing their trajectory when responsible for self-separation by providing monitoring and decision support functions for both strategic and tactical flight modes. The paper focuses on the latter of these modes by describing a capability for tactical intent-based conflict resolution and its role in a comprehensive suite of automation functions supporting trajectory-based operations with self-separation.

  2. 3D SERS imaging based on chemically-synthesized highly-symmetric nanoporous silver microparticles

    NASA Astrophysics Data System (ADS)

    Ozaki, Yukihiro; Vantasin, Sanpon; Ji, Wei; Tanaka, Yoshito; Kitahama, Yasutaka; Wongrawee, Kanet; Ekgasit, Sanong

    2016-09-01

    This study presents the synthesis, SERS properties in three dimensions, and an application of 3D symmetric nanoporous silver microparticles. The particles are synthesized by purely chemical process: controlled precipitation of AgCl to acquire highly symmetric AgCl microparticle, followed by in-place to convert AgCl into nanoporous silver. The particles display highly predictable SERS enhancement pattern in three dimensions, which resembles particle shape and retains symmetry. The highly regular enhancement pattern allows an application in the study of inhomogeneity in two-layer polymer system, by improving spatial resolution in Z axis.

  3. Ground extraction from airborne laser data based on wavelet analysis

    NASA Astrophysics Data System (ADS)

    Xu, Liang; Yang, Yan; Jiang, Bowen; Li, Jia

    2007-11-01

    With the advantages of high resolution and accuracy, airborne laser scanning data are widely used in topographic mapping. In order to generate a DTM, measurements from object features such as buildings, vehicles and vegetation have to be classified and removed. However, the automatic extraction of bare earth from point clouds acquired by airborne laser scanning equipment remains a problem in LIDAR data filtering nowadays. In this paper, a filter algorithm based on wavelet analysis is proposed. Relying on the capability of detecting discontinuities of continuous wavelet transform and the feature of multi-resolution analysis, the object points can be removed, while ground data are preserved. In order to evaluate the performance of this approach, we applied it to the data set used in the ISPRS filter test in 2003. 15 samples have been tested by the proposed approach. Results showed that it filtered most of the objects like vegetation and buildings, and extracted a well defined ground model.

  4. Experimental Investigations on Airborne Gravimetry Based on Compressed Sensing

    PubMed Central

    Yang, Yapeng; Wu, Meiping; Wang, Jinling; Zhang, Kaidong; Cao, Juliang; Cai, Shaokun

    2014-01-01

    Gravity surveys are an important research topic in geophysics and geodynamics. This paper investigates a method for high accuracy large scale gravity anomaly data reconstruction. Based on the airborne gravimetry technology, a flight test was carried out in China with the strap-down airborne gravimeter (SGA-WZ) developed by the Laboratory of Inertial Technology of the National University of Defense Technology. Taking into account the sparsity of airborne gravimetry by the discrete Fourier transform (DFT), this paper proposes a method for gravity anomaly data reconstruction using the theory of compressed sensing (CS). The gravity anomaly data reconstruction is an ill-posed inverse problem, which can be transformed into a sparse optimization problem. This paper uses the zero-norm as the objective function and presents a greedy algorithm called Orthogonal Matching Pursuit (OMP) to solve the corresponding minimization problem. The test results have revealed that the compressed sampling rate is approximately 14%, the standard deviation of the reconstruction error by OMP is 0.03 mGal and the signal-to-noise ratio (SNR) is 56.48 dB. In contrast, the standard deviation of the reconstruction error by the existing nearest-interpolation method (NIPM) is 0.15 mGal and the SNR is 42.29 dB. These results have shown that the OMP algorithm can reconstruct the gravity anomaly data with higher accuracy and fewer measurements. PMID:24647125

  5. Knowledge-based architecture for airborne mine and minefield detection

    NASA Astrophysics Data System (ADS)

    Agarwal, Sanjeev; Menon, Deepak; Swonger, C. W.

    2004-09-01

    One of the primary lessons learned from airborne mid-wave infrared (MWIR) based mine and minefield detection research and development over the last few years has been the fact that no single algorithm or static detection architecture is able to meet mine and minefield detection performance specifications. This is true not only because of the highly varied environmental and operational conditions under which an airborne sensor is expected to perform but also due to the highly data dependent nature of sensors and algorithms employed for detection. Attempts to make the algorithms themselves more robust to varying operating conditions have only been partially successful. In this paper, we present a knowledge-based architecture to tackle this challenging problem. The detailed algorithm architecture is discussed for such a mine/minefield detection system, with a description of each functional block and data interface. This dynamic and knowledge-driven architecture will provide more robust mine and minefield detection for a highly multi-modal operating environment. The acquisition of the knowledge for this system is predominantly data driven, incorporating not only the analysis of historical airborne mine and minefield imagery data collection, but also other "all source data" that may be available such as terrain information and time of day. This "all source data" is extremely important and embodies causal information that drives the detection performance. This information is not being used by current detection architectures. Data analysis for knowledge acquisition will facilitate better understanding of the factors that affect the detection performance and will provide insight into areas for improvement for both sensors and algorithms. Important aspects of this knowledge-based architecture, its motivations and the potential gains from its implementation are discussed, and some preliminary results are presented.

  6. Micro-particle manipulation by single beam acoustic tweezers based on hydrothermal PZT thick film

    PubMed Central

    Zhu, Benpeng; Xu, Jiong; Li, Ying; Wang, Tian; Xiong, Ke; Lee, Changyang; Yang, Xiaofei; Shiiba, Michihisa; Takeuchi, Shinichi; Zhou, Qifa; Shung, K. Kirk

    2016-01-01

    Single-beam acoustic tweezers (SBAT), used in laboratory-on-a-chip (LOC) device has promising implications for an individual micro-particle contactless manipulation. In this study, a freestanding hydrothermal PZT thick film with excellent piezoelectric property (d33 = 270pC/N and kt = 0.51) was employed for SBAT applications and a press-focusing technology was introduced. The obtained SBAT, acting at an operational frequency of 50MHz, a low f-number (∼0.9), demonstrated the capability to trap and manipulate a micro-particle sized 10μm in the distilled water. These results suggest that such a device has great potential as a manipulator for a wide range of biomedical and chemical science applications. PMID:27014504

  7. Food-grade protein-based nanoparticles and microparticles for bioactive delivery: fabrication, characterization, and utilization.

    PubMed

    Davidov-Pardo, Gabriel; Joye, Iris J; McClements, David Julian

    2015-01-01

    Proteins can be used to fabricate nanoparticles and microparticles suitable for use as delivery systems for bioactive compounds in pharmaceutical, food, cosmetic, and other products. Food proteins originate from various animal or vegetal sources and exhibit a wide diversity of molecular and physicochemical characteristics, e.g., molecular weight, conformation, flexibility, polarity, charge, isoelectric point, solubility, and interactions. As a result, protein particles can be assembled using numerous different preparation methods, from one or more types of protein or from a combination of a protein and another type of biopolymer (usually a polysaccharide). The final characteristics of the particles produced are determined by the proteins and/or polysaccharides used, as well as the fabrication techniques employed. This chapter provides an overview of the functional properties of food proteins that can be used to assemble nanoparticles and microparticles, the fabrication techniques available to create those particles, the factors that influence their stability, and their potential applications within the food industry.

  8. Airborne Evaluation and Demonstration of a Time-Based Airborne Inter-Arrival Spacing Tool

    NASA Technical Reports Server (NTRS)

    Lohr, Gary W.; Oseguera-Lohr, Rosa M.; Abbott, Terence S.; Capron, William R.; Howell, Charles T.

    2005-01-01

    An airborne tool has been developed that allows an aircraft to obtain a precise inter-arrival time-based spacing interval from the preceding aircraft. The Advanced Terminal Area Approach Spacing (ATAAS) tool uses Automatic Dependent Surveillance-Broadcast (ADS-B) data to compute speed commands for the ATAAS-equipped aircraft to obtain this inter-arrival spacing behind another aircraft. The tool was evaluated in an operational environment at the Chicago O'Hare International Airport and in the surrounding terminal area with three participating aircraft flying fixed route area navigation (RNAV) paths and vector scenarios. Both manual and autothrottle speed management were included in the scenarios to demonstrate the ability to use ATAAS with either method of speed management. The results on the overall delivery precision of the tool, based on a target spacing of 90 seconds, were a mean of 90.8 seconds with a standard deviation of 7.7 seconds. The results for the RNAV and vector cases were, respectively, M=89.3, SD=4.9 and M=91.7, SD=9.0.

  9. Preparation and characterization of structured hydrogel microparticles based on cross-linked hyperbranched polyglycerol.

    PubMed

    Oudshoorn, Marion H M; Penterman, Roel; Rissmann, Robert; Bouwstra, Joke A; Broer, Dirk J; Hennink, Wim E

    2007-11-06

    The aim of this work was to obtain well-defined HyPG-MA (methacrylated hyperbranched polyglycerol) microparticles with uniform sizes. Therefore, three different preparation methods were evaluated. First, we assessed a micromolding technique using rigid SU-8 (a photoresist based on epoxies) grids. Independent of the surface treatment of the SU-8 grid or the type of polymer used, approximately 50% of the microgels remained attached to the SU-8 grid or broke into smaller particles during the release process in which drying of the gels was followed by a sonication process. Although 90% methacrylate conversion could be obtained, this method has some additional drawbacks as the obtained dried microgels did not rehydrate completely after the drying step. Second, a soft micromolding technique was evaluated using elastomeric PDMS (poly(dimethyl siloxane)) grids. The use of these flexible grids resulted in a high yield (80-90% yield; >90% methacrylate conversion) of microgels with a well-defined size and shape (squares 100 microm x 100 microm x 50 microm or hexagons with Ø 30 microm and a thickness of 20 microm) without the occurrence of water evaporation. However, a number of particles showed a less-defined shape as not all grids could be filled well. The microgels showed restricted swelling, implying that these gels are dimensionally stable. Third, an alternative method referred to as photolithography was evaluated. This method was suitable to tailor accurately the size and shape of HyPG-MA microgels and additionally gained 100% yield. Well-defined HyPG-MA microgels in the size range of 200-1400 microm (thickness of 6, 20, or 50 microm), with a methacrylate conversion of >90%, could easily be prepared by adding an inhibitor (e.g., 1% (w/v) of vitamin C) to the polymer solution to inhibit dark polymerization. Microgels in the size range of 30-100 microm (>90% conversion) could only be obtained when applying the photomask in direct contact with the polymer solution and

  10. Development of a microparticle-based dry powder inhalation formulation of ciprofloxacin hydrochloride applying the quality by design approach.

    PubMed

    Karimi, Keyhaneh; Pallagi, Edina; Szabó-Révész, Piroska; Csóka, Ildikó; Ambrus, Rita

    2016-01-01

    Pulmonary drug delivery of ciprofloxacin hydrochloride offers effective local antibacterial activity and convenience of easy application. Spray drying is a trustworthy technique for the production of ciprofloxacin hydrochloride microparticles. Quality by design (QbD), an up-to-date regulatory-based quality management method, was used to predict the final quality of the product. According to the QbD-based theoretical preliminary parameter ranking and priority classification, dry powder inhalation formulation tests were successfully performed in practice. When focusing on the critical parameters, the practical development was more effective and was in correlation with our previous findings. Spray drying produced spherical microparticles. The dry powder formulations prepared were examined by particle size analysis, scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction, differential scanning calorimetry, and in vitro drug release and aerodynamic particle size analyses were also performed. These formulations showed an appropriate particle size ranging between 2 and 4 μm and displayed an enhanced aerosol performance with fine particle fraction up to 80%.

  11. Development of a microparticle-based dry powder inhalation formulation of ciprofloxacin hydrochloride applying the quality by design approach

    PubMed Central

    Karimi, Keyhaneh; Pallagi, Edina; Szabó-Révész, Piroska; Csóka, Ildikó; Ambrus, Rita

    2016-01-01

    Pulmonary drug delivery of ciprofloxacin hydrochloride offers effective local antibacterial activity and convenience of easy application. Spray drying is a trustworthy technique for the production of ciprofloxacin hydrochloride microparticles. Quality by design (QbD), an up-to-date regulatory-based quality management method, was used to predict the final quality of the product. According to the QbD-based theoretical preliminary parameter ranking and priority classification, dry powder inhalation formulation tests were successfully performed in practice. When focusing on the critical parameters, the practical development was more effective and was in correlation with our previous findings. Spray drying produced spherical microparticles. The dry powder formulations prepared were examined by particle size analysis, scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction, differential scanning calorimetry, and in vitro drug release and aerodynamic particle size analyses were also performed. These formulations showed an appropriate particle size ranging between 2 and 4 μm and displayed an enhanced aerosol performance with fine particle fraction up to 80%. PMID:27784991

  12. Graphene-based electrochemical sensor for detection of 2,4,6-trinitrotoluene (TNT) in seawater: the comparison of single-, few-, and multilayer graphene nanoribbons and graphite microparticles.

    PubMed

    Goh, Madeline Shuhua; Pumera, Martin

    2011-01-01

    The detection of explosives in seawater is of great interest. We compared response single-, few-, and multilayer graphene nanoribbons and graphite microparticle-based electrodes toward the electrochemical reduction of 2,4,6-trinitrotoluene (TNT). We optimized parameters such as accumulation time, accumulation potential, and pH. We found that few-layer graphene exhibits about 20% enhanced signal for TNT after accumulation when compared to multilayer graphene nanoribbons. However, graphite microparticle-modified electrode provides higher sensitivity, and there was no significant difference in the performance of single-, few-, and multilayer graphene nanoribbons and graphite microparticles for the electrochemical detection of TNT. We established the limit of detection of TNT in untreated seawater at 1 μg/mL.

  13. Preparation and Evaluation of Enteric-Coated Chitosan Derivative-Based Microparticles Loaded with Salmon Calcitonin as an Oral Delivery System

    PubMed Central

    Onishi, Hiraku; Tokuyasu, Ayako

    2016-01-01

    Background: The production of protein drugs has recently increased due to advances in biotechnology, but their clinical use is generally limited to parenteral administration due to low absorption in non-parenteral administration. Therefore, non-parenteral delivery systems allowing sufficient absorption draw much attention. Methods: Microparticles (MP) were prepared using chitosan-4-thio-butylamidine conjugate (Ch-TBA), trimethyl-chitosan (TMC), and chitosan (Ch). Using salmon calcitonin (sCT) as a model protein drug, Ch-TBA-, Ch-TBA/TMC (4/1)-, and Ch-based MP were produced, and their Eudragit L100 (Eud)-coated MP, named Ch-TBA-MP/Eud, Ch-TBA/TMC-MP/Eud, and Ch-MP/Eud, respectively, were prepared as oral delivery systems. These enteric-coated microparticles were examined in vitro and in vivo. Results: All microparticles before and after enteric coating had a submicron size (600–800 nm) and micrometer size (1300–1500 nm), respectively. In vitro release patterns were similar among all microparticles; release occurred gradually, and the release rate was slower at pH 1.2 than at pH 6.8. In oral ingestion, Ch-TBA-MP/Eud suppressed plasma Ca levels most effectively among the microparticles tested. The relative effectiveness of Ch-TBA-MP/Eud to the intramuscular injection was 8.6%, while the sCT solution showed no effectiveness. Conclusion: The results suggest that Eud-coated Ch-TBA-based microparticles should have potential as an oral delivery system of protein drugs. PMID:27649146

  14. Graph-based segmentation of airborne lidar point clouds

    NASA Astrophysics Data System (ADS)

    Vilariño, David L.; Martínez, Jorge; Rivera, Francisco F.; Cabaleiro, José C.; Pena, Tomás. F.

    2016-10-01

    In this paper, a graph-based technique originally intended for image processing has been tailored for the segmentation of airborne LiDAR points, that are irregularly distributed. Every LiDAR point is labeled as a node and interconnected as a graph extended to its neighborhood and defined in a 4D feature space (x, y, z, and the reflection intensity). The interconnections between pairs of neighboring nodes are weighted based on the distance in the feature space. The segmentation consists in an iterative process of classification of nodes into homogeneous groups based on their similarity. This approach is intended to be part of a complete system for classification of structures from LiDAR point clouds in applications needing fast response times. In this sense, a study of the performance/accuracy trade-off has been performed, extracting some conclusions about the benefits of the proposed solution.

  15. Airborne LiDAR based Mapping of Alpine Permafrost Distribution

    NASA Astrophysics Data System (ADS)

    Sailer, Rudolf; Bollmann, Erik; Briese, Christian; Fischer, Andrea; Krainer, Karl; Pfeifer, Norbert; Rieg, Lorenzo; Stötter, Johann

    2010-05-01

    Recent global climate change findings show an acceleration of melting of glaciers, ice-sheets and ice caps. Extended remote sensing and in-situ measurements demonstrate that glaciers are losing mass at an increasing rate. In contrast to glaciers with large mass losses (about 5 m per year at the lower parts of the glacier tongue of Hintereisferner, Ötztal Alps, Tyrol, Austria), moderate to small changing rates (centimetres to decimetres per year) characterize the surface variations caused by permafrost degradation in high mountain areas. For a reliable mapping of the spatial permafrost distribution advanced remote sensing techniques with a high degree of vertical accuracy have to be applied. Recent studies have shown that airborne LiDAR survey in mountainous regions provide high-resolution spatial data with a vertical accuracy range of centimetre to decimetre. This prediction is based on a world wide unique dataset of 18 airborne LiDAR campaigns covering the Hintereisferner region . Furthermore, the according multi-temporal dataset offers the opportunity to identify surface changes (altitudinal changes) outside glaciated areas, which have not been observed until now. Excluding gravitational induced processes these altitudinal changes have to be assigned to alpine permafrost degradations, although detailed information from prominent permafrost features like rock glaciers are missing. Beyond the detection of the climate induced permafrost degradation, based on the multi-temporal LiDAR data set, the method (point based and avoiding point to raster conversions) will be applied to identify altitudinal changes and displacement rates of prominent rock glaciers in the Stubai and Ötztal Alps (Tyrol, Austria). In contrast to the multi-temporal approach, with at least one LiDAR terrain model per ablation period (June to September), the analysis of the rock glacier features is based on a data set of only two LiDAR campaigns, which were carried out with a time shift of four

  16. Antimicrobial Properties of Microparticles Based on Carmellose Cross-Linked by Cu2+ Ions

    PubMed Central

    Kejdušová, Martina; Vysloužil, Jakub; Kubová, Kateřina; Celer, Vladimír; Krásna, Magdaléna; Pechová, Alena; Vyskočilová, Věra; Košťál, Vratislav

    2015-01-01

    Carmellose (CMC) is frequently used due to its high biocompatibility, biodegradability, and low immunogenicity for development of site-specific or controlled release drug delivery systems. In this experimental work, CMC dispersions in two different concentrations (1% and 2%) cross-linked by copper (II) ions (0.5, 1, 1.5, or 2.0 M CuCl2) were used to prepare microspheres with antimicrobial activity against Escherichia coli and Candida albicans, both frequently occurring pathogens which cause vaginal infections. The microparticles were prepared by an ionotropic gelation technique which offers the unique possibility to entrap divalent copper ions in a CMC structure and thus ensure their antibacterial activity. Prepared CMC microspheres exhibited sufficient sphericity. Both equivalent diameter and copper content were influenced by CMC concentration, and the molarity of copper (II) solution affected only the copper content results. Selected samples exhibited stable but pH-responsive behaviour in environments which corresponded with natural (pH 4.5) and inflamed (pH 6.0) vaginal conditions. All the tested samples exhibited proven substantial antimicrobial activity against both Gram-negative bacteria Escherichia coli and yeast Candida albicans. Unexpectedly, a crucial parameter for microsphere antimicrobial activity was not found in the copper content but in the swelling capacity of the microparticles and in the degree of CMC surface shrinking. PMID:26090444

  17. Ingestion and digestion studies in Tetrahymena pyriformis based on chemically modified microparticles.

    PubMed

    Dürichen, Hendrike; Siegmund, Lisa; Burmester, Anke; Fischer, Martin S; Wöstemeyer, Johannes

    2016-02-01

    Recognition of food and, in consequence, ingestion of digestible particles is a prerequisite for energy metabolism in Tetrahymena pyriformis. Understanding why some particles are ingested and digested, whereas others are not, is important for many fields of research, e.g. survival of pathogens in single-celled organisms or establishment of endosymbiotic relationships. We offered T. pyriformis synthetical bovine-serum-albumin (BSA)-methacrylate microparticles of approximately 5.5 μm diameter and studied the ciliates' ingestion and digestion behaviour. Different staining techniques as well as co-feeding with a transformant strain of Escherichia coli revealed that T. pyriformis considers these particles as natural food source and shows no feeding preference. Further, they are ingested at normal rates and may serve as sole food source. A pivotal advantage of these particles is the convenient modification of their surface by binding different ligands resulting in defined surface properties. Ingestion rate of modified microparticles either increased (additional BSA, enzymes) or decreased (amino acids). Furthermore, we investigated glycosylation patterns by lectin binding. By binding different substances to the surface in combination with various staining techniques, we provide a versatile experimental tool for elucidating details on food recognition and digestion that may allow to study evading digestion by pathogens or potential endosymbionts, too.

  18. Critical rolling angle of microparticles

    NASA Astrophysics Data System (ADS)

    Farzi, Bahman; Vallabh, Chaitanya K. P.; Stephens, James D.; Cetinkaya, Cetin

    2016-03-01

    At the micrometer-scale and below, particle adhesion becomes particularly relevant as van der Waals force often dominates volume and surface proportional forces. The rolling resistance of microparticles and their critical rolling angles prior to the initiation of free-rolling and/or complete detachment are critical in numerous industrial processes and natural phenomenon involving particle adhesion and granular dynamics. The current work describes a non-contact measurement approach for determining the critical rolling angle of a single microparticle under the influence of a contact-point base-excitation generated by a transient displacement field of a prescribed surface acoustic wave pulse and reports the critical rolling angle data for a set of polystyrene latex microparticles.

  19. An all fiber apparatus for microparticles selective manipulation based on a variable ratio coupler and a microfiber

    NASA Astrophysics Data System (ADS)

    Li, Baoli; Luo, Wei; Xu, Fei; Lu, Yanqing

    2016-09-01

    We propose an all fiber apparatus based on a variable ratio coupler which can transport microparticles controllably and trap particles one by one along a microfiber. By connecting two output ports of a variable ratio coupler with two end pigtails of a microfiber and launching a 980 nm laser into the variable ratio coupler, particles in suspension were trapped to the waist of microfiber due to a gradient force and then transported along the microfiber due to a total scattering force generated by two counter-propagating beams. The direction of transportation was controlled by altering the coupling ratio of the variable ratio coupler. When the intensities of two output ports were equivalent, trapped particles stayed at fixed positions. With time going, another particle around the micro fiber was trapped onto the microfiber. There were three particles trapped in total in our experiment. This technique combines with the function of conventional tweezers and optical conveyor.

  20. Potential application of voltammetry of microparticles for dating porcine blood-based binding media used in Taiwanese architectural polychromies.

    PubMed

    Doménech, Antonio; Doménech-Carbó, María Teresa; Lee, Yu; Osete-Cortina, Laura

    2012-10-01

    A method for dating Hemoglobine-containing archaeological samples using the voltammetry of microparticles is described. This is based on the record of the voltammetric response of such materials attached to paraffin-impregnated graphite electrodes in contact with aqueous acetate buffer. Signals attributable to the Fe(III)/Fe(II) iron couple and their catalytic enhancement in the presence of H(2)O(2) can be correlated, via first-order reaction kinetics, with the time of aging of the samples. The method has been applied to the study and dating of the polychromed architectural decoration of different parts of the architectural complex of the Longshan Temple in Lukang (18(th)  century, Taiwan).

  1. Particulate matter induces prothrombotic microparticle shedding by human mononuclear and endothelial cells.

    PubMed

    Neri, Tommaso; Pergoli, Laura; Petrini, Silvia; Gravendonk, Lotte; Balia, Cristina; Scalise, Valentina; Amoruso, Angela; Pedrinelli, Roberto; Paggiaro, Pierluigi; Bollati, Valentina; Celi, Alessandro

    2016-04-01

    Particulate airborne pollution is associated with increased cardiopulmonary morbidity. Microparticles are extracellular vesicles shed by cells upon activation or apoptosis involved in physiological processes such as coagulation and inflammation, including airway inflammation. We investigated the hypothesis that particulate matter causes the shedding of microparticles by human mononuclear and endothelial cells. Cells, isolated from the blood and the umbilical cords of normal donors, were cultured in the presence of particulate from a standard reference. Microparticles were assessed in the supernatant as phosphatidylserine concentration. Microparticle-associated tissue factor was assessed by an one-stage clotting assay. Nanosight technology was used to evaluate microparticle size distribution. Particulate matter induces a dose- and time- dependent, rapid (1h) increase in microparticle generation in both cells. These microparticles express functional tissue factor. Particulate matter increases intracellular calcium concentration and phospholipase C inhibition reduces microparticle generation. Nanosight analysis confirmed that upon exposure to particulate matter both cells express particles with a size range consistent with the definition of microparticles (50-1000 nm). Exposure of mononuclear and endothelial cells to particulate matter upregulates the generation of microparticles at least partially mediated by calcium mobilization. This observation might provide a further link between airborne pollution and cardiopulmonary morbidity.

  2. Producing xylan/Eudragit® S100-based microparticles by chemical and physico-mechanical approaches as carriers for 5-aminosalicylic acid.

    PubMed

    Silva, Acarilia Eduardo; Oliveira, Elquio Eleamen; Gomes, Monique C Salgado; Marcelino, Henrique Rodrigues; Silva, Karen C Holanda; Souza, Bartolomeu Santos; Nagashima, Toshiyuki; Ayala, Alejandro Pedro; Oliveira, Anselmo Gomes; do Egito, Eryvaldo Sócrates Tabosa

    2013-01-01

    Xylan is a biopolymer found in a variety of cell wall plants. Eudragit® S-100 (ES100), a pH-dependent polymer, is used as a coating material in gastroresistant delivery systems. In this study, microparticles based on both polymers were produced by interfacial cross-linking polymerisation and/or spray-drying technique in order to investigate feasibility and stability of the systems. Size and morphology of the microparticles were characterised by optical and SEM while FT-IR, thermal analysis (TG/DTA), and X-ray diffraction (XRD) evaluated the drug-polymer interactions and the thermal behaviour of the systems. FT-IR confirmed the absence of chemical interaction between the polymers. TG/DTA analysis showed a higher stability for spray-dried microparticles and XRD data proved the amorphous feature of both carriers. The results reveal that xylan/ES100 microparticles can be produced by chemical or physico-mechanical ways, the latter being the best option due to the lack of toxic cross-linking agents and easy scale-up.

  3. Formulation, stability and pharmacokinetics of sugar-based salmon calcitonin-loaded nanoporous/nanoparticulate microparticles (NPMPs) for inhalation.

    PubMed

    Amaro, Maria Inês; Tewes, Frederic; Gobbo, Oliviero; Tajber, Lidia; Corrigan, Owen I; Ehrhardt, Carsten; Healy, Anne Marie

    2015-04-10

    A challenge exists to produce dry powder inhaler (DPI) formulations with appropriate formulation stability, biological activity and suitable physicochemical and aerosolisation characteristics that provide a viable alternative to parenteral formulations. The present study aimed to produce sugar-based nanoporous/nanoparticulate microparticles (NPMPs) loaded with a therapeutic peptide - salmon calcitonin (sCT). The physicochemical properties of the powders and their suitability for pulmonary delivery of sCT were determined. Production of powders composed of sCT loaded into raffinose or trehalose with or without hydroxypropyl-β-cyclodextrin was carried out using a laboratory scale spray dryer. Spray dried microparticles were spherical, porous and of small geometric size (≤2 μm). Aerodynamic assessment showed that the fine particle fraction (FPF) less than 5 μm ranged from 45 to 86%, depending on the formulation. The mass median aerodynamic diameter (MMAD) varied between 1.9 and 4.7 μm. Compared to unprocessed sCT, sCT:raffinose composite systems presented a bioactivity of approximately 100% and sCT:trehalose composite systems between 70-90% after spray drying. Storage stability studies demonstrated composite systems with raffinose to be more stable than those containing trehalose. These sugar-based salmon calcitonin-loaded NPMPs retain reasonable sCT bioactivity and have micromeritic and physicochemical properties which indicate their suitability for pulmonary delivery. Formulations presented a similar pharmacokinetic profile to sCT solution. Hence the advantage of a dry powder formulation is its non-invasive delivery route and ease of administration of the sCT.

  4. Functionalized magnetic microparticle-based colorimetric platform for influenza A virus detection

    NASA Astrophysics Data System (ADS)

    Chen, Chaohui; Zou, Zhong; Chen, Lu; Ji, Xinghu; He, Zhike

    2016-10-01

    A colorimetric platform for influenza A virus detection was developed by using the high efficiency of enzymatic catalysis and the reduction of gold ions with hydrogen peroxide. Aptamer-functionalized magnetic microparticles were synthesized to capture the influenza A virus. This was followed by the binding of ConA-GOx-AuNPs to the H3N2 virus through the ConA-glycan interaction. The sandwich complex was subsequently dispersed in glucose solution to trigger an enzymatic reaction to produce hydrogen peroxide, which controlled the growth of gold nanoparticles and produced colored solutions. The determination of H3N2 concentration was realized by comparing the two differently colored gold nanoparticles. This method could detect the target virus as low as 11.16 μg ml-1. Furthermore, it opens new opportunities for sensitive and colorimetric detection of viruses and proteins.

  5. A wing pod-based millimeter wavelength airborne cloud radar

    NASA Astrophysics Data System (ADS)

    Vivekanandan, J.; Ellis, S.; Tsai, P.; Loew, E.; Lee, W. C.; Emmett, J.; Dixon, M.; Burghart, C.; Rauenbuehler, S.

    2015-04-01

    This paper describes a novel, airborne pod-based millimeter wavelength radar. Its frequency of operation is 94 GHz (3 mm wavelength). The radar has been designed to fly on the NCAR Gulfstream V HIAPER aircraft; however, it could be deployed on other similarly equipped aircraft. The pod-based configuration occupies minimum cabin space and maximizes scan coverage. The radar system is capable of collecting observations in a staring mode between zenith and nadir or in a scanning mode. Standard pulse-pair estimates of moments and raw time series of backscattered signals are recorded. The radar system design and characteristics, as well as techniques for calibrating reflectivity and correcting Doppler velocity for aircraft attitude and motion are described. The radar can alternatively be deployed in a ground-based configuration, housed in the 20 ft shipping container it shares with the High Spectral Resolution Lidar (HSRL). The radar was tested both on the ground and in flight. Preliminary measurements of Doppler and polarization measurements were collected and examples are presented.

  6. A wing pod-based millimeter wavelength airborne cloud radar

    NASA Astrophysics Data System (ADS)

    Vivekanandan, J.; Ellis, S.; Tsai, P.; Loew, E.; Lee, W.-C.; Emmett, J.; Dixon, M.; Burghart, C.; Rauenbuehler, S.

    2015-08-01

    This paper describes a novel, airborne pod-based millimeter (mm) wavelength radar. Its frequency of operation is 94 GHz (3 mm wavelength). The radar has been designed to fly on the NCAR Gulfstream V HIAPER aircraft; however, it could be deployed on other similarly equipped aircraft. The pod-based configuration occupies minimum cabin space and maximizes scan coverage. The radar system is capable of collecting observations in a staring mode between zenith and nadir or in a scanning mode. Standard pulse-pair estimates of moments and raw time series of backscattered signals are recorded. The radar system design and characteristics as well as techniques for calibrating reflectivity and correcting Doppler velocity for aircraft attitude and motion are described. The radar can alternatively be deployed in a ground-based configuration, housed in the 20 ft shipping container it shares with the High Spectral Resolution Lidar (HSRL). The radar was tested both on the ground and in flight. Preliminary measurements of Doppler and polarization measurements were collected and examples are presented.

  7. Design of UV-Absorbing Polypropylene Films with Polymeric Benzotriaziole Based Nano- and Microparticle Coatings.

    PubMed

    Cohen, Sarit; Haham, Hai; Pellach, Michal; Margel, Shlomo

    2017-01-11

    UV-absorbing nanoparticles (NPs) and microparticles (MPs) were prepared by emulsion and dispersion copolymerization of the vinylic monomer 2-(2'-hydroxy-5'-methacryloxyethylphenyl)-2H-benzotriazole (Norbloc (NB)) with the crosslinking monomer divinylbenzene. The effect of the initiator concentration on the size and size distribution of the polyNB (PNB) particles was elucidated. Thin coatings of the formed PNB NPs or MPs of 19 ± 2 and 200 ± 25 nm dry diameter, respectively, onto polypropylene (PP) films were then prepared and characterized. Increasing the concentration or thickness of the PNB NP or MP thin coatings on the PP films decreased their UV transmittance, up to complete UV blocking with just 2 μm of a 4% NP coating. Migration of the UV-absorbing agents from the coated PP films was not observed during three years of storage at room temperature, offering a unique solution to current problems of migration of UV-absorbing additives. The thin coatings obtained by the PNB NPs were superior to those of the PNB MPs, in that no UV transmittance or loss of optical properties of the PP films were observed for the NP coatings, while the coatings produced by the PNB MPs resulted in damaged optical properties, particularly increasing the haze, and achieved incomplete UV blocking.

  8. Tannic acid incorporation in chitosan-based microparticles and in vitro controlled release.

    PubMed

    Aelenei, Neculai; Popa, Marcel Ionel; Novac, Ovidiu; Lisa, Gabriela; Balaita, Lacramioara

    2009-05-01

    Chitosan, a natural polycationic polysaccharide, was coupled with two polyanionic polymers: Na-alginate and carboxymethylcellulose (CMC) and with tannic acid (TA) obtaining three species of self-assembled complexes: chitosan/alginate/TA (sample 1), chitosan/TA (sample 2) and chitosan/CMC/TA (sample 3). The microparticle formation was achieved by dropwise addition of one solution into other by using a coaxial airflow sprayer. These systems were characterized with regard to particle size distribution, thermal stability, tannic acid entrapment efficiency. Sample 2 showed quite a different behavior compared to the other two samples; the particle diameter is located in the nanometric region, the quantity of incorporated tannic acid is higher than in the other two samples and the material shows better thermal stability. The release of tannic acid from these complexes was studied in water (pH = 5.89), phosphates buffer (pH = 7.04) and acetate buffer (pH = 4.11). These studies revealed two distinct periods in tannic acid delivery process: an initial period, varying between 4 and 10 h, characterized by a high release rate with a delivered tannic acid amount of approximately 80% of the incorporated polyphenol and a second period, which starts after 20 to 30 h of delivery and it ends after approximately 120 h, when the release process takes place with low and constant rate and the kinetic curve is linear--characteristic for a zero order kinetic.

  9. In situ microparticle analysis of marine phytoplankton cells with infrared laser-based optical tweezers

    NASA Astrophysics Data System (ADS)

    Sonek, G. J.; Liu, Y.; Iturriaga, R. H.

    1995-11-01

    We describe the application of infrared optical tweezers to the in situ microparticle analysis of marine phytoplankton cells. A Nd:YAG laser (lambda=3D 1064 nm) trap is used to confine and manipulate single Nannochloris and Synechococcus cells in an enriched seawater medium while spectral fluorescence and Lorenz-Mie backscatter signals are simultaneously acquired under a variety of excitation and trapping conditions. Variations in the measured fluorescence intensities of chlorophyll a (Chl a) and phycoerythrin pigments in phytoplankton cells are observed. These variations are related, in part, to basic intrasample variability, but they also indicate that increasing ultraviolet-exposure time and infrared trapping power may have short-term effects on cellular physiology that are related to Chl a photobleaching and laser-induced heating, respectively. The use of optical tweezers to study the factors that affect marine cell physiology and the processes of absorption, scattering, and attenuation by individual cells, organisms, and particulate matter that contribute to optical closure on a microscopic scale are also described. (c)1995 Optical Society of America

  10. (DCT-FY08) Target Detection Using Multiple Modality Airborne and Ground Based Sensors

    DTIC Science & Technology

    2013-03-01

    AFRL-OSR-VA-TR-2013-0005 (DCT-FY08) Target Detection Using Multiple Modality Airborne and Ground Based Sensors Avideh Zakhor...Include area code) 17-08-2012 FINAL 4-1-2008 to 11-30-2011 (DCT-FY08) Target Detection Using Multiple Modality Airborne and Ground Based Sensors ...automatic, photo-realistic 3D models of building interiors. We have developed an ambulatory human operated backpack system made of a suite of sensors

  11. Column Closure Studies of Lower Tropospheric Aerosol and Water Vapor During ACE-Asia Using Airborne Sunphotometer, Airborne In-Situ and Ship-Based Lidar Measurements

    NASA Technical Reports Server (NTRS)

    Schmid, B.; Hegg, A.; Wang, J.; Bates, D.; Redemann, J.; Russells, P. B.; Livingston, J. M.; Jonsson, H. H.; Welton, E. J.; Seinfield, J. H.

    2003-01-01

    We assess the consistency (closure) between solar beam attenuation by aerosols and water vapor measured by airborne sunphotometry and derived from airborne in-situ, and ship-based lidar measurements during the April 2001 Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia). The airborne data presented here were obtained aboard the Twin Otter aircraft. Comparing aerosol extinction o(550 nm) from four different techniques shows good agreement for the vertical distribution of aerosol layers. However, the level of agreement in absolute magnitude of the derived aerosol extinction varied among the aerosol layers sampled. The sigma(550 nm) computed from airborne in-situ size distribution and composition measurements shows good agreement with airborne sunphotometry in the marine boundary layer but is considerably lower in layers dominated by dust if the particles are assumed to be spherical. The sigma(550 nm) from airborne in-situ scattering and absorption measurements are about approx. 13% lower than those obtained from airborne sunphotometry during 14 vertical profiles. Combining lidar and the airborne sunphotometer measurements reveals the prevalence of dust layers at altitudes up to 10 km with layer aerosol optical depth (from 3.5 to 10 km altitude) of approx. 0.1 to 0.2 (500 nm) and extinction-to-backscatter ratios of 59-71 sr (523 nm). The airborne sunphotometer aboard the Twin Otter reveals a relatively dry atmosphere during ACE- Asia with all water vapor columns less than 1.5 cm and water vapor densities w less than 12 g/cu m. Comparing layer water vapor amounts and w from the airborne sunphotometer to the same quantities measured with aircraft in-situ sensors leads to a high correlation (r(sup 3)=0.96) but the sunphotometer tends to underestimate w by 7%.

  12. New synthesis and characterization of (+)-lysergic acid diethylamide (LSD) derivatives and the development of a microparticle-based immunoassay for the detection of LSD and its metabolites.

    PubMed

    Li, Z; Goc-Szkutnicka, K; McNally, A J; Pilcher, I; Polakowski, S; Vitone, S; Wu, R S; Salamone, S J

    1997-01-01

    In this paper are reported the synthesis and characterization of three LSD derivatives. On the basis of several analytical characterization studies, the most stable derivative has been selected and a procedure to covalently link the derivative to polystyrene microparticles through a carrier protein has been developed. In addition, two new LSD immunogens have been synthesized and characterized, and from these immunogens antibodies that recognize not only LSD but also several major LSD metabolites have been generated. Using the selected derivative and antibody, a homogeneous microparticle-based immunoassay has been developed for the detection of LSD in human urine with the required sensitivity and specificity for an effective screening assay. The performance of this LSD OnLine assay has been evaluated using the criteria of precision, cross-reactivity, correlation to the Abuscreen LSD RIA and GC/MS/MS, assay specificity, and limit of detection.

  13. Mapping methane emission sources over California based on airborne measurements

    NASA Astrophysics Data System (ADS)

    Karl, T.; Guha, A.; Peischl, J.; Misztal, P. K.; Jonsson, H.; Goldstein, A. H.; Ryerson, T. B.

    2011-12-01

    The California Global Warming Solutions Act of 2006 (AB 32) has created a need to accurately characterize the emission sources of various greenhouse gases (GHGs) and verify the existing state GHG inventory. Methane (CH4) is a major GHG with a global warming potential of 20 times that of CO2 and currently constitutes about 6% of the total statewide GHG emissions on a CO2 equivalent basis. Some of the major methane sources in the state are area sources where methane is biologically produced (e.g. dairies, landfills and waste treatment plants) making bottom-up estimation of emissions a complex process. Other potential sources include fugitive emissions from oil extraction processes and natural gas distribution network, emissions from which are not well-quantified. The lack of adequate field measurement data to verify the inventory and provide independently generated estimates further contributes to the overall uncertainty in the CH4 inventory. In order to gain a better perspective of spatial distribution of major CH4 sources in California, a real-time measurement instrument based on Cavity Ring Down Spectroscopy (CRDS) was installed in a Twin Otter aircraft for the CABERNET (California Airborne BVOC Emissions Research in Natural Ecosystems Transects) campaign, where the driving research goal was to understand the spatial distribution of biogenic VOC emissions. The campaign took place in June 2011 and encompassed over forty hours of airborne CH4 and CO2 measurements during eight unique flights which covered much of the Central Valley and its eastern edge, the Sacramento-San Joaquin delta and the coastal range. The coincident VOC measurements, obtained through a high frequency proton transfer reaction mass spectrometer (PTRMS), aid in CH4 source identification. High mixing ratios of CH4 (> 2000 ppb) are observed consistently in all the flight transects above the Central Valley. These high levels of CH4 are accompanied by high levels of methanol which is an important

  14. Microparticles with hierarchical porosity

    DOEpatents

    Petsev, Dimiter N; Atanassov, Plamen; Pylypenko, Svitlana; Carroll, Nick; Olson, Tim

    2012-12-18

    The present disclosure provides oxide microparticles with engineered hierarchical porosity and methods of manufacturing the same. Also described are structures that are formed by templating, impregnating, and/or precipitating the oxide microparticles and method for forming the same. Suitable applications include catalysts, electrocatalysts, electrocatalysts support materials, capacitors, drug delivery systems, sensors and chromatography.

  15. The antibody-based magnetic microparticle immunoassay using p-FET sensing platform for Alzheimer's disease pathogenic factor

    NASA Astrophysics Data System (ADS)

    Kim, Chang-Beom; Kim, Kwan-Soo; Song, Ki-Bong

    2013-05-01

    The importance of early Alzheimer's disease (AD) detection has been recognized to diagnose people at high risk of AD. The existence of intra/extracellular beta-amyloid (Aβ) of brain neurons has been regarded as the most archetypal hallmark of AD. The existing computed-image-based neuroimaging tools have limitations on accurate quantification of nanoscale Aβ peptides due to optical diffraction during imaging processes. Therefore, we propose a new method that is capable of evaluating a small amount of Aβ peptides by using photo-sensitive field-effect transistor (p-FET) integrated with magnetic force-based microbead collecting platform and selenium(Se) layer (thickness ~700 nm) as an optical filter. This method demonstrates a facile approach for the analysis of Aβ quantification using magnetic force and magnetic silica microparticles (diameter 0.2~0.3 μm). The microbead collecting platform mainly consists of the p-FET sensing array and the magnet (diameter ~1 mm) which are placed beneath each sensing region of the p-FET, which enables the assembly of the Aβ antibody conjugated microbeads, captures the Aβ peptides from samples, measures the photocurrents generated by the Q-dot tagged with Aβ peptides, and consequently results in the effective Aβ quantification.

  16. Dielectrophoresis-based integrated Lab-on-Chip for nano and micro-particles manipulation and capacitive detection.

    PubMed

    Miled, Mohamed Amine; Massicotte, Geneviève; Sawan, Mohamad

    2012-04-01

    We present in this paper a new Lab-on-Chip (LoC) architecture for dielectrophoresis-based cell manipulation, detection, and capacitive measurement. The proposed LoC is built around a CMOS full-custom chip and a microfluidic structure. The CMOS chip is used to deliver all parameters required to control the dielectrophoresis (DEP) features such as frequency, phase, and amplitude of signals spread on in-channel electrodes of the LoC. It is integrated to the LoC and experimental results are related to micro and nano particles manipulation and detection in a microfluidic platform. The proposed microsystem includes an on-chip 27-bit frequency divider, a digital phase controller with a 3.6° phase shift resolution and a 2.5 V dynamic range. The sensing module is composed of a 3 × 3 capacitive sensor array with 10 fF per mV sensitivity, and a dynamic range of 1.5 V. The obtained results show an efficient nano and micro-particles (PC05N, PA04N and PS03N) separation based on frequency segregation with low voltages less than 1.7 V and a fully integrated and reconfigurable system.

  17. In vivo detection of lipid-based nano- and microparticles in the outermost human stratum corneum by EDX analysis.

    PubMed

    Iannuccelli, Valentina; Coppi, Gilberto; Romagnoli, Marcello; Sergi, Santo; Leo, Eliana

    2013-04-15

    Lipid-based particulate delivery systems have been extensively investigated in the last decade for both pharmaceutical and cosmetic skin application although their translocation across the skin is not yet clarified. The aim of this paper was to investigate on humans the ability of solid lipid nanoparticles (SLN) and solid lipid microparticles (SLM) to penetrate the outermost stratum corneum (SC) and to be modified upon contact with the cutaneous components by using the Tape Stripping Test coupled with the energy dispersive X-ray (EDX) analysis. SLN and SLM were prepared by the melt emulsification technique and loaded with nanosized titanium dioxide (TiO2) to become identifiable by means of X-ray emission. Following human skin application, the translocation of the particulate systems was monitored by the analysis of twelve repetitive stripped tapes using non-encapsulated metal dioxide as the control. Intact SLN as well as non-encapsulated TiO₂ were recorded along the largest SC openings until the 12th stripped tape suggesting the intercluster region as their main pathway. Evidences of a concurrent biodegradation process of the lipid matrix, as the result of SLN interaction with the lipid packing between the corneocyte clusters, were found in the deepest SC layers considered. On the contrary, SLM were retained on the skin surface without undergoing biodegradation so preventing the leaching and the subsequent SC translocation of the loaded TiO₂.

  18. Magnetic and fluorescence-encoded polystyrene microparticles for cell separation

    NASA Astrophysics Data System (ADS)

    Bradbury, Diana; Anglin, Emily J.; Bailey, Sheree; Macardle, Peter J.; Fenech, Michael; Thissen, Helmut; Voelcker, Nicolas H.

    2008-12-01

    Materials assisting with the efforts of cell isolation are attractive for numerous biomedical applications including tissue engineering and cell therapy. Here, we have developed surface modification methods on microparticles for the purposes of advanced cell separation. Iron oxide nanoparticles were incorporated into 200 ım polystyrene microparticles for separation of particle-bound cells from non-bound cells in suspension by means of a permanent magnet. The polystyrene microparticles were further encoded with fluorescent quantum dots (QD) as identification tags to distinguish between specific microparticles in a mixture. Cluster of differentiation (CD) antibodies were displayed on the surface of the microparticles through direct adsorption and various methods of covalent attachment. In addition, a protein A coating was used to orientate the antibodies on the microparticle surface and to maximise accessibility of the antigen-binding sites. Microparticles which carried CD antibodies via covalent attachment showed greater cell attachment over those modifications that were only adsorbed to the surface through weak electrostatic interactions. Greatest extent of cell attachment was observed on microparticles modified with protein A - CD antibody conjugates. B and T lymphocytes were successfully isolated from a mixed population using two types of microparticles displaying B and T cell specific CD antibodies, respectively. Our approach will find application in preparative cell separation from tissue isolates and for microcarrier-based cell expansion.

  19. Development and characterization of coated-microparticles based on whey protein/alginate using the Encapsulator device.

    PubMed

    Hébrard, Géraldine; Hoffart, Valérie; Cardot, Jean-Michel; Subirade, Muriel; Beyssac, Eric

    2013-01-01

    The aim of this study is to prepare whey protein (WP)-based microparticles (MP) using the Encapsulator(®) device. The viscosity dependence of the extrusion device required to mix WP with a food-grade and less viscous polymer. Mixed WP/ALG MP were obtained with the optimized WP/alginate (ALG) ratio (62/38). These particles were further coated with WP or ALG using non-traumatic and solvent-free coating process developed in this study. Size and morphology of coated and uncoated MP were determined. Then, swelling and degradation (WP release) of formulations were investigated in pH 1.2 and 7.5 buffers and in simulated gastric and intestinal fluids (SGF, SIF) and compared to pure ALG and pure WP particle behaviours. At pH 1.2, pure ALG shrank and pure WP swelled, whereas the sizes of mixed WP/ALG matrix were stable. In SGF, WP/ALG MP resisted to pepsin degradation compare to pure WP particles due to ALG shrinkage which limited pepsin diffusion within particles. Coating addition with WP or ALG slowed down pepsin degradation. At pH 7.5, WP/ALG particles were rapidly degraded due to ALG sensitivity but the addition of a WP coating limited effectively the swelling and the degradation of MP. In SIF, pancreatin accelerated MP degradation but ALG-coated MP exhibited interesting robustness. These results confirmed the interest and the feasibility to produce coated WP-based MP which could be a potential orally controlled release drug delivery system.

  20. Synthesis and characterization of microparticles based on poly-methacrylic acid with glucose oxidase for biosensor applications.

    PubMed

    Hervás Pérez, J P; López-Ruiz, B; López-Cabarcos, E

    2016-01-01

    In the line of the applicability of biocompatible monomers pH and temperature dependent, we assayed poly-methacrylic acid (p-MAA) microparticles as immobilization system in the design of enzymatic biosensors. Glucose oxidase was used as enzyme model for the study of microparticles as immobilization matrices and as biological material in the performance of glucose biosensors. The enzyme immobilization method was optimized by investigating the influence of monomer concentration and cross-linker content (N',N'-methylenebisacrylamide), used in the preparation of the microparticles in the response of the biosensors. The kinetics of the polymerization and the effects of the temperature were studied, also the conversion of the polymerization was determinates by a weight method. The structure of the obtained p-MAA microparticles were studied through scanning electron microscopy (SEM) and differential scanning microscopy (DSC). The particle size measurements were performed with a Galai-Cis 1 particle analyzer system. Furthermore, the influence of the swelling behavior of hydrogel matrix as a function of pH and temperature were studied. Analytical properties such as sensitivity, linear range, response time and detection limit were studied for the glucose biosensors. The sensitivity for glucose detection obtained with poly-methacrylic acid (p-MAA) microparticles was 11.98mAM(-1)cm(-2) and 10μM of detection limit. A Nafion® layer was used to eliminate common interferents of the human serum such as uric and ascorbic acids. The biosensors were used to determine glucose in human serum samples with satisfactory results. When stored in a frozen phosphate buffer solution (pH 6.0) at -4°C, the useful lifetime of all biosensors was at least 550 days.

  1. Microparticle Flow Sensor

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R.

    2005-01-01

    The microparticle flow sensor (MFS) is a system for identifying and counting microscopic particles entrained in a flowing liquid. The MFS includes a transparent, optoelectronically instrumented laminar-flow chamber (see figure) and a computer for processing instrument-readout data. The MFS could be used to count microparticles (including micro-organisms) in diverse applications -- for example, production of microcapsules, treatment of wastewater, pumping of industrial chemicals, and identification of ownership of liquid products.

  2. Unfolding a design rule for microparticle buffering and dropping in microring-resonator-based add-drop devices.

    PubMed

    Wang, Jiawei; Poon, Andrew W

    2014-04-21

    We propose an intuitive and quantitative design rule to determine the microparticle transport processes, including buffering and dropping, on microring-resonator-based add-drop devices at cavity resonances in an integrated optofluidic chip. The design rule uses the splitting ratio, S, of the optical-field intensity at the microring feedback-arc just after the output-coupling region to that at the drop-waveguide as a figure-of-merit for particle transport to determine between particle buffering (S > 1) and dropping (S < 1). The particle transport, however, becomes probabilistic in the case that S is close to 1. The S factor thus provides a clearer physical criterion for determining the particle transport processes compared to the cavity quality (Q) factor. We experimentally investigate this design rule on four different devices with different design parameters on a silicon nitride-on-silica substrate, and show that the particle transport behaviours of 2.2 μm- and 0.8 μm-sized polystyrene particles are consistent with the S values extracted from the transmission spectra. Our numerical simulations of the four devices suggest that the S values extracted from the simulated transmission spectra are consistent with those extracted from the simulated mode-field intensity distributions. We calculate the optical force field using Maxwell stress tensor and an effective microdisk model to relate the S values to the particle transport processes. We further experimentally demonstrate the viability of the design rule by switching between deterministic particle buffering and probabilistic particle transport processes by switching the polarization modes.

  3. Data management based on geocoding index and adaptive visualization for airborne LiDAR

    NASA Astrophysics Data System (ADS)

    Zhi, Xiaodong

    2008-10-01

    With more surveying practice and deeper application, data post-process for airborne LiDAR system has been extracted lots of attention in data accuracy, post-process, fusion, modeling, automation and visualization. However, post-process and flexible visualization were found to be the bottle-neck which limits the LiDAR data usage for industrial applications. The cause of above bottle-neck problems is great capacity for LiDAR system. Thus in article a geocoding index based multivariate data management and adaptive visualization will be studied for based on the feature of airborne LiDAR's data to improve automatization of post-process and surveying efficiency.

  4. Rapid and sensitive lateral flow immunoassay method for determining alpha fetoprotein in serum using europium (III) chelate microparticles-based lateral flow test strips.

    PubMed

    Liang, Rong-Liang; Xu, Xu-Ping; Liu, Tian-Cai; Zhou, Jian-Wei; Wang, Xian-Guo; Ren, Zhi-Qi; Hao, Fen; Wu, Ying-Song

    2015-09-03

    Alpha-fetoprotein (AFP), a primary marker for many diseases including various cancers, is important in clinical tumor diagnosis and antenatal screening. Most immunoassays provide high sensitivity and accuracy for determining AFP, but they are expensive, often complex, time-consuming procedures. A simple and rapid point-of-care system that integrates Eu (III) chelate microparticles with lateral flow immunoassay (LFIA) has been developed to determine AFP in serum with an assay time of 15 min. The approach is based on a sandwich immunoassay performed on lateral flow test strips. A fluorescence strip reader was used to measure the fluorescence peak heights of the test line (HT) and the control line (HC); the HT/HC ratio was used for quantitation. The Eu (III) chelate microparticles-based LFIA assay exhibited a wide linear range (1.0-1000 IU mL(-1)) for AFP with a low limit of detection (0.1 IU mL(-1)) based on 5ul of serum. Satisfactory specificity and accuracy were demonstrated and the intra- and inter-assay coefficients of variation (CV) for AFP were both <10%. Furthermore, in the analysis of human serum samples, excellent correlation (n = 284, r = 0.9860, p < 0.0001) was obtained between the proposed method and a commercially available CLIA kit. Results indicated that the Eu (III) chelate microparticles-based LFIA system provided a rapid, sensitive and reliable method for determining AFP in serum, indicating that it would be suitable for development in point-of-care testing.

  5. Evaluating evaporation from field crops using airborne radiometry and ground-based meteorological data

    USGS Publications Warehouse

    Jackson, R. D.; Moran, M.S.; Gay, L.W.; Raymond, L.H.

    1987-01-01

    Airborne measurements of reflected solar and emitted thermal radiation were combined with ground-based measurements of incoming solar radiation, air temperature, windspeed, and vapor pressure to calculate instantaneous evaporation (LE) rates using a form of the Penman equation. Estimates of evaporation over cotton, wheat, and alfalfa fields were obtained on 5 days during a one-year period. A Bowen ratio apparatus, employed simultaneously, provided ground-based measurements of evaporation. Comparison of the airborne and ground techniques showed good agreement, with the greatest difference being about 12% for the instantaneous values. Estimates of daily (24 h) evaporation were made from the instantaneous data. On three of the five days, the difference between the two techniques was less than 8%, with the greatest difference being 25%. The results demonstrate that airborne remote sensing techniques can be used to obtain spatially distributed values of evaporation over agricultural fields. ?? 1987 Springer-Verlag.

  6. Investigation of novel solid lipid microparticles based on homolipids from Bos indicus for the delivery of gentamicin

    PubMed Central

    Kenechukwu, Franklin C.; Momoh, Mumuni A.; Umeyor, Emmanuel C.; Uronnachi, Emmanuel M.; Attama, Anthony A.

    2016-01-01

    Background: The aim of this study was to formulate solidified reverse micellar solution (SRMS)-based solid lipid microparticles (SLMs) using homolipids from tallow fat (Bos indicus) and evaluate its potential for enhanced delivery of gentamicin. Materials and Methods: SLMs were formulated by melt-emulsification using SRMS (15% w/w Phospholipon® 90G in 35% w/w Bos indicus), polyethylene glycol 4000 (PEG) and gentamicin (1.0, 2.0, 3.0% w/w), and characterized with respect to size, morphology, encapsulation efficiency % and pH-dependent stability. The in vitro release of gentamicin from the SLMs was performed in phosphate buffer (pH 7.4) while bioevaluation was carried out using clinical isolates of Staphylococcus aureus and Escherichia coli. Results: Results showed that the lipid matrix accommodated gentamicin in a concentration-dependent manner, and that stable and spherical SLMs with size range of 18.62 ± 1.24-20.59 ± 1.36 μm and 21.35 ± 1.57-50.62 ± 2.37 μm respectively for unloaded and drug-loaded formulations were obtained. The in vitro drug release studies revealed that SRMS-based SLMs could better be used to control the release of gentamicin than gentamicin injection. Results of sensitivity test revealed that the SLMs time-dependently and capacity-limitedly produced greater inhibition zone diameters (IZDs) than the standards, an indication of improved bioactivity against the test organisms, with greater IZDs against S. aureus than E. coli. Overall, SLMs containing 2% w/w SRMS, 3% w/w gentamicin and PEG 4000 entrapped the highest amount of drug, achieved complete drug release and gave highest IZD against the organisms within 420 min, while plain gentamicin gave the least. Conclusion: This research has shown that SLMs based on Bos indicus and P90G is a potential carrier system for dissolution and bioactivity enhancement of gentamicin. PMID:27014617

  7. Toxicodynamics of rigid polystyrene microparticles on pulmonary gas exchange in mice: Implications for microemboli-based drug delivery systems

    SciTech Connect

    Kutscher, H.L.; Gao, D.; Li, S.; Massa, C.B.; Cervelli, J.; Deshmukh, M.; Joseph, L.B.; Laskin, D.L.; Sinko, P.J.

    2013-01-15

    The toxicodynamic relationship between the number and size of pulmonary microemboli resulting from uniformly sized, rigid polystyrene microparticles (MPs) administered intravenously and their potential effects on pulmonary gas exchange were investigated. CD-1 male mice (6–8 weeks) were intravenously administered 10, 25 and 45 μm diameter MPs. Oxygen hemoglobin saturation in the blood (SpO{sub 2}) was measured non-invasively using a pulse oximeter while varying inhaled oxygen concentration (F{sub I}O{sub 2}). The resulting data were fit to a physiologically based non-linear mathematical model that estimates 2 parameters: ventilation–perfusion ratio (V{sub A}/Q) and shunt (percentage of deoxygenated blood returning to systemic circulation). The number of MPs administered prior to a statistically significant reduction in normalized V{sub A}/Q was dependent on particle size. MP doses that resulted in a significant reduction in normalized V{sub A}/Q one day post-treatment were 4000, 40,000 and 550,000 MPs/g for 45, 25 and 10 μm MPs, respectively. The model estimated V{sub A}/Q and shunt returned to baseline levels 7 days post-treatment. Measuring SpO{sub 2} alone was not sufficient to observe changes in gas exchange; however, when combined with model-derived V{sub A}/Q and shunt early reversible toxicity from pulmonary microemboli was detected suggesting that the model and physical measurements are both required for assessing toxicity. Moreover, it appears that the MP load required to alter gas exchange in a mouse prior to lethality is significantly higher than the anticipated required MP dose for effective drug delivery. Overall, the current results indicate that the microemboli-based approach for targeted pulmonary drug delivery is potentially safe and should be further explored. -- Highlights: ► Murine pulmonary gas exchange after microembolization was non-invasively studied. ► A physiologically based model quantified impairment of pulmonary gas exchange.

  8. An airborne multispectral imaging system based on two consumer-grade cameras for agricultural remote sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper describes the design and evaluation of an airborne multispectral imaging system based on two identical consumer-grade cameras for agricultural remote sensing. The cameras are equipped with a full-frame complementary metal oxide semiconductor (CMOS) sensor with 5616 × 3744 pixels. One came...

  9. Detection of airborne microbes in a composting facility by cultivation based and cultivation-independent methods.

    PubMed

    Albrecht, Andreas; Witzenberger, Reinhard; Bernzen, Ulrike; Jäckel, Udo

    2007-01-01

    Standard methods for quantification of airborne bacteria are based on cultivation and counting of grown colonies. From complex natural environments it is known that only a small fraction of the total number of cells can be cultivated on routinely used agar-media. Direct microscopic cell counting after DNA-staining usually generates higher concentrations of one to two magnitudes. The objective of the presented study was to compare the concentrations of airborne bacteria sampled in a composting facility by using for any sample the cultivation on trytic soy agar (TSA)--agar, as well as direct counting after DAPI-staining. The concentrations after counting grown colonies were within a range of 10(5)-10(7) cfu m(-3). Concentrations of direct counted cells ranged between 10(6)-10(9) microbes m(-3). In these comparative measurements only 1.5-15.3% of the airborne bacterial cells enumerated by direct counting formed countable colonies after incubation on TSA-agar. Obviously, cultivation based methods underestimate the real amount of airborne microbes. In addition, from literature it is known that inactive or even dead cells can also have the potential to cause health effects. Consequently, a risk assessment based only on measuring colony forming units may, in some cases, not be sufficient.

  10. Towards a spectrum-based bar code for identification of weakly fluorescent microparticles

    NASA Astrophysics Data System (ADS)

    Petrášek, Zdeněk; Wiedemann, Jens; Schwille, Petra

    2014-03-01

    Spectrally resolved detection of fluorescent probes can be used to identify multiple labeled target molecules in an unknown mixture. We study how the spectral shape, the experimental noise, and the number of spectral detection channels affect the success of identification of weakly fluorescent beads on basis of their emission spectra. The proposed formalism allows to estimate the performance of the spectral identification procedure with a given set of spectral codes on the basis of the reference spectra only. We constructed a simple prism-based setup for spectral detection and demonstrate that seven distinct but overlapping spectral codes realized by combining up to three fluorescent dyes bound to a single bead in a barcode-based manner can be reliably identified. The procedure allows correct identification even in the presence of known autofluorescence background stronger than the actual signal.

  11. Airborne Sunphotometer, Airborne in-situ, Space-borne, and Ground-Based Measurements of Troposoheric Aerosol in Ace-2

    NASA Technical Reports Server (NTRS)

    Schmid, Beat; Collins, D.; Gasso, S.; Ostrom, E.; Powell, D.; Welton, E.; Durkee, P.; Livingstron, J.; Russell, P.; Flagan, R.; Hipskind, R. Stephen (Technical Monitor)

    2000-01-01

    We report on clear-sky column closure experiments performed in the Canary Islands during the second Aerosol Characterization Experiment (ACE-2) in June/July 1997. We present results obtained by combining airborne sunphotometer and in-situ aerosol measurements taken aboard the Pelican aircraft, space-borne NOAA/AVHRR data and ground-based lidars A wide range of aerosol types was encountered throughout the ACE-2 area, including background Atlantic marine, European pollution-derived, and African mineral dust. During !he two days discussed here, vertical profiles flown in cloud free air masses revealed three distinctly different layers: a marine boundary layer (MBL) with varying pollution levels, an elevated dust layer, and a very clean layer between the MBL and the dust layer. We found that the presence of the elevated dust layer removes the good agreement between satellite and sunphotometer AOD usually found in the absence of the dust layer. Using size-resolved composition information we have computed optical properties of the ambient aerosol from the in-situ measurements and subsequently compared those to the sunphotometer results. In the dust, the agreement in layer aerosol optical depth (380-1060 nm) is 3-8%. In the MBL there is tendency for the in-situ results to be slightly lower than the sunphotometer measurements (10-17% at 525 nm), but these differences are within the combined error bars of the measurements and computations.

  12. Solid lipid microparticles containing loratadine prepared using a Micromixer.

    PubMed

    Milak, Spomenka; Medlicott, Natalie; Tucker, Ian G

    2006-12-01

    Solid lipid microparticles were investigated as a taste-masking approach for a lipophilic weak base in a suspension. The idea was that the drug concentration in the aqueous phase of a suspension might be reduced by its partitioning into the solid lipid particles. Loratadine, as a model drug, was used to prepare Precirol ATO 5 microparticles by a Micromixer. The effects of three process variables: drug loading, PVA concentration and water/lipid ratio on the microparticle size, encapsulation efficiency, surface appearance, in-vitro release and drug partitioning in a suspension were studied. Loratadine release was slow in simulated saliva and very fast at the pH of stomach. In suspension of loratadine lipid microparticles, drug was released into the aqueous phase to the same concentration as in a drug suspension. Therefore, the usefulness of these microparticles for taste-masking in liquids is limited. However, they might be useful for taste-masking in solid dosage forms.

  13. FTIR-based airborne spectral imagery for target interrogation

    NASA Astrophysics Data System (ADS)

    Smithson, Tracy L.; St. Germain, Daniel; Nadeau, Denis

    2007-09-01

    DRDC Valcartier is continuing to developed infrared spectral imagery systems for a variety of military applications. Recently a hybrid airborne spectral imager / broadband imager system has been developed for ground target interrogation (AIRIS). This system employs a Fourier Transform Interferometer system coupled to two 8x8 element detector arrays to create spectral imagery in the region from 2.0 to 12 microns (830 to 5000 cm -1) at a spectral resolution of up to 1 cm -1. In addition, coupled to this sensor are three broadband imagers operating in the visible, mid-wave and long-wave infrared regions. AIRIS uses an on-board tracking capability to: dwell on a target, select multiple targets sequentially, or build a mosaic description of the environment around a specified target point. Currently AIRIS is being modified to include real-time spectral imagery calibration and application processing. In this paper the flexibility of the AIRIS system will be described, its concept of operation discussed and examples of measurements will be shown.

  14. Evaluation of multiple-channel OFDM based airborne ultrasonic communications.

    PubMed

    Jiang, Wentao; Wright, William M D

    2016-09-01

    Orthogonal frequency division multiplexing (OFDM) modulation has been extensively used in both wired and wireless communication systems. The use of OFDM technology allows very high spectral efficiency data transmission without using complex equalizers to correct the effect of a frequency-selective channel. This work investigated OFDM methods in an airborne ultrasonic communication system, using commercially available capacitive ultrasonic transducers operating at 50kHz to transmit information through the air. Conventional modulation schemes such as binary phase shift keying (BPSK) and quadrature amplitude modulation (QAM) were used to modulate sub-carrier signals, and the performances were evaluated in an indoor laboratory environment. Line-of-sight (LOS) transmission range up to 11m with no measurable errors was achieved using BPSK at a data rate of 45kb/s and a spectral efficiency of 1b/s/Hz. By implementing a higher order modulation scheme (16-QAM), the system data transfer rate was increased to 180kb/s with a spectral efficiency of 4b/s/Hz at attainable transmission distances up to 6m. Diffraction effects were incorporated into a model of the ultrasonic channel that also accounted for beam spread and attenuation in air. The simulations were a good match to the measured signals and non-LOS signals could be demodulated successfully. The effects of multipath interference were also studied in this work. By adding cyclic prefix (CP) to the OFDM symbols, the bit error rate (BER) performance was significantly improved in a multipath environment.

  15. PPyDEP: a new approach to microparticle manipulation employing polymer-based electrodes.

    PubMed

    Perez-Gonzalez, Victor H; Ho, Vinh; Kulinsky, Lawrence; Madou, Marc; Martinez-Chapa, Sergio O

    2013-12-07

    In this work, a novel approach to 3-dimensional (3D) electrode fabrication, based on electrodeposited polypyrrole (PPy), for dielectrophoresis (DEP) is described. 3D PPy electrodes with post and cage geometries were grown over planar interdigitated electrodes. Computational modelling and experimental work were carried out to assess the performance of the proposed electrode geometries. It was found that these new electrode geometries enhanced the dielectrophoretic trapping efficiency for polystyrene beads by exhibiting larger variations of the electric field and by affecting a larger volume of the fluid sample than planar electrodes. Applications of this work include, but are not limited to, environmental monitoring, food safety control, clinical analysis, and clean energy production.

