Weighted Flow Algorithms (WFA) for stochastic particle coagulation

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

DeVille, R.E.L., E-mail: rdeville@illinois.edu; Riemer, N., E-mail: nriemer@illinois.edu; West, M., E-mail: mwest@illinois.edu

2011-09-20

Stochastic particle-resolved methods are a useful way to compute the time evolution of the multi-dimensional size distribution of atmospheric aerosol particles. An effective approach to improve the efficiency of such models is the use of weighted computational particles. Here we introduce particle weighting functions that are power laws in particle size to the recently-developed particle-resolved model PartMC-MOSAIC and present the mathematical formalism of these Weighted Flow Algorithms (WFA) for particle coagulation and growth. We apply this to an urban plume scenario that simulates a particle population undergoing emission of different particle types, dilution, coagulation and aerosol chemistry along a Lagrangianmore » trajectory. We quantify the performance of the Weighted Flow Algorithm for number and mass-based quantities of relevance for atmospheric sciences applications.« less

Weighted Flow Algorithms (WFA) for stochastic particle coagulation

NASA Astrophysics Data System (ADS)

DeVille, R. E. L.; Riemer, N.; West, M.

2011-09-01

Stochastic particle-resolved methods are a useful way to compute the time evolution of the multi-dimensional size distribution of atmospheric aerosol particles. An effective approach to improve the efficiency of such models is the use of weighted computational particles. Here we introduce particle weighting functions that are power laws in particle size to the recently-developed particle-resolved model PartMC-MOSAIC and present the mathematical formalism of these Weighted Flow Algorithms (WFA) for particle coagulation and growth. We apply this to an urban plume scenario that simulates a particle population undergoing emission of different particle types, dilution, coagulation and aerosol chemistry along a Lagrangian trajectory. We quantify the performance of the Weighted Flow Algorithm for number and mass-based quantities of relevance for atmospheric sciences applications.

Preliminary Sizing Completed for Single- Stage-To-Orbit Launch Vehicles Powered By Rocket-Based Combined Cycle Technology

NASA Technical Reports Server (NTRS)

Roche, Joseph M.

2002-01-01

Single-stage-to-orbit (SSTO) propulsion remains an elusive goal for launch vehicles. The physics of the problem is leading developers to a search for higher propulsion performance than is available with all-rocket power. Rocket-based combined cycle (RBCC) technology provides additional propulsion performance that may enable SSTO flight. Structural efficiency is also a major driving force in enabling SSTO flight. Increases in performance with RBCC propulsion are offset with the added size of the propulsion system. Geometrical considerations must be exploited to minimize the weight. Integration of the propulsion system with the vehicle must be carefully planned such that aeroperformance is not degraded and the air-breathing performance is enhanced. Consequently, the vehicle's structural architecture becomes one with the propulsion system architecture. Geometrical considerations applied to the integrated vehicle lead to low drag and high structural and volumetric efficiency. Sizing of the SSTO launch vehicle (GTX) is itself an elusive task. The weight of the vehicle depends strongly on the propellant required to meet the mission requirements. Changes in propellant requirements result in changes in the size of the vehicle, which in turn, affect the weight of the vehicle and change the propellant requirements. An iterative approach is necessary to size the vehicle to meet the flight requirements. GTX Sizer was developed to do exactly this. The governing geometry was built into a spreadsheet model along with scaling relationships. The scaling laws attempt to maintain structural integrity as the vehicle size is changed. Key aerodynamic relationships are maintained as the vehicle size is changed. The closed weight and center of gravity are displayed graphically on a plot of the synthesized vehicle. In addition, comprehensive tabular data of the subsystem weights and centers of gravity are generated. The model has been verified for accuracy with finite element analysis. The final trajectory was rerun using OTIS (Boeing Corporation's trajectory optimization software package), and the sizing output was incorporated into a solid model of the vehicle using PRO/Engineer computer-aided design software (Parametric Technology Corporation, Waltham, MA).

Benefits of Group Living Include Increased Feeding Efficiency and Lower Mass Loss during Desiccation in the Social and Inbreeding Spider Stegodyphus dumicola

PubMed Central

Vanthournout, Bram; Greve, Michelle; Bruun, Anne; Bechsgaard, Jesper; Overgaard, Johannes; Bilde, Trine

2016-01-01

Group living carries a price: it inherently entails increased competition for resources and reproduction, and may also be associated with mating among relatives, which carries costs of inbreeding. Nonetheless, group living and sociality is found in many animals, and understanding the direct and indirect benefits of cooperation that override the inherent costs remains a challenge in evolutionary ecology. Individuals in groups may benefit from more efficient management of energy or water reserves, for example in the form of reduced water or heat loss from groups of animals huddling, or through reduced energy demands afforded by shared participation in tasks. We investigated the putative benefits of group living in the permanently social spider Stegodyphus dumicola by comparing the effect of group size on standard metabolic rate, lipid/protein content as a body condition measure, feeding efficiency, per capita web investment, and weight/water loss and survival during desiccation. Because energetic expenditure is temperature sensitive, some assays were performed under varying temperature conditions. We found that feeding efficiency increased with group size, and the rate of weight loss was higher in solitary individuals than in animals in groups of various sizes during desiccation. Interestingly, this was not translated into differences in survival or in standard metabolic rate. We did not detect any group size effects for other parameters, and group size effects did not co-vary with experimental temperature in a predictive manner. Both feeding efficiency and mass loss during desiccation are relevant ecological factors as the former results in lowered predator exposure time, and the latter benefits social spiders which occupy arid, hot environments. PMID:26869936

Resonant mode controllers for launch vehicle applications

NASA Technical Reports Server (NTRS)

Schreiner, Ken E.; Roth, Mary Ellen

1992-01-01

Electro-mechanical actuator (EMA) systems are currently being investigated for the National Launch System (NLS) as a replacement for hydraulic actuators due to the large amount of manpower and support hardware required to maintain the hydraulic systems. EMA systems in weight sensitive applications, such as launch vehicles, have been limited to around 5 hp due to system size, controller efficiency, thermal management, and battery size. Presented here are design and test data for an EMA system that competes favorably in weight and is superior in maintainability to the hydraulic system. An EMA system uses dc power provided by a high energy density bipolar lithium thionyl chloride battery, with power conversion performed by low loss resonant topologies, and a high efficiency induction motor controlled with a high performance field oriented controller to drive a linear actuator.

The behavior of nanosatellite body materials during electromagnetic launch

NASA Astrophysics Data System (ADS)

Gerasimov, Yu V.; Konstantinova, I. A.; Konstantinova, L. A.; Rakhimov, R. G.; Selivanov, A. B.

2017-11-01

Current development of aerospace technology and demands for the economic feasibility have led to a reduction in weight and size characteristics of the on-board electronics and other on-board equipment. There is a tendency to use small-scale spacecraft: midi-satellites, mini-satellites, nanosatellites etc. Reducing the weight and size characteristics of the satellites makes electromagnetic launching techniques more promising compared to traditional methods of sending payload into orbit. Electromagnetic launch does not require expensive space centers - it is cost-efficient, environmentally friendly and enables frequent low-cost launches.

Low molecular weight chitosan conjugated with folate for siRNA delivery in vitro: optimization studies

PubMed Central

Fernandes, Julio C; Qiu, Xingping; Winnik, Francoise M; Benderdour, Mohamed; Zhang, Xiaoling; Dai, Kerong; Shi, Qin

2012-01-01

The low transfection efficiency of chitosan is one of its drawbacks as a gene delivery carrier. Low molecular weight chitosan may help to form small-sized polymer-DNA or small interfering RNA (siRNA) complexes. Folate conjugation may improve gene transfection efficiency because of the promoted uptake of folate receptor-bearing cells. In the present study, chitosan was conjugated with folate and investigated for its efficacy as a delivery vector for siRNA in vitro. We demonstrate that the molecular weight of chitosan has a major influence on its biological and physicochemical properties, and very low molecular weight chitosan (below 10 kDa) has difficulty in forming stable complexes with siRNA. In this study, chitosan 25 kDa and 50 kDa completely absorbed siRNA and formed nanoparticles (≤220 nm) at a chitosan to siRNA weight ratio of 50:1. The introduction of a folate ligand onto chitosan decreased nanoparticle toxicity. Compared with chitosan-siRNA, folate-chitosan-siRNA nanoparticles improved gene silencing transfection efficiency. Therefore, folate-chitosan shows potential as a viable candidate vector for safe and efficient siRNA delivery. PMID:23209368

A High-efficiency, Small, Solid-state Laser for Pyrotechnic Ignition

NASA Technical Reports Server (NTRS)

Yang, L. C.; Menichelli, V. J.

1973-01-01

A completely self-contained, small, neodymium laser has been designed and demonstrated for use in a pyrotechnic ignition system. A nominal 16 J of laser energy (1.06 micron wavelength, 1-ms duration) was achieved in a rectangular 10.5-X 15.1-X 25.4-cm package weighting 5.14 kg. This high energy-to-weight ratio is encouraging for laser applications in which specific energy efficiency (energy per unit weight or volume) is important. The laser design concepts are described, and some results on pyrotechnic ignition are given. Some details on a laser currently under construction, which will be 1/8 the size of the above laser, are included.

Genetic determinism of bone and mineral metabolism in meat-type chickens: A QTL mapping study.

PubMed

Mignon-Grasteau, Sandrine; Chantry-Darmon, Céline; Boscher, Marie-Yvonne; Sellier, Nadine; Chabault-Dhuit, Marie; Le Bihan-Duval, Elisabeth; Narcy, Agnès

2016-12-01

Skeletal integrity in meat-type chickens is affected by many factors including rapid growth rate, nutrition and genetics. To investigate the genetic basis of bone and mineral metabolism, a QTL detection study was conducted in an intercross between two lines of meat-type chickens divergently selected for their high (D +) or low (D -) digestive efficiency. Tibia size (length, diameter, volume) and ash content were determined at 3 weeks of age as well as phosphorus (P) retention and plasma concentration. Heritability of these traits and their genetic correlations with digestive efficiency were estimated. A QTL mapping study was performed using 3379 SNP markers. Tibia size, weight, ash content and breaking strength were highly heritable (0.42 to 0.61). Relative tibia diameter and volume as well as P retention were strongly and positively genetically correlated with digestive efficiency (0.57 to 0.80). A total of 35 QTL were identified (9 for tibia weight, 13 for tibia size, 5 for bone strength, 5 for bone mineralization, 2 for plasma P concentration and 1 for P retention). Six QTL were genome-wide significant, and 3 QTL for tibia relative volume, weight and ash weight on chromosome 6 were fixed, the positive allele coming from the D-line. For two QTL for ash content on chromosome 18 and relative tibia length on chromosome 26, the confidence intervals were small enough to identify potential candidate genes. These findings support the evidence of multiple genetic loci controlling bone and mineral metabolism. The identification of candidate genes may provide new perspectives in the understanding of bone regulation, even beyond avian species.

Production of stocker-size hybrid tilapia in an outdoor biofloc production system

USDA-ARS?s Scientific Manuscript database

Production efficiency per unit volume of water can be improved when stocking rate is adjusted to allow rapid growth of the culture organism to the desired target weight. Fingerlings often are grown to stocker size (ca. 100-150 g/fish) at high stocking rates and then the population is thinned to allo...

Design of pilot studies to inform the construction of composite outcome measures.

PubMed

Edland, Steven D; Ard, M Colin; Li, Weiwei; Jiang, Lingjing

2017-06-01

Composite scales have recently been proposed as outcome measures for clinical trials. For example, the Prodromal Alzheimer's Cognitive Composite (PACC) is the sum of z-score normed component measures assessing episodic memory, timed executive function, and global cognition. Alternative methods of calculating composite total scores using the weighted sum of the component measures that maximize signal-to-noise of the resulting composite score have been proposed. Optimal weights can be estimated from pilot data, but it is an open question how large a pilot trial is required to calculate reliably optimal weights. In this manuscript, we describe the calculation of optimal weights, and use large-scale computer simulations to investigate the question of how large a pilot study sample is required to inform the calculation of optimal weights. The simulations are informed by the pattern of decline observed in cognitively normal subjects enrolled in the Alzheimer's Disease Cooperative Study (ADCS) Prevention Instrument cohort study, restricting to n=75 subjects age 75 and over with an ApoE E4 risk allele and therefore likely to have an underlying Alzheimer neurodegenerative process. In the context of secondary prevention trials in Alzheimer's disease, and using the components of the PACC, we found that pilot studies as small as 100 are sufficient to meaningfully inform weighting parameters. Regardless of the pilot study sample size used to inform weights, the optimally weighted PACC consistently outperformed the standard PACC in terms of statistical power to detect treatment effects in a clinical trial. Pilot studies of size 300 produced weights that achieved near-optimal statistical power, and reduced required sample size relative to the standard PACC by more than half. These simulations suggest that modestly sized pilot studies, comparable to that of a phase 2 clinical trial, are sufficient to inform the construction of composite outcome measures. Although these findings apply only to the PACC in the context of prodromal AD, the observation that weights only have to approximate the optimal weights to achieve near-optimal performance should generalize. Performing a pilot study or phase 2 trial to inform the weighting of proposed composite outcome measures is highly cost-effective. The net effect of more efficient outcome measures is that smaller trials will be required to test novel treatments. Alternatively, second generation trials can use prior clinical trial data to inform weighting, so that greater efficiency can be achieved as we move forward.

Preliminary Assessment of Variable Speed Power Turbine Technology on Civil Tiltrotor Size and Performance

NASA Technical Reports Server (NTRS)

Snyder, Christopher A.; Acree, Cecil W., Jr.

2012-01-01

A Large Civil Tiltrotor (LCTR) conceptual design was developed as part of the NASA Heavy Lift Rotorcraft Systems Investigation in order to establish a consistent basis for evaluating the benefits of advanced technology for large tiltrotors. The concept has since evolved into the second-generation LCTR2, designed to carry 90 passengers for 1,000 nm at 300 knots, with vertical takeoff and landing capability. This paper performs a preliminary assessment of variable-speed power turbine technology on LCTR2 sizing, while maintaining the same, advanced technology engine core. Six concepts were studied; an advanced, single-speed engine with a conventional power turbine layout (Advanced Conventional Engine, or ACE) using a multi-speed (shifting) gearbox. There were five variable-speed power turbine (VSPT) engine concepts, comprising a matrix of either three or four turbine stages, and fixed or variable guide vanes; plus a minimum weight, twostage, fixed-geometry VSPT. The ACE is the lightest engine, but requires a multi-speed (shifting) gearbox to maximize its fuel efficiency, whereas the VSPT concepts use a lighter, fixed-ratio gearbox. The NASA Design and Analysis of Rotorcraft (NDARC) design code was used to study the trades between rotor and engine efficiency and weight. Rotor performance was determined by Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II), and engine performance was estimated with the Numerical Propulsion System Simulation (NPSS). Design trades for the ACE vs. VSPT are presented in terms of vehicle gross and empty weight, propulsion system weight and mission fuel burn for the civil mission. Because of its strong effect on gearbox weight and on both rotor and engine efficiency, rotor speed was chosen as the reference design variable for comparing design trades. Major study assumptions are presented and discussed. Impressive engine power-to-weight and fuel efficiency reduced vehicle sensitivity to propulsion system choice. The 10% weight penalty for multi-speed gearbox was more significant than most engine technology weight penalties to the vehicle design because drive system weight is more than two times engine weight. Based on study assumptions, fixed-geometry VSPT concept options performed better than their variable-geometry counterparts. Optimum design gross weights varied 1% or less and empty weights less than 2% among the concepts studied, while optimum fuel burns varied up to 5%. The outcome for some optimum configurations was so unexpected as to recommend a deeper look at the underlying technology assumptions.

A feature-weighting account of priming in conjunction search.

PubMed

Becker, Stefanie I; Horstmann, Gernot

2009-02-01

Previous research on the priming effect in conjunction search has shown that repeating the target and distractor features across displays speeds mean response times but does not improve search efficiency: Repetitions do not reduce the set size effect-that is, the effect of the number of distractor items-but only modulate the intercept of the search function. In the present study, we investigated whether priming modulates search efficiency when a conjunctively defined target randomly changes between red and green. The results from an eyetracking experiment show that repeating the target across trials reduced the set size effect and, thus, did enhance search efficiency. Moreover, the probability of selecting the target as the first item in the display was higher when the target-distractor displays were repeated across trials than when they changed. Finally, red distractors were selected more frequently than green distractors when the previous target had been red (and vice versa). Taken together, these results indicate that priming in conjunction search modulates processes concerned with guiding attention to the target, by assigning more attentional weight to features sharing the previous target's color.

Right sizing prevention. Food portion size effects on children's eating and weight.

PubMed

Birch, Leann L; Savage, Jennifer S; Fisher, Jennifer Orlet

2015-05-01

Experimental findings provide consistent evidence that increasing the portion size of palatable, energy dense entrees relative to an age appropriate reference portion increases children's energy intake of the entree and the meal. Most of these studies have been conducted on preschool aged children between 2 and 6 years of age, in childcare or laboratory settings, using repeated measures designs. In these studies, children's intake is compared across a series of meals, where the size of the entrée portion is varied and other aspects of the meal, including the portion size of other items on the menu, are held constant. This paper provides an overview of what we know from this research, what is not known about the effects of portion size on children's intake and weight status, and points to some of the important unanswered questions and gaps in the literature. Lastly, we discuss how individual characteristics may make someone more or less susceptible to large portions of foods and how the palatability of foods may moderate observed associations among portion size, children's intake, and weight status. Future studies that address the gaps identified in this paper are needed to inform policy and to develop effective and efficient interventions to prevent childhood obesity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Parametric Weight Comparison of Advanced Metallic, Ceramic Tile, and Ceramic Blanket Thermal Protection Systems

NASA Technical Reports Server (NTRS)

Myers, David E.; Martin, Carl J.; Blosser, Max L.

2000-01-01

A parametric weight assessment of advanced metallic panel, ceramic blanket, and ceramic tile thermal protection systems (TPS) was conducted using an implicit, one-dimensional (I-D) finite element sizing code. This sizing code contained models to account for coatings fasteners, adhesives, and strain isolation pads. Atmospheric entry heating profiles for two vehicles, the Access to Space (ATS) vehicle and a proposed Reusable Launch Vehicle (RLV), were used to ensure that the trends were not unique to a certain trajectory. Ten TPS concepts were compared for a range of applied heat loads and substructural heat capacities to identify general trends. This study found the blanket TPS concepts have the lightest weights over the majority of their applicable ranges, and current technology ceramic tiles and metallic TPS concepts have similar weights. A proposed, state-of-the-art metallic system which uses a higher temperature alloy and efficient multilayer insulation was predicted to be significantly lighter than the ceramic tile stems and approaches blanket TPS weights for higher integrated heat loads.

Improved drug loading and antibacterial activity of minocycline-loaded PLGA nanoparticles prepared by solid/oil/water ion pairing method.

PubMed

Kashi, Tahereh Sadat Jafarzadeh; Eskandarion, Solmaz; Esfandyari-Manesh, Mehdi; Marashi, Seyyed Mahmoud Amin; Samadi, Nasrin; Fatemi, Seyyed Mostafa; Atyabi, Fatemeh; Eshraghi, Saeed; Dinarvand, Rassoul

2012-01-01

Low drug entrapment efficiency of hydrophilic drugs into poly(lactic-co-glycolic acid) (PLGA) nanoparticles is a major drawback. The objective of this work was to investigate different methods of producing PLGA nanoparticles containing minocycline, a drug suitable for periodontal infections. Different methods, such as single and double solvent evaporation emulsion, ion pairing, and nanoprecipitation were used to prepare both PLGA and PEGylated PLGA nanoparticles. The resulting nanoparticles were analyzed for their morphology, particle size and size distribution, drug loading and entrapment efficiency, thermal properties, and antibacterial activity. The nanoparticles prepared in this study were spherical, with an average particle size of 85-424 nm. The entrapment efficiency of the nanoparticles prepared using different methods was as follows: solid/oil/water ion pairing (29.9%) > oil/oil (5.5%) > water/oil/water (4.7%) > modified oil/water (4.1%) > nano precipitation (0.8%). Addition of dextran sulfate as an ion pairing agent, acting as an ionic spacer between PEGylated PLGA and minocycline, decreased the water solubility of minocycline, hence increasing the drug entrapment efficiency. Entrapment efficiency was also increased when low molecular weight PLGA and high molecular weight dextran sulfate was used. Drug release studies performed in phosphate buffer at pH 7.4 indicated slow release of minocycline from 3 days to several weeks. On antibacterial analysis, the minimum inhibitory concentration and minimum bactericidal concentration of nanoparticles was at least two times lower than that of the free drug. Novel minocycline-PEGylated PLGA nanoparticles prepared by the ion pairing method had the best drug loading and entrapment efficiency compared with other prepared nanoparticles. They also showed higher in vitro antibacterial activity than the free drug.

Improved drug loading and antibacterial activity of minocycline-loaded PLGA nanoparticles prepared by solid/oil/water ion pairing method

PubMed Central

Kashi, Tahereh Sadat Jafarzadeh; Eskandarion, Solmaz; Esfandyari-Manesh, Mehdi; Marashi, Seyyed Mahmoud Amin; Samadi, Nasrin; Fatemi, Seyyed Mostafa; Atyabi, Fatemeh; Eshraghi, Saeed; Dinarvand, Rassoul

2012-01-01

Background Low drug entrapment efficiency of hydrophilic drugs into poly(lactic-co-glycolic acid) (PLGA) nanoparticles is a major drawback. The objective of this work was to investigate different methods of producing PLGA nanoparticles containing minocycline, a drug suitable for periodontal infections. Methods Different methods, such as single and double solvent evaporation emulsion, ion pairing, and nanoprecipitation were used to prepare both PLGA and PEGylated PLGA nanoparticles. The resulting nanoparticles were analyzed for their morphology, particle size and size distribution, drug loading and entrapment efficiency, thermal properties, and antibacterial activity. Results The nanoparticles prepared in this study were spherical, with an average particle size of 85–424 nm. The entrapment efficiency of the nanoparticles prepared using different methods was as follows: solid/oil/water ion pairing (29.9%) > oil/oil (5.5%) > water/oil/water (4.7%) > modified oil/water (4.1%) > nano precipitation (0.8%). Addition of dextran sulfate as an ion pairing agent, acting as an ionic spacer between PEGylated PLGA and minocycline, decreased the water solubility of minocycline, hence increasing the drug entrapment efficiency. Entrapment efficiency was also increased when low molecular weight PLGA and high molecular weight dextran sulfate was used. Drug release studies performed in phosphate buffer at pH 7.4 indicated slow release of minocycline from 3 days to several weeks. On antibacterial analysis, the minimum inhibitory concentration and minimum bactericidal concentration of nanoparticles was at least two times lower than that of the free drug. Conclusion Novel minocycline-PEGylated PLGA nanoparticles prepared by the ion pairing method had the best drug loading and entrapment efficiency compared with other prepared nanoparticles. They also showed higher in vitro antibacterial activity than the free drug. PMID:22275837

Preparation of a nano emodin transfersome and study on its anti-obesity mechanism in adipose tissue of diet-induced obese rats

PubMed Central

2014-01-01

Objective To describe the preparation of nano emodin transfersome (NET) and investigate its effect on mRNA expression of adipose triglyceride lipase (ATGL) and G0/G1 switch gene 2 (G0S2) in adipose tissue of diet-induced obese rats. Methods NET was prepared by film-ultrasonic dispersion method. The effects of emodin components at different ratios on encapsulation efficiency were investigated.The NET envelopment rate was determined by ultraviolet spectrophotometry. The particle size and Zeta potential of NET were evaluated by Zetasizer analyzer. Sixty male SD rats were assigned to groups randomly. After 8-week treatment, body weight, wet weight of visceral fat and the percentage of body fat (PBF) were measured. Fasting blood glucose and serum lipid levels were determined. The adipose tissue section was HE stained, and the cellular diameter and quantity of adipocytes were evaluated by light microscopy. The mRNA expression of ATGL and G0S2 from the peri-renal fat tissue was assayed by RT-PCR. Results The appropriate formulation was deoxycholic acid sodium salt vs. phospholipids 1:8, cholesterol vs. phospholipids 1:3, vitamin Evs. phospholipids 1:20, and emodin vs. phospholipid 1:6. Zeta potential was −15.11 mV, and the particle size was 292.2 nm. The mean encapsulation efficiency was (69.35 ± 0.25)%. Compared with the obese model group, body weight, wet weight of visceral fat, PBF and mRNA expression of G0S2 from peri-renal fat tissue were decreased significantly after NET treatment (all P < 0.05), while high-density lipoprotein cholesterol (HDL-C), the diameter of adipocytes and mRNA expression of ATGL from peri-renal fat tissue were increased significantly (all P < 0.05). Conclusion The preparation method is simple and reasonable. NET with negative electricity was small and uniform in particle size, with high encapsulation efficiency and stability. NET could reduce body weight and adipocyte size, and this effect was associated with the up-regulation of ATGL, down-regulation of G0S2 expression in the adipose tissue, and improved insulin sensitivity. PMID:24641917

Average weighted receiving time on the non-homogeneous double-weighted fractal networks

NASA Astrophysics Data System (ADS)

Ye, Dandan; Dai, Meifeng; Sun, Yu; Su, Weiyi

2017-05-01

In this paper, based on actual road networks, a model of the non-homogeneous double-weighted fractal networks is introduced depending on the number of copies s and two kinds of weight factors wi ,ri(i = 1 , 2 , … , s) . The double-weights represent the capacity-flowing weights and the cost-traveling weights, respectively. Denote by wijF the capacity-flowing weight connecting the nodes i and j, and denote by wijC the cost-traveling weight connecting the nodes i and j. Let wijF be related to the weight factors w1 ,w2 , … ,ws, and let wijC be related to the weight factors r1 ,r2 , … ,rs. Assuming that the walker, at each step, starting from its current node, moves to any of its neighbors with probability proportional to the capacity-flowing weight of edge linking them. The weighted time for two adjacency nodes is the cost-traveling weight connecting the two nodes. The average weighted receiving time (AWRT) is defined on the non-homogeneous double-weighted fractal networks. AWRT depends on the relationships of the number of copies s and two kinds of weight factors wi ,ri(i = 1 , 2 , … , s) . The obtained remarkable results display that in the large network, the AWRT grows as a power-law function of the network size Ng with the exponent, represented by θ =logs(w1r1 +w2r2 + ⋯ +wsrs) < 1 when w1r1 +w2r2 + ⋯ +wsrs ≠ 1, which means that the smaller the value of w1r1 +w2r2 + ⋯ +wsrs is, the more efficient the process of receiving information is. Especially when w1r1 +w2r2 + ⋯ +wsrs = 1, AWRT grows with increasing order Ng as logNg or (logNg) 2 . In the classic fractal networks, the average receiving time (ART) grows with linearly with the network size Ng. Thus, the non-homogeneous double-weighted fractal networks are more efficient than classic fractal networks in term of receiving information.

Effect of nano/micro B4C and SiC particles on fracture properties of aluminum 7075 particulate composites under chevron-notch plane strain fracture toughness test

NASA Astrophysics Data System (ADS)

Morovvati, M. R.; Lalehpour, A.; Esmaeilzare, A.

2016-12-01

Reinforcing aluminum with SiC and B4C nano/micro particles can lead to a more efficient material in terms of strength and light weight. The influence of adding these particles to an aluminum 7075 matrix is investigated using chevron-notch fracture toughness test method. The reinforcing factors are type, size (micro/nano), and weight percent of the particles. The fracture parameters are maximum load, notch opening displacement, the work up to fracture and chevron notch plane strain fracture toughness. The findings demonstrate that addition of micro and nano size particles improves the fracture properties; however, increasing the weight percent of the particles leads to increase of fracture properties up to a certain level and after that due to agglomeration of the particles, the improvement does not happen for both particle types and size categories. Agglomeration of particles at higher amounts of reinforcing particles results in improper distribution of particles and reduction in mechanical properties.

Hardware implementation of CMAC neural network with reduced storage requirement.

PubMed

Ker, J S; Kuo, Y H; Wen, R C; Liu, B D

1997-01-01

The cerebellar model articulation controller (CMAC) neural network has the advantages of fast convergence speed and low computation complexity. However, it suffers from a low storage space utilization rate on weight memory. In this paper, we propose a direct weight address mapping approach, which can reduce the required weight memory size with a utilization rate near 100%. Based on such an address mapping approach, we developed a pipeline architecture to efficiently perform the addressing operations. The proposed direct weight address mapping approach also speeds up the computation for the generation of weight addresses. Besides, a CMAC hardware prototype used for color calibration has been implemented to confirm the proposed approach and architecture.

Polyethyleneimine Capped Silver Nanoclusters as Efficient Antibacterial Agents.

PubMed

Xu, Dong; Wang, Qingyun; Yang, Tao; Cao, Jianzhong; Lin, Qinlu; Yuan, Zhiqin; Li, Le

2016-03-18

Development of efficient antibacterial agents is critical for human health. In the present study, we investigated the antibacterial activity of polyethyleneimine (PEI)-capped silver nanoclusters (PEI-AgNCs), based on the fact that nanoclusters normally have higher surface-to-volume ratios than traditional nanomaterials and PEI itself has a strong antimicrobial capacity. We synthesized stable silver nanoclusters by altering PEI molecular weight from 0.6 kDa to 25 kDa and characterized them by UV-Vis absorption and fluorescence spectroscopy and high resolution transmission electron microscopy. The sizes of AgNCs were around 2 nm in diameter and were little influenced by the molecular weight of PEIs. The antibacterial abilities of the four PEI-AgNCs were explored on agar plate and in liquid systems. Our results revealed that the antibacterial activity of PEI-AgNCs is excellent and the reduction of PEI molecular weight could result in the increased antibacterial capacity of PEI-AgNCs. Such proposed new materials might be useful as efficient antibacterial agents in practical clinical applications.

Analyses of the response of a complex weighted network to nodes removal strategies considering links weight: The case of the Beijing urban road system

NASA Astrophysics Data System (ADS)

Bellingeri, Michele; Lu, Zhe-Ming; Cassi, Davide; Scotognella, Francesco

2018-02-01

Complex network response to node loss is a central question in different fields of science ranging from physics, sociology, biology to ecology. Previous studies considered binary networks where the weight of the links is not accounted for. However, in real-world networks the weights of connections can be widely different. Here, we analyzed the response of real-world road traffic complex network of Beijing, the most prosperous city in China. We produced nodes removal attack simulations using classic binary node features and we introduced weighted ranks for node importance. We measured the network functioning during nodes removal with three different parameters: the size of the largest connected cluster (LCC), the binary network efficiency (Bin EFF) and the weighted network efficiency (Weg EFF). We find that removing nodes according to weighted rank, i.e. considering the weight of the links as a number of taxi flows along the roads, produced in general the highest damage in the system. Our results show that: (i) in order to model Beijing road complex networks response to nodes (intersections) failure, it is necessary to consider the weight of the links; (ii) to discover the best attack strategy, it is important to use nodes rank accounting links weight.

Effects of geometric design features on truck crashes on limited-access highways.

DOT National Transportation Integrated Search

2012-06-01

Freight can be transported between most points in the country quite efficiently using trucks. However, involvement of large : trucks in crashes can cause much damage and serious injuries, due to their large sizes and heavy weights. Large truck : cras...

Poly(ethylenimine) conjugated bioreducible dendrimer for efficient gene delivery.

PubMed

Nam, Kihoon; Jung, Simhyun; Nam, Joung-Pyo; Kim, Sung Wan

2015-12-28

Branched poly(ethylenimine) (PEI) 25 kDa is an efficient gene delivery vector with outstanding gene condensation ability and great endosome escape activity. However, it also induces higher cytotoxicity. Transfection efficiency and toxicity of PEI are highly dependent upon their molecular weight and structure. We developed a bioreducible poly(ethylenimine) (PEI (-s-s-)) derived from low molecular weight PEI (1.8 kDa) for efficient gene delivery. Bioreducible core molecule is expected to increase molecular weight and reduce the cytotoxicity of the copolymer. PEI (-s-s-) polyplexes showed higher transfection efficiency and lower cytotoxicity compared to branched PEI 25 kDa, Lipofectamine® 2000 and, FuGENE® 6. In addition, PEI (-s-s-) derivative (16 kDa) formed stable polyplexes with a zeta-potential value of +34 mV and polyplex size of 61 nm. PEI (-s-s-) derivative (16 kDa) showed excellent transfection efficiency: 3.6 times higher than branched PEI 25 kDa in HeLa cells and 7.4 times higher than Lipofectamine® 2000 in H9C2 cell. The derivatives also showed lower cytotoxicity compared with Lipofectamine® 2000 and PEI 25 kDa in various cell types. In addition, newly synthesized PEI (-s-s-) derivatives have high reproducibility. Copyright © 2015 Elsevier B.V. All rights reserved.

Ultra-Efficient and Power Dense Electric Motors for U. S. Industry

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

Melfi, Michael J.; Schiferl, Richard F.; Umans, Stephen D.

2013-03-12

The primary purpose of this project was to combine the ease-of-installation and ease-of-use attributes of industrial induction motors with the low-loss and small size and weight advantages of PM motors to create an ultra-efficient, high power density industrial motor that can be started across-the-line or operated from a standard, Volts/Hertz drive without the need for a rotor position feedback device. PM motor products that are currently available are largely variable speed motors that require a special adjustable speed drive with rotor position feedback. The reduced size and weight helps to offset the magnet cost in order make these motors commerciallymore » viable. The scope of this project covers horsepower ratings from 20 ? 500. Prototypes were built and tested at ratings ranging from 30 to 250 HP. Since fans, pumps and compressors make up a large portion of industrial motor applications, the motor characteristics are tailored to those applications. Also, since there is extensive use of adjustable frequency inverters in these applications, there is the opportunity to design for an optimal pole number and operate at other than 60 Hz frequency when inverters are utilized. Designs with four and eight pole configurations were prototyped as part of this work. Four pole motors are the most commonly used configuration in induction motors today. The results of the prototype design, fabrication, and testing were quite successful. The 50 HP rating met all of the design goals including efficiency and power density. Tested values of motor losses at 50 HP were 30% lower than energy efficient induction motors and the motor weight is 35% lower than the energy efficient induction motor of the same rating. Further, when tested at the 30 HP rating that is normally built in this 286T frame size, the efficiency far exceeds the project design goals with 30 HP efficiency levels indicating a 55% reduction in loss compared to energy efficient motors with a motor weight that is a few percentage points lower than the energy efficient motor. This 30 HP rating full load efficiency corresponds to a 46% reduction in loss compared to a 30 HP NEMA Premium? efficient motor. The cost goals were to provide a two year or shorter efficiency-based payback of a price premium associated with the magnet cost in these motors. That goal is based on 24/7 operation with a cost of electricity of 10 cents per kW-hr. Similarly, the 250 HP prototype efficiency testing was quite successful. In this case, the efficiency was maximized with a slightly less aggressive reduction in active material. The measured full load efficiency of 97.6% represents in excess of a 50% loss reduction compared to the equivalent NEMA Premium Efficiency induction motor. The active material weight reduction was a respectable 14.5% figure. This larger rating demonstrated both the scalability of this technology and also the ability to flexibly trade off power density and efficiency. In terms of starting performance, the 30 ? 50 HP prototypes were very extensively tested. The demonstrated capability included the ability to successfully start a load with an inertia of 25 times the motor?s own inertia while accelerating against a load torque following a fan profile at the motor?s full nameplate power rating. This capability will provide very wide applicability of this motor technology. The 250 HP prototype was also tested for starting characteristics, though without a coupled inertia and load torque. As a result it was not definitively proven that the same 25 times the motor?s own inertia could be started and synchronized successfully at 250 HP. Finite element modeling implies that this load could be successfully started, but it has not yet been confirmed by a test.« less

An autosomal dwarfism in the domestic fowl.

PubMed

Cole, R K

2000-11-01

A mutation in the Cornell K-strain of White Leghorns, first recognized when two adult males in a pedigreed family were definitely smaller than their two other brothers, proved to be an autosomal recessive mutation and gave rise to the autosomal dwarf stock. The effect of this gene (adw) can be recognized during embryonic development and leads to a normal adult, except for a 30% reduction in body weight. Selection for small size, egg production, and egg weight over a period of 15 yr yielded an efficient layer. Production for 11 mo from first egg was at a rate of 70%, with egg weight at 56 g and body weight at 1,160 g at 10 to 11 mo of age, based on data for the last four generations. Viability of the caged hens averaged over 95% for the 13 generations involved. Sexual maturity was delayed by about 2 wk, and good incubation (85+%) required 18+/- more hours than normal. When an autosomal dwarf male is used as a sire and mated to sex-linked dwarf (dw) females, all progeny are of normal size. Compared with problems of mating normal size males with dwarf females, the use of the two types of dwarfism can yield good fertility.

Changes in infant disposable diaper weights at selected intervals post-wetting.

PubMed

Carlisle, Joan; Moore, Amanda; Cooper, Alyssa; Henderson, Terri; Mayfield, Debbie; Taylor, Randa; Thomas, Jennifer; Van Fleet, Laduska; Askanazi, David; Fineberg, Naomi; Sun, Yanhui

2012-01-01

Pediatric acute care nurses questioned the practice of weighing disposable infant diapers immediately after voiding. This study asked the research question, "Does volume of saline, diaper configuration, and/or size of diaper statistically effect changes in diaper weights over time?" The method was an experimental, laboratory model. Pre-set volumes of saline were added to disposable diapers that were then left folded or unfolded. Each diaper was weighed immediately post-wetting and re-weighed at hourly intervals for seven hours. Data were analyzed using a repeated measures analysis of variance (RMANOVA) with balanced data (F-test). Diaper weight changes over time were statistically significant for all time points and for all volumes regardless of diaper size; however, the changes in weight were small and without clinical significance. It is appropriate to weigh diapers at the end of eight hours without risk of altering subsequent fluid management of patients in open-air, non-humidified environments. This practice has led to more efficient use of nurses' time with fewer interruptions for patients and families.

Price of Fairness in Kidney Exchange

DTIC Science & Technology

2014-05-01

solver uses branch-and-price, a technique that proves optimality by in- crementally generating only a small part of the model during tree search [8...factors like fail- ure probability and chain position, as in the probabilistic model ). We will use this multiplicative re-weighting in our experiments in...Table 2 gives the average loss in efficiency for each of these models over multiple generated pool sizes, with 40 runs per pool size per model , under

Parametric Weight Comparison of Current and Proposed Thermal Protection System (TPS) Concepts

NASA Technical Reports Server (NTRS)

Myers, David E.; Martin, Carl J.; Blosser, Max L.

1999-01-01

A parametric weight assessment of advanced metallic panel, ceramic blanket, and ceramic tile thermal protection systems (TPS) was conducted using an implicit, one-dimensional (1 -D) thermal finite element sizing code. This sizing code contained models to ac- count for coatings, fasteners, adhesives, and strain isolation pads. Atmospheric entry heating profiles for two vehicles, the Access to Space (ATS) rocket-powered single-stage-to-orbit (SSTO) vehicle and a proposed Reusable Launch Vehicle (RLV), were used to ensure that the trends were not unique to a particular trajectory. Eight TPS concepts were compared for a range of applied heat loads and substructural heat capacities to identify general trends. This study found the blanket TPS concepts have the lightest weights over the majority of their applicable ranges, and current technology ceramic tiles and metallic TPS concepts have similar weights. A proposed, state-of-the-art metallic system which uses a higher temperature alloy and efficient multilayer insulation was predicted to be significantly lighter than the ceramic tile systems and approaches blanket TPS weights for higher integrated heat loads.

Direct and indirect selection of visceral lipid weight, fillet weight, and fillet percentage in a rainbow trout breeding program.

PubMed

Kause, A; Paananen, T; Ritola, O; Koskinen, H

2007-12-01

We assessed whether visceral lipid weight, fillet weight, and percentage fillet from BW, 3 traits laborious to record, could be genetically improved by indirect selection on more easily measured traits in farmed rainbow trout. Visceral lipid is discarded as waste during slaughter, influencing production efficiency and production costs. Fillet weight and fillet percentage directly influence economic returns in trout production. The study comprised 3 steps. First, we assessed the degree to which selection on percentage of visceral weight from BW indirectly changes visceral lipid weight and the size of intestines and internal organs. The phenotypic analysis of weights of viscera, intestines, visceral lipid, liver, and gonads measured from 40 fish revealed that phenotypic selection against visceral weight was most strongly directed to visceral lipid, and to a lesser degree to intestines and gonads. Because genetic relationships among these traits were not established, it is not known whether indirect selection leads to genetic responses. Second, we examined whether direct selection for the fillet traits could be replaced by indirect selection on BW, eviscerated BW, visceral weight, visceral percentage, head volume, and relative head volume (head volume relative to BW). The selection index calculations based on the quantitative genetic parameters obtained from multigenerational pedigree data showed that genetic improvement of fillet percentage through direct selection (selection accuracy, r(TI) = 0.54) was equally efficient compared with indirect selection on visceral percentage ( r(TI) = 0.54). Genetic improvement of fillet weight through direct selection (r(TI) = 0.56) was always more efficient than indirect selection, yet indirect selection for eviscerated BW ( r(TI) = 0.50) was almost as efficient as direct selection. Third, the expected genetic responses to alternative selection indices showed that improved fillet percentage was mainly a result of a moderate decrease in visceral weight rather than of a major increase in absolute fillet weight. Moreover, fillet percentage is challenging to improve, even if it exhibits moderate heritability (h(2) = 0.29). This is because fillet percentage displays low phenotypic variation. In conclusion, fillet weight and fillet percentage can be increased by indirect selection against visceral percentage and for high eviscerated BW.

Real-time dissolution measurement of sized and unsized calcium phosphate glass fibers.

PubMed

Rinehart, J D; Taylor, T D; Tian, Y; Latour, R A

1999-01-01

The objective of this study was to develop an efficient "real time" measurement system able to directly measure, with microgram resolution, the dissolution rate of absorbable glass fibers, and utilize the system to evaluate the effectiveness of silane-based sizing as a means to delay the fiber dissolution process. The absorbable glass fiber used was calcium phosphate (CaP), with tetramethoxysilane selected as the sizing agent. E-glass fiber was used as a relatively nondegrading control. Both the unsized-CaP and sized-CaP degraded linearly at both the 37 degrees C and 60 degrees C test temperature levels used. No significant decrease in weight-loss rate was recorded when the CaP fiber tows were pretreated, using conventional application methods, with the tetramethoxysilane sizing for either temperature condition. The unsized-CaP and sized-CaP weight loss rates were each significantly higher at 60 than at 37 degrees C (both p < 0.02), as expected from dissolution kinetics. In terms of actual weight loss rate measured using our system for phosphate glass fiber, the unsized-CaP fiber we studied dissolved at a rate of 10.90 x 10(-09) and 41.20 x 10(-09) g/min-cm(2) at 37 degrees C and 60 degrees C, respectively. Considering performance validation of the developed system, the slope of the weight loss vs. time plot for the tested E-glass fiber was not significantly different compared to a slope equal to zero for both test temperatures. Copyright 1999 John Wiley & Sons, Inc.

Effects of Aeration of Sawdust Cultivation Bags on Hyphal Growth of Lentinula edodes.

PubMed

Lee, Hwa-Yong; Ham, Eun-Ju; Yoo, Young-Jin; Kim, Eui-Sung; Shim, Kyu-Kwang; Kim, Myung-Kon; Koo, Chang-Duck

2012-09-01

The effects of aeration through lid filters on the hyphal growth of Lentinula edodes (oak mushroom) in sawdust cultivation bags were investigated. The aeration treatment levels were traditional 27 mm hole cotton plugs, cotton balls and combinations of seven hole sizes × two hole positions (up and under) in the lids covering plastic bags containing 1.4 kg sawdust medium at 63% moisture that had been autoclaved for one hour and inoculated with sawdust spawn of L. edodes strain 921. Aeration treatment effects were measured based on the CO(2) concentration at the 15th wk, as well as the hyphal growth rate and degree of weight loss of bags every 14 days for 15 wk. In bags with traditional cotton plugs, the CO(2) concentration was 3.8 ± 1.3%, daily mean hyphal growth was 2.3 ± 0.6 mm and daily mean weight loss was 0.84 ± 0.26 g. In the bags with 15 mm diameter holes, the CO(2) concentration was 6.0 ± 1.6%, daily hyphal growth was 2.8 ± 0.2 mm and daily weight loss was 0.86 ± 0.4 g. The bags with 15 mm holes had a higher CO(2) concentration and lower water loss than bags with other hole sizes, but the hyphal growth was not significantly different from that of other bags. The weight loss of bags increased proportionally relative to the lid hole sizes. Taken together, these results indicate that traditional cotton plugs are economically efficient, but 15 mm hole lids are the most efficient at maintaining hyphal growth and controlling water loss while allowing CO(2) emissions.

Effects of Aeration of Sawdust Cultivation Bags on Hyphal Growth of Lentinula edodes

PubMed Central

Lee, Hwa-Yong; Ham, Eun-Ju; Yoo, Young-Jin; Kim, Eui-Sung; Shim, Kyu-Kwang; Kim, Myung-Kon

2012-01-01

The effects of aeration through lid filters on the hyphal growth of Lentinula edodes (oak mushroom) in sawdust cultivation bags were investigated. The aeration treatment levels were traditional 27 mm hole cotton plugs, cotton balls and combinations of seven hole sizes × two hole positions (up and under) in the lids covering plastic bags containing 1.4 kg sawdust medium at 63% moisture that had been autoclaved for one hour and inoculated with sawdust spawn of L. edodes strain 921. Aeration treatment effects were measured based on the CO2 concentration at the 15th wk, as well as the hyphal growth rate and degree of weight loss of bags every 14 days for 15 wk. In bags with traditional cotton plugs, the CO2 concentration was 3.8 ± 1.3%, daily mean hyphal growth was 2.3 ± 0.6 mm and daily mean weight loss was 0.84 ± 0.26 g. In the bags with 15 mm diameter holes, the CO2 concentration was 6.0 ± 1.6%, daily hyphal growth was 2.8 ± 0.2 mm and daily weight loss was 0.86 ± 0.4 g. The bags with 15 mm holes had a higher CO2 concentration and lower water loss than bags with other hole sizes, but the hyphal growth was not significantly different from that of other bags. The weight loss of bags increased proportionally relative to the lid hole sizes. Taken together, these results indicate that traditional cotton plugs are economically efficient, but 15 mm hole lids are the most efficient at maintaining hyphal growth and controlling water loss while allowing CO2 emissions. PMID:23115508

Technological growth of fuel efficiency in european automobile market 1975–2015

DOE PAGES

Hu, Kejia; Chen, Yuche

2016-08-29

This paper looks at the technological growth of new car fleet fuel efficiency in the European Union between 1975 and 2015. According to the analysis results, from1975 to 2006 the fuel efficiency technology improvements were largely offset by vehicles' increased weight, engine size, and consumer amenities such as acceleration capacity. After 2006, downsizing in weight and engine capacity was observed in new car fleet, while fuel consumption decreased by 32% between 2006 and 2015. We adopt a statistical method and find that from 1975 to 2015, a 1% increase in weight would result in 0.3 to 0.5% increments in fuelmore » consumption per 100 km, and a 1% reduction in 0-100 km/h acceleration time would increase fuel consumption by about 0.3%. Impacts of other attributes on fuel consumption are also assessed. To meet the European Union's 2021 fuel consumption target, downsizing of cars, as well as at least maintaining fuel efficiency technology growth trend observed between 2005 and 2015, are needed. Lastly, government policies on controlling improvement in acceleration performance or promoting alternative fuel vehicles are also important to achieve European Union 2021 target.« less

Technological growth of fuel efficiency in european automobile market 1975–2015

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

Hu, Kejia; Chen, Yuche

This paper looks at the technological growth of new car fleet fuel efficiency in the European Union between 1975 and 2015. According to the analysis results, from1975 to 2006 the fuel efficiency technology improvements were largely offset by vehicles' increased weight, engine size, and consumer amenities such as acceleration capacity. After 2006, downsizing in weight and engine capacity was observed in new car fleet, while fuel consumption decreased by 32% between 2006 and 2015. We adopt a statistical method and find that from 1975 to 2015, a 1% increase in weight would result in 0.3 to 0.5% increments in fuelmore » consumption per 100 km, and a 1% reduction in 0-100 km/h acceleration time would increase fuel consumption by about 0.3%. Impacts of other attributes on fuel consumption are also assessed. To meet the European Union's 2021 fuel consumption target, downsizing of cars, as well as at least maintaining fuel efficiency technology growth trend observed between 2005 and 2015, are needed. Lastly, government policies on controlling improvement in acceleration performance or promoting alternative fuel vehicles are also important to achieve European Union 2021 target.« less

Study on light weight design of truss structures of spacecrafts

NASA Astrophysics Data System (ADS)

Zeng, Fuming; Yang, Jianzhong; Wang, Jian

2015-08-01

Truss structure is usually adopted as the main structure form for spacecrafts due to its high efficiency in supporting concentrated loads. Light-weight design is now becoming the primary concern during conceptual design of spacecrafts. Implementation of light-weight design on truss structure always goes through three processes: topology optimization, size optimization and composites optimization. During each optimization process, appropriate algorithm such as the traditional optimality criterion method, mathematical programming method and the intelligent algorithms which simulate the growth and evolution processes in nature will be selected. According to the practical processes and algorithms, combined with engineering practice and commercial software, summary is made for the implementation of light-weight design on truss structure for spacecrafts.

Using learning automata to determine proper subset size in high-dimensional spaces

NASA Astrophysics Data System (ADS)

Seyyedi, Seyyed Hossein; Minaei-Bidgoli, Behrouz

2017-03-01

In this paper, we offer a new method called FSLA (Finding the best candidate Subset using Learning Automata), which combines the filter and wrapper approaches for feature selection in high-dimensional spaces. Considering the difficulties of dimension reduction in high-dimensional spaces, FSLA's multi-objective functionality is to determine, in an efficient manner, a feature subset that leads to an appropriate tradeoff between the learning algorithm's accuracy and efficiency. First, using an existing weighting function, the feature list is sorted and selected subsets of the list of different sizes are considered. Then, a learning automaton verifies the performance of each subset when it is used as the input space of the learning algorithm and estimates its fitness upon the algorithm's accuracy and the subset size, which determines the algorithm's efficiency. Finally, FSLA introduces the fittest subset as the best choice. We tested FSLA in the framework of text classification. The results confirm its promising performance of attaining the identified goal.

FY 1990/FY 1991 Biennial Budget Descriptive Summaries for the Strategic Defense Initiative Organization

DTIC Science & Technology

1989-01-01

size, weight , power consumption, and radiation hardness, and on software algorithm validity and efficiency. 3. (U) Collection of radar, ctical, and...which have potential to achieve cooling requirements for LWIR sensors with far smaller weight and power penalties. (U) FY1989 Planned Program: o (U...two dollars for every SDI dollar. o (U) Inverted gaili--n arsenide by growing a razor-thin layer of silicon on GaAs and thus cut power loss by two

Electromagnetic machines with Nd-Fe-B magnets

NASA Astrophysics Data System (ADS)

Hanitsch, Rolf

1989-08-01

Permanent magnet motors are now becoming more accepted for general use in industrial fixed and variable speed drives. With the application of high-energy permanent magnets, such as Nd-Fe-B, the new motors offer higher efficiency and reduced size and weight compared with wound field energy converters of the same rating.

A novel transdermal nanoethosomal gel of betahistine dihydrochloride for weight gain control: in-vitro and in-vivo characterization

PubMed Central

El-Menshawe, Shahira F; Ali, Adel Ahmed; Halawa, Abdelkhalk Ali; Srag El-Din, Ahmed SG

2017-01-01

Background Betahistine dihydrochloride (BDH) is a histamine analog used to control weight gain, with short elimination half-life and gastric irritation as side effects. Objective The aim of the current investigation is to formulate and optimize a topical BDH ethosomal gel for weight gain control. Materials and methods Box–Behnken design was applied to study the effect of independent variables: phosphatidylcholine (PC), propylene glycol (PG), and ethanol on vesicle size; entrapment efficiency; % drug release; and flux. The morphology and zeta potential of the optimized formulation were evaluated. The % drug release, flux, and pharmacodynamics of the optimized formulation gel were studied. Results The size and entrapment efficiency percent had a direct positive relationship with the concentration of PC and negative relationship with ethanol and PG. The % drug release and flux decreased with increasing PC and PG, while ethanol enhanced both responses. Regression modeling indicated a good correlation between dependent and independent variables, where F16 was chosen as the optimized formulation. F16 showed well-defined spherical vesicles and zeta potential of −24 mV, and % release from the gel exceeded 99.5% over 16 h with the flux of 0.28 mg/cm2/h. Food intake and weight gain of rats were significantly decreased after transdermal application of the BDH ethosomal gel when compared with control, placebo, and BDH gel. The histopathological findings proved the absence of inflammation and decrease in adipose tissue. Conclusion Results obtained showed a significant, sustained transdermal absorption of BDH ethosomal gel and, consequently, a decrease in food intake and weight gain. PMID:29238164

Cationic flocculants carrying hydrophobic functionalities: applications for solid/liquid separation.

PubMed

Schwarz, S; Jaeger, W; Paulke, B-R; Bratskaya, S; Smolka, N; Bohrisch, J

2007-07-26

The flocculation behaviors of three series of polycations with narrow molecular weight distributions carrying hydrophobic substituents on their backbones [poly(N-vinylbenzyl-N,N,N-trimethylammonium chloride), poly(N-vinylbenzyl-N,N-dimethyl-N-butylammonium chloride), and poly(N-vinylbenzylpyridinium chloride)] were investigated in dispersions of monodisperse polystyrene latexes and kaolin. Apparently, the charge density of the polycations decreases with increasing substituent hydrophobicity and increasing molecular weight of the polyelectrolytes. The necessary amount of flocculant for phase separation in dispersions with high substrate surface charge densities increases with increasing hydrophobicity of the polyelectrolyte. Nevertheless, the introduction of hydrophobic functionalities is beneficial, resulting in a substantial broadening of the range between the minimum and maximum amounts of flocculant necessary for efficient flocculation (flocculation window). An increase in ionic strength supports this effect. When the substrate has a low charge density, the hydrophobic interactions play a much more significant role in the flocculation process. Here, the minimum efficient doses remained the same for all three polyelectrolytes investigated, but the width of the flocculation window increased as the polycation hydrophobicity and the molecular weight increased. The necessary amount of flocculant increased with an increase in particle size at constant solid content of the dispersion, as well as with a decreasing number of particles at a constant particle size.

Performance of Maybach 300-horsepower airplane engine

NASA Technical Reports Server (NTRS)

Sparrow, S W

1923-01-01

This report contains the results of a test made upon a Maybach Engine in the altitude chamber of the Bureau of Standards, where controlled conditions of temperature and pressure can be made the same as those of the desired altitude. The results of this test lead to the following conclusions: from the standpoint of thermal efficiency the full-load performance of the engine is excellent at densities corresponding to altitudes up to and including 15,000 feet. The brake mean effective pressure is rather low even at wide-open throttle. This tends to give a high weight per horsepower, in as much as the weight of many engine parts is governed by the size rather than the power of the engine. At part load the thermal efficiency of the engine is low. Judged on a basis of performance the engine's chief claim to interest would appear to lie in the carburetor design, which is largely responsible excellent full-load efficiency and for its poor part-load efficiency.

Displacement Based Multilevel Structural Optimization

NASA Technical Reports Server (NTRS)

Sobieszezanski-Sobieski, J.; Striz, A. G.

1996-01-01

In the complex environment of true multidisciplinary design optimization (MDO), efficiency is one of the most desirable attributes of any approach. In the present research, a new and highly efficient methodology for the MDO subset of structural optimization is proposed and detailed, i.e., for the weight minimization of a given structure under size, strength, and displacement constraints. Specifically, finite element based multilevel optimization of structures is performed. In the system level optimization, the design variables are the coefficients of assumed polynomially based global displacement functions, and the load unbalance resulting from the solution of the global stiffness equations is minimized. In the subsystems level optimizations, the weight of each element is minimized under the action of stress constraints, with the cross sectional dimensions as design variables. The approach is expected to prove very efficient since the design task is broken down into a large number of small and efficient subtasks, each with a small number of variables, which are amenable to parallel computing.

Hydrophobic modification of low molecular weight polyethylenimine for improved gene transfection.

PubMed

Teo, Pei Yun; Yang, Chuan; Hedrick, James L; Engler, Amanda C; Coady, Daniel J; Ghaem-Maghami, Sadaf; George, Andrew J T; Yang, Yi Yan

2013-10-01

Hydrophobic modification of low molecular weight (LMW) polyethylenimine (PEI) is known to increase gene transfection efficiency of LMW PEI. However, few studies have explored how the conjugated hydrophobic groups influence the properties of the modified LMW PEI mainly due to difficulties in obtaining well defined final product compositions and limitations in current chemical synthesis routes. The aim of this study was to modify LMW PEI (Mn 1.8 kDa, PEI-1.8) judiciously with different hydrophobic functional groups and to investigate how hydrophobicity, molecular structure and inclusion of hydrogen bonding properties in the conjugated side groups as well as the conjugation degree (number of primary amine groups of PEI-1.8 modified with hydrophobic groups) influence PEI-1.8 gene transfection efficiency. The modified polymers were characterized for DNA binding ability, particle size, zeta potential, in vitro gene transfection efficiency and cytotoxicity in SKOV-3 human ovarian cancer and HepG2 human liver carcinoma cell lines. The study shows that modified PEI-1.8 polymers are able to condense plasmid DNA into cationic nanoparticles, of sizes ~100 nm, whereas unmodified polymer/DNA complexes display larger particle sizes of 2 μm. Hydrophobic modification also increases the zeta potential of polymer/DNA complexes. Importantly, modified PEI-1.8 shows enhanced transfection efficiency over the unmodified counterpart. Higher transfection efficiency is obtained when PEI-1.8 is modified with shorter hydrophobic groups (MTC-ethyl) as opposed to longer ones (MTC-octyl and MTC-deodecyl). An aromatic structured functional group (MTC-benzyl) also enhances transfection efficiency more than an alkyl functional group (MTC-octyl). An added hydrogen-bonding urea group in the conjugated functional group (MTC-urea) does not enhance transfection efficiency over one without urea (MTC-benzyl). The study also demonstrates that modification degree greatly influences gene transfection, and ~100% substitution of primary amine groups leads to significantly lower gene transfection efficiency. These findings provide insights to modification of PEI for development of effective and non-cytotoxic non-viral vectors. Copyright © 2013 Elsevier Ltd. All rights reserved.

