Development and Optimization of Osmotically Controlled Asymmetric Membrane Capsules for Delivery of Solid Dispersion of Lycopene

Directory of Open Access Journals (Sweden)

Nitin Jain

2014-01-01

Full Text Available The aim of the present investigation is to develop and statistically optimize the osmotically controlled asymmetric membrane capsules of solid dispersion of lycopene. Solid dispersions of lycopene with β-cyclodextrin in different ratios were prepared using solvent evaporation method. Solubility studies showed that the solid dispersion with 1 : 5 (lycopene : β-cyclodextrin exhibited optimum solubility (56.25 mg/mL for osmotic controlled delivery. Asymmetric membrane capsules (AMCs were prepared on glass mold pins via dip coating method. Membrane characterization by scanning electron microscopy showed inner porous region and outer dense region. Central composite design response surface methodology was applied for the optimization of AMCs. The independent variables were ethyl cellulose (X1, glycerol (X2, and NaCl (X3 which were varied at different levels to analyze the effect on dependent variables (percentage of cumulative drug release (Y1 and correlation coefficient of drug release (Y2. The effect of independent variables on the response was significantly influential. The F18 was selected as optimized formulation based on percentage of CDR (cumulative drug release of 85.63% and correlation coefficient of 0.9994. The optimized formulation was subjected to analyze the effect of osmotic pressure and agitational intensity on percentage of CDR. The drug release was independent of agitational intensity but was dependent on osmotic pressure of dissolution medium.

Neonatal outcomes and operative vaginal delivery versus cesarean delivery.

LENUS (Irish Health Repository)

Contag, Stephen A

2010-06-01

We compared outcomes for neonates with forceps-assisted, vacuum-assisted, or cesarean delivery in the second stage of labor. This is a secondary analysis of a randomized trial in laboring, low-risk, nulliparous women at >or=36 weeks\\' gestation. Neonatal outcomes after use of forceps, vacuum, and cesarean were compared among women in the second stage of labor at station +1 or below (thirds scale) for failure of descent or nonreassuring fetal status. Nine hundred ninety women were included in this analysis: 549 (55%) with an indication for delivery of failure of descent and 441 (45%) for a nonreassuring fetal status. Umbilical cord gases were available for 87% of neonates. We found no differences in the base excess (P = 0.35 and 0.78 for failure of descent and nonreassuring fetal status) or frequencies of pH below 7.0 (P = 0.73 and 0.34 for failure of descent and nonreassuring fetal status) among the three delivery methods. Birth outcomes and umbilical cord blood gas values were similar for those neonates with a forceps-assisted, vacuum-assisted, or cesarean delivery in the second stage of labor. The occurrence of significant fetal acidemia was not different among the three delivery methods regardless of the indication.

Assessment Of The Effectiveness Of Telecommunication Delivery Among Operators Of GSM In Ekiti State.

Directory of Open Access Journals (Sweden)

Olumuyiwa Oludare Fagbohun

2017-11-01

Full Text Available Data survey on the service delivery of the three principal Global System for Mobile Communications GSM Operators in Ekiti State Nigeria was conducted with a questionnaire administered among its citizens. Three locations Ado Ekiti 7o381 5o131 Ikere Ekiti 7o301 5o141 and Aramoko Ekiti 7o431 5o31were selected. Based on the responses from various subscribers using the networks the performance analyses of the operators were assessed using the descriptive statistical method. The assessment was based on the coverage area interconnectivity call quality number of subscribers growth and other supplementary services to assist the various GSM operators know the area of weakness and improve on the quality of the service delivery. It was discovered that the users have more complaints to offer with the performance generally rated below average and a need for fast and better network optimization for needed improvements for an effective telecommunication delivery.

A laboratory dispersant effectiveness test which reflects dispersant efficiency in the field

International Nuclear Information System (INIS)

Lunel, T.; Wood, P.

1996-01-01

Oil dispersion efficiencies of surfactants, from laboratory dispersion tests and field data were compared and calibrated. Data from an oil spill, where dispersants were used as a major part of the response, was analysed. The data was accumulated through the monitoring of the dispersant operation of the Sea Empress spill incident, in which Forties Blend oil was spilled at sea. This detailed data set was used to calibrate existing laboratory dispersant tests, and to devise a new International Dispersant Effectiveness Test. The objective was to create a comprehensive guide to decision making on whether and when to start a dispersant spraying operation. The dispersion efficiencies obtained from the laboratory dispersant tests were compared with field data. Flume tests produced the highest percentage of dispersed oil for all the dispersal tests. However, it was emphasised that the total percentage of oil dispersed should not be the only measure of dispersant effectiveness, since it does not distinguish between the contribution of natural and chemically enhanced dispersion. 9 refs., 1 tab., 9 figs

Operational mesoscale atmospheric dispersion prediction using high performance parallel computing cluster for emergency response

International Nuclear Information System (INIS)

Srinivas, C.V.; Venkatesan, R.; Muralidharan, N.V.; Das, Someshwar; Dass, Hari; Eswara Kumar, P.

2005-08-01

An operational atmospheric dispersion prediction system is implemented on a cluster super computer for 'Online Emergency Response' for Kalpakkam nuclear site. The numerical system constitutes a parallel version of a nested grid meso-scale meteorological model MM5 coupled to a random walk particle dispersion model FLEXPART. The system provides 48 hour forecast of the local weather and radioactive plume dispersion due to hypothetical air borne releases in a range of 100 km around the site. The parallel code was implemented on different cluster configurations like distributed and shared memory systems. Results of MM5 run time performance for 1-day prediction are reported on all the machines available for testing. A reduction of 5 times in runtime is achieved using 9 dual Xeon nodes (18 physical/36 logical processors) compared to a single node sequential run. Based on the above run time results a cluster computer facility with 9-node Dual Xeon is commissioned at IGCAR for model operation. The run time of a triple nested domain MM5 is about 4 h for 24 h forecast. The system has been operated continuously for a few months and results were ported on the IMSc home page. Initial and periodic boundary condition data for MM5 are provided by NCMRWF, New Delhi. An alternative source is found to be NCEP, USA. These two sources provide the input data to the operational models at different spatial and temporal resolutions and using different assimilation methods. A comparative study on the results of forecast is presented using these two data sources for present operational use. Slight improvement is noticed in rainfall, winds, geopotential heights and the vertical atmospheric structure while using NCEP data probably because of its high spatial and temporal resolution. (author)

Petroleum residue upgrading with dispersed catalysts: Part 2. Effect of operating conditions

Energy Technology Data Exchange (ETDEWEB)

Panariti, N.; Del Bianco, A.; Del Piero, G. [ENITECNOLOGIE S.p.A, Via Maritano 26, 20097 San Donato Mil (Italy); Marchionna, M. [SNAMPROGETTI S.p.A, Via Maritano 26, 20097 San Donato Mil (Italy); Carniti, P. [Universita degli Studi di Milano, Dip. Chimica Fisica ed Elettrochimica, Via Celoria 20, Milan (Italy)

2000-12-04

The hydrotreatment of a petroleum residue in the presence of dispersed molybdenite was carried out within a wide range of operating conditions and catalyst loading. The effect of reaction severity as well as of molybdenum concentration on product distribution and quality was studied. Based on the experimental results, a simplified reaction scheme was proposed. The hydroprocessing of the residue was described in terms of the competition between two reactions: the direct conversion of the feedstock to distillate and coke, and the catalytic hydrogenation. Compared to thermal conditions, the presence of dispersed molybdenite controls very well coke formation; however, a trend of increasing formation of solids was observed at high catalyst concentrations. The overall upgrading of the feedstock requires significant amounts of molybdenum as well as relatively high hydrogen pressure.

A clinical prediction model to assess the risk of operative delivery

NARCIS (Netherlands)

Schuit, E.; Kwee, A.; Westerhuis, M. E. M. H.; van Dessel, H. J. H. M.; Graziosi, G. C. M.; van Lith, J. M. M.; Nijhuis, J. G.; Oei, S. G.; Oosterbaan, H. P.; Schuitemaker, N. W. E.; Wouters, M. G. A. J.; Visser, G. H. A.; Mol, B. W. J.; Moons, K. G. M.; Groenwold, R. H. H.

2012-01-01

Please cite this paper as: Schuit E, Kwee A, Westerhuis M, Van Dessel H, Graziosi G, Van Lith J, Nijhuis J, Oei S, Oosterbaan H, Schuitemaker N, Wouters M, Visser G, Mol B, Moons K, Groenwold R. A clinical prediction model to assess the risk of operative delivery. BJOG 2012;119:915923. Objective To

20 CFR 662.270 - How are the costs of providing services through the One-Stop delivery system and the operating...

Science.gov (United States)

2010-04-01

... through the One-Stop delivery system and the operating costs of the system to be funded? 662.270 Section... and the operating costs of the system to be funded? The MOU must describe the particular funding arrangements for services and operating costs of the One-Stop delivery system. Each partner must contribute a...

Solid lipid dispersions: potential delivery system for functional ingredients in foods.

Science.gov (United States)

Asumadu-Mensah, Aboagyewa; Smith, Kevin W; Ribeiro, Henelyta S

2013-07-01

Structured solid lipid (SL) systems have the advantages of long-term physical stability, low surfactant concentrations, and may exhibit controlled release of active ingredients. In this research work, the potential use of high-melting SLs for the production of the above structured SL carrier systems was investigated. Dispersions containing either SL or blend of solid lipid and oil (SL+O) were produced by a hot melt high-pressure homogenization method. Experiments involved the use of 3 different SLs for the disperse phase: stearic acid, candelilla wax and carnauba wax. Sunflower oil was incorporated in the disperse phase for the production of the dispersions containing lipid and oil. In order to evaluate the practical aspects of structured particles, analytical techniques were used including: static light scattering to measure particle sizes, transmission electron microscopy (TEM) for investigating particle morphology and differential scanning calorimetry (DSC) to investigate the crystallization behavior of lipids in bulk and in dispersions. Results showed different mean particle sizes depending on the type of lipid used in the disperse phase. Particle sizes for the 3 lipids were: stearic acid (SL: 195 ± 2.5 nm; SL+O: 138 ± 6.0 nm); candelilla wax (SL: 178 ± 1.7 nm; SL+O: 144 ± 0.6 nm); carnauba wax (SL: 303 ± 1.5 nm; SL+O: 295 ± 5.0 nm). TEM results gave an insight into the practical morphology, showing plate-like and needle-like structures. DSC investigations also revealed that SL dispersions melted and crystallized at lower temperatures than the bulk. This decrease can be explained by the small particle sizes of the dispersion, the high-specific surface area, and the presence of a surfactant. © 2013 Institute of Food Technologists®

Development of 80- and 100- Mile Work Day Cycles Representative of Commercial Pickup and Delivery Operation

Energy Technology Data Exchange (ETDEWEB)

Duran, Adam W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kelly, Kenneth J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kresse, John [Cummins; Li, Ke [Cummins

2018-04-03

When developing and designing new technology for integrated vehicle systems deployment, standard cycles have long existed for chassis dynamometer testing and tuning of the powertrain. However, to this day with recent developments and advancements in plug-in hybrid and battery electric vehicle technology, no true 'work day' cycles exist with which to tune and measure energy storage control and thermal management systems. To address these issues and in support of development of a range-extended pickup and delivery Class 6 commercial vehicle, researchers at the National Renewable Energy Laboratory in collaboration with Cummins analyzed 78,000 days of operational data captured from more than 260 vehicles operating across the United States to characterize the typical daily performance requirements associated with Class 6 commercial pickup and delivery operation. In total, over 2.5 million miles of real-world vehicle operation were condensed into a pair of duty cycles, an 80-mile cycle and a 100-mile cycle representative of the daily operation of U.S. class 3-6 commercial pickup and delivery trucks. Using novel machine learning clustering methods combined with mileage-based weighting, these composite representative cycles correspond to 90th and 95th percentiles for daily vehicle miles traveled by the vehicles observed. In addition to including vehicle speed vs time drive cycles, in an effort to better represent the environmental factors encountered by pickup and delivery vehicles operating across the United States, a nationally representative grade profile and key status information were also appended to the speed vs. time profiles to produce a 'work day' cycle that captures the effects of vehicle dynamics, geography, and driver behavior which can be used for future design, development, and validation of technology.

Learning from experience: development of a cognitive task-list to assess the second stage of labour for operative delivery.

Science.gov (United States)

Hodges, Ryan; Simpson, Andrea; Gurau, David; Secter, Michael; Mocarski, Eva; Pittini, Richard; Snelgrove, John; Windrim, Rory; Higgins, Mary

2015-04-01

Ensuring the availability of operative vaginal delivery is one strategy for reducing the rising Caesarean section rate. However, current training programs appear inadequate. We sought to systematically identify the core steps in assessing women in the second stage of labour for safe operative delivery, and to produce an expert task-list to assist residents and obstetricians in deciding on the safest mode of delivery for their patients. Labour and delivery nursing staff of three large university-associated hospitals identified clinicians they considered to be skilled in operative vaginal deliveries. Obstetricians who were identified consistently were invited to participate in the study. Participants were filmed performing their normal assessment of the second stage of labour on a model. Two clinicians reviewed all videos and documented all verbal and non-verbal components of the assessment; these components were grouped into overarching themes and combined into an integrated expert task-list. The task-list was then circulated to all participants for additional comments, checked against SOGC guidelines, and redrafted, allowing production of a final expert task-list. Thirty clinicians were identified by this process and 20 agreed to participate. Themes identified were assessment of suitability, focused history, physical examination including importance of an abdominal examination, strategies to accurately assess fetal position, station, and the likelihood of success, cautionary signs to prompt reassessment in the operating room, and warning signs to abandon operative delivery for Caesarean section. Communication strategies were emphasized. Having expert clinicians teach assessment in the second stage of labour is an important step in the education of residents and junior obstetricians to improve confidence in managing the second stage of labour.

Experiences of operational costs of HPV vaccine delivery strategies in Gavi-supported demonstration projects

Science.gov (United States)

Holroyd, Taylor; Nanda, Shreya; Bloem, Paul; Griffiths, Ulla K.; Sidibe, Anissa; Hutubessy, Raymond C. W.

2017-01-01

From 2012 to 2016, Gavi, the Vaccine Alliance, provided support for countries to conduct small-scale demonstration projects for the introduction of the human papillomavirus vaccine, with the aim of determining which human papillomavirus vaccine delivery strategies might be effective and sustainable upon national scale-up. This study reports on the operational costs and cost determinants of different vaccination delivery strategies within these projects across twelve countries using a standardized micro-costing tool. The World Health Organization Cervical Cancer Prevention and Control Costing Tool was used to collect costing data, which were then aggregated and analyzed to assess the costs and cost determinants of vaccination. Across the one-year demonstration projects, the average economic and financial costs per dose amounted to US$19.98 (standard deviation ±12.5) and US$8.74 (standard deviation ±5.8), respectively. The greatest activities representing the greatest share of financial costs were social mobilization at approximately 30% (range, 6–67%) and service delivery at about 25% (range, 3–46%). Districts implemented varying combinations of school-based, facility-based, or outreach delivery strategies and experienced wide variation in vaccine coverage, drop-out rates, and service delivery costs, including transportation costs and per diems. Size of target population, number of students per school, and average length of time to reach an outreach post influenced cost per dose. Although the operational costs from demonstration projects are much higher than those of other routine vaccine immunization programs, findings from our analysis suggest that HPV vaccination operational costs will decrease substantially for national introduction. Vaccination costs may be decreased further by annual vaccination, high initial investment in social mobilization, or introducing/strengthening school health programs. Our analysis shows that drivers of cost are dependent on

A novel osmotic pump-based controlled delivery system consisting of pH-modulated solid dispersion for poorly soluble drug flurbiprofen: in vitro and in vivo evaluation.

Science.gov (United States)

Li, Shujuan; Wang, Xiaoyu; Wang, Yingying; Zhao, Qianqian; Zhang, Lina; Yang, Xinggang; Liu, Dandan; Pan, Weisan

2015-01-01

In this study, a novel controlled release osmotic pump capsule consisting of pH-modulated solid dispersion for poorly soluble drug flurbiprofen (FP) was developed to improve the solubility and oral bioavailability of FP and to minimize the fluctuation of plasma concentration. The pH-modulated solid dispersion containing FP, Kollidon® 12 PF and Na2CO3 at a weight ratio of 1/4.5/0.02 was prepared using the solvent evaporation method. The osmotic pump capsule was assembled by semi-permeable capsule shell of cellulose acetate (CA) prepared by the perfusion method. Then, the solid dispersion, penetration enhancer, and suspending agents were tableted and filled into the capsule. Central composite design-response surface methodology was used to evaluate the influence of factors on the responses. A second-order polynomial model and a multiple linear model were fitted to correlation coefficient of drug release profile and ultimate cumulative release in 12 h, respectively. The actual response values were in good accordance with the predicted ones. The optimized formulation showed a complete drug delivery and zero-order release rate. Beagle dogs were used to be conducted in the pharmacokinetic study. The in vivo study indicated that the relative bioavailability of the novel osmotic pump system was 133.99% compared with the commercial preparation. The novel controlled delivery system with combination of pH-modulated solid dispersion and osmotic pump system is not only a promising strategy to improve the solubility and oral bioavailability of poorly soluble ionizable drugs but also an effective way to reduce dosing frequency and minimize the plasma fluctuation.

A history of abuse and operative delivery--results from a European multi-country cohort study.

Directory of Open Access Journals (Sweden)

Berit Schei

Full Text Available OBJECTIVE: The main aim of this study was to assess whether a history of abuse, reported during pregnancy, was associated with an operative delivery. Secondly, we assessed if the association varied according to the type of abuse and if the reported abuse had been experienced as a child or an adult. DESIGN: The Bidens study, a cohort study in six European countries (Belgium, Iceland, Denmark, Estonia, Norway, and Sweden recruited 6724 pregnant women attending routine antenatal care. History of abuse was assessed through questionnaire and linked to obstetric information from hospital records. The main outcome measure was operative delivery as a dichotomous variable, and categorized as an elective caesarean section (CS, or an operative vaginal birth, or an emergency CS. Non-obstetrically indicated were CSs performed on request or for psychological reasons without another medical reason. Binary and multinomial regression analysis were used to assess the associations. RESULTS: Among 3308 primiparous women, sexual abuse as an adult (≥ 18 years increased the risk of an elective CS, Adjusted Odds Ratio 2.12 (1.28-3.49, and the likelihood for a non-obstetrically indicated CS, OR 3.74 (1.24-11.24. Women expressing current suffering from the reported adult sexual abuse had the highest risk for an elective CS, AOR 4.07 (1.46-11.3. Neither physical abuse (in adulthood or childhood <18 years, nor sexual abuse in childhood increased the risk of any operative delivery among primiparous women. Among 3416 multiparous women, neither sexual, nor emotional abuse was significantly associated with any kind of operative delivery, while physical abuse had an increased AOR for emergency CS of 1.51 (1.05-2.19. CONCLUSION: Sexual abuse as an adult increases the risk of an elective CS among women with no prior birth experience, in particular for non-obstetrical reasons. Among multiparous women, a history of physical abuse increases the risk of an emergency CS.

Discrete dispersion models and their Tweedie asymptotics

DEFF Research Database (Denmark)

Jørgensen, Bent; Kokonendji, Célestin C.

2016-01-01

The paper introduce a class of two-parameter discrete dispersion models, obtained by combining convolution with a factorial tilting operation, similar to exponential dispersion models which combine convolution and exponential tilting. The equidispersed Poisson model has a special place in this ap......The paper introduce a class of two-parameter discrete dispersion models, obtained by combining convolution with a factorial tilting operation, similar to exponential dispersion models which combine convolution and exponential tilting. The equidispersed Poisson model has a special place...... in this approach, whereas several overdispersed discrete distributions, such as the Neyman Type A, Pólya-Aeppli, negative binomial and Poisson-inverse Gaussian, turn out to be Poisson-Tweedie factorial dispersion models with power dispersion functions, analogous to ordinary Tweedie exponential dispersion models...... with power variance functions. Using the factorial cumulant generating function as tool, we introduce a dilation operation as a discrete analogue of scaling, generalizing binomial thinning. The Poisson-Tweedie factorial dispersion models are closed under dilation, which in turn leads to a Poisson...

Methodology to Define Delivery Accuracy Under Current Day ATC Operations

Science.gov (United States)

Sharma, Shivanjli; Robinson, John E., III

2015-01-01

In order to enable arrival management concepts and solutions in a NextGen environment, ground- based sequencing and scheduling functions have been developed to support metering operations in the National Airspace System. These sequencing and scheduling algorithms as well as tools are designed to aid air traffic controllers in developing an overall arrival strategy. The ground systems being developed will support the management of aircraft to their Scheduled Times of Arrival (STAs) at flow-constrained meter points. This paper presents a methodology for determining the undelayed delivery accuracy for current day air traffic control operations. This new method analyzes the undelayed delivery accuracy at meter points in order to understand changes of desired flow rates as well as enabling definition of metrics that will allow near-future ground automation tools to successfully achieve desired separation at the meter points. This enables aircraft to meet their STAs while performing high precision arrivals. The research presents a possible implementation that would allow delivery performance of current tools to be estimated and delivery accuracy requirements for future tools to be defined, which allows analysis of Estimated Time of Arrival (ETA) accuracy for Time-Based Flow Management (TBFM) and the FAA's Traffic Management Advisor (TMA). TMA is a deployed system that generates scheduled time-of-arrival constraints for en- route air traffic controllers in the US. This new method of automated analysis provides a repeatable evaluation of the delay metrics for current day traffic, new releases of TMA, implementation of different tools, and across different airspace environments. This method utilizes a wide set of data from the Operational TMA-TBFM Repository (OTTR) system, which processes raw data collected by the FAA from operational TMA systems at all ARTCCs in the nation. The OTTR system generates daily reports concerning ATC status, intent and actions. Due to its

Fickian dispersion is anomalous

Science.gov (United States)

Cushman, John H.; O'Malley, Dan

2015-12-01

The thesis put forward here is that the occurrence of Fickian dispersion in geophysical settings is a rare event and consequently should be labeled as anomalous. What people classically call anomalous is really the norm. In a Lagrangian setting, a process with mean square displacement which is proportional to time is generally labeled as Fickian dispersion. With a number of counter examples we show why this definition is fraught with difficulty. In a related discussion, we show an infinite second moment does not necessarily imply the process is super dispersive. By employing a rigorous mathematical definition of Fickian dispersion we illustrate why it is so hard to find a Fickian process. We go on to employ a number of renormalization group approaches to classify non-Fickian dispersive behavior. Scaling laws for the probability density function for a dispersive process, the distribution for the first passage times, the mean first passage time, and the finite-size Lyapunov exponent are presented for fixed points of both deterministic and stochastic renormalization group operators. The fixed points of the renormalization group operators are p-self-similar processes. A generalized renormalization group operator is introduced whose fixed points form a set of generalized self-similar processes. Power-law clocks are introduced to examine multi-scaling behavior. Several examples of these ideas are presented and discussed.

Operating range, hold-up, droplet size and axial mixing of pulsed plate columns in highly disperse and low-continuity volume flows

International Nuclear Information System (INIS)

Schmidt, H.; Miller, H.

Operating behavior, hold-up, droplet size and axial mixing are investigated in highly disperse and slightly continuous volume flows in a pulsed plate column. The geometry of the column of 4-m length and 10-cm inside diameter was held constant. The hole shape of the column bases was changed, wherby the cylindrical, sharp-edge drilled hole is compared with the punched, nozzle-shaped hole in their effects on the fluid-dynamic behavior. In this case we varied the volume flows, the ratio of volume flows, the pulse frequency and the operating temperature. The operation was held constant for the aqueous, the organic, the continuous and the disperse phases. The objective was to demonstrate the applicability of pulsed plate columns with very large differences between the organic disperse and the aqueous continuous volume flow, to obtain design data for such columns and to perform a scale-up to industrial reprocessing plant-size. 18 references, 11 figures, 3 tables

The Effect of Uncertainties on the Operating Temperature of U-Mo/Al Dispersion Fuel

Energy Technology Data Exchange (ETDEWEB)

Sweidana, Faris B.; Mistarihia, Qusai M.; Ryu Ho Jin [KAIST, Daejeon (Korea, Republic of); Yim, Jeong Sik [KAERI, Daejeon (Korea, Republic of)

2016-05-15

In this study, uncertainty and combined uncertainty studies have been carried out to evaluate the uncertainty of the parameters affecting the operational temperature of U-Mo/Al fuel. The uncertainties related to the thermal conductivity of fuel meat, which consists of the effects of thermal diffusivity, density and specific heat capacity, the interaction layer (IL) that forms between the dispersed fuel and the matrix, fuel plate dimensions, heat flux, heat transfer coefficient and the outer cladding temperature were considered. As the development of low-enriched uranium (LEU) fuels has been pursued for research reactors to replace the use of highly-enriched uranium (HEU) for the improvement of proliferation resistance of fuels and fuel cycle, U-Mo particles dispersed in an Al matrix (UMo/Al) is a promising fuel for conversion of the research reactors that currently use HEU fuels to LEUfueled reactors due to its high density and good irradiation stability. Several models have been developed for the estimation of the thermal conductivity of U–Mo fuel, mainly based on the best fit of the very few measured data without providing uncertainty ranges. The purpose of this study is to provide a reasonable estimation of the upper bounds and lower bounds of fuel temperatures with burnup through the evaluation of the uncertainties in the thermal conductivity of irradiated U-Mo/Al dispersion fuel. The combined uncertainty study using RSS method evaluated the effect of applying all the uncertainty values of all the parameters on the operational temperature of U-Mo/Al fuel. The overall influence on the value of the operational temperature is 16.58 .deg. C at the beginning of life and it increases as the burnup increases to reach 18.74 .deg. C at a fuel meat fission density of 3.50E+21 fission/cm{sup 3}. Further studies are needed to evaluate the behavior more accurately by including other parameters uncertainties such as the interaction layer thermal conductivity.

A Novel Type of Aqueous Dispersible Ultrathin-Layered Double Hydroxide Nanosheets for in Vivo Bioimaging and Drug Delivery.

Science.gov (United States)

Yan, Li; Zhou, Mengjiao; Zhang, Xiujuan; Huang, Longbiao; Chen, Wei; Roy, Vellaisamy A L; Zhang, Wenjun; Chen, Xianfeng

2017-10-04

Layered double hydroxide (LDH) nanoparticles have been widely used for various biomedical applications. However, because of the difficulty of surface functionalization of LDH nanoparticles, the systemic administration of these nanomaterials for in vivo therapy remains a bottleneck. In this work, we develop a novel type of aqueous dispersible two-dimensional ultrathin LDH nanosheets with a size of about 50 nm and a thickness of about 1.4 to 4 nm. We are able to covalently attach positively charged rhodamine B fluorescent molecules to the nanosheets, and the nanohybrid retains strong fluorescence in liquid and even dry powder form. Therefore, it is available for bioimaging. Beyond this, it is convenient to modify the nanosheets with neutral poly(ethylene glycol) (PEG), so the nanohybrid is suitable for drug delivery through systemic administration. Indeed, in the test of using these nanostructures for delivery of a negatively charged anticancer drug, methotrexate (MTX), in a mouse model, dramatically improved therapeutic efficacy is achieved, indicated by the effective inhibition of tumor growth. Furthermore, our systematic in vivo safety investigation including measuring body weight, determining biodistribution in major organs, hematology analysis, blood biochemical assay, and hematoxylin and eosin stain demonstrates that the new material is biocompatible. Overall, this work represents a major development in the path of modifying functional LDH nanomaterials for clinical applications.

From Data to Improved Decisions: Operations Research in Healthcare Delivery.

Science.gov (United States)

Capan, Muge; Khojandi, Anahita; Denton, Brian T; Williams, Kimberly D; Ayer, Turgay; Chhatwal, Jagpreet; Kurt, Murat; Lobo, Jennifer Mason; Roberts, Mark S; Zaric, Greg; Zhang, Shengfan; Schwartz, J Sanford

2017-11-01

The Operations Research Interest Group (ORIG) within the Society of Medical Decision Making (SMDM) is a multidisciplinary interest group of professionals that specializes in taking an analytical approach to medical decision making and healthcare delivery. ORIG is interested in leveraging mathematical methods associated with the field of Operations Research (OR) to obtain data-driven solutions to complex healthcare problems and encourage collaborations across disciplines. This paper introduces OR for the non-expert and draws attention to opportunities where OR can be utilized to facilitate solutions to healthcare problems. Decision making is the process of choosing between possible solutions to a problem with respect to certain metrics. OR concepts can help systematically improve decision making through efficient modeling techniques while accounting for relevant constraints. Depending on the problem, methods that are part of OR (e.g., linear programming, Markov Decision Processes) or methods that are derived from related fields (e.g., regression from statistics) can be incorporated into the solution approach. This paper highlights the characteristics of different OR methods that have been applied to healthcare decision making and provides examples of emerging research opportunities. We illustrate OR applications in healthcare using previous studies, including diagnosis and treatment of diseases, organ transplants, and patient flow decisions. Further, we provide a selection of emerging areas for utilizing OR. There is a timely need to inform practitioners and policy makers of the benefits of using OR techniques in solving healthcare problems. OR methods can support the development of sustainable long-term solutions across disease management, service delivery, and health policies by optimizing the performance of system elements and analyzing their interaction while considering relevant constraints.

Nanoscale Nutrient Delivery Systems for Food Applications: Improving Bioactive Dispersibility, Stability, and Bioavailability.

Science.gov (United States)

McClements, David Julian

2015-07-01

There has been a surge of interest in the development of nanoscale systems for the encapsulation, protection, and delivery of lipophilic nutrients, vitamins, and nutraceuticals. This review article highlights the challenges associated with incorporating these lipophilic bioactive components into foods, and then discusses potential nanoscale delivery systems that can be used to overcome these challenges. In particular, the desirable characteristics required for any nanoscale delivery system are presented, as well as methods of fabricating them and of characterizing them. An overview of different delivery systems is given, such as microemulsions, nanoemulsions, emulsions, microgels, and biopolymer nanoparticles, and their potential applications are discussed. Nanoscale delivery systems have considerable potential within the food industry, but they must be carefully formulated to ensure that they are safe, economically viable, and effective. Nanoscale delivery systems have numerous potential applications in the food industry for encapsulating, protecting, and releasing bioactive agents, such as nutraceuticals and vitamins. This review article highlights methods for designing, fabricating, characterizing, and utilizing edible nanoparticles from a variety of different food-grade ingredients. © 2015 Institute of Food Technologists®

SELLING, DELIVERY AND TRADE MARKETING – AN OPERATIONAL TRIDENT OF THE DISTRIBUTION SYSTEM

Directory of Open Access Journals (Sweden)

Ioana Olariu

2013-12-01

Full Text Available This paper highlights the way in which a distribution system can be made operational in FMCG, starting from the interaction between three components of the system: selling, delivery and trade marketing. On this basis, I have categorized the improvement opportunities of each component, using the appropriate key performance indicators (KPIs of the system objectives. The optimal configuration of instruments and successful interaction of these components, improve the distribution system contribution to company performance. A specific system, defined for solving marketing problems, must be designed according to this purpose, and in this regard, all the significant elements and relationships must be subordinate to the objective by which it will achieve the desired solution. Business objectives achievement can be measured as effectiveness - the degree to which objectives were achieved, or as efficiency - the degree to which objectives have been achieved in the available resources. For evaluating the effectiveness with which an operative marketing system turns its sources into necessary results to solve a problem, it requires certain criteria to measure performance. These three elements: selling, delivery and trade marketing, are a trident of distribution which can lead to an optimal approach of market opportunities.

Operational Criteria for the Design of Front-Office Processes in Multi-Channel Service Delivery Systems

OpenAIRE

Sousa, Rui; Amorim, Marlene

2010-01-01

This paper identifies relevant operational factors that affect the design of front-office processes in Multi-Channel Service Delivery Systems. Based on two in-depth case studies in banking and telecommunications, we distinguish four operational factors: i) characteristics of the inputs and outputs of the service activities; ii) characteristics of the transformation taking place; iii) the expected utilization; iv) the economics of developing the activities in the channels. Building on these re...

The impact of a preloaded intraocular lens delivery system on operating room efficiency in routine cataract surgery.

Science.gov (United States)

Jones, Jason J; Chu, Jeffrey; Graham, Jacob; Zaluski, Serge; Rocha, Guillermo

2016-01-01

The aim of this study was to evaluate the operational impact of using preloaded intraocular lens (IOL) delivery systems compared with manually loaded IOL delivery processes during routine cataract surgeries. Time and motion data, staff and surgery schedules, and cost accounting reports were collected across three sites located in the US, France, and Canada. Time and motion data were collected for manually loaded IOL processes and preloaded IOL delivery systems over four surgery days. Staff and surgery schedules and cost accounting reports were collected during the 2 months prior and after introduction of the preloaded IOL delivery system. The study included a total of 154 routine cataract surgeries across all three sites. Of these, 77 surgeries were performed using a preloaded IOL delivery system, and the remaining 77 surgeries were performed using a manual IOL delivery process. Across all three sites, use of the preloaded IOL delivery system significantly decreased mean total case time by 6.2%-12.0% (Psystem also decreased surgeon lens time, surgeon delays, and eliminated lens touches during IOL preparation. Compared to a manual IOL delivery process, use of a preloaded IOL delivery system for cataract surgery reduced total case time, total surgeon lens time, surgeon delays, and eliminated IOL touches. The time savings provided by the preloaded IOL delivery system provide an opportunity for sites to improve routine cataract surgery throughput without impacting surgeon or staff capacity.

Spatially-varying surface roughness and ground-level air quality in an operational dispersion model

International Nuclear Information System (INIS)

Barnes, M.J.; Brade, T.K.; MacKenzie, A.R.; Whyatt, J.D.; Carruthers, D.J.; Stocker, J.; Cai, X.; Hewitt, C.N.

2014-01-01

Urban form controls the overall aerodynamic roughness of a city, and hence plays a significant role in how air flow interacts with the urban landscape. This paper reports improved model performance resulting from the introduction of variable surface roughness in the operational air-quality model ADMS-Urban (v3.1). We then assess to what extent pollutant concentrations can be reduced solely through local reductions in roughness. The model results suggest that reducing surface roughness in a city centre can increase ground-level pollutant concentrations, both locally in the area of reduced roughness and downwind of that area. The unexpected simulation of increased ground-level pollutant concentrations implies that this type of modelling should be used with caution for urban planning and design studies looking at ventilation of pollution. We expect the results from this study to be relevant for all atmospheric dispersion models with urban-surface parameterisations based on roughness. -- Highlights: • Spatially variable roughness improved performance of an operational model. • Scenario modelling explored effect of reduced roughness on air pollution. • Reducing surface roughness can increase modelled ground-level pollution. • Damped vertical mixing outweighs increased horizontal advection in model study. • Result should hold for any model with a land-surface coupling based on roughness. -- Spatially varying roughness improves model simulations of urban air pollutant dispersion. Reducing roughness does not always decrease ground-level pollution concentrations

Operative vaginal deliveries in Zaria, Nigeria

African Journals Online (AJOL)

2009-10-05

Oct 5, 2009 ... were analyzed with respect to mode of delivery, indication for ... Making these procedures safer will improve safe motherhood in settings where there are performed. ..... training should not use vacuum extraction in real patients ...

Dispersion and stabilization of cochleate nanoparticles.

Science.gov (United States)

Bozó, Tamás; Wacha, András; Mihály, Judith; Bóta, Attila; Kellermayer, Miklós S Z

2017-08-01

Cochleates, calcium-stabilized membrane rolls of nanoscale diameter, promise a unique and efficient way of delivering lipid-soluble drugs, proteins or nucleic acids into biological systems because they protect the encapsulated material against enzymatic or chemical degradation. Self-aggregation, which typically arises during production and storage is a major obstacle that has so far precluded the development of an efficient cochleate-based drug-delivery system. Here we show that citric acid, added transiently in a narrow concentration range, effectively disperses cochleate aggregates, stabilizes the disperse state for long-term storage and preserves the canonical ultrastructure and topological characteristics of cochleate nanoparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

Re-dispersible Li+ and Eu3+ co-doped CdS nanoparticles ...

Indian Academy of Sciences (India)

Also, it can be used as sensor for drug delivery in our body [12,13]. In the present work, we prepare re-dispersible CdS, Li+- and Eu3+-doped CdS nanoparticles in organic solvent by urea hydrolysis at 170◦C and their lumines- cence properties are studied. We propose the mechanism of re-dispersion of CdS nanoparticles ...

Dispersion Compensation of Fiber Optic Systems for KSC Applications

Science.gov (United States)

Kozaitis, Samuel P.; Hand, Larry

1996-01-01

Installed fibers such as those at the Kennedy Space Center (KSC) are optimized for use at 1310 nm because they have zero dispersion at that wavelength. An installed fiber system designed to operate at 1310 nm will operate at a much lower data rate when operated at 1550 nm because the dispersion is not zero at 1550 nm. Using dispersion measurements of both installed and dispersion compensating fibers, we compensated a 21.04 km length of installed fiber with 4.25 km of dispersion compensating fiber. Using the compensated fiber-optic link, we reduced the dispersion to 0.494 ps/nm-km, from an uncompensated dispersion of 16.8 ps/nm-km. The main disadvantage of the compensated link using DC fiber was an increase in attenuation. Although the increase was not necessarily severe, it could be significant when insertion losses, connector losses, and fiber attenuation are taken into account.

Multi-angle VECSEL cavities for dispersion control and multi-color operation

Science.gov (United States)

Baker, Caleb; Scheller, Maik; Laurain, Alexandre; Yang, Hwang-Jye; Ruiz Perez, Antje; Stolz, Wolfgang; Addamane, Sadhvikas J.; Balakrishnan, Ganesh; Jones, R. Jason; Moloney, Jerome V.

2017-02-01

We present a novel Vertical External Cavity Surface Emitting Laser (VECSEL) cavity design which makes use of multiple interactions with the gain region under different angles of incidence in a single round trip. This design allows for optimization of the net, round-trip Group Delay Dispersion (GDD) by shifting the GDD of the gain via cavity fold angle while still maintaining the high gain of resonant structures. The effectiveness of this scheme is demonstrated with femtosecond-regime pulses from a resonant structure and record pulse energies for the VECSEL gain medium. In addition, we show that the interference pattern of the intracavity mode within the active region, resulting from the double-angle multifold, is advantageous for operating the laser in CW on multiple wavelengths simultaneously. Power, noise, and mode competition characterization is presented.

A novel and alternative approach to controlled release drug delivery system based on solid dispersion technique

Directory of Open Access Journals (Sweden)

Tapan Kumar Giri

2012-12-01

Full Text Available The solid dispersion method was originally used to improve the dissolution properties and the bioavailability of poorly water soluble drugs by dispersing them into water soluble carriers. In addition to the above, dissolution retardation through solid dispersion technique using water insoluble and water swellable polymer for the development of controlled release dosage forms has become a field of interest in recent years. Development of controlled release solid dispersion has a great advantage for bypassing the risk of a burst release of drug; since the structure of the solid dispersion is monolithic where drug molecules homogeneously disperse. Despite the remarkable potential and extensive research being conducted on controlled release solid dispersion system, commercialization and large scale production are limited. The author expects that recent technological advances may overcome the existing limitations and facilitate the commercial utilization of the techniques for manufacture of controlled release solid dispersions. This article begins with an overview of the different carriers being used for the preparation of controlled release solid dispersion and also different techniques being used for the purpose. Kinetics of drug release from these controlled release solid dispersions and the relevant mathematical modeling have also been reviewed in this manuscript.

Advanced SLARette delivery machine

International Nuclear Information System (INIS)

Bodner, R.R.

1995-01-01

SLARette 1 equipment, comprising of a SLARette Delivery Machine, SLAR Tools, SLAR power supplies and SLAR Inspection Systems was designed, developed and manufactured to service fuel channels of CANDU 6 stations during the regular yearly station outages. The Mark 2 SLARette Delivery Machine uses a Push Tube system to provide the axial and rotary movements of the SLAR Tool. The Push Tubes are operated remotely but must be attached and removed manually. Since this operation is performed at the Reactor face, there is radiation dose involved for the workers. An Advanced SLARette Delivery Machine which incorporates a computer controlled telescoping Ram in the place of the Push Tubes has been recently designed and manufactured. Utilization of the Advanced SLARette Delivery Machine significantly reduces the amount of radiation dose picked up by the workers because the need to have workers at the face of the Reactor during the SLARette operation is greatly reduced. This paper describes the design, development and manufacturing process utilized to produce the Advanced SLARette Delivery Machine and the experience gained during the Gentilly-2 NGS Spring outage. (author)

Role Of E-Government In Delivery Of Public Services In Tanzania Electric Supply Company In Ruvuma Region Tanzania

Directory of Open Access Journals (Sweden)

Emmanuel Jackson Petro Gunda

2015-06-01

Full Text Available ABSTRACT E-government facilitates delivery of public services of relevant government information in electronic form to citizens in a timely manner and better service delivery to citizens. E-government is a kind of governmental administration which is based on Information Communication and Technology Services. Electronic government describes the use of technologies to facilitate the operation of government and disperse of government information and services. The scope of the work was limited to Tanzania Electric Supply Company Limited TANESCO in Ruvuma region. The population of thirty 31 were selected from a total population of 169 public servants use both purposive and stratified random sampling techniques applied. The major findings of study revealed that about 67.7 of response from respondents agree that ICT infrastructures specifically modern computer connected to internet reliable internet speed well organized organization website power availability in public operation contribute to efficient in delivery of services it also noted by respondents to faster decision making speeding up transaction processing and reduce cost. The study greatly recommends that capacity building to public servants on ICT install and strengthening ICT infrastructures to government organizational are inevitable to realise relevant role of e-government in delivery of public services.

Global Delivery Models

DEFF Research Database (Denmark)

Manning, Stephan; Larsen, Marcus M.; Bharati, Pratyush

2013-01-01

This article examines antecedents and performance implications of global delivery models (GDMs) in global business services. GDMs require geographically distributed operations to exploit both proximity to clients and time-zone spread for efficient service delivery. We propose and empirically show...

Prevention of zebra mussel infestation and dispersal during aquaculture operations

Science.gov (United States)

Waller, D.L.; Fisher, S.W.; Dabrowska, H.

1996-01-01

The zebra mussel Dreissena polymorpha, an exotic invasive species, poses a major threat to North American fish management programs and the aquaculture industry. Fish hatcheries may become infected with zebra mussels from a variety of sources, including the water supply, fish shipments, boats, and equipment. The hatcheries could then serve as agents for the overland dispersal of zebra mussels into stocked waters and to other fish hatcheries. We evaluated the effectiveness and safety of aquaculture chemicals for use in controlling zebra mussels in fish hatcheries and preventing dispersal of veligers during fish transport. Chemicals were evaluated for use in fish transport and as disinfectants for ponds and equipment. Standardized static toxicity tests were conducted with representative species of warmwater, coolwater, and coldwater fishes and with larval (3-d-old veligers), early juvenile (settling larvae), and adult zebra mussels. Chemical concentrations and exposure durations were based on recommended treatment levels for fish, eggs, and ponds. Recommended treatment levels were also exceeded, if necessary, to establish lethal levels for zebra mussels of different developmental stages. Our results indicate that some chemicals currently in use in hatcheries may be effective for controlling zebra mussels in various operations. Chloride salts were the safest and most effective therapeutants tested for use in fish transport. The toxicity of chloride salts to fish varied among species and with temperature; only one treatment regime (sodium chloride at 10,000 mg/L) was safe to all fish species that we tested, but it was only effective on veliger and settler stages of the zebra mussel. Effective disinfectants were benzalkonium chloride for use on equipment and rotenone for use in ponds after fish are harvested. The regulatory status of the identified chemicals is discussed as well as several nonchemical control alternatives.

A higher-order-mode fiber delivery for Ti:Sapphire femtosecond lasers

DEFF Research Database (Denmark)

Jespersen, Kim Giessmann; Le, Tuan; Grüner-Nielsen, Lars Erik

2010-01-01

We report the first higher-order-mode fiber with anomalous dispersion at 800nm and demonstrate its potential in femtosecond pulse delivery for Ti:Sapphire femtosecond lasers. We obtain 125fs pulses after propagating a distance of 3.6 meters in solid-silica fiber. The pulses could be further...... compressed in a quartz rod to nearly chirp-free 110fs pulses. Femtosecond pulse delivery is achieved by launching the laser output directly into the delivery fiber without any pre-chirping of the input pulse. The demonstrated pulse delivery scheme suggests scaling to >20meters for pulse delivery in harsh...

Scaling up delivery of contraceptive implants in sub-Saharan Africa: operational experiences of Marie Stopes International.

Science.gov (United States)

Duvall, Susan; Thurston, Sarah; Weinberger, Michelle; Nuccio, Olivia; Fuchs-Montgomery, Nomi

2014-02-01

Contraceptive implants offer promising opportunities for addressing the high and growing unmet need for modern contraceptives in sub-Saharan Africa. Marie Stopes International (MSI) offers implants as one of many family planning options. Between 2008 and 2012, MSI scaled up voluntary access to implants in 15 sub-Saharan African countries, from 80,041 implants in 2008 to 754,329 implants in 2012. This 9-fold increase amounted to more than 1.7 million implants delivered cumulatively over the 5-year period. High levels of client satisfaction were attained alongside service provision scale up by using existing MSI service delivery channels-mobile outreach, social franchising, and clinics-to implement strategies that broadened access for underserved clients and maintained service quality. Use of adaptive and context-specific service delivery models and attention to key operational components, including sufficient numbers of trained providers, strong supply chains, diverse financing mechanisms, and implant removal services, underpinned our service delivery efforts. Accounting for 70% of the implants delivered by MSI in 2012, mobile outreach services through dedicated MSI provider teams played a central role in scale-up efforts, fueled in part by the provision of free or heavily subsidized services. Social franchising also demonstrated promise for future program growth, along with MSI clinics. Continued high growth in implant provision between 2011 and 2012 in all sub-Saharan African countries indicates the region's capacity for further service delivery expansion. Meeting the expected rising demand for implants and ensuring long-term sustainable access to the method, as part of a comprehensive method mix, will require continued use of appropriate service delivery models, effective operations, and ongoing collaboration between the private, public, and nongovernmental sectors. MSI's experience can be instructive for future efforts to ensure contraceptive access and choice

Scaling up delivery of contraceptive implants in sub-Saharan Africa: operational experiences of Marie Stopes International

Science.gov (United States)

Duvall, Susan; Thurston, Sarah; Weinberger, Michelle; Nuccio, Olivia; Fuchs-Montgomery, Nomi

2014-01-01

Contraceptive implants offer promising opportunities for addressing the high and growing unmet need for modern contraceptives in sub-Saharan Africa. Marie Stopes International (MSI) offers implants as one of many family planning options. Between 2008 and 2012, MSI scaled up voluntary access to implants in 15 sub-Saharan African countries, from 80,041 implants in 2008 to 754,329 implants in 2012. This 9-fold increase amounted to more than 1.7 million implants delivered cumulatively over the 5-year period. High levels of client satisfaction were attained alongside service provision scale up by using existing MSI service delivery channels—mobile outreach, social franchising, and clinics—to implement strategies that broadened access for underserved clients and maintained service quality. Use of adaptive and context-specific service delivery models and attention to key operational components, including sufficient numbers of trained providers, strong supply chains, diverse financing mechanisms, and implant removal services, underpinned our service delivery efforts. Accounting for 70% of the implants delivered by MSI in 2012, mobile outreach services through dedicated MSI provider teams played a central role in scale-up efforts, fueled in part by the provision of free or heavily subsidized services. Social franchising also demonstrated promise for future program growth, along with MSI clinics. Continued high growth in implant provision between 2011 and 2012 in all sub-Saharan African countries indicates the region's capacity for further service delivery expansion. Meeting the expected rising demand for implants and ensuring long-term sustainable access to the method, as part of a comprehensive method mix, will require continued use of appropriate service delivery models, effective operations, and ongoing collaboration between the private, public, and nongovernmental sectors. MSI's experience can be instructive for future efforts to ensure contraceptive access and

Severe primary postpartum hemorrhage due to genital tract laceration after operative vaginal delivery: successful treatment with transcatheter arterial embolization

Energy Technology Data Exchange (ETDEWEB)

Fargeaudou, Yann; Soyer, Philippe; Sirol, Marc; Dref, Olivier le; Boudiaf, Mourad; Dahan, Henri; Rymer, Roland [Hopital Lariboisiere-APHP-GHU Nord et Universite Diderot-Paris 7, Department of Abdominal and Interventional Imaging, Paris (France); Morel, Olivier [Hopital Lariboisiere-APHP-GHU Nord et Universite Diderot-Paris 7, Department of Obstetrics, Paris (France)

2009-09-15

The purpose of this study was to report our experience in the management of severe primary postpartum hemorrhage due to genital tract laceration following operative vaginal delivery with forceps using pelvic transcatheter arterial embolization (TAE). Ten women (mean age, 31.9 years) with severe primary postpartum hemorrhage due to genital tract laceration after operative delivery with forceps were treated with TAE. TAE was indicated because of intractable bleeding that could not be controlled with uterotonic drugs, blood transfusion, attempted suturing and packing in all patients. Postdelivery perineal examination showed cervical or vaginal tears in all women and associated paravaginal hematoma in four. Angiography revealed extravasation of contrast material in six patients. TAE performed with gelatin sponge allowed to control the bleeding in all patients. Cervical and vaginal suturing was made possible and successfully achieved in the six women who had failed suturing attempts before TAE. Paravaginal hematoma was successfully evacuated in four patients in whom it was present after TAE. No complications related to TAE were noted. We conclude that in women with severe primary postpartum hemorrhage due to genital tract laceration after operative delivery with forceps, TAE is effective and safe for stopping the bleeding and helps genital tract suturing and evacuation of hematoma. (orig.)

Severe primary postpartum hemorrhage due to genital tract laceration after operative vaginal delivery: successful treatment with transcatheter arterial embolization

International Nuclear Information System (INIS)

Fargeaudou, Yann; Soyer, Philippe; Sirol, Marc; Dref, Olivier le; Boudiaf, Mourad; Dahan, Henri; Rymer, Roland; Morel, Olivier

2009-01-01

The purpose of this study was to report our experience in the management of severe primary postpartum hemorrhage due to genital tract laceration following operative vaginal delivery with forceps using pelvic transcatheter arterial embolization (TAE). Ten women (mean age, 31.9 years) with severe primary postpartum hemorrhage due to genital tract laceration after operative delivery with forceps were treated with TAE. TAE was indicated because of intractable bleeding that could not be controlled with uterotonic drugs, blood transfusion, attempted suturing and packing in all patients. Postdelivery perineal examination showed cervical or vaginal tears in all women and associated paravaginal hematoma in four. Angiography revealed extravasation of contrast material in six patients. TAE performed with gelatin sponge allowed to control the bleeding in all patients. Cervical and vaginal suturing was made possible and successfully achieved in the six women who had failed suturing attempts before TAE. Paravaginal hematoma was successfully evacuated in four patients in whom it was present after TAE. No complications related to TAE were noted. We conclude that in women with severe primary postpartum hemorrhage due to genital tract laceration after operative delivery with forceps, TAE is effective and safe for stopping the bleeding and helps genital tract suturing and evacuation of hematoma. (orig.)

Medical capability team: the clinical microsystem for combat healthcare delivery in counterinsurgency operations.

Science.gov (United States)

Clark, Susz; Van Steenvort, Jon K

2008-01-01

Today's operational environment in the support of counterinsurgency operations requires greater tactical and operational flexibility and diverse medical capabilities. The skills and organizations required for full spectrum medical operations are different from those of the past. Combat healthcare demands agility and the capacity for rapid change in clinical systems and processes to better support the counterinsurgency environment. This article proposes the Army Medical Department (AMEDD) develop and implement the medical capability team (MCT) for combat healthcare delivery. It discusses using the concept of the brigade combat team to develop medical capability teams as the unit of effectiveness to transform frontline care; provides a theoretical overview of the MCT as a "clinical microsystem"; discusses MCT leadership, training, and organizational support, and the deployment and employment of the MCT in a counterinsurgency environment. Additionally, this article proposes that the AMEDD initiate the development of an AMEDD Combat Training Center of Excellence to train and validate the MCTs. The complexity of combat healthcare demands an agile and campaign quality AMEDD with joint expeditionary capability in order to promote the best patient outcomes in a counterinsurgency environment.

Synthesis and characterization of cloisite-30B clay dispersed poly (acryl amide/sodium alginate)/AgNp hydrogel composites for the study of BSA protein drug delivery and antibacterial activity

Science.gov (United States)

Nanjunda Reddy, B. H.; Ranjan Rauta, Pradipta; Venkatalakshimi, V.; Sreenivasa, Swamy

2018-02-01

The aim of this research is to inspect the effect of Cloisite-30B (C30B) modified clay dispersed poly (acrylamide-co-Sodiumalginate)/AgNp hydrogel nanocomposites (PASA/C30B/Ag) for drug delivery and antibacterial activity. A novel hydrogel composite based sodium alginate (SA) and the inorganic modified clay with silver nano particle (C30B/AgNps)polymer hydrogel composites are synthesized via the graft copolymerization of acrylamide (AAm) in an aqueous medium with methylene bisacrylamide (MBA) as a crosslinking agent and ammonium per sulfate(APS) as an initiator. The UV/Visible spectroscopy of obtained composites is successfully studied, which confirms the occurrence of AgNps in the hydrogel composites. And the swelling capacity and bovine serum albumin (BSA) protein as model drug delivery study for these hydrogel nanocomposites have been carried out. The C30B/Ag filled hydrogel composites exhibit superior water absorbency or swelling capacity compared to pure samples and it is establish that the formulations with clay (C30B) dispersed silver nanocomposite hydrogels show improved and somewhat faster rate of drug delivery than other formulations(pure systems) and SEM and TEM reports suggests that the size of AgNps in the composite hydrogels is in the range of 5-10 nm with shrunken surface and the antibacterial characterizations for gram positive and gram negative bacteria are carried out by using Streptococcus faecalis (S. Faecalis) and Escherichia coli (E.coli) as model bacteria and the hydrogel composites of PASA/C30B/Ag shows exceptional antibacterial activity against both the bacteria as compared to pure hydrogel composites samples.

The impact of a preloaded intraocular lens delivery system on operating room efficiency in routine cataract surgery

Directory of Open Access Journals (Sweden)

Jones JJ

2016-06-01

Full Text Available Jason J Jones,1 Jeffrey Chu,2 Jacob Graham,2 Serge Zaluski,3 Guillermo Rocha4 1Jones Eye Clinic, Sioux City, IA, 2Quorum Consulting Inc., San Francisco, CA, USA; 3VISIS, Perpignan, France; 4Ocular Microsurgery & Laser Centre, Brandon, MB, Canada Purpose: The aim of this study was to evaluate the operational impact of using preloaded intraocular lens (IOL delivery systems compared with manually loaded IOL delivery processes during routine cataract surgeries. Methods: Time and motion data, staff and surgery schedules, and cost accounting reports were collected across three sites located in the US, France, and Canada. Time and motion data were collected for manually loaded IOL processes and preloaded IOL delivery systems over four surgery days. Staff and surgery schedules and cost accounting reports were collected during the 2 months prior and after introduction of the preloaded IOL delivery system. Results: The study included a total of 154 routine cataract surgeries across all three sites. Of these, 77 surgeries were performed using a preloaded IOL delivery system, and the remaining 77 surgeries were performed using a manual IOL delivery process. Across all three sites, use of the preloaded IOL delivery system significantly decreased mean total case time by 6.2%–12.0% (P<0.001 for data from Canada and the US and P<0.05 for data from France. Use of the preloaded delivery system also decreased surgeon lens time, surgeon delays, and eliminated lens touches during IOL preparation. Conclusion: Compared to a manual IOL delivery process, use of a preloaded IOL delivery system for cataract surgery reduced total case time, total surgeon lens time, surgeon delays, and eliminated IOL touches. The time savings provided by the preloaded IOL delivery system provide an opportunity for sites to improve routine cataract surgery throughput without impacting surgeon or staff capacity. Keywords: time and motion, provider impact, surgical throughput, IOL

Combustion performance of an aluminum melting furnace operating with liquid fuel

Energy Technology Data Exchange (ETDEWEB)

Nieckele, Angela Ourivio; Naccache, Monica Feijo; Gomes, Marcos Sebastiao de P. [Pontificia Universidade Catolica (PUC-Rio), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Mecanica], E-mails: nieckele@puc-rio.br, naccache@puc-rio.br, mspgomes@puc-rio.br

2010-10-15

The characteristics associated with the delivery of the fuel to be used as the energy source in any industrial combustion equipment are of extreme importance, as for example, in improving the performance of the combustion process and in the preservation of the equipment. A clean and efficient combustion may be achieved by carefully selecting the fuel and oxidant, as well as the operational conditions of the delivery system for both. In the present work, numerical simulations were carried out using the commercial code FLUENT for analyzing some of the relevant operational conditions inside an aluminum reverb furnace employing liquid fuel and air as the oxidant. Different fuel droplets sizes as well as inlet droplet stream configurations were examined. These characteristics, associated with the burner geometry and the fuel dispersion and delivery system may affect the flame shape, and consequently the temperature and the heat flux distribution within the furnace. Among the results obtained in the simulations, it was shown the possible damages to the equipment, which may occur as a result of the combustion process, if the flame is too long or too intense and concentrated. (author)

A prospective cohort study of the morbidity associated with operative vaginal deliveries performed by day and at night.

Science.gov (United States)

Butler, Katherine; Ramphul, Meenakshi; Dunney, Clare; Farren, Maria; McSweeney, Aoife; McNamara, Karen; Murphy, Deirdre J

2014-10-29

To evaluate maternal and neonatal outcomes associated with operative vaginal deliveries (OVDs) performed by day and at night. Prospective cohort study. Urban maternity unit in Ireland with off-site consultant staff at night. All nulliparous women requiring an OVD with a term singleton fetus in a cephalic presentation from February to November 2013. Delivery outcomes were compared for women who delivered by day (08:00-19:59) or at night (20:00-07:59). The main outcomes included postpartum haemorrhage (PPH), anal sphincter tear and neonatal unit admission. Procedural factors included operator grade, sequential use of instruments and caesarean section. Of the 597 women who required an OVD, 296 (50%) delivered at night. Choice of instrument, place of delivery, sequential use of instruments and caesarean section did not differ significantly in relation to time of birth. Mid-grade operators performed less OVDs by day than at night, OR 0.60 (95% CI 0.43 to 0.83), and a consultant supervisor was more frequently present by day, OR 2.26 (95% CI 1.05 to 4.83). Shoulder dystocia occurred more commonly by day, OR 2.57 (95% CI 1.05 to 6.28). The incidence of PPH, anal sphincter tears, neonatal unit admission, fetal acidosis and neonatal trauma was similar by day and at night. The mean decision to delivery intervals were 12.0 and 12.6 min, respectively. There was no evidence of an association between time of OVD and adverse perinatal outcomes despite off-site consultant obstetric support at night. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Levodopa delivery systems: advancements in delivery of the gold standard.

Science.gov (United States)

Ngwuluka, Ndidi; Pillay, Viness; Du Toit, Lisa C; Ndesendo, Valence; Choonara, Yahya; Modi, Girish; Naidoo, Dinesh

2010-02-01

Despite the fact that Parkinson's disease (PD) was discovered almost 200 years ago, its treatment and management remain immense challenges because progressive loss of dopaminergic nigral neurons, motor complications experienced by the patients as the disease progresses and drawbacks of pharmacotherapeutic management still persist. Various therapeutic agents have been used in the management of PD, including levodopa (l-DOPA), selegiline, amantadine, bromocriptine, entacapone, pramipexole dihydrochloride and more recently istradefylline and rasagiline. Of all agents, l-DOPA although the oldest, remains the most effective. l-DOPA is easier to administer, better tolerated, less expensive and is required by almost all PD patients. However, l-DOPA's efficacy in advanced PD is significantly reduced due to metabolism, subsequent low bioavailability and irregular fluctuations in its plasma levels. Significant strides have been made to improve the delivery of l-DOPA in order to enhance its bioavailability and reduce plasma fluctuations as well as motor complications experienced by patients purportedly resulting from pulsatile stimulation of the striatal dopamine receptors. Drug delivery systems that have been instituted for the delivery of l-DOPA include immediate release formulations, liquid formulations, dispersible tablets, controlled release formulations, dual-release formulations, microspheres, infusion and transdermal delivery, among others. In this review, the l-DOPA-loaded drug delivery systems developed over the past three decades are elaborated. The ultimate aim was to assess critically the attempts made thus far directed at improving l-DOPA absorption, bioavailability and maintenance of constant plasma concentrations, including the drug delivery technologies implicated. This review highlights the fact that neuropharmaceutics is at a precipice, which is expected to spur investigators to take that leap to enable the generation of innovative delivery systems for the

Model, parameter and code of environmental dispersion of gaseous effluent under normal operation from nuclear power plant with 600 MWe

International Nuclear Information System (INIS)

Hu Erbang; Gao Zhanrong

1998-06-01

The model of environmental dispersion of gaseous effluence under normal operation from a nuclear power plant with 600 MWe is established to give a mathematical expression of annual mean atmospheric dispersion factor under mixing release condition based on quality assessment of radiological environment for 30 years of Chinese nuclear industry. In calculation, the impact from calm and other following factors have been taken into account: mixing layer, dry and wet deposition, radioactive decay and buildings. The doses caused from the following exposure pathways are also given by this model: external exposure from immersion cloud and ground deposition, internal exposure due to inhalation and ingestion. The code is named as ROULEA. It contains four modules, i.e. INPUT, ANRTRI, CHIQV and DOSE for calculating 4-dimension joint frequency, annual mean atmospheric dispersion factor and doses

Switchable Q-switched and modelocked operation in ytterbium doped fiber laser under all-normal-dispersion configuration

Energy Technology Data Exchange (ETDEWEB)

Mukhopadhyay, Pranb K., E-mail: pkm@rrcat.gov.in; Gupta, Pradeep K.; Singh, Chandra Pal; Singh, Amarjeet; Sharma, Sunil K.; Bindra, Kushvinder S.; Oak, Shrikant M. [Solid State Laser Division, Raja Ramanna Center for Advanced Technology, Indore, M.P. 452013 (India)

2015-03-15

We have constructed an Yb-doped fiber laser in all-normal-dispersion configuration which can be independently operated in Q-switched or modelocked configuration with the help of a simple fiber optic ring resonator (FORR). In the presence of FORR, the laser operates in Q-switched mode producing stable pulses in the range of 1 μs-200 ns with repetition rate in the range of 45 kHz-82 kHz. On the other hand, the laser can be easily switched to mode-locked operation by disjoining the FORR loop producing train of ultrashort pulses of ∼5 ps duration (compressible to ∼150 fs) at ∼38 MHz repetition rate. The transmission characteristics of FORR in combination with the nonlinear polarization rotation for passive Q-switching operation is numerically investigated and experimentally verified. The laser can serve as a versatile seed source for power amplifier which can be easily configured for application in the fields that require different pulsed fiber lasers.