  16. Biochemical and proteomic characterization of retrovirus Gag based microparticles carrying melanoma antigens

    PubMed Central

    Kurg, Reet; Reinsalu, Olavi; Jagur, Sergei; Õunap, Kadri; Võsa, Liisi; Kasvandik, Sergo; Padari, Kärt; Gildemann, Kiira; Ustav, Mart

    2016-01-01

    Extracellular vesicles are membraneous particles released by a variety of cells into the extracellular microenvironment. Retroviruses utilize the cellular vesiculation pathway for virus budding/assembly and the retrovirus Gag protein induces the spontaneous formation of microvesicles or virus-like particles (VLPs) when expressed in the mammalian cells. In this study, five different melanoma antigens, MAGEA4, MAGEA10, MART1, TRP1 and MCAM, were incorporated into the VLPs and their localization within the particles was determined. Our data show that the MAGEA4 and MAGEA10 proteins as well as MCAM are expressed on the surface of VLPs. The compartmentalization of exogenously expressed cancer antigens within the VLPs did not depend on the localization of the protein within the cell. Comparison of the protein content of VLPs by LC-MS/MS-based label-free quantitative proteomics showed that VLPs carrying different cancer antigens are very similar to each other, but differ to some extent from VLPs without recombinant antigen. We suggest that retrovirus Gag based virus-like particles carrying recombinant antigens have a potential to be used in cancer immunotherapy. PMID:27403717

  17. Control of microparticles packing density in a microfluidic channel for bead based immunoassays applications

    NASA Astrophysics Data System (ADS)

    Caballero-Robledo, Gabriel; Guevara-Pantoja, Pablo

    2014-11-01

    Bead based immunoassays in microfluidic devices have shown to greatly outperform conventional methods. But if functional point-of-care devices are to be developed, precise and reproducible control over the granulate packings inside microchannels is needed. In this work we study the efficiency of a nanoparticles magnetic trap previously developed by B. Teste et al. [Lab Chip 11, 4207 (2011)] when we vary the compaction of micrometric iron beads packed against a restriction inside a microfluidic channel. The packing density of the beads is finely and reproducibly changed by applying a vibrational protocol originally developed for macroscopic, dry granular systems. We find, counterintuitively, that the most compact and stable packings are up to four times less efficient in trapping nano particles than the loosest packings. This work has been supported by Conacyt, Mexico, under Grant No. 180873.

  18. Clogging-free microfluidics for continuous size-based separation of microparticles

    PubMed Central

    Yoon, Yousang; Kim, Seonil; Lee, Jusin; Choi, Jaewoong; Kim, Rae-Kwon; Lee, Su-Jae; Sul, Onejae; Lee, Seung-Beck

    2016-01-01

    In microfluidic filtration systems, one of the leading obstacles to efficient, continuous operation is clogging of the filters. Here, we introduce a lateral flow microfluidic sieving (μ-sieving) technique to overcome clogging and to allow continuous operation of filter based microfluidic separation. A low frequency mechanical oscillation was added to the fluid flow, which made possible the release of aggregated unwanted polystyrene (PS) particles trapped between the larger target PS particles in the filter demonstrating continuous μ-sieving operation. We achieved collection of the target PS particles with 100% separation efficiency. Also, on average, more than 98% of the filtered target particles were retrieved after the filtration showing high retrieval rates. Since the oscillation was applied to the fluid but not to the microfluidic filter system, mechanical stresses to the system was minimized and no additional fabrication procedures were necessary. We also applied the μ-sieving technique to the separation of cancer cells (MDA-MB-231) from whole blood and showed that the fluidic oscillations prevented the filters from being blocked by the filtered cancer cells allowing continuous microfluidic separation with high efficiency. PMID:27198601

  19. Continuous size-based separation of microparticles in a microchannel with symmetric sharp corner structures.

    PubMed

    Fan, Liang-Liang; He, Xu-Kun; Han, Yu; Du, Li; Zhao, Liang; Zhe, Jiang

    2014-03-01

    A new microchannel with a series of symmetric sharp corner structures is reported for passive size-dependent particle separation. Micro particles of different sizes can be completely separated based on the combination of the inertial lift force and the centrifugal force induced by the sharp corner structures in the microchannel. At appropriate flow rate and Reynolds number, the centrifugal force effect on large particles, induced by the sharp corner structures, is stronger than that on small particles; hence after passing a series of symmetric sharp corner structures, large particles are focused to the center of the microchannel, while small particles are focused at two particle streams near the two side walls of the microchannel. Particles of different sizes can then be completely separated. Particle separation with this device was demonstrated using 7.32 μm and 15.5 μm micro particles. Experiments show that in comparison with the prior multi-orifice flow fractionation microchannel and multistage-multiorifice flow fractionation microchannel, this device can completely separate two-size particles with narrower particle stream band and larger separation distance between particle streams. In addition, it requires no sheath flow and complex multi-stage separation structures, avoiding the dilution of analyte sample and complex operations. The device has potentials to be used for continuous, complete particle separation in a variety of lab-on-a-chip and biomedical applications.

  20. Quantitative Macro-Raman Spectroscopy on Microparticle-Based Pharmaceutical Dosage Forms.

    PubMed

    Wang, Hui; Williams, Lisa; Hoe, Susan; Lechuga-Ballesteros, David; Vehring, Reinhard

    2015-07-01

    Quantitative macro-Raman spectroscopy was applied to the analysis of the bulk composition of pharmaceutical drug powders. Powders were extracted from seven commercial lactose-carrier-based dry-powder inhalers: Flixotide 50, 100, 250, and 500 μg/dose (four concentrations of fluticasone propionate) and Seretide 100, 250, and 500 μg/dose (three concentrations of fluticasone propionate, each with 50 μg/dose salmeterol xinafoate ). Also, a carrier-free pressurized metered-dose inhaler of the same combination product, Seretide 50 (50 μg fluticasone propionate and 25 μg salmeterol xinafoate per dose) was tested. The applicability of a custom-designed dispersive macro-Raman instrument with a large sample volume of 0.16 μL was tested to determine the composition of the multicomponent powder samples. To quantify the error caused by sample heterogeneity, a Monte Carlo model was developed to predict the minimum sample volume required for representative sampling of potentially heterogeneous samples at the microscopic level, characterized by different particle-size distributions and compositions. Typical carrier-free respirable powder samples required a minimum sample volume on the order of 10(-4) μL to achieve representative sampling with less than 3% relative error. In contrast, dosage forms containing non-respirable carriers (e.g., lactose) required a sample volume on the order of 0.1 μL for representative measurements. Error analysis of the experimental results showed good agreement with the error predicted by the simulation.

  1. Microparticle analysis system and method

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R. (Inventor)

    2007-01-01

    A device for analyzing microparticles is provided which includes a chamber with an inlet and an outlet for respectively introducing and dispensing a flowing fluid comprising microparticles, a light source for providing light through the chamber and a photometer for measuring the intensity of light transmitted through individual microparticles. The device further includes an imaging system for acquiring images of the fluid. In some cases, the device may be configured to identify and determine a quantity of the microparticles within the fluid. Consequently, a method for identifying and tracking microparticles in motion is contemplated herein. The method involves flowing a fluid comprising microparticles in laminar motion through a chamber, transmitting light through the fluid, measuring the intensities of the light transmitted through the microparticles, imaging the fluid a plurality of times and comparing at least some of the intensities of light between different images of the fluid.

  2. Risk-Based Causal Modeling of Airborne Loss of Separation

    NASA Technical Reports Server (NTRS)

    Geuther, Steven C.; Shih, Ann T.

    2015-01-01

    Maintaining safe separation between aircraft remains one of the key aviation challenges as the Next Generation Air Transportation System (NextGen) emerges. The goals of the NextGen are to increase capacity and reduce flight delays to meet the aviation demand growth through the 2025 time frame while maintaining safety and efficiency. The envisioned NextGen is expected to enable high air traffic density, diverse fleet operations in the airspace, and a decrease in separation distance. All of these factors contribute to the potential for Loss of Separation (LOS) between aircraft. LOS is a precursor to a potential mid-air collision (MAC). The NASA Airspace Operations and Safety Program (AOSP) is committed to developing aircraft separation assurance concepts and technologies to mitigate LOS instances, therefore, preventing MAC. This paper focuses on the analysis of causal and contributing factors of LOS accidents and incidents leading to MAC occurrences. Mid-air collisions among large commercial aircraft are rare in the past decade, therefore, the LOS instances in this study are for general aviation using visual flight rules in the years 2000-2010. The study includes the investigation of causal paths leading to LOS, and the development of the Airborne Loss of Separation Analysis Model (ALOSAM) using Bayesian Belief Networks (BBN) to capture the multi-dependent relations of causal factors. The ALOSAM is currently a qualitative model, although further development could lead to a quantitative model. ALOSAM could then be used to perform impact analysis of concepts and technologies in the AOSP portfolio on the reduction of LOS risk.

  3. Bioerodable PLGA-Based Microparticles for Producing Sustained-Release Drug Formulations and Strategies for Improving Drug Loading

    PubMed Central

    Han, Felicity Y.; Thurecht, Kristofer J.; Whittaker, Andrew K.; Smith, Maree T.

    2016-01-01

    Poly(lactic-co-glycolic acid) (PLGA) is the most widely used biomaterial for microencapsulation and prolonged delivery of therapeutic drugs, proteins and antigens. PLGA has excellent biodegradability and biocompatibility and is generally recognized as safe by international regulatory agencies including the United States Food and Drug Administration and the European Medicines Agency. The physicochemical properties of PLGA may be varied systematically by changing the ratio of lactic acid to glycolic acid. This in turn alters the release rate of microencapsulated therapeutic molecules from PLGA microparticle formulations. The obstacles hindering more widespread use of PLGA for producing sustained-release formulations for clinical use include low drug loading, particularly of hydrophilic small molecules, high initial burst release and/or poor formulation stability. In this review, we address strategies aimed at overcoming these challenges. These include use of low-temperature double-emulsion methods to increase drug-loading by producing PLGA particles with a small volume for the inner water phase and a suitable pH of the external phase. Newer strategies for producing PLGA particles with high drug loading and the desired sustained-release profiles include fabrication of multi-layered microparticles, nanoparticles-in-microparticles, use of hydrogel templates, as well as coaxial electrospray, microfluidics, and supercritical carbon dioxide methods. Another recent strategy with promise for producing particles with well-controlled and reproducible sustained-release profiles involves complexation of PLGA with additives such as polyethylene glycol, poly(ortho esters), chitosan, alginate, caffeic acid, hyaluronic acid, and silicon dioxide. PMID:27445821

  4. Research on the glucose-sensing characteristics of gold microparticle-doped silica microfiber based on refractive index measurement

    NASA Astrophysics Data System (ADS)

    Hu, Haifeng; Li, Jin; Li, Hanyang; Lv, Riqing

    2016-11-01

    A gold microparticle-doped silica microfiber was proposed in this paper. The refractive index sensing properties were experimentally and calculatedly demonstrated by transmission spectra using glucose solution with different concentrations, where the redshift of resonance peaks has been analyzed for the concentrations range from 0 to 0.282 mol/L. The experimental results indicate the detection limit of 53.2 μmol/L. The sensing characteristics of pure silica microfiber were experimentally and calculatedly explored to demonstrate the impact of the gold particles introduction on the sensitivity enhancement. The miniature geometry will prompt the development of the novel wearable or implantable glucose sensor.

  5. Airborne Four-Dimensional Flight Management in a Time-based Air Traffic Control Environment

    NASA Technical Reports Server (NTRS)

    Williams, David H.; Green, Steven M.

    1991-01-01

    Advanced Air Traffic Control (ATC) systems are being developed which contain time-based (4D) trajectory predictions of aircraft. Airborne flight management systems (FMS) exist or are being developed with similar 4D trajectory generation capabilities. Differences between the ATC generated profiles and those generated by the airborne 4D FMS may introduce system problems. A simulation experiment was conducted to explore integration of a 4D equipped aircraft into a 4D ATC system. The NASA Langley Transport Systems Research Vehicle cockpit simulator was linked in real time to the NASA Ames Descent Advisor ATC simulation for this effort. Candidate procedures for handling 4D equipped aircraft were devised and traffic scenarios established which required time delays absorbed through speed control alone or in combination with path stretching. Dissimilarities in 4D speed strategies between airborne and ATC generated trajectories were tested in these scenarios. The 4D procedures and FMS operation were well received by airline pilot test subjects, who achieved an arrival accuracy at the metering fix of 2.9 seconds standard deviation time error. The amount and nature of the information transmitted during a time clearance were found to be somewhat of a problem using the voice radio communication channel. Dissimilarities between airborne and ATC-generated speed strategies were found to be a problem when the traffic remained on established routes. It was more efficient for 4D equipped aircraft to fly trajectories with similar, though less fuel efficient, speeds which conform to the ATC strategy. Heavy traffic conditions, where time delays forced off-route path stretching, were found to produce a potential operational benefit of the airborne 4D FMS.

  6. Chitosan-based nano-in-microparticle carriers for enhanced oral delivery and anticancer activity of propolis.

    PubMed

    Elbaz, Nancy M; Khalil, Islam A; Abd-Rabou, Ahmed A; El-Sherbiny, Ibrahim M

    2016-11-01

    This study reports a promising approach to enhance the oral delivery of propolis, improve its aqueous solubility and bioavailability, and allow its controlled release as well as enhancing its anticancer activity. Propolis was standardized then its solubility was improved via formulation into optimized solid dispersion (SD) matrices, and its release was controlled through incorporation into nanoparticles (NPs) of optimized composition followed by further inclusion into chitosan (Cs) microparticles. The anticancer activity of the newly developed propolis-loaded nano-in-microparticles (NIMs) was evaluated against human liver cancer (HepG2) and human colorectal cancer (HCT 116) cells. The prepared SDs, NPs and NIMs were characterized using SEM, TEM, DLS, FTIR, DSC and UV-vis spectrophotometry. The therapeutic efficiency of formulated propolis was bio-assessed via cytotoxicity measurements, mitochondrial dysfunction, apoptosis-induced cell death and cell cycle arrest. The results demonstrated a considerable enhancement in propolis solubility with a controlled release profile in different GIT environments. In-vitro cytotoxicity studies showed that the propolis-loaded NIMs induce more cytotoxic effect on HepG2 cells than HCT-116 cells and mediated three-fold higher therapeutic efficiency than free propolis. The apoptosis assay indicated that the propolis-loaded NIMs induce apoptosis of HepG2 cells and significantly decrease their number in the proliferative G0/G1, S and G2/M phases.

  7. Dextran-based hydrogel containing chitosan microparticles loaded with growth factors to be used in wound healing.

    PubMed

    Ribeiro, M P; Morgado, P I; Miguel, S P; Coutinho, P; Correia, I J

    2013-07-01

    Skin injuries are traumatic events, which are seldom accompanied by complete structural and functional restoration of the original tissue. Different strategies have been developed in order to make the wound healing process faster and less painful. In the present study in vitro and in vivo assays were carried out to evaluate the applicability of a dextran hydrogel loaded with chitosan microparticles containing epidermal and vascular endothelial growth factors, for the improvement of the wound healing process. The carriers' morphology was characterized by scanning electron microscopy. Their cytotoxicity profile and degradation by-products were evaluated through in vitro assays. In vivo experiments were also performed to evaluate their applicability for the treatment of skin burns. The wound healing process was monitored through macroscopic and histological analysis. The macroscopic analysis showed that the period for wound healing occurs in animals treated with microparticle loaded hydrogels containing growth factors that were considerably smaller than that of control groups. Moreover, the histological analysis revealed the absence of reactive or granulomatous inflammatory reaction in skin lesions. The results obtained both in vitro and in vivo disclosed that these systems and its degradation by-products are biocompatible, contributed to the re-establishment of skin architecture and can be used in a near future for the controlled delivery of other bioactive agents used in regenerative medicine.

  8. [Biodegradable polymer microparticles with entraped herbal extracts: preparation with supercritical carbon dioxide and use for tissue repair].

    PubMed

    Markvicheva, E A; Antonov, E N; Popova, A V; Bogorodskiĭ, S E; Likhareva, V V; Fel'dman, B M; Strukova, S M; Popov, V K; Rumsh, L D

    2009-01-01

    Biodegradable microparticles based on poly-D,L-lactide with entrapped mixture of herbal water-soluble extracts of Plantago major and Calendula officinalis were prepared. For preparation of these microparticles the previously developed method based on the usage of supercritical carbon dioxide (SC-CO2) was proposed. Microparticles were obtained by two techniques: 1) by preparing porous polymer monolith containing entrapped mixture of herbal extracts, which was then reduced to fine microparticles (ca. 0.1 mm) by dry ice grinding (called here as "monolithisation technique") and 2) by spraying of this polymer/extracts mixture through a jet (spray technique). In vitro release kinetic profile of herbal extract mixture was found to depend on the microparticle preparation technique, on the microparticle structure as well as on the initial ratio polymer/extracts (w/w). The microparticles were used for gastric ulcer treatment in a rat model. The extracts released from microparticles were found to accelerate tissue repair.

  9. Strategy for the hemocompatibility testing of microparticles.

    PubMed

    Braune, S; Basu, S; Kratz, K; Johansson, J Bäckemo; Reinthaler, M; Lendlein, A; Jung, F

    2016-01-01

    Polymer-based microparticles are applied as non-thrombogenic or thrombogenic materials in a wide variety of intra- or extra-corporeal medical devices. As demanded by the regulatory agencies, the hemocompatibility of these blood contacting biomaterials has to be evaluated in vitro to ensure that the particle systems appropriately fulfill the envisioned function without causing undesired events such as thrombosis or inflammation. Currently described in vitro assays for hemocompatibility testing of particles comprise tests with different single cell types (e.g. erythrocytes or leukocytes), varying concentrations/dilutions of the used blood cells or whole blood, which are not standardized.Here, we report about an in vitro dynamic test system for studying the hemocompatibility of polymeric microparticles utilizing fresh human whole blood from apparently healthy subjects, collected and processed under standardized conditions. Spherical poly(ether imide) microparticles with an average diameter of 140±30 μm were utilized as model systems. Reported as candidate materials for the removal of uremic toxins, these microparticles are anticipated to facilitate optimal flow conditions in a dialyzer with minimal backflow and blood cell damage. Pristine (PEI) and potassium hydroxide (PEI-KOH) functionalized microparticles exhibited similarly nanoporous surfaces (PEI: ØExternal pore = 90±60 nm; PEI-KOH ØExternal pore = 150±130 nm) but varying water wettabilities (PEI: θadv = 112±10° PEI-KOH θadv = 60±2°). The nanoporosity of the microparticle surfaces allows the exchange of toxic solutes from blood towards the interconnective pores in the particle core, while an immigration of the substantially larger blood cells is inhibited.Sterilized PEI microparticles were incorporated -air-free -in a syringe-based test system and exposed to whole blood for 60 minutes under gentle agitation. Thereafter, thrombi formation on the particles surfaces were analyzed

  10. A Biomimetic Algorithm for Flight Stabilization in Airborne Vehicles, Based on Dragonfly Ocellar Vision

    DTIC Science & Technology

    2006-07-27

    Australia Email: gert.stange@anu.edu.au A biomimetic algorithm for flight stabilization in airborne vehicles, based on dragonfly ocellar vision...27 JUL 2006 2. REPORT TYPE Final Report (Technical) 3. DATES COVERED 10-06-2005 to 01-03-2006 4. TITLE AND SUBTITLE A Biomimetic Algorithm for...anatomy of the dragonfly occeli, it can be concluded that they are simple lens eyes designed for attitude stabilization. 15. SUBJECT TERMS Biomimetics

  11. Point-based and model-based geolocation analysis of airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Sefercik, Umut Gunes; Buyuksalih, Gurcan; Jacobsen, Karsten; Alkan, Mehmet

    2017-01-01

    Airborne laser scanning (ALS) is one of the most effective remote sensing technologies providing precise three-dimensional (3-D) dense point clouds. A large-size ALS digital surface model (DSM) covering the whole Istanbul province was analyzed by point-based and model-based comprehensive statistical approaches. Point-based analysis was performed using checkpoints on flat areas. Model-based approaches were implemented in two steps as strip to strip comparing overlapping ALS DSMs individually in three subareas and comparing the merged ALS DSMs with terrestrial laser scanning (TLS) DSMs in four other subareas. In the model-based approach, the standard deviation of height and normalized median absolute deviation were used as the accuracy indicators combined with the dependency of terrain inclination. The results demonstrate that terrain roughness has a strong impact on the vertical accuracy of ALS DSMs. From the relative horizontal shifts determined and partially improved by merging the overlapping strips and comparison of the ALS, and the TLS, data were found not to be negligible. The analysis of ALS DSM in relation to TLS DSM allowed us to determine the characteristics of the DSM in detail.

  12. Optical beam deflection signal from a single microparticle

    NASA Astrophysics Data System (ADS)

    Wu, Jiaqi; Kitamori, Takehiko; Sawada, Tsuguo

    1990-07-01

    The optical beam deflection (OBD) method was applied to the measurement of a single microparticle, and the signal from one resin microparticle of 200-600 μm in diameter could be detected. Based on the frequency characteristics and size dependence of the OBD signal, this method was found to be more sensitive for a smaller particle, and more effective than the photoacoustic method. Theoretical considerations showed that these characteristics were attributable to the enhancement of the temperature field gradient due to the curvature of the microparticle.

  13. Microfluidics assisted generation of innovative polysaccharide hydrogel microparticles.

    PubMed

    Marquis, M; Davy, J; Cathala, B; Fang, A; Renard, D

    2015-02-13

    Capillary flow-based approach such as microfluidic devices offer a number of advantages over conventional flow control technology because they ensure highly versatile geometry and can be used to produce monodisperse spherical and non-spherical polymeric microparticles. Based on the principle of a flow-focusing device to emulsify the coflow of aqueous solutions in an organic phase, we were able to produce the following innovative polysaccharide hydrogel microparticles: - Janus hydrogel microparticles made of pectin–pectin (homo Janus) and pectin–alginate (hetero Janus) were produced. The efficiency of separation of the two hemispheres was investigated by confocal scanning laser microscopy (CSLM) of previously labelled biopolymers. The Janus structure was confirmed by subjecting each microparticle hemisphere to specific enzymatic degradation. As a proof of concept, free BSA or BSA grafted with dextran, were encapsulated in each hemisphere of the hetero Janus hydrogel microparticles. While BSA, free or grafted with dextran, was always confined in the alginate hemisphere, a fraction of BSA diffused from the pectin to the alginate hemisphere. Methoxy groups along the pectin chain will be responsible of the decrease of the number of attractive electrostatic interactions occurring between amino groups of BSA and carboxylic groups of pectin. - Pectin hydrogel microparticles of complex shapes were successfully produced by combining on-chip the phenomenon of gelation and water diffusion induced self-assembly, using dimethyl carbonate as continuous phase, or by deformation of the pre-gelled droplets off-chip at a fluid–fluid interface. Sphere, oblate ellipsoid, torus or mushroom-type morphologies were thus obtained. Moreover, it was established that after crossing the interface during their collect, mushroom-type microparticles did not migrate in the calcium or DMC phase but stayed at the liquid–liquid interface. These new and original hydrogel microparticles will

  14. Development of an airborne hydrocarbon monitoring system based on FTIR technology

    NASA Astrophysics Data System (ADS)

    Mogan, Paul A.; Mattson, Carl B.; Schwindt, Chris J.

    1998-10-01

    The capability to monitor airborne hydrocarbon compounds is essential in order to protect sensitive optical payloads from performance degradation caused by the deposition of surface films. Commonly used hydrocarbon monitoring instrumentation such as flame ionization detectors yield no information about the source or identity of compounds they detect. The Fourier Transform IR Spectrometer (FTIR) with its inherent ability to discriminate a large number of compounds offers a tremendous advantage over other types of instrumentation. The contamination monitoring laboratory at John F. Kennedy Space Center has developed an airborne hydrocarbon monitoring system based on FTIR technology to support the AXAF payload. This system consist of a portable cart suitable for use in Class 1 Division 2 environments. This paper describes the system in detail.

  15. Development and Characterization of Sodium Hyaluronate Microparticle-Based Sustained Release Formulation of Recombinant Human Growth Hormone Prepared by Spray-Drying.

    PubMed

    Kim, Sun J; Kim, Chan W

    2016-02-01

    The purpose of this study was to develop and characterize a sodium hyaluronate microparticle-based sustained release formulation of recombinant human growth hormone (SR-rhGH) prepared by spray-drying. Compared to freeze-drying, spray-dried SR-rhGH showed not only prolonged release profiles but also better particle property and injectability. The results of size-exclusion high-performance liquid chromatography showed that no aggregate was detected, and dimer was just about 2% and also did not increase with increase of inlet temperature up to 150 °C. Meanwhile, the results of reversed-phase high-performance liquid chromatography revealed that related proteins increased slightly from 4.6% at 100 °C to 6.3% at 150 °C. Thermal mapping test proved that product temperature did not become high to cause protein degradation during spray-drying because thermal energy was used for the evaporation of surface moisture of droplets. The structural characterization by peptide mapping, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and circular dichroism revealed that the primary, secondary, and tertiary structures of rhGH in SR-rhGH were highly comparable to those of reference somatropin materials. The biological characterization by rat weight gain and cell proliferation assays provided that bioactivity of SR-rhGH was equivalent to that of native hGH. These data establish that spray-dried SR-rhGH is highly stable by preserving intact rhGH and hyaluronate microparticle-based formulation by spray-drying can be an alternative delivery system for proteins.

  16. Airborne derivation of microburst alerts from ground-based Terminal Doppler Weather Radar information: A flight evaluation

    NASA Technical Reports Server (NTRS)

    Hinton, David A.

    1993-01-01

    An element of the NASA/FAA windshear program is the integration of ground-based microburst information on the flight deck, to support airborne windshear alerting and microburst avoidance. NASA conducted a windshear flight test program in the summer of 1991 during which airborne processing of Terminal Doppler Weather Radar (TDWR) data was used to derive microburst alerts. Microburst information was extracted from TDWR, transmitted to a NASA Boeing 737 in flight via data link, and processed to estimate the windshear hazard level (F-factor) that would be experienced by the aircraft in each microburst. The microburst location and F-factor were used to derive a situation display and alerts. The situation display was successfully used to maneuver the aircraft for microburst penetrations, during which atmospheric 'truth' measurements were made. A total of 19 penetrations were made of TDWR-reported microburst locations, resulting in 18 airborne microburst alerts from the TDWR data and two microburst alerts from the airborne reactive windshear detection system. The primary factors affecting alerting performance were spatial offset of the flight path from the region of strongest shear, differences in TDWR measurement altitude and airplane penetration altitude, and variations in microburst outflow profiles. Predicted and measured F-factors agreed well in penetrations near microburst cores. Although improvements in airborne and ground processing of the TDWR measurements would be required to support an airborne executive-level alerting protocol, the practicality of airborne utilization of TDWR data link data has been demonstrated.

  17. Assessment of NASA airborne laser altimetry data using ground-based GPS data near Summit Station, Greenland

    NASA Astrophysics Data System (ADS)

    Brunt, Kelly M.; Hawley, Robert L.; Lutz, Eric R.; Studinger, Michael; Sonntag, John G.; Hofton, Michelle A.; Andrews, Lauren C.; Neumann, Thomas A.

    2017-03-01

    A series of NASA airborne lidars have been used in support of satellite laser altimetry missions. These airborne laser altimeters have been deployed for satellite instrument development, for spaceborne data validation, and to bridge the data gap between satellite missions. We used data from ground-based Global Positioning System (GPS) surveys of an 11 km long track near Summit Station, Greenland, to assess the surface-elevation bias and measurement precision of three airborne laser altimeters including the Airborne Topographic Mapper (ATM), the Land, Vegetation, and Ice Sensor (LVIS), and the Multiple Altimeter Beam Experimental Lidar (MABEL). Ground-based GPS data from the monthly ground-based traverses, which commenced in 2006, allowed for the assessment of nine airborne lidar surveys associated with ATM and LVIS between 2007 and 2016. Surface-elevation biases for these altimeters - over the flat, ice-sheet interior - are less than 0.12 m, while assessments of measurement precision are 0.09 m or better. Ground-based GPS positions determined both with and without differential post-processing techniques provided internally consistent solutions. Results from the analyses of ground-based and airborne data provide validation strategy guidance for the Ice, Cloud, and land Elevation Satellite 2 (ICESat-2) elevation and elevation-change data products.

  18. Group sparsity based airborne wide angle SAR imaging

    NASA Astrophysics Data System (ADS)

    Wei, Zhonghao; Zhang, Bingchen; Bi, Hui; Lin, Yun; Wu, Yirong

    2016-10-01

    In this paper, we develop a group sparsity based wide angle synthetic aperture radar (WASAR) imaging model and propose a novel algorithm called backprojection based group complex approximate message passing (GCAMP-BP) to recover the anisotropic scene. Compare to conventional backprojection based complex approximate message passing (CAMP-BP) algorithm for the recovery of isotropic scene, the proposed method accommodates aspect dependent scattering behavior better and can produce better imagery. Simulated and experimental results are presented to demonstrate the validity of the proposed algorithm.

  19. Swellable Microparticles as Carriers for Sustained Pulmonary Drug Delivery

    PubMed Central

    EL-SHERBINY, IBRAHIM M.; MCGILL, SHAYNA; SMYTH, HUGH D.C.

    2012-01-01

    In this investigation, novel biodegradable physically crosslinked hydrogel micro-particles were developed and evaluated in vitro as potential carriers for sustained pulmonary drug delivery. To facilitate sustained release in the lungs, aerosols must first navigate past efficient aerodynamic filtering to penetrate to the deep lung (requires small particle size) where they must then avoid rapid macrophage clearance (enhanced by large particle size). The strategy suggested in this study to solve this problem is to deliver drug-loaded hydrogel microparticles with aerodynamic characteristics allowing them to be respirable when dry but attain large swollen sizes once deposited on moist lung surfaces to reduce macrophage uptake rates. The microparticles are based on PEG graft copolymerized onto chitosan in combination with Pluronic® F-108 and were prepared via cryomilling. The synthesized polymers used in preparation of the microparticles were characterized using FTIR, EA, 2D-XRD, and differential scanning calorimetry (DSC). The microparticles size, morphology, moisture content, and biodegradation rates were investigated. Swelling studies and in vitro drug release profiles were determined. An aerosolization study was conducted and macrophage uptake rates were evaluated against controls. The microparticles showed a respirable fraction of approximately 15% when prepared as dry powders. Enzymatic degradation of microparticles started within the first hour and about 7–41% weights were remaining after 240 h. Microparticles showed sustained release up to 10 and 20 days in the presence and absence of lysozyme, respectively. Preliminary macrophage interaction studies indicate that the developed hydrogel microparticles significantly delayed phagocytosis and may have the potential for sustained drug delivery to the lung. PMID:19967777

  20. Tensor Modeling Based for Airborne LiDAR Data Classification

    NASA Astrophysics Data System (ADS)

    Li, N.; Liu, C.; Pfeifer, N.; Yin, J. F.; Liao, Z. Y.; Zhou, Y.

    2016-06-01

    Feature selection and description is a key factor in classification of Earth observation data. In this paper a classification method based on tensor decomposition is proposed. First, multiple features are extracted from raw LiDAR point cloud, and raster LiDAR images are derived by accumulating features or the "raw" data attributes. Then, the feature rasters of LiDAR data are stored as a tensor, and tensor decomposition is used to select component features. This tensor representation could keep the initial spatial structure and insure the consideration of the neighborhood. Based on a small number of component features a k nearest neighborhood classification is applied.

  1. Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study.

    PubMed

    Berg, Nikolaj Drimer; Linneberg, Allan; Thyssen, Jacob Pontoppidan; Dirksen, Asger; Elberling, Jesper

    2011-06-01

    Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. The aetiology is unknown, but chemical related respiratory symptoms have been found associated with positive patch test. The purpose of this study was to investigate the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened for chemical sensitivity with a standardised questionnaire dividing the participants into four severity groups of chemical sensitivity. Both allergic and non-allergic cutaneous reactions--defined as irritative, follicular, or doubtful allergic reactions--were analysed in relationship with severity of chemical sensitivity. Associations were controlled for the possible confounding effects of sex, age, asthma, eczema, atopic dermatitis, psychological and social factors, and smoking habits. In unadjusted analyses we found associations between allergic and non-allergic cutaneous reactions on patch testing and the two most severe groups of self-reported sensitivity to airborne chemicals. When adjusting for confounding, associations were weakened, and only non-allergic cutaneous reactions were significantly associated with individuals most severely affected by inhalation of airborne chemicals (odds ratio = 2.5, p = 0.006). Our results suggest that individuals with self-reported chemical sensitivity show increased non-allergic cutaneous reactions based on day 2 readings of patch tests.

  2. Thermogelling Bioadhesive Scaffolds for Intervertebral Disc Tissue Engineering: Preliminary In Vitro Comparison of Aldehyde-Based Versus Alginate Microparticle-Mediated Adhesion

    PubMed Central

    Wiltsey, C.; Christiani, T.; Williams, J.; Scaramazza, J.; Van Sciver, C.; Toomer, K.; Sheehan, J.; Branda, A.; Nitzl, A.; England, E.; Kadlowec, J.; Iftode, C.; Vernengo, J.

    2015-01-01

    Tissue engineering of certain load-bearing parts of the body can be dependent on scaffold adhesion or integration with the surrounding tissue to prevent dislocation. One such area is the regeneration of the intervertebral disc (IVD). In this work, poly(N-isopropylacrylamide) (PNIPAAm) was grafted with chondroitin sulfate (CS) (PNIPAAm-g-CS) and blended with aldehyde-modified CS to generate an injectable polymer that can form covalent bonds with tissue upon contact. However, the presence of the reactive aldehyde groups can compromise the viability of encapsulated cells. Thus, liposomes were encapsulated in the blend, designed to deliver the ECM derivative, gelatin, after the polymer has adhered to tissue and reached physiological temperature. This work is based on the hypothesis that the discharge of gelatin will enhance the biocompatibility of the material by covalently reacting with, or “end-capping”, the aldehyde functionalities within the gel that did not participate in bonding with tissue upon contact. As a comparison, formulations were also created without CS aldehyde and with an alternative adhesion mediator, mucoadhesive calcium alginate particles. Gels formed from blends of PNIPAAm-g-CS and CS aldehyde exhibited increased adhesive strength compared to PNIPAAm-g-CS alone (p<0.05). However, the addition of gelatin-loaded liposomes to the blend significantly decreased the adhesive strength (p<0.05). The encapsulation of alginate microparticles within PNIPAAm-g-CS gels caused the tensile strength to increase two-fold over that of PNIPAAm-g-CS blends with CS aldehyde (p<0.05). Cytocompatibility studies indicate that formulations containing alginate particles exhibit reduced cytotoxicity over those containing CS aldehyde. Overall, the results indicated that the adhesives composed of alginate microparticles encapsulated in PNIPAAm-g-CS have the potential to serve as a scaffold for IVD regeneration. PMID:25641647

  3. Thermogelling bioadhesive scaffolds for intervertebral disk tissue engineering: preliminary in vitro comparison of aldehyde-based versus alginate microparticle-mediated adhesion.

    PubMed

    Wiltsey, C; Christiani, T; Williams, J; Scaramazza, J; Van Sciver, C; Toomer, K; Sheehan, J; Branda, A; Nitzl, A; England, E; Kadlowec, J; Iftode, C; Vernengo, J

    2015-04-01

    Tissue engineering of certain load-bearing parts of the body can be dependent on scaffold adhesion or integration with the surrounding tissue to prevent dislocation. One such area is the regeneration of the intervertebral disc (IVD). In this work, poly(N-isopropylacrylamide) (PNIPAAm) was grafted with chondroitin sulfate (CS) (PNIPAAm-g-CS) and blended with aldehyde-modified CS to generate an injectable polymer that can form covalent bonds with tissue upon contact. However, the presence of the reactive aldehyde groups can compromise the viability of encapsulated cells. Thus, liposomes were encapsulated in the blend, designed to deliver the ECM derivative, gelatin, after the polymer has adhered to tissue and reached physiological temperature. This work is based on the hypothesis that the discharge of gelatin will enhance the biocompatibility of the material by covalently reacting with, or "end-capping", the aldehyde functionalities within the gel that did not participate in bonding with tissue upon contact. As a comparison, formulations were also created without CS aldehyde and with an alternative adhesion mediator, mucoadhesive calcium alginate particles. Gels formed from blends of PNIPAAm-g-CS and CS aldehyde exhibited increased adhesive strength compared to PNIPAAm-g-CS alone (p<0.05). However, the addition of gelatin-loaded liposomes to the blend significantly decreased the adhesive strength (p<0.05). The encapsulation of alginate microparticles within PNIPAAm-g-CS gels caused the tensile strength to increase twofold over that of PNIPAAm-g-CS blends with CS aldehyde (p<0.05). Cytocompatibility studies indicate that formulations containing alginate particles exhibit reduced cytotoxicity over those containing CS aldehyde. Overall, the results indicated that the adhesives composed of alginate microparticles encapsulated in PNIPAAm-g-CS have the potential to serve as a scaffold for IVD regeneration.

  4. Airborne and Ground-Based Measurements Using a High-Performance Raman Lidar

    NASA Technical Reports Server (NTRS)

    Whiteman, David N.; Rush, Kurt; Rabenhorst, Scott; Welch, Wayne; Cadirola, Martin; McIntire, Gerry; Russo, Felicita; Adam, Mariana; Venable, Demetrius; Connell, Rasheen; Veselovskii, Igor; Forno, Ricardo; Mielke, Bernd; Stein, Bernhard; Leblanc, Thierry; McDermid, Stuart; Voemel, Holger

    2010-01-01

    A high-performance Raman lidar operating in the UV portion of the spectrum has been used to acquire, for the first time using a single lidar, simultaneous airborne profiles of the water vapor mixing ratio, aerosol backscatter, aerosol extinction, aerosol depolarization and research mode measurements of cloud liquid water, cloud droplet radius, and number density. The Raman Airborne Spectroscopic Lidar (RASL) system was installed in a Beechcraft King Air B200 aircraft and was flown over the mid-Atlantic United States during July August 2007 at altitudes ranging between 5 and 8 km. During these flights, despite suboptimal laser performance and subaperture use of the telescope, all RASL measurement expectations were met, except that of aerosol extinction. Following the Water Vapor Validation Experiment Satellite/Sondes (WAVES_2007) field campaign in the summer of 2007, RASL was installed in a mobile trailer for groundbased use during the Measurements of Humidity and Validation Experiment (MOHAVE-II) field campaign held during October 2007 at the Jet Propulsion Laboratory s Table Mountain Facility in southern California. This ground-based configuration of the lidar hardware is called Atmospheric Lidar for Validation, Interagency Collaboration and Education (ALVICE). During theMOHAVE-II field campaign, during which only nighttime measurements were made, ALVICE demonstrated significant sensitivity to lower-stratospheric water vapor. Numerical simulation and comparisons with a cryogenic frost-point hygrometer are used to demonstrate that a system with the performance characteristics of RASL ALVICE should indeed be able to quantify water vapor well into the lower stratosphere with extended averaging from an elevated location like Table Mountain. The same design considerations that optimize Raman lidar for airborne use on a small research aircraft are, therefore, shown to yield significant dividends in the quantification of lower-stratospheric water vapor. The MOHAVE

  5. a Min-Cut Based Filter for Airborne LIDAR Data

    NASA Astrophysics Data System (ADS)

    Ural, Serkan; Shan, Jie

    2016-06-01

    LiDAR (Light Detection and Ranging) is a routinely employed technology as a 3-D data collection technique for topographic mapping. Conventional workflows for analyzing LiDAR data require the ground to be determined prior to extracting other features of interest. Filtering the terrain points is one of the fundamental processes to acquire higher-level information from unstructured LiDAR point data. There are many ground-filtering algorithms in literature, spanning several broad categories regarding their strategies. Most of the earlier algorithms examine only the local characteristics of the points or grids, such as the slope, and elevation discontinuities. Since considering only the local properties restricts the filtering performance due to the complexity of the terrain and the features, some recent methods utilize global properties of the terrain as well. This paper presents a new ground filtering method, Min-cut Based Filtering (MBF), which takes both local and global properties of the points into account. MBF considers ground filtering as a labeling task. First, an energy function is designed on a graph, where LiDAR points are considered as the nodes on the graph that are connected to each other as well as to two auxiliary nodes representing ground and off-ground labels. The graph is constructed such that the data costs are assigned to the edges connecting the points to the auxiliary nodes, and the smoothness costs to the edges between points. Data and smoothness terms of the energy function are formulated using point elevations and approximate ground information. The data term conducts the likelihood of the points being ground or off-ground while the smoothness term enforces spatial coherence between neighboring points. The energy function is optimized by finding the minimum-cut on the graph via the alpha-expansion algorithm. The resulting graph-cut provides the labeling of the point cloud as ground and off-ground points. Evaluation of the proposed method on

  6. Green microparticles based on a chitosan/lactobionic acid/linoleic acid association. Characterization and evaluation as a new carrier system for cosmetics.

    PubMed

    Chaouat, C; Balayssac, S; Malet-Martino, M; Belaubre, F; Questel, E; Schmitt, A M; Poigny, S; Franceschi, S; Perez, E

    2017-03-27

    The association chitosan/linoleic acid/lactobionic acid in aqueous solution spontaneously led to the formation of stable microparticles with a liquid hydrophobic core consisting of linoleic acid surrounded by a shell of chitosan/lactobionic acid. The originality of the microparticles arises from the fact that they are formed by the association of three ingredients of cosmetic interest, including a skin penetration enhancer (linoleic acid). DLS measurements showed microparticles with a mean diameter of 1 to 2 µm. The presence of a hydrophobic liquid core was observed by TEM. The ability of these microparticles to encapsulate phenylethyl resorcinol, a hydrophobic skin lightener, was evaluated and its encapsulation was confirmed thanks to T2 measurements and nOe signs.

  7. Poly (caprolactone) microparticles and chitosan thermogels based injectable formulation of etoricoxib for the potential treatment of osteoarthritis.

    PubMed

    Arunkumar, P; Indulekha, S; Vijayalakshmi, S; Srivastava, R

    2016-04-01

    This study aimed to evaluate Poly (caprolactone) microparticles (MPs) loaded composite injectable Chitosan gel (CICGs) as a dual purpose (visco-supplement and intra articular drug delivery depot) therapeutic agent for the treatment of Osteoarthritis. Etoricoxib (COX-2 inhibitor), a highly hydrophobic drug was chosen as a model drug for the study. When administered orally, Etoricoxib poses severe cardiovascular toxicity issues. So, we have attempted to deliver this drug intra-articularly, which could retain the drug longer in the joint region and thus could ameliorate these toxicity issues. CICGs were prepared by dispersing MPs in the chitosan-Ammonium hydrogen phosphate solution and incubated at 37 °C. Rheology studies proved that gels were stable and had visco-elastic properties comparable to that of existing visco-supplements. The in vitro drug release profiles of CICGs were found to be more controlled when compared to MPs and bare chitosan gel (BCGs). In vitro and in vivo biocompatibility studies proved that the gels were biocompatible. In vivo synovial drug clearance studies proved that CICGs had a better drug retention capacity than BCGs and MPs. In vivo fluorescence imaging results confirmed that CICGs could stay longer in the joint region when compared to BCGs and MPs. Thus this novel CICGs could be a potential dual purpose gel for the treatment of diseased joint regions especially for Osteoarthritis.

  8. Preconcentration based on paramagnetic microparticles for the separation of sarcosine using hydrophilic interaction liquid chromatography coupled with coulometric detection.

    PubMed

    Zitka, Ondrej; Heger, Zbynek; Kominkova, Marketa; Skalickova, Sylvie; Krizkova, Sona; Adam, Vojtech; Kizek, Rene

    2014-03-01

    Sarcosine has been identified as a potential prostate cancer marker. To provide determination of this compound, a number of methods are developing. In this study, we optimized a method for its separation by hydrophilic interaction LC with electrochemical detection (ED). Due to the fact that mobile phases commonly used for this type of separation altered the LODs measured by electrochemical detectors, we applied postcolumn dosing of buffer suitable for ED. The optimized conditions were mobile phase A acetonitrile, mobile phase B water in the ratio A/B 70:30, with postcolumn addition of mobile phase C (200 mM phosphate buffer pH 9). The optimal mixing ratio was A + B/C 1:1 with a flow rate of 0.80 mL/min (0.40 + 0.40 mL/min) and detection potential of 1000 mV. Due to the optimization of the parameters for effective separation, which had to meet the optimal parameters of ED, we reached a good resolution for separation also with a good LOD (100 nM). In addition, we successfully carried out sarcosine analysis bound on our modified paramagnetic microparticles with the ability to preconcentrate sarcosine isolated from artificial urine.

  9. Voxel Based Representation of Full-Waveform Airborne Laser Scanner Data for Forestry Applications

    NASA Astrophysics Data System (ADS)

    Stelling, N.; Richter, K.

    2016-06-01

    The advantages of using airborne full-waveform laser scanner data in forest applications, e.g. for the description of the vertical vegetation structure or accurate biomass estimation, have been emphasized in many publications. To exploit the full potential offered by airborne full-waveform laser scanning data, the development of voxel based methods for data analysis is essential. In contrast to existing approaches based on the extraction of discrete 3D points by a Gaussian decomposition, it is very promising to derive the voxel attributes from the digitised waveform directly. For this purpose, the waveform data have to be transferred into a 3D voxel representation. This requires a series of radiometric and geometric transformations of the raw full-waveform laser scanner data. Thus, the paper deals with the geometric aspects and describes a processing chain from the raw waveform data to an attenuationcorrected volumetric forest stand reconstruction. The integration of attenuation-corrected waveform data into the voxel space is realised with an efficient parametric voxel traversal method operating on an octree data structure. The voxel attributes are derived from the amplitudes of the attenuation-corrected waveforms. Additionally, a new 3D filtering approach is presented to eliminate non-object voxel. Applying these methods to real full-waveform laser scanning data, a voxel based representation of a spruce was generated combining three flight strips from different viewing directions.

  10. Controlled Lateral Positioning of Microparticles Inside Droplets Using Acoustophoresis.

    PubMed

    Fornell, Anna; Nilsson, Johan; Jonsson, Linus; Periyannan Rajeswari, Prem Kumar; Joensson, Haakan N; Tenje, Maria

    2015-10-20

    In this paper, we utilize bulk acoustic waves to control the position of microparticles inside droplets in two-phase microfluidic systems and demonstrate a method to enrich the microparticles. In droplet microfluidics, different unit operations are combined and integrated on-chip to miniaturize complex biochemical assays. We present a droplet unit operation capable of controlling the position of microparticles during a trident shaped droplet split. An acoustic standing wave field is generated in the microchannel, and the acoustic forces direct the encapsulated microparticles to the center of the droplets. The method is generic, requires no labeling of the microparticles, and is operated in a noncontact fashion. It was possible to achieve 2+-fold enrichment of polystyrene beads (5 μm in diameter) in the center daughter droplet with an average recovery of 89% of the beads. Red blood cells were also successfully manipulated inside droplets. These results show the possibility to use acoustophoresis in two-phase systems to enrich microparticles and open up the possibility for new droplet-based assays that are not performed today.

  11. Porphyrin Microparticles for Biological and Biomedical Applications

    NASA Astrophysics Data System (ADS)

    Huynh, Elizabeth

    Lipids are one of the critical building blocks of life, forming the plasma membrane of cells. In addition, porphyrins also play an equally important role in life, for example, through carrying oxygen in blood. The importance of both these components is evident through the biological and biomedical applications of supramolecular structures generated from lipids and porphyrins. This thesis investigates new porphyrin microparticles based on porphyrin-lipid architecture and their potential applications in biology and medicine. In Chapter 1, a background on lipid and porphyrin-based supramolecular structures is presented and design considerations for generating multifunctional agents. Chapter 2 describes the generation of a monolayer porphyrin microparticle as a dual-modal ultrasound and photoacoustic contrast agent and subsequently, a trimodal ultrasound, photoacoustic and fluorescence contrast agent. Chapter 3 examines the optical and morphological response of these multimodality ultrasound-based contrast agents to low frequency, high duty cycle ultrasound that causes the porphyrin microparticles to convertinto nanoparticles. Chapter 4 examines the generation of bilayer micrometer-sized porphyrin vesicles and their properties. Chapter 5 presents a brief summary and potential future directions. Although these microscale structures are similar in structure, the applications of these structures greatly differ with potential applications in biology and also imaging and therapy of disease. This thesis aims to explore and demonstrate the potential of new simplified, supramolecular structures based on one main building block, porphyrin-lipid.

  12. Road centerline extraction from airborne LiDAR point cloud based on hierarchical fusion and optimization

    NASA Astrophysics Data System (ADS)

    Hui, Zhenyang; Hu, Youjian; Jin, Shuanggen; Yevenyo, Yao Ziggah

    2016-08-01

    Road information acquisition is an important part of city informatization construction. Airborne LiDAR provides a new means of acquiring road information. However, the existing road extraction methods using LiDAR point clouds always decide the road intensity threshold based on experience, which cannot obtain the optimal threshold to extract a road point cloud. Moreover, these existing methods are deficient in removing the interference of narrow roads and several attached areas (e.g., parking lot and bare ground) to main roads extraction, thereby imparting low completeness and correctness to the city road network extraction result. Aiming at resolving the key technical issues of road extraction from airborne LiDAR point clouds, this paper proposes a novel method to extract road centerlines from airborne LiDAR point clouds. The proposed approach is mainly composed of three key algorithms, namely, Skewness balancing, Rotating neighborhood, and Hierarchical fusion and optimization (SRH). The skewness balancing algorithm used for the filtering was adopted as a new method for obtaining an optimal intensity threshold such that the "pure" road point cloud can be obtained. The rotating neighborhood algorithm on the other hand was developed to remove narrow roads (corridors leading to parking lots or sidewalks), which are not the main roads to be extracted. The proposed hierarchical fusion and optimization algorithm caused the road centerlines to be unaffected by certain attached areas and ensured the road integrity as much as possible. The proposed method was tested using the Vaihingen dataset. The results demonstrated that the proposed method can effectively extract road centerlines in a complex urban environment with 91.4% correctness and 80.4% completeness.

  13. Detection of airborne carbon nanotubes based on the reactivity of the embedded catalyst.

    PubMed

    Neubauer, N; Kasper, G

    2015-01-01

    A previously described method for detecting catalyst particles in workplace air((1,2)) was applied to airborne carbon nanotubes (CNT). It infers the CNT concentration indirectly from the catalytic activity of metallic nanoparticles embedded as part of the CNT production process. Essentially, one samples airborne CNT onto a filter enclosed in a tiny chemical reactor and then initiates a gas-phase catalytic reaction on the sample. The change in concentration of one of the reactants is then determined by an IR sensor as measure of activity. The method requires a one-point calibration with a CNT sample of known mass. The suitability of the method was tested with nickel containing (25 or 38% by weight), well-characterized multi-walled CNT aerosols generated freshly in the lab for each experiment. Two chemical reactions were investigated, of which the oxidation of CO to CO2 at 470°C was found to be more effective, because nearly 100% of the nickel was exposed at that temperature by burning off the carbon, giving a linear relationship between CO conversion and nickel mass. Based on the investigated aerosols, a lower detection limit of 1 μg of sampled nickel was estimated. This translates into sampling times ranging from minutes to about one working day, depending on airborne CNT concentration and catalyst content, as well as sampling flow rate. The time for the subsequent chemical analysis is on the order of minutes, regardless of the time required to accumulate the sample and can be done on site.

  14. Kalman Filter Based Feature Analysis for Tracking People from Airborne Images

    NASA Astrophysics Data System (ADS)

    Sirmacek, B.; Reinartz, P.

    2011-09-01

    Recently, analysis of man events in real-time using computer vision techniques became a very important research field. Especially, understanding motion of people can be helpful to prevent unpleasant conditions. Understanding behavioral dynamics of people can also help to estimate future states of underground passages, shopping center like public entrances, or streets. In order to bring an automated solution to this problem, we propose a novel approach using airborne image sequences. Although airborne image resolutions are not enough to see each person in detail, we can still notice a change of color components in the place where a person exists. Therefore, we propose a color feature detection based probabilistic framework in order to detect people automatically. Extracted local features behave as observations of the probability density function (pdf) of the people locations to be estimated. Using an adaptive kernel density estimation method, we estimate the corresponding pdf. First, we use estimated pdf to detect boundaries of dense crowds. After that, using background information of dense crowds and previously extracted local features, we detect other people in non-crowd regions automatically for each image in the sequence. We benefit from Kalman filtering to track motion of detected people. To test our algorithm, we use a stadium entrance image data set taken from airborne camera system. Our experimental results indicate possible usage of the algorithm in real-life man events. We believe that the proposed approach can also provide crucial information to police departments and crisis management teams to achieve more detailed observations of people in large open area events to prevent possible accidents or unpleasant conditions.

  15. [Remote sensing of chlorophyll fluorescence at airborne level based on unmanned airship platform and hyperspectral sensor].

    PubMed

    Yang, Pei-Qi; Liu, Zhi-Gang; Ni, Zhuo-Ya; Wang, Ran; Wang, Qing-Shan

    2013-11-01

    The solar-induced chlorophyll fluorescence (ChlF) has a close relationship with photosynthetic and is considered as a probe of plant photosynthetic activity. In this study, an airborne fluorescence detecting system was constructed by using a hyperspectral imager on board an unmanned airship. Both Fraunhofer Line Discriminator (FLD) and 3FLD used to extract ChlF require the incident solar irradiance, which is always difficult to receive at airborne level. Alternative FLD (aFLD) can overcome the problem by selecting non-fluorescent emitter in the image. However, aFLD is based on the assumption that reflectance is identical around the Fraunhofer line, which is not realistic. A new method, a3FLD, is proposed, which assumes that reflectance varies linearly with the wavelength around Fraunhofer line. The result of simulated data shows that ChlF retrieval error of a3FLD is significantly lower than that of aFLD when vegetation reflectance varies near the Fraunhofer line. The results of hyperspectral remote sensing data with the airborne fluorescence detecting system show that the relative values of retrieved ChlF of 5 kinds of plants extracted by both aFLD and a3FLD are consistent with vegetation growth stage and the ground-level ChlF. The ChlF values of aFLD are about 15% greater than a3FLD. In addition, using aFLD, some non-fluorescent objects have considerable ChlF value, while a3FLD can effectively overcome the problem.

  16. Stable cationic microparticles for enhanced model antigen delivery to dendritic cells.

    PubMed

    Wischke, Christian; Borchert, Hans-Hubert; Zimmermann, Julian; Siebenbrodt, Ingo; Lorenzen, Dirk R

    2006-09-12

    The objectives of this work were (i) to prepare physically stable cationic microparticles and (ii) to study the impact of the surface properties on microparticle phagocytosis and the phenotype of dendritic cells (DC). Protein loaded biodegradable microparticles from poly(lactic-co-glycolic acid) [PLGA] were produced in a micromixer-based w/o/w solvent evaporation procedure. Anionic particles were obtained by using polyvinyl alcohol (PVA) as stabilizing agent; for cationic surfaces cetyltrimethylammonium bromide (CTAB) and chitosan/PVA or DEAE-dextran/PVA blends were evaluated. In phagocytosis studies human monocytes and monocyte-derived DC were incubated with microparticles and analysed by flow cytometry. While CTAB modified microparticles lost their positive charge and aggregated due to CTAB desorption from the particle surface, the modification with chitosan and DEAE-dextran resulted in stable microparticles without cell toxicity. Due to a very low endotoxin content, phagocytosis of anionic and cationic microparticles did not induce an upregulation of maturation-associated surface markers on DC. DEAE-dextran modified microparticles showed an enhanced model protein delivery into phagocytic cells. Overall, PLGA microparticles are suitable vehicles for protein delivery to DC, which might be used for DC-based cell therapies.

  17. Profile negotiation - A concept for integrating airborne and ground-based automation for managing arrival traffic

    NASA Technical Reports Server (NTRS)

    Green, Steven M.; Den Braven, Wim; Williams, David H.

    1991-01-01

    The profile negotiation process (PNP) concept as applied to the management of arrival traffic within the extended terminal area is presented, focusing on functional issues from the ground-based perspective. The PNP is an interactive process between an aircraft and air traffic control (ATC) which combines airborne and ground-based automation capabilities to determine conflict-free trajectories that are as close to an aircraft's preference as possible. Preliminary results from a real-time simulation study show that the controller teams are able to consistently and effectively negotiate conflict-free vertical profiles with 4D-equipped aircraft. The ability of the airborne 4D flight management system to adapt to ATC specified 4D trajectory constraints is found to be a requirement for successful execution of the PNP. It is recommended that the conventional method of cost index iteration for obtaining the minimum fuel 4D trajectory be supplemented by a method which constrains the profile speeds to those desired by ATC.

  18. Understanding the Laminar Distribution of Tropospheric Ozone from Ground-Based, Airborne, Spaceborne, and Modeling Perspectives

    NASA Technical Reports Server (NTRS)

    Newchurch, Mike; Johnson, Matthew S.; Huang, Guanyu; Kuang, Shi; Wang, Lihua; Chance, Kelly; Liu, Xiong

    2016-01-01

    Laminar ozone structure is a ubiquitous feature of tropospheric-ozone distributions resulting from dynamic and chemical atmospheric processes. Understanding the characteristics of these ozone laminae and the mechanisms responsible for producing them is important to outline the transport pathways of trace gases and to quantify the impact of different sources on tropospheric background ozone. In this study, we present a new method to detect ozone laminae to understand their climatological characteristics of occurrence frequency in terms of thickness and altitude. We employ both ground-based and airborne ozone lidar measurements and other synergistic observations and modeling to investigate the sources and mechanisms such as biomass burning transport, stratospheric intrusion, lightning-generated NOx, and nocturnal low-level jets that are responsible for depleted or enhanced tropospheric ozone layers. Spaceborne (e.g., OMI (Ozone Monitoring Instrument), TROPOMI (Tropospheric Monitoring Instrument), TEMPO (Tropospheric Emissions: Monitoring of Pollution)) measurements of these laminae will observe greater horizontal extent and lower vertical resolution than balloon-borne or lidar measurements will quantify. Using integrated ground-based, airborne, and spaceborne observations in a modeling framework affords insight into how to gain knowledge of both the vertical and horizontal evolution of these ubiquitous ozone laminae.

  19. Airborne ultrasonic transducer using polymer-based elastomer with high output-to-weight ratio

    NASA Astrophysics Data System (ADS)

    Wu, Jiang; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2015-08-01

    With the properties of low density, low elastic modulus, and low mechanical loss, poly(phenylene sulfide) (PPS) is a suitable material as the elastomer in an airborne ultrasonic transducer for generating large vibration velocity. In this study, we design and fabricate a transducer composed of a PPS-based longitudinal vibrator and a PPS-based disk of 0.3 mm thickness to obtain high-intensity ultrasound. The rated sound pressure at a distance of 300 mm reached 38.9 Pa (125 dB, 0 dB re. 0.02 mPa) when the frequency and voltage were 58.90 kHz and 20 V. The weight of this transducer is 6.3 g. The ratio of the sound pressure to the weight of the prototype transducer is 1.8 times larger than that of the commercial transducer. The experimental results indicate that PPS is a good substitute for metal as the elastomer for manufacturing airborne ultrasonic transducers with a high output-to-weight ratio.

  20. Image-Based Airborne Sensors: A Combined Approach for Spectral Signatures Classification through Deterministic Simulated Annealing

    PubMed Central

    Guijarro, María; Pajares, Gonzalo; Herrera, P. Javier

    2009-01-01

    The increasing technology of high-resolution image airborne sensors, including those on board Unmanned Aerial Vehicles, demands automatic solutions for processing, either on-line or off-line, the huge amountds of image data sensed during the flights. The classification of natural spectral signatures in images is one potential application. The actual tendency in classification is oriented towards the combination of simple classifiers. In this paper we propose a combined strategy based on the Deterministic Simulated Annealing (DSA) framework. The simple classifiers used are the well tested supervised parametric Bayesian estimator and the Fuzzy Clustering. The DSA is an optimization approach, which minimizes an energy function. The main contribution of DSA is its ability to avoid local minima during the optimization process thanks to the annealing scheme. It outperforms simple classifiers used for the combination and some combined strategies, including a scheme based on the fuzzy cognitive maps and an optimization approach based on the Hopfield neural network paradigm. PMID:22399989

  1. IGF-1 Release Kinetics from Chitosan Microparticles Fabricated Using Environmentally Benign Conditions

    PubMed Central

    Mantripragada, Venkata P.; Jayasuriya, Ambalangodage C.

    2014-01-01

    The main objective of this study is to maximize growth factor encapsulation efficiency into microparticles. The novelty of this study is to maximize the encapsulated growth factors into microparticles by minimizing the use of organic solvents and using relatively low temperatures. The microparticles were fabricated using chitosan biopolymer as a base polymer and cross-linked with tripolyphosphate (TPP). Insulin like-growth factor-1 (IGF-1) was encapsulated into microparticles to study release kinetics and bioactivity. In order to authenticate the harms of using organic solvents like hexane and acetone during microparticle preparation, IGF-1 encapsulated microparticles prepared by the emulsification and coacervation methods were compared. The microparticles fabricated by emulsification method have shown a significant decrease (p<0.05) in IGF-1 encapsulation efficiency, and cumulative release during the two-week period. The biocompatibility of chitosan microparticles and the bioactivity of the released IGF-1 were determined in vitro by live/dead viability assay. The mineralization data observed with Von Kossa assay, was supported by mRNA expression levels of osterix and runx2, which are transcription factors necessary for osteoblasts differentiation. Real time RT-PCR data showed an increased expression of runx 2 and a decreased expression of osterix over time, indicating differentiating osteoblasts. Chitosan microparticles prepared in optimum environmental conditions are a promising controlled delivery system for cells to attach, proliferate, differentiate and mineralize, thereby acting as a suitable bone repairing material. PMID:25063148

  2. Encapsulation of antigen-loaded silica nanoparticles into microparticles for intradermal powder injection.

    PubMed

    Deng, Yibin; Mathaes, Roman; Winter, Gerhard; Engert, Julia

    2014-10-15

    Epidermal powder immunisation (EPI) is being investigated as a promising needle-free delivery methods for vaccination. The objective of this work was to prepare a nanoparticles-in-microparticles (nano-in-micro) system, integrating the advantages of nanoparticles and microparticles into one vaccine delivery system for epidermal powder immunisation. Cationic mesoporous silica nanoparticles (MSNP-NH2) were prepared and loaded with ovalbumin as a model antigen. Loading was driven by electrostatic interactions. Ovalbumin-loaded silica nanoparticles were subsequently formulated into sugar-based microparticles by spray-freeze-drying. The obtained microparticles meet the size requirement for EPI. Confocal microscopy was used to demonstrate that the nanoparticles are homogeneously distributed in the microparticles. Furthermore, the silica nanoparticles in the dry microparticles can be re-dispersed in aqueous solution showing no aggregation. The recovered ovalbumin shows integrity compared to native ovalbumin. The present nano-in-micro system allows (1) nanoparticles to be immobilized and finely distributed in microparticles, (2) microparticle formation and (3) re-dispersion of nanoparticles without subsequent aggregation. The nanoparticles inside microparticles can (1) adsorb proteins to cationic shell/surface voids in spray-dried products without detriment to ovalbumin stability, (2) deliver antigens in nano-sized modes to allow recognition by the immune system.

  3. A new method to measure air-borne pyrogens based on human whole blood cytokine response.

    PubMed

    Kindinger, Ilona; Daneshian, Mardas; Baur, Hans; Gabrio, Thomas; Hofmann, Andreas; Fennrich, Stefan; von Aulock, Sonja; Hartung, Thomas

    2005-03-01

    Air-borne microorganisms, as well as their fragments and components, are increasingly recognized to be associated with pulmonary diseases, e.g. organic dust toxic syndrome, humidifier lung, building-related illness, "Monday sickness." We have previously described and validated a new method for the detection of pyrogenic (fever-inducing) microbial contaminations in injectable drugs, based on the inflammatory reaction of human blood to pyrogens. We have now adapted this test to evaluate the total inflammatory capacity of air samples. Air was drawn onto PTFE membrane filters, which were incubated with human whole blood from healthy volunteers inside the collection device. Cytokine release was measured by ELISA. The test detects endotoxins and non-endotoxins, such as fungal spores, Gram-positive bacteria and their lipoteichoic acid moiety and pyrogenic dust particles with high sensitivity, thus reflecting the total inflammatory capacity of a sample. When air from different surroundings such as working environments and animal housing was assayed, the method yielded reproducible data which correlated with other parameters of microbial burden tested. We further developed a standard material for quantification and showed that this assay can be performed with cryopreserved as well as fresh blood. The method offers a test to measure the integral inflammatory capacity of air-borne microbial contaminations relevant to humans. It could thus be employed to assess air quality in different living and work environments.

  4. Enhanced Feature Based Mosaicing Technique for Visually and Geometrically Degraded Airborne Synthetic Aperture Radar Images

    NASA Astrophysics Data System (ADS)

    Manikandan, S.; Vardhini, J. P.

    2015-11-01

    In airborne synthetic aperture radar (SAR), there was a major problem encountered in the area of image mosaic in the absence of platform information and sensor information (geocoding), when SAR is applied in large-scale scene and the platform faces large changes. In order to enhance real-time performance and robustness of image mosaic, enhancement based Speeded-Up Robust Features (SURF) mosaic method for airborne SAR is proposed in this paper. SURF is a novel scale-invariant and rotation-invariant feature. It is perfect in its high computation, speed and robustness. In this paper, When the SAR image is acquired, initially the image is enhanced by using local statistic techniques and SURF is applied for SAR image matching accord to its characteristic, and then acquires its invariant feature for matching. In the process of image matching, the nearest neighbor rule for initial matching is used, and the wrong points of the matches are removed through RANSAC fitting algorithm. The proposed algorithm is implemented in different SAR images with difference in scale change, rotation change and noise. The proposed algorithm is compared with other existing algorithms and the quantitative and qualitative measures are calculated and tabulated. The proposed algorithm is robust to changes and the threshold is varied accordingly to increase the matching rate more than 95 %.

  5. Bundle Block Adjustment of Airborne Three-Line Array Imagery Based on Rotation Angles

    PubMed Central

    Zhang, Yongjun; Zheng, Maoteng; Huang, Xu; Xiong, Jinxin

    2014-01-01

    In the midst of the rapid developments in electronic instruments and remote sensing technologies, airborne three-line array sensors and their applications are being widely promoted and plentiful research related to data processing and high precision geo-referencing technologies is under way. The exterior orientation parameters (EOPs), which are measured by the integrated positioning and orientation system (POS) of airborne three-line sensors, however, have inevitable systematic errors, so the level of precision of direct geo-referencing is not sufficiently accurate for surveying and mapping applications. Consequently, a few ground control points are necessary to refine the exterior orientation parameters, and this paper will discuss bundle block adjustment models based on the systematic error compensation and the orientation image, considering the principle of an image sensor and the characteristics of the integrated POS. Unlike the models available in the literature, which mainly use a quaternion to represent the rotation matrix of exterior orientation, three rotation angles are directly used in order to effectively model and eliminate the systematic errors of the POS observations. Very good experimental results have been achieved with several real datasets that verify the correctness and effectiveness of the proposed adjustment models. PMID:24811075

  6. Forest tree species clssification based on airborne hyper-spectral imagery

    NASA Astrophysics Data System (ADS)

    Dian, Yuanyong; Li, Zengyuan; Pang, Yong

    2013-10-01

    Forest precision classification products were the basic data for surveying of forest resource, updating forest subplot information, logging and design of forest. However, due to the diversity of stand structure, complexity of the forest growth environment, it's difficult to discriminate forest tree species using multi-spectral image. The airborne hyperspectral images can achieve the high spatial and spectral resolution imagery of forest canopy, so it will good for tree species level classification. The aim of this paper was to test the effective of combining spatial and spectral features in airborne hyper-spectral image classification. The CASI hyper spectral image data were acquired from Liangshui natural reserves area. Firstly, we use the MNF (minimum noise fraction) transform method for to reduce the hyperspectral image dimensionality and highlighting variation. And secondly, we use the grey level co-occurrence matrix (GLCM) to extract the texture features of forest tree canopy from the hyper-spectral image, and thirdly we fused the texture and the spectral features of forest canopy to classify the trees species using support vector machine (SVM) with different kernel functions. The results showed that when using the SVM classifier, MNF and texture-based features combined with linear kernel function can achieve the best overall accuracy which was 85.92%. It was also confirm that combine the spatial and spectral information can improve the accuracy of tree species classification.

  7. Evaluation of meteorological airborne Doppler radar

    NASA Technical Reports Server (NTRS)

    Hildebrand, P. H.; Mueller, C. K.

    1984-01-01

    This paper will discuss the capabilities of airborne Doppler radar for atmospheric sciences research. The evaluation is based on airborne and ground based Doppler radar observations of convective storms. The capability of airborne Doppler radar to measure horizontal and vertical air motions is evaluated. Airborne Doppler radar is shown to be a viable tool for atmospheric sciences research.