Preparation and testing of quaternized chitosan nanoparticles as gene delivery vehicles.

PubMed

Li, Guang-Feng; Wang, Jing-Cheng; Feng, Xin-Min; Liu, Zhen-Dong; Jiang, Chao-Yong; Yang, Jian-Dong

2015-04-01

The aim of this study was to synthesize a chitosan (CS) derivative, a quaternary ammonium salt crystal called N-2-hydroxypropyl trimethyl ammonium chloride chitosan (HACC), and test a series of HACC and pEGFP-DNA complexes at different weight ratios for their efficiency of gene delivery into human cells. CS was modified with cationic etherifying agent to obtain the CS derivative. Fourier transform infrared spectra were recorded on KBr pellets with a spectrometer. (1)H nuclear magnetic resonance (NMR) spectra of HACC were obtained using a spectrometer. HACC was subsequently used to prepare HACC/DNA complexes at different weight ratios by coacervation method. The resulting particle size and surface charge were assessed by laser light scattering using a zeta potential analyzer. The HACC/DNA complex formation and DNA protection in the nanoparticle complex was investigated by gel mobility shift assay and DNase I protection assay, respectively. The cytotoxicity of HACC and HACC/DNA nanoparticles was evaluated by MTT assay using (mesenchymal stem cell) MSC lines. The nanoscale structure of the particles was obtained by transmission electron microscope (TEM). The FTIR spectrum of HACC showed the characteristic quaternary ammonium group absorption band at 1475 cm(-1), which indicated the presence of quaternary ammonium group. The successful synthesis of HACC was also confirmed by (1)H NMR spectrum. HACC showed good solubility in water and was electropositive. HACC efficiently packed and protected pEGFP-DNA at a weight ratio of 10. With increased weight ratios, the surface charge of the composite particle increased from negative to positive, the average particle size increased, and HACC nanoparticle had a higher carrying efficiency. The nanoparticles released DNA in two distinct phases, and 55 % was released within the first 20 h of solubilization. The nanoparticles under TEM showed circular or oval shapes. The particles exhibited no cytotoxicity against human cells. No significant difference in gene delivery efficiency was detected between HACC/pEGFP-GDNF and liposome/pEGFP-GDNF complexes (33.8 vs. 34 %, P = 0.363). In this study, HACC was successfully synthesized, and HACC/DNA complex assembled efficiently. HACC showed strong DNA binding affinity and high protection of DNA and was non-cytotoxic to human cells. The particles had appropriate nanostructure, mean diameter, and DNA release time. The results suggest that HACC nanoparticles are a novel tool for efficient and safe gene delivery.

Onboard Image Processing System for Hyperspectral Sensor

PubMed Central

Hihara, Hiroki; Moritani, Kotaro; Inoue, Masao; Hoshi, Yoshihiro; Iwasaki, Akira; Takada, Jun; Inada, Hitomi; Suzuki, Makoto; Seki, Taeko; Ichikawa, Satoshi; Tanii, Jun

2015-01-01

Onboard image processing systems for a hyperspectral sensor have been developed in order to maximize image data transmission efficiency for large volume and high speed data downlink capacity. Since more than 100 channels are required for hyperspectral sensors on Earth observation satellites, fast and small-footprint lossless image compression capability is essential for reducing the size and weight of a sensor system. A fast lossless image compression algorithm has been developed, and is implemented in the onboard correction circuitry of sensitivity and linearity of Complementary Metal Oxide Semiconductor (CMOS) sensors in order to maximize the compression ratio. The employed image compression method is based on Fast, Efficient, Lossless Image compression System (FELICS), which is a hierarchical predictive coding method with resolution scaling. To improve FELICS’s performance of image decorrelation and entropy coding, we apply a two-dimensional interpolation prediction and adaptive Golomb-Rice coding. It supports progressive decompression using resolution scaling while still maintaining superior performance measured as speed and complexity. Coding efficiency and compression speed enlarge the effective capacity of signal transmission channels, which lead to reducing onboard hardware by multiplexing sensor signals into a reduced number of compression circuits. The circuitry is embedded into the data formatter of the sensor system without adding size, weight, power consumption, and fabrication cost. PMID:26404281

Applications of nano and smart materials in renewable energy production and storage devices

NASA Astrophysics Data System (ADS)

Ghasemi-Nejhad, Mehrdad N.

2015-03-01

This paper presents development of renewable energy production and storage devices employing nanomaterials and smart materials. The use of carbon nanotubes (CNTs) and graphene nanosheets (GNS) to improve the performance and durability of wind turbine and wave rotor blades will be explained. While GNS are primary used for the performance enhancement of the resin system called Nanoresin, CNT Nanoforests and Nanofilms are used to improve the performance of fiber systems in high-performance Nanocomposites. In addition, the use of CNTs and piezo-nanofibers will be explained as the health monitoring and smart systems within the composites. A self-healing mechanism will also be explained within the composites using these materials. Next the use of CNTs as gas diffusion layers and CNTs combined with in-situ generated platinum nanoparticles as catalyst layers will be explained to improve the performance, efficiency, and durability of proton exchange membrane fuel cells while reducing their costs, weight, and size. In addition, the use of CNTs and GNSs to improve the efficiency and performance of polymer solar cells will be explained. Finally, the use of CNTs and GNSs to enhance the performance, efficiency, and durability of batteries and supercapacitors while reducing their costs, weight, and size will be discussed.

Reciprocal longitudinal relations between weight/shape concern and comorbid pathology among women at very high risk for eating disorder onset.

PubMed

Fitzsimmons-Craft, Ellen E; Eichen, Dawn M; Kass, Andrea E; Trockel, Mickey; Crosby, Ross D; Taylor, C Barr; Wilfley, Denise E

2017-12-28

Understanding how known eating disorder (ED) risk factors change in relating to one another over time may inform efficient intervention targets. We examined short-term (i.e., 1 month) reciprocal longitudinal relations between weight/shape concern and comorbid symptoms (i.e., depressed mood, anxiety) and behaviors (i.e., binge drinking) over the course of 24 months using cross-lagged panel models. Participants were 185 women aged 18-25 years at very high risk for ED onset, randomized to an online ED preventive intervention or waitlist control. We also tested whether relations differed based on intervention receipt. Weight/shape concern in 1 month significantly predicted depressed mood the following month; depressed mood in 1 month also predicted weight/shape concern the following month, but the effect size was smaller. Likewise, weight/shape concern in 1 month significantly predicted anxiety the following month, but the reverse was not true. Results showed no temporal relations between weight/shape concern and binge drinking in either direction. Relations between weight/shape concern, and comorbid symptoms and behaviors did not differ based on intervention receipt. Results support focusing intervention on reducing weight/shape concern over reducing comorbid constructs for efficient short-term change. Level I, evidence obtained from a properly designed randomized controlled trial.

Hepatocyte-targeting gene transfer mediated by galactosylated poly(ethylene glycol)-graft-polyethylenimine derivative

PubMed Central

Wang, Yuqiang; Su, Jing; Cai, Wenwei; Lu, Ping; Yuan, Lifen; Jin, Tuo; Chen, Shuyan; Sheng, Jing

2013-01-01

Biscarbamate cross-linked polyethylenimine derivative (PEI-Et) has been reported as a novel nonviral vector for efficient and safe gene transfer in our previous work. However, it had no cell-specificity. To achieve specific delivery of genes to hepatocytes, galactosylated poly(ethylene glycol)-graft-polyethylenimine derivative (GPE) was prepared through modification of PEI-Et with poly(ethylene glycol) and lactobionic acid, bearing a galactose group as a hepatocyte-targeting moiety. The composition of GPE was characterized by proton nuclear magnetic resonance. The weight-average molecular weight of GPE measured with a gel permeation chromatography instrument was 9489 Da, with a polydispersity of 1.44. GPE could effectively condense plasmid DNA (pDNA) into nanoparticles. Gel retardation assay showed that GPE/pDNA complexes were completely formed at weigh ratios (w/w) over 3. The particle size of GPE/pDNA complexes was 79–100 nm and zeta potential was 6–15 mV, values which were appropriate for cellular uptake. The morphology of GPE/pDNA complexes under atomic force microscopy appeared spherical and uniform in size, with diameters of 53–65 nm. GPE displayed much higher transfection efficiency than commercially available PEI 25 kDa in BRL-3A cell lines. Importantly, GPE showed good hepatocyte specificity. Also, the polymer exhibited significantly lower cytotoxicity compared to PEI 25 kDa at the same concentration or weight ratio in BRL-3A cell lines. To sum up, our results indicated that GPE might carry great potential in safe and efficient hepatocyte-targeting gene delivery. PMID:23576866

Effects of interaction with gene carrier polyethyleneimines on conformation and enzymatic activity of pig heart lactate dehydrogenase.

PubMed

Wang, Fan; Mo, Junyong; Huang, Aimin; Zhang, Min; Ma, Lin

2018-06-15

Polyethyleneimine (PEI) has long been considered as "golden standard" for polymeric gene delivery carrier, however also induces cytotoxicity. To make a further insight into the molecular basis of PEI cytotoxicity, fluorescence, absorption and circular dichroism spectroscopy were conducted to investigate the influence of PEI (average molecular weight 25,000 and 1800 Da) on the conformation of pig heart lactate dehydrogenase (LDH) and its catalytic efficiency. Zeta-potential measurement and isothermal titration calorimetry were used to reveal the interaction between PEI and LDH. PEI was found to bind onto the surface of LDH predominantly via hydrophobic interaction, inducing a more compact conformation and an increased surface hydrophobicity of the enzyme. The conformational change of LDH induced by PEI binding had little influence on the complex formation between LDH and reduced nicotinamide adenine dinucleotide (NADH, the co-enzyme). However, the nonspecific binding of PEI on the surface of LDH retarded the turnover of the enzyme. Meanwhile, the large quantity of amine groups on the polymer chain made PEI subject to form complexes with NADH and pyruvate (the substrate) via hydrogen bond and electrostatic interaction, which greatly reduced the binding efficient of LDH. The polymer size played an important role in PEI-LDH interaction. The smaller size of lower molecular weight PEI facilitated the close contact with LDH and consequential reduction of the turnover number of the enzyme. However, higher molecular weight PEI was more favorable for competitive binding with NADH and pyruvate and generally decreased the catalytic efficient of LDH. Copyright © 2018. Published by Elsevier B.V.

Momentum-weighted conjugate gradient descent algorithm for gradient coil optimization.

PubMed

Lu, Hanbing; Jesmanowicz, Andrzej; Li, Shi-Jiang; Hyde, James S

2004-01-01

MRI gradient coil design is a type of nonlinear constrained optimization. A practical problem in transverse gradient coil design using the conjugate gradient descent (CGD) method is that wire elements move at different rates along orthogonal directions (r, phi, z), and tend to cross, breaking the constraints. A momentum-weighted conjugate gradient descent (MW-CGD) method is presented to overcome this problem. This method takes advantage of the efficiency of the CGD method combined with momentum weighting, which is also an intrinsic property of the Levenberg-Marquardt algorithm, to adjust step sizes along the three orthogonal directions. A water-cooled, 12.8 cm inner diameter, three axis torque-balanced gradient coil for rat imaging was developed based on this method, with an efficiency of 2.13, 2.08, and 4.12 mT.m(-1).A(-1) along X, Y, and Z, respectively. Experimental data demonstrate that this method can improve efficiency by 40% and field uniformity by 27%. This method has also been applied to the design of a gradient coil for the human brain, employing remote current return paths. The benefits of this design include improved gradient field uniformity and efficiency, with a shorter length than gradient coil designs using coaxial return paths. Copyright 2003 Wiley-Liss, Inc.

High-efficiency space-based software radio architectures & algorithms (a minimum size, weight, and power TeraOps processor)

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

Dunham, Mark Edward; Baker, Zachary K; Stettler, Matthew W

2009-01-01

Los Alamos has recently completed the latest in a series of Reconfigurable Software Radios, which incorporates several key innovations in both hardware design and algorithms. Due to our focus on satellite applications, each design must extract the best size, weight, and power performance possible from the ensemble of Commodity Off-the-Shelf (COTS) parts available at the time of design. In this case we have achieved 1 TeraOps/second signal processing on a 1920 Megabit/second datastream, while using only 53 Watts mains power, 5.5 kg, and 3 liters. This processing capability enables very advanced algorithms such as our wideband RF compression scheme tomore » operate remotely, allowing network bandwidth constrained applications to deliver previously unattainable performance.« less

Polymeric heat pipe wick

NASA Technical Reports Server (NTRS)

Seidenberg, Benjamin

1988-01-01

A wick for use in a capillary loop pump heat pipe is described. The wick material is an essentially uniformly porous, permeable, open-cell, polyethylene thermoplastic foam having an ultrahigh average molecular weight of from approximately 1 to 5 million, and an average pore size of about 10 to 12 microns. A representative material having these characteristics is POREX UF, which has an average molecular weight of about 3 million. This material is fully compatible with the FREONs and anhydrous ammonia and allows for the use of these very efficient working fluids in capillary loops.

Analytical Micromechanics Modeling Technique Developed for Ceramic Matrix Composites Analysis

NASA Technical Reports Server (NTRS)

Min, James B.

2005-01-01

Ceramic matrix composites (CMCs) promise many advantages for next-generation aerospace propulsion systems. Specifically, carbon-reinforced silicon carbide (C/SiC) CMCs enable higher operational temperatures and provide potential component weight savings by virtue of their high specific strength. These attributes may provide systemwide benefits. Higher operating temperatures lessen or eliminate the need for cooling, thereby reducing both fuel consumption and the complex hardware and plumbing required for heat management. This, in turn, lowers system weight, size, and complexity, while improving efficiency, reliability, and service life, resulting in overall lower operating costs.

A novel measure of ewe efficiency for breeding and benchmarking purposes.

PubMed

McHugh, Nóirín; Pabiou, Thierry; McDermott, Kevin; Wall, Eamon; Berry, Donagh P

2018-06-04

Ewe efficiency has traditionally been defined as the ratio of litter weight to ewe weight; given the statistical properties of ratio traits, an alternative strategy is proposed in the present study. The concept of using the deviation in performance of an animal from the population norm has grown in popularity as a measure of animal-level efficiency. The objective of the present study was to define novel measures of efficiency for sheep, which considers the combined weight of a litter of lambs relative to the weight of their dam, and vice versa. Two novel traits, representing the deviation in total litter weight at 40 d (DEV40L) or weaning (DEVweanL), were calculated as the residuals of a statistical model, with litter weight as the dependent variable and with the fixed effects of litter rearing size, contemporary group, and ewe weight. The deviation in ewe weight at 40-d postlambing (DEV40E) or weaning (DEVweanE) was derived using a similar approach but with ewe weight and litter weight interchanged as the dependent variable. Variance components for each trait were estimated by first deriving the litter or ewe weight deviation phenotype and subsequently estimating the variance components. The phenotypic SD in DEV40L and DEVweanL was 8.46 and 15.37 kg, respectively; the mean litter weight at 40 d and weaning was 30.97 and 47.68 kg, respectively. The genetic SD and heritability for DEV40L was 2.65 kg and 0.12, respectively. For DEVweanL, the genetic SD and heritability was 4.94 kg and 0.13, respectively. The average ewe weight at 40-d postlambing and at weaning was 66.43 and 66.87 kg, respectively. The genetic SD and heritability for DEV40E was 4.33 kg and 0.24, respectively. The heritability estimated for DEVweanE was 0.31. The traits derived in the present study may be useful not only for phenotypic benchmarking of ewes within flock on performance but also for benchmarking flocks against each other; furthermore, the extent of genetic variability in all traits, coupled with the fact that the data required to generate these novel phenotypes are usually readily available, signals huge potential within sheep breeding programs.

Efficient Robust Regression via Two-Stage Generalized Empirical Likelihood

PubMed Central

Bondell, Howard D.; Stefanski, Leonard A.

2013-01-01

Large- and finite-sample efficiency and resistance to outliers are the key goals of robust statistics. Although often not simultaneously attainable, we develop and study a linear regression estimator that comes close. Efficiency obtains from the estimator’s close connection to generalized empirical likelihood, and its favorable robustness properties are obtained by constraining the associated sum of (weighted) squared residuals. We prove maximum attainable finite-sample replacement breakdown point, and full asymptotic efficiency for normal errors. Simulation evidence shows that compared to existing robust regression estimators, the new estimator has relatively high efficiency for small sample sizes, and comparable outlier resistance. The estimator is further illustrated and compared to existing methods via application to a real data set with purported outliers. PMID:23976805

Goals of thermionic program for space power

NASA Technical Reports Server (NTRS)

English, R. E.

1981-01-01

The thermionic and Brayton reactor concepts were compared for application to space power. For a turbine inlet temperature of 15000 K the Brayton powerplant weighted 5 to 40% less than the thermionic concept. The out of core concept separates the thermionic converters from their reactor. Technical risks are diminished by: (1) moving the insolator out of the reactor; (2) allowing a higher thermal flux for the thermionic converters than is required of the reactor fuel; and (3) eliminating fuel swelling's threat against lifetime of the thermionic converters. Overall performance can be improved by including power processing in system optimization for design and technology on more efficient, higher temperature power processors. The thermionic reactors will be larger than those for competitive systems with higher conversion efficiency and lower reactor operating temperatures. It is concluded that although the effect of reactor size on shield weight will be modest for unmanned spacecraft, the penalty in shield weight will be large for manned or man-tended spacecraft.

Advanced rotary engine studies

NASA Technical Reports Server (NTRS)

Jones, C.

1980-01-01

A review of rotary engine developments relevant to a stratified charge rotary aircraft engine is presented. Advantages in module size and weight, fuel efficiency, reliability, and multi-fuel capability are discussed along with developments in turbocharging, increased mean effective pressure, improved apex seal/trochoid wear surfacing materials, and high strength and temperature aluminum casting alloys. A carbureted prototype aircraft engine is also described.

A small and light weight heat exchanger for on-board helium refrigerator

NASA Technical Reports Server (NTRS)

Koizumi, T.; Takahashi, M.; Uchida, T.; Kanazawa, Y.; Suzuki, M.

1983-01-01

A small and light weight heat exchanger used for small helium refrigerator has been developed by Sumitomo Heavy Industries, Ltd. This heat exchanger is a laminated metal heat exchanger which consists of perforated aluminum metal plates and glassfiber reinforced plastic separators. The size is from 100 mm to 28 mm in diameter and about 300 mm in length. The weight is from 2.5 kg to 0.6 kg. Also it can be used between room temperature and liquid helium temperature. The thermal efficiency obtained has been more than 96%. The heat exchanger has been practically used for on-board helium refrigerator in Japanese National Railways' superconducting magnetic levitated trains.

Using microwave heating to improve the desorption efficiency of high molecular weight VOC from beaded activated carbon.

PubMed

Fayaz, Mohammadreza; Shariaty, Pooya; Atkinson, John D; Hashisho, Zaher; Phillips, John H; Anderson, James E; Nichols, Mark

2015-04-07

Incomplete regeneration of activated carbon loaded with organic compounds results in heel build-up that reduces the useful life of the adsorbent. In this study, microwave heating was tested as a regeneration method for beaded activated carbon (BAC) loaded with n-dodecane, a high molecular weight volatile organic compound. Energy consumption and desorption efficiency for microwave-heating regeneration were compared with conductive-heating regeneration. The minimum energy needed to completely regenerate the adsorbent (100% desorption efficiency) using microwave regeneration was 6% of that needed with conductive heating regeneration, owing to more rapid heating rates and lower heat loss. Analyses of adsorbent pore size distribution and surface chemistry confirmed that neither heating method altered the physical/chemical properties of the BAC. Additionally, gas chromatography (with flame ionization detector) confirmed that neither regeneration method detectably altered the adsorbate composition during desorption. By demonstrating improvements in energy consumption and desorption efficiency and showing stable adsorbate and adsorbent properties, this paper suggests that microwave heating is an attractive method for activated carbon regeneration particularly when high-affinity VOC adsorbates are present.

A High Efficiency, Miniaturized Ka Band Traveling Wave Tube Based on a Novel Finned Ladder RF Circuit Design

NASA Technical Reports Server (NTRS)

Wintucky, E. G.; Wilson, J. D.; Vaden, K. R.; Force, D. A.; Freeman, J. C.; Lesny, G. G.; Kory, C. L.; Chevalier, C. T.; Ebihara, B.; Dayton, J. A.;

Biodegradable poly(amine-co-ester) terpolymers for targeted gene delivery

PubMed Central

Zhou, Jiangbing; Liu, Jie; Cheng, Christopher J.; Patel, Toral R.; Weller, Caroline E.; Piepmeier, Joseph M.; Jiang, Zhaozhong; Saltzman, W. Mark

2014-01-01

Many synthetic polycationic vectors for non-viral gene delivery show high efficiency in vitro, but their usually excessive charge density makes them toxic for in vivo applications. Here we describe the synthesis of a series of high molecular weight terpolymers with low charge density, and show that they exhibit efficient gene delivery, some surpassing the efficiency of the commercial transfection reagents Polyethylenimine and Lipofectamine 2000. The terpolymers were synthesized via enzyme-catalyzed copolymerization of lactone with dialkyl diester and amino diol, and their hydrophobicity adjusted by varying the lactone content and by selecting a lactone comonomer of specific ring size. Targeted delivery of the pro-apoptotic TRAIL gene to tumour xenografts by one of the terpolymers results in significant inhibition of tumour growth, with minimal toxicity both in vitro and in vivo. Our findings suggest that the gene delivery ability of the terpolymers stems from their high molecular weight and increased hydrophobicity, which compensates for their low charge density. PMID:22138789

Analysis of a new PM motor design for a rotary dynamic blood Pump.

PubMed

Xu, L; Wang, F; Fu, M; Medvedev, A; Smith, W A; Golding, L A

1997-01-01

The permanent magnet (PM) motor for a rotary dynamic blood pump requires high power density to coordinate the motor size with the limited pump space and high efficiency to reduce the size and weight of the associated batteries. The motor also serves as a passive axial magnetic thrust bearing, a reacting hydraulic force, and provides a stabilizing force for the radial journal bearing. This article presents analysis of a new PM motor for the blood pump application. High power density is achieved by using the Halbach magnetic array, and high efficiency is accomplished by optimizing the rotor magnet assembly and the stator slots/windings. While both radial and axial forces are greatly enhanced, pulsating components of the torque and force are also significantly reduced.

Preliminary design of a long-endurance Mars aircraft

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.

1990-01-01

The preliminary design requirements of a long endurance aircraft capable of flight within the Martian environment was determined. Both radioisotope/heat engine and PV solar array power production systems were considered. Various cases for each power system were analyzed in order to determine the necessary size, weight and power requirements of the aircraft. The analysis method used was an adaptation of the method developed by Youngblood and Talay of NASA-Langley used to design a high altitude earth based aircraft. The analysis is set up to design an aircraft which, for the given conditions, has a minimum wingspan and maximum endurance parameter. The results showed that, for a first approximation, a long endurance aircraft is feasible within the Martian environment. The size and weight of the most efficient solar aircraft were comparable to the radioisotope powered one.

Effects of the Booroola (FecB) genotypes on growth performance, ewe's productivity efficiency and litter size in Garole x Malpura sheep.

PubMed

Kumar, S; Mishra, A K; Kolte, A P; Arora, A L; Singh, D; Singh, V K

2008-05-01

The present study was conducted to evaluate the effects of FecB genotypes on body weight, average daily gain (ADG), ewe's productivity efficiency (EPE) and litter size in FecB introgressed GarolexMalpura (GM) crossbred sheep. A total of 235 GM lambs were selected randomly and screened for FecB mutation using forced RFLP-PCR. The majority (69.8%) of GM individuals were carriers (BB and B+) for the FecB mutation and frequency of the FecB allele was about 0.40. The FecB genotypes were significantly (P<0.01) associated with the lamb's body weights from birth to 12 months of age. The generation wise (F(1), F(2) and F(3)), lamb's body weight did not differ significantly at birth, 6 and 12 months of the age, while it differed significantly (P<0.05) at 3 and 9 months of age. The ADG1 (0-3 months) was significantly associated (P<0.05), but not the ADG2 (3-6 months) and ADG3 (6-12 months) between genotypes. Type of birth and sex significantly (P<0.01) affected the body weight from birth to 12 months of age; and body weight of single born lambs was significantly higher (P<0.01) than that of twins and triplets from birth to 12 months of age. Type of birth significantly (P<0.01) affected the ADG1, but had no significant effect on ADG2 and ADG3. Year of birth did not affect the birth and weaning weights, but it significantly affected (P<0.01) the body weight and ADG's after weaning ages. The EPE was affected significantly (P<0.01) by the FecB genotypes at birth, 3 and 12 months of age. The EPE of B+ and BB ewes were 7.86 kg (36.9%) and 2.32 kg (10.9%) higher as compared to ++ ewes at 12 months of age, respectively. The mean litter size of BB ewes (2.17+/-0.24) was significantly higher (P<0.01) than that of B+ ewes (1.73+/-0.04) and ++ ewes (1.03+/-0.23). The present study indicated that the body weight and ADG of carrier lambs (BB and B+) was comparatively lower than that of non-carriers (++), while EPE of B+ ewes was comparatively higher than that of BB and ++ ewes. Further, it is interesting to note that heterozygous and homozygous state of individuals increased 0.70 and 1.14 extra lambs as compared to non-carriers (++), respectively.

Functionally Relevant Microsatellite Markers From Chickpea Transcription Factor Genes for Efficient Genotyping Applications and Trait Association Mapping

PubMed Central

Kujur, Alice; Bajaj, Deepak; Saxena, Maneesha S.; Tripathi, Shailesh; Upadhyaya, Hari D.; Gowda, C.L.L.; Singh, Sube; Jain, Mukesh; Tyagi, Akhilesh K.; Parida, Swarup K.

2013-01-01

We developed 1108 transcription factor gene-derived microsatellite (TFGMS) and 161 transcription factor functional domain-associated microsatellite (TFFDMS) markers from 707 TFs of chickpea. The robust amplification efficiency (96.5%) and high intra-specific polymorphic potential (34%) detected by markers suggest their immense utilities in efficient large-scale genotyping applications, including construction of both physical and functional transcript maps and understanding population structure. Candidate gene-based association analysis revealed strong genetic association of TFFDMS markers with three major seed and pod traits. Further, TFGMS markers in the 5′ untranslated regions of TF genes showing differential expression during seed development had higher trait association potential. The significance of TFFDMS markers was demonstrated by correlating their allelic variation with amino acid sequence expansion/contraction in the functional domain and alteration of secondary protein structure encoded by genes. The seed weight-associated markers were validated through traditional bi-parental genetic mapping. The determination of gene-specific linkage disequilibrium (LD) patterns in desi and kabuli based on single nucleotide polymorphism-microsatellite marker haplotypes revealed extended LD decay, enhanced LD resolution and trait association potential of genes. The evolutionary history of a strong seed-size/weight-associated TF based on natural variation and haplotype sharing among desi, kabuli and wild unravelled useful information having implication for seed-size trait evolution during chickpea domestication. PMID:23633531

Post-weaning voluntary exercise exerts long-term moderation of adiposity in males but not in females in an animal model of early-onset obesity.

PubMed

Schroeder, Mariana; Shbiro, Liat; Gelber, Vered; Weller, Aron

2010-04-01

Given the alarming increase in childhood, adolescent and adult obesity there is an imperative need for understanding the early factors affecting obesity and for treatments that may help prevent or at least moderate it. Exercise is frequently considered as an effective treatment for obesity however the empirical literature includes many conflicting findings. In the present study, we used the OLETF rat model of early-onset hyperphagia-induced obesity to examine the influence of early exercise on peripheral adiposity-related parameters in both males and females. Rats were provided voluntary access to running wheels from postnatal day (PND) 22 until PND45. We examined fat pad weight (brown, retroperitoneal, inguinal and epididymal); inguinal adipocyte size and number; and leptin, adiponectin, corticosterone and creatinine levels. We also examined body weight, feeding efficiency and spontaneous intake. Early voluntary exercise reduced intake, adiposity and leptin in the OLETF males following a sharp reduction in adipocyte size despite a significant increase in fat cell number. Exercising males from the lean LETO control strain presented stable intake, but reduced body fat, feeding efficiency and increased plasma creatinine, suggesting an increment in muscle mass. OLETF females showed reduced feeding efficiency and liver fat, and a significant increase in brown fat. Exercising LETO control females increased intake, body weight and creatinine, but no changes in body fat. Overall, OLETF rats presented higher adiponectin levels than controls in both basal and post-exercise conditions. The results suggest an effective early time frame, when OLETF males can be successfully "re-programmed" through voluntary exercise; in OLETF females the effect is much more moderate. Findings expose sex-dependent peripheral mechanisms in coping with energy challenges. Copyright 2010 Elsevier Inc. All rights reserved.

Genetic parameters of pelt character, feed efficiency and size traits in Finnish blue fox (Vulpes lagopus).

PubMed

Kempe, R; Koskinen, N; Strandén, I

2013-12-01

Pelt character traits (size, quality, colour clarity, darkness) are important economic traits in blue fox breeding. Better feed efficiency (FE) is another economically important and new breeding goal for fur animals. The purpose of this study was to determine the correlations between pelt character traits, FE and size traits and to estimate genetic parameters for pelt character traits. Pelt size (pSIcm ) had a high positive genetic correlation with animal grading size (gSI), final body weight (BWFin), body length and daily gain (DG), and a moderate correlation with body condition score (BCS). Animal body length and BCS (describing fatness) were considered as genetically different traits. Genetic correlations between pelt quality and size traits were estimated without precision and did not differ from zero, but colour clarity (pCL) had a low antagonistic genetic correlation with FE. Pelt size and DG had a favourable genetic correlation with FE but a fairly high unfavourable genetic correlation with dry matter feed intake. The current emphasis on selection for larger animal and pelt size improves FE indirectly, but selection for larger pelt size favours fast-growing and fat individuals and simultaneously increases feed intake. The detected genetic connections between FE, size, feed intake and pCL should be taken into account in the Finnish blue fox breeding programme. © 2013 Blackwell Verlag GmbH.

The Importance of Powertrain Downsizing in a Benefit-Cost Analysis of Vehicle Lightweighting

NASA Astrophysics Data System (ADS)

Ward, J.; Gohlke, D.; Nealer, R.

2017-04-01

Reducing vehicle weight is an important avenue to improve energy efficiency and decrease greenhouse gas emissions from our cars and trucks. Conventionally, models have estimated acceptable increased manufacturing cost as proportional to the lifetime fuel savings associated with reduced vehicle weight. Vehicle lightweighting also enables a decrease in powertrain size and significant reductions in powertrain cost. Accordingly, we propose and apply a method for calculating the maximum net benefits and breakeven cost of vehicle lightweighting that considers both efficiency and powertrain downsizing for a conventional internal combustion engine vehicle, a battery electric vehicle with a range of 300 miles (BEV300), and a fuel cell electric vehicle (FCEV). We find that excluding powertrain downsizing cost savings undervalues the potential total net benefits of vehicle lightweighting, especially for the BEV300 and FCEV.

Surface engineering on mesoporous silica chips for enriching low molecular weight phosphorylated proteins

NASA Astrophysics Data System (ADS)

Hu, Ye; Peng, Yang; Lin, Kevin; Shen, Haifa; Brousseau, Louis C., III; Sakamoto, Jason; Sun, Tong; Ferrari, Mauro

2011-02-01

Phosphorylated peptides and proteins play an important role in normal cellular activities, e.g., gene expression, mitosis, differentiation, proliferation, and apoptosis, as well as tumor initiation, progression and metastasis. However, technical hurdles hinder the use of common fractionation methods to capture phosphopeptides from complex biological fluids such as human sera. Herein, we present the development of a dual strategy material that offers enhanced capture of low molecular weight phosphoproteins: mesoporous silica thin films with precisely engineered pore sizes that sterically select for molecular size combined with chemically selective surface modifications (i.e. Ga3+, Ti4+ and Zr4+) that target phosphoroproteins. These materials provide high reproducibility (CV = 18%) and increase the stability of the captured proteins by excluding degrading enzymes, such as trypsin. The chemical and physical properties of the composite mesoporous thin films were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy and ellipsometry. Using mass spectroscopy and biostatistics analysis, the enrichment efficiency of different metal ions immobilized on mesoporous silica chips was investigated. The novel technology reported provides a platform capable of efficiently profiling the serum proteome for biomarker discovery, forensic sampling, and routine diagnostic applications.Phosphorylated peptides and proteins play an important role in normal cellular activities, e.g., gene expression, mitosis, differentiation, proliferation, and apoptosis, as well as tumor initiation, progression and metastasis. However, technical hurdles hinder the use of common fractionation methods to capture phosphopeptides from complex biological fluids such as human sera. Herein, we present the development of a dual strategy material that offers enhanced capture of low molecular weight phosphoproteins: mesoporous silica thin films with precisely engineered pore sizes that sterically select for molecular size combined with chemically selective surface modifications (i.e. Ga3+, Ti4+ and Zr4+) that target phosphoroproteins. These materials provide high reproducibility (CV = 18%) and increase the stability of the captured proteins by excluding degrading enzymes, such as trypsin. The chemical and physical properties of the composite mesoporous thin films were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy and ellipsometry. Using mass spectroscopy and biostatistics analysis, the enrichment efficiency of different metal ions immobilized on mesoporous silica chips was investigated. The novel technology reported provides a platform capable of efficiently profiling the serum proteome for biomarker discovery, forensic sampling, and routine diagnostic applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c0nr00720j

Ultra-Tunable Micro-Power Converters

DTIC Science & Technology

2008-12-01

These advantages come at the expense of potentially difficult to integrate magnetic materials and magnetic property limitations/losses that may...that add greatly to the size/weight of a system (or whose properties /efficiency may be compromised to accommodate space constraints). Given the...thin film magnetic core (such as NiFe ). “Taps” are periodically provided through a series of microelectromechanical (MEMS) switches. In the example

Department of Defense Space Science and Technology Strategy 2015

DTIC Science & Technology

2015-01-01

solar cells at 34% efficiency enabling higher power spacecraft capability. These solar cells developed by the Air Force Research Laboratory (AFRL...Reduce size, weight, power , cost, and improve thermal management for SATCOM terminals  Support intelligence surveillance and reconnaissance (ISR...Improve understanding and awareness of the Earth-to-Sun environment  Improve space environment forecast capabilities and tools to predict operational

Fast Constrained Spectral Clustering and Cluster Ensemble with Random Projection

PubMed Central

Liu, Wenfen

2017-01-01

Constrained spectral clustering (CSC) method can greatly improve the clustering accuracy with the incorporation of constraint information into spectral clustering and thus has been paid academic attention widely. In this paper, we propose a fast CSC algorithm via encoding landmark-based graph construction into a new CSC model and applying random sampling to decrease the data size after spectral embedding. Compared with the original model, the new algorithm has the similar results with the increase of its model size asymptotically; compared with the most efficient CSC algorithm known, the new algorithm runs faster and has a wider range of suitable data sets. Meanwhile, a scalable semisupervised cluster ensemble algorithm is also proposed via the combination of our fast CSC algorithm and dimensionality reduction with random projection in the process of spectral ensemble clustering. We demonstrate by presenting theoretical analysis and empirical results that the new cluster ensemble algorithm has advantages in terms of efficiency and effectiveness. Furthermore, the approximate preservation of random projection in clustering accuracy proved in the stage of consensus clustering is also suitable for the weighted k-means clustering and thus gives the theoretical guarantee to this special kind of k-means clustering where each point has its corresponding weight. PMID:29312447

Wider-Opening Dewar Flasks for Cryogenic Storage

NASA Technical Reports Server (NTRS)

Ruemmele, Warren P.; Manry, John; Stafford, Kristin; Bue, Grant; Krejci, John; Evernden, Bent

2010-01-01

Dewar flasks have been proposed as containers for relatively long-term (25 days) storage of perishable scientific samples or other perishable objects at a temperature of 175 C. The refrigeration would be maintained through slow boiling of liquid nitrogen (LN2). For the purposes of the application for which these containers were proposed, (1) the neck openings of commercial off-the-shelf (COTS) Dewar flasks are too small for most NASA samples; (2) the round shapes of the COTS containers give rise to unacceptably low efficiency of packing in rectangular cargo compartments; and (3) the COTS containers include metal structures that are too thermally conductive, such that they cannot, without exceeding size and weight limits, hold enough LN2 for the required long-term-storage. In comparison with COTS Dewar flasks, the proposed containers would be rectangular, yet would satisfy the long-term storage requirement without exceeding size and weight limits; would have larger neck openings; and would have greater sample volumes, leading to a packing efficiency of about double the sample volume as a fraction of total volume. The proposed containers would be made partly of aerospace- type composite materials and would include vacuum walls, multilayer insulation, and aerogel insulation.

A portable high power microwave source with permanent magnets

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

Li, Wei; Zhang, Jun; Li, Zhi-qiang

A high power microwave source with permanent magnets is proposed in this paper. The source has the length 330 mm, maximum diameter 350 mm, and total weight 50 kg, including 25 kg of permanent magnets. 1 GW of microwave power with Gaussian radiation pattern and 24% of microwave power generation efficiency in a pulse duration of 75 ns are obtained in the experiment. Operating frequency of the source is 2.32 GHz. Such a small size, light weight, and highly stable in operation source will be used in portable repetitive high power microwave generation systems.

Power efficient optical communications for space applications

NASA Technical Reports Server (NTRS)

Lesh, J. R.

1982-01-01

Optical communications technology promises substantial size, weight and power consumption savings for space to space high data rate communications over presently used microwave technology. These benefits are further increased by making the most efficient use of the available optical signal energy. This presentation will describe the progress to date on a project to design, build and demonstrate in the laboratory an optical communication system capable of conveying 2.5 bits of information per effective received photon. Such high power efficiencies will reduce the need for photon collection at the receiver and will greatly reduce the requirements for optical pointing accuracy, both at the transmitter as well as the receiver. A longer range program to demonstrate even higher photon efficiencies will also be described.

Efficiency of local Indonesia honey bees (Apis cerana L.) and stingless bee (Trigona iridipennis) on tomato (Lycopersicon esculentum Mill.) pollination.

PubMed

Putra, Ramadhani Eka; Kinasih, Ida

2014-01-01

Tomato (Lycopersicon esculentum Mill.) is considered as one of major agricultural commodity of Indonesia farming. However, monthly production is unstable due to lack of pollination services. Common pollinator agent of tomatoes is bumblebees which is unsuitable for tropical climate of Indonesia and the possibility of alteration of local wild plant interaction with their pollinator. Indonesia is rich with wild bees and some of the species already domesticated for years with prospect as pollinating agent for tomatoes. This research aimed to assess the efficiency of local honey bee (Apis cerana L.) and stingless bee (Trigona iridipennis), as pollinator of tomato. During this research, total visitation rate and total numbers of pollinated flowers by honey bee and stingless bee were compared between them with bagged flowers as control. Total fruit production, average weight and size also measured in order to correlated pollination efficiency with quantity and quality of fruit produced. Result of this research showed that A. cerana has slightly higher rate of visitation (p>0.05) and significantly shorter handling time (p < 0.05) than T. iridipennis due to their larger colony demand and low reward provide by tomato flowers. However, honey bee pollinated tomato flowers more efficient pollinator than stingless bee (80.3 and 70.2% efficiency, respectively; p < 0.05) even though the average weight and size of tomatoes were similar (p>0.05). Based on the results, it is concluded that the use of Apis cerana and Trigona spp., for pollinating tomatoes in tropical climates could be an alternative to the use of non-native Apis mellifera and bumblebees (Bombus spp.). However, more researches are needed to evaluate the cost/benefit on large-scale farming and greenhouse pollination using both bees against other bee species and pollination methods.

Design and Weighting Methods for a Nationally Representative Sample of HIV-infected Adults Receiving Medical Care in the United States-Medical Monitoring Project

PubMed Central

Iachan, Ronaldo; H. Johnson, Christopher; L. Harding, Richard; Kyle, Tonja; Saavedra, Pedro; L. Frazier, Emma; Beer, Linda; L. Mattson, Christine; Skarbinski, Jacek

2016-01-01

Background: Health surveys of the general US population are inadequate for monitoring human immunodeficiency virus (HIV) infection because the relatively low prevalence of the disease (<0.5%) leads to small subpopulation sample sizes. Objective: To collect a nationally and locally representative probability sample of HIV-infected adults receiving medical care to monitor clinical and behavioral outcomes, supplementing the data in the National HIV Surveillance System. This paper describes the sample design and weighting methods for the Medical Monitoring Project (MMP) and provides estimates of the size and characteristics of this population. Methods: To develop a method for obtaining valid, representative estimates of the in-care population, we implemented a cross-sectional, three-stage design that sampled 23 jurisdictions, then 691 facilities, then 9,344 HIV patients receiving medical care, using probability-proportional-to-size methods. The data weighting process followed standard methods, accounting for the probabilities of selection at each stage and adjusting for nonresponse and multiplicity. Nonresponse adjustments accounted for differing response at both facility and patient levels. Multiplicity adjustments accounted for visits to more than one HIV care facility. Results: MMP used a multistage stratified probability sampling design that was approximately self-weighting in each of the 23 project areas and nationally. The probability sample represents the estimated 421,186 HIV-infected adults receiving medical care during January through April 2009. Methods were efficient (i.e., induced small, unequal weighting effects and small standard errors for a range of weighted estimates). Conclusion: The information collected through MMP allows monitoring trends in clinical and behavioral outcomes and informs resource allocation for treatment and prevention activities. PMID:27651851

Globally efficient non-parametric inference of average treatment effects by empirical balancing calibration weighting

PubMed Central

Chan, Kwun Chuen Gary; Yam, Sheung Chi Phillip; Zhang, Zheng

2015-01-01

Summary The estimation of average treatment effects based on observational data is extremely important in practice and has been studied by generations of statisticians under different frameworks. Existing globally efficient estimators require non-parametric estimation of a propensity score function, an outcome regression function or both, but their performance can be poor in practical sample sizes. Without explicitly estimating either functions, we consider a wide class calibration weights constructed to attain an exact three-way balance of the moments of observed covariates among the treated, the control, and the combined group. The wide class includes exponential tilting, empirical likelihood and generalized regression as important special cases, and extends survey calibration estimators to different statistical problems and with important distinctions. Global semiparametric efficiency for the estimation of average treatment effects is established for this general class of calibration estimators. The results show that efficiency can be achieved by solely balancing the covariate distributions without resorting to direct estimation of propensity score or outcome regression function. We also propose a consistent estimator for the efficient asymptotic variance, which does not involve additional functional estimation of either the propensity score or the outcome regression functions. The proposed variance estimator outperforms existing estimators that require a direct approximation of the efficient influence function. PMID:27346982

Globally efficient non-parametric inference of average treatment effects by empirical balancing calibration weighting.

PubMed

Chan, Kwun Chuen Gary; Yam, Sheung Chi Phillip; Zhang, Zheng

2016-06-01

The estimation of average treatment effects based on observational data is extremely important in practice and has been studied by generations of statisticians under different frameworks. Existing globally efficient estimators require non-parametric estimation of a propensity score function, an outcome regression function or both, but their performance can be poor in practical sample sizes. Without explicitly estimating either functions, we consider a wide class calibration weights constructed to attain an exact three-way balance of the moments of observed covariates among the treated, the control, and the combined group. The wide class includes exponential tilting, empirical likelihood and generalized regression as important special cases, and extends survey calibration estimators to different statistical problems and with important distinctions. Global semiparametric efficiency for the estimation of average treatment effects is established for this general class of calibration estimators. The results show that efficiency can be achieved by solely balancing the covariate distributions without resorting to direct estimation of propensity score or outcome regression function. We also propose a consistent estimator for the efficient asymptotic variance, which does not involve additional functional estimation of either the propensity score or the outcome regression functions. The proposed variance estimator outperforms existing estimators that require a direct approximation of the efficient influence function.

Comparison of placental traits and their relation to litter size and parity weight in sheep.

PubMed

Ocak, S; Emsen, E; Köycegiz, F; Kutluca, M; Onder, H

2009-10-01

The relationships between genotype and placental traits, parity and litter weight (LW), and factors affecting these characteristics were investigated in this study. In total, 112 ewes (Romanov crossbred and local breeds) were utilized. One-way ANOVA was used for statistical comparison, and a Pearson correlation was used to determine the relationships between the variables. Significant differences in parity weight within genotype and breed have been determined. A negative correlation was revealed between placental weight (PW) and placental efficiency (r = -0.743, P < 0.01; and r = -0.732, P < 0.01). There was no relationship between litter sex and placental traits. Birth type had a significant effect on PW (P < 0.05), and significant differences within sex-birth type interactions occurred (P < 0.05). The results of the present study have shown a positive correlation between cotyledon density and placental efficiency among all genotypes and breeds that were used in the study. In conclusion, it has been determined that placental traits were affected by LW and Romanov crossbreed ewes had greater PW than local breeds. Further studies are required to investigate the relationship between parity and placental traits in sheep.

Local-world and cluster-growing weighted networks with controllable clustering

NASA Astrophysics Data System (ADS)

Yang, Chun-Xia; Tang, Min-Xuan; Tang, Hai-Qiang; Deng, Qiang-Qiang

2014-12-01

We constructed an improved weighted network model by introducing local-world selection mechanism and triangle coupling mechanism based on the traditional BBV model. The model gives power-law distributions of degree, strength and edge weight and presents the linear relationship both between the degree and strength and between the degree and the clustering coefficient. Particularly, the model is equipped with an ability to accelerate the speed increase of strength exceeding that of degree. Besides, the model is more sound and efficient in tuning clustering coefficient than the original BBV model. Finally, based on our improved model, we analyze the virus spread process and find that reducing the size of local-world has a great inhibited effect on virus spread.

Within-litter variation in birth weight: impact of nutritional status in the sow.

PubMed

Yuan, Tao-lin; Zhu, Yu-hua; Shi, Meng; Li, Tian-tian; Li, Na; Wu, Guo-yao; Bazer, Fuller W; Zang, Jian-jun; Wang, Feng-lai; Wang, Jun-jun

2015-06-01

Accompanying the beneficial improvement in litter size from genetic selection for high-prolificacy sows, within-litter variation in birth weight has increased with detrimental effects on post-natal growth and survival due to an increase in the proportion of piglets with low birth-weight. Causes of within-litter variation in birth weight include breed characteristics that affect uterine space, ovulation rate, degree of maturation of oocytes, duration of time required for ovulation, interval between ovulation and fertilization, uterine capacity for implantation and placentation, size and efficiency of placental transport of nutrients, communication between conceptus/fetus and maternal systems, as well as nutritional status and environmental influences during gestation. Because these factors contribute to within-litter variation in birth weight, nutritional status of the sow to improve fetal-placental development must focus on the following three important stages in the reproductive cycle: pre-mating or weaning to estrus, early gestation and late gestation. The goal is to increase the homogeneity of development of oocytes and conceptuses, decrease variations in conceptus development during implantation and placentation, and improve birth weights of newborn piglets. Though some progress has been made in nutritional regulation of within-litter variation in the birth weight of piglets, additional studies, with a focus on and insights into molecular mechanisms of reproductive physiology from the aspects of maternal growth and offspring development, as well as their regulation by nutrients provided to the sow, are urgently needed.

A National Census of Birth Weight in Purebred Dogs in Italy

PubMed Central

Groppetti, Debora; Pecile, Alessandro; Palestrini, Clara; Marelli, Stefano P.; Boracchi, Patrizia

2017-01-01

Simple Summary Birth weight is a key factor for neonatal mortality and morbidity in most mammalian species. The great morphological variability in size, body weight and breed, as well as in skeletal and cranial conformation makes it challenging to define birth weight standards in dogs. A total of 3293 purebred pups were surveyed to study which maternal aspects can determine birth weight considering head and body shape, size, body weight and breed in bitches, as well as litter size and sex in pups. In our sample, multivariate analysis outcomes suggested that birth weight and litter size were directly proportional to maternal size. The maternal body shape influenced both birth weight and litter size, whereas the maternal head shape had impact only on birth weight. Sex differences in birth weight were found. Birth weight and litter size also varied among breeds. The results of the present study could have practical implications allowing one to identify pups in need of admission to intensive nursing care, as occurs in humans. A deeper knowledge of the factors that significantly influence birth weight could positively affect the canine breeding management helping to prevent and reduce neonatal mortality. Abstract Despite increasing professionalism in dog breeding, the physiological range of birth weight in this species remains unclear. Low birth weight can predispose to neonatal mortality and growth deficiencies in humans. To date, the influence of the morphotype on birth weight has never been studied in dogs. For this purpose, an Italian census of birth weight was collected from 3293 purebred pups based on maternal morphotype, size, body weight and breed, as well as on litter size and sex of pups. Multivariate analysis outcomes showed that birth weight (p < 0.001) and litter size (p < 0.05) increased with maternal size and body weight. Birth weight was also influenced by the maternal head and body shape, with brachycephalic and brachymorph dogs showing the heaviest and the lightest pups, respectively (p < 0.001). Birth weight decreased with litter size (p < 0.001), and male pups were heavier than females (p < 0.001). These results suggest that canine morphotype, not only maternal size and body weight, can affect birth weight and litter size with possible practical implications in neonatal assistance. PMID:28556821

Sheared-root inocula of vesicular-arbuscular mycorrhizal fungi.

PubMed

Sylvia, D M; Jarstfer, A G

1992-01-01

For efficient handling, vesicular-arbuscular mycorrhizal fungi should be processed into small and uniform inocula; however, processing can reduce the inoculum density. In this article we describe the preparation and use of sheared-root inocula of Glomus spp. in which inoculum densities were increased during processing. Our objectives were to determine inoculum viability and density after shearing and to ascertain if the sheared inocula could be pelletized or used with a gel carrier. Root samples were harvested from aeroponic cultures, blotted dry, cut into 1-cm lengths, and sheared in a food processor for up to 80 s. After shearing, the inoculum was washed over sieves, and the propagule density in each fraction was determined. Sheared inocula were also encapsulated in carrageenan or used in a gel carrier. Shearing aeroponically produced root inocula reduced particle size. Propagule density increased with decreasing size fraction down to a size of 63 mum, after which propagule density decreased. The weighted-average propagule density of the inoculum was 135,380 propagules g (dry weight) of sheared root material. Sheared roots were encapsulated successfully in carrageenan, and the gel served as an effective carrier. Aeroponic root inoculum was stored dry at 4 degrees C for 23 months without significant reduction in propagule density; however, this material was not appropriate for shearing. Moist roots, useful for shearing, began to lose propagule density after 1 month of storage. Shearing proved to be an excellent method to prepare viable root inocula of small and uniform size, allowing for more efficient and effective use of limited inoculum supplies.

Thermal-Structural Optimization of Integrated Cryogenic Propellant Tank Concepts for a Reusable Launch Vehicle

NASA Technical Reports Server (NTRS)

Johnson, Theodore F.; Waters, W. Allen; Singer, Thomas N.; Haftka, Raphael T.

2004-01-01

A next generation reusable launch vehicle (RLV) will require thermally efficient and light-weight cryogenic propellant tank structures. Since these tanks will be weight-critical, analytical tools must be developed to aid in sizing the thickness of insulation layers and structural geometry for optimal performance. Finite element method (FEM) models of the tank and insulation layers were created to analyze the thermal performance of the cryogenic insulation layer and thermal protection system (TPS) of the tanks. The thermal conditions of ground-hold and re-entry/soak-through for a typical RLV mission were used in the thermal sizing study. A general-purpose nonlinear FEM analysis code, capable of using temperature and pressure dependent material properties, was used as the thermal analysis code. Mechanical loads from ground handling and proof-pressure testing were used to size the structural geometry of an aluminum cryogenic tank wall. Nonlinear deterministic optimization and reliability optimization techniques were the analytical tools used to size the geometry of the isogrid stiffeners and thickness of the skin. The results from the sizing study indicate that a commercial FEM code can be used for thermal analyses to size the insulation thicknesses where the temperature and pressure were varied. The results from the structural sizing study show that using combined deterministic and reliability optimization techniques can obtain alternate and lighter designs than the designs obtained from deterministic optimization methods alone.

Small Stirling dynamic isotope power system for multihundred-watt robotic missions

NASA Technical Reports Server (NTRS)

Bents, David J.

1991-01-01

Free Piston Stirling Engine (FPSE) and linear alternator (LA) technology is combined with radioisotope heat sources to produce a compact dynamic isotope power system (DIPS) suitable for multihundred watt space application which appears competitive with advance radioisotope thermoelectric generators (RTGs). The small Stirling DIPS is scalable to multihundred watt power levels or lower. The FPSE/LA is a high efficiency convertor in sizes ranging from tens of kilowatts down to only a few watts. At multihundred watt unit size, the FPSE can be directly integrated with the General Purpose Heat Source (GPHS) via radiative coupling; the resulting dynamic isotope power system has a size and weight that compares favorably with the advanced modular (Mod) RTG, but requires less than a third the amount of isotope fuel. Thus the FPSE extends the high efficiency advantage of dynamic systems into a power range never previously considered competitive for DIPS. This results in lower fuel cost and reduced radiological hazard per delivered electrical watt.

Small Stirling dynamic isotope power system for multihundred-watt robotic missions

NASA Technical Reports Server (NTRS)

Bents, David J.

1991-01-01

Free piston Stirling Engine (FPSE) and linear alternator (LA) technology is combined with radioisotope heat sources to produce a compact dynamic isotope power system (DIPS) suitable for multihundred watt space application which appears competitive with advanced radioisotope thermoelectric generators (RTGs). The small Stirling DIPS is scalable to multihundred watt power levels or lower. The FPSE/LA is a high efficiency convertor in sizes ranging from tens of kilowatts down to only a few watts. At multihundred watt unit size, the FPSE can be directly integrated with the General Purpose Heat Source (GPHS) via radiative coupling; the resulting dynamic isotope power system has a size and weight that compares favorably with the advanced modular (Mod) RTG, but requires less than a third the amount of isotope fuel. Thus the FPSE extends the high efficiency advantage of dynamic systems into a power range never previously considered competitive for DIPS. This results in lower fuel cost and reduced radiological hazard per delivered electrical watt.

Influence of Alternative Engine Concepts on LCTR2 Sizing and Mission Profile

NASA Technical Reports Server (NTRS)

Acree, C. W., Jr.; Snyder, Christopher A.

2012-01-01

The Large Civil Tiltrotor (LCTR) was developed as part of the NASA Heavy Lift Rotorcraft Systems Investigation in order to establish a consistent basis for evaluating the benefits of advanced technology for large tiltrotors. The concept has since evolved into the second-generation LCTR2, designed to carry 90 passengers for 1,000 nm at 300 knots, with vertical takeoff and landing. This paper examines the impact of advanced propulsion system concepts on LCTR2 sizing. Two concepts were studied: an advanced, single-speed engine with a conventional power turbine layout (Advanced Conventional Engine, or ACE), and a variable-speed power turbine engine (VSPT). The ACE is the lighter engine, but requires a multi-speed (shifting) gearbox, whereas the VSPT uses a lighter, fixed-ratio gearbox. The NASA Design and Analysis of Rotorcraft (NDARC) design code was used to study the trades between rotor and engine efficiency and weight. Rotor performance was determined by Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II), and engine performance was estimated with the Numerical Propulsion System Simulation (NPSS). Design trades for the ACE vs. VSPT are presented in terms of vehicle weight empty for variations in mission altitude and range; the effect of different One Engine Inoperative (OEI) criteria are also examined. Because of its strong effect on gearbox weight and on both rotor and engine efficiency, rotor speed was chosen as the reference design variable for comparing design trades. The two propulsion concepts had nearly identical vehicle weights and mission fuel consumption, and their relative advantages varied little with cruise altitude, mission range, or OEI criteria; high cruise altitude and low cruise tip speed were beneficial for both concepts.

Convergence and Efficiency of Adaptive Importance Sampling Techniques with Partial Biasing

NASA Astrophysics Data System (ADS)

Fort, G.; Jourdain, B.; Lelièvre, T.; Stoltz, G.

2018-04-01

We propose a new Monte Carlo method to efficiently sample a multimodal distribution (known up to a normalization constant). We consider a generalization of the discrete-time Self Healing Umbrella Sampling method, which can also be seen as a generalization of well-tempered metadynamics. The dynamics is based on an adaptive importance technique. The importance function relies on the weights (namely the relative probabilities) of disjoint sets which form a partition of the space. These weights are unknown but are learnt on the fly yielding an adaptive algorithm. In the context of computational statistical physics, the logarithm of these weights is, up to an additive constant, the free-energy, and the discrete valued function defining the partition is called the collective variable. The algorithm falls into the general class of Wang-Landau type methods, and is a generalization of the original Self Healing Umbrella Sampling method in two ways: (i) the updating strategy leads to a larger penalization strength of already visited sets in order to escape more quickly from metastable states, and (ii) the target distribution is biased using only a fraction of the free-energy, in order to increase the effective sample size and reduce the variance of importance sampling estimators. We prove the convergence of the algorithm and analyze numerically its efficiency on a toy example.

The impact of solar cell technology on planar solar array performance

NASA Technical Reports Server (NTRS)

Mills, Michael W.; Kurland, Richard M.