Reversible pH-Sensitive Chitosan-Based Hydrogels. Influence of Dispersion Composition on Rheological Properties and Sustained Drug Delivery

Directory of Open Access Journals (Sweden)

Nieves Iglesias

2018-04-01

Full Text Available The present work deals with the synthesis of micro-structured biomaterials based on chitosan (CTS for their applications as biocompatible carriers of drugs and bioactive compounds. Twelve dispersions were prepared by means of functional cross-linking with tricarballylic acid (TCA; they were characterized by Fourier transform infrared spectroscopy (FT-IR, modulated temperature differential scanning calorimetry (MTDSC and scanning electron microscopy (SEM, and their rheological properties were studied. To the best of the authors’ knowledge, no study has been carried out on the influence of CTS concentration, degree of cross-linking and drug loading on chitosan hydrogels for drug delivery systems (DDS and is investigated herein for the first time. The influence of dispersion composition (polymer concentration and degree of cross-linking revealed to exert a marked impact on its rheological properties, going from liquid-like to viscoelastic gels. The release profiles of a model drug, diclofenac sodium (DCNa, as well as their relationships with polymer concentration, drug loading and degree of cross-linking were evaluated. Similar to the findings on rheological properties, a wide range of release profiles was encountered. These formulations were found to display a well-controlled drug release strongly dependent on the formulation composition. Cumulative drug release under physiological conditions for 96 h ranged from 8% to 67%. For comparative purpose, Voltaren emulgel® from Novartis Pharmaceuticals was also investigated and the latter was the formulation with the highest cumulative drug release (85%. Some formulations showed similar spreadability values to the commercial hydrogel. The comparative study of three batches confirmed the reproducibility of the method, leading to systems particularly suitable for their use as drug carriers.

Retrospective analysis of dose delivery in intra-operative high dose rate brachytherapy

International Nuclear Information System (INIS)

Oh, M.; Avadhani, J.S.; Malhotra, H.K.; Cunningham, B.; Tripp, P.; Jaggernauth, W.; Podgorsak, M.B.

2007-01-01

Background. This study was performed to quantify the inaccuracy in clinical dose delivery due to the incomplete scatter conditions inherent in intra-operative high dose rate (IOHDR) brachytherapy. Methods. Treatment plans of 10 patients previously treated in our facility, which had irregular shapes of treated areas, were used. Treatment geometries reflecting each clinical case were simulated using a phantom assembly with no added build-up on top of the applicator. The treatment planning geometry (full scatter surrounding the applicator) was subsequently simulated for each case by adding bolus on top of the applicator. Results. For geometries representing the clinical IOHDR incomplete scatter environment, measured doses at the 5 mm and 10 mm prescription depths were lower than the corresponding prescribed doses by about 7.7% and 11.1%, respectively. Also, for the two prescription methods, an analysis of the measured dose distributions and their corresponding treatment plans showed average decreases of 1.2 mm and 2.2 mm in depth of prescription dose, respectively. Conclusions. Dosimetric calculations with the assumption of an infinite scatter environment around the applicator and target volume have shown to result in dose delivery errors that significantly decrease the prescription depth for IOHDR treatment.(author)

UAV Delivery Monitoring System

Directory of Open Access Journals (Sweden)

San Khin Thida

2018-01-01

Full Text Available UAV-based delivery systems are increasingly being used in the logistics field, particularly to achieve faster last-mile delivery. This study develops a UAV delivery system that manages delivery order assignments, autonomous flight operation, real time control for UAV flights, and delivery status tracking. To manage the delivery item assignments, we apply the concurrent scheduler approach with a genetic algorithm. The present paper describes real time flight data based on a micro air vehicle communication protocol (MAVLink. It also presents the detailed hardware components used for the field tests. Finally, we provide UAV component analysis to choose the suitable components for delivery in terms of battery capacity, flight time, payload weight and motor thrust ratio.

Articulating feedstock delivery device

Science.gov (United States)

Jordan, Kevin

2013-11-05

A fully articulable feedstock delivery device that is designed to operate at pressure and temperature extremes. The device incorporates an articulating ball assembly which allows for more accurate delivery of the feedstock to a target location. The device is suitable for a variety of applications including, but not limited to, delivery of feedstock to a high-pressure reaction chamber or process zone.

Development and evaluation of alginate-chitosan gastric floating beads loading with oxymatrine solid dispersion.

Science.gov (United States)

Liu, Yanhua; Chen, Lihong; Zhou, Chengming; Yang, Jianhong; Hou, Yanhui; Wang, Wenping

2016-01-01

Oxymatrine (OM) can be metabolized to matrine in gastrointestinal ileocecal valve after oral administration, which affects pharmacological activity and reduce bioavailability of OM. A type of multiple-unit alginate-chitosan (Alg-Cs) floating beads was prepared by the ionotropic gelation method for gastroretention delivery of OM. A solid dispersion technique was applied and incorporated into beads to enhance the OM encapsulation efficiency (EE) and sustain the drug release. The surface morphology and internal hollow structure of beads were evaluated using optical microscopy and scanning electron microscopy (SEM). The developed Alg-Cs beads were spherical in shape with hollow internal structure and had particle size of 3.49 ± 0.09 mm and 1.33 ± 0.09 mm for wet and dried beads. Over 84% of the optimized OM solid dispersion-loaded Alg-Cs beads were able to continuously float over the simulated gastric fluid for 12 h in vitro. The OM solid dispersion-loaded Alg-Cs beads showed drug EE of 67.07%, which was much higher than that of beads loading with pure OM. Compared with the immediate release of OM capsules and pure OM-loaded beads, the release of OM from solid dispersion-loaded Alg-Cs beads was in a sustained-release manner for 12 h. Prolonged gastric retention time of over 8.5 h was achieved for OM solid dispersion-loaded Alg-Cs floating beads in healthy rabbit in in vivo floating ability evaluated by X-ray imaging. The developed Alg-Cs beads loading with OM solid dispersion displayed excellent performance features characterized by excellent gastric floating ability, high drug EE and sustained-release pattern. The study illustrated the potential use of Alg-Cs floating beads combined with the solid dispersion technique for prolonging gastric retention and sustaining release of OM, which could provide a promising drug delivery system for gastric-specific delivery of OM for bioavailability enhancement.

How Mode of Delivery Affects Comprehension of an Operations Management Simulation: Online vs Face-to-Face Classrooms

Science.gov (United States)

Riley, Jason M.; Ellegood, William A.; Solomon, Stanislaus; Baker, Jerrine

2017-01-01

Purpose: This study aims to understand how mode of delivery, online versus face-to-face, affects comprehension when teaching operations management concepts via a simulation. Conceptually, the aim is to identify factors that influence the students' ability to learn and retain new concepts. Design/methodology/approach: Leveraging Littlefield…

A basic insight into the stability and manufacturing aspects of solid dispersions

Directory of Open Access Journals (Sweden)

Jishnu Vijay

2012-01-01

Full Text Available The development of a bioavailable dosage form is the most challenging task for the researchers. In the arena of advanced drug delivery systems, the solid dispersion techniques seem to be a promising system for the development of an optimized, bioavailable formulation of Class 2 drugs. The methods of formulation of solid dispersion have been summarized. This article is an effort to define a solid dispersion and its classification. The prospective of the stability of solid dispersion has also been discussed. Moreover, the major techniques that have been used so far such as the fusion/melting method, solvent evaporation method, hot melt extrusion method, supercritical fluid methods, have also been detailed.

Dispersion Management in a Harmonically Mode-Locked Fiber Soliton Laser

National Research Council Canada - National Science Library

Carruthers, Thomas F; Duling, III, Irl N; Horowitz, Moshe; Menyuk, Curtis R

1999-01-01

... because of their low-noise, dropout-free operation. We have fabricated such a laser with a strongly dispersion-managed cavity and modeled its operation, and we have found that dispersion management significantly extends the power range...

Comparison of drug delivery with autoinjector versus manual prefilled syringe and between three different autoinjector devices administered in pig thigh

Directory of Open Access Journals (Sweden)

Hill RL

2016-08-01

Full Text Available Robert L Hill,1,* John G Wilmot,1,* Beth A Belluscio,1 Kevin Cleary,2 David Lindisch,3 Robin Tucker,4 Emmanuel Wilson,2 Rajesh B Shukla11Meridian Medical Technologies Inc., Columbia, MD, 2Children’s National Medical Center, 3Washington DC VA Medical Center, 4Georgetown University Medical Center, Washington, DC, USA *These authors have contributed equally to this work Abstract: Parenteral routes of drug administration are often selected to optimize actual dose of drug delivered, assure high bioavailability, bypass first-pass metabolism or harsh gastrointestinal environments, as well as maximize the speed of onset. Intramuscular (IM delivery can be preferred to intravenous delivery when initiating intravenous access is difficult or impossible. Drugs can be injected intramuscularly using a syringe or an automated delivery device (autoinjector. Investigation into the IM delivery dynamics of these methods may guide further improvements in the performance of injection technologies. Two porcine model studies were conducted to compare differences in dispersion of injectate volume for different methods of IM drug administration. The first study compared the differences in the degree of dispersion and uptake of injectate following the use of a manual syringe and an autoinjector. The second study compared the spatial spread of the injected formulation, or dispersion volume, and uptake of injectate following the use of five different autoinjectors (EpiPen® [0.3 mL], EpiPen® Jr [0.3 mL], Twinject® [0.15 mL, 0.3 mL], and Anapen® 300 [0.3 mL] with varying needle length, needle gauge, and force applied to the plunger. In the first study, the autoinjector provided higher peak volumes of injectate, indicating a greater degree of dispersion, compared with manual syringe delivery. In the second study, EpiPen autoinjectors resulted in larger dispersion volumes and higher initial dispersion ratios, which decreased rapidly over time, suggesting a greater

Supersaturating drug delivery systems

DEFF Research Database (Denmark)

Laitinen, Riikka; Löbmann, Korbinian; Grohganz, Holger

2017-01-01

of the bioavailability of poorly water-soluble drugs by increasing the driving force for drug absorption. However, ASDs often require a high weight percentage of carrier (usually a hydrophilic polymer) to ensure molecular mixing of the drug in the carrier and stabilization of the supersaturated state, often leading......Amorphous solid dispersions (ASDs) are probably the most common and important supersaturating drug delivery systems for the formulation of poorly water-soluble compounds. These delivery systems are able to achieve and maintain a sustained drug supersaturation which enables improvement...... strategy for poorly-soluble drugs. While the current research on co-amorphous formulations is focused on preparation and characterization of these systems, more detailed research on their supersaturation and precipitation behavior and the effect of co-formers on nucleation and crystal growth inhibition...

Route of delivery following successful external cephalic version.

Science.gov (United States)

Policiano, Catarina; Costa, Ana; Valentim-Lourenço, Alexandre; Clode, Nuno; Graça, Luís M

2014-09-01

To evaluate the delivery route and the indications for cesarean delivery after successful external cephalic version (ECV). A retrospective matched case-control study was conducted at a hospital in Lisbon, Portugal, between 2002 and 2012. Each woman who underwent successful ECV (n = 44) was compared with the previous and next women who presented for labor management and who had the same parity and a singleton vertex pregnancy at term (n = 88). The outcome measures were route of delivery, indications for cesarean delivery, and incidence of nonreassuring fetal status. Attempts at ECV were successful in 62 (46%) of 134 women, and 44 women whose fetuses remained in a cephalic presentation until delivery were included in the study. The rates of intrapartum cesarean delivery and operative vaginal delivery did not differ significantly between cases and controls (intrapartum cesarean delivery, 9 [20%] vs 16 [18%], P = 0.75; operative vaginal delivery, 14 [32%] vs 19 [22%], P = 0.20). The indications for cesarean delivery after successful ECV did not differ; in both groups, cesarean delivery was mainly performed for labor arrest disorders (cases, 6 [67%] vs controls, 13 [81%]; P = 0.63). Successful ECV was not associated with increased rates of intrapartum cesarean delivery or operative vaginal delivery. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Nanodiamonds as novel nanomaterials for biomedical applications: drug delivery and imaging systems

Directory of Open Access Journals (Sweden)

Kaur R

2013-01-01

Full Text Available Randeep Kaur, Ildiko BadeaDrug Design and Discovery Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, CanadaAbstract: Detonation nanodiamonds (NDs are emerging as delivery vehicles for small chemical drugs and macromolecular biotechnology products due to their primary particle size of 4 to 5 nm, stable inert core, reactive surface, and ability to form hydrogels. Nanoprobe technology capitalizes on the intrinsic fluorescence, high refractive index, and unique Raman signal of the NDs, rendering them attractive for in vitro and in vivo imaging applications. This review provides a brief introduction of the various types of NDs and describes the development of procedures that have led to stable single-digit-sized ND dispersions, a crucial feature for drug delivery systems and nanoprobes. Various approaches used for functionalizing the surface of NDs are highlighted, along with a discussion of their biocompatibility status. The utilization of NDs to provide sustained release and improve the dispersion of hydrophobic molecules, of which chemotherapeutic drugs are the most investigated, is described. The prospects of improving the intracellular delivery of nucleic acids by using NDs as a platform are exemplified. The photoluminescent and optical scattering properties of NDs, together with their applications in cellular labeling, are also reviewed. Considering the progress that has been made in understanding the properties of NDs, they can be envisioned as highly efficient drug delivery and imaging biomaterials for use in animals and humans.Keywords: dispersion, surface functionalization, toxicity, carriers, fluorescence, light scattering

Transport and Dispersion of Nanoparticles in Periodic Nanopost Arrays

KAUST Repository

He, Kai; Retterer, Scott T.; Srijanto, Bernadeta R.; Conrad, Jacinta C.; Krishnamoorti, Ramanan

2014-01-01

Nanoparticles transported through highly confined porous media exhibit faster breakthrough than small molecule tracers. Despite important technological applications in advanced materials, human health, energy, and environment, the microscale mechanisms leading to early breakthrough have not been identified. Here, we measure dispersion of nanoparticles at the single-particle scale in regular arrays of nanoposts and show that for highly confined flows of dilute suspensions of nanoparticles the longitudinal and transverse velocities exhibit distinct scaling behaviors. The distributions of transverse particle velocities become narrower and more non-Gaussian when the particles are strongly confined. As a result, the transverse dispersion of highly confined nanoparticles at low Péclet numbers is significantly less important than longitudinal dispersion, leading to early breakthrough. This finding suggests a fundamental mechanism by which to control dispersion and thereby improve efficacy of nanoparticles applied for advanced polymer nanocomposites, drug delivery, hydrocarbon production, and environmental remediation. © 2014 American Chemical Society.

Transport and Dispersion of Nanoparticles in Periodic Nanopost Arrays

KAUST Repository

He, Kai

2014-05-27

Nanoparticles transported through highly confined porous media exhibit faster breakthrough than small molecule tracers. Despite important technological applications in advanced materials, human health, energy, and environment, the microscale mechanisms leading to early breakthrough have not been identified. Here, we measure dispersion of nanoparticles at the single-particle scale in regular arrays of nanoposts and show that for highly confined flows of dilute suspensions of nanoparticles the longitudinal and transverse velocities exhibit distinct scaling behaviors. The distributions of transverse particle velocities become narrower and more non-Gaussian when the particles are strongly confined. As a result, the transverse dispersion of highly confined nanoparticles at low Péclet numbers is significantly less important than longitudinal dispersion, leading to early breakthrough. This finding suggests a fundamental mechanism by which to control dispersion and thereby improve efficacy of nanoparticles applied for advanced polymer nanocomposites, drug delivery, hydrocarbon production, and environmental remediation. © 2014 American Chemical Society.

Seed Dispersal Anachronisms: Rethinking the Fruits Extinct Megafauna Ate

OpenAIRE

Guimarães, Paulo R.; Galetti, Mauro; Jordano, Pedro

2008-01-01

Background: Some neotropical, fleshy-fruited plants have fruits structurally similar to paleotropical fruits dispersed by megafauna (mammals .103 kg), yet these dispersers were extinct in South America 10–15 Kyr BP. Anachronic dispersal systems are best explained by interactions with extinct animals and show impaired dispersal resulting in altered seed dispersal dynamics. Methodology/Principal Findings: We introduce an operational definition of megafaunal fruits and perform a comparativ...

Frozen dispersions of nanomaterials are a useful operational procedure in nanotoxicology.

Science.gov (United States)

Vila, Laura; Rubio, Laura; Annangi, Balasubramanyam; García-Rodríguez, Alba; Marcos, Ricard; Hernández, Alba

2017-02-01

The variability observed in nanoparticle (NP) dispersions can affect the reliability of the results obtained in short-term tests, and mainly in long-term experiments. In addition, obtaining a good dispersion is time-consuming and acts as a bottleneck in the development of high-throughput screening methodologies. The freezing of different aliquots from a stock dispersion would overcome such limitations, but no studies have explored the impact of freezing thawing the samples on the physico-chemical and biological properties of the nanomaterial (NM). This work aims to compare fresh-prepared and frozen MWCNT, ZnO-, Ag-, TiO 2- and CeO 2 -NP dispersions, used as models. NP characterization (size and morphology by TEM), hydrodynamic size and zeta potential were performed. Viability comparisons were determined in BEAS-2B cells. Cellular NP uptake and induced ROS production was assessed by TEM and flow cytometry, respectively. The obtained results show no important differences between frozen and fresh NP in their physico-chemical characteristics or their biological effects. This study is the first to demonstrate that there is no scientific evidence to dismiss the use of frozen NP, opening the door to the development of short- and long-term experiments with higher consistency, accuracy and reproducibility in a much shorter time and using a simplified procedure.

Transparent dispersion compensator with built-in gain equalizer

DEFF Research Database (Denmark)

Rottwitt, Karsten; Doerr, C.

2002-01-01

In this work we describe a method to obtain a transparent or even an amplifying dispersion compensating module with built-in gain equalization functionality. The principle of operation and experimental results are illustrated.......In this work we describe a method to obtain a transparent or even an amplifying dispersion compensating module with built-in gain equalization functionality. The principle of operation and experimental results are illustrated....

A system for real-time environmental assessment using an operational meteorological data base for dispersion calculations

International Nuclear Information System (INIS)

Appelgren, A.; Hallberg, B.; Nordlinder, S.; Salomonsson, S.

1990-01-01

A method for assessing the meteorological conditions on a local scale, about 20 km, around a specific site was developed, and applied to the area around the Forsmark nuclear power plant, situated on the coast about 100 km north of Stockholm. Meteorological data were collected, for an one-year period, from sensors in a tower and from a Sodar system at Forsmark. In addition, two Sodar systems were placed at several locations around the power plant, out to a distance of approximately 20 km. By statistical compiling, an operational data base was established, consisting of classes of wind speed, wind direction and atmospheric stability. The data from the remote sites were related to those from Forsmark. This gave the possibility to determine the variation of the meteorological conditions in time and space, using data from a single location only. The main objective of the Forsmark project was to identify and indicate situations in which the conditions for dispersion were difficult to model accurately when using measurements taken from a conventional tower, without knowledge of the influence of local mesoscale disturbances. Such could be e.g. sea breeze, large horizontal or vertical wind shear, terrain-induced flow patterns etc. The use of an operational data base, as described above, in connection with real-time dispersion models, such as AIRPAC/EMMA, will improve the performance of such models, as well as consequence analyses, in case of accidental releases from nuclear power plants or other industrial plants

A wireless actuating drug delivery system

International Nuclear Information System (INIS)

Jo, Won-Jun; Baek, Seung-Ki; Park, Jung-Hwan

2015-01-01

A wireless actuating drug delivery system was devised. The system is based on induction heating for drug delivery. In this study, thermally generated nitrogen gas produced by induction heating of azobisisobutyronitrile (AIBN) was utilized for pressure-driven release of the drug. The delivery device consists of an actuator chamber, a drug reservoir, and a microchannel. A semicircular copper disc (5 and 6 mm in diameter and 100 µm thick), and thermal conductive tape were integrated as the heating element in the actuator chamber. The final device was 2.7 mm thick. 28 µl of drug solution were placed in the reservoir and the device released the drug quickly at the rate of 6 µl s −1 by induction heating at 160 µT of magnetic intensity. The entire drug solution was released and dispersed after subcutaneous implantation under identical experimental condition. This study demonstrates that the device was simply prepared and drug delivery could be achieved by wireless actuation of a thin, pressure-driven actuator. (paper)

Development of megestrol acetate solid dispersion nanoparticles for enhanced oral delivery by using a supercritical antisolvent process.

Science.gov (United States)

Ha, Eun-Sol; Kim, Jeong-Soo; Baek, In-Hwan; Yoo, Jin-Wook; Jung, Yunjin; Moon, Hyung Ryong; Kim, Min-Soo

2015-01-01

In the present study, solid dispersion nanoparticles with a hydrophilic polymer and surfactant were developed using the supercritical antisolvent (SAS) process to improve the dissolution and oral absorption of megestrol acetate. The physicochemical properties of the megestrol acetate solid dispersion nanoparticles were characterized using scanning electron microscopy, differential scanning calorimetry, powder X-ray diffraction, and a particle-size analyzer. The dissolution and oral bioavailability of the nanoparticles were also evaluated in rats. The mean particle size of all solid dispersion nanoparticles that were prepared was nanoparticles. Hydroxypropylmethyl cellulose (HPMC) solid dispersion nanoparticles significantly increased the maximum dissolution when compared with polyvinylpyrrolidone K30 solid dispersion nanoparticles. The extent and rate of dissolution of megestrol acetate increased after the addition of a surfactant into the HPMC solid dispersion nanoparticles. The most effective surfactant was Ryoto sugar ester L1695, followed by D-α-tocopheryl polyethylene glycol 1000 succinate. In this study, the solid dispersion nanoparticles with a drug:HPMC:Ryoto sugar ester L1695 ratio of 1:2:1 showed >95% rapid dissolution within 30 minutes, in addition to good oral bioavailability, with approximately 4.0- and 5.5-fold higher area under the curve (0-24 hours) and maximum concentration, respectively, than raw megestrol acetate powder. These results suggest that the preparation of megestrol acetate solid dispersion nanoparticles using the supercritical antisolvent process is a promising approach to improve the dissolution and absorption properties of megestrol acetate.

A new technique for reversible permeabilization of live cells for intracellular delivery of quantum dots

International Nuclear Information System (INIS)

Medepalli, Krishnakiran; Alphenaar, Bruce W; Keynton, Robert S; Sethu, Palaniappan

2013-01-01

A major challenge with the use of quantum dots (QDs) for cellular imaging and biomolecular delivery is the attainment of QDs freely dispersed inside the cells. Conventional methods such as endocytosis, lipids based delivery and electroporation are associated with delivery of QDs in vesicles and/or as aggregates that are not monodispersed. In this study, we demonstrate a new technique for reversible permeabilization of cells to enable the introduction of freely dispersed QDs within the cytoplasm. Our approach combines osmosis driven fluid transport into cells achieved by creating a hypotonic environment and reversible permeabilization using low concentrations of cell permeabilization agents like Saponin. Our results confirm that highly efficient endocytosis-free intracellular delivery of QDs can be accomplished using this method. The best results were obtained when the cells were treated with 50 μg ml −1 Saponin in a hypotonic buffer at a 3:2 physiological buffer:DI water ratio for 5 min at 4 ° C. (paper)

Development of megestrol acetate solid dispersion nanoparticles for enhanced oral delivery by using a supercritical antisolvent process

Directory of Open Access Journals (Sweden)

Ha ES

2015-08-01

Full Text Available Eun-Sol Ha,1 Jeong-Soo Kim,2 In-hwan Baek,3 Jin-Wook Yoo,1 Yunjin Jung,1 Hyung Ryong Moon,1 Min-Soo Kim1 1College of Pharmacy, Pusan National University, 2Dong-A ST Co Ltd, Yongin, 3College of Pharmacy, Kyungsung University, Busan, South Korea Abstract: In the present study, solid dispersion nanoparticles with a hydrophilic polymer and surfactant were developed using the supercritical antisolvent (SAS process to improve the dissolution and oral absorption of megestrol acetate. The physicochemical properties of the megestrol acetate solid dispersion nanoparticles were characterized using scanning electron microscopy, differential scanning calorimetry, powder X-ray diffraction, and a particle-size analyzer. The dissolution and oral bioavailability of the nanoparticles were also evaluated in rats. The mean particle size of all solid dispersion nanoparticles that were prepared was <500 nm. Powder X-ray diffraction and differential scanning calorimetry measurements showed that megestrol acetate was present in an amorphous or molecular dispersion state within the solid dispersion nanoparticles. Hydroxypropylmethyl cellulose (HPMC solid dispersion nanoparticles significantly increased the maximum dissolution when compared with polyvinylpyrrolidone K30 solid dispersion nanoparticles. The extent and rate of dissolution of megestrol acetate increased after the addition of a surfactant into the HPMC solid dispersion nanoparticles. The most effective surfactant was Ryoto sugar ester L1695, followed by d-a-tocopheryl polyethylene glycol 1000 succinate. In this study, the solid dispersion nanoparticles with a drug:HPMC:Ryoto sugar ester L1695 ratio of 1:2:1 showed >95% rapid dissolution within 30 minutes, in addition to good oral bioavailability, with approximately 4.0- and 5.5-fold higher area under the curve (0–24 hours and maximum concentration, respectively, than raw megestrol acetate powder. These results suggest that the preparation of megestrol

blood transfusion requirement during caesarean delivery: risk factors

African Journals Online (AJOL)

PLWAs are getting pregnant and may require operative delivery on account of Preventing ... abnormalities such as bone marrow depression, anaemia9 and ... operative clinical status up to 48 hours post-delivery or death. Transfusion rate was.

Debris Dispersion Model Using Java 3D

Science.gov (United States)

Thirumalainambi, Rajkumar; Bardina, Jorge

2004-01-01

This paper describes web based simulation of Shuttle launch operations and debris dispersion. Java 3D graphics provides geometric and visual content with suitable mathematical model and behaviors of Shuttle launch. Because the model is so heterogeneous and interrelated with various factors, 3D graphics combined with physical models provides mechanisms to understand the complexity of launch and range operations. The main focus in the modeling and simulation covers orbital dynamics and range safety. Range safety areas include destruct limit lines, telemetry and tracking and population risk near range. If there is an explosion of Shuttle during launch, debris dispersion is explained. The shuttle launch and range operations in this paper are discussed based on the operations from Kennedy Space Center, Florida, USA.

Autoshaping with common and distinctive stimulus elements, compact and dispersed arrays.

Science.gov (United States)

Sperling, S E; Perkins, M E

1979-05-01

Four groups of pigeons were trained with a standard autoshaping procedure in which a brief fixed-duration interval always followed by a grain delivery alternated with a longer variable-duration interval never associated with grain delivery. One of two stimuli was always presented during each interval. One of them contained three black dots and a black star on a green background; the other contained four black dots on a green background. The four elements of each stimulus were arranged in a more compact array for two groups and in a more dispersed array for the other two groups. Which of the two stimuli preceded grain delivery was counterbalanced within each pair of groups. The speed of occurrence of the first autoshaped peck was not affected by whether the stimulus containing the distinctive star element preceded grain delivery, but autoshaping was faster when the stimulus arrays were compact than when they were dispersed. During 560 response-independent training trials that followed the first autoshaped peck, this pattern reversed; both discriminative control over responding and the relative frequency of pecking the stimulus that preceded grain delivery were greater for the two groups where this stimulus contained the discriminative element than for the two groups where it contained only common elements. During subsequent testing with stimuli containing only a single element each, the distinctive feature was responded to proportionately more often by the two groups for which it had been an element of the stimulus preceding grain delivery than by the two groups for which it had been an element of the stimulus complex that never was associated with grain delivery. These data add further support to the hypothesis that the initial occurrence of autoshaped responding and its subsequent maintenance are not affected by the same variables. They also suggest that automaintenance is as sensitive as response-dependent training to the presence or absence of a distinctive

Applications of polymeric nanocapsules in field of drug delivery systems.

Science.gov (United States)

Rong, Xinyu; Xie, Yinghua; Hao, Xiaomei; Chen, Tao; Wang, Yingming; Liu, Yuanyuan

2011-09-01

Drug-loaded polymeric nanocapsules have exhibited potential applications in the field of drug delivery systems in recent years. This article entails the biodegradable polymers generally used for preparing nanocapsules, which include both natural polymers and synthetic polymers. Furthermore, the article presents a general review of the different preparation methods: nanoprecipitation method, emulsion-diffusion method, double emulsification method, emulsion-coacervation method, layer-by-layer assembly method. In addition, the analysis methods of nanocapsule characteristics, such as mean size, morphology, surface characteristics, shell thickness, encapsulation efficiency, active substance release, dispersion stability, are mentioned. Also, the applications of nanocapsules as carriers for use in drug delivery systems are reviewed, which primarily involve targeting drug delivery, controlled/sustained release drug delivery systems, transdermal drug delivery systems and improving stability and bioavailability of drugs. Nanocapsules, prepared with different biodegradable polymers, have received more and more attention and have been regarded as one of the most promising drug delivery systems.

Atmospheric dispersion models of radioactivity releases

International Nuclear Information System (INIS)

Oza, R.B.

2016-01-01

In view of the rapid industrialization in recent time, atmospheric dispersion models have become indispensible 'tools' to ensure that the effects of releases are well within the acceptable limits set by the regulatory authority. In the case of radioactive releases from the nuclear facility, though negligible in quantity and many a times not even measurable, it is required to demonstrate the compliance of these releases to the regulatory limits set by the regulatory authority by carrying out radiological impact assessment. During routine operations of nuclear facility, the releases are so low that environmental impact is usually assessed with the help of atmospheric dispersion models as it is difficult to distinguish negligible contribution of nuclear facility to relatively high natural background radiation. The accidental releases from nuclear facility, though with negligible probability of occurrence, cannot be ruled out. In such cases, the atmospheric dispersion models are of great help to emergency planners for deciding the intervention actions to minimize the consequences in public domain and also to workout strategies for the management of situation. In case of accidental conditions, the atmospheric dispersion models are also utilized for the estimation of probable quantities of radionuclides which might have got released to the atmosphere. Thus, atmospheric dispersion models are an essential tool for nuclear facility during routine operation as well as in the case of accidental conditions

Measuring the aerial application of oil dispersant from very large aircraft at moderate altitude

International Nuclear Information System (INIS)

Fay, R.R.; Giammona, C.P.; Binkley, K.; Engelhardt, F.R.

1993-01-01

As part of a study of various aspects of oil dispersant application technology, a comparison study was conducted employing the Airborne Dispersant Delivery System (ADDS) pack and the Modular Aerial Spray System (MASS) in C-130 Hercules aircraft at altitudes of 50-150 ft above ground and at speeds up to 200 knots. Dyed Corexit 9527 was applied at a target dose rate of 5 gal/acre over a collection grid composed of metal trays, Kromekote cards, oil-sensitive cards, a continuous trough, and a WRK string collector. Analysis of the collected dispersant was done by colorimetry, fluorometry, and image analysis. Correlations through the different methodologies demonstrated that high speed, moderate altitude application of oil dispersant could be successful in delivering dispersant to the surface at effective concentration and drop size. Environmental studies of the test area showed no residual dispersant in the soil following cessation of spraying. 1 ref

Fast dissolving cyclodextrin complex of piroxicam in solid dispersion part I: influence of β-CD and HPβ-CD on the dissolution rate of piroxicam.

Science.gov (United States)

Bouchal, F; Skiba, M; Chaffai, N; Hallouard, F; Fatmi, S; Lahiani-Skiba, M

2015-01-30

Sublingual drug delivery is an interesting route for drug having significant hepatic first-pass metabolism or requiring rapid pharmacological effect as for patients suffering from swallowing difficulties, nausea or vomiting. Sublingual absorption could however be limited by the kinetic of drug dissolution. This study evaluated influences of cyclodextrins (β-CD or HP-β-CD) and their different inclusion process (spray-drying or freeze-drying) on the drug dissolution kinetic of solid dispersions in poly(ethylene glycol) (PEG, Mw 6000Da) of piroxicam, used as poor hydrosoluble drug model. A secondary objective was to determine influences of drug dispersion process in PEG (evaporation or melting methods) on the drug dissolution kinetic of piroxicam. Piroxicam solid dispersions containing or not cyclodextrins were characterized by different scanning calorimetry (DSC), Thermogravometry analyser (TGA) and Fourier transform-infrared spectroscopy (FT-IR) spectroscopy. In vitro drug dissolution study of these solid dispersions was then performed. The results demonstrated the high potential and interest of solid dispersions of drug previously included in cyclodextrins for sublingual delivery of hydrophobic drugs. This study also showed the advantages of evaporation method on the melting ones during drug dispersion in PEG. Indeed, drug complexation with cyclodextrins as dispersion by melting prevented the presence in solid dispersions of drug in crystalline form which can represent up to 63%. Moreover, dispersion in PEG by evaporation method gave more porous drug delivery system than with melting methods. This allowed complete (limited at most at 80-90% with melting methods) and quick drug dissolution without rebound effect like with melting ones. Copyright © 2014 Elsevier B.V. All rights reserved.

Instrumental delivery: clinical practice guidelines from the French College of Gynaecologists and Obstetricians.

Science.gov (United States)

Vayssière, Christophe; Beucher, Gael; Dupuis, Olivier; Feraud, Olivia; Simon-Toulza, Caroline; Sentilhes, Loïc; Meunier, Emmanuelle; Parant, Olivier; Schmitz, Thomas; Riethmuller, Didier; Baud, Olivier; Galley-Raulin, Fabienne; Diemunsch, Pierre; Pierre, Fabrice; Schaal, Jean-Patrick; Fournié, Alain; Oury, Jean François

2011-11-01

Routine use of a partograph is associated with a reduction in the use of forceps, but is not associated with a reduction in the use of vacuum extraction (Level A). Early artificial rupture of the membranes, associated with oxytocin perfusion, does not reduce the number of operative vaginal deliveries (Level A), but does increase the rate of fetal heart rate abnormalities (Level B). Early correction of lack of progress in dilatation by oxytocin perfusion can reduce the number of operative vaginal deliveries (Level B). The use of low-concentration epidural infusions of bupivacaine potentiated by morphinomimetics reduces the number of operative interventions compared with larger doses (Level A). Placement of an epidural before 3-cm dilatation does not increase the number of operative vaginal deliveries (Level A). Posterior positions of the fetus result in more operative vaginal deliveries (Level B). Manual rotation of the fetus from a posterior position to an anterior position may reduce the number of operative deliveries (Level C). Walking during labour is not associated with a reduction in the number of operative vaginal deliveries (Level A). Continuous support of the parturient by a midwife or partner/family member during labour reduces the number of operative vaginal deliveries (Level A). Under epidural analgesia, delayed pushing (2h after full dilatation) reduces the number of difficult operative vaginal deliveries (Level A). Ultrasound is recommended if there is any clinical doubt about the presentation of the fetus (Level B). The available scientific data are insufficient to contra-indicate attempted midoperative delivery (professional consensus). The duration of the operative intervention is slightly shorter with forceps than with a vacuum extractor (Level C). Nonetheless, the urgency of operative delivery is not a reason to choose one instrument over another (professional consensus). The cup-shaped vacuum extractor seems to be the instrument of choice for

Nanodiamonds as novel nanomaterials for biomedical applications: drug delivery and imaging systems.

Science.gov (United States)

Kaur, Randeep; Badea, Ildiko

2013-01-01

Detonation nanodiamonds (NDs) are emerging as delivery vehicles for small chemical drugs and macromolecular biotechnology products due to their primary particle size of 4 to 5 nm, stable inert core, reactive surface, and ability to form hydrogels. Nanoprobe technology capitalizes on the intrinsic fluorescence, high refractive index, and unique Raman signal of the NDs, rendering them attractive for in vitro and in vivo imaging applications. This review provides a brief introduction of the various types of NDs and describes the development of procedures that have led to stable single-digit-sized ND dispersions, a crucial feature for drug delivery systems and nanoprobes. Various approaches used for functionalizing the surface of NDs are highlighted, along with a discussion of their biocompatibility status. The utilization of NDs to provide sustained release and improve the dispersion of hydrophobic molecules, of which chemotherapeutic drugs are the most investigated, is described. The prospects of improving the intracellular delivery of nucleic acids by using NDs as a platform are exemplified. The photoluminescent and optical scattering properties of NDs, together with their applications in cellular labeling, are also reviewed. Considering the progress that has been made in understanding the properties of NDs, they can be envisioned as highly efficient drug delivery and imaging biomaterials for use in animals and humans.

New ceramics containing dispersants for improved fracture toughness

Science.gov (United States)

Nevitt, M.V.; Aldred, A.T.; Chan, Sai-Kit

1985-07-01

The invention is a ceramic composition containing a new class of dispersant for hindering crack propagation by means of one or more energy-dissipative mechanisms. The composition is composed of a ceramic matrix with dispersed particles of a transformation-prone rare-earth niobate, tantalate or mixtures of these with each other and/or with a rare-earth vanadate. The dispersants, having a generic composition tRBO/sub 4/, where R is a rare-earth element, B if Nb or Ta and O is oxygen, are mixed in powder form with a powder of the matrix ceramic and sintered to produce a ceramic form or body. The crack-hindering mechanisms operates to provide improved performance over a wide range of temperature and operating conditions.

Autoshaping with common and distinctive stimulus elements, compact and dispersed arrays1

Science.gov (United States)

Sperling, Sally E.; Perkins, Mark E.

1979-01-01

Four groups of pigeons were trained with a standard autoshaping procedure in which a brief fixed-duration interval always followed by a grain delivery alternated with a longer variable-duration interval never associated with grain delivery. One of two stimuli was always presented during each interval. One of them contained three black dots and a black star on a green background; the other contained four black dots on a green background. The four elements of each stimulus were arranged in a more compact array for two groups and in a more dispersed array for the other two groups. Which of the two stimuli preceded grain delivery was counterbalanced within each pair of groups. The speed of occurrence of the first autoshaped peck was not affected by whether the stimulus containing the distinctive star element preceded grain delivery, but autoshaping was faster when the stimulus arrays were compact than when they were dispersed. During 560 response-independent training trials that followed the first autoshaped peck, this pattern reversed; both discriminative control over responding and the relative frequency of pecking the stimulus that preceded grain delivery were greater for the two groups where this stimulus contained the discriminative element than for the two groups where it contained only common elements. During subsequent testing with stimuli containing only a single element each, the distinctive feature was responded to proportionately more often by the two groups for which it had been an element of the stimulus preceding grain delivery than by the two groups for which it had been an element of the stimulus complex that never was associated with grain delivery. These data add further support to the hypothesis that the initial occurrence of autoshaped responding and its subsequent maintenance are not affected by the same variables. They also suggest that automaintenance is as sensitive as response-dependent training to the presence or absence of a distinctive

Spectral dispersion and fringe detection in IOTA

Science.gov (United States)

Traub, W. A.; Lacasse, M. G.; Carleton, N. P.

1990-01-01

Pupil plane beam combination, spectral dispersion, detection, and fringe tracking are discussed for the IOTA interferometer. A new spectrometer design is presented in which the angular dispersion with respect to wavenumber is nearly constant. The dispersing element is a type of grism, a series combination of grating and prism, in which the constant parts of the dispersion add, but the slopes cancel. This grism is optimized for the display of channelled spectra. The dispersed fringes can be tracked by a matched-filter photon-counting correlator algorithm. This algorithm requires very few arithmetic operations per detected photon, making it well-suited for real-time fringe tracking. The algorithm is able to adapt to different stellar spectral types, intensity levels, and atmospheric time constants. The results of numerical experiments are reported.

Cationic PEGylated polycaprolactone nanoparticles carrying post-operation docetaxel for glioma treatment

Directory of Open Access Journals (Sweden)

Cem Varan

2017-07-01

Full Text Available Background: Brain tumors are the most common tumors among adolescents. Although some chemotherapeutics are known to be effective against brain tumors based on cell culture studies, the same effect is not observed in clinical trials. For this reason, the development of drug delivery systems is important to treat brain tumors and prevent tumor recurrence. The aim of this study was to develop core–shell polymeric nanoparticles with positive charge by employing a chitosan coating. Additionally, an implantable formulation for the chemotherapeutic nanoparticles was developed as a bioadhesive film to be applied at the tumor site following surgical operation for brain glioma treatment. To obtain positively charged, implantable nanoparticles, the effects of preparation technique, chitosan coating concentration and presence of surfactants were evaluated to obtain optimal nanoparticles with a diameter of less than 100 nm and a net positive surface charge to facilitate cellular internalization of drug-loaded nanoparticles. Hydroxypropyl cellulose films were prepared to incorporate these nanoparticle dispersions to complete the implantable drug delivery system.Results: The diameter of core–shell nanoparticles were in the range of 70–270 nm, depending on the preparation technique, polymer type and coating. Moreover, the chitosan coating significantly altered the surface charge of the nanoparticles to net positive values of +30 to +50 mV. The model drug docetaxel was successfully loaded into all particles, and the drug release rate from the nanoparticles was slowed down to 48 h by dispersing the nanoparticles in a hydroxypropyl cellulose film. Cell culture studies revealed that docetaxel-loaded nanoparticles cause higher cytotoxicity compared to the free docetaxel solution in DMSO.Conclusion: Docetaxel-loaded nanoparticles dispersed in a bioadhesive film were shown to be suitable for application of chemotherapeutics directly to the action site during

Influence of operating parameters on electrocoagulation of C.I. disperse yellow 3

Directory of Open Access Journals (Sweden)

Djamel Ghernaout

2014-12-01

Full Text Available This work deals with the electrocoagulation (EC process for an organic dye removal. The chosen organic dye is C.I. disperse yellow 3 (DY which is used in textile industry. Experiments were performed in batch mode using Al electrodes and for comparison purposes Fe electrodes. The experimental set-up was composed of 1 L beaker, two identical electrodes which are separated 2 cm from each other. The main operating parameters influencing EC process were examined such as pH, supporting electrolyte concentration CNaCl, current density i, and DY concentration. High performance EC process was shown during 45 min for 200 mg/L dye concentration at i = 350 A m-2 (applied voltage 12 V and CNaCl = 1 g L-1 reaching 98 % for pHs 3 and 10 and 99 % for pH 6. After 10 min, DY was also efficiently removed (86 % showing that EC process may be conveniently applied for textile industry wastewater treatment. EC using Fe electrodes exhibited slightly lower performance comparing EC using Al electrodes.

Cesarean delivery rates and obstetric culture - an Italian register-based study.

Science.gov (United States)

Plevani, Cristina; Incerti, Maddalena; Del Sorbo, Davide; Pintucci, Armando; Vergani, Patrizia; Merlino, Luca; Locatelli, Anna

2017-03-01

Cesarean delivery rates are rising due to multiple factors, including less use of operative vaginal delivery and vaginal birth after cesarean delivery, which often reflect local obstetric practices. Objectives of the study were to analyze the relations between cesarean delivery, these practices, and perinatal outcomes. We included all deliveries in the 72 hospitals of Lombardia, a region in northern Italy, during the year 2013. The delivery certificate was used as data source. Pearson's correlation coefficient and logistic regression were used for statistical analysis. We included 87 896 deliveries. The number of deliveries per hospital ranged from 140 to 6123. The rate of cesarean delivery was 28.3% (range 9.9-86.4%), operative vaginal delivery 4.7% (range 0.2-10.0%), and vaginal birth after cesarean 17.3% (range 0-79.2%). We found a significant inverse correlation between rates of overall cesarean delivery and operative vaginal delivery (r = -0.25, p = 0.04). The correlation between rate of overall cesarean delivery and vaginal birth after cesarean was also inverse and significant (r = -0.57, p cesarean delivery rate and the rates of Apgar score at 5 min cesarean delivery, could reduce the rising cesarean delivery rate. This will require a change in obstetric culture, continuing education of healthcare providers, and leadership. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

An expert system for dispersion model interpretation

International Nuclear Information System (INIS)

Skyllingstad, E.D.; Ramsdell, J.V.

1988-10-01

A prototype expert system designed to diagnose dispersion model uncertainty is described in this paper with application to a puff transport model. The system obtains qualitative information from the model user and through an expert-derived knowledge base, performs a rating of the current simulation. These results can then be used in combination with dispersion model output for deciding appropriate evacuation measures. Ultimately, the goal of this work is to develop an expert system that may be operated accurately by an individual uneducated in meteorology or dispersion modeling. 5 refs., 3 figs

Analysis of site-specific dispersion conditions

International Nuclear Information System (INIS)

Paesler-Sauer, J.

1989-03-01

This report presents an analysis of atmospheric dispersion conditions in the environs of nuclear power stations in the Federal Republic of Germany. The analysis is based on meteorological data measured on the power station sites (KFUe = nuclear reactor remote control records) and by neighbouring stations operated by the German Weather Service. The data are series of hourly mean values of wind and temperature gradient or stability class over the period of one or more years. The aim of the data analysis is to find types of dispersion conditions characterized by the flow field and stratification, and to assess the feasibility of calculating these quantities in the case of an emergency. Influences of terrain structures in the environs of the site are considered. The annual frequencies of types of dispersion situations are assessed, the capability to recognize the dispersion situation from meteorological data measured on the site and the applicability of dispersion models are discussed. (orig.) [de

A new electrospray method for targeted gene delivery.

Science.gov (United States)

Boehringer, Stephan; Ruzgys, Paulius; Tamò, Luca; Šatkauskas, Saulius; Geiser, Thomas; Gazdhar, Amiq; Hradetzky, David

2018-03-05

A challenge for gene therapy is absence of safe and efficient local delivery of therapeutic genetic material. An efficient and reproducible physical method of electrospray for localized and targeted gene delivery is presented. Electrospray works on the principle of coulombs repulsion, under influence of electric field the liquid carrying genetic material is dispersed into micro droplets and is accelerated towards the targeted tissue, acting as a counter electrode. The accelerated droplets penetrate the targeted cells thus facilitating the transfer of genetic material into the cell. The work described here presents the principle of electrospray for gene delivery, the basic instrument design, and the various optimized parameters to enhance gene transfer in vitro. We estimate a transfection efficiency of up to 60% was achieved. We describe an efficient gene transfer method and a potential electrospray-mediated gene transfer mechanism.

A cohort study of maternal and neonatal morbidity in relation to use of sequential instruments at operative vaginal delivery.

LENUS (Irish Health Repository)

Murphy, Deirdre J

2012-02-01

OBJECTIVE: To evaluate the risk factors and maternal and neonatal morbidity associated with sequential use of instruments (vacuum and forceps) at operative vaginal delivery. STUDY DESIGN: A cohort study of 1360 nulliparous women delivered by a single instrument (vacuum or forceps) or by both instruments, within two university teaching hospitals in Scotland and England. Outcomes were compared for use of sequential instruments versus use of any single instrument. A sub-group analysis compared sequential instruments versus forceps alone. Outcomes of interest included anal sphincter tears, postpartum haemorrhage, urinary retention, urinary incontinence, prolonged hospital admission, neonatal trauma, low Apgar scores, abnormal cord bloods and admission to the neonatal intensive care unit (NICU). RESULTS: Use of sequential instruments at operative vaginal delivery was associated with fetal malpositions, Odds Ratio (OR) 1.8 (95% Confidence Interval (CI) 1.3-2.6), and large neonatal head circumference (>37 cm) (OR 5.0, 95% CI 2.6-9.7) but not with maternal obesity or grade of operator. Sequential use of instruments was associated with greater maternal and neonatal morbidity than single instrument use (anal sphincter tear 17.4% versus 8.4%, adjusted OR 2.1, 95% CI 1.2-3.3; umbilical artery pH <7.10, 13.8% versus 5.0%, adjusted OR 3.3, 95% CI 1.7-6.2). Sequential instrument use had greater morbidity than single instrument use with forceps alone (anal sphincter tear OR 1.8, 95% CI 1.1-2.9; umbilical artery pH <7.10 OR 3.0, 95% CI 1.7-5.5). CONCLUSIONS: The use of sequential instruments significantly increases maternal and neonatal morbidity. Obstetricians need training in the appropriate selection and use of instruments with the aim of completing delivery safely with one instrument.

Tranfusion risk: is "two-step" vaginal delivery a risk for postpartum hemorrhage?

Science.gov (United States)

Straface, Gianluca; Bassi, Emma; De Santis, Marco; Scambia, Giovanni; Zanardo, Vincenzo

2015-01-01

In the active management strategy of third stage of labor, the optimal timing for clamping the umbilical cord after birth has been a subject of controversy. We want to evaluate if "two-step" delivery is a risk factor for postpartum hemorrhage (PPH), defined as need of transfusion, comparing to operative delivery, elective caesarean delivery and emergency caesarean delivery. This is a retrospective cohort study conducted in division of Perinatal Medicine, Policlinico Abano Terme. We evaluated the need of transfusion in all cases of PPH verified in all single deliveries between January 2011 and December 2012. The main outcome measure was blood loss and red blood cell transfusion. We found 17 cases of PPH (0.88%). The distribution of PPH in relation to mode of delivery was 0.71%, 2.46% and 1.98% respectively for two-step vaginal delivery (RR = 0.81 (0.56-1.22)), emergency cesarean section (RR = 2.88 (1.27-7.77)) and operative vaginal delivery (RR = 2.88 (0.59-5.66)). In labor induction there is a stronger relative risk association between PPH and as emergency cesarean delivery (p < 0.05) as operative vaginal delivery (p < 0.05). "Two-step" delivery approach did not increase the risk of PPH with respect to operative delivery, elective caesarean section and emergency caesarean section.

Operational challenges in conducting a community-based technology-enabled mental health services delivery model for rural India: Experiences from the SMART Mental Health Project.

Science.gov (United States)

Maulik, Pallab K; Kallakuri, Sudha; Devarapalli, Siddhardha

2018-01-01

Background: There are large gaps in the delivery of mental health care in low- and middle-income countries such as India, and the problems are even more acute in rural settings due to lack of resources, remoteness, and lack of infrastructure, amongst other factors. The Systematic Medical Appraisal Referral and Treatment (SMART) Mental Health Project was conceived as a mental health services delivery model using technology-based solutions for rural India. This paper reports on the operational strategies used to facilitate the implementation of the intervention. Method: Key components of the SMART Mental Health Project included delivering an anti-stigma campaign, training of primary health workers in screening, diagnosing and managing stress, depression and increased suicide risk and task sharing of responsibilities in delivering care; and using mobile technology based electronic decision support systems to support delivery of algorithm based care for such disorders. The intervention was conducted in 42 villages across two sites in the state of Andhra Pradesh in south India. A pre-post mixed methods evaluation was done, and in this paper operational challenges are reported. Results: Both quantitative and qualitative results from the evaluation from one site covering about 5000 adults showed that the intervention was feasible and acceptable, and initial results indicated that it was beneficial in increasing access to mental health care and reducing depression and anxiety symptoms. A number of strategies were initiated in response to operational challenges to ensure smoother conduct of the project and facilitated the project to be delivered as envisaged. Conclusions: The operational strategies initiated for this project were successful in ensuring the delivery of the intervention. Those, coupled with other more systematic processes have informed the researchers to understand key processes that need to be in place to develop a more robust study, that could eventually be

Operative vaginal delivery in case of persistent occiput posterior position after manual rotation failure: a 6-month follow-up on pelvic floor function.

Science.gov (United States)

Guerby, Paul; Parant, Olivier; Chantalat, Elodie; Vayssiere, Christophe; Vidal, Fabien

2018-05-21

To compare the short- and long-term perineal consequences (at 6 months postpartum) and short-term neonatal consequences of instrumental rotation (IR) to those induced by assisted delivery (AD) in the occiput posterior (OP) position, in case of manual rotation failure. A prospective observational cohort study; tertiary referral hospital including all women presenting with persistent OP position who delivered vaginally after manual rotation failure with attempted IR or AD in OP position from September 2015 to October 2016. Maternal and neonatal outcomes of all attempted IR deliveries were compared with OP operative vaginal deliveries. Main outcomes measured were pelvic floor function at 6 months postpartum including Wexner score for anal incontinence and ICIQ-FLUTS for urinary symptoms. Perineal morbidity comprised severe perineal tears, corresponding to third and fourth degree lacerations. Fetal morbidity parameters comprised low neonatal Apgar scores, acidaemia, major and minor fetal injuries and neonatal intensive care unit admissions. Among 5265 women, 495 presented with persistent OP positions (9.4%) and 111 delivered after manual rotation failure followed by AD delivery: 58 in the IR group and 53 in the AD in OP group. The incidence of anal sphincter injuries was significantly reduced after IR attempt (1.7% vs. 24.5%; p < 0.001) without increasing neonatal morbidity. At 6 months postpartum, AD in OP position was associated with higher rate of anal incontinence (30% vs. 5.5%, p = 0.001) and with more urinary symptoms, dyspareunia and perineal pain. OP operative deliveries are associated with significant perineal morbidity and pelvic floor dysfunction at 6 months postpartum.

Effectiveness of dispersants on thick oil slicks

International Nuclear Information System (INIS)

Ross, S.; Belore, R.

1993-01-01

Experiments were conducted to determine the relationship between dispersant effectiveness and oil slick thickness, and thereby determine the optimum time for applying dispersant onto spilled oil at sea. Tests were completed at a lab-scale level by varying the three parameters of oil type, dispersant application, and oil thickness. The tests were intended to be comparative only. The primary oils used were Alberta sweet mix blend and Hibernia B-27 crude. The dispersant, Corexit 9527, was applied either premixed with the oil, dropwise in one application, or dropwise in multiple applications to simulate a multi-hit aircraft operation. The apparatus used in the experiment was an oscillating hoop tank, with oil-containing rings used to obtain and maintain uniform slick thickness. The results indicate that the effectiveness potential of a chemical dispersant does not decrease as slick thickness increases. In fact, results of the tests involving Hibernia oil suggest that oils that tend to herd easily would be treated more effectively if dispersant were applied when the oil was relatively thick (1 mm or greater) to avoid herding problems. The oil slicks premixed with dispersant did not disperse well in the thick oil tests, not because of dispersant-oil interaction problems but because of reduced mixing energy. 6 refs., 4 figs., 1 tab

X-ray fluorescence spectrometers: a comparison of wavelength and energy dispersive instruments

International Nuclear Information System (INIS)

Slates, R.V.

1977-11-01

Wavelength dispersive and energy dispersive x-ray fluorescence spectrometers are compared. Separate sections are devoted to principles of operation, sample excitation, spectral resolution, and x-ray detection. Tabulated data from the literature are cited in the comparison of accuracy, precision, and detection limits. Spectral interferences and distortions are discussed. Advantages and limitations are listed for simultaneous wavelength dispersive spectrometers, sequential wavelength dispersive spectrometers, and Si(Li) energy dispersive spectrometers. Accuracy, precision, and detection limits are generally superior for wavelength dispersive spectrometers

Preliminary report on operational guidelines developed for use in emergency preparedness and response to a radiological dispersal device incident.

Energy Technology Data Exchange (ETDEWEB)

Yu, C.; Cheng, J.-J.; Kamboj, S.; Domotor, S.; Wallo, A.; Environmental Science Division; DOE

2006-12-15

This report presents preliminary operational guidelines and supporting work products developed through the interagency Operational Guidelines Task Group (OGT). The report consolidates preliminary operational guidelines, all ancillary work products, and a companion software tool that facilitates their implementation into one reference source document. The report is intended for interim use and comment and provides the foundation for fostering future reviews of the operational guidelines and their implementation within emergency preparedness and response initiatives in the event of a radiological dispersal device (RDD) incident. The report principally focuses on the technical derivation and presentation of the operational guidelines. End-user guidance providing more details on how to apply these operational guidelines within planning and response settings is being considered and developed elsewhere. The preliminary operational guidelines are categorized into seven groups on the basis of their intended application within early, intermediate, and long-term recovery phases of emergency response. We anticipate that these operational guidelines will be updated and refined by interested government agencies in response to comments and lessons learned from their review, consideration, and trial application. This review, comment, and trial application process will facilitate the selection of a final set of operational guidelines that may be more or less inclusive of the preliminary operational guidelines presented in this report. These and updated versions of the operational guidelines will be made available through the OGT public Web site (http://ogcms.energy.gov) as they become finalized for public distribution and comment.

A remotely operated drug delivery system with dose control

KAUST Repository

Yi, Ying; Kosel, Jü rgen

2017-01-01

include an effective actuation stimulus and a controllable dose release mechanism. This work focuses on remotely powering an implantable drug delivery system and providing a high degree of control over the released dose. This is accomplished by integration

Dispersal of Sediment in the Western Adriatic during Energetic Wintertime Forcing

Science.gov (United States)

Harris, C. K.; Sherwood, C. R.; Mullenbach, B. L.; Pullen, J. D.

2003-12-01

EuroSTRATAFORM aims to relate sediment delivery and reworking to seabed morphology and stratigraphy through observations and modeling of water column transport. The Po River dominates buoyancy and sediment input into the Adriatic Sea, but small Apeninne rivers (the Chienti, Pescara, etc.) may produce locally important signals. Sedimentation is influenced by fluvial supply, resuspension by waves and currents, and transport by oceanographic currents forced by winds and buoyancy. Transport is likely highest during times of energetic forcing; including Bora events with northeasterly winds and Sirocco events with southeasterly winds. It is difficult, from field measurements alone, to characterize dispersal and convergence patterns over the relevant spatial scales. We applied a three-dimensional hydrodynamic model that includes fluvial delivery, transport, resuspension, and deposition of sediment to quantify sediment dispersal with a 2-km resolution over the entire Adriatic. Circulation calculations were driven by spatially- and temporally-varying wind fields for the Fall / Winter of 2002 / 2003 and realistic Po and Apennine river discharges. Waves were hindcast with the SWAN model. Dispersion of both resuspended and river-derived sediment was estimated for periods that contained intense Bora and Sirocco winds. Predicted sediment dispersal rates and patterns are sensitive to forcing winds, buoyancy flux, and wave patterns. Higher sediment flux was predicted during Bora conditions than during Sirocco conditions. Sirocco winds weaken the Western Adriatic Coastal Current (WACC), and because they tend to concentrate over the Eastern Adriatic, they often fail to create especially energetic waves in the Western Adriatic. Bora wind conditions, on the other hand, intensify the WACC and can build high wave energies over the northwestern Adriatic. Most of the sediment transport occurs during Bora, with a net southward flux. These predictions will be compared to field observations

Operational Marine Data Acquisition and Delivery Powered by Web and Geospatial Standards

Science.gov (United States)

Thomas, R.; Buck, J. J. H.

2015-12-01

As novel sensor types and new platforms are deployed to monitor the global oceans, the volumes of scientific and environmental data collected in the marine context are rapidly growing. In order to use these data in both the traditional operational modes and in innovative "Big Data" applications the data must be readily understood by software agents. One approach to achieving this is the application of both World Wide Web and Open Geospatial Consortium standards: namely Linked Data1 and Sensor Web Enablement2 (SWE). The British Oceanographic Data Centre (BODC) is adopting this strategy in a number of European Commission funded projects (NETMAR; SenseOCEAN; Ocean Data Interoperability Platform - ODIP; and AtlantOS) to combine its existing data archiving architecture with SWE components (such as Sensor Observation Services) and a Linked Data interface. These will evolve the data management and data transfer from a process that requires significant manual intervention to an automated operational process enabling the rapid, standards-based, ingestion and delivery of data. This poster will show the current capabilities of BODC and the status of on-going implementation of this strategy. References1. World Wide Web Consortium. (2013). Linked Data. Available:http://www.w3.org/standards/semanticweb/data. Last accessed 7th April 20152. Open Geospatial Consortium. (2014). Sensor Web Enablement (SWE). Available:http://www.opengeospatial.org/ogc/markets-technologies/swe. Last accessed 8th October 2014

Promotion of family-centered birth with gentle cesarean delivery.

Science.gov (United States)

Magee, Susanna R; Battle, Cynthia; Morton, John; Nothnagle, Melissa

2014-01-01

In this commentary we describe our experience developing a "gentle cesarean" program at a community hospital housing a family medicine residency program. The gentle cesarean technique has been popularized in recent obstetrics literature as a viable option to enhance the experience and outcomes of women and families undergoing cesarean delivery. Skin-to-skin placement of the infant in the operating room with no separation of mother and infant, reduction of extraneous noise, and initiation of breastfeeding in the operating room distinguish this technique from traditional cesarean delivery. Collaboration among family physicians, obstetricians, midwives, pediatricians, neonatologists, anesthesiologists, nurses, and operating room personnel facilitated the provision of gentle cesarean delivery to families requiring an operative birth. Among 144 gentle cesarean births performed from 2009 to 2012, complication rates were similar to or lower than those for traditional cesarean births. Gentle cesarean delivery is now standard of care at our institution. By sharing our experience, we hope to help other hospitals develop gentle cesarean programs. Family physicians should play an integral role in this process. © Copyright 2014 by the American Board of Family Medicine.

Reduction of treatment delivery variances with a computer-controlled treatment delivery system

International Nuclear Information System (INIS)

Fraass, B.A.; Lash, K.L.; Matrone, G.M.; Lichter, A.S.