  8. Development and Evaluation of an Airborne Superconducting Quantum Interference Device-Based Magnetic Gradiometer Tensor System for Detection, Characterization and Mapping of Unexploded Ordnance

    DTIC Science & Technology

    2008-08-01

    FINAL REPORT Development and Evaluation of an Airborne Superconducting Quantum Interference Device-Based Magnetic Gradiometer Tensor System...Airborne Superconducting Quantum Interference Device-Based Magnetic Gradiometer Tensor System for Detection, Characterization and Mapping of Unexploded...Demonstration of the difference between a single component total field magnetometer and intrinsic gradiometer . (From Clarke, 1994). 4 Figure 3

  9. Flexible Lamination-Fabricated Ultra-High Frequency Diodes Based on Self-Supporting Semiconducting Composite Film of Silicon Micro-Particles and Nano-Fibrillated Cellulose

    PubMed Central

    Sani, Negar; Wang, Xin; Granberg, Hjalmar; Andersson Ersman, Peter; Crispin, Xavier; Dyreklev, Peter; Engquist, Isak; Gustafsson, Göran; Berggren, Magnus

    2016-01-01

    Low cost and flexible devices such as wearable electronics, e-labels and distributed sensors will make the future “internet of things” viable. To power and communicate with such systems, high frequency rectifiers are crucial components. We present a simple method to manufacture flexible diodes, operating at GHz frequencies, based on self-adhesive composite films of silicon micro-particles (Si-μPs) and glycerol dispersed in nanofibrillated cellulose (NFC). NFC, Si-μPs and glycerol are mixed in a water suspension, forming a self-supporting nanocellulose-silicon composite film after drying. This film is cut and laminated between a flexible pre-patterned Al bottom electrode and a conductive Ni-coated carbon tape top contact. A Schottky junction is established between the Al electrode and the Si-μPs. The resulting flexible diodes show current levels on the order of mA for an area of 2 mm2, a current rectification ratio up to 4 × 103 between 1 and 2 V bias and a cut-off frequency of 1.8 GHz. Energy harvesting experiments have been demonstrated using resistors as the load at 900 MHz and 1.8 GHz. The diode stack can be delaminated away from the Al electrode and then later on be transferred and reconfigured to another substrate. This provides us with reconfigurable GHz-operating diode circuits. PMID:27357006

  10. 68Ga and 188Re Starch-Based Microparticles as Theranostic Tool for the Hepatocellular Carcinoma: Radiolabeling and Preliminary In Vivo Rat Studies

    PubMed Central

    Drion, Pierre; Meffre, Geneviève; Bernard, Claire; Duwez, Luc; Lepareur, Nicolas; Couturier, Olivier; Hindré, François

    2016-01-01

    Purpose This work aims to develop, validate and optimize the radiolabeling of Starch-Based Microparticles (SBMP) by 188Re and 68Ga in the form of ready-to-use radiolabeling kits, the ultimate goal being to obtain a unique theranostic vector for the treatment of Hepatocellular Carcinoma. Methods Optimal labeling conditions and composition of freeze-dried kits were defined by monitoring the radiochemical purity while varying several parameters. In vitro stability studies were carried out, as well as an in vivo biodistribution as a preliminary approach with the intra-arterial injection of 68Ga radiolabeled SBMP into the hepatic artery of DENA-induced rats followed by PET/CT imaging. Results Kits were optimized for 188Re and 68Ga with high and stable radiochemical purity (>95% and >98% respectively). The in vivo preliminary study was successful with more than 95% of activity found in the liver and mostly in the tumorous part. Conclusion SBMP are a promising theranostic agent for the Selective Internal Radiation Therapy of Hepatocellular carcinoma. PMID:27741267

  11. Flexible Lamination-Fabricated Ultra-High Frequency Diodes Based on Self-Supporting Semiconducting Composite Film of Silicon Micro-Particles and Nano-Fibrillated Cellulose

    NASA Astrophysics Data System (ADS)

    Sani, Negar; Wang, Xin; Granberg, Hjalmar; Andersson Ersman, Peter; Crispin, Xavier; Dyreklev, Peter; Engquist, Isak; Gustafsson, Göran; Berggren, Magnus

    2016-06-01

    Low cost and flexible devices such as wearable electronics, e-labels and distributed sensors will make the future “internet of things” viable. To power and communicate with such systems, high frequency rectifiers are crucial components. We present a simple method to manufacture flexible diodes, operating at GHz frequencies, based on self-adhesive composite films of silicon micro-particles (Si-μPs) and glycerol dispersed in nanofibrillated cellulose (NFC). NFC, Si-μPs and glycerol are mixed in a water suspension, forming a self-supporting nanocellulose-silicon composite film after drying. This film is cut and laminated between a flexible pre-patterned Al bottom electrode and a conductive Ni-coated carbon tape top contact. A Schottky junction is established between the Al electrode and the Si-μPs. The resulting flexible diodes show current levels on the order of mA for an area of 2 mm2, a current rectification ratio up to 4 × 103 between 1 and 2 V bias and a cut-off frequency of 1.8 GHz. Energy harvesting experiments have been demonstrated using resistors as the load at 900 MHz and 1.8 GHz. The diode stack can be delaminated away from the Al electrode and then later on be transferred and reconfigured to another substrate. This provides us with reconfigurable GHz-operating diode circuits.

  12. Verification of the calibration technique of airborne hyperspectral raw data to reflectance based on sky light reference data

    NASA Astrophysics Data System (ADS)

    Suhama, T.; Rikimaru, A.; Takahashi, K.; Takemine, S.

    Airborne hyperspectral sensor is increasingly being used for the precision agriculture and for the monitoring our environment In general data obtained by airborne hyperspectral sensor are affected by atmospheric conditions and solar illumination geometry Therefore airborne hyperspectral sensor data are commonly expressed as relative radiance value For measuring and monitoring ground surface changes through time it is important to calibrate hyperspectral sensor data to amount of reflectance A number of calibration techniques have been developed ranging from empirical approaches to analytical radiative transfer approaches These methods require a priori knowledge such as field reflectance observations or atmospheric conditions Several airborne hyperspectral sensor systems which are used for commercial purpose include a fiber optic probe on the aircraft roof A fiber optic probe is able to monitor sky light reference data to ratio to hyperspectral raw data This is a simple and practical calibration technique However there is a problem that small inaccuracies in sky right reference data calibrations may lead to unacceptable errors in calculated apparent reflectance In this paper simple calibration technique based on sky light reference data was discussed The resultant reflectance estimates are compared with field reflectance observations of flat and homogeneous ground target and illustrate that proposed calibration technique is possible to derive reasonable reflectance from airborne hyperspectral raw data

  13. Inertial Focusing of Microparticles in Curvilinear Microchannels

    NASA Astrophysics Data System (ADS)

    Özbey, Arzu; Karimzadehkhouei, Mehrdad; Akgönül, Sarp; Gozuacik, Devrim; Koşar, Ali

    2016-12-01

    A passive, continuous and size-dependent focusing technique enabled by “inertial microfluidics”, which takes advantage of hydrodynamic forces, is implemented in this study to focus microparticles. The objective is to analyse the decoupling effects of inertial forces and Dean drag forces on microparticles of different sizes in curvilinear microchannels with inner radius of 800 μm and curvature angle of 280°, which have not been considered in the literature related to inertial microfluidics. This fundamental approach gives insight into the underlying physics of particle dynamics and offers continuous, high-throughput, label-free and parallelizable size-based particle separation. Our design allows the same footprint to be occupied as straight channels, which makes parallelization possible with optical detection integration. This feature is also useful for ultrahigh-throughput applications such as flow cytometers with the advantages of reduced cost and size. The focusing behaviour of 20, 15 and 10 μm fluorescent polystyrene microparticles was examined for different channel Reynolds numbers. Lateral and vertical particle migrations and the equilibrium positions of these particles were investigated in detail, which may lead to the design of novel microfluidic devices with high efficiency and high throughput for particle separation, rapid detection and diagnosis of circulating tumour cells with reduced cost.

  14. Inertial Focusing of Microparticles in Curvilinear Microchannels

    PubMed Central

    Özbey, Arzu; Karimzadehkhouei, Mehrdad; Akgönül, Sarp; Gozuacik, Devrim; Koşar, Ali

    2016-01-01

    A passive, continuous and size-dependent focusing technique enabled by “inertial microfluidics”, which takes advantage of hydrodynamic forces, is implemented in this study to focus microparticles. The objective is to analyse the decoupling effects of inertial forces and Dean drag forces on microparticles of different sizes in curvilinear microchannels with inner radius of 800 μm and curvature angle of 280°, which have not been considered in the literature related to inertial microfluidics. This fundamental approach gives insight into the underlying physics of particle dynamics and offers continuous, high-throughput, label-free and parallelizable size-based particle separation. Our design allows the same footprint to be occupied as straight channels, which makes parallelization possible with optical detection integration. This feature is also useful for ultrahigh-throughput applications such as flow cytometers with the advantages of reduced cost and size. The focusing behaviour of 20, 15 and 10 μm fluorescent polystyrene microparticles was examined for different channel Reynolds numbers. Lateral and vertical particle migrations and the equilibrium positions of these particles were investigated in detail, which may lead to the design of novel microfluidic devices with high efficiency and high throughput for particle separation, rapid detection and diagnosis of circulating tumour cells with reduced cost. PMID:27991494

  15. Overview and Initial Results from the DEEPWAVE Airborne and Ground-Based Measurement Program

    NASA Astrophysics Data System (ADS)

    Fritts, D. C.

    2015-12-01

    The deep-propagating gravity wave experiment (DEEPWAVE) was performed on and over New Zealand, the Tasman Sea, and the Southern Ocean with core airborne measurements extending from 5 June to 21 July 2014 and supporting ground-based measurements spanning a longer interval. The NSF/NCAR GV employed standard flight-level measurements and new airborne lidar and imaging measurements of gravity waves (GWs) from sources at lower altitudes throughout the stratosphere and into the mesosphere and lower thermosphere (MLT). The new GV lidars included a Rayleigh lidar measuring atmospheric density and temperature from ~20-60 km and a sodium resonance lidar measuring sodium density and temperature at ~75-105 km. An airborne Advanced Mesosphere Temperature Mapper (AMTM) and two IR "wing" cameras imaged the OH airglow temperature and/or intensity fields extending ~900 km across the GV flight track. The DLR Falcon was equipped with its standard flight-level instruments and an aerosol Doppler lidar measuring radial winds below the Falcon. DEEPWAVE also included extensive ground-based measurements in New Zealand, Tasmania, and Southern Ocean Islands. DEEPWAVE performed 26 GV flights and 13 Falcon flights, and ground-based measurements occurred whether or not the aircraft were flying. Collectively, many diverse cases of GW forcing, propagation, refraction, and dissipation spanning altitudes of 0-100 km were observed. Examples include strong mountain wave (MW) forcing and breaking in the lower and middle stratosphere, weak MW forcing yielding MW penetration into the MLT having very large amplitudes and momentum fluxes, MW scales at higher altitudes ranging from ~10-250 km, large-scale trailing waves from orography refracting into the polar vortex and extending to high altitudes, GW generation by deep convection, large-scale GWs arising from jet stream sources, and strong MWs in the MLT arising from strong surface flow over a small island. DEEPWAVE yielded a number of surprises, among

  16. Complementing airborne laser bathymetry with UAV-based lidar for capturing alluvial landscapes

    NASA Astrophysics Data System (ADS)

    Mandlburger, Gottfried; Pfennigbauer, Martin; Riegl, Ursula; Haring, Alexander; Wieser, Martin; Glira, Philipp; Winiwarter, Lukas

    2015-10-01

    In this paper we report on a flight experiment employing airborne laser bathymetry (ALB) and unmanned aerial vehicle (UAV) based laser scanning (ULS) for capturing very high resolution topography of shallow water areas and the surrounding littoral zone at the pre-alpine Pielach River in Austria. The aim of the research is to assess how information gained from non-bathymetric, ultra-high resolution ULS can support the ALB data. We focus first on the characterization of the water surface of a lowland river and provide validation results using the data of a topographic airborne laser scanning (ALS) sensor and a low flying ULS system. By repeat ULS survey of a the meandering river reach we are able to quantify short-term water level changes due to surface waves in high resolution. Based on a hydrodynamic-numerical (HN) model we assess the accuracy of the water surface derived from a water penetrating ALB sensor. In the second part of the paper we investigate the ability of ALB, ALS, and ULS to describe the complex topography and vegetation structure of the alluvial area. This is carried out by comparing the Digital Terrain Models (DTM) derived from different sensor configurations. Finally we demonstrate the potential of ULS for estimating single tree positions and stem diameters for detailed floodplain roughness characterization in HN simulations. The key findings are: (i) NIR scan data from ALS or ULS provide more precise water level height estimates (no bias, 1σ: 2 cm) compared to ALB (bias: 3 cm, 1σ: 4 cm), (ii) within the studied reach short-term water level dynamics irrelevant for ALB data acquisition considering a 60 cm footprint diameter, and (iii) stem diameters can be estimated based on ULS point clouds but not from ALS and ALB.

  17. Enzyme-responsive hydrogel microparticles for pulmonary drug delivery.

    PubMed

    Secret, Emilie; Kelly, Stefan J; Crannell, Kelsey E; Andrew, Jennifer S

    2014-07-09

    Poly(ethylene glycol) based hydrogel microparticles were developed for pulmonary drug delivery. Hydrogels are particularly attractive for pulmonary delivery because they can be size engineered for delivery into the bronchi, yet also swell upon reaching their destination to avoid uptake and clearance by alveolar macrophages. To develop enzyme-responsive hydrogel microparticles for pulmonary delivery a new synthesis method based on a solution polymerization was developed. This method produces spherical poly(ethylene glycol) (PEG) microparticles from high molecular weight poly(ethylene glycol) diacrylate (PEGDA)-based precursors that incorporate peptides in the polymer chain. Specifically, we have synthesized hydrogel microparticles that degrade in response to matrix metalloproteinases that are overexpressed in pulmonary diseases. Small hydrogel microparticles with sizes suitable for lung delivery by inhalation were obtained from solid precursors when PEGDA was dissolved in water at a high concentration. The average diameter of the particles was between 2.8 and 4 μm, depending on the molecular weight of the precursor polymer used and its concentration in water. The relation between the physical properties of the particles and their enzymatic degradation is also reported, where an increased mesh size corresponds to increased degradation.

  18. Aqueous Two Phase System Assisted Self-Assembled PLGA Microparticles

    NASA Astrophysics Data System (ADS)

    Yeredla, Nitish; Kojima, Taisuke; Yang, Yi; Takayama, Shuichi; Kanapathipillai, Mathumai

    2016-06-01

    Here, we produce poly(lactide-co-glycolide) (PLGA) based microparticles with varying morphologies, and temperature responsive properties utilizing a Pluronic F127/dextran aqueous two-phase system (ATPS) assisted self-assembly. The PLGA polymer, when emulsified in Pluronic F127/dextran ATPS, forms unique microparticle structures due to ATPS guided-self assembly. Depending on the PLGA concentration, the particles either formed a core-shell or a composite microparticle structure. The microparticles facilitate the simultaneous incorporation of both hydrophobic and hydrophilic molecules, due to their amphiphilic macromolecule composition. Further, due to the lower critical solution temperature (LCST) properties of Pluronic F127, the particles exhibit temperature responsiveness. The ATPS based microparticle formation demonstrated in this study, serves as a novel platform for PLGA/polymer based tunable micro/nano particle and polymersome development. The unique properties may be useful in applications such as theranostics, synthesis of complex structure particles, bioreaction/mineralization at the two-phase interface, and bioseparations.

  19. An entropy-based filtering approach for airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Zeng, Zhe; Wan, Jiaxin; Liu, Hui

    2016-03-01

    Parameter-tuning is a challenging task when generating digital terrain models from airborne laser scanning (light detection and ranging, LiDAR) data. To address this issue, this paper presents a filtering method for near-infrared laser scanning data that exploits the principle of entropy maximization as the optimization objective. The proposed approach generates ground elevation of point cloud by constructing a triangulated irregular network, calculates the entropy of the elevation from different parts, and automatically separates ground and non-ground points by the principle of entropy maximization. Experimental results from different ground surfaces show that the proposed entropy-based filtering method can effectively extract bare-earth points from the point cloud without adjusting thresholds.

  20. Regolith landform mapping based on remote sensing data and airborne geophysics in Western Burkina Faso

    NASA Astrophysics Data System (ADS)

    Metelka, Vaclav; Baratoux, Lenka; Jessell, Mark; Naba, Seta

    2010-05-01

    The Precambrian granite-greenstone belts of West Africa are currently of great interest both to scientific community as well as the exploration industry. Studying and observing the geology of these ancient terrains is not an easy task mainly due to complex, deep weathering, which effectively masks the underlying bedrock. It is the weathered regolith material and its landforms that can be directly accessed by surface mapping. Knowing the distribution of these regolith landform units and understanding the processes which led to their formation is crucial for any kind of successful geological mapping or geochemical exploration project. In our research we have focused on regolith units in the Houndé and Boromo greenstone belts in Western Burkina Faso. We examined three approaches to map regolith material and subsequently regolith landform units: subpixel classification, based on spectral characteristics of indicative materials, a polarimetric segmentation of radar data, and a classification of an integrated dataset of remote sensing data and airborne gamma-ray spectrometry data. In situ spectral measurements were used to calibrate ASTER and LANDSAT scenes and served as endmember identifiers. A spectral library has been created containing over three hundred unique spectral measurements. ASTER and Landsat data were classified using the Mixture tuned matched filtering method. Wishart supervised classifier was used on ALOS PALSAR data. Classifications based on supervised maximum likelihood method and neural networks have been applied to an integrated dataset which included SRTM elevation data and airborne gamma-ray spectrometry. Feruginous duricrusts rich in hematite and goethite, clay rich mottled zones relics and fluvial sediments were mapped successfully in the region. The results were compared with existing regolith landform maps and field observations.

  1. Airborne and Ground-Based Measurements Using a High-Performance Raman Lidar. Part 2; Ground Based

    NASA Technical Reports Server (NTRS)

    Whiteman, David N.; Cadirola, Martin; Venable, Demetrius; Connell, Rasheen; Rush, Kurt; Leblanc, Thierry; McDermid, Stuart

    2009-01-01

    The same RASL hardware as described in part I was installed in a ground-based mobile trailer and used in a water vapor lidar intercomparison campaign, hosted at Table Mountain, CA, under the auspices of the Network for the Detection of Atmospheric Composition Change (NDACC). The converted RASL hardware demonstrated high sensitivity to lower stratospheric water vapor indicating that profiling water vapor at those altitudes with sufficient accuracy to monitor climate change is possible. The measurements from Table Mountain also were used to explain the reason, and correct , for sub-optimal airborne aerosol extinction performance during the flight campaign.

  2. Erythrocyte-derived microparticles supporting activated protein C-mediated regulation of blood coagulation.

    PubMed

    Koshiar, Ruzica Livaja; Somajo, Sofia; Norström, Eva; Dahlbäck, Björn

    2014-01-01

    Elevated levels of erythrocyte-derived microparticles are present in the circulation in medical conditions affecting the red blood cells. Erythrocyte-derived microparticles expose phosphatidylserine thus providing a suitable surface for procoagulant reactions leading to thrombin formation via the tenase and prothrombinase complexes. Patients with elevated levels of circulating erythrocyte-derived microparticles have increased thrombin generation in vivo. The aim of the present study was to investigate whether erythrocyte-derived microparticles are able to support the anticoagulant reactions of the protein C system. Erythrocyte-derived microparticles were isolated using ultracentrifugation after incubation of freshly prepared erythrocytes with the ionophore A23187 or from outdated erythrocyte concentrates, the different microparticles preparations yielding similar results. According to flow cytometry analysis, the microparticles exposed phoshatidylserine and bound lactadherin, annexin V, and protein S, which is a cofactor to activated protein C. The microparticles were able to assemble the tenase and prothrombinase complexes and to stimulate the formation of thrombin in plasma-based thrombin generation assay both in presence and absence of added tissue factor. The addition of activated protein C in the thrombin generation assay inhibited thrombin generation in a dose-dependent fashion. The anticoagulant effect of activated protein C in the thrombin generation assay was inhibited by a monoclonal antibody that prevents binding of protein S to microparticles and also attenuated by anti-TFPI antibodies. In the presence of erythrocyte-derived microparticles, activated protein C inhibited tenase and prothrombinase by degrading the cofactors FVIIIa and FVa, respectively. Protein S stimulated the Arg306-cleavage in FVa, whereas efficient inhibition of FVIIIa depended on the synergistic cofactor activity of protein S and FV. In summary, the erythrocyte-derived microparticle

  3. Development of a Sustainable Release System for a Ranibizumab Biosimilar Using Poly(lactic-co-glycolic acid) Biodegradable Polymer-Based Microparticles as a Platform.

    PubMed

    Tanetsugu, Yusuke; Tagami, Tatsuaki; Terukina, Takayuki; Ogawa, Takaya; Ohta, Masato; Ozeki, Tetsuya

    2017-01-01

    Ranibizumab is a humanized monoclonal antibody fragment against vascular endothelial growth factor (VEGF)-A and is widely used to treat age-related macular degeneration (AMD) caused by angiogenesis. Ranibizumab has a short half-life in the eye due to its low molecular weight and susceptibility to proteolysis. Monthly intravitreal injection of a large amount of ranibizumab formulation is a burden for both patients and medical staff. We therefore sought to develop a sustainable release system for treating the eye with ranibizumab using a drug carrier. A ranibizumab biosimilar (RB) was incorporated into microparticles of poly(lactic-co-glycolic acid) (PLGA) biodegradable polymer. Ranibizumab was sustainably released from PLGA microparticles (80+% after 3 weeks). Assay of tube formation by endothelial cells indicated that RB released from PLGA microparticles inhibited VEGF-induced tube formation and this tendency was confirmed by a cell proliferation assay. These results indicate that RB-loaded PLGA microparticles are useful for sustainable RB release and suggest the utility of intraocular sustainable release systems for delivering RB site-specifically to AMD patients.

  4. A graph-based segmentation algorithm for tree crown extraction using airborne LiDAR data

    NASA Astrophysics Data System (ADS)

    Strîmbu, Victor F.; Strîmbu, Bogdan M.

    2015-06-01

    This work proposes a segmentation method that isolates individual tree crowns using airborne LiDAR data. The proposed approach captures the topological structure of the forest in hierarchical data structures, quantifies topological relationships of tree crown components in a weighted graph, and finally partitions the graph to separate individual tree crowns. This novel bottom-up segmentation strategy is based on several quantifiable cohesion criteria that act as a measure of belief on weather two crown components belong to the same tree. An added flexibility is provided by a set of weights that balance the contribution of each criterion, thus effectively allowing the algorithm to adjust to different forest structures. The LiDAR data used for testing was acquired in Louisiana, inside the Clear Creek Wildlife management area with a RIEGL LMS-Q680i airborne laser scanner. Three 1 ha forest areas of different conditions and increasing complexity were segmented and assessed in terms of an accuracy index (AI) accounting for both omission and commission. The three areas were segmented under optimum parameterization with an AI of 98.98%, 92.25% and 74.75% respectively, revealing the excellent potential of the algorithm. When segmentation parameters are optimized locally using plot references the AI drops to 98.23%, 89.24%, and 68.04% on average with plot sizes of 1000 m2 and 97.68%, 87.78% and 61.1% on average with plot sizes of 500 m2. More than introducing a segmentation algorithm, this paper proposes a powerful framework featuring flexibility to support a series of segmentation methods including some of those recurring in the tree segmentation literature. The segmentation method may extend its applications to any data of topological nature or data that has a topological equivalent.

  5. [Winter wheat growth spatial variation study based on temporal airborne high-spectrum images].

    PubMed

    Song, Xiao-yu; Wang, Ji-hua; Yan, Guang-jian; Huang, Wen-jiang; Liu, Liang-yun

    2010-07-01

    Precision agriculture technology is defined as an information-and technology-based agriculture management system to identify, analyze and manage crop spatial and temporal variation within fields for optimum profitability, sustainability and protection of the environment. In the present study, push-broom hyperspectral image sensor (PHI) image was used to investigate the spatial variance of winter wheat growth. The variable-rate fertilization contrast experiment was carried out on the National Experimental Station for Precision Agriculture of China during 2001-2002. Three airborne PHI images were acquired during the wheat growth season of 2002. Then contrast analysis about the wheat growth spatial variation was applied to the variable-rate fertilization area and uniformity fertilization area. The results showed that the spectral reflectance standard deviation increased significantly in red edge and short infrared wave band for all images. The wheat milky stage spectral reflectance has the maximum standard deviation in short infrared wave band, then the wheat jointing stage and wheat filling stage. Then six spectrum parameters that sensitive to wheat growth variation were defined and analyzed. The results indicate that parameters spatial variation coefficient for variable-rate experiment area was higher than that of contrast area in jointing stage. However, it decreased after the variable-rate fertilization application. The parameters spatial variation coefficient for variable-rate area was lower than that of contrast area in filling and milking stages. In addition, the yield spatial variation coefficient for variable-rate area was lower than that of contrast area. However, the yield mean value for variable-rate area was lower than that of contrast area. The study showed that the crop growth spatial variance information can be acquired through airborne remote sensing images timely and exactly. Remote sensing technology has provided powerful analytical tools for

  6. Airborne wireless communication systems, airborne communication methods, and communication methods

    DOEpatents

    Deaton, Juan D [Menan, ID; Schmitt, Michael J [Idaho Falls, ID; Jones, Warren F [Idaho Falls, ID

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  7. Scanning Web-based ICARTT File Tool (SWIFT): an online tool used to validate ICARTT-formatted airborne science data

    NASA Astrophysics Data System (ADS)

    Lucker, P. L.; Mangosing, D. C.; Chen, G.; Rinsland, P.; Brennan, J. H.; Clodius, B. F.

    2011-12-01

    The ICARTT (International Consortium for Atmospheric Research on Transport and Transformation) file format was recently endorsed by the NASA Earth Science Data Systems Standards Process Group (ESDS SPG) as a standard (ESDS-RFC-019) for specifying airborne-based Earth System Data Records (ESDR). In order to accelerate adoption of the new standard in the airborne science data community, SWIFT (Scanning Web-based ICARTT File Tool) was developed to provide a means for data providers to validate their own originated ICARTT-formatted file before submission to data archival facilities provided by NASA Langley's Atmospheric Science Data Center and the NASA Langley Airborne Science Data for Atmospheric Composition group. SWIFT builds upon a predecessor, a software utility named: FSCAN (File Scan). A major upgrade to FSCAN, the objective of SWIFT is to support all valid ICARTT files and to extract and store the file metadata in an ESDR relational database. The SWIFT-validated search metadata make it possible for COTS software and web applications to leverage the built-in spatial and temporal query capabilities of the relational database and to enable file and parameter sub-setting capabilities, as well as facilitating the generation of airborne science data merge products. These enhancements help to minimize development time of other related web applications and open up opportunities for robust data queries.

  8. Solid microparticles based on chitosan or methyl-β-cyclodextrin: a first formulative approach to increase the nose-to-brain transport of deferoxamine mesylate.

    PubMed

    Rassu, Giovanna; Soddu, Elena; Cossu, Massimo; Brundu, Antonio; Cerri, Guido; Marchetti, Nicola; Ferraro, Luca; Regan, Raymond F; Giunchedi, Paolo; Gavini, Elisabetta; Dalpiaz, Alessandro

    2015-03-10

    We propose the formulation and characterization of solid microparticles as nasal drug delivery systems able to increase the nose-to-brain transport of deferoxamine mesylate (DFO), a neuroprotector unable to cross the blood brain barrier and inducing negative peripheral impacts. Spherical chitosan chloride and methyl-β-cyclodextrin microparticles loaded with DFO (DCH and MCD, respectively) were obtained by spray drying. Their volume-surface diameters ranged from 1.77 ± 0.06 μm (DCH) to 3.47 ± 0.05 μm (MCD); the aerodynamic diameters were about 1.1 μm and their drug content was about 30%. In comparison with DCH, MCD enhanced the in vitro DFO permeation across lipophilic membranes, similarly as shown by ex vivo permeation studies across porcine nasal mucosa. Moreover, MCD were able to promote the DFO permeation across monolayers of PC 12 cells (neuron-like), but like DCH, it did not modify the DFO permeation pattern across Caco-2 monolayers (epithelial-like). Nasal administration to rats of 200 μg DFO encapsulated in the microparticles resulted in its uptake into the cerebrospinal fluid (CSF) with peak values ranging from 3.83 ± 0.68 μg/mL (DCH) to 14.37 ± 1.69 μg/mL (MCD) 30 min after insufflation of microparticles. No drug CSF uptake was detected after nasal administration of a DFO water solution. The DFO systemic absolute bioavailabilities obtained by DCH and MCD nasal administration were 6% and 15%, respectively. Chitosan chloride and methyl-β-cyclodextrins appear therefore suitable to formulate solid microparticles able to promote the nose to brain uptake of DFO and to limit its systemic exposure.

  9. Compiling a national resistivity atlas of Denmark based on airborne and ground-based transient electromagnetic data

    NASA Astrophysics Data System (ADS)

    Barfod, Adrian A. S.; Møller, Ingelise; Christiansen, Anders V.

    2016-11-01

    We present a large-scale study of the petrophysical relationship of resistivities obtained from densely sampled ground-based and airborne transient electromagnetic surveys and lithological information from boreholes. The overriding aim of this study is to develop a framework for examining the resistivity-lithology relationship in a statistical manner and apply this framework to gain a better description of the large-scale resistivity structures of the subsurface. In Denmark very large and extensive datasets are available through the national geophysical and borehole databases, GERDA and JUPITER respectively. In a 10 by 10 km grid, these data are compiled into histograms of resistivity versus lithology. To do this, the geophysical data are interpolated to the position of the boreholes, which allows for a lithological categorization of the interpolated resistivity values, yielding different histograms for a set of desired lithological categories. By applying the proposed algorithm to all available boreholes and airborne and ground-based transient electromagnetic data we build nation-wide maps of the resistivity-lithology relationships in Denmark. The presented Resistivity Atlas reveals varying patterns in the large-scale resistivity-lithology relations, reflecting geological details such as available source material for tills. The resistivity maps also reveal a clear ambiguity in the resistivity values for different lithologies. The Resistivity Atlas is highly useful when geophysical data are to be used for geological or hydrological modeling.

  10. Prospects of pharmaceuticals and biopharmaceuticals loaded microparticles prepared by double emulsion technique for controlled delivery

    PubMed Central

    Giri, Tapan Kumar; Choudhary, Chhatrapal; Ajazuddin; Alexander, Amit; Badwaik, Hemant; Tripathi, Dulal Krishna

    2012-01-01

    Several methods and techniques are potentially useful for the preparation of microparticles in the field of controlled drug delivery. The type and the size of the microparticles, the entrapment, release characteristics and stability of drug in microparticles in the formulations are dependent on the method used. One of the most common methods of preparing microparticles is the single emulsion technique. Poorly soluble, lipophilic drugs are successfully retained within the microparticles prepared by this method. However, the encapsulation of highly water soluble compounds including protein and peptides presents formidable challenges to the researchers. The successful encapsulation of such compounds requires high drug loading in the microparticles, prevention of protein and peptide degradation by the encapsulation method involved and predictable release, both rate and extent, of the drug compound from the microparticles. The above mentioned problems can be overcome by using the double emulsion technique, alternatively called as multiple emulsion technique. Aiming to achieve this various techniques have been examined to prepare stable formulations utilizing w/o/w, s/o/w, w/o/o, and s/o/o type double emulsion methods. This article reviews the current state of the art in double emulsion based technologies for the preparation of microparticles including the investigation of various classes of substances that are pharmaceutically and biopharmaceutically active. PMID:23960828

  11. Facile and High-Throughput Synthesis of Functional Microparticles with Quick Response Codes.

    PubMed

    Ramirez, Lisa Marie S; He, Muhan; Mailloux, Shay; George, Justin; Wang, Jun

    2016-06-01

    Encoded microparticles are high demand in multiplexed assays and labeling. However, the current methods for the synthesis and coding of microparticles either lack robustness and reliability, or possess limited coding capacity. Here, a massive coding of dissociated elements (MiCODE) technology based on innovation of a chemically reactive off-stoichimetry thiol-allyl photocurable polymer and standard lithography to produce a large number of quick response (QR) code microparticles is introduced. The coding process is performed by photobleaching the QR code patterns on microparticles when fluorophores are incorporated into the prepolymer formulation. The fabricated encoded microparticles can be released from a substrate without changing their features. Excess thiol functionality on the microparticle surface allows for grafting of amine groups and further DNA probes. A multiplexed assay is demonstrated using the DNA-grafted QR code microparticles. The MiCODE technology is further characterized by showing the incorporation of BODIPY-maleimide (BDP-M) and Nile Red fluorophores for coding and the use of microcontact printing for immobilizing DNA probes on microparticle surfaces. This versatile technology leverages mature lithography facilities for fabrication and thus is amenable to scale-up in the future, with potential applications in bioassays and in labeling consumer products.

  12. Conductivity depth imaging of Airborne Electromagnetic data with double pulse transmitting current based on model fusion

    NASA Astrophysics Data System (ADS)

    Li, Jing; Dou, Mei; Lu, Yiming; Peng, Cong; Yu, Zining; Zhu, Kaiguang

    2017-01-01

    The airborne electromagnetic (AEM) systems have been used traditionally in mineral exploration. Typically the system transmits a single pulse waveform to detect conductive anomaly. Conductivity-depth imaging (CDI) of data is generally applied in identifying conductive targets. A CDI algorithm with double-pulse transmitting current based on model fusion is developed. The double-pulse is made up of a half-sine pulse of high power and a trapezoid pulse of low power. This CDI algorithm presents more shallow information than traditional CDI with a single pulse. The electromagnetic response with double-pulse transmitting current is calculated by linear convolution based on forward modeling. The CDI results with half-sine and trapezoid pulse are obtained by look-up table method, and the two results are fused to form a double-pulse conductivity-depth imaging result. This makes it possible to obtain accurate conductivity and depth. Tests on synthetic data demonstrate that CDI algorithm with double-pulse transmitting current based on model fusion maps a wider range of conductivities and does a better job compared with CDI with a single pulse transmitting current in reflecting the whole geological conductivity changes.

  13. A rule-based classification from a region-growing segmentation of airborne lidar

    NASA Astrophysics Data System (ADS)

    Martínez, Jorge; Rivera, Francisco F.; Cabaleiro, José C.; Vilariño, David L.; Pena, Tomás. F.; Miranda B., David

    2016-10-01

    Light Detection and Ranging (LiDAR) has attracted the interest of the research community in many fields, including object classification of the earth surface. In this paper we present an object-based classification method for airborne LiDAR that distinguishes three main classes (buildings, vegetation and ground) based only on LiDAR information. The key components of our proposal are the following: First, the LiDAR point cloud is stored in an octree for its efficient processing and the normal vector of each point is estimated using an adaptive neighborhood algorithm. Then, the points are segmented using a two-phase region growing algorithm where planar and non-planar objects are handled differently. The utilization of an epicenter point is introduced to allow regions to expand without losing homogeneity. Finally, a ruled-based procedure is performed to classify the segmented clusters. In order to evaluate our approach, a building detection was carried out, and results were obtained in terms of accuracy and computational time.

  14. Detection of microparticles from human red blood cells by multiparametric flow cytometry

    PubMed Central

    Grisendi, Giulia; Finetti, Elena; Manganaro, Daniele; Cordova, Nicoletta; Montagnani, Giuliano; Spano, Carlotta; Prapa, Malvina; Guarneri, Valentina; Otsuru, Satoru; Horwitz, Edwin M.; Mari, Giorgio; Dominici, Massimo

    2015-01-01

    Background During storage, red blood cells (RBC) undergo chemical and biochemical changes referred to as “storage lesions”. These events determine the loss of RBC integrity, resulting in lysis and release of microparticles. There is growing evidence of the clinical importance of microparticles and their role in blood transfusion-related side effects and pathogen transmission. Flow cytometry is currently one of the most common techniques used to quantify and characterise microparticles. Here we propose multiparametric staining to monitor and quantify the dynamic release of microparticles by stored human RBC. Material and methods RBC units (n=10) were stored under blood bank conditions for up to 42 days. Samples were tested at different time points to detect microparticles and determine the haemolysis rate (HR%). Microparticles were identified by flow cytometry combining carboxyfluorescein diacetate succinimidyl ester (CFSE) dye, annexin V and anti-glycophorin A antibody. Results We demonstrated that CFSE can be successfully used to label closed vesicles with an intact membrane. The combination of CFSE and glycophorin A antibody was effective for monitoring and quantifying the dynamic release of microparticles from RBC during storage. Double staining with CFSE/glycophorin A was a more precise approach, increasing vesicle detection up to 4.7-fold vs the use of glycophorin A/annexin V alone. Moreover, at all the time points tested, we found a robust correlation (R=0.625; p=0.0001) between HR% and number of microparticles detected. Discussion Multiparametric staining, based on a combination of CFSE, glycophorin A antibody and annexin V, was able to detect, characterise and monitor the release of microparticles from RBC units during storage, providing a sensitive approach to labelling and identifying microparticles for transfusion medicine and, more broadly, for cell-based therapies. PMID:25369588

  15. Nitrous oxide (N2O) emissions from California based on 2010 CalNex airborne measurements

    NASA Astrophysics Data System (ADS)

    Xiang, Bin; Miller, Scot M.; Kort, Eric A.; Santoni, Gregory W.; Daube, Bruce C.; Commane, Roisin; Angevine, Wayne M.; Ryerson, Tom B.; Trainer, Michael K.; Andrews, Arlyn E.; Nehrkorn, Thomas; Tian, Hanqin; Wofsy, Steven C.

    2013-04-01

    Nitrous oxide (N2O) is an important gas for climate and for stratospheric chemistry, with a lifetime exceeding 100 years. Global concentrations have increased steadily since the 18th century, apparently due to human-associated emissions, principally from the application of nitrogen fertilizers. However, quantitative studies of agricultural emissions at large spatial scales are lacking, inhibited by the difficulty of measuring small enhancements in atmospheric concentration. Here we derive regional emission rates for N2O in the agricultural heartland of California based on analysis of in-situ airborne atmospheric observations collected using a new quantum cascade laser spectrometer. The data were obtained on board the NOAA WP-3 research aircraft during the CalNex (California Research at the Nexus of Air Quality and Climate Change) program in late spring 2010. We coupled the WRF (weather research and forecasting) model, a meso-scale meteorology model, with the STILT (stochastic time-inverted Lagrangian transport) model, a Lagrangian particle dispersion model, to link our in-situ airborne observations to surface emissions. We then used a variety of statistical methods to identify source areas and to optimize emission rates. Our results are consistent with the view that fertilizer application is the largest source of N2O in the Central Valley. The spatial distribution of surface emissions, based on California land use and activity maps, was very different than indicated in the leading emission inventory (EDGAR 4.0). Our estimated total emission flux of N2O for California in May and June was 3 - 4 times larger than the annual mean given for the state by EDGAR and other inventories, indicating a strong seasonal variation. We estimated the statewide total annual emissions of N2O to be 0.042 ± 0.011 Tg N/year, roughly equivalent to inventory values if we account for seasonal variations using observations obtained in the midwestern United States. This state total N2O

  16. Airborne electromagnetic mapping of the base of aquifer in areas of western Nebraska

    USGS Publications Warehouse

    Abraham, Jared D.; Cannia, James C.; Bedrosian, Paul A.; Johnson, Michaela R.; Ball, Lyndsay B.; Sibray, Steven S.

    2012-01-01

    Airborne geophysical surveys of selected areas of the North and South Platte River valleys of Nebraska, including Lodgepole Creek valley, collected data to map aquifers and bedrock topography and thus improve the understanding of groundwater - surface-water relationships to be used in water-management decisions. Frequency-domain helicopter electromagnetic surveys, using a unique survey flight-line design, collected resistivity data that can be related to lithologic information for refinement of groundwater model inputs. To make the geophysical data useful to multidimensional groundwater models, numerical inversion converted measured data into a depth-dependent subsurface resistivity model. The inverted resistivity model, along with sensitivity analyses and test-hole information, is used to identify hydrogeologic features such as bedrock highs and paleochannels, to improve estimates of groundwater storage. The two- and three-dimensional interpretations provide the groundwater modeler with a high-resolution hydrogeologic framework and a quantitative estimate of framework uncertainty. The new hydrogeologic frameworks improve understanding of the flow-path orientation by refining the location of paleochannels and associated base of aquifer highs. These interpretations provide resource managers high-resolution hydrogeologic frameworks and quantitative estimates of framework uncertainty. The improved base of aquifer configuration represents the hydrogeology at a level of detail not achievable with previously available data.

  17. Airborne Linear Array Image Geometric Rectification Method Based on Unequal Segmentation

    NASA Astrophysics Data System (ADS)

    Li, J. M.; Li, C. R.; Zhou, M.; Hu, J.; Yang, C. M.

    2016-06-01

    As the linear array sensor such as multispectral and hyperspectral sensor has great potential in disaster monitoring and geological survey, the quality of the image geometric rectification should be guaranteed. Different from the geometric rectification of airborne planar array images or multi linear array images, exterior orientation elements need to be determined for each scan line of single linear array images. Internal distortion persists after applying GPS/IMU data directly to geometrical rectification. Straight lines may be curving and jagged. Straight line feature -based geometrical rectification algorithm was applied to solve this problem, whereby the exterior orientation elements were fitted by piecewise polynomial and evaluated with the straight line feature as constraint. However, atmospheric turbulence during the flight is unstable, equal piecewise can hardly provide good fitting, resulting in limited precision improvement of geometric rectification or, in a worse case, the iteration cannot converge. To solve this problem, drawing on dynamic programming ideas, unequal segmentation of line feature-based geometric rectification method is developed. The angle elements fitting error is minimized to determine the optimum boundary. Then the exterior orientation elements of each segment are fitted and evaluated with the straight line feature as constraint. The result indicates that the algorithm is effective in improving the precision of geometric rectification.

  18. A building extraction approach for Airborne Laser Scanner data utilizing the Object Based Image Analysis paradigm

    NASA Astrophysics Data System (ADS)

    Tomljenovic, Ivan; Tiede, Dirk; Blaschke, Thomas

    2016-10-01

    In the past two decades Object-Based Image Analysis (OBIA) established itself as an efficient approach for the classification and extraction of information from remote sensing imagery and, increasingly, from non-image based sources such as Airborne Laser Scanner (ALS) point clouds. ALS data is represented in the form of a point cloud with recorded multiple returns and intensities. In our work, we combined OBIA with ALS point cloud data in order to identify and extract buildings as 2D polygons representing roof outlines in a top down mapping approach. We performed rasterization of the ALS data into a height raster for the purpose of the generation of a Digital Surface Model (DSM) and a derived Digital Elevation Model (DEM). Further objects were generated in conjunction with point statistics from the linked point cloud. With the use of class modelling methods, we generated the final target class of objects representing buildings. The approach was developed for a test area in Biberach an der Riß (Germany). In order to point out the possibilities of the adaptation-free transferability to another data set, the algorithm has been applied "as is" to the ISPRS Benchmarking data set of Toronto (Canada). The obtained results show high accuracies for the initial study area (thematic accuracies of around 98%, geometric accuracy of above 80%). The very high performance within the ISPRS Benchmark without any modification of the algorithm and without any adaptation of parameters is particularly noteworthy.

  19. Short-range order and fractal cluster structure of aggregates of barium titanate microparticles in a composite based on cyano-ethyl ester of polyvinyl alcohol

    NASA Astrophysics Data System (ADS)

    Krasovskii, A. N.; Novikov, D. V.; Vasina, E. S.; Matveichikova, P. V.; Sychev, M. M.; Rozhkova, N. N.

    2015-12-01

    The distribution of barium titanate (BaTiO3) microparticles in the matrix of cyano-ethyl ester of polyvinyl alcohol and the change in the surface energy upon introduction of shungite carbon nanoclusters into the dielectric composite have been investigated using the methods of scanning electron microscopy and contact angles. The computer processing of the electron microscopy data has demonstrated that the introduction of 0.04% shungite carbon nanoparticles into the composite leads to a decrease in the spatial homogeneity of the quasi-lattice and to an increase in the local density distribution of BaTiO3 microparticles, as well as in the correlation length corresponding to the formation of an infinite cluster of BaTiO3 particles. It has been found that, in this case, the surface energy and dielectric permittivity of the composite extremely increase.

  20. Dynamics of rigid microparticles at the interface of co-flowing immiscible liquids in a microchannel.

    PubMed

    Jayaprakash, K S; Banerjee, U; Sen, A K

    2017-05-01

    We report the dynamical migration behavior of rigid polystyrene microparticles at an interface of co-flowing streams of primary CP1 (aqueous) and secondary CP2 (oils) immiscible phases at low Reynolds numbers (Re) in a microchannel. The microparticles initially suspended in the CP1 either continue to flow in the bulk CP1 or migrate across the interface into CP2, when the stream width of the CP1 approaches the diameter of the microparticles. Experiments were performed with different secondary phases and it is found that the migration criterion depends on the sign of the spreading parameter S and the presence of surfactant at the interface. To substantiate the migration criterion, experiments were also carried out by suspending the microparticles in CP2 (oil phase). Our study reveals that in case of aqueous-silicone oil combination, the microparticles get attached to the interface since S<0 and the three phase contact angle, θ>90°. For complete detachment of microparticles from the interface into the secondary phase, additional energy ΔG is needed. We discuss the role of interfacial perturbation, which causes detachment of microparticles from the interface. In case of mineral and olive oils, the surfactants present at the interface prevents attachment of the microparticles to the interface due to the repulsive disjoining pressure. Finally, using a aqueous-silicone oil system, we demonstrate size based sorting of microparticles of size 25μm and 15μm respectively from that of 15μm and 10μm and study the variation of separation efficiency η with the ratio of the width of the aqueous stream to the diameter of the microparticles ρ.

  1. A wavelet-based baseline drift correction method for grounded electrical source airborne transient electromagnetic signals

    NASA Astrophysics Data System (ADS)

    Wang, Yuan 1Ji, Yanju 2Li, Suyi 13Lin, Jun 12Zhou, Fengdao 1Yang, Guihong

    2013-09-01

    A grounded electrical source airborne transient electromagnetic (GREATEM) system on an airship enjoys high depth of prospecting and spatial resolution, as well as outstanding detection efficiency and easy flight control. However, the movement and swing of the front-fixed receiving coil can cause severe baseline drift, leading to inferior resistivity image formation. Consequently, the reduction of baseline drift of GREATEM is of vital importance to inversion explanation. To correct the baseline drift, a traditional interpolation method estimates the baseline `envelope' using the linear interpolation between the calculated start and end points of all cycles, and obtains the corrected signal by subtracting the envelope from the original signal. However, the effectiveness and efficiency of the removal is found to be low. Considering the characteristics of the baseline drift in GREATEM data, this study proposes a wavelet-based method based on multi-resolution analysis. The optimal wavelet basis and decomposition levels are determined through the iterative comparison of trial and error. This application uses the sym8 wavelet with 10 decomposition levels, and obtains the approximation at level-10 as the baseline drift, then gets the corrected signal by removing the estimated baseline drift from the original signal. To examine the performance of our proposed method, we establish a dipping sheet model and calculate the theoretical response. Through simulations, we compare the signal-to-noise ratio, signal distortion, and processing speed of the wavelet-based method and those of the interpolation method. Simulation results show that the wavelet-based method outperforms the interpolation method. We also use field data to evaluate the methods, compare the depth section images of apparent resistivity using the original signal, the interpolation-corrected signal and the wavelet-corrected signal, respectively. The results confirm that our proposed wavelet-based method is an

  2. Coordinated Airborne, Spaceborne, and Ground-Based Measurements of Massive, Thick Aerosol Layers During the Dry Season in Southern Africa

    NASA Technical Reports Server (NTRS)

    Schmid, B.; Redemann, J.; Russell, P. B.; Hobbs, P. V.; Hlavka, D. L.; McGill, M. J.; Holben, B. N.; Welton, E. J.; Campbell, J.; Torres, O.; Hipskind, R. Stephen (Technical Monitor)

    2002-01-01

    During the dry-season airborne campaign of the Southern African Regional Science Initiative (SAFARI 2000), unique coordinated observations were made of massive, thick aerosol layers. These layers were often dominated by aerosols from biomass burning. We report on airborne Sunphotometer measurements of aerosol optical depth (lambda=354-1558 nm), columnar water vapor, and vertical profiles of aerosol extinction and water vapor density that were obtained aboard the University of Washington's Convair-580 research aircraft. We compare these with ground-based AERONET Sun/sky radiometer results, with ground based lidar data MPL-Net), and with measurements from a downward-pointing lidar aboard the high-flying NASA ER-2 aircraft. Finally, we show comparisons between aerosol optical depths from the Sunphotometer and those retrieved over land and over water using four spaceborne sensors (TOMS (Total Ozone Mapping Spectrometer), MODIS (Moderate Resolution Imaging Spectrometer), MISR (Multiangle Imaging Spectroradiometer) and ATSR-2 (Along Track Scanning Radiometer)).

  3. Coordinated Airborne, Spaceborne and Ground-based Measurements of Massive Thick Aerosol Layers during the Dry Season in Southern Africa

    NASA Technical Reports Server (NTRS)

    Schmid, B.; Redemann, J.; Russell, P. B.; Hobbs, P. V.; Hlavka, D. L.; McGill, M. J.; Holben, B. N.; Welton, E. J.; Campbell, J. R.; Torres, O.

    2003-01-01

    During the dry season airborne campaign of the Southern African Regional Science Initiative (SAFARI 2000), coordinated observations were made of massive thick aerosol layers. These layers were often dominated by aerosols from biomass burning. We report on airborne Sun photometer measurements of aerosol optical depth (lambda = 0.354- 1.557 microns), columnar water vapor, and vertical profiles of aerosol extinction and water vapor density that were obtained aboard the University of Washington's Convair-580 research aircraft. We compare these with ground-based AERONET Sun/sky radiometer results, with ground based lidar data (MPL-Net), and with measurements from a downward pointing lidar aboard the high-flying NASA ER-2 aircraft. Finally, we show comparisons between aerosol optical depths fiom the Sun photometer and those retrieved over land and over water using four spaceborne sensors (TOMS, MODIS, MISR, and ATSR-2).

  4. 3-D airborne ultrasound synthetic aperture imaging based on capacitive micromachined ultrasonic transducers.

    PubMed

    Park, Kwan Kyu; Khuri-Yakub, Butrus T

    2013-09-01

    In this paper, we present an airborne 3-D volumetric imaging system based on capacitive micromachined ultrasonic transducers (CMUTs). For this purpose we fabricated 89-kHz CMUTs where each CMUT is made of a circular single-crystal silicon plate with a radius of 1mm and a thickness of 20 μm, which is actuated by electrostatic force through a 20-μm vacuum gap. The measured transmit sensitivity at 300-V DC bias is 14.6 Pa/V and 24.2 Pa/V, when excited by a 30-cycle burst and a continuous wave, respectively. The measured receive sensitivity at 300-V DC bias is 16.6 mV/Pa (-35.6 dB re 1 V/Pa) for a 30-cycle burst. A 26×26 2-D array was implemented by mechanical scanning a co-located transmitter and receiver using the classic synthetic aperture (CSA) method. The measurement of a 1.6λ-size target at a distance of 500 mm presented a lateral resolution of 3.17° and also showed good agreement with the theoretical point spread function. The 3-D imaging of two plates at a distance of 350 mm and 400 mm was constructed to exhibit the capability of the imaging system. This study experimentally demonstrates that a 2-D CMUT array can be used for practical 3-D imaging applications in air, such as a human-machine interface.

  5. Evaluating Sentinel-2 for Lakeshore Habitat Mapping Based on Airborne Hyperspectral Data.

    PubMed

    Stratoulias, Dimitris; Balzter, Heiko; Sykioti, Olga; Zlinszky, András; Tóth, Viktor R

    2015-09-11

    Monitoring of lakeshore ecosystems requires fine-scale information to account for the high biodiversity typically encountered in the land-water ecotone. Sentinel-2 is a satellite with high spatial and spectral resolution and improved revisiting frequency and is expected to have significant potential for habitat mapping and classification of complex lakeshore ecosystems. In this context, investigations of the capabilities of Sentinel-2 in regard to the spatial and spectral dimensions are needed to assess its potential and the quality of the expected output. This study presents the first simulation of the high spatial resolution (i.e., 10 m and 20 m) bands of Sentinel-2 for lakeshore mapping, based on the satellite's Spectral Response Function and hyperspectral airborne data collected over Lake Balaton, Hungary in August 2010. A comparison of supervised classifications of the simulated products is presented and the information loss from spectral aggregation and spatial upscaling in the context of lakeshore vegetation classification is discussed. We conclude that Sentinel-2 imagery has a strong potential for monitoring fine-scale habitats, such as reed beds.

  6. Effective localized collection and identification of airborne species through electrodynamic precipitation and SERS-based detection

    PubMed Central

    Lin, En-Chiang; Fang, Jun; Park, Se-Chul; Johnson, Forrest W.; Jacobs, Heiko O.

    2013-01-01

    Various nanostructured sensor designs currently aim to achieve or claim single molecular detection by a reduction of the active sensor size. However, a reduction of the sensor size has the negative effect of reducing the capture probability considering the diffusion-based analyte transport commonly used. Here we introduce and apply a localized programmable electrodynamic precipitation concept as an alternative to diffusion. The process provides higher collection rates of airborne species and detection at lower concentration. As an example, we compare an identical nanostructured surfaced-enhanced Raman spectroscopy sensor with and without localized delivery and find that the sensitivity and detection time is improved by at least two orders of magnitudes. Localized collection in an active-matrix array-like fashion is also tested, yielding hybrid molecular arrays on a single chip over a broad range of molecular weights, including small benzenethiol (110.18 Da) and 4-fluorobenzenethiol (128.17 Da), or large macromolecules such as anti-mouse IgG (~150 kDa). PMID:23535657

  7. A wavelet based algorithm for DTM extraction from airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Xu, Liang; Yang, Yan; Tian, Qingjiu

    2007-06-01

    The automatic extraction of Digital Terrain Model (DTM) from point clouds acquired by airborne laser scanning (ALS) equipment remains a problem in ALS data filtering nowadays. Many filter algorithms have been developed to remove object points and outliers, and to extract DTM automatically. However, it is difficult to filter in areas where few points have identical morphological or geological features that can present the bare earth. Especially in sloped terrain covered by dense vegetation, points representing bare earth are often identified as noisy data below ground. To extract terrain surface in these areas, a new algorithm is proposed. First, the point clouds are cut into profiles based on a scan line segmentation algorithm. In each profile, a 1D filtering procedure is determined from the wavelet theory, which is superior in detecting high frequency discontinuities. After combining profiles from different directions, an interpolated grid data representing DTM is generated. In order to evaluate the performance of this new approach, we applied it to the data set used in the ISPRS filter test in 2003. 2 samples containing mostly vegetation on slopes have been processed by the proposed algorithm. It can be seen that it filtered most of the objects like vegetation and buildings in sloped area, and smoothed the hilly mountain to be more close to its real terrain surface.

  8. Evaluating Sentinel-2 for Lakeshore Habitat Mapping Based on Airborne Hyperspectral Data

    PubMed Central

    Stratoulias, Dimitris; Balzter, Heiko; Sykioti, Olga; Zlinszky, András; Tóth, Viktor R.

    2015-01-01

    Monitoring of lakeshore ecosystems requires fine-scale information to account for the high biodiversity typically encountered in the land-water ecotone. Sentinel-2 is a satellite with high spatial and spectral resolution and improved revisiting frequency and is expected to have significant potential for habitat mapping and classification of complex lakeshore ecosystems. In this context, investigations of the capabilities of Sentinel-2 in regard to the spatial and spectral dimensions are needed to assess its potential and the quality of the expected output. This study presents the first simulation of the high spatial resolution (i.e., 10 m and 20 m) bands of Sentinel-2 for lakeshore mapping, based on the satellite’s Spectral Response Function and hyperspectral airborne data collected over Lake Balaton, Hungary in August 2010. A comparison of supervised classifications of the simulated products is presented and the information loss from spectral aggregation and spatial upscaling in the context of lakeshore vegetation classification is discussed. We conclude that Sentinel-2 imagery has a strong potential for monitoring fine-scale habitats, such as reed beds. PMID:26378538

  9. Novel hierarchical microparticles super-assembled from nanoparticles with the induction of casein micelles

    NASA Astrophysics Data System (ADS)

    Xiong, Xiaopeng; Duan, Jiangjiang; Wang, Yong; Yu, Zhaoju

    2013-08-01

    We have demonstrated a solution-based synthesis of novel waxberry-like hierarchical ZnO microparticles in the presence casein micelles under mild conditions. The microstructures of the sub-micrometer-sized hierarchical microparticles were characterized, and the synthesis conditions were optimized. The formation mechanism of the hierarchical microparticle was analyzed through control experiments. The hierarchical ZnO microparticles are found to be super-assemblies of 30-70 nm ZnO nanoparticles, which are thought to be based on casein micelle induction followed by Ostwald ripening. In the same manner, copper-based hierarchical microparticles with a similar morphology have also been successfully synthesized. By controlling the synthetic time or temperature, solid or hollow microparticles can be fabricated. The narrowly distributed ZnO microparticles have a high specific surface area, exhibiting great potential application in fields such as photocatalytic and energy conversion. Our findings may meanwhile open a new bottom-up strategy in order to construct structurally sophisticated nanomaterials.

  10. High Resolution Airborne Gravity Gradiometer Based on an Othogonal Mass Quadruploe

    NASA Astrophysics Data System (ADS)

    Tryggvason, B. V.

    2003-04-01

    The Gedex Airborne Gravity Gradiometer (AGG) uses an orthogonal quadrupole responder (OQR) developed at the University of Western Australia with support from Rio Tinto. The OQR design is based on pairs of balance beams orientated at 90 degrees to one another, with each beam supported on a micro-flexure. A gradient along the length of a beam in the gravitational acceleration component that is perpendicular to the beam axis and the web axis will generate a small torque about the flexure. With two orthogonal beams, rotations of the base will result in both beams rotating in a common direction compared to the base, whereas the beams will rotate in opposite, or differential, directions due to gravity gradients. The differential rotation arises because of the properties of the gravity gradient tensor. The sensor can thus in principle distinguish between base rotations and gravity gradients. Additionally the beams are designed such that the center of rotation about the supporting flexures coincides with the location of the center of mass of the beams. This eliminates rotational response of the beams when subjected to linear accelerations. Thus the OQR configuration provides a sensor that is inherently insensitive to both rotational and linear accelerations of the support. However, the practical world has a habit of complicating seemingly simple situations. The first design challenge is that fabrication of the beams and the supporting flexures has to be done to very stringent tolerances, which has only recently become possible with the development of technologies such as Electric Discharge Machining (EDM). The second major obstacle is that there are higher order terms in the response of the sensing elements that can be driven by base vibrations and aircraft motions. These require mounting the sensor on an isolation system designed to provide a very low level of disturbance to the gradiometer. In the Gedex development this isolation system is based on technology developed

  11. Strategies for minimizing sample size for use in airborne LiDAR-based forest inventory

    USGS Publications Warehouse

    Junttila, Virpi; Finley, Andrew O.; Bradford, John B.; Kauranne, Tuomo

    2013-01-01

    Recently airborne Light Detection And Ranging (LiDAR) has emerged as a highly accurate remote sensing modality to be used in operational scale forest inventories. Inventories conducted with the help of LiDAR are most often model-based, i.e. they use variables derived from LiDAR point clouds as the predictive variables that are to be calibrated using field plots. The measurement of the necessary field plots is a time-consuming and statistically sensitive process. Because of this, current practice often presumes hundreds of plots to be collected. But since these plots are only used to calibrate regression models, it should be possible to minimize the number of plots needed by carefully selecting the plots to be measured. In the current study, we compare several systematic and random methods for calibration plot selection, with the specific aim that they be used in LiDAR based regression models for forest parameters, especially above-ground biomass. The primary criteria compared are based on both spatial representativity as well as on their coverage of the variability of the forest features measured. In the former case, it is important also to take into account spatial auto-correlation between the plots. The results indicate that choosing the plots in a way that ensures ample coverage of both spatial and feature space variability improves the performance of the corresponding models, and that adequate coverage of the variability in the feature space is the most important condition that should be met by the set of plots collected.

  12. Relationships between MODIS black-sky shortwave albedo and airborne lidar based forest canopy structure

    NASA Astrophysics Data System (ADS)

    Korhonen, Lauri; Rautiainen, Miina; Arumäe, Tauri; Lang, Mait; Flewelling, James; Tokola, Timo; Stenberg, Pauline

    2016-04-01

    Albedo is one of the essential climate variables affecting the Earth's radiation balance. It is however not well understood how changes in forest canopy structure influence the albedo. Canopy structure can be mapped consistently for fairly large areas using airborne lidar sensors. Our objective was to study the relationships between MODIS shortwave black sky albedo product and lidar-based estimates of canopy structure in different biomes ranging from arctic to tropical. Our study is based on six structurally different forest sites located in Finland, Estonia, USA and Laos. Lidar-based mean height of the canopy, canopy cover and their transformations were used as predictor variables to describe the canopy structure. Tree species composition was also included for the three sites where it was available. We noticed that the variables predicting albedo best were different in open and closed canopy forests. In closed canopy forests, the species information was more important than canopy structure variables (R2=0.31-0.32) and using only structural variables resulted in poor R2 (0.13-0.15). If the 500 m MODIS pixel contained a mixture of forests and other land cover types, the albedo was strongly related to the forest area percent. In open canopy forests, structural variables such as canopy cover or height explained albedo well, but species information still improved the models (R2=0.27-0.52). We obtained the highest R2=0.52 using only structural variables in Laos on a partially degraded tropical forest with large variation in canopy cover. The different canopy structure variables were often correlated and the one that provided the best model changed from site to site.

  13. Chemical characterization of individual microparticles using an ion trap: real-time chemical analysis of aerosol particles

    SciTech Connect

    Yang, Mo; Whitten, W.B.; Reilly, P.T.A.; Gieray, R.; Ramsey, J.M.

    1996-10-01

    This paper describes initial experiments to perform laser ablation mass spectrometry in real time on airborne microparticles. The microparticles are sampled directly from the air by a particle inlet system into the vacuum chamber of a mass spectrometer. An incoming particle is detected as it passes through two CW laser beams and a pulsed laser is triggered to intercept the particle for laser ablation/ionization in the mass spectrometer. The initial studies were made with an existing ion trap mass spectrometer with the particle sampling occurring at the center of the trap electrodes. Performance of the inlet system, particle detection, and preliminary results are described.

  14. Biocompatibility of polysebacic anhydride microparticles with chondrocytes in engineered cartilage

    PubMed Central

    Ponnurangam, Sathish; O'Connell, Grace D.; Hung, Clark T.; Somasundaran, Ponisseril

    2015-01-01

    One of main challenges in developing clinically relevant engineered cartilage is overcoming limited nutrient diffusion due to progressive elaboration of extracellular matrix at the periphery of the construct. Macro-channels have been used to decrease the nutrient path-length; however, the channels become occluded with matrix within weeks in culture, reducing nutrient diffusion. Alternatively, microparticles can be imbedded throughout the scaffold to provide localized nutrient delivery. In this study, we evaluated biocompatibility of polysebacic anhydride (PSA) polymers and the effectiveness of PSA-based microparticles for short-term delivery of nutrients in engineered cartilage. PSA-based microparticles were biocompatible with juvenile bovine chondrocytes for concentrations up to 2mg/mL; however, cytotoxicity was observed at 20mg/mL. Cytotoxicity at high concentrations is likely due to intracellular accumulation of PSA degradation products and resulting lipotoxicity. Cytotoxicity of PSA was partially reversed in the presence of bovine serum albumin. In conclusion, the findings from this study demonstrate concentration-dependent biocompatibility of PSA-based microparticles and potential application as a nutrient delivery vehicle that can be imbedded in scaffolds for tissue engineering. PMID:26398146

  15. Evaluation of DNA damage and cytotoxicity of polyurethane-based nano- and microparticles as promising biomaterials for drug delivery systems

    NASA Astrophysics Data System (ADS)

    Caon, Thiago; Zanetti-Ramos, Betina Giehl; Lemos-Senna, Elenara; Cloutet, Eric; Cramail, Henri; Borsali, Redouane; Soldi, Valdir; Simões, Cláudia Maria Oliveira

    2010-06-01

    The in vitro cytotoxicity and DNA damage evaluation of biodegradable polyurethane-based micro- and nanoparticles were carried out on animal fibroblasts. For cytotoxicity measurement and primary DNA damage evaluation, MTT and Comet assays were used, respectively. Different formulations were tested to evaluate the influence of chemical composition and physicochemical characteristics of particles on cell toxicity. No inhibition of cells growth surrounding the polyurethane particles was observed. On the other hand, a decrease of cell viability was verified when the anionic surfactant sodium dodecyl sulfate (SDS) was used as droplets stabilizer of monomeric phase. Polyurethane nanoparticles stabilized with Tween 80 and Pluronic F68 caused minor cytotoxic effects. These results indicated that the surface charge plays an important role on cytotoxicity. Particles synthesized from MDI displayed a higher cytotoxicity than those synthesized from IPDI. Size and physicochemical properties of the particles may explain the higher degree of DNA damage produced by two tested formulations. In this way, a rational choice of particles' constituents based on their cytotoxicity and genotoxicity could be very useful for conceiving biomaterials to be used as drug delivering systems.

  16. A comparison of airborne and ground-based radar observations with rain gages during the CaPE experiment

    NASA Technical Reports Server (NTRS)

    Satake, Makoto; Short, David A.; Iguchi, Toshio

    1992-01-01

    The vicinity of KSC, where the primary ground truth site of the Tropical Rainfall Measuring Mission (TRMM) program is located, was the focal point of the Convection and Precipitation/Electrification (CaPE) experiment in Jul. and Aug. 1991. In addition to several specialized radars, local coverage was provided by the C-band (5 cm) radar at Patrick AFB. Point measurements of rain rate were provided by tipping bucket rain gage networks. Besides these ground-based activities, airborne radar measurements with X- and Ka-band nadir-looking radars on board an aircraft were also recorded. A unique combination data set of airborne radar observations with ground-based observations was obtained in the summer convective rain regime of central Florida. We present a comparison of these data intending a preliminary validation. A convective rain event was observed simultaneously by all three instrument types on the evening of 27 Jul. 1991. The high resolution aircraft radar was flown over convective cells with tops exceeding 10 km and observed reflectivities of 40 to 50 dBZ at 4 to 5 km altitude, while the low resolution surface radar observed 35 to 55 dBZ echoes and a rain gage indicated maximum surface rain rates exceeding 100 mm/hr. The height profile of reflectivity measured with the airborne radar show an attenuation of 6.5 dB/km (two way) for X-band, corresponding to a rainfall rate of 95 mm/hr.

  17. Oil Spill Detection along the Gulf of Mexico Coastline based on Airborne Imaging Spectrometer Data

    NASA Astrophysics Data System (ADS)

    Arslan, M. D.; Filippi, A. M.; Guneralp, I.

    2013-12-01

    The Deepwater Horizon oil spill in the Gulf of Mexico between April and July 2010 demonstrated the importance of synoptic oil-spill monitoring in coastal environments via remote-sensing methods. This study focuses on terrestrial oil-spill detection and thickness estimation based on hyperspectral images acquired along the coastline of the Gulf of Mexico. We use AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) imaging spectrometer data collected over Bay Jimmy and Wilkinson Bay within Barataria Bay, Louisiana, USA during September 2010. We also employ field-based observations of the degree of oil accumulation along the coastline, as well as in situ measurements from the literature. As part of our proposed spectroscopic approach, we operate on atmospherically- and geometrically-corrected hyperspectral AVIRIS data to extract image-derived endmembers via Minimum Noise Fraction transform, Pixel Purity Index-generation, and n-dimensional visualization. Extracted endmembers are then used as input to endmember-mapping algorithms to yield fractional-abundance images and crisp classification images. We also employ Multiple Endmember Spectral Mixture Analysis (MESMA) for oil detection and mapping in order to enable the number and types of endmembers to vary on a per-pixel basis, in contast to simple Spectral Mixture Analysis (SMA). MESMA thus better allows accounting for spectral variabiltiy of oil (e.g., due to varying oil thicknesses, states of degradation, and the presence of different oil types, etc.) and other materials, including soils and salt marsh vegetation of varying types, which may or may not be affected by the oil spill. A decision-tree approach is also utilized for comparison. Classification results do indicate that MESMA provides advantageous capabilities for mapping several oil-thickness classes for affected vegetation and soils along the Gulf of Mexico coastline, relative to the conventional approaches tested. Oil thickness-mapping results from MESMA

  18. Evaluation of Operational Procedures for Using a Time-Based Airborne Inter-arrival Spacing Tool

    NASA Technical Reports Server (NTRS)

    Oseguera-Lohr, Rosa M.; Lohr, Gary W.; Abbott, Terence S.; Eischeid, Todd M.

    2002-01-01

    An airborne tool has been developed based on the concept of an aircraft maintaining a time-based spacing interval from the preceding aircraft. The Advanced Terminal Area Approach Spacing (ATAAS) tool uses Automatic Dependent Surveillance-Broadcast (ADS-B) aircraft state data to compute a speed command for the ATAAS-equipped aircraft to obtain a required time interval behind another aircraft. The tool and candidate operational procedures were tested in a high-fidelity, full mission simulator with active airline subject pilots flying an arrival scenario using three different modes for speed control. The objectives of this study were to validate the results of a prior Monte Carlo analysis of the ATAAS algorithm and to evaluate the concept from the standpoint of pilot acceptability and workload. Results showed that the aircraft was able to consistently achieve the target spacing interval within one second (the equivalent of approximately 220 ft at a final approach speed of 130 kt) when the ATAAS speed guidance was autothrottle-coupled, and a slightly greater (4-5 seconds), but consistent interval with the pilot-controlled speed modes. The subject pilots generally rated the workload level with the ATAAS procedure as similar to that with standard procedures, and also rated most aspects of the procedure high in terms of acceptability. Although pilots indicated that the head-down time was higher with ATAAS, the acceptability of head-down time was rated high. Oculometer data indicated slight changes in instrument scan patterns, but no significant change in the amount of time spent looking out the window between the ATAAS procedure versus standard procedures.