1989-01-01

The results of a study into the potential impact of advanced solar cell technologies on the characteristics (weight, cost, area) of typical planar solar arrays designed for low, medium and geosynchronous altitude earth orbits are discussed. The study considered planar solar array substrate designs of lightweight, rigid-panel graphite epoxy and ultra-lightweight Kapton. The study proposed to answer the following questions: Do improved cell characteristics translate into array-level weight, size and cost improvements; What is the relative importance of cell efficiency, weight and cost with respect to array-level performance; How does mission orbital environment affect array-level performance. Comparisons were made at the array level including all mechanisms, hinges, booms, and harnesses. Array designs were sized to provide 5kW of array power (not spacecraft bus power, which is system dependent but can be scaled from given values). The study used important grass roots issues such as use of the GaAs radiation damage coefficients as determined by Anspaugh. Detailed costing was prepared, including cell and cover costs, and manufacturing attrition rates for the various cell types.

Efficient isoparametric integration over arbitrary space-filling Voronoi polyhedra for electronic structure calculations

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

Alam, Aftab; Khan, S. N.; Wilson, Brian G.

2011-07-06

A numerically efficient, accurate, and easily implemented integration scheme over convex Voronoi polyhedra (VP) is presented for use in ab initio electronic-structure calculations. We combine a weighted Voronoi tessellation with isoparametric integration via Gauss-Legendre quadratures to provide rapidly convergent VP integrals for a variety of integrands, including those with a Coulomb singularity. We showcase the capability of our approach by first applying it to an analytic charge-density model achieving machine-precision accuracy with expected convergence properties in milliseconds. For contrast, we compare our results to those using shape-functions and show our approach is greater than 10 5 times faster and 10more » 7 times more accurate. Furthermore, a weighted Voronoi tessellation also allows for a physics-based partitioning of space that guarantees convex, space-filling VP while reflecting accurate atomic size and site charges, as we show within KKR methods applied to Fe-Pd alloys.« less

Application of response surface methodology for optimization of parameters for microwave heating of rare earth carbonates

NASA Astrophysics Data System (ADS)

Yin, Shaohua; Lin, Guo; Li, Shiwei; Peng, Jinhui; Zhang, Libo

2016-09-01

Microwave heating has been applied in the field of drying rare earth carbonates to improve drying efficiency and reduce energy consumption. The effects of power density, material thickness and drying time on the weight reduction (WR) are studied using response surface methodology (RSM). The results show that RSM is feasible to describe the relationship between the independent variables and weight reduction. Based on the analysis of variance (ANOVA), the model is in accordance with the experimental data. The optimum experiment conditions are power density 6 w/g, material thickness 15 mm and drying time 15 min, resulting in an experimental weight reduction of 73%. Comparative experiments show that microwave drying has the advantages of rapid dehydration and energy conservation. Particle analysis shows that the size distribution of rare earth carbonates after microwave drying is more even than those in an oven. Based on these findings, microwave heating technology has an important meaning to energy-saving and improvement of production efficiency for rare earth smelting enterprises and is a green heating process.

Sizing of complex structure by the integration of several different optimal design algorithms

NASA Technical Reports Server (NTRS)

Sobieszczanski, J.

1974-01-01

Practical design of large-scale structures can be accomplished with the aid of the digital computer by bringing together in one computer program algorithms of nonlinear mathematical programing and optimality criteria with weight-strength and other so-called engineering methods. Applications of this approach to aviation structures are discussed with a detailed description of how the total problem of structural sizing can be broken down into subproblems for best utilization of each algorithm and for efficient organization of the program into iterative loops. Typical results are examined for a number of examples.

Single phase bi-directional AC-DC converter with reduced passive components size and common mode electro-magnetic interference

DOEpatents

Mi, Chris; Li, Siqi

2017-01-31

A bidirectional AC-DC converter is presented with reduced passive component size and common mode electro-magnetic interference. The converter includes an improved input stage formed by two coupled differential inductors, two coupled common and differential inductors, one differential capacitor and two common mode capacitors. With this input structure, the volume, weight and cost of the input stage can be reduced greatly. Additionally, the input current ripple and common mode electro-magnetic interference can be greatly attenuated, so lower switching frequency can be adopted to achieve higher efficiency.

Analysis of regenerative fuel cells

NASA Technical Reports Server (NTRS)

Gross, S.

1982-01-01

The concept of a rechargeable fuel cell (RFC) system is considered. A newer type of rechargeable battery, the nickel hydrogen (Ni-H2) battery, is also evaluated. A review was made of past studies which showed large variations in weight, cost, and efficiency. Hydrogen-bromine and hydrogen-chlorine regenerable fuel cells were studied, and were found to have a potential for higher energy storage efficiency then the hydrogen-oxygen system. A reduction of up to 15 percent in solar array size may be possible as a result. These systems are not yet developed, but further study of them is recommended.

Toroidal transformer design program with application to inverter circuitry

NASA Technical Reports Server (NTRS)

Dayton, J. A., Jr.

1972-01-01

Estimates of temperature, weight, efficiency, regulation, and final dimensions are included in the output of the computer program for the design of transformers for use in the basic parallel inverter. The program, written in FORTRAN 4, selects a tape wound toroidal magnetic core and, taking temperature, materials, core geometry, skin depth, and ohmic losses into account, chooses the appropriate wire sizes and number of turns for the center tapped primary and single secondary coils. Using the program, 2- and 4-kilovolt-ampere transformers are designed for frequencies from 200 to 3200 Hz and the efficiency of a basic transistor inverter is estimated.

Study of advanced rotary combustion engines for commuter aircraft

NASA Technical Reports Server (NTRS)

Berkowitz, M.; Jones, C.; Myers, D.

1983-01-01

Performance, weight, size, and maintenance data for advanced rotary aircraft engines suitable for comparative commuter aircraft system evaluation studies of alternate engine candidates are provided. These are turbocharged, turbocompounded, direct injected, stratified charge rotary engines. Hypothetical engines were defined (an RC4-74 at 895 kW and an RC6-87 at 1490 kW) based on the technologies and design approaches used in the highly advanced engine of a study of advanced general aviation rotary engines. The data covers the size range of shaft power from 597 kW (800 hp) to 1865 kW (2500 hp) and is in the form of drawings, tables, curves and written text. These include data on internal geometry and configuration, installation information, turbocharging and turbocompounding arrangements, design features and technologies, engine cooling, fuels, scaling for weight size BSFC and heat rejection for varying horsepower, engine operating and performance data, and TBO and maintenance requirements. The basic combustion system was developed and demonstrated; however the projected power densities and performance efficiencies require increases in engine internal pressures, thermal loading, and rotative speed.

Characterization of advanced electric propulsion systems

NASA Technical Reports Server (NTRS)

Ray, P. K.

1982-01-01

Characteristics of several advanced electric propulsion systems are evaluated and compared. The propulsion systems studied are mass driver, rail gun, MPD thruster, hydrogen free radical thruster and mercury electron bombardment ion engine. These are characterized by specific impulse, overall efficiency, input power, average thrust, power to average thrust ratio and average thrust to dry weight ratio. Several important physical characteristics such as dry system mass, accelerator length, bore size and current pulse requirement are also evaluated in appropriate cases. Only the ion engine can operate at a specific impulse beyond 2000 sec. Rail gun, MPD thruster and free radical thruster are currently characterized by low efficiencies. Mass drivers have the best performance characteristics in terms of overall efficiency, power to average thrust ratio and average thrust to dry weight ratio. But, they can only operate at low specific impulses due to large power requirements and are extremely long due to limitations of driving current. Mercury ion engines have the next best performance characteristics while operating at higher specific impulses. It is concluded that, overall, ion engines have somewhat better characteristics as compared to the other electric propulsion systems.

Upregulation of genes encoding digestive enzymes and nutrient transporters in the digestive system of broiler chickens by dietary supplementation of fiber and inclusion of coarse particle size corn.

PubMed

Kheravii, Sarbast K; Swick, Robert A; Choct, Mingan; Wu, Shu-Biao

2018-03-20

Measures to improve bird performance have been sought due to the imminent phase out of in-feed antibiotics in poultry and continued demand for higher poultry feeding efficiency. Increasing grain particle size and dietary fibre may improve gizzard function, digestive efficiency and nutrient absorption. This study was conducted to evaluate the effect increased particle size of corn and inclusion of sugarcane bagasse (SB) on mRNA expression of genes encoding digestive enzymes and nutrient transporters in broilers. A total of 336 day-old Ross 308 males were assigned in a 2 × 2 factorial arrangement of treatments with corn particle size - coarse 3576 μm or fine 1113 μm geometric mean diameter, and SB - 0 or 2% inclusion. Feed conversion ratio (FCR), weight gain and feed intake were measured from d 0-10 and d 10-24. The relative gizzard weight and mRNA expression of genes encoding digestive enzymes and intestinal nutrient transporters were measured on d 24. During d 10-24, a particle size × SB interaction was observed for FCR (P < 0.01), where birds fed coarsely ground corn (CC) with 2% SB had lower FCR than those fed CC without SB. A particle size × SB interaction was observed for both expression of pepsinogen A and C (P < 0.01) which were negatively correlated with FCR on d 24. Addition of 2% SB upregulated pepsinogen A and C only in CC fed birds. Further, 2% SB also upregulated pancreatic amylase (AMY2A) and intestinal cationic amino acid transporter-1 (CAT1). Inclusion of dietary CC upregulated duodenal amino peptidase N (APN), jejunal alanine, serine, cysteine and threonine transporter-1 (ASCT1), and ileal peptide transporter-2 (PepT2). These results suggest that both SB and coarse particle size modulate expression of genes encoding important digestive enzymes and nutrient transporters and thus are directly related to bird performance. These findings provide insights into the combination effects of dietary fiber and particle size in the future management of broiler feeding.

Enhancement of partial robust M-regression (PRM) performance using Bisquare weight function

NASA Astrophysics Data System (ADS)

Mohamad, Mazni; Ramli, Norazan Mohamed; Ghani@Mamat, Nor Azura Md; Ahmad, Sanizah

2014-09-01

Partial Least Squares (PLS) regression is a popular regression technique for handling multicollinearity in low and high dimensional data which fits a linear relationship between sets of explanatory and response variables. Several robust PLS methods are proposed to accommodate the classical PLS algorithms which are easily affected with the presence of outliers. The recent one was called partial robust M-regression (PRM). Unfortunately, the use of monotonous weighting function in the PRM algorithm fails to assign appropriate and proper weights to large outliers according to their severity. Thus, in this paper, a modified partial robust M-regression is introduced to enhance the performance of the original PRM. A re-descending weight function, known as Bisquare weight function is recommended to replace the fair function in the PRM. A simulation study is done to assess the performance of the modified PRM and its efficiency is also tested in both contaminated and uncontaminated simulated data under various percentages of outliers, sample sizes and number of predictors.

Genome-wide association studies identified multiple genetic loci for body size at four growth stages in Chinese Holstein cattle.

PubMed

Zhang, Xu; Chu, Qin; Guo, Gang; Dong, Ganghui; Li, Xizhi; Zhang, Qin; Zhang, Shengli; Zhang, Zhiwu; Wang, Yachun

2017-01-01

The growth and maturity of cattle body size affect not only feed efficiency, but also productivity and longevity. Dissecting the genetic architecture of body size is critical for cattle breeding to improve both efficiency and productivity. The volume and weight of body size are indicated by several measurements. Among them, Heart Girth (HG) and Hip Height (HH) are the most important traits. They are widely used as predictors of body weight (BW). Few association studies have been conducted for HG and HH in cattle focusing on single growth stage. In this study, we extended the Genome-wide association studies to a full spectrum of four growth stages (6-, 12-, 18-, and 24-months after birth) in Chinese Holstein heifers. The whole genomic single nucleotide polymorphisms (SNPs) were obtained from the Illumina BovineSNP50 v2 BeadChip genotyped on 3,325 individuals. Estimated breeding values (EBVs) were derived for both HG and HH at the four different ages and analyzed separately for GWAS by using the Fixed and random model Circuitous Probability Unification (FarmCPU) method. In total, 27 SNPs were identified to be significantly associated with HG and HH at different growth stages. We found 66 candidate genes located nearby the associated SNPs, including nine genes that were known as highly related to development and skeletal and muscular growth. In addition, biological function analysis was performed by Ingenuity Pathway Analysis and an interaction network related to development was obtained, which contained 16 genes out of the 66 candidates. The set of putative genes provided valuable resources and can help elucidate the genomic architecture and mechanisms underlying growth traits in dairy cattle.

Influence of Roost Site Selection on the Energetic Efficiency and Distribution of Starlings and Blackbirds: A Way of Controlling Blackbird Populations Near Airports.

DTIC Science & Technology

1981-05-01

differences present since males and females are sexually dimorphic with regard to body weight and MR is affected by the size of t the bird. Hart (1962...810). Birds were kept at ambient temperatures ranging from 5.0 to -10.0 C on natural photoperiods and were provided turkey pellets (Ralston Purina Co

Individualism in plant populations: using stochastic differential equations to model individual neighbourhood-dependent plant growth.

PubMed

Lv, Qiming; Schneider, Manuel K; Pitchford, Jonathan W

2008-08-01

We study individual plant growth and size hierarchy formation in an experimental population of Arabidopsis thaliana, within an integrated analysis that explicitly accounts for size-dependent growth, size- and space-dependent competition, and environmental stochasticity. It is shown that a Gompertz-type stochastic differential equation (SDE) model, involving asymmetric competition kernels and a stochastic term which decreases with the logarithm of plant weight, efficiently describes individual plant growth, competition, and variability in the studied population. The model is evaluated within a Bayesian framework and compared to its deterministic counterpart, and to several simplified stochastic models, using distributional validation. We show that stochasticity is an important determinant of size hierarchy and that SDE models outperform the deterministic model if and only if structural components of competition (asymmetry; size- and space-dependence) are accounted for. Implications of these results are discussed in the context of plant ecology and in more general modelling situations.

Life cycle efficiency of beef production: II. Relationship of cow efficiency ratios to traits of the dam and progeny weaned.

PubMed

Davis, M E; Rutledge, J J; Cundiff, L V; Hauser, E R

1983-10-01

Several measures of life cycle cow efficiency were calculated using weights and individual feed consumptions recorded on 160 dams of beef, dairy and beef X dairy breeding and their progeny. Ratios of output to input were used to estimate efficiency, where outputs included weaning weights of progeny plus salvage value of the dam and inputs included creep feed consumed by progeny plus feed consumed by the dam over her entire lifetime. In one approach to estimating efficiency, inputs and outputs were weighted by probabilities that were a function of the cow herd age distribution and percentage calf crop in a theoretical herd. The second approach to estimating cow efficiency involved dividing the sum of the weights by the sum of the feed consumption values, with all pieces of information being given equal weighting. Relationships among efficiency estimates and various traits of dams and progeny were examined. Weights, heights, and weight:height ratios of dams at 240 d of age were not correlated significantly with subsequent efficiency of calf production, indicating that indirect selection for lifetime cow efficiency at an early age based on these traits would be ineffective. However, females exhibiting more efficient weight gains from 240 d to first calving tended to become more efficient dams. Correlations of efficiency with weight of dam at calving and at weaning were negative and generally highly significant. Height at withers was negatively related to efficiency. Ratio of weight to height indicated that fatter dams generally were less efficient. The effect of milk production on efficiency depended upon the breed combinations involved. Dams calving for the first time at an early age and continuing to calve at short intervals were superior in efficiency. Weaning rate was closely related to life cycle efficiency. Large negative correlations between efficiency and feed consumption of dams were observed, while correlations of efficiency with progeny weights and feed consumptions in individual parities tended to be positive though nonsignificant. However, correlations of efficiency with accumulative progeny weights and feed consumptions generally were significant.

Technology Assessment for Large Vertical-Lift Transport Tiltrotors

NASA Technical Reports Server (NTRS)

Germanowski, Peter J.; Stille, Brandon L.; Strauss, Michael P.

2010-01-01

The technical community has identified rotor efficiency as a critical enabling technology for large vertical-lift transport (LVLT) rotorcraft. The size and performance of LVLT aircraft will be far beyond current aircraft capabilities, enabling a transformational change in cargo transport effectiveness. Two candidate approaches for achieving high efficiency were considered for LVLT applications: a variable-diameter tiltrotor (VDTR) and a variable-speed tiltrotor (VSTR); the former utilizes variable-rotor geometry and the latter utilizes variable-rotor speed. Conceptual aircraft designs were synthesized for the VDTR and VSTR and compared to a conventional tiltrotor (CTR). The aircraft were optimized to a common objective function and bounded by a set of physical- and requirements-driven constraints. The resulting aircraft were compared for weight, size, performance, handling qualities, and other attributes. These comparisons established a measure of the relative merits of the variable-diameter and -speed rotor systems as enabling technologies for LVLT capability.

Evaluation of the Criollo breed Romosinuano as purebred and crossbred cows with Brahman and Angus in Florida. II. Maternal influence on calf traits, cow weight, and measures of maternal efficiency.

PubMed

Riley, D G; Chase, C C; Coleman, S W; Olson, T A

2014-05-01

The objectives of this work were to compare the Criollo breed Romosinuano as straightbred and crossbred cows with Angus and Brahman in subtropical Florida and to estimate heterosis for size traits of their calves, their own weight, and maternal efficiency traits. Cows (n = 404) were born from 2002 to 2005. After their first exposure to bulls as young cows, crossbred cows were bred to bulls of the third breed, and straightbred cows were bred in to bulls of the other 2 breeds. Calves were spring-born from 2005 through 2011. Evaluated calf (n = 1,254) traits included birth weight and weight, ADG, BCS, and hip height at weaning. Cow weight (n = 1,389) was recorded at weaning. Maternal efficiency traits evaluated included weaning weight per 100 kg cow weight, weaning weight per calving interval, and weaning weight per cow exposed to breeding (n = 1,442). Fixed effects and their interactions were investigated included sire and dam breed of cow, sire breed of calf, cow age, year, calf gender, and weaning age as a linear covariate (calf traits at weaning). Direct and maternal additive genetic effects were random in models for calf traits; only direct additive effects were modeled for cow traits. Cows sired by Angus bulls from outside the research herd had calves that were heavier at birth and weaning and greater ADG, BCS, and hip height (P < 0.05). Estimates of heterosis for weaning weight, BCS, and ADG ranged from 1.3 to 13.2% for all pairs of breeds (P < 0.05). Estimates of heterosis for birth weight (3.2 to 8.2%) and hip height (2.3%) were significant for Romosinuano-Angus and Brahman-Angus. Heterosis for cow weight was 65 ± 8 kg for Brahman-Angus (P < 0.001), and estimates for other pairs of breeds were approximately one-half that value. Heterosis for weaning weight/100 kg cow weight was 3.4 ± 0.75 kg for Romosinuano-Angus. Heterosis estimates for weaning weight/calving interval (P < 0.001) ranged from 0.08 ± 0.01 to 0.12 ± 0.01. Heterosis for weaning weight/cow exposed were 31.6 7.7, 36.9 ± 7.4, and 59.1 ± 7.5 kg for Romosinuano-Angus, Romosinuano-Brahman, and Brahman-Angus, respectively (P < 0.001). Most aspects of Romosinuano crossbred maternal performance were acceptable; maternal performance of Brahman-Angus cows excelled.

Detonation charge size versus coda magnitude relations in California and Nevada

USGS Publications Warehouse

Brocher, T.M.

2003-01-01

Magnitude-charge size relations have important uses in forensic seismology and are used in Comprehensive Nuclear-Test-Ban Treaty monitoring. I derive empirical magnitude versus detonation-charge-size relationships for 322 detonations located by permanent seismic networks in California and Nevada. These detonations, used in 41 different seismic refraction or network calibration experiments, ranged in yield (charge size) between 25 and 106 kg; coda magnitudes reported for them ranged from 0.5 to 3.9. Almost all represent simultaneous (single-fired) detonations of one or more boreholes. Repeated detonations at the same shotpoint suggest that the reported coda magnitudes are repeatable, on average, to within 0.1 magnitude unit. An empirical linear regression for these 322 detonations yields M = 0.31 + 0.50 log10(weight [kg]). The detonations compiled here demonstrate that the Khalturin et al. (1998) relationship, developed mainly for data from large chemical explosions but which fits data from nuclear blasts, can be used to estimate the minimum charge size for coda magnitudes between 0.5 and 3.9. Drilling, loading, and shooting logs indicate that the explosive specification, loading method, and effectiveness of tamp are the primary factors determining the efficiency of a detonation. These records indicate that locating a detonation within the water table is neither a necessary nor sufficient condition for an efficient shot.

Weight optimization of plane truss using genetic algorithm

NASA Astrophysics Data System (ADS)

Neeraja, D.; Kamireddy, Thejesh; Santosh Kumar, Potnuru; Simha Reddy, Vijay

2017-11-01

Optimization of structure on basis of weight has many practical benefits in every engineering field. The efficiency is proportionally related to its weight and hence weight optimization gains prime importance. Considering the field of civil engineering, weight optimized structural elements are economical and easier to transport to the site. In this study, genetic optimization algorithm for weight optimization of steel truss considering its shape, size and topology aspects has been developed in MATLAB. Material strength and Buckling stability have been adopted from IS 800-2007 code of construction steel. The constraints considered in the present study are fabrication, basic nodes, displacements, and compatibility. Genetic programming is a natural selection search technique intended to combine good solutions to a problem from many generations to improve the results. All solutions are generated randomly and represented individually by a binary string with similarities of natural chromosomes, and hence it is termed as genetic programming. The outcome of the study is a MATLAB program, which can optimise a steel truss and display the optimised topology along with element shapes, deflections, and stress results.

36 CFR § 1004.11 - Load, weight and size limits.

Code of Federal Regulations, 2013 CFR

2013-07-01

... designate more restrictive limits when appropriate for traffic safety or protection of the road surface. The... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Load, weight and size limits... TRAFFIC SAFETY § 1004.11 Load, weight and size limits. (a) Vehicle load, weight and size limits...

Scaling and biomechanics of surface attachment in climbing animals

PubMed Central

Labonte, David; Federle, Walter

2015-01-01

Attachment devices are essential adaptations for climbing animals and valuable models for synthetic adhesives. A major unresolved question for both natural and bioinspired attachment systems is how attachment performance depends on size. Here, we discuss how contact geometry and mode of detachment influence the scaling of attachment forces for claws and adhesive pads, and how allometric data on biological systems can yield insights into their mechanism of attachment. Larger animals are expected to attach less well to surfaces, due to their smaller surface-to-volume ratio, and because it becomes increasingly difficult to distribute load uniformly across large contact areas. In order to compensate for this decrease of weight-specific adhesion, large animals could evolve overproportionally large pads, or adaptations that increase attachment efficiency (adhesion or friction per unit contact area). Available data suggest that attachment pad area scales close to isometry within clades, but pad efficiency in some animals increases with size so that attachment performance is approximately size-independent. The mechanisms underlying this biologically important variation in pad efficiency are still unclear. We suggest that switching between stress concentration (easy detachment) and uniform load distribution (strong attachment) via shear forces is one of the key mechanisms enabling the dynamic control of adhesion during locomotion. PMID:25533088

Assessing the lipophilicity of fragments and early hits

NASA Astrophysics Data System (ADS)

Mortenson, Paul N.; Murray, Christopher W.

2011-07-01

A key challenge in many drug discovery programs is to accurately assess the potential value of screening hits. This is particularly true in fragment-based drug design (FBDD), where the hits often bind relatively weakly, but are correspondingly small. Ligand efficiency (LE) considers both the potency and the size of the molecule, and enables us to estimate whether or not an initial hit is likely to be optimisable to a potent, druglike lead. While size is a key property that needs to be controlled in a small molecule drug, there are a number of additional properties that should also be considered. Lipophilicity is amongst the most important of these additional properties, and here we present a new efficiency index (LLEAT) that combines lipophilicity, size and potency. The index is intuitively defined, and has been designed to have the same target value and dynamic range as LE, making it easily interpretable by medicinal chemists. Monitoring both LE and LLEAT should help both in the selection of more promising fragment hits, and controlling molecular weight and lipophilicity during optimisation.

Cycle of a closed gas-turbine plant with a gas-dynamic energy-separation device

NASA Astrophysics Data System (ADS)

Leontiev, A. I.; Burtsev, S. A.

2017-09-01

The efficiency of closed gas-turbine space-based plants is analyzed. The weight-size characteristics of closed gas-turbine plants are shown in many respects as determined by the refrigerator-radiator parameters. The scheme of closed gas-turbine plants with a gas-dynamic temperature-stratification device is proposed, and a calculation model is developed. This model shows that the cycle efficiency decreases by 2% in comparison with that of the closed gas-turbine plants operating by the traditional scheme with increasing temperature at the output from the refrigerator-radiator by 28 K and decreasing its area by 13.7%.

[Method for concentration determination of mineral-oil fog in the air of workplace].

PubMed

Xu, Min; Zhang, Yu-Zeng; Liu, Shi-Feng

2008-05-01

To study the method of concentration determination of mineral-oil fog in the air of workplace. Four filter films such as synthetic fabric filter film, beta glass fiber filter film, chronic filter paper and microporous film were used in this study. Two kinds of dust samplers were used to collect the sample, one sampling at fast flow rate in a short time and the other sampling at slow flow rate with long duration. Subsequently, the filter membrane was weighed with electronic analytical balance. According to sampling efficiency and incremental size, the adsorbent ability of four different filter membranes was compared. When the flow rate was between 10 approximately 20 L/min and the sampling time was between 10 approximately 15 min, the average sampling efficiency of synthetic fabric filter film was 95.61% and the increased weight ranged from 0.87 to 2.60 mg. When the flow rate was between 10 approximately 20 L/min and sampling time was between 10 approximately 15 min, the average sampling efficiency of beta glass fiber filter film was 97.57% and the increased weight was 0.75 approximately 2.47 mg. When the flow rate was between 5 approximately 10 L/min and the sampling time between 10 approximately 20 min, the average sampling efficiency of chronic filter paper and microporous film was 48.94% and 63.15%, respectively and the increased weight was 0.75 approximately 2.15 mg and 0.23 approximately 0.85 mg, respectively. When the flow rate was 3.5 L/min and the sampling time was between 100 approximately 166 min, the average sampling efficiency of filter film were 94.44% and 93.45%, respectively and the average increased weight was 1.28 mg for beta glass fiber filter film and 0.78 mg for beta glass fiber filter film and synthetic fabric synthetic fabric filter film. The average sampling efficiency of chronic filter paper and microporous film were 37.65% and 88.21%, respectively. The average increased weight was 4.30 mg and 1.23 mg, respectively. Sampling with synthetic fabric filter film and beta glass fiber filter film is credible, accurate, simple and feasible for determination of the concentration of mineral-oil fog in workplaces.

Guidance for the utility of linear models in meta-analysis of genetic association studies of binary phenotypes.

PubMed

Cook, James P; Mahajan, Anubha; Morris, Andrew P

2017-02-01

Linear mixed models are increasingly used for the analysis of genome-wide association studies (GWAS) of binary phenotypes because they can efficiently and robustly account for population stratification and relatedness through inclusion of random effects for a genetic relationship matrix. However, the utility of linear (mixed) models in the context of meta-analysis of GWAS of binary phenotypes has not been previously explored. In this investigation, we present simulations to compare the performance of linear and logistic regression models under alternative weighting schemes in a fixed-effects meta-analysis framework, considering designs that incorporate variable case-control imbalance, confounding factors and population stratification. Our results demonstrate that linear models can be used for meta-analysis of GWAS of binary phenotypes, without loss of power, even in the presence of extreme case-control imbalance, provided that one of the following schemes is used: (i) effective sample size weighting of Z-scores or (ii) inverse-variance weighting of allelic effect sizes after conversion onto the log-odds scale. Our conclusions thus provide essential recommendations for the development of robust protocols for meta-analysis of binary phenotypes with linear models.

36 CFR 1004.11 - Load, weight and size limits.

Code of Federal Regulations, 2012 CFR

2012-07-01

... limits when appropriate for traffic safety or protection of the road surface. The Board may require a... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Load, weight and size limits... § 1004.11 Load, weight and size limits. (a) Vehicle load, weight and size limits established by State law...

36 CFR 1004.11 - Load, weight and size limits.

Code of Federal Regulations, 2014 CFR

2014-07-01

... limits when appropriate for traffic safety or protection of the road surface. The Board may require a... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Load, weight and size limits... § 1004.11 Load, weight and size limits. (a) Vehicle load, weight and size limits established by State law...

36 CFR 1004.11 - Load, weight and size limits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... limits when appropriate for traffic safety or protection of the road surface. The Board may require a... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Load, weight and size limits... § 1004.11 Load, weight and size limits. (a) Vehicle load, weight and size limits established by State law...

Quiet Supersonic Platform (QSP) Materials and Structures Focus Group Meeting, 26 June 2001

DTIC Science & Technology

2001-07-01

variety of size scales. Woven metal microtubes offer efficient heat -transfer capability. An inexpensive approach to creating lattice structures uses...because of their light weight and as heat exchangers , by using a metal with high thermal conductivity to draw heat into the lattice, where it can...tubes woven into metal sheets, which are then stacked, sprayed with a transient liquid-phase sintering/bonding agent, and heated . The result is a

Intelligent Systems for Power Management and Distribution

NASA Technical Reports Server (NTRS)

Button, Robert M.

2002-01-01

The motivation behind an advanced technology program to develop intelligent power management and distribution (PMAD) systems is described. The program concentrates on developing digital control and distributed processing algorithms for PMAD components and systems to improve their size, weight, efficiency, and reliability. Specific areas of research in developing intelligent DC-DC converters and distributed switchgear are described. Results from recent development efforts are presented along with expected future benefits to the overall PMAD system performance.

Further Studies in Filmwise Condensation of Steam on Horizontal Finned Tubes

DTIC Science & Technology

1992-03-01

which to base their design of Ocean Thermal Energy Conversion ( OTEC ) heat exchangers . ANL used two shell-and-tube heat exchangers , with no inserts, for...throughout the duration of this study. xiii~q I. INTRODUCTON A. BACKGROUND A reduction in size and weight of all types of heat exchangers aboard Naval...vessels will allow more efficient use of space. The benefits might include greater equipment accessibility for maintenance or greater heat exchanger

Extending the Endurance, Missions and Capabilities of Most UAVs Using Advanced Flexible/Ridged Solar Cells and New High Power Density Batteries Technology

DTIC Science & Technology

2011-03-01

68 3. Photovoltaic Effect ..........................69 4. Factors Affecting Cell Efficiency ............69 D. THIN-FILM...resistance. (After [3])...........................................120  xvi Table 21.  Average battery capacity (AH) and battery energy capacity (WH...which is directly limited by the on-board battery capacity . The other key drawbacks are the weight and size of the mini- xviii UAV, which restrict the

Advanced general aviation engine/airframe integration study

NASA Technical Reports Server (NTRS)

Zmroczek, L. A.

1982-01-01

A comparison of the in-airframe performance and efficiency of the advanced engine concepts is presented. The results indicate that the proposed advanced engines can significantly improve the performance and economy of general aviation airplanes. The engine found to be most promising is the highly advanced version of a rotary combustion (Wankel) engine. The low weight and fuel consumption of this engine, as well as its small size, make it suited for aircraft use.

Compensatory growth in hybrid tilapia ( Oreochromis mossambicus ×O. niloticus) reared in seawater, following restricted feeding

NASA Astrophysics Data System (ADS)

Wang, Yan; Cui, Yibo; Yang, Yunxia; Cai, Fasheng

2004-12-01

Hybrid tilapia weighing 7.71 g were reared in seawater at 24.0 29.0°C for 8 weeks. The controls were fed to satiation twice a day throughout the experiment, whereas treatment groups were fed at 0.5%, 1.5% or 3.0% body weight per day for 4 weeks, and then to satiation for the remainder of the experiment. During the first 4-week period, there was a curvilinear relationship between growth rate and ration size. Fish fed 0.5% and 1.5% rations displayed compensatory growth response of 2 weeks duration during realimentation. The weight-adjusted growth rate of fish fed at 3% ration was not significantly different from that of the controls by the end of the experiment, when none of the treatment groups had caught up in body weight with the controls. Hyperphagia was observed for the first 2 weeks of realimenatation in fish previously fed at 3% ration, but persisted for the whole realimentation period in groups previously fed at 0.5% and 1.5% rations. None of the feed restricted groups showed improved digestibility, feed efficiency, or protein and energy retention efficiency.

Structure relationship of cationic lipids on gene transfection mediated by cationic liposomes.

PubMed

Paecharoenchai, Orapan; Niyomtham, Nattisa; Apirakaramwong, Auayporn; Ngawhirunpat, Tanasait; Rojanarata, Theerasak; Yingyongnarongkul, Boon-ek; Opanasopit, Praneet

2012-12-01

The aim of this study was to investigate the transfection efficiency of cationic liposomes formulated with phosphatidylcholine (PC) and novel synthesized diethanolamine-based cationic lipids at a molar ratio of 5:1 in comparison with Lipofectamine™ 2000. Factors affecting transfection efficiency and cell viability, including the chemical structure of the cationic lipids, such as different amine head group (diamine and polyamine; and non-spermine and spermine) and acyl chain lengths (C14, C16, and C18) and the weight ratio of liposomes to DNA were evaluated on a human cervical carcinoma cell line (HeLa cells) using the pDNA encoding green fluorescent protein (pEGFP-C2). Characterizations of these lipoplexes in terms of size and charge measurement and agarose gel electrophoresis were performed. The results from this study revealed that almost no transfection was observed in the liposome formulations composed of cationic lipids with a non-spermine head group. In addition, the transfection efficiency of these cationic liposomes was in the following order: spermine-C14 > spermine-C16 > spermine-C18. The highest transfection efficiency was observed in the formulation of spermine-C14 liposomes at a weight ratio of 25; furthermore, this formulation was safe for use in vitro. In conclusion, cationic liposomes containing spermine head groups demonstrated promising potential as gene carriers.

Assessing survey measures of infant birth weight and birth size in Ecuador.

PubMed

Eggleston, E; Tsui, A O; Fortney, J

2000-07-01

The purpose of this study was to assess the utility of using maternal assessments of infant birth size as proxy measures for birth weight in Ecuador, a country in which a sizeable proportion of births take place at home, where birth weight is typically not recorded. Four thousand and seventy-eight women who experienced a live singleton birth between January 1992 and August 1994 were interviewed in the Ecuador Demographic and Maternal-Child Health Survey. All women were asked if their child was weighed at birth, his/her weight, and what they considered to be his/her birth size relative to other newborns. The consistency between birth size and birth weight measures was assessed, and the differences between infants with and without reported birth weights were explored. The authors conclude that maternal assessments of birth size are poor proxy indicators of birth weight. Estimates of low birth weight based on maternal assessments of birth size as very small should be recognized as underestimates of the actual prevalence of low birth weight. Moreover, infants for whom birth weights are missing should not be considered similar to those for whom weight was reported. Those without reported birth weights are more likely to be low birth weight. Thus, relying solely on reports of numeric birth weight will underestimate the prevalence of low birth weight.

NASA Puffin Electric Tailsitter VTOL Concept

NASA Technical Reports Server (NTRS)

Moore, Mark D.

2010-01-01

Electric propulsion offers dramatic new vehicle mission capabilities, not possible with turbine or reciprocating engines; including high reliability and efficiency, low engine weight and maintenance, low cooling drag and volume required, very low noise and vibration, and zero emissions. The only penalizing characteristic of electric propulsion is the current energy storage technology level, which is set to triple over the next 5-10 years through huge new investments in this field. Most importantly, electric propulsion offers incredible new degrees of freedom in aircraft system integration to achieve unprecedented levels of aerodynamic, propulsive, control, and structural synergistic coupling. A unique characteristic of electric propulsion is that the technology is nearly scale-free, permitting small motors to be parallelized for fail-safe redundancy, or distributed across the airframe for tightly coupled interdisciplinary functionality without significant impacts in motor-controller efficiency or specific weight. Maximizing the potential benefit of electric propulsion is dependent on applying this technology to synergistic mission concepts. The vehicle missions with the most benefit include those which constrain environmental impact (or limit noise, exhaust, or emission signatures) are short range, or where large differences exist in the propulsion system sizing between takeoff and cruise conditions. Electric propulsion offers the following unique capabilities that other propulsion systems can t provide for short range Vertical Takeoff and Landing (VTOL) aircraft; elimination of engine noise and emissions, drastic reduction in engine cooling and radiated heat, drastic reduction in vehicle vibration levels, drastic improvement in reliability and operating costs, variable speed output at full power, for improved cruise efficiency at low tip-speed, elimination of high/hot sizing penalty, and reduction of engine-out penalties.

Development of a high permeability cored transintegumental power transformer.

PubMed

Helmicki, A J; Melvin, D M; Henderson, H T; Nebrigic, D; Venkat, R; Glos, D L

1996-01-01

Circulatory support devices require 10-20 W. Currently, several devices are under development for the transmission of this power via transcutaneous transformers, with the secondary implanted subcutaneously and the primary worn externally. Because these devices are air cored, they have relatively large, bulky external appliances, poor coil to coil coupling, and result in significant stray fields passing through adjacent tissues. This article reports on the engineering design of a novel, high permeability cored transformer implanted in a transenteric configuration using an isolated intestinal pouch. Such an approach offers greater energy transmission efficiency, less heat dissipation, less stray electromagnetic energy, and greatly reduced device size. Two competing designs using this concept have been developed and tested. Each consists of the transformer, together with power interface electronics, forming a direct current (DC)/DC resonant converter. Operating frequencies are 90.2 and 14.7 kHz, respectively, with primary/secondary turns ratios of 10/10 and 11/14, respectively. In addition, data interface electronics allows communication across the transformer of up to four signals at a per channel sample rate of 10 Hz. Both designs are able to continuously transmit 25 W at an output level of 12 Vdc into a 5.8 omega load. Calorimetry tests indicate DC to DC efficiencies greater than 75% and coil to coil efficiencies greater than 96%. Total package size for the implantable portion of each device (including sensor internal interface electronics) is less than 40 ml, with a weight weight of less than 100 g. The results of short-term implantation studies have been favorable. Long-term implantation studies currently are under way.

Space Operation of the MOLA Laser

NASA Technical Reports Server (NTRS)

Afzal, Robert S.

2000-01-01

Interest in lasers for space applications such as active remote sensing in Earth orbit, planetary science, and inter-satellite laser communications is growing. These instruments typically use diode-pumped solid state lasers for the laser transmitter. The mission specifications and constraints of space qualification, place strict requirements on the design and operation of the laser. Although a laser can be built in the laboratory to meet performance specifications relatively routinely, tile mission constraints demand unique options and compromises in the materials used, and design to ensure the success of the mission. Presently, the best laser architecture for a light weight, rugged, high peak power and efficient transmitter is a diode laser pumped ND:YAG laser. Diode lasers can often obviate the need for water cooling, reduce the size and weight of the laser, increase the electrical to optical efficiency, system reliability, and lifetime. This paper describes the in-space operation and performance of the Mars Orbiter Laser Altimeter (MOLA) laser transmitter, representing the current state-of-the-art in space-based solid- state lasers.

Synthetic Fiber Capstan Drives for Highly Efficient, Torque Controlled, Robotic Applications

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

Mazumdar, Anirban; Spencer, Steven James; Hobart, Clinton

Here this paper describes the design and performance of a synthetic rope on sheave drive system. This system uses synthetic ropes instead of steel cables to achieve low weight and a compact form factor. We demonstrate how this system is capable of 28-Hz torque control bandwidth, 95% efficiency, and quiet operation, making it ideal for use on legged robots and other dynamic physically interactive systems. Component geometry and tailored maintenance procedures are used to achieve high endurance. Endurance tests based on walking data predict that the ropes will survive roughly 247,000 cycles when used on large (90 kg), fully actuatedmore » bipedal robot systems. The drive systems have been incorporated into two novel bipedal robots capable of three-dimensional unsupported walking. Robot data illustrate effective torque tracking and nearly silent operation. Finally, comparisons with alternative transmission designs illustrate the size, weight, and endurance advantages of using this type of synthetic rope drive system.« less

Synthetic Fiber Capstan Drives for Highly Efficient, Torque Controlled, Robotic Applications

DOE PAGES

Mazumdar, Anirban; Spencer, Steven James; Hobart, Clinton; ...

2017-01-05

Here this paper describes the design and performance of a synthetic rope on sheave drive system. This system uses synthetic ropes instead of steel cables to achieve low weight and a compact form factor. We demonstrate how this system is capable of 28-Hz torque control bandwidth, 95% efficiency, and quiet operation, making it ideal for use on legged robots and other dynamic physically interactive systems. Component geometry and tailored maintenance procedures are used to achieve high endurance. Endurance tests based on walking data predict that the ropes will survive roughly 247,000 cycles when used on large (90 kg), fully actuatedmore » bipedal robot systems. The drive systems have been incorporated into two novel bipedal robots capable of three-dimensional unsupported walking. Robot data illustrate effective torque tracking and nearly silent operation. Finally, comparisons with alternative transmission designs illustrate the size, weight, and endurance advantages of using this type of synthetic rope drive system.« less

Fragmentation efficiency of explosive volcanic eruptions: A study of experimentally generated pyroclasts

NASA Astrophysics Data System (ADS)

Kueppers, Ulrich; Scheu, Bettina; Spieler, Oliver; Dingwell, Donald B.

2006-05-01

Products of magma fragmentation can pose a severe threat to health, infrastructure, environment, and aviation. Systematic evaluation of the mechanisms and the consequences of volcanic fragmentation is very difficult as the adjacent processes cannot be observed directly and their deposits undergo transport-related sorting. However, enhanced knowledge is required for hazard assessment and risk mitigation. Laboratory experiments on natural samples allow the precise characterization of the generated pyroclasts and open the possibility for substantial advances in the quantification of fragmentation processes. They hold the promise of precise characterization and quantification of fragmentation efficiency and its dependence on changing material properties and the physical conditions at fragmentation. We performed a series of rapid decompression experiments on three sets of natural samples from Unzen volcano, Japan. The analysis comprised grain-size analysis and surface area measurements. The grain-size analysis is performed by dry sieving for particles larger than 250 μm and wet laser refraction for smaller particles. For all three sets of samples, the grain-size of the most abundant fraction decreases and the weight fraction of newly generated ash particles (up to 40 wt.%) increases with experimental pressure/potential energy for fragmentation. This energy can be estimated from the volume of the gas fraction and the applied pressure. The surface area was determined through Argon adsorption. The fragmentation efficiency is described by the degree of fine-particle generation. Results show that the fragmentation efficiency and the generated surface correlate positively with the applied energy.

Nanoassemblies from homostructured polypeptides as efficient nanoplatforms for oral drug delivery.

PubMed

Jia, Yi; Tang, Yuan; He, Hongmei; Li, Shuhui; Che, Ling; Zhou, Xing; Dou, Yin; Zhang, Jianxiang; Li, Xiaohui

2013-04-01

The assembly of homostructured polypeptides bearing various side groups into well-defined nanostructures was presented, with their size and topology mainly dominated by the chemical structure and molecular weight of peptides. Pharmacokinetic and pharmacodynamic studies based on rat models suggested these newly constructed nanoassemblies with low cytotoxicity may function as novel nanoplatforms to efficiently and safely deliver therapeutics to achieve better efficacy but lower side effects. Other applications in biomedical fields, such as biotechnology, medical imaging, and tissue engineering, may also be expected. This research team investigated the assembly of homostructured polypeptides bearing various side groups into well-defined nanostructures, and demonstrated low cytotoxicity in rat disease models, suggesting that these novel nanoplatforms may safely and efficiently deliver therapeutics with low side effects. Copyright © 2013 Elsevier Inc. All rights reserved.

How reliably can a material be classified as a nanomaterial? Available particle-sizing techniques at work

NASA Astrophysics Data System (ADS)

Babick, Frank; Mielke, Johannes; Wohlleben, Wendel; Weigel, Stefan; Hodoroaba, Vasile-Dan

2016-06-01

Currently established and projected regulatory frameworks require the classification of materials (whether nano or non-nano) as specified by respective definitions, most of which are based on the size of the constituent particles. This brings up the question if currently available techniques for particle size determination are capable of reliably classifying materials that potentially fall under these definitions. In this study, a wide variety of characterisation techniques, including counting, fractionating, and spectroscopic techniques, has been applied to the same set of materials under harmonised conditions. The selected materials comprised well-defined quality control materials (spherical, monodisperse) as well as industrial materials of complex shapes and considerable polydispersity. As a result, each technique could be evaluated with respect to the determination of the number-weighted median size. Recommendations on the most appropriate and efficient use of techniques for different types of material are given.

Profiling analysis of low molecular weight heparins by multiple heart-cutting two dimensional chromatography with quadruple time-of-flight mass spectrometry.

PubMed

Ouyang, Yilan; Zeng, Yangyang; Rong, Yinxiu; Song, Yue; Shi, Lv; Chen, Bo; Yang, Xinlei; Xu, Naiyu; Linhardt, Robert J; Zhang, Zhenqing

2015-09-01

Low molecular weight heparins (LMWHs) are polydisperse and microheterogenous mixtures of polysaccharides used as anticoagulant drugs. Profiling analysis is important for obtaining deeper insights into the structure of LMWHs. Previous oligosaccharide mapping methods are relatively low resolution and are unable to show an entire picture of the structural complexity of LMWHs. In the current study a profiling method was developed relying on multiple heart-cutting, two-dimensional, ultrahigh performance liquid chromatography with quadruple time-of-flight mass spectrometry. This represents an efficient, automated, and robust approach for profiling LMWHs. Using size-exclusion chromatography and ion-pairing reversed-phase chromatography in a two-dimensional separation, LMW components of different sizes and LMW components of the same size but with different charges and polarities can be resolved, providing a more complete picture of a LMWH. Structural information on each component was then obtained with quadrupole time-of-flight mass spectrometry. More than 80 and 120 oligosaccharides were observed and unambiguously assigned from the LMWHs, nadroparin and enoxaparin, respectively. This method might be useful for quality control of LMWHs and as a powerful tool for heparin-related glycomics.

Modification of fast-growing Chinese Fir wood with unsaturated polyester resin: Impregnation technology and efficiency

NASA Astrophysics Data System (ADS)

Ma, Qing; Zhao, Zijian; Yi, Songlin; Wang, Tianlong

In this study, Chinese Fir was impregnated with unsaturated polyester resin to enhance its properties. Samples 20 mm × 20 mm × 20 mm in size were split into different sections with epoxy resin and tinfoil and subjected to an impregnation experiment under various parameters. Vacuum degree was -0.04 MPa, -0.06 MPa or -0.08 MPa and vacuum duration was 15 min, 30 min, or 45 min. The results indicated that impregnation weight percent gain is linearly dependent on curing weight percent gain. Vacuum duration appears to have less influence on the curing weight percent gain than vacuum degree, and impregnation was most successful at the transverse section compared to other sections. The optimal impregnation parameters were 30 min modification under -0.08 MPa vacuum followed by 120 min at atmospheric pressure for samples 200 mm × 100 mm × 20 mm in size. Uneven distribution of weight percent gain and cracking during the curing process suggested that 30 min post-processing at -0.09 MPa vacuum was the most effective way to complete the impregnation process. The sample's bending strength and modulus of elasticity increased after impregnation treatment. Bending strength after impregnation without post-processing reached 112.85%, but reached 71.65% with vacuum-processing; modulus of elasticity improved 67.13% and 58.28% without and with post-processing, respectively.

Regenerative fuel cell energy storage system for a low earth orbit space station

NASA Technical Reports Server (NTRS)

Martin, R. E.; Garow, J.; Michaels, K. B.

1988-01-01

A study was conducted to define characteristics of a Regenerative Fuel Cell System (RFCS) for low earth orbit Space Station missions. The RFCS's were defined and characterized based on both an alkaline electrolyte fuel cell integrated with an alkaline electrolyte water electrolyzer and an alkaline electrolyte fuel cell integrated with an acid solid polymer electrolyte (SPE) water electrolyzer. The study defined the operating characteristics of the systems including system weight, volume, and efficiency. A maintenance philosophy was defined and the implications of system reliability requirements and modularization were determined. Finally, an Engineering Model System was defined and a program to develop and demonstrate the EMS and pacing technology items that should be developed in parallel with the EMS were identified. The specific weight of an optimized RFCS operating at 140 F was defined as a function of system efficiency for a range of module sizes. An EMS operating at a nominal temperature of 180 F and capable of delivery of 10 kW at an overall efficiency of 55.4 percent is described. A program to develop the EMS is described including a technology development effort for pacing technology items.

Effects of consistent food presentation on efficiency of eating and nutritive value of food consumed by children with severe neurological impairment.

PubMed

Pinnington, L; Hegarty, J

1999-01-01

The purpose of this investigation was to determine what implications consistent presentation of food, delivered by an assistive feeding device at a position regarded as optimal, would have for the maintenance of food intake, duration of meals, and efficiency of eating. The trial employed an AB within-subjects design and extended over a 9-month period. Twenty children, aged 7 to 17 years, with severe neurological impairment and associated eating difficulties, were studied. The effects of the intervention were compared by examination of diaries recording the sizes and composition of meals consumed during designated periods and by precautionary measures of growth and weight. Although no statistically significant changes in weight were recorded overall, meals presented consistently were consumed less efficiently and sometimes more slowly than were standard ones, where food was presented by hand. However, no change occurred in the amount of energy and protein consumed, which suggested that the children's ability to thrive was neither improved nor further compromised by participation in the study. The findings have implications for the way in which children are assisted during mealtimes by their caregivers.

Generation of a large volume of clinically relevant nanometre-sized ultra-high-molecular-weight polyethylene wear particles for cell culture studies

PubMed Central

Ingham, Eileen; Fisher, John; Tipper, Joanne L

2014-01-01

It has recently been shown that the wear of ultra-high-molecular-weight polyethylene in hip and knee prostheses leads to the generation of nanometre-sized particles, in addition to micron-sized particles. The biological activity of nanometre-sized ultra-high-molecular-weight polyethylene wear particles has not, however, previously been studied due to difficulties in generating sufficient volumes of nanometre-sized ultra-high-molecular-weight polyethylene wear particles suitable for cell culture studies. In this study, wear simulation methods were investigated to generate a large volume of endotoxin-free clinically relevant nanometre-sized ultra-high-molecular-weight polyethylene wear particles. Both single-station and six-station multidirectional pin-on-plate wear simulators were used to generate ultra-high-molecular-weight polyethylene wear particles under sterile and non-sterile conditions. Microbial contamination and endotoxin levels in the lubricants were determined. The results indicated that microbial contamination was absent and endotoxin levels were low and within acceptable limits for the pharmaceutical industry, when a six-station pin-on-plate wear simulator was used to generate ultra-high-molecular-weight polyethylene wear particles in a non-sterile environment. Different pore-sized polycarbonate filters were investigated to isolate nanometre-sized ultra-high-molecular-weight polyethylene wear particles from the wear test lubricants. The use of the filter sequence of 10, 1, 0.1, 0.1 and 0.015 µm pore sizes allowed successful isolation of ultra-high-molecular-weight polyethylene wear particles with a size range of < 100 nm, which was suitable for cell culture studies. PMID:24658586

Generation of a large volume of clinically relevant nanometre-sized ultra-high-molecular-weight polyethylene wear particles for cell culture studies.

PubMed

Liu, Aiqin; Ingham, Eileen; Fisher, John; Tipper, Joanne L

2014-04-01

It has recently been shown that the wear of ultra-high-molecular-weight polyethylene in hip and knee prostheses leads to the generation of nanometre-sized particles, in addition to micron-sized particles. The biological activity of nanometre-sized ultra-high-molecular-weight polyethylene wear particles has not, however, previously been studied due to difficulties in generating sufficient volumes of nanometre-sized ultra-high-molecular-weight polyethylene wear particles suitable for cell culture studies. In this study, wear simulation methods were investigated to generate a large volume of endotoxin-free clinically relevant nanometre-sized ultra-high-molecular-weight polyethylene wear particles. Both single-station and six-station multidirectional pin-on-plate wear simulators were used to generate ultra-high-molecular-weight polyethylene wear particles under sterile and non-sterile conditions. Microbial contamination and endotoxin levels in the lubricants were determined. The results indicated that microbial contamination was absent and endotoxin levels were low and within acceptable limits for the pharmaceutical industry, when a six-station pin-on-plate wear simulator was used to generate ultra-high-molecular-weight polyethylene wear particles in a non-sterile environment. Different pore-sized polycarbonate filters were investigated to isolate nanometre-sized ultra-high-molecular-weight polyethylene wear particles from the wear test lubricants. The use of the filter sequence of 10, 1, 0.1, 0.1 and 0.015 µm pore sizes allowed successful isolation of ultra-high-molecular-weight polyethylene wear particles with a size range of < 100 nm, which was suitable for cell culture studies.

Bioprospecting of powdered pineapple rind as an organic supplement of composted sawdust for Pleurotus ostreatus mushroom cultivation.

PubMed

Narh Mensah, Deborah L; Addo, Peter; Dzomeku, Matilda; Obodai, Mary

2018-03-01

Pineapple rind is a by-product of the pineapple processing industry and contains nutrients and other compounds which must be utilized as a bioresource for socio-economic benefits while preventing the potential problems of improper agroindustrial biomass disposal methods. Pleurotus ostreatus is an edible oyster mushroom with medicinal properties and can be cultivated on various agroindustrial biomass, including sawdust containing supplements. Pineapple rind was powdered and used as a supplement of composted sawdust at 2%, 5%, 10%, 12%, 15%, and 20% (w/w) on dry weight basis. A control treatment consisted of composted sawdust supplemented with rice bran at 12% (the most utilized composition in Ghana). P. ostreatus strain EM-1 was cultivated on these treatments. Factors investigated included the spawn run period, yield, fruiting body weight and size, biological efficiency, and nutritional composition (proximate composition and Copper, Zinc and Lead content) of fruiting bodies harvested from selected high-yielding treatments and the control treatment. Full colonization of all treatments occurred by the 34th day of incubation. Enhanced yield, fruiting body weight and size, and biological efficiency were generally recorded with supplementation at lower concentrations (2% and 5%) compared to treatments supplemented at higher concentrations. There was also a supplement concentration-dependent alteration of the nutritional composition of the mushroom. Powdered pineapple rind can be utilized as an organic supplement at relatively low concentrations in composted sawdust for P. ostreatus strain EM-1 cultivation. The use of lower concentrations of powdered pineapple rind in composted sawdust is advantageous as relatively less input will be required to produce higher P. ostreatus strain EM-1 yields. Utilization of pineapple rind for mushroom cultivation will extend the pineapple plant value chain, intensify mushroom production in a sustainable way, and minimize agricultural losses.

Assessment of reproductive parameters in female Dwarf goat (Capra hircus) on the basis of progesterone profiles.

PubMed

Khanum, Shahnaz Adeeb; Hussain, Mujahid; Kausar, Rehana

2007-12-01

A study was undertaken to look into the reproductive performance of female Dwarf goats reared under traditional conditions at NIAB Farm, Faisalabad, Pakistan. The serum progesterone profile was used to monitor various reproductive parameters (length of postpartum period, resumption of cyclicity, gestation period, prepartum period, parturition) in two lots of goats. Litter size, birth weight of kids and kidding interval were also observed. Most of the animals conceived within 15-59 days of postpartum period. All the does conceived at first or second estrus. During gestation period, higher levels of progesterone were maintained with wide variations falling in the range of 3-13 ng ml(-1). However, a few days before parturition a decline was noticed at 6+/-0.9 days and it reached to the basal level of 0.1 ng ml(-1) after the completion of parturition process. The length of gestation period was found to be 145.8+/-5 days in the first lot and 145.2+/-4 days in the second lot. A very short kidding interval (203.7+/-46 days) and considerably bigger litter size (1.8+/-0.8) was observed. All the parturitions were normal and a considerable weight gain (8.2+/-0.3 kg) of mothers was recorded during pregnancy. The initial birth weight of kids was averaged as 2.1+/-0.5 kg in the first and 1.6+/-0.2 kg in the second lot. It was concluded that Dwarf goat has short gestation length, postpartum period and kidding interval along with multiple births being common. Due to these factors, its reproductive efficiency can be exploited for efficient goat meat production.

Compact, Interactive Electric Vehicle Charger: Gallium-Nitride Switch Technology for Bi-directional Battery-to-Grid Charger Applications

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

None

2010-10-01

ADEPT Project: HRL Laboratories is using gallium nitride (GaN) semiconductors to create battery chargers for electric vehicles (EVs) that are more compact and efficient than traditional EV chargers. Reducing the size and weight of the battery charger is important because it would help improve the overall performance of the EV. GaN semiconductors process electricity faster than the silicon semiconductors used in most conventional EV battery chargers. These high-speed semiconductors can be paired with lighter-weight electrical circuit components, which helps decrease the overall weight of the EV battery charger. HRL Laboratories is combining the performance advantages of GaN semiconductors with anmore » innovative, interactive battery-to-grid energy distribution design. This design would support 2-way power flow, enabling EV battery chargers to not only draw energy from the power grid, but also store and feed energy back into it.« less

Noncontact manipulation using a transversely magnetized rolling robot

NASA Astrophysics Data System (ADS)

Tung, Hsi-Wen; Peyer, Kathrin E.; Sargent, David F.; Nelson, Bradley J.

2013-09-01

A type of magnetic, wireless microrobot has been designed for non-contact manipulation of micro-objects in liquids. The agent, named the RodBot, has typical dimensions of 300 μm × 60 μm × 50 μm. The RodBot is transversely magnetized and rolls around its long axis on a surface in a rotating external magnetic field. In liquid environments, the RodBot generates a rising flow in front of it and a vortex above its body. The flow and vortex are efficient for picking-up and trapping micro-objects of sizes ranging from microns to one millimeter. In viscous solutions, a RodBot can transport objects many times its own size and weight.

Reduced size first-order subsonic and supersonic aeroelastic modeling

NASA Technical Reports Server (NTRS)

Karpel, Mordechay

1990-01-01

Various aeroelastic, aeroservoelastic, dynamic-response, and sensitivity analyses are based on a time-domain first-order (state-space) formulation of the equations of motion. The formulation of this paper is based on the minimum-state (MS) aerodynamic approximation method, which yields a low number of aerodynamic augmenting states. Modifications of the MS and the physical weighting procedures make the modeling method even more attractive. The flexibility of constraint selection is increased without increasing the approximation problem size; the accuracy of dynamic residualization of high-frequency modes is improved; and the resulting model is less sensitive to parametric changes in subsequent analyses. Applications to subsonic and supersonic cases demonstrate the generality, flexibility, accuracy, and efficiency of the method.