1997-01-01

Purpose: To analyze treatment delivery variances for 3-D conformal therapy performed at various levels of treatment delivery automation, ranging from manual field setup to virtually complete computer-controlled treatment delivery using a computer-controlled conformal radiotherapy system. Materials and Methods: All external beam treatments performed in our department during six months of 1996 were analyzed to study treatment delivery variances versus treatment complexity. Treatments for 505 patients (40,641 individual treatment ports) on four treatment machines were studied. All treatment variances noted by treatment therapists or quality assurance reviews (39 in all) were analyzed. Machines 'M1' (CLinac (6(100))) and 'M2' (CLinac 1800) were operated in a standard manual setup mode, with no record and verify system (R/V). Machines 'M3' (CLinac 2100CD/MLC) and ''M4'' (MM50 racetrack microtron system with MLC) treated patients under the control of a computer-controlled conformal radiotherapy system (CCRS) which 1) downloads the treatment delivery plan from the planning system, 2) performs some (or all) of the machine set-up and treatment delivery for each field, 3) monitors treatment delivery, 4) records all treatment parameters, and 5) notes exceptions to the electronically-prescribed plan. Complete external computer control is not available on M3, so it uses as many CCRS features as possible, while M4 operates completely under CCRS control and performs semi-automated and automated multi-segment intensity modulated treatments. Analysis of treatment complexity was based on numbers of fields, individual segments (ports), non-axial and non-coplanar plans, multi-segment intensity modulation, and pseudo-isocentric treatments (and other plans with computer-controlled table motions). Treatment delivery time was obtained from the computerized scheduling system (for manual treatments) or from CCRS system logs. Treatment therapists rotate among the machines, so this analysis

Polymer Inclusion Membranes with Strip Dispersion

Directory of Open Access Journals (Sweden)

Yueh-Hsien Li

2017-06-01

Full Text Available The present work investigated the permeation of indium ions through a polymer inclusion membrane (PIM, prepared with cellulose triacetate (CTA as the base polymer, tris(2-butoxyethyl phosphate (TBEP as the plasticizer and di-(2-ethylhexylphosphoric acid (D2EHPA as the extractant. With 5 M HCl aqueous solution as the strip solution, we observed an initial indium permeability of 2.4 × 10−4 m/min. However, the permeability decreases with time, dropping to about 3.4 × 10−5 m/min after 200 min of operation. Evidence was obtained showing that hydrolysis of CTA occurred, causing a dramatic decrease in the feed pH (protons transported from strip to feed solutions and a loss of extractant and plasticizer from the membrane, and then leading to the loss of indium permeability. To alleviate the problem of hydrolysis, we proposed an operation scheme called polymer inclusion membranes with strip dispersion: dispersing the strip solution in extractant-containing oil and then bringing the dispersion to contact with the polymer membrane. Since the strong acid was dispersed in oil, the membrane did not directly contact the strong acid at all times, and membrane hydrolysis was thus alleviated and the loss of indium permeability was effectively prevented. With the proposed scheme, a stable indium permeability of 2.5 × 10−4 m/min was obtained during the whole time period of the permeation experiment.

The effectiveness of mediolateral episiotomy in preventing obstetric anal sphincter injuries during operative vaginal delivery: a ten-year analysis of a national registry.

Science.gov (United States)

van Bavel, Jeroen; Hukkelhoven, Chantal W P M; de Vries, Charlotte; Papatsonis, Dimitri N M; de Vogel, Joey; Roovers, Jan-Paul W R; Mol, Ben Willem; de Leeuw, Jan Willem

2018-03-01

Obstetric anal sphincter injuries (OASIS) are associated with an increased risk of faecal incontinence after vaginal delivery. The aim of this retrospective population-based cohort study was to assess whether mediolateral episiotomy is associated with a reduction in the rate of OASIS during operative vaginal delivery. We used data from the Dutch Perinatal Registry (Perined) that includes records of almost all births between 2000 and 2010 in The Netherlands. In a cohort of 170,969 primiparous and multiparous women whose delivery was recorded, we estimated the association between mediolateral episiotomy and OASIS following both vacuum and forceps deliveries using univariate and multivariate logistic regression analysis. The incidences of OASIS following vacuum delivery in 130,157 primiparous women were 2.5% and 14% in those with and without a mediolateral episiotomy, respectively (adjusted OR 0.14, 95% CI 0.13-0.15), and in 29,183 multiparous women were 2.0% and 7.5%, respectively (adjusted OR 0.23, 95% CI 0.21-0.27). The incidences of OASIS following forceps delivery in 9,855 primiparous women were 3.4% and 26.7% in those with and without a mediolateral episiotomy, respectively (adjusted OR 0.09, 95% CI 0.07-0.11), and in 1,774 multiparous women were 2.6% and 14.2%, respectively (adjusted OR 0.13, 95% CI 0.08-0.22). The use of a mediolateral episiotomy during both vacuum delivery and forceps delivery is associated with a fivefold to tenfold reduction in the rate of OASIS in primiparous and multiparous women.

Spectral phase shift and residual angular dispersion of an accousto-optic programme dispersive filter

International Nuclear Information System (INIS)

Boerzsoenyi, A.; Meroe, M.

2010-01-01

, respectively). In case of continuous mode operation of the AOPDF, the angular deviation and angular dispersion was found to vary more than 0.15 mrad and 1 mrad/μm when the GDD was changed from 0 fs 2 to ± 10 4 fs 2 . This effect is attributed to thermally induced refractive index gradient in the acousto-optical crystal caused by the dissipated acoustic power. In low repetition rate triggered mode, however, this phenomenon was experimentally negligible. In all cases the angular dispersion had actually a non-zero offset value of 0.5 μrad/nm, but this is practically negligible in almost every case of use.

Melt dispersion granules: formulation and evaluation to improve oral delivery of poorly soluble drugs - a case study with valsartan.

Science.gov (United States)

Chella, Naveen; Tadikonda, Ramarao

2015-06-01

Solid dispersion (SD) technique is a promising strategy to improve the solubility and dissolution of BCS class II drugs. However, only few products are marketed till today based on SD technology due to poor flow properties and stability. The present work was intended to solve these problems by using combination approach, melt dispersion and surface adsorption technologies. The main aim of the present work is to improve the absorption in the stomach (at lower pH) where the absorption window exists for the drug by improving the dissolution, resulting in the enhancement of oral bioavailability of poorly soluble, weakly acidic drug with pH dependant solubility, i.e. valsartan. Melt dispersion granules were prepared in different ratios using different carriers (Gelucire 50/13, PEG 8000 and Pluronic F-68) and lactose as an adsorbent. Similarly, physical mixtures were also prepared at corresponding ratios. The prepared dispersion granules and physical mixtures were characterized by FTIR, DSC and in vitro dissolution studies. DSC studies revealed reduction in the crystallinity with a possibility of presence of amorphous character of drug in the dispersion granules. From dissolution studies, valsartan Gelucire dispersion (GSD4; 1:4 ratio) showed complete drug release in 30 min against the plain drug which showed only 11.31% of drug release in 30 min. Pharmacokinetic studies of optimized formulation in male Wistar rats showed 2.65-fold higher bioavailability and 1.47-fold higher Cmax compared to pure drug. The melt dispersion technology has the potential to improve dissolution and the bioavailability of BCS class II drugs.

Operations management in health care.

Science.gov (United States)

Henderson, M D

1995-01-01

Health care operations encompass the totality of those health care functions that allow those who practice health care delivery to do so. As the health care industry undergoes dramatic reform, so will the jobs of those who manage health care delivery systems. Although health care operations managers play one of the most vital and substantial roles in the new delivery system, the criteria for their success (or failure) are being defined now. Yet, the new and vital role of the operations manager has been stunted in its development, which is primarily because of old and outdated antipathy between hospital administrators and physicians. This article defines the skills and characteristics of today's health care operations managers.

Silica hollow core microstructured fibers for beam delivery in industrial and medical applications

Directory of Open Access Journals (Sweden)

Jonathan Dale Shephard

2015-04-01

Full Text Available The focus of this review is our recent work to develop microstructured hollow core fibers for two applications where the flexible delivery of a single mode beam is desired. Also, a review of other fiber based solutions is included.High power, short-pulsed lasers are widely used for micro-machining, providing high precision and high quality. However, the lack of truly flexible beam delivery systems limits their application to the processing of relatively small planar components. To address this, we developed hollow-core optical fibers for the 1 μm and green wavelength ranges. The hollow core overcomes the power delivery limitations of conventional silica fibers arising from nonlinear effects and material damage in the solid core. We have characterized such fibers in terms of power handling capability, damage threshold, bend loss and dispersion, and practically demonstrated delivery of high peak power pulses from the nanosecond to the femtosecond regime. Such fibers are ideal candidates for industrial laser machining applications.In laser surgical applications, meanwhile, an Er:YAG laser (2.94 μm is frequently the laser of choice because the water contained in tissue strongly absorbs this wavelength. If this laser beam is precisely delivered damage to surrounding tissue can be minimized. A common delivery method of surgical lasers, for use in the operating theatre, is articulated arms that are bulky, cumbersome and unsuitable for endoscopic procedures. To address this need for flexible mid-IR delivery we developed silica based hollow core fibers. By minimizing the overlap of the light with glass it is possible to overcome the material absorption limits of silica and achieve low attenuation. Additionally, it is possible to deliver pulse energies suitable for the ablation of both hard and soft tissue even with very small bend radii. The flexibility and small physical size of systems based on these fibers will enable new minimally invasive surgical

A study of factors influencing surgical cesarean delivery times in an academic tertiary center.

Science.gov (United States)

Gonzalez Fiol, A; Meng, M-L; Danhakl, V; Kim, M; Miller, R; Smiley, R

2018-05-01

Knowledge of hospital-specific average cesarean delivery operative times, and factors influencing length of surgery, can serve as a guide for anesthesiologists when choosing the optimal anesthetic technique. The aim of this study was to determine operative times and the factors influencing those times for cesarean delivery. We conducted a retrospective review of all 1348 cesarean deliveries performed at an academic hospital in 2011. The primary outcome was mean operative time for first, second, third and fourth or more cesarean deliveries. The secondary goal was to identify factors influencing operative time. Variables included age, body mass index, previous surgery, gestational age, urgency of cesarean delivery, anesthesia type, surgeon's seniority, layers closed, and performance of tubal ligation. Mean (standard deviation) operative times for first (n=857), second (n=353), third (n=108) and fourth or more (n=30) cesarean deliveries were 56 (19), 60 (19), 69 (28) and 82 (31) minutes, respectively (P cesarean delivery or the presence of other factors that could increase operative time may warrant catheter-based anesthetic techniques or the addition of adjunctive medications to prolong spinal anesthetic block. Institutional and individual surgeon factors may play an even more important role in determining surgical time. Copyright © 2018 Elsevier Ltd. All rights reserved.

Interlibrary loan and document delivery best practices for operating and managing interlibrary loan services in all libraries

CERN Document Server

Hilyer, Lee Andrew

2013-01-01

A must-have for librarians and their staffs working at all levels?from beginner to expertInterlibrary Loan and Document Delivery is a how-to guide to organizing an interlibrary loan department, providing extensive content on copyright law, ILL management systems, and human resources. This comprehensive book includes an introduction to ILL operations, governing policies, up-to-date information on borrowing and lending, and considerations for medicals libraries and distance learning. It also includes an extensive listing of resources relevant to today's ILL that serves as a handy des

Information delivery in team communication of MCR operators for an emergency task

Energy Technology Data Exchange (ETDEWEB)

Jeong, Kwang Sub; Park, Jin Kyun; Jung, Won Dae

2005-01-01

Team performance is a major measure to evaluate the ability of team when a lot of people perform a task of common purpose such as the main control room operators in the nuclear power plant. A team performance is affected the collaboration and communication among operators under dynamic situation as well as by the cognitive process of each team member. Specially, under the emergency situation, more clear and apparent communication in a team is a critical key for the appropriate response to emergency situation. As a general human factor analysis accesses the operator's behavior, it leads to a resulting action of planning, decision, problem-solving. In order to access the internal information and background information of his/her behavior, the verbal protocol analysis is applied. The impact factors on the team performance are derived from the state of the art for team performance, and it is found that the communication is a common key for all impact factors. And, in turn, the impact factors for the communication are accesses and the more detailed analysis is performed. The recorded data for the operator training for emergency situation of nuclear power plant training center are analyzed according to the verbal protocol analysis that are being generally utilized in cognitive psychology, educational psychology, and cognitive science. Two aspects, external (syntax) and internal (symantic) aspects of communication are reviewed. From the syntax analysis, it is found that the task of each step in EOP is separated according to each corresponding operator and the ordinary training is important, and the weak-points for a sentence presentation can be found team-by-team. And, from the symantic analysis for the diagnostic procedure of EOP is performed and the communication errors due to different situation awareness by operators could be found, and it lead to a diagnosis failure. The factors for different symantic cognition for a situation are analyzed and the affecting

Deepwater Horizon MC252 response operations data from the Environmental Response Management Application (ERMA) containing dispersant operations and related data collected during the DWH response between 2010-04-22 to 2010-07-19 in the Northern Gulf of Mexico (NCEI Accession 0163801)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This Archival Information Package (AIP) contains Environmental Resource Management Application (ERMA) GIS layers that represent dispersant operation datasets...

Dispersive-cavity actively mode-locked fiber laser for stable radio frequency delivery

International Nuclear Information System (INIS)

Dai, Yitang; Wang, Ruixin; Yin, Feifei; Xu, Kun; Li, Jianqiang; Lin, Jintong

2013-01-01

We report a novel technique for highly stable transfer of a radio frequency (RF) comb over long optical fiber link, which is highly dispersive and is a part of an actively mode-locked fiber laser. Phase fluctuation along the fiber link, which is mainly induced by physical vibration and temperature fluctuations, is automatically compensated by the self-adapted wavelength shifting. Without phase-locking loop or any tunable parts, stable radio frequency is transferred over a 2-km fiber link, with a time jitter suppression ratio larger than 110. (letter)

High dispersity of carbon nanotubes diminishes immunotoxicity in spleen.

Science.gov (United States)

Lee, Soyoung; Khang, Dongwoo; Kim, Sang-Hyun

2015-01-01

From the various physiochemical material properties, the chemical functionalization order of single-walled carbon nanotubes (swCNTs) has not been considered as a critical factor for modulating immunological responses and toxicological aspects in drug delivery applications. Although most nanomaterials, including carbon nanotubes, are specifically accumulated in spleen, few studies have focused on spleen immunotoxicity. For this reason, this study demonstrated that the dispersity of swCNTs significantly influenced immunotoxicity in vitro and in vivo. For cytotoxicity of swCNTs, MTT assay, reactive oxygen species production, superoxide dismutase activity, cellular uptake, and confocal microscopy were used in macrophages. In the in vivo study, female BALB/c mice were intravenously administered with 1 mg/kg/day of swCNTs for 2 weeks. The body weight, organ weight, hematological change, reverse-transcription polymerase chain reaction, and lymphocyte population were evaluated. Different orders of chemical functionalization of swCNTs controlled immunotoxicity. In short, less-dispersed swCNTs caused cytotoxicity in macrophages and abnormalities in immune organs such as spleen, whereas highly dispersed swCNTs did not result in immunotoxicity. This study clarified that increasing carboxyl groups on swCNTs significantly mitigated immunotoxicity in vitro and in vivo. Our findings clarified the effective immunotoxicological factors of swCNTs by increasing dispersity of swCNTs and provided useful guidelines for the effective use of nanomaterials.

Dispersion of nanoparticulate suspensions using self-assembled surfactant aggregates

Science.gov (United States)

Singh, Pankaj Kumar

The dispersion of particles is critical for several industrial applications such as paints, inks, coatings, and cosmetics. Several emerging applications such as abrasives for precision polishing, and drug delivery systems are increasingly relying on nanoparticulates to achieve the desired performance. In the case of nanoparticles, the dispersion becomes more challenging because of the lack of fundamental understanding of dispersant adsorption and interparticle force prediction. Additionally, many of these processes use severe processing environments such as high normal forces (>100 mN/m), high shear forces (>10,000 s -1), and high ionic strengths (>0.1 M). Under such processing conditions, traditionally used dispersants based on electrostatics, and steric force repulsion mechanism may not be adequate. Hence, the development of optimally performing dispersants requires a fundamental understanding of the dispersion mechanism at the atomic/molecular scale. This study explores the use of self-assembled surfactant aggregates at the solid-liquid interface for dispersing nanoparticles in severe processing environments. Surfactant molecules can provide a feasible alternative to polymeric or inorganic dispersants for stabilizing ultrafine particles. The barrier to aggregation in the presence of surfactant molecules was measured using atomic force microscopy. The barrier heights correlated to suspension stability. To understand the mechanism for nanoparticulate suspension stability in the presence of surfactant films, the interface was characterized using zeta potential, contact angle, adsorption, and FT-IR (adsorbed surfactant film structure measurements). The effect of solution conditions such as pH and ionic strength on the suspension stability, and the self-assembled surfactant films was also investigated. It was determined that a transition from a random to an ordered orientation of the surfactant molecules at the interface was responsible for stability of

Experimental Measurements of Temporal Dispersion for Underwater Laser Communications and Imaging

Science.gov (United States)

Cochenour, Brandon Michael

The challenge in implementing optical sensors underwater lies in the high variability of the ocean environment where propagation of light in the ocean is complicated by absorption and scattering. Most underwater optical sensors operate in the blue/green portion of the electromagnetic spectrum where seawater exhibits an absorption minimum. Mitigating scattering however is a greater challenge. In particular, scattering causes both spatial distortion (beam spreading) and temporal dispersion (pulse spreading or distortion). Each of type of dispersion decreases sensor performance (operating range, image resolution, data bandwidth, etc.). While spatial dispersion has received a great deal of attention in previous decades, technological limitations of sensor hardware have made experimental measurements of temporal dispersion underwater difficult until now. The main contribution of this thesis are experimental measurements of temporal dispersion of optical beams in turbid water, made with a high sensitivity/high dynamic range experimental technique. Measurements are performed as a function of water clarity (0-20 attenuation lengths), transmitter/receiver alignment (0-30 degrees, half angle), receiver field of view (1-7 degrees, full angle), and transmitter beam divergence (collimated and diffuse). Special attention is paid to the interdependency between spatial and temporal dispersion. This work provides severable notable contributions: 1. While experimental characterization of spatial dispersion has received significant attention underwater, there has been a lack of measurements characterizing temporal dispersion underwater. This work provides the most comprehensive set of experimental measurements to date regarding the temporal dispersion of optical beams underwater. 2. An experimental analysis of the influence of scattering phase function on temporal dispersion. Coarse estimates of the scattering phase function are used to determine the ranges (or attenuation lengths

Spatially Dispersed Employee Recovery

DEFF Research Database (Denmark)

Hvass, Kristian Anders; Torfadóttir, Embla

2014-01-01

Employee recovery addresses either employee well-being or management's practices in aiding employees in recovering themselves following a service failure. This paper surveys the cabin crew at a small, European, low-cost carrier and investigates employees' perceptions of management practices to aid...... personnel achieve service recovery. Employee recovery within service research often focuses on front-line employees that work in a fixed location, however a contribution to the field is made by investigating the recovery of spatially dispersed personnel, such as operational personnel in the transport sector......, who have a work place away from a fixed or central location and have minimal management contact. Results suggest that the support employees receive from management, such as recognition, information sharing, training, and strategic awareness are all important for spatially dispersed front...

Comment on “Frequency-dependent dispersion in porous media”

KAUST Repository

Davit, Yohan

2012-07-10

In a recent paper, Valdès-Parada and Alvarez-Ramirez used the technique of volume averaging to derive a "frequency-dependent" dispersion tensor, Dγ*, the goal of which is to describe solute transport in porous media undergoing periodic processes. We describe two issues related to this dispersion tensor. First, we demonstrate that the definition of Dγ* is erroneous and derive a corrected version, Dγ*c. With this modification, the approach of Valdès-Parada and Alvarez-Ramirez becomes strictly equivalent to the one devised by Moyne. Second, we show that the term "frequency-dependent dispersion" is misleading because Dγ* and Dγ*c do not depend on the process operating frequency, χ. The study carried out by Valdès-Parada and Alvarez-Ramirez represents a spectral analysis of the relaxation of Dγ* towards its steady-state, independent of any periodic operation or excitation. © 2012 American Physical Society.

A remotely operated drug delivery system with dose control

KAUST Repository

Yi, Ying

2017-05-08

“On demand” implantable drug delivery systems can provide optimized treatments, due to their ability to provide targeted, flexible and precise dose release. However, two important issues that need to be carefully considered in a mature device include an effective actuation stimulus and a controllable dose release mechanism. This work focuses on remotely powering an implantable drug delivery system and providing a high degree of control over the released dose. This is accomplished by integration of a resonance-based wireless power transfer system, a constant voltage control circuit and an electrolytic pump. Upon the activation of the wireless power transfer system, the electrolytic actuator is remotely powered by a constant voltage regardless of movements of the device within an effective range of translation and rotation. This in turn contributes to a predictable dose release rate and greater flexibility in the positioning of external powering source. We have conducted proof-of-concept drug delivery studies using the liquid drug in reservoir approach and the solid drug in reservoir approach, respectively. Our experimental results demonstrate that the range of flow rate is mainly determined by the voltage controlled with a Zener diode and the resistance of the implantable device. The latter can be adjusted by connecting different resistors, providing control over the flow rate to meet different clinical needs. The flow rate can be maintained at a constant level within the effective movement range. When using a solid drug substitute with a low solubility, solvent blue 38, the dose release can be kept at 2.36μg/cycle within the effective movement range by using an input voltage of 10Vpp and a load of 1.5 kΩ, which indicates the feasibility and controllability of our system without any complicated closed-loop sensor.

Efficiency and economics of hydrogen delivery

International Nuclear Information System (INIS)

Liu, Y.; Bharadwaj, R.; Balan, C.; Garces, L.; Smith, D.

2003-01-01

The viability and penetration of fuel cell based electricity production will be mainly determined by the efficient, cost effective production and delivery of hydrogen. This study focuses on the transportation efficiency and cost of hydrogen delivery for both centrally produced hydrogen as well as electricity scenarios. The efficiency and economics of energy delivery depend on the quantity of energy to be transported and transportation distance. Energy delivery models were developed for Hydrogen delivery as compressed gas or cryogenic liquid using truck or pipeline. For comparison, models were also developed for high voltage AC electricity transmission. Major parameters that influence the performance of the energy transmission systems under normal operating conditions were modeled. The models use energy transported and delivery distance as independent variables. The results were validated against similar reports, government surveys and other publications. Energy delivery efficiency and costs were used to compare and evaluate the different delivery options. Effect of uncertainty and sensitivity of parameters on modeling results were also studied. The systems were compared on an equivalent basis. The analysis also identifies the trade-offs for electricity transmission and electrolysis application at the point of use for Hydrogen delivery. These results provide a consistent framework for evaluation of delivery options on energy efficiency basis. (author)

Quantifying sediment-associated metal dispersal using Pb isotopes: Application of binary and multivariate mixing models at the catchment-scale

International Nuclear Information System (INIS)

Bird, Graham; Brewer, Paul A.; Macklin, Mark G.; Nikolova, Mariyana; Kotsev, Tsvetan; Mollov, Mihail; Swain, Catherine

2010-01-01

In this study Pb isotope signatures were used to identify the provenance of contaminant metals and establish patterns of downstream sediment dispersal within the River Maritsa catchment, which is impacted by the mining of polymetallic ores. A two-fold modelling approach was undertaken to quantify sediment-associated metal delivery to the Maritsa catchment; employing binary mixing models in tributary systems and a composite fingerprinting and mixing model approach in the wider Maritsa catchment. Composite fingerprints were determined using Pb isotopic and multi-element geochemical data to characterize sediments delivered from tributary catchments. Application of a mixing model allowed a quantification of the percentage contribution of tributary catchments to the sediment load of the River Maritsa. Sediment delivery from tributaries directly affected by mining activity contributes 42-63% to the sediment load of the River Maritsa, with best-fit regression relationships indicating that sediments originating from mining-affected tributaries are being dispersed over 200 km downstream. - Pb isotopic evidence used to quantify sediment-associated metal delivery within a mining-affected river catchment.

Flexible power delivery system and its intelligent functions

International Nuclear Information System (INIS)

Glamochanin, Vlastimir; Andonov, Dragan

1996-01-01

This paper presents some of the features and capabilities of the novel energy distribution system called FRIENDS. The main FRIENDS objective is distribution system reliability, with flexible system structure reconfiguration, inclusion of dispersed energy generation systems. Altogether, it represents a new concept of reliable and economic electric power delivery to end users. The FRIENDS project is a challenge for future research and development, including new technology and devices for the implementation of such an integrated system. (author)

Evaluation of twin-head electrospray nanoparticle disperser for nanotoxicity study

Science.gov (United States)

Liu, Qiaoling; Budiman, Thomas; Chen, Da-Ren

2014-08-01

With the rapid development of nanotechnology, nanoparticles with various sizes and compositions have been synthesized and proposed for industrial applications. At the same time, the health effects and environmental impacts of nanoparticles become an emerging concern to be addressed. Both in vitro and in vivo studies are of importance to better understand the toxicity of nanoparticles. It is thus essential to have a nanoparticle disperser capable of dispersing individual nanoparticles for these studies. A twin-head electrospray (THES) nanoparticle disperser for animal inhalation exposure studies has recently become commercially available from TSE Systems Inc. Different from the cone-jet electrospray method used in the majority of literature, this particular disperser operates at the multi-jet mode. In this study, we reported our finding on the performance evaluation of the THES disperser with respect to its mass throughput and quality of size distribution of aerosol produced. Three different nanomaterials (TiO2, ZnO, and NiO) were used in this study. It is found that the maximal mass throughput of the studied disperser was achieved by keeping the distance between two opposite spray capillary tips at 3.0 cm, operating the primary carrier-to-capillary sheath flow rates at the ratio of 4:3, and feeding spray suspensions at a flow rate of 20 µl/min. Under the above settings and operations, the highest mass concentration for nano-ZnO was measured at 14.56 mg/m3. Nanoparticle streams with higher concentrations can be further produced by lowering the total carrier gas flow rate and spraying suspensions of higher nanomaterial concentrations. Our study also found that the particle mass throughput of the studied disperser had a good linear relationship with the mass concentration of spray suspension. In addition, the spatial uniformity of nano aerosol distribution in a TSE head-nose-only exposure chamber was investigated. An acceptable nano aerosol uniformity result was

Photo-redox activated drug delivery systems operating under two photon excitation in the near-IR.

Science.gov (United States)

Guardado-Alvarez, Tania M; Devi, Lekshmi Sudha; Vabre, Jean-Marie; Pecorelli, Travis A; Schwartz, Benjamin J; Durand, Jean-Olivier; Mongin, Olivier; Blanchard-Desce, Mireille; Zink, Jeffrey I

2014-05-07

We report the design and synthesis of a nano-container consisting of mesoporous silica nanoparticles with the pore openings covered by "snap-top" caps that are opened by near-IR light. A photo transducer molecule that is a reducing agent in an excited electronic state is covalently attached to the system. Near IR two-photon excitation causes inter-molecular electron transfer that reduces a disulfide bond holding the cap in place, thus allowing the cargo molecules to escape. We describe the operation of the "snap-top" release mechanism by both one- and two-photon activation. This system presents a proof of concept of a near-IR photoredox-induced nanoparticle delivery system that may lead to a new type of photodynamic drug release therapy.

Influence of lipid composition and drug load on the in vitro performance of self-nanoemulsifying drug delivery systems

DEFF Research Database (Denmark)

Thomas, Nicky; Müllertz, Anette; Graf, Anja

2012-01-01

The influence of lipid composition and drug load on the in vitro performance of lipid-based drug delivery systems was investigated during dispersion and in vitro lipolysis of two self-nanoemulsifying drug delivery systems (SNEDDS). SNEDDS preconcentrates consisted of the same mass ratios of lipid...... of SNEDDS. © 2012 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 101:1721–1731, 2012...

The impact of treatment complexity and computer-control delivery technology on treatment delivery errors

International Nuclear Information System (INIS)

Fraass, Benedick A.; Lash, Kathy L.; Matrone, Gwynne M.; Volkman, Susan K.; McShan, Daniel L.; Kessler, Marc L.; Lichter, Allen S.

1998-01-01

Purpose: To analyze treatment delivery errors for three-dimensional (3D) conformal therapy performed at various levels of treatment delivery automation and complexity, ranging from manual field setup to virtually complete computer-controlled treatment delivery using a computer-controlled conformal radiotherapy system (CCRS). Methods and Materials: All treatment delivery errors which occurred in our department during a 15-month period were analyzed. Approximately 34,000 treatment sessions (114,000 individual treatment segments [ports]) on four treatment machines were studied. All treatment delivery errors logged by treatment therapists or quality assurance reviews (152 in all) were analyzed. Machines 'M1' and 'M2' were operated in a standard manual setup mode, with no record and verify system (R/V). MLC machines 'M3' and 'M4' treated patients under the control of the CCRS system, which (1) downloads the treatment delivery plan from the planning system; (2) performs some (or all) of the machine set up and treatment delivery for each field; (3) monitors treatment delivery; (4) records all treatment parameters; and (5) notes exceptions to the electronically-prescribed plan. Complete external computer control is not available on M3; therefore, it uses as many CCRS features as possible, while M4 operates completely under CCRS control and performs semi-automated and automated multi-segment intensity modulated treatments. Analysis of treatment complexity was based on numbers of fields, individual segments, nonaxial and noncoplanar plans, multisegment intensity modulation, and pseudoisocentric treatments studied for a 6-month period (505 patients) concurrent with the period in which the delivery errors were obtained. Treatment delivery time was obtained from the computerized scheduling system (for manual treatments) or from CCRS system logs. Treatment therapists rotate among the machines; therefore, this analysis does not depend on fixed therapist staff on particular

Fleet DNA: Commercial Fleet Vehicle Operating Data | Transportation

Science.gov (United States)

Charts Related Studies Learn more about the operation of delivery vans through these studies. Hydraulic beverage delivery trucks ranging in size from class 3 to class 7 with primary vocations of delivering Charts Related Studies Learn more about the operation of delivery trucks through these studies. In-Use

Atmospheric dispersion of radionuclides released by a nuclear plant

International Nuclear Information System (INIS)

Barboza, A.A.

1989-01-01

A numerical model has been developed to simulate the atmospheric dispersion of radionuclides released by a nuclear plant operating under normal conditions. The model, based on gaussian plume representation, accouts for and evaluates several factors which affect the concentraction of effluents in the atmosphere, such as: ressuspension, deposition, radioactive decay, energy and type of the radiation emitted, among others. The concentraction of effluents in the atmosphere is calculated for a uniform mesh of points around the plant, allowing the equivalent doses to be then evaluated. Simulations of the atmosphere dispersion of radioactive plumes of Cs 137 and Ar 41 have been performed assuming a constant rate of release, as expected from the normal operation of a nuclear plant. Finally, this work analyzes the equivalent doses at ground level due to the dispersion of Cs 137 and Ar 41 , accumulated over one year and determines the isodose curves for a hypothetical site. (author) [pt

Surface modification of graphene oxide nanosheets by protamine sulfate/sodium alginate for anti-cancer drug delivery application

Science.gov (United States)

Xie, Meng; Zhang, Feng; Liu, Lijiao; Zhang, Yanan; Li, Yeping; Li, Huaming; Xie, Jimin

2018-05-01

In order to improve the efficiency of anticancer drug delivery, a graphene oxide (GO) based drug delivery system modificated by natural peptide protamine sulfate (PRM) and sodium alginate (SA) was established via electrostatic attraction at each step of adsorption based on layer-by-layer self-assembly. The nanocomposites were then loaded with anticancer drug doxorubicin hydrochloride (DOX) to estimate the feasibility as drug carriers. The nanocomposites loaded with DOX revealed a remarkable pH-sensitive drug release property. The modification with protamine sulfate and sodium alginate could not only impart the nanocomposites an improved dispersibility and stability under physiological pH, but also suppress the protein adhesion. Due to the high water dispersibility and the small particle size, GO-PRM/SA nanocomposites were able to be uptaken by MCF-7 cells. It was found that GO-PRM/SA nanocomposites exhibited no obvious cytotoxicity towards MCF-7 cells, while GO-PRM/SA-DOX exhibited better cytotoxicity than GO-DOX. Therefore, the GO-PRM/SA nanocomposites were feasible as drug delivery vehicles.

Dissecting the structure of surface stabilizer on the dispersion of inorganic nanoparticles in aqueous medium

Energy Technology Data Exchange (ETDEWEB)

Ding, Yong; Yu, Zongzhi; Zheng, Junping, E-mail: jpzheng@tju.edu.cn [Tianjin University, Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering (China)

2017-03-15

Dispersing inorganic nanoparticles in aqueous solutions is a key requirement for a great variety of products and processes, including carriers in drug delivery or fillers in polymers. To be highly functional in the final product, inorganic particles are required to be finely dispersed in nanoscale. In this study, silica was selected as a representative inorganic particle. Surface stabilizers with different chain length and charged group were designed to reveal the influence of electrostatic and van der Waals forces between silica and stabilizer on the dispersion of silica particles in aqueous medium. Results showed surface stabilizer with longer alkyl chain and charged group exerted best ability to deaggregate silica, leading to a hydrodynamic size of 51.1 nm. Surface stabilizer designing with rational structure is a promising solution for deagglomerating and reducing process time and energy. Giving the designability and adaptability of surface stabilizer, this method is of potential for dispersion of other inorganic nanoparticles.

Dissecting the structure of surface stabilizer on the dispersion of inorganic nanoparticles in aqueous medium

Science.gov (United States)

Ding, Yong; Yu, Zongzhi; Zheng, Junping

2017-03-01

Dispersing inorganic nanoparticles in aqueous solutions is a key requirement for a great variety of products and processes, including carriers in drug delivery or fillers in polymers. To be highly functional in the final product, inorganic particles are required to be finely dispersed in nanoscale. In this study, silica was selected as a representative inorganic particle. Surface stabilizers with different chain length and charged group were designed to reveal the influence of electrostatic and van der Waals forces between silica and stabilizer on the dispersion of silica particles in aqueous medium. Results showed surface stabilizer with longer alkyl chain and charged group exerted best ability to deaggregate silica, leading to a hydrodynamic size of 51.1 nm. Surface stabilizer designing with rational structure is a promising solution for deagglomerating and reducing process time and energy. Giving the designability and adaptability of surface stabilizer, this method is of potential for dispersion of other inorganic nanoparticles.

Elective cesarean delivery for term breech

DEFF Research Database (Denmark)

Krebs, Lone; Langhoff-Roos, Jens

2003-01-01

and anemia (RR 0.91; 95% CI 0.84, 0.97), and operations for wound infection (RR 0.69; 95% CI 0.57, 0.83) than emergency cesarean delivery. There was a higher rate of puerperal fever and pelvic infection (RR 1.20; 95% CI 1.11, 1.25) than for vaginal delivery. Thromboembolic disease occurred in 0.1% of women......OBJECTIVE: To compare the maternal complications of elective cesarean delivery for breech at term with those after vaginal or emergency cesarean delivery. METHODS: We conducted a population-based, retrospective cohort study of 15441 primiparas who delivered singleton breech at term. Information...... was obtained from the Danish Medical Birth Register, the Register of Death Causes, and the Denmark Patient Register. RESULTS: Elective cesarean delivery was associated with lower rates of puerperal fever and pelvic infection (relative risk [RR] 0.81; 95% confidence interval [CI] 0.70, 0.92), hemorrhage...

Comparison of CFD and operational dispersion models in an urban-like environment

NARCIS (Netherlands)

Antonioni, G.; Burkhart, S.; Burman, J.; Dejoan, A.; Fusco, A.; Gaasbeek, R.; Gjesdal, T.; Jäppinen, A.; Riikonen, K.; Morra, P.; Parmhed, O.; Santiago, J.L.

2012-01-01

Chemical plants, refineries, transportation of hazardous materials are some of the most attractive facilities for external attacks aimed at the release of toxic substances. Dispersion of these substances into the atmosphere forms a concentration distribution of airborne pollutants with severe

Auditing Information System : Delivery Product Service

Directory of Open Access Journals (Sweden)

Purwoko Purwoko

2011-05-01

Full Text Available Purpose of the research is to ensure the securities of information system asset and to ensure if informa-tion system support the operational and data collected was valid. Research method that used in this research were library studies and field studies. Field studies such an observation, questioner, and inter-view. the expected result are founding the weakness of security management control, operational man-agement control, input control, and output control of risk happened in the company. Conclusion of this research are the system on the company work good and there’s no potential risk happened and make an impact to the delivery process of information system.Index Terms - Auditing Information system, Delivery product process.

Postpartum urinary tract infection by mode of delivery: a Danish nationwide cohort study.

Science.gov (United States)

Gundersen, Tina Djernis; Krebs, Lone; Loekkegaard, Ellen Christine Leth; Rasmussen, Steen Christian; Glavind, Julie; Clausen, Tine Dalsgaard

2018-03-14

To examine the association between postpartum urinary tract infection and intended mode of delivery as well as actual mode of delivery. Retrospective cohort study. All live births in Denmark between 2004 and 2010 (n=450 856). Births were classified by intended caesarean delivery (n=45 053) or intended vaginal delivery (n=405 803), and by actual mode of delivery: spontaneous vaginal delivery, operative vaginal delivery, emergency or planned caesarean delivery in labour or prelabour. The primary outcome measure was postpartum urinary tract infection (n=16 295) within 30 days post partum, defined as either a diagnosis of urinary tract infection in the National Patient Registry or redemption of urinary tract infection-specific antibiotics recorded in the Register of Medicinal Product Statistics. We found that 4.6% of women with intended caesarean delivery and 3.5% of women with intended vaginal delivery were treated for postpartum urinary tract infection.Women with intended caesarean delivery had a significantly increased risk of postpartum urinary tract infection compared with women with intended vaginal delivery (OR 1.33, 95% CI 1.27 to 1.40), after adjustment for age at delivery, smoking, body mass index, educational level, gestational diabetes mellitus, infection during pregnancy, birth weight, preterm delivery, preterm prelabour rupture of membranes, pre-eclampsia, parity and previous caesarean delivery (adjusted OR 1.24, 95% CI 1.17 to 1.46).Using actual mode of delivery as exposure, all types of operative delivery had an equally increased risk of postpartum urinary tract infection compared with spontaneous vaginal delivery. Compared with intended vaginal delivery, intended caesarean delivery was significantly associated with a higher risk of postpartum urinary tract infection. Future studies should focus on reducing routine catheterisation prior to operative vaginal delivery as well as improving procedures related to catheterisation. © Article author

Filled carbon nanotubes in biomedical imaging and drug delivery.

Science.gov (United States)

Martincic, Markus; Tobias, Gerard

2015-04-01

Carbon nanotubes have been advocated as promising candidates in the biomedical field in the areas of diagnosis and therapy. In terms of drug delivery, the use of carbon nanotubes can overcome some limitations of 'free' drugs by improving the formulation of poorly water-soluble drugs, allowing targeted delivery and even enabling the co-delivery of two or more drugs for combination therapy. Two different approaches are currently being explored for the delivery of diagnostic and therapeutic agents by carbon nanotubes, namely attachment of the payload to the external sidewalls or encapsulation into the inner cavities. Although less explored, the latter confers additional stability to the chosen diagnostic or therapeutic agents, and leaves the backbone structure of the nanotubes available for its functionalization with dispersing and targeting moieties. Several drug delivery systems and diagnostic agents have been developed in the last years employing the inner tubular cavities of carbon nanotubes. The research discussed in this review focuses on the use of carbon nanotubes that contain in their interior drug molecules and diagnosis-related compounds. The approaches employed for the development of such nanoscale vehicles along with targeting and releasing strategies are discussed. The encapsulation of both biomedical contrast agents and drugs inside carbon nanotubes is further expanding the possibilities to allow an early diagnosis and treatment of diseases.

Do oil dispersants make spilled oil more toxic to fish?

International Nuclear Information System (INIS)

Hodson, P.

2010-01-01

The Deepwater Horizon blowout in the Gulf of Mexico was the world's largest oil spill in terms of duration and volume spilled. Clean-up operations, which involved the continuous and wide-spread use of oil dispersant at the surface and at the seabed discharge point at 1500 metres depth, gave rise to public concern about dispersant toxicity. Reports from the United States Environmental Protection Agency (EPA) claimed little difference in acute toxicity to marine fish and invertebrate species among commonly available dispersants and between dispersed and non-dispersed Louisiana Sweet Crude. Technically, the toxicity of waterborne hydrocarbons does not vary with chemical dispersion. However, the EPA omitted any consideration of loading, and misled the public about the risks of dispersant use in oil clean-up. This study examined the chronic toxicity of dispersed oil to fish embryos. The study revealed that toxicity expressed as oil loading increases by a factor of 10 to 1000 times with dispersion, largely because 10 to 1000 times more oil enters the water column. Since the action of dispersant is on the exposure component of the risk equation, not on the potency of the toxic components of oil, then the risk of oil toxicity to fish increases an equivalent amount.

Process development work plan for waste feed delivery system

International Nuclear Information System (INIS)

Papp, I.G.

1998-01-01

This work plan defines the process used to develop project definition for Waste Feed Delivery (WFD). Project definition provides the direction for development of definitive design media required for the ultimate implementation of operational processing hardware and software. Outlines for the major deliverables are attached as appendices. The implementation of hardware and software will accommodate requirements for safe retrieval and delivery of waste currently stored in Hanford's underground storage tanks. Operations and maintenance ensure the availability of systems, structures, and components for current and future planned operations within the boundary of the Tank Waste Remediation System (TWRS) authorization basis

Influence of implant properties and local delivery systems on the outcome in operative fracture care.

Science.gov (United States)

Metsemakers, W-J; Moriarty, T F; Nijs, S; Pape, H C; Richards, R G

2016-03-01

Fracture fixation devices are implanted into a growing number of patients each year. This may be attributed to an increase in the popularity of operative fracture care and the development of ever more sophisticated implants, which may be used in even the most difficult clinical cases. Furthermore, as the general population ages, fragility fractures become more frequent. With the increase in number of surgical interventions, the absolute number of complications of these surgical treatments will inevitably rise. Implant-related infection and compromised fracture healing remain the most challenging and prevalent complications in operative fracture care. Any strategy that can help to reduce these complications will not only lead to a faster and more complete resumption of activities, but will also help to reduce the socio-economic impact. In this review we describe the influence of implant design and material choice on complication rates in trauma patients. Furthermore, we discuss the importance of local delivery systems, such as implant coatings and bone cement, and how these systems may have an impact on the prevalence, prevention and treatment outcome of these complications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of the use of dispersants on oil spills in California marine waters

International Nuclear Information System (INIS)

Trudel, K.; Ross, S.; Belore, R.; Buffington, S.; Ogawa, C.; Panzer, D.

2002-01-01

The technical issues regarding the use of dispersants to clean up oil spills from offshore production sources and transportation sources in California were assessed in this study which examined both operational and environmental issues. The operational issues included the dispersibility of produced and imported oils, along with the capabilities of California response resources to deal with typical spills and limiting environmental impacts to offshore environments. The environmental issues include the risks associated with typical spills and potential net environmental benefit of chemically dispersing oil spills. Most crude oils produced offshore California are heavy and border on the undispersable range, but the imported crudes are somewhat lighter. Modeling has shown that most produced oils and some imported oils emulsify quickly and weather more quickly to the point where they are no longer dispersible. There is a very narrow window of time for chemical dispersions to be used effectively. The net environmental benefit analysis demonstrates that the use of dispersants lessens the total environmental impact of spill scenarios. It was emphasized that it is necessary to act quickly if chemical dispersion is to be effective. Rapid response strategies are needed, including locally based vessel and helicopter spraying systems. 19 refs., 8 tabs., 1 fig

A linearized dispersion relation for orthorhombic pseudo-acoustic modeling

KAUST Repository

Song, Xiaolei; Alkhalifah, Tariq Ali

2012-01-01

Wavefield extrapolation in acoustic orthorhombic anisotropic media suffers from wave-mode coupling and stability limitations in the parameter range. We introduce a linearized form of the dispersion relation for acoustic orthorhombic media to model acoustic wavefields. We apply the lowrank approximation approach to handle the corresponding space-wavenumber mixed-domain operator. Numerical experiments show that the proposed wavefield extrapolator is accurate and practically free of dispersions. Further, there is no coupling of qSv and qP waves, because we use the analytical dispersion relation. No constraints on Thomsen's parameters are required for stability. The linearized expression may provide useful application for parameter estimation in orthorhombic media.

A linearized dispersion relation for orthorhombic pseudo-acoustic modeling

KAUST Repository

Song, Xiaolei

2012-11-04

Wavefield extrapolation in acoustic orthorhombic anisotropic media suffers from wave-mode coupling and stability limitations in the parameter range. We introduce a linearized form of the dispersion relation for acoustic orthorhombic media to model acoustic wavefields. We apply the lowrank approximation approach to handle the corresponding space-wavenumber mixed-domain operator. Numerical experiments show that the proposed wavefield extrapolator is accurate and practically free of dispersions. Further, there is no coupling of qSv and qP waves, because we use the analytical dispersion relation. No constraints on Thomsen\\'s parameters are required for stability. The linearized expression may provide useful application for parameter estimation in orthorhombic media.

Energy dispersive x-ray spectrometry by microcalorimetry for the SEM

CERN Document Server

Newbury, D; Sae Woo Nam; Hilton, G; Irwin, K; Small, J; Martinis, J

2002-01-01

Analytical x-ray spectrometry for electron beam instruments has advanced significantly with the development of the microcalorimeter energy dispersive x-ray spectrometer (mu cal EDS). The mu cal EDS operates by measuring the temperature rise when a single photon is absorbed in a metal target. A cryoelectronic circuit with electrothermal feedback and a superconducting transition edge sensor serves as the thermometer. Spectral resolution approaching 4.5 eV for high energy photons (6000 eV) and 2 eV for low energy photons below 2000 eV has been demonstrated in energy dispersive operation across a photon energy range from 250 eV to 8 keV. Spectra of a variety of materials demonstrate the power of the mu cal EDS to solve practical problems while operating on a scanning electron microscope platform. (author)

Optimization of European call options considering physical delivery network and reservoir operation rules

Science.gov (United States)

Cheng, Wei-Chen; Hsu, Nien-Sheng; Cheng, Wen-Ming; Yeh, William W.-G.

2011-10-01

This paper develops alternative strategies for European call options for water purchase under hydrological uncertainties that can be used by water resources managers for decision making. Each alternative strategy maximizes its own objective over a selected sequence of future hydrology that is characterized by exceedance probability. Water trade provides flexibility and enhances water distribution system reliability. However, water trade between two parties in a regional water distribution system involves many issues, such as delivery network, reservoir operation rules, storage space, demand, water availability, uncertainty, and any existing contracts. An option is a security giving the right to buy or sell an asset; in our case, the asset is water. We extend a flow path-based water distribution model to include reservoir operation rules. The model simultaneously considers both the physical distribution network as well as the relationships between water sellers and buyers. We first test the model extension. Then we apply the proposed optimization model for European call options to the Tainan water distribution system in southern Taiwan. The formulation lends itself to a mixed integer linear programming model. We use the weighing method to formulate a composite function for a multiobjective problem. The proposed methodology provides water resources managers with an overall picture of water trade strategies and the consequence of each strategy. The results from the case study indicate that the strategy associated with a streamflow exceedence probability of 50% or smaller should be adopted as the reference strategy for the Tainan water distribution system.

Evaluation of hovercraft for dispersant application

Energy Technology Data Exchange (ETDEWEB)

Dickens, D; Belore, R; Buist, I; Humphrey, B

1988-01-01

A series of field trials were carried out in Vancouver, Canada in July and August 1986 to determine whether or not hovercraft should be considered for dispersant application. Questions are: the ability of the hovercraft to ''fly'' over an oil slick at high speed without displacing the oil out of the path, the potential for using the hovercraft to impart vertical mixing energy into the water column to aid in the dispersant process and, the ability to mount a suitable spray boom and obtain a uniform spray pattern across the swath width. The field trials and subsequent interpretation of results provide positive answers to the first and second question. The question of mixing energy requires some qualification. The hovercraft contributes considerable mixing energy to the immediate water surface through air entrainment but this effect is short lived and there does not appear to be significant long term vertical mixing in the hovercraft wake. Recommendations are made for operating procedures and boom mounting which should ensure a uniform drop size and dose rate across a swath up to 18 m. The cushion air escaping from around the craft perimeter is not an important factor in adversly affecting the dispersant spray pattern. Depending on the type of machine available, hovcercraft have the capability of treating up to a 1km/sup 2/ slick between loads, at average speeds in the 15 to 25 knot range. The inherent advantages of high transit speed to the site (up to 45 Knots), amphibious operation (i.e. not draft limited) and lack of ceiling or visibility restrictions provide hovercarft with unique capabilities in the dispersant application role. Two patents relating to the process have been abstracted. Appendix B gives the sprecifications of two different models of hovercrafts. 14 refs., 29 figs., 6 tabs.

Internet Based Simulations of Debris Dispersion of Shuttle Launch

Science.gov (United States)

Bardina, Jorge; Thirumalainambi, Rajkumar

2004-01-01

The debris dispersion model (which dispersion model?) is so heterogeneous and interrelated with various factors, 3D graphics combined with physical models are useful in understanding the complexity of launch and range operations. Modeling and simulation in this area mainly focuses on orbital dynamics and range safety concepts, including destruct limits, telemetry and tracking, and population risk. Particle explosion modeling is the process of simulating an explosion by breaking the rocket into many pieces. The particles are scattered throughout their motion using the laws of physics eventually coming to rest. The size of the foot print explains the type of explosion and distribution of the particles. The shuttle launch and range operations in this paper are discussed based on the operations of the Kennedy Space Center, Florida, USA. Java 3D graphics provides geometric and visual content with suitable modeling behaviors of Shuttle launches.

Operational challenges in conducting a community-based technology-enabled mental health services delivery model for rural India: Experiences from the SMART Mental Health Project [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Pallab K. Maulik

2018-04-01

Full Text Available Background: There are large gaps in the delivery of mental health care in low- and middle-income countries such as India, and the problems are even more acute in rural settings due to lack of resources, remoteness, and lack of infrastructure, amongst other factors. The Systematic Medical Appraisal Referral and Treatment (SMART Mental Health Project was conceived as a mental health services delivery model using technology-based solutions for rural India. This paper reports on the operational strategies used to facilitate the implementation of the intervention. Method: Key components of the SMART Mental Health Project included delivering an anti-stigma campaign, training of primary health workers in screening, diagnosing and managing stress, depression and increased suicide risk and task sharing of responsibilities in delivering care; and using mobile technology based electronic decision support systems to support delivery of algorithm based care for such disorders. The intervention was conducted in 42 villages across two sites in the state of Andhra Pradesh in south India. A pre-post mixed methods evaluation was done, and in this paper operational challenges are reported. Results: Both quantitative and qualitative results from the evaluation from one site covering about 5000 adults showed that the intervention was feasible and acceptable, and initial results indicated that it was beneficial in increasing access to mental health care and reducing depression and anxiety symptoms. A number of strategies were initiated in response to operational challenges to ensure smoother conduct of the project and facilitated the project to be delivered as envisaged. Conclusions: The operational strategies initiated for this project were successful in ensuring the delivery of the intervention. Those, coupled with other more systematic processes have informed the researchers to understand key processes that need to be in place to develop a more robust study, that

Seed dispersal anachronisms: rethinking the fruits extinct megafauna ate.

Directory of Open Access Journals (Sweden)

Paulo R Guimarães

Full Text Available BACKGROUND: Some neotropical, fleshy-fruited plants have fruits structurally similar to paleotropical fruits dispersed by megafauna (mammals > 10(3 kg, yet these dispersers were extinct in South America 10-15 Kyr BP. Anachronic dispersal systems are best explained by interactions with extinct animals and show impaired dispersal resulting in altered seed dispersal dynamics. METHODOLOGY/PRINCIPAL FINDINGS: We introduce an operational definition of megafaunal fruits and perform a comparative analysis of 103 Neotropical fruit species fitting this dispersal mode. We define two megafaunal fruit types based on previous analyses of elephant fruits: fruits 4-10 cm in diameter with up to five large seeds, and fruits > 10 cm diameter with numerous small seeds. Megafaunal fruits are well represented in unrelated families such as Sapotaceae, Fabaceae, Solanaceae, Apocynaceae, Malvaceae, Caryocaraceae, and Arecaceae and combine an overbuilt design (large fruit mass and size with either a single or few ( 100 seeds. Within-family and within-genus contrasts between megafaunal and non-megafaunal groups of species indicate a marked difference in fruit diameter and fruit mass but less so for individual seed mass, with a significant trend for megafaunal fruits to have larger seeds and seediness. CONCLUSIONS/SIGNIFICANCE: Megafaunal fruits allow plants to circumvent the trade-off between seed size and dispersal by relying on frugivores able to disperse enormous seed loads over long-distances. Present-day seed dispersal by scatter-hoarding rodents, introduced livestock, runoff, flooding, gravity, and human-mediated dispersal allowed survival of megafauna-dependent fruit species after extinction of the major seed dispersers. Megafauna extinction had several potential consequences, such as a scale shift reducing the seed dispersal distances, increasingly clumped spatial patterns, reduced geographic ranges and limited genetic variation and increased among

Evaluation of three oil spill laboratory dispersant effectiveness tests

International Nuclear Information System (INIS)

Sullivan, D.; Farlow, J.; Sahatjian, K.A.

1993-01-01

Chemical dispersants can be used to reduce the interfacial tension of floating oil slicks so that the oils disperse more rapidly into the water column and thus pose less of a threat to shorelines, birds, and marine mammals. The laboratory test currently specified in federal regulations to measure dispersant effectiveness is not especially easy or inexpensive, and generates a rather large quantity of oily waste water. This paper describes the results of an effort by the EPA to identify a more suitable laboratory dispersant effectiveness test. EPA evaluated three laboratory methods: the Revised Standard Dispersant Effectiveness Test currently used (and required by regulation) in the United States, the swirling flask test (developed by Environment Canada), and the IFP-dilution test (used in france and other European countries). Six test oils and three dispersants were evaluated; dispersants were applied to the oil at an average 1:10 ratio (dispersant to oil) for each of the three laboratory methods. Screening efforts were used to focus on the most appropriate oil/dispersant combination for detailed study. A screening criterion was established that required a combination that gave at least 20% effectiveness results. The selected combination turned out to be Prudhoe Bay crude oil and the dispersant Corexit 9527. This combination was also most likely to be encountered in US coastal waters. The EPA evaluation concluded that the three tests gave similar precision results, but that the swirling flask test was fastest, cheapest, simplest, and required least operator skill. Further, EPA is considering conducting the dispersant effectiveness test itself, rather than having data submitted by a dispersant manufacturer, and establishing an acceptability criterion (45% efficiency) which would have to be met before a dispersant could be placed on the Product Schedule of the National Contingency Plan (NCP)

Waste Feed Delivery Planning at Hanford - 13232

International Nuclear Information System (INIS)

Certa, Paul J.; Hohl, Ted M.; Kelly, James W.; Larsen, Douglas C.; West, Elizha B.; Ritari, Jaakob S.; Rodriguez, Juissepp S.

2013-01-01

The Integrated Waste Feed Delivery Plan (IWFDP) describes how waste feed will be delivered to the Waste Treatment and Immobilization Plant (WTP) to safely and efficiently accomplish the River Protection Project (RPP) mission. The IWFDP, which is integrated with the Baseline Case operating scenario, is comprised of three volumes. Volume 1 - Process Strategy provides an overview of waste feed delivery (WFD) and describes how the WFD system will be used to prepare and deliver feed to the WTP based on the equipment configuration and functional capabilities of the WFD system. Volume 2 - Campaign Plan describes the plans for the first eight campaigns for delivery to the WTP, evaluates projected feed for systematic issues, projects 242-A Evaporator campaigns, and evaluates double-shell tank (DST) space and availability of contingency feed. Volume 3 - Project Plan identifies the scope and timing of the DST and infrastructure upgrade projects necessary to feed the WTP, and coordinates over 30 projectized projects and operational activities that comprise the needed WFD upgrades. (authors)

Waste Feed Delivery Planning at Hanford - 13232

Energy Technology Data Exchange (ETDEWEB)

Certa, Paul J.; Hohl, Ted M.; Kelly, James W.; Larsen, Douglas C.; West, Elizha B.; Ritari, Jaakob S.; Rodriguez, Juissepp S. [Washington River Protection Solutions, LLC, P.O. 850, Richland, WA 99352 (United States)

2013-07-01

The Integrated Waste Feed Delivery Plan (IWFDP) describes how waste feed will be delivered to the Waste Treatment and Immobilization Plant (WTP) to safely and efficiently accomplish the River Protection Project (RPP) mission. The IWFDP, which is integrated with the Baseline Case operating scenario, is comprised of three volumes. Volume 1 - Process Strategy provides an overview of waste feed delivery (WFD) and describes how the WFD system will be used to prepare and deliver feed to the WTP based on the equipment configuration and functional capabilities of the WFD system. Volume 2 - Campaign Plan describes the plans for the first eight campaigns for delivery to the WTP, evaluates projected feed for systematic issues, projects 242-A Evaporator campaigns, and evaluates double-shell tank (DST) space and availability of contingency feed. Volume 3 - Project Plan identifies the scope and timing of the DST and infrastructure upgrade projects necessary to feed the WTP, and coordinates over 30 projectized projects and operational activities that comprise the needed WFD upgrades. (authors)

Waste feed delivery planning at Hanford-13232

International Nuclear Information System (INIS)

Certa, Paul J.; West, Elizha B.; Rodriguez, Juissepp S.; Hohl, Ted M.; Larsen, Douglas C.; Ritari, Jaakob S.; Kelly, James W.

2013-01-01

The Integrated Waste Feed Delivery Plan (IWFDP) describes how waste feed will be delivered to the Waste Treatment and Immobilization Plant (WTP) to safely and efficiently accomplish the River Protection Project (RPP) mission. The IWFDP, which is integrated with the Baseline Case operating scenario, is comprised of three volumes. Volume 1 - Process Strategy provides an overview of waste feed delivery (WFD) and describes how the WFD system will be used to prepare and deliver feed to the WTP based on the equipment configuration and functional capabilities of the WFD system. Volume 2 - Campaign Plan describes the plans for the first eight campaigns for delivery to the WTP, evaluates projected feed for systematic issues, projects 242-A Evaporator campaigns, and evaluates double-shell tank (DST) space and availability of contingency feed. Volume 3 - Project Plan identifies the scope and timing of the DST and infrastructure upgrade projects necessary to feed the WTP, and coordinates over 30 projectized projects and operational activities that comprise the needed WFD upgrades

Online monitoring of dispersion functions and transfer matrices at the SLC

International Nuclear Information System (INIS)

Emma, P.; Fieguth, T.H.; Lohse, T.; Burchat, P.R.; Panvini, R.S.

1989-03-01

The symmetries of the chromatic correction sections in the SLC Final Focus System allow a high-resolution determination of the pulse-to-pulse energy fluctuations by exploiting the information from beam position monitors (BPMs) in regions of large dispersion. By correlating this signal with other BPMs, one can infer the dispersion function as well as spatial components of transfer matrices anywhere in the arcs and the Final Focus System without interrupting normal machine operation. We present results from data recorded during either periods of stable operation or periods when the linac energy was intentionally varied. 6 refs., 7 figs

Dispersive stresses in wind farms

Science.gov (United States)

Segalini, Antonio; Braunbehrens, Robert; Hyvarinen, Ann

2017-11-01

One of the most famous models of wind farms is provided by the assumption that the farm can be approximated as a horizontally-homogeneous forest canopy with vertically-varying force intensity. By means of this approximation, the flow-motion equations become drastically simpler, as many of the three-dimensional effects are gone. However, the application of the horizontal average operator to the RANS equations leads to the appearance of new transport terms (called dispersive stresses) originating from the horizontal (small-scale) variation of the mean velocity field. Since these terms are related to the individual turbine signature, they are expected to vanish outside the roughness sublayer, providing a definition for the latter. In the present work, an assessment of the dispersive stresses is performed by means of a wake-model approach and through the linearised code ORFEUS developed at KTH. Both approaches are very fast and enable the characterization of a large number of wind-farm layouts. The dispersive stress tensor and its effect on the turbulence closure models are investigated, providing guidelines for those simulations where it is impossible to resolve the farm at a turbine scale due to grid requirements (as, for instance, mesoscale simulations).

The role of the lens in pigment dispersion syndrome.

Science.gov (United States)

Liu, Lance

2010-12-01

In patients with pigment dispersion syndrome, changes of the iris configuration can occur with accommodation, blinking, miotics, and following a laser iridotomy. This observational case series looks at the changes following cataract surgery in 3 eyes with signs of pigment dispersion, symptomatic cataracts, and no previous laser iridotomy that were imaged with optical coherence tomography. The iris was concave posteriorly in dark and light lighting conditions, and became flat following an uncomplicated cataract operation. This may be explained by the elimination of iridolenticular contact, which contributes to the mechanism of reverse pupil block. These iris changes suggest the lens plays an important role in the mechanism of pigment dispersion. Copyright 2010, SLACK Incorporated.

Chromatic dispersion compensation and Coherent Direct-Sequence OCDMA operation on a single super structured FBG.

Science.gov (United States)

Baños, Rocío; Pastor, Daniel; Amaya, Waldimar; Garcia-Munoz, Victor

2012-06-18

We have proposed, fabricated and demonstrated experimentally a set of Coherent Direct Sequence-OCDMA en/decoders based on Super Structured Fiber Bragg Gratings (SSFBGs) which are able to compensate the fiber chromatic dispersion at the same time that they perform the en/decoding task. The proposed devices avoid the use of additional dispersion compensation stages reducing system complexity and losses. This performance was evaluated for 5.4, 11.4 and 16.8 km of SSMF. The twofold performance was verified in Low Reflectivity regime employing only one GVD compensating device at decoder or sharing out the function between encoder and decoder devices. Shared functionality requires shorter SSFBGs designs and also provides added flexibility to the optical network design. Moreover, dispersion compensated en/decoders were also designed into the High Reflectivity regime employing synthesis methods achieving more than 9 dB reduction of insertion loss for each device.

Dispersion engineering of mode-locked fibre lasers

Science.gov (United States)

Woodward, R. I.

2018-03-01

Mode-locked fibre lasers are important sources of ultrashort pulses, where stable pulse generation is achieved through a balance of periodic amplitude and phase evolutions. A range of distinct cavity pulse dynamics have been revealed, arising from the interplay between dispersion and nonlinearity in addition to dissipative processes such as filtering. This has led to the discovery of numerous novel operating regimes, offering significantly improved laser performance. In this Topical Review, we summarise the main steady-state pulse dynamics reported to date through cavity dispersion engineering, including average solitons, dispersion-managed solitons, dissipative solitons, giant-chirped pulses and similaritons. Characteristic features and the stabilisation mechanism of each regime are described, supported by numerical modelling, in addition to the typical performance and limitations. Opportunities for further pulse energy scaling are discussed, in addition to considering other recent advances including automated self-tuning cavities and fluoride-fibre-based mid-infrared mode-locked lasers.