  19. MEMS-based silicon cantilevers with integrated electrothermal heaters for airborne ultrafine particle sensing

    NASA Astrophysics Data System (ADS)

    Wasisto, Hutomo Suryo; Merzsch, Stephan; Waag, Andreas; Peiner, Erwin

    2013-05-01

    The development of low-cost and low-power MEMS-based cantilever sensors for possible application in hand-held airborne ultrafine particle monitors is described in this work. The proposed resonant sensors are realized by silicon bulk micromachining technology with electrothermal excitation, piezoresistive frequency readout, and electrostatic particle collection elements integrated and constructed in the same sensor fabrication process step of boron diffusion. Built-in heating resistor and full Wheatstone bridge are set close to the cantilever clamp end for effective excitation and sensing, respectively, of beam deflection. Meanwhile, the particle collection electrode is located at the cantilever free end. A 300 μm-thick, phosphorus-doped silicon bulk wafer is used instead of silicon-on-insulator (SOI) as the starting material for the sensors to reduce the fabrication costs. To etch and release the cantilevers from the substrate, inductively coupled plasma (ICP) cryogenic dry etching is utilized. By controlling the etching parameters (e.g., temperature, oxygen content, and duration), cantilever structures with thicknesses down to 10 - 20 μm are yielded. In the sensor characterization, the heating resistor is heated and generating thermal waves which induce thermal expansion and further cause mechanical bending strain in the out-of-plane direction. A resonant frequency of 114.08 +/- 0.04 kHz and a quality factor of 1302 +/- 267 are measured in air for a fabricated rectangular cantilever (500x100x13.5 μm3). Owing to its low power consumption of a few milliwatts, this electrothermal cantilever is suitable for replacing the current external piezoelectric stack actuator in the next generation of the miniaturized cantilever-based nanoparticle detector (CANTOR).

  20. Nitrous Oxide (N2O) Emissions from California based on 2010 CalNex Airborne Measurements

    NASA Astrophysics Data System (ADS)

    Xiang, B.; Miller, S.; Kort, E. A.; Santoni, G. W.; Daube, B.; Commane, R.; Angevine, W. M.; Ryerson, T. B.; Trainer, M.; Andrews, A. E.; Nehrkorn, T.; Tian, H.; Wofsy, S. C.

    2012-12-01

    Nitrous oxide (N2O) is an important gas for climate and for stratospheric chemistry, with an atmospheric lifetime exceeding 100 years. Global concentrations have increased steadily since the 18th century, apparently due to human-associated emissions, principally from application of nitrogen fertilizers. However, quantitative studies of agricultural emissions at large spatial scales are lacking, inhibited by the difficulty of measuring small enhancements of atmospheric concentrations. Here we derive regional emission rates for N2O in the Central Valley of California, based on analysis of in-situ airborne atmospheric observations collected using a quantum cascade laser spectrometer. The data were obtained on board the NOAA P-3 research aircraft during the CalNex (California Research at the Nexus of Air Quality and Climate Change) program in May and June, 2010. We coupled WRF (Weather Research and Forecasting) model to STILT (Stochastic Time-Inverted Lagrangian Transport) to link our in-situ observations to surface emissions, and then used a variety of statistical methods to identify source areas and to extract optimized emission rates from the inversion. Our results support the view that fertilizer application is the largest source of N2O in the Central Valley. But the spatial distribution of derived surface emissions, based on California land use and activity maps, was very different than indicated in the leading emissions inventory (EDGAR 4.0), and our estimated total emission flux of N2O for California during the study period was 3 - 4 times larger than EDGAR and other inventories.

  1. Designing Web-Based Science Lesson Plans That Use Problem-Based Learning To Inspire Middle School Kids: KaAMS (Kids as Airborne Mission Scientists).

    ERIC Educational Resources Information Center

    Koszalka, Tiffany A.; Grabowski, Barbara; Kim, Younghoon

    Problem-based learning (PBL) has great potential for inspiring K-12 learning. KaAMS (Kids as Airborne Mission Scientists), an example of PBL, was designed to help teachers inspire middle school students to learning science, math, technology, and geography. The children participate as scientists investigating environmental problems using NASA…

  2. Microparticles as Potential Biomarkers of Cardiovascular Disease

    PubMed Central

    França, Carolina Nunes; Izar, Maria Cristina de Oliveira; do Amaral, Jônatas Bussador; Tegani, Daniela Melo; Fonseca, Francisco Antonio Helfenstein

    2015-01-01

    Primary prevention of cardiovascular disease is a choice of great relevance because of its impact on health. Some biomarkers, such as microparticles derived from different cell populations, have been considered useful in the assessment of cardiovascular disease. Microparticles are released by the membrane structures of different cell types upon activation or apoptosis, and are present in the plasma of healthy individuals (in levels considered physiological) and in patients with different pathologies. Many studies have suggested an association between microparticles and different pathological conditions, mainly the relationship with the development of cardiovascular diseases. Moreover, the effects of different lipid-lowering therapies have been described in regard to measurement of microparticles. The studies are still controversial regarding the levels of microparticles that can be considered pathological. In addition, the methodologies used still vary, suggesting the need for standardization of the different protocols applied, aiming at using microparticles as biomarkers in clinical practice. PMID:25626759

  3. Method for determining surface properties of microparticles

    DOEpatents

    Eisenthal, Kenneth B.

    2000-01-01

    Second harmonic generation (SHG), sum frequency generation (SFG) and difference frequency generation (DFG) can be used for surface analysis or characterization of microparticles having a non-metallic surface feature. The microparticles can be centrosymmetric or such that non-metallic molecules of interest are centrosymmetrically distributed inside and outside the microparticles but not at the surface of the microparticles where the asymmetry aligns the molecules. The signal is quadratic in incident laser intensity or proportional to the product of two incident laser intensities for SFG, it is sharply peaked at the second harmonic wavelength, quadratic in the density of molecules adsorbed onto the microparticle surface, and linear in microparticles density. In medical or pharmacological applications, molecules of interest may be of drugs or toxins, for example.

  4. In vitro assessment of biopolymer-modified porous silicon microparticles for wound healing applications.

    PubMed

    Mori, Michela; Almeida, Patrick V; Cola, Michela; Anselmi, Giulia; Mäkilä, Ermei; Correia, Alexandra; Salonen, Jarno; Hirvonen, Jouni; Caramella, Carla; Santos, Hélder A

    2014-11-01

    The wound healing stands as very complex and dynamic process, aiming the re-establishment of the damaged tissue's integrity and functionality. Thus, there is an emerging need for developing biopolymer-based composites capable of actively promoting cellular proliferation and reconstituting the extracellular matrix. The aims of the present work were to prepare and characterize biopolymer-functionalized porous silicon (PSi) microparticles, resulting in the development of drug delivery microsystems for future applications in wound healing. Thermally hydrocarbonized PSi (THCPSi) microparticles were coated with both chitosan and a mixture of chondroitin sulfate/hyaluronic acid, and subsequently loaded with two antibacterial model drugs, vancomycin and resveratrol. The biopolymer coating, drug loading degree and drug release behavior of the modified PSi microparticles were evaluated in vitro. The results showed that both the biopolymer coating and drug loading of the THCPSi microparticles were successfully achieved. In addition, a sustained release was observed for both the drugs tested. The viability and proliferation profiles of a fibroblast cell line exposed to the modified THCPSi microparticles and the subsequent reactive oxygen species (ROS) production were also evaluated. The cytotoxicity and proliferation results demonstrated less toxicity for the biopolymer-coated THCPSi microparticles at different concentrations and time points comparatively to the uncoated counterparts. The ROS production by the fibroblasts exposed to both uncoated and biopolymer-coated PSi microparticles showed that the modified PSi microparticles did not induce significant ROS production at the concentrations tested. Overall, the biopolymer-based PSi microparticles developed in this study are promising platforms for wound healing applications.

  5. An automatic approach and grip method of micro-particle in 3D space

    NASA Astrophysics Data System (ADS)

    Zhang, Juan; Wu, Wenrong; Bi, Lie

    2017-03-01

    Micro-particle is hard to be observed as small scale and hard to be gripped as micro-force from substrate, an automatic approach and grip method of micro-particle in the guide of microscopic vision systems is proposed in the paper to grip micro-particle. First, the micro-gripper driven by electrostatic force is introduced and forces in gripping process are analyzed. Second, a micro-assembly robot composed of two microscopic vision systems is established to monitor micro-operation process and to operate micro-particle. Image features of micro-particle and micro-gripper end-effector are extracted by image feature extraction method to calculate relative position of micro-particle and micro-gripper in image space. Last, a movement control strategy in 3D space based on image Jacobian matrix is studied to control micro-gripper approach and align with micro-particle. Experimental results verified the effectiveness of proposed methods.

  6. Tunneling holes in microparticles to facilitate the transport of lithium ions for high volumetric density batteries.

    PubMed

    Zhu, Jian; Ng, K Y Simon; Deng, Da

    2015-09-14

    Microscale materials generally have a higher tap density than that of random nanoparticles. Therefore, microparticles have been attracting much attention for application as high volumetric density electrodes for lithium ion batteries. However, microparticles have much longer electrolyte diffusion and Li-ion migration length and less accessibility to the electrolyte than that of nanoparticles. Therefore, it will be interesting to tunnel-holes in the high volumetric density microparticles to facilitate the reversible storage of lithium ions. Here, tunnel-like holes were generated in microparticles to dramatically increase the accessibility of the active materials to facilitate the lithium ion transfer. A plausible formation mechanism to explain the generation of tunnel-like holes was proposed based on time-course experiments and intensive characterization. Impressively, the as-prepared microbeads with tunnels demonstrated dramatically improved performance compared to the solid microbeads without tunnels in lithium ion storage. The microparticles with tunnels could achieve comparable electrochemical performances to those nanoparticles reported in the literature, suggesting that microparticles, properly tuned, could be promising candidates as negative electrodes for lithium-ion batteries and worthy of further studies. We also directly measured the volumetric density of the microparticles. We would like to highlight that a superior volumetric capacity of 514 mA h cm(-3) has been achieved. We hope to promote more frequent use of the unit mA h cm(-3) in addition to the conventional unit mA h g(-1) in the battery community.

  7. Optoelectrofluidic printing system for fabricating hydrogel sheets with on-demand patterned cells and microparticles.

    PubMed

    Gi, Hyun Ji; Han, Dongsik; Park, Je-Kyun

    2017-01-16

    This paper presents a novel optoelectrofluidic printing system that facilitates not only the optoelectrofluidic patterning of microparticles and mammalian cells but also the harvesting of the patterned microparticles encapsulated within poly(ethylene glycol) dicarylate (PEGDA) hydrogel sheets. Although optoelectrofluidic technology has numerous advantages for programmable and on-demand patterning and the feasibility of manipulating single microparticles, practical applications using existing laboratory infrastructure in biological and clinical research fields have been strictly restricted due to the impossibility of recovering the final patterned product. In order to address these harvesting limitations, PEGDA was employed to utilize optoelectrofluidic printing. The Clausius-Mossotti factor was calculated to investigate the dielectrophoretic mobility of the microparticle and the cell in the PEGDA precursor solution. As a proof of concept, three basic controllabilities of the optoelectrofluidic printing system were characterized: the number of microparticles, the distance between the microparticle columns, and the ratio of two different microparticles. Furthermore, the optoelectrofluidic patterning and printing of human liver carcinoma cells (HepG2) were demonstrated in 5 min with a single-cell level of resolution. The appropriate ranges of frequency were experimentally defined based on the calculated result of the dielectrophoretic mobility of HepG2 cells. Finally, optoelectrofluidically cell-patterned hydrogel sheets were successfully recovered under a highly viable physiological condition.

  8. Overview of the first Multicenter Airborne Coherent Atmospheric Wind Sensor (MACAWS) experiment: conversion of a ground-based lidar for airborne applications

    NASA Astrophysics Data System (ADS)

    Howell, James N.; Hardesty, R. Michael; Rothermel, Jeffrey; Menzies, Robert T.

    1996-11-01

    The first Multi center Airborne Coherent Atmospheric Wind Sensor (MACAWS) field experiment demonstrated an airborne high energy TEA CO2 Doppler lidar system for measurement of atmospheric wind fields and aerosol structure. The system was deployed on the NASA DC-8 during September 1995 in a series of checkout flights to observe several important atmospheric phenomena, including upper level winds in a Pacific hurricane, marine boundary layer winds, cirrus cloud properties, and land-sea breeze structure. The instrument, with its capability to measure 3D winds and backscatter fields, promises to be a valuable tool for climate and global change, severe weather, and air quality research. In this paper, we describe the airborne instrument, assess its performance, discuss future improvements, and show some preliminary results from the September experiments.

  9. Overview of the first Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) experiment: Conversion of a ground-based lidar for airborne applications

    SciTech Connect

    Howell, J.N.; Hardesty, R.M.; Rothermel, J.; Menzies, R.T.

    1996-12-31

    The first Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) field experiment demonstrated an airborne high energy TEA CO{sub 2} Doppler lidar system for measurement of atmospheric wind fields and aerosol structure. The system was deployed on the NASA DC-8 during September 1995 in a series of checkout flights to observe several important atmospheric phenomena, including upper level winds in a Pacific hurricane, marine boundary layer winds, cirrus cloud properties, and land-sea breeze structure. The instrument, with its capability to measure three-dimensional winds and backscatter fields, promises to be a valuable tool for climate and global change, severe weather, and air quality research. In this paper, the authors describe the airborne instrument, assess its performance, discuss future improvements, and show some preliminary results from September experiments.

  10. High diversity of airborne fungi in the hospital environment as revealed by meta-sequencing-based microbiome analysis

    PubMed Central

    Tong, Xunliang; Xu, Hongtao; Zou, Lihui; Cai, Meng; Xu, Xuefeng; Zhao, Zuotao; Xiao, Fei; Li, Yanming

    2017-01-01

    Invasive fungal infections acquired in the hospital have progressively emerged as an important cause of life-threatening infection. In particular, airborne fungi in hospitals are considered critical pathogens of hospital-associated infections. To identify the causative airborne microorganisms, high-volume air samplers were utilized for collection, and species identification was performed using a culture-based method and DNA sequencing analysis with the Illumina MiSeq and HiSeq 2000 sequencing systems. Few bacteria were grown after cultivation in blood agar. However, using microbiome sequencing, the relative abundance of fungi, Archaea species, bacteria and viruses was determined. The distribution characteristics of fungi were investigated using heat map analysis of four departments, including the Respiratory Intensive Care Unit, Intensive Care Unit, Emergency Room and Outpatient Department. The prevalence of Aspergillus among fungi was the highest at the species level, approximately 17% to 61%, and the prevalence of Aspergillus fumigatus among Aspergillus species was from 34% to 50% in the four departments. Draft genomes of microorganisms isolated from the hospital environment were obtained by sequence analysis, indicating that investigation into the diversity of airborne fungi may provide reliable results for hospital infection control and surveillance. PMID:28045065

  11. Two-UAV Intersection Localization System Based on the Airborne Optoelectronic Platform

    PubMed Central

    Bai, Guanbing; Liu, Jinghong; Song, Yueming; Zuo, Yujia

    2017-01-01

    To address the limitation of the existing UAV (unmanned aerial vehicles) photoelectric localization method used for moving objects, this paper proposes an improved two-UAV intersection localization system based on airborne optoelectronic platforms by using the crossed-angle localization method of photoelectric theodolites for reference. This paper introduces the makeup and operating principle of intersection localization system, creates auxiliary coordinate systems, transforms the LOS (line of sight, from the UAV to the target) vectors into homogeneous coordinates, and establishes a two-UAV intersection localization model. In this paper, the influence of the positional relationship between UAVs and the target on localization accuracy has been studied in detail to obtain an ideal measuring position and the optimal localization position where the optimal intersection angle is 72.6318°. The result shows that, given the optimal position, the localization root mean square error (RMS) will be 25.0235 m when the target is 5 km away from UAV baselines. Finally, the influence of modified adaptive Kalman filtering on localization results is analyzed, and an appropriate filtering model is established to reduce the localization RMS error to 15.7983 m. Finally, An outfield experiment was carried out and obtained the optimal results: σB=1.63×10−4 (°), σL=1.35×10−4 (°), σH=15.8 (m), σsum=27.6 (m), where σB represents the longitude error, σL represents the latitude error, σH represents the altitude error, and σsum represents the error radius. PMID:28067814

  12. Two-UAV Intersection Localization System Based on the Airborne Optoelectronic Platform.

    PubMed

    Bai, Guanbing; Liu, Jinghong; Song, Yueming; Zuo, Yujia

    2017-01-06

    To address the limitation of the existing UAV (unmanned aerial vehicles) photoelectric localization method used for moving objects, this paper proposes an improved two-UAV intersection localization system based on airborne optoelectronic platforms by using the crossed-angle localization method of photoelectric theodolites for reference. This paper introduces the makeup and operating principle of intersection localization system, creates auxiliary coordinate systems, transforms the LOS (line of sight, from the UAV to the target) vectors into homogeneous coordinates, and establishes a two-UAV intersection localization model. In this paper, the influence of the positional relationship between UAVs and the target on localization accuracy has been studied in detail to obtain an ideal measuring position and the optimal localization position where the optimal intersection angle is 72.6318°. The result shows that, given the optimal position, the localization root mean square error (RMS) will be 25.0235 m when the target is 5 km away from UAV baselines. Finally, the influence of modified adaptive Kalman filtering on localization results is analyzed, and an appropriate filtering model is established to reduce the localization RMS error to 15.7983 m. Finally, An outfield experiment was carried out and obtained the optimal results: σ B = 1.63 × 10 - 4 ( ° ) , σ L = 1.35 × 10 - 4 ( ° ) , σ H = 15.8 ( m ) , σ s u m = 27.6 ( m ) , where σ B represents the longitude error, σ L represents the latitude error, σ H represents the altitude error, and σ s u m represents the error radius.

  13. Simulation tests to assess occupational exposure to airborne asbestos from asphalt-based roofing products.

    PubMed

    Mowat, Fionna; Weidling, Ryan; Sheehan, Patrick

    2007-07-01

    This study sought to evaluate exposure from specific products to evaluate potential risk from roof repair activities. Five asbestos-containing fibered roof coatings and plastic cements, representing a broad range of these types of products, were tested in exposure simulations. These products were applied to representative roof substrates. Release of asbestos fibers during application and sanding of the product shortly thereafter (wet sanding) were tested initially. Other roof substrates were cured to simulate a product that had been on a rooftop for several months and then were tested to evaluate release of fibers during hand sanding and hand scraping activities. Additional tests were also conducted to evaluate asbestos release during product removal from tools and clothing. Two personal (n = 84) and background/clearance (n = 49) samples were collected during each 30-min test and analyzed for total fiber concentration [phase-contrast microscopy (PCM)] and for asbestos fiber count [transmission electron microscopy (TEM)]. PCM concentrations ranged from <0.005 to 0.032 fibers per cubic centimeter (f cc(-1)). Chrysotile fibers were detected in 28 of 84 personal samples collected. TEM concentrations ranged from <0.0021 to 0.056 f cc(-1). Calculated 8-h time-weighted averages (TWAs) ranged from 0.0003 to 0.002 f cc(-1) and were comparable to the background TWA concentration of 0.0002 f cc(-1) measured in this study. Based on these results, it is unlikely that roofers were exposed to airborne asbestos concentrations above the current or historical occupational guidelines during scraping and sanding of these products during roof repair.

  14. Gravity for Detecting Caves: Airborne and Terrestrial Simulations Based on a Comprehensive Karstic Cave Benchmark

    NASA Astrophysics Data System (ADS)

    Braitenberg, Carla; Sampietro, Daniele; Pivetta, Tommaso; Zuliani, David; Barbagallo, Alfio; Fabris, Paolo; Rossi, Lorenzo; Fabbri, Julius; Mansi, Ahmed Hamdi

    2016-04-01

    Underground caves bear a natural hazard due to their possible evolution into a sink hole. Mapping of all existing caves could be useful for general civil usages as natural deposits or tourism and sports. Natural caves exist globally and are typical in karst areas. We investigate the resolution power of modern gravity campaigns to systematically detect all void caves of a minimum size in a given area. Both aerogravity and terrestrial acquisitions are considered. Positioning of the gravity station is fastest with GNSS methods the performance of which is investigated. The estimates are based on a benchmark cave of which the geometry is known precisely through a laser-scan survey. The cave is the Grotta Gigante cave in NE Italy in the classic karst. The gravity acquisition is discussed, where heights have been acquired with dual-frequency geodetic GNSS receivers and Total Station. Height acquisitions with non-geodetic low-cost receivers are shown to be useful, although the error on the gravity field is larger. The cave produces a signal of -1.5 × 10-5 m/s2, with a clear elliptic geometry. We analyze feasibility of airborne gravity acquisitions for the purpose of systematically mapping void caves. It is found that observations from fixed wing aircraft cannot resolve the caves, but observations from slower and low-flying helicopters or drones do. In order to detect the presence of caves the size of the benchmark cave, systematic terrestrial acquisitions require a density of three stations on square 500 by 500 m2 tiles. The question has a large impact on civil and environmental purposes, since it will allow planning of urban development at a safe distance from subsurface caves. The survey shows that a systematic coverage of the karst would have the benefit to recover the position of all of the greater existing void caves.

  15. Single immunization with a suboptimal antigen dose encapsulated into polyanhydride microparticles promotes high titer and avid antibody responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microparticle adjuvants based on biodegradable polyanhydrides were used to provide controlled delivery of a model antigen, ovalbumin (Ova), to mice. Ova was encapsulated into two different polyanhydride microparticle formulations to evaluate the influence of polymer chemistry on the nature and magn...

  16. Comparison of different detection methods for citrus greening disease based on airborne multispectral and hyperspectral imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus greening or Huanglongbing (HLB) is a devastating disease spread in many citrus groves since first found in 2005 in Florida. Multispectral (MS) and hyperspectral (HS) airborne images of citrus groves in Florida were taken to detect citrus greening infected trees in 2007 and 2010. Ground truthi...

  17. Plasma dragged microparticles as a method to measure plasma flows

    SciTech Connect

    Ticos, Catalin M.; Wang Zhehui; Delzanno, Gian Luca; Lapenta, Giovanni

    2006-10-15

    The physics of microparticle motion in flowing plasmas is studied in detail for plasmas with electron and ion densities n{sub e,i}{approx}10{sup 19} m{sup -3}, electron and ion temperatures of no more than 15 eV, and plasma flows on the order of the ion thermal speed, v{sub f}{approx}v{sub ti}. The equations of motion due to Coulomb interactions and direct impact with ions and electrons, of charge variation, as well as of heat exchange with the plasma, are solved numerically for isolated particles (or dust grains) of micron sizes. It is predicted that microparticles can survive in plasma long enough, and can be dragged in the direction of the local ion flow. Based on the theoretical analysis, we describe a new plasma flow measurement technique called microparticle tracer velocimetry (mPTV), which tracks microparticle motion in a plasma with a high-speed camera. The mPTV can reveal the directions of the plasma flow vectors at multiple locations simultaneously and at submillimeter scales, which is hard to achieve by most other techniques. Thus, mPTV can be used to study plasma flows produced in the laboratory.

  18. Image-Based Airborne LiDAR Point Cloud Encoding for 3d Building Model Retrieval

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Chen; Lin, Chao-Hung

    2016-06-01

    With the development of Web 2.0 and cyber city modeling, an increasing number of 3D models have been available on web-based model-sharing platforms with many applications such as navigation, urban planning, and virtual reality. Based on the concept of data reuse, a 3D model retrieval system is proposed to retrieve building models similar to a user-specified query. The basic idea behind this system is to reuse these existing 3D building models instead of reconstruction from point clouds. To efficiently retrieve models, the models in databases are compactly encoded by using a shape descriptor generally. However, most of the geometric descriptors in related works are applied to polygonal models. In this study, the input query of the model retrieval system is a point cloud acquired by Light Detection and Ranging (LiDAR) systems because of the efficient scene scanning and spatial information collection. Using Point clouds with sparse, noisy, and incomplete sampling as input queries is more difficult than that by using 3D models. Because that the building roof is more informative than other parts in the airborne LiDAR point cloud, an image-based approach is proposed to encode both point clouds from input queries and 3D models in databases. The main goal of data encoding is that the models in the database and input point clouds can be consistently encoded. Firstly, top-view depth images of buildings are generated to represent the geometry surface of a building roof. Secondly, geometric features are extracted from depth images based on height, edge and plane of building. Finally, descriptors can be extracted by spatial histograms and used in 3D model retrieval system. For data retrieval, the models are retrieved by matching the encoding coefficients of point clouds and building models. In experiments, a database including about 900,000 3D models collected from the Internet is used for evaluation of data retrieval. The results of the proposed method show a clear superiority

  19. Issues in long-term protein delivery using biodegradable microparticles.

    PubMed

    Ye, Mingli; Kim, Sungwon; Park, Kinam

    2010-09-01

    Recently, a variety of bioactive protein drugs have been available in large quantities as a result of advances in biotechnology. Such availability has prompted development of long-term protein delivery systems. Biodegradable microparticulate systems have been used widely for controlled release of protein drugs for days and months. The most widely used biodegradable polymer has been poly(d,l-lactic-co-glycolic acid) (PLGA). Protein-containing microparticles are usually prepared by the water/oil/water (W/O/W) double emulsion method, and variations of this method, such as solid/oil/water (S/O/W) and water/oil/oil (W/O/O), have also been used. Other methods of preparation include spray drying, ultrasonic atomization, and electrospray methods. The important factors in developing biodegradable microparticles for protein drug delivery are protein release profile (including burst release, duration of release, and extent of release), microparticle size, protein loading, encapsulation efficiency, and bioactivity of the released protein. Many studies used albumin as a model protein, and thus, the bioactivity of the release protein has not been examined. Other studies which utilized enzymes, insulin, erythropoietin, and growth factors have suggested that the right formulation to preserve bioactivity of the loaded protein drug during the processing and storage steps is important. The protein release profiles from various microparticle formulations can be classified into four distinct categories (Types A, B, C, and D). The categories are based on the magnitude of burst release, the extent of protein release, and the protein release kinetics followed by the burst release. The protein loading (i.e., the total amount of protein loaded divided by the total weight of microparticles) in various microparticles is 6.7+/-4.6%, and it ranges from 0.5% to 20.0%. Development of clinically successful long-term protein delivery systems based on biodegradable microparticles requires

  20. Original research paper. Characterization and taste masking evaluation of microparticles with cetirizine dihydrochloride and methacrylate-based copolymer obtained by spray drying.

    PubMed

    Amelian, Aleksandra; Szekalska, Marta; Ciosek, Patrycja; Basa, Anna; Winnicka, Katarzyna

    2017-03-01

    Taste of a pharmaceutical formulation is an important parameter for the effectiveness of pharmacotherapy. Cetirizine dihydrochloride (CET) is a second-generation antihistamine that is commonly administered in allergy treatment. CET is characterized by extremely bitter taste and it is a great challenge to successfully mask its taste; therefore the goal of this work was to formulate and characterize the microparticles obtained by the spray drying method with CET and poly(butyl methacrylate-co-(2-dimethylaminoethyl) methacrylate-co-methyl methacrylate 1:2:1 copolymer (Eudragit E PO) as a barrier coating. Assessment of taste masking by the electronic tongue has revealed that designed formulations created an effective taste masking barrier. Taste masking effect was also confirmed by the in vivo model and the in vitro release profile of CET. Obtained data have shown that microparticles with a drug/polymer ratio (0.5:1) are promising CET carriers with efficient taste masking potential and might be further used in designing orodispersible dosage forms with CET.

  1. Fourth Airborne Geoscience Workshop

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The focus of the workshop was on how the airborne community can assist in achieving the goals of the Global Change Research Program. The many activities that employ airborne platforms and sensors were discussed: platforms and instrument development; airborne oceanography; lidar research; SAR measurements; Doppler radar; laser measurements; cloud physics; airborne experiments; airborne microwave measurements; and airborne data collection.

  2. A Coordinated Ice-based and Airborne Snow and Ice Thickness Measurement Campaign on Arctic Sea Ice

    NASA Astrophysics Data System (ADS)

    Richter-Menge, J.; Farrell, S.; Elder, B. C.; Gardner, J. M.; Brozena, J. M.

    2011-12-01

    A rare opportunity presented itself in March 2011 when the Naval Research Laboratory (NRL) and NASA IceBridge teamed with scientists from the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) to coordinate a multi-scale approach to mapping snow depth and sea ice thickness distribution in the Arctic. Ground-truth information for calibration/validation of airborne and CryoSat-2 satellite data were collected near a manned camp deployed in support of the US Navy's Ice Expedition 2011 (ICEX 2011). The ice camp was established at a location approximately 230 km north of Prudhoe Bay, Alaska, at the edge of the perennial ice zone. The suite of measurements was strategically organized around a 9-km-long survey line that covered a wide range of ice types, including refrozen leads, deformed and undeformed first year ice, and multiyear ice. A highly concentrated set of in situ measurements of snow depth and ice thickness were taken along the survey line. Once the survey line was in place, NASA IceBridge flew a dedicated mission along the survey line, collecting data with an instrument suite that included the Airborne Topographic Mapper (ATM), a high precision, airborne scanning laser altimeter; the Digital Mapping System (DMS), nadir-viewing digital camera; and the University of Kansas ultra-wideband Frequency Modulated Continuous Wave (FMCW) snow radar. NRL also flew a dedicated mission over the survey line with complementary airborne radar, laser and photogrammetric sensors (see Brozena et al., this session). These measurements were further leveraged by a series of CryoSat-2 under flights made in the region by the instrumented NRL and NASA planes, as well as US Navy submarine underpasses of the 9-km-long survey line to collect ice draft measurements. This comprehensive suite of data provides the full spectrum of sampling resolutions from satellite, to airborne, to ground-based, to submarine and will allow for a careful determination of

  3. Biodiversity and concentrations of airborne fungi in large US office buildings from the BASE study

    NASA Astrophysics Data System (ADS)

    Tsai, Feng C.; Macher, Janet M.; Hung, Yun-Yi

    The Building Assessment Survey and Evaluation (BASE) study measured baseline concentrations of airborne fungi in 100 representative US office buildings in 1994-1998. Multiple samples for different sampling durations, sites, and times of the day were aggregated into building-wide indoor and outdoor average concentrations. Fungal concentrations were compared between locations (indoor vs. outdoor), sampling and analytical methods (culture vs. microscopy), and season (summer vs. winter). The arithmetic means (standard deviations) of the indoor/outdoor concentrations of culturable fungi and fungal spores were 100/680 (230/840) CFUm-3 and 270/6540 (1190/6780) sporem-3, respectively. Although fewer groups were observed indoors than outdoors, at lower average concentrations (except in two buildings), site-specific and building-wide indoor measurements had higher coefficients of variation. More groups were seen in summer, and aggregated concentrations tended to be higher than in winter except for culturable Aureobasidium spp. and Botrytis spp. outdoors and non-sporulating fungi in both locations. Rankings of the predominant fungi identified by both methods were similar, but overall indoor and outdoor spore concentrations were approximately 3 and 10 times higher, respectively, than concentrations of culturable fungi. In the 44 buildings with both measurements, the indoor and outdoor total culturable fungi to fungal spore ratios (total C/S ratios) were 1.27 and 0.25, with opposite seasonal patterns. The indoor C/S ratio was higher in summer than in winter (1.47 vs. 0.86; N=29 and 15, respectively), but the outdoor ratio was lower in summer (0.19 vs. 0.36, respectively). Comparison of the number of different fungal groups and individual occurrence in buildings and samples indicated that the outdoor environment and summer season were more diverse, but the proportional contributions of the groups were very similar suggesting that the indoor and outdoor environments were related

  4. Semi-automated based ground-truthing GUI for airborne imagery

    NASA Astrophysics Data System (ADS)

    Phan, Chung; Lydic, Rich; Moore, Tim; Trang, Anh; Agarwal, Sanjeev; Tiwari, Spandan

    2005-06-01

    Over the past several years, an enormous amount of airborne imagery consisting of various formats has been collected and will continue into the future to support airborne mine/minefield detection processes, improve algorithm development, and aid in imaging sensor development. The ground-truthing of imagery is a very essential part of the algorithm development process to help validate the detection performance of the sensor and improving algorithm techniques. The GUI (Graphical User Interface) called SemiTruth was developed using Matlab software incorporating signal processing, image processing, and statistics toolboxes to aid in ground-truthing imagery. The semi-automated ground-truthing GUI is made possible with the current data collection method, that is including UTM/GPS (Universal Transverse Mercator/Global Positioning System) coordinate measurements for the mine target and fiducial locations on the given minefield layout to support in identification of the targets on the raw imagery. This semi-automated ground-truthing effort has developed by the US Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD), Countermine Division, Airborne Application Branch with some support by the University of Missouri-Rolla.

  5. Monitoring and Modeling Crop Health and Water Use via in-situ, Airborne and Space-based Platforms

    NASA Astrophysics Data System (ADS)

    McCabe, M. F.

    2014-12-01

    The accurate retrieval of plant water use, health and function together with soil state and condition, represent key objectives in the management and monitoring of large-scale agricultural production. In regions of water shortage or stress, understanding the sustainable use of available water supplies is critical. Unfortunately, this need is all too often limited by a lack of reliable observations. Techniques that balance the demand for reliable ground-based data with the rapid retrieval of spatially distributed crop characteristics represent a needed line of research. Data from in-situ monitoring coupled with advances in satellite retrievals of key land surface variables, provide the information necessary to characterize many crop health and water use features, including evaporation, leaf-chlorophyll and other common vegetation indices. With developments in UAV and quadcopter solutions, the opportunity to bridge the spatio-temporal gap between satellite and ground based sensing now exists, along with the capacity for customized retrievals of crop information. While there remain challenges in the routine application of autonomous airborne systems, the state of current technology and sensor developments provide the capacity to explore the operational potential. While this presentation will focus on the multi-scale estimation of crop-water use and crop-health characteristics from satellite-based sensors, the retrieval of high resolution spatially distributed information from near-surface airborne and ground-based systems will also be examined.

  6. Functionalised alginate flow seeding microparticles for use in Particle Image Velocimetry (PIV).

    PubMed

    Varela, Sylvana; Balagué, Isaac; Sancho, Irene; Ertürk, Nihal; Ferrando, Montserrat; Vernet, Anton

    2016-01-01

    Alginate microparticles as flow seeding fulfil all the requirements that are recommended for the velocity measurements in Particle Image Velocimetry (PIV). These spherical microparticles offer the advantage of being environmentally friendly, having excellent seeding properties and they can be produced via a very simple process. In the present study, the performances of alginate microparticles functionalised with a fluorescent dye, Rhodamine B (RhB), for PIV have been studied. The efficacy of fluorescence is appreciated in a number of PIV applications since it can boost the signal-to-noise ratio. Alginate microparticles functionalised with RhB have high emission efficiency, desirable match with fluid density and controlled size. The study of the particles behaviour in strong acid and basic solutions and ammonia is also included. This type of particles can be used for measurements with PIV and Planar Laser Induced Fluorescence (PLIF) simultaneously, including acid-base reactions.

  7. Preparation and anti-tumor evaluation of polyactin A microparticles from supercritical CO 2 processing

    NASA Astrophysics Data System (ADS)

    Bi, Jianhong; Zhao, Jinglan; Bao, Lang; Liu, Yan; Wu, Caosong

    2008-11-01

    This paper reports the use of a coating process based on supercritical fluid technology to prepare a solvent-free microparticles, loaded with a polymannopeptide (polyactin A, PAA) for enhancing optimal host response in cancer immunotherapy. Microparticles were characterized as regards their morphology, drug content and in vitro release. A prolonged release of the PAA had been achieved over a 24 h period from microparticles coated with the lipidic compound, which produced a more homogeneous, film-forming coating. Furthermore, it was shown that PAA did not undergo any degradation under the supercritical conditions used in the coating process. In vitro immunoactivity and anti-tumor effect analysis results showed that the PAA microparticle could efficiently trigger the induction of cytotoxic T lymphocytes (CTLs) in a sustained manner.

  8. Dusty plasma microparticle cloud control and rapid electrostatic mutual-repulsion expansion in a DC glow discharge

    NASA Astrophysics Data System (ADS)

    Gillman, Eric; Amatucci, Bill

    2016-10-01

    Microparticles in plasma discharges rapidly charge up, typically collecting a net negative charge due to the relatively high mobility of electrons compared to ions. Electrostatic forces can be utilized to control charged microparticle behavior and motion in a plasma discharge. In these experiments a metal wire loop is supplied with an electric potential that can be controlled independently from the DC plasma glow discharge electrodes. By varying the voltage on the wire loop, we can attract, trap, manipulate, suspend, and/or repel microparticles that originate from the DC glow discharge. Experiments studied the properties of electrostatic self-repulsion of a cloud of charged microparticles. By pulsing the plasma and controlling wire loop potential, a cloud of trapped microparticles is released and allowed to rapidly expand. A simple force balance simulation code is used as a model to compare and benchmark actual experimental results. This work was supported by the Naval Research Laboratory base program.

  9. Coordinated airborne, space borne, and ground based measurements of massive, thick haze layers during the SAFARI-2000 Dry Season Campaign

    NASA Astrophysics Data System (ADS)

    Schmid, B.; Russell, P.; Pilewskie, P.; Redemann, J.; Hobbs, P.; Holben, B.; Welton, E.; Campbell, J.; Hlavka, D.; McGill, M.; Chu, A.; Remer, L.; Torres, O.; Kahn, R.

    2001-12-01

    From August 13 to September 25, the Southern African Regional Science Initiative's (SAFARI 2000) dry-season airborne campaign coordinated ground-based measurement teams, multiple research aircraft, and satellite overpasses across nine African nations. Among many others, unique coordinated observations were made of the evolution of massive, thick haze layers produced by biomass burning, industrial emissions, marine and biogenic sources. The NASA Ames Airborne Tracking 14-channel Sunphotometer (AATS-14) was operated successfully aboard the University of Washington CV-580 during 24 data flights. The AATS-14 instrument measures the transmission of the direct solar beam at 14 discrete wavelengths (354-1558 nm) from which we derive spectral aerosol optical depths (AOD), columnar water vapor (CWV) and columnar ozone. Flying at different altitudes over a fixed location allows derivation of layer AOD and CWV. Data taken during feasible vertical profiles allows derivation of aerosol extinction and water vapor density. In the talk, we show comparisons with ground-based AERONET sun/sky photometer results, with ground based MPL-Net lidar data, and with measurements from a lidar (CPL) aboard the high-flying ER-2 aircraft. We will use measurements from the Ames Solar Spectral Flux Radiometer to derive estimates of solar spectral forcing as a function of aerosol thickness. Validations of MODIS, MISR and TOMS satellite aerosol and water vapor retrievals will also be presented.

  10. Extraction of Urban Trees from Integrated Airborne Based Digital Image and LIDAR Point Cloud Datasets - Initial Results

    NASA Astrophysics Data System (ADS)

    Dogon-yaro, M. A.; Kumar, P.; Rahman, A. Abdul; Buyuksalih, G.

    2016-10-01

    Timely and accurate acquisition of information on the condition and structural changes of urban trees serves as a tool for decision makers to better appreciate urban ecosystems and their numerous values which are critical to building up strategies for sustainable development. The conventional techniques used for extracting tree features include; ground surveying and interpretation of the aerial photography. However, these techniques are associated with some constraint, such as labour intensive field work, a lot of financial requirement, influences by weather condition and topographical covers which can be overcome by means of integrated airborne based LiDAR and very high resolution digital image datasets. This study presented a semi-automated approach for extracting urban trees from integrated airborne based LIDAR and multispectral digital image datasets over Istanbul city of Turkey. The above scheme includes detection and extraction of shadow free vegetation features based on spectral properties of digital images using shadow index and NDVI techniques and automated extraction of 3D information about vegetation features from the integrated processing of shadow free vegetation image and LiDAR point cloud datasets. The ability of the developed algorithms shows a promising result as an automated and cost effective approach to estimating and delineated 3D information of urban trees. The research also proved that integrated datasets is a suitable technology and a viable source of information for city managers to be used in urban trees management.

  11. Airborne Particles.

    ERIC Educational Resources Information Center

    Ojala, Carl F.; Ojala, Eric J.

    1987-01-01

    Describes an activity in which students collect airborne particles using a common vacuum cleaner. Suggests ways for the students to convert their data into information related to air pollution and human health. Urges consideration of weather patterns when analyzing the results of the investigation. (TW)

  12. Airborne Imagery

    NASA Technical Reports Server (NTRS)

    1983-01-01

    ATM (Airborne Thematic Mapper) was developed for NSTL (National Space Technology Companies) by Daedalus Company. It offers expanded capabilities for timely, accurate and cost effective identification of areas with prospecting potential. A related system is TIMS, Thermal Infrared Multispectral Scanner. Originating from Landsat 4, it is also used for agricultural studies, etc.

  13. Airborne Laser Scanning - based vegetation classification in grasslands: a feasibility study

    NASA Astrophysics Data System (ADS)

    Zlinszky, András; Vári, Ágnes; Deák, Balázs; Mücke, Werner; Székely, Balázs

    2013-04-01

    Airborne Laser Scanning is traditionally used for topography mapping, exploiting its ability to map terrain elevation under vegetation cover. Parallel to this, the application of ALS for vegetation classification and mapping of ecological variables is rapidly emerging. Point clouds surveyed by ALS provide accurate representations of vegetation structure and are therefore considered suitable for mapping vegetation classes as long as their vertical structure is characteristic. For this reason, most ALS-based vegetation mapping studies have been carried out in forests, with some rare applications for shrublands or tall grass vegetation such as reeds. The use of remote-sensing derived vegetation maps is widespread in ecological research and is also gaining importance in practical conservation. There is an increasing demand for reliable, high-resolution datasets covering large protected areas. ALS can provide both the coverage and the high resolution, and can prove to be an economical solution due to the potential for automatic processing and the wide range of uses that allows spreading costs. Grasslands have a high importance in nature conservation as due to the drastical land use changes (arable lands, afforestation, fragmentation by linear structures) in the last centuries the extent of these habitats have been considerably reduced. Among the habitat types protected by the Habitat Directive of the Natura 2000 system, several grassland habitat types (e.g. hay meadows, dry grasslands harbouring rare Orchid species) have special priority for conservation. For preserving these habitat types application of a proper management - including mowing or grazing - has a crucial role. Therefore not only the mapping of the locations of habitats but the way of management is needed for representing the natural processes. The objective of this study was to test the applicability of airborne laser scanning for ecological vegetation mapping in and around grasslands. The study site is

  14. Investigating Baseline, Alternative and Copula-based Algorithm for combining Airborne Active and Passive Microwave Observations in the SMAP Context

    NASA Astrophysics Data System (ADS)

    Montzka, C.; Lorenz, C.; Jagdhuber, T.; Laux, P.; Hajnsek, I.; Kunstmann, H.; Entekhabi, D.; Vereecken, H.

    2015-12-01

    The objective of the NASA Soil Moisture Active & Passive (SMAP) mission is to provide global measurements of soil moisture and freeze/thaw states. SMAP integrates L-band radar and radiometer instruments as a single observation system combining the respective strengths of active and passive remote sensing for enhanced soil moisture mapping. Airborne instruments will be a key part of the SMAP validation program. Here, we present an airborne campaign in the Rur catchment, Germany, in which the passive L-band system Polarimetric L-band Multi-beam Radiometer (PLMR2) and the active L-band system F-SAR of DLR were flown simultaneously on the same platform on six dates in 2013. The flights covered the full heterogeneity of the area under investigation, i.e. all types of land cover and experimental monitoring sites with in situ sensors. Here, we used the obtained data sets as a test-bed for the analysis of three active-passive fusion techniques: A) The SMAP baseline algorithm: Disaggregation of passive microwave brightness temperature by active microwave backscatter and subsequent inversion to soil moisture, B), the SMAP alternative algorithm: Estimation of soil moisture by passive sensor data and subsequent disaggregation by active sensor backscatter and C) Copula-based combination of active and passive microwave data. For method C empirical Copulas were generated and theoretical Copulas fitted both on the level of the raw products brightness temperature and backscatter as well as two soil moisture products. Results indicate that the regression parameters for method A and B are dependent on the radar vegetation index (RVI). Similarly, for method C the best performance was gained by generating separate Copulas for individual land use classes. For more in-depth analyses longer time series are necessary as can obtained by airborne campaigns, therefore, the methods will be applied to SMAP data.

  15. Mapping, Assessment and Analysis of Large-Scale Landslides Based on Airborne LIDAR Data

    NASA Astrophysics Data System (ADS)

    Elsner, Bernhard

    2015-04-01

    In the context of the integrated risk management of the Austrian Service for Torrent and Avalanche Control (WLV) large-scale landslides - per definition only areas larger than 10 ha - were mapped in a study area in the South of Innsbruck/Tyrol. The large-scale landslides to be identified are mostly very slow and deep-seated including complex processes like mountain slope deformations ("Talzuschübe"). The mapping method for the first time developed in this study is based on hillshades of high-resolution airborne LIDAR data which recently has been made nearly nationwide available for Austria. These data have the advantage faced with other remote-sensing data like orthophotos that dense and high vegetation and other distracting objects on the ground are eliminated. This guarantees everywhere a high visibility of the terrain surface which is very helpful for the detection of landslides. These aspects allowed developing a new systematic approach for the identification and rough classification of large-scale landslides according to their activity. Using an iterative comparison of first results with other existing methods and field observations the methodology was developed as objective as possible. For this reason these landslides are divided in four distinct segments showing typical characteristics like double ridges or a surface of rupture. According to the characteristics and to the importance of these four segments all detected landslides are then assigned to one of the four classes of activity: "active", "likely active", "inactive" or "possibly inactive". Using this method, large-scale landslides were identified in 26 % of the entire study area. The major part of these landslides (65 %) is supposed to be "inactive" and only 0.5 % are classified as "active". In addition some analyses in the context of natural hazard research were carried out to interpret the quantitative occurrence and spatial distribution of the mapped landslides. Glacial overdeepening in valleys

  16. Precise mapping of annual river bed changes based on airborne laser bathymetry

    NASA Astrophysics Data System (ADS)

    Mandlburger, Gottfried; Wieser, Martin; Pfeifer, Norbert; Pfennigbauer, Martin; Steinbacher, Frank; Aufleger, Markus

    2014-05-01

    Airborne Laser Bathymtery (ALB) is a method for capturing relatively shallow water bodies from the air using a pulsed green laser (wavelength=532nm). While this technique was first used for mapping coastal waters only, recent progress in sensor technology has opened the field to apply ALB to running inland waters. Especially for alpine rivers the precise mapping of the channel topography is a challenging task as the flow velocities are often high and the area is difficult and/or dangerous to access by boat or by feet. Traditional mapping techniques like tachymetry or echo sounding fail in such situations while ALB provides, both, high spot position accuracy in the cm range and high spatial resolution in the dm range. Furthermore, state-of-the-art ALB systems allow simultaneous mapping of the river bed and the riparian area and, therefore, represent a comprehensive and efficient technology for mapping the entire floodplain area. The maximum penetration depth depends on, both, water turbidity and bottom reflectivity. Consequently, ALB provides the highest accuracy and resolution over bright gravel rivers with relatively clear water. We demonstrate the capability of ALB for precise mapping of river bed changes based on three flight campaigns in April, May and October 2013 at the River Pielach (Lower Austria) carried out with Riegl's VQ-820-G topo-bathymetric laser scanner. Operated at a flight height of 600m above ground with a pulse repetition rate of 510kHz (effective measurement rate 200kHz) this yielded a mean point spacing within the river bed of 20cm (i.e. point density: 25 points/m2). The positioning accuracy of the river bed points is approx. 2-5cm and depends on the overall ranging precision (20mm), the quality of the water surface model (derived from the ALB point cloud), and the signal intensity (decreasing with water depth). All in all, the obtained point cloud allowed the derivation of a dense grid model of the channel topography (0.25m cell size) for all

  17. Controlled release of an extract of Calendula officinalis flowers from a system based on the incorporation of gelatin-collagen microparticles into collagen I scaffolds: design and in vitro performance.

    PubMed

    Jiménez, Ronald A; Millán, Diana; Suesca, Edward; Sosnik, Alejandro; Fontanilla, Marta R

    2015-06-01

    Aiming to develop biological skin dresses with improved performance in the treatment of skin wounds, acellular collagen I scaffolds were modified with polymeric microparticles and the subsequent loading of a hydroglycolic extract of Calendula officinalis flowers. Microparticles made of gelatin-collagen were produced by a water-in-oil emulsion/cross-linking method. Thereafter, these microparticles were mixed with collagen suspensions at three increasing concentrations and the resulting mixtures lyophilized to make microparticle-loaded porous collagen scaffolds. Resistance to enzymatic degradation, ability to associate with the C. officinalis extract, and the extract release profile of the three gelatin-collagen microparticle-scaffold prototypes were assessed in vitro and compared to collagen scaffolds without microparticles used as control. Data indicated that the incorporation of gelatin-collagen microparticles increased the resistance of the scaffolds to in vitro enzymatic degradation, as well as their association with the C. officinalis flower extract. In addition, a sharp decrease in cytotoxicity, as well as more prolonged release of the extract, was attained. Overall results support the potential of these systems to develop innovative dermal substitutes with improved features. Furthermore, the gelatin-collagen mixture represents a low-cost and scalable alternative with high clinical transferability, especially appealing in developing countries.

  18. Cefazolin-loaded mesoporous silicon microparticles show sustained bactericidal effect against Staphylococcus aureus

    PubMed Central

    Yazdi, Iman K; Murphy, Matthew B; Loo, Christopher; Liu, Xuewu; Ferrari, Mauro; Weiner, Bradley K

    2014-01-01

    Cefazolin is an antibiotic frequently used in preoperative prophylaxis of orthopedic surgery and to fight secondary infections post-operatively. Although its systemic delivery in a bulk or bolus dose is usually effective, the local and controlled release can increase its effectiveness by lowering dosages, minimizing total drug exposure, abating the development of antibiotic resistance and avoiding the cytotoxic effect. A delivery system based on mesoporous silicon microparticles was developed that is capable of efficiently loading and continuously releasing cefazolin over several days. The in vitro release kinetics from mesoporous silicon microparticles with three different nanopore sizes was evaluated, and minimal inhibitory concentration of cefazolin necessary to eliminate a culture of Staphylococcus aureus was identified to be 250 µg/mL. A milder toxicity toward mesenchymal stem cells was observed from mesoporous silicon microparticles over a 7-day period. Medium pore size-loaded mesoporous silicon microparticles exhibited long-lasting bactericidal properties in a zone inhibition assay while they were able to kill all the bacteria growing in suspension cultures within 24 h. This study demonstrates that the sustained release of cefazolin from mesoporous silicon microparticles provides immediate and long-term control over bacterial growth both in suspension and adhesion while causing minimal toxicity to a population of mesenchymal stem cell. Mesoporous silicon microparticles offer significant advantageous properties for drug delivery applications in tissue engineering as it favorably extends drug bioavailability and stability, while reducing concomitant cytotoxicity to the surrounding tissues. PMID:24904728

  19. Furosemide Loaded Silica-Lipid Hybrid Microparticles: Formulation Development, in vitro and ex vivo Evaluation

    PubMed Central

    Sambaraj, Swapna; Ammula, Divya; Nagabandi, Vijaykumar

    2015-01-01

    Purpose: The main objective of the current research work was to formulate and evaluate furosemide loaded silica lipid hybrid microparticles for improved oral delivery. A novel silica-lipid hybrid microparticulate system is used for enhancing the oral absorption of low solubility and low permeability of (BCS Class IV) drugs. Silica-lipid hybrid microparticles include the drug solubilising effect of dispersed lipids and stabilizing effect of hydrophilic silica particles to increase drug solubilisation, which leads to enhanced oral bioavailability. Methods: The slica lipid hybrid (SLH) microparticles were composed of poorly soluble drug (furosemide), dispersion of oil phase (Soya bean oil and miglyol) in lecithin (Phospholipoid 90H), non-ionic surfactant (Polysorbate 80) and adsorbent (Aerosol 380). Saturation solubility studies were performed in different oils and surfactants with increased concentration of drug revealed increased solubility of furosemide. Results: In vitro dissolution studies conducted under simulated gastric medium revealed 2-4 fold increase in dissolution efficiencies for SLH microparticles compared to that of pure drug (furosemide) and marketed formulation Lasix®. Ex vivo studies showed enhanced lipid digestibility, which improved drug permeability. Solid-state characterization of SLH microparticles by X-ray powder diffraction and Fourier transform infrared spectroscopic analysis confirmed non-crystalline nature and more compatibility of furosemide in silica-lipid hybrid microparticles. Conclusion: It can be concluded that the role of lipids and hydrophilic silica based carrier highlighted in enhancing solubility and permeability, and hence the oral bioavailability of poorly soluble drugs. PMID:26504763

  20. Height-resolved Scaling Properties of Tropospheric Water Vapour based on Airborne Lidar Observations

    NASA Astrophysics Data System (ADS)

    Kiemle, Christoph; Fischer, Lucas; Craig, George C.

    2013-04-01

    Two-dimensional vertical water vapour cross sections of the free troposphere between altitudes of 2 and 10 km, measured by nadir-viewing airborne differential-absorption lidar with high spatial resolution, were analyzed using structure functions up to the fifth order. We found scale invariance, i.e. a power-law dependency of structure function on length scale, for scales between 5 and 100 km, for the horizontal time series of water vapour mixing ratio. In contrast to one-dimensional in situ measurements, the two-dimensional water vapor lidar observations allow height-resolved analyses of power-law scaling exponents at a vertical resolution of 200 m. The data reveal significantly different scaling properties above and below an air-mass boundary. They stem from three very dissimilar aircraft campaigns: COPS/ETReC over middle and southern Europe in summer 2007, T-PARC around Japan mostly over sea in late summer 2008, and T-IPY around Spitsbergen over sea in winter 2008. After discarding flight segments with low lidar signals or large data gaps, and after averaging horizontally to a resolution of between 1 and 5 km to obtain a high signal to noise ratio, structure functions were computed for 20 flights at various heights, adding up to a length of more than 300,000 km. The power-law scaling exponents of the structure functions do not show significant latitudinal, seasonal or land/sea dependency, but they do differ between air masses influenced by moist convection and air masses aloft, not influenced. A classification of the horizontal water vapour time series into two groups according to whether the series occurred above or below the level of nearby convective cloud tops could be performed by detecting the cloud top height from the lidar backscatter signal in the corresponding flight segment. We found that the scaling exponents can be divided into two groups depending on the respective air mass: The smoothness of the time series, expressed by the first-order scaling

  1. Nitric oxide scavenging by red cell microparticles.

    PubMed

    Liu, Chen; Zhao, Weixin; Christ, George J; Gladwin, Mark T; Kim-Shapiro, Daniel B

    2013-12-01

    Red cell microparticles form during the storage of red blood cells and in diseases associated with red cell breakdown and asplenia, including hemolytic anemias such as sickle cell disease. These small phospholipid vesicles that are derived from red blood cells have been implicated in the pathogenesis of transfusion of aged stored blood and hemolytic diseases, via activation of the hemostatic system and effects on nitric oxide (NO) bioavailability. Red cell microparticles react with the important signaling molecule NO almost as fast as cell-free hemoglobin, about 1000 times faster than red-cell-encapsulated hemoglobin. The degree to which this fast reaction with NO by red cell microparticles influences NO bioavailability depends on several factors that are explored here. In the context of stored blood preserved in ADSOL, we find that both cell-free hemoglobin and red cell microparticles increase as a function of duration of storage, and the proportion of extra erythrocytic hemoglobin in the red cell microparticle fraction is about 20% throughout storage. Normalized by hemoglobin concentration, the NO-scavenging ability of cell-free hemoglobin is slightly higher than that of red cell microparticles as determined by a chemiluminescence NO-scavenging assay. Computational simulations show that the degree to which red cell microparticles scavenge NO will depend substantially on whether they enter the cell-free zone next to the endothelial cells. Single-microvessel myography experiments performed under laminar flow conditions demonstrate that microparticles significantly enter the cell-free zone and inhibit acetylcholine, endothelial-dependent, and NO-dependent vasodilation. Taken together, these data suggest that as little as 5 μM hemoglobin in red cell microparticles, an amount formed after the infusion of one unit of aged stored packed red blood cells, has the potential to reduce NO bioavailability and impair endothelial-dependent vasodilation.

  2. Relating urban airborne particle concentrations to shipping using carbon based elemental emission ratios

    NASA Astrophysics Data System (ADS)

    Johnson, Graham R.; Juwono, Alamsyah M.; Friend, Adrian J.; Cheung, Hing-Cho; Stelcer, Eduard; Cohen, David; Ayoko, Godwin A.; Morawska, Lidia

    2014-10-01

    This study demonstrates a novel method for testing the hypothesis that variations in primary and secondary particle number concentration (PNC) in urban air are related to residual fuel oil combustion at a coastal port lying 30 km upwind, by examining the correlation between PNC and airborne particle composition signatures chosen for their sensitivity to the elemental contaminants present in residual fuel oil. Residual fuel oil combustion indicators were chosen by comparing the sensitivity of a range of concentration ratios to airborne emissions originating from the port. The most responsive were combinations of vanadium and sulphur concentration ([S], [V]) expressed as ratios with respect to black carbon concentration ([BC]). These correlated significantly with ship activity at the port and with the fraction of time during which the wind blew from the port. The average [V] when the wind was predominantly from the port was 0.52 ng m-3 (87%) higher than the average for all wind directions and 0.83 ng m-3 (280%) higher than that for the lowest vanadium yielding wind direction considered to approximate the natural background. Shipping was found to be the main source of V impacting urban air quality in Brisbane. However, contrary to the stated hypothesis, increases in PNC related measures did not correlate with ship emission indicators or ship traffic. Hence at this site ship emissions were not found to be a major contributor to PNC compared to other fossil fuel combustion sources such as road traffic, airport and refinery emissions.

  3. Distance measurement to high remote targets based on the airborne chaotic laser

    NASA Astrophysics Data System (ADS)

    Kou, Renke; Wang, Haiyan; Wu, Xueming

    2016-10-01

    According to the characteristics of chaotic laser, which has ability of novel anti-jamming, high bandwidth and detecting distance of the movement target to the millimeter precision, a modeling method of using airborne chaotic laser system to detect distance of high remote targets is proposed for the first time. The characteristics of chaotic laser and principle of interferometry distance were analyzed and the model of airborne chaotic laser ranging is established. Meanwhile, the influence of detection accuracy, which inducted by the main peak width of chaotic laser and the jamming signal is analyzed. According to the results of simulation analysis, we can get conclusions that the main factors of affecting the distance measurement are transmitted power, receiving sensitivity, and various losses of transmission medium. Autocorrelation characteristic of chaotic signal can also affect the dynamic range of the whole system. The main peak width of chaotic laser is the main factor of influencing the accuracy of measurement. However, the jamming signal affect distance measuring range and accuracy of measurement little. Finally, the model's effectiveness is proved by comparing the experience data and simulation data.

  4. Detection of trees using airborne lidar data based on ArcGIS

    NASA Astrophysics Data System (ADS)

    Tang, Feifei; Liu, Jingnan; Zhang, Xiaohong

    2006-10-01

    In this article, we use the height difference between the first pulse and last pulse recorded by the airborne laser scanning system to implement a strategy for detection of trees, especially for relatively tall trees. The airborne lidar data we use include 3D coordinates and intensity information of first pulse and last pulse respectively, and the image file of the test area are also available. ArcGIS version 9.0, has been used as the implementation platform as which as effective data processing function and outstanding performance of data analysis such as TIN interpolation and 3D display. To extract trees from the raw data, the data is loaded into ArcGIS to create shapefile recognized by ArcGIS at first, and the corresponding attributes, coordinates, intensity and height difference computed by programming are stored. Then we select the data accord with the filtering condition, a threshold for height difference is given. All the comparisons of 3D coordinates and intensity occur between point data in the same row, in other words, between the first pulse and last pulse. We accept the first pulse which satisfies the height difference threshold as vegetation points. At last, a considerable result of detection of trees has been achieved.

  5. Combining ground-based and airborne EM through Artificial Neural Networks for modelling hydrogeological units under saline groundwater conditions

    NASA Astrophysics Data System (ADS)

    Gunnink, J. L.; Bosch, J. H. A.; Siemon, B.; Roth, B.; Auken, E.

    2012-03-01

    Airborne Electro Magnetic (EM) methods supply data over large areas in a cost-effective way. We used Artificial Neural Networks (ANN) to classify the geophysical signal into a meaningful geological parameter. By using examples of known relations between ground-based geophysical data (in this case electrical conductivity, EC, from Electrical Cone Penetration Tests) and geological parameters (presence of glacial till), we extracted learning rules that could be applied to map the presence of a glacial till using the EC profiles from the airborne EM data. The saline groundwater in the area was obscuring the EC signal from the till but by using ANN we were able to extract subtle and often non-linear, relations in EC that were representative for the presence of the till. The ANN results were interpreted as the probability of having till and showed a good agreement with drilling data. The glacial till is acting as a layer that inhibits groundwater flow, due to its high clay-content, and is therefore an important layer in hydrogeological modelling and for predicting the effects of climate change on groundwater quantity and quality.

  6. Hydrogel microparticles for biosensing

    PubMed Central

    Le Goff, Gaelle C.; Srinivas, Rathi L.; Hill, W. Adam; Doyle, Patrick S.

    2015-01-01

    Due to their hydrophilic, biocompatible, and highly tunable nature, hydrogel materials have attracted strong interest in the recent years for numerous biotechnological applications. In particular, their solution-like environment and non-fouling nature in complex biological samples render hydrogels as ideal substrates for biosensing applications. Hydrogel coatings, and later, gel dot surface microarrays, were successfully used in sensitive nucleic acid assays and immunoassays. More recently, new microfabrication techniques for synthesizing encoded particles from hydrogel materials have enabled the development of hydrogel-based suspension arrays. Lithography processes and droplet-based microfluidic techniques enable generation of libraries of particles with unique spectral or graphical codes, for multiplexed sensing in biological samples. In this review, we discuss the key questions arising when designing hydrogel particles dedicated to biosensing. How can the hydrogel material be engineered in order to tune its properties and immobilize bioprobes inside? What are the strategies to fabricate and encode gel particles, and how can particles be processed and decoded after the assay? Finally, we review the bioassays reported so far in the literature that have used hydrogel particle arrays and give an outlook of further developments of the field. PMID:26594056

  7. Routing architecture and security for airborne networks

    NASA Astrophysics Data System (ADS)

    Deng, Hongmei; Xie, Peng; Li, Jason; Xu, Roger; Levy, Renato

    2009-05-01

    Airborne networks are envisioned to provide interconnectivity for terrestial and space networks by interconnecting highly mobile airborne platforms. A number of military applications are expected to be used by the operator, and all these applications require proper routing security support to establish correct route between communicating platforms in a timely manner. As airborne networks somewhat different from traditional wired and wireless networks (e.g., Internet, LAN, WLAN, MANET, etc), security aspects valid in these networks are not fully applicable to airborne networks. Designing an efficient security scheme to protect airborne networks is confronted with new requirements. In this paper, we first identify a candidate routing architecture, which works as an underlying structure for our proposed security scheme. And then we investigate the vulnerabilities and attack models against routing protocols in airborne networks. Based on these studies, we propose an integrated security solution to address routing security issues in airborne networks.

  8. Biomass Burning Airborne and Spaceborne Experiment in the Amazonas (BASE-A)

    NASA Technical Reports Server (NTRS)

    Kaufman, Y. J.; Setzer, A.; Ward, D.; Tanre, D.; Holben, B. N.; Menzel, P.; Pereira, M. C.; Rasmussen, R.

    1992-01-01

    Results are presented on measurements of the trace gas and particulate matter emissions due to biomass burning during deforestation and grassland fires in South America, conducted as part of the Biomass Burning Airborne and Spaceborne Experiment in the Amazonas in September 1989. Field observations by an instrumented aircraft were used to estimate concentrations of O3, CO2, CO, CH4, and particulate matter. Fires were observed from satellite imagery, and the smoke optical thickness, particle size, and profiles of the extinction coefficient were measured from the aircraft and from the ground. Four smoke plumes were sampled, three vertical profiles were measured, and extensive ground measurements of smoke optical characteristics were carried out for different smoke types. The simultaneous measurements of the trace gases, smoke particles, and the distribution of fires were used to correlate biomass burning with the elevated levels of ozone.

  9. Comparison of Airborne and Ground-Based Function Allocation Concepts for NextGen Using Human-In-The-Loop Simulations

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Prevot, Thomas; Murdoch, Jennifer L.; Cabrall, Christopher D.; Homola, Jeffrey R.; Martin, Lynne H.; Mercer, Joey S.; Hoadley, Sherwood T.; Wilson, Sara R.; Hubbs, Clay E.; Chamberlain, James P.; Chartrand, Ryan C.; Consiglio, Maria C.; Palmer, Michael T.

    2010-01-01

    This paper presents an air/ground functional allocation experiment conducted by the National Aeronautics and Space Administration (NASA) using two human-in-the-Loop simulations to compare airborne and ground-based approaches to NextGen separation assurance. The approaches under investigation are two trajectory-based four-dimensional (4D) concepts; one referred to as "airborne trajectory management with self-separation" (airborne) the other as "ground-based automated separation assurance" (ground-based). In coordinated simulations at NASA's Ames and Langley Research Centers, the primary operational participants -controllers for the ground-based concept and pilots for the airborne concept - manage the same traffic scenario using the two different 4D concepts. The common scenarios are anchored in traffic problems that require a significant increase in airspace capacity - on average, double, and in some local areas, close to 250% over current day levels - in order to enable aircraft to safely and efficiently traverse the test airspace. The simulations vary common independent variables such as traffic density, sequencing and scheduling constraints, and timing of trajectory change events. A set of common metrics is collected to enable a direct comparison of relevant results. The simulations will be conducted in spring 2010. If accepted, this paper will be the first publication of the experimental approach and early results. An initial comparison of safety and efficiency as well as operator acceptability under the two concepts is expected.

  10. Airborne Precision Spacing: A Trajectory-based Approach to Improve Terminal Area Operations

    NASA Technical Reports Server (NTRS)

    Barmore, Bryan

    2006-01-01

    Airborne Precision Spacing has been developed by the National Aeronautics and Space Administration (NASA) over the past seven years as an attempt to benefit from the capabilities of the flight deck to precisely space their aircraft relative to another aircraft. This development has leveraged decades of work on improving terminal area operations, especially the arrival phase. With APS operations, the air traffic controller instructs the participating aircraft to achieve an assigned inter-arrival spacing interval at the runway threshold, relative to another aircraft. The flight crew then uses airborne automation to manage the aircraft s speed to achieve the goal. The spacing tool is designed to keep the speed within acceptable operational limits, promote system-wide stability, and meet the assigned goal. This reallocation of tasks with the controller issuing strategic goals and the flight crew managing the tactical achievement of those goals has been shown to be feasible through simulation and flight test. A precision of plus or minus 2-3 seconds is generally achievable. Simulations of long strings of arriving traffic show no signs of instabilities or compression waves. Subject pilots have rated the workload to be similar to current-day operations and eye-tracking data substantiate this result. This paper will present a high-level review of research results over the past seven years from a variety of tests and experiments. The results will focus on the precision and accuracy achievable, flow stability and some major sources of uncertainty. The paper also includes a summary of the flight crew s procedures and interface and a brief concept overview.

  11. A microfluidics-based on-chip impinger for airborne particle collection.

    PubMed

    Mirzaee, I; Song, M; Charmchi, M; Sun, H

    2016-06-21

    Capturing airborne particles from air into a liquid is a critical process for the development of many sensors and analytical systems. A miniaturized airborne particle sampling device (microimpinger) has been developed in this research. The microimpinger relies on a controlled bubble generation process produced by driving air through microchannel arrays. The particles confined in the microscale bubbles are captured in the sampling liquid while the bubbles form, are released and travel in a millimetre-scale sealed liquid reservoir. The microchannel arrays in the impinger are fabricated using a soft-lithography method with polydimethylsiloxane (PDMS) as the structural material. To prevent air leakage at the connections, a PDMS-only sealing technique is successfully developed. The hydrophobicity of the microchannel surface is found to be critical for generating continuous and stable bubbles in the bubbling process. A Teflon layer is coated on the walls of a microchannel array by vapor deposition which effectively increases the hydrophobicity of the PDMS. The collection efficiency of the microimpinger is measured by counting different sizes of fluorescent polystyrene latex particles on polycarbonate membrane filters. Collection efficiencies above 90% are achieved. Furthermore, the particle capturing mechanisms during the injection, formation and rise of a single microbubble are investigated by a computational fluid dynamics (CFD) model. The Navier-Stokes equations are solved along with the use of the volume-of-fluid (VOF) method to capture the bubble deformations and the particles are tracked using a Lagrangian equation of motion. The model is also employed to study the effect of bubble size on the collection efficiency of the microimpinger.

  12. Local coordination and dynamics of a protic ammonium based ionic liquid immobilized in nano-porous silica micro-particles probed by Raman and NMR spectroscopy.

    PubMed

    Garaga, Mounesha N; Persson, Michael; Yaghini, Negin; Martinelli, Anna

    2016-03-07

    Room temperature ionic liquids confined in a solid material, for example, nano-porous silica, are particularly propitious for energy related applications. The aim of this study is to probe the molecular interactions established between the protic ionic liquid diethylmethylammonium methanesulfonate (DEMA-OMs) and silica, where the latter consists of nano-porous micro-particles with pores in the size range of 10 nm. The changes in the local coordination and transport properties induced by the nano-confinement of the ionic liquid are investigated by a combination of Raman and solid-state NMR spectroscopy. In particular, one-dimensional (1D) (1)H and (29)Si and two-dimensional (2D) (29)Si{(1)H} HETOCR solid-state NMR are combined to identify the sites of interaction at the silica-ionic liquid interface. Pulsed field gradient (PFG) NMR experiments are performed to estimate the self-diffusion of both bulk and nano-confined DEMA-OMs. Complementary information on the overall coordination and interaction scheme is achieved by Raman spectroscopy. All these advanced experimental techniques are revealed to be crucial to differentiate between ionic liquid molecules residing in the inter- or intra-particle domains.