Research and Development of Laser Diode Based Instruments for Applications in Space

NASA Technical Reports Server (NTRS)

Krainak, Michael; Abshire, James; Cornwell, Donald; Dragic, Peter; Duerksen, Gary; Switzer, Gregg

1999-01-01

Laser diode technology continues to advance at a very rapid rate due to commercial applications such as telecommunications and data storage. The advantages of laser diodes include, wide diversity of wavelengths, high efficiency, small size and weight and high reliability. Semiconductor and fiber optical-amplifiers permit efficient, high power master oscillator power amplifier (MOPA) transmitter systems. Laser diode systems which incorporate monolithic or discrete (fiber optic) gratings permit single frequency operation. We describe experimental and theoretical results of laser diode based instruments currently under development at NASA Goddard Space Flight Center including miniature lidars for measuring clouds and aerosols, water vapor and wind for Earth and planetary (Mars Lander) use.

Climate and the weight/height relationship in sub-Saharan Africa.

PubMed

Hiernaux, J; Rudan, P; Brambati, A

1975-01-01

25 populations of the rain forest and 44 of the open country, all descended from the West-Central African stock which lived in the latter biome, are compared for body weight and height. On a log weight/height diagram, the 69 populations cluster along a straight line which intersects the lines of equal body weight/surface ratio: the shorter the body size, the lower the ratio tends to be. The rain forest populations are concentrated in the lower part of the bivariate distribution. The shortest one, the Mbuti Pygmies, has a very low ratio despite a relatively heavy weight. The shorter stature of the rain forest populations seems to be largely genetic in origin; it probably results from selective pressure exerted by the thermal stres in this hot and wet biome where sweating is of low thermolytic efficiency. The amount of reduction of adult stature depends for a large part on the number of generations spent in the forest by the population. Line A (in figure 1) is similar to a growth trend. The 69 populations differ genetically by the target that growth has to reach on a common log weight/height trend line. They achieve this differentiation through different speeds of growth.

A comparison study of size-specific dose estimate calculation methods.

PubMed

Parikh, Roshni A; Wien, Michael A; Novak, Ronald D; Jordan, David W; Klahr, Paul; Soriano, Stephanie; Ciancibello, Leslie; Berlin, Sheila C

2018-01-01

The size-specific dose estimate (SSDE) has emerged as an improved metric for use by medical physicists and radiologists for estimating individual patient dose. Several methods of calculating SSDE have been described, ranging from patient thickness or attenuation-based (automated and manual) measurements to weight-based techniques. To compare the accuracy of thickness vs. weight measurement of body size to allow for the calculation of the size-specific dose estimate (SSDE) in pediatric body CT. We retrospectively identified 109 pediatric body CT examinations for SSDE calculation. We examined two automated methods measuring a series of level-specific diameters of the patient's body: method A used the effective diameter and method B used the water-equivalent diameter. Two manual methods measured patient diameter at two predetermined levels: the superior endplate of L2, where body width is typically most thin, and the superior femoral head or iliac crest (for scans that did not include the pelvis), where body width is typically most thick; method C averaged lateral measurements at these two levels from the CT projection scan, and method D averaged lateral and anteroposterior measurements at the same two levels from the axial CT images. Finally, we used body weight to characterize patient size, method E, and compared this with the various other measurement methods. Methods were compared across the entire population as well as by subgroup based on body width. Concordance correlation (ρ c ) between each of the SSDE calculation methods (methods A-E) was greater than 0.92 across the entire population, although the range was wider when analyzed by subgroup (0.42-0.99). When we compared each SSDE measurement method with CTDI vol, there was poor correlation, ρ c <0.77, with percentage differences between 20.8% and 51.0%. Automated computer algorithms are accurate and efficient in the calculation of SSDE. Manual methods based on patient thickness provide acceptable dose estimates for pediatric patients <30 cm in body width. Body weight provides a quick and practical method to identify conversion factors that can be used to estimate SSDE with reasonable accuracy in pediatric patients with body width ≥20 cm.

Adaptive significance of small body size: strength and motor performance of school children in Mexico and Papua New Guinea.

PubMed

Malina, R M; Little, B B; Shoup, R F; Buschang, P H

1987-08-01

The postulated superior functional efficiency in association with reduced body size under conditions of chronic protein-energy undernutrition was considered in school children from rural Mexico and coastal Papua New Guinea. Grip strength and three measures of motor performance were measured in cross-sectional samples of children 6-16 years of age from a rural agricultural community in Oaxaca, Mexico, and from the coastal community Pere on Manus Island, Papua New Guinea. The strength and performance of a mixed-longitudinal sample of well nourished children from Philadelphia was used as a reference. The Oaxaca and Pere children are significantly shorter and lighter and are not as strong as the well nourished children. Motor performances of Pere children compare favorably to those of the better-nourished Philadelphia children, whereas those of the Oaxaca children are poorer. Throwing performance is more variable. When expressed relative to body size, strength is similar in the three samples, but the running and jumping performances of Pere children per unit body size are better than the relative performances of Oaxaca and Philadelphia children. Throwing performance per unit body size is better in the undernourished children. The influence of age, stature, and weight on the performance of Oaxaca and Pere children is generally similar to that for well nourished children. These results suggest that the hypothesized adaptive significance of small body size for the functional efficiency of populations living under conditions of chronic undernutrition varies between populations and with performance tasks.

Size-weight illusion and anticipatory grip force scaling following unilateral cortical brain lesion.

PubMed

Li, Yong; Randerath, Jennifer; Goldenberg, Georg; Hermsdörfer, Joachim

2011-04-01

The prediction of object weight from its size is an important prerequisite of skillful object manipulation. Grip and load forces anticipate object size during early phases of lifting an object. A mismatch between predicted and actual weight when two different sized objects have the same weight results in the size-weight illusion (SWI), the small object feeling heavier. This study explores whether lateralized brain lesions in patients with or without apraxia alter the size-weight illusion and impair anticipatory finger force scaling. Twenty patients with left brain damage (LBD, 10 with apraxia, 10 without apraxia), ten patients with right brain damage (RBD), and matched control subjects lifted two different-sized boxes in alternation. All subjects experienced a similar size-weight illusion. The anticipatory force scaling of all groups was in correspondence with the size cue: higher forces and force rates were applied to the big box and lower forces and force rates to the small box during the first lifts. Within few lifts, forces were scaled to actual object weight. Despite the lack of significant differences at group level, 5 out of 20 LBD patients showed abnormal predictive scaling of grip forces. They differed from the LBD patients with normal predictive scaling by a greater incidence of posterior occipito-parietal lesions but not by a greater incidence of apraxia. The findings do not support a more general role for the motor-dominant left hemisphere, or an influence of apraxia per se, in the scaling of finger force according to object properties. However, damage in the vicinity of the parietal-occipital junction may be critical for deriving predictions of weight from size. Copyright © 2011 Elsevier Ltd. All rights reserved.

Relationships Between Body Size Satisfaction and Weight Control Practices Among US Adults

PubMed Central

Millstein, Rachel A.; Carlson, Susan A.; Fulton, Janet E.; Galuska, Deborah A.; Zhang, Jian; Blanck, Heidi M.; Ainsworth, Barbara E.

2008-01-01

Context Few studies of US adults have specifically examined body size satisfaction Objectives Describe correlates of body size satisfaction and examine whether satisfaction was associated with trying to lose weight or specific weight control practices among US adults using a national sample of women and men. Design, Setting & Participants The National Physical Activity and Weight Loss Survey (NPAWLS) was a population-based, cross-sectional telephone survey of US adults (n = 9740). Main Outcome Measures Participants reported their weight, height, body size satisfaction, and weight loss practices. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each dependent variable. Results Among women and men, higher body mass index (BMI) was significantly associated with body size dissatisfaction. Dissatisfaction, compared with being very satisfied, was positively associated with trying to lose weight among women and men. This association was modified by BMI for women (OR normal weight = 19.69, overweight = 8.79, obese = 4.05; P < .01 for interaction) but not men (OR normal weight = 8.72, overweight = 10.50, obese = 7.86; P = 0.93 for interaction). Compared with women who were very satisfied, dissatisfied women used diet more (OR = 2.03), but not physical activity/exercise (OR = 0.55) or both strategies (OR = 0.63), to try to lose weight. Men who were somewhat satisfied, compared with those who were very satisfied, were more likely to use physical activity/exercise (OR = 1.64) and both diet and physical activity/exercise (OR = 1.54) to try to lose weight. Conclusion These findings highlight the sex differences in body size satisfaction, actions taken to try to lose weight, and the importance of considering body size satisfaction when designing weight-management programs. PMID:18596944

Thermal Management and Reliability of Power Electronics and Electric Machines

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

Narumanchi, Sreekant

2016-09-19

Increasing the number of electric-drive vehicles (EDVs) on America's roads has been identified as a strategy with near-term potential for dramatically decreasing the nation's dependence on oil - by the U.S. Department of Energy, the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management. Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, andmore » in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines are presented.« less

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

Narumanchi, Sreekant

Increasing the number of electric-drive vehicles (EDVs) on America's roads has been identified as a strategy with near-term potential for dramatically decreasing the nation's dependence on oil - by the U.S. Department of Energy, the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management. Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, andmore » in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines are presented.« less

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

Narumanchi, Sreekant

Increasing the number of electric-drive vehicles (EDVs) on America's roads has been identified as a strategy with near-term potential for dramatically decreasing the nation's dependence on oil -- by the U.S. Department of Energy, the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management. Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, andmore » in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines will be presented.« less

Modeling and Optimization for Morphing Wing Concept Generation

NASA Technical Reports Server (NTRS)

Skillen, Michael D.; Crossley, William A.

2007-01-01

This report consists of two major parts: 1) the approach to develop morphing wing weight equations, and 2) the approach to size morphing aircraft. Combined, these techniques allow the morphing aircraft to be sized with estimates of the morphing wing weight that are more credible than estimates currently available; aircraft sizing results prior to this study incorporated morphing wing weight estimates based on general heuristics for fixed-wing flaps (a comparable "morphing" component) but, in general, these results were unsubstantiated. This report will show that the method of morphing wing weight prediction does, in fact, drive the aircraft sizing code to different results and that accurate morphing wing weight estimates are essential to credible aircraft sizing results.

New Method to Prepare Mitomycin C Loaded PLA-Nanoparticles with High Drug Entrapment Efficiency

NASA Astrophysics Data System (ADS)

Hou, Zhenqing; Wei, Heng; Wang, Qian; Sun, Qian; Zhou, Chunxiao; Zhan, Chuanming; Tang, Xiaolong; Zhang, Qiqing

2009-07-01

The classical utilized double emulsion solvent diffusion technique for encapsulating water soluble Mitomycin C (MMC) in PLA nanoparticles suffers from low encapsulation efficiency because of the drug rapid partitioning to the external aqueous phase. In this paper, MMC loaded PLA nanoparticles were prepared by a new single emulsion solvent evaporation method, in which soybean phosphatidylcholine (SPC) was employed to improve the liposolubility of MMC by formation of MMC-SPC complex. Four main influential factors based on the results of a single-factor test, namely, PLA molecular weight, ratio of PLA to SPC (wt/wt) and MMC to SPC (wt/wt), volume ratio of oil phase to water phase, were evaluated using an orthogonal design with respect to drug entrapment efficiency. The drug release study was performed in pH 7.2 PBS at 37 °C with drug analysis using UV/vis spectrometer at 365 nm. MMC-PLA particles prepared by classical method were used as comparison. The formulated MMC-SPC-PLA nanoparticles under optimized condition are found to be relatively uniform in size (594 nm) with up to 94.8% of drug entrapment efficiency compared to 6.44 μm of PLA-MMC microparticles with 34.5% of drug entrapment efficiency. The release of MMC shows biphasic with an initial burst effect, followed by a cumulated drug release over 30 days is 50.17% for PLA-MMC-SPC nanoparticles, and 74.1% for PLA-MMC particles. The IR analysis of MMC-SPC complex shows that their high liposolubility may be attributed to some weak physical interaction between MMC and SPC during the formation of the complex. It is concluded that the new method is advantageous in terms of smaller size, lower size distribution, higher encapsulation yield, and longer sustained drug release in comparison to classical method.

Poly(ethylene glycol) analogs grafted with low molecular weight poly(ethylene imine) as non-viral gene vectors.

PubMed

Zhang, Zhenfang; Yang, Cuihong; Duan, Yajun; Wang, Yanming; Liu, Jianfeng; Wang, Lianyong; Kong, Deling

2010-07-01

A novel class of non-viral gene vectors consisting of low molecular weight poly(ethylene imine) (PEI) (molecular weight 800 Da) grafted onto degradable linear poly(ethylene glycol) (PEG) analogs was synthesized. First, a Michael addition reaction between poly(ethylene glycol) diacrylates (PEGDA) (molecular weight 258 Da) and d,l-dithiothreitol (DTT) was carried out to generate a linear polymer (PEG-DTT) having a terminal thiol, methacrylate and pendant hydroxyl functional groups. Five PEG-DTT analogs were synthesized by varying the molar ratio of diacrylates to thiols from 1.2:1 to 1:1.2. Then PEI (800 Da) was grafted onto the main chain of the PEG-DTTs using 1,1'-carbonyldiimidazole as the linker. The above reaction gave rise to a new class of non-viral gene vectors, (PEG-DTT)-g-PEI copolymers, which can effectively complex DNA to form nanoparticles. The molecular weights and structures of the copolymers were characterized by gel permeation chromatography, (1)H nuclear magnetic resonance and Fourier transform infrared spectroscopy. The size of the nanoparticles was<200 nm and the surface charge of the nanoparticles, expressed as the zeta potential, was between+20 and+40 mV. Cytotoxicity assays showed that the copolymers exhibited much lower cytotoxicities than high molecular weight PEI (25 kDa). Transfection was performed in cultured HeLa, HepG2, MCF-7 and COS-7 cells. The copolymers showed higher transfection efficiencies than PEI (25 kDa) tested in four cell lines. The presence of serum (up to 30%) had no inhibitory effect on the transfection efficiency. These results indicate that this new class of non-viral gene vectors may be a promising gene carrier that is worth further investigation. Copyright 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Growth and energy budget of juvenile lenok Brachymystax lenok in relation to ration level

NASA Astrophysics Data System (ADS)

Liu, Yang; Li, Zhongjie; Zhang, Tanglin; Yuan, Jing; Mou, Zhenbo; Liu, Jiashou

2015-03-01

We evaluated the effect of ration level (RL) on the growth and energy budget of lenok Brachymystax lenok. Juvenile lenok (initial mean body weight 3.06±0.13 g) were fed for 21 d at five different ration levels: starvation, 2%, 3%, 4% bwd (body weight per day, based on initial mean values), and apparent satiation. Feed consumption, apparent digestibility, and growth were directly measured. Specific growth rates in terms of wet weight, dry weight, protein, and energy increased logarithmically with an increase in ration levels. The relationship between specific growth rate in terms of wet weight (SGRw, %/d) and RL (%) was characterized by a decelerating curve: SGRw=-1.417+3.166ln(RL+1). The apparent digestibility coefficients of energy exhibited a decreasing pattern with increasing ration level, and there was a significant difference among different RLs. Body composition was significantly affected by ration size. The relationship between feed efficiency rate in terms of energy (FERe) and RL was: FERe=-14.167+23.793RL-3.367(RL)2, and the maximum FERe was observed at a 3.53% ration. The maintenance requirement for energy of juvenile lenok was 105.39 kJ BW (kg)-0.80/d, the utilization efficiency of DE for growth was 0.496. The energy budget equation at satiation was: 100IE=29.03FE+5.78(ZE+UE)+39.56 HE+25.63 RE, where IE is feed energy, FE is fecal energy, ZE+UE is excretory energy, HE is heat production, and RE is recovered energy. Our results suggest that the most suitable feeding rate for juvenile lenok aquaculture for wet weight growth is 2.89% bwd, whereas for energy growth, the suggested rate is 3.53% bwd at this growth stage.

High-strength cellular ceramic composites with 3D microarchitecture.

PubMed

Bauer, Jens; Hengsbach, Stefan; Tesari, Iwiza; Schwaiger, Ruth; Kraft, Oliver

2014-02-18

To enhance the strength-to-weight ratio of a material, one may try to either improve the strength or lower the density, or both. The lightest solid materials have a density in the range of 1,000 kg/m(3); only cellular materials, such as technical foams, can reach considerably lower values. However, compared with corresponding bulk materials, their specific strength generally is significantly lower. Cellular topologies may be divided into bending- and stretching-dominated ones. Technical foams are structured randomly and behave in a bending-dominated way, which is less weight efficient, with respect to strength, than stretching-dominated behavior, such as in regular braced frameworks. Cancellous bone and other natural cellular solids have an optimized architecture. Their basic material is structured hierarchically and consists of nanometer-size elements, providing a benefit from size effects in the material strength. Designing cellular materials with a specific microarchitecture would allow one to exploit the structural advantages of stretching-dominated constructions as well as size-dependent strengthening effects. In this paper, we demonstrate that such materials may be fabricated. Applying 3D laser lithography, we produced and characterized micro-truss and -shell structures made from alumina-polymer composite. Size-dependent strengthening of alumina shells has been observed, particularly when applied with a characteristic thickness below 100 nm. The presented artificial cellular materials reach compressive strengths up to 280 MPa with densities well below 1,000 kg/m(3).

Relationship between Device Size and Body Weight in Dogs with Patent Ductus Arteriosus Undergoing Amplatz Canine Duct Occluder Deployment.

PubMed

Wesselowski, S; Saunders, A B; Gordon, S G

2017-09-01

Deployment of the Amplatz Canine Duct Occluder (ACDO) is the preferred method for minimally invasive occlusion of patent ductus arteriosus (PDA) in dogs, with appropriate device sizing crucial to successful closure. Dogs of any body weight can be affected by PDA. To describe the range of ACDO sizes deployed in dogs of various body weights for improved procedural planning and inventory selection and to investigate for correlation between minimal ductal diameter (MDD) and body weight. A total of 152 dogs undergoing ACDO deployment between 2008 and 2016. Body weight, age, breed, sex, and MDD obtained by angiography (MDD-A), MDD obtained by transesophageal echocardiography (MDD-TEE), and ACDO size deployed were retrospectively evaluated. Correlation between body weight and ACDO size, MDD-A and MDD-TEE was poor, with R-squared values of 0.4, 0.36, and 0.3, respectively. Femoral artery diameter in the smallest population of dogs placed inherent limitations on the use of larger device sizes, with no limitations on the wide range of device sizes required as patient size increased. The most commonly used ACDO devices were size 3 through 6, representing 57% of the devices deployed within the entire study population. Patent ductus arteriosus anatomy varies on an individual basis, with poor correlation between MDD and body weight. Weight-based assumptions about expected ACDO device size for a given patient are not recommended. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Truck size and weight enforcement technologies : state of the practice

DOT National Transportation Integrated Search

2009-05-01

This report is a deliverable of Task 2 of FHWAs Truck Size and Weight Enforcement Technology Project. The primary project objective was to recommend strategies to encourage the deployment of roadside technologies to improve truck size and weight e...

An efficiency study of the simultaneous analysis and design of structures

NASA Technical Reports Server (NTRS)

Striz, Alfred G.; Wu, Zhiqi; Sobieski, Jaroslaw

1995-01-01

The efficiency of the Simultaneous Analysis and Design (SAND) approach in the minimum weight optimization of structural systems subject to strength and displacement constraints as well as size side constraints is investigated. SAND allows for an optimization to take place in one single operation as opposed to the more traditional and sequential Nested Analysis and Design (NAND) method, where analyses and optimizations alternate. Thus, SAND has the advantage that the stiffness matrix is never factored during the optimization retaining its original sparsity. One of SAND's disadvantages is the increase in the number of design variables and in the associated number of constraint gradient evaluations. If SAND is to be an acceptable player in the optimization field, it is essential to investigate the efficiency of the method and to present a possible cure for any inherent deficiencies.

The Effect of Rotor Cruise Tip Speed, Engine Technology and Engine/Drive System RPM on the NASA Large Civil Tiltrotor (LCTR2) Size and Performance

NASA Technical Reports Server (NTRS)

Robuck, Mark; Wilkerson, Joseph; Maciolek, Robert; Vonderwell, Dan

2012-01-01

A multi-year study was conducted under NASA NNA06BC41C Task Order 10 and NASA NNA09DA56C task orders 2, 4, and 5 to identify the most promising propulsion system concepts that enable rotor cruise tip speeds down to 54% of the hover tip speed for a civil tiltrotor aircraft. Combinations of engine RPM reduction and 2-speed drive systems were evaluated. Three levels of engine and the drive system advanced technology were assessed; 2015, 2025 and 2035. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified. Design variables included engine speed reduction, drive system speed reduction, technology, and rotor cruise propulsion efficiency. The NASA Large Civil Tiltrotor, LCTR, aircraft served as the base vehicle concept for this study and was resized for over thirty combinations of operating cruise RPM and technology level, quantifying LCTR2 Gross Weight, size, and mission fuel. Additional studies show design sensitivity to other mission ranges and design airspeeds, with corresponding relative estimated operational cost. The lightest vehicle gross weight solution consistently came from rotor cruise tip speeds between 422 fps and 500 fps. Nearly equivalent results were achieved with operating at reduced engine RPM with a single-speed drive system or with a two-speed drive system and 100% engine RPM. Projected performance for a 2025 engine technology provided improved fuel flow over a wide range of operating speeds relative to the 2015 technology, but increased engine weight nullified the improved fuel flow resulting in increased aircraft gross weights. The 2035 engine technology provided further fuel flow reduction and 25% lower engine weight, and the 2035 drive system technology provided a 12% reduction in drive system weight. In combination, the 2035 technologies reduced aircraft takeoff gross weight by 14% relative to the 2015 technologies.

Efficiency and Pressure Loss Characteristics of an Ultra-Compact Combustor with Bulk Swirl

DTIC Science & Technology

2007-06-01

al., 2004a:3). Besides offering size and weight reductions, the UCC opens the door to adding a reheat step to the Brayton cycle currently used in...possible include a reheat step in the Brayton cycle to gain enhanced performance. Sirignano and Liu (Sirignano and Liu, 1998:1-2) pioneered the idea of...increase in speed for a subsonic flow resulting in a given loss in total pressure. This pressure loss is not desired in the constant pressure Brayton

Windvan laser study

NASA Technical Reports Server (NTRS)

1985-01-01

The goal of defining a CO2 laser transmitter approach suited to Shuttle Coherent Atmospheric Lidar Experiment (SCALE) requirements is discussed. The adaptation of the existing WINDVAN system to the shuttle environment is addressed. The size, weight, reliability, and efficiency of the existing WINDVAN system are largely compatible with SCALE requirements. Repacking is needed for compatibility with vacuum and thermal environments. Changes are required to ensure survival through launch and landing, mechanical, vibration, and acoustic loads. Existing WINDVAN thermal management approaches depending on convection need to be upgraded zero gravity operations.

Ectopically expressing MdPIP1;3, an aquaporin gene, increased fruit size and enhanced drought tolerance of transgenic tomatoes.

PubMed

Wang, Lin; Li, Qing-Tian; Lei, Qiong; Feng, Chao; Zheng, Xiaodong; Zhou, Fangfang; Li, Lingzi; Liu, Xuan; Wang, Zhi; Kong, Jin

2017-12-19

Water deficit severely reduces apple growth and production, is detrimental to fruit quality and size. This problem is exacerbated as global warming is implicated in producing more severe drought stress. Thus water-efficiency has becomes the major target for apple breeding. A desired apple tree can absorb and transport water efficiently, which not only confers improved drought tolerance, but also guarantees fruit size for higher income returns. Aquaporins, as water channels, control water transportation across membranes and can regulate water flow by changing their amount and activity. The exploration of molecular mechanism of water efficiency and the gene wealth will pave a way for molecular breeding of drought tolerant apple tree. In the current study, we screened out a drought inducible aquaporin gene MdPIP1;3, which specifically enhanced its expression during fruit expansion in 'Fuji' apple (Malus domestica Borkh. cv. Red Fuji). It localized on plasma membranes and belonged to PIP1 subfamily. The tolerance to drought stress enhanced in transgenic tomato plants ectopically expressing MdPIP1;3, showing that the rate of losing water in isolated transgenic leaves was slower than wild type, and stomata of transgenic plants closed sensitively to respond to drought compared with wild type. Besides, length and diameter of transgenic tomato fruits increased faster than wild type, and in final, fruit sizes and fresh weights of transgenic tomatoes were bigger than wild type. Specially, in cell levels, fruit cell size from transgenic tomatoes was larger than wild type, showing that cell number per mm 2 in transgenic fruits was less than wild type. Altogether, ectopically expressing MdPIP1;3 enhanced drought tolerance of transgenic tomatoes partially via reduced water loss controlled by stomata closure in leaves. In addition, the transgenic tomato fruits are larger and heavier with larger cells via more efficient water transportation across membranes. Our research will contribute to apple production, by engineering apples with big fruits via efficient water transportation when well watered and enhanced drought tolerance in transgenic apples under water deficit.

Preparation and characterization of monodisperse large-porous silica microspheres as the matrix for protein separation.

PubMed

Xia, Hongjun; Wan, Guangping; Zhao, Junlong; Liu, Jiawei; Bai, Quan

2016-11-04

High performance liquid chromatography (HPLC) is a kind of efficient separation technology and has been used widely in many fields. Micro-sized porous silica microspheres as the most popular matrix have been used for fast separation and analysis in HPLC. In this paper, the monodisperse large-porous silica microspheres with controllable size and structure were successfully synthesized with polymer microspheres as the templates and characterized. First, the poly(glycidyl methacrylate-co-ethyleneglycol dimethacrylate) microspheres (P GMA-EDMA ) were functionalized with tetraethylenepentamine (TEPA) to generate amino groups which act as a catalyst in hydrolysis of tetraethyl orthosilicate (TEOS) to form Si-containing low molecular weight species. Then the low molecular weight species diffused into the functionalized P GMA-EDMA microspheres by induction force of the amino groups to form polymer/silica hybrid microspheres. Finally, the organic polymer templates were removed by calcination, and the large-porous silica microspheres were obtained. The compositions, morphology, size distribution, specific surface area and pore size distribution of the porous silica microspheres were characterized by infrared analyzer, scanning-electron microscopy, dynamic laser scattering, the mercury intrusion method and thermal gravimetric analysis, respectively. The results show that the agglomeration of the hybrid microspheres can be overcome when the templates were functionalized with TEPA as amination reagent, and the yield of 95.7% of the monodisperse large-porous silica microspheres can be achieved with high concentration of polymer templates. The resulting large-porous silica microspheres were modified with octadecyltrichlorosilane (ODS) and the chromatographic evaluation was performed by separating the proteins and the digest of BSA. The baseline separation of seven kinds of protein standards was achieved, and the column delivered a better performance when separating BSA digests comparing with the commercial one currently available. The high column efficiency and good reproducibility present that the large-porous silica microspheres obtained can be used as a matrix for peptide and protein separation. Copyright © 2016 Elsevier B.V. All rights reserved.

Design and Field Procedures in the US National Comorbidity Survey Replication Adolescent Supplement (NCS-A)

PubMed Central

Kessler, Ronald C.; Avenevoli, Shelli; Costello, E. Jane; Green, Jennifer Greif; Gruber, Michael J.; Heeringa, Steven; Merikangas, Kathleen R.; Pennell, Beth-Ellen; Sampson, Nancy A.; Zaslavsky, Alan M.

2009-01-01

An overview is presented of the design and field procedures of the US National Comorbidity Survey Replication Adolescent Supplement (NCS-A), a US face-to-face household survey of the prevalence and correlates of DSM-IV mental disorders. The survey was based on a dual-frame design that included 904 adolescent residents of the households that participated in the US National Comorbidity Survey Replication (85.9% response rate) and 9,244 adolescent students selected from a nationally representative sample of 320 schools (74.7% response rate). After expositing the logic of dual-frame designs, comparisons are presented of sample and population distributions on Census socio-demographic variables and, in the school sample, school characteristics. These document only minor differences between the samples and the population. The results of statistical analysis of the bias-efficiency trade-off in weight trimming are then presented. These show that modest trimming meaningfully reduces mean squared error. Analysis of comparative sample efficiency shows that the household sample is more efficient than the school sample, leading to the household sample getting a higher weight relative to its size in the consolidated sample relative to the school sample. Taken together, these results show that the NCS-A is an efficient sample of the target population with good representativeness on a range of socio-demographic and geographic variables. PMID:19507169

Generalized Redistribute-to-the-Right Algorithm: Application to the Analysis of Censored Cost Data

PubMed Central

CHEN, SHUAI; ZHAO, HONGWEI

2013-01-01

Medical cost estimation is a challenging task when censoring of data is present. Although researchers have proposed methods for estimating mean costs, these are often derived from theory and are not always easy to understand. We provide an alternative method, based on a replace-from-the-right algorithm, for estimating mean costs more efficiently. We show that our estimator is equivalent to an existing one that is based on the inverse probability weighting principle and semiparametric efficiency theory. We also propose an alternative method for estimating the survival function of costs, based on the redistribute-to-the-right algorithm, that was originally used for explaining the Kaplan–Meier estimator. We show that this second proposed estimator is equivalent to a simple weighted survival estimator of costs. Finally, we develop a more efficient survival estimator of costs, using the same redistribute-to-the-right principle. This estimator is naturally monotone, more efficient than some existing survival estimators, and has a quite small bias in many realistic settings. We conduct numerical studies to examine the finite sample property of the survival estimators for costs, and show that our new estimator has small mean squared errors when the sample size is not too large. We apply both existing and new estimators to a data example from a randomized cardiovascular clinical trial. PMID:24403869

NDARC NASA Design and Analysis of Rotorcraft - Input, Appendix 4

NASA Technical Reports Server (NTRS)

Johnson, Wayne

2016-01-01

The NDARC code performs design and analysis tasks. The design task involves sizing the rotorcraft to satisfy specified design conditions and missions. The analysis tasks can include off-design mission performance analysis, flight performance calculation for point operating conditions, and generation of subsystem or component performance maps. The principal tasks (sizing, mission analysis, flight performance analysis) are shown in the figure as boxes with heavy borders. Heavy arrows show control of subordinate tasks. The aircraft description consists of all the information, input and derived, that denes the aircraft. The aircraft consists of a set of components, including fuselage, rotors, wings, tails, and propulsion. This information can be the result of the sizing task; can come entirely from input, for a fixed model; or can come from the sizing task in a previous case or previous job. The aircraft description information is available to all tasks and all solutions. The sizing task determines the dimensions, power, and weight of a rotorcraft that can perform a specified set of design conditions and missions. The aircraft size is characterized by parameters such as design gross weight, weight empty, rotor radius, and engine power available. The relations between dimensions, power, and weight generally require an iterative solution. From the design flight conditions and missions, the task can determine the total engine power or the rotor radius (or both power and radius can be fixed), as well as the design gross weight, maximum takeoff weight, drive system torque limit, and fuel tank capacity. For each propulsion group, the engine power or the rotor radius can be sized. Missions are defined for the sizing task, and for the mission performance analysis. A mission consists of a number of mission segments, for which time, distance, and fuel burn are evaluated. For the sizing task, certain missions are designated to be used for design gross weight calculations; for transmission sizing; and for fuel tank sizing. The mission parameters include mission takeoff gross weight and useful load. For specified takeoff fuel weight with adjustable segments, the mission time or distance is adjusted so the fuel required for the mission equals the takeoff fuel weight. The mission iteration is on fuel weight or energy. Flight conditions are specified for the sizing task, and for the flight performance analysis. For the sizing task, certain flight conditions are designated to be used for design gross weight calculations; for transmission sizing; for maximum takeoff weight calculations; and for anti-torque or auxiliary thrust rotor sizing. The flight condition parameters include gross weight and useful load. For flight conditions and mission takeoff, the gross weight can be maximized, such that the power required equals the power available. A flight state is defined for each mission segment and each flight condition. The aircraft performance can be analyzed for the specified state, or a maximum effort performance can be identified. The maximum effort is specified in terms of a quantity such as best endurance or best range, and a variable such as speed, rate of climb, or altitude.

--No Title--

Science.gov Websites

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Visual body size norms and the under‐detection of overweight and obesity

PubMed Central

Robinson, E.

2017-01-01

Summary Objectives The weight status of men with overweight and obesity tends to be visually underestimated, but visual recognition of female overweight and obesity has not been formally examined. The aims of the present studies were to test whether people can accurately recognize both male and female overweight and obesity and to examine a visual norm‐based explanation for why weight status is underestimated. Methods The present studies examine whether both male and female overweight and obesity are visually underestimated (Study 1), whether body size norms predict when underestimation of weight status occurs (Study 2) and whether visual exposure to heavier body weights adjusts visual body size norms and results in underestimation of weight status (Study 3). Results The weight status of men and women with overweight and obesity was consistently visually underestimated (Study 1). Body size norms predicted underestimation of weight status (Study 2) and in part explained why visual exposure to heavier body weights caused underestimation of overweight (Study 3). Conclusions The under‐detection of overweight and obesity may have been in part caused by exposure to larger body sizes resulting in an upwards shift in the range of body sizes that are perceived as being visually ‘normal’. PMID:29479462

Study design and the estimation of the size of key populations at risk of HIV: lessons from Viet Nam.

PubMed

Safarnejad, Ali; Groot, Wim; Pavlova, Milena

2018-01-30

Estimation of the size of populations at risk of HIV is a key activity in the surveillance of the HIV epidemic. The existing framework for considering future research needs may provide decision-makers with a basis for a fair process of deciding on the methods of the estimation of the size of key populations at risk of HIV. This study explores the extent to which stakeholders involved with population size estimation agree with this framework, and thus, the study updates the framework. We conducted 16 in-depth interviews with key informants from city and provincial governments, NGOs, research institutes, and the community of people at risk of HIV. Transcripts were analyzed and reviewed for significant statements pertaining to criteria. Variations and agreement around criteria were analyzed, and emerging criteria were validated against the existing framework. Eleven themes emerged which are relevant to the estimation of the size of populations at risk of HIV in Viet Nam. Findings on missing criteria, inclusive participation, community perspectives and conflicting weight and direction of criteria provide insights for an improved framework for the prioritization of population size estimation methods. The findings suggest that the exclusion of community members from decision-making on population size estimation methods in Viet Nam may affect the validity, use, and efficiency of the evidence generated. However, a wider group of decision-makers, including community members among others, may introduce diverse definitions, weight and direction of criteria. Although findings here may not apply to every country with a transitioning economy or to every emerging epidemic, the principles of fair decision-making, value of community participation in decision-making and the expected challenges faced, merit consideration in every situation.

[Spectral scatter correction of coal samples based on quasi-linear local weighted method].

PubMed

Lei, Meng; Li, Ming; Ma, Xiao-Ping; Miao, Yan-Zi; Wang, Jian-Sheng

2014-07-01

The present paper puts forth a new spectral correction method based on quasi-linear expression and local weighted function. The first stage of the method is to search 3 quasi-linear expressions to replace the original linear expression in MSC method, such as quadratic, cubic and growth curve expression. Then the local weighted function is constructed by introducing 4 kernel functions, such as Gaussian, Epanechnikov, Biweight and Triweight kernel function. After adding the function in the basic estimation equation, the dependency between the original and ideal spectra is described more accurately and meticulously at each wavelength point. Furthermore, two analytical models were established respectively based on PLS and PCA-BP neural network method, which can be used for estimating the accuracy of corrected spectra. At last, the optimal correction mode was determined by the analytical results with different combination of quasi-linear expression and local weighted function. The spectra of the same coal sample have different noise ratios while the coal sample was prepared under different particle sizes. To validate the effectiveness of this method, the experiment analyzed the correction results of 3 spectral data sets with the particle sizes of 0.2, 1 and 3 mm. The results show that the proposed method can eliminate the scattering influence, and also can enhance the information of spectral peaks. This paper proves a more efficient way to enhance the correlation between corrected spectra and coal qualities significantly, and improve the accuracy and stability of the analytical model substantially.

The impact of preparation parameters on typical attributes of chitosan-heparin nanohydrogels: particle size, loading efficiency, and drug release.

PubMed

Shahbazi, Mohammad-Ali; Hamidi, Mehrdad

2013-11-01

Today, developing an optimized nanoparticle (NP) preparation procedure is of paramount importance in all nanoparticulate drug delivery researches, leading to expanding more operative and clinically validated nanomedicines. In this study, a one-at-a-time experimental approach was used for evaluating the effect of various preparation factors on size, loading, and drug release of hydrogel NPs prepared with ionotropic gelation between heparin and chitosan. The size, loading efficiency (LE) and drug release profile of the NPs were evaluated when the chitosan molecular weight, chitosan concentration, heparin addition time to chitosan solution, heparin concentration, pH value of chitosan solution, temperature, and mixing rate were changed separately while other factors were in optimum condition. The results displayed that size and LE are highly influenced by chitosan concentration, getting an optimum of 63 ± 0.57 and 75.19 ± 2.65, respectively, when chitosan concentration was 0.75 mg/ml. Besides, heparin addition time of 3 min leaded to 74.1 ± 0.79 % LE with no sensible effect on size and release profile. In addition, pH 5.5 showed a minimum size of 63 ± 1.87, maximum LE of 73.81 ± 3.13 and the slowest drug release with 63.71 ± 3.84 % during one week. Although LE was not affected by temperature, size and release reduced to 63 ± 0 and 74.21 ± 1.99% when temperature increased from 25°C to 55°C. Also, continuous increase of mixer rate from 500 to 3500 rpm resulted in constant enhancement of LE from 58.3 ± 3.6 to 74.4 ± 2.59 as well as remarkable decrease in size from 148 ± 4.88 to 63 ± 2.64.

77 FR 32013 - Truck Size and Weight; Technical Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-31

...-2012-0037] RIN 2125-AF45 Truck Size and Weight; Technical Correction AGENCY: Federal Highway...: This rule makes a technical correction to the regulations that govern Longer Combination Vehicles (LCV... INFORMATION CONTACT: John Nicholas, Truck Size and Weight Program Manager, Office of Freight Management and...

A Standalone Solar Photovoltaic Power Generation using Cuk Converter and Single Phase Inverter

NASA Astrophysics Data System (ADS)

Verma, A. K.; Singh, B.; Kaushika, S. C.

2013-03-01

In this paper, a standalone solar photovoltaic (SPV) power generating system is designed and modeled using a Cuk dc-dc converter and a single phase voltage source inverter (VSI). In this system, a dc-dc boost converter boosts a low voltage of a PV array to charge a battery at 24 V using a maximum power point tracking control algorithm. To step up a 24 V battery voltage to 360 V dc, a high frequency transformer based isolated dc-dc Cuk converter is used to reduce size, weight and losses. The dc voltage of 360 V is fed to a single phase VSI with unipolar switching to achieve a 230 Vrms, 50 Hz ac. The main objectives of this investigation are on efficiency improvement, reduction in cost, weight and size of the system and to provide an uninterruptible power to remotely located consumers. The complete SPV system is designed and it is modeled in MATLAB/Simulink. The simulated results are presented to demonstrate its satisfactory performance for validating the proposed design and control algorithm.

Determination of digestible and metabolizable energy of fishmeal and soybean meal in rainbow trout with two different sizes (Oncorhynchus mykiss).

PubMed

Allameh, Sayed Kamaleddin; Soofiani, Nasrollah Mahboobi; Pourreza, Javad

2007-10-15

The present research carried out to measure digestible (DE) and Metabolizable Energy (ME) for fishmeal and soybean meal in rainbow trout with two different sizes (120 and 220 g mean body weights). DE and ME are evaluation systems for feedstuffs and also, necessary for diet formulation. The fishes were maintained in metabolic chamber with single ingredient assay of feeding and chromic oxide (Cr2O3) was used as an external marker using total fecal collection method. Gross energy and chromic oxide values measured in feces, fishmeal and soybean meal. The results indicated that DE offishmeal was 3700 and 3591 kcal kg(-1) in 120 and 220 g body weight rainbow trout, respectively. Soybean meal had 3004 and 2889 kcal kg(-1) respectively. Calculated ME from DE were 3204 and 3110 kcal kg(-1) for fishmeal and 2601 and 2502 kcal kg(-1) for soybean meal in 120 and 220 g rainbow trout, respectively. The results showed that rainbow trout can utilize fishmeal more efficiently than soybean meal.

Approximated affine projection algorithm for feedback cancellation in hearing aids.

PubMed

Lee, Sangmin; Kim, In-Young; Park, Young-Cheol

2007-09-01

We propose an approximated affine projection (AP) algorithm for feedback cancellation in hearing aids. It is based on the conventional approach using the Gauss-Seidel (GS) iteration, but provides more stable convergence behaviour even with small step sizes. In the proposed algorithm, a residue of the weighted error vector, instead of the current error sample, is used to provide stable convergence. A new learning rate control scheme is also applied to the proposed algorithm to prevent signal cancellation and system instability. The new scheme determines step size in proportion to the prediction factor of the input, so that adaptation is inhibited whenever tone-like signals are present in the input. Simulation results verified the efficiency of the proposed algorithm.

Weighting by Inverse Variance or by Sample Size in Random-Effects Meta-Analysis

ERIC Educational Resources Information Center

Marin-Martinez, Fulgencio; Sanchez-Meca, Julio

2010-01-01

Most of the statistical procedures in meta-analysis are based on the estimation of average effect sizes from a set of primary studies. The optimal weight for averaging a set of independent effect sizes is the inverse variance of each effect size, but in practice these weights have to be estimated, being affected by sampling error. When assuming a…

Excessive backfat of sows at 109 d of gestation induces lipotoxic placental environment and is associated with declining reproductive performance.

PubMed

Zhou, Yuanfei; Xu, Tao; Cai, Anle; Wu, Yinghui; Wei, Hongkui; Jiang, Siwen; Peng, Jian

2018-02-15

This study investigated the influence of sow backfat thickness at 109 d of gestation on sow and piglet performance. Data from 846 farrowing multiparous Yorkshire sows with parity from 3 to 5 were collected from a pig breeding farm. Sows were divided into six groups based on backfat thickness (≤16, 17-18, 19-20, 21-22, 23-24, and ≥25 mm) at 109 d of gestation. The evaluation of reproductive performance included the litter size, litter weight at birth and at weaning of 21 d, weight of placenta at parturition, placental efficiency, and sow daily feed intake of lactation. Parameters related to plasma lipids and the placental-lipid concentration were measured. Data were analyzed to determine the relationships among backfat thickness, placental lipids, and piglet performance. No differences were observed in the number of piglets born, born alive, after cross-foster, and at weaning among groups (P > 0.05). The litter weight at birth and weaning, piglet birth weight, weaning weight, placental efficiency, and the number and percentage of piglets born with weight of <800 g showed a significantly quadratic effect of the backfat thickness (P < 0.05). During lactation, sow daily feed intake linearly decreased with increased backfat thickness at 109 d of gestation (P < 0.05). Although triglycerides and low-density lipoprotein cholesterol (LDL-C) showed no significant difference, cholesterol and high-density lipoprotein cholesterol (HDL-C) and free fatty acid (FFA) concentrations significantly increased (P < 0.05) in both maternal and umbilical cord blood with increased backfat thickness of sow. Placental-lipid concentrations also significantly increased (P < 0.05) with increased backfat thickness. Moreover, backfat thickness and placental-lipid concentration were positively correlated with the number of piglets weighing <800 g (P < 0.01) but negatively correlated with birth weight, litter birth weight, and piglet weaned weight (P < 0.01). In conclusion, backfat thickness of sow at end of gestation correlates with birth and weaning weight of piglets. Placental ectopic lipid accumulation-induced lipotoxicity is likely responsible for such correlation.

Integrated application of active controls (IAAC) technology to an advanced subsonic transport project. Initial ACT configuration design study

NASA Technical Reports Server (NTRS)

1980-01-01

The initial ACT configuration design task of the integrated application of active controls (IAAC) technology project within the Energy Efficient Transport Program is summarized. A constrained application of active controls technology (ACT) resulted in significant improvements over a conventional baseline configuration previously established. The configuration uses the same levels of technology, takeoff gross weight, payload, and design requirements/objectives as the baseline, except for flying qualities, flutter, and ACT. The baseline wing is moved forward 1.68 m. The configuration incorporates pitch-augmented stability (which enabled an approximately 10% aft shift in cruise center of gravity and a 45% reduction in horizontal tail size), lateral/directional-augmented stability, an angle of attack limiter, wing load alleviation, and flutter mode control. This resulted in a 930 kg reduction in airplane operating empty weight and a 3.6% improvement in cruise efficiency, yielding a 13% range increase. Adjusted to the 3590 km baseline mission range, this amounts to 6% block fuel reduction and a 15.7% higher incremental return on investment, using 1978 dollars and fuel cost.

Potential low cost, safe, high efficiency propellant for future space program

NASA Astrophysics Data System (ADS)

Zhou, D.

2005-03-01

Mixtures of nanometer or micrometer sized carbon powder suspended in hydrogen and methane/hydrogen mixtures are proposed as candidates for low cost, high efficiency propellants for future space programs. While liquid hydrogen has low weight and high heat of combustion per unit mass, because of the low mass density the heat of combustion per unit volume is low, and the liquid hydrogen storage container must be large. The proposed propellants can produce higher gross heat combustion with small volume with trade off of some weight increase. Liquid hydrogen can serve as the fluid component of the propellant in the mixtures and thus used by current rocket engine designs. For example, for the same volume a mixture of 5% methane and 95% hydrogen, can lead to an increase in the gross heat of combustion by about 10% and an increase in the Isp (specific impulse) by 21% compared to a pure liquid hydrogen propellant. At liquid hydrogen temperatures of 20.3 K, methane will be in solid state, and must be formed as fine granules (or slush) to satisfy the requirement of liquid propellant engines.

Multi-Target Tracking Using an Improved Gaussian Mixture CPHD Filter.

PubMed

Si, Weijian; Wang, Liwei; Qu, Zhiyu

2016-11-23

The cardinalized probability hypothesis density (CPHD) filter is an alternative approximation to the full multi-target Bayesian filter for tracking multiple targets. However, although the joint propagation of the posterior intensity and cardinality distribution in its recursion allows more reliable estimates of the target number than the PHD filter, the CPHD filter suffers from the spooky effect where there exists arbitrary PHD mass shifting in the presence of missed detections. To address this issue in the Gaussian mixture (GM) implementation of the CPHD filter, this paper presents an improved GM-CPHD filter, which incorporates a weight redistribution scheme into the filtering process to modify the updated weights of the Gaussian components when missed detections occur. In addition, an efficient gating strategy that can adaptively adjust the gate sizes according to the number of missed detections of each Gaussian component is also presented to further improve the computational efficiency of the proposed filter. Simulation results demonstrate that the proposed method offers favorable performance in terms of both estimation accuracy and robustness to clutter and detection uncertainty over the existing methods.

Amphiphilic graft copolymer based on poly(styrene-co-maleic anhydride) with low molecular weight polyethylenimine for efficient gene delivery

PubMed Central

Duan, Xiaopin; Xiao, Jisheng; Yin, Qi; Zhang, Zhiwen; Mao, Shirui; Li, Yaping

2012-01-01

Background and methods A new amphiphilic comb-shaped copolymer (SP) was synthesized by conjugating poly(styrene-co-maleic anhydride) with low molecular weight polyethyleneimine for gene delivery. Fourier transform infrared spectrum, 1H nuclear magnetic resonance, and gel permeation chromatography were used to characterize the graft copolymer. Results The buffering capability of SP was similar to that of polyethyleneimine within the endosomal pH range. The copolymer could condense DNA effectively to form complexes with a positive charge (13–30 mV) and a small particle size (130–200 nm) at N/P ratios between 5 and 20, and protect DNA from degradation by DNase I. In addition, SP showed much lower cytotoxicity than polyethyleneimine 25,000. Importantly, the gene transfection activity and cellular uptake of SP-DNA complexes were all markedly higher than that of complexes of polyethyleneimine 25,000 and DNA in MCF-7 and MCF-7/ADR cell lines. Conclusion This work highlights the promise of SP as a safe and efficient synthetic vector for DNA delivery. PMID:23028224

Development of subcutaneous sustained release nanoparticles encapsulating low molecular weight heparin

PubMed Central

Jogala, Satheesh; Rachamalla, Shyam Sunder; Aukunuru, Jithan

2015-01-01

The objective of the present research work was to prepare and evaluate sustained release subcutaneous (s.c.) nanoparticles of low molecular weight heparin (LMWH). The nanoparticles were prepared by water–in-oil in-water (w/o/w) emulsion and evaporation method using different grades of polylactide co-glycolide (50:50, 85:15), and different concentrations of polyvinyl alcohol (0.1%, 0.5%, 1%) aqueous solution as surfactant. The fabricated nanoparticles were evaluated for size, shape, zeta potential, encapsulation efficiency, in vitro drug release, and in vivo biological activity (anti-factor Xa activity) using the standard kit. The drug and excipient compatibility was analyzed by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies. The formation of nanoparticles was confirmed by scanning electron microscopy; nanoparticles were spherical in shape. The size of prepared nanoparticles was found between 195 nm and 251 nm. The encapsulation efficiency of the nanoparticles was found between 46% and 70%. In vitro drug, release was about 16–38% for 10 days. In vivo drug, release shows the sustained release of drug for 10 days in rats. FTIR studies indicated that there was no loss in chemical integrity of the drug upon fabrication into nanoparticles. DSC and XRD results demonstrated that the drug was changed from the crystalline form to the amorphous form in the formulation during the fabrication process. The results of this study revealed that the s.c. nanoparticles were suitable candidates for sustained delivery of LMWH. PMID:25878975

Freeform Fluidics

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

Love, Lonnie J; Richardson, Bradley S; Lind, Randall F

This work explores the integration of miniaturized fluid power and additive manufacturing. Oak Ridge National Laboratory (ORNL) has been developing an approach to miniaturized fluidic actuation and control that enables high dexterity, low cost and a pathway towards energy efficiency. Previous work focused on mesoscale digital control valves (high pressure, low flow) and the integration of actuation and fluid passages directly with the structure. The primary application being fluid powered robotics. The fundamental challenge was part complexity. Additive manufacturing technologies (E-Beam, Laser and Ultrasonic deposition) enable freeform manufacturing using conventional metal alloys with excellent mechanical properties. The combination of thesemore » two technologies (miniaturized fluid power and additive manufacturing) can enable a paradigm shift in fluid power, increasing efficiency while simultaneously reducing weight, size, complexity and cost.« less

Airframe-integrated propulsion system for hypersonic cruise vehicles

NASA Technical Reports Server (NTRS)

Jones, R. A.; Huber, P. W.

1978-01-01

The paper describes a new hydrogen-burning airframe-integrated scramjet concept which offers good potential for efficient hypersonic cruise vehicles. The characteristics of the engine which assure good performance are extensive engine-airframe integration, fixed geometry, low cooling, and control of heat release in the supersonic combustor by mixed modes of fuel injection from the combustor entrance. The present paper describes the concept and presents results from inlet tests, direct-connect combustor tests, and tests of two subscale boiler-plate research engines currently underway under conditions which simulate flight at Mach 4 and 7. It is concluded that this engine concept has the potential for high thrust and efficiency, low drag and weight, low cooling requirement, and application to a wide range of vehicle sizes.

Probabilistic treatment of the uncertainty from the finite size of weighted Monte Carlo data

NASA Astrophysics Data System (ADS)

Glüsenkamp, Thorsten

2018-06-01

Parameter estimation in HEP experiments often involves Monte Carlo simulation to model the experimental response function. A typical application are forward-folding likelihood analyses with re-weighting, or time-consuming minimization schemes with a new simulation set for each parameter value. Problematically, the finite size of such Monte Carlo samples carries intrinsic uncertainty that can lead to a substantial bias in parameter estimation if it is neglected and the sample size is small. We introduce a probabilistic treatment of this problem by replacing the usual likelihood functions with novel generalized probability distributions that incorporate the finite statistics via suitable marginalization. These new PDFs are analytic, and can be used to replace the Poisson, multinomial, and sample-based unbinned likelihoods, which covers many use cases in high-energy physics. In the limit of infinite statistics, they reduce to the respective standard probability distributions. In the general case of arbitrary Monte Carlo weights, the expressions involve the fourth Lauricella function FD, for which we find a new finite-sum representation in a certain parameter setting. The result also represents an exact form for Carlson's Dirichlet average Rn with n > 0, and thereby an efficient way to calculate the probability generating function of the Dirichlet-multinomial distribution, the extended divided difference of a monomial, or arbitrary moments of univariate B-splines. We demonstrate the bias reduction of our approach with a typical toy Monte Carlo problem, estimating the normalization of a peak in a falling energy spectrum, and compare the results with previously published methods from the literature.

GTX Reference Vehicle Structural Verification Methods and Weight Summary

NASA Technical Reports Server (NTRS)

Hunter, J. E.; McCurdy, D. R.; Dunn, P. W.

2002-01-01

The design of a single-stage-to-orbit air breathing propulsion system requires the simultaneous development of a reference launch vehicle in order to achieve the optimal mission performance. Accordingly, for the GTX study a 300-lb payload reference vehicle was preliminary sized to a gross liftoff weight (GLOW) of 238,000 lb. A finite element model of the integrated vehicle/propulsion system was subjected to the trajectory environment and subsequently optimized for structural efficiency. This study involved the development of aerodynamic loads mapped to finite element models of the integrated system in order to assess vehicle margins of safety. Commercially available analysis codes were used in the process along with some internally developed spread-sheets and FORTRAN codes specific to the GTX geometry for mapping of thermal and pressure loads. A mass fraction of 0.20 for the integrated system dry weight has been the driver for a vehicle design consisting of state-of-the-art composite materials in order to meet the rigid weight requirements. This paper summarizes the methodology used for preliminary analyses and presents the current status of the weight optimization for the structural components of the integrated system.

GTX Reference Vehicle Structural Verification Methods and Weight Summary

NASA Technical Reports Server (NTRS)

Hunter, J. E.; McCurdy, D. R.; Dunn, P. W.

2002-01-01

The design of a single-stage-to-orbit air breathing propulsion system requires the simultaneous development of a reference launch vehicle in order to achieve the optimal mission performance. Accordingly, for the GTX study a 300-lb payload reference vehicle was preliminarily sized to a gross liftoff weight (GLOW) of 238,000 lb. A finite element model of the integrated vehicle/propulsion system was subjected to the trajectory environment and subsequently optimized for structural efficiency. This study involved the development of aerodynamic loads mapped to finite element models of the integrated system in order to assess vehicle margins of safety. Commercially available analysis codes were used in the process along with some internally developed spreadsheets and FORTRAN codes specific to the GTX geometry for mapping of thermal and pressure loads. A mass fraction of 0.20 for the integrated system dry weight has been the driver for a vehicle design consisting of state-of-the-art composite materials in order to meet the rigid weight requirements. This paper summarizes the methodology used for preliminary analyses and presents the current status of the weight optimization for the structural components of the integrated system.

Drude weight fluctuations in many-body localized systems

NASA Astrophysics Data System (ADS)

Filippone, Michele; Brouwer, Piet W.; Eisert, Jens; von Oppen, Felix

2016-11-01

We numerically investigate the distribution of Drude weights D of many-body states in disordered one-dimensional interacting electron systems across the transition to a many-body localized phase. Drude weights are proportional to the spectral curvatures induced by magnetic fluxes in mesoscopic rings. They offer a method to relate the transition to the many-body localized phase to transport properties. In the delocalized regime, we find that the Drude weight distribution at a fixed disorder configuration agrees well with the random-matrix-theory prediction P (D ) ∝(γ2+D2) -3 /2 , although the distribution width γ strongly fluctuates between disorder realizations. A crossover is observed towards a distribution with different large-D asymptotics deep in the many-body localized phase, which however differs from the commonly expected Cauchy distribution. We show that the average distribution width <γ >, rescaled by L Δ ,Δ being the average level spacing in the middle of the spectrum and L the systems size, is an efficient probe of the many-body localization transition, as it increases (vanishes) exponentially in the delocalized (localized) phase.

System design of an optical interferometer based on compressive sensing

NASA Astrophysics Data System (ADS)

Liu, Gang; Wen, De-Sheng; Song, Zong-Xi

2018-07-01

In this paper, we develop a new optical interferometric telescope architecture based on compressive sensing (CS) theory. Traditional optical telescopes with large apertures must be large in size, heavy and have high-power consumption, which limits the development of space-based telescopes. A turning point has occurred in the advent of imaging technology that utilizes Fourier-domain interferometry. This technology can reduce the system size, weight and power consumption by an order of magnitude compared to traditional optical telescopes at the same resolution. CS theory demonstrates that incomplete and noisy Fourier measurements may suffice for the exact reconstruction of sparse or compressible signals. Our proposed architecture combines advantages from the two frameworks, and the performance is evaluated through simulations. The results indicate the ability to efficiently sample spatial frequencies, while being lightweight and compact in size. Another attractive property of our architecture is the strong denoising ability for Gaussian noise.

Size-exclusion chromatography using core-shell particles.

PubMed

Pirok, Bob W J; Breuer, Pascal; Hoppe, Serafine J M; Chitty, Mike; Welch, Emmet; Farkas, Tivadar; van der Wal, Sjoerd; Peters, Ron; Schoenmakers, Peter J

2017-02-24

Size-exclusion chromatography (SEC) is an indispensable technique for the separation of high-molecular-weight analytes and for determining molar-mass distributions. The potential application of SEC as second-dimension separation in comprehensive two-dimensional liquid chromatography demands very short analysis times. Liquid chromatography benefits from the advent of highly efficient core-shell packing materials, but because of the reduced total pore volume these materials have so far not been explored in SEC. The feasibility of using core-shell particles in SEC has been investigated and contemporary core-shell materials were compared with conventional packing materials for SEC. Columns packed with very small core-shell particles showed excellent resolution in specific molar-mass ranges, depending on the pore size. The analysis times were about an order of magnitude shorter than what could be achieved using conventional SEC columns. Copyright © 2016 Elsevier B.V. All rights reserved.