Updating the U.S. SMART dispersant efficacy monitoring protocol

International Nuclear Information System (INIS)

Trudel, K.; Belore, R.; VanHaverbeke, M.; Mullin, J.

2009-01-01

The Special Monitoring of Applied Response Technologies (SMART) is a written dispersant effectiveness monitoring protocol developed in the United States in the mid 1990s. It has been the subject of considerable review and research since its development. This paper reported on the 2007-2008 review of the SMART dispersant effectiveness monitoring protocol which involved the following 3 tasks: (1) stakeholders reviewed their experience with SMART and identified the key deficiencies in the current protocol, (2) the SMART monitoring experience gathered during dispersant effectiveness testing at the Ohmsett National Oil Spill Response Test Facility was reviewed to evaluate the usefulness of existing SMART decision criteria, (3) available commercial off-the-shelf instruments (COTS) were surveyed to identify the instruments that might be more effective or simpler to use than those presently in use. The review concluded that the three-tiered approach in SMART was appropriate, but better guidance was needed for users. In addition, the fluorometer historically used for monitoring of dispersed oil was found to have several operating challenges and should be replaced with more modern equipment. It was recommended that all U.S. government sponsored monitoring teams work with identical instruments and operating protocols. The COTS survey identified 6 potentially suitable submersible and field-portable fluorometers and three particle-size analyzers. 26 refs., 5 tabs., 1 fig

Feasibility of Capsule Endoscopy for Direct Imaging of Drug Delivery Systems in the Fasted Upper-Gastrointestinal Tract

DEFF Research Database (Denmark)

Pedersen, Pernille Barbre; Bar-Shalom, Daniel; Baldursdottir, Stefania

2014-01-01

To develop a minimally-invasive method for direct visualization of drug delivery systems in the human stomach and to compare the obtained results with an established in vitro model. The method should provide the capsule rupture, dispersion characteristics, and knowledge regarding the surrounding ...

Crosslinked hydrogels?a promising class of insoluble solid molecular dispersion carriers for enhancing the delivery of poorly soluble drugs

OpenAIRE

Sun, Dajun D.; Lee, Ping I.

2014-01-01

Water-insoluble materials containing amorphous solid dispersions (ASD) are an emerging category of drug carriers which can effectively improve dissolution kinetics and kinetic solubility of poorly soluble drugs. ASDs based on water-insoluble crosslinked hydrogels have unique features in contrast to those based on conventional water-soluble and water-insoluble carriers. For example, solid molecular dispersions of poorly soluble drugs in poly(2-hydroxyethyl methacrylate) (PHEMA) can maintain a ...

Bioaccessibility of nutrients and micronutrients from dispersed food systems: impact of the multiscale bulk and interfacial structures.

Science.gov (United States)

Marze, Sébastien

2013-01-01

Many food systems are dispersed systems, that is, they possess at least two immiscible phases. This is generally due to the coexistence of domains with different physicochemical properties separated by many interfaces which control the apparent thermodynamic equilibrium. This feature was and is still largely studied to design pharmaceutical delivery systems. In food science, the recent intensification of in vitro digestion tests to complement the in vivo ones holds promises in the identification of the key parameters controlling the bioaccessibility of nutrients and micronutrients. In this review, we present the developments of in vitro digestion tests for dispersed food systems (mainly emulsions, dispersions and gels). We especially highlight the evidences detailing the roles of the constituting multiscale structures. In a perspective section, we show the potential of structured interfaces to allow controlled bioaccessibility.

A remotely operated drug delivery system with an electrolytic pump and a thermo-responsive valve

KAUST Repository

Yi, Ying

2015-07-22

Implantable drug delivery devices are becoming attractive due to their abilities of targeted and controlled dose release. Currently, two important issues are functional lifetime and non-controlled drug diffusion. In this work, we present a drug delivery device combining an electrolytic pump and a thermo-responsive valve, which are both remotely controlled by an electromagnetic field (40.5 mT and 450 kHz). Our proposed device exhibits a novel operation mechanism for long-term therapeutic treatments using a solid drug in reservoir approach. Our device also prevents undesired drug liquid diffusions. When the electromagnetic field is on, the electrolysis-induced bubble drives the drug liquid towards the Poly (N-Isopropylacrylamide) (PNIPAM) valve that consists of PNIPAM and iron micro-particles. The heat generated by the iron micro-particles causes the PNIPAM to shrink, resulting in an open valve. When the electromagnetic field is turned off, the PNIPAM starts to swell. In the meantime, the bubbles are catalytically recombined into water, reducing the pressure inside the pumping chamber, which leads to the refilling of the fresh liquid from outside the device. A catalytic reformer is included, allowing more liquid refilling during the limited valve\\'s closing time. The amount of body liquid that refills the drug reservoir can further dissolve the solid drug, forming a reproducible drug solution for the next dose. By repeatedly turning on and off the electromagnetic field, the drug dose can be cyclically released, and the exit port of the device is effectively controlled.

A remotely operated drug delivery system with an electrolytic pump and a thermo-responsive valve

KAUST Repository

Yi, Ying; Zaher, Amir; Yassine, Omar; Kosel, Jü rgen; Foulds, Ian G.

2015-01-01

Implantable drug delivery devices are becoming attractive due to their abilities of targeted and controlled dose release. Currently, two important issues are functional lifetime and non-controlled drug diffusion. In this work, we present a drug delivery device combining an electrolytic pump and a thermo-responsive valve, which are both remotely controlled by an electromagnetic field (40.5 mT and 450 kHz). Our proposed device exhibits a novel operation mechanism for long-term therapeutic treatments using a solid drug in reservoir approach. Our device also prevents undesired drug liquid diffusions. When the electromagnetic field is on, the electrolysis-induced bubble drives the drug liquid towards the Poly (N-Isopropylacrylamide) (PNIPAM) valve that consists of PNIPAM and iron micro-particles. The heat generated by the iron micro-particles causes the PNIPAM to shrink, resulting in an open valve. When the electromagnetic field is turned off, the PNIPAM starts to swell. In the meantime, the bubbles are catalytically recombined into water, reducing the pressure inside the pumping chamber, which leads to the refilling of the fresh liquid from outside the device. A catalytic reformer is included, allowing more liquid refilling during the limited valve's closing time. The amount of body liquid that refills the drug reservoir can further dissolve the solid drug, forming a reproducible drug solution for the next dose. By repeatedly turning on and off the electromagnetic field, the drug dose can be cyclically released, and the exit port of the device is effectively controlled.

Alginate-caseinate composites: Molecular interactions and characterization of cross-linked beads for the delivery of anticandidals.

Science.gov (United States)

Khlibsuwan, Rapee; Khunkitti, Watcharee; Pongjanyakul, Thaned

2018-04-19

Polysaccharide-protein composites offer potential utility for the delivery of drugs. The objectives of this work were to investigate the molecular interactions between sodium alginate (SA) and sodium caseinate (SC) in dispersions and films and to characterize calcium alginate (CA) beads mixed with SC for the delivery of fluconazole (FZ) and clotrimazole (CZ). The results demonstrated that SA could interact with SC, which caused a viscosity synergism in the dispersions. Hydrogen bonding between the carboxyl or hydroxyl groups of SA and the amide groups of SC led to the formation of soluble complexes that could reinforce the CA beads prepared by calcium cross-linking. The SC-CA beads provided higher drug entrapment efficiency, lower water uptake and erosion, and slower drug release than for the CA beads. The loaded FZ was an amorphous form, but CZ crystals were embedded in the bead matrix due to the low water solubility of this drug. However, SC micellization could enhance the water solubility and efficacy of CZ against Candida albicans. This finding indicates that SA can interact with SC via hydrogen bonding to form complexes and that the anticandidal-loaded SC-CA beads can be used as drug delivery systems and drug reservoirs in tablets for oral candidiasis. Copyright © 2018 Elsevier B.V. All rights reserved.

A clinical prediction model to assess the risk of operative delivery

NARCIS (Netherlands)

Schuit, E.; Kwee, A.; Westerhuis, M.E.M.H.; Dessel, van H.J.H.M.; Graziosi, G.C.M.; Lith, van J.M.M.; Nijhuis, J.G.; Oei, S.G.; Oosterbaan, H.P.; Schuitemaker, N.W.E.; Wouters, M.G.A.J.; Visser, G.H.A.; Mol, B.W.J.; Moons, K.G.M.; Groenwold, R.H.H.

2012-01-01

Objective To predict instrumental vaginal delivery or caesarean section for suspected fetal distress or failure to progress. Design Secondary analysis of a randomised trial. Setting Three academic and six non-academic teaching hospitals in the Netherlands. Population 5667 labouring women with a

Use of fractional laser microablation and ultrasound to facilitate the delivery of gold nanoparticles into skin in vivo

Energy Technology Data Exchange (ETDEWEB)

Terentyuk, G S; Genina, Elina A; Bashkatov, A N; Ryzhova, M V; Tsyganova, N A; Chumakov, D S; Khlebtsov, B N; Sazonov, A A; Dolotov, L E; Tuchin, Valerii V; Khlebtsov, Nikolai G; Inozemtseva, O A

2012-06-30

The delivery of gold nanoparticles (nanocages coated with a layer of silicon dioxide (40/20 nm)) dispersed in the solution (glycerol + polyethylene glycol-400, 1 : 1) into the skin tissue is studied experimentally in vivo. From the data of optical coherence tomography and histochemical analysis it follows that simple application of suspension of nanoparticles is not efficient enough for delivery of the particles into the skin as a result of passive diffusion. It is shown that fractional laser microablation of skin before the application of the suspension, followed by the topical treatment by ultrasound allows penetration through the epidermis layer and delivery of nanoparticles into dermis and hypodermis.

Use of fractional laser microablation and ultrasound to facilitate the delivery of gold nanoparticles into skin in vivo

International Nuclear Information System (INIS)

Terentyuk, G S; Genina, Elina A; Bashkatov, A N; Ryzhova, M V; Tsyganova, N A; Chumakov, D S; Khlebtsov, B N; Sazonov, A A; Dolotov, L E; Tuchin, Valerii V; Khlebtsov, Nikolai G; Inozemtseva, O A

2012-01-01

The delivery of gold nanoparticles (nanocages coated with a layer of silicon dioxide (40/20 nm)) dispersed in the solution (glycerol + polyethylene glycol-400, 1 : 1) into the skin tissue is studied experimentally in vivo. From the data of optical coherence tomography and histochemical analysis it follows that simple application of suspension of nanoparticles is not efficient enough for delivery of the particles into the skin as a result of passive diffusion. It is shown that fractional laser microablation of skin before the application of the suspension, followed by the topical treatment by ultrasound allows penetration through the epidermis layer and delivery of nanoparticles into dermis and hypodermis.

Use of fractional laser microablation and ultrasound to facilitate the delivery of gold nanoparticles into skin in vivo

Science.gov (United States)

Terentyuk, G. S.; Genina, Elina A.; Bashkatov, A. N.; Ryzhova, M. V.; Tsyganova, N. A.; Chumakov, D. S.; Khlebtsov, B. N.; Sazonov, A. A.; Dolotov, L. E.; Tuchin, Valerii V.; Khlebtsov, Nikolai G.; Inozemtseva, O. A.

2012-06-01

The delivery of gold nanoparticles (nanocages coated with a layer of silicon dioxide (40/20 nm)) dispersed in the solution (glycerol + polyethylene glycol-400, 1 : 1) into the skin tissue is studied experimentally in vivo. From the data of optical coherence tomography and histochemical analysis it follows that simple application of suspension of nanoparticles is not efficient enough for delivery of the particles into the skin as a result of passive diffusion. It is shown that fractional laser microablation of skin before the application of the suspension, followed by the topical treatment by ultrasound allows penetration through the epidermis layer and delivery of nanoparticles into dermis and hypodermis

Dispersant optimization using design of experiments for SiC/vinyl ester nanocomposites

Science.gov (United States)

Yong, Virginia; Hahn, H. Thomas

2005-04-01

The effect of dispersants on particle dispersion and flexural properties of SiC/vinyl ester nanocomposites was studied by factorial and response surface designs. The results show that the coupling agent 'gamma-methacryloxy propyl trimethoxy silane (MPS)' has no adverse side effect on the flexural properties as illustrated by the good correlation between maximizing the flexural strength and minimizing the agglomerates. However, the dispersant 'BYK-W 966' has a slight adverse side effect on the flexural properties although it improves dispersion at higher dosage. With an optimal dosage of MPS and W966, a small amount of SiC in 0.5 wt% results in 8% increase in strength and 14% increase in modulus. The flushing operation using the dispersant '1-octanol/decane' achieves an excellent SiC dispersion but it does not result in improved flexural properties. This confirmed that a better state of nanoparticle dispersion does not necessarily lead to improved flexural properties. A good dispersion coupling with a strong filler/matrix interfacial bonding is the key to obtain enhanced flexural properties.

Studies of emulsification, emulsion prevention and underwater dispersion

Energy Technology Data Exchange (ETDEWEB)

Celius, H.K.; Vassbotn, T.

1985-03-01

This is a report from the work performed under task 2: ''Effect of demulsifiers and despersants injected into a blowing oil stream'' of the research program ''Dispersion of oil on sea''. Three ad hoc experiments have been carried out involving laboratory studies in a small turbulent oil plume, tests with revolving flasks, and a small scale field test with a combined gas/oil plume. The results show that emulsion is formed in plume from underwater blowouts, and that this formation is prevented by small amounts (250 ppM) of demulsifiers or dispersants. Larger concentrations of dispersants (ca 2%) disperse the oil, and the oil is transported to the upper water layer in the gas/oil plume. None of the experiments have been designed as true scale tests, and the results cannot be directly transferred to operational, full scale conditions. The experiments have however narroved the necessary extent of studies, and allows for a simpler experimental procedure in the full scale field test planned for June 1985. 19 references.

Curcumin containing monoolein aqueous dispersions: A preformulative study

International Nuclear Information System (INIS)

Esposito, Elisabetta; Ravani, Laura; Mariani, Paolo; Contado, Catia; Drechsler, Markus; Puglia, Carmelo; Cortesi, Rita

2013-01-01

The present study describes the production and characterization of monoolein aqueous dispersions (MAD) as drug delivery systems for curcumin (CR). MAD based on monoolein and different emulsifiers have been produced and characterized. Morphology and dimensional distribution have been investigated by Cryogenic Transmission Electron Microscopy (cryo-TEM), X-ray and Photon Correlation Spectroscopy (PCS). Monoolein in different mixtures with sodium cholate, sodium caseinate, bentonite and poloxamer resulted in heterogeneous dispersions constituted of unilamellar vesicles, cubosomes and sponge type phases, depending on the employed components, as found by cryo-TEM and X-ray studies. CR was encapsulated with entrapment efficiencies depending on the MAD composition, particularly the highest was reached in the case of monoolein/poloxamer/sodium cholate mixture. The same mixture was able to maintain CR stability also after 6 months. CR release modalities were in vitro investigated in order to mimic a possible subcutaneous administration of MAD. It was found that MAD constituted of monoolein/poloxamer and monoolein/poloxamer/sodium cholate mixtures were able to sustain CR release. MAD viscous vehicles were produced by xanthan gum. CR percutaneous absorption has been studied in vitro using excised human skin membranes [stratum corneum epidermis (SCE)] mounted into Franz cells. It was found that fluxes (F n ) of CR incorporated in MAD are influenced by the presence of monoolein based nanosystems. In particular xanthan gum based MAD better control CR diffusion from MAD. - Highlights: • Curcumin (CR) can be solubilized in monoolein aqueous dispersions (MAD). • Different emulsifiers result in different inner structures in the disperse phase. • Monoolein/poloxamer/sodium cholate mixture (MCP) results in the highest CR encapsulation. • MCP maintains CR stability for 6 months. • Xanthan gum based MAD better control CR fluxes with respect to plain gel and liquid MAD

Curcumin containing monoolein aqueous dispersions: A preformulative study

Energy Technology Data Exchange (ETDEWEB)

Esposito, Elisabetta, E-mail: ese@unife.it [Department of Life Sciences and Biotechnology, University of Ferrara, I-44121 Ferrara (Italy); Ravani, Laura [Department of Life Sciences and Biotechnology, University of Ferrara, I-44121 Ferrara (Italy); Mariani, Paolo [Department of Life and Environmental Sciences and CNISM, Università Politecnica delle Marche, I-60100 Ancona (Italy); Contado, Catia [Department of Chemistry, University of Ferrara, I-44121 Ferrara (Italy); Drechsler, Markus [Macromolecular Chemistry II, University of Bayreuth (Germany); Puglia, Carmelo [Department of Drug Sciences, University of Catania, I-95125 Catania (Italy); Cortesi, Rita [Department of Life Sciences and Biotechnology, University of Ferrara, I-44121 Ferrara (Italy)

2013-12-01

The present study describes the production and characterization of monoolein aqueous dispersions (MAD) as drug delivery systems for curcumin (CR). MAD based on monoolein and different emulsifiers have been produced and characterized. Morphology and dimensional distribution have been investigated by Cryogenic Transmission Electron Microscopy (cryo-TEM), X-ray and Photon Correlation Spectroscopy (PCS). Monoolein in different mixtures with sodium cholate, sodium caseinate, bentonite and poloxamer resulted in heterogeneous dispersions constituted of unilamellar vesicles, cubosomes and sponge type phases, depending on the employed components, as found by cryo-TEM and X-ray studies. CR was encapsulated with entrapment efficiencies depending on the MAD composition, particularly the highest was reached in the case of monoolein/poloxamer/sodium cholate mixture. The same mixture was able to maintain CR stability also after 6 months. CR release modalities were in vitro investigated in order to mimic a possible subcutaneous administration of MAD. It was found that MAD constituted of monoolein/poloxamer and monoolein/poloxamer/sodium cholate mixtures were able to sustain CR release. MAD viscous vehicles were produced by xanthan gum. CR percutaneous absorption has been studied in vitro using excised human skin membranes [stratum corneum epidermis (SCE)] mounted into Franz cells. It was found that fluxes (F{sub n}) of CR incorporated in MAD are influenced by the presence of monoolein based nanosystems. In particular xanthan gum based MAD better control CR diffusion from MAD. - Highlights: • Curcumin (CR) can be solubilized in monoolein aqueous dispersions (MAD). • Different emulsifiers result in different inner structures in the disperse phase. • Monoolein/poloxamer/sodium cholate mixture (MCP) results in the highest CR encapsulation. • MCP maintains CR stability for 6 months. • Xanthan gum based MAD better control CR fluxes with respect to plain gel and liquid MAD.

The materials science synchrotron beamline EDDI for energy-dispersive diffraction analysis

International Nuclear Information System (INIS)

Genzel, Ch.; Denks, I.A.; Gibmeier, J.; Klaus, M.; Wagener, G.

2007-01-01

In April 2005 the materials science beamline EDDI (Energy Dispersive DIffraction) at the Berlin synchrotron storage ring BESSY started operation. The beamline is operated in the energy-dispersive mode of diffraction using the high energy white photon beam provided by a superconducting 7 T multipole wiggler. Starting from basic information on the beamline set-up, its measuring facilities and data processing concept, the wide range of applications for energy-dispersive diffraction is demonstrated by a series of examples coming from different fields in materials sciences. It will be shown, that the EDDI beamline is especially suitable for the investigation of structural properties and gradients in the near surface region of polycrystalline materials. In particular, this concerns the analysis of multiaxial residual stress fields in the highly stressed surface zone of technical parts. The high photon flux further facilitates fast in situ experiments at room as well as high temperature to monitor for example the growth kinetics and reaction in thin film growth

A completely automatic operation type super-safe fast reactor, RAPID. Its application to dispersion source on lunar and earth surfaces

International Nuclear Information System (INIS)

Kanbe, Mitsuru; Tsunoda, Hirokazu; Mishima, Kaichiro; Kawasaki, Akira; Iwamura, Takamichi

2002-01-01

At a viewpoint of flexible measures to future electric power demands, expectation onto a small-scale reactor for dispersion source is increasing gradually. This is thought to increase its importance not only for a source at proximity of its market in advanced nations but also for the one in developing nations. A study on development of the completely automatic operation type super-safe fast reactor, RAPID (refueling by all pins integrated design) has been carried out as a part of the nuclear energy basic research promoting system under three years project since 1999 by a trust of the Japan Atomic Energy Research Institute to a group of the Central Research Institute of Electric Power Industry (CRIEPI) and so on. As the reactor is a lithium cooled fast reactor with 200 Kw of electric output supposing to use at lunar surface, it can be applied to a super-small scale nuclear reactor on the earth, and has feasibility to become a new option of future nuclear power generation. On the other hand, CRIEPI has investigated on various types of fast reactors (RAPID series) for fast reactor for dispersion source on the earth. Here was introduced on such super-safe fast reactors at a center of RAPID-L. (G.K.)

Mars Exploration Rovers Landing Dispersion Analysis

Science.gov (United States)

Knocke, Philip C.; Wawrzyniak, Geoffrey G.; Kennedy, Brian M.; Desai, Prasun N.; Parker, TImothy J.; Golombek, Matthew P.; Duxbury, Thomas C.; Kass, David M.

2004-01-01

Landing dispersion estimates for the Mars Exploration Rover missions were key elements in the site targeting process and in the evaluation of landing risk. This paper addresses the process and results of the landing dispersion analyses performed for both Spirit and Opportunity. The several contributors to landing dispersions (navigation and atmospheric uncertainties, spacecraft modeling, winds, and margins) are discussed, as are the analysis tools used. JPL's MarsLS program, a MATLAB-based landing dispersion visualization and statistical analysis tool, was used to calculate the probability of landing within hazardous areas. By convolving this with the probability of landing within flight system limits (in-spec landing) for each hazard area, a single overall measure of landing risk was calculated for each landing ellipse. In-spec probability contours were also generated, allowing a more synoptic view of site risks, illustrating the sensitivity to changes in landing location, and quantifying the possible consequences of anomalies such as incomplete maneuvers. Data and products required to support these analyses are described, including the landing footprints calculated by NASA Langley's POST program and JPL's AEPL program, cartographically registered base maps and hazard maps, and flight system estimates of in-spec landing probabilities for each hazard terrain type. Various factors encountered during operations, including evolving navigation estimates and changing atmospheric models, are discussed and final landing points are compared with approach estimates.

Volume Fraction Dependent Thermal Performance of UAlx-Al Dispersion Target

Energy Technology Data Exchange (ETDEWEB)

Kong, Eui Hyun; Tahk, Young Wook; Kim, Hyun Jung; Oh, Jae Yong; Yim, Jeong Sik [KAERI, Daejeon (Korea, Republic of)

2016-05-15

Unlike U-Al alloys, properties of UAl{sub x}-Al dispersion target can be highly sensitive to volume fraction of UAlx in a target meat due to the interface resistance between target particles and matrix. The interface resistance effects on properties of the target meat including thermal conductivity, thermal expansion coefficient, specific heat, elastic modulus and so on. Thermal performances of a dispersion target meat were theoretically evaluated under normal operation condition of KJRR (Kijang Research Reactor) during short effective full power days (EFPD) of 7 days, based on reported measured thermal conductivities of UAl{sub x}-Al dispersion fuels. Effective thermal conductivity determines maximum temperature of dispersion target plate. And for that volume fraction of UAlx in target meat has to be determined considering manufacturing of target plate without degradation of physical and mechanical characteristics.

A Microfluidic Ion Pump for In Vivo Drug Delivery

KAUST Repository

Uguz, Ilke

2017-05-15

Implantable devices offer an alternative to systemic delivery of drugs for the treatment of neurological disorders. A microfluidic ion pump (µFIP), capable of delivering a drug without the solvent through electrophoresis, is developed. The device is characterized in vitro by delivering γ-amino butyric acid to a target solution, and demonstrates low-voltage operation, high drug-delivery capacity, and high ON/OFF ratio. It is also demonstrated that the device is suitable for cortical delivery in vivo by manipulating the local ion concentration in an animal model and altering neural behavior. These results show that µFIPs represent a significant step forward toward the development of implantable drug-delivery systems.

Distribution and clearance of PEG-single-walled carbon nanotube cancer drug delivery vehicles in mice.

Science.gov (United States)

Bhirde, Ashwin A; Patel, Sachin; Sousa, Alioscka A; Patel, Vyomesh; Molinolo, Alfredo A; Ji, Youngmi; Leapman, Richard D; Gutkind, J Silvio; Rusling, James F

2010-12-01

To study the distribution and clearance of polyethylene glycol (PEG)-ylated single-walled carbon nanotube (SWCNTs) as drug delivery vehicles for the anticancer drug cisplatin in mice. PEG layers were attached to SWCNTs and dispersed in aqueous media and characterized using dynamic light scattering, scanning transmission electron microscopy and Raman spectroscopy. Cytotoxicity was assessed in vitro using Annexin-V assay, and the distribution and clearance pathways in mice were studied by histological staining and Raman spectroscopy. Efficacy of PEG-SWCNT-cisplatin for tumor growth inhibition was studied in mice. PEG-SWCNTs were efficiently dispersed in aqueous media compared with controls, and did not induce apoptosis in vitro. Hematoxylin and eosin staining, and Raman bands for SWCNTs in tissues from several vital organs from mice injected intravenously with nanotube bioconjugates revealed that control SWCNTs were lodged in lung tissue as large aggregates compared with the PEG-SWCNTs, which showed little or no accumulation. Characteristic SWCNT Raman bands in feces revealed the presence of bilary or renal excretion routes. Attachment of cisplatin on bioconjugates was visualized with Z-contrast scanning transmission electron microscopy. PEG-SWCNT-cisplatin with the attached targeting ligand EGF successfully inhibited growth of head and neck tumor xenografts in mice. PEG-SWCNTs, as opposed to control SWCNTs, form more highly dispersed delivery vehicles that, when loaded with both cisplatin and EGF, inhibit growth of squamous cell tumors.

Impact of epidural analgesia on cesarean and operative vaginal delivery rates classified by the Ten Groups Classification System.

Science.gov (United States)

Lucovnik, M; Blajic, I; Verdenik, I; Mirkovic, T; Stopar Pintaric, T

2018-05-01

The Ten Group Classification System (TGCS) allows critical analysis according to the obstetric characteristics of women in labor: singleton or multiple pregnancy, nulliparous, multiparous, or multiparous with a previous cesarean delivery, cephalic, breech presentation or other malpresentation, spontaneous or induced labor, and term or preterm births. Labor outcomes associated with epidural analgesia may be different among the different labor classification groups. The aim of this study was to explore associations between epidural analgesia and cesarean delivery, and epidural analgesia and assisted vaginal delivery, in women classified using the TGCS. Slovenian National Perinatal Information System data for the period 2007-2014 were analyzed. All women after spontaneous onset or induction of labor were classified according to the TGCS, within which cesarean and vaginal assisted delivery rates were investigated (P cesarean delivery rates. Women in group 1 (nulliparous term women with singleton fetuses in cephalic presentation in spontaneous labor) with epidural analgesia had a higher cesarean delivery rate. In most TGCS groups women with epidural analgesia had higher assisted vaginal delivery rates. Epidural analgesia is associated with different effects on cesarean delivery and assisted vaginal delivery rates in different TGCS groups. Copyright © 2018. Published by Elsevier Ltd.

Intelligent layered nanoflare: ``lab-on-a-nanoparticle'' for multiple DNA logic gate operations and efficient intracellular delivery

Science.gov (United States)

Yang, Bin; Zhang, Xiao-Bing; Kang, Li-Ping; Huang, Zhi-Mei; Shen, Guo-Li; Yu, Ru-Qin; Tan, Weihong

2014-07-01

DNA strand displacement cascades have been engineered to construct various fascinating DNA circuits. However, biological applications are limited by the insufficient cellular internalization of naked DNA structures, as well as the separated multicomponent feature. In this work, these problems are addressed by the development of a novel DNA nanodevice, termed intelligent layered nanoflare, which integrates DNA computing at the nanoscale, via the self-assembly of DNA flares on a single gold nanoparticle. As a ``lab-on-a-nanoparticle'', the intelligent layered nanoflare could be engineered to perform a variety of Boolean logic gate operations, including three basic logic gates, one three-input AND gate, and two complex logic operations, in a digital non-leaky way. In addition, the layered nanoflare can serve as a programmable strategy to sequentially tune the size of nanoparticles, as well as a new fingerprint spectrum technique for intelligent multiplex biosensing. More importantly, the nanoflare developed here can also act as a single entity for intracellular DNA logic gate delivery, without the need of commercial transfection agents or other auxiliary carriers. By incorporating DNA circuits on nanoparticles, the presented layered nanoflare will broaden the applications of DNA circuits in biological systems, and facilitate the development of DNA nanotechnology.DNA strand displacement cascades have been engineered to construct various fascinating DNA circuits. However, biological applications are limited by the insufficient cellular internalization of naked DNA structures, as well as the separated multicomponent feature. In this work, these problems are addressed by the development of a novel DNA nanodevice, termed intelligent layered nanoflare, which integrates DNA computing at the nanoscale, via the self-assembly of DNA flares on a single gold nanoparticle. As a ``lab-on-a-nanoparticle'', the intelligent layered nanoflare could be engineered to perform a variety of

Controlling service delivery in service triads

NARCIS (Netherlands)

Iwaarden, van J.; Valk, van der W.; Aalders, L.; Virolainen, V.-M.

2010-01-01

Organizations are increasingly sourcing services that are directly delivered to their (end) customers by external providers. Buying organization, supplier and (end) customer operate in a triadic service relationship. In these triads, the buying organization lacks direct control over service delivery

[Effect of different bone cement dispersion types in the treatment of osteoporotic vertebral compression fracture].

Science.gov (United States)

Zhao, Yong-Sheng; Li, Qiang; Li, Qiang; Zheng, Yan-Ping

2017-05-25

To observe different bone cement dispersion types of PVP, PKP and manipulative reduction PVP and their effects in the treatment of senile osteoporotic vertebral compression fractures and the bone cement leakage rate. The clinical data of patients with osteoporotic vertebral compression fractures who underwent unilateral vertebroplasty from January 2012 to January 2015 was retrospectively analyzed. Of them, 56 cases including 22 males and 34 females aged from 60 to 78 years old were treated by PVP operation; Fouty-eight cases including 17 males and 31 females aged from 61 to 79 years old were treated by PKP operation; Forty-three cases including 15 males and 28 females aged from 60 to 76 years old were treated by manipulative reduction PVP operation. AP and lateral DR films were taken after the operation; the vertebral bone cement diffusion district area and mass district area were calculated with AutoCAD graphics processing software by AP and lateral DR picture, then ratio(K) of average diffusion area and mass area were calculated, defining K100% as diffusion type. Different bone cement dispersion types of PVP, PKP and manipulative reduction PVP operation were analyzed. According to bone cement dispersion types, patients were divided into diffusion type, mixed type and mass type groups.Visual analogue scale (VAS), vertebral body compression rate, JOA score and bone cement leakage rate were observed. All patients were followed up for 12-24 months with an average of 17.2 months. There was significant difference in bone cement dispersion type among three groups ( P <0.05). The constituent ratio of diffusion type, mixed type and mass type in PVP operation was 46.43%, 35.71%, 17.86%, in PKP was 16.67%, 37.50% , 45.83%, and in manipulative reduction PVP was 37.21%, 44.19% and 18.60%, respectively. PVP operation and manipulative reduction PVP were mainly composed of diffusion type and mixed type, while PKP was mainly composed of mass type and mixed type. There was no

Closed-loop controlled noninvasive ultrasonic glucose sensing and insulin delivery

Science.gov (United States)

Park, Eun-Joo; Werner, Jacob; Jaiswal, Devina; Smith, Nadine Barrie

2010-03-01

To prevent complications in diabetes, the proper management of blood glucose levels is essential. Previously, ultrasonic transdermal methods using a light-weight cymbal transducer array has been studied for noninvasive methods of insulin delivery for Type-1 diabetes and glucose level monitoring. In this study, the ultrasound systems of insulin delivery and glucose sensing have been combined by a feedback controller. This study was designed to show the feasibility of the feedback controlled ultrasound system for the noninvasive glucose control. For perspective human application, in vivo experiments were performed on large animals that have a similar size to humans. Four in vivo experiments were performed using about 200 lbs pigs. The cymbal array of 3×3 pattern has been used for insulin delivery at 30 kHz with the spatial-peak temporal-peak intensity (Isptp) of 100 mW/cm2. For glucose sensing, a 2×2 array was operated at 20 kHz with Isptp = 100 mW/cm2. Based on the glucose level determined by biosensors after the ultrasound exposure, the ultrasound system for the insulin delivery was automatically operated. The glucose level of 115 mg/dl was set as a reference value for operating the insulin delivery system. For comparison, the glucose levels of blood samples collected from the ear vein were measured by a commercial glucose meter. Using the ultrasound system operated by the close-loop, feed-back controller, the glucose levels of four pigs were determined every 20 minutes and continuously controlled for 120 minutes. In comparison to the commercial glucose meter, the glucose levels determined by the biosensor were slightly higher. The results of in vivo experiments indicate the feasibility of the feedback controlled ultrasound system using the cymbal array for noninvasive glucose sensing and insulin delivery. Further studies on the extension of the glucose control will be continued for the effective method of glucose control.

New photonic devices for ultrafast pulse processing operating on the basis of the diffraction-dispersion analogy

Energy Technology Data Exchange (ETDEWEB)

Torres-Company, Victor; Minguez-Vega, Gladys; Climent, Vicent; Lands, Jesus [GROC-UJI, Departament de Fisica, Universitat Jaume I, 12080 Castello (Spain); Andres, Pedro [Departament d' Optica, Universitat de Valencia, 46100 Burjassot (Spain)], E-mail: lancis@fca.uji.es

2008-11-01

The space-time analogy is a well-known topic within wave optics that brings together some results from beam diffraction and pulse dispersion. On the above basis, and taking as starting point some classical concepts in Optics, several photonic devices have been proposed during the last few years with application in rapidly evolving fields such as ultrafast (femtosecond) optics or RF and microwave signal processing. In this contribution, we briefly review the above ideas with particular emphasis in the generation of trains of ultrafast pulses from periodic modulation of the phase of a CW laser source. This is the temporal analogue of Fresnel diffraction by a pure phase grating. Finally, we extend the analogy to the partially coherent case, what enables us to design an original technique for wavelength-to-time mapping of the spectrum of a temporally stationary source. Results of laboratory experiments concerning the generation of user-defined radio-frequency waveforms and filtering of microwave signals will be shown. The devices are operated with low-cost incoherent sources.

Dispersion bias, dispersion effect, and the aerosol-cloud conundrum

International Nuclear Information System (INIS)

Liu Yangang; Daum, Peter H; Guo Huan; Peng Yiran

2008-01-01

This work examines the influences of relative dispersion (the ratio of the standard deviation to the mean radius of the cloud droplet size distribution) on cloud albedo and cloud radiative forcing, derives an analytical formulation that accounts explicitly for the contribution from droplet concentration and relative dispersion, and presents a new approach to parameterize relative dispersion in climate models. It is shown that inadequate representation of relative dispersion in climate models leads to an overestimation of cloud albedo, resulting in a negative bias of global mean shortwave cloud radiative forcing that can be comparable to the warming caused by doubling CO 2 in magnitude, and that this dispersion bias is likely near its maximum for ambient clouds. Relative dispersion is empirically expressed as a function of the quotient between cloud liquid water content and droplet concentration (i.e., water per droplet), yielding an analytical formulation for the first aerosol indirect effect. Further analysis of the new expression reveals that the dispersion effect not only offsets the cooling from the Twomey effect, but is also proportional to the Twomey effect in magnitude. These results suggest that unrealistic representation of relative dispersion in cloud parameterization in general, and evaluation of aerosol indirect effects in particular, is at least in part responsible for several outstanding puzzles of the aerosol-cloud conundrum: for example, overestimation of cloud radiative cooling by climate models compared to satellite observations; large uncertainty and discrepancy in estimates of the aerosol indirect effect; and the lack of interhemispheric difference in cloud albedo.

Preparation of Well-Dispersed Chitosan/Alginate Hollow Multilayered Microcapsules for Enhanced Cellular Internalization

Directory of Open Access Journals (Sweden)

Carla Ribeiro

2018-03-01

Full Text Available Hollow multilayered capsules have shown massive potential for being used in the biomedical and biotechnology fields, in applications such as cellular internalization, intracellular trafficking, drug delivery, or tissue engineering. In particular, hollow microcapsules, developed by resorting to porous calcium carbonate sacrificial templates, natural-origin building blocks and the prominent Layer-by-Layer (LbL technology, have attracted increasing attention owing to their key features. However, these microcapsules revealed a great tendency to aggregate, which represents a major hurdle when aiming for cellular internalization and intracellular therapeutics delivery. Herein, we report the preparation of well-dispersed polysaccharide-based hollow multilayered microcapsules by combining the LbL technique with an optimized purification process. Cationic chitosan (CHT and anionic alginate (ALG were chosen as the marine origin polysaccharides due to their biocompatibility and structural similarity to the extracellular matrices of living tissues. Moreover, the inexpensive and highly versatile LbL technology was used to fabricate core-shell microparticles and hollow multilayered microcapsules, with precise control over their composition and physicochemical properties, by repeating the alternate deposition of both materials. The microcapsules’ synthesis procedure was optimized to extensively reduce their natural aggregation tendency, as shown by the morphological analysis monitored by advanced microscopy techniques. The well-dispersed microcapsules showed an enhanced uptake by fibroblasts, opening new perspectives for cellular internalization.

Recent results of PADReS, the Photon Analysis Delivery and REduction System, from the FERMI FEL commissioning and user operations.

Science.gov (United States)

Zangrando, Marco; Cocco, Daniele; Fava, Claudio; Gerusina, Simone; Gobessi, Riccardo; Mahne, Nicola; Mazzucco, Eric; Raimondi, Lorenzo; Rumiz, Luca; Svetina, Cristian

2015-05-01

The Photon Analysis Delivery and REduction System of FERMI (PADReS) has been routinely used during the machine commissioning and operations of FERMI since 2011. It has also served the needs of several user runs at the facility from late 2012. The system is endowed with online and shot-to-shot diagnostics giving information about intensity, spatial-angular distribution, spectral content, as well as other diagnostics to determine coherence, pulse length etc. Moreover, PADReS is capable of manipulating the beam in terms of intensity and optical parameters. Regarding the optics, besides a standard refocusing system based on an ellipsoidal mirror, the Kirkpatrick-Baez active optics systems are key elements and have been used intensively to meet users' requirements. A general description of the system is given, together with some selected results from the commissioning/operations/user beam time.

Oral fast-dissolving drug delivery membranes prepared from electrospun polyvinylpyrrolidone ultrafine fibers

International Nuclear Information System (INIS)

Yu Dengguang; Shen Xiaxia; Zhu Limin; Branford-White, Chris; White, Kenneth; Annie Bligh, S W

2009-01-01

Oral fast-dissolving drug delivery membranes (FDMs) for poorly water-soluble drugs were prepared via electrospinning technology with ibuprofen as the model drug and polyvinylpyrrolidone (PVP) K30 as the filament-forming polymer and drug carrier. Results from differential scanning calorimetry, x-ray diffraction, and morphological observations demonstrated that ibuprofen was distributed in the ultrafine fibers in the form of nanosolid dispersions and the physical status of drug was an amorphous or molecular form, different from that of the pure drug and a physical mixture of PVP and ibuprofen. Fourier-transform infrared spectroscopy results illustrated that the main interactions between PVP and ibuprofen were mediated through hydrogen bonding. Pharmacotechnical tests showed that FDMs with different drug contents had almost the same wetting and disintegrating times, about 15 and 8 s, respectively, but significantly different drug dissolution rates due to the different physical status of the drug and the different drug-release-controlled mechanisms. 84.9% and 58.7% of ibuprofen was released in the first 20 s for FDMs with a drug-to-PVP ratio of 1:4 and 1:2, respectively. Electrospun ultrafine fibers have the potential to be used as solid dispersions to improve the dissolution profiles of poorly water-soluble drugs or as oral fast disintegrating drug delivery systems.

Dispersion, sorption and photodegradation of petroleum hydrocarbons in dispersant-seawater-sediment systems.

Science.gov (United States)

Zhao, Xiao; Liu, Wen; Fu, Jie; Cai, Zhengqing; O'Reilly, S E; Zhao, Dongye

2016-08-15

This work examined effects of model oil dispersants on dispersion, sorption and photodegradation of petroleum hydrocarbons in simulated marine systems. Three dispersants (Corexit 9500A, Corexit 9527A and SPC 1000) were used to prepare dispersed water accommodated oil (DWAO). While higher doses of dispersants dispersed more n-alkanes and PAHs, Corexit 9500A preferentially dispersed C11-C20 n-alkanes, whereas Corexit 9527A was more favorable for smaller alkanes (C10-C16), and SPC 1000 for C12-C28 n-alkanes. Sorption of petroleum hydrocarbons on sediment was proportional to TPH types/fractions in the DWAOs. Addition of 18mg/L of Corexit 9500A increased sediment uptake of 2-3 ring PAHs, while higher dispersant doses reduced the uptake, due to micelle-enhanced solubilization effects. Both dispersed n-alkanes and PAHs were susceptible to photodegradation under simulated sunlight. For PAHs, both photodegradation and photo-facilitated alkylation were concurrently taking place. The information can facilitate sounder assessment of fate and distribution of dispersed oil hydrocarbons in marine systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

A novel technique to determine concentration-dependent solvent dispersion in Vapex

Energy Technology Data Exchange (ETDEWEB)

Abukhalifeh, H.; Lohi, A.; Upreti, S. R. [Department of Chemical Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3 (Canada)

2009-07-01

Vapex (vapor extraction of heavy oil and bitumen) is a promising recovery technology because it consumes low energy, and is very environmentally-friendly. The dispersion of solvents into heavy oil and bitumen is a crucial transport property governing Vapex. The accurate determination of solvent dispersion in Vapex is essential to effectively predict the amount and time scale of oil recovery as well to optimize the field operations. In this work, a novel technique is developed to experimentally determine the concentration-dependent dispersion coefficient of a solvent in Vapex process. The principles of variational calculus are utilized in conjunction with a mass transfer model of the experimental Vapex process. A computational algorithm is developed to optimally compute solvent dispersion as a function of its concentration in heavy oil. The developed technique is applied to Vapex utilizing propane as a solvent. The results show that dispersion of propane is a unimodal function of its concentration in bitumen. (author)

A Novel Technique to Determine Concentration-Dependent Solvent Dispersion in Vapex

Directory of Open Access Journals (Sweden)

Hadil Abukhalifeh

2009-10-01

Full Text Available Vapex (vapor extraction of heavy oil and bitumen is a promising recovery technology because it consumes low energy, and is very environmentally-friendly. The dispersion of solvents into heavy oil and bitumen is a crucial transport property governing Vapex. The accurate determination of solvent dispersion in Vapex is essential to effectively predict the amount and time scale of oil recovery as well to optimize the field operations. In this work, a novel technique is developed to experimentally determine the concentration-dependent dispersion coefficient of a solvent in Vapex process. The principles of variational calculus are utilized in conjunction with a mass transfer model of the experimental Vapex process. A computational algorithm is developed to optimally compute solvent dispersion as a function of its concentration in heavy oil. The developed technique is applied to Vapex utilizing propane as a solvent. The results show that dispersion of propane is a unimodal function of its concentration in bitumen.

Fabrication of luminescent hydroxyapatite nanorods through surface-initiated RAFT polymerization: Characterization, biological imaging and drug delivery applications

Energy Technology Data Exchange (ETDEWEB)

Heng, Chunning [Shaanxi Key Laboratory of Degradable Biomedical Materials, Shaanxi R& D Center of Biomaterials and Fermentation Engineering, School of Chemical and Engineering, Northwest University, Xi’an, 710069 (China); Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Zheng, Xiaoyan [Shaanxi Key Laboratory of Degradable Biomedical Materials, Shaanxi R& D Center of Biomaterials and Fermentation Engineering, School of Chemical and Engineering, Northwest University, Xi’an, 710069 (China); Liu, Meiying; Xu, Dazhuang; Huang, Hongye; Deng, Fengjie [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Hui, Junfeng, E-mail: huijunfeng@126.com [Shaanxi Key Laboratory of Degradable Biomedical Materials, Shaanxi R& D Center of Biomaterials and Fermentation Engineering, School of Chemical and Engineering, Northwest University, Xi’an, 710069 (China); Zhang, Xiaoyong, E-mail: xiaoyongzhang1980@gmail.com [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Wei, Yen, E-mail: weiyen@tsinghua.edu.cn [Department of Chemistry and the Tsinghua Center for Frontier Polymer Research, Tsinghua University, Beijing, 100084 (China)

2016-11-15

Highlights: • Hydrophobic hydroxyapatite nanorods were obtained from hydrothermal synthesis. • Surface initiated RAFT polymerization was adopted to surface modification of hydroxyapatite nanorods. • These modified hydroxyapatite nanorods showed high water dispersibility and biocompatibility. • These modified hydroxyapatite nanorods can be used for controlled drug delivery. - Abstract: Hydroxyapatite nanomaterials as an important class of nanomaterials, have been widely applied for different biomedical applications for their excellent biocompatibility, biodegradation potential and low cost. In this work, hydroxyapatite nanorods with uniform size and morphology were prepared through hydrothermal synthesis. The surfaces of these hydroxyapatite nanorods are covered with hydrophobic oleic acid, making them poor dispersibility in aqueous solution and difficult for biomedical applications. To overcome this issue, a simple surface initiated polymerization strategy has been developed via combination of the surface ligand exchange and reversible addition fragmentation chain transfer (RAFT) polymerization. Hydroxyapatite nanorods were first modified with Riboflavin-5-phosphate sodium (RPSSD) via ligand exchange reaction between the phosphate group of RPSSD and oleic acid. Then hydroxyl group of nHAp-RPSSD was used to immobilize chain transfer agent, which was used as the initiator for surface-initiated RAFT polymerization. The nHAp-RPSSD-poly(IA-PEGMA) nanocomposites were characterized by means of {sup 1}H nuclear magnetic resonance, Fourier transform infrared spectroscopy, fluorescence spectroscopy and thermal gravimetric analysis in detailed. The biocompatibility, biological imaging and drug delivery of nHAp-RPSSD-poly(IA-PEGMA) were also investigated. Results showed that nHAp-RPSSD-poly(IA-PEGMA) exhibited excellent water dispersibility, desirable optical properties, good biocompatibility and high drug loading capability, making them promising candidates for

Fabrication of luminescent hydroxyapatite nanorods through surface-initiated RAFT polymerization: Characterization, biological imaging and drug delivery applications

International Nuclear Information System (INIS)

Heng, Chunning; Zheng, Xiaoyan; Liu, Meiying; Xu, Dazhuang; Huang, Hongye; Deng, Fengjie; Hui, Junfeng; Zhang, Xiaoyong; Wei, Yen

2016-01-01

Highlights: • Hydrophobic hydroxyapatite nanorods were obtained from hydrothermal synthesis. • Surface initiated RAFT polymerization was adopted to surface modification of hydroxyapatite nanorods. • These modified hydroxyapatite nanorods showed high water dispersibility and biocompatibility. • These modified hydroxyapatite nanorods can be used for controlled drug delivery. - Abstract: Hydroxyapatite nanomaterials as an important class of nanomaterials, have been widely applied for different biomedical applications for their excellent biocompatibility, biodegradation potential and low cost. In this work, hydroxyapatite nanorods with uniform size and morphology were prepared through hydrothermal synthesis. The surfaces of these hydroxyapatite nanorods are covered with hydrophobic oleic acid, making them poor dispersibility in aqueous solution and difficult for biomedical applications. To overcome this issue, a simple surface initiated polymerization strategy has been developed via combination of the surface ligand exchange and reversible addition fragmentation chain transfer (RAFT) polymerization. Hydroxyapatite nanorods were first modified with Riboflavin-5-phosphate sodium (RPSSD) via ligand exchange reaction between the phosphate group of RPSSD and oleic acid. Then hydroxyl group of nHAp-RPSSD was used to immobilize chain transfer agent, which was used as the initiator for surface-initiated RAFT polymerization. The nHAp-RPSSD-poly(IA-PEGMA) nanocomposites were characterized by means of "1H nuclear magnetic resonance, Fourier transform infrared spectroscopy, fluorescence spectroscopy and thermal gravimetric analysis in detailed. The biocompatibility, biological imaging and drug delivery of nHAp-RPSSD-poly(IA-PEGMA) were also investigated. Results showed that nHAp-RPSSD-poly(IA-PEGMA) exhibited excellent water dispersibility, desirable optical properties, good biocompatibility and high drug loading capability, making them promising candidates for biological

The operation and maintenance of the SLAR system at Bruce A

Energy Technology Data Exchange (ETDEWEB)

Ahuja, S [Ontario Hydro, Tiverton, ON (Canada). Bruce Nuclear Generating Station-A

1997-12-31

The SLAR (Spacer Location And Repositioning) system at Bruce A consists of two (2) Delivery Machines and a Fuelling Machine Trolley equipped with the D{sub 2}0 and Air auxiliary systems. The Delivery Machines are designed to perform all the Fuelling Machine operations and have the capability to rapidly defuel/refuel a reactor channel and traverse the SLAR tool to locate and reposition the spacers in the channel. The number of functions that a Delivery Machine must perform makes it more complex as compared to the operations of a Fuelling Machine. The paper discusses the operation of the SLAR Delivery Machines and the problems encountered with the operation and maintenance of this system at Bruce A. (author). 8 figs.

A novel nanoemulsion-based method to produce ultrasmall, water-dispersible nanoparticles from chitosan, surface modified with cell-penetrating peptide for oral delivery of proteins and peptides

Directory of Open Access Journals (Sweden)

Barbari GR

2017-05-01

Full Text Available Ghullam Reza Barbari,1 Farid Abedin Dorkoosh,1 Mohsen Amini,2 Mohammad Sharifzadeh,3 Fateme Atyabi,1 Saeed Balalaie,4 Niyousha Rafiee Tehrani,5 Morteza Rafiee Tehrani1 1Department of Pharmaceutics, 2Department of Medicinal Chemistry, 3Department of Pharmacology, School of Pharmacy, Tehran University of Medical Sciences, 4Department of Chemistry, Khaje Nasiroddin University, 5Department of Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Abstract: A simple and reproducible water-in-oil (W/O nanoemulsion technique for making ultrasmall (<15 nm, monodispersed and water-dispersible nanoparticles (NPs from chitosan (CS is reported. The nano-sized (50 nm water pools of the W/O nanoemulsion serve as “nano-containers and nano-reactors”. The entrapped polymer chains of CS inside these “nano-reactors” are covalently cross-linked with the chains of polyethylene glycol (PEG, leading to rigidification and formation of NPs. These NPs possess excessive swelling properties in aqueous medium and preserve integrity in all pH ranges due to chemical cross-linking with PEG. A potent and newly developed cell-penetrating peptide (CPP is further chemically conjugated to the surface of the NPs, leading to development of a novel peptide-conjugated derivative of CS with profound tight-junction opening properties. The CPP-conjugated NPs can easily be loaded with almost all kinds of proteins, peptides and nucleotides for oral delivery applications. Feasibility of this nanoparticulate system for oral delivery of a model peptide (insulin is investigated in Caco-2 cell line. The cell culture results for translocation of insulin across the cell monolayer are very promising (15%–19% increase, and animal studies are actively under progress and will be published separately. Keywords: ultrasmall, cell-penetrating peptide, chitosan, oral insulin, nanoemulsion, Caco-2 cell

Risk Factors Associated with Preterm Delivery after Fetoscopic Laser Surgery for Twin Twin Transfusion Syndrome

Science.gov (United States)

PAPANNA, Ramesha; BLOCK-ABRAHAM, Dana; Mann, Lovepreet K; BUHIMSCHI, Irina A.; BEBBINGTON, Michael; GARCIA, Elisa; KAHLEK, Nahla; HARMAN, Christopher; JOHNSON, Anthony; BASCHAT, Ahmet; MOISE, Kenneth J.

2014-01-01

OBJECTIVE Despite improved perinatal survival following fetoscopic laser surgery (FLS) for twin twin transfusion syndrome (TTTS), prematurity remains an important contributor to perinatal mortality and morbidity. The objective of the study was to identify risk factors for complicated preterm delivery after FLS. STUDY DESIGN Retrospective cohort study of prospectively collected data on maternal/fetal demographics and pre-operative, operative and post-operative variables of 459 patients treated in 3 U.S. fetal centers. Multivariate linear regression was performed to identify significant risk factors associated with preterm delivery, which was cross-validated using K-fold method. Multivariate logistic regression was performed to identify risk factors for early vs. late preterm delivery based on median gestational age at delivery of 32 weeks. RESULTS There were significant differences in case selection and outcomes between the centers. After controlling for the center of surgery, a multivariate analysis indicated a lower maternal age at procedure, history of previous prematurity, shortened cervical length, use of amnioinfusion, 12 Fr cannula diameter, lack of a collagen plug placement and iatrogenic preterm premature rupture of membranes (iPPROM) were significantly associated with a lower gestational age at delivery. CONCLUSION Specific fetal/maternal and operative variables are associated with preterm delivery after FLS for the treatment of TTTS. Further studies to modify some of these variables may decrease the perinatal morbidity after laser therapy. PMID:24013922

Post delivery test report for light duty utility arm optical alignment system (OAS)

International Nuclear Information System (INIS)

Pardini, A.F.

1996-01-01

This report documents the post delivery testing of the Optical Alignment System (OAS) LDUA system, designed for use by the Light Duty Utility Arm (LDUA) project. The post delivery test shows by demonstration that the optical alignment system is fully operational to perform the task of aligning the LDUA arm and mast with the entry riser during deployment operations within a Hanford Site waste tank

Post delivery test report for light duty utility arm optical alignment system (OAS)

Energy Technology Data Exchange (ETDEWEB)

Pardini, A.F.

1996-04-18

This report documents the post delivery testing of the Optical Alignment System (OAS) LDUA system, designed for use by the Light Duty Utility Arm (LDUA) project. The post delivery test shows by demonstration that the optical alignment system is fully operational to perform the task of aligning the LDUA arm and mast with the entry riser during deployment operations within a Hanford Site waste tank.

Enteric-coated capsules filled with mono-disperse micro-particles containing PLGA-lipid-PEG nanoparticles for oral delivery of insulin.

Science.gov (United States)

Yu, Fei; Li, Yang; Liu, Chang Sheng; Chen, Qin; Wang, Gui Huan; Guo, Wei; Wu, Xue E; Li, Dong Hui; Wu, Winston Duo; Chen, Xiao Dong

2015-04-30

The success of the oral delivery of insulin (INS) as a therapeutic protein drug would significantly improve the quality of life of diabetic patients who would otherwise receive multiple daily INS injections. The oral delivery of INS, however, is still limited in its delivery efficiency, which could be due to the chemical, enzymatic, and adsorption barriers. In this work, in an attempt to improve the delivery efficiency, the INS-loaded polymer-lipid hybrid nanoparticles (INS-PLGA-lipid-PEG NPs) were designed and constructed through a double-emulsion solvent evaporation technique, followed by formulation of the spherical micro-particles using a spray freeze dryer (SFD). This kind of dryers has a uniquely designed microfluidic aerosol nozzle (MFAN), ensuring the formation of uniform particles. The resulted particles of ∼212 μm could easily be reverted to discrete INS-PLGA-lipid-PEG NPs in an aqueous solution. The INS-PLGA-lipid-PEG NPs created in this work showed a highly negative surface charge, excellent entrapment efficiency (92.3%) and a sustained drug release (∼24 h). Confocal laser scanning microscopy and flow cytometer were used to show that the cellular uptake efficiency for the INS-PLGA-lipid-PEG NPs was more effective than the INS in Caco-2 cells. More importantly, the in vivo pharmacodynamics demonstrated that the orally delivered system induced a prolonged decrease in blood glucose levels among diabetic rats. The relative bioavailability of INS compared with subcutaneous injection in diabetic rats was found to be approximately 12%. These results suggested that the encapsulated INS-PLGA-lipid-PEG NPs are promising and should be investigated further in the near future as an effective INS oral delivery system. Copyright © 2015. Published by Elsevier B.V.

Effects of chemical dispersants on oil physical properties and dispersion. Volume 1

International Nuclear Information System (INIS)

Khelifa, A.; Fingas, M.; Hollebone, B.P.; Brown, C.E.; Pjontek, D.

2007-01-01

Laboratory and field testing have shown that the dispersion of oil spilled in water is influenced by chemical dispersants via the modification of the interfacial properties of the oil, such as oil-brine interfacial tension (IFT). This study focused on new laboratory experiments that measured the effects on the physical properties and dispersion of oil, with particular reference to the effects of chemical dispersants on IFT and oil viscosity and the subsequent effects on oil droplet formation. Experiments were conducted at 15 degrees C using Arabian Medium, Alaska North Slope and South Louisiana crude and Corexit 9500 and Corexit 9527 chemical dispersants. The dispersants were denser than the 3 oils. The effect of IFT reduction on oil dispersion was measured and showed substantial reduction in the size and enhancement of the concentration of oil droplets in the water column. It was shown that the brine-oil IFT associated with the 3 crudes reduced to less than 3.6 mN/m with the application of the chemical dispersants, even at a low dispersant-to-oil ratio (DOR) value of 1:200. The use of chemical dispersants increased the viscosity of the dispersant-oil mixture up to 40 per cent over the neat crude oil. It was shown that for each mixing condition, an optimum value of DOR exists that provides for maximal dispersant effectiveness. The IFT reaches maximum reduction at optimum DOR. It was suggested that oil spill modelling can be improved with further study of IFT reduction with DOR and variations of critical micelle concentration with the type and solubility of chemical dispersant, oil type and oil to water ratio. 13 refs., 3 tabs., 7 figs

Delivery after external cephalic version, is there an increased rate of cesarian section?

Science.gov (United States)

Lago Leal, Victor; Pradillo Aramendi, Tamara; Nicolas Montero, Estefania; Ocaña Martínez, Vanesa; Del Barrio Fernández, Pablo; Martínez-Cortés, Luis

2016-04-01

The aim of this study was to compare the obstetric outcomes after successful external cephalic version (cases) with a group of pregnant women with a spontaneous cephalic fetal position at delivery (controls). Retrospective review of the cohort of study was performed at the University Hospital of Getafe (Madrid, Spain) between January 2012 and January 2013. 1516 patients (48 cases; 1468 controls). We compared the type of delivery in pregnant women after ECV performed successfully (cases) with spontaneous cephalic presentations (controls). Pregnancies with vaginal delivery contraindicated, elective cesarean section (CS) justified by maternal disease, multiple pregnancies, or pregnancies below 37 weeks were excluded. Maternal age, BMI, parity, gestational age at delivery, and onset of labor (spontaneous or induced) were controlled. Prevalence of CS and operative delivery in both groups. Women who underwent a successful ECV had a significantly higher CS rate compared with the women of the control group (12/48 [25%] vs. 202/1468 [13.76%]; P=0.028). There was no difference in the rate of operative delivery (6/48 [12.5%] vs. 177/1468 [12.05%] P=0.92). Deliveries following a successful ECV are associated with an increased CS rate compared with deliveries of fetuses with spontaneous cephalic presentations.

Operational evaluation of the RLINE dispersion model for studies of traffic-related air pollutants

Science.gov (United States)

Milando, Chad W.; Batterman, Stuart A.

2018-06-01

Exposure to traffic-related air pollutants (TRAP) remains a key public health issue, and improved exposure measures are needed to support health impact and epidemiologic studies and inform regulatory responses. The recently developed Research LINE source model (RLINE), a Gaussian line source dispersion model, has been used in several epidemiologic studies of TRAP exposure, but evaluations of RLINE's performance in such applications have been limited. This study provides an operational evaluation of RLINE in which predictions of NOx, CO and PM2.5 are compared to observations at air quality monitoring stations located near high traffic roads in Detroit, MI. For CO and NOx, model performance was best at sites close to major roads, during downwind conditions, during weekdays, and during certain seasons. For PM2.5, the ability to discern local and particularly the traffic-related portion was limited, a result of high background levels, the sparseness of the monitoring network, and large uncertainties for certain processes (e.g., formation of secondary aerosols) and non-mobile sources (e.g., area, fugitive). Overall, RLINE's performance in near-road environments suggests its usefulness for estimating spatially- and temporally-resolved exposures. The study highlights considerations relevant to health impact and epidemiologic applications, including the importance of selecting appropriate pollutants, using appropriate monitoring approaches, considering prevailing wind directions during study design, and accounting for uncertainty.

Health care operations management

NARCIS (Netherlands)

Carter, M.W.; Hans, Elias W.; Kolisch, R.

2012-01-01

Health care operations management has become a major topic for health care service providers and society. Operations research already has and further will make considerable contributions for the effective and efficient delivery of health care services. This special issue collects seven carefully

Constructing of DNA vectors with controlled nanosize and single dispersion by block copolymer coating gold nanoparticles as template assembly

Energy Technology Data Exchange (ETDEWEB)

Li, Junbo, E-mail: Lijunbo@haust.edu.cn [Henan University of Science and Technology, School of Chemical Engineering and Pharmaceutics (China); Wu, Wenlan [Henan University of Science and Technology, School of Medicine (China); Gao, Jiayu; Liang, Ju; Zhou, Huiyun; Liang, Lijuan [Henan University of Science and Technology, School of Chemical Engineering and Pharmaceutics (China)

2017-03-15

Synthesized vectors with nanoscale size and stable colloid dispersion are highly desirable for improving gene delivery efficiency. Here, a core-shell template particle was constructed with polyethylene glycol-b-poly1-(3-aminopropyl)-3-(2-methacryloyloxy propylimidazolium bromine) (PEG-b-PAMPImB) coating gold nanoparticles (PEG-b-PAMPImB-@-Au NPs) for loading DNA and delivering in vitro. Data from transmission electron microscopy (TEM) and dynamic light scattering (DLS) suggest that these nanoplexes, by forming an electrostatic complex with DNA at the inner PAMPImB shell, offer steric protection for the outer PEG corona leading to single dispersion and small size. Notably, higher colloid stability and lower cytotoxicity were achieved with these nanoplexes when compared with PAMPImB monolayer-coated gold nanoparticles (Au NPs). Confocal laser scanning microscopy and intracellular trafficking TEM further indicate that the nanoplexes can translocate across the cell membrane and partly enter the nucleus for high efficient expression. Thus, template assembly represents a promising approach to control the size and colloid stability of gene vectors and ensure safety and efficiency of DNA delivery.