  13. Coupled solid phase extraction and microparticle-based stability and purity-indicating immunosensor for the determination of recombinant human myelin basic protein in transgenic milk.

    PubMed

    Al-Ghobashy, Medhat A; Williams, Martin A K; Laible, Götz; Harding, David R K

    2013-05-15

    An optical immunosensor was developed and validated on the surface of microparticles for the determination of a biopharmaceutical protein. The recombinant human myelin basic protein (rhMBP) was produced in milk of transgenic cows as a His-tagged fusion protein. Previous work indicated exclusive association of rhMBP with milk casein micelles that hindered direct determination of the protein in milk. In this work, a solid phase extraction using a cation exchange matrix was developed in order to liberate rhMBP from casein micelles. A sandwich-type immunoassay was then used for in-process monitoring of the full-length protein in the presence of major milk proteins. The assay was successfully employed for detection of ultra-traces of rhMBP (LOD=6.04 ng mL(-1)≈0.3 n mol L(-1)) and for quantitative determination over a wide concentration range (10.00-10,000.00 ng mL(-1)). The assay was able also to detect the rhMBP in the presence of its human counterpart that lacks the His-tag. The high sensitivity along with the ability of the assay to determine the full length protein enabled monitoring of the stability of rhMBP. The testing protocol is particularly useful for intrinsically unstructured proteins that are extremely sensitive to proteolysis and lack a traceable enzymatic activity. This immunosensor provides a specific, ultrasensitive high throughput tool for in-process monitoring in biopharmaceutical industry.

  14. Initial Results from the DEEPWAVE Airborne and Ground-Based Measurement Program in New Zealand in 2014

    NASA Astrophysics Data System (ADS)

    Fritts, Dave; Smith, Ron; Taylor, Mike; Doyle, Jim; Eckermann, Steve; Dörnbrack, Andreas; Rapp, Markus; Williams, Biff; Bossert, Katrina; Pautet, Dominique

    2015-04-01

    The deep-propagating gravity wave experiment (DEEPWAVE) was performed on and over New Zealand, Tasmania, the Tasman Sea, and the Southern Ocean with core airborne measurements extending from 5 June to 21 July 2014 and supporting ground-based measurements beginning in late May and extending beyond the airborne component. DEEPWAVE employed two aircraft, the NSF/NCAR GV and the German DLR Falcon. The GV carried the standard flight-level instruments, dropsondes, and the Microwave Temperature Profiler (MTP). It also hosted new airborne lidar and imaging instruments built specifically to allow quantification of gravity waves (GWs) from sources at lower altitudes (e.g., orography, convection, jet streams, fronts, and secondary GW generation) throughout the stratosphere and into the mesosphere and lower thermosphere (MLT). The new GV lidars included a Rayleigh lidar measuring atmospheric density and temperature from ~20-60 km and a sodium resonance lidar measuring sodium density and temperature at ~75-100 km. An airborne Advanced Mesosphere Temperature Mapper (AMTM) was also developed for the GV, and together with additional IR "wing" cameras, imaged the OH airglow temperature and/or intensity fields extending ~900 km across the GV flight track. The DLR Falcon was equipped with its standard flight-level instruments and an aerosol Doppler lidar able to measure radial winds below the Falcon where aerosol backscatter was sufficient. Additional ground-based instruments included a 449 MHz boundary layer radar, balloons at multiple sites, two ground-based Rayleigh lidars, a second ground-based AMTM, a Fabry Perot interferometer measuring winds and temperatures at ~87 and 95 km, and a meteor radar measuring winds from ~80-100 km. DEEPWAVE performed 26 GV flights, 13 Falcon flights, and an extensive series of ground-based measurements whether or not the aircraft were flying. Together, these observed many diverse cases of GW forcing, propagation, refraction, and dissipation

  15. Trojan Microparticles for Drug Delivery

    PubMed Central

    Anton, Nicolas; Jakhmola, Anshuman; Vandamme, Thierry F.

    2012-01-01

    During the last decade, the US Food and Drug Administration (FDA) have regulated a wide range of products, (foods, cosmetics, drugs, devices, veterinary, and tobacco) which may utilize micro and nanotechnology or contain nanomaterials. Nanotechnology allows scientists to create, explore, and manipulate materials in nano-regime. Such materials have chemical, physical, and biological properties that are quite different from their bulk counterparts. For pharmaceutical applications and in order to improve their administration (oral, pulmonary and dermal), the nanocarriers can be spread into microparticles. These supramolecular associations can also modulate the kinetic releases of drugs entrapped in the nanoparticles. Different strategies to produce these hybrid particles and to optimize the release kinetics of encapsulated drugs are discussed in this review. PMID:24300177

  16. Microparticles and type 2 diabetes.

    PubMed

    Leroyer, A S; Tedgui, A; Boulanger, C M

    2008-02-01

    Cell activation or apoptosis leads to plasma membrane blebbing and microparticles (MPs) release in the extracellular space. MPs are submicron membrane vesicles, which harbour a panel of oxidized phospholipids and proteins specific to the cells they derived from. MPs are found in the circulating blood of healthy volunteers. MPs levels are increased in many diseases, including cardiovascular diseases with high thrombotic risk. Exposure of negatively charged phospholipids and tissue factor confers a procoagulant potential to MPs. Elevation of plasma MPs levels, particularly those of endothelial origin, reflects cellular injury and appears now as a surrogate marker of vascular dysfunction. Recent studies demonstrate an elevation of circulating levels of MPs in diabetes. MPs could also be involved in the development of vascular complications in diabetes for they stimulate pro-inflammatory responses in target cells and promote thrombosis, endothelial dysfunction and angiogenesis. Thus, these studies provide new insight in the pathogenesis and treatment of vascular complications of diabetes.

  17. GTE: a new FFT based software to compute terrain correction on airborne gravity surveys in spherical approximation.

    NASA Astrophysics Data System (ADS)

    Capponi, Martina; Sampietro, Daniele; Sansò, Fernando

    2016-04-01

    The computation of the vertical attraction due to the topographic masses (Terrain Correction) is still a matter of study both in geodetic as well as in geophysical applications. In fact it is required in high precision geoid estimation by the remove-restore technique and it is used to isolate the gravitational effect of anomalous masses in geophysical exploration. This topographical effect can be evaluated from the knowledge of a Digital Terrain Model in different ways: e.g. by means of numerical integration, by prisms, tesseroids, polyedra or Fast Fourier Transform (FFT) techniques. The increasing resolution of recently developed digital terrain models, the increasing number of observation points due to extensive use of airborne gravimetry and the increasing accuracy of gravity data represents nowadays major issues for the terrain correction computation. Classical methods such as prism or point masses approximations are indeed too slow while Fourier based techniques are usually too approximate for the required accuracy. In this work a new software, called Gravity Terrain Effects (GTE), developed in order to guarantee high accuracy and fast computation of terrain corrections is presented. GTE has been thought expressly for geophysical applications allowing the computation not only of the effect of topographic and bathymetric masses but also those due to sedimentary layers or to the Earth crust-mantle discontinuity (the so called Moho). In the present contribution we summarize the basic theory of the software and its practical implementation. Basically the GTE software is based on a new algorithm which, by exploiting the properties of the Fast Fourier Transform, allows to quickly compute the terrain correction, in spherical approximation, at ground or airborne level. Some tests to prove its performances are also described showing GTE capability to compute high accurate terrain corrections in a very short time. Results obtained for a real airborne survey with GTE

  18. Feasibility of Leadless Cardiac Pacing Using Injectable Magnetic Microparticles

    PubMed Central

    Rotenberg, Menahem Y.; Gabay, Hovav; Etzion, Yoram; Cohen, Smadar

    2016-01-01

    A noninvasive, effective approach for immediate and painless heart pacing would have invaluable implications in several clinical scenarios. Here we present a novel strategy that utilizes the well-known mechano-electric feedback of the heart to evoke cardiac pacing, while relying on magnetic microparticles as leadless mechanical stimulators. We demonstrate that after localizing intravenously-injected magnetic microparticles in the right ventricular cavity using an external electromagnet, the application of magnetic pulses generates mechanical stimulation that provokes ventricular overdrive pacing in the rat heart. This temporary pacing consistently managed to revert drug-induced bradycardia, but could only last up to several seconds in the rat model, most likely due to escape of the particles between the applied pulses using our current experimental setting. In a pig model with open chest, MEF-based pacing was induced by banging magnetic particles and has lasted for a longer time. Due to overheating of the electromagnet, we intentionally terminated the experiments after 2 min. Our results demonstrate for the first time the feasibility of external leadless temporary pacing, using injectable magnetic microparticles that are manipulated by an external electromagnet. This new approach can have important utilities in clinical settings in which immediate and painless control of cardiac rhythm is required. PMID:27091192

  19. Design and characterization of core-shell mPEG-PLGA composite microparticles for development of cell-scaffold constructs.

    PubMed

    Wen, Yanhong; Gallego, Monica Ramos; Nielsen, Lene Feldskov; Jorgensen, Lene; Møller, Eva Horn; Nielsen, Hanne Mørck

    2013-09-01

    Appropriate scaffolds capable of providing suitable biological and structural guidance are of great importance to generate cell-scaffold constructs for cell-based tissue engineering. The aim of the present study was to develop composite microparticles with a structure to provide functionality as a combined drug delivery/scaffold system. Composite microparticles were produced by incorporating either alginate/dermatan sulfate (Alg/DS) or alginate/chitosan/dermatan sulfate (Alg/CS/DS) particles in mPEG-PLGA microparticles using coaxial ultrasonic atomization. The encapsulation and distribution of Alg/DS or Alg/CS/DS particles in the mPEG-PLGA microparticles were significantly dependent on the operating conditions, including the flow rate ratio (Qout/Qin) and the viscosity of the polymer solutions (Vout, Vin) between the outer and the inner feeding channels. The core-shell composite microparticles containing the Alg/DS particles or the Alg/CS/DS particles displayed 40% and 65% DS release in 10 days, respectively, as compared to the DS directly loaded microparticles showing 90% DS release during the same time interval. The release profiles of DS correlate with the cell proliferation of fibroblasts, i.e. more sustainable cell growth was induced by the DS released from the core-shell composite microparticles comprising Alg/CS/DS particles. After seeding fibroblasts onto the composite microparticles, excellent cell adhesion was observed, and a successful assembly of the cell-scaffold constructs was induced within 7 days. Therefore, the present study demonstrates a novel strategy for fabrication of core-shell composite microparticles comprising additional particulate drug carriers in the core, which provides controlled delivery of DS and favorable cell biocompatibility; an approach to potentially achieve cell-based tissue regeneration.

  20. Chitosan microparticles: influence of the gelation process on the release profile and oral bioavailability of albendazole, a class II compound.

    PubMed

    Piccirilli, Gisela N; García, Agustina; Leonardi, Darío; Mamprin, María E; Bolmaro, Raúl E; Salomón, Claudio J; Lamas, María C

    2014-11-01

    Encapsulation of albendazole, a class II compound, into polymeric microparticles based on chitosan-sodium lauryl sulfate was investigated as a strategy to improve drug dissolution and oral bioavailability. The microparticles were prepared by spray drying technique and further characterized by means of X-ray powder diffractometry, infrared spectroscopy and scanning electron microscopy. The formation of a novel polymeric structure between chitosan and sodium lauryl sulfate, after the internal or external gelation process, was observed by infrared spectroscopy. The efficiency of encapsulation was found to be between 60 and 85% depending on the internal or external gelation process. Almost spherically spray dried microparticles were observed using scanning electron microscopy. In vitro dissolution results indicated that the microparticles prepared by internal gelation released 8% of the drug within 30 min, while the microparticles prepared by external gelation released 67% within 30 min. It was observed that the AUC and Cmax values of ABZ from microparticles were greatly improved, in comparison with the non-encapsulated drug. In conclusion, the release properties and oral bioavailability of albendazole were greatly improved by using spraydried chitosan-sodium lauryl sulphate microparticles.

  1. Proteomics of Microparticles with SILAC Quantification (PROMIS-Quan): A Novel Proteomic Method for Plasma Biomarker Quantification*

    PubMed Central

    Harel, Michal; Oren-Giladi, Pazit; Kaidar-Person, Orit; Shaked, Yuval; Geiger, Tamar

    2015-01-01

    Unbiased proteomic analysis of plasma samples holds the promise to reveal clinically invaluable disease biomarkers. However, the tremendous dynamic range of the plasma proteome has so far hampered the identification of such low abundant markers. To overcome this challenge we analyzed the plasma microparticle proteome, and reached an unprecedented depth of over 3000 plasma proteins in single runs. To add a quantitative dimension, we developed PROMIS-Quan—PROteomics of MIcroparticles with Super-Stable Isotope Labeling with Amino Acids in Cell Culture (SILAC) Quantification, a novel mass spectrometry-based technology for plasma microparticle proteome quantification. PROMIS-Quan enables a two-step relative and absolute SILAC quantification. First, plasma microparticle proteomes are quantified relative to a super-SILAC mix composed of cell lines from distinct origins. Next, the absolute amounts of selected proteins of interest are quantified relative to the super-SILAC mix. We applied PROMIS-Quan to prostate cancer and compared plasma microparticle samples of healthy individuals and prostate cancer patients. We identified in total 5374 plasma-microparticle proteins, and revealed a predictive signature of three proteins that were elevated in the patient-derived plasma microparticles. Finally, PROMIS-Quan enabled determination of the absolute quantitative changes in prostate specific antigen (PSA) upon treatment. We propose PROMIS-Quan as an innovative platform for biomarker discovery, validation, and quantification in both the biomedical research and in the clinical worlds. PMID:25624350

  2. Cetirizine dihydrochloride loaded microparticles design using ionotropic cross-linked chitosan nanoparticles by spray-drying method.

    PubMed

    Li, Feng-Qian; Ji, Rui-Rui; Chen, Xu; You, Ben-Ming; Pan, Yong-Hua; Su, Jia-Can

    2010-12-01

    To control the release rate and mask the bitter taste, cetirizine dihydrochloride (CedH) was entrapped within chitosan nanoparticles (CS-NPs) using an ionotropic gelation process, followed by microencapsulation to produce CS matrix microparticles using a spray-drying method. The aqueous colloidal CS-NPs dispersions with a drug encapsulation efficiency (EE) of <15%, were then spray dried to produce a powdered nanoparticles-in-microparticles system with an EE of >70%. The resultant spherical CS microparticles had a smooth surface, were free of organic solvent residue and showed a diameter range of 0.5~5 μm. The in vitro drug release properties of CedH encapsulated microparticles showed an initial burst effect during the first 2 h. Drug release from the matrix CS microparticles could be retarded by the crosslinking agent pentasodium tripolyphosphate or the wall material. The technique of 'ionotropic gelation' combined with 'spray-drying' could be applicable for preparation of CS nanoparticlesin-microparticles drug delivery systems. CS-NPs based microparticles might provide a potential micro-carrier for oral administration of the freely water-soluble drug--CedH.

  3. Airborne and Ground-Based Platforms for Data Collection in Small Vineyards: Examples from the UK and Switzerland

    NASA Astrophysics Data System (ADS)

    Green, David R.; Gómez, Cristina; Fahrentrapp, Johannes

    2015-04-01

    This paper presents an overview of some of the low-cost ground and airborne platforms and technologies now becoming available for data collection in small area vineyards. Low-cost UAV or UAS platforms and cameras are now widely available as the means to collect both vertical and oblique aerial still photography and airborne videography in vineyards. Examples of small aerial platforms include the AR Parrot Drone, the DJI Phantom (1 and 2), and 3D Robotics IRIS+. Both fixed-wing and rotary wings platforms offer numerous advantages for aerial image acquisition including the freedom to obtain high resolution imagery at any time required. Imagery captured can be stored on mobile devices such as an Apple iPad and shared, written directly to a memory stick or card, or saved to the Cloud. The imagery can either be visually interpreted or subjected to semi-automated analysis using digital image processing (DIP) software to extract information about vine status or the vineyard environment. At the ground-level, a radio-controlled 'rugged' model 4x4 vehicle can also be used as a mobile platform to carry a number of sensors (e.g. a Go-Pro camera) around a vineyard, thereby facilitating quick and easy field data collection from both within the vine canopy and rows. For the small vineyard owner/manager with limited financial resources, this technology has a number of distinct advantages to aid in vineyard management practices: it is relatively cheap to purchase; requires a short learning-curve to use and to master; can make use of autonomous ground control units for repetitive coverage enabling reliable monitoring; and information can easily be analysed and integrated within a GIS with minimal expertise. In addition, these platforms make widespread use of familiar and everyday, off-the-shelf technologies such as WiFi, Go-Pro cameras, Cloud computing, and smartphones or tablets as the control interface, all with a large and well established end-user support base. Whilst there are

  4. Tunneling holes in microparticles to facilitate the transport of lithium ions for high volumetric density batteries

    NASA Astrophysics Data System (ADS)

    Zhu, Jian; Ng, K. Y. Simon; Deng, Da

    2015-08-01

    Microscale materials generally have a higher tap density than that of random nanoparticles. Therefore, microparticles have been attracting much attention for application as high volumetric density electrodes for lithium ion batteries. However, microparticles have much longer electrolyte diffusion and Li-ion migration length and less accessibility to the electrolyte than that of nanoparticles. Therefore, it will be interesting to tunnel-holes in the high volumetric density microparticles to facilitate the reversible storage of lithium ions. Here, tunnel-like holes were generated in microparticles to dramatically increase the accessibility of the active materials to facilitate the lithium ion transfer. A plausible formation mechanism to explain the generation of tunnel-like holes was proposed based on time-course experiments and intensive characterization. Impressively, the as-prepared microbeads with tunnels demonstrated dramatically improved performance compared to the solid microbeads without tunnels in lithium ion storage. The microparticles with tunnels could achieve comparable electrochemical performances to those nanoparticles reported in the literature, suggesting that microparticles, properly tuned, could be promising candidates as negative electrodes for lithium-ion batteries and worthy of further studies. We also directly measured the volumetric density of the microparticles. We would like to highlight that a superior volumetric capacity of 514 mA h cm-3 has been achieved. We hope to promote more frequent use of the unit mA h cm-3 in addition to the conventional unit mA h g-1 in the battery community.Microscale materials generally have a higher tap density than that of random nanoparticles. Therefore, microparticles have been attracting much attention for application as high volumetric density electrodes for lithium ion batteries. However, microparticles have much longer electrolyte diffusion and Li-ion migration length and less accessibility to the

  5. Comparison of Ground-Based and Airborne Function Allocation Concepts for NextGen Using Human-In-The-Loop Simulations

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Prevot, Thomas; Murdoch, Jennifer L.; Cabrall, Christopher D.; Homola, Jeffrey R.; Martin, Lynne H.; Mercer, Joey S.; Hoadley, Sherwood T.; Wilson, Sara R.; Hubbs, Clay E.; Chamberlain, James P.; Chartrand, Ryan C.; Consiglio, Maria C.; Palmer, Michael T.

    2010-01-01

    Investigation of function allocation for the Next Generation Air Transportation System is being conducted by the National Aeronautics and Space Administration (NASA). To provide insight on comparability of different function allocations for separation assurance, two human-in-the-loop simulation experiments were conducted on homogeneous airborne and ground-based approaches to four-dimensional trajectory-based operations, one referred to as ground-based automated separation assurance (groundbased) and the other as airborne trajectory management with self-separation (airborne). In the coordinated simulations at NASA s Ames and Langley Research Centers, controllers for the ground-based concept at Ames and pilots for the airborne concept at Langley managed the same traffic scenarios using the two different concepts. The common scenarios represented a significant increase in airspace demand over current operations. Using common independent variables, the simulations varied traffic density, scheduling constraints, and the timing of trajectory change events. Common metrics were collected to enable a comparison of relevant results. Where comparisons were possible, no substantial differences in performance or operator acceptability were observed. Mean schedule conformance and flight path deviation were considered adequate for both approaches. Conflict detection warning times and resolution times were mostly adequate, but certain conflict situations were detected too late to be resolved in a timely manner. This led to some situations in which safety was compromised and/or workload was rated as being unacceptable in both experiments. Operators acknowledged these issues in their responses and ratings but gave generally positive assessments of the respective concept and operations they experienced. Future studies will evaluate technical improvements and procedural enhancements to achieve the required level of safety and acceptability and will investigate the integration of

  6. How Cities Breathe: Ground-Referenced, Airborne Hyperspectral Imaging Precursor Measurements To Space-Based Monitoring

    NASA Technical Reports Server (NTRS)

    Leifer, Ira; Tratt, David; Quattrochi, Dale; Bovensmann, Heinrich; Gerilowski, Konstantin; Buchwitz, Michael; Burrows, John

    2013-01-01

    Methane's (CH4) large global warming potential (Shindell et al., 2012) and likely increasing future emissions due to global warming feedbacks emphasize its importance to anthropogenic greenhouse warming (IPCC, 2007). Furthermore, CH4 regulation has far greater near-term climate change mitigation potential versus carbon dioxide CO2, the other major anthropogenic Greenhouse Gas (GHG) (Shindell et al., 2009). Uncertainties in CH4 budgets arise from the poor state of knowledge of CH4 sources - in part from a lack of sufficiently accurate assessments of the temporal and spatial emissions and controlling factors of highly variable anthropogenic and natural CH4 surface fluxes (IPCC, 2007) and the lack of global-scale (satellite) data at sufficiently high spatial resolution to resolve sources. Many important methane (and other trace gases) sources arise from urban and mega-urban landscapes where anthropogenic activities are centered - most of humanity lives in urban areas. Studying these complex landscape tapestries is challenged by a wide and varied range of activities at small spatial scale, and difficulty in obtaining up-to-date landuse data in the developed world - a key desire of policy makers towards development of effective regulations. In the developing world, challenges are multiplied with additional political access challenges. As high spatial resolution satellite and airborne data has become available, activity mapping applications have blossomed - i.e., Google maps; however, tap a minute fraction of remote sensing capabilities due to limited (three band) spectral information. Next generation approaches that incorporate high spatial resolution hyperspectral and ultraspectral data will allow detangling of the highly heterogeneous usage megacity patterns by providing diagnostic identification of chemical composition from solids (refs) to gases (refs). To properly enable these next generation technologies for megacity include atmospheric radiative transfer modeling

  7. A new method for GPS-based wind speed determinations during airborne volcanic plume measurements

    USGS Publications Warehouse

    Doukas, Michael P.

    2002-01-01

    Begun nearly thirty years ago, the measurement of gases in volcanic plumes is today an accepted technique in volcano research. Volcanic plume measurements, whether baseline gas emissions from quiescent volcanoes or more substantial emissions from volcanoes undergoing unrest, provide important information on the amount of gaseous output of a volcano to the atmosphere. Measuring changes in gas emission rates also allows insight into eruptive behavior. Some of the earliest volcanic plume measurements of sulfur dioxide were made using a correlation spectrometer (COSPEC). The COSPEC, developed originally for industrial pollution studies, is an upward-looking optical spectrometer tuned to the ultraviolet absorption wavelength of sulfur dioxide (Millán and Hoff, 1978). In airborne mode, the COSPEC is mounted in a fixed-wing aircraft and flown back and forth just underneath a volcanic plume, perpendicular to the direction of plume travel (Casadevall and others, 1981; Stoiber and others, 1983). Similarly, for plumes close to the ground, the COSPEC can be mounted in an automobile and driven underneath a plume if a suitable road system is available (Elias and others, 1998). The COSPEC can also be mounted on a tripod and used to scan a volcanic plume from a fixed location on the ground, although the effectiveness of this configuration declines with distance from the plume (Kyle and others, 1990). In the 1990’s, newer airborne techniques involving direct sampling of volcanic plumes with infrared spectrometers and electrochemical sensors were developed in order to measure additional gases such as CO2 and H2S (Gerlach and others, 1997; Gerlach and others, 1999; McGee and others, 2001). These methods involve constructing a plume cross-section from several measurement traverses through the plume in a vertical plane. Newer instruments such as open-path Fourier transform infrared (FTIR) spectrometers are now being used to measure the gases in volcanic plumes mostly from fixed

  8. Biodegradable microparticles and fiber fabrics for sustained delivery of cisplatin to treat C6 glioma in vitro.

    PubMed

    Xie, Jingwei; Tan, Ruo Shan; Wang, Chi-Hwa

    2008-06-15

    The duration of cisplatin release from most of the drug delivery devices seemed to be shorter than 14 days except large microparticles. The objective of this study was to fabricate and characterize cisplatin-loaded PLA microparticles, PLA/PLGA (30/70) composite microparticles, and fibers as formulations for long-term sustained delivery of cisplatin to treat C6 glioma in vitro by electrospray and electrospinning techniques. Cisplatin-loaded biodegradable microparticles with particle size of around 5 microm and fiber fabrics with diameter of 0.5-1.7 microm were obtained using electrospray and electrospinning techniques. Encapsulation efficiency and in vitro release of formulations were measured by ICP-OES. The encapsulation efficiency for different samples of microparticles was approximately from 33% to 72% and the fiber fabrics had encapsulation efficiency greater than 90%. Cisplatin-loaded microparticles showed typical characteristics of cisplatin release profile: a large initial burst followed by a sustained slow release of 35 days. The composite PLA/PLGA (30/70) microparticles could reduce the initial burst release of cisplatin because of their core-shell structures. In contrast, more than 75 days sustained release could be achieved by fiber fabric formulations without large initial burst. MTT assay was used to quantify the cytotoxicity of different formulations against C6 glioma cells. Microparticle formulations had slightly higher cytotoxicity than free drug. In contrast, the cytotoxicity of fiber fabrics formulation was around 4 times higher than of the free drug based on the actual amount of drug released. The microparticle and fiber fabric formulations presented may be promising for the sustained delivery of cisplatin to eliminate the undesired side effects caused by direct injection of cisplatin solution in systemic administration.

  9. PITBUL: a physics-based modeling package for imaging and tracking of airborne targets for HEL applications including active illumination

    NASA Astrophysics Data System (ADS)

    Van Zandt, Noah R.; McCrae, Jack E.; Fiorino, Steven T.

    2013-05-01

    Aimpoint acquisition and maintenance is critical to high energy laser (HEL) system performance. This study demonstrates the development by the AFIT/CDE of a physics-based modeling package, PITBUL, for tracking airborne targets for HEL applications, including atmospheric and sensor effects and active illumination, which is a focus of this work. High-resolution simulated imagery of the 3D airborne target in-flight as seen from the laser position is generated using the HELSEEM model, and includes solar illumination, laser illumination, and thermal emission. Both CW and pulsed laser illumination are modeled, including the effects of illuminator scintillation, atmospheric backscatter, and speckle, which are treated at a first-principles level. Realistic vertical profiles of molecular and aerosol absorption and scattering, as well as optical turbulence, are generated using AFIT/CDE's Laser Environmental Effects Definition and Reference (LEEDR) model. The spatially and temporally varying effects of turbulence are calculated and applied via a fast-running wave optical method known as light tunneling. Sensor effects, for example blur, sampling, read-out noise, and random photon arrival, are applied to the imagery. Track algorithms, including centroid and Fitts correlation, as a part of a closed loop tracker are applied to the degraded imagery and scored, to provide an estimate of overall system performance. To gauge performance of a laser system against a UAV target, tracking results are presented as a function of signal to noise ratio. Additionally, validation efforts to date involving comparisons between simulated and experimental tracking of UAVs are presented.

  10. Stress indicators based on airborne thermal imagery for field phenotyping a heterogeneous tree population for response to water constraints.

    PubMed

    Virlet, Nicolas; Lebourgeois, Valentine; Martinez, Sébastien; Costes, Evelyne; Labbé, Sylvain; Regnard, Jean-Luc

    2014-10-01

    As field phenotyping of plant response to water constraints constitutes a bottleneck for breeding programmes, airborne thermal imagery can contribute to assessing the water status of a wide range of individuals simultaneously. However, the presence of mixed soil-plant pixels in heterogeneous plant cover complicates the interpretation of canopy temperature. Moran's Water Deficit Index (WDI = 1-ETact/ETmax), which was designed to overcome this difficulty, was compared with surface minus air temperature (T s-T a) as a water stress indicator. As parameterization of the theoretical equations for WDI computation is difficult, particularly when applied to genotypes with large architectural variability, a simplified procedure based on quantile regression was proposed to delineate the Vegetation Index-Temperature (VIT) scatterplot. The sensitivity of WDI to variations in wet and dry references was assessed by applying more or less stringent quantile levels. The different stress indicators tested on a series of airborne multispectral images (RGB, near-infrared, and thermal infrared) of a population of 122 apple hybrids, under two irrigation regimes, significantly discriminated the tree water statuses. For each acquisition date, the statistical method efficiently delineated the VIT scatterplot, while the limits obtained using the theoretical approach overlapped it, leading to inconsistent WDI values. Once water constraint was established, the different stress indicators were linearly correlated to the stem water potential among a tree subset. T s-T a showed a strong sensitivity to evaporative demand, which limited its relevancy for temporal comparisons. Finally, the statistical approach of WDI appeared the most suitable for high-throughput phenotyping.

  11. Stress indicators based on airborne thermal imagery for field phenotyping a heterogeneous tree population for response to water constraints

    PubMed Central

    Virlet, Nicolas; Lebourgeois, Valentine; Martinez, Sébastien; Costes, Evelyne; Labbé, Sylvain; Regnard, Jean-Luc

    2014-01-01

    As field phenotyping of plant response to water constraints constitutes a bottleneck for breeding programmes, airborne thermal imagery can contribute to assessing the water status of a wide range of individuals simultaneously. However, the presence of mixed soil–plant pixels in heterogeneous plant cover complicates the interpretation of canopy temperature. Moran’s Water Deficit Index (WDI = 1–ETact/ETmax), which was designed to overcome this difficulty, was compared with surface minus air temperature (T s–T a) as a water stress indicator. As parameterization of the theoretical equations for WDI computation is difficult, particularly when applied to genotypes with large architectural variability, a simplified procedure based on quantile regression was proposed to delineate the Vegetation Index–Temperature (VIT) scatterplot. The sensitivity of WDI to variations in wet and dry references was assessed by applying more or less stringent quantile levels. The different stress indicators tested on a series of airborne multispectral images (RGB, near-infrared, and thermal infrared) of a population of 122 apple hybrids, under two irrigation regimes, significantly discriminated the tree water statuses. For each acquisition date, the statistical method efficiently delineated the VIT scatterplot, while the limits obtained using the theoretical approach overlapped it, leading to inconsistent WDI values. Once water constraint was established, the different stress indicators were linearly correlated to the stem water potential among a tree subset. T s–T a showed a strong sensitivity to evaporative demand, which limited its relevancy for temporal comparisons. Finally, the statistical approach of WDI appeared the most suitable for high-throughput phenotyping. PMID:25080086

  12. Supervised and unsupervised MRF based 3D scene classification in multiple view airborne oblique images

    NASA Astrophysics Data System (ADS)

    Gerke, M.; Xiao, J.

    2013-10-01

    In this paper we develop and compare two methods for scene classification in 3D object space, that is, not single image pixels get classified, but voxels which carry geometric, textural and color information collected from the airborne oblique images and derived products like point clouds from dense image matching. One method is supervised, i.e. relies on training data provided by an operator. We use Random Trees for the actual training and prediction tasks. The second method is unsupervised, thus does not ask for any user interaction. We formulate this classification task as a Markov-Random-Field problem and employ graph cuts for the actual optimization procedure. Two test areas are used to test and evaluate both techniques. In the Haiti dataset we are confronted with largely destroyed built-up areas since the images were taken after the earthquake in January 2010, while in the second case we use images taken over Enschede, a typical Central European city. For the Haiti case it is difficult to provide clear class definitions, and this is also reflected in the overall classification accuracy; it is 73% for the supervised and only 59% for the unsupervised method. If classes are defined more unambiguously like in the Enschede area, results are much better (85% vs. 78%). In conclusion the results are acceptable, also taking into account that the point cloud used for geometric features is not of good quality and no infrared channel is available to support vegetation classification.

  13. Field-Based and Airborne Hyperspectral Imaging for Applied Research in the State of Alaska

    NASA Astrophysics Data System (ADS)

    Prakash, A.; Buchhorn, M.; Cristobal, J.; Kokaly, R. F.; Graham, P. R.; Waigl, C. F.; Hampton, D. L.; Werdon, M.; Guldager, N.; Bertram, M.; Stuefer, M.

    2015-12-01

    Hyperspectral imagery acquired using Hyspex VNIR-1800 and SWIR-384 camera systems have provided unique information on terrestrial and aquatic biogeochemical parameters, and diagnostic mineral properties in exposed outcrops in selected sites in the state of Alaska. The Hyspex system was configured for in-situ and field scanning by attaching it to a gimbal-mounted rotational stage on a robust tripod. Scans of vertical faces of vegetation and rock outcrops were made close to the campus of the University of Alaska Fairbanks, in an abandoned mine near Fairbanks, and on exposures of Orange Hill in Wrangell-St. Elias National Park. Atmospherically corrected integrated VNIR_SWIR spectra were extracted which helped to study varying nitrogen content in the vegetation, and helped to distinguish the various micas. Processed imagery helped to pull out carbonates, clays, sulfates, and alteration-related minerals. The same instrument was also mounted in airborne configuration on two different aircrafts, a DeHavilland Beaver and a Found Bush Hawk. Test flights were flown over urban and wilderness areas that presented a variety of landcover types. Processed imagery shows promise in mapping man-made surfaces, phytoplankton, and dissolved materials in inland water bodies. Sample data and products are available on the University of Alaska Fairbanks Hyperspectral Imaging Laboratory (HyLab) website at http://hyperspectral.alaska.edu.

  14. Preparation of thiomer microparticles and in vitro evaluation of parameters influencing their mucoadhesive properties.

    PubMed

    Albrecht, K; Zirm, E J; Palmberger, T F; Schlocker, W; Bernkop-Schnürch, A

    2006-01-01

    It was the aim of this study to develop mucoadhesive microparticulate delivery systems based on thiomers and to investigate parameters influencing their mucoadhesive properties. Microparticles were prepared via coazervation of thiolated or unmodified polycarbophil with fluorescein-diacetate as marker. The protective effect of the polymers toward enzymatic hydrolysis by intestinal enzymes was investigated. Mucoadhesion studies with microparticles, applied in dry and prehydrated form, were performed by ascertaining their residence time on intestinal mucosa. Furthermore, the influence of the amount of thiol groups on mucoadhesion was studied in vitro. Results showed that in comparison to unmodified polycarbophil, thiolated polycarbophil provided a more than 3-fold higher protective effect for the incorporated marker fluorescein-diacetate toward hydrolysis. When being applied in dry form 23.4 +/- 4.8% of the fluorescence marker being embedded in thiomer microparticles remained adhering to the intestinal mucosa within 3 h. In contrast, only 11.6 +/- 2.0% of the marker remained on the mucosa, when the thiomer microparticles were applied in prehydrated form. In addition, tests performed to assess the impact of the amount of thiol groups pointed out that a high amount of thiol groups is advantageous in order to further improve mucoadhesive properties. This knowledge should contribute to the design of highly efficient drug delivery systems being based on thiomer microparticles.

  15. Thermal evaporation and condensation synthesis of metallic Zn layered polyhedral microparticles

    SciTech Connect

    Khan, Waheed S.; Cao, Chuanbao; Usman, Zahid; Hussain, Sajad; Nabi, Ghulam; Butt, Faheem K.; Ali, Zulfiqar; Mahmood, Tariq; Niaz, Niaz Ahmad

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Zn polyhedral microparticles prepared by thermal evaporation and condensation route. Black-Right-Pointing-Pointer Vapour-solid process based growth model governs the formation of Zn microparticles. Black-Right-Pointing-Pointer A strong PL emission band is observed at 369 nm in UV region. Black-Right-Pointing-Pointer Radiative recombination of electrons in the s, p conduction band and the holes in the d bands causes this emission. -- Abstract: Metallic zinc layered polyhedral microparticles have been fabricated by thermal evaporation and condensation technique using zinc as precursor at 750 Degree-Sign C for 120 min and NH{sub 3} as a carrier gas. The zinc polyhedral microparticles with oblate spherical shape are observed to be 2-9 {mu}m in diameter along major axes and 1-7 {mu}m in thickness along minor axes. The structural, compositional and morphological characterizations were performed by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). A vapour-solid (VS) mechanism based growth model has been proposed for the formation of Zn microparticles. Room temperature photoluminescence (PL) emission spectrum of the product exhibited a strong emission band at 369 nm attributed to the radiative recombination of electrons in the s, p conduction band near Fermi surface and the holes in the d bands generated by the optical excitation.

  16. Bead mediated separation of microparticles in droplets

    PubMed Central

    Sung, Ki-Joo; Lin, Xiaoxia Nina; Burns, Mark A.

    2017-01-01

    Exchange of components such as particles and cells in droplets is important and highly desired in droplet microfluidic assays, and many current technologies use electrical or magnetic fields to accomplish this process. Bead-based microfluidic techniques offer an alternative approach that uses the bead’s solid surface to immobilize targets like particles or biological material. In this paper, we demonstrate a bead-based technique for exchanging droplet content by separating fluorescent microparticles in a microfluidic device. The device uses posts to filter surface-functionalized beads from a droplet and re-capture the filtered beads in a new droplet. With post spacing of 7 μm, beads above 10 μm had 100% capture efficiency. We demonstrate the efficacy of this system using targeted particles that bind onto the functionalized beads and are, therefore, transferred from one solution to another in the device. Binding capacity tests performed in the bulk phase showed an average binding capacity of 5 particles to each bead. The microfluidic device successfully separated the targeted particles from the non-targeted particles with up to 98% purity and 100% yield. PMID:28282412

  17. Temperature and emissivity separation and mineral mapping based on airborne TASI hyperspectral thermal infrared data

    NASA Astrophysics Data System (ADS)

    Cui, Jing; Yan, Bokun; Dong, Xinfeng; Zhang, Shimin; Zhang, Jingfa; Tian, Feng; Wang, Runsheng

    2015-08-01

    Thermal infrared remote sensing (8-12 μm) (TIR) has great potential for geologic remote sensing studies. TIR has been successfully used for terrestrial and planetary geologic studies to map surface materials. However, the complexity of the physics and the lack of hyperspectral data make the studies under-investigated. A new generation of commercial hyperspectral infrared sensors, known as Thermal Airborne Spectrographic Imager (TASI), was used for image analysis and mineral mapping in this study. In this paper, a combined method integrating normalized emissivity method (NEM), ratio algorithm (RATIO) and maximum-minimum apparent emissivity difference (MMD), being applied in multispectral data, has been modified and used to determine whether this method is suitable for retrieving emissivity from TASI hyperspectral data. MODTRAN 4 has been used for the atmospheric correction. The retrieved emissivity spectra matched well with the field measured spectra except for bands 1, 2, and 32. Quartz, calcite, diopside/hedenbergite, hornblende and microcline have been mapped by the emissivity image. Mineral mapping results agree with the dominant minerals identified by laboratory X-ray powder diffraction and spectroscopic analyses of field samples. Both of the results indicated that the atmospheric correction method and the combined temperature-emissivitiy method are suitable for TASI image. Carbonate skarnization was first found in the study area by the spatial extent of diopside. Chemical analyses of the skarn samples determined that the Au content was 0.32-1.74 g/t, with an average Au content of 0.73 g/t. This information provides an important resource for prospecting for skarn type gold deposits. It is also suggested that TASI is suitable for prospect and deposit scale exploration.

  18. Object-Based Land Use Classification using Airborne LiDAR

    NASA Astrophysics Data System (ADS)

    Antonarakis, A. S.; Richards, K. S.; Brasington, J.

    2007-12-01

    Better information on roughness of various types of vegetation is needed for use in resistance equations and eventually in flood modelling. These types include woody riparian species with different structural characteristics. Remote Sensing information such as 3D point cloud data from LiDAR can be used as a tool for extracting simple roughness information relevant for the condition of below canopy flow, as well as roughness relevant for more complex tree morphology that affects the flow when it enters the canopy levels. A strategy for extracting roughness parameters from remote sensing techniques is to use a data fusion object classification model. This means that multiple datasets such as LiDAR, digital aerial photography, ground data and satellite data can be combined to produce roughness parameters estimated for different vegetative patches, which can subsequently be mapped spatially using a classification methodology. Airborne LiDAR is used in this study in order to classify forest and ground types quickly and efficiently without the need for manipulating multispectral image files. LiDAR has the advantage of being able to create elevation surfaces that are in 3D, while also having information on LiDAR intensity values, thus it is a spatial and spectral segmentation tool. This classification method also uses point distribution frequency criteria to differentiate between land cover types. The classification of three meanders of the Garonne and Allier rivers in France has demonstrated overall classification accuracies of 95%. Five types of riparian forest were classified with accuracies between 66-98%. These forest types included planted and natural forest stands of different ages. Classifications of short vegetation and bare earth also produced high accuracies averaging above 90%.

  19. The Influence of Aerosol Composition on Photolysis Rates Based on Airborne Observations

    NASA Astrophysics Data System (ADS)

    Corr, C.; Barrick, J. D. W.; Beyersdorf, A. J.; Chen, G.; Crawford, J. H.; Jordan, C. E.; Moore, R.; Shook, M.; Thornhill, K. L., II; Winstead, E.; Ziemba, L. D.; Madronich, S.; Anderson, B. E.

    2015-12-01

    The potential variability in modeled photolysis rates introduced by aerosol optical properties measured at visible wavelengths is presented here. Aerosol scattering and absorption were measured aboard the NASA P-3B aircraft during the Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) using a TSI Nephelometer and a Radiance Research Particle Soot Absorption Photometer (PSAP), respectively. To isolate the effect of aerosols on photolysis rates, cloud-free case studies were identified using aircraft videos for the four DISCOVER-AQ deployments: Baltimore, MD-Washington, D.C. in July 2011, the California Central Valley in January/February 2013, Houston, TX in September 2013, and Denver, CO in July 2014. For these case studies, absorption measurements at 470 and 532 nm were extrapolated to the Nephelometer wavelengths (450 and 550nm) using the 470-532nm absorption Angstrom exponent (AAE470-532) to calculate aerosol extinction and SSAs at these wavelengths. Photolysis rates were modeled using the Tropospheric Ultraviolet model version 5.2 (TUV 5.2) for three scenarios: 1) an aerosol-free case, 2) using a spectrally-flat SSA at 550nm and 3) using a spectrally-dependent SSA derived from scattering and absorption measurements. Modeled photolysis rates were compared to those measured aboard the P-3B during DISCOVER-AQ. The relationship between airborne measurements of water soluble organic carbon (WSOC) made by a Particle-Into-Liquid-Sampler (PILS), AAE470-532 and model/measurement discrepancies were explored to assess the influence of aerosol composition on photolysis rates. Additional comparisons between photolysis rates modeled with vertically-resolved aerosol optical properties and those modeled using column-average values were performed to assess the influence of aerosol vertical distribution on photolysis rates.

  20. Absolute airborne gravimetry

    NASA Astrophysics Data System (ADS)

    Baumann, Henri

    This work consists of a feasibility study of a first stage prototype airborne absolute gravimeter system. In contrast to relative systems, which are using spring gravimeters, the measurements acquired by absolute systems are uncorrelated and the instrument is not suffering from problems like instrumental drift, frequency response of the spring and possible variation of the calibration factor. The major problem we had to resolve were to reduce the influence of the non-gravitational accelerations included in the measurements. We studied two different approaches to resolve it: direct mechanical filtering, and post-processing digital compensation. The first part of the work describes in detail the different mechanical passive filters of vibrations, which were studied and tested in the laboratory and later in a small truck in movement. For these tests as well as for the airborne measurements an absolute gravimeter FG5-L from Micro-G Ltd was used together with an Inertial navigation system Litton-200, a vertical accelerometer EpiSensor, and GPS receivers for positioning. These tests showed that only the use of an optical table gives acceptable results. However, it is unable to compensate for the effects of the accelerations of the drag free chamber. The second part describes the strategy of the data processing. It is based on modeling the perturbing accelerations by means of GPS, EpiSensor and INS data. In the third part the airborne experiment is described in detail, from the mounting in the aircraft and data processing to the different problems encountered during the evaluation of the quality and accuracy of the results. In the part of data processing the different steps conducted from the raw apparent gravity data and the trajectories to the estimation of the true gravity are explained. A comparison between the estimated airborne data and those obtained by ground upward continuation at flight altitude allows to state that airborne absolute gravimetry is feasible and

  1. Airborne field strength monitoring

    NASA Astrophysics Data System (ADS)

    Bredemeyer, J.; Kleine-Ostmann, T.; Schrader, T.; Münter, K.; Ritter, J.

    2007-06-01

    In civil and military aviation, ground based navigation aids (NAVAIDS) are still crucial for flight guidance even though the acceptance of satellite based systems (GNSS) increases. Part of the calibration process for NAVAIDS (ILS, DME, VOR) is to perform a flight inspection according to specified methods as stated in a document (DOC8071, 2000) by the International Civil Aviation Organization (ICAO). One major task is to determine the coverage, or, in other words, the true signal-in-space field strength of a ground transmitter. This has always been a challenge to flight inspection up to now, since, especially in the L-band (DME, 1GHz), the antenna installed performance was known with an uncertainty of 10 dB or even more. In order to meet ICAO's required accuracy of ±3 dB it is necessary to have a precise 3-D antenna factor of the receiving antenna operating on the airborne platform including all losses and impedance mismatching. Introducing precise, effective antenna factors to flight inspection to achieve the required accuracy is new and not published in relevant papers yet. The authors try to establish a new balanced procedure between simulation and validation by airborne and ground measurements. This involves the interpretation of measured scattering parameters gained both on the ground and airborne in comparison with numerical results obtained by the multilevel fast multipole algorithm (MLFMA) accelerated method of moments (MoM) using a complex geometric model of the aircraft. First results will be presented in this paper.

  2. Radon potential mapping of the Tralee-Castleisland and Cavan areas (Ireland) based on airborne gamma-ray spectrometry and geology.

    PubMed

    Appleton, J D; Doyle, E; Fenton, D; Organo, C

    2011-06-01

    The probability of homes in Ireland having high indoor radon concentrations is estimated on the basis of known in-house radon measurements averaged over 10 km × 10 km grid squares. The scope for using airborne gamma-ray spectrometer data for the Tralee-Castleisland area of county Kerry and county Cavan to predict the radon potential (RP) in two distinct areas of Ireland is evaluated in this study. Airborne data are compared statistically with in-house radon measurements in conjunction with geological and ground permeability data to establish linear regression models and produce radon potential maps. The best agreement between the percentage of dwellings exceeding the reference level (RL) for radon concentrations in Ireland (% > RL), estimated from indoor radon data, and modelled RP in the Tralee-Castleisland area is produced using models based on airborne gamma-ray spectrometry equivalent uranium (eU) and ground permeability data. Good agreement was obtained between the % > RL from indoor radon data and RP estimated from eU data in the Cavan area using terrain specific models. In both areas, RP maps derived from eU data are spatially more detailed than the published 10 km grid map. The results show the potential for using airborne radiometric data for producing RP maps.

  3. Airborne light detection and ranging laser return intensity-based investigation into crown-inside? A case study on Quercus robur trees

    NASA Astrophysics Data System (ADS)

    Lin, Yi; Zhang, Lifu; Wang, Cheng

    2016-04-01

    The significance of laser return intensity has been widely verified in airborne light detection and ranging (LiDAR)-based forest canopy mapping, but this does not mean that all of its roles have been played. People still ask such questions as "Is it possible using this optical attribute of lasers to investigate individual tree-crown insides wherein laser intensity data are typically yielded in complicated echo-triggering modes?" To answer this question, this study examined the characteristics of the intensities of the laser points within 10 Quercus robur trees by fitting their peak amplitudes into default Gaussian distributions and then analyzing the resulting asymmetric tails. Exploratory data analyses showed that the laser points lying within the distribution tails can indicate primary tree branches in a sketchy way. This suggests that the question can be positively answered, and the traditional restriction of airborne LiDAR in canopy mapping at the crown level has been broken. Overall, this study found a unique way to detect primary tree branches in airborne LiDAR data and pointed out how to explore more ways this optical intensity attribute of airborne LiDAR data can measure tree organs at fine scales and further learn their properties.

  4. Porous microwells for geometry-selective, large-scale microparticle arrays

    PubMed Central

    Kim, Jae Jung; Bong, Ki Wan; Reátegui, Eduardo; Irimia, Daniel; Doyle, Patrick S.

    2016-01-01

    Large-scale microparticle arrays (LSMA) are key for material science and bioengineering applications. However, previous approaches suffer from tradeoffs between scalability, precision, specificity, and versatility. Here, we present a porous microwell-based approach to create large-scale microparticle arrays with complex motifs. Microparticles are guided to and pushed into microwells by fluid flow through small open pores at the bottom of the porous well arrays. A scaling theory allows for the rational design of LSMAs to sort and array particles based on their size, shape or modulus. Sequential particle assembly allows for proximal and nested particle arrangements, as well as particle recollection and pattern transfer. We demonstrate the capabilities of the approach by means of three applications: high-throughput single-cell arrays; microenvironment fabrication for neutrophil chemotaxis; and complex, covert tags by the transfer of an upconversion nanocrystal laden LSMA. PMID:27595351

  5. Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: a case study of Irish Sea beaches.

    PubMed

    Cresswell, A J; Sanderson, D C W

    2012-10-15

    In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the public who may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq (137)Cs within large areas (10-20 km(2)h(-1)), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15m whilst maintaining speeds covering 1-2 km(2) h(-1) can detect buried (137)Cs sources of 0.5MBq or greater activity. A survey design to detect 100 kBq (137)Cs sources at 10 cm depth has also been defined, requiring surveys at <15m ground clearance and <2 ms(-1) ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed.

  6. Uniform biodegradable microparticle systems for controlled release

    PubMed Central

    Xia, Yujie; Pack, Daniel W.

    2014-01-01

    Drug delivery methods can impact efficacy as much as the nature of the drug itself. Microparticles made of biodegradable polymers such as poly(D,L-lactide-co-glycolide) and poly(lactic acid) (PLA) have been studied extensively for controlled release of diverse drugs. By using a modified solvent extraction/evaporation method called precision particle fabrication (PPF), uniform microparticles such as single-wall microspheres, double-wall microspheres and liquid-core microcapsules have been fabricated with precise control of their geometric structures. By producing particles of uniform size, which has crucial impact on drug release behaviors, PPF-fabricated microparticles provide unique insights about drug release mechanism. Using small-molecule and macromolecule model drugs, our group demonstrated that physicochemical properties of the polymers and drugs and structural properties of the matrix can greatly impact drug distribution within microparticles, particle erosion and drug release rates. By careful selection of particle size and shell thickness, uniform microparticles can achieve “zero-order”, pulsatile or tandem release of drugs. PMID:12106984

  7. HLA-E inhibitor enhances the killing of neuroblastoma stem cells by co-cultured dendritic cells and cytokine-induced killer cells loaded with membrane-based microparticles

    PubMed Central

    Zhen, Zijun; Yang, Kaibin; Ye, Litong; You, Zhiyao; Chen, Rirong; Liu, Ying; He, Youjian

    2017-01-01

    Neuroblastoma stem cells (NSCs) can cause drug resistance and tumor recurrence. This study aimed to enhance the lytic effect of dendritic cells (DCs) co-cultured with cytokine-induced killer (CIK) cells. NSCs were obtained by suspension culture, and DC-CIK cells were loaded with extracted NSC membrane-based microparticles (MMPs) before evaluating the lytic effect of DC-CIK cells on NSCs. After inhibiting the function or expression of human leukocyte antigen-E (HLA-E) in NSCs by anti-HLA-E monoclonal antibody or siRNA, the DC-CIK cell lytic effect on NSCs was re-assessed. NSC nestin expression was high, but glial fibrillary acid protein expression and class IIIβ-tubulin-1 expression were low. Moreover, NSCs exhibited strong tumorigenic ability in nude mice. Loading DCs with NSC-derived MMPs induced the differentiation of DCs and CIK cells and enhanced the killing of NSCs by DC-CIK cells. Inhibiting the function or expression of HLA-E in NSCs further enhanced the cytolytic capability of DC-CIK cells loaded with NSC-derived MMPs. HLA-E inhibitor can enhance the killing of NSC by DC-CIK cells loaded with NSC-derived MMPs. PMID:28337381

  8. Circulating microparticles: square the circle

    PubMed Central

    2013-01-01

    Background The present review summarizes current knowledge about microparticles (MPs) and provides a systematic overview of last 20 years of research on circulating MPs, with particular focus on their clinical relevance. Results MPs are a heterogeneous population of cell-derived vesicles, with sizes ranging between 50 and 1000 nm. MPs are capable of transferring peptides, proteins, lipid components, microRNA, mRNA, and DNA from one cell to another without direct cell-to-cell contact. Growing evidence suggests that MPs present in peripheral blood and body fluids contribute to the development and progression of cancer, and are of pathophysiological relevance for autoimmune, inflammatory, infectious, cardiovascular, hematological, and other diseases. MPs have large diagnostic potential as biomarkers; however, due to current technological limitations in purification of MPs and an absence of standardized methods of MP detection, challenges remain in validating the potential of MPs as a non-invasive and early diagnostic platform. Conclusions Improvements in the effective deciphering of MP molecular signatures will be critical not only for diagnostics, but also for the evaluation of treatment regimens and predicting disease outcomes. PMID:23607880

  9. The use of airborne laser scanning to develop a pixel-based stratification for a verified carbon offset project

    PubMed Central

    2011-01-01

    Background The voluntary carbon market is a new and growing market that is increasingly important to consider in managing forestland. Monitoring, reporting, and verifying carbon stocks and fluxes at a project level is the single largest direct cost of a forest carbon offset project. There are now many methods for estimating forest stocks with high accuracy that use both Airborne Laser Scanning (ALS) and high-resolution optical remote sensing data. However, many of these methods are not appropriate for use under existing carbon offset standards and most have not been field tested. Results This paper presents a pixel-based forest stratification method that uses both ALS and optical remote sensing data to optimally partition the variability across an ~10,000 ha forest ownership in Mendocino County, CA, USA. This new stratification approach improved the accuracy of the forest inventory, reduced the cost of field-based inventory, and provides a powerful tool for future management planning. This approach also details a method of determining the optimum pixel size to best partition a forest. Conclusions The use of ALS and optical remote sensing data can help reduce the cost of field inventory and can help to locate areas that need the most intensive inventory effort. This pixel-based stratification method may provide a cost-effective approach to reducing inventory costs over larger areas when the remote sensing data acquisition costs can be kept low on a per acre basis. PMID:22004847

  10. Caesium-rich micro-particles: A window into the meltdown events at the Fukushima Daiichi Nuclear Power Plant.

    PubMed

    Furuki, Genki; Imoto, Junpei; Ochiai, Asumi; Yamasaki, Shinya; Nanba, Kenji; Ohnuki, Toshihiko; Grambow, Bernd; Ewing, Rodney C; Utsunomiya, Satoshi

    2017-02-15

    The nuclear disaster at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 caused partial meltdowns of three reactors. During the meltdowns, a type of condensed particle, a caesium-rich micro-particle (CsMP), formed inside the reactors via unknown processes. Here we report the chemical and physical processes of CsMP formation inside the reactors during the meltdowns based on atomic-resolution electron microscopy of CsMPs discovered near the FDNPP. All of the CsMPs (with sizes of 2.0-3.4 μm) comprise SiO2 glass matrices and ~10-nm-sized Zn-Fe-oxide nanoparticles associated with a wide range of Cs concentrations (1.1-19 wt% Cs as Cs2O). Trace amounts of U are also associated with the Zn-Fe oxides. The nano-texture in the CsMPs records multiple reaction-process steps during meltdown in the severe FDNPP accident: Melted fuel (molten core)-concrete interactions (MCCIs), incorporating various airborne fission product nanoparticles, including CsOH and CsCl, proceeded via SiO2 condensation over aggregates of Zn-Fe oxide nanoparticles originating from the failure of the reactor pressure vessels. Still, CsMPs provide a mechanism by which volatile and low-volatility radionuclides such as U can reach the environment and should be considered in the migration model of Cs and radionuclides in the current environment surrounding the FDNPP.

  11. Clear-Sky Closure Studies of Lower Tropospheric Aerosol and Water Vapor During ACE-2 Using Airborne Sunphotometer, Airborne In-Situ, Space-Borne, and Ground-Based Measurements

    NASA Technical Reports Server (NTRS)

    Schmid, Beat; Livingston, John M.; Russell, Philip B.; Durkee, Philip A.; Jonsson, Haflidi H.; Collins, Donald R.; Flagan, Richard C.; Seinfield, John H.; Gasso, Santiago; Hegg, Dean A.

    2000-01-01

    We report on clear-sky column closure experiments (CLEARCOLUMN) performed in the Canary Islands during the second Aerosol Characterization Experiment (ACE-2) in June/July 1997. We present CLEARCOLUMN results obtained by combining airborne sunphotometer and in-situ (optical particle counter, nephelometer, and absorption photometer) measurements taken aboard the Pelican aircraft, space-borne NOAA/AVHRR data and ground-based lidar and sunphotometer measurements. During both days discussed here, vertical profiles flown in cloud-free air masses revealed 3 distinctly different layers: a marine boundary layer (MBL) with varying pollution levels, an elevated dust layer, and a very clean layer between the MBL and the dust layer. A key result of this study is the achievement of closure between extinction or layer aerosol optical depth (AOD) computed from continuous in-situ aerosol size-distributions and composition and those measured with the airborne sunphotometer. In the dust, the agreement in layer AOD (lambda = 380-1060 nm) is 3-8%. In the MBL there is a tendency for the in-situ results to be slightly lower than the sunphotometer measurements (10-17% at lambda = 525 nm), but these differences are within the combined error bars of the measurements and computations.

  12. Agglomeration of microparticles in complex plasmas

    SciTech Connect

    Du, Cheng-Ran; Thomas, Hubertus M.; Ivlev, Alexei V.; Konopka, Uwe; Morfill, Gregor E.

    2010-11-15

    Agglomeration of highly charged microparticles was observed and studied in complex plasma experiments carried out in a capacitively coupled rf discharge. The agglomeration was caused by strong waves triggered in a particle cloud by decreasing neutral gas pressure. Using a high-speed camera during this unstable regime, it was possible to resolve the motion of individual microparticles and to show that the relative velocities of some particles were sufficiently high to overcome the mutual Coulomb repulsion and hence to result in agglomeration. After stabilizing the cloud again through the increase of the pressure, we were able to observe the aggregates directly with a long-distance microscope. We show that the agglomeration rate deduced from our experiments is in good agreement with theoretical estimates. In addition, we briefly discuss the mechanisms that can provide binding of highly charged microparticles in a plasma.

  13. Microparticle trapping in an ultrasonic Bessel beam.

    PubMed

    Choe, Youngki; Kim, Jonathan W; Shung, K Kirk; Kim, Eun Sok

    2011-12-05

    This paper describes an acoustic trap consisting of a multi-foci Fresnel lens on 127 μm thick lead zirconate titanate sheet. The multi-foci Fresnel lens was designed to have similar working mechanism to an Axicon lens and generates an acoustic Bessel beam, and has negative axial radiation force capable of trapping one or more microparticle(s). The fabricated acoustic tweezers trapped lipid particles ranging in diameter from 50 to 200 μm and microspheres ranging in diameter from 70 to 90 μm at a distance of 2 to 5 mm from the tweezers without any contact between the transducer and microparticles.

  14. Microparticle trapping in an ultrasonic Bessel beam

    PubMed Central

    Choe, Youngki; Kim, Jonathan W.; Shung, K. Kirk; Kim, Eun Sok

    2011-01-01

    This paper describes an acoustic trap consisting of a multi-foci Fresnel lens on 127 μm thick lead zirconate titanate sheet. The multi-foci Fresnel lens was designed to have similar working mechanism to an Axicon lens and generates an acoustic Bessel beam, and has negative axial radiation force capable of trapping one or more microparticle(s). The fabricated acoustic tweezers trapped lipid particles ranging in diameter from 50 to 200 μm and microspheres ranging in diameter from 70 to 90 μm at a distance of 2 to 5 mm from the tweezers without any contact between the transducer and microparticles. PMID:22247566

  15. A multi-scale permafrost investigation along the Alaska Highway Corridor based on airborne electromagnetic and auxiliary geophysical data

    NASA Astrophysics Data System (ADS)

    Minsley, B. J.; Kass, M. A.; Bloss, B.; Pastick, N.; Panda, S. K.; Smith, B. D.; Abraham, J. D.; Burns, L. E.

    2012-12-01

    More than 8000 square kilometers of airborne electromagnetic (AEM) data were acquired along the Alaska Highway Corridor in 2005-2006 by the Alaska Department of Natural Resources Division of Geological and Geophysical Surveys. Because this large AEM dataset covers diverse geologic and permafrost settings, it is an excellent testbed for studying the electrical geophysical response from a wide range of subsurface conditions. These data have been used in several recent investigations of geology, permafrost, and infrastructure along the highway corridor. In this study, we build on existing interpretations of permafrost features by re-inverting the AEM data using traditional least squares inversion techniques as well as recently developed stochastic methods aimed at quantifying uncertainty in geophysical data. Ground-based geophysical measurements, including time-domain electromagnetic soundings, surface nuclear magnetic resonance soundings, and shallow frequency-domain electromagnetic profiles, have also been acquired to help validate and extend the AEM interpretations. Here, we focus on the integration of different types of data to yield an improved characterization of permafrost, including: methods to discriminate between geologic and thermal controls on resistivity; identifying relationships between shallow resistivity and active layer thickness by incorporating auxiliary remote sensing data and ground-based measurements; quantifying apparent slope-aspect-resistivity relationships, where south-facing slopes appear less resistive than north-facing slopes within similar geologic settings; and investigating an observed decrease in resistivity beneath several areas associated with recent fires.

  16. [Building Change Detection Based on Multi-Level Rules Classification with Airborne LiDAR Data and Aerial Images].

    PubMed

    Gong, Yi-long; Yan, Li

    2015-05-01

    The present paper proposes a new building change detection method combining Lidar point cloud with aerial image, using multi-level rules classification algorithm, to solve building change detection problem between these two kinds of heterogeneous data. Then, a morphological post-processing method combined with area threshold is proposed. Thus, a complete building change detection processing flow that can be applied to actual production is proposed. Finally, the effectiveness of the building change detection method is evaluated, processing the 2010 airborne LiDAR point cloud data and 2009 high resolution aerial image of Changchun City, Jilin province, China; in addition, compared with the object-oriented building change detection method based on support vector machine (SVM) classification, more analysis and evaluation of the suggested method is given. Experiment results show that the performance of the proposed building change detection method is ideal. Its Kappa index is 0. 90, and correctness is 0. 87, which is higher than the object-oriented building change detection method based on SVM classification.

  17. Modeling of mean radiant temperature based on comparison of airborne remote sensing data with surface measured data

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Cheng; Chen, Chih-Yu; Matzarakis, Andreas; Liu, Jin-King; Lin, Tzu-Ping

    2016-06-01

    Assessment of outdoor thermal comfort is becoming increasingly important due to the urban heat island effect, which strongly affects the urban thermal environment. The mean radiant temperature (Tmrt) quantifies the effect of the radiation environment on humans, but it can only be estimated based on influencing parameters and factors. Knowledge of Tmrt is important for quantifying the heat load on human beings, especially during heat waves. This study estimates Tmrt using several methods, which are based on climatic data from a traditional weather station, microscale ground surface measurements, land surface temperature (LST) and light detection and ranging (LIDAR) data measured using airborne devices. Analytical results reveal that the best means of estimating Tmrt combines information about LST and surface elevation information with meteorological data from the closest weather station. The application in this method can eliminate the inconvenience of executing a wide range ground surface measurement, the insufficient resolution of satellite data and the incomplete data of current urban built environments. This method can be used to map a whole city to identify hot spots, and can be contributed to understanding human biometeorological conditions quickly and accurately.

  18. Simultaneous Retrieval of Aerosol and Surface Optical Properties from Combined Airborne- and Ground-Based Direct and Diffuse Radiometric Measurements

    NASA Technical Reports Server (NTRS)

    Gatebe, C. K.; Dubovik, O.; King, M. D.; Sinyuk, A.

    2010-01-01

    This paper presents a new method for simultaneously retrieving aerosol and surface reflectance properties from combined airborne and ground-based direct and diffuse radiometric measurements. The method is based on the standard Aerosol Robotic Network (AERONET) method for retrieving aerosol size distribution, complex index of refraction, and single scattering albedo, but modified to retrieve aerosol properties in two layers, below and above the aircraft, and parameters on surface optical properties from combined datasets (Cloud Absorption Radiometer (CAR) and AERONET data). A key advantage of this method is the inversion of all available spectral and angular data at the same time, while accounting for the influence of noise in the inversion procedure using statistical optimization. The wide spectral (0.34-2.30 m) and angular range (180 ) of the CAR instrument, combined with observations from an AERONET sunphotometer, provide sufficient measurement constraints for characterizing aerosol and surface properties with minimal assumptions. The robustness of the method was tested on observations made during four different field campaigns: (a) the Southern African Regional Science Initiative 2000 over Mongu, Zambia, (b) the Intercontinental Transport Experiment-Phase B over Mexico City, Mexico (c) Cloud and Land Surface Interaction Campaign over the Atmospheric Radiation Measurement (ARM) Central Facility, Oklahoma, USA, and (d) the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) over Elson Lagoon in Barrow, Alaska, USA. The four areas are dominated by different surface characteristics and aerosol types, and therefore provide good test cases for the new inversion method.

  19. Porous microwells for geometry-selective, large-scale microparticle arrays

    NASA Astrophysics Data System (ADS)

    Kim, Jae Jung; Bong, Ki Wan; Reátegui, Eduardo; Irimia, Daniel; Doyle, Patrick S.

    2017-01-01

    Large-scale microparticle arrays (LSMAs) are key for material science and bioengineering applications. However, previous approaches suffer from trade-offs between scalability, precision, specificity and versatility. Here, we present a porous microwell-based approach to create large-scale microparticle arrays with complex motifs. Microparticles are guided to and pushed into microwells by fluid flow through small open pores at the bottom of the porous well arrays. A scaling theory allows for the rational design of LSMAs to sort and array particles on the basis of their size, shape, or modulus. Sequential particle assembly allows for proximal and nested particle arrangements, as well as particle recollection and pattern transfer. We demonstrate the capabilities of the approach by means of three applications: high-throughput single-cell arrays; microenvironment fabrication for neutrophil chemotaxis; and complex, covert tags by the transfer of an upconversion nanocrystal-laden LSMA.

  20. Development and in vitro characterization of insulin loaded whey protein and alginate microparticles.

    PubMed

    Déat-Lainé, Emmanuelle; Hoffart, Valérie; Cardot, Jean-Michel; Subirade, Muriel; Beyssac, Eric

    2012-12-15

    Insulin was encapsulated into microparticles (MP) made of denaturized whey proteins (WP) and alginate (ALG) using an extrusion/cold gelation process with calcium ions. High encapsulation efficiency of 85% was obtained. Influence of insulin on polymeric viscosity and on microparticle behavior was evaluated. Insulin seemed to interact with WP chains by non covalent binding and steric hindrance. This influence was balanced by ALG addition. Nevertheless, insulin was released rapidly by diffusion at both acidic and intestinal dissolution media. Despite this fast in vitro release, WP/ALG MP showed an important enzymatic inhibition effect on trypsin and alpha-chymotrypsin. Thus, WP/ALG MP contributed to an effective insulin protection towards enzymatic degradation. The aforementioned results suggested that WP based microparticles are a promising carrier for improving oral delivery of insulin.

  1. Fabrication and application of porous silicon multilayered microparticles in sustained drug delivery

    NASA Astrophysics Data System (ADS)

    Maniya, Nalin H.; Patel, Sanjaykumar R.; Murthy, Z. V. P.

    2015-09-01

    In the present study, the ability of porous silicon (PSi) based distributed Bragg reflector (DBR) microparticles for sustained and observable delivery of the antiviral agent acyclovir (ACV) is demonstrated. DBR was fabricated by electrochemical etching of single crystal silicon wafers and ultrasonic fractured to prepare microparticles. The hydrogen-terminated native surface of DBR microparticles was modified by thermal oxidation and thermal hydrosilylation. Particles were loaded with ACV and drug release experiments were conducted in phosphate buffered saline. Drug loading and surface chemistry of particles were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Drug release profiles from PSi DBR particles show sustained release behavior from all three studied surface chemistries. Drug release from particles was also monitored from change in color of particles.

  2. Dynamic transformation of self-assembled structures using anisotropic magnetized hydrogel microparticles

    NASA Astrophysics Data System (ADS)

    Yoshida, Satoru; Takinoue, Masahiro; Iwase, Eiji; Onoe, Hiroaki

    2016-08-01

    This paper describes a system through which the self-assembly of anisotropic hydrogel microparticles is achieved, which also enables dynamic transformation of the assembled structures. Using a centrifuge-based microfluidic device, anisotropic hydrogel microparticles encapsulating superparamagnetic materials on one side are fabricated, which respond to a magnetic field. We successfully achieve dynamic assembly using these hydrogel microparticles and realize three different self-assembled structures (single and double pearl chain structures, and close-packed structures), which can be transformed to other structures dynamically via tuning of the precessional magnetic field. We believe that the developed system has potential application as an effective platform for a dynamic cell manipulation and cultivation system, in biomimetic autonomous microrobot organization, and that it can facilitate further understanding of the self-organization and complex systems observed in nature.