Design of PEI-conjugated bio-reducible polymer for efficient gene delivery.

PubMed

Nam, Joung-Pyo; Kim, Soyoung; Kim, Sung Wan

2018-07-10

The poly(cystaminebis(acrylamide)-diaminohexane) (poly(CBA-DAH)) was designed previously as a bio-reducible efficient gene delivery carrier. However, the high weight ratio required to form the polyplexes between poly(CBA-DAH) with pDNA is still a problem that needs to be addressed. To solve this problem and increase the transfection efficiency, poly(ethylenimine) (PEI, 1.8 kDa) was conjugated to poly(CBA-DAH) via disulfide bond. The PEI conjugated poly(CBA-DAH) (PCDP) can bind with pDNA at a very low weight ratio of 0.5 and above, like PEI 25 kDa, and form the polyplexes with nano-size (102-128 nm) and positive surface charge (27-34 mV). PCDP and PCDP polyplexes had negligible cytotoxicity and indicated similar or better cellular uptake than the comparison groups such as PEI 25 kDa and Lipofectamine® polyplexes. To confirm the transfection efficiency, the plasmid DNA (pDNA) encoded with the luciferase reporter gene (gWiz-Luc) and green fluorescent protein reporter gene (GFP) were used and treated with PCDP into the A549, Huh-7, and Mia PaCa-2 cells. PCDP/pDNA polyplexes showed highest transfection efficiency in all tested cell lines. In the luciferase assay, PCDP polyplexes showed 10.2 times higher gene transfection efficiency than Lipofectamine® polyplexes in mimic in vivo conditions (30% FBS, A549 cells). The VEGF siRNA expressing plasmid (pshVEGF), which is constructed as a therapeutic gene by our previous work, was delivered by PCDP into the cancer cells. The VEGF gene expression of PCDP/pshVEGF polyplexes was dramatically lower than control and the VEGF gene silencing efficiencies of PCDP/pshVEGF (w/w; 10/1) polyplexes were 54% (A549 cells), 77% (Huh-7 cells), and 66% (Mia PaCa-2 cells). In addition, PCDP/pshVEGF had reduced cell viability rates of about 31% (A549 cells), 39% (Huh-7 cells), and 42% (Mia PaCa-2 cells) and showed better results than all comparison groups. In the transfection efficiency and VEGF silencing assay, PCDP polyplexes showed better results than poly(CBA-DAH) at 4-fold lower weight ratio. The data of all experiments demonstrate that the synthesized PCDP could be used for efficient gene delivery and could be widely applied. Published by Elsevier B.V.

Application of power transistors to residential and intermediate rating photovoltaic array power conditioners

NASA Astrophysics Data System (ADS)

Steigerwald, R. L.; Ferraro, A.; Turnbull, F. G.

1983-04-01

Power conditioning systems that interface with photovoltaic arrays are presently investigated for the cases of 5-30 kW residential systems interfacing with a 240-V single-phase utility connection, and 30-200 kW intermediate systems interfacing with a 480-V three-phase utility connection. Both systems require an isolation transformer between the array and the utility interface. A tradeoff study is conducted for numerous transistor and thyristor circuits and configurations, with weighting criteria that include full- and part-load efficiency, size, weight, reliability, ease of control, injected harmonics, reactive power requirements, and parts cost. On the basis of study results, a 10-kW high frequency transistor inverter feeding a high frequency isolation transformer with a sinusoidally shaped current wave was selected.

Two stage to orbit design

NASA Technical Reports Server (NTRS)

1991-01-01

A preliminary design of a two-stage to orbit vehicle was conducted with the requirements to carry a 10,000 pound payload into a 300 mile low-earth orbit using an airbreathing first stage, and to take off and land unassisted on a 15,000 foot runway. The goal of the design analysis was to produce the most efficient vehicle in size and weight which could accomplish the mission requirements. Initial parametric analysis indicated that the weight of the orbiter and the transonic performance of the system were the two parameters that had the largest impact on the design. The resulting system uses a turbofan ramjet powered first stage to propel a scramjet and rocket powered orbiter to the stage point of Mach 6 to 6.5 at an altitude of 90,000 ft.

The Conserved and Unique Genetic Architecture of Kernel Size and Weight in Maize and Rice1[OPEN

PubMed Central

Lan, Liu; Wang, Hongze; Xu, Yuancheng; Yang, Xiaohong; Li, Wenqiang; Tong, Hao; Xiao, Yingjie; Pan, Qingchun; Qiao, Feng; Raihan, Mohammad Sharif; Liu, Haijun; Yang, Ning; Wang, Xiaqing; Deng, Min; Jin, Minliang; Zhao, Lijun; Luo, Xin; Zhan, Wei; Liu, Nannan; Wang, Hong; Chen, Gengshen

2017-01-01

Maize (Zea mays) is a major staple crop. Maize kernel size and weight are important contributors to its yield. Here, we measured kernel length, kernel width, kernel thickness, hundred kernel weight, and kernel test weight in 10 recombinant inbred line populations and dissected their genetic architecture using three statistical models. In total, 729 quantitative trait loci (QTLs) were identified, many of which were identified in all three models, including 22 major QTLs that each can explain more than 10% of phenotypic variation. To provide candidate genes for these QTLs, we identified 30 maize genes that are orthologs of 18 rice (Oryza sativa) genes reported to affect rice seed size or weight. Interestingly, 24 of these 30 genes are located in the identified QTLs or within 1 Mb of the significant single-nucleotide polymorphisms. We further confirmed the effects of five genes on maize kernel size/weight in an independent association mapping panel with 540 lines by candidate gene association analysis. Lastly, the function of ZmINCW1, a homolog of rice GRAIN INCOMPLETE FILLING1 that affects seed size and weight, was characterized in detail. ZmINCW1 is close to QTL peaks for kernel size/weight (less than 1 Mb) and contains significant single-nucleotide polymorphisms affecting kernel size/weight in the association panel. Overexpression of this gene can rescue the reduced weight of the Arabidopsis (Arabidopsis thaliana) homozygous mutant line in the AtcwINV2 gene (Arabidopsis ortholog of ZmINCW1). These results indicate that the molecular mechanisms affecting seed development are conserved in maize, rice, and possibly Arabidopsis. PMID:28811335

The Conserved and Unique Genetic Architecture of Kernel Size and Weight in Maize and Rice.

PubMed

Liu, Jie; Huang, Juan; Guo, Huan; Lan, Liu; Wang, Hongze; Xu, Yuancheng; Yang, Xiaohong; Li, Wenqiang; Tong, Hao; Xiao, Yingjie; Pan, Qingchun; Qiao, Feng; Raihan, Mohammad Sharif; Liu, Haijun; Zhang, Xuehai; Yang, Ning; Wang, Xiaqing; Deng, Min; Jin, Minliang; Zhao, Lijun; Luo, Xin; Zhou, Yang; Li, Xiang; Zhan, Wei; Liu, Nannan; Wang, Hong; Chen, Gengshen; Li, Qing; Yan, Jianbing

2017-10-01

Maize ( Zea mays ) is a major staple crop. Maize kernel size and weight are important contributors to its yield. Here, we measured kernel length, kernel width, kernel thickness, hundred kernel weight, and kernel test weight in 10 recombinant inbred line populations and dissected their genetic architecture using three statistical models. In total, 729 quantitative trait loci (QTLs) were identified, many of which were identified in all three models, including 22 major QTLs that each can explain more than 10% of phenotypic variation. To provide candidate genes for these QTLs, we identified 30 maize genes that are orthologs of 18 rice ( Oryza sativa ) genes reported to affect rice seed size or weight. Interestingly, 24 of these 30 genes are located in the identified QTLs or within 1 Mb of the significant single-nucleotide polymorphisms. We further confirmed the effects of five genes on maize kernel size/weight in an independent association mapping panel with 540 lines by candidate gene association analysis. Lastly, the function of ZmINCW1 , a homolog of rice GRAIN INCOMPLETE FILLING1 that affects seed size and weight, was characterized in detail. ZmINCW1 is close to QTL peaks for kernel size/weight (less than 1 Mb) and contains significant single-nucleotide polymorphisms affecting kernel size/weight in the association panel. Overexpression of this gene can rescue the reduced weight of the Arabidopsis ( Arabidopsis thaliana ) homozygous mutant line in the AtcwINV2 gene (Arabidopsis ortholog of ZmINCW1 ). These results indicate that the molecular mechanisms affecting seed development are conserved in maize, rice, and possibly Arabidopsis. © 2017 American Society of Plant Biologists. All Rights Reserved.

Conformation and activity alteration of horseradish peroxidase induced by the interaction with gene carrier polyethyleneimines

NASA Astrophysics Data System (ADS)

Huang, Aimin; Wei, Bangzhi; Mo, Junyong; Wang, Yajing; Ma, Lin

2018-01-01

Polyethyleneimine (PEI) has long been considered as "golden standard" for polymeric gene delivery carriers. However the molecular basis of the cytotoxicity of PEI is poorly understood. Little is known about the effects of PEI on the structure and functions of biomacromolecules. In this work, fluorescence, UV-vis absorption, circular dichroism spectroscopy were conducted to investigate the influence of PEI of average molecular weight 25, 10 and 1.8 kDa (denoted as PEI25k, PEI10k and PEI1.8k) on the conformation of horseradish peroxidase (HRP) and its catalytic efficiency. Zeta-potential measurement and isothermal titration calorimetry were used to reveal the mechanism of the interaction between PEIs and HRP. PEIs were found to bind onto the surface of HRP predominantly via hydrophobic interaction and hydrogen bond or van der Waals interaction. The complex formation between HRP and PEI induced a more compact conformation of the enzyme and an increased hydrophobicity of the microenvironment surrounding heme pocket. The conformational change of HRP had little impact on the affinity towards H2O2 and phenol. However, the increase in the non-planarity of porphyrin ring in the heme group led to an increase in the exposure degree of the active center and thus an enhancement of catalytic efficiency of HRP in the presence of high molecular weight PEIs (PEI25k and PEI10k). The polymer size played an important role in PEI-HRP interaction. PEI of low molecular weight (PEI1.8k) was less efficient to alter the conformation and catalytic activity of HRP in aqueous solutions.

Compact 2100 nm laser diode module for next-generation DIRCM

NASA Astrophysics Data System (ADS)

Dvinelis, Edgaras; Greibus, Mindaugas; TrinkÅ«nas, Augustinas; NaujokaitÄ--, Greta; Vizbaras, Augustinas; Vizbaras, Dominykas; Vizbaras, Kristijonas

2017-10-01

Compact high-power 2100 nm laser diode module for next-generation directional infrared countermeasure (DIRCM) systems is presented. Next-generation DIRCM systems require compact, light-weight and robust laser modules which could provide intense IR light emission capable of disrupting the tracking sensor of heat-seeking missile. Currently used solid-state and fiber laser solutions for mid-IR band are bulky and heavy making them difficult to implement in smaller form-factor DIRCM systems. Recent development of GaSb laser diode technology greatly improved optical output powers and efficiencies of laser diodes working in 1900 - 2450 nm band [1] while also maintaining very attractive size, weight, power consumption and cost characteristics. 2100 nm laser diode module presented in this work performance is based on high-efficiency broad emitting area GaSb laser diode technology. Each laser diode emitter is able to provide 1 W of CW output optical power with working point efficiency up to 20% at temperature of 20 °C. For output beam collimation custom designed fast-axis collimator and slow-axis collimator lenses were used. These lenses were actively aligned and attached using UV epoxy curing. Total 2 emitters stacked vertically were used in 2100 nm laser diode module. Final optical output power of the module goes up to 2 W at temperature of 20 °C. Total dimensions of the laser diode module are 35 x 25 x 16 mm (L x W x H) with a weight of 28 grams. Finally output beam is bore-sighted to mechanical axes of the module housing allowing for easy integration into next-generation DIRCM systems.

Adsorption of Poly(methyl methacrylate) on Concave Al2O3 Surfaces in Nanoporous Membranes

PubMed Central

Nunnery, Grady; Hershkovits, Eli; Tannenbaum, Allen; Tannenbaum, Rina

2009-01-01

The objective of this study was to determine the influence of polymer molecular weight and surface curvature on the adsorption of polymers onto concave surfaces. Poly(methyl methacrylate) (PMMA) of various molecular weights was adsorbed onto porous aluminum oxide membranes having various pore sizes, ranging from 32 to 220 nm. The surface coverage, expressed as repeat units per unit surface area, was observed to vary linearly with molecular weight for molecular weights below ~120 000 g/mol. The coverage was independent of molecular weight above this critical molar mass, as was previously reported for the adsorption of PMMA on convex surfaces. Furthermore, the coverage varied linearly with pore size. A theoretical model was developed to describe curvature-dependent adsorption by considering the density gradient that exists between the surface and the edge of the adsorption layer. According to this model, the density gradient of the adsorbed polymer segments scales inversely with particle size, while the total coverage scales linearly with particle size, in good agreement with experiment. These results show that the details of the adsorption of polymers onto concave surfaces with cylindrical geometries can be used to calculate molecular weight (below a critical molecular weight) if pore size is known. Conversely, pore size can also be determined with similar adsorption experiments. Most significantly, for polymers above a critical molecular weight, the precise molecular weight need not be known in order to determine pore size. Moreover, the adsorption developed and validated in this work can be used to predict coverage also onto surfaces with different geometries. PMID:19415910

Loss Analysis of High Power Stirling-Type Pulse Tube Cryocooler

NASA Astrophysics Data System (ADS)

Nakano, K.; Hiratsuka, Y.

2015-12-01

For the purpose of cooling high-temperature superconductor (HTS) devices, such as superconductor motors, superconducting magnetic energy storage (SMES) and current fault limiters, cryocoolers should be compact in size, light-weight, and have high efficiency and reliability. In order to meet the demand of HTS devices world-wide, the cryocooler needs to have COP efficiency >0.1. We have developed a high power Stirling-type pulse tube cryocooler (SPTC) with an in-line expander. The experimental results were reported in June 2012[1]. The cooling capacity was 210 W at 77 K and the minimum temperature was 37 K when the compressor input power was 3.8 kW. Accordingly, the COP was about 0.055. To further improve the efficiency, the energy losses in the cryocooler were analyzed. The experimental results and the numerical calculation results are reported in this paper.

Growth and device processing of hexagonal boron nitride epilayers for thermal neutron and deep ultraviolet detectors

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

Doan, T. C.; Li, J.; Lin, J. Y.

2016-07-15

Solid-state neutron detectors with high performance are highly sought after for the detection of fissile materials. However, direct-conversion neutron detectors based on semiconductors with a measureable efficiency have not been realized. We report here the first successful demonstration of a direct-conversion semiconductor neutron detector with an overall detection efficiency for thermal neutrons of 4% and a charge collection efficiency as high as 83%. The detector is based on a 2.7 μm thick {sup 10}B-enriched hexagonal boron nitride (h-BN) epitaxial layer. The results represent a significant step towards the realization of practical neutron detectors based on h-BN epilayers. Neutron detectors basedmore » on h-BN are expected to possess all the advantages of semiconductor devices including wafer-scale processing, compact size, light weight, and ability to integrate with other functional devices.« less

Efficient, High-Power Mid-Infrared Laser for National Securityand Scientific Applications

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

Kiani, Leily S.

The LLNL fiber laser group developed a unique short-wave-infrared, high-pulse energy, highaverage- power fiber based laser. This unique laser source has been used in combination with a nonlinear frequency converter to generate wavelengths, useful for remote sensing and other applications in the mid-wave infrared (MWIR). Sources with high average power and high efficiency in this MWIR wavelength region are not yet available with the size, weight, and power requirements or energy efficiency necessary for future deployment. The LLNL developed Fiber Laser Pulsed Source (FiLPS) design was adapted to Erbium doped silica fibers for 1.55 μm pumping of Cadmium Silicon Phosphidemore » (CSP). We have demonstrated, for the first time optical parametric amplification of 2.4 μm light via difference frequency generation using CSP with an Erbium doped fiber source. In addition, for efficiency comparison purposes, we also demonstrated direct optical parametric generation (OPG) as well as optical parametric oscillation (OPO).« less

36 CFR 4.11 - Load, weight and size limits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... INTERIOR VEHICLES AND TRAFFIC SAFETY § 4.11 Load, weight and size limits. (a) Vehicle load, weight and size limits established by State law apply to a vehicle operated on a park road. However, the superintendent may designate more restrictive limits when appropriate for traffic safety or protection of the road...

A WHO Collaborative Study of Maternal Anthropometry and Pregnancy Outcomes.

PubMed

Kelly, A; Kevany, J; de Onis, M; Shah, P M

1996-06-01

To evaluate to what degree anthropometric measurements are useful and efficient in predicting maternal and fetal outcomes in different country settings and to develop appropriate reference curves for maternal weight gain. A meta-analysis of 25 data sets providing information on over 111,000 births worldwide. Attained weight indicators from pre-pregnancy (Pp) through 9 lunar months demonstrated high odds ratios (O.R.) for both low birth weight (LBW) and intra-uterine growth retardation (IUGR). The strongest effect size (O.R. = 4.0) was provided by attained weight at 7 lunar months for IUGR, when applied to women of below average pre-pregnancy weight. The study indicators showed only minor and inconsistent O.R. for preterm birth (PTB). The ability of study indicators to predict the three maternal outcomes was much weaker. Maternal height as a predictor of assisted delivery showed the highest positive O.R. (1.6), but did not meet the screening criteria. A single measurement of attained weight at 5 or 7 lunar months (16-20 or 24-28 weeks) is the most practical screening instrument for LBW and IUGR in most primary health care settings and provides warning of the need for intervention. The operational value of these findings should be demonstrated through their successful large-scale application in service settings.

Whole body counter calibration using Monte Carlo modeling with an array of phantom sizes based on national anthropometric reference data

NASA Astrophysics Data System (ADS)

Shypailo, R. J.; Ellis, K. J.

2011-05-01

During construction of the whole body counter (WBC) at the Children's Nutrition Research Center (CNRC), efficiency calibration was needed to translate acquired counts of 40K to actual grams of potassium for measurement of total body potassium (TBK) in a diverse subject population. The MCNP Monte Carlo n-particle simulation program was used to describe the WBC (54 detectors plus shielding), test individual detector counting response, and create a series of virtual anthropomorphic phantoms based on national reference anthropometric data. Each phantom included an outer layer of adipose tissue and an inner core of lean tissue. Phantoms were designed for both genders representing ages 3.5 to 18.5 years with body sizes from the 5th to the 95th percentile based on body weight. In addition, a spherical surface source surrounding the WBC was modeled in order to measure the effects of subject mass on room background interference. Individual detector measurements showed good agreement with the MCNP model. The background source model came close to agreement with empirical measurements, but showed a trend deviating from unity with increasing subject size. Results from the MCNP simulation of the CNRC WBC agreed well with empirical measurements using BOMAB phantoms. Individual detector efficiency corrections were used to improve the accuracy of the model. Nonlinear multiple regression efficiency calibration equations were derived for each gender. Room background correction is critical in improving the accuracy of the WBC calibration.

Advanced Multilayer Composite Heavy-Oxide Scintillator Detectors for High Efficiency Fast Neutron Detection

NASA Astrophysics Data System (ADS)

Ryzhikov, Vladimir D.; Naydenov, Sergei V.; Pochet, Thierry; Onyshchenko, Gennadiy M.; Piven, Leonid A.; Smith, Craig F.

2018-01-01

We have developed and evaluated a new approach to fast neutron and neutron-gamma detection based on large-area multilayer composite heterogeneous detection media consisting of dispersed granules of small-crystalline scintillators contained in a transparent organic (plastic) matrix. Layers of the composite material are alternated with layers of transparent plastic scintillator material serving as light guides. The resulting detection medium - designated as ZEBRA - serves as both an active neutron converter and a detection scintillator which is designed to detect both neutrons and gamma-quanta. The composite layers of the ZEBRA detector consist of small heavy-oxide scintillators in the form of granules of crystalline BGO, GSO, ZWO, PWO and other materials. We have produced and tested the ZEBRA detector of sizes 100x100x41 mm and greater, and determined that they have very high efficiency of fast neutron detection (up to 49% or greater), comparable to that which can be achieved by large sized heavy-oxide single crystals of about Ø40x80 cm3 volume. We have also studied the sensitivity variation to fast neutron detection by using different types of multilayer ZEBRA detectors of 100 cm2 surface area and 41 mm thickness (with a detector weight of about 1 kg) and found it to be comparable to the sensitivity of a 3He-detector representing a total cross-section of about 2000 cm2 (with a weight of detector, including its plastic moderator, of about 120 kg). The measured count rate in response to a fast neutron source of 252Cf at 2 m for the ZEBRA-GSO detector of size 100x100x41 mm3 was 2.84 cps/ng, and this count rate can be doubled by increasing the detector height (and area) up to 200x100 mm2. In summary, the ZEBRA detectors represent a new type of high efficiency and low cost solid-state neutron detector that can be used for stationary neutron/gamma portals. They may represent an interesting alternative to expensive, bulky gas counters based on 3He or 10B neutron detection technologies.

Multifunctional biodegradable polymer nanoparticles with uniform sizes: generation and in vitro anti-melanoma activity

NASA Astrophysics Data System (ADS)

Liang, Ruijing; Wang, Jing; Wu, Xian; Dong, Liyun; Deng, Renhua; Wang, Ke; Sullivan, Martin; Liu, Shanqin; Wu, Min; Tao, Juan; Yang, Xiangliang; Zhu, Jintao

2013-11-01

We present a simple, yet versatile strategy for the fabrication of uniform biodegradable polymer nanoparticles (NPs) with controllable sizes by a hand-driven membrane-extrusion emulsification approach. The size and size distribution of the NPs can be easily tuned by varying the experimental parameters, including initial polymer concentration, surfactant concentration, number of extrusion passes, membrane pore size, and polymer molecular weight. Moreover, hydrophobic drugs (e.g., paclitaxel (PTX)) and inorganic NPs (e.g., quantum dots (QDs) and magnetic NPs (MNPs)) can be effectively and simultaneously encapsulated into the polymer NPs to form the multifunctional hybrid NPs through this facile route. These PTX-loaded NPs exhibit high encapsulation efficiency and drug loading density as well as excellent drug sustained release performance. As a proof of concept, the A875 cell (melanoma cell line) experiment in vitro, including cellular uptake analysis by fluorescence microscope, cytotoxicity analysis of NPs, and magnetic resonance imaging (MRI) studies, indicates that the PTX-loaded hybrid NPs produced by this technique could be potentially applied as a multifunctional delivery system for drug delivery, bio-imaging, and tumor therapy, including malignant melanoma therapy.

Effect of wild mint (Mentha longifolia) infusion on the over all performance of broiler chicks.

PubMed

Durrani, F R; Sultan, A; Marri, Muhammad Latif; Chand, N; Durrani, Z

2007-04-01

An attempt was made to evaluate the effect of aqueous extract of wild mint (Mentha Ingifolia) on the overall performance of broiler chicks at NWFP Agricultural University, Peshawar in July 2005. Three levels of fresh wild mint infusion at the rate of 50, 40 and 30 mL L(-1) of fresh drinking water were provided to chicks in groups A, B and C, respectively and group D was kept as control, each group was replicated four times with 10 chicks per replicate, reared for 35 days, in an open sided house in cages of the same size. No vaccination was practiced. Data were recorded daily for feed intake, water intake and for weight gain on weekly basis. Feed conversion efficiency, dressing percentage, percent mortality, weight of different body organs (breast, thigh and leg), giblets (liver, heart and gizzard), intestine and economics for each group was calculated at the end of experimental period. It was found that group B receiving 40 mL L(-1) of wild mint infusion in drinking water had a significant (p < 0.05) effect on mean body weight gain, feed intake, water intake, feed conversion efficiency, dressing percentage and weight of different body organs (breast, thigh and leg). Significant (p < 0.05) differences were also found in mortality, highest mortality was observed in group D (10%) as compared with groups A, B and C, however there was no significant effect on giblets (liver, heart, gizzard), intestine and weight of abdominal fat. Mean feed cost and gross return was significantly (p < 0.05) effected for group B. Feed cost was lower and gross return was significantly (p < 0.05) higher for group B than other treated groups and control.

The role of haptic versus visual volume cues in the size-weight illusion.

PubMed

Ellis, R R; Lederman, S J

1993-03-01

Three experiments establish the size-weight illusion as a primarily haptic phenomenon, despite its having been more traditionally considered an example of vision influencing haptic processing. Experiment 1 documents, across a broad range of stimulus weights and volumes, the existence of a purely haptic size-weight illusion, equal in strength to the traditional illusion. Experiment 2 demonstrates that haptic volume cues are both sufficient and necessary for a full-strength illusion. In contrast, visual volume cues are merely sufficient, and produce a relatively weaker effect. Experiment 3 establishes that congenitally blind subjects experience an effect as powerful as that of blindfolded sighted observers, thus demonstrating that visual imagery is also unnecessary for a robust size-weight illusion. The results are discussed in terms of their implications for both sensory and cognitive theories of the size-weight illusion. Applications of this work to a human factors design and to sensor-based systems for robotic manipulation are also briefly considered.

Critical weight mediates sex-specific body size plasticity and sexual dimorphism in the yellow dung fly Scathophaga stercoraria (Diptera: Scathophagidae).

PubMed

Rohner, Patrick T; Blanckenhorn, Wolf U; Schäfer, Martin A

2017-05-01

Ultimate factors driving insect body size are rather well understood, while-apart from a few model species-the underlying physiological and developmental mechanisms received less attention. We investigate the physiological basis of adaptive size variation in the yellow dung fly Scathophaga stercoraria, which shows pronounced male-biased sexual size dimorphism and strong body size plasticity. We estimate variation of a major physiological threshold, the critical weight, which is the mass at which a larva initiates pupariation. Critical weight was associated with sexual size dimorphism and sex-specific plasticity, and is thus a likely target of selection on adult size. Detailed larval growth trajectories derived from individuals raised at two food and temperature treatments further reveal that sex-specific size plasticity is mediated by faster initial growth of males that later becomes reduced by higher male weight loss during the wandering stage. We further demonstrate that integral growth rates, which are typically calculated as simple ratios of egg-to-adult development time and adult weight, do not necessarily well reflect variation in instantaneous growth rates. We illustrate the importance of detailed assessments of ontogenetic growth trajectories for the understanding of adaptive size variation and discuss the mechanistic basis of size determination in shaping sex-specific phenotypic plasticity. © 2017 Wiley Periodicals, Inc.

Factors influencing the dosimetry for high-intensity focused ultrasound ablation of uterine fibroids: a retrospective study.

PubMed

Peng, Song; Zhang, Lian; Hu, Liang; Chen, Jinyun; Ju, Jin; Wang, Xi; Zhang, Rong; Wang, Zhibiao; Chen, Wenzhi

2015-04-01

The aim of this article is to analyze factors affecting sonication dose and build a dosimetry model of high-intensity focused ultrasound (HIFU) ablation for uterine fibroids. Four hundred and three patients with symptomatic uterine fibroids who underwent HIFU were retrospectively analyzed. The energy efficiency factor (EEF) was set as dependent variable, and the factors possibly affecting sonication dose included age, body mass index, size of uterine fibroid, abdominal wall thickness, the distance from uterine fibroid dorsal side to sacrum, the distance from uterine fibroid ventral side to skin, location of uterus, location of uterine fibroids, type of uterine fibroids, abdominal wall scar, signal intensity on T2-weighted imaging (T2WI), and enhancement type on T1-weighted imaging (T1WI) were set as predictors to build a multiple regression model. The size of uterine fibroid, distance from fibroid ventral side to skin, location of uterus, location of uterine fibroids, type of uterine fibroids, signal intensity on T2WI, and enhancement type on T1WI had a linear correlation with EEF. The distance from fibroid ventral side to skin, enhancement type on T1WI, size of uterine fibroid, and signal intensity on T2WI were eventually incorporated into the dosimetry model. The distance from fibroid ventral side to skin, enhancement type on T1WI, size of uterine fibroid, and signal intensity on T2WI can be used as dosimetric predictors for HIFU for uterine fibroids.

A lexicographic weighted Tchebycheff approach for multi-constrained multi-objective optimization of the surface grinding process

NASA Astrophysics Data System (ADS)

Khalilpourazari, Soheyl; Khalilpourazary, Saman

2017-05-01

In this article a multi-objective mathematical model is developed to minimize total time and cost while maximizing the production rate and surface finish quality in the grinding process. The model aims to determine optimal values of the decision variables considering process constraints. A lexicographic weighted Tchebycheff approach is developed to obtain efficient Pareto-optimal solutions of the problem in both rough and finished conditions. Utilizing a polyhedral branch-and-cut algorithm, the lexicographic weighted Tchebycheff model of the proposed multi-objective model is solved using GAMS software. The Pareto-optimal solutions provide a proper trade-off between conflicting objective functions which helps the decision maker to select the best values for the decision variables. Sensitivity analyses are performed to determine the effect of change in the grain size, grinding ratio, feed rate, labour cost per hour, length of workpiece, wheel diameter and downfeed of grinding parameters on each value of the objective function.

Lightweight High Efficiency Electric Motors for Space Applications

NASA Technical Reports Server (NTRS)

Robertson, Glen A.; Tyler, Tony R.; Piper, P. J.

2011-01-01

Lightweight high efficiency electric motors are needed across a wide range of space applications from - thrust vector actuator control for launch and flight applications to - general vehicle, base camp habitat and experiment control for various mechanisms to - robotics for various stationary and mobile space exploration missions. QM Power?s Parallel Path Magnetic Technology Motors have slowly proven themselves to be a leading motor technology in this area; winning a NASA Phase II for "Lightweight High Efficiency Electric Motors and Actuators for Low Temperature Mobility and Robotics Applications" a US Army Phase II SBIR for "Improved Robot Actuator Motors for Medical Applications", an NSF Phase II SBIR for "Novel Low-Cost Electric Motors for Variable Speed Applications" and a DOE SBIR Phase I for "High Efficiency Commercial Refrigeration Motors" Parallel Path Magnetic Technology obtains the benefits of using permanent magnets while minimizing the historical trade-offs/limitations found in conventional permanent magnet designs. The resulting devices are smaller, lower weight, lower cost and have higher efficiency than competitive permanent magnet and non-permanent magnet designs. QM Power?s motors have been extensively tested and successfully validated by multiple commercial and aerospace customers and partners as Boeing Research and Technology. Prototypes have been made between 0.1 and 10 HP. They are also in the process of scaling motors to over 100kW with their development partners. In this paper, Parallel Path Magnetic Technology Motors will be discussed; specifically addressing their higher efficiency, higher power density, lighter weight, smaller physical size, higher low end torque, wider power zone, cooler temperatures, and greater reliability with lower cost and significant environment benefit for the same peak output power compared to typically motors. A further discussion on the inherent redundancy of these motors for space applications will be provided.

Mass is all that matters in the size-weight illusion.

PubMed

Plaisier, Myrthe A; Smeets, Jeroen B J

2012-01-01

An object in outer space is weightless due to the absence of gravity, but astronauts can still judge whether one object is heavier than another one by accelerating the object. How heavy an object feels depends on the exploration mode: an object is perceived as heavier when holding it against the pull of gravity than when accelerating it. At the same time, perceiving an object's size influences the percept: small objects feel heavier than large objects with the same mass (size-weight illusion). Does this effect depend on perception of the pull of gravity? To answer this question, objects were suspended from a long wire and participants were asked to push an object and rate its heaviness. This way the contribution of gravitational forces on the percept was minimised. Our results show that weight is not at all necessary for the illusion because the size-weight illusion occurred without perception of weight. The magnitude of the illusion was independent of whether inertial or gravitational forces were perceived. We conclude that the size-weight illusion does not depend on prior knowledge about weights of object, but instead on a more general knowledge about the mass of objects, independent of the contribution of gravity. Consequently, the size-weight illusion will have the same magnitude on Earth as it should have on the Moon or even under conditions of weightlessness.

Investigation of Truck Size and Weight Limits - Technical Supplement. Vol. 1. Analysis of Truck Payloads Under Various Limits of Size, Weight and Configuration

DOT National Transportation Integrated Search

1981-02-01

This volume documents the results of an analysis of the impact that various truck size and weight limits have on the carrier equipment selection process as a result of changes, in the design payload and design density of individual trucks. An analysi...

Common determinants of body size and eye size in chickens from an advanced intercross line.

PubMed

Prashar, Ankush; Hocking, Paul M; Erichsen, Jonathan T; Fan, Qiao; Saw, Seang Mei; Guggenheim, Jeremy A

2009-06-15

Myopia development is characterised by an increased axial eye length. Therefore, identifying factors that influence eye size may provide new insights into the aetiology of myopia. In humans, axial length is positively correlated to height and weight, and in mice, eye weight is positively correlated with body weight. The purpose of this study was to examine the relationship between eye size and body size in chickens from a genetic cross in which alleles with major effects on eye and body size were segregating. Chickens from a cross between a layer line (small body size and eye size) and a broiler line (large body and eye size) were interbred for 10 generations so that alleles for eye and body size would have the chance to segregate independently. At 3 weeks of age, 510 chicks were assessed using in vivo high resolution A-scan ultrasonography and keratometry. Equatorial eye diameter and eye weight were measured after enucleation. The variations in eye size parameters that could be explained by body weight (BW), body length (BL), head width (HW) and sex were examined using multiple linear regression. It was found that BW, BL and HW and sex together predicted 51-56% of the variation in eye weight, axial length, corneal radius, and equatorial eye diameter. By contrast, the same variables predicted only 22% of the variation in lens thickness. After adjusting for sex, the three body size parameters predicted 45-49% of the variation in eye weight, axial length, corneal radius, and eye diameter, but only 0.4% of the variation in lens thickness. In conclusion, about half of the variation in eye size in the chickens of this broiler-layer advanced intercross line is likely to be determined by pleiotropic genes that also influence body size. Thus, mapping the quantitative trait loci (QTL) that determine body size may be useful in understanding the genetic determination of eye size (a logical inference of this result is that the 20 or more genetic variants that have recently been shown to influence human height may also be found to influence axial eye length). Furthermore, adjusting for body size will be essential in mapping pure eye size QTL in this chicken population, and may also have value in mapping eye size QTL in humans.

Polyelectrolyte Complexes of Low Molecular Weight PEI and Citric Acid as Efficient and Nontoxic Vectors for in Vitro and in Vivo Gene Delivery.

PubMed

Giron-Gonzalez, M Dolores; Salto-Gonzalez, Rafael; Lopez-Jaramillo, F Javier; Salinas-Castillo, Alfonso; Jodar-Reyes, Ana Belen; Ortega-Muñoz, Mariano; Hernandez-Mateo, Fernando; Santoyo-Gonzalez, Francisco

2016-03-16

Gene transfection mediated by the cationic polymer polyethylenimine (PEI) is considered a standard methodology. However, while highly branched PEIs form smaller polyplexes with DNA that exhibit high transfection efficiencies, they have significant cell toxicity. Conversely, low molecular weight PEIs (LMW-PEIs) with favorable cytotoxicity profiles display minimum transfection activities as a result of inadequate DNA complexation and protection. To solve this paradox, a novel polyelectrolyte complex was prepared by the ionic cross-linking of branched 1.8 kDa PEI with citric acid (CA). This system synergistically exploits the good cytotoxicity profile exhibited by LMW-PEI with the high transfection efficiencies shown by highly branched and high molecular weight PEIs. The polyectrolyte complex (1.8 kDa-PEI@CA) was obtained by a simple synthetic protocol based on the microwave irradiation of a solution of 1.8 kDa PEI and CA. Upon complexation with DNA, intrinsic properties of the resulting particles (size and surface charge) were measured and their ability to form stable polyplexes was determined. Compared with unmodified PEIs the new complexes behave as efficient gene vectors and showed enhanced DNA binding capability associated with facilitated intracellular DNA release and enhanced DNA protection from endonuclease degradation. In addition, while transfection values for LMW-PEIs are almost null, transfection efficiencies of the new reagent range from 2.5- to 3.8-fold to those of Lipofectamine 2000 and 25 kDa PEI in several cell lines in culture such as CHO-k1, FTO2B hepatomas, L6 myoblasts, or NRK cells, simultaneously showing a negligible toxicity. Furthermore, the 1.8 kDa-PEI@CA polyelectrolyte complexes retained the capability to transfect eukaryotic cells in the presence of serum and exhibited the capability to promote in vivo transfection in mouse (as an animal model) with an enhanced efficiency compared to 25 kDa PEI. Results support the polyelectrolyte complex of LMW-PEI and CA as promising generic nonviral gene carriers.

The deterministic optical alignment of the HERMES spectrograph

NASA Astrophysics Data System (ADS)

Gers, Luke; Staszak, Nicholas

2014-07-01

The High Efficiency and Resolution Multi Element Spectrograph (HERMES) is a four channel, VPH-grating spectrograph fed by two 400 fiber slit assemblies whose construction and commissioning has now been completed at the Anglo Australian Telescope (AAT). The size, weight, complexity, and scheduling constraints of the system necessitated that a fully integrated, deterministic, opto-mechanical alignment system be designed into the spectrograph before it was manufactured. This paper presents the principles about which the system was assembled and aligned, including the equipment and the metrology methods employed to complete the spectrograph integration.

Oligomer Molecules for Efficient Organic Photovoltaics.

PubMed

Lin, Yuze; Zhan, Xiaowei

2016-02-16

Solar cells, a renewable, clean energy technology that efficiently converts sunlight into electricity, are a promising long-term solution for energy and environmental problems caused by a mass of production and the use of fossil fuels. Solution-processed organic solar cells (OSCs) have attracted much attention in the past few years because of several advantages, including easy fabrication, low cost, lightweight, and flexibility. Now, OSCs exhibit power conversion efficiencies (PCEs) of over 10%. In the early stage of OSCs, vapor-deposited organic dye materials were first used in bilayer heterojunction devices in the 1980s, and then, solution-processed polymers were introduced in bulk heterojunction (BHJ) devices. Relative to polymers, vapor-deposited small molecules offer potential advantages, such as a defined molecular structure, definite molecular weight, easy purification, mass-scale production, and good batch-to-batch reproducibility. However, the limited solubility and high crystallinity of vapor-deposited small molecules are unfavorable for use in solution-processed BHJ OSCs. Conversely, polymers have good solution-processing and film-forming properties and are easily processed into flexible devices, whereas their polydispersity of molecular weights and difficulty in purification results in batch to batch variation, which may hamper performance reproducibility and commercialization. Oligomer molecules (OMs) are monodisperse big molecules with intermediate molecular weights (generally in the thousands), and their sizes are between those of small molecules (generally with molecular weights <1000) and polymers (generally with molecular weights >10000). OMs not only overcome shortcomings of both vapor-deposited small molecules and solution-processed polymers, but also combine their advantages, such as defined molecular structure, definite molecular weight, easy purification, mass-scale production, good batch-to-batch reproducibility, good solution processability, and film-forming properties. Therefore, OMs are a good choice for solution-processed reproducible OSCs toward scalable commercialized applications. Considerable efforts have been dedicated to developing new OM electron donors and electron acceptors for OSCs. So far, the highest PCEs of solution-processed OSCs based on OM donors and acceptors are 9-10% and 6-7%, respectively. OM materials have become promising alternatives to polymer and/or fullerene materials for efficient and stable OSCs. In this Account, we present a brief survey of the recent developments in solution-processable OM electron donors and acceptors and their application in OSCs. Rational design of OMs with star- and linear-shaped structures based on triphenylamine, benzodithiophene, and indacenodithiophene units and their impacts on device performance are discussed. Structure-property relationships are also proposed. Furthermore, the remaining challenges and the key research directions in the near future are also addressed. In the next years, an interdisciplinary approach involving novel OM materials, especially electron acceptor materials, accurate morphology optimization, and advanced device technologies will probably bring high-efficiency and stable OSCs to final commercialization.

Muscle regeneration during hindlimb unloading results in a reduction in muscle size after reloading

NASA Technical Reports Server (NTRS)

Mozdziak, P. E.; Pulvermacher, P. M.; Schultz, E.

2001-01-01

The hindlimb-unloading model was used to study the ability of muscle injured in a weightless environment to recover after reloading. Satellite cell mitotic activity and DNA unit size were determined in injured and intact soleus muscles from hindlimb-unloaded and age-matched weight-bearing rats at the conclusion of 28 days of hindlimb unloading, 2 wk after reloading, and 9 wk after reloading. The body weights of hindlimb-unloaded rats were significantly (P < 0.05) less than those of weight-bearing rats at the conclusion of hindlimb unloading, but they were the same (P > 0.05) as those of weight-bearing rats 2 and 9 wk after reloading. The soleus muscle weight, soleus muscle weight-to-body weight ratio, myofiber diameter, number of nuclei per millimeter, and DNA unit size were significantly (P < 0.05) smaller for the injured soleus muscles from hindlimb-unloaded rats than for the soleus muscles from weight-bearing rats at each recovery time. Satellite cell mitotic activity was significantly (P < 0.05) higher in the injured soleus muscles from hindlimb-unloaded rats than from weight-bearing rats 2 wk after reloading, but it was the same (P > 0.05) as in the injured soleus muscles from weight-bearing rats 9 wk after reloading. The injured soleus muscles from hindlimb-unloaded rats failed to achieve weight-bearing muscle size 9 wk after reloading, because incomplete compensation for the decrease in myonuclear accretion and DNA unit size expansion occurred during the unloading period.

Displacement based multilevel structural optimization

NASA Technical Reports Server (NTRS)

Striz, Alfred G.

1995-01-01

Multidisciplinary design optimization (MDO) is expected to play a major role in the competitive transportation industries of tomorrow, i.e., in the design of aircraft and spacecraft, of high speed trains, boats, and automobiles. All of these vehicles require maximum performance at minimum weight to keep fuel consumption low and conserve resources. Here, MDO can deliver mathematically based design tools to create systems with optimum performance subject to the constraints of disciplines such as structures, aerodynamics, controls, etc. Although some applications of MDO are beginning to surface, the key to a widespread use of this technology lies in the improvement of its efficiency. This aspect is investigated here for the MDO subset of structural optimization, i.e., for the weight minimization of a given structure under size, strength, and displacement constraints. Specifically, finite element based multilevel optimization of structures (here, statically indeterminate trusses and beams for proof of concept) is performed. In the system level optimization, the design variables are the coefficients of assumed displacement functions, and the load unbalance resulting from the solution of the stiffness equations is minimized. Constraints are placed on the deflection amplitudes and the weight of the structure. In the subsystems level optimizations, the weight of each element is minimized under the action of stress constraints, with the cross sectional dimensions as design variables. This approach is expected to prove very efficient, especially for complex structures, since the design task is broken down into a large number of small and efficiently handled subtasks, each with only a small number of variables. This partitioning will also allow for the use of parallel computing, first, by sending the system and subsystems level computations to two different processors, ultimately, by performing all subsystems level optimizations in a massively parallel manner on separate processors. It is expected that the subsystems level optimizations can be further improved through the use of controlled growth, a method which reduces an optimization to a more efficient analysis with only a slight degradation in accuracy. The efficiency of all proposed techniques is being evaluated relative to the performance of the standard single level optimization approach where the complete structure is weight minimized under the action of all given constraints by one processor and to the performance of simultaneous analysis and design which combines analysis and optimization into a single step. It is expected that the present approach can be expanded to include additional structural constraints (buckling, free and forced vibration, etc.) or other disciplines (passive and active controls, aerodynamics, etc.) for true MDO.

Reference values of left heart echocardiographic dimensions and mass in male peri-pubertal athletes.

PubMed

Cavarretta, Elena; Maffessanti, Francesco; Sperandii, Fabio; Guerra, Emanuele; Quaranta, Federico; Nigro, Antonia; Minati, Monia; Rebecchi, Marco; Fossati, Chiara; Calò, Leonardo; Pigozzi, Fabio

2018-01-01

Background Several articles have proposed reference values in healthy paediatric subjects, but none of them has evaluated a large population of healthy trained adolescents. Design The study purpose was to establish normal echocardiographic measurements of left heart (aortic root, left atrium and left ventricular dimensions and mass) in relation to age, weight, height, body mass index, body surface area and training hours in this specific population. Methods We retrospectively evaluated 2151 consecutive, healthy, peri-pubertal athletes (100% male, mean age 12.4 ± 1.4 years, range 8-18) referred to a single centre for pre-participation screening. All participants were young soccer athletes who trained for a mean of 7.2 ± 1.1 h per week. Results Left ventricular internal diameters, wall thickness, left ventricular mass, aortic root and left atrium diameters were significantly correlated to age, body surface area, height and weight ( p < 0.01). Age, height, weight and body surface area were found associated with chamber size, while body mass index and training hours were not. Inclusion of both age and body size parameters in the statistical models resulted in improved overall explained variance for diameters and left ventricular mass. Conclusion Equations, mean values and percentile charts for the different age groups may be useful as reference data in efficiently assessing left ventricular parameters in young athletes.

Ultra-compact swept-source optical coherence tomography handheld probe with motorized focus adjustment (Conference Presentation)

NASA Astrophysics Data System (ADS)

LaRocca, Francesco; Nankivil, Derek; Keller, Brenton; Farsiu, Sina; Izatt, Joseph A.

2017-02-01

Handheld optical coherence tomography (OCT) systems facilitate imaging of young children, bedridden subjects, and those with less stable fixation. Smaller and lighter OCT probes allow for more efficient imaging and reduced operator fatigue, which is critical for prolonged use in either the operating room or neonatal intensive care unit. In addition to size and weight, the imaging speed, image quality, field of view, resolution, and focus correction capability are critical parameters that determine the clinical utility of a handheld probe. Here, we describe an ultra-compact swept source (SS) OCT handheld probe weighing only 211 g (half the weight of the next lightest handheld SSOCT probe in the literature) with 20.1 µm lateral resolution, 7 µm axial resolution, 102 dB peak sensitivity, a 27° x 23° field of view, and motorized focus adjustment for refraction correction between -10 to +16 D. A 2D microelectromechanical systems (MEMS) scanner, a converging beam-at-scanner telescope configuration, and an optical design employing 6 different custom optics were used to minimize device size and weight while achieving diffraction limited performance throughout the system's field of view. Custom graphics processing unit (GPU)-accelerated software was used to provide real-time display of OCT B-scans and volumes. Retinal images were acquired from adult volunteers to demonstrate imaging performance.

Nearest neighbor density ratio estimation for large-scale applications in astronomy

NASA Astrophysics Data System (ADS)

Kremer, J.; Gieseke, F.; Steenstrup Pedersen, K.; Igel, C.

2015-09-01

In astronomical applications of machine learning, the distribution of objects used for building a model is often different from the distribution of the objects the model is later applied to. This is known as sample selection bias, which is a major challenge for statistical inference as one can no longer assume that the labeled training data are representative. To address this issue, one can re-weight the labeled training patterns to match the distribution of unlabeled data that are available already in the training phase. There are many examples in practice where this strategy yielded good results, but estimating the weights reliably from a finite sample is challenging. We consider an efficient nearest neighbor density ratio estimator that can exploit large samples to increase the accuracy of the weight estimates. To solve the problem of choosing the right neighborhood size, we propose to use cross-validation on a model selection criterion that is unbiased under covariate shift. The resulting algorithm is our method of choice for density ratio estimation when the feature space dimensionality is small and sample sizes are large. The approach is simple and, because of the model selection, robust. We empirically find that it is on a par with established kernel-based methods on relatively small regression benchmark datasets. However, when applied to large-scale photometric redshift estimation, our approach outperforms the state-of-the-art.

Effect of Experimental Parameters on Alginate/Chitosan Microparticles for BCG Encapsulation

PubMed Central

Caetano, Liliana A.; Almeida, António J.; Gonçalves, Lídia M.D.

2016-01-01

The aim of the present study was to develop novel Mycobacterium bovis bacille Calmette-Guérin (BCG)-loaded polymeric microparticles with optimized particle surface characteristics and biocompatibility, so that whole live attenuated bacteria could be further used for pre-exposure vaccination against Mycobacterium tuberculosis by the intranasal route. BCG was encapsulated in chitosan and alginate microparticles through three different polyionic complexation methods by high speed stirring. For comparison purposes, similar formulations were prepared with high shear homogenization and sonication. Additional optimization studies were conducted with polymers of different quality specifications in a wide range of pH values, and with three different cryoprotectors. Particle morphology, size distribution, encapsulation efficiency, surface charge, physicochemical properties and biocompatibility were assessed. Particles exhibited a micrometer size and a spherical morphology. Chitosan addition to BCG shifted the bacilli surface charge from negative zeta potential values to strongly positive ones. Chitosan of low molecular weight produced particle suspensions of lower size distribution and higher stability, allowing efficient BCG encapsulation and biocompatibility. Particle formulation consistency was improved when the availability of functional groups from alginate and chitosan was close to stoichiometric proportion. Thus, the herein described microparticulate system constitutes a promising strategy to deliver BCG vaccine by the intranasal route. PMID:27187418

Effective L/D: A Theoretical Approach to the Measurement of Aero-Structural Efficiency in Aircraft Design

NASA Technical Reports Server (NTRS)

Guynn, Mark D.

2015-01-01

There are many trade-offs in aircraft design that ultimately impact the overall performance and characteristics of the final design. One well recognized and well understood trade-off is that of wing weight and aerodynamic efficiency. Higher aerodynamic efficiency can be obtained by increasing wing span, usually at the expense of higher wing weight. The proper balance of these two competing factors depends on the objectives of the design. For example, aerodynamic efficiency is preeminent for sailplanes and long slender wings result. Although the wing weight-drag trade is universally recognized, aerodynamic efficiency and structural efficiency are not usually considered in combination. This paper discusses the concept of "aero-structural efficiency," which combines weight and drag characteristics. A metric to quantify aero-structural efficiency, termed effective L/D, is then derived and tested with various scenarios. Effective L/D is found to be a practical and robust means to simultaneously characterize aerodynamic and structural efficiency in the context of aircraft design. The primary value of the effective L/D metric is as a means to better communicate the combined system level impacts of drag and structural weight.

Hermes CX-7: Air transport system design simulation

NASA Technical Reports Server (NTRS)

Amer, Brian; Barter, John; Colucci, Jay; Foley, Caryn; Kockler, James; Rapp, David; Zeiger, Matthew

1992-01-01

The Hermes CX-7 has been designed to service the overnight parcel package delivery needs of the cities of Aeroworld as determined in the G-Dome Enterprises market survey. The design optimization centers on the prime goal of servicing the needs of these cities as efficiently and profitably as possible. The greatest factors which affect the design of an aircraft for the mission outlined in the Request for Proposal are cost, construction feasibility and effectiveness of the design. Other influencing factors are given by the constraints of the market, including a maximum takeoff and landing distance of 60 feet, storage capability in a container of size 5 ft. x 3 ft. x 2 ft., cargo packages of 2 inch and 4 inch cubes, and ability to turn with a radius no larger than 60 feet. Safety considerations such as flying at or below Mach one (30 ft/s) and controllability and maintainability of the aircraft must also be designed into the aircraft. Another influential factor is the efficiency of the aircraft which involves optimizations and tradeoffs of such factors as weight, lifting surface sizing, structural redundancy, and material costs.

A self-sustained, complete and miniaturized methanol fuel processor for proton exchange membrane fuel cell

NASA Astrophysics Data System (ADS)

Yang, Mei; Jiao, Fengjun; Li, Shulian; Li, Hengqiang; Chen, Guangwen

2015-08-01

A self-sustained, complete and miniaturized methanol fuel processor has been developed based on modular integration and microreactor technology. The fuel processor is comprised of one methanol oxidative reformer, one methanol combustor and one two-stage CO preferential oxidation unit. Microchannel heat exchanger is employed to recover heat from hot stream, miniaturize system size and thus achieve high energy utilization efficiency. By optimized thermal management and proper operation parameter control, the fuel processor can start up in 10 min at room temperature without external heating. A self-sustained state is achieved with H2 production rate of 0.99 Nm3 h-1 and extremely low CO content below 25 ppm. This amount of H2 is sufficient to supply a 1 kWe proton exchange membrane fuel cell. The corresponding thermal efficiency of whole processor is higher than 86%. The size and weight of the assembled reactors integrated with microchannel heat exchangers are 1.4 L and 5.3 kg, respectively, demonstrating a very compact construction of the fuel processor.

Sensor Deployment for Geographic, Load Balanced Hierarchical Organization in Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Gautam, Amit Kr.; Gautam, Ajay Kr.; Patel, R. B.

2010-11-01

In order to provide load balancing in clustered sensor deployment, the upstream clusters (near the BS) are kept smaller in size as compared to downstream ones (away from BS). Moreover, geographic awareness is also desirable in order to further enhance energy efficiency. But, this must be cost effective, since most of current location awareness strategies are either cost and weight inefficient (GPS) or are complex, inaccurate and unreliable in operation. This paper presents design and implementation of a Geographic LOad BALanced (GLOBAL) Clustering Protocol for Wireless Sensor Networks. A mathematical formulation is provided for determining the number of sensor nodes in each cluster. This enables uniform energy consumption after the multi-hop data transmission towards BS. Either the sensors can be manually deployed or the clusters be so formed that the sensor are efficiently distributed as per formulation. The latter strategy is elaborated in this contribution. Methods to provide static clustering and custom cluster sizes with location awareness are also provided in the given work. Finally, low mobility node applications can also implement the proposed work.

Combined sphere-spheroid particle model for the retrieval of the microphysical aerosol parameters via regularized inversion of lidar data

NASA Astrophysics Data System (ADS)

Samaras, Stefanos; Böckmann, Christine; Nicolae, Doina

2016-06-01

In this work we propose a two-step advancement of the Mie spherical-particle model accounting for particle non-sphericity. First, a naturally two-dimensional (2D) generalized model (GM) is made, which further triggers analogous 2D re-definitions of microphysical parameters. We consider a spheroidal-particle approach where the size distribution is additionally dependent on aspect ratio. Second, we incorporate the notion of a sphere-spheroid particle mixture (PM) weighted by a non-sphericity percentage. The efficiency of these two models is investigated running synthetic data retrievals with two different regularization methods to account for the inherent instability of the inversion procedure. Our preliminary studies show that a retrieval with the PM model improves the fitting errors and the microphysical parameter retrieval and it has at least the same efficiency as the GM. While the general trend of the initial size distributions is captured in our numerical experiments, the reconstructions are subject to artifacts. Finally, our approach is applied to a measurement case yielding acceptable results.

Appearance-related teasing, body dissatisfaction, and disordered eating: A meta-analysis.

PubMed

Menzel, Jessie E; Schaefer, Lauren M; Burke, Natasha L; Mayhew, Laura L; Brannick, Michael T; Thompson, J Kevin

2010-09-01

A meta-analysis was conducted to determine the relationship between appearance and weight-based teasing and three outcome measures: body dissatisfaction, restrictive eating, and bulimic behaviors. Four meta-analyses were conducted. Fifty effect sizes (N=10,618) resulted in a moderate effect size of .39 for the relationship between weight teasing and body dissatisfaction; 24 effect sizes (N=7190) resulted in an effect size of .32 for the relationship between appearance teasing and body dissatisfaction; 20 effect sizes (N=4792) resulted in an effect size of .35 for the relationship between weight teasing and dietary restraint; and 22 effect sizes (N=5091) resulted in an effect size of .36 for the relationship between weight teasing and bulimic behaviors. Significant moderators that emerged were teasing measure type, publication type, study type, age group, and gender. The findings offer further support for the inclusion of strategies in body image and eating disorders' prevention and intervention programs that focus on handling negative, appearance-related commentary. Copyright © 2010 Elsevier Ltd. All rights reserved.

Vibroacoustic Tailoring of a Rod-Stiffened Composite Fuselage Panel with Multidisciplinary Considerations

NASA Technical Reports Server (NTRS)

Allen, Albert R.; Przekop, Adam

2015-01-01

An efficient multi-objective design tailoring procedure seeking to improve the vibroacoustic performance of a fuselage panel while maintaining or reducing weight is presented. The structure considered is the pultruded rod stitched efficient unitized structure, a highly integrated composite structure concept designed for a noncylindrical, next-generation flight vehicle fuselage. Modifications to a baseline design are evaluated within a six-parameter design space including spacing, flange width, and web height for both frame and stringer substructure components. The change in sound power radiation attributed to a design change is predicted using finite-element models sized and meshed for analyses in the 500 Hz, 1 kHz, and 2 kHz octave bands. Three design studies are carried out in parallel while considering a diffuse acoustic field excitation and two types of turbulent boundary-layer excitation. Kriging surrogate models are used to reduce the computational costs of resolving the vibroacoustic and weight objective Pareto fronts. The resulting Pareto optimal designs are then evaluated under a static pressurization ultimate load to assess structural strength and stability. Results suggest that choosing alternative configurations within the considered design space can reduce weight and improve vibroacoustic performance without compromising strength and stability of the structure under the static load condition considered, but the tradeoffs are significantly influenced by the spatial characteristics of the assumed excitation field.

Beak measurements of octopus ( Octopus variabilis) in Jiaozhou Bay and their use in size and biomass estimation

NASA Astrophysics Data System (ADS)

Xue, Ying; Ren, Yiping; Meng, Wenrong; Li, Long; Mao, Xia; Han, Dongyan; Ma, Qiuyun

2013-09-01

Cephalopods play key roles in global marine ecosystems as both predators and preys. Regressive estimation of original size and weight of cephalopod from beak measurements is a powerful tool of interrogating the feeding ecology of predators at higher trophic levels. In this study, regressive relationships among beak measurements and body length and weight were determined for an octopus species ( Octopus variabilis), an important endemic cephalopod species in the northwest Pacific Ocean. A total of 193 individuals (63 males and 130 females) were collected at a monthly interval from Jiaozhou Bay, China. Regressive relationships among 6 beak measurements (upper hood length, UHL; upper crest length, UCL; lower hood length, LHL; lower crest length, LCL; and upper and lower beak weights) and mantle length (ML), total length (TL) and body weight (W) were determined. Results showed that the relationships between beak size and TL and beak size and ML were linearly regressive, while those between beak size and W fitted a power function model. LHL and UCL were the most useful measurements for estimating the size and biomass of O. variabilis. The relationships among beak measurements and body length (either ML or TL) were not significantly different between two sexes; while those among several beak measurements (UHL, LHL and LBW) and body weight (W) were sexually different. Since male individuals of this species have a slightly greater body weight distribution than female individuals, the body weight was not an appropriate measurement for estimating size and biomass, especially when the sex of individuals in the stomachs of predators was unknown. These relationships provided essential information for future use in size and biomass estimation of O. variabilis, as well as the estimation of predator/prey size ratios in the diet of top predators.