Constructing of DNA vectors with controlled nanosize and single dispersion by block copolymer coating gold nanoparticles as template assembly

Science.gov (United States)

Li, Junbo; Wu, Wenlan; Gao, Jiayu; Liang, Ju; Zhou, Huiyun; Liang, Lijuan

2017-03-01

Synthesized vectors with nanoscale size and stable colloid dispersion are highly desirable for improving gene delivery efficiency. Here, a core-shell template particle was constructed with polyethylene glycol- b-poly1-(3-aminopropyl)-3-(2-methacryloyloxy propylimidazolium bromine) (PEG- b-PAMPImB) coating gold nanoparticles (PEG- b-PAMPImB-@-Au NPs) for loading DNA and delivering in vitro. Data from transmission electron microscopy (TEM) and dynamic light scattering (DLS) suggest that these nanoplexes, by forming an electrostatic complex with DNA at the inner PAMPImB shell, offer steric protection for the outer PEG corona leading to single dispersion and small size. Notably, higher colloid stability and lower cytotoxicity were achieved with these nanoplexes when compared with PAMPImB monolayer-coated gold nanoparticles (Au NPs). Confocal laser scanning microscopy and intracellular trafficking TEM further indicate that the nanoplexes can translocate across the cell membrane and partly enter the nucleus for high efficient expression. Thus, template assembly represents a promising approach to control the size and colloid stability of gene vectors and ensure safety and efficiency of DNA delivery.

ENSEMBLE methods to reconcile disparate national long range dispersion forecasting

Energy Technology Data Exchange (ETDEWEB)

Mikkelsen, T; Galmarini, S; Bianconi, R; French, S [eds.

2003-11-01

ENSEMBLE is a web-based decision support system for real-time exchange and evaluation of national long-range dispersion forecasts of nuclear releases with cross-boundary consequences. The system is developed with the purpose to reconcile among disparate national forecasts for long-range dispersion. ENSEMBLE addresses the problem of achieving a common coherent strategy across European national emergency management when national long-range dispersion forecasts differ from one another during an accidental atmospheric release of radioactive material. A series of new decision-making 'ENSEMBLE' procedures and Web-based software evaluation and exchange tools have been created for real-time reconciliation and harmonisation of real-time dispersion forecasts from meteorological and emergency centres across Europe during an accident. The new ENSEMBLE software tools is available to participating national emergency and meteorological forecasting centres, which may choose to integrate them directly into operational emergency information systems, or possibly use them as a basis for future system development. (au)

ENSEMBLE methods to reconcile disparate national long range dispersion forecasting

Energy Technology Data Exchange (ETDEWEB)

Mikkelsen, T.; Galmarini, S.; Bianconi, R.; French, S. (eds.)

2003-11-01

ENSEMBLE is a web-based decision support system for real-time exchange and evaluation of national long-range dispersion forecasts of nuclear releases with cross-boundary consequences. The system is developed with the purpose to reconcile among disparate national forecasts for long-range dispersion. ENSEMBLE addresses the problem of achieving a common coherent strategy across European national emergency management when national long-range dispersion forecasts differ from one another during an accidental atmospheric release of radioactive material. A series of new decision-making 'ENSEMBLE' procedures and Web-based software evaluation and exchange tools have been created for real-time reconciliation and harmonisation of real-time dispersion forecasts from meteorological and emergency centres across Europe during an accident. The new ENSEMBLE software tools is available to participating national emergency and meteorological forecasting centres, which may choose to integrate them directly into operational emergency information systems, or possibly use them as a basis for future system development. (au)

Removal of Disperse Blue 56 and Disperse Red 135 dyes from aqueous dispersions by modified montmorillonite nanoclay

Directory of Open Access Journals (Sweden)

Ahmadishoar Javad

2017-01-01

Full Text Available In this study modified montmorillonite was used as an adsorbent for the removal of two selected disperse dyes i.e., Disperse Blue 56 (DB and Disperse Red 135 (DR from dye dispersions. The adsorption equilibrium data of dyes adsorption were investigated by using Nernst, Freundlich and Langmuir isotherm models. The adsorption kinetics was analyzed by using different models including pseudo-first-order, pseudo-second-order, Elovich and Intraparticle diffusion model. The Freundlich isotherm was found to be the most appropriate model for describing the sorption of the dyes on modified nanoclay. The best fit to the experimental results was obtained by using the pseudo-second-order kinetic equation, which satisfactorily described the process of dye adsorption. Although different kinetic models may control the rate of the adsorption process, the results indicated that the main rate limiting step was the intraparticle diffusion. The results showed that the proposed modified montmorillonite could be used as an effective adsorbent for the removal of disperse dyes even from highly concentrated dispersions.

Formulation and characterization of lipid-based drug delivery system of raloxifene-microemulsion and self-microemulsifying drug delivery system

Directory of Open Access Journals (Sweden)

Hetal Thakkar

2011-01-01

Full Text Available Background : Raloxifene, a second-generation selective estrogen receptor modulator (SERM used to prevent osteoporosis in postmenopausal women is administered orally in the form of a tablet. The absolute bioavailability of the drug is only 2% because of extensive hepatic first-pass metabolism. Lipid-based formulations are reported to reduce the first-pass metabolism by promoting its lymphatic uptake. Materials and Methods : In the present investigation, microemulsion and Self-Microemulsifying Drug Delivery System (SMEDDS formulations of Raloxifene were prepared. The prepared formulations were characterized for drug loading, size, transparency, zeta potential, Transmission Electron Microscopy (TEM and in vitro intestinal permeability. Results : The results indicated that high drug loading, optimum size and desired zeta potential and transparency could be achieved with both SMEDDS and microemulsion. The TEM studies indicated the absence of aggregation with both the systems. The in vitro intestinal permeability results showed that the permeation of the drug from the microemulsion and SMEDDs was significantly higher than that obtained from the drug dispersion and marketed formulation. Conclusion : Lipid based formulations such as microemulsion and Self Microemulsifying drug delivery systems are expected to increase the oral bioavailability as evidenced by the increased intestinal permeation.

Formulation and characterization of lipid-based drug delivery system of raloxifene-microemulsion and self-microemulsifying drug delivery system

Science.gov (United States)

Thakkar, Hetal; Nangesh, Jitesh; Parmar, Mayur; Patel, Divyakant

2011-01-01

Background: Raloxifene, a second-generation selective estrogen receptor modulator (SERM) used to prevent osteoporosis in postmenopausal women is administered orally in the form of a tablet. The absolute bioavailability of the drug is only 2% because of extensive hepatic first-pass metabolism. Lipid-based formulations are reported to reduce the first-pass metabolism by promoting its lymphatic uptake. Materials and Methods: In the present investigation, microemulsion and Self-Microemulsifying Drug Delivery System (SMEDDS) formulations of Raloxifene were prepared. The prepared formulations were characterized for drug loading, size, transparency, zeta potential, Transmission Electron Microscopy (TEM) and in vitro intestinal permeability. Results: The results indicated that high drug loading, optimum size and desired zeta potential and transparency could be achieved with both SMEDDS and microemulsion. The TEM studies indicated the absence of aggregation with both the systems. The in vitro intestinal permeability results showed that the permeation of the drug from the microemulsion and SMEDDs was significantly higher than that obtained from the drug dispersion and marketed formulation. Conclusion: Lipid based formulations such as microemulsion and Self Microemulsifying drug delivery systems are expected to increase the oral bioavailability as evidenced by the increased intestinal permeation. PMID:21966167

Delivery through innovation: CSIR research on water services infrastructure operation through franchising

CSIR Research Space (South Africa)

Wall, K

2006-02-01

Full Text Available There is a great need for institutional innovations aimed at improving access to basic water services in South Africa, and sustaining that improvement. In support of effective delivery, the CSIR, with the support of the Water Research Commission...

Nanocomposite thin films for triggerable drug delivery.

Science.gov (United States)

Vannozzi, Lorenzo; Iacovacci, Veronica; Menciassi, Arianna; Ricotti, Leonardo

2018-05-01

Traditional drug release systems normally rely on a passive delivery of therapeutic compounds, which can be partially programmed, prior to injection or implantation, through variations in the material composition. With this strategy, the drug release kinetics cannot be remotely modified and thus adapted to changing therapeutic needs. To overcome this issue, drug delivery systems able to respond to external stimuli are highly desirable, as they allow a high level of temporal and spatial control over drug release kinetics, in an operator-dependent fashion. Areas covered: On-demand drug delivery systems actually represent a frontier in this field and are attracting an increasing interest at both research and industrial level. Stimuli-responsive thin films, enabled by nanofillers, hold a tremendous potential in the field of triggerable drug delivery systems. The inclusion of responsive elements in homogeneous or heterogeneous thin film-shaped polymeric matrices strengthens and/or adds intriguing properties to conventional (bare) materials in film shape. Expert opinion: This Expert Opinion review aims to discuss the approaches currently pursued to achieve an effective on-demand drug delivery, through nanocomposite thin films. Different triggering mechanisms allowing a fine control on drug delivery are described, together with current challenges and possible future applications in therapy and surgery.

Magnetite Nanoparticles Coated with Rifampicin and Chlortetracycline for Drug Delivery Applications

International Nuclear Information System (INIS)

Nadejde, Claudia; Ciurlica, Ecaterina Foca-nici; Creanga, Dorina; Carlescu, Aurelian; Badescu, Vasile

2010-01-01

Four types of biocompatible magnetic fluids based on superparamagnetic nanoparticles with Fe 3 O 4 cores were functionalized with antibiotics (rifampicin or chlortetracycline) as potential candidates for in vivo biomedical applications, such as magnetically controlled drug delivery. The synthesis consisted in coprecipitation of iron oxide in basic, as well as in acid medium, followed by the dispersion of the resulted magnetite nanoparticles in aqueous solution containing the antibiotic. The chosen method to prepare the magnetite-core/drug-shell systems avoided intermediate organic coating of the magnetic nanoparticles. Comparative analysis of the rheological features of the aqueous magnetic fluid samples was performed. The structural features of the coated magnetic particles were investigated by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Vibrating Sample Magnetometry (VSM). Good crystallinity and adequate stability in time were evidenced. Drug delivery curves were spectrophotometrically provided.

Micelles As Delivery System for Cancer Treatment.

Science.gov (United States)

Keskin, Dilek; Tezcaner, Aysen

2017-01-01

Micelles are nanoparticles formed by the self-assembly of amphiphilic block copolymers in certain solvents above concentrations called critical micelle concentration (CMC). Micelles are used in different fields like food, cosmetics, medicine, etc. These nanosized delivery systems are under spotlight in the recent years with new achievements in terms of their in vivo stability, ability to protect entrapped drug, release kinetics, ease of cellular penetration and thereby increased therapeutic efficacy. Drug loaded micelles can be prepared by dialysis, oil-in-water method, solid dispersion, freezing, spray drying, etc. The aim of this review is to give an overview of the research on micelles (in vitro, in vivo and clinical) as delivery system for cancer treatment. Passive targeting is one route for accumulation of nanosized micellar drug formulations. Many research groups from both academia and industry focus on developing new strategies for improving the therapeutic efficacy of micellar systems (active targeting to the tumor site, designing multidrug delivery systems for overcoming multidrug resistance or micelles formed by prodrug conjugates, etc). There is only one micellar drug formulation in South Korea that has reached clinical practice. However, there are many untargeted anticancer drug loaded micellar formulations in clinical trials, which have potential for use in clinics. Many more products are expected to be on the market in the near future. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Evaluation of the dispersion effect in through movement bicycles at signalized intersection via cellular automata simulation

Science.gov (United States)

Jiang, Hang; Ma, Yongjian; Jiang, Lin; Chen, Guozhou; Wang, Dongwei

2018-05-01

At signalized intersection areas, bicycle traffic presents a dispersion feature which may influence the movements of vehicles during peak period. The primary objective of this study is to simulate the dispersion effect in through-movement bicycle traffic at intersection areas and evaluate its influence on through-movement traffic. A cellular automata (CA) model is developed and validated to simulate the operations of through-movement bicycle traffic departing from two types of intersection approaches. Simulation results show that bicycles benefit from the dispersion effect when they depart from the approach with an exclusive right-turn vehicle lane. But when bicycles travel from the approach with a shared right-turn and through vehicle lane, the dispersion effect will result in friction interference and block interference on through-movement vehicles. Bicycle interferences reduce the vehicle speed and increase the delay of through-movement vehicles. The policy implications in regard to the dispersion effect from two types of approaches are discussed to improve the performance of through-movement traffic operations at signalized intersections.

The case for using vessel-based systems to apply oil-spill dispersants

International Nuclear Information System (INIS)

Ross, S.

1998-01-01

Most emergency plans for dealing with marine oil spills include the use of chemical dispersants. This paper presents a comparison between the capabilities of aircraft-based dispersant application systems and vessel-based systems. The comparison was presented in terms of the logistics of treating offshore spills. Vessel-based systems have certain advantages in terms of their availability and cost. They have better spray control and accuracy and can dose thick slicks in one pass. However, this advantage is lost if the dispersant payload on the vessel is relatively small and the spill is located very far from the base of operations. Under certain conditions, vessel-based dispersant application systems can treat spills as quickly as aircraft-based systems. Most marine spills tend to occur in restricted waters near ports where dispersant stockpiles could be stored for ready use by vessels in the area. Development of a modern vessel-based, fire-monitor system for applying chemical dispersant onto marine oil spills was one of the recommendations emerging from the study. 32 refs., 6 tabs., 1 fig

Transfer function of radio over fiber multimode fiber optic links considering third-order dispersion.

Science.gov (United States)

Capmany, J; Gasulla, Ivana

2007-08-20

Although a considerable number of multimode fiber (MMF) links operate in a wavelength region around 850 nm where chromatic dispersion of a given modal group mu is described adequately by the second derivative beta(mu) (2) of the propagation constant beta(mu)(omega), there is also an increasing interest in MMF links transmitting in the second spectral window (@1300nm) where this second derivative vanishes being thus necessary to consider the third derivative beta(mu) (3) in the evaluation of the transfer function of the multimode fiber link. We present in this paper, for the first time to our knowledge, an analytical model for the transfer function of a multimode fiber (MMF) optic link taken into account the impact of third-order dispersion. The model extends the operation of a previously reported one for second-order dispersion. Our results show that the performance of broadband radio over fiber transmission through middle-reach distances can be improved by working at the minimum-dispersion wavelength as long as low-linewidth lasers are employed.

[Delivery of the IUGR fetus].

Science.gov (United States)

Perrotin, F; Simon, E G; Potin, J; Laffon, M

2013-12-01

The purpose of this paper is to review available data regarding the management of delivery in intra uterine growth retarded fetuses and try to get recommendations for clinical obstetrical practice. Bibliographic research performed by consulting PubMed database and recommendations from scientific societies with the following words: small for gestational age, intra-uterine growth restriction, fetal growth restriction, very low birth weight infants, as well as mode of delivery, induction of labor, cesarean section and operative delivery. The diagnosis of severe IUGR justifies the orientation of the patient to a referral centre with all necessary resources for very low birth weight or premature infants Administration of corticosteroids for fetal maturation (before 34 WG) and a possible neuroprotective treatment by with magnesium sulphate (before 32-33 WG) should be discussed. Although elective caesarean section is common, there is no current evidence supporting the use of systematic cesarean section, especially when the woman is in labor. Induction of labor, even with unfavorable cervix is possible under continuous FHR monitoring, in favorable obstetric situations and in the absence of severe fetal hemodynamic disturbances. Instrumental delivery and routine episiotomy are not recommended. For caesarean section under spinal anesthesia, an adequate anesthetic management must ensure the maintenance of basal blood pressure. Compared with appropriate for gestational age fetus, IUGR fetus is at increased risk of metabolic acidosis or perinatal asphyxia during delivery. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

MINI-SLAR delivery system

International Nuclear Information System (INIS)

Alstein, D.

1996-01-01

In the Spring of 1993, a need to complete Spacer Location and Repositioning (SLAR) on the Bruce 'A', Unit 1 Reactor was identified. An alternate SLAR delivery system was required due to conversion constraints that prevented the existing Bruce SLAR System from being used in Unit 1. A Portable SLAR Delivery System called MINI-SLAR Delivery System was developed, designed and fabricated in a 14 month period, then used to successfully SLAR 109 channels. The system is a portable remotely operated Nuclear Class 1 registered fitting that is independent of the Fuelling Machine, allowing the station to continue normal Fuelling and Maintenance activities. It is designed to a Level 'D' faulted condition of HPECI Pressure thus minimizing PHT Heat Sink configuration requirements and minimizing outage set-up times. The system is based on a modular design allowing for easy fabrication, assembly and repair. It consists of a Snout Assembly, a Closure Plug Assembly, Shield Plug Assembly, SLAR Ram assembly, Work Table Assembly and Control Panel. Controls are through a Programmable Logic Controller with software tested and certified to a Software Quality Assurance of Level Ill. (author). 2 refs., 2 figs

MINI-SLAR delivery system

Energy Technology Data Exchange (ETDEWEB)

Alstein, D [Ontario Hydro, Tiverton, ON (Canada). Bruce Nuclear Generating Station-A; Dalton, K [Spectrum Engineering, Peterborough, ON (Canada)

1997-12-31

In the Spring of 1993, a need to complete Spacer Location and Repositioning (SLAR) on the Bruce `A`, Unit 1 Reactor was identified. An alternate SLAR delivery system was required due to conversion constraints that prevented the existing Bruce SLAR System from being used in Unit 1. A Portable SLAR Delivery System called MINI-SLAR Delivery System was developed, designed and fabricated in a 14 month period, then used to successfully SLAR 109 channels. The system is a portable remotely operated Nuclear Class 1 registered fitting that is independent of the Fuelling Machine, allowing the station to continue normal Fuelling and Maintenance activities. It is designed to a Level `D` faulted condition of HPECI Pressure thus minimizing PHT Heat Sink configuration requirements and minimizing outage set-up times. The system is based on a modular design allowing for easy fabrication, assembly and repair. It consists of a Snout Assembly, a Closure Plug Assembly, Shield Plug Assembly, SLAR Ram assembly, Work Table Assembly and Control Panel. Controls are through a Programmable Logic Controller with software tested and certified to a Software Quality Assurance of Level Ill. (author). 2 refs., 2 figs.

Ensemble dispersion forecasting - Part 1. Concept, approach and indicators

DEFF Research Database (Denmark)

Galmarini, S.; Bianconi, R.; Klug, W.

2004-01-01

and is based on the simultaneous analysis of several model simulations by means of ad-hoc statistical treatments and parameters. The models considered in this study are operational long-range transport and dispersion models used to support decision making in various countries in case of accidental releases...

Nanocomposites from Stable Dispersions of Carbon Nanotubes in Polymeric Matrices Using Dispersion Interaction

Science.gov (United States)

Wise, Kristopher Eric (Inventor); Park, Cheol (Inventor); Kang, Jin Ho (Inventor); Siochi, Emilie J. (Inventor); Harrison, Joycelyn S. (Inventor)

2016-01-01

Stable dispersions of carbon nanotubes (CNTs) in polymeric matrices include CNTs dispersed in a host polymer or copolymer whose monomers have delocalized electron orbitals, so that a dispersion interaction results between the host polymer or copolymer and the CNTs dispersed therein. Nanocomposite products, which are presented in bulk, or when fabricated as a film, fiber, foam, coating, adhesive, paste, or molding, are prepared by standard means from the present stable dispersions of CNTs in polymeric matrices, employing dispersion interactions, as presented hereinabove.

Infectious morbidity, operative blood loss, and length of the operative procedure after cesarean delivery by method of placental removal and site of uterine repair.

Science.gov (United States)

Magann, E F; Washburne, J F; Harris, R L; Bass, J D; Duff, W P; Morrison, J C

1995-12-01

This study was done to determine the impact of the method of placental removal and the site of uterine repair on postcesarean infectious morbidity rates in women receiving prophylactic antibiotics at cesarean delivery. This prospective study included 284 women who underwent cesarean delivery and who were randomly assigned to four groups based on the method of placental removal and the site of uterine repair: group 1, spontaneous placental removal and in situ uterine repair; group 2, spontaneous placental removal and exteriorized uterine repair; group 3, manual placental removal and in situ uterine repair; and group 4, manual placental removal with exteriorized uterine repair. Exclusion criteria were repeat cesarean deliveries without labor, active infection at the time of cesarean delivery, and patient refusal to participate. There was no significant difference among the groups in maternal age, race, parity, weight, the length of time from rupture of membranes (ROM) or the number of vaginal examinations from ROM to cesarean delivery, or preoperative hematocrit. Intraoperatively, the type of uterine incision, anesthesia administered, incidence of meconium-stained amniotic fluid, Apgar scores, and cord gases were similar between groups. The incidence of postcesarean endometritis was greater in group 4 (32 [45 percent] of 71, p = 0.003) compared with group 1 (17 [24 percent] of 71), group 2 (12 [30 percent] of 71); and group 3 (13 [18 percent] of 71). Manual placental removal and exteriorization of the uterus for repair of the surgical incision increases the infectious morbidity rate in women receiving prophylactic antibiotics at the time of cesarean delivery and increases the length of hospitalization.

Increased risk of pregnancy-induced hypertension and operative delivery after conception induced by in vitro fertilization/intracytoplasmic sperm injection in women aged 40 years and older.

Science.gov (United States)

Toshimitsu, Masatake; Nagamatsu, Takeshi; Nagasaka, Takaaki; Iwasawa-Kawai, Yuki; Komatsu, Atsushi; Yamashita, Takahiro; Osuga, Yutaka; Fujii, Tomoyuki

2014-10-01

To clarify the association between preconception fertility status and obstetric outcomes in women aged 40 years and older. Retrospective study by reviewing medical records. Tertiary perinatal center in a university hospital. 330 women aged 40 years and older who delivered a singleton from 2006 to 2010, and 450 women aged 30 to 34 years who delivered at the same facility as controls. None. Incidence of pregnancy-induced hypertension, gestational diabetes mellitus, preterm birth, low birth weight, and mode of delivery assessed based on the mode of conception; spontaneous conception (SC) and in vitro fertilization/intracytoplasmic sperm injection conception (IVF-ICSI). The incidence of pregnancy-induced hypertension was statistically significantly higher in IVF-ICSI group than the SC group. This gap was commonly observed in both the women aged 40 years and older and those in the 30 to 34 age group. No statistically significant difference was observed in the frequency of gestational diabetes mellitus, preterm birth, or low birth weight. As a characteristic of nulliparous women of advanced age, the rate of operative delivery, which includes emergency cesarean section and instrumental delivery, was statistically significantly higher in IVF-ICSI group than in the SC group. Detailed investigation into the medical indications for operative delivery revealed that the difference was attributable to the elevated incidence of labor protraction and arrest. Preconception fertility status can be a predicting factor of the incidence of pregnancy-induced hypertension and labor outcome, especially for women aged 40 years and older. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

The North American power delivery system: Balancing market restructuring and environmental economics with infrastructure security

International Nuclear Information System (INIS)

Massoud Amin, S.; Gellings, Clark W.

2006-01-01

The North American electric power system was developed over the last 100 years without a conscious awareness and analysis of the system-wide implications of its current evolution under the forces of deregulation, system complexity, power-market impacts, terrorism, and human error. The possibility of power delivery beyond neighboring areas was a distant secondary consideration. Today, the North American power network may realistically be considered to be the largest machine in the world. With the advent of deregulation and competition in the electric power industry, new ways are being sought to improve the efficiency of that network without seriously diminishing its reliability and security. Controlling a heterogeneous, widely dispersed, yet globally interconnected system is a serious technological problem in any case. It is even more complex and difficult to control it for optimal efficiency and maximum benefit to the ultimate consumers while still allowing all its business components to compete fairly and freely. In this paper we present an overview of key issues and the context in which the electricity infrastructure is being operated under the above forces along with a strategic vision extending to a decade, or longer, that would enable more secure and robust systems operation, security monitoring, and efficient energy markets. (author)

Intradermal delivery of vaccines: potential benefits and current challenges

Science.gov (United States)

Hickling, JK; Jones, KR; Friede, M; Chen, D; Kristensen, D

2011-01-01

Abstract Delivery of vaccine antigens to the dermis and/or epidermis of human skin (i.e. intradermal delivery) might be more efficient than injection into the muscle or subcutaneous tissue, thereby reducing the volumes of antigen. This is known as dose-sparing and has been demonstrated in clinical trials with some, but not all, vaccines. Dose-sparing could be beneficial to immunization programmes by potentially reducing the costs of purchase, distribution and storage of vaccines; increasing vaccine availability and effectiveness. The data obtained with intradermal delivery of some vaccines are encouraging and warrant further study and development; however significant gaps in knowledge and operational challenges such as reformulation, optimizing vaccine presentation and development of novel devices to aid intradermal vaccine delivery need to be addressed. Modelling of the costs and potential savings resulting from intradermal delivery should be done to provide realistic expectations of the potential benefits and to support cases for investment. Implementation and uptake of intradermal vaccine delivery requires further research and development, which depends upon collaboration between multiple stakeholders in the field of vaccination. PMID:21379418

Controlled delivery of antiangiogenic drug to human eye tissue using a MEMS device

KAUST Repository

Pirmoradi, Fatemeh Nazly; Ou, Kevin; Jackson, John K.; Letchford, Kevin; Cui, Jing; Wolf, Ki Tae; Graber, Florian; Zhao, Tom; Matsubara, Joanne A.; Burt, Helen; Chiao, Mu; Lin, Liwei

2013-01-01

We demonstrate an implantable MEMS drug delivery device to conduct controlled and on-demand, ex vivo drug transport to human eye tissue. Remotely operated drug delivery to human post-mortem eyes was performed via a MEMS device. The developed curved

Design, characterization, and aerosolization of organic solution advanced spray-dried moxifloxacin and ofloxacin dipalmitoylphosphatidylcholine (DPPC) microparticulate/nanoparticulate powders for pulmonary inhalation aerosol delivery

Science.gov (United States)

Duan, Jinghua; Vogt, Frederick G; Li, Xiaojian; Hayes, Don; Mansour, Heidi M

2013-01-01

The aim of this study was to design and develop respirable antibiotics moxifloxacin (MOXI) hydrochloride and ofloxacin (OFLX) microparticles and nanoparticles, and multifunctional antibiotics particles with or without lung surfactant 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) for targeted dry powder inhalation delivery as a pulmonary nanomedicine. Particles were rationally designed and produced by advanced spray-drying particle engineering from an organic solution in closed mode (no water) from dilute solution. Scanning electron microscopy indicated that these particles had both optimal particle morphology and surface morphology, and the particle size distributions were suitable for pulmonary delivery. Comprehensive and systematic physicochemical characterization and in vitro aerosol dispersion performance revealed significant differences between these two fluoroquinolone antibiotics following spray drying as drug aerosols and as cospray-dried antibiotic drug: DPPC aerosols. Fourier transform infrared spectroscopy and confocal Raman microspectroscopy were employed to probe composition and interactions in the solid state. Spray-dried MOXI was rendered noncrystalline (amorphous) following organic solution advanced spray drying. This was in contrast to spray-dried OFLX, which retained partial crystallinity, as did OFLX:DPPC powders at certain compositions. Aerosol dispersion performance was conducted using inertial impaction with a dry powder inhaler device approved for human use. The present study demonstrates that the use of DPPC offers improved aerosol delivery of MOXI as cospray-dried microparticulate/nanoparticulate powders, whereas residual partial crystallinity influenced aerosol dispersion of OFLX and most of the compositions of OFLX:DPPC inhalation powders. PMID:24092972

Marine radioactivity studies in the Suez Canal: Modelling hydrodynamics and dispersion

International Nuclear Information System (INIS)

Abril, J.M.; Abdel-Aal, M.M.

1999-01-01

This paper comprises the work carried out under the IAEA Technical Co-operation Project EGY/07/002. The main goal was to develop a modelling study on the dispersion of radioactive pollution in the Suez Canal

A case of vesicouterine fistula after cesarean section with delivery through the bladder

DEFF Research Database (Denmark)

Schroeder, T; Kristensen, J K

1983-01-01

We report a case of a vesicouterine fistula subsequent to delivery at cesarean section through the bladder. A first attempt to close the fistula failed but a second operation adhering to the general principles of fistula repair was successful.......We report a case of a vesicouterine fistula subsequent to delivery at cesarean section through the bladder. A first attempt to close the fistula failed but a second operation adhering to the general principles of fistula repair was successful....

Electrodeless-discharge-vapor-lamp-based Faraday anomalous-dispersion optical filter.

Science.gov (United States)

Sun, Qinqing; Zhuang, Wei; Liu, Zhiwen; Chen, Jingbiao

2011-12-01

We report an excited-state Faraday anomalous-dispersion optical filter operating on the rubidium 5P(3/2)-5D(5/2) transition (775.9 nm in vacuum) without the use of a pump laser. An electrodeless discharge vapor lamp is employed to replace the Rb vapor cell in a traditional Faraday anomalous-dispersion optical filter system. Atoms can be excited by power rather than a complex frequency-locked pump laser. A proof-of-concept experimental demonstration with a maximum transmission of 1.9% and a filter bandwidth of 650 MHz is presented. © 2011 Optical Society of America

Thermal behavior analysis of U-Mo/Al dispersion fuel

Energy Technology Data Exchange (ETDEWEB)

Ryu, Ho Jin; Park, Jong Mang; Lee, Yoon Sang; Kim, Chang Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2004-07-01

According to the non-proliferation policy under the reduced enrichment for research and test reactors (RERTR) program, low enriched uranium(LEU) fuel such as uranium silicide dispersion fuels are being used in research reactors. Because of a lower enrichment higher uranium density fuels are required for some high performance research reactors. Some uranium alloys with a high uranium density such as U-Mo alloys have been considered as one of the most promising candidates for a dispersion fuel due to the good irradiation performance. An international qualification program to replace the uranium silicide dispersion fuel with U-Mo dispersion fuel is being carried out under the RERTR program. Although U-Mo powders are conventionally supplied by the mechanical comminuting of as-cast U-Mo alloys, KAERI developed a centrifugal atomization method in order to simplify the preparation process and improve the properties. The centrifugally atomized powders have a rapidly solidified gamma uranium structure and a spherical shape. During the in-reactor operation of a dispersion fuel, interdiffusion or chemical reactions between the fuel particles and the matrix occurr. Intermetallic compounds in the form of UAlx are formed as a result of the diffusional reaction. Because the intermetallic compounds are less dense than the combined reactants, the volume of the fuel element increases after the reaction. In addition to the effect on the swelling performance, the reaction layers between the U-Mo and the Al matrix induces a degradation of the thermal properties of the U-Mo/Al dispersion fuels. It is important to investigate the thermal behavior of U-Mo/Al dispersion fuel according to reaction between the fuel particles and the matrix with the burnup and linear power. In this study, a finite element analysis was used for the calculation of the temperature distribution of the U-Mo/Al dispersion fuel with a burnup and linear power. Kinetics data of the reaction layers such as the growth

Thermal behavior analysis of U-Mo/Al dispersion fuel

International Nuclear Information System (INIS)

Ryu, Ho Jin; Park, Jong Mang; Lee, Yoon Sang; Kim, Chang Kyu

2004-01-01

According to the non-proliferation policy under the reduced enrichment for research and test reactors (RERTR) program, low enriched uranium(LEU) fuel such as uranium silicide dispersion fuels are being used in research reactors. Because of a lower enrichment higher uranium density fuels are required for some high performance research reactors. Some uranium alloys with a high uranium density such as U-Mo alloys have been considered as one of the most promising candidates for a dispersion fuel due to the good irradiation performance. An international qualification program to replace the uranium silicide dispersion fuel with U-Mo dispersion fuel is being carried out under the RERTR program. Although U-Mo powders are conventionally supplied by the mechanical comminuting of as-cast U-Mo alloys, KAERI developed a centrifugal atomization method in order to simplify the preparation process and improve the properties. The centrifugally atomized powders have a rapidly solidified gamma uranium structure and a spherical shape. During the in-reactor operation of a dispersion fuel, interdiffusion or chemical reactions between the fuel particles and the matrix occurr. Intermetallic compounds in the form of UAlx are formed as a result of the diffusional reaction. Because the intermetallic compounds are less dense than the combined reactants, the volume of the fuel element increases after the reaction. In addition to the effect on the swelling performance, the reaction layers between the U-Mo and the Al matrix induces a degradation of the thermal properties of the U-Mo/Al dispersion fuels. It is important to investigate the thermal behavior of U-Mo/Al dispersion fuel according to reaction between the fuel particles and the matrix with the burnup and linear power. In this study, a finite element analysis was used for the calculation of the temperature distribution of the U-Mo/Al dispersion fuel with a burnup and linear power. Kinetics data of the reaction layers such as the growth

Study of axial mixing, holdup and slip velocity of dispersed phase in a pulsed sieve plate extraction column using radiotracer technique.

Science.gov (United States)

Ghiyas Ud Din; Imran Rafiq Chughtai; Hameed Inayat, Mansoor; Hussain Khan, Iqbal

2009-01-01

Axial mixing, holdup and slip velocity of dispersed phase which are parameters of fundamental importance in the design and operation of liquid-liquid extraction pulsed sieve plate columns have been investigated. Experiments for residence time distribution (RTD) analysis have been carried out for a range of pulsation frequency and amplitude in a liquid-liquid extraction pulsed sieve plate column with water as dispersed and kerosene as continuous phase using radiotracer technique. The column was operated in emulsion region and (99m)Tc in the form of sodium pertechnetate eluted from a (99)Mo/(99m)Tc generator was used to trace the dispersed phase. Axial dispersed plug flow model with open-open boundary condition and two points measurement method was used to simulate the hydrodynamics of dispersed phase. It has been observed that the axial mixing and holdup of dispersed phase increases with increase in pulsation frequency and amplitude until a maximum value is achieved while slip velocity decreases with increase in pulsation frequency and amplitude until it approaches a minimum value. Short lived and low energy radiotracer (99m)Tc in the form of sodium pertechnetate was found to be a good water tracer to study the hydrodynamics of a liquid-liquid extraction pulsed sieve plate column operating with two immiscible liquids, water and kerosene. Axial dispersed plug flow model with open-open boundary condition was found to be a suitable model to describe the hydrodynamics of dispersed phase in the pulsed sieve plate extraction column.

Study of axial mixing, holdup and slip velocity of dispersed phase in a pulsed sieve plate extraction column using radiotracer technique

International Nuclear Information System (INIS)

Ghiyas Ud Din; Imran Rafiq Chughtai; Mansoor Hameed Inayat; Iqbal Hussain Khan

2009-01-01

Axial mixing, holdup and slip velocity of dispersed phase which are parameters of fundamental importance in the design and operation of liquid-liquid extraction pulsed sieve plate columns have been investigated. Experiments for residence time distribution (RTD) analysis have been carried out for a range of pulsation frequency and amplitude in a liquid-liquid extraction pulsed sieve plate column with water as dispersed and kerosene as continuous phase using radiotracer technique. The column was operated in emulsion region and 99m Tc in the form of sodium pertechnetate eluted from a 99 Mo/ 99m Tc generator was used to trace the dispersed phase. Axial dispersed plug flow model with open-open boundary condition and two points measurement method was used to simulate the hydrodynamics of dispersed phase. It has been observed that the axial mixing and holdup of dispersed phase increases with increase in pulsation frequency and amplitude until a maximum value is achieved while slip velocity decreases with increase in pulsation frequency and amplitude until it approaches a minimum value. Short lived and low energy radiotracer 99m Tc in the form of sodium pertechnetate was found to be a good water tracer to study the hydrodynamics of a liquid-liquid extraction pulsed sieve plate column operating with two immiscible liquids, water and kerosene. Axial dispersed plug flow model with open-open boundary condition was found to be a suitable model to describe the hydrodynamics of dispersed phase in the pulsed sieve plate extraction column.

Coordination of atmospheric dispersion activities for the real-time decision support system RODOS

International Nuclear Information System (INIS)

Mikkelsen, T.

1997-05-01

This projects task has been to coordinate activities among the RODOS Atmospheric Dispersion sub-group A participants, with the overall objective of developing and integrating an atmospheric transport and dispersion module for the joint European Real-time On-line DecisiOn Support system RODOS headed by FZK (formerly KfK), Germany. The project's final goal is the establishment of a fully operational, system-integrated atmospheric transport module for the RODOS system by year 2000, capable of consistent now- and forecasting of radioactive airborne spread over all types of terrain and on all scales of interest, including in particular complex terrain and the different scales of operation, such as the local, the national and the European scale. (au)

Dispersion Forces

CERN Document Server

Buhmann, Stefan Yoshi

2012-01-01

In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

Preliminary results from direct-to-facility vaccine deliveries in Kano, Nigeria.

Science.gov (United States)

Aina, Muyi; Igbokwe, Uchenna; Jegede, Leke; Fagge, Rabiu; Thompson, Adam; Mahmoud, Nasir

2017-04-19

As part of its vaccine supply chain redesign efforts, Kano state now pushes vaccines directly from 6 state stores to primary health centers equipped with solar refrigerators. Our objective is to describe preliminary results from the first 20months of Kano's direct vaccine delivery operations. This is a retrospective review of Kano's direct vaccine delivery program. We analyzed trends in health facility vaccine stock levels, and examined the relationship between stock-out rates and each of cascade vaccine deliveries and timeliness of deliveries. Analysis of vaccination trends was based on administrative data from 27 sentinel health facilities. Costs for both the in-sourced and out-sourced approaches were estimated using a bottoms-up model-based approach. Overall stock adequacy increased from 54% in the first delivery cycle to 68% by cycle 33. Conversely, stock-out rates decreased from 41% to 10% over the same period. Similar trends were observed in the out-sourced and in-sourced programs. Stock-out rates rose incrementally with increasing number of cascade facilities, and delays in vaccine deliveries correlated strongly with stock-out rates. Recognizing that stock availability is one of many factors contributing to vaccinations, we nonetheless compared pre- and post- direct deliveries vaccinations in sentinel facilities, and found statistically significant upward trends for 4 out of 6 antigens. 1 antigen (measles) showed an upward trend that was not statistically significant. Hepatitis b vaccinations declined during the period. Overall, there appeared to be a one-year lag between commencement of direct deliveries and the increase in number of vaccinations. Weighted average cost per delivery is US$29.8 and cost per child immunized is US$0.7 per year. Direct vaccine delivery to health facilities in Kano, through a streamlined architecture, has resulted in decreased stock-outs and improved stock adequacy. Concurrent operation of insourced and outsourced programs has

Perinatal outcomes of unplanned out-of-hospital deliveries: a case-control study.

Science.gov (United States)

Pasternak, Yael; Wintner, Eliana Muskin; Shechter-Maor, Gil; Pasternak, Yehonatan; Miller, Netanella; Biron-Shental, Tal

2018-04-01

To compare the pregnancy and perinatal outcomes of unplanned home or car births vs. in-hospital deliveries. A retrospective, case-control study of women who underwent unplanned out-of-hospital deliveries vs. in-hospital deliveries from 2004 through 2014. Matching was based on gestational age and parity in a ratio of 2:1. There were no significant differences between the groups regarding demographic criteria, prenatal care and delivery complications. Women who delivered out of hospital (n = 90) had significantly fewer cesarean deliveries (1.1 vs. 10.6%; p = 0.05) and operative deliveries (2.2 vs. 13.3%; p = 0.004) in their obstetrical history than did the control group (n = 180). Significantly more newborns delivered out of the hospital had polycythemia (25.6 vs. 1.7%; p unplanned out-of-hospital deliveries tend to have fewer complications in their previous deliveries. Higher rates of polycythemia and hypothermia require attention for neonates born out of the hospital.

Magnetic drug delivery with FePd nanowires

Energy Technology Data Exchange (ETDEWEB)

Pondman, Kirsten M.; Bunt, Nathan D. [Neuro Imaging, MIRA Institute, University of Twente, Enschede (Netherlands); Maijenburg, A. Wouter [Inorganic Material Science, MESA+ Institute for Nanotechnology, University of Twente, Enschede (Netherlands); Wezel, Richard J.A. van [Biomedical Signals and Systems, MIRA, Twente University, Enschede (Netherlands); Kishore, Uday [Centre for Infection, Immunity and Disease Mechanisms, Biosciences, Brunel University, London (United Kingdom); Abelmann, Leon [Transducer Science and Technology group, MESA+ Institute for nanotechnology, University of Twente, Enschede (Netherlands); Elshof, Johan E. ten [Inorganic Material Science, MESA+ Institute for Nanotechnology, University of Twente, Enschede (Netherlands); Haken, Bennie ten, E-mail: b.tenhaken@utwente.nl [Neuro Imaging, MIRA Institute, University of Twente, Enschede (Netherlands)

2015-04-15

Magnetic drug delivery is a promising method to target a drug to a diseased area while reducing negative side effects caused by systemic administration of drugs. In magnetic drug delivery a therapeutic agent is coupled to a magnetic nanoparticle. The particles are injected and at the target location withdrawn from blood flow by a magnetic field. In this study a FePd nanowire is developed with optimised properties for magnetic targeting. The nanowires have a high magnetic moment to reduce the field gradient needed to capture them with a magnet. The dimensions and the materials of the nanowire and coating are such that they are dispersable in aqueous media, non-cytotoxic, easily phagocytosed and not complement activating. This is established in several in-vitro tests with macrophage and endothelial cell lines. Along with the nanowires a magnet is designed, optimised for capture of the nanowires from the blood flow in the hind leg of a rat. The system is used in a pilot scale in-vivo experiment. No negative side effects from injection of the nanowires were found within the limited time span of the experiment. In this first pilot experiment no nanowires were found to be targeted by the magnet, or in the liver, kidneys or spleen, most likely the particles were removed during the fixation procedure. - Highlights: • Description of the magnetic properties of nanowires. • Design and characterisation of a biocompatible FePd nanowire. • In-vitro cytotoxicity analysis and immune system responses. • In-vivo magnetic drug delivery using the developed nanowires.

Determination of dispersion coefficients in the River Plate

International Nuclear Information System (INIS)

Maggio, G.E.; Graino, J.G.; Kopp, U.I.; Tripoli, C.R.

1987-01-01

The determination of dispersion coefficients of contaminants through a radioactive tracer was performed as a contribution to the development of a mathematical model for a zone of the River Plate, close to the effluent discharge. During March 1987, six operations of tracer (I-131) injection and follow-up were carried out. The injection was performed by breaking a bulb under water and the follow-up of the 'radioactive spot' was done by means of a boat. Once the 'radioactive spot' was located (approximately 2 hours after the injection) a series of transversal movements over it was effected, measuring the activity concentration by means of a submerged detector. At the same time the coordinates of each point were determined in order to draw a map of the activity distribution. This procedure was repeated for different spot positions. This set of data can be plotted on a map of the zone under study, so as to obtain a set of iso activity curves. However, these curves would be representative provided that corrections are made for the boat speed, the water speed and the half-life of radionuclide. From each set of iso activity curves, the variance and the increase of variance, as well as the dispersion coefficients, can be determined. This procedure was applied to each one of the six above mentioned operations. Presently, different values of dispersion coefficient are available for different river conditions. These values, together with other parameters, such as wind velocity, temperature, salinity, bacterial behaviour, etc., will allow the calibration of the mathematical model. (Author)

Discontinuous Galerkin Time-Domain Modeling of Graphene Nano-Ribbon Incorporating the Spatial Dispersion Effects

KAUST Repository

Li, Ping; Jiang, Li Jun; Bagci, Hakan

2018-01-01

It is well known that graphene demonstrates spatial dispersion properties, i.e., its conductivity is nonlocal and a function of spectral wave number (momentum operator) q. In this paper, to account for effects of spatial dispersion on transmission of high speed signals along graphene nano-ribbon (GNR) interconnects, a discontinuous Galerkin time-domain (DGTD) algorithm is proposed. The atomically-thick GNR is modeled using a nonlocal transparent surface impedance boundary condition (SIBC) incorporated into the DGTD scheme. Since the conductivity is a complicated function of q (and one cannot find an analytical Fourier transform pair between q and spatial differential operators), an exact time domain SIBC model cannot be derived. To overcome this problem, the conductivity is approximated by its Taylor series in spectral domain under low-q assumption. This approach permits expressing the time domain SIBC in the form of a second-order partial differential equation (PDE) in current density and electric field intensity. To permit easy incorporation of this PDE with the DGTD algorithm, three auxiliary variables, which degenerate the second-order (temporal and spatial) differential operators to first-order ones, are introduced. Regarding to the temporal dispersion effects, the auxiliary differential equation (ADE) method is utilized to eliminates the expensive temporal convolutions. To demonstrate the applicability of the proposed scheme, numerical results, which involve characterization of spatial dispersion effects on the transfer impedance matrix of GNR interconnects, are presented.

Discontinuous Galerkin Time-Domain Modeling of Graphene Nano-Ribbon Incorporating the Spatial Dispersion Effects

KAUST Repository

Li, Ping

2018-04-13

It is well known that graphene demonstrates spatial dispersion properties, i.e., its conductivity is nonlocal and a function of spectral wave number (momentum operator) q. In this paper, to account for effects of spatial dispersion on transmission of high speed signals along graphene nano-ribbon (GNR) interconnects, a discontinuous Galerkin time-domain (DGTD) algorithm is proposed. The atomically-thick GNR is modeled using a nonlocal transparent surface impedance boundary condition (SIBC) incorporated into the DGTD scheme. Since the conductivity is a complicated function of q (and one cannot find an analytical Fourier transform pair between q and spatial differential operators), an exact time domain SIBC model cannot be derived. To overcome this problem, the conductivity is approximated by its Taylor series in spectral domain under low-q assumption. This approach permits expressing the time domain SIBC in the form of a second-order partial differential equation (PDE) in current density and electric field intensity. To permit easy incorporation of this PDE with the DGTD algorithm, three auxiliary variables, which degenerate the second-order (temporal and spatial) differential operators to first-order ones, are introduced. Regarding to the temporal dispersion effects, the auxiliary differential equation (ADE) method is utilized to eliminates the expensive temporal convolutions. To demonstrate the applicability of the proposed scheme, numerical results, which involve characterization of spatial dispersion effects on the transfer impedance matrix of GNR interconnects, are presented.

Ocular Insert: Dosage Form for Sustain Opthalmic Drug Delivery

Directory of Open Access Journals (Sweden)

Sunil Kumar

2012-06-01

Full Text Available Except for skin, the eye is the most easily accessible site for topical administration of a medication. Traditional topical ophthalmic formulations (eye drops and ointments have poor bioavailability because of rapid pre-corneal elimination, conjunctival absorption, solution drainage by gravity, induced lacrimation and normal tear turnover. This leads to frequent installations of concentrated medication to achieve a therapeutic effect. The typical “pulse-entry” type drug release observed with ocular aqueous solutions (eye drops, suspensions and ointments can be replaced by more controlled, sustained, and continuous drug delivery, using a controlled-release ocular drug delivery system. Ocular inserts are solid or semisolid sterile preparations, of appropriate size and shape, designed to be inserted behind the eyelid or held on the eye and to deliver drugs for topical or systemic effect. These are polymeric systems into which the drug is incorporated as a solution or dispersion. They are better tolerated as to drainage and tear flow compared with other ophthalmic formulation and produce reliable drug release in the conjunctival cul-de-sac.

Advanced pigment dispersion glaucoma secondary to phakic intraocular collamer lens implant

Directory of Open Access Journals (Sweden)

Clara Ye

2018-06-01

Full Text Available Purpose: We report a case of pigment dispersion glaucoma secondary to uncomplicated phakic intraocular collamer lens (ICL (Visian ICL™, Staar Inc., Monrovia, CA implant that resulted in advanced visual field loss. Observations: A 50-year-old man presented for routine follow-up status post bilateral phakic intraocular collamer lens (ICL placement 8 years earlier. He was incidentally found to have a decline in visual acuity from an anterior subcapsular cataract and elevated intraocular pressure (IOP in the left eye. There were signs of pigment dispersion and no evidence of angle closure. Diffuse optic nerve thinning was consistent with advanced glaucomatous visual field defects. Pigment dispersion was also present in the patient's right eye, but without elevated IOP or visual field defects. The patient was treated with topical glaucoma medications and the phakic ICL in the left eye was removed concurrently with cataract surgery to prevent further visual field loss. Conclusions and importance: Pigment dispersion glaucoma is a serious adverse outcome after phakic ICL implantation and regular post-operative monitoring may prevent advanced visual field loss. Keywords: Phakic intraocular lens, Intraocular collamer lens, Pigment dispersion, Glaucoma

Quantum treatment of field propagation in a fiber near the zero dispersion wavelength

Science.gov (United States)

Safaei, A.; Bassi, A.; Bolorizadeh, M. A.

2018-05-01

In this report, we present a quantum theory describing the propagation of the electromagnetic radiation in a fiber in the presence of the third order dispersion coefficient. We obtained the quantum photon-polariton field, hence, we provide herein a coupled set of operator forms for the corresponding nonlinear Schrödinger equations when the third order dispersion coefficient is included. Coupled stochastic nonlinear Schrödinger equations were obtained by applying a positive P-representation that governs the propagation and interaction of quantum solitons in the presence of the third-order dispersion term. Finally, to reduce the fluctuations near solitons in the first approximation, we developed coupled stochastic linear equations.

Two-relaxation-time lattice Boltzmann method for the anisotropic dispersive Henry problem

Science.gov (United States)

Servan-Camas, Borja; Tsai, Frank T.-C.

2010-02-01

This study develops a lattice Boltzmann method (LBM) with a two-relaxation-time collision operator (TRT) to cope with anisotropic heterogeneous hydraulic conductivity and anisotropic velocity-dependent hydrodynamic dispersion in the saltwater intrusion problem. The directional-speed-of-sound technique is further developed to address anisotropic hydraulic conductivity and dispersion tensors. Forcing terms are introduced in the LBM to correct numerical errors that arise during the recovery procedure and to describe the sink/source terms in the flow and transport equations. In order to facilitate the LBM implementation, the forcing terms are combined with the equilibrium distribution functions (EDFs) to create pseudo-EDFs. This study performs linear stability analysis and derives LBM stability domains to solve the anisotropic advection-dispersion equation. The stability domains are used to select the time step at which the lattice Boltzmann method provides stable solutions to the numerical examples. The LBM was implemented for the anisotropic dispersive Henry problem with high ratios of longitudinal to transverse dispersivities, and the results compared well to the solutions in the work of Abarca et al. (2007).

A net normal dispersion all-fiber laser using a hybrid mode-locking mechanism

International Nuclear Information System (INIS)

Xu, Bo; Martinez, Amos; Yamashita, Shinji; Set, Sze Yun; Goh, Chee Seong

2014-01-01

We propose and demonstrate an all-fiber, dispersion-mapped, erbium-doped fiber laser with net normal dispersion generating dissipative solitons. The laser is mode-locked by a hybrid mode-locking mechanism consisting of a nonlinear amplifying loop mirror and a carbon nanotube saturable absorber. We achieve self-starting, mode-locked operation generating 2.75 nJ pulses at a fundamental repetition rate of 10.22 MHz with remarkable long term stability. (letter)

Peptide and protein delivery using new drug delivery systems.

Science.gov (United States)

Jain, Ashish; Jain, Aviral; Gulbake, Arvind; Shilpi, Satish; Hurkat, Pooja; Jain, Sanjay K

2013-01-01

Pharmaceutical and biotechnological research sorts protein drug delivery systems by importance based on their various therapeutic applications. The effective and potent action of the proteins/peptides makes them the drugs of choice for the treatment of numerous diseases. Major research issues in protein delivery include the stabilization of proteins in delivery devices and the design of appropriate target-specific protein carriers. Many efforts have been made for effective delivery of proteins/peptidal drugs through various routes of administrations for successful therapeutic effects. Nanoparticles made of biodegradable polymers such as poly lactic acid, polycaprolactone, poly(lactic-co-glycolic acid), the poly(fumaric-co-sebacic) anhydride chitosan, and modified chitosan, as well as solid lipids, have shown great potential in the delivery of proteins/peptidal drugs. Moreover, scientists also have used liposomes, PEGylated liposomes, niosomes, and aquasomes, among others, for peptidal drug delivery. They also have developed hydrogels and transdermal drug delivery systems for peptidal drug delivery. A receptor-mediated delivery system is another attractive strategy to overcome the limitation in drug absorption that enables the transcytosis of the protein across the epithelial barrier. Modification such as PEGnology is applied to various proteins and peptides of the desired protein and peptides also increases the circulating life, solubility and stability, pharmacokinetic properties, and antigenicity of protein. This review focuses on various approaches for effective protein/peptidal drug delivery, with special emphasis on insulin delivery.

A model for the dispersion of pollution from a road network

Energy Technology Data Exchange (ETDEWEB)

Haerkoenen, J.; Valkonen, E.; Kukkonen, J.; Rantakarans, E.; Lahtinen, K.; Karppinen, A.; Jalkanen, L.

1996-12-31

A mathematical model for predicting the dispersion of pollution from a road network, for use in a regulatory context is presented in the report. The model includes an emission model a treatment of the meteorological and background concentration time series, a dispersion model statistical analysis of the computed time series of concentrations and a Windows-based user interface. The dispersion model is based on a partly analytical solution of the Gaussian diffusion equation for a finite dine source. It allows for any wind direction with respect to the road. The dispersion parameters are modelled in a form which facilitates the use of the meteorological preprocessor. The chemical transformation is modelled by using a modified form of the discrete parcel method, developed in this study. The chemistry model contains the basic reactions of nitrogen oxides, oxygen and ozone. An operational model for evaluating the meteorological and background concentration data for the model applications is also presented. The model does not take into account the influence of buildings and inhomogeneous terrain on the dispersion processes. The validity of the mathematical solution presented has been tested against a more detailed numerical model. The overall differences are reasonable, and the solution can be used with confidence in an operational model. The program has been implemented on a personal computer and on a main-frame computer, and in the later case also executed on a Cray C94 supercomputer. The validation of the model against experimental data is reported elsewhere. Testing of the model near a major road Turunvaeylae Finland 1994 showed that the overall agreement of the measured and predicted values for NO{sub x} and NO{sub 2} concentrations was fairly good 30 refs.

Theory of dispersive microlenses

Science.gov (United States)

Herman, B.; Gal, George

1993-01-01

A dispersive microlens is a miniature optical element which simultaneously focuses and disperses light. Arrays of dispersive mircolenses have potential applications in multicolor focal planes. They have a 100 percent optical fill factor and can focus light down to detectors of diffraction spot size, freeing up areas on the focal plane for on-chip analog signal processing. Use of dispersive microlenses allows inband color separation within a pixel and perfect scene registration. A dual-color separation has the potential for temperature discrimination. We discuss the design of dispersive microlenses and present sample results for efficient designs.

Evaluation of critical formulation parameters in design and differentiation of self-microemulsifying drug delivery systems (SMEDDSs) for oral delivery of aciclovir.

Science.gov (United States)

Janković, Jovana; Djekic, Ljiljana; Dobričić, Vladimir; Primorac, Marija

2016-01-30

The study investigated the influence of formulation parameters for design of self-microemulsifying drug delivery systems (SMEDDSs) comprising oil (medium chain triglycerides) (10%), surfactant (Labrasol(®), polysorbate 20, or Kolliphor(®) RH40), cosurfactant (Plurol(®) Oleique CC 497) (q.s. ad 100%), and cosolvent (glycerol or macrogol 400) (20% or 30%), and evaluate their potential as carriers for oral delivery of a poorly permeable antivirotic aciclovir (acyclovir). The drug loading capacity of the prepared formulations ranged from 0.18-31.66 mg/ml. Among a total of 60 formulations, three formulations meet the limits for average droplet size (Z-ave) and polydispersity index (PdI) that have been set for SMEDDSs (Z-ave≤100nm, PdI<0.250) upon spontaneous dispersion in 0.1M HCl and phosphate buffer pH 7.2. SMEDDSs with the highest aciclovir loading capacity (24.06 mg/ml and 21.12 mg/ml) provided the in vitro drug release rates of 0.325 mg cm(-2)min(-1) and 0.323 mg cm(-2)min(-1), respectively, and significantly enhanced drug permeability in the parallel artificial membrane permeability assay (PAMPA), in comparison with the pure drug substance. The results revealed that development of SMEDDSs with enhanced drug loading capacity and oral delivery potential, required optimization of hydrophilic ingredients, in terms of size of hydrophilic moiety of the surfactant, surfactant-to-cosurfactant mass ratio (Km), and log P of the cosolvent. Copyright © 2015 Elsevier B.V. All rights reserved.

Delivery outcomes after day and night onset of labour.

Science.gov (United States)

Kanwar, Sandeep; Rabindran, Ranjit; Lindow, Stephen W

2015-11-01

To describe the outcome of night onset of labour as compared with the day onset of labour to investigate if labour that begins at night is more efficient. Retrospective review of labour and delivery data. A large United Kingdom maternity service. Over the period of 10 years, there were 30,022 deliveries, of which 19,842 were studied. A United Kingdom maternity department database was used to identify deliveries over a 10-year period, and the delivery outcomes were retrieved from these records. The 19,842 labours were divided into two categories: night onset (22.00-06.00 h) and day onset (10.00-18.00 h). Rates of operative intervention, augmentation, epidural usage and labour duration. A significant difference in delivery outcome was noted (P=0.004) with the night-onset labours having more normal deliveries (83.6% vs. 82.5%), fewer caesarean sections (8.7% vs. 10.1%), fewer labour augmentations with syntocinon (14.9% vs. 19.5%, Pnight-onset group and 2414 (30%) in the day-onset group (χ2=1.3, P=NS) Conclusions: Labours that start at night appear to be more efficient than labours that start during the day.

Comparison of numerical dispersion for finite-difference algorithms in transversely isotropic media with a vertical symmetry axis

International Nuclear Information System (INIS)

Liang, Wen-Quan; Wang, Yan-Fei; Yang, Chang-Chun

2015-01-01

Numerical simulation of the wave equation is widely used to synthesize seismograms theoretically and is also the basis of the reverse time migration and full waveform inversion. For the finite difference methods, grid dispersion often exists because of the discretization of the time and the spatial derivatives in the wave equation. How to suppress the grid dispersion is therefore a key problem for finite difference (FD) approaches. The FD operators for the space derivatives are usually obtained in the space domain. However, the wave equations are discretized in the time and space directions simultaneously. So it would be better to design the FD operators in the time–space domain. We improved the time–space domain method for obtaining the FD operators in an acoustic vertically transversely isotropic (VTI) media so as to cover a much wider range of frequencies. Dispersion analysis and seismic numerical simulation demonstrate the effectiveness of the proposed method. (paper)

Cefuroxime axetil solid dispersions prepared using solution enhanced dispersion by supercritical fluids.

Science.gov (United States)

Jun, Seoung Wook; Kim, Min-Soo; Jo, Guk Hyun; Lee, Sibeum; Woo, Jong Soo; Park, Jeong-Sook; Hwang, Sung-Joo

2005-12-01

Cefuroxime axetil (CA) solid dispersions with HPMC 2910/PVP K-30 were prepared using solution enhanced dispersion by supercritical fluids (SEDS) in an effort to increase the dissolution rate of poorly water-soluble drugs. Their physicochemical properties in solid state were characterized by differential scanning calorimeter (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared spectrometry (FT-IR) and scanning electron microscopy. No endothermic and characteristic diffraction peaks corresponding to CA were observed for the solid dispersions in DSC and PXRD. FTIR analysis demonstrated the presence of intermolecular hydrogen bonds between CA and HPMC 2910/PVP K-30 in solid dispersions, resulting in the formation of amorphous or non-crystalline CA. Dissolution studies indicated that the dissolution rates were remarkably increased in solid dispersions compared with those in the physical mixture and drug alone. In conclusion, an amorphous or non-crystalline CA solid dispersion prepared using SEDS could be very useful for the formulation of solid dosage forms.

A phase space approach to wave propagation with dispersion.

Science.gov (United States)

Ben-Benjamin, Jonathan S; Cohen, Leon; Loughlin, Patrick J

2015-08-01

A phase space approximation method for linear dispersive wave propagation with arbitrary initial conditions is developed. The results expand on a previous approximation in terms of the Wigner distribution of a single mode. In contrast to this previously considered single-mode case, the approximation presented here is for the full wave and is obtained by a different approach. This solution requires one to obtain (i) the initial modal functions from the given initial wave, and (ii) the initial cross-Wigner distribution between different modal functions. The full wave is the sum of modal functions. The approximation is obtained for general linear wave equations by transforming the equations to phase space, and then solving in the new domain. It is shown that each modal function of the wave satisfies a Schrödinger-type equation where the equivalent "Hamiltonian" operator is the dispersion relation corresponding to the mode and where the wavenumber is replaced by the wavenumber operator. Application to the beam equation is considered to illustrate the approach.

Analysis of a nanocrystalline polymer dispersion of ebselen using solid-state NMR, Raman microscopy, and powder X-ray diffraction.

Science.gov (United States)

Vogt, Frederick G; Williams, Glenn R

2012-07-01

Nanocrystalline drug-polymer dispersions are of significant interest in pharmaceutical delivery. The purpose of this work is to demonstrate the applicability of methods based on two-dimensional (2D) and multinuclear solid-state NMR (SSNMR) to a novel nanocrystalline pharmaceutical dispersion of ebselen with polyvinylpyrrolidone-vinyl acetate (PVP-VA), after initial characterization with other techniques. A nanocrystalline dispersion of ebselen with PVP-VA was prepared and characterized by powder X-ray diffraction (PXRD), confocal Raman microscopy and mapping, and differential scanning calorimetry (DSC), and then subjected to detailed 1D and 2D SSNMR analysis involving ¹H, ¹³C, and ⁷⁷Se isotopes and ¹H spin diffusion. PXRD was used to show that dispersion contains nanocrystalline ebselen in the 35-60 nm size range. Confocal Raman microscopy and spectral mapping were able to detect regions where short-range interactions may occur between ebselen and PVP-VA. Spin diffusion effects were analyzed using 2D SSNMR experiments and are able to directly detect interactions between ebselen and the surrounding PVP-VA. The methods used here, particularly the 2D SSNMR methods based on spin diffusion, provided detailed structural information about a nanocrystalline polymer dispersion of ebselen, and should be useful in other studies of these types of materials.