  3. Summary of flight tests of an airborne lighting locator system and comparison with ground-based measurements of precipitation and turbulence

    NASA Technical Reports Server (NTRS)

    Fisher, B. D.; Crabill, N. L.

    1981-01-01

    Data from an airborne lightning locator system and data relating to storm intensity obtained by ground-based Doppler radars and the S-band research radar are presented. When comparing lightning locations from the airborne lightning locator system with ground-based Doppler radar measurements of reflectivity and spectrum width, the lightning locations tended to be further from the aircraft position than the Doppler radar contours, but at the same relative bearing from the aircraft as the Doppler contours. The results also show that convective storms generate little or no lightning for a significant part of their life cycle, but can produce at least moderate turbulence. Therefore, it is concluded that a lack of lightning activity cannot be accepted as an inference of a corresponding lack of other hazards to the flight of aircraft through convective storms.

  4. Use of In Situ and Airborne Multiangle Data to Assess MODIS- and Landsat-based Estimates of Surface Albedo

    NASA Technical Reports Server (NTRS)

    Roman, Miguel O.; Gatebe, Charles K.; Shuai, Yanmin; Wang, Zhuosen; Gao, Feng; Masek, Jeff; Schaaf, Crystal B.

    2012-01-01

    The quantification of uncertainty of global surface albedo data and products is a critical part of producing complete, physically consistent, and decadal land property data records for studying ecosystem change. A current challenge in validating satellite retrievals of surface albedo is the ability to overcome the spatial scaling errors that can contribute on the order of 20% disagreement between satellite and field-measured values. Here, we present the results from an uncertain ty analysis of MODerate Resolution Imaging Spectroradiometer (MODIS) and Landsat albedo retrievals, based on collocated comparisons with tower and airborne multi-angular measurements collected at the Atmospheric Radiation Measurement Program s (ARM) Cloud and Radiation Testbed (CART) site during the 2007 Cloud and Land Surface Interaction Campaign (CLAS33 IC 07). Using standard error propagation techniques, airborne measurements obtained by NASA s Cloud Absorption Radiometer (CAR) were used to quantify the uncertainties associated with MODIS and Landsat albedos across a broad range of mixed vegetation and structural types. Initial focus was on evaluating inter-sensor consistency through assessments of temporal stability, as well as examining the overall performance of satellite-derived albedos obtained at all diurnal solar zenith angles. In general, the accuracy of the MODIS and Landsat albedos remained under a 10% margin of error in the SW(0.3 - 5.0 m) domain. However, results reveal a high degree of variability in the RMSE (root mean square error) and bias of albedos in both the visible (0.3 - 0.7 m) and near-infrared (0.3 - 5.0 m) broadband channels; where, in some cases, retrieval uncertainties were found to be in excess of 20%. For the period of CLASIC 07, the primary factors that contributed to uncertainties in the satellite-derived albedo values include: (1) the assumption of temporal stability in the retrieval of 500 m MODIS BRDF values over extended periods of cloud

  5. Airborne laser scanning based quantification of dead-ice melting in recently deglaciated terrain

    NASA Astrophysics Data System (ADS)

    Klug, C.; Sailer, R.; Schümberg, M.; Stötter, J.

    2012-04-01

    Dead-ice is explained as stagnant glacial ice, not influenced by glacier flow anymore. Whenever glaciers have negative mass balances and an accumulation of debris-cover on the surface, dead-ice may form. Although, there are numerous conceptual process-sediment-landform models for the melt-out of dead-ice bodies and areas of dead-ice environments at glacier margins are easily accessible, just a few quantitative studies of dead-ice melting have been carried out so far. Processes and rates of dead-ice melting are commonly believed to be controlled by climate and debris-cover properties, but there is still a lack of knowledge about this fact. This study has a focus on the quantification of process induced volumetric changes caused by dead-ice melting. The research for this project was conducted at Hintereisferner (Ötztal Alps, Austria), Gepatschferner (Ötztal Alps, Austria) and Schrankar (Stubai Alps, Austria), areas for which a good data basis of ALS (Airborne Laser Scanning) measurements is available. 'Hintereisferner' can be characterized as a typical high alpine environment in mid-latitudes, which ranges between approximately 2250 m and 3740 m a.s.l.. The Hintereisferner region has been investigated intensively since many decades. Two dead ice bodies at the orographic right side and one at the orographic left side of the Hintereisferner glacier terminus (approx. at 2500 m to 2550 m a.s.l.) were identified. Since 2001, ALS measurements have been carried out regularly at Hintereisferner resulting in a unique data record of 21 ALS flight campaigns, allowing long-term explorations of the two dead-ice areas. The second study area of 'Gepatschferner' in the Kaunertal ranges between 2060 m and 3520 m a.s.l. and is the second largest glacier of Austria. Near the glacier tongue at the orographic right side a significant dead ice body has formed. The ALS data used for quantification include a period of time of 4 years (2006 - 2010). 'Schrankar' is located in the Western

  6. Circulating Microparticles Alter Formation, Structure, and Properties of Fibrin Clots

    PubMed Central

    Zubairova, Laily D.; Nabiullina, Roza M.; Nagaswami, Chandrasekaran; Zuev, Yuriy F.; Mustafin, Ilshat G.; Litvinov, Rustem I.; Weisel, John W.

    2015-01-01

    Despite the importance of circulating microparticles in haemostasis and thrombosis, there is limited evidence for potential causative effects of naturally produced cell-derived microparticles on fibrin clot formation and its properties. We studied the significance of blood microparticles for fibrin formation, structure, and susceptibility to fibrinolysis by removing them from platelet-free plasma using filtration. Clots made in platelet-free and microparticle-depleted plasma samples from the same healthy donors were analyzed in parallel. Microparticles accelerate fibrin polymerisation and support formation of more compact clots that resist internal and external fibrinolysis. These variations correlate with faster thrombin generation, suggesting thrombin-mediated kinetic effects of microparticles on fibrin formation, structure, and properties. In addition, clots formed in the presence of microparticles, unlike clots from the microparticle-depleted plasma, contain 0.1–0.5-μm size granular and CD61-positive material on fibres, suggesting that platelet-derived microparticles attach to fibrin. Therefore, the blood of healthy individuals contains functional microparticles at the levels that have a procoagulant potential. They affect the structure and stability of fibrin clots indirectly through acceleration of thrombin generation and through direct physical incorporation into the fibrin network. Both mechanisms underlie a potential role of microparticles in haemostasis and thrombosis as modulators of fibrin formation, structure, and resistance to fibrinolysis. PMID:26635081

  7. Microparticles: new light shed on the understanding of venous thromboembolism

    PubMed Central

    Zhou, Lin; Qi, Xiao-long; Xu, Ming-xin; Mao, Yu; Liu, Ming-lin; Song, Hao-ming

    2014-01-01

    Microparticles are small membrane fragments shed primarily from blood and endothelial cells during either activation or apoptosis. There is mounting evidence suggesting that microparticles perform a large array of biological functions and contribute to various diseases. Of these disease processes, a significant link has been established between microparticles and venous thromboembolism. Advances in research on the role of microparticles in thrombosis have yielded crucial insights into possible mechanisms, diagnoses and therapeutic targets of venous thromboembolism. In this review, we discuss the definition and properties of microparticles and venous thromboembolism, provide a synopsis of the evidence detailing the contributions of microparticles to venous thromboembolism, and propose potential mechanisms, by which venous thromboembolism occurs. Moreover, we illustrate a possible role of microparticles in cancer-related venous thromboembolism. PMID:25152025

  8. Using object-based analysis to derive surface complexity information for improved filtering of airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Yan, Menglong; Blaschke, Thomas; Tang, Hongzhao; Xiao, Chenchao; Sun, Xian; Zhang, Daobing; Fu, Kun

    2017-03-01

    Airborne laser scanning (ALS) is a technique used to obtain Digital Surface Models (DSM) and Digital Terrain Models (DTM) efficiently, and filtering is the key procedure used to derive DTM from point clouds. Generating seed points is an initial step for most filtering algorithms, whereas existing algorithms usually define a regular window size to generate seed points. This may lead to an inadequate density of seed points, and further introduce error type I, especially in steep terrain and forested areas. In this study, we propose the use of objectbased analysis to derive surface complexity information from ALS datasets, which can then be used to improve seed point generation.We assume that an area is complex if it is composed of many small objects, with no buildings within the area. Using these assumptions, we propose and implement a new segmentation algorithm based on a grid index, which we call the Edge and Slope Restricted Region Growing (ESRGG) algorithm. Surface complexity information is obtained by statistical analysis of the number of objects derived by segmentation in each area. Then, for complex areas, a smaller window size is defined to generate seed points. Experimental results show that the proposed algorithm could greatly improve the filtering results in complex areas, especially in steep terrain and forested areas.

  9. Retrieval of Component Temperatures of Leaf, Sunlit and Shaded Soil in Maize Canopy Based on Airborne Thermal Infrared Multiangular Observations

    NASA Astrophysics Data System (ADS)

    Li, H.; Yongming, D.; Bian, Z.; Cao, B.; Xiao, Q.; Liu, Q.

    2015-12-01

    Land surface temperature is the key parameter to determine land surface energy budget. Due to land surface rugged geometric structure and different components, pixels in the remote sensing image measured from space are often non-isothermal. Several approaches of decomposing temperatures have been developed recent years. These approaches only focus on two components, soil and leaf. In fact ground-based measurements indicate temperatures of sunlit and shaded leaf are nearly the same while temperatures of sunlit and shaded soil are different significantly. In order to retrieve three component temperatures including leaf, sunlit soil and shaded soil, an analytical parameterized model named FR97 was modified in this paper. The modified FR97 model was calibrated by 4SAIL (Scattering by Arbitrarily Inclined Leaves) model. Bayesian algorithm was used to solve the inversion problem. Finally the inversion algorithm was verified by the airborne observed datasets of Wide-angle Infrared Dual mode line / area Array Scanner (WIDAS) over dense maize area during the Heihe Watershed Allied Telemetry Experimental Research (HiWATER) campaign. The results indicate that the modified FR97 model improves a lot for hotspot effect than original FR97 model. And more accurate component temperatures were retrieved especially for sunlit soil component (RMSE = 1.378°C).

  10. Airborne DIAL and ground-based Raman lidar measurements of water vapor over the Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Ferrare, Richard A.; Browell, Edward V.; Ismail, Syed; Kooi, Susan; Brackett, Vince G.; Clayton, Marian; Notari, Anthony; Butler, Carolyn F.; Barrick, John; Diskin, Glenn; Lesht, Barry; Schmidlin, Frank J.; Turner, Dave; Whiteman, David; Miloshevich, Larry

    2003-12-01

    Measurements of water vapor profiles over the Southern Great Plains acquired by two different lidars are presented. NASA's airborne DIAL Lidar Atmospheric Sensing Experiment (LASE) system measured water vapor, aerosol, and cloud profiles during the ARM/FIRE Water Vapor Experiment (AFWEX) in November-December 2000 and during the International H2O Project (IHOP) in May-June 2002. LASE measurements acquired during AFWEX are used to characterize upper troposphere water vapor measured by ground-based Raman lidars, radiosondes, and in situ aircraft sensors. LASE measurements acquired during IHOP are being used to better understand the influence water vapor variability on the initiation of deep convection and to improve the quantification and prediction of precipitation associated with these storms. The automated Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) Raman Lidar (CARL) has been routinely measuring profiles of water vapor mixing ratio, relative humidity, aerosol extinction, aerosol backscattering, and aerosol and cloud depolarization during both daytime and nighttime operations. Aerosol and water vapor profiles acquired since March 1998 are used to investigate the seasonal variability of the vertical distributions of water vapor and aerosols.

  11. The dynamic monitoring of warm-water discharge based on the airborne high-resolution thermal infrared remote sensing data

    NASA Astrophysics Data System (ADS)

    Shao, Honglan; Xie, Feng; Liu, Chengyu; Liu, Zhihui; Zhang, Changxing; Yang, Gui; Wang, Jianyu

    2016-04-01

    The cooling water discharged from the coastal plants flow into the sea continuously, whose temperature is higher than original sea surface temperature (SST). The fact will have non-negligible influence on the marine environment in and around where the plants site. Hence, it's significant to monitor the temporal and spatial variation of the warm-water discharge for the assessment of the effect of the plant on its surrounding marine environment. The paper describes an approach for the dynamic monitoring of the warm-water discharge of coastal plants based on the airborne high-resolution thermal infrared remote sensing technology. Firstly, the geometric correction was carried out for the thermal infrared remote sensing images acquired on the aircraft. Secondly, the atmospheric correction method was used to retrieve the sea surface temperature of the images. Thirdly, the temperature-rising districts caused by the warm-water discharge were extracted. Lastly, the temporal and spatial variations of the warm-water discharge were analyzed through the geographic information system (GIS) technology. The approach was applied to Qinshan nuclear power plant (NPP), in Zhejiang Province, China. In considering with the tide states, the diffusion, distribution and temperature-rising values of the warm-water discharged from the plant were calculated and analyzed, which are useful to the marine environment assessment.

  12. Neutron Activated Samarium-153 Microparticles for Transarterial Radioembolization of Liver Tumour with Post-Procedure Imaging Capabilities

    PubMed Central

    Hashikin, Nurul Ab. Aziz; Yeong, Chai-Hong; Abdullah, Basri Johan Jeet; Ng, Kwan-Hoong; Chung, Lip-Yong; Dahalan, Rehir; Perkins, Alan Christopher

    2015-01-01

    Introduction Samarium-153 (153Sm) styrene divinylbenzene microparticles were developed as a surrogate for Yttrium-90 (90Y) microspheres in liver radioembolization therapy. Unlike the pure beta emitter 90Y, 153Sm possess both therapeutic beta and diagnostic gamma radiations, making it possible for post-procedure imaging following therapy. Methods The microparticles were prepared using commercially available cation exchange resin, Amberlite IR-120 H+ (620–830 μm), which were reduced to 20–40 μm via ball mill grinding and sieve separation. The microparticles were labelled with 152Sm via ion exchange process with 152SmCl3, prior to neutron activation to produce radioactive 153Sm through 152Sm(n,γ)153Sm reaction. Therapeutic activity of 3 GBq was referred based on the recommended activity used in 90Y-microspheres therapy. The samples were irradiated in 1.494 x 1012 n.cm-2.s-1 neutron flux for 6 h to achieve the nominal activity of 3.1 GBq.g-1. Physicochemical characterisation of the microparticles, gamma spectrometry, and in vitro radiolabelling studies were carried out to study the performance and stability of the microparticles. Results Fourier Transform Infrared (FTIR) spectroscopy of the Amberlite IR-120 resins showed unaffected functional groups, following size reduction of the beads. However, as shown by the electron microscope, the microparticles were irregular in shape. The radioactivity achieved after 6 h neutron activation was 3.104 ± 0.029 GBq. The specific activity per microparticle was 53.855 ± 0.503 Bq. Gamma spectrometry and elemental analysis showed no radioactive impurities in the samples. Radiolabelling efficiencies of 153Sm-Amberlite in distilled water and blood plasma over 48 h were excellent and higher than 95%. Conclusion The laboratory work revealed that the 153Sm-Amberlite microparticles demonstrated superior characteristics for potential use in hepatic radioembolization. PMID:26382059

  13. Paclitaxel-loaded polymeric microparticles: Quantitative relationships between in vitro drug release rate and in vivo pharmacodynamics

    PubMed Central

    Tsai, Max; Lu, Ze; Wientjes, M. Guillaume; Au, Jessie L.-S.

    2013-01-01

    Intraperitoneal therapy (IP) has demonstrated survival advantages in patients with peritoneal cancers, but has not become a widely practiced standard-of-care in part due to local toxicity and sub-optimal drug delivery. Paclitaxel-loaded, polymeric microparticles were developed to overcome these limitations. The present study evaluated the effects of microparticle properties on paclitaxel release (extent and rate) and in vivo pharmacodynamics. In vitro paclitaxel release from microparticles with varying physical characteristics (i.e., particle size, copolymer viscosity and composition) was evaluated. A method was developed to simulate the dosing rate and cumulative dose released in the peritoneal cavity based on the in vitro release data. The relationship between the simulated drug delivery and treatment outcomes of seven microparticle compositions was studied in mice bearing IP human pancreatic tumors, and compared to that of the intravenous Cremophor micellar paclitaxel solution used off-label in previous IP studies. Paclitaxel release from polymeric microparticles in vitro was multi-phasic; release was greater and more rapid from microparticles with lower polymer viscosities and smaller diameters (e.g., viscosity of 0.17 vs. 0.67 dl/g and diameter of 5–6 vs. 50–60 μm). The simulated drug release in the peritoneal cavity linearly correlated with treatment efficacy in mice (r2>0.8, p<0.001). The smaller microparticles, which distribute more evenly in the peritoneal cavity compared to the large microparticles, showed greater dose efficiency. For single treatment, the microparticles demonstrated up to 2-times longer survival extension and 4-times higher dose efficiency, relative to the paclitaxel/Cremophor micellar solution. Upon repeated dosing, the paclitaxel/Cremophor micellar solution showed cumulative toxicity whereas the microparticle that yielded 2-times longer survival did not display cumulative toxicity. The efficacy of IP therapy depended on both

  14. Comparison of field and airborne laser scanning based crown cover estimates across land cover types in Kenya

    NASA Astrophysics Data System (ADS)

    Heiskanen, J.; Korhonen, L.; Hietanen, J.; Heikinheimo, V.; Schafer, E.; Pellikka, P. K. E.

    2015-04-01

    Tree crown cover (CC) provides means for the continuous land cover characterization of complex tropical landscapes with multiple land uses and variable degrees of degradation. It is also a key parameter in the international forest definitions that are basis for monitoring global forest cover changes. Recently, airborne laser scanning (ALS) has emerged as a practical method for accurate CC mapping, but ALS derived CC estimates have rarely been assessed with field data in the tropics. Here, our objective was to compare the various field and ALS based CC estimates across multiple land cover types in the Taita Hills, Kenya. The field data was measured from a total of 178 sample plots (0.1 ha) in 2013 and 2014. The most accurate field measurement method, line intersect sampling using Cajanus tube, was used in 37 plots. Other methods included CC estimate based on the tree inventory data (144 plots), crown relascope (43 plots) and hemispherical photography (30 plots). Three ALS data sets, including two scanners and flying heights, were acquired concurrently with the field data collection. According to the results, the first echo cover index (FCI) from ALS data had good agreement with the most accurate field based CC estimates (RMSD 7.1% and 2.7% depending on the area and scan). The agreement with other field based methods was considerably worse. Furthermore, we observed that ALS cover indices were robust between the different scans in the overlapping area. In conclusion, our results suggest that ALS provides a reliable method for continuous CC mapping across tropical land cover types although dense shrub layer and tree-like herbaceous plants can cause overestimation of CC.

  15. Comparison of Northern Ireland radon maps based on indoor radon measurements and geology with maps derived by predictive modelling of airborne radiometric and ground permeability data.

    PubMed

    Appleton, J D; Miles, J C H; Young, M

    2011-03-15

    Publicly available information about radon potential in Northern Ireland is currently based on indoor radon results averaged over 1-km grid squares, an approach that does not take into account the geological origin of the radon. This study describes a spatially more accurate estimate of the radon potential of Northern Ireland using an integrated radon potential mapping method based on indoor radon measurements and geology that was originally developed for mapping radon potential in England and Wales. A refinement of this method was also investigated using linear regression analysis of a selection of relevant airborne and soil geochemical parameters from the Tellus Project. The most significant independent variables were found to be eU, a parameter derived from airborne gamma spectrometry measurements of radon decay products in the top layer of soil and exposed bedrock, and the permeability of the ground. The radon potential map generated from the Tellus data agrees in many respects with the map based on indoor radon data and geology but there are several areas where radon potential predicted from the airborne radiometric and permeability data is substantially lower. This under-prediction could be caused by the radon concentration being lower in the top 30 cm of the soil than at greater depth, because of the loss of radon from the surface rocks and soils to air.

  16. Improvement of an encapsulation process for the preparation of pro- and prebiotics-loaded bioadhesive microparticles by using experimental design.

    PubMed

    Pliszczak, D; Bourgeois, S; Bordes, C; Valour, J P; Mazoyer, M A; Orecchioni, A M; Nakache, E; Lantéri, P

    2011-09-18

    The purpose of this study was to design a new vaginal bioadhesive delivery system based on pectinate-hyaluronic acid microparticles for probiotics and prebiotics encapsulation. Probiotic strains and prebiotic were selected for their abilities to restore vaginal ecosystem. Microparticles were produced by emulsification/gelation method using calcium as cross-linking agent. In the first step, preliminary experiments were conducted to study the influence of the main formulation and process parameters on the size distribution of unloaded microparticles. Rheological measurements were also performed to investigate the bioadhesive properties of the gels used to obtain the final microparticles. Afterwards an experimental design was performed to determine the operating conditions suitable to obtain bioadhesive microparticles containing probiotics and prebiotics. Experimental design allowed us to define two important parameters during the microencapsulation process: the stirring rate during the emulsification step and the pectin concentration. The final microparticles had a mean diameter of 137μm and allowed a complete release of probiotic strains after 16h in a simulated vaginal fluid at +37°C.

  17. Diclofenac sodium loaded-cellulose acetate butyrate: effect of processing variables on microparticles properties, drug release kinetics and ulcerogenic activity.

    PubMed

    Barakat, Nahla S; Ahmad, Amany A E

    2008-02-01

    The aim of this study was to develop and characterize diclofenac sodium loaded-cellulose acetate butyrate microparticles in order to obtain a controlled-release system. The influence of the type of polymer, the volume and composition of the internal phase, drug loading, surfactant concentration and additive added on microparticles characteristics (particle size, encapsulation efficiency, surface morphology and in vitro release profiles) was studied to optimize the microparticles system. The resultant microparticles were evaluated for the recovery, average particle size, drug loading and incorporation efficiency. The microparticles exhibited good flowing nature and compressibility index when compared to pure drug. Dissolution rate of diclofenac sodium in phosphate buffer (pH 6.8) increased with increases in initial drug loading, surfactant concentration and addition of alcohol as co-solvent but decreased with increases in the concentration of additives such as Gantrez AN or Eudragit S100 in the internal phase. The dissolution data showed a Higuchi diffusion pattern for most of the formulations. About 56-81% reduction in ulcerogenic activity was observed with microparticles containing Eudragit S100 17-25%, based on total polymer concentration, when compared with pure diclofenac sodium.

  18. Airborne Visible Laser Optical Communications Program (AVLOC)

    NASA Technical Reports Server (NTRS)

    Ward, J. H.

    1975-01-01

    The design, development, and operation of airborne and ground-based laser communications and laser radar hardware is described in support of the Airborne Visible Laser Optical Communication program. The major emphasis is placed on the development of a highly flexible test bed for the evaluation of laser communications systems techniques and components in an operational environment.

  19. Dissolution of two-phase microsystems: Gas and liquid microparticle dissolution and dehydration of biomaterials

    NASA Astrophysics Data System (ADS)

    Duncan, Phillip Brent

    A main focus of this research is to develop techniques to study the dissolution process of two-phase microsystems on a single microparticle basis. This dissertation introduces a systematic approach to investigate the formation of microparticles to fulfill the need for rational design of microspheres for a range of applications. This novel method is based on the micropipet manipulation technique and can essentially test any system, where the continuous phase is a liquid and the dispersed phase is practically any phase, a gas (foam), a liquid (emulsion), or a solid (suspension). It is possible to study single microparticle volumes in the picoliter to nanoliter scale, which is on the same size-scale as particles created in bulk suspensions, microsphere processes, and applications. The ability to create, isolate, observe, and manipulate individual gas, liquid or solid microparticles in a well-defined and controlled liquid environment was found to be ideal to study gas microbubbles and microparticles, liquid microdroplets, and the dehydration of dissolved solutes. Subsequently, one can directly measure the dissolution rate and, when a solute is present, calculate its concentration during the dissolution process. Microbubble or microdroplet dissolution in a second phase is driven by two independent factors, a concentration gradient (undersaturation of the dispersed phase in the continuous phase) and a pressure gradient (due to the Laplace-overpressure inside the microparticle created by the surface tension). Experimentally, each of these driving forces can be independently tested. Both the gas microparticle and pure liquid microdroplet dissolution can be predicted by a simple theory based on the diffusion coefficient and solubility limit of the dispersed phase in the continuous phase. The dehydration of a salt ion solution microdroplet results in the nucleation and growth of a crystal, while the dehydration of proteins leads to glassification of the protein. The water

  20. Encapsulation of Volatile Compounds in Silk Microparticles.

    PubMed

    Elia, Roberto; Guo, Jin; Budijono, Stephanie; Normand, Valery; Benczédi, Daniel; Omenetto, Fiorenzo; Kaplan, David L

    2015-07-01

    Various techniques have been employed to entrap fragrant oils within microcapsules or microparticles in the food, pharmaceutical, and chemical industries for improved stability and delivery. In the present work we describe the use of silk protein microparticles for encapsulating fragrant oils using ambient processing conditions to form an all-natural biocompatible matrix. These microparticles are stabilized via physical crosslinking, requiring no chemical agents, and are prepared with aqueous and ambient processing conditions using polyvinyl alcohol-silk emulsions. The particles were loaded with fragrant oils via direct immersion of the silk particles within an oil bath. The oil-containing microparticles were coated using alternating silk and polyethylene oxide layers to control the release of the oil from the microspheres. Particle morphology and size, oil loading capacity, release rates as well as silk-oil interactions and coating treatments were characterized. Thermal analysis demonstrated that the silk coatings can be tuned to alter both retention and release profiles of the encapsulated fragrance. These oil containing particles demonstrate the ability to adsorb and controllably release oils, suggesting a range of potential applications including cosmetic and fragrance utility.

  1. Hydrophobicity of silver surfaces with microparticle geometry

    NASA Astrophysics Data System (ADS)

    Macko, Ján; Oriňaková, Renáta; Oriňak, Andrej; Kovaľ, Karol; Kupková, Miriam; Erdélyi, Branislav; Kostecká, Zuzana; Smith, Roger M.

    2016-11-01

    The effect of the duration of the current deposition cycle and the number of current pulses on the geometry of silver microstructured surfaces and on the free surface energy, polarizability, hydrophobicity and thus adhesion force of the silver surfaces has been investigated. The changes in surface hydrophobicity were entirely dependent on the size and density of the microparticles on the surface. The results showed that formation of the silver microparticles was related to number of current pulses, while the duration of one current pulse played only a minor effect on the final surface microparticle geometry and thus on the surface tension and hydrophobicity. The conventional geometry of the silver particles has been transformed to the fractal dimension D. The surface hydrophobicity depended predominantly on the length of the dendrites not on their width. The highest silver surface hydrophobicity was observed on a surface prepared by 30 current pulses with a pulse duration of 1 s, the lowest one when deposition was performed by 10 current pulses with a duration of 0.1 s. The partial surface tension coefficients γDS and polarizability kS of the silver surfaces were calculated. Both parameters can be applied in future applications in living cells adhesion prediction and spectral method selection. Silver films with microparticle geometry showed a lower variability in final surface hydrophobicity when compared to nanostructured surfaces. The comparisons could be used to modify surfaces and to modulate human cells and bacterial adhesion on body implants, surgery instruments and clean surfaces.

  2. Scaffold pore space modulation through intelligent design of dissolvable microparticles.

    PubMed

    Liebschner, Michael A K; Wettergreen, Matthew

    2012-01-01

    The goal of this area of research is to manipulate the pore space of scaffolds through the application of an intelligent design concept on dissolvable microparticles. To accomplish this goal, we developed an efficient and repeatable process for fabrication of microparticles from multiple materials using a combination of rapid prototyping (RP) and soft lithography. Phase changed 3D printing was used to create masters for PDMS molds. A photocrosslinkable polymer was then delivered into these molds to make geometrically complex 3D microparticles. This repeatable process has demonstrated to generate the objects with greater than 95% repeatability with complete pattern transfer. This process was illustrated for three different shapes of various complexities. The shapes were based on the extrusion of 2D shapes. This may allow simplification of the fabrication process in the future combined with a direct transfer of the findings. Altering the shapes of particles used for porous scaffold fabrication will allow for tailoring of the pore shapes, and therefore their biological function within a porous tissue engineering scaffold. Through permeation experiments, we have shown that the pore geometry may alter the permeability coefficient of scaffolds while influencing mechanical properties to a lesser extent. By selecting different porogen shapes, the nutrition transport and scaffold degradation can be significantly influenced with minimal effect on the mechanical integrity of the construct. In addition, the different shapes may allow a control of drug release by modifying their surface-to-volume ratio, which could modulate drug delivery over time. While soft lithography is currently used with photolithography, its high precision is offset by high cost of production. The employment of RP to a specific resolution offers a much less expensive alternative with increased throughput due to the speed of current RP systems.

  3. Evaluation of alternative strategies to MERV 16-based air filtration systems for reduction of the risk of airborne spread of porcine reproductive and respiratory syndrome virus.

    PubMed

    Dee, Scott; Pitkin, Andrea; Deen, John

    2009-07-02

    Porcine reproductive and respiratory syndrome (PRRS) is a re-emerging disease of pigs and a growing threat to the global swine industry. For sustainable disease control it is critical to prevent the airborne spread of the etiologic agent, PRRS virus, between pig populations. The application of MERV 16-based air filtration systems to swine facilities in an effort to reduce this risk has been proposed; however, due to the cost and air flow restrictions of such systems the need for alternative strategies has arisen. Therefore, the objective of this study was to evaluate 3 groups of alternative biosecurity strategies for reducing the risk of the airborne spread of PRRSV. Strategies evaluated included mechanical filters, antimicrobial filters and a disinfectant-EVAP (evaporative cooling) system. Results from this study indicate that while alternatives to MERV 16-based biosecurity protocols for protecting farms from the airborne spread of PRRSV are available, further information on their efficacy in the field is needed before conclusions can be drawn.

  4. CALIOPE airborne CO{sub 2} DIAL (CACDI) system design

    SciTech Connect

    Mietz, D.; Archuleta, B.; Archuleta, J.

    1997-09-01

    Los Alamos National Laboratory is currently developing an airborne CO{sub 2} Differential Absorption Lidar (DIAL) system based on second generation technology demonstrated last summer at NTS. The CALIOPE Airborne CO{sub 2} DIAL (CACDI) system requirements have been compiled based on the mission objectives and SONDIAL model trade studies. Subsystem designs have been developed based on flow down from these system requirements, as well as experience gained from second generation ground tests and N-ABLE (Non-proliferation AirBorne Lidar Experiments) airborne experiments. This paper presents the CACDI mission objectives, system requirements, the current subsystem design, and provides an overview of the airborne experimental plan.

  5. Hierarchical assembly of viral nanotemplates with encoded microparticles via nucleic acid hybridization.

    PubMed

    Tan, Wui Siew; Lewis, Christina L; Horelik, Nicholas E; Pregibon, Daniel C; Doyle, Patrick S; Yi, Hyunmin

    2008-11-04

    We demonstrate hierarchical assembly of tobacco mosaic virus (TMV)-based nanotemplates with hydrogel-based encoded microparticles via nucleic acid hybridization. TMV nanotemplates possess a highly defined structure and a genetically engineered high density thiol functionality. The encoded microparticles are produced in a high throughput microfluidic device via stop-flow lithography (SFL) and consist of spatially discrete regions containing encoded identity information, an internal control, and capture DNAs. For the hybridization-based assembly, partially disassembled TMVs were programmed with linker DNAs that contain sequences complementary to both the virus 5' end and a selected capture DNA. Fluorescence microscopy, atomic force microscopy (AFM), and confocal microscopy results clearly indicate facile assembly of TMV nanotemplates onto microparticles with high spatial and sequence selectivity. We anticipate that our hybridization-based assembly strategy could be employed to create multifunctional viral-synthetic hybrid materials in a rapid and high-throughput manner. Additionally, we believe that these viral-synthetic hybrid microparticles may find broad applications in high capacity, multiplexed target sensing.

  6. Dating archaeological copper/bronze artifacts by using the voltammetry of microparticles.

    PubMed

    Doménech-Carbó, Antonio; Doménech-Carbó, María Teresa; Capelo, Sofia; Pasíes, Trinidad; Martínez-Lázaro, Isabel

    2014-08-25

    A method for dating copper/bronze archaeological objects aged in atmospheric environments is proposed based on the specific signals for cuprite and tenorite corrosion products measured through the voltammtry of microparticles method. The tenorite/cuprite ratio increased with the corrosion time and fitted to a potential law that yielded a calibration curve usable for dating purposes.

  7. Simultaneous observations of lower tropospheric continental aerosols with a ground-based, an airborne, and the spaceborne CALIOP lidar system

    NASA Astrophysics Data System (ADS)

    Chazette, P.; Raut, J.-C.; Dulac, F.; Berthier, S.; Kim, S.-W.; Royer, P.; Sanak, J.; Loaëc, S.; Grigaut-Desbrosses, H.

    2010-08-01

    We present an original experiment with multiple lidar systems operated simultaneously to study the capability of the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP), on board the Cloud-Aerosol Lidar Pathfinder Satellite Observation (CALIPSO), to infer aerosol optical properties in the lower troposphere over a midlatitude continental site where the aerosol load is low to moderate. The experiment took place from 20 June to 10 July 2007 in southern France. The results are based on three case studies with measurements coincident to CALIOP observations: the first case study illustrates a large-scale pollution event with an aerosol optical thickness at 532 nm (τa532) of ˜0.25, and the two other case studies are devoted to background conditions due to aerosol scavenging by storms with τa532 <0.1. Our experimental approach involved ground-based and airborne lidar systems as well as Sun photometer measurements when the conditions of observation were favorable. Passive spaceborne instruments, namely the Spinning Enhanced Visible and Infrared Imager (SEVERI) and the Moderate-resolution Imaging Spectroradiometer (MODIS), are used to characterize the large-scale aerosol conditions. We show that complex topographical structures increase the complexity of the aerosol analysis in the planetary boundary layer by CALIOP when τa532 is lower than 0.1 because the number of available representative profiles is low to build a mean CALIOP profile with a good signal-to-noise ratio. In a comparison, the aerosol optical properties inferred from CALIOP and those deduced from the other active and passive remote sensing observations in the pollution plume are found to be in reasonable agreement. Level-2 aerosol products of CALIOP are consistent with our retrievals.

  8. Clinical Relevance of Microparticles from Platelets and Megakaryocytes

    PubMed Central

    Italiano, Joseph E.; Mairuhu, Albert T.A.; Flaumenhaft, Robert

    2011-01-01

    Purpose of review Platelet microparticles were identified more than forty years ago and are the most abundant circulating microparticle subtype. Yet fundamental questions about their formation and role in human disease are just beginning to be understood at the cellular and molecular level. This review will address mechanisms of platelet microparticle generation and evaluate our current understanding of their clinical relevance. Recent findings New evidence indicates that the majority of CD41+ microparticles circulating in healthy individuals derive directly from megakaryocytes. CD41+ microparticles also form from activated platelets upon loss of cytoskeleton-membrane adhesion, which occurs in a multitude of disease states characterized by elevated platelet microparticle levels. More recent studies have demonstrated that platelet microparticles function as a transport and delivery system for bioactive molecules, participating in hemostasis and thrombosis, inflammation, malignancy infection transfer, angiogenesis, and immunity. The mechanism of platelet microparticle participation in specific disease entities such as rheumatoid arthritis has been elucidated. Summary Continued research into how platelet microparticles are generated and function as a transcellular delivery system will advance our basic understanding of microparticle physiology and may enable new strategies for treatment of select disease entities. PMID:20739880

  9. High resolution mapping of the tropospheric NO2 distribution in three Belgian cities based on airborne APEX remote sensing

    NASA Astrophysics Data System (ADS)

    Tack, Frederik; Merlaud, Alexis; Fayt, Caroline; Danckaert, Thomas; Iordache, Daniel; Meuleman, Koen; Deutsch, Felix; Adriaenssens, Sandy; Fierens, Frans; Van Roozendael, Michel

    2015-04-01

    An approach is presented to retrieve tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs) and to map the NO2 two dimensional distribution at high resolution, based on Airborne Prism EXperiment (APEX) observations. APEX, developed by a Swiss-Belgian consortium on behalf of ESA (European Space Agency), is a pushbroom hyperspectral imager with a high spatial (approximately 3 m at 5000 m ASL), spectral (413 to 2421 nm in 533 narrow, contiguous spectral bands) and radiometric (14-bit) resolution. VCDs are derived, following a similar approach as described in the pioneering work of Popp et al. (2012), based on (1) spectral calibration and spatial binning of the observed radiance spectra in order to improve the spectral resolution and signal-to-noise ratio, (2) Differential Optical Absorption Spectroscopy (DOAS) analysis of the pre-processed spectra in the visible wavelength region, with a reference spectrum containing low NO2 absorption, in order to quantify the abundance of NO2 along the light path, based on its molecular absorption structures and (3) radiative transfer modeling for air mass factor calculation in order to convert slant to vertical columns. This study will be done in the framework of the BUMBA (Belgian Urban NO2 Monitoring Based on APEX hyperspectral data) project. Dedicated flights with APEX mounted in a Dornier DO-228 airplane, operated by Deutsches Zentrum für Luft- und Raumfahrt (DLR), are planned to be performed in Spring 2015 above the three largest and most heavily polluted Belgian cities, i.e. Brussels, Antwerp and Liège. The retrieved VCDs will be validated by comparison with correlative ground-based and car-based DOAS observations. Main objectives are (1) to assess the operational capabilities of APEX to map the NO2 field over an urban area at high spatial and spectral resolution in a relatively short time and cost-effective way, and to characterise all aspects of the retrieval approach; (2) to use the APEX NO2 measurements

  10. a Segment-Based Approach for DTM Derivation of Airborne LIDAR Data

    NASA Astrophysics Data System (ADS)

    Tang, Dejin; Zhou, Xiaoming; Jiang, Jie; Li, Caiping

    2016-06-01

    With the characteristics of LIDAR system, raw point clouds represent both terrain and non-terrain surface. In order to generate DTM, the paper introduces one improved filtering method based on the segment-based algorithms. The method generates segments by clustering points based on surface fitting and uses topological and geometric properties for classification. In the process, three major steps are involved. First, the whole datasets is split into several small overlapping tiles. For each tile, by removing wall and vegetation points, accurate segments are found. The segments from all tiles are assigned unique segment number. In the following step, topological descriptions for the segment distribution pattern and height jump between adjacent segments are identified in each tile. Based on the topology and geometry, segment-based filtering algorithm is performed for classification in each tile. Then, based on the spatial location of the segment in one tile, two confidence levels are assigned to the classified segments. The segments with low confidence level are because of losing geometric or topological information in one tile. Thus, a combination algorithm is generated to detect corresponding parts of incomplete segment from multiple tiles. Then another classification algorithm is performed for these segments. The result of these segments will have high confidence level. After that, all the segments in one tile have high confidence level of classification result. The final DTM will add all the terrain segments and avoid duplicate points. At the last of the paper, the experiment show the filtering result and be compared with the other classical filtering methods, the analysis proves the method has advantage in the precision of DTM. But because of the complicated algorithms, the processing speed is little slower, that is the future improvement which should been researched.

  11. Poly(vinyl alcohol)-coated chitosan microparticles act as an effective oral vaccine delivery system for hepatitis B vaccine in rat model.

    PubMed

    Shrestha, Bijaya; Rath, Jyoti Prakash

    2014-12-01

    The present study focused on the development of an effective oral vaccine delivery system of poly(vinyl alcohol)-coated chitosan microparticles-based recombinant hepatitis B vaccine. Chitosan microparticles were prepared by ionotropic gelation technique; they were loaded with recombinant hepatitis B vaccine and coated with poly(vinyl alcohol). The average sizes of the microparticles were measured in the range of 100-410 nm. The optimal loading capacity and loading efficiency were recorded around 3.4 and 74%, respectively. In vitro release study shows that the prepared microparticles release the antigen in a sustained manner. Moreover, the microparticles were resistant to simulated gastric environment and release the antigen in the targeted intestinal milieu. Furthermore, oral immunisation of rats with poly(vinyl alcohol)-coated chitosan hepatitis-B microparticles vaccine shows comparable seroprotective immune response to presently practiced intramuscular vaccination. The results demonstrated that poly(vinyl alcohol)-coated chitosan microparticles have the potential for being used as an oral vaccine delivery system for hepatitis B vaccine and may be a suitable alternative for needle-based vaccination.

  12. Summertime tropospheric ozone enhancement associated with a cold front passage due to stratosphere-to-troposphere transport and biomass burning: Simultaneous ground-based lidar and airborne measurements

    NASA Astrophysics Data System (ADS)

    Kuang, Shi; Newchurch, Michael J.; Johnson, Matthew S.; Wang, Lihua; Burris, John; Pierce, Robert B.; Eloranta, Edwin W.; Pollack, Ilana B.; Graus, Martin; Gouw, Joost; Warneke, Carsten; Ryerson, Thomas B.; Markovic, Milos Z.; Holloway, John S.; Pour-Biazar, Arastoo; Huang, Guanyu; Liu, Xiong; Feng, Nan

    2017-01-01

    Stratosphere-to-troposphere transport (STT) and biomass burning (BB) are two important natural sources for tropospheric ozone that can result in elevated ozone and air-quality episode events. High-resolution observations of multiple related species are critical for complex ozone source attribution. In this article, we present an analysis of coinciding ground-based and airborne observations, including ozone lidar, ozonesonde, high spectral resolution lidar (HSRL), and multiple airborne in situ measurements, made on 28 and 29 June 2013 during the Southeast Nexus field campaign. The ozone lidar and HSRL reveal detailed ozone and aerosol structures as well as the temporal evolution associated with a cold front passage. The observations also captured two enhanced (+30 ppbv) ozone layers in the free troposphere (FT), which were determined from this study to be caused by a mixture of BB and stratospheric sources. The mechanism for this STT is tropopause folding associated with a cutoff upper level low-pressure system according to the analysis of its potential vorticity structure. The depth of the tropopause fold appears to be shallow for this case compared to events observed in other seasons; however, the impact on lower tropospheric ozone was clearly observed. This event suggests that strong STT may occur in the southeast United States during the summer and can potentially impact lower troposphere during these times. Statistical analysis of the airborne observations of trace gases suggests a coincident influence of BB transport in the FT impacting the vertical structure of ozone during this case study.

  13. Optimal attributes for the object based detection of giant reed in riparian habitats: A comparative study between Airborne High Spatial Resolution and WorldView-2 imagery

    NASA Astrophysics Data System (ADS)

    Fernandes, Maria Rosário; Aguiar, Francisca C.; Silva, João M. N.; Ferreira, Maria Teresa; Pereira, José M. C.

    2014-10-01

    Giant reed is an aggressive invasive plant of riparian ecosystems in many sub-tropical and warm-temperate regions, including Mediterranean Europe. In this study we tested a set of geometric, spectral and textural attributes in an object based image analysis (OBIA) approach to map giant reed invasions in riparian habitats. Bagging Classification and Regression Tree were used to select the optimal attributes and to build the classification rules sets. Mapping accuracy was performed using landscape metrics and the Kappa coefficient to compare the topographical and geometric similarity between the giant reed patches obtained with the OBIA map and with a validation map derived from on-screen digitizing. The methodology was applied in two high spatial resolution images: an airborne multispectral imagery and the newly WorldView-2 imagery. A temporal coverage of the airborne multispectral images was radiometrically calibrated with the IR-Mad transformation and used to assess the influence of the phenological variability of the invader. We found that optimal attributes for giant reed OBIA detection are a combination of spectral, geometric and textural information, with different scoring selection depending on the spectral and spatial characteristics of the imagery. WorldView-2 showed higher mapping accuracy (Kappa coefficient of 77%) and spectral attributes, including the newly yellow band, were preferentially selected, although a tendency to overestimate the total invaded area, due to the low spatial resolution (2 m of pixel size vs. 50 cm) was observed. When airborne images were used, geometric attributes were primarily selected and a higher spatial detail of the invasive patches was obtained, due to the higher spatial resolution. However, in highly heterogeneous landscapes, the low spectral resolution of the airborne images (4 bands instead of the 8 of WorldView-2) reduces the capability to detect giant reed patches. Giant reed displays peculiar spectral and geometric

  14. Steroid/mucokinetic hybrid nanoporous microparticles for pulmonary drug delivery.

    PubMed

    Tewes, Frederic; Paluch, Krzysztof J; Tajber, Lidia; Gulati, Karan; Kalantri, Devesh; Ehrhardt, Carsten; Healy, Anne Marie

    2013-11-01

    In a number of pulmonary diseases, patients may develop abnormally viscous mucus reducing drug efficacy. To increase budesonide diffusion within lung fluid, we developed nanoporous microparticles (NPMPs) composed of budesonide and a mucokinetic, ambroxol hydrochloride, to be inhaled as a dry powder. Budesonide/ambroxol-HCl particles were formulated by spray drying and characterised by various physicochemicals methods. Aerodynamic properties were evaluated using a cascade impactor. Drugs apparent permeability coefficients were calculated across mucus producing Calu-3 cell monolayers cultivated at an air-liquid interface. Microparticles made only from budesonide and ambroxol-HCl had smooth surfaces. In the presence of ammonium carbonate ((NH4)2CO3), NPMPs were formulated, with significantly (P<0.05) superior aerodynamic properties (MMAD=1.87±0.22 μm and FPF=84.0±2.6%). The formation of nanopores and the increase in the specific surface area in the presence of (NH4)2CO3 were mainly attributed to the neutralisation of ambroxol-HCl to form ambroxol base. Thus, ambroxol base could behave in the same manner as budesonide and prompt nanoprecipitation when spray dried from an ethanol/water mix occurs. All formulations were amorphous, which should enhance dissolution rate and diffusion through lung fluid. These NPMPs were able to improve budesonide permeability across mucus producing Calu-3 cell monolayers (P<0.05) suggesting that they should be able to enhance budesonide diffusion in the lungs through viscous mucus.

  15. Assessment of seismic loading on structures based on airborne LiDAR data from the Kalochori urban area (N. Greece)

    NASA Astrophysics Data System (ADS)

    Rovithis, Emmanouil; Kirtas, Emmanouil; Marini, Eleftheria; Bliziotis, Dimitris; Maltezos, Evangelos; Pitilakis, Dimitris; Makra, Konstantia; Savvaidis, Alexandros

    2016-08-01

    Airborne LiDAR monitoring integrated with field data is employed to assess the fundamental period and the seismic loading of structures composing an urban area under prescribed earthquake scenarios. Α piecewise work-flow is adopted by combining geometrical data of the building stock derived from a LiDAR-based 3D city model, structural data from in-situ inspections on representative city blocks and results of soil response analyses. The procedure is implemented in the residential area of Kalochori, (west of Thessaloniki in Northern Greece). Special attention is paid to the in-situ inspection of the building stock in order to discriminate recordings between actual buildings and man-made constructions that do not conform to seismic design codes and to acquire additional building stock data on structural materials, typologies and number of stories which is not feasible by the LiDAR process. The processed LiDAR and field data are employed to compute the fundamental period of each building by means of code-defined formulas. Knowledge of soil conditions in the Kalochoti area allows for soil response analyses to obtain free-field at ground surface under earthquake scenarios with varying return period. Upon combining the computed vibrational characteristics of the structures with the free-field response spectra, the seismic loading imposed on the structures of the urban area under investigation is derived for each one of the prescribed seismic motions. Results are presented in GIS environment in the form of spatially distributed spectral accelerations with direct implications in seismic vulnerability studies of an urban area.

  16. Airborne In Situ and Ground-based Polarimetric Radar Measurements of Tropical Convection in Support of CRYSTAL-FACE

    NASA Technical Reports Server (NTRS)

    Poellot, Michael R.; Kucera, Paul A.

    2004-01-01

    This report describes the work performed by the University of North Dakota (UND) under NASA Grant NAG5-11509, titled Airborne In Situ and Ground-based Polarimetric Radar Measurements of Tropical Convection in Support of CRYSTAL-FACE. This work focused on the collection of data by two key platforms: the UND Citation II research aircraft and the NASA NPOL radar system. The CRYSTAL-FACE (C-F) mission addresses several key issues from the NASA Earth System Enterprise, including the variability of water in the atmosphere, the forcing provided by tropical cirrus and the response of the Earth system to this forcing. In situ measurements and radar observations of tropical convection, cirrus clouds and their environment are core elements of C-F. One of the primary issues that C-F is addressing is the relationship of tropical cirrus anvils to precipitating deep convection. The in situ measurements from C-F are being used to validate remote sensing of Earth-Atmosphere properties, increase our knowledge of upper tropospheric water vapor and its distribution, and increase our knowledge of tropical cirrus cloud morphology and composition. Radar measurements, especially polarimetric diversity observations available fiom the NASA NPOL radar, are providing essential information about the initiation, modulation, and dissipation of convective cores and the generation of associated anvils in tropical convection. Specifically, NPOL radar measurements contain information about convective intensity and its vertical structure for comparison with thermodynamic and kinematic environmental measurements observed from soundings. Because of the polarimetric diversity of MOL, statistics on bulk microphysical properties can be retrieved and compared to the other characteristics of convection and associated cirrus anvils. In summary, the central objectives of this proposal were to deploy the UND Citation research aircraft as an in situ sensing platform for this mission and to provide collaborative

  17. Airborne and ground-based measurements of the trace gases and particles emitted from prescribed fires in the United States

    SciTech Connect

    Burling, Ian; Yokelson, Robert J.; Akagi, Sheryl; Urbanski, Shawn; Wold, Cyle E.; Griffith, David WT; Johnson, Timothy J.; Reardon, James; Weise, David

    2011-12-07

    We measured the emission factors for 19 trace gas species and particulate matter (PM2.5) from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation. We also measured the emissions of phenol, another aqueous phase secondary organic aerosol precursor. Our data confirm previous suggestions that urban deposition can impact the NOx emission factors and thus subsequent plume chemistry. For two fires, we measured the emissions in the convective smoke plume from our airborne platform at the same time the unlofted residual smoldering combustion emissions were measured with our ground-based platform after the flame front passed through. The smoke from residual smoldering combustion was characterized by emission factors for hydrocarbon and oxygenated organic species that were up to ten times higher than in the lofted plume, including significant 1,3-butadiene and isoprene concentrations which were not observed in the lofted plume. This should be considered in modeling the air quality impacts of smoke that disperses at ground level, and we show that the normally-ignored unlofted emissions can also significantly impact estimates of total emissions. Preliminary evidence of large emissions of monoterpenes was seen in the residual smoldering spectra, but we have not yet quantified these emissions. These data should lead to an improved capacity to model the impacts of biomass burning in similar

  18. Developing an Evaluation Method for Middleware-Based Software Architectures of Airborne Mission Systems

    DTIC Science & Technology

    2007-07-01

    documented using an architecture knowledge management tool also developed at NICTA. 31 DSTO-TR-2204 9. References [Ali- Babar & Gorton 2004] [Ali... Babar et al. 2005] [Allen et al. 2002] [Bachmann et al. 2003] [Barbacci et al. 1995] [Bass et al. 2003] [Basse/al. 2001] [Bengstsson et al. 2004...Boehm&In 1996] [CORBA 2006] [Clements et al. 2001] Ali- Babar , M. & Gorton, I. (2004) Comparison of Scenario-Based Software Architecture

  19. A Web-Based Library and Algorithm System for Satellite and Airborne Image Products

    DTIC Science & Technology

    2011-06-28

    Sequoia Scientific, Inc., and Dr. Paul Bissett at FERI, under other 6.1/6.2 program funding. 2 A Web-Based Library And Algorithm System For...of the spectrum matching approach to inverting hyperspectral imagery created by Drs. C. Mobley ( Sequoia Scientific) and P. Bissett (FERI...algorithms developed by Sequoia Scientific and FERI. Testing and Implementation of Library This project will result in the delivery of a WeoGeo

  20. LIF-instrument for Airborne and Ground-Based Measurement of OH and HO2 Radicals in the Troposphere.

    NASA Astrophysics Data System (ADS)

    Broch, Sebastian; Bachner, Mathias; Dahlhoff, Knut; Holland, Frank; Hofzumahaus, Andreas; Jansen, Peter; Meier, Andreas; Raak, Dominik; Wolters, Jörg; Wahner, Andreas

    2010-05-01

    The radicals OH and HO2 (also named HOx) play an important role in the chemical degradation and transformation of most trace gases in the troposphere. The rate of these processes depends strongly on the magnitude of the radical concentrations. Due to their high reactivity, their concentrations are very low (sub pptv and pptv range) and exhibit a strong regional variability. Therefore exact measurement of HOx in different regions and at different altitudes in the troposphere are very important for the understanding and modelling of the self cleaning ability of the atmosphere. Here, we present the technical concept and results of laboratory test measurements of a new, mobile instrument for measurement of OH and HO2 radicals based on the proven laser induced fluorescence (LIF) technique (Holland et al., 1995, 2003; Schlosser et al., 2007, 2009). The instrument is planned to be used for ground-based field measurements, for airborne application on a Zeppelin (h = 0-2 km) and on the new German research aircraft HALO (Gulfstream V, h = 0-15 km). The setup of the new instrument is modular to allow different configurations for different applications and all components are newly designed to reduce weight, size and power requirement. For the implementation on HALO completely new air-inlet systems for OH and HO2 were developed at Forschungszentrum Jülich. The OH inlet is based on the shrouded-inlet design by Eisele et al. (1997). The design has been modified to reduce size and weight, and cope with the flight conditions and certification requirements of HALO. These are different than those for the original design, like higher speed, greater ceiling height and strength against bird strike. Compared to our ground-based measurement system, the aircraft inlet requires long inlet tubes which modify the detection sensitivity and possible interferences. Since the sensitivity of our instrument depends on ambient pressure, the OH inlet system is equipped with a calibration system

  1. Theoretical analysis of ferromagnetic microparticles in streaming liquid under the influence of external magnetic forces

    NASA Astrophysics Data System (ADS)

    Brandl, Martin; Mayer, Michael; Hartmann, Jens; Posnicek, Thomas; Fabian, Christian; Falkenhagen, Dieter

    2010-09-01

    The microsphere based detoxification system (MDS) is designed for high specific toxin removal in extracorporeal blood purification using functionalized microparticles. A thin wall hollow fiber membrane filter separates the microparticle-plasma suspension from the bloodstream. For patient safety, it is necessary to have a safety system to detect membrane ruptures that could lead to the release of microparticles into the bloodstream. A non-invasive optical detection system including a magnetic trap is developed to monitor the extracorporeal venous bloodstream for the presence of released microparticles. For detection, fluorescence-labeled ferromagnetic beads are suspended together with adsorbent particles in the MDS circuit. In case of a membrane rupture, the labeled particles would be released into the venous bloodstream and partly captured by the magnetic trap of the detector. A physical model based on fluidic, gravitational and magnetic forces was developed to simulate the motion and sedimentation of ferromagnetic particles in a magnetic trap. In detailed simulation runs, the concentrations of accumulated particles under different applied magnetic fields within the magnetic trap are shown. The simulation results are qualitatively compared with laboratory experiments and show excellent accordance. Additionally, the sensitivity of the particle detection system is proofed in a MDS laboratory experiment by simulation of a membrane rupture.

  2. Procoagulant, Tissue Factor-Bearing Microparticles in Bronchoalveolar Lavage of Interstitial Lung Disease Patients: An Observational Study

    PubMed Central

    Tavanti, Laura; Armani, Chiara; Noce, Concettina; Falaschi, Fabio; Bartoli, Maria Laura; Martino, Federica; Palla, Antonio; Celi, Alessandro; Paggiaro, Pierluigi

    2014-01-01

    Coagulation factor Xa appears involved in the pathogenesis of pulmonary fibrosis. Through its interaction with protease activated receptor-1, this protease signals myofibroblast differentiation in lung fibroblasts. Although fibrogenic stimuli induce factor X synthesis by alveolar cells, the mechanisms of local posttranslational factor X activation are not fully understood. Cell-derived microparticles are submicron vesicles involved in different physiological processes, including blood coagulation; they potentially activate factor X due to the exposure on their outer membrane of both phosphatidylserine and tissue factor. We postulated a role for procoagulant microparticles in the pathogenesis of interstitial lung diseases. Nineteen patients with interstitial lung diseases and 11 controls were studied. All subjects underwent bronchoalveolar lavage; interstitial lung disease patients also underwent pulmonary function tests and high resolution CT scan. Microparticles were enumerated in the bronchoalveolar lavage fluid with a solid-phase assay based on thrombin generation. Microparticles were also tested for tissue factor activity. In vitro shedding of microparticles upon incubation with H2O2 was assessed in the human alveolar cell line, A549 and in normal bronchial epithelial cells. Tissue factor synthesis was quantitated by real-time PCR. Total microparticle number and microparticle-associated tissue factor activity were increased in interstitial lung disease patients compared to controls (84±8 vs. 39±3 nM phosphatidylserine; 293±37 vs. 105±21 arbitrary units of tissue factor activity; mean±SEM; p<.05 for both comparisons). Microparticle-bound tissue factor activity was inversely correlated with lung function as assessed by both diffusion capacity and forced vital capacity (r2 = .27 and .31, respectively; p<.05 for both correlations). Exposure of lung epithelial cells to H2O2 caused an increase in microparticle-bound tissue factor without affecting tissue

  3. Airborne and Ground-Based Optical Characterization of Legacy Underground Nuclear Test Sites

    NASA Astrophysics Data System (ADS)

    Vigil, S.; Craven, J.; Anderson, D.; Dzur, R.; Schultz-Fellenz, E. S.; Sussman, A. J.

    2015-12-01

    Detecting, locating, and characterizing suspected underground nuclear test sites is a U.S. security priority. Currently, global underground nuclear explosion monitoring relies on seismic and infrasound sensor networks to provide rapid initial detection of potential underground nuclear tests. While seismic and infrasound might be able to generally locate potential underground nuclear tests, additional sensing methods might be required to further pinpoint test site locations. Optical remote sensing is a robust approach for site location and characterization due to the ability it provides to search large areas relatively quickly, resolve surface features in fine detail, and perform these tasks non-intrusively. Optical remote sensing provides both cultural and surface geological information about a site, for example, operational infrastructure, surface fractures. Surface geological information, when combined with known or estimated subsurface geologic information, could provide clues concerning test parameters. We have characterized two legacy nuclear test sites on the Nevada National Security Site (NNSS), U20ak and U20az using helicopter-, ground- and unmanned aerial system-based RGB imagery and light detection and ranging (lidar) systems. The multi-faceted information garnered from these different sensing modalities has allowed us to build a knowledge base of how a nuclear test site might look when sensed remotely, and the standoff distances required to resolve important site characteristics.

  4. Recent Findings Based on Airborne Measurements at the Interface of Coastal California Clouds and Clear Air

    NASA Astrophysics Data System (ADS)

    Sorooshian, A.; Crosbie, E.; Wang, Z.; Chuang, P. Y.; Craven, J. S.; Coggon, M. M.; Brunke, M.; Zeng, X.; Jonsson, H.; Woods, R. K.; Flagan, R. C.; Seinfeld, J.

    2015-12-01

    Recent aircraft field experiments with the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter have targeted interfaces between clear and cloudy areas along the California coast. These campaigns, based out of Marina, California in the July-August time frame, include the Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE, 2011), Nucleation in California Experiment (NiCE, 2013), and the Biological Ocean Atmospheric Study (BOAS, 2015). Results will be presented related to (i) aqueous processing of natural and anthropogenic emissions, (ii) vertical re-distribution of ocean micronutrients, and (iii) stratocumulus cloud clearings and notable thermodynamic and aerosol contrasts across the clear-cloudy interface. The results have implications for modeling and observational studies of marine boundary layer clouds, especially in relation to aerosol-cloud interactions.

  5. Low-cost lightweight airborne laser-based sensors for pipeline leak detection and reporting

    NASA Astrophysics Data System (ADS)

    Frish, Michael B.; Wainner, Richard T.; Laderer, Matthew C.; Allen, Mark G.; Rutherford, James; Wehnert, Paul; Dey, Sean; Gilchrist, John; Corbi, Ron; Picciaia, Daniele; Andreussi, Paolo; Furry, David

    2013-05-01

    Laser sensing enables aerial detection of natural gas pipeline leaks without need to fly through a hazardous gas plume. This paper describes adaptations of commercial laser-based methane sensing technology that provide relatively low-cost lightweight and battery-powered aerial leak sensors. The underlying technology is near-infrared Standoff Tunable Diode Laser Absorption Spectroscopy (sTDLAS). In one configuration, currently in commercial operation for pipeline surveillance, sTDLAS is combined with automated data reduction, alerting, navigation, and video imagery, integrated into a single-engine single-pilot light fixed-wing aircraft or helicopter platform. In a novel configuration for mapping landfill methane emissions, a miniaturized ultra-lightweight sTDLAS sensor flies aboard a small quad-rotor unmanned aerial vehicle (UAV).

  6. Airborne and ground based lidar measurements of the atmospheric pressure profile

    NASA Technical Reports Server (NTRS)

    Korb, C. Laurence; Schwemmer, Geary K.; Dombrowski, Mark; Weng, Chi Y.

    1989-01-01

    The first high accuracy remote measurements of the atmospheric pressure profile have been made. The measurements were made with a differential absorption lidar system that utilizes tunable alexandrite lasers. The absorption in the trough between two lines in the oxygen A-band near 760 nm was used for probing the atmosphere. Measurements of the two-dimensional structure of the pressure field were made in the troposphere from an aircraft looking down. Also, measurements of the one-dimensional structure were made from the ground looking up. Typical pressure accuracies for the aircraft measurements were 1.5-2 mbar with a 30-m vertical resolution and a 100-shot average (20 s), which corresponds to a 2-km horizontal resolution. Typical accuracies for the upward viewing ground based measurements were 2.0 mbar for a 30-m resolution and a 100-shot average.

  7. Quantifying greenhouse gas emissions from coal fires using airborne and ground-based methods

    USGS Publications Warehouse

    Engle, M.A.; Radke, L.F.; Heffern, E.L.; O'Keefe, J. M. K.; Smeltzer, C.D.; Hower, J.C.; Hower, J.M.; Prakash, A.; Kolker, A.; Eatwell, R.J.; ter, Schure A.; Queen, G.; Aggen, K.L.; Stracher, G.B.; Henke, K.R.; Olea, R.A.; Roman-Colon, Y.

    2011-01-01

    Coal fires occur in all coal-bearing regions of the world and number, conservatively, in the thousands. These fires emit a variety of compounds including greenhouse gases. However, the magnitude of the contribution of combustion gases from coal fires to the environment is highly uncertain, because adequate data and methods for assessing emissions are lacking. This study demonstrates the ability to estimate CO2 and CH4 emissions for the Welch Ranch coal fire, Powder River Basin, Wyoming, USA, using two independent methods: (a) heat flux calculated from aerial thermal infrared imaging (3.7-4.4td-1 of CO2 equivalent emissions) and (b) direct, ground-based measurements (7.3-9.5td-1 of CO2 equivalent emissions). Both approaches offer the potential for conducting inventories of coal fires to assess their gas emissions and to evaluate and prioritize fires for mitigation. ?? 2011.

  8. INNOSLAB-based single-frequency MOPA for airborne lidar detection of CO2 and methane

    NASA Astrophysics Data System (ADS)

    Löhring, Jens; Luttmann, Jörg; Kasemann, Raphael; Schlösser, Michael; Klein, Jürgen; Hoffmann, Hans-Dieter; Amediek, Axel; Büdenbender, Christian; Fix, Andreas; Wirth, Martin; Quatrevalet, Mathieu; Ehret, Gerhard

    2014-02-01

    For the CO2 and CH4 IPDA lidar CHARM-F two single frequency Nd:YAG based MOPA systems were developed. Both lasers are used for OPO/OPA-pumping in order to generate laser radiation at 1645 nm for CH4 detection and 1572 nm for CO2 detection. By the use of a Q-switched, injection seeded and actively length-stabilized oscillator and a one-stage INNOSLAB amplifier about 85 mJ pulse energy could be generated for the CH4 system. For the CO2 system the energy was boosted in second INNOSLAB-stage to about 150 mJ. Both lasers emit laser pulses of about 30 ns pulse duration at a repetition rate of 100 Hz.

  9. Nano-based chemical sensor array systems for uninhabited ground and airborne vehicles

    NASA Astrophysics Data System (ADS)

    Brantley, Christina; Ruffin, Paul B.; Edwards, Eugene

    2009-03-01

    In a time when homemade explosive devices are being used against soldiers and in the homeland security environment, it is becoming increasingly evident that there is an urgent need for high-tech chemical sensor packages to be mounted aboard ground and air vehicles to aid soldiers in determining the location of explosive devices and the origin of bio-chemical warfare agents associated with terrorist activities from a safe distance. Current technologies utilize relatively large handheld detection systems that are housed on sizeable robotic vehicles. Research and development efforts are underway at the Army Aviation & Missile Research, Development, and Engineering Center (AMRDEC) to develop novel and less expensive nano-based chemical sensors for detecting explosives and chemical agents used against the soldier. More specifically, an array of chemical sensors integrated with an electronics control module on a flexible substrate that can conform to and be surface-mounted to manned or unmanned vehicles to detect harmful species from bio-chemical warfare and other explosive devices is being developed. The sensor system under development is a voltammetry-based sensor system capable of aiding in the detection of any chemical agent and in the optimization of sensor microarray geometry to provide nonlinear Fourier algorithms to characterize target area background (e.g., footprint areas). The status of the research project is reviewed in this paper. Critical technical challenges associated with achieving system cost, size, and performance requirements are discussed. The results obtained from field tests using an unmanned remote controlled vehicle that houses a CO2/chemical sensor, which detects harmful chemical agents and wirelessly transmits warning signals back to the warfighter, are presented. Finally, the technical barriers associated with employing the sensor array system aboard small air vehicles will be discussed.

  10. Autonomous and Remote-Controlled Airborne and Ground-Based Robotic Platforms for Adaptive Geophysical Surveying

    NASA Astrophysics Data System (ADS)

    Spritzer, J. M.; Phelps, G. A.

    2011-12-01

    Low-cost autonomous and remote-controlled robotic platforms have opened the door to precision-guided geophysical surveying. Over the past two years, the U.S. Geological Survey, Senseta, NASA Ames Research Center, and Carnegie Mellon University Silicon Valley, have developed and deployed small autonomous and remotely controlled vehicles for geophysical investigations. The purpose of this line of investigation is to 1) increase the analytical capability, resolution, and repeatability, and 2) decrease the time, and potentially the cost and map-power necessary to conduct near-surface geophysical surveys. Current technology has advanced to the point where vehicles can perform geophysical surveys autonomously, freeing the geoscientist to process and analyze the incoming data in near-real time. This has enabled geoscientists to monitor survey parameters; process, analyze and interpret the incoming data; and test geophysical models in the same field session. This new approach, termed adaptive surveying, provides the geoscientist with choices of how the remainder of the survey should be conducted. Autonomous vehicles follow pre-programmed survey paths, which can be utilized to easily repeat surveys on the same path over large areas without the operator fatigue and error that plague man-powered surveys. While initial deployments with autonomous systems required a larger field crew than a man-powered survey, over time operational experience costs and man power requirements will decrease. Using a low-cost, commercially available chassis as the base for autonomous surveying robotic systems promise to provide higher precision and efficiency than human-powered techniques. An experimental survey successfully demonstrated the adaptive techniques described. A magnetic sensor was mounted on a small rover, which autonomously drove a prescribed course designed to provide an overview of the study area. Magnetic data was relayed to the base station periodically, processed and gridded. A

  11. The preservation of living cells with biocompatible microparticles

    NASA Astrophysics Data System (ADS)

    Yang, Jing; Zhu, Yingnan; Xu, Tong; Pan, Chao; Cai, Nana; Huang, He; Zhang, Lei

    2016-07-01

    Biomedical applications of living cells have rapidly expanded in many fields such as toxic detection, drug screening, and regenerative medicine, etc. Efficient methods to support cell survival and maintain activity in vitro have become increasingly important. However, traditional cryopreservation for living cell-based applications is limited by several problems. Here, we report that magnetic hydrogel microparticles can physically assemble into a 3D environment for efficient cell preservation in physiological conditions, avoiding any chemical reactions that would damage the cells. Two representative cell lines (loosely and firmly adherent) were tested to evaluate the versatility of this method. The results showed that cell longevity was significantly extended to at least 15 days, while the control cell samples without microparticles quickly died within 3 days. Moreover, after preservation, cells can be easily retrieved by applying a magnet to separate the magnetic particles. This strategy can also inhibit cell over-proliferation while avoiding the use of temperature extremes or toxic cryoprotectants that are essential in cryopreservation.