The size-weight illusion induced through human echolocation.

PubMed

Buckingham, Gavin; Milne, Jennifer L; Byrne, Caitlin M; Goodale, Melvyn A

2015-02-01

Certain blind individuals have learned to interpret the echoes of self-generated sounds to perceive the structure of objects in their environment. The current work examined how far the influence of this unique form of sensory substitution extends by testing whether echolocation-induced representations of object size could influence weight perception. A small group of echolocation experts made tongue clicks or finger snaps toward cubes of varying sizes and weights before lifting them. These echolocators experienced a robust size-weight illusion. This experiment provides the first demonstration of a sensory substitution technique whereby the substituted sense influences the conscious perception through an intact sense. © The Author(s) 2014.

Estimating regional centile curves from mixed data sources and countries.

PubMed

van Buuren, Stef; Hayes, Daniel J; Stasinopoulos, D Mikis; Rigby, Robert A; ter Kuile, Feiko O; Terlouw, Dianne J

2009-10-15

Regional or national growth distributions can provide vital information on the health status of populations. In most resource poor countries, however, the required anthropometric data from purpose-designed growth surveys are not readily available. We propose a practical method for estimating regional (multi-country) age-conditional weight distributions based on existing survey data from different countries. We developed a two-step method by which one is able to model data with widely different age ranges and sample sizes. The method produces references both at the country level and at the regional (multi-country) level. The first step models country-specific centile curves by Box-Cox t and Box-Cox power exponential distributions implemented in generalized additive model for location, scale and shape through a common model. Individual countries may vary in location and spread. The second step defines the regional reference from a finite mixture of the country distributions, weighted by population size. To demonstrate the method we fitted the weight-for-age distribution of 12 countries in South East Asia and the Western Pacific, based on 273 270 observations. We modeled both the raw body weight and the corresponding Z score, and obtained a good fit between the final models and the original data for both solutions. We briefly discuss an application of the generated regional references to obtain appropriate, region specific, age-based dosing regimens of drugs used in the tropics. The method is an affordable and efficient strategy to estimate regional growth distributions where the standard costly alternatives are not an option. Copyright (c) 2009 John Wiley & Sons, Ltd.

Body size preference and body weight perception among two migrant groups of non-Western origin.

PubMed

Nicolaou, Mary; Doak, Colleen; Dam, Rob van; Hosper, Karen; Seidell, Jaap; Stronks, Karien

2008-12-01

To evaluate body size preference, body weight perception and their relationship with actual weight in two migrant groups of non-Western origin, Turks and Moroccans; additionally, to study the association between body size preference and acculturation. Cross-sectional study. Amsterdam, The Netherlands. Males and females (18-30 years) were randomly selected from the population registry (n 451); participants, or at least one of their parents, were born in Turkey or Morocco. Body size preference was assessed using seven silhouette drawings and body weight perception was assessed by asking participants' opinion of own weight. Acculturation variables were generation status and two scale measures, cultural orientation and social contacts. Participants showed preference for a thin body size. The discrepancy between ideal and current size was significant in women but not men (P < 0.001). Perceived current body size was correlated with BMI (Spearman's correlation coefficient 0.60, P < 0.001 (men) and 0.73, P < 0.001 (women)). Among overweight participants (BMI = 25.0-29.9 kg/m2), 63-82 % of men and 35 % of women perceived themselves as 'average'. Paying attention to own body weight was associated with a discrepancy between ideal and current size among women and with perceiving oneself as 'overweight' among men. Body size preference was not significantly associated with the three acculturation variables. We did not observe a preference for large body sizes in these two non-Western migrant groups. Similar to Western populations, most women wished to be thinner than they were. This was not the case among men, the majority of whom were also unaware of being overweight.

The Exposure Effects of Online Model Pictures and Weight-Related Persuasive Messages on Women's Weight-Loss Planned Behaviors.

PubMed

Pan, Wenjing; Peña, Jorge

2017-10-01

This study examined how exposure to pictures of women with different body sizes (thin, obese), physical attractiveness levels (attractive, unattractive), along with exposure to weight-related messages (pro-anorexia, anti-anorexia) embedded in a fashion website affected female participants' planned behavior toward weight loss. Participants exposed to attractive model pictures showed higher intentions, attitudes, and subjective norms to lose weight compared with unattractive models. Additionally, participants exposed to thin and attractive model pictures indicated the highest attitudes and self-efficacy to lose weight, whereas those exposed to thin and unattractive model pictures indicated the lowest. Furthermore, weight-related messages moderated the effect of model appearance (body size and attractiveness) on controllability of weight-loss activities. However, website pictures' body size differences had no main effects on planned behavior toward weight loss. These effects are discussed in the light of social comparison mechanisms.

Analysis of Basis Weight Uniformity of Microfiber Nonwovens and Its Impact on Permeability and Filtration Properties

NASA Astrophysics Data System (ADS)

Amirnasr, Elham

It is widely recognized that nonwoven basis weight non-uniformity affects various properties of nonwovens. However, few studies can be found in this topic. The development of uniformity definition and measurement methods and the study of their impact on various web properties such as filtration properties and air permeability would be beneficial both in industrial applications and in academia. They can be utilized as a quality control tool and would provide insights about nonwoven behaviors that cannot be solely explained by average values. Therefore, for quantifying nonwoven web basis weight uniformity we purse to develop an optical analytical tool. The quadrant method and clustering analysis was utilized in an image analysis scheme to help define "uniformity" and its spatial variation. Implementing the quadrant method in an image analysis system allows the establishment of a uniformity index that can be used to quantify the degree of uniformity. Clustering analysis has also been modified and verified using uniform and random simulated images with known parameters. Number of clusters and cluster properties such as cluster size, member and density was determined. We also utilized this new measurement method to evaluate uniformity of nonwovens produced with different processes and investigated impacts of uniformity on filtration and permeability. The results of quadrant method shows that uniformity index computed from quadrant method demonstrate a good range for non-uniformity of nonwoven webs. Clustering analysis is also been applied on reference nonwoven with known visual uniformity. From clustering analysis results, cluster size is promising to be used as uniformity parameter. It is been shown that non-uniform nonwovens has provide lager cluster size than uniform nonwovens. It was been tried to find a relationship between web properties and uniformity index (as a web characteristic). To achieve this, filtration properties, air permeability, solidity and uniformity index of meltblown and spunbond samples was measured. Results for filtration test show some deviation between theoretical and experimental filtration efficiency by considering different types of fiber diameter. This deviation can occur due to variation in basis weight non-uniformity. So an appropriate theory is required to predict the variation of filtration efficiency with respect to non-uniformity of nonwoven filter media. And the results for air permeability test showed that uniformity index determined by quadrant method and measured properties have some relationship. In the other word, air permeability decreases as uniformity index on nonwoven web increase.

How Weight Affects the Perceived Spacing between the Thumb and Fingers during Grasping

PubMed Central

Butler, Annie A.; Héroux, Martin E.; Gandevia, Simon C.

2015-01-01

We know much about mechanisms determining the perceived size and weight of lifted objects, but little about how these properties of size and weight affect the body representation (e.g. grasp aperture of the hand). Without vision, subjects (n = 16) estimated spacing between fingers and thumb (perceived grasp aperture) while lifting canisters of the same width (6.6cm) but varied weights (300, 600, 900, and 1200 g). Lifts were performed by movement of either the wrist, elbow or shoulder to examine whether lifting with different muscle groups affects the judgement of grasp aperture. Results for perceived grasp aperture were compared with changes in perceived weight of objects of different sizes (5.2, 6.6, and 10 cm) but the same weight (600 g). When canisters of the same width but different weights were lifted, perceived grasp aperture decreased 4.8% [2.2 ‒ 7.4] (mean [95% CI]; P < 0.001) from the lightest to the heaviest canister, no matter how they were lifted. For objects of the same weight but different widths, perceived weight decreased 42.3% [38.2 ‒ 46.4] from narrowest to widest (P < 0.001), as expected from the size-weight illusion. Thus, despite a highly distorted perception of the weight of objects based on their size, we conclude that proprioceptive afferents maintain a reasonably stable perception of the aperture of the grasping hand over a wide range of object weights. Given the small magnitude of this ‘weight-grasp aperture’ illusion, we propose the brain has access to a relatively stable ‘perceptual ruler’ to aid the manipulation of different objects. PMID:25996760

Glass Fiber Reinforced Metal Pressure Vessel Design Guide

NASA Technical Reports Server (NTRS)

Landes, R. E.

1972-01-01

The Engineering Guide presents curves and general equations for safelife design of lightweight glass fiber reinforced (GFR) metal pressure vessels operating under anticipated Space Shuttle service conditions. The high composite vessel weight efficiency is shown to be relatively insensitive to shape, providing increased flexibility to designers establishing spacecraft configurations. Spheres, oblate speroids, and cylinders constructed of GFR Inconel X-750, 2219-T62 aluminum, and cryoformed 301 stainless steel are covered; design parameters and performance efficiencies for each configuration are compared at ambient and cryogenic temperature for an operating pressure range of 690 to 2760 N/sq cm (1000 to 4000 psi). Design variables are presented as a function of metal shell operating to sizing (proof) stress ratios for use with fracture mechanics data generated under a separate task of this program.

Recent development in the design, testing and impact-damage tolerance of stiffened composite panels

NASA Technical Reports Server (NTRS)

Williams, J. G.; Anderson, M. S.; Rhodes, M. D.; Starnes, J. H., Jr.; Stroud, W. J.

1979-01-01

Structural technology of laminated filamentary-composite stiffened-panel structures under combined inplane and lateral loadings is discussed. Attention is focused on: (1) methods for analyzing the behavior of these structures under load and for determining appropriate structural proportions for weight-efficient configurations; and (2) effects of impact damage and geometric imperfections on structural performance. Recent improvements in buckling analysis involving combined inplane compression and shear loadings and transverse shear deformations are presented. A computer code is described for proportioning or sizing laminate layers and cross-sectional dimensions, and the code is used to develop structural efficiency data for a variety of configurations, loading conditions, and constraint conditions. Experimental data on buckling of panels under inplane compression is presented. Mechanisms of impact damage initiation and propagation are described.

SU-E-T-110: An Investigation On Monitor Unit Threshold and Effects On IMPT Delivery in Proton Pencil Beam Planning System

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

Syh, J; Ding, X; Syh, J

2015-06-15

Purpose: An approved proton pencil beam scanning (PBS) treatment plan might not be able to deliver because of existed extremely low monitor unit per beam spot. A dual hybrid plan with higher efficiency of higher spot monitor unit and the efficacy of less number of energy layers were searched and optimized. The range of monitor unit threshold setting was investigated and the plan quality was evaluated by target dose conformity. Methods: Certain limitations and requirements need to be checks and tested before a nominal proton PBS treatment plan can be delivered. The plan needs to be met the machine characterization,more » specification in record and verification to deliver the beams. Minimal threshold of monitor unit, e.g. 0.02, per spot was set to filter the low counts and plan was re-computed. Further MU threshold increment was tested in sequence without sacrificing the plan quality. The number of energy layer was also alternated due to elimination of low count layer(s). Results: Minimal MU/spot threshold, spot spacing in each energy layer and total number of energy layer and the MU weighting of beam spots of each beam were evaluated. Plan optimization between increases of the spot MU (efficiency) and less energy layers of delivery (efficacy) was adjusted. 5% weighting limit of total monitor unit per beam was feasible. Scarce spreading of beam spots was not discouraging as long as target dose conformity within 3% criteria. Conclusion: Each spot size is equivalent to the relative dose in the beam delivery system. The energy layer is associated with the depth of the targeting tumor. Our work is crucial to maintain the best possible quality plan. To keep integrity of all intrinsic elements such as spot size, spot number, layer number and the carried weighting of spots in each layer is important in this study.« less

Energy metabolism and hematology of white-tailed deer fawns

USGS Publications Warehouse

Rawson, R.E.; DelGiudice, G.D.; Dziuk, H.E.; Mech, L.D.

1992-01-01

Resting metabolic rates, weight gains and hematologic profiles of six newborn, captive white-tailed deer (Odocoileus virginianus) fawns (four females, two males) were determined during the first 3 mo of life. Estimated mean daily weight gain of fawns was 0.2 kg. The regression equation for metabolic rate was: Metabolic rate (kcal/kg0.75/day) = 56.1 +/- 1.3 (age in days), r = 0.65, P less than 0.001). Regression equations were also used to relate age to red blood cell count (RBC), hemoglobin concentration (Hb), packed cell volume, white blood cell count, mean corpuscular volume, mean corpuscular hemoglobin concentration (MCHC), and mean corpuscular hemoglobin. The age relationships of Hb, MCHC, and smaller RBC's were indicative of an increasing and more efficient oxygen-carrying and exchange capacity to fulfill the increasing metabolic demands for oxygen associated with increasing body size.

Fatigue Behavior of AM60B Subjected to Variable Amplitude Loading

NASA Astrophysics Data System (ADS)

Kang, H.; Kari, K.; Khosrovaneh, A. K.; Nayaki, R.; Su, X.; Zhang, L.; Lee, Y.-L.

Magnesium alloys are considered as an alternative material to reduce vehicle weight due to their weight which are 33% lighter than aluminum alloys. There has been a significant expansion in the applications of magnesium alloys in automotives components in an effort to improve fuel efficiency through vehicle mass reduction. In this project, a simple front shock tower of passenger vehicle is constructed with various magnesium alloys. To predict the fatigue behavior of the structure, fatigue properties of the magnesium alloy (AM60B) were determined from strain controlled fatigue tests. Notched specimens were also tested with three different variable amplitude loading profiles obtained from the shock tower of the similar size of vehicle. The test results were compared with various fatigue prediction results. The effect of mean stress and fatigue prediction method were discussed.

Change of the nutritional habits and anthropometric measurements of type 2 diabetic patients - advantages of the nutritional education carried out.

PubMed

Szczepańska, Elżbieta; Klocek, Mariola; Kardas, Marek; Dul, Lechosław

2014-01-01

Diabetes is one of many diseases in which prevention and treatment are essentially based on proper nutrition. Nutritional education should be a constant, integral and indispensable part of the therapeutic procedure in diabetes. The aim of the study was an estimation of the nutritional habits of patients with type 2 diabetes before and after individual nutritional education and the answers to the question what influence this education had on the change of nutritional habits and the change of the anthropometric measurements of the patients. 148 patients of diabetes outpatient clinics participated in our study, which contained, among others, anthropometric measurements and carrying out a questionnaire that tested dietary habits. An individual nutrition plan was established and the individual dietary education of the patients was carried out on the basis of the gathered data. The nutritional habits and the anthropometric measurements were verified again three months after the education. The analysis of the results received revealed an occurrence of the differences between the incidence of proper nutritional habits and middle-values of body weight and waist size in the period before and after education. Before the education, an enormous amount of improper nutritional habits were found and the values of body weight and waist size were higher, while after the education the improvement of habits and a reduction in body weight and waist size were observed. The results of our study carried out before the education revealed the occurrence of many unfavorable nutritional habits. As a result of the education, nutritional habits improved, which were simultaneously reflected in an improvement of the anthropometric parameters. The results of the studies carried out proved the efficiency and profitable influence of dietary education on changes to the nutritional habits of respondents).

Hyaluronic acid-functionalized polymeric nanoparticles for colon cancer-targeted combination chemotherapy

NASA Astrophysics Data System (ADS)

Xiao, Bo; Han, Moon Kwon; Viennois, Emilie; Wang, Lixin; Zhang, Mingzhen; Si, Xiaoying; Merlin, Didier

2015-10-01

Nanoparticle (NP)-based combination chemotherapy has been proposed as an effective strategy for achieving synergistic effects and targeted drug delivery for colon cancer therapy. Here, we fabricated a series of hyaluronic acid (HA)-functionalized camptothecin (CPT)/curcumin (CUR)-loaded polymeric NPs (HA-CPT/CUR-NPs) with various weight ratios of CPT to CUR (1 : 1, 2 : 1 and 4 : 1). The resultant spherical HA-CPT/CUR-NPs had a desirable particle size (around 289 nm), relative narrow size distribution, and slightly negative zeta potential. These NPs exhibited a simultaneous sustained release profile for both drugs throughout the time frame examined. Subsequent cellular uptake experiments demonstrated that the introduction of HA to the NP surface endowed NPs with colon cancer-targeting capability and markedly increased cellular uptake efficiency compared with chitosan-coated NPs. Importantly, the combined delivery of CPT and CUR in one HA-functionalized NP exerted strong synergistic effects. HA-CPT/CUR-NP (1 : 1) showed the highest antitumor activity among the three HA-CPT/CUR-NPs, resulting in an extremely low combination index. Collectively, our findings indicate that this HA-CPT/CUR-NP can be exploited as an efficient formulation for colon cancer-targeted combination chemotherapy.Nanoparticle (NP)-based combination chemotherapy has been proposed as an effective strategy for achieving synergistic effects and targeted drug delivery for colon cancer therapy. Here, we fabricated a series of hyaluronic acid (HA)-functionalized camptothecin (CPT)/curcumin (CUR)-loaded polymeric NPs (HA-CPT/CUR-NPs) with various weight ratios of CPT to CUR (1 : 1, 2 : 1 and 4 : 1). The resultant spherical HA-CPT/CUR-NPs had a desirable particle size (around 289 nm), relative narrow size distribution, and slightly negative zeta potential. These NPs exhibited a simultaneous sustained release profile for both drugs throughout the time frame examined. Subsequent cellular uptake experiments demonstrated that the introduction of HA to the NP surface endowed NPs with colon cancer-targeting capability and markedly increased cellular uptake efficiency compared with chitosan-coated NPs. Importantly, the combined delivery of CPT and CUR in one HA-functionalized NP exerted strong synergistic effects. HA-CPT/CUR-NP (1 : 1) showed the highest antitumor activity among the three HA-CPT/CUR-NPs, resulting in an extremely low combination index. Collectively, our findings indicate that this HA-CPT/CUR-NP can be exploited as an efficient formulation for colon cancer-targeted combination chemotherapy. Electronic supplementary information (ESI) available: Representative flow cytometry plots of cells incubated with or without cationic CPT/CUR-NPs (1 : 1) for 3 h; Cytotoxicity of blank chitosan-coated NPs and blank HA-functionalized NPs at different concentrations against Colon-26 cells after 48 h of co-incubation. See DOI: 10.1039/c5nr04831a

Effect of mature body weight and stocking rate on cow and calf performance, cow herd efficiency, and economics in the southeastern United States.

PubMed

Beck, P A; Stewart, C B; Gadberry, M S; Haque, M; Biermacher, J

2016-04-01

Eight 4-ha mixed warm-season grass pastures in southwestern Arkansas (33°40'4″ N, 93°35'24″ W, and elevation 107 m) were stocked with either large mature size (571 kg [SD 55.2] BW) or small mature size (463 kg [SD 58.2] BW) spring-calving cows at 4 stocking rates (SR; 1, 1.5, 2, or 2.5 cow-calf pairs/ha) over 4 yr to test the effects of SR and mature body size on cow and calf performance and system economics. Each pasture received 112 kg/ha N as ammonium nitrate in May and was broadcast seeded to annual ryegrass ( Lam.) in mid October each fall along with 112 kg/ha N as ammonium nitrate. Data were analyzed by regression to determine the effects of cow size and SR on calf performance, cow BW change, calf gain, weaning weight per hectare, hay feeding requirements, and net returns. As SR increased, cow BW and BCS at weaning decreased ( < 0.01) by 26 kg and 0.36 condition scores, respectively, for each additional cow stocked per hectare ( = 0.44). Calf BW at weaning in October increased ( < 0.01) 19 kg for each 100-kg increase in cow BW but was not affected ( = 0.66) by SR. As cow BW increased, calf BW at weaning per 100 kg cow BW decreased ( < 0.01) 6.7 kg for each 100-kg increase in cow BW but was not affected ( = 0.44) by SR. Neither cow BW nor SR affected ( ≥ 0.53) pregnancy percentage, which averaged 88% over the 4-yr experiment. Calf BW weaned per hectare was not affected ( = 0.75) by cow BW but linearly increased ( < 0.01) by 217 kg for each additional cow per hectare SR. Hay feeding days and cost of hay per cow increased ( ≤ 0.05) and kilograms of hay offered per cow tended ( = 0.09) to linearly increase with increasing SR, yet cow BW had no effects ( > 0.22). Although there were no effects ( ≥ 0.38) of cow BW on carrying cost or net returns, increasing SR decreased ( < 0.01) total expenses by US$102/cow and increased net returns by $70/cow and $438/ha for each cow per hectare increase in SR. These data indicate that increasing cow size can increase weaning BW of calves but does not affect total production per hectare or profitability, even though weaning weight efficiency ratios were reduced. Increasing SR reduced cow BW and BCS at weaning and increased feeding of conserved forages but did not affect pregnancy rates and led to increases in total calf BW weaned per hectare and net returns.

Perceptions and beliefs about body size, weight, and weight loss among obese African American women: a qualitative inquiry.

PubMed

Befort, Christie A; Thomas, Janet L; Daley, Christine M; Rhode, Paula C; Ahluwalia, Jasjit S

2008-06-01

The purpose of this qualitative study was to explore perceptions and beliefs about body size, weight, and weight loss among obese African American women in order to form a design of weight loss intervention with this target population. Six focus groups were conducted at a community health clinic. Participants were predominantly middle-aged with a mean Body Mass Index of 40.3 +/- 9.2 kg/m(2). Findings suggest that participants (a) believe that people can be attractive and healthy at larger sizes; (b) still feel dissatisfied with their weight and self-conscious about their bodies; (c) emphasize eating behavior as the primary cause for weight gain; (d) view pregnancy, motherhood, and caregiving as major precursors to weight gain; (e) view health as the most important reason to lose weight; (f) have mixed experiences and expectations for social support for weight loss; and (g) prefer treatments that incorporate long-term lifestyle modification rather than fad diets or medication.

Effects of chitosan molecular weight on the physical and dissolution characteristics of amorphous curcumin-chitosan nanoparticle complex.

PubMed

Yu, Hong; Nguyen, Minh-Hiep; Hadinoto, Kunn

2018-01-01

To investigate the effects of varying molecular weight (MW) of chitosan (CHI) used in the complexation with curcumin (CUR) on the physical and dissolution characteristics of the amorphous CUR-CHI nanoparticle complex produced. Amorphous CUR-CHI nanoparticle complex (or CUR nanoplex in short) recently emerged as a promising bioavailability enhancement strategy of CUR attributed to its fast dissolution, supersaturation generation capability, and simple preparation. Existing CUR nanoplex prepared using low MW CHI, however, exhibited poor colloidal stability during storage. Herein we hypothesized that the colloidal stability could be improved by using CHI of higher MW. The effects of this approach on the nanoplex's other characteristics were simultaneously investigated. The CUR nanoplex was prepared by electrostatically driven self-assembled complexation between CUR and oppositely charged CHI of three different MWs (i.e. low, medium, and high). Besides colloidal stability, the effects of MW variation were investigated for the nanoplex's (1) other physical characteristics (i.e. size, zeta potential, CUR payload, amorphous state stability), (2) preparation efficiency (i.e. CUR utilization rate, yield), and (3) dissolutions under sink condition and supersaturation generation. CUR nanoplex prepared using CHI of high MW exhibited improved colloidal stability, larger size, superior morphology, and prolonged supersaturation generation. On the other hand, the effects of MW variation on the payload, amorphous state stability, preparation efficiency, and dissolution under sink condition were found to be insignificant. Varying MW of CHI used was an effective means to improve certain aspects of the CUR nanoplex characteristics with minimal adverse effects on the others.

The influence of life history trade-offs and the size of the incubation gravels on egg size variation in sockeye salmon Onchorhynchus nerka

USGS Publications Warehouse

Quinn, Thomas P.; Hendry , Andrew P.; Wetzel, Lisa A.

1995-01-01

Egg size is a critical life history trait, reflecting female investment and affecting off- spring fitness. We investigated several factors which may influence variation in egg weight for sockeye salmon (Oncorhynchus nerka). Comparisons were based on col- lections from 18 Alaskan populations, among which adult migration distance and ju- venile rearing habitat were similar but the size composition of incubation gravels was different. Among populations, most of the variation in egg weight could be explained by a positive correlation with different measures of the size composition of incubation gravels (Pearson's r = 0.45-0.91). In contrast, egg weight was poorly correlated with female body length and with female snout length, a morphological feature used during intra-sexual competition. Within each of the Alaskan populations, however, egg weight and snout length were positively correlated with female body length and hence with each other. A positive association between snout length and egg weight was still evident even after the effects of covariance with body size were removed using resid- uals analysis: for all of the fish pooled and within 6 of the 16 populations. A signifi- cant relationship was not detected in the other populations but the trend was neverthe- less positive in 8 of the other 10. Examination of reproductive traits (gonad weight, egg weight, egg number, snout length and hump size) within another population iden- tified a trade-off between egg weight and egg number for females of a given body length. In contrast, positive correlations between reproductive traits were more com- mon, suggesting that energy-rich individuals produce large eggs and large secondary sexual characteristics rather than sacrificing one for the other.

Effect of relative weight group change on nuclear magnetic resonance spectroscopy derived lipoprotein particle size and concentrations among adolescents.

PubMed

Jago, Russell; Drews, Kimberly L; Otvos, James D; Foster, Gary D; Marcus, Marsha D; Buse, John B; Mietus-Snyder, Michele; Willi, Steven M

2014-05-01

To examine whether longitudinal changes in relative weight category (as indicated by change in body mass index [BMI] classification group) were associated with changes in nuclear magnetic resonance (NMR)-derived lipoprotein particles among US youth. Secondary analysis of data from a clustered randomized controlled trial. BMI and fasting blood samples were obtained from 2069 participants at the start of the 6th grade and end of the 8th grade. BMI was categorized as normal weight, overweight, or obese at both time points. Lipoprotein particle profiles were measured with NMR spectroscopy at both time points. Regression models were used to examine changes in relative weight group and change in lipoprotein variables. A total of 38% of participants changed relative weight category (BMI group) during the 2.5-year study period. Low-density lipoprotein (LDL) cholesterol and non-high-density lipoprotein (HDL) cholesterol decreased almost universally, but more with improved BMI category. There were adverse effects on LDL size and total LDL particles, HDL size, and cholesterol for participants who remained obese or whose relative weight group worsened. Changes in relative category had no impact on HDL particles. Improvement in relative weight group from 6th to 8th grade was associated with favorable changes in non-HDL cholesterol, very low-density lipoprotein size, LDL size, HDL size, and LDL particles but had no effect on HDL particles. Findings indicate that an improvement in relative weight group between 6th and 8th grade had an effect on NMR-derived particles sizes and concentrations among a large group of adolescents, which overrepresented low-income minorities. Copyright © 2014 Elsevier Inc. All rights reserved.

Single-Trait and Antagonistic Index Selection for Litter Size and Body Weight in Mice

PubMed Central

Eisen, E. J.

1978-01-01

Individual selection based on female performance only was conducted in four lines of mice: L+ for increased litter size, W+ for increased 6-week body weight, L-W+ for a selection index aimed at decreasing litter size and increasing 6-week body weight and L+W- for a selection index aimed at increasing litter size and decreasing 6-week body weight. A fifth line (K) served as an unselected control. All litters were standardized to eight mice at one day of age. Expected heritability was based on twice the regression of offspring on dam (h2d), which contains additive genetic variance due to direct (σ2Ao) and maternal (σ2Am) effects and their covariance (σAoAm). Responses and correlated responses were measured either deviated (method 1) or not deviated (method 2) from the control line. Realized heritabilities (h2R) for litter size were 0.19 ± 0.04 (1) and 0.16 ± 0.03 (2), which were similar to h 2d of 0.17 ± 0.04. The h2 R for 6-week body weight of 0.55 ± 0.07 (1) and 0.44 ± 0.07 (2) agreed with h2d of 0.42 ± 0.02. Realized genetic correlations (r*GR) between litter size and 6-week body weight calculated from the double-selection experiment were 0.52 ± 0.10 (1) and 0.52 ± 0.13 (2), which were not significantly different from the base population estimate of r* Gd = 0.63 ± 0.14. Divergence (L-W + minus L+W-) in the antagonistic index selection lines was 0.21 ± 0.01 index units (I = 0.305 PW - 0.436 PL, where P W and PL are the phenotypic values for 6-week body weight and litter size, respectively.). The h2 R of index units of 0.14 ± 0.02 calculated from divergence agreed with h2d of 0.14 ± 0.04. Divergences in litter size (-0.19 ± 0.07) and 6-week body weight (0.46 ± 0.10) were in the expected direction. Antagonistic index selection yielded about one-half the expected divergence in litter size, while divergence in 6-week body weight was only slightly less than expected. Realized genetic correlations indicated that litter size, 6-week body weight and index units each showed positive pleiotropy with 3-week body weight, postweaning gain and weight at vaginal introitus and negative pleiotropy with age at vaginal introitus. Sex ratio and several components of fitness (days from joining to parturition, percent fertile matings and percent perinatal survival) did not change significantly in the selected lines. PMID:17248819

Size misperception among overweight and obese families.

PubMed

Paul, Tracy K; Sciacca, Robert R; Bier, Michael; Rodriguez, Juviza; Song, Sharon; Giardina, Elsa-Grace V

2015-01-01

Perception of body size is a key factor driving health behavior. Mothers directly influence children's nutritional and exercise behaviors. Mothers of ethnic minority groups and lower socioeconomic status are less likely to correctly identify young children as overweight or obese. Little evaluation has been done of the inverse--the child's perception of the mother's weight. To determine awareness of weight status among mother-child dyads (n = 506). Cross-sectional study conducted in an outpatient pediatric dental clinic of Columbia University Medical Center, New York, NY. Primarily Hispanic (82.2 %) mothers (n = 253), 38.8 ± 7.5 years of age, and children (n = 253), 10.5 ± 1.4 years of age, responding to a questionnaire adapted from the validated Behavioral Risk Factor Surveillance System. Anthropometric measures-including height, weight, and waist circumference-and awareness of self-size and size of other generation were obtained. 71.4 % of obese adults and 35.1 % of overweight adults underestimated size, vs. 8.6 % of normal-weight (NW) adults (both p < 0.001). Among overweight and obese children, 86.3 % and 62.3 % underestimated their size, vs. 14.9 % NW children (both p < 0.001). Among mothers with overweight children, 80.0 % underestimated their child's weight, vs. 7.1 % of mothers with NW children (p < 0.001); 23.1 % of mothers with obese children also underestimated their child's weight (p < 0.01). Among children with obese mothers, only 13.0 % correctly classified the adult's size, vs. 76.5 % with NW mothers (p < 0.001). Among obese mothers, 20.8 % classified overweight body size as ideal, vs. 1.2 % among NW mothers (p < 0.001). Overweight/obese adults and children frequently underestimate their size. Adults misjudge overweight/obese children as being of normal weight, and children of obese mothers often underestimate the adult's size. Failure to recognize overweight/obesity status among adults and children can lead to prolonged exposure to obesity-related comorbidities.

Effects of Preseason Training on the Sleep Characteristics of Professional Rugby League Players.

PubMed

Thornton, Heidi R; Delaney, Jace A; Duthie, Grant M; Dascombe, Ben J

2018-02-01

To investigate the influence of daily and exponentially weighted moving training loads on subsequent nighttime sleep. Sleep of 14 professional rugby league athletes competing in the National Rugby League was recorded using wristwatch actigraphy. Physical demands were quantified using GPS technology, including total distance, high-speed distance, acceleration/deceleration load (SumAccDec; AU), and session rating of perceived exertion (AU). Linear mixed models determined effects of acute (daily) and subacute (3- and 7-d) exponentially weighted moving averages (EWMA) on sleep. Higher daily SumAccDec was associated with increased sleep efficiency (effect-size correlation; ES = 0.15; ±0.09) and sleep duration (ES = 0.12; ±0.09). Greater 3-d EWMA SumAccDec was associated with increased sleep efficiency (ES = 0.14; ±0.09) and an earlier bedtime (ES = 0.14; ±0.09). An increase in 7-d EWMA SumAccDec was associated with heightened sleep efficiency (ES = 0.15; ±0.09) and earlier bedtimes (ES = 0.15; ±0.09). The direction of the associations between training loads and sleep varied, but the strongest relationships showed that higher training loads increased various measures of sleep. Practitioners should be aware of the increased requirement for sleep during intensified training periods, using this information in the planning and implementation of training and individualized recovery modalities.

Using age on clothes size label to estimate weight in emergency paediatric patients.

PubMed

Elgie, Laura D; Williams, Andrew R

2012-10-01

To study formulae that estimate children's weight using their actual age. To determine whether using the age on their clothes size label in these formulae can estimate weight when their actual age is unknown. The actual age and age on the clothes labels of 188 children were inserted into formulae that estimate children's weight. These estimates were compared with their actual weight. Bland-Altman plots calculated the precision and accuracy of each of these estimates. In all formulae, using age on the clothes sizes label provided a more precise estimate than the child's actual age. In emergencies where a child's age is unknown, use of the age on their clothes label in weight-estimating formulae yields acceptable weight estimates. Even in situations where a child's age is known, the age on their clothes label may provide a more accurate and precise weight estimate than the actual age.

Modeling the retention of rumen boluses for the electronic identification of goats.

PubMed

Carné, S; Caja, G; Ghirardi, J J; Salama, A A K

2011-02-01

We constructed a regression model to estimate the retention of electronic boluses in goats. With this aim, 2,482 boluses were administered to goats from dairy (Murciano-Granadina, n=1,326; French Alpine, n=381) and meat (Blanca de Rasquera, n=532) breeds. A total of 19 bolus types made of materials (ceramic, plastic tubes filled with concrete or silicone, and ballasts) differing in their specific gravity (SG) were used, thereby obtaining a wide variation in bolus features: diameter (9 to 22 mm), length (37 to 84 mm), weight (5 to 111 g), volume (2.6 to 26 mL), and SG (1.0 to 5.5). Each bolus contained a half-duplex glass encapsulated transponder (32 × 3.8mm) and was administered using adapted balling guns. Murciano-Granadina and Blanca de Rasquera goats also wore 2 visual plastic ear tags: V1 (double flag, 5.1g) and V2 (flag-button, 4.2g). No data on ear tags in French Alpine goats was available. Bolus and ear tag retention [(retained/monitored) × 100] was recorded for at least 1 yr. Dynamic reading efficiency [(dynamic reading/static reading) × 100] was also evaluated from 1,496 bolus readings. No administration incidences or apparent negative behavior or performance effects were observed for any bolus type. Static reading efficiency of retained boluses was 100%, except for the prototypes with metal ballasts, which yielded a 93.3% reading efficiency. Retention of metal-ballasted boluses was confirmed using x-ray equipment. Excluding ballasted boluses, a 99.5% dynamic reading efficiency was obtained. Ear tag losses were 6.5% for V1 and 3.7% for V2, ranging from 3.2 to 7.8% depending on ear tag type and goat breed. Bolus retention varied (0 to 100%) according to their physical features. Obtained data allowed the fitting of a logistic model of bolus retention rate according to bolus volume and weight (R(2) = 0.98); the SG was implicitly considered. Estimated weight and SG to produce medium- (15 mL) and standard-sized (22 mL) boluses for 99.95% retention rate in goats were 73.0 and 94.1g, and 4.87 and 4.28, respectively. Mini-boluses are not recommended, as none of the available radio translucent materials reach the required SG. In conclusion, increase of SG was fundamental to optimize bolus retention. Medium-sized boluses (10 to 15 mL; SG 5.8 to 4.9) for early administration and efficient retention in adult goats could be produced, thereby addressing the problem of using proper boluses for goat identification. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The Relationship between Vehicle Weight/Size and Safety

NASA Astrophysics Data System (ADS)

Wenzel, Tom; Ross, Marc

2008-09-01

Light-duty vehicles account for about 20% of US CO2 emissions. However, new vehicle fuel economy standards have not been significantly tightened since they were first enacted three decades ago. A historical impediment to imposing tougher fuel economy standards has been the long-standing perception that reducing the mass of a car or truck would make it more dangerous to its occupants in a crash. One often hears that this perception is dictated by "simple physics:" that, all else being equal, you are at greater risk in a lighter vehicle than in a heavier one. Our research on driver fatality risk has found that, when it comes to vehicle safety, all else is never equal. Vehicle mass is not the most important variable in determining occupant safety, not even in frontal crashes between two vehicles. You are at no greater risk driving an average car than you are driving a much heavier (and less fuel efficient) truck-based SUV. And larger and heavier truck-based SUVs and pickups impose enormous risks on car occupants. We summarize the most recent research on the interplay between vehicle weight, size and safety, and what the implications are for new state and federal standards to reduce vehicle CO2 emissions.

A comparison of long-chain triglycerides and medium-chain triglycerides on weight loss and tumour size in a cachexia model.

PubMed Central

Tisdale, M. J.; Brennan, R. A.

1988-01-01

A comparison has been made between the ability of long-chain triglycerides (LCT) and medium-chain triglycerides (MCT) to prevent weight loss induced by the cachexia-inducing colon adenocarcinoma (MAC16) and to reduce tumour size. There was no difference in calorie consumption or nitrogen intake between the various groups. When compared with a normal control high carbohydrate, low fat diet, animals fed MCT showed a reduced weight loss and a marked reduction in tumour size. In contrast neither weight loss nor tumour size differed significantly from the controls in animals fed the LCT diet. An elevated plasma level of 3-hydroxybuturate was found only in the animals fed the MCT diets. Administration of LCT caused an increase in the plasma level of FFA, which was not observed in the MCT group. These results suggest that diets containing MCT would provide the best ketogenic regime to reverse the weight loss in cancer cachexia with a concomitant reduction in tumour size. PMID:3219268

Hispanic maternal influences on daughters' unhealthy weight control behaviors: The role of maternal acculturation, adiposity, and body image disturbances.

PubMed

Olvera, Norma; Matthews-Ewald, Molly R; McCarley, Kendall; Scherer, Rhonda; Posada, Alexandria

2016-12-01

This study examined whether maternal adiposity, acculturation, and perceived-ideal body size discrepancy for daughters were associated with daughters' engagement in unhealthy weight control behaviors. A total of 97 Hispanic mother-daughter dyads completed surveys, rated a figure scale, and had their height, weight, and adiposity assessed. Mothers (M age =39.00, SD=6.20 years) selected larger ideal body sizes for their daughters (M age =11.12, SD=1.53 years) than their daughters selected for themselves. Mothers had a smaller difference between their perception of their daughters' body size and ideal body size compared to the difference between their daughters' selection of their perceived and ideal body size. More acculturated mothers and those mothers with larger waist-to-hip ratios were more likely to have daughters who engaged in unhealthy weight control behaviors. These findings highlight the relevant role that maternal acculturation and adiposity may have in influencing daughters' unhealthy weight control behaviors. Published by Elsevier Ltd.

Development of a weight/sizing design synthesis computer program. Volume 1: Program formulation

NASA Technical Reports Server (NTRS)

Garrison, J. M.

1973-01-01

The development of a weight/sizing design synthesis methodology for use in support of the main line space shuttle program is discussed. The methodology has a minimum number of data inputs and quick turn around capabilities. The methodology makes it possible to: (1) make weight comparisons between current shuttle configurations and proposed changes, (2) determine the effects of various subsystems trades on total systems weight, and (3) determine the effects of weight on performance and performance on weight.

Influence of method of whole wheat inclusion and xylanase supplementation on the performance, apparent metabolisable energy, digestive tract measurements and gut morphology of broilers.

PubMed

Wu, Y B; Ravindran, V; Thomas, D G; Birtles, M J; Hendriks, W H

2004-06-01

1. The aim of the present study was to examine the influence of whole wheat inclusion and xylanase supplementation on the performance, apparent metabolisable energy (AME), digesta viscosity, and digestive tract measurements of broilers fed on wheat-based diets. The influence of the method of whole wheat inclusion (pre- or post-pelleting) was also compared. A 3 x 2 factorial arrangement of treatments was used with three diet forms (648 g/kg ground wheat [GW], GW replaced by 200 g/kg of whole wheat before [WW1] or after cold-pelleting [WW2]) and two xylanase levels (0 and 1000 XU/kg diet). 2. Birds given diets containing whole wheat had improved weight gains, feed efficiency and AME compared to those fed on diets containing ground wheat. The relative gizzard weight of birds fed WW2 diets was higher than in those fed GW and WW1 diets. Pre-pelleting inclusion of whole wheat had no effect on relative gizzard weight. Post-pelleting inclusion of whole wheat resulted in greater improvements in feed efficiency and AME than the pre-pelleting treatment. 3. Xylanase supplementation significantly improved weight gain, feed efficiency and AME, irrespective of the wheat form used. Viscosity of the digesta in the duodenum, jejunum and ileum were reduced by xylanase addition. Xylanase supplementation reduced the relative weight of the pancreas. 4. Neither xylanase supplementation nor whole wheat inclusion influenced the relative weight and length of the small intestine. 5. Xylanase supplementation increased ileal villus height. A significant interaction between diet form and xylanase was observed for ileal crypt depth. Xylanase supplementation had no effect on crypt depth in birds fed on diets containing GW, but increased the crypt depth in WW2 diets. No significant effects of diet form and xylanase supplementation were observed for the thickness of the tunica muscularis layer of gizzard or villus height, crypt depth, goblet cell numbers or epithelial thickness in the ileum. 6. Improved performance observed with post-pelleting inclusion of whole wheat was associated with increased size of the gizzard and improved AME. The gizzard development hypothesis, however, will not explain the improvements observed with pre-pelleting inclusion of whole wheat, suggesting the involvement of other factors.

Preliminary Weight Savings Estimate for a Commercial Transport Wing Using Rod-Stiffened Stitched Composite Technology

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.

2015-01-01

A structural concept called pultruded rod stitched efficient unitized structure (PRSEUS) was developed by the Boeing Company to address the complex structural design aspects associated with a pressurized hybrid wing body (HWB) aircraft configuration. While PRSEUS was an enabling technology for the pressurized HWB structure, limited investigation of PRSEUS for other aircraft structures, such as circular fuselages and wings, has been done. Therefore, a study was undertaken to investigate the potential weight savings afforded by using the PRSEUS concept for a commercial transport wing. The study applied PRSEUS to the Advanced Subsonic Technology (AST) Program composite semi-span test article, which was sized using three load cases. The initial PRSEUS design was developed by matching cross-sectional stiffnesses for each stringer/skin combination within the wing covers, then the design was modified to ensure that the PRSEUS design satisfied the design criteria. It was found that the PRSEUS wing design exhibited weight savings over the blade-stiffened composite AST Program wing of nearly 9%, and a weight savings of 49% and 29% for the lower and upper covers, respectively, compared to an equivalent metallic wing.

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

Beltran, C; Kamal, H

Purpose: To provide a multicriteria optimization algorithm for intensity modulated radiation therapy using pencil proton beam scanning. Methods: Intensity modulated radiation therapy using pencil proton beam scanning requires efficient optimization algorithms to overcome the uncertainties in the Bragg peaks locations. This work is focused on optimization algorithms that are based on Monte Carlo simulation of the treatment planning and use the weights and the dose volume histogram (DVH) control points to steer toward desired plans. The proton beam treatment planning process based on single objective optimization (representing a weighted sum of multiple objectives) usually leads to time-consuming iterations involving treatmentmore » planning team members. We proved a time efficient multicriteria optimization algorithm that is developed to run on NVIDIA GPU (Graphical Processing Units) cluster. The multicriteria optimization algorithm running time benefits from up-sampling of the CT voxel size of the calculations without loss of fidelity. Results: We will present preliminary results of Multicriteria optimization for intensity modulated proton therapy based on DVH control points. The results will show optimization results of a phantom case and a brain tumor case. Conclusion: The multicriteria optimization of the intensity modulated radiation therapy using pencil proton beam scanning provides a novel tool for treatment planning. Work support by a grant from Varian Inc.« less

Refined Exploration of Turbofan Design Options for an Advanced Single-Aisle Transport

NASA Technical Reports Server (NTRS)

Guynn, Mark D.; Berton, Jeffrey J.; Fisher, Kenneth L.; Haller, William J.; Tong, Michael T.; Thurman, Douglas R.

2011-01-01

A comprehensive exploration of the turbofan engine design space for an advanced technology single-aisle transport (737/A320 class aircraft) was conducted previously by the authors and is documented in a prior report. Through the course of that study and in a subsequent evaluation of the approach and results, a number of enhancements to the engine design ground rules and assumptions were identified. A follow-on effort was initiated to investigate the impacts of these changes on the original study results. The fundamental conclusions of the prior study were found to still be valid with the revised engine designs. The most significant impact of the design changes was a reduction in the aircraft weight and block fuel penalties incurred with low fan pressure ratio, ultra-high bypass ratio designs. This enables lower noise levels to be pursued (through lower fan pressure ratio) with minor negative impacts on aircraft weight and fuel efficiency. Regardless of the engine design selected, the results of this study indicate the potential for the advanced aircraft to realize substantial improvements in fuel efficiency, emissions, and noise compared to the current vehicles in this size class.

Investigation on the feasibility of coffee husk (endocarp) as efficient filler material for enhancing physical and mechanical properties of styrofoam based particleboard

NASA Astrophysics Data System (ADS)

Milawarni; Nurlaili; Ernayusnianti

2018-03-01

This research focuses on introducing a coffee husk as viable and efficient filler for enhancing physical and mechanical properties of Styrofoam based particleboard. Heat treatment method was adopted to produce the particleboard from the mixture of coffee husk (CH) with Styrofoam (PS). Styrofoam is material derived from polystyrene. The aim of this research is to get the appropriate weight composition between coffee husks with PS and to identify the physical and mechanical properties of the produced particleboard. The composition of coffee husk varies between 0-90%wt. The manufacture of particleboard i.e. coffee husk milled with size 20/10 mesh then soak with 10% NaOH for 2 hours, rinsed with clean water and dried and weight according to the composition. The mixture of CH and PS is inserted into mold and put into hot-press. The result shows from physical properties that density, water absorption and thick development test corresponding with SNI 03-2105-2006 standard, the mechanical properties shows MOR test meets the standard on the addition of CH 10-50%, while the MOE test has not meet the standard.

Bimodal porous TiO2 structures templated by graft copolymer/homopolymer blend for dye-sensitized solar cells with polymer electrolyte

NASA Astrophysics Data System (ADS)

Kim, Jin Kyu; Lee, Chang Soo; Lee, Sang-Yup; Cho, Hyung Hee; Kim, Jong Hak

2016-12-01

Bimodal porous TiO2 (BP-TiO2) with large surface area, high porosity, good interconnectivity, and excellent light-scattering ability are synthesized via a facile one-step method using a self-assembled blend template consisting of an amphiphilic poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) graft copolymer and a hydrophobic poly(vinyl chloride) (PVC) homopolymer. The hydrophilically surface-modified TiO2 nanoparticles selectively interact with the hydrophilic POEM chains, while the addition of the PVC homopolymer increases the hydrophobic domain size, resulting in the formation of dual pores (i.e., macropores and mesopores). The sizes and numbers of macropores can easily be controlled by changing the molecular weight and amount of the PVC homopolymer. The polymer electrolyte dye-sensitized solar cells (DSSCs) fabricated with BP-TiO2 photoanodes exhibited energy conversion efficiencies of up to 7.6% at 100 mW cm-2, which is much higher than those of mesoporous TiO2 (5.8%) with PVC-g-POEM only and conventional nanocrystalline TiO2 (4.9%) with commercial Dyesol paste. The enhanced energy conversion efficiencies mostly resulted from the light-scattering effects of the macropores, which increased the light-harvesting efficiencies. The improved light-harvesting and photovoltaic performances of the DSSCs were characterized by UV-vis spectroscopy, incident photon-to-current conversion efficiency analysis, electrochemical impedance spectroscopy, intensity-modulated photocurrent spectroscopy, and intensity-modulated photovoltage spectroscopy.

Maternal anthropometrics are associated with fetal size in different periods of pregnancy and at birth. The Generation R Study.

PubMed

Ay, L; Kruithof, C J; Bakker, R; Steegers, E A P; Witteman, J C M; Moll, H A; Hofman, A; Mackenbach, J P; Hokken-Koelega, A C S; Jaddoe, V W V

2009-06-01

We aimed to examine the associations of maternal anthropometrics with fetal weight measured in different periods of pregnancy and with birth outcomes. Population-based birth cohort study. Data of pregnant women and their children in Rotterdam, the Netherlands. In 8541 mothers, height, prepregnancy body mass index (BMI) and gestational weight gain were available. Fetal growth was measured by ultrasound in mid- and late pregnancy. Regression analyses were used to assess the impact of maternal anthropometrics on fetal weight and birth outcomes. Fetal weight and birth outcomes: weight (grams) and the risks of small (<5th percentile) and large (>95th percentile) size for gestational age at birth. Maternal BMI in pregnancy was positively associated with estimated fetal weight during pregnancy. The effect estimates increased with advancing gestational age. All maternal anthropometrics were positively associated with fetal size (P-values for trend <0.01). Mothers with both their prepregnancy BMI and gestational weight gain quartile in the lowest and highest quartiles showed the highest risks of having a small and large size for gestational age child at birth, respectively. The effect of prepregnancy BMI was strongly modified by gestational weight gain. Fetal growth is positively affected by maternal BMI during pregnancy. Maternal height, prepregnancy BMI and gestational weight gain are all associated with increased risks of small and large size for gestational age at birth in the offspring, with an increased effect when combined.

Effects of Vertex Activity and Self-organized Criticality Behavior on a Weighted Evolving Network

NASA Astrophysics Data System (ADS)

Zhang, Gui-Qing; Yang, Qiu-Ying; Chen, Tian-Lun

2008-08-01

Effects of vertex activity have been analyzed on a weighted evolving network. The network is characterized by the probability distribution of vertex strength, each edge weight and evolution of the strength of vertices with different vertex activities. The model exhibits self-organized criticality behavior. The probability distribution of avalanche size for different network sizes is also shown. In addition, there is a power law relation between the size and the duration of an avalanche and the average of avalanche size has been studied for different vertex activities.

Optimal Settings for the Noncontact Holmium:YAG Stone Fragmentation Popcorn Technique.

PubMed

Emiliani, Esteban; Talso, Michele; Cho, Sung-Yong; Baghdadi, Mohammed; Mahmoud, Sadam; Pinheiro, Hugo; Traxer, Olivier

2017-09-01

The purpose of this study was to evaluate the popcorn technique using a wide range of holmium laser settings and fiber sizes in a systematic in vitro assessment. Evaluations were done with 4 artificial stones in a collection tube. A fixed ureteroscope was inserted through a ureteral access sheath to provide constant irrigation flow and the laser was placed 1 mm from the bottom. Combinations of 0.5 to 1.5 J, 10 to 20 and 40 Hz, and long and short pulses were tested for 2 and 4 minutes. We used 273 and 365 μm laser fibers. All tests were repeated 3 times. The stones were weighed before and after the experiments to evaluate the setting efficiency. Significant predictors of a highly efficient technique were assessed. A total of 144 tests were performed. Mean starting weight of the stones was 0.23 gm, which was consistent among the groups. After the experiment the median weight difference was 0.07 gm (range 0.01 to 0.24). When designating a 50% reduction in stone volume as the threshold indicating high efficiency, the significant predictors of an efficient popcorn technique were a long pulse (OR 2.7, 95% CI 1.05-7.15), a longer duration (OR 11.4, 95% CI 3.88-33.29), a small (273 μm) laser fiber (OR 0.23, 95% CI 0.08-0.70) and higher power (W) (OR 1.14, 95% CI 1.09-1.20). Higher energy, a longer pulse, frequencies higher than 10 Hz, a longer duration and a smaller laser fiber predict a popcorn technique that is more efficient at reducing stone volume. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Gadolinium embedded iron oxide nanoclusters as T1-T2 dual-modal MRI-visible vectors for safe and efficient siRNA delivery

NASA Astrophysics Data System (ADS)

Wang, Xiaoyong; Zhou, Zijian; Wang, Zhiyong; Xue, Yunxin; Zeng, Yun; Gao, Jinhao; Zhu, Lei; Zhang, Xianzhong; Liu, Gang; Chen, Xiaoyuan

2013-08-01

This report illustrates a new strategy of designing a T1-T2 dual-modal magnetic resonance imaging (MRI)-visible vector for siRNA delivery and MRI. Hydrophobic gadolinium embedded iron oxide (GdIO) nanocrystals are self-assembled into nanoclusters in the water phase with the help of stearic acid modified low molecular weight polyethylenimine (stPEI). The resulting water-dispersible GdIO-stPEI nanoclusters possess good stability, monodispersity with narrow size distribution and competitive T1-T2 dual-modal MR imaging properties. The nanocomposite system is capable of binding and delivering siRNA for knockdown of a gene of interest while maintaining its magnetic properties and biocompatibility. This new gadolinium embedded iron oxide nanocluster provides an important platform for safe and efficient gene delivery with non-invasive T1-T2 dual-modal MRI monitoring capability.This report illustrates a new strategy of designing a T1-T2 dual-modal magnetic resonance imaging (MRI)-visible vector for siRNA delivery and MRI. Hydrophobic gadolinium embedded iron oxide (GdIO) nanocrystals are self-assembled into nanoclusters in the water phase with the help of stearic acid modified low molecular weight polyethylenimine (stPEI). The resulting water-dispersible GdIO-stPEI nanoclusters possess good stability, monodispersity with narrow size distribution and competitive T1-T2 dual-modal MR imaging properties. The nanocomposite system is capable of binding and delivering siRNA for knockdown of a gene of interest while maintaining its magnetic properties and biocompatibility. This new gadolinium embedded iron oxide nanocluster provides an important platform for safe and efficient gene delivery with non-invasive T1-T2 dual-modal MRI monitoring capability. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr02797j

Tracking the behavior of different size fractions of dissolved organic matter in a full-scale advanced drinking water treatment plant.

PubMed

Quang, Viet Ly; Choi, Ilhwan; Hur, Jin

2015-11-01

In this study, five different dissolved organic matter (DOM) fractions, defined based on a size exclusion chromatography with simultaneous detection of organic carbon (OCD) and ultraviolet (UVD), were quantitatively tracked with a treatment train of coagulation/flocculation-sand filtration-ozonation-granular activated carbon (GAC) filtration in a full-scale advanced drinking water treatment plant (DWTP). Five DOM samples including raw water were taken after each treatment process in the DWTP every month over the period of three years. A higher abundance of biopolymer (BP) fraction was found in the raw water during spring and winter than in the other seasons, suggesting an influence of algal bloom and/or meltwater on DOM composition. The greater extent of removal was observed upon the coagulation/flocculation for high-molecular-weight fractions including BP and humic substances (HS) and aromatic moieties, while lower sized fractions were preferentially removed by the GAC filtration. Ozone treatment produced the fraction of low-molecular-weight neutrals probably resulting from the breakdown of double-bonded carbon structures by ozone oxidation. Coagulation/flocculation was the only process that revealed significant effects of influent DOM composition on the treatment efficiency, as revealed by a high correlation between the DOM removal rate and the relative abundance of HS for the raw water. Our study demonstrated that SEC-OCD-UVD was successful in monitoring size-based DOM composition for the advanced DWTP, providing an insight into optimizing the treatment options and the operational conditions for the removal of particular fractions within the bulk DOM.

Grouping methods for estimating the prevalences of rare traits from complex survey data that preserve confidentiality of respondents.

PubMed

Hyun, Noorie; Gastwirth, Joseph L; Graubard, Barry I

2018-03-26

Originally, 2-stage group testing was developed for efficiently screening individuals for a disease. In response to the HIV/AIDS epidemic, 1-stage group testing was adopted for estimating prevalences of a single or multiple traits from testing groups of size q, so individuals were not tested. This paper extends the methodology of 1-stage group testing to surveys with sample weighted complex multistage-cluster designs. Sample weighted-generalized estimating equations are used to estimate the prevalences of categorical traits while accounting for the error rates inherent in the tests. Two difficulties arise when using group testing in complex samples: (1) How does one weight the results of the test on each group as the sample weights will differ among observations in the same group. Furthermore, if the sample weights are related to positivity of the diagnostic test, then group-level weighting is needed to reduce bias in the prevalence estimation; (2) How does one form groups that will allow accurate estimation of the standard errors of prevalence estimates under multistage-cluster sampling allowing for intracluster correlation of the test results. We study 5 different grouping methods to address the weighting and cluster sampling aspects of complex designed samples. Finite sample properties of the estimators of prevalences, variances, and confidence interval coverage for these grouping methods are studied using simulations. National Health and Nutrition Examination Survey data are used to illustrate the methods. Copyright © 2018 John Wiley & Sons, Ltd.