Simple fibre based dispersion management for two-photon excited fluorescence imaging through an endoscope

DEFF Research Database (Denmark)

Dimopoulos, Konstantinos; Marti, Dominik; Andersen, Peter E.

2018-01-01

We want to implement two-photon excitation fluorescence microscopy (TPEFM) into endoscopes, since TPEFM can provide relevant biomarkers for cancer staging and grading in hollow organs, endoscopically accessible through natural orifices. However, many obstacles must be overcome, among others...... the delivery of short laser pulses to the distal end of the endoscope. To this avail, we present imaging results using an all-fibre dispersion management scheme in a TPEFM setup. The scheme has been conceived by Jespersen et al. in 20101 and relies on the combination of a single mode fibre with normal...

Wave-equation dispersion inversion

KAUST Repository

Li, Jing; Feng, Zongcai; Schuster, Gerard T.

2016-01-01

We present the theory for wave-equation inversion of dispersion curves, where the misfit function is the sum of the squared differences between the wavenumbers along the predicted and observed dispersion curves. The dispersion curves are obtained

REFLECTING ON THE DELIVERY OF A LONGITUDINAL COPING INTERVENTION AMONGST JUNIOR NATIONAL NETBALL PLAYERS

Directory of Open Access Journals (Sweden)

Tracey J. Devonport

2009-06-01

Full Text Available Recent research suggests that appropriately-tailored interventions can assist adolescents enhance their coping skills (Frydenberg and Lewis, 2004. The present paper reflects upon the delivery of a longitudinal coping intervention utilized by junior national netball players. Reflection is focused on issues such as the rationale for the intervention, operational issues surrounding the delivery and management of the work. It is also focused on interpersonal issues relating to intervention implementation. We contend that being explicit about developmental and applied processes may enable theoretically sound and efficacious practices to be identified. In addition, unpacking operational issues related to delivery may assist applied sport and exercise psychologists in the development of related work.

Preserving the Helmholtz dispersion relation: One-way acoustic wave propagation using matrix square roots

Science.gov (United States)

Keefe, Laurence

2016-11-01

Parabolized acoustic propagation in transversely inhomogeneous media is described by the operator update equation U (x , y , z + Δz) =eik0 (- 1 +√{ 1 + Z }) U (x , y , z) for evolution of the envelope of a wavetrain solution to the original Helmholtz equation. Here the operator, Z =∇T2 + (n2 - 1) , involves the transverse Laplacian and the refractive index distribution. Standard expansion techniques (on the assumption Z << 1)) produce pdes that approximate, to greater or lesser extent, the full dispersion relation of the original Helmholtz equation, except that none of them describe evanescent/damped waves without special modifications to the expansion coefficients. Alternatively, a discretization of both the envelope and the operator converts the operator update equation into a matrix multiply, and existing theorems on matrix functions demonstrate that the complete (discrete) Helmholtz dispersion relation, including evanescent/damped waves, is preserved by this discretization. Propagation-constant/damping-rates contour comparisons for the operator equation and various approximations demonstrate this point, and how poorly the lowest-order, textbook, parabolized equation describes propagation in lined ducts.

Effect of the Duration of Meteorological Data Collection on the Atmospheric Dispersion Assessment

International Nuclear Information System (INIS)

Choi, Yoo-mi; Kim, Eun-hee

2017-01-01

This study regards the duration of meteorological data record for a prospective assessment of the environmental impact of gas release from Kori nuclear power plant under normal operation. We compared the atmospheric dispersion factors obtained by employing the meteorological data from 2- and 5-year durations with the corresponding values obtained by employing yearly meteorological data in the period of 2001 to 2008. Influence of the duration of meteorological data collection on short-term atmospheric dispersion factors was previously studied. In this study, long-term dispersion factors were assessed to investigate the influence of the duration of meteorological data collection on the assessment of environmental impact by gas release from Kori nuclear power plant under normal operation. We counted how many yearly meteorological conditions would be represented by 2 or 5 years of long-term data collection. The distribution of shaded cells in Tables I and II indicated that some of the yearly meteorological condition could be properly represented by the conditions averaged over 2- or 5-year durations.

Carbon Nanofibers-Poly-3-hydroxyalkanoates Nanocomposite: Ultrasound-Assisted Dispersion and Thermostructural Properties

Directory of Open Access Journals (Sweden)

A. M. Gumel

2014-01-01

Full Text Available The conductivity and high surface-to-volume ratio of carbon nanofibers (CNFs composited with the medium-chain-length poly-3-hydroxyalkanoate (mcl-PHA have attracted much attention as smart biomaterial. However, poor CNF dispersion leads to tactoid agglomerated composite with poor crystallite morphology resulting in inferior thermomechanical properties. We employed acoustic sonication to enhance the construction of exfoliated PHA/CNFs nanocomposites. The effects of CNF loading and the insonation variables (power intensity, frequency, and time on the stability and microscopic morphology of the nanocomposites were studied. Sonication improved the dispersion of CNFs into the polymer matrix, thereby improving the physical morphology, crystallinity, and thermomechanical properties of the nanocomposites. For example, compositing the polymer with 10% w/w CNF resulted in 66% increase in crystallite size, 46% increase in micromolecular elastic strain, and 17% increase in lattice strain. Nevertheless, polymer degradation was observed following the ultrasound exposure. The constructed bionanocomposite could potentially be applied for organic electroconductive materials, biosensors and stimuli-responsive drug delivery devices.

Stable Dispersions of Covalently Tethered Polymer Improved Graphene Oxide Nanoconjugates as an Effective Vector for siRNA Delivery.

Science.gov (United States)

Yadav, Nisha; Kumar, Naveen; Prasad, Peeyush; Shirbhate, Shivani; Sehrawat, Seema; Lochab, Bimlesh

2018-05-02

Conjugates of poly(amidoamine) (PAMAM) with modified graphene oxide (GO) are attractive nonviral vectors for gene-based cancer therapeutics. GO protects siRNA from enzymatic cleavage and showed reasonable transfection efficiency along with simultaneous benefits of low cost and large scale production. PAMAM is highly effective in siRNA delivery but suffers from high toxicity with poor in vivo efficacy. Co-reaction of GO and PAMAM led to aggregation and more importantly, have detrimental effect on stability of dispersion at physiological pH preventing their exploration at clinical level. In the current work, we have designed, synthesized, characterized and explored a new type of hybrid vector (GPD), using GO synthesized via improved method which was covalently tethered with poly(ethylene glycol) (PEG) and PAMAM. The existence of covalent linkage, relative structural changes and properties of GPD is well supported by Fourier transform infrared (FTIR), UV-visible (UV-vis), Raman, X-ray photoelectron (XPS), elemental analysis, powder X-ray diffraction (XRD), thermogravimetry analysis (TGA), dynamic light scattering (DLS), and zeta potential. Scanning electron microscopy (SEM), and transmission electron microscopy (TEM) of GPD showed longitudinally aligned columnar self-assembled ∼10 nm thick polymeric nanoarchitectures onto the GO surface accounting to an average size reduction to ∼20 nm. GPD revealed an outstanding stability in both phosphate buffer saline (PBS) and serum containing cell medium. The binding efficiency of EPAC1 siRNA to GPD was supported by gel retardation assay, DLS, zeta potential and photoluminescence (PL) studies. A lower cytotoxicity with enhanced cellular uptake and homogeneous intracellular distribution of GPD/siRNA complex is confirmed by imaging studies. GPD exhibited a higher transfection efficiency with remarkable inhibition of cell migration and lower invasion than PAMAM and Lipofectamine 2000 suggesting its role in prevention of breast

Paclitaxel-Nanodiamond Nanocomplexes Enhance Aqueous Dispersibility and Drug Retention in Cells.

Science.gov (United States)

Lim, Dae Gon; Jung, Joo Hyun; Ko, Hyuk Wan; Kang, Eunah; Jeong, Seong Hoon

2016-09-14

Nanodiamonds (NDs) with 5 nm crystalline structures have been recognized as emerging carbon delivery vehicles due to their biocompatible inertness, high surface-to-volume ratio, and energy absorbance properties. In this study, carboxylated nanodiamond (ND-COOH) was reduced to hydroxylated nanodiamond (ND-OH) for stable and pH-independent colloidal dispersity. The poorly water-soluble paclitaxel (PTX) was physically loaded into ND-OH clusters, forming amorphous PTX nanostructure on the interparticle nanocage of the ND substrate. Stable physical PTX loading onto the ND substrate with stable colloidal stability showed enhanced PTX release. ND-OH/PTX complexes retained the sustained release of PTX by up to 97.32% at 70 h, compared with the 47.33% release of bare crystalline PTX. Enhanced PTX release from ND substrate showed low cell viability in Hela, MCF-9, and A549 cancer cells due to sustained release and stable dispersity in a biological aqueous environment. Especially, the IC50 values of ND-OH/PTX complexes and PTX in Hela cells were 0.037 μg/mL and 0.137 μg/mL, respectively. Well-dispersed cellular uptake of suprastructure ND-OH/PTX nanocomplexes was directly observed from the TEM images. ND-OH/PTX nanocomplexes assimilated into cells might provide convective diffusion with high PTX concentration, inducing initial necrosis. This study suggests that poorly water-soluble drugs can be formulated into a suprastructure with ND and acts as a highly concentrated drug reservoir directly within a cell.

Study on an alternating current electrothermal micropump for microneedle-based fluid delivery systems

Science.gov (United States)

Zhang, Rumi; Jullien, Graham A.; Dalton, Colin

2013-07-01

In this paper, we report on a modeling study of an AC electrothermal (ACET) micropump with high operating pressures as well as fast flow rates. One specific application area is for fluid delivery using microneedle arrays which require higher pressures and faster flow rates than have been previously reported with ACET devices. ACET is very suitable for accurate actuation and control of fluid flow, since the technique has been shown to be very effective in high conductivity fluids and has the ability to create a pulsation free flow. However, AC electrokinetic pumps usually can only generate low operating pressures of 1 to 100 Pa, where flow reversal is likely to occur with an external load. In order to realize a high performance ACET micropump for continuous fluid delivery, applying relatively high AC operating voltages (20 to 36 Vrms) to silicon substrate ACET actuators and using long serpentine channel allows the boosting of operating pressure as well as increasing the flow rates. Fast pumping flow rates (102-103 nl/s) and high operating pressures (1-12 kPa) can be achieved by applying both methods, making them of significant importance for continuous fluid delivery applications using microneedle arrays and other such biomedical devices.

Seed dispersal in fens

NARCIS (Netherlands)

Middleton, Beth; van Diggelen, Rudy; Jensen, Kai

Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and

Intracellular delivery of nanomaterials for sub-cellular imaging and tracking of biomolecules

Science.gov (United States)

Medepalli, Krishna Kiran

Nanomaterials have many intriguing applications in biology and medicine. Unique properties such as enhanced electrical properties, increased chemical reactivity and resistance to degradation, novel optical properties and comparable size to that of biological systems have led to their use in various biomedical applications. The most important applications of nanomaterials for medicine are in drug delivery and imaging. This research focuses on utilizing the biocompatibility of single walled Carbon nanotubes (SWCNTs) and optical properties colloidal quantum dots (QDs) for cellular drug delivery and imaging of biomolecules. The first part of this research deals with single walled carbon nanotubes which are excellent candidates for targeted drug delivery applications due their unique structural and functional properties. However, prior to their use in therapeutics, their biocompatibility needs to be thoroughly investigated. The objectives of this research were to establish the biocompatibility of SWCNTs and demonstrate their use as drug delivery carriers into cells. Blood, a living tissue, is chosen as the biological system as it contains various cells which can potentially interact with SWCNTs during the delivery mechanism. The interactions of these cells in the blood (specifically white blood cells or leukocytes) with the SWCNTs provide vital information regarding the immune response of the host to the nanotubes. This research investigates the immune response of white blood cells due to SWCNTs via (a) direct interaction---presence of nanotubes in the blood and, (b) indirect interaction---presentation of nanotubes by antigen-presenting-cells to white blood cells. These two interactions recreate the innate and adaptive immune responses occurring in the body to any foreign substance. SWCNTs are functionalized with single stranded DNA (ss-DNA), which serves as a dispersant of nanotubes as well as a backbone for further attachment of other biomolecules of interest

Dispersal and population state of an endangered island lizard following a conservation translocation.

Science.gov (United States)

Angeli, Nicole F; Lundgren, Ian F; Pollock, Clayton G; Hillis-Starr, Zandy M; Fitzgerald, Lee A

2018-03-01

Population size is widely used as a unit of ecological analysis, yet to estimate population size requires accounting for observed and latent heterogeneity influencing dispersion of individuals across landscapes. In newly established populations, such as when animals are translocated for conservation, dispersal and availability of resources influence patterns of abundance. We developed a process to estimate population size using N-mixture models and spatial models for newly established and dispersing populations. We used our approach to estimate the population size of critically endangered St. Croix ground lizards (Ameiva polops) five years after translocation of 57 individuals to Buck Island, an offshore island of St. Croix, United States Virgin Islands. Estimates of population size incorporated abiotic variables, dispersal limits, and operative environmental temperature available to the lizards to account for low species detection. Operative environmental temperature and distance from the translocation site were always important in fitting the N-mixture model indicating effects of dispersal and species biology on estimates of population size. We found that the population is increasing its range across the island by 5-10% every six months. We spatially interpolated site-specific abundance from the N-mixture model to the entire island, and we estimated 1,473 (95% CI, 940-1,802) St. Croix ground lizards on Buck Island in 2013 corresponding to survey results. This represents a 26-fold increase since the translocation. We predicted the future dispersal of the lizards to all habitats on Buck Island, with the potential for the population to increase by another five times in the future. Incorporating biologically relevant covariates as explicit parameters in population models can improve predictions of population size and the future spread of species introduced to new localities. © 2018 by the Ecological Society of America.

Simultaneous chromatic dispersion, polarization-mode-dispersion and OSNR monitoring at 40Gbit/s.

Science.gov (United States)

Baker-Meflah, Lamia; Thomsen, Benn; Mitchell, John; Bayvel, Polina

2008-09-29

A novel method for independent and simultaneous monitoring of chromatic dispersion (CD), first-order PMD and OSNR in 40Gbit/s systems is proposed and demonstrated. This is performed using in-band tone monitoring of 5GHz, optically down-converted to a low intermediate-frequency (IF) of 10kHz. The measurement provides a large monitoring range with good accuracies for CD (4742+/-100ps/nm), differential group delay (DGD) (200+/-4ps) and OSNR (23+/-1dB), independently of the bit-rate. In addition, the use of electro-absorption modulators (EAM) for the simultaneous down-conversion of all channels and the use of low-speed detectors makes it cost effective for multi-channel operation.

Determination of solvent concentration-dependent dispersion in the vapor extraction (VAPEX) process

Energy Technology Data Exchange (ETDEWEB)

Abukhalifeh, H.; Lohi, A.; Upreti, S. [Ryerson Polytechnic Univ., Toronto, ON (Canada)

2008-07-01

This paper presented the results of a computational algorithm that revealed the optimal conditions required for vapor extraction (VAPEX) for a solvent gas-heavy oil system. VAPEX is a promising recovery process because it requires low energy use and emits fewer greenhouse gases to the atmosphere compared to other enhanced oil recovery methods. The process is governed by the dispersion of solvent gases into heavy oil and bitumen. As such, it is essential to accurately determine solvent dispersion in VAPEX in order to effectively predict the amount and time scale of oil recovery, and to optimize field operations. VAPEX experiments were conducted in this study to determined the dispersion coefficient of a solvent as a function of its concentration in heavy oil and bitumen. The principles of variational calculus were used together with a mass transfer model of the experimental process. It was concluded that the oil production determined by the model should agree with its experimental counterpart, given the optimal gas dispersion versus concentration function.

Dispersed Fringe Sensing Analysis - DFSA

Science.gov (United States)

Sigrist, Norbert; Shi, Fang; Redding, David C.; Basinger, Scott A.; Ohara, Catherine M.; Seo, Byoung-Joon; Bikkannavar, Siddarayappa A.; Spechler, Joshua A.

2012-01-01

Dispersed Fringe Sensing (DFS) is a technique for measuring and phasing segmented telescope mirrors using a dispersed broadband light image. DFS is capable of breaking the monochromatic light ambiguity, measuring absolute piston errors between segments of large segmented primary mirrors to tens of nanometers accuracy over a range of 100 micrometers or more. The DFSA software tool analyzes DFS images to extract DFS encoded segment piston errors, which can be used to measure piston distances between primary mirror segments of ground and space telescopes. This information is necessary to control mirror segments to establish a smooth, continuous primary figure needed to achieve high optical quality. The DFSA tool is versatile, allowing precise piston measurements from a variety of different optical configurations. DFSA technology may be used for measuring wavefront pistons from sub-apertures defined by adjacent segments (such as Keck Telescope), or from separated sub-apertures used for testing large optical systems (such as sub-aperture wavefront testing for large primary mirrors using auto-collimating flats). An experimental demonstration of the coarse-phasing technology with verification of DFSA was performed at the Keck Telescope. DFSA includes image processing, wavelength and source spectral calibration, fringe extraction line determination, dispersed fringe analysis, and wavefront piston sign determination. The code is robust against internal optical system aberrations and against spectral variations of the source. In addition to the DFSA tool, the software package contains a simple but sophisticated MATLAB model to generate dispersed fringe images of optical system configurations in order to quickly estimate the coarse phasing performance given the optical and operational design requirements. Combining MATLAB (a high-level language and interactive environment developed by MathWorks), MACOS (JPL s software package for Modeling and Analysis for Controlled Optical

Chemical countermeasures: Dispersants overview of dispersant use (including application) and research issues

International Nuclear Information System (INIS)

Butler, J.N.

1992-01-01

I will attempt in twenty minutes to summarize the state of research on oil spill dispersants as I perceive it. The expertise I bring to this task includes 20 years of experience with the fate and effects of petroleum in the marine environment, including participation in the 1973 and 1981 NRC studies and three years as chairman of the NRC committee on oil spill dispersants. I More recently I served on a committee of the International Maritime Organization which reviewed the open-quotes Impact of oil and related chemicals and wastes on the marine environment.close quotes That report will be published this year. However, my statements in this paper are not made as a representative of either NRC or IMO. They are my own interpretation of scientific literature cited in the above reviews. Dispersants are chemical formulations, which include surface active agents, designed to decrease the interfacial tension between oil and water. Because the first attempts to disperse oil on a large scale, at the Torrey Canyon spill of 1967, used highly toxic degreasing agents, dispersants have an undeserved reputation for toxicity. In fact, for twenty years dispersant formulations have been developed with an emphasis on reducing their toxicity to marine life. The dispersal of oil in water has been documented in the laboratory by dozens of papers (see references in NRC 1989, pp 70-79), and in the field by dozens of studies (NRC 1989, pp 165- 193). The toxicity of commercial dispersant formulations (NRC 1989, pp 81-123) and dispersed oil (NRC 1989, pp 123-147) has been tested on a wide variety of marine organisms ranging from algae to salmonid fishes. The NRC review has been updated by the IMO/GESAMP (1992) study, but the conclusions remain unchanged

Dispersing powders in liquids

CERN Document Server

Nelson, RD

1988-01-01

This book provides powder technologists with laboratory procedures for selecting dispersing agents and preparing stable dispersions that can then be used in particle size characterization instruments. Its broader goal is to introduce industrial chemists and engineers to the phenomena, terminology, physical principles, and chemical considerations involved in preparing and handling dispersions on a commercial scale. The book introduces novices to: - industrial problems due to improper degree of dispersion; - the nomenclature used in describing particles; - the basic physica

Delivery presentations

Science.gov (United States)

Pregnancy - delivery presentation; Labor - delivery presentation; Occiput posterior; Occiput anterior; Brow presentation ... The mother can walk, rock, and try different delivery positions during labor to help encourage the baby ...

Advanced pigment dispersion glaucoma secondary to phakic intraocular collamer lens implant.

Science.gov (United States)

Ye, Clara; Patel, Cajal K; Momont, Anna C; Liu, Yao

2018-06-01

We report a case of pigment dispersion glaucoma secondary to uncomplicated phakic intraocular collamer lens (ICL) (Visian ICL™, Staar Inc., Monrovia, CA) implant that resulted in advanced visual field loss. A 50-year-old man presented for routine follow-up status post bilateral phakic intraocular collamer lens (ICL) placement 8 years earlier. He was incidentally found to have a decline in visual acuity from an anterior subcapsular cataract and elevated intraocular pressure (IOP) in the left eye. There were signs of pigment dispersion and no evidence of angle closure. Diffuse optic nerve thinning was consistent with advanced glaucomatous visual field defects. Pigment dispersion was also present in the patient's right eye, but without elevated IOP or visual field defects. The patient was treated with topical glaucoma medications and the phakic ICL in the left eye was removed concurrently with cataract surgery to prevent further visual field loss. Pigment dispersion glaucoma is a serious adverse outcome after phakic ICL implantation and regular post-operative monitoring may prevent advanced visual field loss.

Advanced Space Transportation Concepts and Propulsion Technologies for a New Delivery Paradigm

Science.gov (United States)

Robinson, John W.; McCleskey, Carey M.; Rhodes, Russel E.; Lepsch, Roger A.; Henderson, Edward M.; Joyner, Claude R., III; Levack, Daniel J. H.

2013-01-01

This paper describes Advanced Space Transportation Concepts and Propulsion Technologies for a New Delivery Paradigm. It builds on the work of the previous paper "Approach to an Affordable and Productive Space Transportation System". The scope includes both flight and ground system elements, and focuses on their compatibility and capability to achieve a technical solution that is operationally productive and also affordable. A clear and revolutionary approach, including advanced propulsion systems (advanced LOX rich booster engine concept having independent LOX and fuel cooling systems, thrust augmentation with LOX rich boost and fuel rich operation at altitude), improved vehicle concepts (autogeneous pressurization, turbo alternator for electric power during ascent, hot gases to purge system and keep moisture out), and ground delivery systems, was examined. Previous papers by the authors and other members of the Space Propulsion Synergy Team (SPST) focused on space flight system engineering methods, along with operationally efficient propulsion system concepts and technologies. This paper continues the previous work by exploring the propulsion technology aspects in more depth and how they may enable the vehicle designs from the previous paper. Subsequent papers will explore the vehicle design, the ground support system, and the operations aspects of the new delivery paradigm in greater detail.

Seed dispersal in fens

Science.gov (United States)

Middleton, B.; Van Diggelen, R.; Jensen, K.

2006-01-01

Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower reproductive success, which can lead to biodiversity loss. While fens may have always been relatively isolated from each other, they have become increasingly fragmented in modern times within agricultural and urban landscapes in both Europe and North America. Dispersal by water, animals and wind has been hampered by changes related to development in landscapes surrounding fens. Because the seeds of certain species are long-lived in the seed bank, frequent episodes of dispersal are not always necessary to maintain the biodiversity of fens. However, of particular concern to restoration is that some dominant species, such as the tussock sedge Carex stricta, may not disperse readily between fens. Conclusions: Knowledge of seed dispersal can be used to maintain and restore the biodiversity of fens in fragmented landscapes. Given that development has fragmented landscapes and that this situation is not likely to change, the dispersal of seeds might be enhanced by moving hay or cattle from fens to damaged sites, or by reestablishing lost hydrological connections. ?? IAVS; Opulus Press.

Cyclic delivery scheduling to customers with different priorities

Directory of Open Access Journals (Sweden)

Katarzyna Zofia Gdowska

2013-12-01

Full Text Available Background: In this paper a cyclic delivery scheduling problem for customers with different priorities is presented. Shops, which are provided with deliveries, are occasionally located in places which are crucial for the proper flow of traffic. In such places coordination of deliveries is crucial; therefore it allows to completely eliminate the phenomenon of the simultaneous arrivals of suppliers. Methods: In this paper the cyclic delivery scheduling problem for customers with different priorities was presented. To this theoretical problem a mix integer programming model was developed. Specific approach to the cyclic delivery scheduling problem is inspired by timetabling problem for urban public transport. Results: Mixed integer programming model was employed for solving four cases of cyclic delivery scheduling problem for customers with different priorities. When the value of the synchronization priority assigned to a single customer raised then the total number of synchronizations in the whole network decreased. In order to compare solutions a synchronization rate was utilized. A simple factor was utilized - the proportion of number of synchronizations of deliveries to a given customer to the total number of synchronizations obtained for the whole network. When the value of synchronization priority raised then the value of synchronization rate of this customer improved significantly. Conclusions: The mixed integer programming model for the cyclic delivery scheduling problem for customers with different priorities presented in this paper can be utilized for generating schedules of serving customers located in places where only one delivery can be received and unloaded at one go and where there is no space for other suppliers to wait in a queue. Such a schedule can be very useful for organizing deliveries to small shops united in a franchising network, since they operate in a way that is very similar to the network presented in this paper

Nanoemulsion: A new concept of delivery system

Directory of Open Access Journals (Sweden)

Nitin Sharma

2010-01-01

Full Text Available Nanoemulsion has been identified as a promising delivery system for various drugs including biopharmaceuticals. Nanoemulsion is a heterogeneous system composed of one immiscible liquid dispersed as droplets within another liquid. The droplets size of nano emulsion is between 20 to 500 nm. Diameter and surface properties of droplets of nanoemulsion plays an important role in the biological behavior of the formulation. Small droplet sizes lead to transparent emulsions so that product appearance is not altered by the addition of an oil phase. In this paper various aspects of nanoemulsion have been discussed including advantages, disadvantages and methods of preparation. Furthermore new approaches of stability of formulation, effect of types and concentration of surfactant, process variables and method are also discussed to improve the stability of nanoemulsion formulation

Wave-equation dispersion inversion

KAUST Repository

Li, Jing

2016-12-08

We present the theory for wave-equation inversion of dispersion curves, where the misfit function is the sum of the squared differences between the wavenumbers along the predicted and observed dispersion curves. The dispersion curves are obtained from Rayleigh waves recorded by vertical-component geophones. Similar to wave-equation traveltime tomography, the complicated surface wave arrivals in traces are skeletonized as simpler data, namely the picked dispersion curves in the phase-velocity and frequency domains. Solutions to the elastic wave equation and an iterative optimization method are then used to invert these curves for 2-D or 3-D S-wave velocity models. This procedure, denoted as wave-equation dispersion inversion (WD), does not require the assumption of a layered model and is significantly less prone to the cycle-skipping problems of full waveform inversion. The synthetic and field data examples demonstrate that WD can approximately reconstruct the S-wave velocity distributions in laterally heterogeneous media if the dispersion curves can be identified and picked. The WD method is easily extended to anisotropic data and the inversion of dispersion curves associated with Love waves.

Simulation of robotic courier deliveries in hospital distribution services.

Science.gov (United States)

Rossetti, M D; Felder, R A; Kumar, A

2000-06-01

Flexible automation in the form of robotic couriers holds the potential for decreasing operating costs while improving delivery performance in hospital delivery systems. This paper discusses the use of simulation modeling to analyze the costs, benefits, and performance tradeoffs related to the installation and use of a fleet of robotic couriers within hospital facilities. The results of this study enable a better understanding of the delivery and transportation requirements of hospitals. Specifically, we examine how a fleet of robotic couriers can meet the performance requirements of the system while maintaining cost efficiency. We show that for clinical laboratory and pharmaceutical deliveries a fleet of six robotic couriers can achieve significant performance gains in terms of turn-around time and delivery variability over the current system of three human couriers per shift or 13 FTEs. Specifically, the simulation results indicate that using robotic couriers to perform both clinical laboratory and pharmaceutical deliveries would result in a 34% decrease in turn-around time, and a 38% decrease in delivery variability. In addition, a break-even analysis indicated that a positive net present value occurs if nine or more FTEs are eliminated with a resulting ROI of 12%. This analysis demonstrates that simulation can be a valuable tool for examining health care distribution services and indicates that a robotic courier system may yield significant benefits over a traditional courier system in this application.

Spurious dispersion effects at FLASH

International Nuclear Information System (INIS)

Prat, Eduard

2009-07-01

The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)

Spurious dispersion effects at FLASH

Energy Technology Data Exchange (ETDEWEB)

Prat, Eduard

2009-07-15

The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)

Counting systems in wavelength and energy dispersive spectrometry: the principle and how to check and to adjust

International Nuclear Information System (INIS)

Maurice, Francoise

1978-03-01

The purpose of this report is to define the optimum operating conditions of the whole counting systems in wavelength dispersive spectrometry (mostly used in conjunction with electron microprobes) and in energy dispersive spectrometry (more often connected to scanning electron microscopes). For both these techniques, the principle of the detector and its attached counting electronics is recalled; a check list is then given for verifying the qualities of the apparatus and detecting the defects; finally the best operating conditions are defined as essential in an analytical instrument whose reliability has to be perfect [fr

An application of interactive computer graphics technology to the design of dispersal mechanisms

Science.gov (United States)

Richter, B. J.; Welch, B. H.

1977-01-01

Interactive computer graphics technology is combined with a general purpose mechanisms computer code to study the operational behavior of three guided bomb dispersal mechanism designs. These studies illustrate the use of computer graphics techniques to discover operational anomalies, to assess the effectiveness of design improvements, to reduce the time and cost of the modeling effort, and to provide the mechanism designer with a visual understanding of the physical operation of such systems.

Metapopulation extinction risk: dispersal's duplicity.

Science.gov (United States)

Higgins, Kevin

2009-09-01

Metapopulation extinction risk is the probability that all local populations are simultaneously extinct during a fixed time frame. Dispersal may reduce a metapopulation's extinction risk by raising its average per-capita growth rate. By contrast, dispersal may raise a metapopulation's extinction risk by reducing its average population density. Which effect prevails is controlled by habitat fragmentation. Dispersal in mildly fragmented habitat reduces a metapopulation's extinction risk by raising its average per-capita growth rate without causing any appreciable drop in its average population density. By contrast, dispersal in severely fragmented habitat raises a metapopulation's extinction risk because the rise in its average per-capita growth rate is more than offset by the decline in its average population density. The metapopulation model used here shows several other interesting phenomena. Dispersal in sufficiently fragmented habitat reduces a metapopulation's extinction risk to that of a constant environment. Dispersal between habitat fragments reduces a metapopulation's extinction risk insofar as local environments are asynchronous. Grouped dispersal raises the effective habitat fragmentation level. Dispersal search barriers raise metapopulation extinction risk. Nonuniform dispersal may reduce the effective fraction of suitable habitat fragments below the extinction threshold. Nonuniform dispersal may make demographic stochasticity a more potent metapopulation extinction force than environmental stochasticity.

Computer system operation

International Nuclear Information System (INIS)

Lee, Young Jae; Lee, Hae Cho; Lee, Ho Yeun; Kim, Young Taek; Lee, Sung Kyu; Park, Jeong Suk; Nam, Ji Wha; Kim, Soon Kon; Yang, Sung Un; Sohn, Jae Min; Moon, Soon Sung; Park, Bong Sik; Lee, Byung Heon; Park, Sun Hee; Kim, Jin Hee; Hwang, Hyeoi Sun; Lee, Hee Ja; Hwang, In A.

1993-12-01

The report described the operation and the trouble shooting of main computer and KAERINet. The results of the project are as follows; 1. The operation and trouble shooting of the main computer system. (Cyber 170-875, Cyber 960-31, VAX 6320, VAX 11/780). 2. The operation and trouble shooting of the KAERINet. (PC to host connection, host to host connection, file transfer, electronic-mail, X.25, CATV etc.). 3. The development of applications -Electronic Document Approval and Delivery System, Installation the ORACLE Utility Program. 22 tabs., 12 figs. (Author) .new

Computer system operation

Energy Technology Data Exchange (ETDEWEB)

Lee, Young Jae; Lee, Hae Cho; Lee, Ho Yeun; Kim, Young Taek; Lee, Sung Kyu; Park, Jeong Suk; Nam, Ji Wha; Kim, Soon Kon; Yang, Sung Un; Sohn, Jae Min; Moon, Soon Sung; Park, Bong Sik; Lee, Byung Heon; Park, Sun Hee; Kim, Jin Hee; Hwang, Hyeoi Sun; Lee, Hee Ja; Hwang, In A [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1993-12-01

The report described the operation and the trouble shooting of main computer and KAERINet. The results of the project are as follows; 1. The operation and trouble shooting of the main computer system. (Cyber 170-875, Cyber 960-31, VAX 6320, VAX 11/780). 2. The operation and trouble shooting of the KAERINet. (PC to host connection, host to host connection, file transfer, electronic-mail, X.25, CATV etc.). 3. The development of applications -Electronic Document Approval and Delivery System, Installation the ORACLE Utility Program. 22 tabs., 12 figs. (Author) .new.

Air-guided photonic-crystal-fiber pulse-compression delivery of multimegawatt femtosecond laser output for nonlinear-optical imaging and neurosurgery

Science.gov (United States)

Lanin, Aleksandr A.; Fedotov, Il'ya V.; Sidorov-Biryukov, Dmitrii A.; Doronina-Amitonova, Lyubov V.; Ivashkina, Olga I.; Zots, Marina A.; Sun, Chi-Kuang; Ömer Ilday, F.; Fedotov, Andrei B.; Anokhin, Konstantin V.; Zheltikov, Aleksei M.

2012-03-01

Large-core hollow photonic-crystal fibers (PCFs) are shown to enable a fiber-format air-guided delivery of ultrashort infrared laser pulses for neurosurgery and nonlinear-optical imaging. With an appropriate dispersion precompensation, an anomalously dispersive 15-μm-core hollow PCF compresses 510-fs, 1070-nm light pulses to a pulse width of about 110 fs, providing a peak power in excess of 5 MW. The compressed PCF output is employed to induce a local photodisruption of corpus callosum tissues in mouse brain and is used to generate the third harmonic in brain tissues, which is captured by the PCF and delivered to a detector through the PCF cladding.

Water insoluble and soluble lipids for gene delivery.

Science.gov (United States)

Mahato, Ram I

2005-04-05

Among various synthetic gene carriers currently in use, liposomes composed of cationic lipids and co-lipids remain the most efficient transfection reagents. Physicochemical properties of lipid/plasmid complexes, such as cationic lipid structure, cationic lipid to co-lipid ratio, charge ratio, particle size and zeta potential have significant influence on gene expression and biodistribution. However, most cationic lipids are toxic and cationic liposomes/plasmid complexes do not disperse well inside the target tissues because of their large particle size. To overcome the problems associated with cationic lipids, we designed water soluble lipopolymers for gene delivery to various cells and tissues. This review provides a critical discussion on how the components of water insoluble and soluble lipids affect their transfection efficiency and biodistribution of lipid/plasmid complexes.

Paraffin dispersant application for cleaning subsea flow lines in the deep water Gulf of Mexico cottonwood development

Energy Technology Data Exchange (ETDEWEB)

Jennings, David; White, Jake; Pogoson, Oje [Baker Hughes Inc., Houston, TX (United States); Barros, Dalmo; Ramachandran, Kartik; Bonin, George; Waltrich, Paulo; Shecaira, Farid [PETROBRAS America, Houston, TX (United States); Ziglio, Claudio [Petroleo Brasileiro S.A. (CENPES/PETROBRAS), Rio de Janeiro, RJ (Brazil). Centro de Pesquisa e Desenvolvimento

2012-07-01

This paper discusses a paraffin dispersant (in seawater) application to clean paraffin deposition from a severely restricted 17.4-mile dual subsea flow line system in the Gulf of Mexico Cottonwood development. In principle, dispersant treatments are simple processes requiring effective dispersant packages and agitation to break-up and disperse deposition. Dispersants have been used onshore for treating wax deposition for decades. Implementation of a treatment in a long deep water production system, however, poses numerous challenges. The Cottonwood application was one of the first ever deep water dispersant applications. The application was designed in four separate phases: pre-treatment displacement for hydrate protection, dispersant treatment for paraffin deposition removal, pigging sequence for final flow line cleaning, and post-treatment displacement for hydrate protection. In addition, considerable job planning was performed to ensure the application was executed in a safe and environmentally responsible manner. Two dynamically positioned marine vessels were used for pumping fluids and capturing returns. The application was extremely successful in restoring the deep water flow lines back to near pre-production state. Final pigging operations confirmed the flow lines were cleaned of all restrictions. Significant paraffin deposition was removed in the application. Approximately 900 bbls of paraffin sludge was recovered from the 4000 bbl internal volume flow line loop. Furthermore, the application was completed with zero discharge of fluids. The application provided significant value for the Cottonwood development. It allowed production from wells to be brought on-line at a higher capacity, thereby generating increased revenue. It also allowed resumption of routine pigging operations. As such, the Cottonwood dispersant application illustrates that with proper planning and execution, paraffin dispersant treatments can be highly effective solutions for cleaning

Implications of formulation design on lipid-based nanostructured carrier system for drug delivery to brain.

Science.gov (United States)

Salunkhe, Sachin S; Bhatia, Neela M; Bhatia, Manish S

2016-05-01

The aim of present investigation was to formulate and develop lipid-based nanostructured carriers (NLCs) containing Idebenone (IDE) for delivery to brain. Attempts have been made to evaluate IDE NLCs for its pharmacokinetic and pharmacodynamic profile through the objective of enhancement in bioavailability and effectivity of drug. Nanoprecipitation technique was used for development of drug loaded NLCs. The components solid lipid Precirol ATO 5, oil Miglyol 840, surfactants Tween 80 and Labrasol have been screened out for formulation development by consideration of preformulation parameters including solubility, Required Hydrophilic lipophilic balance (HLB) of lipids and stability study. Developed IDE NLCs were subjected for particle size, zeta potential, entrapment efficiency (%EE), crystallographic investigation, transmission electron microscopy, in vitro drug release, pharmacokinetics, in vivo and stability study. Formulation under investigation has particle size 174.1 ± 2.6 nm, zeta potential -18.65 ± 1.13 mV and% EE 90.68 ± 2.90. Crystallographic studies exemplified for partial amorphization of IDE by molecularly dispersion within lipid crust. IDE NLCs showed drug release 93.56 ± 0.39% at end of 24 h by following Higuchi model which necessitates for appropriate drug delivery with enhancement in bioavailability of drug by 4.6-fold in plasma and 2.8-fold in brain over plain drug loaded aqueous dispersions. In vivo studies revealed that effect of drug was enhanced by prepared lipid nanocarriers. IDE lipid-based nanostructured carriers could have potential for efficient drug delivery to brain with enhancement in bioavailability of drug over the conventional formulations.

Dispersion stability of thermal nanofluids

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Fan Yu

2017-10-01

Full Text Available Thermal nanofluids, the engineered fluids with dispersed functional nanoparticles, have exhibited extraordinary thermophysical properties and added functionalities, and thus have enabled a broad range of important applications. The poor dispersion stability of thermal nanofluids, however, has been considered as a long-existing issue that limits their further development and practical application. This review overviews the recent efforts and progresses in improving the dispersion stability of thermal nanofluids such as mechanistic understanding of dispersion behavior of nanofluids, examples of both water-based and oil-based nanofluids, strategies to stabilize nanofluids, and characterization techniques for dispersion behavior of nanofluids. Finally, on-going research needs, and possible solutions to research challenges and future research directions in exploring stably dispersed thermal nanofluids are discussed. Keywords: Thermal nanofluids, Dispersion, Aggregation, Electrostatic stabilization, Steric stabilization

Safe Active Scanning for Energy Delivery Systems Final Report

Energy Technology Data Exchange (ETDEWEB)

Helms, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Salazar, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Scheibel, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Engels, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reiger, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-09-30

The Department of Energy’s Cybersecurity for Energy Delivery Systems Program has funded Safe(r) Active Scanning for Energy Delivery Systems, led by Lawrence Livermore National Laboratory, to investigate and analyze the impacts of active scanning in the operational environment of energy delivery systems. In collaboration with Pacific Northwest National Laboratory and Idaho National Laboratory, active scans across three testbeds including 38 devices were performed. This report gives a summary of the initial literature survey performed on the SASEDS project as well as industry partner interview summaries and main findings from Phase 1 of the project. Additionally, the report goes into the details of scanning techniques, methodologies for testing, testbed descriptions, and scanning results, with appendices to elaborate on the specific scans that were performed. As a result of testing, a single device out of 38 exhibited problems when actively scanned, and a reboot was required to fix it. This single failure indicates that active scanning is not likely to have a detrimental effect on the safety and resilience of energy delivery systems. We provide a path forward for future research that could enable wide adoption of active scanning and lead utilities to incorporate active scanning as part of their default network security plans to discover and rectify rogue devices, adversaries, and services that may be on the network. This increased network visibility will allow operational technology cybersecurity practitioners to improve their situational awareness of networks and their vulnerabilities.

Model analysis of local oxygen delivery with liposome-encapsulated hemoglobin.

Science.gov (United States)

Matsumoto, Takeshi; Mano, Katsuhiko; Ueha, Ryohei; Naito, Hisashi; Tanaka, Masao

2009-03-01

Liposome-encapsulated hemoglobins (LHs) are comparable to red blood cells (RBCs) in terms of oxygen (O(2))-carrying capacity. The smaller particle size of LHs than of platelets allows their homogeneous dispersion in circulating plasma. In this study, we evaluated the effect of LH transfusion on arterial O(2) delivery through vascular trees by simulation. A mathematical model was established on the basis of the coronary arterial anatomy, the conservation of flow and RBC flux, and Poiseuille's law. The Fåhraeus-Lindqvist, Fåhraeus, and phase separation effects were considered in the model. By assuming steady perfusion, the arterial flow and O(2) delivery were calculated for five model trees undergoing the isovolumic replacement of RBCs (0.3 mg hemoglobin (Hb)/mL) with LHs (0.2 mg Hb/mL) or a plasma volume expander (PVE). The RBC-LH exchange increased both the total flow and the total O(2) flux but had almost no effect on the relative distribution of O(2) flux. In contrast, the RBC-PVE exchange decreased the total O(2) flux and increased the proportion of regions receiving a relatively low O(2) supply. Thus, LH transfusion may compensate for an enhanced bias in RBC-associated O(2) flux under hemodilution and is expected to be beneficial for both total and local O(2) delivery.

Hydrodynamic disperser

Energy Technology Data Exchange (ETDEWEB)

Bulatov, A.I.; Chernov, V.S.; Prokopov, L.I.; Proselkov, Yu.M.; Tikhonov, Yu.P.

1980-01-15

A hydrodynamic disperser is suggested which contains a housing, slit nozzles installed on a circular base arranged opposite from each other, resonators secured opposite the nozzle and outlet sleeve. In order to improve the effectiveness of dispersion by throttling the flow, each resonator is made in the form of a crimped plate with crimpings that decrease in height in a direction towards the nozzle.

Cluster observations of ion dispersion discontinuities in the polar cusp

Science.gov (United States)

Escoubet, C. P.; Berchem, J.; Pitout, F.; Richard, R. L.; Trattner, K. J.; Grison, B.; Taylor, M. G.; Masson, A.; Dunlop, M. W.; Dandouras, I. S.; Reme, H.; Fazakerley, A. N.

2009-12-01

The reconnection between the interplanetary magnetic field (IMF) and the Earth’s magnetic field is taking place at the magnetopause on magnetic field lines threading through the polar cusp. When the IMF is southward, reconnection occurs near the subsolar point, which is magnetically connected to the equatorward boundary of the polar cusp. Subsequently the ions injected through the reconnection point precipitate in the cusp and are dispersed poleward. If reconnection is continuous and operates at constant rate, the ion dispersion is smooth and continuous. On the other hand if the reconnection rate varies, we expect interruption in the dispersion forming energy steps or staircase. Similarly, multiple entries near the magnetopause could also produce steps at low or mid-altitude when a spacecraft is crossing subsequently the field lines originating from these multiple sources. In addition, motion of the magnetopause induced by solar wind pressure changes or erosion due to reconnection can also induce a motion of the polar cusp and a disruption of the ions dispersion observed by a spacecraft. Cluster with four spacecraft following each other in the mid-altitude cusp can be used to distinguish between these “temporal” and “spatial” effects. We will present a cusp crossing with two spacecraft, separated by around two minutes. The two spacecraft observed a very similar dispersion with a step in energy in its centre and two other dispersions poleward. We will show that the steps could be temporal (assuming that the time between two reconnection bursts corresponds to the time delay between the two spacecraft) but it would be a fortuitous coincidence. On the other hand the steps and the two poleward dispersions could be explained by spatial effects if we take into account the motion of the open-closed boundary between the two spacecraft crossings.

FedEx Gasoline Hybrid Electric Delivery Truck Evaluation: 6-Month Interim Report

Energy Technology Data Exchange (ETDEWEB)

Barnitt, R.

2010-05-01

This interim report presents partial (six months) results for a technology evaluation of gasoline hybrid electric parcel delivery trucks operated by FedEx in and around Los Angeles, CA. A 12 month in-use technology evaluation comparing in-use fuel economy and maintenance costs of GHEVs and comparative diesel parcel delivery trucks was started in April 2009. Comparison data was collected and analyzed for in-use fuel economy and fuel costs, maintenance costs, total operating costs, and vehicle uptime. In addition, this interim report presents results of parcel delivery drive cycle collection and analysis activities as well as emissions and fuel economy results of chassis dynamometer testing of a gHEV and a comparative diesel truck at the National Renewable Energy Laboratory's (NREL) ReFUEL laboratory. A final report will be issued when 12 months of in-use data have been collected and analyzed.

Polymeric dispersants for control of steam generator fouling

International Nuclear Information System (INIS)

Balakrishnan, P.V.; Klimas, S.J.; Lepine, L.; Turner, C.W.

1999-05-01

Fouling of steam generators by corrosion products from the feedtrain leads to loss of heat-transfer efficiency, disturbances in thermalhydraulics, and potential corrosion problems resulting from the development of sites for localized accumulation of aggressive chemicals. This report summarizes studies of the use of polymeric dispersants for the control of fouling, which were conducted at the Chalk River Laboratories. High-temperature settling studies on magnetite suspensions were performed to screen available generic dispersants, and the dispersants were ranked in terms of their dispersion efficiency; polyacrylic acid (PAA) and the phosphonate, HEDP, were ranked as the most efficient. Polyacrylic acid was considered more suitable than HEDP for nuclear steam generators, and more emphasis was given to the former in these studies. The dispersants had no effect on the particle deposition rates under single-phase forced-convective flow, but did reduce the deposition rates under flow-boiling conditions. The extent to which the deposition rates were reduced increased in proportion to the dispersant concentration. Preliminary corrosion tests indicated that pitting or general corrosion of steam generator tube materials in the presence of PAA was negligible. Corrosion of carbon steel, although higher in a magnetite-packed crevice under heat flux than in bulk water, was lower in the presence of PAA than in its absence. Some impurities (e.g., sulphate, sodium) were observed in commercially available PAA products at small, though significant concentrations, making these products unacceptable for use in nuclear plants. However, the PAA could be purified by ion exchange. Preliminary experiments, to assess the thermal stability of PAA at steam generator operating temperature, showed the polymer to break down in deaerated solutions and under argon cover to give hydrogen and carbon dioxide as the two major products in the gas phase and variable concentrations of acetate and formate

Newborns from deliveries with epidural anaesthesia

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Avramović Lidija

2010-01-01

Full Text Available Introduction. The use of epidural anaesthesia in delivery with the purpose to reduce pain and fear in a pregnant woman has the influence on the physiological status of the woman in childbirth and the course of delivery. From the epidural space of the pregnant woman, one part of free anaesthetic comes in the foetal circulation through the mother's circulation and placenta and connects with the foetal proteins. A lower value of albumins and serum proteins in the foetal circulation give bigger free fraction of anaesthetic which is accumulated in the foetal liver, brain and heart full of blood. Objective. The aim of the study was to examine the influence of epidural anaesthesia on the newborn. Methods. Retrospective study of 6,398 documents of newborns was performed in our Clinic of Gynaecology and Obstetrics 'Narodni front' during 2006. The first group was made of 455 newborns from deliveries with epidural anaesthesia and the second was the control group of 5,943 remaining newborns. In both groups we analysed the following: sex, week of gestation, weight, Apgar score, measure of care and resuscitation, perinatal morbidity and then the obtained results were compared. Results. Most of deliveries were vaginal without obstetric intervention (86.6%. The number of deliveries finished with vacuum extractor (4.6% was statistically significantly bigger in the group with epidural anaesthesia than in the control group. Most of the newborns in the first group were born on time (96.5% in 39.0±1.0 week of gestation and with foetal weight 3448±412 grammes. There was no statistical significance in Apgar score between both groups. Epidural anaesthesia does not increase the degree of the newborn's injury. Lower pH of blood was found in the newborns from deliveries with vacuum extractor or operated on (the Ceasarean section. Conclusion. Application of epidural anaesthesia decreases duration of delivery and has no adverse effects on the newborn and hypoxic

Dispersal and metapopulation stability

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Shaopeng Wang

2015-10-01

Full Text Available Metapopulation dynamics are jointly regulated by local and spatial factors. These factors may affect the dynamics of local populations and of the entire metapopulation differently. Previous studies have shown that dispersal can stabilize local populations; however, as dispersal also tends to increase spatial synchrony, its net effect on metapopulation stability has been controversial. Here we present a simple metapopulation model to study how dispersal, in interaction with other spatial and local processes, affects the temporal variability of metapopulations in a stochastic environment. Our results show that in homogeneous metapopulations, the local stabilizing and spatial synchronizing effects of dispersal cancel each other out, such that dispersal has no effect on metapopulation variability. This result is robust to moderate heterogeneities in local and spatial parameters. When local and spatial dynamics exhibit high heterogeneities, however, dispersal can either stabilize or destabilize metapopulation dynamics through various mechanisms. Our findings have important theoretical and practical implications. We show that dispersal functions as a form of spatial intraspecific mutualism in metapopulation dynamics and that its effect on metapopulation stability is opposite to that of interspecific competition on local community stability. Our results also suggest that conservation corridors should be designed with appreciation of spatial heterogeneities in population dynamics in order to maximize metapopulation stability.

Meeting global health challenges through operational research and management science.

Science.gov (United States)

Royston, Geoff

2011-09-01

This paper considers how operational research and management science can improve the design of health systems and the delivery of health care, particularly in low-resource settings. It identifies some gaps in the way operational research is typically used in global health and proposes steps to bridge them. It then outlines some analytical tools of operational research and management science and illustrates how their use can inform some typical design and delivery challenges in global health. The paper concludes by considering factors that will increase and improve the contribution of operational research and management science to global health.

Dispersion of multi-walled carbon nanotubes in biocompatible dispersants

International Nuclear Information System (INIS)

Piret, J.-P.; Detriche, S.; Vigneron, R.; Vankoningsloo, S.; Rolin, S.; Mejia Mendoza, J. H.; Masereel, B.; Lucas, S.; Delhalle, J.; Luizi, F.; Saout, C.; Toussaint, O.

2010-01-01

Owing to their phenomenal electrical and mechanical properties, carbon nanotubes (CNT) have been an area of intense research since their discovery in 1991. Different applications for these nanoparticles have been proposed, among others, in electronics and optics but also in the medical field. In parallel, emerging studies have suggested potential toxic effects of CNT while others did not, generating some conflicting outcomes. These discrepancies could be, in part, due to different suspension approaches used and to the agglomeration state of CNT in solution. In this study, we described a standardized protocol to obtain stable CNT suspensions, using two biocompatible dispersants (Pluronic F108 and hydroxypropylcellulose) and to estimate the concentration of CNT in solution. CNT appear to be greatly individualized in these two dispersants with no detection of remaining bundles or agglomerates after sonication and centrifugation. Moreover, CNT remained perfectly dispersed when added to culture medium used for in vitro cell experiments. We also showed that Pluronic F108 is a better dispersant than hydroxypropylcellulose. In conclusion, we have developed a standardized protocol using biocompatible surfactants to obtain reproducible and stable multi-walled carbon nanotubes suspensions which can be used for in vitro or in vivo toxicological studies.

Non-technical skills for obstetricians conducting forceps and vacuum deliveries: qualitative analysis by interviews and video recordings.

Science.gov (United States)

Bahl, Rachna; Murphy, Deirdre J; Strachan, Bryony

2010-06-01

Non-technical skills are cognitive and social skills required in an operational task. These skills have been identified and taught in the surgical domain but are of particular relevance to obstetrics where the patient is awake, the partner is present and the clinical circumstances are acute and often stressful. The aim of this study was to define the non-technical skills of an operative vaginal delivery (forceps or vacuum) to facilitate transfer of skills from expert obstetricians to trainee obstetricians. Qualitative study using interviews and video recordings. The study was conducted at two university teaching hospitals (St. Michael's Hospital, Bristol and Ninewells Hospital, Dundee). Participants included 10 obstetricians and eight midwives identified as experts in conducting or supporting operative vaginal deliveries. Semi-structured interviews were carried out using routine clinical scenarios. The experts were also video recorded conducting forceps and vacuum deliveries in a simulation setting. The interviews and video recordings were transcribed verbatim and analysed using thematic coding. The anonymised data were independently coded by the three researchers and then compared for consistency of interpretation. The experts reviewed the coded data for respondent validation and clarification. The themes that emerged were used to identify the non-technical skills required for conducting an operative vaginal delivery. The final skills list was classified into seven main categories. Four categories (situational awareness, decision making, task management, and team work and communication) were similar to the categories identified in surgery. Three further categories unique to obstetrics were also identified (professional relationship with the woman, maintaining professional behaviour and cross-monitoring of performance). This explicitly defined skills taxonomy could aid trainees' understanding of the non-technical skills to be considered when conducting an operative

Engaging Faculty in Telecommunications-Based Instructional Delivery Systems.

Science.gov (United States)

Swalec, John J.

In the design and development of telecommunications-based instructional delivery systems, attention to faculty involvement and training is often overlooked until the system is operational. The Waubonsee Telecommunications Instructional Consortium (TIC), in Illinois, is one network that benefited from early faculty input. Even before the first…

IMPROVEMENTS IN THE QUALITY OF COURIER DELIVERY

Directory of Open Access Journals (Sweden)

Jacek Karcz

2016-06-01

Full Text Available The functioning of courier companies is a vital component of modern trade. E-commerce services are changing the way of shopping. Along with them, also courier services change and become more advance. Customers of courier companies become more aware of quality, which they should expect from supplier of these services. The article presents the result of the research of the effectiveness and the timelines of deliveries realized by one of the terminals of a leading courier operator in Poland. The survey involved 55 courier routes over the course of 10 business days. The author analyses weak points of the supply chain and presents two solutions, which may improve quality of delivery processes.

Development and characterization of an atorvastatin solid dispersion formulation using skimmed milk for improved oral bioavailability

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Ankush Choudhary

2012-08-01

Full Text Available Atorvastatin has low aqueous solubility resulting in low oral bioavailability (12% and thus presents a challenge in formulating a suitable dosage form. To improve the aqueous solubility, a solid dispersion formulation of atorvastatin was prepared by lyophilization utilising skimmed milk as a carrier. Six different formulations were prepared with varying ratios of drug and carrier and the corresponding physical mixtures were also prepared. The formation of a solid dispersion formulation was confirmed by differential scanning calorimetry and X-ray diffraction studies. The optimum drug-to-carrier ratio of 1:9 enhanced solubility nearly 33-fold as compared to pure drug. In vitro drug release studies exhibited a cumulative release of 83.69% as compared to 22.7% for the pure drug. Additionally, scanning electron microscopy studies suggested the conversion of crystalline atorvastatin to an amorphous form. In a Triton-induced hyperlipidemia model, a 3-fold increase in the lipid lowering potential was obtained with the reformulated drug as compared to pure drug. These results suggest that solid dispersion of atorvastatin using skimmed milk as carrier is a promising approach for oral delivery of atorvastatin.

Transdermal drug delivery

Science.gov (United States)

Prausnitz, Mark R.; Langer, Robert

2009-01-01

Transdermal drug delivery has made an important contribution to medical practice, but has yet to fully achieve its potential as an alternative to oral delivery and hypodermic injections. First-generation transdermal delivery systems have continued their steady increase in clinical use for delivery of small, lipophilic, low-dose drugs. Second-generation delivery systems using chemical enhancers, non-cavitational ultrasound and iontophoresis have also resulted in clinical products; the ability of iontophoresis to control delivery rates in real time provides added functionality. Third-generation delivery systems target their effects to skin’s barrier layer of stratum corneum using microneedles, thermal ablation, microdermabrasion, electroporation and cavitational ultrasound. Microneedles and thermal ablation are currently progressing through clinical trials for delivery of macromolecules and vaccines, such as insulin, parathyroid hormone and influenza vaccine. Using these novel second- and third-generation enhancement strategies, transdermal delivery is poised to significantly increase impact on medicine. PMID:18997767

Better resolved low frequency dispersions by the apt use of Kramers-Kronig relations, differential operators and all-in-1 modelling

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Jan van Turnhout

2016-05-01

Full Text Available The dielectric spectra of colloidal systems often contain a typical low frequency dispersion, which usually remains unnoticed, because of the presence of strong conduction losses. The KK relations offer a means for converting  into  data. This allows us to calculate conduction free  spectra in which the l.f. dispersion will show up undisturbed. This interconversion can be done on line with a moving frame of logarithmically spaced  data. The coefficients of the conversion frames were obtained by kernel matching and by using symbolic differential operators. Logarithmic derivatives and differences of  and  provide another option for conduction free data analysis. These difference-based functions actually derived from approximations to the distribution function, have the additional advantage of improving the resolution power of dielectric studies. A high resolution is important because of the rich relaxation structure of colloidal suspensions. The development of all-in-1 modelling facilitates the conduction free and high resolution data analysis. This mathematical tool allows the apart-together fitting of multiple data and multiple model functions. It proved also useful to go around the KK conversion altogether. This was achieved by the combined approximating  and  data with a complex rational fractional power function. The all-in-1 minimization turned out to be also highly useful for the dielectric modelling of a suspension with the complex dipolar coefficient. It guarantees a secure correction for the electrode polarization, so that the modelling with the help of the differences  and  can zoom in on the genuine colloidal relaxations.

Analytical formulation of directly modulated OOFDM signals transmitted over an IM/DD dispersive link.

Science.gov (United States)

Sánchez, C; Ortega, B; Wei, J L; Tang, J; Capmany, J

2013-03-25

We provide an analytical study on the propagation effects of a directly modulated OOFDM signal through a dispersive fiber and subsequent photo-detection. The analysis includes the effects of the laser operation point and the interplay between chromatic dispersion and laser chirp. The final expression allows to understand the physics behind the transmission of a multi-carrier signal in the presence of residual frequency modulation and the description of the induced intermodulation distortion gives us a detailed insight into the diferent intermodulation products which impair the recovered signal at the receiver-end side. Numerical comparisons between transmission simulations results and those provided by evaluating the expression obtained are carried out for different laser operation points. Results obtained by changing the fiber length, laser parameters and using single mode fiber with negative and positive dispersion are calculated in order to demonstrate the validity and versatility of the theory provided in this paper. Therefore, a novel analytical formulation is presented as a versatile tool for the description and study of IM/DD OOFDM systems with variable design parameters.

Managing Evolving Global Operations Networks

DEFF Research Database (Denmark)

Mykhaylenko, Alona; Wæhrens, Brian Vejrum; Johansen, John

2015-01-01

For many globally dispersed organisations, the home base (HB) is a historic locus of integrative and coordinating efforts that safeguard overall performance. However, the dynamism of global operations networks is increasingly pulling the centre of gravity away from the HB and dispersing it across...... the network, challenging the HB’s ability to sustain its centrality over time. To counteract this tendency, this paper addresses the gap in the literature regarding the development of the network management capability of the HB within the context of its network. Data was collected through a retrospective...... longitudinal case study of an intra-organisational operations network of one OEM and its three foreign subsidiaries. The findings suggest a row of strategic roles and corresponding managerial capabilities, which the HB needs to develop depending on the changing subsidiaries’ competencies and HB...

Polymeric composite membranes for temperature and pH-responsive delivery of doxorubicin hydrochloride

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Sahar Mohamaddoust Aliabadi

2015-07-01

Full Text Available Objective(s: Nowadays hydrogels are one of the upcoming classes of polymer-based controlled-release drug delivery systems. Temperature and pH-responsive delivery systems have drawn much attention because some diseases reveal themselves by a change in temperature and/or pH. The objective of this work is to prepare and characterize composite membrane using responsive nanoparticles into a polymer matrix. Materials and Methods: These nanoparticles were made of the copolymer poly (N-isopropylacrylamide-co-methaçrylic acid by an aqueous dispersion polymerization process and are responsible for dual sensitivity to temperature and pH. Morphology study with SEM, swelling behavior with Dynamic Light Scattering Technique, in vitro drug release behavior with side-by-side Diffusion Cells were also investigated in this paper. Doxorubicin hydrochloride was used as a model solute. Results:The study on the release of doxorubicin hydrochloride showed that the release rate was higher at pH 5 than pH 7.4, increased with the increase of temperature. Nevertheless, ionic strength only poses a minor direct effect at higher pH. Conclusion:Such system may be potentially used as a tumor-targeting doxorubicin hydrochloride delivery in the body.