  12. Object-Based Point Cloud Analysis of Full-Waveform Airborne Laser Scanning Data for Urban Vegetation Classification.

    PubMed

    Rutzinger, Martin; Höfle, Bernhard; Hollaus, Markus; Pfeifer, Norbert

    2008-08-04

    Airborne laser scanning (ALS) is a remote sensing technique well-suited for 3D vegetation mapping and structure characterization because the emitted laser pulses are able to penetrate small gaps in the vegetation canopy. The backscattered echoes from the foliage, woody vegetation, the terrain, and other objects are detected, leading to a cloud of points. Higher echo densities (> 20 echoes/m2) and additional classification variables from full-waveform (FWF) ALS data, namely echo amplitude, echo width and information on multiple echoes from one shot, offer new possibilities in classifying the ALS point cloud. Currently FWF sensor information is hardly used for classification purposes. This contribution presents an object-based point cloud analysis (OBPA) approach, combining segmentation and classification of the 3D FWF ALS points designed to detect tall vegetation in urban environments. The definition tall vegetation includes trees and shrubs, but excludes grassland and herbage. In the applied procedure FWF ALS echoes are segmented by a seeded region growing procedure. All echoes sorted descending by their surface roughness are used as seed points. Segments are grown based on echo width homogeneity. Next, segment statistics (mean, standard deviation, and coefficient of variation) are calculated by aggregating echo features such as amplitude and surface roughness. For classification a rule base is derived automatically from a training area using a statistical classification tree. To demonstrate our method we present data of three sites with around 500,000 echoes each. The accuracy of the classified vegetation segments is evaluated for two independent validation sites. In a point-wise error assessment, where the classification is compared with manually classified 3D points, completeness and correctness better than 90% are reached for the validation sites. In comparison to many other algorithms the proposed 3D point classification works on the original measurements

  13. Object-Based Point Cloud Analysis of Full-Waveform Airborne Laser Scanning Data for Urban Vegetation Classification

    PubMed Central

    Rutzinger, Martin; Höfle, Bernhard; Hollaus, Markus; Pfeifer, Norbert

    2008-01-01

    Airborne laser scanning (ALS) is a remote sensing technique well-suited for 3D vegetation mapping and structure characterization because the emitted laser pulses are able to penetrate small gaps in the vegetation canopy. The backscattered echoes from the foliage, woody vegetation, the terrain, and other objects are detected, leading to a cloud of points. Higher echo densities (>20 echoes/m2) and additional classification variables from full-waveform (FWF) ALS data, namely echo amplitude, echo width and information on multiple echoes from one shot, offer new possibilities in classifying the ALS point cloud. Currently FWF sensor information is hardly used for classification purposes. This contribution presents an object-based point cloud analysis (OBPA) approach, combining segmentation and classification of the 3D FWF ALS points designed to detect tall vegetation in urban environments. The definition tall vegetation includes trees and shrubs, but excludes grassland and herbage. In the applied procedure FWF ALS echoes are segmented by a seeded region growing procedure. All echoes sorted descending by their surface roughness are used as seed points. Segments are grown based on echo width homogeneity. Next, segment statistics (mean, standard deviation, and coefficient of variation) are calculated by aggregating echo features such as amplitude and surface roughness. For classification a rule base is derived automatically from a training area using a statistical classification tree. To demonstrate our method we present data of three sites with around 500,000 echoes each. The accuracy of the classified vegetation segments is evaluated for two independent validation sites. In a point-wise error assessment, where the classification is compared with manually classified 3D points, completeness and correctness better than 90% are reached for the validation sites. In comparison to many other algorithms the proposed 3D point classification works on the original measurements

  14. Cellulose acetate butyrate microparticles for controlled release of carbamazepine.

    PubMed

    Arnaud, P; Boué, C; Chaumeil, J C

    1996-01-01

    Cellulose acetate butyrate microparticles loaded in carbamazepine were prepared by a solvent evaporation technique. A decrease of the amount of organic solvent (from 80 to 40 ml of methylene chloride) increased the microparticle average diameter (73-111 and 207 microns) and decreased the carbamazepine release rate (T50% increased from 3.3 to 16.8 and 166.4 min). The microparticle area under the curve at 120 min was similar to that obtained with Tegretol LP 200 tablets.

  15. An analysis of the photochemical environment over the western, North Pacific based on airborne field observations

    NASA Astrophysics Data System (ADS)

    Crawford, James Henry

    1997-12-01

    This study examines the influence of photochemistry on ozone distributions over the western, North Pacific based on observations gathered during NASA's PEM-West B campaign (February-March, 1994). During this time, strong outflow of continental emissions from Asia into the Pacific at extratropical latitudes (i.e., north of 20oN) resulted in elevated levels of photochemically important trace species (e.g., O3, NO, CO, and nonmethane hydrocarbons). Tropical data south of 20oN was more representative of remote marine tropospheric air. A major observation within the tropical region was the large shift in NO levels as a function of geographic location. High altitude NO levels exceeding 100 pptv were observed during portions of flights 5-8 while values almost never exceeded 20 pptv during flights 9 and 10. The geographic domains defined by these two flight groupings are labeled as 'high' and 'low' NO x regimes. A comparison of these two regimes based on back trajectories and chemical tracers suggests that the low NO x regime was predominantly impacted by marine convection; whereas, the high NO x regime shows evidence of having been more influenced by deep convection over a continental land mass. DMSP satellite observations point strongly toward lightning as a major source of NO x in the latter regime. Estimates of the net photochemical effect on the O3 column revealed that the high NO x regime led to a small net production. By contrast, the low NO x regime was shown to destroy O3 at the rate of 3.4%/day. Possible mechanisms for offsetting this large photochemical deficit are explored. Within the extratropical region (i.e., 20-50oN), two distinct photochemical environments were identified based on an abrupt drop in the tropopause height at 30oN accompanied by an increase in the O3 column density of nearly 150 Dobson units. This difference resulted in much lower rates of O3 formation and destruction for 30-50oN; however, both latitude ranges still exhibited net O3

  16. Quantitative study of tectonic geomorphology along Haiyuan fault based on airborne LiDAR

    USGS Publications Warehouse

    Chen, Tao; Zhang, Pei Zhen; Liu, Jing; Li, Chuan You; Ren, Zhi Kun; Hudnut, Kenneth W.

    2014-01-01

    High-precision and high-resolution topography are the fundamental data for active fault research. Light detection and ranging (LiDAR) presents a new approach to build detailed digital elevation models effectively. We take the Haiyuan fault in Gansu Province as an example of how LiDAR data may be used to improve the study of active faults and the risk assessment of related hazards. In the eastern segment of the Haiyuan fault, the Shaomayin site has been comprehensively investigated in previous research because of its exemplary tectonic topographic features. Based on unprecedented LiDAR data, the horizontal and vertical coseismic offsets at the Shaomayin site are described. The measured horizontal value is about 8.6 m, and the vertical value is about 0.8 m. Using prior dating ages sampled from the same location, we estimate the horizontal slip rate as 4.0 ± 1.0 mm/a with high confidence and define that the lower bound of the vertical slip rate is 0.4 ± 0.1 mm/a since the Holocene. LiDAR data can repeat the measurements of field work on quantifying offsets of tectonic landform features quite well. The offset landforms are visualized on an office computer workstation easily, and specialized software may be used to obtain displacement quantitatively. By combining precious chronological results, the fundamental link between fault activity and large earthquakes is better recognized, as well as the potential risk for future earthquake hazards.

  17. Collagen-coated microparticles in drug delivery.

    PubMed

    Sehgal, Praveen Kumar; Srinivasan, Aishwarya

    2009-07-01

    Advantages of drug-incorporated collagen particles have been described for the controlled delivery system for therapeutic actions. The attractiveness of collagen lies in its low immunogenicity and high biocompatibility. It is also recognized by the body as a natural constituent rather than a foreign body. Our research and development efforts are focused towards addressing some of the limitations of collagen, like the high viscosity of an aqueous phase, nondissolution in neutral pH buffers, thermal instability (denaturation) and biodegradability, to make it an ideal material for drug delivery with particular reference to microparticles. These limitations could be overcome by making collagen conjugates with other biomaterials or chemically modifying collagen monomer without affecting its triple helical conformation and maintaining its native properties. This article highlights collagen microparticles' present status as a carrier in drug delivery.

  18. Magnetic barcoded hydrogel microparticles for multiplexed detection.

    PubMed

    Bong, Ki Wan; Chapin, Stephen C; Doyle, Patrick S

    2010-06-01

    Magnetic polymer particles have been used in a wide variety of applications ranging from targeting and separation to diagnostics and imaging. Current synthesis methods have limited these particles to spherical or deformations of spherical morphologies. In this paper, we report the use of stop flow lithography to produce magnetic hydrogel microparticles with a graphical code region, a probe region, and a magnetic tail region. These anisotropic multifunctional magnetic polymer particles are an enhanced version of previously synthesized "barcoded" particles (Science, 2007, 315, 1393-1396) developed for the sensitive and rapid multiplexed sensing of nucleic acids. The newly added magnetic region has acquired dipole moments in the presence of weak homogeneous magnetic fields, allowing the particles to align along the applied field direction. The novel magnetic properties have led to practical applications in the efficient orientation and separation of the barcoded microparticles during biological assays without disrupting detection capabilities.

  19. Adsorption of monoclonal antibodies to glass microparticles.

    PubMed

    Hoehne, Matthew; Samuel, Fauna; Dong, Aichun; Wurth, Christine; Mahler, Hanns-Christian; Carpenter, John F; Randolph, Theodore W

    2011-01-01

    Microparticulate glass represents a potential contamination to protein formulations that may occur as a result of processing conditions or glass types. The effect of added microparticulate glass to formulations of three humanized antibodies was tested. Under the three formulation conditions tested, all three antibodies adsorbed irreversibly at near monolayer surface coverages to the glass microparticles. Analysis of the secondary structure of the adsorbed antibodies by infrared spectroscopy reveal only minor perturbations as a result of adsorption. Likewise, front-face fluorescence quenching measurements reflected minimal tertiary structural changes upon adsorption. In contrast to the minimal effects on protein structure, adsorption of protein to suspensions of glass microparticles induced significant colloidal destabilization and flocculation of the suspension.

  20. Magnetic microparticles for harvesting Dunaliella tertiolecta microalgae

    NASA Astrophysics Data System (ADS)

    Manousakis, Emmanouil; Manariotis, Ioannis D.

    2016-04-01

    Microalgae based biofuels have been considered as a sustainable alternative to traditional fuels due to the higher biomass yield and lipid productivity, and the ability to be cultivated in non arable land making them not antagonistic with food supply chain. Due to the dilute nature of algal cultures and the small size of algae cells, the cost of microalgae harvesting is so far a bottleneck in microalgal based biofuel production. It is estimated that the algal recovery cost is at least 20-30% of the total biomass production cost. Various processes have been employed for the recovery of microalgal biomass, which include centrifugation, gravity separation, filtration, flocculation, and flotation. Recently, magnetophoric harvesting has received increased attention for algal separation, although it has been first applied for algal removal since the mid of 1970s. The magnetic separation process is based on bringing in contact the algal cells with the magnetic particles, and separating them from the liquid by an external magnetic force. The aim of this work was to investigate the harvesting of microalgae cells using Fe3O4 magnetic microparticles (MPs). Dunaliella tertiolecta was selected as a representative for marine microalgae. D. tertiolecta was cultivated under continuous artificial light, in 20 L flasks. Fe3O4 MPs were prepared by microwave irradiation of FeSO4 7H2O in an alkaline solution. Numerous batch and flow-through experiments were conducted in order to investigate the effect of the magnetic material addition on microalgae removal. Batch experiments were conducted examining different initial algal and MPs concentration, and algal culture volume. Flow-through experiments were conducted in a laboratory scale column made of Plexiglass. External magnetic field was applied by arranging at various points across the column length NdFeB magnets. Algal removal in flow-through experiments ranged from 70 to 85% depending on the initial MPs concentration and the hydraulic

  1. Formulations for modulation of protein release from large-size PLGA microparticles for tissue engineering.

    PubMed

    Qodratnama, Roozbeh; Serino, Lorenzo Pio; Cox, Helen C; Qutachi, Omar; White, Lisa J

    2015-02-01

    In this study we present an approach to pre-program lysozyme release from large size (100-300 μm) poly(DL-lactic acid-co-glycolic acid) (PLGA) microparticles. This approach involved blending in-house synthesized triblock copolymers with a PLGA 85:15. In this work it is demonstrated that the lysozyme release rate and the total release are related to the mass of triblock copolymer present in polymer formulation. Two triblock copolymers (PLGA-PEG1500-PLGA and PLGA-PEG1000-PLGA) were synthesized and used in this study. In a like-for-like comparison, these two triblock copolymers appeared to have similar effects on the release of lysozyme. It was shown that blending resulted in the increase of the total lysozyme release and shortened the release period (70% release within 30 days). These results demonstrated that blending PLGA-PEG-PLGA triblock copolymer with PLGA 85:15 can be used as a method to pre-program protein release from microparticles. These microparticles with modulated protein release properties may be used to create microparticle-based tissue engineering constructs with pre-programmed release properties.

  2. Light-scattering flow cytometry for identification and characterization of blood microparticles

    NASA Astrophysics Data System (ADS)

    Konokhova, Anastasiya I.; Yurkin, Maxim A.; Moskalensky, Alexander E.; Chernyshev, Andrei V.; Tsvetovskaya, Galina A.; Chikova, Elena D.; Maltsev, Valeri P.

    2012-05-01

    We describe a novel approach to study blood microparticles using the scanning flow cytometer, which measures light scattering patterns (LSPs) of individual particles. Starting from platelet-rich plasma, we separated spherical microparticles from non-spherical plasma constituents, such as platelets and cell debris, based on similarity of their LSP to that of sphere. This provides a label-free method for identification (detection) of microparticles, including those larger than 1 μm. Next, we rigorously characterized each measured particle, determining its size and refractive index including errors of these estimates. Finally, we employed a deconvolution algorithm to determine size and refractive index distributions of the whole population of microparticles, accounting for largely different reliability of individual measurements. Developed methods were tested on a blood sample of a healthy donor, resulting in good agreement with literature data. The only limitation of this approach is size detection limit, which is currently about 0.5 μm due to used laser wavelength of 0.66 μm.

  3. Toolsets for Airborne Data Web Application

    Atmospheric Science Data Center

    2014-09-17

    ... relevant issues. Features Include Select data based on mission, date and/or scientific parameter Output original data ... Details:  Toolsets for Airborne Data (TAD) Web Application Category:  Instrument Specific Search, ...

  4. Spectral combination of land-based, airborne, shipborne and altimeter-derived gravity values: examples in Taiwan and Tahiti

    NASA Astrophysics Data System (ADS)

    Hwang, Cheinway

    2016-04-01

    Taiwan and Tahiti are bordered by seas and are islands with mountain ranges up to 4000 m height. The gravity fields here are rough due to the geodynamic processes that create the islands. On and around the two islands, gravity data have been collected by land gravimeters in relative gravity networks (point-wise), by airborne and shipborne (along-track) methods and by transformations from sea surface heights (altimeter-derived). Typically, network-adjusted land gravity values have accuracies of few tens of micro gals and contain the full gravity spectrum. Airborne gravity values are obtained by filtering original one-HZ along-track gravity values collected at varying flight altitudes that are affected by aircraft dynamics, GPS positioning error and gravimeter error. At a 5000-m flight height, along-track airborne gravity has a typical spatial resolution of 4 km and an accuracy of few mgal. Shipborne gravity is similar to airborne gravity, but with higher spatial resolutions because of ship's lower speed. Altimeter-derived gravity has varying spatial resolutions and accuracies, depending on altimeter data, processing method and extent of waveform interference. Using the latest versions of Geosat/GM, ERS-1/GM, ENVISAT, Jason-1/GM, Cryosat-2 and SARAL altimeter data, one can achieve accuracies at few mgal. The synergy of the four kinds of gravity datasets is made by the band-limited least-squares collocation, which best integrates datasets of different accuracies and spatial resolutions. The method uses the best contributions from a DEM, a global gravity model, available gravity datasets to form an optimal gravity grid. We experiment with different optimal spherical harmonic degrees of EGM08 for use around the two islands. For Tahiti, the optimal degree is 1500. New high-resolution gravity and geoid grids are constructed for the two islands and can be used in future geophysical and geodetic studies.

  5. Prospects of the ICESat-2 laser altimetry mission for savanna ecosystem structural studies based on airborne simulation data

    NASA Astrophysics Data System (ADS)

    Gwenzi, David; Lefsky, Michael A.; Suchdeo, Vijay P.; Harding, David J.

    2016-08-01

    The next planned spaceborne lidar mission is the Ice, Cloud and land Elevation Satellite 2 (ICESat-2), which will use the Advanced Topographic Laser Altimeter System (ATLAS) sensor, a photon counting technique. To pre-validate the capability of this mission for studying three dimensional vegetation structure in savannas, we assessed the potential of the measurement approach to estimate canopy height in an oak savanna landscape. We used data from the Multiple Altimeter Beam Experimental Lidar (MABEL), an airborne photon counting lidar sensor developed by NASA's Goddard Space Flight Center. ATLAS-like data was generated using the MATLAS simulator, which adjusts MABEL data's detected number of signal and noise photons to that expected from the ATLAS instrument. Transects flown over the Tejon ranch conservancy in Kern County, California, USA were used for this work. For each transect we chose to use data from the near infrared channel that had the highest number of photons. We segmented each transect into 50 m, 25 m and 14 m long blocks and aggregated the photons in each block into a histogram based on their elevation values. We then used an automated algorithm to identify cut off points where the cumulative density of photons from the highest elevation indicates the presence of the canopy top and likewise where such cumulative density from the lowest elevation indicates the mean terrain elevation. MABEL derived height metrics were moderately correlated to discrete return lidar (DRL) derived height metrics (r2 and RMSE values ranging from 0.60 to 0.73 and 2.9 m to 4.4 m respectively) but MATLAS simulation resulted in more modest correlations with DRL indices (r2 ranging from 0.5 to 0.64 and RMSE from 3.6 m to 4.6 m). Simulations also indicated that the expected number of signal photons from ATLAS will be substantially lower, a situation that reduces canopy height estimation precision especially in areas of low density vegetation cover. On the basis of the simulated

  6. Retrieval of Vegetation Structure and Carbon Balance Parameters Using Ground-Based Lidar and Scaling to Airborne and Spaceborne Lidar Sensors

    NASA Astrophysics Data System (ADS)

    Strahler, A. H.; Ni-Meister, W.; Woodcock, C. E.; Li, X.; Jupp, D. L.; Culvenor, D.

    2006-12-01

    This research uses a ground-based, upward hemispherical scanning lidar to retrieve forest canopy structural information, including tree height, mean tree diameter, basal area, stem count density, crown diameter, woody biomass, and green biomass. These parameters are then linked to airborne and spaceborne lidars to provide large-area mapping of structural and biomass parameters. The terrestrial lidar instrument, Echidna(TM), developed by CSIRO Australia, allows rapid acquisition of vegetation structure data that can be readily integrated with downward-looking airborne lidar, such as LVIS (Laser Vegetation Imaging Sensor), and spaceborne lidar, such as GLAS (Geoscience Laser Altimeter System) on ICESat. Lidar waveforms and vegetation structure are linked for these three sensors through the hybrid geometric-optical radiative-transfer (GORT) model, which uses basic vegetation structure parameters and principles of geometric optics, coupled with radiative transfer theory, to model scattering and absorption of light by collections of individual plant crowns. Use of a common model for lidar waveforms at ground, airborne, and spaceborne levels facilitates integration and scaling of the data to provide large-area maps and inventories of vegetation structure and carbon stocks. Our research plan includes acquisition of Echidna(TM) under-canopy hemispherical lidar scans at North American test sites where LVIS and GLAS data have been or are being acquired; analysis and modeling of spatially coincident lidar waveforms acquired by the three sensor systems; linking of the three data sources using the GORT model; and mapping of vegetation structure and carbon-balance parameters at LVIS and GLAS resolutions based on Echidna(TM) measurements.

  7. Backscatter Modeling at 2.1 Micron Wavelength for Space-Based and Airborne Lidars Using Aerosol Physico-Chemical and Lidar Datasets

    NASA Technical Reports Server (NTRS)

    Srivastava, V.; Rothermel, J.; Jarzembski, M. A.; Clarke, A. D.; Cutten, D. R.; Bowdle, D. A.; Spinhirne, J. D.; Menzies, R. T.

    1999-01-01

    Space-based and airborne coherent Doppler lidars designed for measuring global tropospheric wind profiles in cloud-free air rely on backscatter, beta from aerosols acting as passive wind tracers. Aerosol beta distribution in the vertical can vary over as much as 5-6 orders of magnitude. Thus, the design of a wave length-specific, space-borne or airborne lidar must account for the magnitude of 8 in the region or features of interest. The SPAce Readiness Coherent Lidar Experiment under development by the National Aeronautics and Space Administration (NASA) and scheduled for launch on the Space Shuttle in 2001, will demonstrate wind measurements from space using a solid-state 2 micrometer coherent Doppler lidar. Consequently, there is a critical need to understand variability of aerosol beta at 2.1 micrometers, to evaluate signal detection under varying aerosol loading conditions. Although few direct measurements of beta at 2.1 micrometers exist, extensive datasets, including climatologies in widely-separated locations, do exist for other wavelengths based on CO2 and Nd:YAG lidars. Datasets also exist for the associated microphysical and chemical properties. An example of a multi-parametric dataset is that of the NASA GLObal Backscatter Experiment (GLOBE) in 1990 in which aerosol chemistry and size distributions were measured concurrently with multi-wavelength lidar backscatter observations. More recently, continuous-wave (CW) lidar backscatter measurements at mid-infrared wavelengths have been made during the Multicenter Airborne Coherent Atmospheric Wind Sensor (MACAWS) experiment in 1995. Using Lorenz-Mie theory, these datasets have been used to develop a method to convert lidar backscatter to the 2.1 micrometer wavelength. This paper presents comparison of modeled backscatter at wavelengths for which backscatter measurements exist including converted beta (sub 2.1).

  8. Bonding Strength Properties of Adhesively-Timber Joint with Thixotropic and Room Temperature Cured Epoxy Based Adhesive Reinforced with Nano- and Micro-particles

    NASA Astrophysics Data System (ADS)

    Ahmad, Z.; Ansell, M. P.; Smedley, D.

    2011-02-01

    This research work is concerned with in situ bonded-in timber connection using pultruded rod; where the manufacturing of such joint requires adhesive which can produce thick glue-lines and does not allow any use of pressure and heat. Four types of thixotropic (for ease application) and room temperature cured epoxy based were used namely CB10TSS (regarded as standards adhesive), Nanopox (modification of CB10TSS with addition of nanosilica), Albipox (modification of CB10TSS with addition of liquid rubber) and Timberset (an epoxy-based adhesive with addition of micro-size ceramic particles). The quality of the adhesive bonds was accessed using block shear test in accordance with ASTM D905. The bond strength depends on how good the adhesive wet the timber surface. Therefore the viscosity and contact angle was also measured. The nano- and microfiller additions increased the bond strength significantly. The viscosity correlates well with contact angle measurements where lower viscosities are associated with lower contact angles. However contact angle contradicts with measured strength and wettability.

  9. Ground-based multispectral measurements for airborne data verification in non-operating open pit mine "Kremikovtsi"

    NASA Astrophysics Data System (ADS)

    Borisova, Denitsa; Nikolov, Hristo; Petkov, Doyno

    2013-10-01

    The impact of mining industry and metal production on the environment is presented all over the world. In our research we set focus on the impact of already non-operating ferrous "Kremikovtsi"open pit mine and related waste dumps and tailings which we consider to be the major factor responsible for pollution of one densely populated region in Bulgaria. The approach adopted is based on correct estimation of the distribution of the iron oxides inside open pit mines and the neighboring regions those considered in this case to be the key issue for the ecological state assessment of soils, vegetation and water. For this study the foremost source of data are those of airborne origin and those combined with ground-based in-situ and laboratory acquired data were used for verification of the environmental variables and thus in process of assessment of the present environmental status influenced by previous mining activities. The percentage of iron content was selected as main indicator for presence of metal pollution since it could be reliably identified by multispectral data used in this study and also because the iron compounds are widely spread in the most of the minerals, rocks and soils. In our research the number of samples from every source (air, field, lab) was taken in the way to be statistically sound and confident. In order to establish relationship between the degree of pollution of the soil and mulspectral data 40 soil samples were collected during a field campaign in the study area together with GPS measurements for two types of laboratory measurements: the first one, chemical and mineralogical analysis and the second one, non-destructive spectroscopy. In this work for environmental variables verification over large areas mulspectral satellite data from Landsat instruments TM/ETM+ and from ALI/OLI (Operational Land Imager) were used. Ground-based (laboratory and in-situ) spectrometric measurements were performed using the designed and constructed in Remote

  10. Silicon-on-insulator multimode-interference waveguide-based arrayed optical tweezers (SMART) for two-dimensional microparticle trapping and manipulation.

    PubMed

    Lei, Ting; Poon, Andrew W

    2013-01-28

    We demonstrate two-dimensional optical trapping and manipulation of 1 μm and 2.2 μm polystyrene particles in an 18 μm-thick fluidic cell at a wavelength of 1565 nm using the recently proposed Silicon-on-insulator Multimode-interference (MMI) waveguide-based ARrayed optical Tweezers (SMART) technique. The key component is a 100 μm square-core silicon waveguide with mm length. By tuning the fiber-coupling position at the MMI waveguide input facet, we demonstrate various patterns of arrayed optical tweezers that enable optical trapping and manipulation of particles. We numerically simulate the physical mechanisms involved in the arrayed trap, including the optical force, the heat transfer and the thermal-induced microfluidic flow.

  11. Nitric oxide regulates neutrophil migration through microparticle formation.

    PubMed

    Nolan, Sarah; Dixon, Rachel; Norman, Keith; Hellewell, Paul; Ridger, Victoria

    2008-01-01

    The role of nitric oxide (NO) in regulating neutrophil migration has been investigated. Human neutrophil migration to interleukin (IL)-8 (1 nmol/L) was measured after a 1-hour incubation using a 96-well chemotaxis plate assay. The NO synthase inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME) significantly (P < 0.001) enhanced IL-8-induced migration by up to 45%. Anti-CD18 significantly (P < 0.001) inhibited both IL-8-induced and L-NAME enhanced migration. Antibodies to L-selectin or PSGL-1 had no effect on IL-8-induced migration but prevented the increased migration to IL-8 induced by L-NAME. L-NAME induced generation of neutrophil-derived microparticles that was significantly (P < 0.01) greater than untreated neutrophils or D-NAME. This microparticle formation was dependent on calpain activity and superoxide production. Only microparticles from L-NAME and not untreated or D-NAME-treated neutrophils induced a significant (P < 0.01) increase in IL-8-induced migration and transendothelial migration. Pretreatment of microparticles with antibodies to L-selectin (DREG-200) or PSGL-1 (PL-1) significantly (P < 0.001) inhibited this effect. The ability of L-NAME-induced microparticles to enhance migration was found to be dependent on the number of microparticles produced and not an increase in microparticle surface L-selectin or PSGL-1 expression. These data show that NO can modulate neutrophil migration by regulating microparticle formation.

  12. Cavitational Iron Microparticles Generation By Plasma Procedures For Medical Applications

    NASA Astrophysics Data System (ADS)

    Bica, Ioan; Bunoiu, Madalin; Chirigiu, Liviu; Spunei, Marius; Juganaru, Iulius

    2012-12-01

    The paper presents the experimental installation for the production, in argon plasma, of cavitational iron microparticles (pore microspheres, microtubes and octopus-shaped microparticles). Experimental results are presented and discussed and it is shown that absorbant particles with a minimum iron content are obtained by the plasma procedures

  13. The CU Airborne MAX-DOAS instrument: ground based validation, and vertical profiling of aerosol extinction and trace gases

    NASA Astrophysics Data System (ADS)

    Baidar, S.; Oetjen, H.; Coburn, S.; Dix, B.; Ortega, I.; Sinreich, R.; Volkamer, R.

    2012-09-01

    The University of Colorado Airborne Multi Axis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS) instrument uses solar stray light remote sensing to detect and quantify multiple trace gases, including nitrogen dioxide (NO2), glyoxal (CHOCHO), formaldehyde (HCHO), water vapor (H2O), nitrous acid (HONO), iodine monoxide (IO), bromine monoxide (BrO), and oxygen dimers (O4) at multiple wavelengths (360 nm, 477 nm, 577 nm and 632 nm) simultaneously, and sensitively in the open atmosphere. The instrument is unique, in that it presents the first systematic implementation of MAX-DOAS on research aircraft, i.e. (1) includes measurements of solar stray light photons from nadir, zenith, and multiple elevation angles forward and below the plane by the same spectrometer/detector system, and (2) features a motion compensation system that decouples the telescope field of view (FOV) from aircraft movements in real-time (< 0.35° accuracy). Sets of solar stray light spectra collected from nadir to zenith scans provide some vertical profile information within 2 km above and below the aircraft altitude, and the vertical column density (VCD) below the aircraft is measured in nadir view. Maximum information about vertical profiles is derived simultaneously for trace gas concentrations and aerosol extinction coefficients over similar spatial scales and with a vertical resolution of typically 250 m during aircraft ascent/descent. The instrument is described, and data from flights over California during the CalNex and CARES air quality field campaigns is presented. Horizontal distributions of NO2 VCDs (below the aircraft) maps are sampled with typically 1 km resolution, and show good agreement with two ground based CU MAX-DOAS instruments (slope 0.95 ± 0.09, R2 = 0.86). As a case study vertical profiles of NO2, CHOCHO, HCHO, and H2O mixing ratios and aerosol extinction coefficients, ɛ, at 477nm calculated from O4 measurements from a low approach at Brackett airfield inside the

  14. Airborne agent concentration analysis

    DOEpatents

    Gelbard, Fred

    2004-02-03

    A method and system for inferring airborne contaminant concentrations in rooms without contaminant sensors, based on data collected by contaminant sensors in other rooms of a building, using known airflow interconnectivity data. The method solves a least squares problem that minimizes the difference between measured and predicted contaminant sensor concentrations with respect to an unknown contaminant release time. Solutions are constrained to providing non-negative initial contaminant concentrations in all rooms. The method can be used to identify a near-optimal distribution of sensors within the building, when then number of available sensors is less than the total number of rooms. This is achieved by having a system-sensor matrix that is non-singular, and by selecting that distribution which yields the lowest condition number of all the distributions considered. The method can predict one or more contaminant initial release points from the collected data.

  15. Airborne Lidar-Based Estimates of Tropical Forest Structure in Complex Terrain: Opportunities and Trade-Offs for REDD+

    NASA Technical Reports Server (NTRS)

    Leitold, Veronika; Keller, Michael; Morton, Douglas C.; Cook, Bruce D.; Shimabukuro, Yosio E.

    2015-01-01

    Background: Carbon stocks and fluxes in tropical forests remain large sources of uncertainty in the global carbon budget. Airborne lidar remote sensing is a powerful tool for estimating aboveground biomass, provided that lidar measurements penetrate dense forest vegetation to generate accurate estimates of surface topography and canopy heights. Tropical forest areas with complex topography present a challenge for lidar remote sensing. Results: We compared digital terrain models (DTM) derived from airborne lidar data from a mountainous region of the Atlantic Forest in Brazil to 35 ground control points measured with survey grade GNSS receivers. The terrain model generated from full-density (approx. 20 returns/sq m) data was highly accurate (mean signed error of 0.19 +/-0.97 m), while those derived from reduced-density datasets (8/sq m, 4/sq m, 2/sq m and 1/sq m) were increasingly less accurate. Canopy heights calculated from reduced-density lidar data declined as data density decreased due to the inability to accurately model the terrain surface. For lidar return densities below 4/sq m, the bias in height estimates translated into errors of 80-125 Mg/ha in predicted aboveground biomass. Conclusions: Given the growing emphasis on the use of airborne lidar for forest management, carbon monitoring, and conservation efforts, the results of this study highlight the importance of careful survey planning and consistent sampling for accurate quantification of aboveground biomass stocks and dynamics. Approaches that rely primarily on canopy height to estimate aboveground biomass are sensitive to DTM errors from variability in lidar sampling density.

  16. Caesium-rich micro-particles: A window into the meltdown events at the Fukushima Daiichi Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    Furuki, Genki; Imoto, Junpei; Ochiai, Asumi; Yamasaki, Shinya; Nanba, Kenji; Ohnuki, Toshihiko; Grambow, Bernd; Ewing, Rodney C.; Utsunomiya, Satoshi

    2017-02-01

    The nuclear disaster at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 caused partial meltdowns of three reactors. During the meltdowns, a type of condensed particle, a caesium-rich micro-particle (CsMP), formed inside the reactors via unknown processes. Here we report the chemical and physical processes of CsMP formation inside the reactors during the meltdowns based on atomic-resolution electron microscopy of CsMPs discovered near the FDNPP. All of the CsMPs (with sizes of 2.0–3.4 μm) comprise SiO2 glass matrices and ~10-nm-sized Zn–Fe-oxide nanoparticles associated with a wide range of Cs concentrations (1.1–19 wt% Cs as Cs2O). Trace amounts of U are also associated with the Zn–Fe oxides. The nano-texture in the CsMPs records multiple reaction-process steps during meltdown in the severe FDNPP accident: Melted fuel (molten core)-concrete interactions (MCCIs), incorporating various airborne fission product nanoparticles, including CsOH and CsCl, proceeded via SiO2 condensation over aggregates of Zn-Fe oxide nanoparticles originating from the failure of the reactor pressure vessels. Still, CsMPs provide a mechanism by which volatile and low-volatility radionuclides such as U can reach the environment and should be considered in the migration model of Cs and radionuclides in the current environment surrounding the FDNPP.

  17. Caesium-rich micro-particles: A window into the meltdown events at the Fukushima Daiichi Nuclear Power Plant

    PubMed Central

    Furuki, Genki; Imoto, Junpei; Ochiai, Asumi; Yamasaki, Shinya; Nanba, Kenji; Ohnuki, Toshihiko; Grambow, Bernd; Ewing, Rodney C.; Utsunomiya, Satoshi

    2017-01-01

    The nuclear disaster at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 caused partial meltdowns of three reactors. During the meltdowns, a type of condensed particle, a caesium-rich micro-particle (CsMP), formed inside the reactors via unknown processes. Here we report the chemical and physical processes of CsMP formation inside the reactors during the meltdowns based on atomic-resolution electron microscopy of CsMPs discovered near the FDNPP. All of the CsMPs (with sizes of 2.0–3.4 μm) comprise SiO2 glass matrices and ~10-nm-sized Zn–Fe-oxide nanoparticles associated with a wide range of Cs concentrations (1.1–19 wt% Cs as Cs2O). Trace amounts of U are also associated with the Zn–Fe oxides. The nano-texture in the CsMPs records multiple reaction-process steps during meltdown in the severe FDNPP accident: Melted fuel (molten core)-concrete interactions (MCCIs), incorporating various airborne fission product nanoparticles, including CsOH and CsCl, proceeded via SiO2 condensation over aggregates of Zn-Fe oxide nanoparticles originating from the failure of the reactor pressure vessels. Still, CsMPs provide a mechanism by which volatile and low-volatility radionuclides such as U can reach the environment and should be considered in the migration model of Cs and radionuclides in the current environment surrounding the FDNPP. PMID:28198440

  18. Sampling for Airborne Radioactivity

    DTIC Science & Technology

    2007-10-01

    compared to betas, gammas and neutrons. For an airborne radioactivity detection system, it is most important to be able to detect alpha particles and... Airborne radioactive particles may emit alpha, beta, gamma or neutron radiation, depending on which radioisotope is present. From a health perspective...

  19. The effect of boreal forest canopy to reflectance of snow covered terrain based on airborne imaging spectrometer observations

    NASA Astrophysics Data System (ADS)

    Heinilä, Kirsikka; Salminen, Miia; Pulliainen, Jouni; Cohen, Juval; Metsämäki, Sari; Pellikka, Petri

    2014-04-01

    Optical remote sensing methods for mapping of the seasonal snow cover are often obstructed by the masking effect of forest canopy. Therefore, optical algorithms tend to underestimate the amount of snow cover in forested regions. In this paper, we investigate the influence of boreal forest stand characteristics on the observed scene reflectance under full dry snow cover conditions by applying an advantageous experimental setup combining airborne hyperspectral imaging and LIDAR data sets from a test region in Sodankylä, northern Finland. This is particularly useful to the understanding of the composition of the mixed satellite scene reflectance behavior and it is relation to the natural ground targets' spectral signatures.

  20. Magnetophoresis of diamagnetic microparticles in a weak magnetic field.

    PubMed

    Zhu, Gui-Ping; Hejiazan, Majid; Huang, Xiaoyang; Nguyen, Nam-Trung

    2014-12-21

    Magnetic manipulation is a promising technique for lab-on-a-chip platforms. The magnetic approach can avoid problems associated with heat, surface charge, ionic concentration and pH level. The present paper investigates the migration of diamagnetic particles in a ferrofluid core stream that is sandwiched between two diamagnetic streams in a uniform magnetic field. The three-layer flow is expanded in a circular chamber for characterisation based on imaging of magnetic nanoparticles and fluorescent microparticles. A custom-made electromagnet generates a uniform magnetic field across the chamber. In a relatively weak uniform magnetic field, the diamagnetic particles in the ferrofluid move and spread across the chamber. Due to the magnetization gradient formed by the ferrofluid, diamagnetic particles undergo negative magnetophoresis and move towards the diamagnetic streams. The effects of magnetic field strength and the concentration of diamagnetic particles are studied in detail.

  1. Noncontact charge measurement of moving microparticles contacting dielectric surfaces

    NASA Astrophysics Data System (ADS)

    Nesterov, Alexander; Löffler, Felix; König, Kai; Trunk, Ulrich; Leibe, Klaus; Felgenhauer, Thomas; Stadler, Volker; Bischoff, Ralf; Breitling, Frank; Lindenstruth, Volker; Hausmann, Michael

    2007-07-01

    In this study examples for a noncontact procedure that allow the description of instant electric charging of moving microparticles that contact dielectric surfaces, for instance, of a flow hose are presented. The described principle is based on the measurement of induced currents in grounded metal wire probes, as moving particles pass close to the probe. The feasibility of the approach was tested with laser printer toner particles of a given size for different basic particle flow and charging conditions. An analytic description for the induced currents was developed and compared to observed effects in order to interpret the results qualitatively. The implementation of the presented procedure can be applied to transparent and nontransparent particle containers and flow lines of complex geometry which can be composed from the presented basic flow stream configurations.

  2. Complex-shaped three-dimensional multi-compartmental microparticles generated by diffusional and Marangoni microflows in centrifugally discharged droplets

    NASA Astrophysics Data System (ADS)

    Hayakawa, Masayuki; Onoe, Hiroaki; Nagai, Ken H.; Takinoue, Masahiro

    2016-02-01

    We report a versatile method for the generation of complex-shaped three-dimensional multi-compartmental (3D-MC) microparticles. Complex-shaped microparticles have recently received much attention for potential application in self-assemblies, micromachines, and biomedical and environmental engineering. Here, we have developed a method based on 3D nonequilibrium-induced microflows (Marangoni and diffusional flows) of microdroplets that are discharged from the tip of a thin capillary in a simple centrifugal microfluidic device. The microparticle shapes can be tuned by the partial dissolution of specific compartments and by the deformation of the precursor microdroplets by manipulating the 3D microflows. We believe that this method will have wide applications in nano- and microscience and technologies.

  3. Detection of microparticles in dynamic processes

    NASA Astrophysics Data System (ADS)

    Ten, K. A.; Pruuel, E. R.; Kashkarov, A. O.; Rubtsov, I. A.; Shechtman, L. I.; Zhulanov, V. V.; Tolochko, B. P.; Rykovanov, G. N.; Muzyrya, A. K.; Smirnov, E. B.; Stolbikov, M. Yu; Prosvirnin, K. M.

    2016-11-01

    When a metal plate is subjected to a strong shock impact, its free surface emits a flow of particles of different sizes (shock-wave “dusting”). Traditionally, the process of dusting is investigated by the methods of pulsed x-ray or piezoelectric sensor or via an optical technique. The particle size ranges from a few microns to hundreds of microns. The flow is assumed to include also finer particles, which cannot be detected with the existing methods yet. On the accelerator complex VEPP-3-VEPP-4 at the BINP there are two experiment stations for research on fast processes, including explosion ones. The stations enable measurement of both passed radiation (absorption) and small-angle x-ray scattering on synchrotron radiation (SR). Radiation is detected with a precision high-speed detector DIMEX. The detector has an internal memory of 32 frames, which enables recording of the dynamics of the process (shooting of movies) with intervals of 250 ns to 2 μs. Flows of nano- and microparticles from free surfaces of various materials (copper and tin) have been examined. Microparticle flows were emitted from grooves of 50-200 μs in size and joints (gaps) between metal parts. With the soft x-ray spectrum of SR one can explore the dynamics of a single microjet of micron size. The dynamics of density distribution along micro jets were determined. Under a shock wave (∼ 60 GPa) acting on tin disks, flows of microparticles from a smooth surface were recorded.

  4. Analysis of tissue factor positive microparticles.

    PubMed

    Key, Nigel S

    2010-04-01

    There has recently been intense interest in the clinical measurement of tissue factor (TF)-positive microparticles (MPs) in clinical disease states. This interest has been driven by the demonstration of an putative role for circulating TF-positive MPs in animal models of thrombus propagation. Both immunological and functional assays for MP-TF have been described. While each approach has its own advantages and drawbacks, neither has yet been truly established as the 'gold standard'. Heterogeneity of TF-bearing MPs, such as the variable co-expression of surface phosphatidylserine, may determine not only their procoagulant potential, but also additional properties including rate of clearance from the circulation.

  5. The research of remote sensing in karst collapse remote sense based on airborne LiDAR system: taking Meitanba mining area in Hunan Province as an example

    NASA Astrophysics Data System (ADS)

    An, Zhihong; Wang, Hao; Wu, Fang; Guo, Zhaocheng

    2014-11-01

    Taking Meitanba mining area in Hunan Province as an example, by using the achieved high accuracy and high resolution point-cloud data and digital image data by airborne LiDAR system, this research built the 3D landform of the vegetation-covered areas, got the features of micro landform in the areas, and offered quantity factors for research of geo phenomenon which related to regional landforms and geoscience process. Based on the high accuracy data from airborne LiDAR system and combined with the basic data of geology,the forming mechanism of the karst collapse of Meitanba mining area in Hunan Province and the relationship of surface collapse and mining activities are analyzed. The research mentioned that the reason of the karst collapse in Meitanba mining area is with the basic conditions of forming karst landform and plus the increasing water flow and exchange rate of the underground water, and then the water level decrease, finally different degrees of the regional karst collapse have happened.

  6. Development of Airborne LiDAR based Sky View Factors to Estimate Micro-scale Energy Budget of Forest Areas: a Case Study of Taehwa Forest, Korea

    NASA Astrophysics Data System (ADS)

    An, S.; Woo, J.; Kim, B.; Hong, J.; Kim, S.; Choi, S.; Kim, Y.; Quan, S.

    2012-12-01

    About 6% of earth incoming solar radiation energy (nearly 173 petawatts) is absorbed by the ground surface, which fuels earth surface energy budget and physical/biological/ecological cycles including biogenic emission processes. Many key factors and indices have been proposed to understand the phenomenon initiated from solar energy. In this study, we proposed a new solar energy estimation parameter, the Sky View Factor (SVF), to understand energy budget of vegetated surface. The SVF is a ratio between an open sky area and covered surroundings, such as building and colonnade, which represents an estimation of the visible area of the sky from an earth view point. The high resolution airborne Light Detection And Ranging (LiDAR) dataset instead of low resolution satellite information was used to develop SVFs, because the more reliable ground surface information are very important to correctly estimate the factors. The airborne LiDAR-based SVF calculator tool was also developed to estimate SVFs efficiently then applied to estimate SVFs at Taehwa forest area in support of surface landcover composition analysis. The validation results using shortwave and longwave radiation flux data monitored from Taehwa flux tower and the satellite remote sensing data (LANDSAT ETM+) will be discussed.

  7. Prediction of dosage-based parameters from the puff dispersion of airborne materials in urban environments using the CFD-RANS methodology

    NASA Astrophysics Data System (ADS)

    Efthimiou, G. C.; Andronopoulos, S.; Bartzis, J. G.

    2017-02-01

    One of the key issues of recent research on the dispersion inside complex urban environments is the ability to predict dosage-based parameters from the puff release of an airborne material from a point source in the atmospheric boundary layer inside the built-up area. The present work addresses the question of whether the computational fluid dynamics (CFD)-Reynolds-averaged Navier-Stokes (RANS) methodology can be used to predict ensemble-average dosage-based parameters that are related with the puff dispersion. RANS simulations with the ADREA-HF code were, therefore, performed, where a single puff was released in each case. The present method is validated against the data sets from two wind-tunnel experiments. In each experiment, more than 200 puffs were released from which ensemble-averaged dosage-based parameters were calculated and compared to the model's predictions. The performance of the model was evaluated using scatter plots and three validation metrics: fractional bias, normalized mean square error, and factor of two. The model presented a better performance for the temporal parameters (i.e., ensemble-average times of puff arrival, peak, leaving, duration, ascent, and descent) than for the ensemble-average dosage and peak concentration. The majority of the obtained values of validation metrics were inside established acceptance limits. Based on the obtained model performance indices, the CFD-RANS methodology as implemented in the code ADREA-HF is able to predict the ensemble-average temporal quantities related to transient emissions of airborne material in urban areas within the range of the model performance acceptance criteria established in the literature. The CFD-RANS methodology as implemented in the code ADREA-HF is also able to predict the ensemble-average dosage, but the dosage results should be treated with some caution; as in one case, the observed ensemble-average dosage was under-estimated slightly more than the acceptance criteria. Ensemble

  8. Airborne particulate matter in spacecraft

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

  9. Improved small molecule drug release from in situ forming poly(lactic-co-glycolic acid) scaffolds incorporating poly(β-amino ester) and hydroxyapatite microparticles.

    PubMed

    Fisher, Paul D; Palomino, Pablo; Milbrandt, Todd A; Hilt, J Zach; Puleo, David A

    2014-01-01

    In situ forming implants are an attractive choice for controlled drug release into a fixed location. Currently, rapidly solidifying solvent exchange systems suffer from a high initial burst, and sustained release behavior is tied to polymer precipitation and degradation rate. The present studies investigated addition of hydroxyapatite (HA) and drug-loaded poly(β-amino ester) (PBAE) microparticles to in situ forming poly(lactic-co-glycolic acid) (PLGA)-based systems to prolong release and reduce burst. PBAEs were synthesized, imbibed with simvastatin (osteogenic) or clodronate (anti-resorptive), and then ground into microparticles. Microparticles were mixed with or without HA into a PLGA solution, and the mixture was injected into buffer, leading to precipitation and creating solid scaffolds with embedded HA and PBAE microparticles. Simvastatin release was prolonged through 30 days, and burst release was reduced from 81 to 39% when loaded into PBAE microparticles. Clodronate burst was reduced from 49 to 32% after addition of HA filler, but release kinetics were unaffected after loading into PBAE microparticles. Scaffold dry mass remained unchanged through day 15, with a pronounced increase in degradation rate after day 30, while wet scaffolds experienced a mass increase through day 25 due to swelling. Porosity and pore size changed throughout degradation, likely due to a combination of swelling and degradation. The system offers improved release kinetics, multiple release profiles, and rapid solidification compared to traditional in situ forming implants.

  10. Improved small molecule drug release from in situ forming poly(lactic-co-glycolic acid) scaffolds incorporating poly(β-amino ester) and hydroxyapatite microparticles

    PubMed Central

    Fisher, Paul D.; Palomino, Pablo; Milbrandt, Todd A.; Hilt, J. Zach; Puleo, David A.

    2014-01-01

    In situ forming implants are an attractive choice for controlled drug release into a fixed location. Currently, rapidly solidifying solvent exchange systems suffer from a high initial burst, and sustained release behavior is tied to polymer precipitation and degradation rate. The present studies investigated addition of hydroxyapatite (HA) and drug-loaded poly(β-amino ester) (PBAE) microparticles to in situ forming poly(lactic-co-glycolic acid) (PLGA)–based systems to prolong release and reduce burst. PBAEs were synthesized, imbibed with simvastatin (osteogenic) or clodronate (anti-resorptive), and then ground into microparticles. Microparticles were mixed with or without HA into a PLGA solution, and the mixture was injected into buffer, leading to precipitation and creating solid scaffolds with embedded HA and PBAE microparticles. Simvastatin release was prolonged through 30 days, and burst release was reduced from 81% to 39% when loaded into PBAE microparticles. Clodronate burst was reduced from 49% to 32% after addition of HA filler, but release kinetics were unaffected after loading into PBAE microparticles. Scaffold dry mass remained unchanged through day 15, with a pronounced increase in degradation rate after day 30, while wet scaffolds experienced a mass increase through day 25 due to swelling. Porosity and pore size changed throughout degradation, likely due to a combination of swelling and degradation. The system offers improved release kinetics, multiple release profiles, and rapid solidification compared to traditional in situ forming implants. PMID:24903524

  11. Expert system-based mineral mapping in northern Death Valley, California/Nevada, using the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)

    NASA Technical Reports Server (NTRS)

    Kruse, F. A.; Lefkoff, A. B.; Dietz, J. B.

    1993-01-01

    Integrated analysis of imaging spectrometer data and field spectral measurements were used in conjunction with conventional geologic field mapping to characterize bedrock and surficial geology at the northern end of Death Valley, California and Nevada. A knowledge-based expert system was used to automatically produce image maps showing the principal surface mineralogy from Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data. Linear spectral unmixing of the AVIRIS data allowed further determination of relative mineral, abundances and identification of mineral assemblages and mixtures. The imaging spectrometer data show the spatial distribution of spectrally distinct minerals occurring both as primary rockforming minerals and as alteration and weathering products. Field spectral measurements were used to verify the mineral maps and field mapping was used to extend the remote sensing results. Geographically referenced image maps produced from these data form new base maps from which to develop improved understanding of the processes of deposition and erosion affecting the present land surface.

  12. In vivo biocompatibility of the PLGA microparticles in parotid gland

    PubMed Central

    Cantín, Mario; Miranda, Patricio; Suazo Galdames, Iván; Zavando, Daniela; Arenas, Patricia; Velásquez, Luis; Vilos, Cristian

    2013-01-01

    Poly(lactic-co-glycolic acid) (PLGA) microparticles are used in various disorders for the controlled or sustained release of drugs, with the management of salivary gland pathologies possible using this technology. There is no record of the response to such microparticles in the glandular parenchyma. The purpose of this study was to assess the morphological changes in the parotid gland when injected with a single dose of PLGA microparticles. We used 12 adult female Sprague Dawley rats (Rattus norvegicus) that were injected into their right parotid gland with sterile vehicle solution (G1, n=4), 0.5 mg PLGA microparticles (G2, n=4), and 0.75 mg PLGA microparticles (G3, n=4); the microparticles were dissolved in a sterile vehicle solution. The intercalar and striated ducts lumen, the thickness of the acini and the histology aspect in terms of the parenchyma organization, cell morphology of acini and duct system, the presence of polymeric residues, and inflammatory response were determined at 14 days post-injection. The administration of the compound in a single dose modified some of the morphometric parameters of parenchyma (intercalar duct lumen and thickness of the glandular acini) but did not induce tissue inflammatory response, despite the visible presence of polymer waste. This suggests that PLGA microparticles are biocompatible with the parotid tissue, making it possible to use intraglandular controlled drug administration. PMID:24228103

  13. Electrospray of multifunctional microparticles for image-guided drug delivery

    NASA Astrophysics Data System (ADS)

    Zhang, Leilei; Yan, Yan; Mena, Joshua; Sun, Jingjing; Letson, Alan; Roberts, Cynthia; Zhou, Chuanqing; Chai, Xinyu; Ren, Qiushi; Xu, Ronald

    2012-03-01

    Anti-VEGF therapies have been widely explored for the management of posterior ocular disease, like neovascular age-related macular degeneration (AMD). Loading anti-VEGF therapies in biodegradable microparticles may enable sustained drug release and improved therapeutic outcome. However, existing microfabrication processes such as double emulsification produce drug-loaded microparticles with low encapsulation rate and poor antibody bioactivity. To overcome these limitations, we fabricate multifunctional microparticles by both single needle and coaxial needle electrospray. The experimental setup for the process includes flat-end syringe needles (both single needle and coaxial needle), high voltage power supplies, and syringe pumps. Microparticles are formed by an electrical field between the needles and the ground electrode. Droplet size and morphology are controlled by multiple process parameters and material properties, such as flow rate and applied voltage. The droplets are collected and freezing dried to obtain multifunctional microparticles. Fluorescent beads encapsulated poly(DL-lactide-co-glycolide) acid (PLGA) microparticles are injected into rabbits eyes through intravitreal injection to test the biodegradable time of microparticles.

  14. Shock wave driven microparticles for pharmaceutical applications

    NASA Astrophysics Data System (ADS)

    Menezes, V.; Takayama, K.; Gojani, A.; Hosseini, S. H. R.

    2008-10-01

    Ablation created by a Q-switched Nd:Yttrium Aluminum Garnet (Nd:YAG) laser beam focusing on a thin aluminum foil surface spontaneously generates a shock wave that propagates through the foil and deforms it at a high speed. This high-speed foil deformation can project dry micro- particles deposited on the anterior surface of the foil at high speeds such that the particles have sufficient momentum to penetrate soft targets. We used this method of particle acceleration to develop a drug delivery device to deliver DNA/drug coated microparticles into soft human-body targets for pharmaceutical applications. The device physics has been studied by observing the process of particle acceleration using a high-speed video camera in a shadowgraph system. Though the initial rate of foil deformation is over 5 km/s, the observed particle velocities are in the range of 900-400 m/s over a distance of 1.5-10 mm from the launch pad. The device has been tested by delivering microparticles into liver tissues of experimental rats and artificial soft human-body targets, modeled using gelatin. The penetration depths observed in the experimental targets are quite encouraging to develop a future clinical therapeutic device for treatments such as gene therapy, treatment of cancer and tumor cells, epidermal and mucosal immunizations etc.

  15. Clear-Sky Closure Studies of Tropospheric Aerosol and Water Vapor During ACE-2 Using Airborne Sunphotometer, Airborne In-Situ, Space-Borne, and Ground-Based Measurements

    NASA Technical Reports Server (NTRS)

    Schmid, Beat; Collins, Donald R.; Gasso, Santiago; Oestroem, Elisabeth; Powell, Donna M.; Welton, Ellsworth J.; Durkee, Philip A.; Livingston, John M.; Russell, Philip B.; Flagan, Richard C.; Seinfeld, John H.; Hegg, Dean A.; Noone, Kevin J.; Voss, Kenneth J.; Gordon, Howard R.; Reagan, John A.; Spinhirne, James D.

    2000-01-01

    We report on clear-sky column closure experiments (CLEARCOLUMN) performed in the Canary Islands during the second Aerosol Characterization Experiment (ACE-2) in June/July 1997. We present CLEARCOLUMN results obtained by combining airborne sunphotometer and in-situ (a differential mobility analyzer, three optical particle counters, three nephelometers, and one absorption photometer) measurements taken aboard the Pelican aircraft, space-borne NOAA/AVHRR data and ground-based lidars. A wide range of aerosol types was encountered throughout the ACE-2 area, including background Atlantic marine, European pollution-derived, and (although less frequently than expected) African mineral dust. During the two days discussed here, vertical profiles flown in cloud free air masses revealed three distinctly different layers: a marine boundary layer (MBL) with varying pollution levels, an elevated dust layer, and a very clean layer between the MBL and the dust layer. Based on size-resolved composition information we have established an aerosol model that allows us to compute optical properties of the ambient aerosol using the optical particle counter results. In the dust, the agreement in layer AOD (lambda=380-1060 nm) is 3-8%. In the MBL there is a tendency for the in-situ results to be slightly lower than the sunphotometer measurements (10-17% at lambda=525 nm), but these differences are within the combined error bars of the measurements and computations. Aerosol size-distribudon closure based on in-situ size distributions and inverted sunphotometer extinction spectra has been achieved in the MBL (total surface area and volume agree within 0.2, and 7%, respectively) but not in the dust layer. The fact that the three nephelometers operated at three different relative humidities (RH) allowed to parameterize hygroscopic growth and to therefore estimate optical properties at ambient RH. The parameters derived for different aerosol types are themselves useful for the aerosol modeling

  16. Devices for monitoring content of microparticles and bacterium in injection solutions in pharmaceutical production

    NASA Astrophysics Data System (ADS)

    Bilyi, Olexander I.; Getman, Vasyl B.; Konyev, Fedir A.; Sapunkov, Olexander; Sapunkov, Pavlo G.

    2001-06-01

    The devices for monitoring of parameters of efficiency of water solutions filtration, which are based on the analysis of scattered light by microparticles are considered in this article. The efficiency of using of devices in pharmaceutics in technological processes of manufacturing medical injection solutions is shown. The examples of monitoring of contents of bacterial cultures Pseudomonas aeruginosa, Escherichia coli, and Micrococcus luteus in water solutions of glucose are indicated.

  17. Microwave-synthesized magnetic chitosan microparticles for the immobilization of yeast cells.

    PubMed

    Safarik, Ivo; Pospiskova, Kristyna; Maderova, Zdenka; Baldikova, Eva; Horska, Katerina; Safarikova, Mirka

    2015-01-01

    An extremely simple procedure has been developed for the immobilization of Saccharomyces cerevisiae cells on magnetic chitosan microparticles. The magnetic carrier was prepared using an inexpensive, simple, rapid, one-pot process, based on the microwave irradiation of chitosan and ferrous sulphate at high pH. Immobilized yeast cells have been used for sucrose hydrolysis, hydrogen peroxide decomposition and the adsorption of selected dyes.

  18. Airborne gravity is here

    SciTech Connect

    Hammer, S.

    1982-01-11

    After 20 years of development efforts, the airborne gravity survey has finally become a practical exploration method. Besides gravity data, the airborne survey can also collect simultaneous, continuous records of high-precision magneticfield data as well as terrain clearance; these provide a topographic contour map useful in calculating terrain conditions and in subsequent planning and engineering. Compared with a seismic survey, the airborne gravity method can cover the same area much more quickly and cheaply; a seismograph could then detail the interesting spots.

  19. Airborne Particulate Threat Assessment

    SciTech Connect

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

    Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our

  20. Chitosan microparticles as injectable scaffolds for tissue engineering.

    PubMed

    Cruz, Dunia Mercedes García; Ivirico, Jorge Luis Escobar; Gomes, Manuela M; Ribelles, Jose Luis Gómez; Sánchez, Manuel Salmerón; Reis, Rui L; Mano, João F

    2008-08-01

    The use of chitosan microparticles as injectable carriers for cell transplantation represents a promising alternative to avoid the drawbacks of the implantation of other forms of three-dimensional (3D) scaffolds seeded with cells. In this study, a 3D construct is obtained in vitro by combining chitosan microparticles crosslinked with genipin and goat bone marrow stromal cells (GBMCs). Cell viability and the morphology of GBMCs were evaluated after culture for 7 and 14 days. Our results show the feasibility of chitosan microparticles as potential injectable scaffolds for tissue engineering and regenerative medicine.

  1. Fabrication of dielectrophoretic microfluidic chips using a facile screen-printing technique for microparticle trapping

    NASA Astrophysics Data System (ADS)

    Wee, Wei Hong; Li, Zedong; Hu, Jie; Adib Kadri, Nahrizul; Xu, Feng; Li, Fei; Pingguan-Murphy, Belinda

    2015-10-01

    Trapping of microparticles finds wide applications in numerous fields. Microfluidic chips based on a dielectrophoresis (DEP) technique hold several advantages for trapping microparticles, such as fast result processing, a small amount of sample required, high spatial resolution, and high accuracy of target selection. There is an unmet need to develop DEP microfluidic chips on different substrates for different applications in a low cost, facile, and rapid way. This study develops a new facile method based on a screen-printing technique for fabrication of electrodes of DEP chips on three types of substrates (i.e. polymethyl-methacrylate (PMMA), poly(ethylene terephthalate) and A4 paper). The fabricated PMMA-based DEP microfluidic chip was selected as an example and successfully used to trap and align polystyrene microparticles in a suspension and cardiac fibroblasts in a cell culture solution. The developed electrode fabrication method is compatible with different kinds of DEP substrates, which could expand the future application field of DEP microfluidic chips, including new forms of point-of care diagnostics and trapping circulating tumor cells.

  2. Airborne/Space-Based Doppler Lidar Wind Sounders Sampling the PBL and Other Regions of Significant Beta and U Inhomogeneities

    NASA Technical Reports Server (NTRS)

    Emmitt, Dave

    1998-01-01

    This final report covers the period from April 1994 through March 1998. The proposed research was organized under four main tasks. Those tasks were: (1) Investigate the vertical and horizontal velocity structures within and adjacent to thin and subvisual cirrus; (2) Investigate the lowest 1 km of the PBL and develop algorithms for processing pulsed Doppler lidar data obtained from single shots into regions of significant inhomogeneities in Beta and U; (3) Participate in OSSEs including those designed to establish shot density requirements for meso-gamma scale phenomena with quasi-persistent locations (e.g., jets, leewaves, tropical storms); and (4) Participate in the planning and execution of an airborne mission to measure winds with a pulsed CO2 Doppler lidar. Over the four year period of this research contract, work on all four tasks has yielded significant results which have led to 38 professional presentations (conferences and publications) and have been folded into the science justification for an approved NASA space mission, SPARCLE (SPAce Readiness Coherent Lidar Experiment), in 2001. Also this research has, through Task 4, led to a funded proposal to work directly on a NASA field campaign, CAMEX III, in which an airborne Doppler wind lidar will be used to investigate the cloud-free circulations near tropical storms. Monthly progress reports required under this contract are on file. This final report will highlight major accomplishments, including some that were not foreseen in the original proposal. The presentation of this final report includes this written document as well as material that is better presented via the internet (web pages). There is heavy reference to appended papers and documents. Thus, the main body of the report will serve to summarize the key efforts and findings.

  3. Electrocatalytic hydrogenation using precious metal microparticles in redox-active polymer films

    SciTech Connect

    Coche, L.; Ehui, B.; Limosin, D.; Moutet, J.C. )

    1990-11-09

    Glassy carbon felt electrodes have been modified by electrodeposition of poly(pyrrole-viologen) films (derived from N,N{prime}-dialkyl-4,4{prime}-bipyridinium salts), followed by electroprecipitation of precious metal (Pt, Pd, Rh, or Ru) microparticles. The resulting electrodes have been proved to be active for the electrocatalytic hydrogenation of conjugated enones (2-cyclohexen-1-one, cryptone, carvone, isophorone), styrene, and benzonitrile in aqueous media (pH 1). Despite low loadings of metal catalysts, high electric and products yields and a long term stability of these cathodes have been observed. The influence of the metal loading and the polymer structure on the catalytic efficiency as well as the selectivity obtained according to the metal catalyst used have been studied. Comparison with results previously reported for other catalytic cathodes like Pt/Pt, Pd/C, or Raney nickel electrodes proves the high efficiency of these metal microparticles within redox polymer film based electrodes.

  4. Detection and quantification of microparticles from different cellular lineages using flow cytometry. Evaluation of the impact of secreted phospholipase A2 on microparticle assessment.

    PubMed

    Rousseau, Matthieu; Belleannee, Clemence; Duchez, Anne-Claire; Cloutier, Nathalie; Levesque, Tania; Jacques, Frederic; Perron, Jean; Nigrovic, Peter A; Dieude, Melanie; Hebert, Marie-Josee; Gelb, Michael H; Boilard, Eric

    2015-01-01

    Microparticles, also called microvesicles, are submicron extracellular vesicles produced by plasma membrane budding and shedding recognized as key actors in numerous physio(patho)logical processes. Since they can be released by virtually any cell lineages and are retrieved in biological fluids, microparticles appear as potent biomarkers. However, the small dimensions of microparticles and soluble factors present in body fluids can considerably impede their quantification. Here, flow cytometry with improved methodology for microparticle resolution was used to detect microparticles of human and mouse species generated from platelets, red blood cells, endothelial cells, apoptotic thymocytes and cells from the male reproductive tract. A family of soluble proteins, the secreted phospholipases A2 (sPLA2), comprises enzymes concomitantly expressed with microparticles in biological fluids and that catalyze the hydrolysis of membrane phospholipids. As sPLA2 can hydrolyze phosphatidylserine, a phospholipid frequently used to assess microparticles, and might even clear microparticles, we further considered the impact of relevant sPLA2 enzymes, sPLA2 group IIA, V and X, on microparticle quantification. We observed that if enriched in fluids, certain sPLA2 enzymes impair the quantification of microparticles depending on the species studied, the source of microparticles and the means of detection employed (surface phosphatidylserine or protein antigen detection). This study provides analytical considerations for appropriate interpretation of microparticle cytofluorometric measurements in biological samples containing sPLA2 enzymes.

  5. Detection and Quantification of Microparticles from Different Cellular Lineages Using Flow Cytometry. Evaluation of the Impact of Secreted Phospholipase A2 on Microparticle Assessment

    PubMed Central

    Rousseau, Matthieu; Belleannee, Clemence; Duchez, Anne-Claire; Cloutier, Nathalie; Levesque, Tania; Jacques, Frederic; Perron, Jean; Nigrovic, Peter A.; Dieude, Melanie; Hebert, Marie-Josee; Gelb, Michael H.; Boilard, Eric

    2015-01-01

    Microparticles, also called microvesicles, are submicron extracellular vesicles produced by plasma membrane budding and shedding recognized as key actors in numerous physio(patho)logical processes. Since they can be released by virtually any cell lineages and are retrieved in biological fluids, microparticles appear as potent biomarkers. However, the small dimensions of microparticles and soluble factors present in body fluids can considerably impede their quantification. Here, flow cytometry with improved methodology for microparticle resolution was used to detect microparticles of human and mouse species generated from platelets, red blood cells, endothelial cells, apoptotic thymocytes and cells from the male reproductive tract. A family of soluble proteins, the secreted phospholipases A2 (sPLA2), comprises enzymes concomitantly expressed with microparticles in biological fluids and that catalyze the hydrolysis of membrane phospholipids. As sPLA2 can hydrolyze phosphatidylserine, a phospholipid frequently used to assess microparticles, and might even clear microparticles, we further considered the impact of relevant sPLA2 enzymes, sPLA2 group IIA, V and X, on microparticle quantification. We observed that if enriched in fluids, certain sPLA2 enzymes impair the quantification of microparticles depending on the species studied, the source of microparticles and the means of detection employed (surface phosphatidylserine or protein antigen detection). This study provides analytical considerations for appropriate interpretation of microparticle cytofluorometric measurements in biological samples containing sPLA2 enzymes. PMID:25587983

  6. Differences in magnetically induced motion of diamagnetic, paramagnetic, and superparamagnetic microparticles detected by cell tracking velocimetry.

    PubMed

    Jin, Xiaoxia; Zhao, Yang; Richardson, Aaron; Moore, Lee; Williams, P Stephen; Zborowski, Maciej; Chalmers, Jeffrey J

    2008-12-01

    Magnetic separation in biomedical applications is based on differential magnetophoretic mobility (MM) of microparticulate matter in viscous media. Typically, the difference in MM is obtained by selectively labeling the target cells with superparamagnetic iron oxide nanoparticles (SPIONs). We have measured the MM of monodisperse, polystyrene microspheres (PSMs), with and without attached SPIONs as a model of cell motion induced by nanoparticle magnetization, using variable H field and cell tracking velocimetry (CTV). As a model of paramagnetic microparticle motion, the MM measurements were performed on the same PSMs in paramagnetic gadolinium solutions, and on spores of a prokaryotic organism, Bacillus globigii (shown to contain paramagnetic manganese). The CTV analysis was sensitive to the type of the microparticle magnetization, producing a value of MM independent of the applied H field for the paramagnetic species, and a decreasing MM value with an increasing field for superparamagnetic species, as predicted from theory. The SPION-labeled PSMs exhibited a saturation magnetization above H approximately = 64,000 A m(-1) (or 0.08 tesla). Based on those data, the average saturation magnetizations of the SPIONs was calculated and shown to vary between different commercial sources. The results demonstrate sensitivity of the CTV analysis to different magnetization mechanisms of the microparticles.

  7. Differences in magnetically induced motion of diamagnetic, paramagnetic, and superparamagnetic microparticles detected by Cell Tracking Velocimetry

    PubMed Central

    Jin, Xiaoxia; Zhao, Yang; Richardson, Aaron; Moore, Lee; Williams, P. Stephen; Zborowski, Maciej; Chalmers, Jeffrey J.

    2009-01-01

    Magnetic separation in biomedical applications is based on differential magnetophoretic mobility (MM) of microparticulate matter in viscous media. Typically, the difference in MM is obtained by selectively labeling the target cells with superparamagnetic iron oxide nanoparticles(SPIONs). We have measured the MM of monodisperse, polystyrene microspheres (PSMs), with and without attached SPIONs as a model of cell motion induced by nanoparticle magnetization, using variable H field and Cell Tracking Velocimetry (CTV). As a model of paramagnetic microparticle motion, the MM measurements were performed on the same PSMs in paramagnetic gadolinium solutions, and on spores of a prokaryotic organism, Bacillus globigii (shown to contain paramagnetic manganese). The CTV analysis was sensitive to the type of the microparticle magnetization, producing a value of MM independent of the applied H field for the paramagnetic species, and a decreasing MM value with an increasing field for superparamagnetic species, as predicted from theory. The SPION-labeled PSMs exhibited a saturation magnetization above H ≅ 64,000 A m−1 (or 0.08 tesla). Based on those data, the average saturation magnetizations of the SPIONs was calculated and shown to vary between different commercial sources. The results demonstrate sensitivity of the CTV analysis to different magnetization mechanisms of the microparticles. PMID:19082082

  8. Polymer-grafted starch microparticles for oral and nasal immunization.

    PubMed

    McDermott, M R; Heritage, P L; Bartzoka, V; Brook, M A

    1998-06-01

    Microparticle delivery systems for oral vaccine administration are receiving considerable attention. A novel silicone polymer-grafted starch microparticle system was developed that is efficacious both orally and intranasally. Unlike most other microparticle systems, this novel system does not appear to retard the release of antigen or to protect antigen from degradation. The results indicate that a unique physiochemical relationship occurs between protein antigen and silicone in a starch matrix that facilitates the mucosal immunogenicity of antigen. This leads to predominance of Th2 antibody response. Taken together, these findings indicate that this novel microparticle system may be advantageous for the delivery of small quantities of antigen, especially intranasally, and may be useful for the induction of oral tolerance.