Fuel Economy Regulations and Efficiency Technology Improvements in U.S. Cars Since 1975

NASA Astrophysics Data System (ADS)

MacKenzie, Donald Warren

Light-duty vehicles account for 43% of petroleum consumption and 23% of greenhouse gas emissions in the United States. Corporate Average Fuel Economy (CAFE) standards are the primary policy tool addressing petroleum consumption in the U.S., and are set to tighten substantially through 2025. In this dissertation, I address several interconnected questions on the technical, policy, and market aspects of fuel consumption reduction. I begin by quantifying historic improvements in fuel efficiency technologies since the 1970s. First. I develop a linear regression model of acceleration performance conditional on power, weight, powertrain, and body characteristics, showing that vehicles today accelerate 20-30% faster than vehicles with similar specifications in the 1970s. Second, I find that growing use of alternative materials and a switch to more weight-efficient vehicle architectures since 1975 have cut the weight of today's new cars by approximately 790 kg (46%). Integrating these results with model-level specification data, I estimate that the average fuel economy of new cars could have tripled from 1975-2009, if not for changes in performance, size, and features over this period. The pace of improvements was not uniform, averaging 5% annually from 1975-1990, but only 2% annually since then. I conclude that the 2025 standards can be met through improvements in efficiency technology, if we can return to 1980s rates of improvement, and growth in acceleration performance and feature content is curtailed. I next test the hypotheses that higher fuel prices and more stringent CAFE standards cause automotive firms to deploy efficiency technologies more rapidly. I find some evidence that higher fuel prices cause more rapid changes in technology, but little to no evidence that tighter CAFE standards increase rates of technology change. I conclude that standards alone, without continued high gasoline prices, may not drive technology improvements at rates needed to meet the 2025 CAFE standards factors determining industry support for nationwide fuel economy regulations. (Copies available exclusively from MIT Libraries, libraries.mit.edu/docs - docs@mit.edu)

Micellization and Single-Particle Encapsulation with Dimethylammoniopropyl Sulfobetaines

PubMed Central

2017-01-01

Sulfobetaines (SBs) are a class of zwitterionic surfactants with a reputation for enhancing colloidal stability at high salt concentrations. Here, we present a systematic study on the self-assembly of SB amphiphiles (sultaines or hydroxysultaines) in aqueous solutions, as a function of chain length and composition, ionic strength, and in the presence of alkanethiol-coated Au nanoparticles (GNPs). The diameters of the micelles assembled from SB and amidosulfobetaine (ASB) generally increase monotonically with chain length, although ASB micelles are smaller relative to alkyl SB micelles with similarly sized tailgroups, and oleyl sulfobetaine (OSB) micelles are slightly larger. SB amphiphiles can stabilize alkanethiol-coated GNPs in physiologically relevant buffers at concentrations well below their CMC, with size increases corresponding to single-particle encapsulation. SB-encapsulated GNPs were prepared by three different methods with SB:GNP weight ratios of 10:1, followed by dispersion in water or 1 M NaCl. The low hydrodynamic size of the SB micelles and SB-coated NPs is within the range needed for efficient renal clearance. PMID:28474008

Micellization and Single-Particle Encapsulation with Dimethylammoniopropyl Sulfobetaines.

PubMed

Wang, Jianxin; Morales-Collazo, Oscar; Wei, Alexander

2017-04-30

Sulfobetaines (SBs) are a class of zwitterionic surfactants with a reputation for enhancing colloidal stability at high salt concentrations. Here, we present a systematic study on the self-assembly of SB amphiphiles (sultaines or hydroxysultaines) in aqueous solutions, as a function of chain length and composition, ionic strength, and in the presence of alkanethiol-coated Au nanoparticles (GNPs). The diameters of the micelles assembled from SB and amidosulfobetaine (ASB) generally increase monotonically with chain length, although ASB micelles are smaller relative to alkyl SB micelles with similarly sized tailgroups, and oleyl sulfobetaine (OSB) micelles are slightly larger. SB amphiphiles can stabilize alkanethiol-coated GNPs in physiologically relevant buffers at concentrations well below their CMC, with size increases corresponding to single-particle encapsulation. SB-encapsulated GNPs were prepared by three different methods with SB:GNP weight ratios of 10:1, followed by dispersion in water or 1 M NaCl. The low hydrodynamic size of the SB micelles and SB-coated NPs is within the range needed for efficient renal clearance.

Preparation of polycaprolactone nanoparticles via supercritical carbon dioxide extraction of emulsions.

PubMed

Ajiboye, Adejumoke Lara; Trivedi, Vivek; Mitchell, John C

2017-08-21

Polycaprolactone (PCL) nanoparticles were produced via supercritical fluid extraction of emulsions (SFEE) using supercritical carbon dioxide (scCO 2 ). The efficiency of the scCO 2 extraction was investigated and compared to that of solvent extraction at atmospheric pressure. The effects of process parameters including polymer concentration (0.6-10% w/w in acetone), surfactant concentration (0.07 and 0.14% w/w) and polymer-to-surfactant weight ratio (1:1-16:1 w/w) on the particle size and surface morphology were also investigated. Spherical PCL nanoparticles with mean particle sizes between 190 and 350 nm were obtained depending on the polymer concentration, which was the most important factor where increase in the particle size was directly related to total polymer content in the formulation. Nanoparticles produced were analysed using dynamic light scattering and scanning electron microscopy. The results indicated that SFEE can be applied for the preparation of PCL nanoparticles without agglomeration and in a comparatively short duration of only 1 h.

SlimCS—compact low aspect ratio DEMO reactor with reduced-size central solenoid

NASA Astrophysics Data System (ADS)

Tobita, K.; Nishio, S.; Sato, M.; Sakurai, S.; Hayashi, T.; Shibama, Y. K.; Isono, T.; Enoeda, M.; Nakamura, H.; Sato, S.; Ezato, K.; Hayashi, T.; Hirose, T.; Ide, S.; Inoue, T.; Kamada, Y.; Kawamura, Y.; Kawashima, H.; Koizumi, N.; Kurita, G.; Nakamura, Y.; Mouri, K.; Nishitani, T.; Ohmori, J.; Oyama, N.; Sakamoto, K.; Suzuki, S.; Suzuki, T.; Tanigawa, H.; Tsuchiya, K.; Tsuru, D.

2007-08-01

The concept for a compact DEMO reactor named 'SlimCS' is presented. Distinctive features of the concept are low aspect ratio (A = 2.6) and use of a reduced-size centre solenoid (CS) which has the function of plasma shaping rather than poloidal flux supply. The reduced-size CS enables us to introduce a thin toroidal field coil system which contributes to reducing the weight and perhaps lessening the construction cost. Low-A has merits of vertical stability for high elongation (κ) and high normalized beta (βN), which leads to a high power density with reasonable physics requirements. This is because high κ facilitates high nGW (because of an increase in Ip), which allows efficient use of the capacity of high βN. From an engineering aspect, low-A may ensure ease in designing blanket modules robust to electromagnetic forces acting on disruptions. Thus, a superconducting low-A tokamak reactor such as SlimCS can be a promising DEMO concept with physics and engineering advantages.

High temperature semiconductor diode laser pumps for high energy laser applications

NASA Astrophysics Data System (ADS)

Campbell, Jenna; Semenic, Tadej; Guinn, Keith; Leisher, Paul O.; Bhunia, Avijit; Mashanovitch, Milan; Renner, Daniel

2018-02-01

Existing thermal management technologies for diode laser pumps place a significant load on the size, weight and power consumption of High Power Solid State and Fiber Laser systems, thus making current laser systems very large, heavy, and inefficient in many important practical applications. To mitigate this thermal management burden, it is desirable for diode pumps to operate efficiently at high heat sink temperatures. In this work, we have developed a scalable cooling architecture, based on jet-impingement technology with industrial coolant, for efficient cooling of diode laser bars. We have demonstrated 60% electrical-to-optical efficiency from a 9xx nm two-bar laser stack operating with propylene-glycolwater coolant, at 50 °C coolant temperature. To our knowledge, this is the highest efficiency achieved from a diode stack using 50 °C industrial fluid coolant. The output power is greater than 100 W per bar. Stacks with additional laser bars are currently in development, as this cooler architecture is scalable to a 1 kW system. This work will enable compact and robust fiber-coupled diode pump modules for high energy laser applications.

Feeding damage to plants increases with plant size across 21 Brassicaceae species.

PubMed

Schlinkert, Hella; Westphal, Catrin; Clough, Yann; Ludwig, Martin; Kabouw, Patrick; Tscharntke, Teja

2015-10-01

Plant size is a major predictor of ecological functioning. We tested the hypothesis that feeding damage to plants increases with plant size, as the conspicuousness of large plants makes resource finding and colonisation easier. Further, large plants can be attractive to herbivores, as they offer greater amounts and ranges of resources and niches, but direct evidence from experiments testing size effects on feeding damage and consequently on plant fitness is so far missing. We established a common garden experiment with a plant size gradient (10-130 cm height) using 21 annual Brassicaceae species, and quantified plant size, biomass and number of all aboveground components (flowers, fruits, leaves, stems) and their proportional feeding damage. Plant reproductive fitness was measured using seed number, 1000 seed weight and total seed weight. Feeding damage to the different plant components increased with plant size or component biomass, with mean damage levels being approximately 30 % for flowers, 5 % for fruits and 1 % for leaves and stems. Feeding damage affected plant reproductive fitness depending on feeding damage type, with flower damage having the strongest effect, shown by greatly reduced seed number, 1000 seed weight and total seed weight. Finally, we found an overall negative effect of plant size on 1000 seed weight, but not on seed number and total seed weight. In conclusion, being conspicuous and attractive to herbivores causes greater flower damage leading to higher fitness costs for large plants, which might be partly counterbalanced by benefits such as enhanced competitive/compensatory abilities or more mutualistic pollinator visits.

Metabolic adaptation to weight loss: implications for the athlete

PubMed Central

2014-01-01

Optimized body composition provides a competitive advantage in a variety of sports. Weight reduction is common among athletes aiming to improve their strength-to-mass ratio, locomotive efficiency, or aesthetic appearance. Energy restriction is accompanied by changes in circulating hormones, mitochondrial efficiency, and energy expenditure that serve to minimize the energy deficit, attenuate weight loss, and promote weight regain. The current article reviews the metabolic adaptations observed with weight reduction and provides recommendations for successful weight reduction and long term reduced-weight maintenance in athletes. PMID:24571926

Economic evaluation of alternative crossbreeding systems involving four breeds of swine. I. The simulation model.

PubMed

McLaren, D G; Buchanan, D S; Williams, J E

1987-10-01

A static, deterministic computer model, programmed in Microsoft Basic for IBM PC and Apple Macintosh computers, was developed to calculate production efficiency (cost per kg of product) for nine alternative types of crossbreeding system involving four breeds of swine. The model simulates efficiencies for four purebred and 60 alternative two-, three- and four-breed rotation, rotaterminal, backcross and static cross systems. Crossbreeding systems were defined as including all purebred, crossbred and commercial matings necessary to maintain a total of 10,000 farrowings. Driving variables for the model are mean conception rate at first service and for an 8-wk breeding season, litter size born, preweaning survival rate, postweaning average daily gain, feed-to-gain ratio and carcass backfat. Predictions are computed using breed direct genetic and maternal effects for the four breeds, plus individual, maternal and paternal specific heterosis values, input by the user. Inputs required to calculate the number of females farrowing in each sub-system include the proportion of males and females replaced each breeding cycle in purebred and crossbred populations, the proportion of male and female offspring in seedstock herds that become breeding animals, and the number of females per boar. Inputs required to calculate the efficiency of terminal production (cost-to-product ratio) for each sub-system include breeding herd feed intake, gilt development costs, feed costs and labor and overhead costs. Crossbreeding system efficiency is calculated as the weighted average of sub-system cost-to-product ratio values, weighting by the number of females farrowing in each sub-system.

Ceramic heat pipe wick

NASA Technical Reports Server (NTRS)

Seidenberg, Benjamin (Inventor); Swanson, Theodore (Inventor)

1989-01-01

A wick for use in a capillary loop pump heat pipe is disclosed. The wick material is an essentially uniformly porous, permeable, open-cell, silicon dioxide/aluminum oxide inorganic ceramic foam having a silica fiber ratio, by weight, of about 78 to 22, respectively, a density of 6 lbs/cu ft, and an average pore size of less than 5 microns. A representative material having these characteristics is Lockheed Missile and Space Company, Inc.'s HTP 6-22. This material is fully compatible with the freons and anhydrous ammonia and allows for the use of these very efficient working fluids, and others, in capillary loops.

Metal band drives in spacecraft mechanisms

NASA Technical Reports Server (NTRS)

Maus, Daryl

1993-01-01

Transmitting and changing the characteristics of force and stroke is a requirement in nearly all mechanisms. Examples include changing linear to rotary motion, providing a 90 deg change in direction, and amplifying stroke or force. Requirements for size, weight, efficiency and reliability create unique problems in spacecraft mechanisms. Flexible metal band and cam drive systems provide powerful solutions to these problems. Band drives, rack and pinion gears, and bell cranks are compared for effectiveness. Band drive issues are discussed including materials, bend radius, fabrication, attachment and reliability. Numerous mechanisms are shown which illustrate practical applications of band drives.

An improved waste collection system for space flight

NASA Technical Reports Server (NTRS)

Thornton, William E.; Lofland, William W., Jr.; Whitmore, Henry

1986-01-01

Waste collection systems are a critical part of manned space flight. Systems to date have had a number of deficiencies. A new system, which uses a simple mechanical piston compactor and disposable pads allows a clean area for defecation and maximum efficiency of waste collection and storage. The concept has been extensively tested. Flight demonstration units are being built, tested, and scheduled for flight. A prototype operational unit is under construction. This system offers several advantages over existing or planned systems in the areas of crew interface and operation, cost, size, weight, and maintenance and power consumption.

Effects of ration size on preferred temperature of lake charr Salvelinus namaycush

USGS Publications Warehouse

Mac, Michael J.

1985-01-01

I tested the effects of different ration sizes on preferred temperatures of yearling lake charr,Salvelinus namaycush, by feeding them for about 2 weeks on one of four rations and then allowing them to thermoregulate in a temporal thermal gradient for 2 to 3 days. Selected temperatures and ration were directly and linearly correlated: the larger the ration, the higher the temperature selected. Mean preferred temperatures at different rations (shown in parentheses as percent of body weight per day) were as follows: 9.2°C (0.3); 10.6°C (0.8); 11.7°C (2.0); and 12.6°C (5.5). While the shift to lower temperature, under restricted ration, would maximize food conversion efficiency, previous growth studies indicate that even lower selected temperature would have been more beneficial.

HASA: Hypersonic Aerospace Sizing Analysis for the Preliminary Design of Aerospace Vehicles

NASA Technical Reports Server (NTRS)

Harloff, Gary J.; Berkowitz, Brian M.

1988-01-01

A review of the hypersonic literature indicated that a general weight and sizing analysis was not available for hypersonic orbital, transport, and fighter vehicles. The objective here is to develop such a method for the preliminary design of aerospace vehicles. This report describes the developed methodology and provides examples to illustrate the model, entitled the Hypersonic Aerospace Sizing Analysis (HASA). It can be used to predict the size and weight of hypersonic single-stage and two-stage-to-orbit vehicles and transports, and is also relevant for supersonic transports. HASA is a sizing analysis that determines vehicle length and volume, consistent with body, fuel, structural, and payload weights. The vehicle component weights are obtained from statistical equations for the body, wing, tail, thermal protection system, landing gear, thrust structure, engine, fuel tank, hydraulic system, avionics, electral system, equipment payload, and propellant. Sample size and weight predictions are given for the Space Shuttle orbiter and other proposed vehicles, including four hypersonic transports, a Mach 6 fighter, a supersonic transport (SST), a single-stage-to-orbit (SSTO) vehicle, a two-stage Space Shuttle with a booster and an orbiter, and two methane-fueled vehicles.

Body image, body dissatisfaction and weight status in South Asian children: a cross-sectional study.

PubMed

Pallan, Miranda J; Hiam, Lucinda C; Duda, Joan L; Adab, Peymane

2011-01-09

Childhood obesity is a continuing problem in the UK and South Asian children represent a group that are particularly vulnerable to its health consequences. The relationship between body dissatisfaction and obesity is well documented in older children and adults, but is less clear in young children, particularly South Asians. A better understanding of this relationship in young South Asian children will inform the design and delivery of obesity intervention programmes. The aim of this study is to describe body image size perception and dissatisfaction, and their relationship to weight status in primary school aged UK South Asian children. Objective measures of height and weight were undertaken on 574 predominantly South Asian children aged 5-7 (296 boys and 278 girls). BMI z-scores, and weight status (underweight, healthy weight, overweight or obese) were calculated based on the UK 1990 BMI reference charts. Figure rating scales were used to assess perceived body image size (asking children to identify their perceived body size) and dissatisfaction (difference between perceived current and ideal body size). The relationship between these and weight status were examined using multivariate analyses. Perceived body image size was positively associated with weight status (partial regression coefficient for overweight/obese vs. non-overweight/obese was 0.63 (95% CI 0.26-0.99) and for BMI z-score was 0.21 (95% CI 0.10-0.31), adjusted for sex, age and ethnicity). Body dissatisfaction was also associated with weight status, with overweight and obese children more likely to select thinner ideal body size than healthy weight children (adjusted partial regression coefficient for overweight/obese vs. non-overweight/obese was 1.47 (95% CI 0.99-1.96) and for BMI z-score was 0.54 (95% CI 0.40-0.67)). Awareness of body image size and increasing body dissatisfaction with higher weight status is established at a young age in this population. This needs to be considered when designing interventions to reduce obesity in young children, in terms of both benefits and harms.

Body image, body dissatisfaction and weight status in south asian children: a cross-sectional study

PubMed Central

2011-01-01

Background Childhood obesity is a continuing problem in the UK and South Asian children represent a group that are particularly vulnerable to its health consequences. The relationship between body dissatisfaction and obesity is well documented in older children and adults, but is less clear in young children, particularly South Asians. A better understanding of this relationship in young South Asian children will inform the design and delivery of obesity intervention programmes. The aim of this study is to describe body image size perception and dissatisfaction, and their relationship to weight status in primary school aged UK South Asian children. Methods Objective measures of height and weight were undertaken on 574 predominantly South Asian children aged 5-7 (296 boys and 278 girls). BMI z-scores, and weight status (underweight, healthy weight, overweight or obese) were calculated based on the UK 1990 BMI reference charts. Figure rating scales were used to assess perceived body image size (asking children to identify their perceived body size) and dissatisfaction (difference between perceived current and ideal body size). The relationship between these and weight status were examined using multivariate analyses. Results Perceived body image size was positively associated with weight status (partial regression coefficient for overweight/obese vs. non-overweight/obese was 0.63 (95% CI 0.26-0.99) and for BMI z-score was 0.21 (95% CI 0.10-0.31), adjusted for sex, age and ethnicity). Body dissatisfaction was also associated with weight status, with overweight and obese children more likely to select thinner ideal body size than healthy weight children (adjusted partial regression coefficient for overweight/obese vs. non-overweight/obese was 1.47 (95% CI 0.99-1.96) and for BMI z-score was 0.54 (95% CI 0.40-0.67)). Conclusions Awareness of body image size and increasing body dissatisfaction with higher weight status is established at a young age in this population. This needs to be considered when designing interventions to reduce obesity in young children, in terms of both benefits and harms. PMID:21214956

Evaluation of the Multi-Chambered Treatment Train, a retrofit water-quality management device

USGS Publications Warehouse

Corsi, Steven R.; Greb, Steven R.; Bannerman, Roger T.; Pitt, Robert E.

1999-01-01

This paper presents the results of an evaluation of the benefits and efficiencies of a device called the Multi-Chambered Treatment Train (MCTT), which was installed below the pavement surface at a municipal maintenance garage and parking facility in Milwaukee, Wisconsin. Flow-weighted water samples were collected at the inlet and outlet of the device during 15 storms, and the efficiency of the device was based on reductions in the loads of 68 chemical constituents and organic compounds. High reduction efficiencies were achieved for all particulate-associated constituents, including total suspended solids (98 percent), total phosphorus (88 percent), and total recoverable zinc (91 percent). Reduction rates for dissolved fractions of the constituents were substantial, but somewhat lower (dissolved solids, 13 percent; dissolved phosphorus, 78 percent; dissolved zinc, 68 percent). The total dissolved solids load, which originated from road salt storage, was more than four times the total suspended solids load. No appreciable difference was detected between particle-size distributions in inflow and outflow samples.

Multidisciplinary optimization of aeroservoelastic systems using reduced-size models

NASA Technical Reports Server (NTRS)

Karpel, Mordechay

1992-01-01

Efficient analytical and computational tools for simultaneous optimal design of the structural and control components of aeroservoelastic systems are presented. The optimization objective is to achieve aircraft performance requirements and sufficient flutter and control stability margins with a minimal weight penalty and without violating the design constraints. Analytical sensitivity derivatives facilitate an efficient optimization process which allows a relatively large number of design variables. Standard finite element and unsteady aerodynamic routines are used to construct a modal data base. Minimum State aerodynamic approximations and dynamic residualization methods are used to construct a high accuracy, low order aeroservoelastic model. Sensitivity derivatives of flutter dynamic pressure, control stability margins and control effectiveness with respect to structural and control design variables are presented. The performance requirements are utilized by equality constraints which affect the sensitivity derivatives. A gradient-based optimization algorithm is used to minimize an overall cost function. A realistic numerical example of a composite wing with four controls is used to demonstrate the modeling technique, the optimization process, and their accuracy and efficiency.

One-pot green synthesis of doxorubicin loaded-silica nanoparticles for in vivo cancer therapy.

PubMed

Jiang, Shan; Hua, Li; Guo, Zilong; Sun, Lin

2018-09-01

The present work reveals a new and simple one-pot green method to load doxorubicin (DOX) drugs in silica nanoparticles for efficient in vivo cancer therapy. The synthesis of DOX loaded silica nanoparticles (SiNPs/DOX) is based on the efficient encapsulation of DOX in surfactant Tween 80 micelles which act as a template for the formation of silica nanoparticles. The release profile, cellular uptake behavior, cytotoxicity and antitumor effect of SiNPs/DOX nanoparticles were investigated and compared to free DOX. The silica nanoparticles improved the cellular drug delivery efficiency and exhibited high cytotoxicity, successfully achieving the inhibition of tumor growth. Notably, the tumor size and weight of SiNPs/DOX group was 2-fold and 1.7-fold smaller than that of free DOX group, and 4-fold and 2-fold smaller than that of PBS group. The one-pot green synthesis system may have the potential to be developed as a promising drug delivery system. Copyright © 2018 Elsevier B.V. All rights reserved.

Meal size is a critical driver of weight gain in early childhood.

PubMed

Syrad, Hayley; Llewellyn, Clare H; Johnson, Laura; Boniface, David; Jebb, Susan A; van Jaarsveld, Cornelia H M; Wardle, Jane

2016-06-20

Larger serving sizes and more frequent eating episodes have been implicated in the rising prevalence of obesity at a population level. This study examines the relative contributions of meal size and frequency to weight gain in a large sample of British children. Using 3-day diet diaries from 1939 children aged 21 months from the Gemini twin cohort, we assessed prospective associations between meal size, meal frequency and weight gain from two to five years. Separate longitudinal analyses demonstrated that every 10 kcal increase in meal size was associated with 1.5 g/wk or 4% (p = 0.005) faster growth rate, while meal frequency was not independently associated with growth (β = 0.3 g/wk p = 0.20). Including both meal parameters in the model strengthened associations (meal size: β = 2.6 g/wk, p < 0.001; meal frequency: β = 1.0 g/wk, p = 0.001). Taken together, the implication is that meal size promotes faster growth regardless of frequency, but meal frequency has a significant effect only if meal size is assumed to be held constant. Clearer advice on meal size and frequency, especially advice on appropriate meal size, may help prevent excess weight gain.

Macrofaunal involvement in the sublittoral decay of kelp debris: The sea urchin Psammechinus miliaris (Gmelin) (Echinodermata: Echinoidea)

NASA Astrophysics Data System (ADS)

Bedford, A. P.; Moore, P. G.

1985-01-01

Psammechinus miliaris occurs in the Clyde Sea area in large numbers (<18 individuals per 100 g -1 weed dry wt) on sublittoral beds of detached Laminaria saccharina. Its rôle in weed decomposition has been examined by comparing its responses (behavioural choice, growth rate, absorption efficiencies of both carbon and protein, gut retention times and rate of faecal output) to fresh and rotting weed. Younger urchins grew faster than older individuals on a diet of rotting weed but not on fresh weed. Large seasonal variation existed, however, with fast growth occurring in June-August and little, or no, growth in December-February, irrespective of diet. Starved controls did not grow. Correcting for seasonality, rotting kelp still promoted faster growth of young urchins than did fresh weed. Larger (older) individuals showed no difference. Urchins fed fresh weed had significantly longer gut retention times. Protein absorption efficiency was higher on fresh than rotting weed, varying with weed protein content and size of urchin. Very young individuals can only digest high protein weed efficiently, eg. material derived from near the frond meristem. Organic carbon content of rotting weed was significantly lower than fresh weed. Carbon absorption efficiencies were significantly higher on fresh weed which related to organic carbon content. Standard-sized urchins fed rotting weed produced larger dry weights of faeces per day, reflecting increased ingestion rate. In closed-system choice experiments urchins preferred rotting weed kinetically. Size-frequency analysis of field populations suggested that weed beds are principally colonized by larval settlement from the plankton. Mature Psammechinus have evolved different 'strategies' for exploiting fresh and rotting weed. Fresh weed is relatively difficult to digest and long gut retention times allow high protein absorption efficiencies to be attained. Rotting weed has microbial protein in quantities and a lower organic carbon fraction. Some bacterial protein is seemingly unavailable though and lower protein absorption efficiencies result. Thus gut retention time is shortened and more food passed through the gut. Growth remains equivalent. Substratum digestion is of paramount importance for Psammechinus feeding on either fresh or rotting weed, cf. the 'classical' microbe-stripping detritivore of Fenchel.

Relationships between media use, body fatness and physical activity in children and youth: a meta-analysis.

PubMed

Marshall, S J; Biddle, S J H; Gorely, T; Cameron, N; Murdey, I

2004-10-01

To review the empirical evidence of associations between television (TV) viewing, video/computer game use and (a) body fatness, and (b) physical activity. Meta-analysis. Published English-language studies were located from computerized literature searches, bibliographies of primary studies and narrative reviews, and manual searches of personal archives. Included studies presented at least one empirical association between TV viewing, video/computer game use and body fatness or physical activity among samples of children and youth aged 3-18 y. The mean sample-weighted corrected effect size (Pearson r). Based on data from 52 independent samples, the mean sample-weighted effect size between TV viewing and body fatness was 0.066 (95% CI=0.056-0.078; total N=44,707). The sample-weighted fully corrected effect size was 0.084. Based on data from six independent samples, the mean sample-weighted effect size between video/computer game use and body fatness was 0.070 (95% CI=-0.048 to 0.188; total N=1,722). The sample-weighted fully corrected effect size was 0.128. Based on data from 39 independent samples, the mean sample-weighted effect size between TV viewing and physical activity was -0.096 (95% CI=-0.080 to -0.112; total N=141,505). The sample-weighted fully corrected effect size was -0.129. Based on data from 10 independent samples, the mean sample-weighted effect size between video/computer game use and physical activity was -0.104 (95% CI=-0.080 to -0.128; total N=119,942). The sample-weighted fully corrected effect size was -0.141. A statistically significant relationship exists between TV viewing and body fatness among children and youth although it is likely to be too small to be of substantial clinical relevance. The relationship between TV viewing and physical activity is small but negative. The strength of these relationships remains virtually unchanged even after correcting for common sources of bias known to impact study outcomes. While the total amount of time per day engaged in sedentary behavior is inevitably prohibitive of physical activity, media-based inactivity may be unfairly implicated in recent epidemiologic trends of overweight and obesity among children and youth. Relationships between sedentary behavior and health are unlikely to be explained using single markers of inactivity, such as TV viewing or video/computer game use.

78 FR 76888 - MAP-21 Comprehensive Truck Size and Weight Limits Study Materials

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-19

... Weight Limits Study Materials AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice of...) Comprehensive Truck Size and Weight Limits Study, which were referenced in a notice published on November 29... commenting additional time to submit comments while maintaining the schedule required to deliver this study...

A Dual Polarization, Active, Microstrip Antenna for an Orbital Imaging Radar System Operating at L-Band

NASA Technical Reports Server (NTRS)

Kelly, Kenneth C.; Huang, John

1999-01-01

A highly successful Earth orbiting synthetic antenna aperture radar (SAR) system, known as the SIR-C mission, was carried into orbit in 1994 on a U.S. Shuttle (Space Transportation System) mission. The radar system was mounted in the cargo bay with no need to fold, or in any other way reduce the size of the antennas for launch. Weight and size were not limited for the L-Band, C-Band, and X-Band radar systems of the SIR-C radar imaging mission; the set of antennas weighed 10,500 kg, the L-Band antenna having the major share of the weight. This paper treats designing an L-Band antenna functionally similar to that used for SIR-C, but at a fraction of the cost and at a weight in the order of 250 kg. Further, the antenna must be folded to fit into the small payload shroud of low cost booster rocket systems. Over 31 square meters of antenna area is required. This low weight, foldable, electronic scanning antenna is for the proposed LightSAR radar system which is to be placed in Earth orbit on a small, dedicated space craft at the lowest possible cost for an efficient L-Band radar imaging system. This LightSAR spacecraft radar is to be continuously available for at least five operational years, and have the ability to map or repeat-map any area on earth within a few days of any request. A microstrip patch array, with microstrip transmission lines heavily employed in the aperture and in the corporate feed network, was chosen as the low cost approach for this active dual-polarization, 80 MHz (6.4%) bandwidth antenna design.

A Dual Polarization, Active, Microstrip Antenna for an Orbital Imaging Radar System Operating at L-Band

NASA Technical Reports Server (NTRS)

Kelly, Kenneth C.; Huang, John

2000-01-01

A highly successful Earth orbiting synthetic antenna aperture radar (SAR) system, known as the SIR-C mission, was carried into orbit in 1994 on a U.S. Shuttle (Space Transportation System) mission. The radar system was mounted in the cargo bay with no need to fold, or in any other way reduce the size of the antennas for launch. Weight and size were not limited for the L-Band, C-Band, and X-Band radar systems of the SIR-C radar imaging mission; the set of antennas weighed 10,500 kg, the L-Band antenna having the major share of the weight. This paper treats designing an L-Band antenna functionally similar to that used for SIR-C, but at a fraction of the cost and at a weight in the order of 250 kg. Further, the antenna must be folded to fit into the small payload shroud of low cost booster rocket systems. Over 31 square meters of antenna area is required. This low weight, foldable, electronic scanning antenna is for the proposed LightSAR radar system which is to be placed in Earth orbit on a small, dedicated space craft at the lowest possible cost for an efficient L- Band radar imaging system. This LightSAR spacecraft radar is to be continuously available for at least five operational years, and have the ability to map or repeat-map any area on earth within a few days of any request. A microstrip patch array, with microstrip transmission lines heavily employed in the aperture and in the corporate feed network, was chosen as the low cost approach for this active dual-polarization, 80 MHz (6.4%) bandwidth antenna design.

The Use of Steady and Unsteady Detonation Waves for Propulsion Systems

NASA Technical Reports Server (NTRS)

Adelman, Henry G.; Menees, Gene P.; Cambier, Jean-Luc; Bowles, Jeffrey V.; Cavolowsky, John A. (Technical Monitor)

1995-01-01

Detonation wave enhanced supersonic combustors such as the Oblique Detonation Wave Engine (ODWE) are attractive propulsion concepts for hypersonic flight. These engines utilize detonation waves to enhance fuel-air mixing and combustion. The benefits of wave combustion systems include shorter and lighter engines which require less cooling and generate lower internal drag. These features allow air-breathing operation at higher Mach numbers than the diffusive burning scramjet delaying the need for rocket engine augmentation. A comprehensive vehicle synthesis code has predicted the aerodynamic characteristics and structural size and weight of a typical single-stage-to-orbit vehicle using an ODWE. Other studies have focused on the use of unsteady or pulsed detonation waves. For low speed applications, pulsed detonation engines (PDE) have advantages in low weight and higher efficiency than turbojets. At hypersonic speeds, the pulsed detonations can be used in conjunction with a scramjet type engine to enhance mixing and provide thrust augmentation.

Over-the-wing propeller

NASA Technical Reports Server (NTRS)

Johnson, Joseph L., Jr. (Inventor); White, E. Richard (Inventor)

1986-01-01

This invention is an aircraft with a system for increasing the lift drag ratio over a broad range of operating conditions. The system positions the engines and nacelles over the wing in such a position that gains in propeller efficiency is achieved simultaneously with increases in wing lift and a reduction in wing drag. Adverse structural and torsional effects on the wings are avoided by fuselage mounted pylons which attach to the upper portion of the fuselage aft of the wings. Similarly, pylon-wing interference is eliminated by moving the pylons to the fuselage. Further gains are achieved by locating the pylon surface area aft of the aircraft center of gravity, thereby augmenting both directional and longitudinal stability. This augmentation has the further effect of reducing the size, weight and drag of empennage components. The combination of design changes results in improved cruise performance and increased climb performance while reducing fuel consumption and drag and weight penalties.

Optical properties of flexible fluorescent films prepared by screen printing technology

NASA Astrophysics Data System (ADS)

Chen, Yan; Ke, Taiyan; Chen, Shuijin; He, Xin; Zhang, Mei; Li, Dong; Deng, Jinfeng; Zeng, Qingguang

2018-05-01

In this work, we prepared a fluorescent film comprised phosphors and silicone on flexible polyethylene terephthalate (PET) substrate using a screen printing technology. The effects of mesh number and weight ratio of phosphors to silicone on the optical properties of the flexible films were investigated. The results indicate that the emission intensity of the film increase as the mesh decreased from 400 to 200, but the film surface gradually becomes uneven. The fluorescent film with high emission intensity and smooth surface can be obtained when the weight ratio of phosphor to gel is 2:1, and mesh number is 300. The luminous efficiency of the fabricated LEDs combined the fluorescent films with 460 nm Ga(In)N chip module can reach 75 lm/W. The investigation indicates that the approach can be applied in the remote fluorescent film conversion and decreases the requirements of the particle size and the dispersion state of fluorescent materials.

Structural design considerations for a Personnel Launch System

NASA Technical Reports Server (NTRS)

Bush, Lance B.; Lentz, Christopher A.; Robinson, James C.; Macconochie, Ian O.

1990-01-01

A vehicle capable of performing the transfer of eight people to and from the Space Station Freedom is currently in the conceptual/preliminary design stages at the NASA Langley Research Center. Structural definition of this Personnel Launch System (PLS) and the considerations leading to it are described. Issues such as cost, technology level, human factors, and maintainability are used as guidelines for the structural definition. A synergistic design technique involving aerodynamics, performance, mission, packaging, and weights and sizing analyses is utilized to evaluate the structural design. A closed-loop design is achieved when the mission requirements are met by each previously mentioned analysis for a particular vehicle weight. Although satisfactory, the structural concept presented herein is not to be treated as a final answer, but one promising solution. An examination of alternative designs and more detailed analyses can be undertaken in order to identify design inadequacies and more efficient approaches.

Relative efficiency and sample size for cluster randomized trials with variable cluster sizes.

PubMed

You, Zhiying; Williams, O Dale; Aban, Inmaculada; Kabagambe, Edmond Kato; Tiwari, Hemant K; Cutter, Gary

2011-02-01

The statistical power of cluster randomized trials depends on two sample size components, the number of clusters per group and the numbers of individuals within clusters (cluster size). Variable cluster sizes are common and this variation alone may have significant impact on study power. Previous approaches have taken this into account by either adjusting total sample size using a designated design effect or adjusting the number of clusters according to an assessment of the relative efficiency of unequal versus equal cluster sizes. This article defines a relative efficiency of unequal versus equal cluster sizes using noncentrality parameters, investigates properties of this measure, and proposes an approach for adjusting the required sample size accordingly. We focus on comparing two groups with normally distributed outcomes using t-test, and use the noncentrality parameter to define the relative efficiency of unequal versus equal cluster sizes and show that statistical power depends only on this parameter for a given number of clusters. We calculate the sample size required for an unequal cluster sizes trial to have the same power as one with equal cluster sizes. Relative efficiency based on the noncentrality parameter is straightforward to calculate and easy to interpret. It connects the required mean cluster size directly to the required sample size with equal cluster sizes. Consequently, our approach first determines the sample size requirements with equal cluster sizes for a pre-specified study power and then calculates the required mean cluster size while keeping the number of clusters unchanged. Our approach allows adjustment in mean cluster size alone or simultaneous adjustment in mean cluster size and number of clusters, and is a flexible alternative to and a useful complement to existing methods. Comparison indicated that we have defined a relative efficiency that is greater than the relative efficiency in the literature under some conditions. Our measure of relative efficiency might be less than the measure in the literature under some conditions, underestimating the relative efficiency. The relative efficiency of unequal versus equal cluster sizes defined using the noncentrality parameter suggests a sample size approach that is a flexible alternative and a useful complement to existing methods.

Destruction of problematic airborne contaminants by hydrogen reduction using a Catalytically Active, Regenerable Sorbent (CARS)

NASA Technical Reports Server (NTRS)

Thompson, John O.; Akse, James R.

1993-01-01

Thermally regenerable sorbent beds were demonstrated to be a highly efficient means for removal of toxic airborne trace organic contaminants aboard spacecraft. The utilization of the intrinsic weight savings available through this technology was not realized since many of the contaminants desorbed during thermal regeneration are poisons to the catalytic oxidizer or form highly toxic oxidation by-products in the Trace Contaminant Control System (TCCS). Included in this class of compounds are nitrogen, sulfur, silicon, and halogen containing organics. The catalytic reduction of these problematic contaminants using hydrogen at low temperatures (200-300 C) offers an attractive route for their destruction since the by-products of such reactions, hydrocarbons and inorganic gases, are easily removed by existing technology. In addition, the catalytic oxidizer can be operated more efficiently due to the absence of potential poisons, and any posttreatment beds can be reduced in size. The incorporation of the catalyst within the sorbent bed further improves the system's efficiency. The demonstration of this technology provides the basis for an efficient regenerable TCCS for future NASA missions and can be used in more conventional settings to efficiently remove environmental pollutants.

Small and inconsistent effects of whole body vibration on athletic performance: a systematic review and meta-analysis.

PubMed

Hortobágyi, Tibor; Lesinski, Melanie; Fernandez-Del-Olmo, Miguel; Granacher, Urs

2015-08-01

We quantified the acute and chronic effects of whole body vibration on athletic performance or its proxy measures in competitive and/or elite athletes. Systematic literature review and meta-analysis. Whole body vibration combined with exercise had an overall 0.3 % acute effect on maximal voluntary leg force (-6.4 %, effect size = -0.43, 1 study), leg power (4.7 %, weighted mean effect size = 0.30, 6 studies), flexibility (4.6 %, effect size = -0.12 to 0.22, 2 studies), and athletic performance (-1.9 %, weighted mean effect size = 0.26, 6 studies) in 191 (103 male, 88 female) athletes representing eight sports (overall effect size = 0.28). Whole body vibration combined with exercise had an overall 10.2 % chronic effect on maximal voluntary leg force (14.6 %, weighted mean effect size = 0.44, 5 studies), leg power (10.7 %, weighted mean effect size = 0.42, 9 studies), flexibility (16.5 %, effect size = 0.57 to 0.61, 2 studies), and athletic performance (-1.2 %, weighted mean effect size = 0.45, 5 studies) in 437 (169 male, 268 female) athletes (overall effect size = 0.44). Whole body vibration has small and inconsistent acute and chronic effects on athletic performance in competitive and/or elite athletes. These findings lead to the hypothesis that neuromuscular adaptive processes following whole body vibration are not specific enough to enhance athletic performance. Thus, other types of exercise programs (e.g., resistance training) are recommended if the goal is to improve athletic performance.

Fine-mapping of qGW4.05, a major QTL for kernel weight and size in maize.

PubMed

Chen, Lin; Li, Yong-xiang; Li, Chunhui; Wu, Xun; Qin, Weiwei; Li, Xin; Jiao, Fuchao; Zhang, Xiaojing; Zhang, Dengfeng; Shi, Yunsu; Song, Yanchun; Li, Yu; Wang, Tianyu

2016-04-12

Kernel weight and size are important components of grain yield in cereals. Although some information is available concerning the map positions of quantitative trait loci (QTL) for kernel weight and size in maize, little is known about the molecular mechanisms of these QTLs. qGW4.05 is a major QTL that is associated with kernel weight and size in maize. We combined linkage analysis and association mapping to fine-map and identify candidate gene(s) at qGW4.05. QTL qGW4.05 was fine-mapped to a 279.6-kb interval in a segregating population derived from a cross of Huangzaosi with LV28. By combining the results of regional association mapping and linkage analysis, we identified GRMZM2G039934 as a candidate gene responsible for qGW4.05. Candidate gene-based association mapping was conducted using a panel of 184 inbred lines with variable kernel weights and kernel sizes. Six polymorphic sites in the gene GRMZM2G039934 were significantly associated with kernel weight and kernel size. The results of linkage analysis and association mapping revealed that GRMZM2G039934 is the most likely candidate gene for qGW4.05. These results will improve our understanding of the genetic architecture and molecular mechanisms underlying kernel development in maize.

Comparison of known food weights with image-based portion-size automated estimation and adolescents' self-reported portion size.

PubMed

Lee, Christina D; Chae, Junghoon; Schap, TusaRebecca E; Kerr, Deborah A; Delp, Edward J; Ebert, David S; Boushey, Carol J

2012-03-01

Diet is a critical element of diabetes self-management. An emerging area of research is the use of images for dietary records using mobile telephones with embedded cameras. These tools are being designed to reduce user burden and to improve accuracy of portion-size estimation through automation. The objectives of this study were to (1) assess the error of automatically determined portion weights compared to known portion weights of foods and (2) to compare the error between automation and human. Adolescents (n = 15) captured images of their eating occasions over a 24 h period. All foods and beverages served were weighed. Adolescents self-reported portion sizes for one meal. Image analysis was used to estimate portion weights. Data analysis compared known weights, automated weights, and self-reported portions. For the 19 foods, the mean ratio of automated weight estimate to known weight ranged from 0.89 to 4.61, and 9 foods were within 0.80 to 1.20. The largest error was for lettuce and the most accurate was strawberry jam. The children were fairly accurate with portion estimates for two foods (sausage links, toast) using one type of estimation aid and two foods (sausage links, scrambled eggs) using another aid. The automated method was fairly accurate for two foods (sausage links, jam); however, the 95% confidence intervals for the automated estimates were consistently narrower than human estimates. The ability of humans to estimate portion sizes of foods remains a problem and a perceived burden. Errors in automated portion-size estimation can be systematically addressed while minimizing the burden on people. Future applications that take over the burden of these processes may translate to better diabetes self-management. © 2012 Diabetes Technology Society.

Preparation of Robust Metal-Free Magnetic Nanoemulsions Encapsulating Low-Molecular-Weight Nitroxide Radicals and Hydrophobic Drugs Directed Toward MRI-Visible Targeted Delivery.

PubMed

Nagura, Kota; Takemoto, Yusa; Moronaga, Satori; Uchida, Yoshiaki; Shimono, Satoshi; Shiino, Akihiko; Tanigaki, Kenji; Amano, Tsukuru; Yoshino, Fumi; Noda, Yohei; Koizumi, Satoshi; Komatsu, Naoki; Kato, Tatsuhisa; Yamauchi, Jun; Tamura, Rui

2017-11-07

With a view to developing a theranostic nanomedicine for targeted drug delivery systems visible by magnetic resonance (MR) imaging, robust metal-free magnetic nanoemulsions (mean particle size less than 20 nm) consisting of a biocompatible surfactant and hydrophobic, low molecular weight 2,2,5-trimethyl-5-(4-alkoxy)phenylpyrrolidine-N-oxyl radicals were prepared in pH 7.4 phosphate-buffered saline (PBS). The structure of the nanoemulsions was characterized by electron paramagnetic resonance spectroscopy, and dynamic light scattering and small-angle neutron-scattering measurements. The nanoemulsions showed high colloidal stability, low cytotoxicity, enough reduction resistance to excess ascorbic acid, and sufficient contrast enhancement in the proton longitudinal relaxation time (T 1 ) weighted MR images in PBS in vitro (and preliminarily in vivo). Furthermore, the hydrophobic anticancer drug paclitaxel could be encapsulated inside the nanoparticles, and the resulting paclitaxel-loaded nanoemulsions were efficiently incorporated into HeLa cells to suppress cell growth. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multiple-Purpose Subsonic Naval Aircraft (MPSNA) Multiple Application Propfan Study (MAPS)

NASA Technical Reports Server (NTRS)

Winkeljohn, D. M.; Mayrand, C. H.

1986-01-01

A conceptual design study compared a selected propfan-powered aircraft to a turbofan-powered aircraft for multiple Navy carrier-based support missions in the 1995 timeframe. Conventional takeoff and landing (CTOL) propfan and turbofan-powered designs and short takeoff/vertical landing (STOVL) propfan-powered designs are presented. Ten support mission profiles were defined and the aircraft were sized to be able to perform all ten missions. Emphasis was placed on efficient high altitude loiter for Airborne Early Warning (AEW) and low altitude high speed capability for various offensive and tactical support missions. The results of the study show that the propfan-powered designs have lighter gross weights, lower fuel fractions, and equal or greater performance capability than the turbofan-powered designs. Various sensitives were developed in the study, including the effect of using single-rotation versus counter-rotation propfans and the effect of AEW loiter altitude on vehicle gross weight and empty weight. A propfan technology development plan was presented which illustrates that the development of key components can be achieved without accelerated schedules through the extension of current and planned government and civil propfan programs.

Performance of transonic fan stage with weight flow per unit annulus area of 198 kilograms per second per square meter (40.6(lb/sec)/sq ft)

NASA Technical Reports Server (NTRS)

Kovich, G.; Moore, R. D.; Urasek, D. C.

1973-01-01

The overall and blade-element performance are presented for an air compressor stage designed to study the effect of weight flow per unit annulus area on efficiency and flow range. At the design speed of 424.8 m/sec the peak efficiency of 0.81 occurred at the design weight flow and a total pressure ratio of 1.56. Design pressure ratio and weight flow were 1.57 and 29.5 kg/sec (65.0 lb/sec), respectively. Stall margin at design speed was 19 percent based on the weight flow and pressure ratio at peak efficiency and at stall.

Simultaneous removal of dissolved organic matter and bromide from drinking water source by anion exchange resins for controlling disinfection by-products.

PubMed

Phetrak, Athit; Lohwacharin, Jenyuk; Sakai, Hiroshi; Murakami, Michio; Oguma, Kumiko; Takizawa, Satoshi

2014-06-01

Anion exchange resins (AERs) with different properties were evaluated for their ability to remove dissolved organic matter (DOM) and bromide, and to reduce disinfection by-product (DBP) formation potentials of water collected from a eutrophic surface water source in Japan. DOM and bromide were simultaneously removed by all selected AERs in batch adsorption experiments. A polyacrylic magnetic ion exchange resin (MIEX®) showed faster dissolved organic carbon (DOC) removal than other AERs because it had the smallest resin bead size. Aromatic DOM fractions with molecular weight larger than 1600 Da and fluorescent organic fractions of fulvic acid- and humic acid-like compounds were efficiently removed by all AERs. Polystyrene AERs were more effective in bromide removal than polyacrylic AERs. This result implied that the properties of AERs, i.e. material and resin size, influenced not only DOM removal but also bromide removal efficiency. MIEX® showed significant chlorinated DBP removal because it had the highest DOC removal within 30 min, whereas polystyrene AERs efficiently removed brominated DBPs, especially brominated trihalomethane species. The results suggested that, depending on source water DOM and bromide concentration, selecting a suitable AER is a key factor in effective control of chlorinated and brominated DBPs in drinking water. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Superparamagnetic iron oxide coated on the surface of cellulose nanospheres for the rapid removal of textile dye under mild condition

NASA Astrophysics Data System (ADS)

Qin, Yunfeng; Qin, Zongyi; Liu, Yannan; Cheng, Miao; Qian, Pengfei; Wang, Qian; Zhu, Meifang

2015-12-01

Magnetic composite nanoparticles (MNPs) were prepared by anchoring iron oxide (Fe3O4) on the surface of carboxyl cellulose nanospheres through a facile chemical co-precipitation method. The as-prepared MNPs were characterized by atomic force microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, wide-angle X-ray diffraction measurement, thermal gravity analysis and vibrating sample magnetometry. These MNPs were of a generally spherical shape with a narrow size distribution, and exhibited superparamagnetic behaviors with high saturation magnetization. High efficient removal of Navy blue in aqueous solution was demonstrated at room temperature in a Fenton-like system containing the MNPs and H2O2, which benefited from small particle size, large surface area, high chemical activity, and good dispersibility of the MNPs. The removal efficiency of Navy blue induced by the MNPs prepared at a weight ratio of cellulose to iron of 1:2 were 90.6% at the first minute of the degradation reaction, and 98.0% for 5 min. Furthermore, these MNPs could be efficiently recycled and reused by using an external magnetic field. The approach presented in this paper promotes the use of renewable natural resources as templates for the preparation and stabilization of various inorganic nanomaterials for the purpose of catalysis, magnetic resonance imaging, biomedical and other potential applications.

Optimization of controlled release nanoparticle formulation of verapamil hydrochloride using artificial neural networks with genetic algorithm and response surface methodology.

PubMed

Li, Yongqiang; Abbaspour, Mohammadreza R; Grootendorst, Paul V; Rauth, Andrew M; Wu, Xiao Yu

2015-08-01

This study was performed to optimize the formulation of polymer-lipid hybrid nanoparticles (PLN) for the delivery of an ionic water-soluble drug, verapamil hydrochloride (VRP) and to investigate the roles of formulation factors. Modeling and optimization were conducted based on a spherical central composite design. Three formulation factors, i.e., weight ratio of drug to lipid (X1), and concentrations of Tween 80 (X2) and Pluronic F68 (X3), were chosen as independent variables. Drug loading efficiency (Y1) and mean particle size (Y2) of PLN were selected as dependent variables. The predictive performance of artificial neural networks (ANN) and the response surface methodology (RSM) were compared. As ANN was found to exhibit better recognition and generalization capability over RSM, multi-objective optimization of PLN was then conducted based upon the validated ANN models and continuous genetic algorithms (GA). The optimal PLN possess a high drug loading efficiency (92.4%, w/w) and a small mean particle size (∼100nm). The predicted response variables matched well with the observed results. The three formulation factors exhibited different effects on the properties of PLN. ANN in coordination with continuous GA represent an effective and efficient approach to optimize the PLN formulation of VRP with desired properties. Copyright © 2015 Elsevier B.V. All rights reserved.

Perceived size of friends and weight evaluation among low-income adolescents

PubMed Central

Milan, Stephanie

2018-01-01

Drawing from social comparison theory, we examine how perceptions of friends’ body sizes may influence adolescents’ subjective evaluations of their own body (e.g., how accurate they are in judging their weight, how much body dissatisfaction they feel), particularly for adolescent females. Participants were low-income, minority adolescents (Study 1: N = 194 females, Mean age = 15.4; Study 2: N = 409 males and females; Mean age = 14.9). Adolescents used figure rating scales to indicate their perceived size and that of four of their closest friends and completed several measures of subjective weight evaluation (e.g., weight classification, body dissatisfaction, internalized weight bias). In both studies, how adolescents perceived their body size and the body sizes of their thinnest and heaviest friends were positively correlated. In Study 1, overweight females based on measured BMI were less likely to accurately judge themselves as overweight if they had a close friend they perceived as heavy. In addition, females who viewed themselves as having a larger figure reported more internalized weight bias when they had friends they viewed as relatively thin. Findings from Study 2 suggest that how friends’ bodies are perceived is predictive of subjective weight evaluation measures only for adolescent females. Programs that address negative aspects of social comparison may be important in preventing both obesity and eating disorder symptoms in adolescent females. PMID:26403505

The relationship between nephron number, kidney size and body weight in two inbred mouse strains.

PubMed

Murawski, Inga J; Maina, Rita W; Gupta, Indra R

2010-01-01

While some reports in humans have shown that nephron number is positively correlated with height, body weight or kidney weight, other studies have not reproduced these findings. To understand the impact of genetic and environmental variation on these relationships, we examined whether nephron number correlates with body weight, kidney planar surface area, or kidney weight in two inbred mouse strains with contrasting kidney sizes but no overt renal pathology: C3H/HeJ and C57BL/6J. C3H/HeJ mice had smaller kidneys at birth and larger kidneys by adulthood, however there was no significant difference in nephron number between the two strains. We did observe a correlation between kidney size and body weight at birth and at adulthood for both strains. However, there was no relationship between nephron number and body weight or between nephron number and kidney size. From other studies, it appears that a greater than two-fold variation is required in each of these parameters in order to demonstrate these relationships, suggesting they are highly dependent on scale. Our results are therefore not surprising since there was a less than two-fold variation in each of the parameters examined. In summary, the relationship between nephron number and body or kidney size is most likely to be demonstrated when there is greater phenotypic variation either from genetic and/or environmental factors.

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Science.gov Websites

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Size, weight and position: ion mobility spectrometry and imaging MS combined.

PubMed

Kiss, András; Heeren, Ron M A

2011-03-01

Size, weight and position are three of the most important parameters that describe a molecule in a biological system. Ion mobility spectrometry is capable of separating molecules on the basis of their size or shape, whereas imaging mass spectrometry is an effective tool to measure the molecular weight and spatial distribution of molecules. Recent developments in both fields enabled the combination of the two technologies. As a result, ion-mobility-based imaging mass spectrometry is gaining more and more popularity as a (bio-)analytical tool enabling the determination of the size, weight and position of several molecules simultaneously on biological surfaces. This paper reviews the evolution of ion-mobility-based imaging mass spectrometry and provides examples of its application in analytical studies of biological surfaces.

Development of weight/sizing design synthesis computer program. Volume 3: User Manual

NASA Technical Reports Server (NTRS)

Garrison, J. M.

1973-01-01

The user manual for the weight/sizing design synthesis program is presented. The program is applied to an analysis of the basic weight relationships for the space shuttle which contribute significant portions of the inert weight. The relationships measure the parameters of load, geometry, material, and environment. A verbal description of the processes simulated, data input procedures, output data, and values present in the program is included.

Weight status and the perception of body image in men

PubMed Central

Gardner, Rick M

2014-01-01

Understanding the role of body size in relation to the accuracy of body image perception in men is an important topic because of the implications for avoiding and treating obesity, and it may serve as a potential diagnostic criterion for eating disorders. The early research on this topic produced mixed findings. About one-half of the early studies showed that obese men overestimated their body size, with the remaining half providing accurate estimates. Later, improvements in research technology and methodology provided a clearer indication of the role of weight status in body image perception. Research in our laboratory has also produced diverse findings, including that obese subjects sometimes overestimate their body size. However, when examining our findings across several studies, obese subjects had about the same level of accuracy in estimating their body size as normal-weight subjects. Studies in our laboratory also permitted the separation of sensory and nonsensory factors in body image perception. In all but one instance, no differences were found overall between the ability of obese and normal-weight subjects to detect overall changes in body size. Importantly, however, obese subjects are better at detecting changes in their body size when the image is distorted to be too thin as compared to too wide. Both obese and normal-weight men require about a 3%–7% change in the width of their body size in order to detect the change reliably. Correlations between a range of body mass index values and body size estimation accuracy indicated no relationship between these variables. Numerous studies in other laboratories asked men to place their body size into discrete categorizes, ranging from thin to obese. Researchers found that overweight and obese men underestimate their weight status, and that men are less accurate in their categorizations than are women. Cultural influences have been found to be important, with body size underestimations occurring in cultures where a larger body is found to be desirable. Methodological issues are reviewed with recommendations for future studies. PMID:25114606

Nano and microparticle engineering of water insoluble drugs using a novel spray-drying process.

PubMed

Schafroth, Nina; Arpagaus, Cordin; Jadhav, Umesh Y; Makne, Sushil; Douroumis, Dennis

2012-02-01

In the current study nano and microparticle engineering of water insoluble drugs was conducted using a novel piezoelectric spray-drying approach. Cyclosporin A (CyA) and dexamethasone (DEX) were encapsulated in biodegradable poly(D,L-lactide-co-glycolide) (PLGA) grades of different molecular weights. Spray-drying studies carried out with the Nano Spray Dryer B-90 employed with piezoelectric driven actuator. The processing parameters including inlet temperature, spray mesh diameter, sample flow rate, spray rate, applied pressure and sample concentration were examined in order to optimize the particle size and the obtained yield. The process parameters and the solute concentration showed a profound effect on the particle engineering and the obtained product yield. The produced powder presented consistent and reproducible spherical particles with narrow particle size distribution. Cyclosporin was found to be molecularly dispersed while dexamethasone was in crystalline state within the PLGA nanoparticles. Further evaluation revealed excellent drug loading, encapsulation efficiency and production yield. In vitro studies demonstrated sustained release patterns for the active substances. This novel spray-drying process proved to be efficient for nano and microparticle engineering of water insoluble active substances. Copyright © 2011 Elsevier B.V. All rights reserved.

Phase Behavior and Conductivity of Phosphonated Block Copolymers Containing Ionic Liquids

NASA Astrophysics Data System (ADS)

Jung, Ha Young; Kim, Sung Yeon; Park, Moon Jeong

2015-03-01

As the focus on proton exchange fuel cells continues to escalate in the era of alternative energy systems, the rational design of sulfonated polymers has emerged as a key technique for enhancing device efficiency. While the sulfonic acid group guarantees high proton conductivity of membranes under humidified conditions, the growing need for high temperature operation has discouraged their practical uses in fuel cells. In this respect, phosphonated polymers have drawn intensive attention in recent years owing to their self-dissociation ability. In this study, we have synthesized a set of phosphonated block copolymers, poly(styrenephosphonate-methylbutylene) (PSP- b - PMB), by varying phosphonation level (PL). A wide variety of self-assembled morphologies, i.e., disordered, lamellar, hexagonally perforated lamellae and hexagonally packed cylindrical phases, were observed with PL. Remarkably, upon comparing the morphology of PSP- b-PMB and that of sulfonated analog, we found distinctly dissimilar domain sizes at the same molecular weight and composition. A range of ionic liquids (ILs) were incorporated into the PSP- b-PMB block copolymers and their ion transport properties were examined. It has been revealed that the degree of confinement of ionic phases (domain size) impacts the ion mobility and proton dissociation efficiency of IL-containing polymers.

Nanosized soy phytosome-based thermogel as topical anti-obesity formulation: an approach for acceptable level of evidence of an effective novel herbal weight loss product.