Electrospun fibers of layered double hydroxide/biopolymer nanocomposites as effective drug delivery systems

Energy Technology Data Exchange (ETDEWEB)

Miao, Yue-E.; Zhu Hong; Chen Dan; Wang Ruiyu [State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433 (China); Tjiu, Weng Weei [Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Liu Tianxi, E-mail: txliu@fudan.edu.cn [State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433 (China)

2012-06-15

Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on a combination of LDH-IBU with two kinds of biopolymers (i.e. PCL and PLA), to act as effective drug delivery systems. Ibuprofen (IBU) is chosen as a model drug, which is intercalated in MgAl-LDH by coprecipitation. Poly(oxyethylene-b-oxypropylene-b-oxyethylene) (Pluronic) is also added into PLA-based fibers as hydrophilicity enhancer and release modulator. LDH-IBU nanoparticles are uniformly dispersed throughout the nanocomposite fibers, as evidenced by transmission electron microscopy (TEM) observations. In vitro drug release studies show that initial IBU liberation from LDH-IBU/PCL composite fibers is remarkably slower than that from IBU/PCL fibers due to the sustained release property of LDH-IBU and heterogeneous nucleation effect of LDH-IBU on PCL chain segments. Surprisingly, the initial IBU release from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers is faster than that from the corresponding IBU/PLA and IBU/PLA/Pluronic fibers. This effect can be attributed to the strong interaction between alkyl groups in IBU molecules and methyl substituent groups of PLA as well as the hydrophilicity of LDH-IBU, which lead to an easier diffusion of water with a faster release of IBU from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers. - Graphical abstract: Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on the combination of LDHs with two kinds of biopolymers (i.e. PCL and PLA). LDH-IBU nanoparticles are uniformly dispersed throughout all the electrospun nanocomposite fibers even at a high loading level of 5 wt%. By combining the tunable drug release property of LDHs and electrospinning technique, the new drug delivery system is anticipated for effective loading and sustained release of drugs

Electrospun fibers of layered double hydroxide/biopolymer nanocomposites as effective drug delivery systems

International Nuclear Information System (INIS)

Miao, Yue-E.; Zhu Hong; Chen Dan; Wang Ruiyu; Tjiu, Weng Weei; Liu Tianxi

2012-01-01

Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on a combination of LDH-IBU with two kinds of biopolymers (i.e. PCL and PLA), to act as effective drug delivery systems. Ibuprofen (IBU) is chosen as a model drug, which is intercalated in MgAl-LDH by coprecipitation. Poly(oxyethylene-b-oxypropylene-b-oxyethylene) (Pluronic) is also added into PLA-based fibers as hydrophilicity enhancer and release modulator. LDH-IBU nanoparticles are uniformly dispersed throughout the nanocomposite fibers, as evidenced by transmission electron microscopy (TEM) observations. In vitro drug release studies show that initial IBU liberation from LDH-IBU/PCL composite fibers is remarkably slower than that from IBU/PCL fibers due to the sustained release property of LDH-IBU and heterogeneous nucleation effect of LDH-IBU on PCL chain segments. Surprisingly, the initial IBU release from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers is faster than that from the corresponding IBU/PLA and IBU/PLA/Pluronic fibers. This effect can be attributed to the strong interaction between alkyl groups in IBU molecules and methyl substituent groups of PLA as well as the hydrophilicity of LDH-IBU, which lead to an easier diffusion of water with a faster release of IBU from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers. - Graphical abstract: Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on the combination of LDHs with two kinds of biopolymers (i.e. PCL and PLA). LDH-IBU nanoparticles are uniformly dispersed throughout all the electrospun nanocomposite fibers even at a high loading level of 5 wt%. By combining the tunable drug release property of LDHs and electrospinning technique, the new drug delivery system is anticipated for effective loading and sustained release of drugs

Perivascular delivery of Notch 1 siRNA inhibits injury-induced arterial remodeling.

Directory of Open Access Journals (Sweden)

Eileen M Redmond

Full Text Available To determine the efficacy of perivascular delivery of Notch 1 siRNA in preventing injury-induced arterial remodeling.Carotid artery ligation was performed to induce arterial remodeling. After 14 days, morphometric analysis confirmed increased vSMC growth and subsequent media thickening and neointimal formation. Laser capture microdissection, quantitative qRT-PCR and immunoblot analysis of medial tissue revealed a significant increase in Notch1 receptor and notch target gene, Hrt 1 and 2 expression in the injured vessels. Perivascular delivery of Notch 1 siRNA by pluronic gel inhibited the injury-induced increase in Notch 1 receptor and target gene expression when compared to scrambled siRNA controls while concomitantly reducing media thickening and neointimal formation to pre-injury, sham-operated levels. Selective Notch 1 knockdown also reversed the injury-induced inhibition of pro-apoptotic Bax expression while decreasing injury-induced anti-apoptotic Bcl-XL expression to sham-operated control levels. In parallel experiments, proliferative cyclin levels, as measured by PCNA expression, were reversed to sham-operated control levels following selective Notch 1 knockdown.These results suggest that injury-induced arterial remodeling can be successfully inhibited by localized perivascular delivery of Notch 1 siRNA.

Nanodiamonds-mediated doxorubicin nuclear delivery to inhibit lung metastasis of breast cancer.

Science.gov (United States)

Xiao, Jisheng; Duan, Xiaopin; Yin, Qi; Zhang, Zhiwen; Yu, Haijun; Li, Yaping

2013-12-01

Lung metastasis is one of the greatest challenges for breast cancer treatment. Here, a nanodiamonds (NDs)-mediated doxorubicin (DOX) delivery system was first designed to inhibit the lung metastasis of breast cancer effectively. DOX was non-covalently bound to NDs via physical adsorption in an aqueous solution, then DSPE-PEG 2K was coated to the NDs-DOX complex (NDX) to increase the dispersibility and prolong the circulation time. DSPE-PEG 2K coating NDX (DNX) displayed high drug loading and excellent ability to deliver DOX to the nucleus, thereby significantly enhancing cytotoxicity and inducing cell apoptosis. Furthermore, DNX showed good histocompatibility and could improve drug accumulation in lung, as a result, markedly inhibited the lung metastasis of breast cancer. The high anti-metastasis efficacy with the decreased systemic toxicity suggested that DNX could be a promising drug delivery system for the therapy of lung metastasis of breast cancer. Copyright © 2013 Elsevier Ltd. All rights reserved.

Particle engineering using sonocrystallization: salbutamol sulphate for pulmonary delivery.

Science.gov (United States)

Dhumal, Ravindra S; Biradar, Shailesh V; Paradkar, Anant R; York, Peter

2009-02-23

The aim of present work was to produce fine elongated crystals of salbutamol sulphate (SS) by sonocrystallization for pulmonary delivery and compare with micronized and spray dried SS (SDSS) for in vitro aerosolization behavior. Application of ultrasound during anti-solvent crystallization resulted in fine elongated crystals (sonocrystallized SS; SCSS) compared to aggregates of large irregular crystals obtained without sonication. Higher sonication amplitude, time, concentration and lower processing temperatures favored formation of smaller crystals with narrow particle size distribution (PSD). SCSS was separated from dispersion by spray drying in the form of loose aggregates (SD-SCSS). The fine particle fraction (FPF) of formulations with coarse lactose carrier in cascade impactor increased from 16.66% for micronized SS to 31.12% for SDSS (obtained by spray drying aqueous SS solution) and 44.21% for SD-SCSS, due to reduced cohesive/adhesive forces and aerodynamic size by virtue of elongated shape of crystals. SD-SCSS was stable without any change in crystallinity and aerodynamic behavior for 3 months at 40 degrees C/75% RH, but amorphous SDSS showed recrystallization with poor aerosolization performance on storage. Sonocrystallization, a rapid and simple technique is reported for production of SS crystals suitable for inhalation delivery.

Assisted Vaginal Delivery

Science.gov (United States)

... Education & Events Advocacy For Patients About ACOG Assisted Vaginal Delivery Home For Patients Search FAQs Assisted Vaginal ... Vaginal Delivery FAQ192, February 2016 PDF Format Assisted Vaginal Delivery Labor, Delivery, and Postpartum Care What is ...

On-land and offshore testing of a new helicopter bucket for dispersant application - response 3000D

International Nuclear Information System (INIS)

Brandvik, P. J.; Lewis, A.; Daling, P. S.; Strom-Kristiansen, T.; Larsen, E.

1997-01-01

Development of a new helicopter bucket for dispersant applications to serve the dispersant spraying needs of Norwegian oil companies was described. Testing two existing helicopter buckets and practical experience with firefighting helicopter operations provided the foundations for this developmental experiment, combined with the dispersant applications experience of SINTEF. The newly designed bucket, 3000D, has two dispersant spray systems (high and low flow rates) and a large capacity ( three cu m). It is capable of direct filling of dispersant via a suction hose while the helicopter is hovering and is equipped for remote control of all functions. It is robustly designed for use under harsh offshore conditions in the North Sea. The bucket has been subjected to extensive testing on land and offshore with experimental oil slicks. The results were fully satisfactory. 9 refs., 1 tab., 13 figs

47 CFR 63.02 - Exemptions for extensions of lines and for systems for the delivery of video programming.

Science.gov (United States)

2010-10-01

... systems for the delivery of video programming. 63.02 Section 63.02 Telecommunication FEDERAL... systems for the delivery of video programming. (a) Any common carrier is exempt from the requirements of... with respect to the establishment or operation of a system for the delivery of video programming. [64...

Can a Unified Service Delivery Philosophy Be Identified in Aging and Disability Organizations? Exploring Competing Service Delivery Models Through the Voices of the Workforce in These Organizations.

Science.gov (United States)

Keefe, Bronwyn

2018-01-01

Services for older adults and younger people with disabilities are increasingly merging, as reflected in the creation of Aging and Disability Resource Centers (ADRCs). Using ADRCs to coordinate services is challenging, primarily because these fields have different service delivery philosophies. Independent Living Centers, which serve people with disabilities, have a philosophy that emphasizes consumer control and peer mentoring. However, the aging service delivery philosophy is based in a case management or medical model in which the role of consumers directing their services is less pronounced. Using institutional logics theory and a qualitative research design, this study explored whether a unified service delivery philosophy for ADRCs was emerging. Based on focus groups and questionnaires with staff from ADRCs, findings revealed that competing service delivery models continue to operate in the aging and disability fields.

Modeling of transdermal drug delivery with a microneedle array

Science.gov (United States)

Lv, Y.-G.; Liu, J.; Gao, Y.-H.; Xu, B.

2006-11-01

Transdermal drug delivery is generally limited by the extraordinary barrier properties of the stratum corneum, the outer 10-15 µm layer of skin. A conventional needle inserted across this barrier and into deeper tissues could effectively deliver drugs. However, it would lead to infection and cause pain, thereby reducing patient compliance. In order to administer a frequent injection of insulin and other therapeutic agents more efficiently, integrated arrays with very short microneedles were recently proposed as very good candidates for painless injection or extraction. A variety of microneedle designs have thus been made available by employing the fabrication tools of the microelectronics industry and using materials such as silicon, metals, polymers and glass with feature sizes ranging from sub-micron to nanometers. At the same time, experiments were also made to test the capability of the microneedles to inject drugs into tissues. However, due to the difficulty encountered in measurement, a detailed understanding of the spatial and transient drug delivery process still remains unclear up to now. To better grasp the mechanisms involved, quantitative theoretical models were developed in this paper to simultaneously characterize the flow and drug transport, and numerical solutions were performed to predict the kinetics of dispersed drugs injected into the skin from a microneedle array. Calculations indicated that increasing the initial injection velocity and accelerating the blood circulation in skin tissue with high porosity are helpful to enhance the transdermal drug delivery. This study provides the first quantitative simulation of fluid injection through a microneedle array and drug species transport inside the skin. The modeling strategy can also possibly be extended to deal with a wider range of clinical issues such as targeted nanoparticle delivery for therapeutics or molecular imaging.

Improved Ant Colony Optimization for Seafood Product Delivery Routing Problem

Directory of Open Access Journals (Sweden)

Baozhen Yao

2014-02-01

Full Text Available This paper deals with a real-life vehicle delivery routing problem, which is a seafood product delivery routing problem. Considering the features of the seafood product delivery routing problem, this paper formulated this problem as a multi-depot open vehicle routing problem. Since the multi-depot open vehicle routing problem is a very complex problem, a method is used to reduce the complexity of the problem by changing the multi-depot open vehicle routing problem into an open vehicle routing problem with a dummy central depot in this paper. Then, ant colony optimization is used to solve the problem. To improve the performance of the algorithm, crossover operation and some adaptive strategies are used. Finally, the computational results for the benchmark problems of the multi-depot vehicle routing problem indicate that the proposed ant colony optimization is an effective method to solve the multi-depot vehicle routing problem. Furthermore, the computation results of the seafood product delivery problem from Dalian, China also suggest that the proposed ant colony optimization is feasible to solve the seafood product delivery routing problem.

Tracer dispersion - experiment and CFD

International Nuclear Information System (INIS)

Zitny, R.

2004-01-01

Description of tracer distribution by means of dispersion models is a method successfully used in process engineering for fifty years. Application of dispersion models in reactor engineering for characterization of flows in column apparatus, heat exchangers, etc. is summarized and experimental tracer techniques as well as CFD methods for dispersion coefficients evaluation are discussed. Possible extensions of thermal axial dispersion model (ADM) and a core-wall ADM model suitable for description of tracer dispersion in laminar flows are suggested as well as CFD implementation as 1D finite elements. (author)

A Multi-Modality Mobility Concept for a Small Package Delivery UAV

Science.gov (United States)

Young, L. A.

2017-01-01

This paper will discuss a different approach to the typical notional small package delivery drone concept. Most delivery drone concepts employ a point-to-point aerial delivery CONOPS (Concept of Operations) from a warehouse directly to the front or back yards of a customers residence or a commercial office space. Instead, the proposed approach is somewhat analogous to current postal deliveries: a small aerial vehicle flies from a warehouse to designated neighborhood VTOL (Vertical Take-Off and Landing) landing spots where the aerial vehicle then converts to a "roadable" (ground-mobility) vehicle that then transits on sidewalks and/or bicycle paths till it arrives to the residence/office drop-off points. This concept and associated platform or vehicle will be referred in this paper as MICHAEL (Multimodal Intra-City Hauling and Aerial-Effected Logistics) concept. It is suggested that the MICHAEL concept potentially results in a more community friendly "delivery drone" approach.

Self-nanoemulsifying drug delivery systems for oral insulin delivery

DEFF Research Database (Denmark)

Li, Ping; Tan, Angel; Prestidge, Clive A

2014-01-01

This study aims at evaluating the combination of self-nanoemulsifying drug delivery systems (SNEDDS) and enteric-coated capsules as a potential delivery strategy for oral delivery of insulin. The SNEDDS preconcentrates, loaded with insulin-phospholipid complex at different levels (0, 2.5 and 10% w...

PEG-lipid-PLGA hybrid nanoparticles loaded with berberine-phospholipid complex to facilitate the oral delivery efficiency.

Science.gov (United States)

Yu, Fei; Ao, Mingtao; Zheng, Xiao; Li, Nini; Xia, Junjie; Li, Yang; Li, Donghui; Hou, Zhenqing; Qi, Zhongquan; Chen, Xiao Dong

2017-11-01

The natural product berberine (BBR), present in various plants, arouses great interests because of its numerous pharmacological effects. However, the further development and application of BBR had been hampered by its poor oral bioavailability. In this work, we report on polymer-lipid hybrid nanoparticles (PEG-lipid-PLGA NPs) loaded with BBR phospholipid complex using a solvent evaporation method for enhancing the oral BBR efficiency. The advantage of this new drug delivery system is that the BBR-soybean phosphatidylcholine complex (BBR-SPC) could be used to enhance the liposolubility of BBR and improve the affinity with the biodegradable polymer to increase the drug-loading capacity and controlled/sustained release. The entrapment efficiency of the PEG-lipid-PLGA NPs/BBR-SPC was observed to approach approximately 89% which is more than 2.4 times compared with that of the PEG-lipid-PLGA NPs/BBR. To the best of our knowledge, this is the first report on using polymer material for effective encapsulation of BBR to improve its oral bioavailability. The prepared BBR delivery systems demonstrated a uniform spherical shape, a well-dispersed core-shell structure and a small particle size (149.6 ± 5.1 nm). The crystallographic and thermal analysis has indicated that the BBR dispersed in the PEG-lipid-PLGA NPs matrix is in an amorphous form. More importantly, the enhancement in the oral relative bioavailability of the PEG-lipid-PLGA NPs/BBR-SPC was ∼343% compared with that of BBR. These positive results demonstrated that PEG-lipid-PLGA NPs/BBR-SPC may have the potential for facilitating the oral drug delivery of BBR.

Transdermal drug delivery

OpenAIRE

Prausnitz, Mark R.; Langer, Robert

2008-01-01

Transdermal drug delivery has made an important contribution to medical practice, but has yet to fully achieve its potential as an alternative to oral delivery and hypodermic injections. First-generation transdermal delivery systems have continued their steady increase in clinical use for delivery of small, lipophilic, low-dose drugs. Second-generation delivery systems using chemical enhancers, non-cavitational ultrasound and iontophoresis have also resulted in clinical products; the ability ...

Waste Feed Delivery System Phase 1 Preliminary RAM Analysis

International Nuclear Information System (INIS)

DYKES, A.A.

2000-01-01

This report presents the updated results of the preliminary reliability, availability, and maintainability (RAM) analysis of selected waste feed delivery (WFD) operations to be performed by the Tank Farm Contractor (TFC) during Phase I activities in support of the Waste Treatment and Immobilization Plant (WTP). For planning purposes, waste feed tanks are being divided into five classes in accordance with the type of waste in each tank and the activities required to retrieve, qualify, and transfer waste feed. This report reflects the baseline design and operating concept, as of the beginning of Fiscal Year 2000, for the delivery of feed from three of these classes, represented by source tanks 241-AN-102, 241-AZ-101 and 241-AN-105. The preliminary RAM analysis quantifies the potential schedule delay associated with operations and maintenance (OBM) field activities needed to accomplish these operations. The RAM analysis is preliminary because the system design, process definition, and activity planning are in a state of evolution. The results are being used to support the continuing development of an O and M Concept tailored to the unique requirements of the WFD Program, which is being documented in various volumes of the Waste Feed Delivery Technical Basis (Carlson. 1999, Rasmussen 1999, and Orme 2000). The waste feed provided to the WTP must: (1) meet limits for chemical and radioactive constituents based on pre-established compositional envelopes (i.e., feed quality); (2) be in acceptable quantities within a prescribed sequence to meet feed quantities; and (3) meet schedule requirements (i.e., feed timing). In the absence of new criteria related to acceptable schedule performance due to the termination of the TWRS Privatization Contract, the original criteria from the Tank Waste Remediation System (77443s) Privatization Contract (DOE 1998) will continue to be used for this analysis

Strongly coupled dispersed two-phase flows; Ecoulements diphasiques disperses fortement couples

Energy Technology Data Exchange (ETDEWEB)

Zun, I.; Lance, M.; Ekiel-Jezewska, M.L.; Petrosyan, A.; Lecoq, N.; Anthore, R.; Bostel, F.; Feuillebois, F.; Nott, P.; Zenit, R.; Hunt, M.L.; Brennen, C.E.; Campbell, C.S.; Tong, P.; Lei, X.; Ackerson, B.J.; Asmolov, E.S.; Abade, G.; da Cunha, F.R.; Lhuillier, D.; Cartellier, A.; Ruzicka, M.C.; Drahos, J.; Thomas, N.H.; Talini, L.; Leblond, J.; Leshansky, A.M.; Lavrenteva, O.M.; Nir, A.; Teshukov, V.; Risso, F.; Ellinsen, K.; Crispel, S.; Dahlkild, A.; Vynnycky, M.; Davila, J.; Matas, J.P.; Guazelli, L.; Morris, J.; Ooms, G.; Poelma, C.; van Wijngaarden, L.; de Vries, A.; Elghobashi, S.; Huilier, D.; Peirano, E.; Minier, J.P.; Gavrilyuk, S.; Saurel, R.; Kashinsky, O.; Randin, V.; Colin, C.; Larue de Tournemine, A.; Roig, V.; Suzanne, C.; Bounhoure, C.; Brunet, Y.; Tanaka, A.T.; Noma, K.; Tsuji, Y.; Pascal-Ribot, S.; Le Gall, F.; Aliseda, A.; Hainaux, F.; Lasheras, J.; Didwania, A.; Costa, A.; Vallerin, W.; Mudde, R.F.; Van Den Akker, H.E.A.; Jaumouillie, P.; Larrarte, F.; Burgisser, A.; Bergantz, G.; Necker, F.; Hartel, C.; Kleiser, L.; Meiburg, E.; Michallet, H.; Mory, M.; Hutter, M.; Markov, A.A.; Dumoulin, F.X.; Suard, S.; Borghi, R.; Hong, M.; Hopfinger, E.; Laforgia, A.; Lawrence, C.J.; Hewitt, G.F.; Osiptsov, A.N.; Tsirkunov, Yu. M.; Volkov, A.N.

2003-07-01

This document gathers the abstracts of the Euromech 421 colloquium about strongly coupled dispersed two-phase flows. Behaviors specifically due to the two-phase character of the flow have been categorized as: suspensions, particle-induced agitation, microstructure and screening mechanisms; hydrodynamic interactions, dispersion and phase distribution; turbulence modulation by particles, droplets or bubbles in dense systems; collective effects in dispersed two-phase flows, clustering and phase distribution; large-scale instabilities and gravity driven dispersed flows; strongly coupled two-phase flows involving reacting flows or phase change. Topic l: suspensions particle-induced agitation microstructure and screening mechanisms hydrodynamic interactions between two very close spheres; normal stresses in sheared suspensions; a critical look at the rheological experiments of R.A. Bagnold; non-equilibrium particle configuration in sedimentation; unsteady screening of the long-range hydrodynamic interactions of settling particles; computer simulations of hydrodynamic interactions among a large collection of sedimenting poly-disperse particles; velocity fluctuations in a dilute suspension of rigid spheres sedimenting between vertical plates: the role of boundaries; screening and induced-agitation in dilute uniform bubbly flows at small and moderate particle Reynolds numbers: some experimental results. Topic 2: hydrodynamic interactions, dispersion and phase distribution: hydrodynamic interactions in a bubble array; A 'NMR scattering technique' for the determination of the structure in a dispersion of non-brownian settling particles; segregation and clustering during thermo-capillary migration of bubbles; kinetic modelling of bubbly flows; velocity fluctuations in a homogeneous dilute dispersion of high-Reynolds-number rising bubbles; an attempt to simulate screening effects at moderate particle Reynolds numbers using an hybrid formulation; modelling the two

Reviews of Geospatial Information Technology and Collaborative Data Delivery for Disaster Risk Management

Directory of Open Access Journals (Sweden)

Hiroyuki Miyazaki

2015-09-01

Full Text Available Due to the fact that geospatial information technology is considered necessary for disaster risk management (DRM, the need for more effective collaborations between providers and end users in data delivery is increasing. This paper reviews the following: (i schemes of disaster risk management and collaborative data operation in DRM; (ii geospatial information technology in terms of applications to the schemes reviewed; and (iii ongoing practices of collaborative data delivery with the schemes reviewed. This paper concludes by discussing the future of collaborative data delivery and the progress of the technologies.

A Comparative Study of Dispersion Characteristics Determination of a Trapezoidally Corrugated Slow Wave Structure Using Different Techniques

International Nuclear Information System (INIS)

Saber, Md. Ghulam; Sagor, Rakibul Hasan; Amin, Md. Ruhul

2016-01-01

The linear dispersion relation of a trapezoidally corrugated slow wave structure (TCSWS) is analyzed and presented. The size parameters of the TCSWS are chosen in such a way that they operate in the x-band frequency range. The dispersion relation is solved by utilizing the Rayleigh–Fourier method by expressing the radial function in terms of the Fourier series. A highly accurate synthetic technique is also applied to determine the complete dispersion characteristics from experimentally measured resonances (cold test). Periodic structures resonate at specific frequencies when the terminals are shorted appropriately. The dispersion characteristics obtained from numerical calculation, synthetic technique and cold test are compared, and an excellent agreement is achieved. (paper)

Construction Operations Building Information Exchange (COBIE)

Science.gov (United States)

2007-06-01

Swalley U.S. Department of State, Overseas Buildings Operations Toby Wilson U.S. Army, Corps of Engineers, Engineer R&D Center Jeff Wix AEC3 The...exchanged in COBIE. To map those information exchanges to the IFC model, the Information Delivery Manual (IDM) process [ Wix 2007] was also used. The...Folksonomy. Wikimedia Foundation. http://en.wikipedia.org/wiki/Folksonomy/, accessed 3 August 2007. Wix , Jeffrey. 2007. Information Delivery Manual

A new methodology for studying nanoparticle interactions in biological systems: Dispersing titania in biocompatible media using chemical stabilisers

Science.gov (United States)

Ramirez-Garcia, Sonia; Chen, Lan; Morris, Michael A.; Dawson, Kenneth A.

2011-11-01

We report here a highly successful and original protocol for the dispersion of nanoparticles in biocompatible fluids for in vitro and in vivo studies of the nanoparticle-biology interaction. Titania is chosen as a suitable model as it is one of the priority materials listed by the OECD and small particles of the anatase structure are extensively used as e.g. photocatalysts in solar cells. Consequently, its delivery into the environment and its interaction with biological organisms is unavoidable. Therefore, its biological effect needs to be understood. In this work, we prepared stable nanoparticle dispersions of anatase aggregates using citrate stabilisations between 45 and 55 nm at concentrations of up to 10 mg mL-1. The optimum pH for this type of suspension was 7, resulting in ζ-potentials of approximately -50 mV. The stabilised aggregates were the subject of dialysis to produce stable dispersions without the chemical stabiliser, thus allowing studies in the absence of potentially toxic chemicals. Different sizing techniques such as Dynamic Light Scattering (DLS), Nanoparticle Tracking Analysis (NTA) and Differential Centrifuge Sedimentation (DCS) were used to characterise the different suspensions. The results obtained with each of these techniques are compared and a critical analysis of the suitability of each technique is given.We report here a highly successful and original protocol for the dispersion of nanoparticles in biocompatible fluids for in vitro and in vivo studies of the nanoparticle-biology interaction. Titania is chosen as a suitable model as it is one of the priority materials listed by the OECD and small particles of the anatase structure are extensively used as e.g. photocatalysts in solar cells. Consequently, its delivery into the environment and its interaction with biological organisms is unavoidable. Therefore, its biological effect needs to be understood. In this work, we prepared stable nanoparticle dispersions of anatase aggregates

Sensitivity of the deep-sea amphipod Eurythenes gryllus to chemically dispersed oil.

Science.gov (United States)

Olsen, Gro Harlaug; Coquillé, Nathalie; Le Floch, Stephane; Geraudie, Perrine; Dussauze, Matthieu; Lemaire, Philippe; Camus, Lionel

2016-04-01

In the context of an oil spill accident and the following oil spill response, much attention is given to the use of dispersants. Dispersants are used to disperse an oil slick from the sea surface into the water column generating a cloud of dispersed oil droplets. The main consequence is an increasing of the sea water-oil interface which induces an increase of the oil biodegradation. Hence, the use of dispersants can be effective in preventing oiling of sensitive coastal environments. Also, in case of an oil blowout from the seabed, subsea injection of dispersants may offer some benefits compared to containment and recovery of the oil or in situ burning operation at the sea surface. However, biological effects of dispersed oil are poorly understood for deep-sea species. Most effects studies on dispersed oil and also other oil-related compounds have been focusing on more shallow water species. This is the first approach to assess the sensitivity of a macro-benthic deep-sea organism to dispersed oil. This paper describes a toxicity test which was performed on the macro-benthic deep-sea amphipod (Eurythenes gryllus) to determine the concentration causing lethality to 50% of test individuals (LC50) after an exposure to dispersed Brut Arabian Light (BAL) oil. The LC50 (24 h) was 101 and 24 mg L(-1) after 72 h and 12 mg L(-1) at 96 h. Based on EPA scale of toxicity categories to aquatic organisms, an LC50 (96 h) of 12 mg L(-1) indicates that the dispersed oil was slightly to moderately toxic to E. gryllus. As an attempt to compare our results to others, a literature study was performed. Due to limited amount of data available for dispersed oil and amphipods, information on other crustacean species and other oil-related compounds was also collected. Only one study on dispersed oil and amphipods was found, the LC50 value in this study was similar to the LC50 value of E. gryllus in our study. Since toxicity data are important input to risk assessment and net environmental

[Severe Adverse Pregnancy Outcomes in Placenta Previa and Prior Cesarean Delivery].

Science.gov (United States)

Zhou, Mi; Chen, Meng; Zhang, Li; He, Guo-Lin; He, Lei; Wei, Qiang; Li, Tao; Liu, Xing-Hui

2017-09-01

To investigate the severe adverse pregnancy outcomes in pregnancies with placenta previa and prior cesarean delivery and its risk factors. This retrospective casecontrol study reviewed all pregnancies with placenta previa and prior cesarean delivery delivered by repeat cesarean section in our institution between January 2005 and June 2015,and investigated the incidence of severe adverse pregnancy outcome. A composite of severe adverse pregnancy outcomes (including transfusion of 10 units or more red blood cells,maternal ICU admission,unanticipated injuries,repeat operation,hysterectomy,and maternal death) and other maternal and neonatal outcomes were described. Univariate and multivariable logistic regression analysis were used to quantify the effects of risk factors on severe adverse pregnancy outcomes. There were 478 women with placenta previa and prior cesarean delivery in our hospital over the last decade. The average age of them was 32.5±4.8 years old,most women were beyond 30 years old,the average gravidity and parity were 4 and 1,131 cases (27.4%) had severe adverse pregnancy outcomes. Transfusion of 10 units or more red blood cells happened in 75 cases (15.7%,75/478); 44 cases (9.2%,44/478) necessitated maternal ICU admission; unanticipated bladder injury occurred in 11 cases,but non ureter or bowel injury happened; All 4 repeat operations were due to delayed hemorrhage after conservative management during cesarean delivery,and an emergent hysterectomy was performed for all of the 4 cases. Hysterectomy (107 cases,22.4%) was the most common severe adverse pregnancy outcome. Among all 311 morbidly adherent placenta cases finally confirmed by pathological or surgical findings or both,only 172 (55.3%) were suspected before delivery. Multivariable logistic regression analysis showed that the risk of severe adverse pregnancy outcomes was significantly increased by pernicious placenta previa (i.e. anterior placenta overlying the prior cesarean scar),suspicion of

Methods and metrics challenges of delivery-system research

Directory of Open Access Journals (Sweden)

Alexander Jeffrey A

2012-03-01

Full Text Available Abstract Background Many delivery-system interventions are fundamentally about change in social systems (both planned and unplanned. This systems perspective raises a number of methodological challenges for studying the effects of delivery-system change--particularly for answering questions related to whether the change will work under different conditions and how the change is integrated (or not into the operating context of the delivery system. Methods The purpose of this paper is to describe the methodological and measurement challenges posed by five key issues in delivery-system research: (1 modeling intervention context; (2 measuring readiness for change; (3 assessing intervention fidelity and sustainability; (4 assessing complex, multicomponent interventions; and (5 incorporating time in delivery-system models to discuss recommendations for addressing these issues. For each issue, we provide recommendations for how research may be designed and implemented to overcome these challenges. Results and conclusions We suggest that a more refined understanding of the mechanisms underlying delivery-system interventions (treatment theory and the ways in which outcomes for different classes of individuals change over time are fundamental starting points for capturing the heterogeneity in samples of individuals exposed to delivery-system interventions. To support the research recommendations outlined in this paper and to advance understanding of the "why" and "how" questions of delivery-system change and their effects, funding agencies should consider supporting studies with larger organizational sample sizes; longer duration; and nontraditional, mixed-methods designs. A version of this paper was prepared under contract with the Agency for Healthcare Research and Quality (AHRQ, US Department of Health and Human Services for presentation and discussion at a meeting on "The Challenge and Promise of Delivery System Research," held in Sterling, VA, on

The Intention of Delivery Room Staff to Encourage the Presence of Husbands/Partners at Cesarean Sections

Directory of Open Access Journals (Sweden)

Yaira Gutman

2011-01-01

Full Text Available Objective. In recent years, more and more delivery rooms have allowed husbands/partners to be present during a Cesarean section Nonetheless, many still oppose the idea. The study is designed to investigate the attitudes of Israeli gynecologists, anesthetists, operating-room nurses, and midwives on this issue. Design. The study's theoretical model comes from Fishbein and Ajzen's theory of reasoned action. A self-administered questionnaire was submitted to convenience sample. Subjects. 96 gynecologists, anesthetists, midwives, and operating-room nurses. Results. Significant differences were found between the occupational subgroups. Most of the findings supported the four hypotheses tested and confirmed earlier studies designed to verify the theoretical model. Conclusions. The main conclusion drawn is that delivery and operating-room staff need to be trained in the skills needed to promote the active participation of the baby's father in delivery and, if necessary, in a Cesarean section.

Spin squeezing and entanglement in a dispersive cavity

International Nuclear Information System (INIS)

Deb, R. N.; Abdalla, M. Sebawe; Hassan, S. S.; Nayak, N.

2006-01-01

We consider a system of N two-level atoms (spins) interacting with the radiation field in a dispersive but high-Q cavity. Under an adiabatic condition, the interaction Hamiltonian reduces to a function of spin operators which is capable of producing spin squeezing. For a bipartite system (N=2), the expressions for spin squeezing get very simple, giving a clear indication of close to 100% noise reduction. We analyse this squeezing as a measure of bipartite entanglement

Medium-Duty Plug-in Electric Delivery Truck Fleet Evaluation

Energy Technology Data Exchange (ETDEWEB)

Prohaska, Robert; Ragatz, Adam; Simpson, Mike; Kelly, Kenneth

2016-06-29

In this paper, the authors present an overview of medium-duty electric vehicle (EV) operating behavior based on in-use data collected from Smith Newton electric delivery vehicles and compare their performance and operation to conventional diesel trucks operating in the same fleet. The vehicles' drive cycles and operation are analyzed and compared to demonstrate the importance of matching specific EV technologies to the appropriate operational duty cycle. The results of this analysis show that the Smith Newton EVs demonstrated a 68% reduction in energy consumption over the data reporting period compared to the conventional diesel vehicles, as well as a 46.4% reduction in carbon dioxide equivalent emissions based on the local energy generation source.

Human resource management in the delivery of postal items

Directory of Open Access Journals (Sweden)

Kujačić Momčilo D.

2015-01-01

Full Text Available Delivery of postal items is the last phase in the postal conveyance process. This phase involved up to 57% in total costs of postal items conveyance. In order to reduce the costs of delivery phase, postal organizations apply different methods and techniques. Legal and technological regulations, various restrictions regarding the selection and deployment of employees influence the choice of appropriate methods. Also, the principle of availability of the universal postal service is an essential factor in defining the optimal model. In this paper, the model for assessing and planning of the number of employees in the delivery service observed postal operator has been proposed, with respect to the principles of productivity and accessibility constraints of the universal postal service. This paper will analyze the impact of daily fluctuations in the number of full-time employees and the possibility of hiring a part-time workers in the days with increased traffic volume in the delivery of items, when usually the items from large customers are delivered.

Fine-grained sediment dispersal along the California coast

Science.gov (United States)

Warrick, Jonathan A.; Storlazzi, Curt D.

2013-01-01

Fine-grained sediment (silt and clay) enters coastal waters from rivers, eroding coastal bluffs, resuspension of seabed sediment, and human activities such as dredging and beach nourishment. The amount of sediment in coastal waters is an important factor in ocean ecosystem health, but little information exists on both the natural and human-driven magnitudes of fine-grained sediment delivery to the coastal zone, its residence time there, and its transport out of the system—information upon which to base environmental assessments. To help fill these information gaps, the U.S. Geological Survey has partnered with Federal, State, and local agencies to monitor fine-grained sediment dispersal patterns and fate in the coastal regions of California. Results of these studies suggest that the waves and currents of many of the nearshore coastal settings of California are adequately energetic to transport fine-grained sediment quickly through coastal systems. These findings will help with the management and regulation of fine-grained sediment along the U.S. west coast.

A Multi-organisational Approach to Service Delivery

Science.gov (United States)

Purchase, Valerie; Mills, John; Parry, Glenn

Who is involved in delivering a service? There has been growing recognition in a wide variety of contexts that service is increasingly being delivered by multi-rather than single-organisational entities. Such recognition is evident not only in our experience but in a number of areas of literature including strategy development, core competence analysis, operations and supply chain management, and is reflected in and further facilitated by ICT developments. Customers have always been involved in some degree in the process of value delivery and such involvement is increasing to include complex co-creation of value. Such interactions are challenging when they involve individual customers, however, this becomes ever more challenging when the 'customer' is another organisation or when there are multiple 'customers'. Within this chapter we will consider some of the key drivers for a multi-organisational approach to service delivery; examine the ways in which the parties involved in service co-creation have expanded to include multiple service providers and customers; and finally, identify some of the challenges created by a multi-organisational approach to service delivery.

Operating experience with TFTR's Tritium Storage and Delivery System

International Nuclear Information System (INIS)

Voorhees, D.R.

1995-01-01

The Tritium Storage and Delivery System (TSDS) at TFTR was fabricated at Monsanto Mound Lab in the late 1970's and delivered to PPPL in the early 1980's. Commissioning progressed slowly and was finally completed in 1992 following a series of Preoperational tests and Integrated Systems tests. Those tests included thorough leak testing of glove boxes and process piping, electrical interlocks and controls, instrumentation calibrations, volume determinations and verification of uranium bed capacity. The system accepted tritium in dilute form in May of 1993 and began serious usage of pure tritium in November 1993. As the throughput of high purity tritium increased, shortcomings of the system became evident and extensive repairs were implemented. System leakage and material compatibility were the primary causes of the problems. To date, the system has received, stored and delivered over 500 kCi of tritium and is performing very well. The dedicated quadrupole mass spectrometer and beta scintillator system has been analyzing tritium bearing and pure gas streams for over 3 years with minimal downtime

Quality of IT service delivery — Analysis and framework for human error prevention

KAUST Repository

Shwartz, L.

2010-12-01

In this paper, we address the problem of reducing the occurrence of Human Errors that cause service interruptions in IT Service Support and Delivery operations. Analysis of a large volume of service interruption records revealed that more than 21% of interruptions were caused by human error. We focus on Change Management, the process with the largest risk of human error, and identify the main instances of human errors as the 4 Wrongs: request, time, configuration item, and command. Analysis of change records revealed that the humanerror prevention by partial automation is highly relevant. We propose the HEP Framework, a framework for execution of IT Service Delivery operations that reduces human error by addressing the 4 Wrongs using content integration, contextualization of operation patterns, partial automation of command execution, and controlled access to resources.

Pseudospectral modeling and dispersion analysis of Rayleigh waves in viscoelastic media

Science.gov (United States)

Zhang, K.; Luo, Y.; Xia, J.; Chen, C.

2011-01-01

Multichannel Analysis of Surface Waves (MASW) is one of the most widely used techniques in environmental and engineering geophysics to determine shear-wave velocities and dynamic properties, which is based on the elastic layered system theory. Wave propagation in the Earth, however, has been recognized as viscoelastic and the propagation of Rayleigh waves presents substantial differences in viscoelastic media as compared with elastic media. Therefore, it is necessary to carry out numerical simulation and dispersion analysis of Rayleigh waves in viscoelastic media to better understand Rayleigh-wave behaviors in the real world. We apply a pseudospectral method to the calculation of the spatial derivatives using a Chebyshev difference operator in the vertical direction and a Fourier difference operator in the horizontal direction based on the velocity-stress elastodynamic equations and relations of linear viscoelastic solids. This approach stretches the spatial discrete grid to have a minimum grid size near the free surface so that high accuracy and resolution are achieved at the free surface, which allows an effective incorporation of the free surface boundary conditions since the Chebyshev method is nonperiodic. We first use an elastic homogeneous half-space model to demonstrate the accuracy of the pseudospectral method comparing with the analytical solution, and verify the correctness of the numerical modeling results for a viscoelastic half-space comparing the phase velocities of Rayleigh wave between the theoretical values and the dispersive image generated by high-resolution linear Radon transform. We then simulate three types of two-layer models to analyze dispersive-energy characteristics for near-surface applications. Results demonstrate that the phase velocity of Rayleigh waves in viscoelastic media is relatively higher than in elastic media and the fundamental mode increases by 10-16% when the frequency is above 10. Hz due to the velocity dispersion of P

Guidebook : using public transportation to facilitate last mile package delivery.

Science.gov (United States)

2017-03-01

This guidebook is designed to inform rural transit operators of how to implement a package delivery service using information and input gathered from the state-of-the practice scan, the fact-finding questionnaire, and stakeholder workshops. The guide...

Chitosan/lecithin liposomal nanovesicles as an oral insulin delivery system.

Science.gov (United States)

Al-Remawi, Mayyas; Elsayed, Amani; Maghrabi, Ibrahim; Hamaidi, Mohammad; Jaber, Nisrein

2017-05-01

In the present work, insulin-chitosan polyelectrolyte complexes associated to lecithin liposomes were investigated as a new carrier for oral delivery of insulin. The preparation was characterized in terms of particle size, zeta potential and encapsulation efficiency. Surface tension measurements revealed that insulin-chitosan polyelectrolyte complexes have some degree of hydrophobicity and should be added to lecithin liposomal dispersion and not the vice versa to prevent their adsorption on the surface. Stability of insulin was enhanced when it was associated to liposomes. Significant reduction of blood glucose levels was noticed after oral administration of liposomal preparation to streptozotocin diabetic rats compared to control. The hypoglycemic activity was more prolonged compared to subcutaneously administered insulin.

Development of the electric utility dispersed use PAFC stack

Energy Technology Data Exchange (ETDEWEB)

Horiuchi, Hiroshi; Kotani, Ikuo [Mitsubishi Electric Co., Kobe (Japan); Morotomi, Isamu [Kansai Electric Power Co., Hyogo (Japan)] [and others

1996-12-31

Kansai Electric Power Co. and Mitsubishi Electric Co. have been developing the electric utility dispersed use PAFC stack operated under the ambient pressure. The new cell design have been developed, so that the large scale cell (1 m{sup 2} size) was adopted for the stack. To confirm the performance and the stability of the 1 m{sup 2} scale cell design, the short stack study had been performed.

Development of polymethacrylate nanospheres as targeted delivery systems for catechin within the gastrointestinal tract

Science.gov (United States)

Pool, Hector; Luna-Barcenas, Gabriel; McClements, David Julian; Mendoza, Sandra

2017-09-01

In this study, pH-sensitive nanospheres were fabricated using a polymethacrylate-based copolymer to encapsulate, protect, and release catechin, and thereby overcome its poor water solubility and low oral bioaccessibility. The polymer used was a polymethacrylic acid-co-ethyl acrylate 1:1 copolymer that dissolves above pH 5.5, and so can be used to retain and protect bioactives within the stomach but releases them in the small intestine. Catechin-loaded nanospheres were fabricated using the solvent displacement method. Physicochemical characterization of the nanospheres indicated that they were relatively small ( d = 160 nm) and had a high negative charge ( ζ = - 36 mV), which meant that they had good stability to aggregation under physiological conditions (pH 7.2). Catechin was trapped within the nanospheres at an encapsulation efficiency of about 51% in an amorphous state. A simulated gastrointestinal study showed that catechin was slowly released under gastric conditions (pH 2.5), but rapidly released under small intestine conditions (pH 7.2). The observed improvement in the antioxidant activity and bioaccessibility of catechin after encapsulation was attributed to the fact that it was in an amorphous state and had good water dispersibility. This study provides useful information for the formulation of novel delivery systems to improve the dispersibility, bioaccessibility, and bioactivity of catechin and potentially other active components. These delivery systems could be used to improve the efficacy of bioactive components in foods, supplements, and pharmaceutical products.

Design and development of a dust dispersion chamber to quantify the dispersibility of rock dust.

Science.gov (United States)

Perera, Inoka E; Sapko, Michael J; Harris, Marcia L; Zlochower, Isaac A; Weiss, Eric S

2016-01-01

Dispersible rock dust must be applied to the surfaces of entries in underground coal mines in order to inert the coal dust entrained or made airborne during an explosion and prevent propagating explosions. 30 CFR. 75.2 states that "… [rock dust particles] when wetted and dried will not cohere to form a cake which will not be dispersed into separate particles by a light blast of air …" However, a proper definition or quantification of "light blast of air" is not provided. The National Institute for Occupational Safety and Health (NIOSH) has, consequently, designed a dust dispersion chamber to conduct quantitative laboratory-scale dispersibility experiments as a screening tool for candidate rock dusts. A reproducible pulse of air is injected into the chamber and across a shallow tray of rock dust. The dust dispersed and carried downwind is monitored. The mass loss of the dust tray and the airborne dust measurements determine the relative dispersibility of the dust with respect to a Reference rock dust. This report describes the design and the methodology to evaluate the relative dispersibility of rock dusts with and without anti-caking agents. Further, the results of this study indicate that the dispersibility of rock dusts varies with particle size, type of anti-caking agent used, and with the untapped bulk density. Untreated rock dusts, when wetted and dried forming a cake that was much less dispersible than the reference rock dust used in supporting the 80% total incombustible content rule.

Requirements for materials of dispersion fuel elements

International Nuclear Information System (INIS)

Samojlov, A.G.; Kashtanov, A.I.; Volkov, V.S.

1982-01-01

Requirements for materials of dispersion fuel elements are considered. The necessity of structural and fissile materials compatibility at maximum permissible operation temperatures and temperatures arising in a fuel element during manufacture is pointed out. The fuel element structural material must be ductile, possess high mechanical strength minimum neutron absorption cross section, sufficient heat conductivity, good corrosion resistance in a coolant and radiation resistance. The fissile material must have high fissile isotope concentration, radiation resistance, high thermal conductivity, certain porosity high melting temperature must not change the composition under irradiation

Leadership Perspectives on Operationalizing the Learning Health Care System in an Integrated Delivery System.

Science.gov (United States)

Psek, Wayne; Davis, F Daniel; Gerrity, Gloria; Stametz, Rebecca; Bailey-Davis, Lisa; Henninger, Debra; Sellers, Dorothy; Darer, Jonathan

2016-01-01

Healthcare leaders need operational strategies that support organizational learning for continued improvement and value generation. The learning health system (LHS) model may provide leaders with such strategies; however, little is known about leaders' perspectives on the value and application of system-wide operationalization of the LHS model. The objective of this project was to solicit and analyze senior health system leaders' perspectives on the LHS and learning activities in an integrated delivery system. A series of interviews were conducted with 41 system leaders from a broad range of clinical and administrative areas across an integrated delivery system. Leaders' responses were categorized into themes. Ten major themes emerged from our conversations with leaders. While leaders generally expressed support for the concept of the LHS and enhanced system-wide learning, their concerns and suggestions for operationalization where strongly aligned with their functional area and strategic goals. Our findings suggests that leaders tend to adopt a very pragmatic approach to learning. Leaders expressed a dichotomy between the operational imperative to execute operational objectives efficiently and the need for rigorous evaluation. Alignment of learning activities with system-wide strategic and operational priorities is important to gain leadership support and resources. Practical approaches to addressing opportunities and challenges identified in the themes are discussed. Continuous learning is an ongoing, multi-disciplinary function of a health care delivery system. Findings from this and other research may be used to inform and prioritize system-wide learning objectives and strategies which support reliable, high value care delivery.

Sparse and Dispersion-Based Matching Pursuit for Minimizing the Dispersion Effect Occurring when Using Guided Wave for Pipe Inspection.

Science.gov (United States)

Rostami, Javad; Tse, Peter W T; Fang, Zhou

2017-06-06

Ultrasonic guided wave is an effective tool for structural health monitoring of structures for detecting defects. In practice, guided wave signals are dispersive and contain multiple modes and noise. In the presence of overlapped wave-packets/modes and noise together with dispersion, extracting meaningful information from these signals is a challenging task. Handling such challenge requires an advanced signal processing tool. The aim of this study is to develop an effective and robust signal processing tool to deal with the complexity of guided wave signals for non-destructive testing (NDT) purpose. To achieve this goal, Sparse Representation with Dispersion Based Matching Pursuit (SDMP) is proposed. Addressing the three abovementioned facts that complicate signal interpretation, SDMP separates overlapped modes and demonstrates good performance against noise with maximum sparsity. With the dispersion taken into account, an overc-omplete and redundant dictionary of basic atoms based on a narrowband excitation signal is designed. As Finite Element Method (FEM) was used to predict the form of wave packets propagating along structures, these atoms have the maximum resemblance with real guided wave signals. SDMP operates in two stages. In the first stage, similar to Matching Pursuit (MP), the approximation improves by adding, a single atom to the solution set at each iteration. However, atom selection criterion of SDMP utilizes the time localization of guided wave reflections that makes a portion of overlapped wave-packets to be composed mainly of a single echo. In the second stage of the algorithm, the selected atoms that have frequency inconsistency with the excitation signal are discarded. This increases the sparsity of the final representation. Meanwhile, leading to accurate approximation, as discarded atoms are not representing guided wave reflections, it simplifies extracting physical meanings for defect detection purpose. To verify the effectiveness of SDMP for

Sparse and Dispersion-Based Matching Pursuit for Minimizing the Dispersion Effect Occurring when Using Guided Wave for Pipe Inspection

Directory of Open Access Journals (Sweden)

Javad Rostami

2017-06-01

Full Text Available Ultrasonic guided wave is an effective tool for structural health monitoring of structures for detecting defects. In practice, guided wave signals are dispersive and contain multiple modes and noise. In the presence of overlapped wave-packets/modes and noise together with dispersion, extracting meaningful information from these signals is a challenging task. Handling such challenge requires an advanced signal processing tool. The aim of this study is to develop an effective and robust signal processing tool to deal with the complexity of guided wave signals for non-destructive testing (NDT purpose. To achieve this goal, Sparse Representation with Dispersion Based Matching Pursuit (SDMP is proposed. Addressing the three abovementioned facts that complicate signal interpretation, SDMP separates overlapped modes and demonstrates good performance against noise with maximum sparsity. With the dispersion taken into account, an overc-omplete and redundant dictionary of basic atoms based on a narrowband excitation signal is designed. As Finite Element Method (FEM was used to predict the form of wave packets propagating along structures, these atoms have the maximum resemblance with real guided wave signals. SDMP operates in two stages. In the first stage, similar to Matching Pursuit (MP, the approximation improves by adding, a single atom to the solution set at each iteration. However, atom selection criterion of SDMP utilizes the time localization of guided wave reflections that makes a portion of overlapped wave-packets to be composed mainly of a single echo. In the second stage of the algorithm, the selected atoms that have frequency inconsistency with the excitation signal are discarded. This increases the sparsity of the final representation. Meanwhile, leading to accurate approximation, as discarded atoms are not representing guided wave reflections, it simplifies extracting physical meanings for defect detection purpose. To verify the

Dispersal kernel estimation: A comparison of empirical and modelled particle dispersion in a coastal marine system

Science.gov (United States)

Hrycik, Janelle M.; Chassé, Joël; Ruddick, Barry R.; Taggart, Christopher T.

2013-11-01

Early life-stage dispersal influences recruitment and is of significance in explaining the distribution and connectivity of marine species. Motivations for quantifying dispersal range from biodiversity conservation to the design of marine reserves and the mitigation of species invasions. Here we compare estimates of real particle dispersion in a coastal marine environment with similar estimates provided by hydrodynamic modelling. We do so by using a system of magnetically attractive particles (MAPs) and a magnetic-collector array that provides measures of Lagrangian dispersion based on the time-integration of MAPs dispersing through the array. MAPs released as a point source in a coastal marine location dispersed through the collector array over a 5-7 d period. A virtual release and observed (real-time) environmental conditions were used in a high-resolution three-dimensional hydrodynamic model to estimate the dispersal of virtual particles (VPs). The number of MAPs captured throughout the collector array and the number of VPs that passed through each corresponding model location were enumerated and compared. Although VP dispersal reflected several aspects of the observed MAP dispersal, the comparisons demonstrated model sensitivity to the small-scale (random-walk) particle diffusivity parameter (Kp). The one-dimensional dispersal kernel for the MAPs had an e-folding scale estimate in the range of 5.19-11.44 km, while those from the model simulations were comparable at 1.89-6.52 km, and also demonstrated sensitivity to Kp. Variations among comparisons are related to the value of Kp used in modelling and are postulated to be related to MAP losses from the water column and (or) shear dispersion acting on the MAPs; a process that is constrained in the model. Our demonstration indicates a promising new way of 1) quantitatively and empirically estimating the dispersal kernel in aquatic systems, and 2) quantitatively assessing and (or) improving regional hydrodynamic

Operative meteorological data base in Forsmark

International Nuclear Information System (INIS)

Appelgren, A.; Hallberg, B.; Nordlinder, S.

1990-01-01

This report describes how data collected during a field measurement campaign were analysed and compiled to create a data base for operative use. The data base gives information about the wind and the atmospheric stability at five locations around the Forsmark nuclear power plant. In the measurement campaign, sodar systems and a 100 m high tower at Forsmark were used. Temperature, wind speed and wind direction were measured by sensors on the tower, while wind speed and direction, and the standard deviation of the vertical wind, were monitored by the sodar systems. This gave meteorological data from several heights. At Forsmark, the temperature difference and the wind speed from the tower were used to determine the atmospheric stability. At the sodar locations, the stability was deduced by employing a scheme which considered the season, the time of day, the wind direction and the wind speed. To create the operative data base, the wind speeds and wind directions, respectively, from two locations at the time were correlated. A code for graphical and numerical presentation of the data from the data base was developed. A special system of warnings was included, featuring notification about phenomena such as sea breeze, warnings about large variation in the wind conditions within the area, and warnings for situations in which the meteorological conditions make the results from the atmospheric dispersion calculations uncertain. This feature was implemented to alert the user to the fact that ordinary dispersion and dose calculations, using meteorological data from a single point, might give erroneous results. The operative data base and the presentation code were integrated with the dispersion and dose calculation code AIRPAC/EMMA, which is to be used in case of increased releases from nuclear power plants. The possibility to use the data from the operative data base in the dispersion calculations was investigated. It was found that a modification of AIRPAC/EMMA, in such a

Optimisation of Oil Spill Dispersants on Weathered Oils. A New Approach Using Experimental Design and Multivariate Data Analysis

Energy Technology Data Exchange (ETDEWEB)

Brandvik, Per Johan

1997-12-31

This thesis describes how laboratory experiments combined with numerical modelling were used to predict weathering of an oil slick at different environmental conditions (temperature, wind etc.). It also applies laboratory test methods to screen dispersant effectiveness under different temperatures and salinities. A new approach is developed for dispersant optimization based on statistical design and multivariate analysis; this resulted in a new dispersant with low toxicity and high effectiveness on a broad selection of oil types. The thesis illustrates the potential of dispersant used as an operational response method on oil spills by discussing three different oil spill scenarios and compares the effect of using dispersants to using mechanical recovery and to doing nothing. Some recommendations that may increase the effectiveness of the Norwegian oil spill contingency are also given. 172 refs., 65 figs., 9 tabs.

Mechanisms of dispersion during liquid hydrogen leakage

International Nuclear Information System (INIS)

Proust, C.; Gaston, D.

2000-01-01

INERIS conducts research programs with a mission of assessing and preventing accidental and chronic risks to people and the environment due to industrial plants, chemical substances and underground operation. This paper is a study of the dispersion mechanism of cryogenic hydrogen and the mechanisms of flame propagation in clouds of hydrogen. The objective is to contribute to the industrial control implementation of significant storage of hydrogen liquid that has pressure close to the atmospheric pressure. Within the framework of this program, the only interest is with the risk presented by escape of significant flow. This corresponds to accidental ruptures in tanks. The following four phases are looked at: the escape incident and the determination of the leak flow; the formation of the liquid layer and the vaporization of the hydrogen; the formation of the Hydrogen cloud in air; and the explosive ignition in the atmosphere, propagation of the explosive flame and evaluation of the pressure wave. This situation has been limited to dispersion in free air and does not consider the impact of containment

Factors in the dispersant use decision-making process : historical overview and look to the future

International Nuclear Information System (INIS)

Etkin, D.S.

1998-01-01

The history of chemical dispersant use in response to marine oil spills was reviewed. A series of case histories were presented to show the political, technical, and financial issues that have influenced the decision-making process and which are likely to influence dispersant use in the future. It was shown that response coordinators must consider the potential effectiveness of dispersant treatment and also the potential for environmental benefit or environmental damage. The safety and effectiveness of dispersant use were shown to depend on: (1) the type of oil or product spilled, (2) the amount of oil spilled, (3) the proximity to the shore and to sensitive habitats, (4) the weather and sea conditions at the time of the spill and during the response, (5) the types of dispersant chemicals on the market at the time of the spill, and (6) the potential efficiency of other cleanup methodologies available. It was noted that more than 37 per cent of the marine oil spills recorded in the Oil Spill Intelligence Report's international oil spill database involve the use of dispersants during the cleanup operations. 21 refs., 4 tabs

Laser control of natural disperse systems

Science.gov (United States)

Vlasova, Olga L.; Bezrukova, Alexandra G.

2003-10-01

Different water disperse systems were studied by integral (spectroturbidemetry) and differential light scattering method with a laser as a source of light. The investigation done concerns the state of kaolin dispersions at storage and under dilution as an example of mineral dispersion systems such as natural water. The role of some light scattering parameters for an optical analysis of water dispersions, like the dispersion of erythrocytes and bacterial cells -Escherichia coli is discussed. The results obtained can help to elaborate the methods for on-line optical control fo natural disperse systems (water, air) with mineral and biological particles.

Dispersion of UO2F2 aerosol and HF vapor in the operating floor during winter ventilation at the Paducah Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Kim, S.H.; Chen, N.C.J.; Taleyarkhan, R.P.; Keith, K.D.; Schmidt, R.W.; Carter, J.C.

1996-01-01

The gaseous diffusion process is currently employed at two plants in the US: the Paducah Gaseous Diffusion Plant and the Portsmouth Gaseous Diffusion Plant. As part of a facility-wide safety evaluation, a postulated design basis accident involving large line-rupture induced releases of uranium hexafluoride (UF 6 ) into the process building of a gaseous diffusion plant (GDP) is evaluated. When UF 6 is released into the atmosphere, it undergoes an exothermic chemical reaction with moisture (H 2 O) in the air to form vaporized hydrogen fluoride (HF) and aerosolized uranyl fluoride (UO 2 F 2 ). These reactants disperse in the process building and transport through the building ventilation system. The ventilation system draws outside air into the process building, distributes it evenly throughout the building, and discharges it to the atmosphere at an elevated temperature. Since air is recirculated from the cell floor area to the operating floor, issues concerning in-building worker safety and evacuation need to be addressed. Therefore, the objective of this study is to evaluate the transport of HF vapor and UO 2 F 2 aerosols throughout the operating floor area following B-line break accident in the cell floor area

Atmospheric dispersion models for real-time application in the decision support system being developed within the CEC

International Nuclear Information System (INIS)

Mikkelsen, T.

1992-01-01

A number of Commission of the European Communities member states are presently coordinating their research and development of a ''Real-time On-line DecisiOn Support'' (RODOS) for emergency assistance in the event of nuclear accident. In addition to atmospheric dispersion, the system involves multiple other radiological disciplines. The ability to estimate a specific atmospheric dispersion scenarios in real-time becomes a first-priority task and is of uttermost importance for the subsequent success or failure of such a comprehensive decision support system to guide off-site emergency situations. No single dispersion model is at present able to cover all possible release-types and scales of dispersion. A hierarchy of atmospheric flow and dispersion models is presently being ranked for suitability to real-time calculate air and integrated-air concentrations. Starting at the short-range scale, models are discriminated with respect to principle, adequacy and flexibility, CPU-time constraints, experimental evaluation record, instantaneous or short-time release handling, deposition measures (wet and dry), input and output data flexibility and uncertainty-handling and model-interpretation. Additional features of particular importance are: Robustness in schemes for meteorological preprocessing of meteorological input data, and on-line backfitting and data-assimilation procedures. Models demonstrating practical and operational use, including real-time operational experience, have in this context the highest priority, as opposed to the more sophisticated and theoretical ''development-type'' models. Real-time methods founded on our present knowledge and data concerning flow and dispersion in the atmospheric boundary layer, are of primary interest. (au) (18 refs.)

Gas phase dispersion in a small rotary kiln

International Nuclear Information System (INIS)

Spencer, B.B.

1981-07-01

A study was made of nonideal flow of gas in a rotary kiln reactor. A rotating tube 0.165 m in diameter by 2.17 m long, with internal lifting flights, was operated at room temperature. Rotational speeds from 2.0 to 7.0 rpm, air flow rates from 0.351 to 4.178 m 3 /h, and solid contents of 0.0, 5.1, and 15.3% of tube volume were studied. Residence time distribution of the gas was measured by means of the pulse injection technique using a helium tracer. A model was developed based on dispersive flow that exchanges with a deadwater region. Two parameters, a dispersion number describing bulk gas flow and an interchange factor describing exchange between the flow region and the gas trapped in the solids bed, were sufficient to correlate the data, but these parameters are sensitive to experimental error. The model is applicable to analysis of other flow systems, such as packed beds

Method for manufacturing carrier containing e.g. proteins for human during oral drug delivery operation for food and drug administration application in pharmaceutical industry, involves providing active ingredient to core layer

DEFF Research Database (Denmark)

2015-01-01

NOVELTY - The method involves preparing a multi-layered film comprising a core layer and a barrier layer, where the core layer comprises active ingredient. The multi-layered film is subjected to a hot embossing step using an embossing stamp including protrusions that allows for generation...... delivery operation for a food and drug administration (FDA) application in a pharmaceutical industry. ADVANTAGE - The method enables allowing an individual micro-structure stuck in an embossing stamp to be demolded under the conditions such that demolding operation is done by treating elastically...

Experimental demonstration of the maximum likelihood-based chromatic dispersion estimator for coherent receivers

DEFF Research Database (Denmark)

Borkowski, Robert; Johannisson, Pontus; Wymeersch, Henk

2014-01-01

We perform an experimental investigation of a maximum likelihood-based (ML-based) algorithm for bulk chromatic dispersion estimation for digital coherent receivers operating in uncompensated optical networks. We demonstrate the robustness of the method at low optical signal-to-noise ratio (OSNR...

Does an ant-dispersed plant, Viola reichenbachiana, suffer from reduced seed dispersal under inundation disturbances?

NARCIS (Netherlands)

Prinzing, A.; Dauber, J.; Hammer, E.; Hammouti, N.; Bohning-Gaese, K.

2008-01-01

Many plant species use ants as seed dispersers. This dispersal mode is considered to be susceptible to disturbances, but the effect of natural, small-scale disturbances is still unknown. We investigated how small-scale disturbances due to inundation affect seed dispersal in Viola reichenbachiana, a

Clock synchronization and dispersion

International Nuclear Information System (INIS)

Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo; Wong, Franco N C

2002-01-01

We present a method to defeat effects of dispersion of timing signals when synchronizing clocks. It is based on the recently proposed 'conveyor belt synchronization' scheme and on the quantum dispersion cancellation effect

Nozzle for electric dispersion reactor

Science.gov (United States)

Sisson, W.G.; Basaran, O.A.; Harris, M.T.