  9. Microfabrication of encoded microparticle array for multiplexed DNA hybridization detection.

    PubMed

    Zhi, Zheng-Liang; Morita, Yasutaka; Yamamura, Shouhei; Tamiya, Eiichi

    2005-05-21

    A strategy for the high-sensitivity, high-selectivity, and multiplexed detection of oligonucleotide hybridizations has been developed with an encoded Ni microparticle random array that was manufactured by a "top-down" approach using micromachining and microfabrication techniques.

  10. Enhancement of laminar convective heat transfer using microparticle suspensions

    NASA Astrophysics Data System (ADS)

    Zhu, Jiu Yang; Tang, Shiyang; Yi, Pyshar; Baum, Thomas; Khoshmanesh, Khashayar; Ghorbani, Kamran

    2017-01-01

    This paper investigates the enhancement of convective heat transfer within a sub-millimetre diameter copper tube using Al2O3, Co3O4 and CuO microparticle suspensions. Experiments are conducted at different particle concentrations of 1.0, 2.0 and 5.0 wt% and at various flow rates ranging from 250 to 1000 µl/min. Both experimental measurements and numerical analyses are employed to obtain the convective heat transfer coefficient. The results indicate a significant enhancement in convective heat transfer coefficient due to the implementation of microparticle suspensions. For the case of Al2O3 microparticle suspension with 5.0 wt% concentration, a 20.3 % enhancement in convective heat transfer coefficient is obtained over deionised water. This is comparable to the case of Al2O3 nanofluid at the same concentration. Hence, there is a potential for the microparticle suspensions to be used for cooling of compact integrated systems.

  11. Photonic nanojet shaping of dielectric non-spherical microparticles

    NASA Astrophysics Data System (ADS)

    Liu, Cheng-Yang

    2014-11-01

    The photonic nanojet shaping effect in the dielectric non-spherical microparticles is reported. The specific spatial electromagnetic field is studied by using finite-difference time-domain calculation which constitutes the so-called photonic nanojet. The dielectric non-spherical microparticle is truncated by the cutting thickness. The latitudinal and longitudinal dimensions of the photonic nanojet and its peak intensity depending on the variation of cutting thickness are numerically researched. The shape dependence of the photonic nanojet in the non-spherical microparticles has been investigated by quality criterion. The practical results are drawn concerning the possible procedures to gain the control over the properties of photonic nanojet in the non-spherical microparticles. The shaping mechanism has a significant impact on the use of photonic nanojet to distinguish nanoscale specimens.

  12. Effect of surface temperature on microparticle-surface adhesion

    NASA Astrophysics Data System (ADS)

    Vallabh, Chaitanya Krishna Prasad; Stephens, James D.; Cetinkaya, Cetin

    2015-07-01

    The effect of surface temperature on the adhesion properties of the bond between a substrate and a single micro-particle is investigated in a non-contact/non-invasive manner by monitoring the rolling/rocking motion dynamics of acoustically excited single microparticles. In the current work, a set of experiments were performed to observe the change in the rocking resonance frequency of the particles with the change of surface temperature. At various substrate surface temperature levels, the work-of-adhesion values of the surface-particle bond are evaluated from the resonance frequencies of the rocking motion of a set of microparticles driven by an orthogonal ultrasonic surface acoustic wave field. The dependence of adhesion bonds of a microparticle and the substrate on the surface temperature has been clearly demonstrated by the performed experiments. It was also observed and noted that the relative humidity plays a vital role in the rolling behavior of particles.

  13. The picobalance for single microparticle measurements

    NASA Astrophysics Data System (ADS)

    Davis, E. James

    The picobalance or quadrupole levitator is an outgrowth of the classical Millikan oil drop experiment and has been used for a wide variety of studies of micron and submicron size particles and droplets. A new version of the picobalance, which uses automatic feedback control for particle suspension and a linear photodiode array for light-scattering measurements, is described. The instrument has been used to measure the aerodynamic drag on microparticles suspended in a flow field and to measure evaporation rates and optical properties of liquid droplets. The instrument can also be used to examine spectroscopically the optical and chemical properties of atmospheric and interplanetary particles and any number of phoretic forces on such particles.

  14. Numerical Simulations of the Digital Microfluidic Manipulation of Single Microparticles.

    PubMed

    Lan, Chuanjin; Pal, Souvik; Li, Zhen; Ma, Yanbao

    2015-09-08

    Single-cell analysis techniques have been developed as a valuable bioanalytical tool for elucidating cellular heterogeneity at genomic, proteomic, and cellular levels. Cell manipulation is an indispensable process for single-cell analysis. Digital microfluidics (DMF) is an important platform for conducting cell manipulation and single-cell analysis in a high-throughput fashion. However, the manipulation of single cells in DMF has not been quantitatively studied so far. In this article, we investigate the interaction of a single microparticle with a liquid droplet on a flat substrate using numerical simulations. The droplet is driven by capillary force generated from the wettability gradient of the substrate. Considering the Brownian motion of microparticles, we utilize many-body dissipative particle dynamics (MDPD), an off-lattice mesoscopic simulation technique, in this numerical study. The manipulation processes (including pickup, transport, and drop-off) of a single microparticle with a liquid droplet are simulated. Parametric studies are conducted to investigate the effects on the manipulation processes from the droplet size, wettability gradient, wetting properties of the microparticle, and particle-substrate friction coefficients. The numerical results show that the pickup, transport, and drop-off processes can be precisely controlled by these parameters. On the basis of the numerical results, a trap-free delivery of a hydrophobic microparticle to a destination on the substrate is demonstrated in the numerical simulations. The numerical results not only provide a fundamental understanding of interactions among the microparticle, the droplet, and the substrate but also demonstrate a new technique for the trap-free immobilization of single hydrophobic microparticles in the DMF design. Finally, our numerical method also provides a powerful design and optimization tool for the manipulation of microparticles in DMF systems.

  15. Electrodeposition of microparticles on polarized ion exchange membranes

    SciTech Connect

    Verbich, S.V.; Ponomarev, M.I.; Grebenyuk, V.D.; Dukhin, S.S.

    1986-11-01

    The use of ion exchange membranes to extract microparticles from an aqueous solution is considered. The efficiency of removing negatively charged aerosil particles depends substantially on the nature of the membrane located at the anode. It has been established that besides an increase in the electric field intensity the principal factor ensuring an increase in the efficiency of purifying a solution by electrodeposition of microparticles on a membrane surface is a reduction in the flowrate relative to the membrane surface.

  16. Persistence, distribution, and impact of distinctly segmented microparticles on cochlear health following in vivo infusion.

    PubMed

    Ross, Astin M; Rahmani, Sahar; Prieskorn, Diane M; Dishman, Acacia F; Miller, Josef M; Lahann, Joerg; Altschuler, Richard A

    2016-06-01

    Delivery of pharmaceuticals to the cochleae of patients with auditory dysfunction could potentially have many benefits from enhancing auditory nerve survival to protecting remaining sensory cells and their neuronal connections. Treatment would require platforms to enable drug delivery directly to the cochlea and increase the potential efficacy of intervention. Cochlear implant recipients are a specific patient subset that could benefit from local drug delivery as more candidates have residual hearing; and since residual hearing directly contributes to post-implantation hearing outcomes, it requires protection from implant insertion-induced trauma. This study assessed the feasibility of utilizing microparticles for drug delivery into cochlear fluids, testing persistence, distribution, biocompatibility, and drug release characteristics. To allow for delivery of multiple therapeutics, particles were composed of two distinct compartments; one containing polylactide-co-glycolide (PLGA), and one composed of acetal-modified dextran and PLGA. Following in vivo infusion, image analysis revealed microparticle persistence in the cochlea for at least 7 days post-infusion, primarily in the first and second turns. The majority of subjects maintained or had only slight elevation in auditory brainstem response thresholds at 7 days post-infusion compared to pre-infusion baselines. There was only minor to limited loss of cochlear hair cells and negligible immune response based on CD45+ immunolabling. When Piribedil-loaded microparticles were infused, Piribedil was detectable within the cochlear fluids at 7 days post-infusion. These results indicate that segmented microparticles are relatively inert, can persist, release their contents, and be functionally and biologically compatible with cochlear function and therefore are promising vehicles for cochlear drug delivery. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1510-1522, 2016.

  17. In-situ crosslinking hydrogels for combinatorial delivery of chemokines and siRNA-DNA carrying microparticles to dendritic cells

    PubMed Central

    Singh, Ankur; Suri, Shalu; Roy, Krishnendu

    2009-01-01

    Polymer-based, injectable systems that can simultaneously deliver multiple bioactive agents in a controlled manner could significantly enhance the efficacy of next generation therapeutics. For immunotherapies to be effective, both prophylactically or therapeutically, it is not only critical to drive the antigen (Ag) specific immune response strongly towards either T helper type 1 (Th1) or Th2 phenotype, but also to promote recruitment of a high number of antigen-presenting cells (APCs) at the site of immunization. We have recently reported a microparticle-based system capable of simultaneously delivering siRNA and DNA to APCs. Here we present an in situ crosslinkable, injectable formulation containing dendritic cell (DC)-chemoattractants and dual-mode DNA-siRNA loaded microparticles to attract immature DCs and simultaneously deliver, to the migrated cells, immunomodulatory siRNA and plasmid DNA antigens. These low crosslink density hydrogels were designed to degrade within 2–7 days in-vitro and released chemokines in a sustained manner. Chemokine carrying gels attracted 4–6 folds more DCs over a sustained period in vitro, compared to an equivalent bolus dose. Interestingly, migrated DCs were able to infiltrate the hydrogels and efficiently phagocytose the siRNA/DNA carrying microparticles. Hydrogel embedded microparticles co-delivering Interleukin-10 siRNA and plasmid DNA antigens exhibited efficient Interleukin-10 gene knockdown in migrated primary DCs in-vitro. PMID:19560815

  18. Geodetic Imaging Lidar: Applications for high-accuracy, large area mapping with NASA's upcoming high-altitude waveform-based airborne laser altimetry Facility

    NASA Astrophysics Data System (ADS)

    Blair, J. B.; Rabine, D.; Hofton, M. A.; Citrin, E.; Luthcke, S. B.; Misakonis, A.; Wake, S.

    2015-12-01

    Full waveform laser altimetry has demonstrated its ability to capture highly-accurate surface topography and vertical structure (e.g. vegetation height and structure) even in the most challenging conditions. NASA's high-altitude airborne laser altimeter, LVIS (the Land Vegetation, and Ice Sensor) has produced high-accuracy surface maps over a wide variety of science targets for the last 2 decades. Recently NASA has funded the transition of LVIS into a full-time NASA airborne Facility instrument to increase the amount and quality of the data and to decrease the end-user costs, to expand the utilization and application of this unique sensor capability. Based heavily on the existing LVIS sensor design, the Facility LVIS instrument includes numerous improvements for reliability, resolution, real-time performance monitoring and science products, decreased operational costs, and improved data turnaround time and consistency. The development of this Facility instrument is proceeding well and it is scheduled to begin operations testing in mid-2016. A comprehensive description of the LVIS Facility capability will be presented along with several mission scenarios and science applications examples. The sensor improvements included increased spatial resolution (footprints as small as 5 m), increased range precision (sub-cm single shot range precision), expanded dynamic range, improved detector sensitivity, operational autonomy, real-time flight line tracking, and overall increased reliability and sensor calibration stability. The science customer mission planning and data product interface will be discussed. Science applications of the LVIS Facility include: cryosphere, territorial ecology carbon cycle, hydrology, solid earth and natural hazards, and biodiversity.

  19. An Airborne Ultrasonic Imaging System Based on 16 Elements: 150 kHz Piezopolymer Transducer Arrays—Preliminary Simulated and Experimental Results for Cylindrical Targets Detection

    NASA Astrophysics Data System (ADS)

    Capineri, L.; Bulletti, A.; Calzolai, M.; Giannelli, P.

    2016-12-01

    This paper describes the design and fabrication of a 16-element transducer array for airborne ultrasonic imaging operating at 150 kHz, that can operate both at close range (50 mm) in the near field of a synthetic aperture, and up to 250 mm. The proposed imaging technique is based on a modified version of the delay and sum algorithm implemented with a synthetic aperture where each pixel amplitude is determined by the integration of the signal obtained by the coherent summation of the acquired signals over a delayed window with fixed length. The image reconstruction methods using raw data provides the possibility to detect targets with smaller feature size on the order of one wavelength because the coherent signals summation over the selected window length while the image reconstruction methods using the summation of enveloped signals increases the amplitude response at the expenses of a lower spatial resolution. For the implementation of this system it is important to design compact airborne transducers with large field of view and this can be obtained with a new design of hemi-cylindrical polyvinylidene fluoride film transducers directly mounted on a printed circuit board. This new method is low cost and has repeatable transducer characteristics. The complete system is compact, with a modular architecture, in which eight boards with dual ultrasonic channels are mounted on a mother board. Each daughter board hosts a microcontroller unit and can operate with transducers in the bandwidth 40-200 kHz with on-board data acquisition, pre-processing and transfer on a dedicated bus.

  20. Combined AC electroosmosis and dielectrophoresis for controlled rotation of microparticles

    PubMed Central

    Walid Rezanoor, Md.; Dutta, Prashanta

    2016-01-01

    Electrorotation is widely used for characterization of biological cells and materials using a rotating electric field. Generally, multiphase AC electric fields and quadrupolar electrode configuration are needed to create a rotating electric field for electrorotation. In this study, we demonstrate a simple method to rotate dielectrophoretically trapped microparticles using a stationary AC electric field. Coplanar interdigitated electrodes are used to create a linearly polarized nonuniform AC electric field. This nonuniform electric field is employed for dielectrophoretic trapping of microparticles as well as for generating electroosmotic flow in the vicinity of the electrodes resulting in rotation of microparticles in a microfluidic device. The rotation of barium titanate microparticles is observed in 2-propanol and methanol solvent at a frequency below 1 kHz. A particle rotation rate as high as 240 revolutions per minute is observed. It is demonstrated that precise manipulation (both rotation rate and equilibrium position) of the particles is possible by controlling the frequency of the applied electric field. At low frequency range, the equilibrium positions of the microparticles are observed between the electrode edge and electrode center. This method of particle manipulation is different from electrorotation as it uses induced AC electroosmosis instead of electric torque as in the case of electrorotation. Moreover, it has been shown that a microparticle can be rotated along its own axis without any translational motion. PMID:27014394

  1. Theory of optical beam deflection for single microparticles

    NASA Astrophysics Data System (ADS)

    Wu, Jiaqi; Kitamori, Takehiko; Sawada, Tsuguo

    1991-05-01

    A theory was developed for the optical beam deflection (OBD) signal generated from a single microparticle. From the thermal-diffusion equations, the temperature fields inside and outside the microparticle, which has a two-layer structure, was deduced. A three-dimensional theoretical treatment was established for the deflection signal of the probe beam passing through the temperature field formed by photothermal conversion of the excitation beam energy absorbed by the sample. The proprieties of the theoretical model and its results were confirmed by comparing the theoretical values of the frequency characteristics, probe beam offset dependencies, and particle size dependencies of the OBD signal with the experimental ones for 25-300-μm-radius microparticles. From the theory, the unique particle size dependencies and frequency characteristics of the OBD method for the single microparticle, i.e., higher sensitivity for smaller particles and at high frequencies, were identified as due to the microparticle surface curvature. The optimal experimental conditions in the OBD measurement of the single microparticle were also obtained using theoretical analysis.

  2. Uniform Microparticles with Controllable Highly Interconnected Hierarchical Porous Structures.

    PubMed

    Zhang, Mao-Jie; Wang, Wei; Yang, Xiu-Lan; Ma, Bing; Liu, Ying-Mei; Xie, Rui; Ju, Xiao-Jie; Liu, Zhuang; Chu, Liang-Yin

    2015-07-01

    A simple and versatile strategy is developed for one-step fabrication of uniform polymeric microparticles with controllable highly interconnected hierarchical porous structures. Monodisperse water-in-oil-in-water (W/O/W) emulsions, with methyl methacrylate, ethylene glycol dimethacrylate, and glycidyl methacrylate as the monomer-containing oil phase, are generated from microfluidics and used for constructing the microparticles. Due to the partially miscible property of oil/aqueous phases, the monodisperse W/O/W emulsions can deform into desired shapes depending on the packing structure of inner aqueous microdrops, and form aqueous nanodrops in the oil phase. The deformed W/O/W emulsions allow template syntheses of highly interconnected hierarchical porous microparticles with precisely and individually controlled pore size, porosity, functionality, and particle shape. The microparticles elaborately combine the advantages of enhanced mass transfer, large functional surface area, and flexibly tunable functionalities, providing an efficient strategy to physically and chemically achieve enhanced synergetic performances for extensive applications. This is demonstrated by using the microparticles for oil removal for water purification and protein adsorption for bioseparation. The method proposed in this study provides full versatility for fabrication of functional polymeric microparticles with controllable hierarchical porous structures for enhancing and even broadening their applications.

  3. Encapsulation of protein drugs in biodegradable microparticles by co-axial electrospray.

    PubMed

    Xie, Jingwei; Ng, Wei Jun; Lee, Lai Yeng; Wang, Chi-Hwa

    2008-01-15

    A co-axial electrospray process was developed to encapsulate protein-based drugs in biodegradable polymeric microparticles eliminating the key problem faced by other conventional methods of protein encapsulation--the primary emulsion being a major cause for protein denaturation and aggregation. Bovine serum albumin (BSA) and lysozyme were chosen as model protein drugs for this study. Scanning electron microscopy observation of the morphology of particles showed spherical microparticles of several microns could be achieved. In vitro release profiles measured using Micro-BCA assay indicated sustained release of proteins for more than 30 days. The results of circular dichroism suggested that the secondary structure of released BSA can be retained. The bioactivity of released lysozyme was found to be more than 90% which is higher than the values reported from most literatures. Therefore, co-axial electrospray could be a very promising approach to encapsulate biomacromolecules such as proteins, enzymes, DNA plasmids or living cells inside microparticles for controlled release drug delivery applications.

  4. Pressure sensitive microparticle adhesion through biomimicry of the pollen-stigma interaction.

    PubMed

    Lin, Haisheng; Qu, Zihao; Meredith, J Carson

    2016-03-21

    Many soft biomimetic synthetic adhesives, optimized to support macroscopic masses (∼kg), have been inspired by geckos, insects and other animals. Far less work has investigated bioinspired adhesion that is tuned to micro- and nano-scale sizes and forces. However, such adhesive forces are extremely important in the adhesion of micro- and nanoparticles to surfaces, relevant to a wide range of industrial and biological systems. Pollens, whose adhesion is critical to plant reproduction, are an evolutionary-optimized system for biomimicry to engineer tunable adhesion between particles and micro-patterned soft matter surfaces. In addition, the adhesion of pollen particles is relevant to topics as varied as pollinator ecology, transport of allergens, and atmospheric phenomena. We report the first observation of structurally-derived pressure-sensitive adhesion of a microparticle by using the sunflower pollen and stigma surfaces as a model. This strong, pressure-sensitive adhesion results from interlocking between the pollen's conical spines and the stigma's receptive papillae. Inspired by this behavior, we fabricated synthetic polymeric patterned surfaces that mimic the stigma surface's receptivity to pollen. These soft mimics allow the magnitude of the pressure-sensitive response to be tuned by adjusting the size and spacing of surface features. These results provide an important new insight for soft material adhesion based on bio-inspired principles, namely that ornamented microparticles and micro-patterned surfaces can be designed with complementarity that enable a tunable, pressure-sensitive adhesion on the microparticle size and length scale.

  5. From The Cover: Poly- amino ester-containing microparticles enhance the activity of nonviral genetic vaccines

    NASA Astrophysics Data System (ADS)

    Little, Steven R.; Lynn, David M.; Ge, Qing; Anderson, Daniel G.; Puram, Sidharth V.; Chen, Jianzhu; Eisen, Herman N.; Langer, Robert

    2004-06-01

    Current nonviral genetic vaccine systems are less effective than viral vaccines, particularly in cancer systems where epitopes can be weakly immunogenic and antigen-presenting cell processing and presentation to T cells is down-regulated. A promising nonviral delivery method for genetic vaccines involves microencapsulation of antigen-encoding DNA, because such particles protect plasmid payloads and target them to phagocytic antigen-presenting cells. However, conventional microparticle formulations composed of poly lactic-co-glycolic acid take too long to release encapsulated payload and fail to induce high levels of target gene expression. Here, we describe a microparticle-based DNA delivery system composed of a degradable, pH-sensitive poly- amino ester and poly lactic-co-glycolic acid. These formulations generate an increase of 3-5 orders of magnitude in transfection efficiency and are potent activators of dendritic cells in vitro. When used as vaccines in vivo, these microparticle formulations, unlike conventional formulations, induce antigen-specific rejection of transplanted syngenic tumor cells.

  6. Effects of Antibiotic Physicochemical Properties on their Release Kinetics from Biodegradable Polymer Microparticles

    PubMed Central

    Shah, Sarita R.; Henslee, Allan M.; Spicer, Patrick P.; Yokota, Shun; Petrichenko, Sophia; Allahabadi, Sachin; Bennett, George N.; Wong, Mark E.; Kasper, F. Kurtis; Mikos, Antonios G.

    2014-01-01

    Purpose This study investigated the effects of the physicochemical properties of antibiotics on the morphology, loading efficiency, size, release kinetics, and antibiotic efficacy of loaded poly(DL-lactic-co-glycolic acid) (PLGA) microparticles (MPs) at different loading percentages. Methods Cefazolin, ciprofloxacin, clindamycin, colistin, doxycycline, and vancomycin were loaded at 10 and 20 weight percent into PLGA MPs using a water-in-oil-in water double emulsion fabrication protocol. Microparticle morphology, size, loading efficiency, release kinetics, and antibiotic efficacy were assessed. Results The results from this study demonstrate that the chemical nature of loaded antibiotics, especially charge and molecular weight, influence the incorporation into and release of antibiotics from PLGA MPs. Drugs with molecular weights less than 600 Da displayed biphasic release while those with molecular weights greater than 1000 Da displayed triphasic release kinetics. Large molecular weight drugs also had a longer delay before release than smaller molecular weight drugs. The negatively charged antibiotic cefazolin had lower loading efficiency than positively charged antibiotics. Microparticle size appeared to be mainly controlled by fabrication parameters, and partition and solubility coefficients did not appear to have an obvious effect on loading efficiency or release. Released antibiotics maintained their efficacy against susceptible strains over the duration of release. Duration of release varied between 17–49 days based on the type of antibiotic loaded. Conclusions The data from this study indicate that the chemical nature of antibiotics affects properties of antibiotic-loaded PLGA MPs and allows for general prediction of loading and release kinetics. PMID:24874603

  7. Airborne Doppler lidar at 532nm based on a tunable dual-channel Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Feng, Jian-mei; Xing, Ting-wen; Lin, Wi-mei

    2009-07-01

    The aim of this paper is to explore a high-precision, a wide range of a frequency discrimination technique, and to study the application of this technique in the optical air data system (MOADS). To overcome the traditional equipment's shortcomings of short velocity detecting range such as pilot static tubes and wind wane, this technique can provide precision aviation data for various aerocrafts , without influencing pneumatic shape and performance of aerocraft. A tunable dual channel Fabry-Perot interferometer is used as a frequency discriminator in an airborne wind lidar system. This new frequency discriminator has been proposed to overcome the exiting frequency discriminator shortcoming. By adjusting the cavity length of interferometer, the speed of aerocraft can be detected and cut into several dynamic range. By this way, the Doppler wind lidar system can detect atmospheric parameters at the meantime, such as speed of aerocraft and temperature of atmosphere around the aerocraft, by analyzing the information of Rayleigh backscattering light. There are three main contribution in this paper: the first is discussing the basic theory of MOADS, calculational method and mathematic model of relative wind velocity between aircraft and wind are put forward.; the second is the parameter optimization of the dual-channel Fabry-Perot interferometer and the structure design of the interferometer; the third is the simulation of the performance and the accuracy of this system. Theory analysis and simulation results show this method is reasonable and practical.

  8. Levee crest elevation profiles derived from airborne lidar-based high resolution digital elevation models in south Louisiana

    USGS Publications Warehouse

    Palaseanu-Lovejoy, Monica; Thatcher, Cindy A.; Barras, John A.

    2014-01-01

    This study explores the feasibility of using airborne lidar surveys to construct high-resolution digital elevation models (DEMs) and develop an automated procedure to extract levee longitudinal elevation profiles for both federal levees in Atchafalaya Basin and local levees in Lafourche Parish, south Lousiana. This approach can successfully accommodate a high degree of levee sinuosity and abrupt changes in levee orientation (direction) in planar coordinates, variations in levee geometries, and differing DEM resolutions. The federal levees investigated in Atchafalaya Basin have crest elevations between 5.3 and 12 m while the local counterparts in Lafourche Parish are between 0.76 and 2.3 m. The vertical uncertainty in the elevation data is considered when assessing federal crest elevation against the U.S. Army Corps of Engineers minimum height requirements to withstand the 100-year flood. Only approximately 5% of the crest points of the two federal levees investigated in the Atchafalaya Basin region met this requirement.

  9. Spectrum correction algorithm for detectors in airborne radioactivity monitoring equipment NH-UAV based on a ratio processing method

    NASA Astrophysics Data System (ADS)

    Cao, Ye; Tang, Xiao-Bin; Wang, Peng; Meng, Jia; Huang, Xi; Wen, Liang-Sheng; Chen, Da

    2015-10-01

    The unmanned aerial vehicle (UAV) radiation monitoring method plays an important role in nuclear accidents emergency. In this research, a spectrum correction algorithm about the UAV airborne radioactivity monitoring equipment NH-UAV was studied to measure the radioactive nuclides within a small area in real time and in a fixed place. The simulation spectra of the high-purity germanium (HPGe) detector and the lanthanum bromide (LaBr3) detector in the equipment were obtained using the Monte Carlo technique. Spectrum correction coefficients were calculated after performing ratio processing techniques about the net peak areas between the double detectors on the detection spectrum of the LaBr3 detector according to the accuracy of the detection spectrum of the HPGe detector. The relationship between the spectrum correction coefficient and the size of the source term was also investigated. A good linear relation exists between the spectrum correction coefficient and the corresponding energy (R2=0.9765). The maximum relative deviation from the real condition reduced from 1.65 to 0.035. The spectrum correction method was verified as feasible.

  10. Land cover classification based on object-oriented with airborne lidar and high spectral resolution remote sensing image

    NASA Astrophysics Data System (ADS)

    Li, Fangfang; Liu, Zhengjun; Xu, Qiangqiang; Ren, Haicheng; Zhou, Xingyu; Yuan, Yonghua

    2016-10-01

    In order to improve land cover classification accuracy of the coastal tidal wetland area in Dafeng, this paper take advantage of hyper-spectral remote sensing image with high spatial resolution airborne Lidar data. The introduction of feature extraction, band selection and nDSM models to reduce the dimension of the original image. After segmentation process that combining FNEA segmentation with spectral differences segmentation method, the paper finalize the study area through the establishment of the rule set classification of land cover classification. The results show that the proposed classification for land cover classification accuracy has improved significantly, including housing, shadow, water, vegetation classification of high precision. That is to say that the method can meet the needs of land cover classification of the coastal tidal wetland area in Dafeng. This innovation is the introduction of principal component analysis, and the use of characteristic index, shape and characteristics of various types of data extraction nDSM feature to improve the accuracy and speed of land cover classification.

  11. Measurement of Attenuation with Airborne and Ground-Based Radar in Convective Storms Over Land and Its Microphysical Implications

    NASA Technical Reports Server (NTRS)

    Tian, Lin; Heymsfield, G. M.; Srivastava, R. C.; Starr, D. OC. (Technical Monitor)

    2001-01-01

    Observations by the airborne X-band Doppler radar (EDOP) and the NCAR S-band polarimetric (S-POL) radar from two field experiments are used to evaluate the Surface ref'ercnce technique (SRT) for measuring the path integrated attenuation (PIA) and to study attenuation in deep convective storms. The EDOP, flying at an altitude of 20 km, uses a nadir beam and a forward pointing beam. It is found that over land, the surface scattering cross-section is highly variable at nadir incidence but relatively stable at forward incidence. It is concluded that measurement by the forward beam provides a viable technique for measuring PIA using the SRT. Vertical profiles of peak attenuation coefficient are derived in vxo deep convective storms by the dual-wavelength method. Using the measured Doppler velocity, the reflectivities at. the two wavelengths, the differential reflectivity and the estimated attenuation coefficients, it is shown that: supercooled drops and dry ice particles probably co-existed above the melting level in regions of updraft, that water-coated partially melted ice particles probably contributed to high attenuation below the melting level, and that the data are not readil explained in terms of a gamma function raindrop size distribution.

  12. Measurement of Attenuation with Airborne and Ground-Based Radar in Convective Storms Over Land Its Microphysical Implications

    NASA Technical Reports Server (NTRS)

    Tian, Lin; Heymsfield, G. M.; Srivastava, R. C.; O'C.Starr, D. (Technical Monitor)

    2001-01-01

    Observations by the airborne X-band Doppler radar (EDOP) and the NCAR S-band polarimetric (S-Pol) radar from two field experiments are used to evaluate the surface reference technique (SRT) for measuring the path integrated attenuation (PIA) and to study attenuation in deep convective storms. The EDOP, flying at an altitude of 20 km, uses a nadir beam and a forward pointing beam. It is found that over land, the surface scattering cross-section is highly variable at nadir incidence but relatively stable at forward incidence. It is concluded that measurement by the forward beam provides a viable technique for measuring PIA using the SRT. Vertical profiles of peak attenuation coefficient are derived in two deep convective storms by the dual-wavelength method. Using the measured Doppler velocity, the reflectivities at the two wavelengths, the differential reflectivity and the estimated attenuation coefficients, it is shown that: supercooled drops and (dry) ice particles probably co-existed above the melting level in regions of updraft, that water-coated partially melted ice particles probably contributed to high attenuation below the melting level.

  13. Microparticles: Facile and High-Throughput Synthesis of Functional Microparticles with Quick Response Codes (Small 24/2016).

    PubMed

    Ramirez, Lisa Marie S; He, Muhan; Mailloux, Shay; George, Justin; Wang, Jun

    2016-06-01

    Microparticles carrying quick response (QR) barcodes are fabricated by J. Wang and co-workers on page 3259, using a massive coding of dissociated elements (MiCODE) technology. Each microparticle can bear a special custom-designed QR code that enables encryption or tagging with unlimited multiplexity, and the QR code can be easily read by cellphone applications. The utility of MiCODE particles in multiplexed DNA detection and microtagging for anti-counterfeiting is explored.

  14. Airborne Next: Rethinking Airborne Organization and Applying New Concepts

    DTIC Science & Technology

    2015-06-01

    structures since its employment on a large scale during World War II. It is puzzling to consider how little airborne organizational structures and employment...future potential of airborne concepts by rethinking traditional airborne organizational structures and employment concepts. Using a holistic approach in... structures of airborne forces to model a “small and many” approach over a “large and few” approach, while incorporating a “swarming” concept. Utilizing

  15. 54. DETAIL OF GENERAL ELECTRIC AIRBORNE BEACON EQUIPMENT TEST SET ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. DETAIL OF GENERAL ELECTRIC AIRBORNE BEACON EQUIPMENT TEST SET (LEFT) AND ASSOCIATED GOULD BRUSH CHART RECORDERS (RIGHT). ELAPSED TIME COUNTER SITS ATOP AIRBORNE BEACON EQUIPMENT TEST SET. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  16. Lidar-Based Estimates of Above-Ground Biomass in the Continental US and Mexico Using Ground, Airborne, and Satellite Observations

    NASA Technical Reports Server (NTRS)

    Nelson, Ross; Margolis, Hank; Montesano, Paul; Sun, Guoqing; Cook, Bruce; Corp, Larry; Andersen, Hans-Erik; DeJong, Ben; Pellat, Fernando Paz; Fickel, Thaddeus; Kauffman, Jobriath; Prisley, Stephen

    2016-01-01

    Existing national forest inventory plots, an airborne lidar scanning (ALS) system, and a space profiling lidar system (ICESat-GLAS) are used to generate circa 2005 estimates of total aboveground dry biomass (AGB) in forest strata, by state, in the continental United States (CONUS) and Mexico. The airborne lidar is used to link ground observations of AGB to space lidar measurements. Two sets of models are generated, the first relating ground estimates of AGB to airborne laser scanning (ALS) measurements and the second set relating ALS estimates of AGB (generated using the first model set) to GLAS measurements. GLAS then, is used as a sampling tool within a hybrid estimation framework to generate stratum-, state-, and national-level AGB estimates. A two-phase variance estimator is employed to quantify GLAS sampling variability and, additively, ALS-GLAS model variability in this current, three-phase (ground-ALS-space lidar) study. The model variance component characterizes the variability of the regression coefficients used to predict ALS-based estimates of biomass as a function of GLAS measurements. Three different types of predictive models are considered in CONUS to determine which produced biomass totals closest to ground-based national forest inventory estimates - (1) linear (LIN), (2) linear-no-intercept (LNI), and (3) log-linear. For CONUS at the national level, the GLAS LNI model estimate (23.95 +/- 0.45 Gt AGB), agreed most closely with the US national forest inventory ground estimate, 24.17 +/- 0.06 Gt, i.e., within 1%. The national biomass total based on linear ground-ALS and ALS-GLAS models (25.87 +/- 0.49 Gt) overestimated the national ground-based estimate by 7.5%. The comparable log-linear model result (63.29 +/-1.36 Gt) overestimated ground results by 261%. All three national biomass GLAS estimates, LIN, LNI, and log-linear, are based on 241,718 pulses collected on 230 orbits. The US national forest inventory (ground) estimates are based on 119

  17. Endothelial Dysfunction Caused by Circulating Microparticles from Patients with Metabolic Syndrome

    PubMed Central

    Agouni, Abdelali; Lagrue-Lak-Hal, Anne Hélène; Ducluzeau, Pierre Henri; Mostefai, Hadj Ahmed; Draunet-Busson, Catherine; Leftheriotis, Georges; Heymes, Christophe; Martinez, Maria Carmen; Andriantsitohaina, Ramaroson

    2008-01-01

    Microparticles are membrane vesicles that are released during cell activation and apoptosis. Elevated levels of microparticles occur in many cardiovascular diseases; therefore, we characterized circulating microparticles from both metabolic syndrome (MS) patients and healthy patients. We evaluated microparticle effects on endothelial function; however, links between circulating microparticles and endothelial dysfunction have not yet been demonstrated. Circulating microparticles and their cellular origins were examined by flow cytometry of blood samples from patients and healthy subjects. Microparticles were used either to treat human endothelial cells in vitro or to assess endothelium function in mice after intravenous injection. MS patients had increased circulating levels of microparticles compared with healthy patients, including microparticles from platelet, endothelial, erythrocyte, and procoagulant origins. In vitro treatment of endothelial cells with microparticles from MS patients reduced both nitric oxide (NO) and superoxide anion production, resulting in protein tyrosine nitration. These effects were associated with enhanced phosphorylation of endothelial NO synthase at the site of inhibition. The reduction of O2− was linked to both reduced expression of p47phox of NADPH oxidase and overexpression of extracellular superoxide dismutase. The decrease in NO production was triggered by nonplatelet-derived microparticles. In vivo injection of MS microparticles into mice impaired endothelium-dependent relaxation and decreased endothelial NO synthase expression. These data provide evidence that circulating microparticles from MS patients influence endothelial dysfunction. PMID:18772329

  18. Agglomerated oral dosage forms of artemisinin/β-cyclodextrin spray-dried primary microparticles showing increased dissolution rate and bioavailability.

    PubMed

    Balducci, Anna Giulia; Magosso, Enrico; Colombo, Gaia; Sonvico, Fabio; Khan, Nurzalina Abdul Karim; Yuen, Kah Hay; Bettini, Ruggero; Colombo, Paolo; Rossi, Alessandra

    2013-09-01

    Artemisinin, a poorly water-soluble antimalarial drug, presents a low and erratic bioavailability upon oral administration. The aim of this work was to study an agglomerated powder dosage form for oral administration of artemisinin based on the artemisinin/β-cyclodextrin primary microparticles. These primary microparticles were prepared by spray-drying a water-methanol solution of artemisinin/β-cyclodextrin. β-Cyclodextrin in spray-dried microparticles increased artemisinin water apparent solubility approximately sixfold. The thermal analysis evidenced a reduction in the enthalpy value associated with drug melting, due to the decrease in drug crystallinity. The latter was also evidenced by powder X-ray diffraction analysis, while (13)C-NMR analysis indicated the partial complexation with β-cyclodextrin. Agglomerates obtained by sieve vibration of spray-dried artemisinin/β-cyclodextrin primary microparticles exhibited free flowing and close packing properties compared with the non-flowing microparticulate powder. The in vitro dissolution rate determination of artemisinin from the agglomerates showed that in 10 min about 70% of drug was released from the agglomerates, whereas less than 10% of artemisinin was dissolved from raw material powder. Oral administration of agglomerates in rats yielded higher artemisinin plasma levels compared to those of pure drug. In the case of the agglomerated powder, a 3.2-fold increase in drug fraction absorbed was obtained.

  19. A new method for the production of gelatin microparticles for controlled protein release from porous polymeric scaffolds.

    PubMed

    Ozkizilcik, Asya; Tuzlakoglu, Kadriye

    2014-03-01

    Tissue engineering using scaffolds and growth factors is a crucial approach in bone regeneration and repair. The combination of bioactive agents carrying microparticles with porous scaffolds can be an efficient solution when controlled release of bio-signalling molecules is required. The present study was based on a recent approach using a biodegradable scaffold and protein-loaded microparticles produced in an innovative manner in which protein loss is minimized during the loading process. Bovine serum albumin (BSA)-loaded gelatin microparticles were obtained by grinding freeze-dried membranes of gelatin and BSA. Porous scaffolds (250-355 µm pore size) produced from a polyactide (PLLA) and polycaprolactone (PCL) blend by salt leaching/supercritical CO₂ methods were used for the experiments. Gelatin microparticles containing three different BSA amounts were incorporated into the porous scaffolds by using a surfactant. In vitro release profiles showed up to 90% protein loading efficiency. This novel method appears to be an effective approach for producing particles that can minimize protein loss during the loading process.

  20. Simulation tests to assess occupational exposure to airborne asbestos from artificially weathered asphalt-based roofing products.

    PubMed

    Sheehan, Patrick; Mowat, Fionna; Weidling, Ryan; Floyd, Mark

    2010-11-01

    Historically, asbestos-containing roof cements and coatings were widely used for patching and repairing leaks. Although fiber releases from these materials when newly applied have been studied, there are virtually no useful data on airborne asbestos fiber concentrations associated with the repair or removal of weathered roof coatings and cements, as most studies involve complete tear-out of old roofs, rather than only limited removal of the roof coating or cement during a repair job. This study was undertaken to estimate potential chrysotile asbestos fiber exposures specific to these types of roofing products following artificially enhanced weathering. Roof panels coated with plastic roof cement and fibered roof coating were subjected to intense solar radiation and daily simulated precipitation events for 1 year and then scraped to remove the weathered materials to assess chrysotile fiber release and potential worker exposures. Analysis of measured fiber concentrations for hand scraping of the weathered products showed 8-h time-weighted average concentrations that were well below the current Occupational Safety and Health Administration permissible exposure limit for asbestos. There was, however, visibly more dust and a few more fibers collected during the hand scraping of weathered products compared to the cured products previously tested. There was a notable difference between fibers released from weathered and cured roofing products. In weathered samples, a large fraction of chrysotile fibers contained low concentrations of or essentially no magnesium and did not meet the spectral, mineralogical, or morphological definitions of chrysotile asbestos. The extent of magnesium leaching from chrysotile fibers is of interest because several researchers have reported that magnesium-depleted chrysotile fibers are less toxic and produce fewer mesothelial tumors in animal studies than normal chrysotile fibers.

  1. Functionality Based Detection of Airborne Engineered Nanoparticles in Quasi Real Time: A New Type of Detector and a New Metric

    PubMed Central

    Neubauer, Nicole

    2013-01-01

    A new type of detector which we call the Catalytic Activity Aerosol Monitor (CAAM) was investigated towards its capability to detect traces of commonly used industrial catalysts in ambient air in quasi real time. Its metric is defined as the catalytic activity concentration (CAC) expressed per volume of sampled workplace air. We thus propose a new metric which expresses the presence of nanoparticles in terms of their functionality - in this case a functionality of potential relevance for damaging effects - rather than their number, surface, or mass concentration in workplace air. The CAAM samples a few micrograms of known or anticipated airborne catalyst material onto a filter first and then initiates a chemical reaction which is specific to that catalyst. The concentration of specific gases is recorded using an IR sensor, thereby giving the desired catalytic activity. Due to a miniaturization effort, the laboratory prototype is compact and portable. Sensitivity and linearity of the CAAM response were investigated with catalytically active palladium and nickel nano-aerosols of known mass concentration and precisely adjustable primary particle size in the range of 3–30nm. With the miniature IR sensor, the smallest detectable particle mass was found to be in the range of a few micrograms, giving estimated sampling times on the order of minutes for workplace aerosol concentrations typically reported in the literature. Tests were also performed in the presence of inert background aerosols of SiO2, TiO2, and Al2O3. It was found that the active material is detectable via its catalytic activity even when the particles are attached to a non-active background aerosol. PMID:23504803

  2. The 2007 September 1 Aurigid meteor shower: predictions and first results from airborne and ground based observations

    NASA Astrophysics Data System (ADS)

    Jenniskens, P.; Vaubaillon, J.

    2007-12-01

    We predicted the encounter of Earth with the dust trail of comet C/1911 N1 (Kiess) on 2007 September 1, when an outburst of meteors was expected from a radiant in the constellation of Auriga (EOS, Aug 7 issue). We anticipated that the shower would be best seen from the western states of the USA, Canada, and Mexico, including Hawaii and Alaska. It would be the only such Aurigid shower outburst in our lifetime. The meteoroids dated back to ejection around 4 A.D., give or take 40 years. These Aurigids were our best chance yet to study the 1-revolution dust trail of a known long-period comet, for measurements of the dust ejection conditions, and for clues about the possible presence of a cosmic ray induced crust in a comet which only recently returned from the Oort cloud. An airborne observing campaign was organized, called the Aurigid Multi-Instrument Aircraft Campaign, involving two Gulfstream GV aircraft, which were deployed from NASA Ames Research Center in Moffett Field, California. This enabled a team of 24 researchers, with an array of different cameras, to observe the shower from an altitude of 47,000 ft. The shower manifested much as expected, with a peak rate of about ZHR = 100 /hr, a peak time of 11:15 +/- 5 min. UTC, a duration of about 2 hours, and an abundance of bright +3 to -2 magnitude meteors. The shower was also well observed from the ground by both professional and amateur astronomers. Here, we will present some of those first results, discuss the shower's impact on the public, summarize the predictions, compare those to the observed shower activity, and report on the ongoing investigation of comet Kiess and its meteoroid stream.

  3. A Web-GIS Procedure Based on Satellite Multi-Spectral and Airborne LIDAR Data to Map the Road blockage Due to seismic Damages of Built-Up Urban Areas

    NASA Astrophysics Data System (ADS)

    Costanzo, Antonio; Montuori, Antonio; Silva, Juan Pablo; Silvestri, Malvina; Musacchio, Massimo; Buongiorno, Maria Fabrizia; Stramondo, Salvatore

    2016-08-01

    In this work, a web-GIS procedure to map the risk of road blockage in urban environments through the combined use of space-borne and airborne remote sensing sensors is presented. The methodology concerns (1) the provision of a geo-database through the integration of space-borne multispectral images and airborne LiDAR data products; (2) the modeling of building vulnerability, based on the corresponding 3D geometry and construction time information; (3) the GIS-based mapping of road closure due to seismic- related building collapses based on the building characteristic height and the width of the road. Experimental results, gathered for the Cosenza urban area, allow demonstrating the benefits of both the proposed approach and the GIS-based integration of multi-platforms remote sensing sensors and techniques for seismic road assessment purposes.

  4. Quick response airborne command post communications

    NASA Astrophysics Data System (ADS)

    Blaisdell, Randy L.

    1988-08-01

    National emergencies and strategic crises come in all forms and sizes ranging from natural disasters at one end of the scale up to and including global nuclear warfare at the other. Since the early 1960s the U.S. Government has spent billions of dollars fielding airborne command posts to ensure continuity of government and the command and control function during times of theater conventional, theater nuclear, and global nuclear warfare. Unfortunately, cost has prevented the extension of the airborne command post technology developed for these relatively unlikely events to the lower level, though much more likely to occur, crises such as natural disasters, terrorist acts, political insurgencies, etc. This thesis proposes the implementation of an economical airborne command post concept to address the wide variety of crises ignored by existing military airborne command posts. The system is known as the Quick Response Airborne Command Post (QRAC Post) and is based on the exclusive use of commercially owned and operated aircraft, and commercially available automated data processing and communications resources. The thesis addresses the QRAC Post concept at a systems level and is primarily intended to demonstrate how current technology can be exploited to economically achieve a national objective.

  5. Optical manipulation of microparticles and biological structures

    NASA Astrophysics Data System (ADS)

    Gahagan, Kevin Thomas

    1998-06-01

    We report experimental and theoretical investigations of the trapping of microparticles and biological objects using radiation pressure. Part I of this thesis presents a technique for trapping both low and high index microparticles using a single, stationary focused laser beam containing an optical vortex. Advantages of this vortex trap include the ease of implementation, a lower exposure level for high-index particles compared to a standard Gaussian beam trap, and the ability to isolate individual low-index particles in concentrated dispersions. The vortex trap is modeled using ray-tracing methods and a more precise electromagnetic model, which is accurate for particles less than 10 μm in diameter. We have measured the stable equilibrium position for two low-index particle systems (e.g., hollow glass spheres (HGS) in water, and water droplets in acetophenone (W/A)). The strength of the trap was measured for the HGS system along the longitudinal and transverse directions. We also demonstrate simultaneous trapping of a low and high index particle with a vortex beam. The stability of this dual-particle trap is found to depend on the relative particle size, the divergence angle of the beam, and the depth of the particles within the trapping chamber. Part II presents results from an interdisciplinary and collaborative investigation of an all-optical genetic engineering technique whereby Agrobacterium rhizogenes were inserted through a laser-ablated hole in the cell wall of the plant, Gingko biloba. We describe a protocol which includes the control of osmotic conditions, culturing procedures, viability assays and laser microsurgery. We succeeded in placing up to twelve viable bacteria into a single plant cell using this technique. The bacteria are believed to be slightly heated by the Gaussian beam trap. A numerical model is presented predicting a temperature rise of just a few degrees. Whereas G. biloba and A. rhitogenes were chosen for this study because of Ginkgo

  6. Elemental analyses of hypervelocity microparticle impact sites on Interplanetary Dust Experiment sensor surfaces

    NASA Technical Reports Server (NTRS)

    Simon, Charles G.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. A.; Wortman, Jim J.; Brownlee, D. E.

    1993-01-01

    The Interplanetary Dust Experiment (IDE) had over 450 electrically active ultra-high purity metal-oxide-silicon impact detectors located on the six primary sides of the Long Duration Exposure Facility (LDEF). Hypervelocity microparticles (approximately 0.2 to approximately 100 micron diameter) that struck the active sensors with enough energy to break down the 0.4 or 1.0 micron thick SIO2 insulator layer separating the silicon base (the negative electrode), and the 1000 A thick surface layer of aluminum (the positive electrode) caused electrical discharges that were recorded for the first year of orbit. The high purity Al-SiO2-Si substrates allowed detection of trace (ppm) amounts of hypervelocity impactor residues. After sputtering through a layer of surface contamination, secondary ion mass spectrometry (SIMS) was used to create two-dimensional elemental ion intensity maps of microparticle impact sites on the IDE sensors. The element intensities in the central craters of the impacts were corrected for relative ion yields and instrumental conditions and then normalized to silicon. The results were used to classify the particles' origins as 'manmade,' 'natural,' or 'indeterminate.' The last classification resulted from the presence of too little impactor residue, analytical interference from high background contamination, the lack of information on silicon and aluminum residues, or a combination of these circumstances. Several analytical 'blank' discharges were induced on flight sensors by pressing down on the sensor surface with a pure silicon shard. Analyses of these blank discharges showed that the discharge energy blasts away the layer of surface contamination. Only Si and Al were detected inside the discharge zones, including the central craters of these features. Thus far a total of 79 randomly selected microparticle impact sites from the six primary sides of the LDEF have been analyzed: 36 from tray C-9 (Leading (ram), or East, side), 18 from tray C-3

  7. Elemental Analyses of Hypervelocity Microparticle Impact Sites on Interplanetary Dust Experiment Sensor Surfaces

    NASA Technical Reports Server (NTRS)

    Simon, C. G.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. A.; Wortman, J. J.; Brownlee, D. E.

    1992-01-01

    The Interplanetary Dust Experiment (IDE) had over 450 electrically active ultra-high purity metal-oxide-silicon impact detectors located on the six primary sides of the Long Duration Exposure Facility (LDEF). Hypervelocity microparticles (approximately 0.2 to approximately 100 micron diameter) that struck the active sensors with enough energy to breakdown the 0.4 or 1.0 micron thick SiO2 insulator layer separating the silicon base (the negative electrode), and the 1000 A thick surface layer of aluminum (the positive electrode) caused electrical discharges that were recorded for the first year of orbit. The high purity Al-SiO2-Si substrates allowed detection of trace (ppm) amounts of hypervelocity impactor residues. After sputtering through a layer of surface contamination, secondary ion mass spectrometry (SIMS) was used to create two-dimensional elemental ion intensity maps of microparticle sites on the IDE sensors. The element intensities in the central craters of the impacts were corrected for relative ion yields and instrumental conditions and then normalized to silicon. The results classification resulted from the particles' origins as 'manmade', 'natural', or 'indeterminate'. The last classification resulted from the presence of too little impactor residue, analytical interference from high background contamination, the lack of information on silicon and aluminum residues, or a combination of these circumstances. Several analytical 'blank' discharges were induced on flight sensors by pressing down on the sensor surface with a pure silicon shard. Analyses of these blank discharges showed that the discharge energy blasts away the layer of surface contamination. Only Si and Al were detected inside the discharge zones, including the central craters, of these features. Thus far, a total of 79 randomly selected microparticle impact sites from the six primary sides of the LDEF were analyzed: 36 from tray C-9 (Leading (ram), or east, side), 18 from tray C-3 (Trailing

  8. Elemental analyses of hypervelocity microparticle impact sites on Interplanetary Dust Experiment sensor surfaces

    NASA Astrophysics Data System (ADS)

    Simon, Charles G.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. A.; Wortman, Jim J.; Brownlee, D. E.

    1993-04-01

    The Interplanetary Dust Experiment (IDE) had over 450 electrically active ultra-high purity metal-oxide-silicon impact detectors located on the six primary sides of the Long Duration Exposure Facility (LDEF). Hypervelocity microparticles (approximately 0.2 to approximately 100 micron diameter) that struck the active sensors with enough energy to break down the 0.4 or 1.0 micron thick SIO2 insulator layer separating the silicon base (the negative electrode), and the 1000 A thick surface layer of aluminum (the positive electrode) caused electrical discharges that were recorded for the first year of orbit. The high purity Al-SiO2-Si substrates allowed detection of trace (ppm) amounts of hypervelocity impactor residues. After sputtering through a layer of surface contamination, secondary ion mass spectrometry (SIMS) was used to create two-dimensional elemental ion intensity maps of microparticle impact sites on the IDE sensors. The element intensities in the central craters of the impacts were corrected for relative ion yields and instrumental conditions and then normalized to silicon. The results were used to classify the particles' origins as 'manmade,' 'natural,' or 'indeterminate.' The last classification resulted from the presence of too little impactor residue, analytical interference from high background contamination, the lack of information on silicon and aluminum residues, or a combination of these circumstances. Several analytical 'blank' discharges were induced on flight sensors by pressing down on the sensor surface with a pure silicon shard. Analyses of these blank discharges showed that the discharge energy blasts away the layer of surface contamination. Only Si and Al were detected inside the discharge zones, including the central craters of these features. Thus far a total of 79 randomly selected microparticle impact sites from the six primary sides of the LDEF have been analyzed: 36 from tray C-9 (Leading (ram), or East, side), 18 from tray C-3

  9. Analysis of the diurnal development of a lake-valley circulation in the Alps based on airborne and surface measurements

    NASA Astrophysics Data System (ADS)

    Laiti, L.; Zardi, D.; de Franceschi, M.; Rampanelli, G.; Giovannini, L.

    2014-09-01

    This study investigates the thermal structures of the atmospheric boundary layer (ABL) and the near-surface wind field associated with a lake-valley circulation in the south-eastern Italian Alps - the so-called Ora del Garda. Two flights of an equipped motorglider allowed for the exploration of the diurnal evolution of this circulation, from the onset, on Lake Garda's shoreline, throughout its development along the Sarca Valley and Lakes Valley (Valle dei Laghi), to the outflow into the Adige Valley. At the same time, surface observations, both from a targeted field campaign and from routinely operated weather stations, supported the analysis of the development of the Ora del Garda at the valley floor. In particular, in the valleys typical ABL vertical structures, characterized by rather shallow convective mixed layers (~ 500 m) and (deeper) weakly stable layers above, up to the lateral crest height, are identified in the late morning. In contrast, close to the lake the ABL is stably stratified down to very low heights, as a consequence of the intense advection of colder air associated with the Ora del Garda flow (up to 6 m s-1). The combined analysis of surface and airborne observations (remapped over 3-D high-resolution grids) suggests that the lake-breeze front propagating up-valley from the shoreline in the late morning penetrates slightly later at the eastern end of the valley inlet (delay: ~ 1 h), probably due to the asymmetric radiative forcing caused by the N-S valley orientation. On the other hand, in the early afternoon the Ora del Garda overflows through an elevated gap, producing an anomalous, strong cross-valley wind (5 m s-1) at the Adige Valley floor north of Trento, which overwhelms the local up-valley wind. This feature is associated with a strong deepening of the local mixed layer (from 400 to 1300 m). The potential temperature 3-D field suggests that the intense turbulent mixing may be attributed to the development of a downslope wind across the

  10. Airborne Research Experience for Educators

    NASA Astrophysics Data System (ADS)

    Costa, V. B.; Albertson, R.; Smith, S.; Stockman, S. A.

    2009-12-01

    The Airborne Research Experience for Educators (AREE) Program, conducted by the NASA Dryden Flight Research Center Office of Education in partnership with the AERO Institute, NASA Teaching From Space Program, and California State University Fullerton, is a complete end-to-end residential research experience in airborne remote sensing and atmospheric science. The 2009 program engaged ten secondary educators who specialize in science, technology, engineering or mathematics in a 6-week Student Airborne Research Program (SARP) offered through NSERC. Educators participated in collection of in-flight remote sensor data during flights aboard the NASA DC-8 as well as in-situ research on atmospheric chemistry (bovine emissions of methane); algal blooms (remote sensing to determine location and degree of blooms for further in-situ analysis); and crop classification (exploration of how drought conditions in Central California have impacted almond and cotton crops). AREE represents a unique model of the STEM teacher-as-researcher professional development experience because it asks educators to participate in a research experience and then translate their experiences into classroom practice through the design, implementation, and evaluation of instructional materials that emphasize the scientific research process, inquiry-based investigations, and manipulation of real data. Each AREE Master Educator drafted a Curriculum Brief, Teachers Guide, and accompanying resources for a topic in their teaching assignment Currently, most professional development programs offer either a research experience OR a curriculum development experience. The dual nature of the AREE model engaged educators in both experiences. Educators’ content and pedagogical knowledge of STEM was increased through the review of pertinent research articles during the first week, attendance at lectures and workshops during the second week, and participation in the airborne and in-situ research studies, data

  11. Production and characterization of hyaluronic acid microparticles for the controlled delivery of growth factors using a spray/dehydration method.

    PubMed

    Babo, Pedro S; Reis, Rui L; Gomes, Manuela E

    2016-11-01

    Hyaluronic acid is the main polysaccharide present in the connective tissue. Besides its structural function as backbone of the extracellular matrix, hyaluronic acid plays staple roles in several biological processes including the modulation of inflammation and wound healing processes. The application of hyaluronic acid in regenerative medicine, either as cells and/or drug/growth factors delivery vehicles, relies on its ability to be cross-linked using a plethora of reactions, producing stable hydrogels. In this work, we propose a novel method for the production of hyaluronic acid microparticles that presents several advantages over others that have been used. Basically, droplets of hyaluronic acid solution produced with a nozzle are collected in an isopropanol dehydration bath, and stabilized after crosslinking with adipic acid dihydrazide, using a cabodiimide-based chemistry. The size and morphology of the hyaluronic acid microparticles produced by this method varied with the molecular weight and concentration of the hyaluronic acid solution, the nozzle chamber pressure, the distance between the nozzle and the crosslinking solution, and the number of crosslinking steps. The degree of crosslinking of the hyaluronic acid microparticles produced was tunable and allowed to control the rate of the degradation promoted by hyaluronidase. Moreover, the particles were loaded with platelet lysate, a hemoderivative rich in cytokines with interest for regenerative medicine applications. The hyaluronic acid microparticles showed potential to bind selectively to positively charged molecules, as the factors present in the platelet lysate. It is envisioned that these can be further released in a sustained manner by ion exchange or by the degradation of the hyaluronic acid microparticles matrix promoted by extracellular matrix remodeling.

  12. A de-noising algorithm based on wavelet threshold-exponential adaptive window width-fitting for ground electrical source airborne transient electromagnetic signal

    NASA Astrophysics Data System (ADS)

    Ji, Yanju; Li, Dongsheng; Yu, Mingmei; Wang, Yuan; Wu, Qiong; Lin, Jun

    2016-05-01

    The ground electrical source airborne transient electromagnetic system (GREATEM) on an unmanned aircraft enjoys considerable prospecting depth, lateral resolution and detection efficiency, etc. In recent years it has become an important technical means of rapid resources exploration. However, GREATEM data are extremely vulnerable to stationary white noise and non-stationary electromagnetic noise (sferics noise, aircraft engine noise and other human electromagnetic noises). These noises will cause degradation of the imaging quality for data interpretation. Based on the characteristics of the GREATEM data and major noises, we propose a de-noising algorithm utilizing wavelet threshold method and exponential adaptive window width-fitting. Firstly, the white noise is filtered in the measured data using the wavelet threshold method. Then, the data are segmented using data window whose step length is even logarithmic intervals. The data polluted by electromagnetic noise are identified within each window based on the discriminating principle of energy detection, and the attenuation characteristics of the data slope are extracted. Eventually, an exponential fitting algorithm is adopted to fit the attenuation curve of each window, and the data polluted by non-stationary electromagnetic noise are replaced with their fitting results. Thus the non-stationary electromagnetic noise can be effectively removed. The proposed algorithm is verified by the synthetic and real GREATEM signals. The results show that in GREATEM signal, stationary white noise and non-stationary electromagnetic noise can be effectively filtered using the wavelet threshold-exponential adaptive window width-fitting algorithm, which enhances the imaging quality.

  13. Evaluation of HPβCD-PEG microparticles for salmon calcitonin administration via pulmonary delivery.

    PubMed

    Tewes, Frederic; Gobbo, Oliviero L; Amaro, Maria I; Tajber, Lidia; Corrigan, Owen I; Ehrhardt, Carsten; Healy, Anne Marie

    2011-10-03

    For therapeutic peptides, the lung represents an attractive, noninvasive route into the bloodstream. To achieve optimal bioavailability and control their fast rate of absorption, peptides can be protected by coprocessing with polymers such as polyethylene glycol (PEG). Here, we formulated and characterized salmon calcitonin (sCT)-loaded microparticles using linear or branched PEG (L-PEG or B-PEG) and hydroxypropyl-beta-cyclodextrin (HPβCD) for pulmonary administration. Mixtures of sCT, L-PEG or B-PEG and HPβCD were co-spray dried. Based on the particle properties, the best PEG:HPβCD ratio was 1:1 w:w for both PEGs. In the sCT-loaded particles, the L-PEG was more crystalline than B-PEG. Thus, L-PEG-based particles had lower surface free energy and better aerodynamic behavior than B-PEG-based particles. However, B-PEG-based particles provided better protection against chemical degradation of sCT. A decrease in sCT permeability, measured across Calu-3 bronchial epithelial monolayers, occurred when the PEG and HPβCD concentrations were both 1.6 wt %. This was attributed to an increase in buffer viscosity, caused by the two excipients. sCT pharmacokinetic profiles in Wistar rats were evaluated using a 2-compartment model after iv injection or lung insufflation. The maximal sCT plasma concentration was reached within 3 min following nebulization of sCT solution. L-PEG and B-PEG-based microparticles were able to increase T(max) to 20 ± 1 min and 18 ± 8 min, respectively. Furthermore, sCT absolute bioavailability after L-PEG-based microparticle aerosolization at 100 μg/kg was 2.3 times greater than for the nebulized sCT solution.

  14. Airborne space laser communication system and experiments

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Ming; Zhang, Li-zhong; Meng, Li-Xin

    2015-11-01

    Airborne space laser communication is characterized by its high speed, anti-electromagnetic interference, security, easy to assign. It has broad application in the areas of integrated space-ground communication networking, military communication, anti-electromagnetic communication. This paper introduce the component and APT system of the airborne laser communication system design by Changchun university of science and technology base on characteristic of airborne laser communication and Y12 plan, especially introduce the high communication speed and long distance communication experiment of the system that among two Y12 plans. In the experiment got the aim that the max communication distance 144Km, error 10-6 2.5Gbps - 10-7 1.5Gbps capture probability 97%, average capture time 20s. The experiment proving the adaptability of the APT and the high speed long distance communication.

  15. Curved PVDF airborne transducer.

    PubMed

    Wang, H; Toda, M

    1999-01-01

    In the application of airborne ultrasonic ranging measurement, a partially cylindrical (curved) PVDF transducer can effectively couple ultrasound into the air and generate strong sound pressure. Because of its geometrical features, the ultrasound beam angles of a curved PVDF transducer can be unsymmetrical (i.e., broad horizontally and narrow vertically). This feature is desired in some applications. In this work, a curved PVDF air transducer is investigated both theoretically and experimentally. Two resonances were observed in this transducer. They are length extensional mode and flexural bending mode. Surface vibration profiles of these two modes were measured by a laser vibrometer. It was found from the experiment that the surface vibration was not uniform along the curvature direction for both vibration modes. Theoretical calculations based on a model developed in this work confirmed the experimental results. Two displacement peaks were found in the piezoelectric active direction of PVDF film for the length extensional mode; three peaks were found for the flexural bending mode. The observed peak positions were in good agreement with the calculation results. Transient surface displacement measurements revealed that vibration peaks were in phase for the length extensional mode and out of phase for the flexural bending mode. Therefore, the length extensional mode can generate a stronger ultrasound wave than the flexural bending mode. The resonance frequencies and vibration amplitudes of the two modes strongly depend on the structure parameters as well as the material properties. For the transducer design, the theoretical model developed in this work can be used to optimize the ultrasound performance.

  16. Airborne Turbulence Detection System Certification Tool Set

    NASA Technical Reports Server (NTRS)

    Hamilton, David W.; Proctor, Fred H.

    2006-01-01

    A methodology and a corresponding set of simulation tools for testing and evaluating turbulence detection sensors has been presented. The tool set is available to industry and the FAA for certification of radar based airborne turbulence detection systems. The tool set consists of simulated data sets representing convectively induced turbulence, an airborne radar simulation system, hazard tables to convert the radar observable to an aircraft load, documentation, a hazard metric "truth" algorithm, and criteria for scoring the predictions. Analysis indicates that flight test data supports spatial buffers for scoring detections. Also, flight data and demonstrations with the tool set suggest the need for a magnitude buffer.

  17. Formation of monodisperse mesoporous silica microparticles via spray-drying.

    PubMed

    Waldron, Kathryn; Wu, Winston Duo; Wu, Zhangxiong; Liu, Wenjie; Selomulya, Cordelia; Zhao, Dongyuan; Chen, Xiao Dong

    2014-03-15

    In this work, a protocol to synthesize monodisperse mesoporous silica microparticles via a unique microfluidic jet spray-drying route is reported for the first time. The microparticles demonstrated highly ordered hexagonal mesostructures with surface areas ranging from ~900 up to 1500 m(2)/g and pore volumes from ~0.6 to 0.8 cm(3)/g. The particle size could be easily controlled from ~50 to 100 μm from the same diameter nozzle via changing the initial solute content, or changing the drying temperature. The ratio of the surfactant (CTAB) and silica (TEOS), and the amount of water in the precursor were found to affect the degree of ordering of mesopores by promoting either the self-assembly of the surfactant-silica micelles or the condensation of the silica as two competing processes in evaporation induced self-assembly. The drying rate and the curvature of particles also affected the self-assembly of the mesostructure. The particle mesostructure is not influenced by the inlet drying temperature in the range of 92-160 °C, with even a relatively low temperature of 92 °C producing highly ordered mesoporous microparticles. The spray-drying derived mesoporous silica microparticles, while of larger sizes and more rapidly synthesized, showed a comparable performance with the conventional mesoporous silica MCM-41 in controlled release of a dye, Rhodamine B, indicating that these spray dried microparticles could be used for the immobilisation and controlled release of small molecules.

  18. Titanium Dioxide Nanofibers and Microparticles Containing Nickel Nanoparticles

    PubMed Central

    Sheikh, Faheem A.; Macossay, Javier; Kanjwal, Muzafar A.; Abdal-hay, Abdalla; Tantry, Mudasir A.; Kim, Hern

    2013-01-01

    The present study reports on the introduction of various nanocatalysts containing nickel (Ni) nanoparticles (NPs) embedded within TiO2 nanofibers and TiO2 microparticles. Typically, a sol-gel consisting of titanium isopropoxide and Ni NPs was prepared to produce TiO2 nanofibers by the electrospinning process. Similarly, TiO2 microparticles containing Ni were prepared using a sol-gel syntheses process. The resultant structures were studied by SEM analyses, which confirmed well-obtained nanofibers and microparticles. Further, the XRD results demonstrated the crystalline feature of both TiO2 and Ni in the obtained composites. Internal morphology of prepared nanofibers and microparticles containing Ni NPs was characterized by TEM, which demonstrated characteristic structures with good dispersion of Ni NPs. In addition, the prepared structures were studied as a model for hydrogen production applications. The catalytic activity of the prepared materials was studied by in situ hydrolysis of NaBH4, which indicated that the nanofibers containing Ni NPs can lead to produce higher amounts of hydrogen when compared to other microparticles, also reported in this paper. Overall, these results confirm the potential use of these materials in hydrogen production systems. PMID:24436780

  19. International Symposium on Airborne Geophysics

    NASA Astrophysics Data System (ADS)

    Mogi, Toru; Ito, Hisatoshi; Kaieda, Hideshi; Kusunoki, Kenichiro; Saltus, Richard W.; Fitterman, David V.; Okuma, Shigeo; Nakatsuka, Tadashi

    2006-05-01

    Airborne geophysics can be defined as the measurement of Earth properties from sensors in the sky. The airborne measurement platform is usually a traditional fixed-wing airplane or helicopter, but could also include lighter-than-air craft, unmanned drones, or other specialty craft. The earliest history of airborne geophysics includes kite and hot-air balloon experiments. However, modern airborne geophysics dates from the mid-1940s when military submarine-hunting magnetometers were first used to map variations in the Earth's magnetic field. The current gamut of airborne geophysical techniques spans a broad range, including potential fields (both gravity and magnetics), electromagnetics (EM), radiometrics, spectral imaging, and thermal imaging.

  20. Detection and Monitoring of Microparticles Under Skin by Optical Coherence Tomography as an Approach to Continuous Glucose Sensing Using Implanted Retroreflectors

    PubMed Central

    Wang, Shang; Sherlock, Tim; Salazar, Betsy; Sudheendran, Narendran; Manapuram, Ravi Kiran; Kourentzi, Katerina; Ruchhoeft, Paul; Willson, Richard C.; Larin, Kirill V.

    2015-01-01

    We demonstrate the feasibility of using optical coherence tomography (OCT) to image and detect 2.8 μm diameter microparticles (stationary and moving) on a highly-reflective gold surface both in clear media and under skin in vitro. The OCT intensity signal can clearly report the microparticle count, and the OCT response to the number of microparticles shows a good linearity. The detect ability of the intensity change (2.9% ± 0.5%) caused by an individual microparticle shows the high sensitivity of monitoring multiple particles using OCT. An optical sensing method based on this feasibility study is described for continuously measuring blood sugar levels in the subcutaneous tissue, and a molecular recognition unit is designed using competitive binding to modulate the number of bound microparticles as a function of glucose concentration. With further development, an ultra-small, implantable sensor might provide high specificity and sensitivity for long-term continuous monitoring of blood glucose concentration. PMID:26413034