1995-11-07

A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 4 figs.

Generalized algorithm for control of numerical dispersion in explicit time-domain electromagnetic simulations

Directory of Open Access Journals (Sweden)

Benjamin M. Cowan

2013-04-01

Full Text Available We describe a modification to the finite-difference time-domain algorithm for electromagnetics on a Cartesian grid which eliminates numerical dispersion error in vacuum for waves propagating along a grid axis. We provide details of the algorithm, which generalizes previous work by allowing 3D operation with a wide choice of aspect ratio, and give conditions to eliminate dispersive errors along one or more of the coordinate axes. We discuss the algorithm in the context of laser-plasma acceleration simulation, showing significant reduction—up to a factor of 280, at a plasma density of 10^{23}  m^{-3}—of the dispersion error of a linear laser pulse in a plasma channel. We then compare the new algorithm with the standard electromagnetic update for laser-plasma accelerator stage simulations, demonstrating that by controlling numerical dispersion, the new algorithm allows more accurate simulation than is otherwise obtained. We also show that the algorithm can be used to overcome the critical but difficult challenge of consistent initialization of a relativistic particle beam and its fields in an accelerator simulation.

Effectiveness of selected dispersants on magnetite deposition at simulated PWR heat transfer surfaces

International Nuclear Information System (INIS)

Burgmayer, P.; Crovetto, R.; Turner, C.; Klimas, S.

1998-01-01

The effectiveness of three different dispersants - a polyphosphonic acid (PIPPA); a polymethacrylic acid (PMA); and a hydroxyethylidene methacrylic acid (HEME) - at controlling magnetite deposition has been examined under steam generator operating conditions. Tests in a cycling research model boiler showed that the dispersants resulted in corrosion products with a smaller average size and a bimodal size distribution. At a concentration in the boiler of 10 mg/kg, density weight deposit on heated probes was reduced 4-, 3-, and 2-fold for PMA, PIPPA, and HEME, respectively. PIPPA was the most effective at increasing iron transport out of the boiler. In deposition loop tests using a 59-Fe radiotracer, only PIPPA and HEME were effective at reducing the particle deposition rate under flow-boiling conditions. None of the dispersants had any impact on deposition under single-phase forced-convective flow. (author)

Efficient approximations of dispersion relations in optical waveguides with varying refractive-index profiles.

Science.gov (United States)

Li, Yutian; Zhu, Jianxin

2015-05-04

In this paper we consider the problem of computing the eigen-modes for the varying refractive-index profile in an open waveguide. We first approximate the refractive-index by a piecewise polynomial of degree two, and the corresponding Sturm-Liouville problem (eigenvalue problem) of the Helmholtz operator in each layer can be solved analytically by the Kummer functions. Then, analytical approximate dispersion equations are established for both TE and TM cases. Furthermore, the approximate dispersion equations converge fast to the exact ones for the continuous refractive-index function as the maximum value of the subinterval sizes tends to zero. Suitable numerical methods, such as Müller's method or the chord secant method, may be applied to the dispersion relations to compute the eigenmodes. Numerical simulations show that our method is very practical and efficient for computing eigenmodes.

Effectiveness of selected dispersants on magnetite deposition at simulated PWR heat-transfer surfaces

International Nuclear Information System (INIS)

Burgmayer, P.; Crovetto, R.; Turner, C.; Klimas, S.J.

1999-07-01

The effectiveness of 3 different dispersants-a polyphosphonic acid (PIPPA), a polymethacrylic acid (PMA), and a hydroxyethylidene methacrylic acid (HEME)-at controlling magnetite deposition was examined under steam generator operating conditions. Tests in a cycling research model boiler showed that the dispersants resulted in corrosion products of a smaller average size and a bimodal size distribution. At a concentration in the boiler of 10 mg/kg, density weight deposit on heated probes was reduced 4-, 3-, and 2-fold for PMA, PIPPA, and HEME, respectively. PIPPA was the most effective at increasing iron transport out of the boiler. In deposition loop tests using an 59 Fe radiotracer, only PIPPA and HEME were effective at reducing the particle deposition rate under flow-boiling conditions. None of the dispersants had any effect on deposition under single-phase forced-convective flow. (author)

Effectiveness of selected dispersants on magnetite deposition at simulated PWR heat transfer surfaces

Energy Technology Data Exchange (ETDEWEB)

Burgmayer, P.; Crovetto, R. [Betz Dearborn Labs., Revose, PA (United States); Turner, C.; Klimas, S. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

1998-07-01

The effectiveness of three different dispersants - a polyphosphonic acid (PIPPA); a polymethacrylic acid (PMA); and a hydroxyethylidene methacrylic acid (HEME) - at controlling magnetite deposition has been examined under steam generator operating conditions. Tests in a cycling research model boiler showed that the dispersants resulted in corrosion products with a smaller average size and a bimodal size distribution. At a concentration in the boiler of 10 mg/kg, density weight deposit on heated probes was reduced 4-, 3-, and 2-fold for PMA, PIPPA, and HEME, respectively. PIPPA was the most effective at increasing iron transport out of the boiler. In deposition loop tests using a 59-Fe radiotracer, only PIPPA and HEME were effective at reducing the particle deposition rate under flow-boiling conditions. None of the dispersants had any impact on deposition under single-phase forced-convective flow. (author)

Effectiveness of selected dispersants on magnetite deposition at simulated PWR heat-transfer surfaces

Energy Technology Data Exchange (ETDEWEB)

Burgmayer, P.; Crovetto, R. [Betz Dearborn Labs., Revose, PA (United States); Turner, C.; Klimas, S.J

1999-07-01

The effectiveness of 3 different dispersants-a polyphosphonic acid (PIPPA), a polymethacrylic acid (PMA), and a hydroxyethylidene methacrylic acid (HEME)-at controlling magnetite deposition was examined under steam generator operating conditions. Tests in a cycling research model boiler showed that the dispersants resulted in corrosion products of a smaller average size and a bimodal size distribution. At a concentration in the boiler of 10 mg/kg, density weight deposit on heated probes was reduced 4-, 3-, and 2-fold for PMA, PIPPA, and HEME, respectively. PIPPA was the most effective at increasing iron transport out of the boiler. In deposition loop tests using an {sup 59}Fe radiotracer, only PIPPA and HEME were effective at reducing the particle deposition rate under flow-boiling conditions. None of the dispersants had any effect on deposition under single-phase forced-convective flow. (author)

Hydraulic Hybrid Parcel Delivery Truck Deployment, Testing & Demonstration

Energy Technology Data Exchange (ETDEWEB)

Gallo, Jean-Baptiste [Calstart Incorporated, Pasadena, CA (United States)

2014-03-07

Although hydraulic hybrid systems have shown promise over the last few years, commercial deployment of these systems has primarily been limited to Class 8 refuse trucks. In 2005, the Hybrid Truck Users Forum initiated the Parcel Delivery Working Group including the largest parcel delivery fleets in North America. The goal of the working group was to evaluate and accelerate commercialization of hydraulic hybrid technology for parcel delivery vehicles. FedEx Ground, Purolator and United Parcel Service (UPS) took delivery of the world’s first commercially available hydraulic hybrid parcel delivery trucks in early 2012. The vehicle chassis includes a Parker Hannifin hydraulic hybrid drive system, integrated and assembled by Freightliner Custom Chassis Corp., with a body installed by Morgan Olson. With funding from the U.S. Department of Energy, CALSTART and its project partners assessed the performance, reliability, maintainability and fleet acceptance of three pre-production Class 6 hydraulic hybrid parcel delivery vehicles using information and data from in-use data collection and on-road testing. This document reports on the deployment of these vehicles operated by FedEx Ground, Purolator and UPS. The results presented provide a comprehensive overview of the performance of commercial hydraulic hybrid vehicles in parcel delivery applications. This project also informs fleets and manufacturers on the overall performance of hydraulic hybrid vehicles, provides insights on how the technology can be both improved and more effectively used. The key findings and recommendations of this project fall into four major categories: -Performance, -Fleet deployment, -Maintenance, -Business case. Hydraulic hybrid technology is relatively new to the market, as commercial vehicles have been introduced only in the past few years in refuse and parcel delivery applications. Successful demonstration could pave the way for additional purchases of hydraulic hybrid vehicles throughout the

Fractional-calculus-based FDTD algorithm for ultrawideband electromagnetic characterization of arbitrary dispersive dielectric materials

NARCIS (Netherlands)

Caratelli, Diego; Mescia, Luciano; Bia, Pietro; Stukach, Oleg V.

2016-01-01

A novel finite-difference time-domain algorithm for modeling ultrawideband electromagnetic pulse propagation in arbitrary multirelaxed dispersive media is presented. The proposed scheme is based on a general, yet computationally efficient, series representation of the fractional derivative operators

Statistical Thermodynamics of Disperse Systems

DEFF Research Database (Denmark)

Shapiro, Alexander

1996-01-01

Principles of statistical physics are applied for the description of thermodynamic equilibrium in disperse systems. The cells of disperse systems are shown to possess a number of non-standard thermodynamic parameters. A random distribution of these parameters in the system is determined....... On the basis of this distribution, it is established that the disperse system has an additional degree of freedom called the macro-entropy. A large set of bounded ideal disperse systems allows exact evaluation of thermodynamic characteristics. The theory developed is applied to the description of equilibrium...

Geometry of physical dispersion relations

International Nuclear Information System (INIS)

Raetzel, Dennis; Rivera, Sergio; Schuller, Frederic P.

2011-01-01

To serve as a dispersion relation, a cotangent bundle function must satisfy three simple algebraic properties. These conditions are derived from the inescapable physical requirements that local matter field dynamics must be predictive and allow for an observer-independent notion of positive energy. Possible modifications of the standard relativistic dispersion relation are thereby severely restricted. For instance, the dispersion relations associated with popular deformations of Maxwell theory by Gambini-Pullin or Myers-Pospelov are not admissible. Dispersion relations passing the simple algebraic checks derived here correspond to physically admissible Finslerian refinements of Lorentzian geometry.

Phase Transitions of Isotropic to Anisotropic Biocompatible Lipid-Based Drug Delivery Systems Overcoming Insoluble Benznidazole Loading

Science.gov (United States)

Streck, Letícia; Sarmento, Víctor H. V.; Machado, Paula R. L.; Farias, Kleber J. S.; Fernandes-Pedrosa, Matheus F.; da Silva-Júnior, Arnóbio Antônio

2016-01-01

Previous studies reported low benznidazole (BNZ) loading in conventional emulsions due to the weak interaction of the drug with the most common oils used to produce foods or pharmaceuticals. In this study, we focused on how the type of surfactant, surfactant-to-oil ratio w/w (SOR) and oil-to-water ratio w/w (OWR) change the phase behavior of different lipid-based drug delivery systems (LBDDS) produced by emulsion phase inversion. The surfactant mixture composed of soy phosphatidylcholine and sodium oleate (1:7, w/w, hydrophilic lipophilic balance = 16) stabilized medium chain triglyceride in water. Ten formulations with the clear aspect or less turbid dispersions (five with the SOR ranging from 0.5 to 2.5 and five with the OWR from 0.06 to 0.4) were selected from the phase behavior diagram to assess structural features and drug-loading capacity. The rise in the SOR induced the formation of distinct lipid-based drug delivery systems (nanoemulsions and liquid crystal lamellar type) that were identified using rheological measurements and cross-polarized light microscopy images. Clear dispersions of small and narrow droplet-sized liquid-like nanoemulsions, Newtonian flow-type, were produced at SOR from 0.5 to 1.5 and OWR from 0.12 to 0.4, while clear liquid or gel-like liquid crystals were produced at SOR from 1.5 to 2.5. The BNZ loading was improved according to the composition and type of LBDDS produced, suggesting possible drug location among surfactant layers. The cell viability assays proved the biocompatibility for all of the prepared nanoemulsions at SOR less than 1.5 and liquid crystals at SOR less than 2.5, demonstrating their promising features for the oral or parenteral colloidal delivery systems containing benznidazole for Chagas disease treatment. PMID:27376278

Phase Transitions of Isotropic to Anisotropic Biocompatible Lipid-Based Drug Delivery Systems Overcoming Insoluble Benznidazole Loading

Directory of Open Access Journals (Sweden)

Letícia Streck

2016-06-01

Full Text Available Previous studies reported low benznidazole (BNZ loading in conventional emulsions due to the weak interaction of the drug with the most common oils used to produce foods or pharmaceuticals. In this study, we focused on how the type of surfactant, surfactant-to-oil ratio w/w (SOR and oil-to-water ratio w/w (OWR change the phase behavior of different lipid-based drug delivery systems (LBDDS produced by emulsion phase inversion. The surfactant mixture composed of soy phosphatidylcholine and sodium oleate (1:7, w/w, hydrophilic lipophilic balance = 16 stabilized medium chain triglyceride in water. Ten formulations with the clear aspect or less turbid dispersions (five with the SOR ranging from 0.5 to 2.5 and five with the OWR from 0.06 to 0.4 were selected from the phase behavior diagram to assess structural features and drug-loading capacity. The rise in the SOR induced the formation of distinct lipid-based drug delivery systems (nanoemulsions and liquid crystal lamellar type that were identified using rheological measurements and cross-polarized light microscopy images. Clear dispersions of small and narrow droplet-sized liquid-like nanoemulsions, Newtonian flow-type, were produced at SOR from 0.5 to 1.5 and OWR from 0.12 to 0.4, while clear liquid or gel-like liquid crystals were produced at SOR from 1.5 to 2.5. The BNZ loading was improved according to the composition and type of LBDDS produced, suggesting possible drug location among surfactant layers. The cell viability assays proved the biocompatibility for all of the prepared nanoemulsions at SOR less than 1.5 and liquid crystals at SOR less than 2.5, demonstrating their promising features for the oral or parenteral colloidal delivery systems containing benznidazole for Chagas disease treatment.

Mode of Delivery Preferences in a Diverse Population of Pregnant Women

Science.gov (United States)

YEE, Lynn M.; KAIMAL, Anjali J.; HOUSTON, Kathryn A.; WU, Erica; THIET, Mari-Paule; NAKAGAWA, Sanae; CAUGHEY, Aaron B.; FIROUZIAN, Atoosa; KUPPERMANN, Miriam

2014-01-01

OBJECTIVE To assess women’s preferences for vaginal versus cesarean delivery in four contexts: prior cesarean, twins, breech presentation, and absent indication for cesarean. STUDY DESIGN Cross-sectional study of pregnant women at 24-40 weeks gestation. After assessing stated preferences for vaginal or cesarean delivery, we used the standard gamble metric to measure the strength of these preferences and the time tradeoff metric to determine how women value the potential processes and outcomes associated with these two delivery approaches. RESULTS Among the 240 participants, 90.8% had a stated preference for vaginal delivery. Across the four contexts, these women indicated that, on average, they would accept a 59-75% chance of an attempted vaginal birth ending in a cesarean before choosing a planned cesarean, indicating strong preferences for spontaneous, uncomplicated vaginal delivery. Variations in preferences for labor processes emerged. While uncomplicated labor ending in vaginal birth was assigned mean utilities of 0.993 or higher (on a 0-to-1 scale with higher scores indicating more preferred outcomes), the need for oxytocin, antibiotics, or operative vaginal delivery resulted in lower mean scores, comparable to those assigned to uncomplicated cesarean delivery. Substantially lower scores (ranging from 0.432 to 0.598) were obtained for scenarios ending in severe maternal or neonatal morbidity. CONCLUSIONS While most women expressed strong preferences for vaginal delivery, their preferences regarding interventions frequently employed to achieve that goal varied. These data underscore the importance of educating patients about the process of labor and delivery to facilitate incorporation of informed patient preferences in shared decision making regarding delivery approach. PMID:25446662

Magnetic lipid nanoparticles loading doxorubicin for intracellular delivery: Preparation and characteristics

International Nuclear Information System (INIS)

Ying Xiaoying; Du Yongzhong; Hong Linghong; Yuan Hong; Hu Fuqiang

2011-01-01

Tumor intracellular delivery is an effective route for targeting chemotherapy to enhance the curative effect and minimize the side effect of a drug. In this study, the magnetic lipid nanoparticles with an uptake ability by tumor cells were prepared dispersing ferroso-ferric oxide nanoparticles in aqueous phase using oleic acid (OA) as a dispersant, and following the solvent dispersion of lipid organic solution. The obtained nanoparticles with 200 nm volume average diameter and -30 mV surface zeta potential could be completely removed by external magnetic field from aqueous solution. Using doxorubicin (DOX) as a model drug, the drug-loaded magnetic lipid nanoparticles were investigated in detail, such as the effects of OA, drug and lipid content on volume average diameter, zeta potential, drug encapsulation efficiency, drug loading, and in vitro drug release. The drug loading capacity and encapsulation efficiency were enhanced with increasing drug or lipid content, reduced with increasing OA content. The in vitro drug release could be controlled by changing drug or lipid content. Cellular uptake by MCF-7 cells experiment presented the excellent internalization ability of the prepared magnetic lipid nanoparticles. These results evidenced that the present magnetic lipid nanoparticles have potential for targeting therapy of antitumor drugs. - Research highlights: → A simple solvent diffusion method was developed to prepare magnetic lipid nanoparticles. → The doxorubicin-loaded magnetic lipid nanoparticles could be controlled by preparation recipe. → Magnetic lipid nanoparticles had internalization ability into tumor cells.

[Analysis of the Effect of Non-phacoemulsification Cataract Operation on Corneal Endothelial Cell Nucleus Division].

Science.gov (United States)

Huang, Zufeng; Miao, Xiaoqing

2015-09-01

To investigate the effect of non-phacoemulsification cataract operation in two different patterns of nucleus delivery on the quantity and morphology of corneal endothelial cells and postoperative visual acuity. Forty patients diagnosed with cataract underwent cataract surgery and were assigned into the direct nuclear delivery and semi-nuclear delivery groups. Lens density was measured and divided into the hard and soft lenses according to Emery-little lens nucleus grading system. Non-phacoemulsification cataract operation was performed. At 3 d after surgery, the quantity and morphology of corneal endothelium were counted and observed under corneal endothelial microscope. During 3-month postoperative follow-up, the endothelial cell loss rate, morphological changes and visual acuity were compared among four groups. Corneal endothelial cell loss rate in the direct delivery of hard nucleus group significantly differed from those in the other three groups before and 3 months after operation (P nucleus, semi-delivery of hard nucleus and semi-delivery soft nucleus groups (all P > 0.05). Preoperative and postoperative 2-d visual acuity did not differ between the semi-delivery of hard nucleus and direct delivery of soft nucleus groups (P = 0.49), significantly differed from those in the semi-delivery of soft nucleus (P = 0.03) and direct delivery of hard nucleus groups (P = 0.14). Visual acuity at postoperative four months did not differ among four groups (P = 0.067). During non-phacoemulsification cataract surgery, direct delivery of hard nucleus caused severe injury to corneal endothelium and semi-delivery of soft nucleus yielded mild corneal endothelial injury. Slight corneal endothelial injury exerted no apparent effect upon visual acuity and corneal endothelial morphology at three months after surgery.

Behavioral Design Teams: The Next Frontier in Clinical Delivery Innovation?

Science.gov (United States)

Robertson, Ted; Darling, Matthew; Leifer, Jennifer; Footer, Owen; Gordski, Dani

2017-11-01

A deep understanding of human behavior is critical to designing effective health care delivery models, tools, and processes. Currently, however, few mechanisms exist to systematically apply insights about human behavior to improve health outcomes. Behavioral design teams (BDTs) are a successful model for applying behavioral insights within an organization. Already operational within government, this model can be adapted to function in a health care setting. To explore how BDTs could be applied to clinical care delivery and review models for integrating these teams within health care organizations. Interviews with experts in clinical delivery innovation and applied behavioral science, as well as leaders of existing government BDTs. BDTs are most effective when they enjoy top-level executive support, are co-led by a domain expert and behavioral scientist, collaborate closely with key staff and departments, have access to data and IT support, and operate a portfolio of projects. BDTs could be embedded in health care organizations in multiple ways, including in or just below the CEO’s office, within a quality improvement unit, or within an internal innovation center. When running a portfolio, BDTs achieve a greater number and diversity of insights at lower costs. They also become a platform for strategic learning and scaling.

Determination of dispersity of crushed granite

International Nuclear Information System (INIS)

Liu Dejun; Fan Xianhua; Zhang Yingjie; Yao Jun; Zhou Duo; Wang Yong

2004-01-01

The experimental crushed granite column breakthrough curves, using 99 Tc as spike tracer and 3 H as invariant tracer, are analyzed by different linear regression techniques. Dispersity of crushed granite and retardation factor of 99 TcO 4 - on the crushed granite are determined simultaneously by one linear regression technique. Dispersity of crushed granite is also obtained with 3 H as invariant tracer by the other linear regression technique. The dispersities found by spike source and invariant source methods are compared. The experimental results show that the dispersity found by spike source method is close to that found by invariant source method. It indicates that dispersity is only the characteristic of dispersion medium

Determination of dispersity of crushed granite

International Nuclear Information System (INIS)

Liu, D.J.; Fan, X.H.

2005-01-01

Experimental crushed granite column breakthrough curves, using 99 Tc as spike tracer and 3 H as invariant tracer, were analyzed by different linear regression techniques. Dispersity of crushed granite and the retardation factor of 99 TcO 4 - on the crushed granite were determined simultaneously by one linear regression. Dispersity of crushed granite was also obtained with 3 H as invariant tracer by the other linear regression. The dispersities found by spike source and invariant source methods are compared. Experimental results show that the dispersity found by the spike source method is close to that found by the invariant source method. This indicates that dispersity is only a characteristic of the dispersion medium. (author)

Exteriorization or in-situ repair, comparison of options for uterine repair at cesarean delivery

International Nuclear Information System (INIS)

Zafar, B.; Shehzad, F.; Safdar, C.A.

2016-01-01

Objective of study is to compare peri-operative complications between exteriorization and intraabdominal repair of uterus after cesarean delivery. Study Design: Randomized controlled trial. Place and Duration of Study: Obstetrics and Gynecology Department of Pakistan Ordinance Factory Hospital, Wah Cantt, from 1st April 2010 to 30th September 2010. Material and Methods: Patients planned for 1st cesarean section under spinal anesthesia were randomly allocated by lottery method to exteriorized (A) or in situ uterine repair (B) group. Patients with history of uterine surgeries and cesarean section were excluded from study. Variables analyzed were operation time, peri-operative hemoglobin (Hb) fall, nausea and vomiting during the cesarean delivery. Results: The study analyzed 170 patients and divided them in 2 groups, having no significant difference with respect to maternal demographics, procedure statistics and indication of cesarean section. Significant difference was observed in operation time being 32.78 min in exteriorized group and 36.38 min in situ uterine repair group (p-value 0.0001). Hb percent fall was 0.85 g/dl and 0.92 g/dl respectively in both groups (p-value 0.62) Nausea and vomiting was 23.5 percent in group A and 11.8 percent in group B (p-value 0.02, 0.04 respectively) Conclusion: Peri-operative complications like operative time and Hb fall are less in uterine repair after temporary exteriorization as compared to intra-abdominal repair of uterus after cesarean delivery. Nausea and vomiting were increased in exteriorized group but proper regional anesthetic technique and achieving adequate analgesia can reduce patient discomfort. (author)

Dispersive shock waves in systems with nonlocal dispersion of Benjamin-Ono type

Science.gov (United States)

El, G. A.; Nguyen, L. T. K.; Smyth, N. F.

2018-04-01

We develop a general approach to the description of dispersive shock waves (DSWs) for a class of nonlinear wave equations with a nonlocal Benjamin-Ono type dispersion term involving the Hilbert transform. Integrability of the governing equation is not a pre-requisite for the application of this method which represents a modification of the DSW fitting method previously developed for dispersive-hydrodynamic systems of Korteweg-de Vries (KdV) type (i.e. reducible to the KdV equation in the weakly nonlinear, long wave, unidirectional approximation). The developed method is applied to the Calogero-Sutherland dispersive hydrodynamics for which the classification of all solution types arising from the Riemann step problem is constructed and the key physical parameters (DSW edge speeds, lead soliton amplitude, intermediate shelf level) of all but one solution type are obtained in terms of the initial step data. The analytical results are shown to be in excellent agreement with results of direct numerical simulations.

Heat delivery from Bohunice NPP, Slovakia

International Nuclear Information System (INIS)

Paley, I.

1998-01-01

Experience with nuclear district heating in the Slovak Republic is reported. The heating system of the town of Trnava is supplied by the Bohunice NPP and conventional sources. Construction of the hot water heating system from the Bohunice NPP began in 1983. Commercial operation began on 10 December 1987. Heat delivery has gradually increased from 478 TJ in 1988, to 1,104 TJ in 1995. The heat cost is low, resulting in an increasing number of consumers. (author)

Glycoprotein CD98 as a receptor for colitis-targeted delivery of nanoparticle.

Science.gov (United States)

Xiao, Bo; Yang, Yang; Viennois, Emilie; Zhang, Yuchen; Ayyadurai, Saravanan; Baker, Mark; Laroui, Hamed; Merlin, Didier

2014-03-21

Treatment strategies for inflammatory bowel disease have been constrained by limited therapeutic efficacy and serious adverse effects owing to a lack of receptor for targeted drug delivery to the inflamed colon. Upon inflammation, CD98 expression is highly elevated in colonic epithelial cells and infiltrating immune cells. To investigate whether CD98 can be used as a colitis-targeted delivery receptor, we constructed CD98 Fab'-bearing quantum dots (QDs)-loaded nanoparticles (Fab'-NPs). The resultant Fab'-NPs had desired particle size (~458 nm) with a narrow size distribution and zeta-potential (approximately +19 mV), low cytotoxicity, and excellent fluorescence properties. Electron microscopy images provided direct evidence for the well-dispersed distribution of QDs within spherical Fab'-NPs. Cellular uptake experiments demonstrated that Fab'-NPs were efficiently internalized into Colon-26 and RAW 264.7 cells through the CD98-mediated endocytosis pathway, and showed that the targeting effect of CD98 Fab' markedly increased their cellular uptake efficiency compared with control pegylated QDs-loaded NPs (PEG-NPs). Furthermore, ex vivo studies showed much more effective accumulation of Fab'-NPs in colitis tissue than that of PEG-NPs. These findings suggest that because of inflammation-dependent over-expression of CD98, active colitis-targeted delivery can be accomplished using NPs decorated with CD98 antibody.

Interdelivery weight gain and risk of cesarean delivery following a prior vaginal delivery.

Science.gov (United States)

Dude, Annie M; Lane-Cordova, Abbi D; Grobman, William A

2017-09-01

Approximately one third of all deliveries in the United States are via cesarean. Previous research indicates weight gain during pregnancy is associated with an increased risk of cesarean delivery. It remains unclear, however, whether and to what degree weight gain between deliveries (ie, interdelivery weight gain) is associated with cesarean delivery in a subsequent pregnancy following a vaginal delivery. The objective of the study was to determine whether interdelivery weight gain is associated with an increased risk of intrapartum cesarean delivery following a vaginal delivery. This was a case-control study of women who had 2 consecutive singleton births of at least 36 weeks' gestation between 2005 and 2016, with a vaginal delivery in the index pregnancy. Women were excluded if they had a contraindication to a trial of labor (eg, fetal malpresentation or placenta previa) in the subsequent pregnancy. Maternal characteristics and delivery outcomes for both pregnancies were abstracted from the medical record. Maternal weight gain between deliveries was measured as the change in body mass index at delivery. Women who underwent a subsequent cesarean delivery were compared with those who had a repeat vaginal delivery using χ 2 statistics for categorical variables and Student t tests or analysis of variance for continuous variables. Multivariable logistic regression was used to determine whether interdelivery weight gain remained independently associated with intrapartum cesarean delivery after adjusting for potential confounders. Of 10,396 women who met eligibility criteria and had complete data, 218 (2.1%) had a cesarean delivery in the subsequent pregnancy. Interdelivery weight gain was significantly associated with cesarean delivery and remained significant in multivariable analysis for women with a body mass index increase of at least 2 kg/m 2 (adjusted odds ratio, 1.53, 95% confidence interval, 1.03-2.27 for a body mass index increase of 2 kg/m 2 to gained 2 kg

Optimizing optical pre-dispersion using transmit DSP for mitigation of Kerr nonlinearities in dispersion managed cables

Science.gov (United States)

Hopkins, James; Gaudette, Jamie; Mehta, Priyanth

2013-10-01

With the advent of digital signal processing (DSP) in optical transmitters and receivers, the ability to finely tune the ratio of pre and post dispersion compensation can be exploited to best mitigate the nonlinear penalties caused by the Kerr effect. A portion of the nonlinear penalty in optical communication channels has been explained by an increase in peak to average power ratio (PAPR) inherent in highly dispersed signals. The standard approach for minimizing these impairments applies 50% pre dispersion compensation and 50% post dispersion compensation, thereby decreasing average PAPR along the length of the cable, as compared with either 100% pre or post dispersion compensation. In this paper we demonstrate that simply considering the net accumulated dispersion, and applying 50/50 pre/post dispersion is not necessarily the best way to minimize PAPR and subsequent Kerr nonlinearities. Instead, we consider the cumulative dispersion along the entire length of the cable, and, taking into account this additional information, derive an analytic formula for the minimization of PAPR. Alignment with simulation and experimental measurements is presented using a commercially available 100Gb/s dual-polarization binary phase-shift-keying (DP-BPSK) coherent modem, with transmitter and receiver DSP. Measurements are provided from two different 5000km dispersion managed Submarine test-beds, as well as a 3800km terrestrial test-bed with a mixture of SMF-28 and TWRS optical fiber. This method is shown to deviate significantly from the conventional 50/50 method described above, in dispersion managed communications systems, and more closely aligns with results obtained from simulation and data collected from laboratory test-beds.

Hydraulic Hybrid and Conventional Parcel Delivery Vehicles' Measured Laboratory Fuel Economy on Targeted Drive Cycles

Energy Technology Data Exchange (ETDEWEB)

Lammert, M. P.; Burton, J.; Sindler, P.; Duran, A.

2014-10-01

This research project compares laboratory-measured fuel economy of a medium-duty diesel powered hydraulic hybrid vehicle drivetrain to both a conventional diesel drivetrain and a conventional gasoline drivetrain in a typical commercial parcel delivery application. Vehicles in this study included a model year 2012 Freightliner P100H hybrid compared to a 2012 conventional gasoline P100 and a 2012 conventional diesel parcel delivery van of similar specifications. Drive cycle analysis of 484 days of hybrid parcel delivery van commercial operation from multiple vehicles was used to select three standard laboratory drive cycles as well as to create a custom representative cycle. These four cycles encompass and bracket the range of real world in-use data observed in Baltimore United Parcel Service operations. The NY Composite cycle, the City Suburban Heavy Vehicle Cycle cycle, and the California Air Resources Board Heavy Heavy-Duty Diesel Truck (HHDDT) cycle as well as a custom Baltimore parcel delivery cycle were tested at the National Renewable Energy Laboratory's Renewable Fuels and Lubricants Laboratory. Fuel consumption was measured and analyzed for all three vehicles. Vehicle laboratory results are compared on the basis of fuel economy. The hydraulic hybrid parcel delivery van demonstrated 19%-52% better fuel economy than the conventional diesel parcel delivery van and 30%-56% better fuel economy than the conventional gasoline parcel delivery van on cycles other than the highway-oriented HHDDT cycle.

Combined microfluidization and ultrasonication: a synergistic protocol for high-efficient processing of SWCNT dispersions with high quality

Energy Technology Data Exchange (ETDEWEB)

Luo, Sida, E-mail: s.luo@buaa.edu.cn [Beihang University, School of Mechanical Engineering and Automation (China); Liu, Tao, E-mail: tliu@fsu.edu [Florida State University, High-Performance Materials Institute (United States); Wang, Yong; Li, Liuhe [Beihang University, School of Mechanical Engineering and Automation (China); Wang, Guantao; Luo, Yun [China University of Geosciences, Center of Safety Research, School of Engineering and Technology (China)

2016-08-15

High-efficient and large-scale production of high-quality CNT dispersions is necessary for meeting the future needs to develop various CNT-based electronic devices. Herein, we have designed novel processing protocols by combining conventional ultrasonication process with a new microfluidization technique to produce high-quality SWCNT dispersions with improved processing efficiency. To judge the quality of SWCNT dispersions, one critical factor is the degree of exfoliation, which could be quantified by both geometrical dimension of the exfoliated nanotubes and percentage of individual tubes in a given dispersion. In this paper, the synergistic effect of the combined protocols was systematically investigated through evaluating SWCNT dispersions with newly developed characterization techniques, namely preparative ultracentrifuge method (PUM) and simultaneous Raman scattering and photoluminescence spectroscopy (SRSPL). The results of both techniques draw similar conclusions that as compared with either of the processes operated separately, a low-pass microfluidization followed by a reasonable duration of ultrasonication could substantially improve the processing efficiency to produce high-quality SWCNT dispersions with averaged particle length and diameter as small as ~600 and ~2 nm, respectively.Graphical abstract.

eDelivery

Data.gov (United States)

US Agency for International Development — eDelivery provides the electronic packaging and delivery of closed and complete OPM investigation files to government agencies, including USAID, in a secure manner....

Increases of QT dispersion, corrected QT dispersion and QT interval in young healthy individuals during Ramadan fasting

Directory of Open Access Journals (Sweden)

Moradmand S

2003-06-01

Full Text Available Ramadan fasting is one of the most important religious duties of Muslims, that its effect on the heart has not been determined yet. Our objective was to evaluate the effect of Ramadan fasting on ventricular repolarization as assessed by QT interval, corrected QT interval, QT dispersion or corrected QT dispersion. Sixthy healthy subjects aged 20 to 35 years were dispersion included in this study. QT interval, corrected QT interval (QTc QT dispersion QTc dispersion, RR interval and QRS axis were measured in 12-lead surface electrocardiogram, once during fasting (10 to 11.5 hours of absolute fasting from food and liquid and another time, 15 tp 60 minutes after eating food at sunset, All of the subjects had been fasting 11 to 12 hours each day at least for 25 days during Ramadan. The study was performed at Amir Alam hospital in the year 2000. Maximal QT interval, mean QT interval and RR-interval, were longer during fasting (P<0.05, and both QT dispersion and QTc dispersion were increased (P<0.05. (QT dispersion: mean ±SD= 57.2±20.1 ms during fasting Vs 41.6±15.1 ms after meal, QTc dispersion=75.4±24.6 ms during fasting Vs 64.1±22.8 ms after meal. But mean QTc interval maximal QTc interval and QRS axis showed no significant difference. Prolongation of QT interval and RR interval during fasting, instead of no significant changes in corrected QT interval may primarily suggest that prolongation of RR-interval causes QTc interval not to have significant difference. But increases of QT dispersion and corrected QT dispersion (QTc dispersion during fasting -that are more reliable indicators of ventricular repolarization-support the idea that ventricular repolarization may be changed during Ramadan fasting. QT dispersion in cardiac patients is showed to increase from normal values of 30-40 to 64-138 ms, but in our study their increases did not reach critical value.

A Soft X-ray Spectrometer using a Highly Dispersive Multilayer Grating

International Nuclear Information System (INIS)

Warwick, Tony; Padmore, Howard; Voronov, Dmitriy; Yashchuk, Valeriy

2010-01-01

There is a need for higher resolution spectrometers as a tool for inelastic x-ray scattering. Currently, resolving power around R = 10,000 is advertised. Measured RIXS spectra are often limited by this instrumental resolution and higher resolution spectrometers using conventional gratings would be prohibitively large. We are engaged in a development program to build blazed multilayer grating structures for diffracting soft x-rays in high order. This leads to spectrometers with dispersion much higher than is possible using metal coated-gratings. The higher dispersion then provides higher resolution and the multilayer gratings are capable of operating away from grazing incidence as required. A spectrometer design is presented with a total length 3.8 m and capable of 10 5 resolving power.

A Soft X-ray Spectrometer using a Highly Dispersive Multilayer Grating

International Nuclear Information System (INIS)

Warwick, Tony; Padmore, Howard; Voronov, Dmitriy; Yashchuk, Valeriy

2010-01-01

There is a need for higher resolution spectrometers as a tool for inelastic x-ray scattering. Currently, resolving power around R = 10,000 is advertised. Measured RIXS spectra are often limited by this instrumental resolution and higher resolution spectrometers using conventional gratings would be prohibitively large. We are engaged in a development program to build blazed multilayer grating structures for diffracting soft x-rays in high order. This leads to spectrometers with dispersion much higher than is possible using metal coated-gratings. The higher dispersion then provides higher resolution and the multilayer gratings are capable of operating away from grazing incidence as required. A spectrometer design is presented with a total length 3.8m and capable of 10 5 resolving power.

Confinement of surface waves at the air-water interface to control aerosol size and dispersity

Science.gov (United States)

Nazarzadeh, Elijah; Wilson, Rab; King, Xi; Reboud, Julien; Tassieri, Manlio; Cooper, Jonathan M.

2017-11-01

The precise control over the size and dispersity of droplets, produced within aerosols, is of great interest across many manufacturing, food, cosmetic, and medical industries. Amongst these applications, the delivery of new classes of high value drugs to the lungs has recently attracted significant attention from pharmaceutical companies. This is commonly achieved through the mechanical excitation of surface waves at the air liquid interface of a parent liquid volume. Previous studies have established a correlation between the wavelength on the surface of liquid and the final aerosol size. In this work, we show that the droplet size distribution of aerosols can be controlled by constraining the liquid inside micron-sized cavities and coupling surface acoustic waves into different volumes of liquid inside micro-grids. In particular, we show that by reducing the characteristic physical confinement size (i.e., either the initial liquid volume or the cavities' diameters), higher harmonics of capillary waves are revealed with a consequent reduction of both aerosol mean size and dispersity. In doing so, we provide a new method for the generation and fine control of aerosols' sizes distribution.

Numerical Study of Traffic Pollutant Dispersion within Different Street Canyon Configurations

Directory of Open Access Journals (Sweden)

Yucong Miao

2014-01-01

Full Text Available The objective of this study is to numerically study flow and traffic exhaust dispersion in urban street canyons with different configurations to find out the urban-planning strategies to ease the air pollution. The Computational Fluid Dynamics (CFD model used in this study—Open Source Field Operation and Manipulation (OpenFOAM software package—was firstly validated against the wind-tunnel experiment data by using three different k-ε turbulence models. And then the patterns of flow and dispersion within three different kinds of street canyon configuration under the perpendicular approaching flow were numerically studied. The result showed that the width and height of building can dramatically affect the pollution level inside the street canyon. As the width or height of building increases, the pollution at the pedestrian level increases. And the asymmetric configuration (step-up or step-down street canyon could provide better ventilation. It is recommended to design a street canyon with nonuniform configurations. And the OpenFOAM software package can be used as a reliable tool to study flows and dispersions around buildings.

Sub-100 fs pulses from an all-polarization maintaining Yb-fiber oscillator with an anomalous dispersion higher-order-mode fiber

DEFF Research Database (Denmark)

Verhoef, A. J.; Zhu, L.; Israelsen, Stine Møller

2015-01-01

, was investigated for different settings of the intracavity dispersion. When the cavity is operated with close to zero net dispersion, highly stable 0.5-nJ pulses externally compressed to sub-100-fs are generated. These are to our knowledge the shortest pulses generated from an all-polarization-maintaining Yb-fiber......We present an Yb-fiber oscillator with an all-polarizationmaintaining cavity with a higher-order-mode fiber for dispersion compensation. The polarization maintaining higher order mode fiber introduces not only negative second order dispersion but also negative third order dispersion in the cavity......, in contrast to dispersion compensation schemes used in previous demonstrations of all-polarization maintaining Yb-fiber oscillators. The performance of the saturable absorber mirror modelocked oscillator, that employs a free space scheme for coupling onto the saturable absorber mirror and output coupling...

Sub-100 fs pulses from an all-polarization maintaining Yb-fiber oscillator with an anomalous dispersion higher-order-mode fiber

DEFF Research Database (Denmark)

Verhoef, A.J.; Zhu, L.; Israelsen, Stine Møller

2015-01-01

, was investigated for different settings of the intracavity dispersion. When the cavity is operated with close to zero net dispersion, highly stable 0.5-nJ pulses externally compressed to sub-100-fs are generated. These are to our knowledge the shortest pulses generated from an all-polarization-maintaining Yb-fiber......We present an Yb-fiber oscillator with an all-polarization-maintaining cavity with a higher-order-mode fiber for dispersion compensation. The polarization maintaining higher order mode fiber introduces not only negative second order dispersion but also negative third order dispersion in the cavity......, in contrast to dispersion compensation schemes used in previous demonstrations of all-polarization maintaining Yb-fiber oscillators. The performance of the saturable absorber mirror modelocked oscillator, that employs a free space scheme for coupling onto the saturable absorber mirror and output coupling...

The rheology of oxide dispersions and the role of concentrated electrolyte solutions

International Nuclear Information System (INIS)

Biggs, Simon; Tindley, Amy

2007-01-01

Stability control of particulate dispersions is critical to a wide range of industrial processes. In the UK nuclear industry, significant volumes of waste materials arising from the corrosion products of Magnox fuel rods currently require treatment and storage. The majority of this waste is present as aqueous dispersions of oxide particulates. Treatment of these dispersions will require a variety of unit operations including mobilisation, transport and solid- liquid separation. Typically these processes must operate across a narrow optimal range of pH and the dispersions are, almost without exception, found in complex electrolyte conditions of high overall concentration. Knowledge of the behaviour of oxides in various electrolyte conditions and over a large pH range is essential for the efficient design and control of any waste processing approach. The transport properties of particle dispersions are characterised by the rheological properties. It is well known that particle dispersion rheology is strongly influenced by particle-particle interaction forces, and that particle-particle interactions are strongly influenced by adsorbed ions on the particle surfaces. Here we correlate measurements of the shear yield stress and the particle zeta potentials to provide insight as to the role of ions in moderating particle interactions. The zeta potential of model TiO 2 suspensions were determined (Colloidal Dynamics Zeta Probe) over a range of pH for a series of alkali metal halides and quaternary ammonium halides at a range of solution concentrations (0.001 M - 1 M). The results show some surprising co-ion effects at high electrolyte concentrations (>0.5 M) and indicate that even ions generally considered to be indifferent induce a shift in iso-electric point (i.e.p.) which is inferred as being due to specific adsorption of ions. The shear yield stress values of concentrated titania dispersions were measured using a Bohlin C-VOR stress controlled rheometer. The shear

Pollen Forecast and Dispersion Modelling

Science.gov (United States)

Costantini, Monica; Di Giuseppe, Fabio; Medaglia, Carlo Maria; Travaglini, Alessandro; Tocci, Raffaella; Brighetti, M. Antonia; Petitta, Marcello

2014-05-01

The aim of this study is monitoring, mapping and forecast of pollen distribution for the city of Rome using in-situ measurements of 10 species of common allergenic pollens and measurements of PM10. The production of daily concentration maps, associated to a mobile phone app, are innovative compared to existing dedicated services to people who suffer from respiratory allergies. The dispersal pollen is one of the most well-known causes of allergic disease that is manifested by disorders of the respiratory functions. Allergies are the third leading cause of chronic disease and it is estimated that tens millions of people in Italy suffer from it. Recent works reveal that during the last few years there was a progressive increase of affected subjects, especially in urban areas. This situation may depend: on the ability to transport of pollutants, on the ability to react between pollutants and pollen and from a combination of other irritants, existing in densely populated and polluted urban areas. The methodology used to produce maps is based on in-situ measurements time series relative to 2012, obtained from networks of air quality and pollen stations in the metropolitan area of Rome. The monitoring station aerobiological of University of Rome "Tor Vergata" is located at the Department of Biology. The instrument used to pollen monitoring is a volumetric sampler type Hirst (Hirst 1952), Model 2000 VPPS Lanzoni; the data acquisition is carried out as reported in Standard UNI 11008:2004 - "Qualità dell'aria - Metodo di campionamento e conteggio dei granuli pollinici e delle spore fungine aerodisperse" - the protocol that describes the procedure for measuring of the concentration of pollen grains and fungal spores dispersed into the atmosphere, and reported in the "Manuale di gestione e qualità della R.I.M.A" (Travaglini et. al. 2009). All 10 allergenic pollen are monitored since 1996. At Tor Vergata university is also operating a meteorological station (SP2000, CAE

Modelling solute dispersion in periodic heterogeneous porous media: Model benchmarking against intermediate scale experiments

Science.gov (United States)

Majdalani, Samer; Guinot, Vincent; Delenne, Carole; Gebran, Hicham

2018-06-01

This paper is devoted to theoretical and experimental investigations of solute dispersion in heterogeneous porous media. Dispersion in heterogenous porous media has been reported to be scale-dependent, a likely indication that the proposed dispersion models are incompletely formulated. A high quality experimental data set of breakthrough curves in periodic model heterogeneous porous media is presented. In contrast with most previously published experiments, the present experiments involve numerous replicates. This allows the statistical variability of experimental data to be accounted for. Several models are benchmarked against the data set: the Fickian-based advection-dispersion, mobile-immobile, multirate, multiple region advection dispersion models, and a newly proposed transport model based on pure advection. A salient property of the latter model is that its solutions exhibit a ballistic behaviour for small times, while tending to the Fickian behaviour for large time scales. Model performance is assessed using a novel objective function accounting for the statistical variability of the experimental data set, while putting equal emphasis on both small and large time scale behaviours. Besides being as accurate as the other models, the new purely advective model has the advantages that (i) it does not exhibit the undesirable effects associated with the usual Fickian operator (namely the infinite solute front propagation speed), and (ii) it allows dispersive transport to be simulated on every heterogeneity scale using scale-independent parameters.

Structured emulsion-based delivery systems: controlling the digestion and release of lipophilic food components.

Science.gov (United States)

McClements, David Julian; Li, Yan

2010-09-15

There is a need for edible delivery systems to encapsulate, protect and release bioactive and functional lipophilic constituents within the food and pharmaceutical industries. These delivery systems could be used for a number of purposes: controlling lipid bioavailability; targeting the delivery of bioactive components within the gastrointestinal tract; and designing food matrices that delay lipid digestion and induce satiety. Emulsion technology is particularly suited for the design and fabrication of delivery systems for lipids. In this article we provide an overview of a number of emulsion-based technologies that can be used as edible delivery systems by the food and other industries, including conventional emulsions, nanoemulsions, multilayer emulsions, solid lipid particles, and filled hydrogel particles. Each of these delivery systems can be produced from food-grade (GRAS) ingredients (e.g., lipids, proteins, polysaccharides, surfactants, and minerals) using relatively simple processing operations (e.g., mixing, homogenizing, and thermal processing). The structure, preparation, and utilization of each type of delivery system for controlling lipid digestion are discussed. This knowledge can be used to select the most appropriate emulsion-based delivery system for specific applications, such as encapsulation, controlled digestion, and targeted release. Copyright 2010 Elsevier B.V. All rights reserved.

Dispersion Distance and the Matter Distribution of the Universe in Dispersion Space.

Science.gov (United States)

Masui, Kiyoshi Wesley; Sigurdson, Kris

2015-09-18

We propose that "standard pings," brief broadband radio impulses, can be used to study the three-dimensional clustering of matter in the Universe even in the absence of redshift information. The dispersion of radio waves as they travel through the intervening plasma can, like redshift, be used as a cosmological distance measure. Because of inhomogeneities in the electron density along the line of sight, dispersion is an imperfect proxy for radial distance and we show that this leads to calculable dispersion-space distortions in the apparent clustering of sources. Fast radio bursts (FRBs) are a new class of radio transients that are the prototypical standard ping and, due to their high observed dispersion, have been interpreted as originating at cosmological distances. The rate of fast radio bursts has been estimated to be several thousand over the whole sky per day and, if cosmological, the sources of these events should trace the large-scale structure of the Universe. We calculate the dispersion-space power spectra for a simple model where electrons and FRBs are biased tracers of the large-scale structure of the Universe, and we show that the clustering signal could be measured using as few as 10 000 events. Such a survey is in line with what may be achieved with upcoming wide-field radio telescopes.

Revealing facts behind spray dried solid dispersion technology used for solubility enhancement

Science.gov (United States)

Patel, Bhavesh B.; Patel, Jayvadan K.; Chakraborty, Subhashis; Shukla, Dali

2013-01-01

Poor solubility and bioavailability of an existing or newly synthesized drug always pose challenge in the development of efficient pharmaceutical formulation. Numerous technologies can be used to improve the solubility and among them amorphous solid dispersion based spray drying technology can be successfully useful for development of product from lab scale to commercial scale with a wide range of powder characteristics. Current review deals with the importance of spray drying technology in drug delivery, basically for solubility and bioavailability enhancement. Role of additives, selection of polymer, effect of process and formulation parameters, scale up optimization, and IVIVC have been covered to gain the interest of readers about the technology. Design of experiment (DoE) to optimize the spray drying process has been covered in the review. A lot more research work is required to evaluate spray drying as a technology for screening the right polymer for solid dispersion, especially to overcome the issue related to drug re-crystallization and to achieve a stable product both in vitro and in vivo. Based on the recent FDA recommendation, the need of the hour is also to adopt Quality by Design approach in the manufacturing process to carefully optimize the spray drying technology for its smooth transfer from lab scale to commercial scale. PMID:27134535

The mean energy loss by neutrino with magnetic moment in strong magnetic field with consideration of positronium contribution to photon dispersion

Science.gov (United States)

Mosichkin, A. F.

2017-11-01

The process of radiative decay of the neutrino with a magnetic moment in a strong magnetic field with consideration of positronium influence on photon dispersion has been studied. Positronium contribution to the photon polarization operator induces significant modifications of the photon dispersion law and neutrino radiative decay amplitude. It has been shown that the mean energy loss of a neutrino with magnetic a moment significantly increases, when the positronium contribution to photon dispersion is taken into account.

Experimental study on full-scale ZrCo and depleted uranium beds applied for fast recovery and delivery of hydrogen isotopes

International Nuclear Information System (INIS)

Kou, Huaqin; Huang, Zhiyong; Luo, Wenhua; Sang, Ge; Meng, Daqiao; Luo, Deli; Zhang, Guanghui; Chen, Hao; Zhou, Ying; Hu, Changwen

2015-01-01

Highlights: • Thin double-layered annulus beds with ZrCo and depleted uranium were fabricated. • Depleted uranium bed delivered 16.41 mol H 2 at rate of 20 Pa m 3 /s within 30 min. • The delivery property of depleted uranium bed was very stable during the 10 cycles. - Abstract: Metal hydride bed is an important component for the deuterium–tritium fusion energy under development in International Thermonuclear Experimental Reactor (ITER), in which the hydrogen recovery and delivery properties are influenced by the bed configuration, operation conditions and the hydrogen storage materials contained in the bed. In this work, a thin double-layered annulus bed configuration was adopted and full-scale beds loaded with ZrCo and depleted uranium (DU) for fast recovery and delivery of hydrogen isotopes were fabricated. The properties of hydrogen recovery/delivery together with the inner structure variation in the fabricated beds were systematically studied. The effects of operation conditions on the performances of the bed were also investigated. It was found that both of the fabricated ZrCo and DU beds were able to achieve the hydrogen storage target of 17.5 mol with fast recovery rate. In addition, experimental results showed that operation of employing extra buffer vessel and scroll pump could not only promote the hydrogen delivery process but also reduce the possibility about disproportionation of ZrCo. Compared with ZrCo bed, DU bed exhibited superior hydrogen delivery performances in terms of fast delivery rate and high hydrogen delivery amount, which could deliver over 16.4 mol H 2 (93.7% of recovery amount) within 30 min at the average delivery rate of 20 Pa m 3 /s. Good reversibility as high as 10 cycles without obvious degradation tendency in both of hydrogen delivery amount and delivery rate for DU bed was also achieved in our study. It was suggested that the fabricated thin double-layered annulus DU bed was a good candidate to rapidly deliver and recover

Normal-dispersion microresonator Kerr frequency combs

Directory of Open Access Journals (Sweden)

Xue Xiaoxiao

2016-06-01

Full Text Available Optical microresonator-based Kerr frequency comb generation has developed into a hot research area in the past decade. Microresonator combs are promising for portable applications due to their potential for chip-level integration and low power consumption. According to the group velocity dispersion of the microresonator employed, research in this field may be classified into two categories: the anomalous dispersion regime and the normal dispersion regime. In this paper, we discuss the physics of Kerr comb generation in the normal dispersion regime and review recent experimental advances. The potential advantages and future directions of normal dispersion combs are also discussed.

Dispersion modeling by kinematic simulation: Cloud dispersion model

International Nuclear Information System (INIS)

Fung, J C H; Perkins, R J

2008-01-01

A new technique has been developed to compute mean and fluctuating concentrations in complex turbulent flows (tidal current near a coast and deep ocean). An initial distribution of material is discretized into any small clouds which are advected by a combination of the mean flow and large scale turbulence. The turbulence can be simulated either by kinematic simulation (KS) or direct numerical simulation. The clouds also diffuse relative to their centroids; the statistics for this are obtained from a separate calculation of the growth of individual clouds in small scale turbulence, generated by KS. The ensemble of discrete clouds is periodically re-discretized, to limit the size of the small clouds and prevent overlapping. The model is illustrated with simulations of dispersion in uniform flow, and the results are compared with analytic, steady state solutions. The aim of this study is to understand how pollutants disperses in a turbulent flow through a numerical simulation of fluid particle motion in a random flow field generated by Fourier modes. Although this homogeneous turbulent is rather a 'simple' flow, it represents a building block toward understanding pollutant dispersion in more complex flow. The results presented here are preliminary in nature, but we expect that similar qualitative results should be observed in a genuine turbulent flow.

An evaluation of dry deposition from the long range atmospheric dispersion

International Nuclear Information System (INIS)

Suh, K.S.; Kim, E.H.; Hwang, W.T.; Han, M.H.; Lee, H.S.; Lee, C.W.

2003-01-01

The dry deposition of pollutants released into the atmosphere must be evaluated to estimate the radiological dose of terrestrial plants and foodstuffs in the ecosystem. Especially, the atmospheric dispersion and dry deposition models have been widely developed to predict and minimize the radiological damage for the surrounding environment after the TMI-2 and the Chernobyl accidents. A Lagrangian particle model for the evaluation the long-range dispersion has been firstly developed in Korea since 2001. The particle tracking method was used for the estimation of the concentration distribution of the radioactive materials released into the atmosphere. The model is designed to estimate air concentration and ground deposition at distances up to some thousands of kilometers from the source point in the horizontal direction. The turbulent motion is considered to separate the treatment of particles within the mixing layer and above the mixing layer. Also, the dispersion model is designed to receive the results of the MM5 model being operated by KMA (Korea Meteorological Administration). The test run of the long-range dispersion model has been performed in the area which covered extends from 102.47deg E to 173.34deg E and from 12.27deg N to 53.72deg N in Northeast Asia. The release point of Cs-137 assumed in the east part of the China. The long range dispersion model has been firstly developed to estimate the radiological consequences against a nuclear accident. The model will be supplemented by the comparative study using the data of the ETEX experiments. (author)

Core–shell composite particles composed of biodegradable polymer particles and magnetic iron oxide nanoparticles for targeted drug delivery

Energy Technology Data Exchange (ETDEWEB)

Oka, Chiemi; Ushimaru, Kazunori [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Horiishi, Nanao [Bengala Techno Laboratory, 9-5-1006, 1-1 Kodai, Miyamae-ku, Kawasaki 216-0007 (Japan); Tsuge, Takeharu [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Kitamoto, Yoshitaka, E-mail: kitamoto.y.aa@m.titech.ac.jp [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan)

2015-05-01

Core–shell composite particles with biodegradability and superparamagnetic behavior were prepared using a Pickering emulsion for targeted drug delivery based on magnetic guidance. The composite particles were composed of a core of biodegradable polymer and a shell of assembled magnetic iron oxide nanoparticles. It was found that the dispersibility of the nanoparticles is crucial for controlling the core–shell structure. The addition of a small amount of dispersant into the nanoparticle's suspension could improve the dispersibility and led to the formation of composite particles with a thin magnetic shell covering a polymeric core. The composite particles were also fabricated with a model drug loaded into the core, which was released via hydrolysis of the core under strong alkaline conditions. Because the core can also be biodegraded by lipase, this result suggests that the slow release of the drug from the composite particles should occur inside the body. - Highlights: • Core−shell composites with biodegradability and magnetism are prepared. • O/W emulsion stabilized by iron oxide nanoparticles is utilized for the preparation. • The nanoparticle's dispersibility is crucial for controlling the composite structure. • Composites loading a model drug are also prepared. • The model drug is released with decomposition of the composites.

Field Evaluation of Medium-Duty Plug-in Electric Delivery Trucks

Energy Technology Data Exchange (ETDEWEB)

Prohaska, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States); Simpson, Mike [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ragatz, Adam [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kelly, Kenneth [National Renewable Energy Lab. (NREL), Golden, CO (United States); Smith, Kandler [National Renewable Energy Lab. (NREL), Golden, CO (United States); Walkowicz, Kevin [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-12-01

This report focuses on medium-duty electric delivery vehicles operated by Frito-Lay North America (FLNA) at its Federal Way, Washington, distribution center. The 100% electric drive system is an alternative to conventional diesel delivery trucks and reduces both energy consumption and carbon dioxide (CO2) emissions. The vehicles' drive cycles and operation are analyzed and compared to demonstrate the importance of matching specific electric vehicle (EV) technologies to the appropriate operational duty cycle. The results of this analysis show that the Smith Newton EVs demonstrated a 68% reduction in energy consumption over the data reporting period compared to the conventional diesel vehicles, as well as a 46.4% reduction in CO₂ equivalent emissions based on the local energy generation source. In addition to characterizing the in-use performance of the EVs compared to the conventional diesels, detailed facility load data were collected at the main building power feed as well as from each of the 10 EV chargers to better understand the broader implications associated with commercial EV deployment. These facility loads were incorporated into several modeling scenarios to demonstrate the potential benefits of integrating onsite renewables.

Sonographic prediction of outcome of vacuum deliveries

DEFF Research Database (Denmark)

Kahrs, Birgitte H; Usman, Sana; Ghi, Tullio

2017-01-01

of vacuum extraction in relation to ultrasound measured head-perineum distance with a predefined cut-off of 25 mm, and 220 women were needed to discriminate between groups using a hazard ratio of 1.5 with 80% power and alpha 5%. Secondary outcomes were delivery mode and umbilical artery cord blood samples...... outcome in nulliparous women with prolonged second stage of labor. STUDY DESIGN: We performed a prospective cohort study in nulliparous women at term with prolonged second stage of labor in 7 European maternity units from 2013 through 2016. Fetal head position and station were determined using...... after birth. The time interval was evaluated using survival analyses, and the outcomes of delivery were evaluated using receiver operating characteristic curves and descriptive statistics. Results were analyzed according to intention to treat. RESULTS: The study population comprised 222 women...

Outcome of deliveries in healthy but obese women: obesity and delivery outcome

Directory of Open Access Journals (Sweden)

Kaplan-Sturk Rebecka

2013-02-01

Full Text Available Abstract Background Obesity among fertile women is a global problem. 25% of pregnant Swedish women are overweight at admission to the antenatal clinic and 12% of them are considered as obese. Previous studies have shown an increased risk of delivery complications with an elevated maternal BMI. The aim of this study was to evaluate delivery outcomes in relation to maternal BMI on admission to the antenatal clinic. A healthy group of 787 women with full-term pregnancies and spontaneous onset of labor were included in the study. Delivery outcome was assessed in relation to maternal BMI when attending the antenatal clinic. Results The results indicated that in deliveries where the maternal BMI was >30 a high frequency of abnormal CTG trace during the last 30 minutes of labor was shown. A blood sample for evaluation of risk of fetal hypoxia was performed in only eight percent of these deliveries. A spontaneous vaginal delivery without intervention was noted in 85.7%, and 12% of neonates were delivered with an adverse fetal outcome compared to 2.8% in the group with a maternal BMI Conclusion These results indicate an increased risk at delivery for healthy, but obese women in labor. Furthermore, the delivery management may not always be optimal in these deliveries.

Contributions of Women to U.S. Combat Operations

National Research Council Canada - National Science Library

Burnes, Thresa

2008-01-01

.... combat operations from the Revolutionary War to present-day conflicts. The U.S. military continues to fight a transnational, dispersed enemy that employs irregular tactics and asymmetric warfare...

Timing of delivery after external cephalic version and the risk for cesarean delivery.

Science.gov (United States)

Kabiri, Doron; Elram, Tamar; Aboo-Dia, Mushira; Elami-Suzin, Matan; Elchalal, Uriel; Ezra, Yossef

2011-08-01

To estimate the association between time of delivery after external cephalic version at term and the risk for cesarean delivery. This retrospective cohort study included all successful external cephalic versions performed in a tertiary center between January 1997 and January 2010. Stepwise logistic regression was used to calculate the odds ratio (OR) for cesarean delivery. We included 483 external cephalic versions in this study, representing 53.1% of all external cephalic version attempts. The incidence of cesarean delivery for 139 women (29%) who gave birth less than 96 hours from external cephalic version was 16.5%; for 344 women (71%) who gave birth greater than 96 hours from external cephalic version, the incidence of cesarean delivery was 7.8% (P = .004). The adjusted OR for cesarean delivery was 2.541 (95% confidence interval 1.36-4.72). When stratified by parity, the risk for cesarean delivery when delivery occurred less than 96 hours after external cephalic version was 2.97 and 2.28 for nulliparous and multiparous women, respectively. Delivery at less than 96 hours after successful external cephalic version was associated with an increased risk for cesarean delivery. III.

UV curable aqueous dispersions for wood coatings

International Nuclear Information System (INIS)

Peeters, S.; Bleus, J.P.; Wang, Z.J.; Arceneaux, J. A.; Hall, J.

1999-01-01

In this paper the characterisation of aqueous dispersions of UV curable resins is described. Two types of dispersions were used: dispersions that are tacky after water evaporation and tack - free before cure dispersions. The physical and rheological properties of these products have been determined and the performance of these dispersions in various formulations, especially for wood applications has been studied. With these dispersions, it is possible to produce coatings having a good cure speed, good surface hardness and good solvent -, chemical - and water resistance