PubMed

El-Menshawe, Shahira F; Ali, Adel A; Rabeh, Mohamed A; Khalil, Nermeen M

2018-01-01

Herbal supplements are currently available as a safer alternative to manage obesity, which has become a rising problem over the recent years. Many chemical drugs on the market are designed to prevent or manage obesity but high cost, low efficacy, and multiple side effects limit its use. Nano lipo-vesicles phytosomal thermogel of Soybean, Glycine max ( L .) Merrill, was formulated and evaluated in an attempt to investigate its anti-obesity action on body weight gain, adipose tissue size, and lipid profile data. Three different techniques were used to prepare phytosome formulations including solvent evaporation, cosolvency, and salting out. The optimized phytosome formulation was then selected using Design Expert ® (version 7.0.0) depending on the highest entrapment efficiency, minimum particle size (PS), and maximum drug release within 2 hours as responses for further evaluation. The successful phytosome complex formation was investigated by means of Fourier-transform infrared spec troscopy and determination of PS and zeta potential. Phytosome vesicles' shape was evaluated using transmission electron microscope to ensure its spherical shape. After characterization of the optimized phytosome formulation, it was incorporated into a thermogel formulation. The obtained phytosomal thermogel formulation was evaluated for its clarity, homogeneity, pH, and gel transformation temperature besides rheology behavior and permeation study. An in vivo study was done to investigate the anti-weight-gain effect of soy phytosomal ther mogel. EE was found to be >99% for all formulations, PS ranging from 51.66-650.67 while drug release was found to be (77.61-99.78) in range. FTIR and TEM results confirmed the formation of phytosome complex. In vivo study showed a marked reduction in body weight, adipose tissue weight and lipid profile. Concisely, soy phytosomal thermogel was found to have a local anti-obesity effect on the abdomen of experimental male albino rats with a slight systemic effect on the lipid profile data.

An experimental and theoretical study of new phosphors for full color field emission displays

NASA Astrophysics Data System (ADS)

Zhang, Fu-Li

An in depth study is reported of the cathodoluminescent (CL) properties of three new highly efficiency blue phosphors for field emission display (FED) applications doped with fast activators. The superior performance of a new Eu-doped green SrGa2S4 will also be reported. This work addresses four main topics: (1) a detailed study of the dependence of the luminescent intensity on activator concentration, as a function of electron beam voltage and current density; (2) the optical properties of thew phosphors and the development of a CL efficiency characterization technique using a critical screen weight method, which can obtain maximum light output and improve measurement accuracy; (3) understanding the low voltage CL mechanism associated with nanocrystal size by developing a thin film and disk model based on transportation theory and experimental results; (4) Development of a comprehensive evaluation method of red, green, and blue (RGB) phosphors for full color displays by calculation of luminance ratios, required luminance, and measurements of spectra, efficiency and saturation behavior. For FEDs which combine the best properties of CRT and flat panel displays, the development of efficient phosphors at low voltages and high current densities is shown to be critical to meet the luminance and power requirement demands for portable displays. Of particular importance is the need for a good blue phosphor, and to understand the dependence of the CL efficiency on nanocrystal size, penetration depth, diffusion length and surface recombination rate. This has been obtained from the thin film and disk models and fits to experiment. Comparisons between full color phosphor sets show that the performance of a display can vary by over a factor of three depending on the choice of the RGB set. Other factors that are important for optimizing the performance of FED phosphors are reviewed.

A High Salt Diet Inhibits Obesity and Delays Puberty in the Female Rat

PubMed Central

Pitynski-Miller, Dori; Ross, Micah; Schmill, Margaret; Schambow, Rachel; Fuller, Teresa; Flynn, Francis W.; Skinner, Donal C.

2017-01-01

Background/Objectives Processed foods are considered major contributors to the worldwide obesity epidemic. In addition to high sugar and fat contents, processed foods contain large amounts of salt. Due to correlations with rising adiposity, salt has recently been proposed to be obesogenic. This study investigated three hypotheses: i) high salt contributes to weight gain and adiposity in juvenile female rats, ii) puberty onset would be altered because salt is known to affect neuronal systems involved in activating the reproductive system, and iii) enhanced adiposity will act synergistically with salt to drive early puberty onset. Design Female weanling rats (post-natal day 21, n=105) were fed a low fat/low salt diet, low fat/high salt diet, high fat/low salt diet, or a high salt/high fat diet for 24 days. Metabolic measures, including weight gain, food intake, fecal output, activity, and temperature were recorded in subsets of animals. Results Body weight, retroperitoneal and perirenal fat pad weight, and adipocyte size were all lower in animals fed high fat/high salt compared to animals fed high fat alone. Leptin levels were reduced in high fat/high salt fed animals compared to high fat/low salt fed animals. Daily calorie intake was higher initially but declined with adjusted food intake and was not different among groups after 5 days. Osmolality and corticosterone were not different among groups. Fecal analysis showed excess fat excretion and a decreased digestive efficiency in animals fed high fat/low salt but not in animals fed high fat/high salt. Although respiratory exchange ratio was reduced by high dietary fat or salt, aerobic resting metabolic rate was not affected by diet. High salt delayed puberty onset, regardless of dietary fat content. Conclusions Salt delays puberty and prevents the obesogenic effect of a high fat diet. The reduced weight gain evident in high salt fed animals is not due to differences in food intake or digestive efficiency. PMID:28674441

Extending Three-Dimensional Weighted Cone Beam Filtered Backprojection (CB-FBP) Algorithm for Image Reconstruction in Volumetric CT at Low Helical Pitches

PubMed Central

Hsieh, Jiang; Nilsen, Roy A.; McOlash, Scott M.

2006-01-01

A three-dimensional (3D) weighted helical cone beam filtered backprojection (CB-FBP) algorithm (namely, original 3D weighted helical CB-FBP algorithm) has already been proposed to reconstruct images from the projection data acquired along a helical trajectory in angular ranges up to [0, 2 π]. However, an overscan is usually employed in the clinic to reconstruct tomographic images with superior noise characteristics at the most challenging anatomic structures, such as head and spine, extremity imaging, and CT angiography as well. To obtain the most achievable noise characteristics or dose efficiency in a helical overscan, we extended the 3D weighted helical CB-FBP algorithm to handle helical pitches that are smaller than 1: 1 (namely extended 3D weighted helical CB-FBP algorithm). By decomposing a helical over scan with an angular range of [0, 2π + Δβ] into a union of full scans corresponding to an angular range of [0, 2π], the extended 3D weighted function is a summation of all 3D weighting functions corresponding to each full scan. An experimental evaluation shows that the extended 3D weighted helical CB-FBP algorithm can improve noise characteristics or dose efficiency of the 3D weighted helical CB-FBP algorithm at a helical pitch smaller than 1: 1, while its reconstruction accuracy and computational efficiency are maintained. It is believed that, such an efficient CB reconstruction algorithm that can provide superior noise characteristics or dose efficiency at low helical pitches may find its extensive applications in CT medical imaging. PMID:23165031

High-pressure size exclusion chromatography analysis of dissolved organic matter isolated by tangential-flow ultra filtration

USGS Publications Warehouse

Everett, C.R.; Chin, Y.-P.; Aiken, G.R.

1999-01-01

A 1,000-Dalton tangential-flow ultrafiltration (TFUF) membrane was used to isolate dissolved organic matter (DOM) from several freshwater environments. The TFUF unit used in this study was able to completely retain a polystyrene sulfonate 1,800-Dalton standard. Unaltered and TFUF-fractionated DOM molecular weights were assayed by high-pressure size exclusion chromatography (HPSEC). The weight-averaged molecular weights of the retentates were larger than those of the raw water samples, whereas the filtrates were all significantly smaller and approximately the same size or smaller than the manufacturer-specified pore size of the membrane. Moreover, at 280 nm the molar absorptivity of the DOM retained by the ultrafilter is significantly larger than the material in the filtrate. This observation suggests that most of the chromophoric components are associated with the higher molecular weight fraction of the DOM pool. Multivalent metals in the aqueous matrix also affected the molecular weights of the DOM molecules. Typically, proton-exchanged DOM retentates were smaller than untreated samples. This TFUF system appears to be an effective means of isolating aquatic DOM by size, but the ultimate size of the retentates may be affected by the presence of metals and by configurational properties unique to the DOM phase.

Tris[2-(acryloyloxy)ethyl]isocyanurate cross-linked low-molecular-weight polyethylenimine as gene delivery carriers in cell culture and dystrophic mdx mice.

PubMed

Wang, Mingxing; Tucker, Jay D; Lu, Peijuan; Wu, Bo; Cloer, Caryn; Lu, Qilong

2012-04-18

Hyperbranched poly(ester amine)s (PEAs) were successfully synthesized by Michael addition reaction between tris[2-(acryloyloxy)ethyl]isocyanurate (TAEI) and low-molecular-weight polyethylenimine (LPEI, M(w) 0.8k, 1.2k, and 2.0k) and evaluated in vitro and in vivo as gene carriers. PEAs effectively condensed plasmid DNA with particle sizes below 200 nm and surface charges between 11.5 and 33.5 mV under tested doses [at the ratios 2-10:1 of polymer/pDNA(w/w)]. The PEAs showed significantly lower cytotoxicities when compared with PEI 25k in two different cell lines. The PEAs (C series) composed of PEI 2k showed higher transgene expression compared to PEAs of PEI 0.8k (A series) or 1.2k (B series). Highest gene transfection efficiency in CHO, C2C12 myoblast, and human skeletal muscle (HSK) cell lines was obtained with TAEI/PEI-2K (C12) at a ratio of 1:2. Both C12, C14(TAEI/PEI-2K at a ratio of 1:4) demonstrated 5-8-fold higher gene expression as compared with PEI 25k in mdx mice in vivo through intramuscular administration. No obvious muscle damage was observed with these new polymers. Higher transfection efficiency and lower toxicity indicate the potential of the biodegradable PEAs as safe and efficient transgene delivery vectors. © 2012 American Chemical Society

[Family intervention for the management of overweight and obesity in schoolchildren].

PubMed

González-Heredia, Ricardo; Castañeda-Sánchez, Oscar; López-Morales, Cruz Mónica; Brito-Zurita, Olga Rosa; Sabag-Ruize, Enrique

2014-01-01

The management of obesity is complex and it must be multidisciplinary. Behavioral treatments for control of childhood obesity are based on family; these have a high degree of efficiency. It has been argued that when children and their parents are the main goal of the changes of behavior as a group, results of weight loss generally are better. The objective of this study was to establish the effect of an intervention based on family to reduce weight in students with overweight or obesity. Quasi-experimental study in schoolchildren from 6 to 12 years of age, from a family medicine unit in Ciudad Obregón, Sonora, México. The intervention group corresponded to 30 schoolchildren with overweight or obesity, and one or both of their parents with overweight or obesity; the control group included 30 schoolchildren with overweight or obesity, and normal-weight parents. Weight, height and body mass index (BMI) were measured at baseline, monthly, and at the end of the study. Student t test was used to contrast quantitative variables using the SPSS v.15 program. There were differences in weight, but not in BMI, probably due to the effect of size. Compared with the control group, a higher proportion of schoolchildren showed an improvement with regard to nutritional status. The family intervention is basic for the treatment of overweight and obesity in schoolchildren.

Effect Size Measures for Differential Item Functioning in a Multidimensional IRT Model

ERIC Educational Resources Information Center

Suh, Youngsuk

2016-01-01

This study adapted an effect size measure used for studying differential item functioning (DIF) in unidimensional tests and extended the measure to multidimensional tests. Two effect size measures were considered in a multidimensional item response theory model: signed weighted P-difference and unsigned weighted P-difference. The performance of…

Formation of enriched black tea extract loaded chitosan nanoparticles via electrospraying

NASA Astrophysics Data System (ADS)

Hammond, Samuel James

Creating nanoparticles of beneficial nutraceuticals and pharmaceuticals has had a large surge of research due to the enhancement of absorption and bioavailability by decreasing their size. One of these ways is by electrohydrodynamic atomization, also known as electrospraying. In general, this novel process is done by forcing a liquid through a capillary nozzle and which is subjected to an electrical field. While there are different ways to create nanoparticles, the novel method of electrospraying can be beneficial over other types of nanoparticle formation. Reasons include high control over particle size and distribution by altering electrospray parameters (voltage, flow rate, distance, and time), higher encapsulation efficiency than other methods, and also it is a one step process without exposure to extreme conditions (Gomez-Estaca et. al. 2012, Jaworek and Sobcyzk 2008). The current study aimed to create a chitosan encapsulated theaflavin-2 enriched black tea extract (BTE) nanoparticles via electrospraying. The first step of this process was to create the smallest chitosan nanoparticles possible by altering the electrospray parameters and the chitosan-acetic acid solution parameters. The solution properties altered include chitosan molecular weight, acetic acid concentration, and chitosan concentration. Specifically, the electrospray parameters such as voltage, flow rate and distance from syringe to collector are the most important in determining particle size. After creating the smallest chitosan particles, the TF-2 enriched black tea extract was added to the chitosan-acetic acid solution to be electrosprayed. The particles were assessed with the following procedures: Atomic force microscopy (AFM) and scanning electron microscopy (SEM) for particle morphology and size, and loading efficiency with ultraviolet--visible spectrophotometer (UV-VIS). Chitosan-BTE nanoparticles were successfully created in a one step process. Diameter of the particles on average ranged from 255 nm to 560 nm. Encapsulation efficiency was above 95% for all but one sample set. Future work includes MTT assay and cellular uptake.

Progress toward the development of dual junction GaAs/Ge solar cells

NASA Technical Reports Server (NTRS)

Lillington, D. R.; Krut, D. D.; Cavicchi, B. T.; Ralph, E.; Chung, M.

1991-01-01

Large area GaAs/Ge cells offer substantial promise for increasing the power output from existing silicon solar array designs and for providing an enabled technology for missions hitherto impossible using silicon. Single junction GaAs/Ge cells offer substantial advantages in both size, weight, and cost compared to GaAs cells but the efficiency is limited to approximately 19.2 to 20 percent AMO. The thermal absorptance of GaAs/Ge cells is also worse than GaAs/GaAs cells (0.88 vs 0.81 typ.) due to the absorption in the Ge substrate. On the other hand dual junction GaAs/Ge cells offer efficiencies up to ultimately 24 percent AMO in sizes up to 8 x 8 cm but there are still technological issues remaining to achieve current matching in the GaAs and Ge cells. This can be achieved through tuned antireflection (AR) coatings, improved quality of the GaAs growth, improved quality Ge wafers and the use of a Back Surface Field (BSF)/Back Surface Reflector (BSR) in the Ge cell. Although the temperature coefficients of efficiency and voltage are higher for dual junction GaAs/Ge cells, it has been shown elsewhere that for typical 28 C cell efficiencies of 22 percent (dual junction) vs 18.5 percent (single junction) there is a positive power tradeoff up to temperatures as high as 120 C. Due to the potential ease of fabrication of GaAs/Ge dual junction cells there is likely to be only a small cost differential compared to single junction cells.

The Impact of the Polymer Chain Length on the Catalytic Activity of Poly(N-vinyl-2-pyrrolidone)-supported Gold Nanoclusters.

PubMed

Haesuwannakij, Setsiri; Kimura, Tetsunari; Furutani, Yuji; Okumura, Kazu; Kokubo, Ken; Sakata, Takao; Yasuda, Hidehiro; Yakiyama, Yumi; Sakurai, Hidehiro

2017-08-29

Poly(N-vinyl-2-pyrrolidone) (PVP) of varying molecular weight (M w  = 40-360 kDa) were employed to stabilize gold nanoclusters of varying size. The resulting Au:PVP clusters were subsequently used as catalysts for a kinetic study on the sized-dependent aerobic oxidation of 1-indanol, which was monitored by time-resolved in situ infrared spectroscopy. The obtained results suggest that the catalytic behaviour is intimately correlated to the size of the clusters, which in turn depends on the molecular weight of the PVPs. The highest catalytic activity was observed for clusters with a core size of ~7 nm, and the size of the cluster should increase with the molecular weight of the polymer in order to maintain optimal catalytic activity. Studies on the electronic and colloid structure of these clusters revealed that the negative charge density on the cluster surface also strongly depends on the molecular weight of the stabilizing polymers.

Low midpregnancy placental volume in rural Indian women: A cause for low birth weight?

PubMed

Kinare, A S; Natekar, A S; Chinchwadkar, M C; Yajnik, C S; Coyaji, K J; Fall, C H; Howe, D T

2000-02-01

We sought to study midpregnancy placental volume in rural Indian women, its maternal determinants, and its relationship to neonatal size. We performed a prospective community-based study of maternal nutrition and fetal growth in 6 villages near the city of Pune. Measurements included midpregnancy placental volume determined by means of ultrasonography at 15 to 18 weeks' gestation, maternal anthropometric measurements before and during pregnancy, and maternal blood pressure and biochemical parameters during pregnancy. Neonatal size and placental weight were measured at birth. The mothers were short and underweight (mean height, 1.52 m; weight, 42 kg; body mass index, 18 kg/m(2)) and produced small babies (mean birth weight, 2648 g). Midpregnancy placental volume (median, 144 mL) was related to the mother's prepregnancy weight (r = 0.15; P <.001) but not to weight gain during pregnancy, blood pressure, or circulating hemoglobin, ferritin, red blood cell folate, or glucose concentrations. Midpregnancy placental volume was related to placental weight at birth (r = 0.29; P <.001) and birth weight (r = 0.25; P <.001) independent of maternal size. In Indian mothers midpregnancy placental volume is significantly associated with prepregnant maternal weight and is an independent predictor of birth weight. Our findings may provide clues to the high prevalence of low-birth-weight infants in India.

Optimum structural sizing of conventional cantilever and joined wing configurations using equivalent beam models

NASA Technical Reports Server (NTRS)

Hajela, P.; Chen, J. L.

1986-01-01

The present paper describes an approach for the optimum sizing of single and joined wing structures that is based on representing the built-up finite element model of the structure by an equivalent beam model. The low order beam model is computationally more efficient in an environment that requires repetitive analysis of several trial designs. The design procedure is implemented in a computer program that requires geometry and loading data typically available from an aerodynamic synthesis program, to create the finite element model of the lifting surface and an equivalent beam model. A fully stressed design procedure is used to obtain rapid estimates of the optimum structural weight for the beam model for a given geometry, and a qualitative description of the material distribution over the wing structure. The synthesis procedure is demonstrated for representative single wing and joined wing structures.

Development of a portable analyzer with polymer lab-on-a-chip (LOC) for continuous sampling and monitoring of Pb(II).

PubMed

Jang, A; Zou, Z; MacKnight, E; Wu, P M; Kim, I S; Ahn, C H; Bishop, P L

2009-01-01

A new portable analyzer with polymer lab-on-a-chip (LOC) has been designed, fabricated and fully characterized for continuous sampling and monitoring of lead (Pb(II)) in this work. As the working electrodes of the sensor, bismuth (Bi (III)) which allowed the advantage of being more environmentally friendly than traditional mercury drop electrodes was used, while maintaining similar sensitivity and other desirable characteristics. The size of a portable analyzer was 30 cmx23 cmx7 cm, and the weight was around 3 kg. The small size gives the advantage of being portable for field use while not sacrificing portability for accuracy of measurement. Furthermore, the autonomous system developed in coordination with the development of new polymer LOC integrated with electrochemical sensors can provide an innovative way to monitor surface waters in an efficient, cost-effective and sustainable manner.

Series-Connected Buck Boost Regulators

NASA Technical Reports Server (NTRS)

Birchenough, Arthur G.

2005-01-01

A series-connected buck boost regulator (SCBBR) is an electronic circuit that bucks a power-supply voltage to a lower regulated value or boosts it to a higher regulated value. The concept of the SCBBR is a generalization of the concept of the SCBR, which was reported in "Series-Connected Boost Regulators" (LEW-15918), NASA Tech Briefs, Vol. 23, No. 7 (July 1997), page 42. Relative to prior DC-voltage-regulator concepts, the SCBBR concept can yield significant reductions in weight and increases in power-conversion efficiency in many applications in which input/output voltage ratios are relatively small and isolation is not required, as solar-array regulation or battery charging with DC-bus regulation. Usually, a DC voltage regulator is designed to include a DC-to-DC converter to reduce its power loss, size, and weight. Advances in components, increases in operating frequencies, and improved circuit topologies have led to continual increases in efficiency and/or decreases in the sizes and weights of DC voltage regulators. The primary source of inefficiency in the DC-to-DC converter portion of a voltage regulator is the conduction loss and, especially at high frequencies, the switching loss. Although improved components and topology can reduce the switching loss, the reduction is limited by the fact that the converter generally switches all the power being regulated. Like the SCBR concept, the SCBBR concept involves a circuit configuration in which only a fraction of the power is switched, so that the switching loss is reduced by an amount that is largely independent of the specific components and circuit topology used. In an SCBBR, the amount of power switched by the DC-to-DC converter is only the amount needed to make up the difference between the input and output bus voltage. The remaining majority of the power passes through the converter without being switched. The weight and power loss of a DC-to-DC converter are determined primarily by the amount of power processed. In the SCBBR, the unswitched majority of the power is passed through with very little power loss, and little if any increase in the sizes of the converter components is needed to enable the components to handle the unswitched power. As a result, the power-conversion efficiency of the regulator can be very high, as shown in the example of Figure 1. A basic SCBBR includes a DC-to-DC converter (see Figure 2). The switches and primary winding of a transformer in the converter is connected across the input bus, while the secondary winding and switches are connected in series with the output bus, so that the output voltage is the sum of the input voltage and the secondary voltage of the converter. In the breadboard SCBBR, the input voltage applied to the primary winding is switched by use of metal oxide/semiconductor field-effect transistors (MOSFETs) in a full bridge circuit; the secondary winding is center-tapped, with two MOSFET switches and diode rectifiers connected in opposed series in each leg. The sets of opposed switches and rectifiers are what enable operation in either a boost or a buck mode. In the boost mode, input voltage and current, and the output voltage and current are all positive; that is, the secondary voltage is added to the input voltage and the net output voltage can be regulated at a value equal or greater than the input voltage. In the buck mode, input voltage is still positive and the current still flows in the same direction in the secondary, but the switches are controlled such that some power flows from the secondary to the primary. The voltage across the secondary and the current into the primary are reversed. The result is that the output voltage is lower than the input voltage, and some power is recirculated from the converter secondary back to the input. Quantitatively, the advantage of an SCBBR is a direct function of the regulation range required. If, for example, a regulation range of 20 percent is required for a 500-W supply, th it suffices to design the DC-to-DC converter in the SCBBR for a power rating of only 100 W. The switching loss and size are much smaller than those of a conventional regulator that must be rated for switching of all 500 W. The reduction in size and the increase in efficiency are not directly proportional to switched-power ratio of 5:1 because the additional switches contribute some conduction loss and the input and output filters must be larger than those typically required for a 100-W converter. Nevertheless, the power loss and the size can be much smaller than those of a 500-W converter.

The potential impact of new power system technology on the design of a manned space station

NASA Technical Reports Server (NTRS)

Fordyce, J. S.; Schwartz, H. J.

1984-01-01

Larger, more complex spacecraft of the future such as a manned Space Station will require electric power systems of 100 kW and more, orders of magnitude greater than the present state of the art. Power systems at this level will have a significant impact on the spacecraft design. Historically, long-lived spacecraft have relied on silicon solar cell arrays, a nickel-cadmium storage battery and operation at 28 V dc. These technologies lead to large array areas and heavy batteries for a Space Station application. This, in turn, presents orbit altitude maintenance, attitude control, energy management and launch weight and volume constraints. Size (area) and weight of such a power system can be reduced if new higher efficiency conversion and lighter weight storage technologies are used. Several promising technology options including concentrator solar photovoltaic arrays, solar thermal dynamic and ultimately nuclear dynamic systems to reduce area are discussed. Also, higher energy storage systems such as nickel-hydrogen and the regenerative fuel cell (RFC) and higher voltage power distribution which add system flexibility, simplicity and reduce weight are examined. Emphasis is placed on the attributes and development status of emerging technologies that are sufficiently developed so that they could be available for flight use in the early to mid 1990's.

The potential impact of new power system technology on the design of a manned Space Station

NASA Technical Reports Server (NTRS)

Fordyce, J. S.; Schwartz, H. J.

1984-01-01

Larger, more complex spacecraft of the future such as a manned Space Station will require electric power systems of 100 kW and more, orders of magnitude greater than the present state of the art. Power systems at this level will have a significant impact on the spacecraft design. Historically, long-lived spacecraft have relied on silicon solar cell arrays, a nickel-cadmium storage battery and operation at 28 V dc. These technologies lead to large array areas and heavy batteries for a Space Station application. This, in turn, presents orbit altitude maintenance, attitude control, energy management and launch weight and volume constraints. Size (area) and weight of such a power system can be reduced if new higher efficiency conversion and lighter weight storage technologies are used. Several promising technology options including concentrator solar photovoltaic arrays, solar thermal dynamic and ultimately nuclear dynamic systems to reduce area are discussed. Also, higher energy storage systems such as nickel-hydrogen and the regenerative fuel cell (RFC) and higher voltage power distribution which add system flexibility, simplicity and reduce weight are examined. Emphasis placed on the attributes and development status of emerging technologies that are sufficiently developed so that they could be available for flight use in the early to mid 1990's.

Tutorial for Collecting and Processing Images of Composite Structures to Determine the Fiber Volume Fraction

NASA Technical Reports Server (NTRS)

Conklin, Lindsey

2017-01-01

Fiber-reinforced composite structures have become more common in aerospace components due to their light weight and structural efficiency. In general, the strength and stiffness of a composite structure are directly related to the fiber volume fraction, which is defined as the fraction of fiber volume to total volume of the composite. The most common method to measure the fiber volume fraction is acid digestion, which is a useful method when the total weight of the composite, the fiber weight, and the total weight can easily be obtained. However, acid digestion is a destructive test, so the material will no longer be available for additional characterization. Acid digestion can also be difficult to machine out specific components of a composite structure with complex geometries. These disadvantages of acid digestion led the author to develop a method to calculate the fiber volume fraction. The developed method uses optical microscopy to calculate the fiber area fraction based on images of the cross section of the composite. The fiber area fraction and fiber volume fraction are understood to be the same, based on the assumption that the shape and size of the fibers are consistent in the depth of the composite. This tutorial explains the developed method for optically determining fiber area fraction performed at NASA Langley Research Center.

Freeway management and operations handbook

DOT National Transportation Integrated Search

1995-02-01

This paper: (1) describes current logistics practices as they are affected by truck size and weight limits; (2) examines how changes in truck size and weight limits might affect logistics practices; and (3) where possible, identifies research needed ...

A Modified ELISA Accurately Measures Secretion of High Molecular Weight Hyaluronan (HA) by Graves' Disease Orbital Cells

PubMed Central

Krieger, Christine C.

2014-01-01

Excess production of hyaluronan (hyaluronic acid [HA]) in the retro-orbital space is a major component of Graves' ophthalmopathy, and regulation of HA production by orbital cells is a major research area. In most previous studies, HA was measured by ELISAs that used HA-binding proteins for detection and rooster comb HA as standards. We show that the binding efficiency of HA-binding protein in the ELISA is a function of HA polymer size. Using gel electrophoresis, we show that HA secreted from orbital cells is primarily comprised of polymers more than 500 000. We modified a commercially available ELISA by using 1 million molecular weight HA as standard to accurately measure HA of this size. We demonstrated that IL-1β-stimulated HA secretion is at least 2-fold greater than previously reported, and activation of the TSH receptor by an activating antibody M22 from a patient with Graves' disease led to more than 3-fold increase in HA production in both fibroblasts/preadipocytes and adipocytes. These effects were not consistently detected with the commercial ELISA using rooster comb HA as standard and suggest that fibroblasts/preadipocytes may play a more prominent role in HA remodeling in Graves' ophthalmopathy than previously appreciated. PMID:24302624

Composites reinforced via mechanical interlocking of surface-roughened microplatelets within ductile and brittle matrices.

PubMed

Libanori, R; Carnelli, D; Rothfuchs, N; Binelli, M R; Zanini, M; Nicoleau, L; Feichtenschlager, B; Albrecht, G; Studart, A R

2016-04-12

Load-bearing reinforcing elements in a continuous matrix allow for improved mechanical properties and can reduce the weight of structural composites. As the mechanical performance of composite systems are heavily affected by the interfacial properties, tailoring the interactions between matrices and reinforcing elements is a crucial problem. Recently, several studies using bio-inspired model systems suggested that interfacial mechanical interlocking is an efficient mechanism for energy dissipation in platelet-reinforced composites. While cheap and effective solutions are available at the macroscale, the modification of surface topography in micron-sized reinforcing elements still represents a challenging task. Here, we report a simple method to create nanoasperities with tailored sizes and densities on the surface of alumina platelets and investigate their micromechanical effect on the energy dissipation mechanisms of nacre-like materials. Composites reinforced with roughened platelets exhibit improved mechanical properties for both organic ductile epoxy and inorganic brittle cement matrices. Mechanical interlocking increases the modulus of toughness (area under the stress-strain curve) by 110% and 56% in epoxy and cement matrices, respectively, as compared to those reinforced with flat platelets. This interlocking mechanism can potentially lead to a significant reduction in the weight of mechanical components while retaining the structural performance required in the application field.

Preharvest application of oxalic acid increased fruit size, bioactive compounds, and antioxidant capacity in sweet cherry cultivars (Prunus avium L.).

PubMed

Martínez-Esplá, Alejandra; Zapata, Pedro Javier; Valero, Daniel; García-Viguera, Cristina; Castillo, Salvador; Serrano, María

2014-04-16

Trees of 'Sweet Heart' and 'Sweet Late' sweet cherry cultivars (Prunus avium L.) were treated with oxalic acid (OA) at 0.5, 1.0, and 2.0 mM at 98, 112, and 126 days after full blossom. Results showed that all treatments increased fruit size at harvest, manifested by higher fruit volume and weight in cherries from treated trees than from controls, the higher effect being found with 2.0 mM OA (18 and 30% higher weight for 'Sweet Heart' and 'Sweet Late', respectively). Other quality parameters, such as color and firmness, were also increased by OA treatments, although no significant differences were found in total soluble solids or total acidity, showing that OA treatments did not affect the on-tree ripening process of sweet cherry. However, the increases in total anthocyanins, total phenolics, and antioxidant activity associated with the ripening process were higher in treated than in control cherries, leading to fruit with high bioactive compounds and antioxidant potential at commercial harvest (≅45% more anthocyanins and ≅20% more total phenolics). In addition, individual anthocyanins, flavonols, and chlorogenic acid derivatives were also increased by OA treatment. Thus, OA preharvest treatments could be an efficient and natural way to increase the quality and functional properties of sweet cherries.

Adaptation of the low-cost and low-power tactical split Stirling cryogenic cooler for aerospace applications

NASA Astrophysics Data System (ADS)

Veprik, A.; Zechtzer, S.; Pundak, N.; Kirkconnell, C.; Freeman, J.; Riabzev, S.

2011-06-01

Cryogenic coolers are often used in modern spacecraft in conjunction with sensitive electronics and sensors of military, commercial and scientific instrumentation. The typical space requirements are: power efficiency, low vibration export, proven reliability, ability to survive launch vibration/shock and long-term exposure to space radiation. A long-standing paradigm of exclusively using "space heritage" equipment has become the standard practice for delivering high reliability components. Unfortunately, this conservative "space heritage" practice can result in using outdated, oversized, overweight and overpriced cryogenic coolers and is becoming increasingly unacceptable for space agencies now operating within tough monetary and time constraints. The recent trend in developing mini and micro satellites for relatively inexpensive missions has prompted attempts to adapt leading-edge tactical cryogenic coolers for suitability in the space environment. The primary emphasis has been on reducing cost, weight and size. The authors are disclosing theoretical and practical aspects of a collaborative effort to develop a space qualified cryogenic refrigerator system based on the tactical cooler model Ricor K527 and the Iris Technology radiation hardened Low Cost Cryocooler Electronics (LCCE). The K27/LCCE solution is ideal for applications where cost, size, weight, power consumption, vibration export, reliability and time to spacecraft integration are of concern.

Bicriteria Network Optimization Problem using Priority-based Genetic Algorithm

NASA Astrophysics Data System (ADS)

Gen, Mitsuo; Lin, Lin; Cheng, Runwei

Network optimization is being an increasingly important and fundamental issue in the fields such as engineering, computer science, operations research, transportation, telecommunication, decision support systems, manufacturing, and airline scheduling. In many applications, however, there are several criteria associated with traversing each edge of a network. For example, cost and flow measures are both important in the networks. As a result, there has been recent interest in solving Bicriteria Network Optimization Problem. The Bicriteria Network Optimization Problem is known a NP-hard. The efficient set of paths may be very large, possibly exponential in size. Thus the computational effort required to solve it can increase exponentially with the problem size in the worst case. In this paper, we propose a genetic algorithm (GA) approach used a priority-based chromosome for solving the bicriteria network optimization problem including maximum flow (MXF) model and minimum cost flow (MCF) model. The objective is to find the set of Pareto optimal solutions that give possible maximum flow with minimum cost. This paper also combines Adaptive Weight Approach (AWA) that utilizes some useful information from the current population to readjust weights for obtaining a search pressure toward a positive ideal point. Computer simulations show the several numerical experiments by using some difficult-to-solve network design problems, and show the effectiveness of the proposed method.

Preparation of coenzyme Q10 liposomes using supercritical anti-solvent technique.

PubMed

Xia, Fei; Jin, Heyang; Zhao, Yaping; Guo, Xinqiu

2012-01-01

Coenzyme Q(10) (CoQ(10)) proliposomes were prepared using the supercritical anti-solvent (SAS) technique to encapsulate CoQ(10). The mixture of cholesterol and soya bean phosphatidylcholine (PC) was chosen as wall materials. The effects of operation conditions (temperature, pressure and components) on the recovery of CoQ(10) and the CoQ(10) loading in CoQ(10) proliposomes were studied. At the optimum conditions of pressure of 8.0 MPa, temperature of 35°C, the weight ratio of 1/10 between CoQ(10) and PC, and the weight ratio of 1/3 between cholesterol and PC, the CoQ(10) loading reached 8.92%. CoQ(10) liposomes were obtained by hydrating CoQ(10) proliposomes and the entrapment efficiency of CoQ(10) reached 82.28%. The morphologies of CoQ(10) proliposomes were characterized by scanning electron microscope, and their solid states were characterized by X-ray diffractometer. The structures of CoQ(10) liposomes were characterized by transmission electron microscope. The particle size distribution of CoQ(10) liposomes was determined by dynamic light scattering instrument. The results indicate that CoQ(10) liposomes with particle sizes about 50 nm can be easily obtained from hydrating CoQ(10) proliposomes prepared by SAS technique.

Preferred child body size and parental underestimation of child weight in Mexican American families

PubMed Central

Pasch, Lauri A.; Penilla, Carlos; Tschann, Jeanne M.; Martinez, Suzanna M.; Deardorff, Julianna; de Groat, Cynthia L.; Gregorich, Steven E.; Flores, Elena; Butte, Nancy F.; Greenspan, Louise C.

2016-01-01

Objective To determine whether parents who prefer a heavier child would underestimate their child's weight more than those who prefer a leaner child. Methods Participants were Mexican American families (312 mothers, 173 fathers, and 312 children ages 8-10) who were interviewed and had height and weight measurements. Parents reported their preferred child body size and their perceptions of their child's weight. Parents’ underestimation of their child's weight was calculated as the standardized difference between parent's perception of their child's weight and the child's body mass index (BMI) z-score. Demographic factors and parental BMI were also assessed. Results Although 50% of children were overweight or obese, only 11% of mothers and 10% of fathers perceived their children as being somewhat or very overweight. Multiple regressions controlling for covariates (parental BMI and child age) showed that parents who preferred a heavier child body size underestimated their children's weight more, compared to those who preferred a leaner child (β for mothers = .13, p < .03; (β for fathers = .17, p < .03). Conclusions for Practice Parents who preferred a heavier child body size underestimated their child's weight to a greater degree than parents who preferred a leaner child. Attempts by pediatricians to correct parents’ misperceptions about child weight may damage rapport and ultimately fail if the misperception is actually a reflection of parents’ preferences, which may not be readily amenable to change. Future research should address optimal methods of communication about child overweight which take into account parent preferences. PMID:27016351

Associations of health, physical activity and weight status with motorised travel and transport carbon dioxide emissions: a cross-sectional, observational study

PubMed Central

2012-01-01

Background Motorised travel and associated carbon dioxide (CO2) emissions generate substantial health costs; in the case of motorised travel, this may include contributing to rising obesity levels. Obesity has in turn been hypothesised to increase motorised travel and/or CO2 emissions, both because heavier people may use motorised travel more and because heavier people may choose larger and less fuel-efficient cars. These hypothesised associations have not been examined empirically, however, nor has previous research examined associations with other health characteristics. Our aim was therefore to examine how and why weight status, health, and physical activity are associated with transport CO2 emissions. Methods 3463 adults completed questionnaires in the baseline iConnect survey at three study sites in the UK, reporting their health, weight, height and past-week physical activity. Seven-day recall instruments were used to assess travel behaviour and, together with data on car characteristics, were used to estimate CO2 emissions. We used path analysis to examine the extent to which active travel, motorised travel and car engine size explained associations between health characteristics and CO2 emissions. Results CO2 emissions were higher in overweight or obese participants (multivariable standardized probit coefficients 0.16, 95% CI 0.08 to 0.25 for overweight vs. normal weight; 0.16, 95% CI 0.04 to 0.28 for obese vs. normal weight). Lower active travel and, particularly for obesity, larger car engine size explained 19-31% of this effect, but most of the effect was directly explained by greater distance travelled by motor vehicles. Walking for recreation and leisure-time physical activity were associated with higher motorised travel distance and therefore higher CO2 emissions, while active travel was associated with lower CO2 emissions. Poor health and illness were not independently associated with CO2 emissions. Conclusions Establishing the direction of causality between weight status and travel behaviour requires longitudinal data, but the association with engine size suggests that there may be at least some causal effect of obesity on CO2 emissions. More generally, transport CO2 emissions are associated in different ways with different health-related characteristics. These include associations between health goods and environmental harms (recreational physical activity and high emissions), indicating that environment-health ‘co-benefits’ cannot be assumed. Instead, attention should also be paid to identifying and mitigating potential areas of tension, for example by promoting low-carbon recreational physical activity. PMID:22862811

Associations of health, physical activity and weight status with motorised travel and transport carbon dioxide emissions: a cross-sectional, observational study.

PubMed

Goodman, Anna; Brand, Christian; Ogilvie, David

2012-08-03

Motorised travel and associated carbon dioxide (CO₂) emissions generate substantial health costs; in the case of motorised travel, this may include contributing to rising obesity levels. Obesity has in turn been hypothesised to increase motorised travel and/or CO₂ emissions, both because heavier people may use motorised travel more and because heavier people may choose larger and less fuel-efficient cars. These hypothesised associations have not been examined empirically, however, nor has previous research examined associations with other health characteristics. Our aim was therefore to examine how and why weight status, health, and physical activity are associated with transport CO₂ emissions. 3463 adults completed questionnaires in the baseline iConnect survey at three study sites in the UK, reporting their health, weight, height and past-week physical activity. Seven-day recall instruments were used to assess travel behaviour and, together with data on car characteristics, were used to estimate CO2 emissions. We used path analysis to examine the extent to which active travel, motorised travel and car engine size explained associations between health characteristics and CO₂ emissions. CO₂ emissions were higher in overweight or obese participants (multivariable standardized probit coefficients 0.16, 95% CI 0.08 to 0.25 for overweight vs. normal weight; 0.16, 95% CI 0.04 to 0.28 for obese vs. normal weight). Lower active travel and, particularly for obesity, larger car engine size explained 19-31% of this effect, but most of the effect was directly explained by greater distance travelled by motor vehicles. Walking for recreation and leisure-time physical activity were associated with higher motorised travel distance and therefore higher CO₂ emissions, while active travel was associated with lower CO₂ emissions. Poor health and illness were not independently associated with CO₂ emissions. Establishing the direction of causality between weight status and travel behaviour requires longitudinal data, but the association with engine size suggests that there may be at least some causal effect of obesity on CO₂ emissions. More generally, transport CO₂ emissions are associated in different ways with different health-related characteristics. These include associations between health goods and environmental harms (recreational physical activity and high emissions), indicating that environment-health 'co-benefits' cannot be assumed. Instead, attention should also be paid to identifying and mitigating potential areas of tension, for example by promoting low-carbon recreational physical activity.

Energy Efficient and Stable Weight Based Clustering for Mobile Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Bouk, Safdar H.; Sasase, Iwao

Recently several weighted clustering algorithms have been proposed, however, to the best of our knowledge; there is none that propagates weights to other nodes without weight message for leader election, normalizes node parameters and considers neighboring node parameters to calculate node weights. In this paper, we propose an Energy Efficient and Stable Weight Based Clustering (EE-SWBC) algorithm that elects cluster heads without sending any additional weight message. It propagates node parameters to its neighbors through neighbor discovery message (HELLO Message) and stores these parameters in neighborhood list. Each node normalizes parameters and efficiently calculates its own weight and the weights of neighboring nodes from that neighborhood table using Grey Decision Method (GDM). GDM finds the ideal solution (best node parameters in neighborhood list) and calculates node weights in comparison to the ideal solution. The node(s) with maximum weight (parameters closer to the ideal solution) are elected as cluster heads. In result, EE-SWBC fairly selects potential nodes with parameters closer to ideal solution with less overhead. Different performance metrics of EE-SWBC and Distributed Weighted Clustering Algorithm (DWCA) are compared through simulations. The simulation results show that EE-SWBC maintains fewer average numbers of stable clusters with minimum overhead, less energy consumption and fewer changes in cluster structure within network compared to DWCA.

Efficient second harmonic generation by para-nitroaniline embedded in electro-spun polymeric nanofibres

NASA Astrophysics Data System (ADS)

Gonçalves, Hugo; Saavedra, Inês; Ferreira, Rute AS; Lopes, PE; de Matos Gomes, Etelvina; Belsley, Michael

2018-03-01

Intense well polarized second harmonic light was generated by poly(methyl methacrylate) nanofibres with embedded para-nitroaniline nanocrystals. Subwavelength diameter fibres were electro-spun using a 1:2 weight ratio of chromophore to polymer. Analysis of the generated second harmonic light indicates that the para-nitroaniline molecules, which nominally crystalize in the centrosymmetric space group, were organized into noncentrosymmetric structures leading to a second order susceptibility dominated by a single tensor element. Under the best deposition conditions, the nanofibrers display an effective nonlinear optical susceptibility approximately two orders of magnitude greater than that of potassium dihydrogen phosphate. Generalizing this approach to a broad range of organic molecules with strong individual molecular second order nonlinear responses, but which nominally form centrosymmetric organic crystals, could open a new pathway for the fabrication of efficient sub-micron sized second harmonic light generators.

Extended Performance 8-cm Mercury Ion Thruster

NASA Technical Reports Server (NTRS)

Mantenieks, M. A.

1981-01-01

A slightly modified 8-cm Hg ion thruster demonstrated significant increase in performance. Thrust was increased by almost a factor of five over that of the baseline thruster. Thruster operation with various three grid ion optics configurations; thruster performance as a function of accelerator grid open area, cathode baffle, and cathode orifice size; and a life test of 614 hours at a beam current of 250 mA (17.5 mN thrust) are discussed. Highest thruster efficiency was obtained with the smallest open area accelerator grid. The benefits in efficiency from the low neutral loss grids were mitigated, however, by the limitation such grids place on attainable ion beam current densities. The thruster components suffered negligible weight losses during a life test, which indicated that operation of the 8-cm thruster at extended levels of thrust and power is possible with no significant loss of lifetime.

Refractory metal alloys and composites for space power systems

NASA Technical Reports Server (NTRS)

Stephens, Joseph R.; Petrasek, Donald W.; Titran, Robert H.

1988-01-01

Space power requirements for future NASA and other U.S. missions will range from a few kilowatts to megawatts of electricity. Maximum efficiency is a key goal of any power system in order to minimize weight and size so that the space shuttle may be used a minimum number of times to put the power supply into orbit. Nuclear power has been identified as the primary source to meet these high levels of electrical demand. One way to achieve maximum efficiency is to operate the power supply, energy conversion system, and related components at relatively high temperatures. NASA Lewis Research Center has undertaken a research program on advanced technology of refractory metal alloys and composites that will provide baseline information for space power systems in the 1900's and the 21st century. Basic research on the tensile and creep properties of fibers, matrices, and composites is discussed.

Multifunctional gadolinium-based dendritic macromolecules as liver targeting imaging probes.

PubMed

Luo, Kui; Liu, Gang; He, Bin; Wu, Yao; Gong, Qingyong; Song, Bin; Ai, Hua; Gu, Zhongwei

2011-04-01

The quest for highly efficient and safe contrast agents has become the key factor for successful application of magnetic resonance imaging (MRI). The gadolinium (Gd) based dendritic macromolecules, with precise and tunable nanoscopic sizes, are excellent candidates as multivalent MRI probes. In this paper, a novel series of Gd-based multifunctional peptide dendritic probes (generation 2, 3, and 4) possessing highly controlled structures and single molecular weight were designed and prepared as liver MRI probes. These macromolecular Gd-ligand agents exhibited up to 3-fold increase in T(1) relaxivity comparing to Gd-DTPA complexes. No obvious in vitro cytotoxicity was observed from the measured concentrations. These dendritic probes were further functionalized with multiple galactosyl moieties and led to much higher cell uptake in vitro as demonstrated in T(1)-weighted scans. During in vivo animal studies, the probes provided better signal intensity (SI) enhancement in mouse liver, especially at 60 min post-injection, with the most efficient enhancement from the galactosyl moiety decorated third generation dendrimer. The imaging results were verified with analysis of Gd content in liver tissues. The design strategy of multifunctional Gd-ligand peptide dendritic macromolecules in this study may be used for developing other sensitive MRI probes with targeting capability. Copyright © 2011 Elsevier Ltd. All rights reserved.

Machine learning framework for analysis of transport through complex networks in porous, granular media: A focus on permeability

NASA Astrophysics Data System (ADS)

van der Linden, Joost H.; Narsilio, Guillermo A.; Tordesillas, Antoinette

2016-08-01

We present a data-driven framework to study the relationship between fluid flow at the macroscale and the internal pore structure, across the micro- and mesoscales, in porous, granular media. Sphere packings with varying particle size distribution and confining pressure are generated using the discrete element method. For each sample, a finite element analysis of the fluid flow is performed to compute the permeability. We construct a pore network and a particle contact network to quantify the connectivity of the pores and particles across the mesoscopic spatial scales. Machine learning techniques for feature selection are employed to identify sets of microstructural properties and multiscale complex network features that optimally characterize permeability. We find a linear correlation (in log-log scale) between permeability and the average closeness centrality of the weighted pore network. With the pore network links weighted by the local conductance, the average closeness centrality represents a multiscale measure of efficiency of flow through the pore network in terms of the mean geodesic distance (or shortest path) between all pore bodies in the pore network. Specifically, this study objectively quantifies a hypothesized link between high permeability and efficient shortest paths that thread through relatively large pore bodies connected to each other by high conductance pore throats, embodying connectivity and pore structure.

FY2017 Materials Annual Progress Report

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

Wu, Felix; Gibbs, Jerry; Kleinbaum, Sarah

The Materials Technology subprogram supports the Vehicle Technology Office’s mission to help consumers and businesses reduce their transportation energy costs while meeting or exceeding vehicle performance expectations. The Propulsion Materials research portfolio seeks to develop higher performance materials that can withstand increasingly extreme environments and address the future properties needs of a variety of high efficiency powertrain types, sizes, fueling concepts, and combustion modes. Advanced Lightweight Materials research enables improvements in fuel economy by providing properties that are equal to or better than traditional materials at a lower weight. Because it takes less energy to accelerate a lighter object, replacingmore » cast iron and traditional steel components with lightweight materials such as high-strength steel, magnesium (Mg), aluminum (Al), and polymer composites can directly reduce a vehicle’s fuel consumption. Materials technology activities focus on the following cost and performance targets: (1) enable a 25 percent weight reduction for light-duty vehicles including body, chassis, and interior as compared to a 2012 baseline at no more than a $5/lb-saved increase in cost; and (2) validate a 25 percent improvement in high temperature (300°C) component strength relative to components made with 2010 baseline cast Al alloys (A319 or A356) for improved efficiency light-duty engines.« less

Overexpression of neuropeptide Y in the dorsomedial hypothalamus causes hyperphagia and obesity in rats.

PubMed

Zheng, Fenping; Kim, Yonwook J; Chao, Pei-Ting; Bi, Sheng

2013-06-01

We sought to determine a role for NPY overexpression in the dorsomedial hypothalamus (DMH) in obesity etiology using the rat model of adeno-associated virus (AAV)-mediated expression of NPY (AAVNPY) in the DMH. Rats received bilateral DMH injections of AAVNPY or control vector and were fed on regular chow. Five-week postviral injection, half the rats from each group were switched to access to a high-fat diet for another 11 weeks. We examined variables including body weight, food intake, energy efficiency, meal patterns, glucose tolerance, fat mass, plasma insulin, plasma leptin, and hypothalamic gene expression. Rats with DMH NPY overexpression had increased food intake and body weight and lowered metabolic efficiency. The hyperphagia was mediated through increased meal size during the dark. Although these rats had normal blood glucose, their plasma insulin levels were increased in both basal and glucose challenge conditions. While high-fat diet induced hyperphagia, obesity, and hyperinsulinemia, these effects were amplified in rats with DMH NPY overexpression. Arcuate Npy, agouti-related protein and proopiomelanocortin expression was appropriately regulated in response to positive energy balance. These results indicate that DMH NPY overexpression can cause hyperphagia and obesity and DMH NPY may have actions in glucose homeostasis. Copyright © 2013 The Obesity Society.

Development of highly compact and low power consumption athermal military laser designators

NASA Astrophysics Data System (ADS)

Sijan, A.

2012-10-01

The utility of military lasers, particularly in the area of laser designation for laser-guided weapons, is well understood. Laser systems based on Nd:YAG have been fielded since the 1980's and over the last three decades have introduced incremental technology steps to improve performance and weight. The most recent technology step has been the introduction of athermal lasers based on laser-diode pumping of Nd:YAG and products are now emerging for use on the battlefield. The technical performance, efficiency, size, weight and power for these lasers, has been key to driving the new production designs. In this paper, we review the development of the laser designs and their introduction since the advent of laser designation. In particular, we compare the relative performance and characteristics over the evolution of fielded laser designators. Moreover, we will review the key building blocks for the design of athermal lasers and describe some critical design issues for engineering and productionisation of a military laser system, including removal of thermal lensing, novel diode-pumping schemes and robustness over the environment. These will be exemplified using results from the development of the SELEX Galileo Type 163 Laser Target Designators. These will cover not only technical performance, power and efficiency, but also thermal management, mass, volume, cost and overall complexity for manufacture.

More efficient parameter estimates for factor analysis of ordinal variables by ridge generalized least squares.

PubMed

Yuan, Ke-Hai; Jiang, Ge; Cheng, Ying

2017-11-01

Data in psychology are often collected using Likert-type scales, and it has been shown that factor analysis of Likert-type data is better performed on the polychoric correlation matrix than on the product-moment covariance matrix, especially when the distributions of the observed variables are skewed. In theory, factor analysis of the polychoric correlation matrix is best conducted using generalized least squares with an asymptotically correct weight matrix (AGLS). However, simulation studies showed that both least squares (LS) and diagonally weighted least squares (DWLS) perform better than AGLS, and thus LS or DWLS is routinely used in practice. In either LS or DWLS, the associations among the polychoric correlation coefficients are completely ignored. To mend such a gap between statistical theory and empirical work, this paper proposes new methods, called ridge GLS, for factor analysis of ordinal data. Monte Carlo results show that, for a wide range of sample sizes, ridge GLS methods yield uniformly more accurate parameter estimates than existing methods (LS, DWLS, AGLS). A real-data example indicates that estimates by ridge GLS are 9-20% more efficient than those by existing methods. Rescaled and adjusted test statistics as well as sandwich-type standard errors following the ridge GLS methods also perform reasonably well. © 2017 The British Psychological Society.

Evaluation of the method of collecting suspended sediment from large rivers by discharge-weighted pumping and separation by continuous- flow centrifugation

USGS Publications Warehouse

Moody, J.A.; Meade, R.H.

1994-01-01

The efficacy of the method is evaluated by comparing the particle size distributions of sediment collected by the discharge-weighted pumping method with the particle size distributions of sediment collected by depth integration and separated by gravitational settling. The pumping method was found to undersample the suspended sand sized particles (>63 ??m) but to collect a representative sample of the suspended silt and clay sized particles (<63??m). The success of the discharge-weighted pumping method depends on how homogeneously the silt and clay sized particles (<63 ??m) are distributed in the vertical direction in the river. The degree of homogeneity depends on the composition and degree of aggregation of the suspended sediment particles. -from Authors

Association between excess weight and beverage portion size consumed in Brazil

PubMed Central

Bezerra, Ilana Nogueira; de Alencar, Eudóxia Sousa

2018-01-01

ABSTRACT OBJECTIVE To describe the beverage portion size consumed and to evaluate their association with excess weight in Brazil. METHODS We used data from the National Dietary Survey, which included individuals with two days of food record aged over 20 years (n = 24,527 individuals). The beverages were categorized into six groups: soft drink, 100% fruit juice, fruit drink, alcoholic beverage, milk, and coffee or tea. We estimated the average portion consumed for each group and we evaluated, using linear regression, the association between portion size per group and the variables of age, sex, income, and nutritional status. We tested the association between portion size and excess weight using Poisson regression, adjusted for age, sex, income, and total energy intake. RESULTS The most frequently consumed beverages in Brazil were coffee and tea, followed by 100% fruit juices, soft drinks, and milk. Alcoholic beverages presented the highest average in the portion size consumed, followed by soft drinks, 100% fruit juice, fruit drink, and milk. Portion size showed positive association with excess weight only in the soft drink (PR = 1.19, 95%CI 1.10–1.27) and alcoholic beverage groups (PR = 1.20, 95%CI, 1.11–1.29), regardless of age, sex, income, and total energy intake. CONCLUSIONS Alcoholic beverages and soft drinks presented the highest averages in portion size and positive association with excess weight. Public health interventions should address the issue of portion sizes offered to consumers by discouraging the consumption of large portions, especially sweetened and low nutritional beverages. PMID:29489988

75 FR 61815 - Agency Information Collection Activities: Notice of Request for Extension of Currently Approved...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-06

... Street, NW., Washington, DC 20503, Attention DOT Desk Officer. You are asked to comment on any aspect of... Vehicle Size and Weight Laws. OMB Control Number: 2125-0034. Background: Title 23, U.S.C., section 141... enforcing their size and weight laws on Federal-aid highways and that their Interstate System weight limits...

Oxygen reduction reaction on highly-durable Pt/nanographene fuel cell catalyst synthesized employing in-liquid plasma

NASA Astrophysics Data System (ADS)

Amano, Tomoki; Kondo, Hiroki; Takeda, Keigo; Ishikawa, Kenji; Kano, Hiroyuki; Hiramatsu, Mineo; Sekine, Makoto; Hori, Masaru

2016-09-01

We recently have established ultrahigh-speed synthesis method of nanographene materials employing in-liquid plasma, and reported high durability of Pt/nanographene composites as a fuel cell catalyst. Crystallinity and domain size of nanographene materials were essential to their durability. However, their mechanism is not clarified yet. In this study, we investigated the oxygen reduction reaction using three-types of nanographene materials with different crystallinity and domain sizes, which were synthesized using ethanol, 1-propanol and 1-butanol, respectively. According to our previous studies, the nanographene material synthesized using the lower molecular weight alcohol has the higher crystallinity and larger domain size. Pt nanoparticles were supported on the nanographene surfaces by reducing 8 wt% H2PtCl6 diluted with H2O. Oxygen reduction current densities at a potential of 0.2 V vs. RHE were 5.43, 5.19 and 3.69 mA/cm2 for the samples synthesized using ethanol, 1-propanol and 1-butanol, respectively. This means that the higher crystallinity nanographene showed the larger oxygen reduction current density. The controls of crystallinity and domain size of nanographene materials are essential to not only their durability but also highly efficiency as catalyst electrodes.

Novel cryomilled physically cross-linked biodegradable hydrogel microparticles as carriers for inhalation therapy.

PubMed

El-Sherbiny, I M; Smyth, H D C

2010-01-01

In this study, novel biodegradable physically cross-linked hydrogel microparticles were developed and evaluated in-vitro as potential carriers for inhalation therapy. These hydrogel microparticles were prepared to be respirable (desired aerodynamic size) when dry and also designed to avoid the macrophage uptake (attain large swollen size once deposited in lung). The swellable microparticles, prepared using cryomilling, were based on Pluronic® F-108 in combination with PEG grafted onto both chitosan (Cs) and its N-phthaloyl derivative (NPHCs). Polymers synthesized in the study were characterized using EA, FTIR, 2D-XRD and DSC. Morphology, particle size, density, biodegradation and moisture content of the microparticles were quantified. Swelling characteristics for both drug-free and drug-loaded microparticles showed excellent size increases (between 700-1300%) and the release profiles indicated sustained release could be achieved for up to 20 days. The respirable microparticles showed drug loading efficiency up to 92%. The enzymatic degradation of developed microparticles started within the first hour and only ∼10% weights were remaining after 10 days. In conclusion, these respirable microparticles demonstrated promising in-vitro performance for potential sustained release vectors in pulmonary drug delivery.

Propulsion requirements for reusable single-stage-to-orbit rocket vehicles

NASA Astrophysics Data System (ADS)

Stanley, Douglas O.; Engelund, Walter C.; Lepsch, Roger

1994-05-01

The conceptual design of a single-stage-to-orbit (SSTO) vehicle using a wide variety of evolutionary technologies has recently been completed as a part of NASA's Advanced Manned Launch System (AMLS) study. The employment of new propulsion system technologies is critical to the design of a reasonably sized, operationally efficient SSTO vehicle. This paper presents the propulsion system requirements identified for this near-term AMLS SSTO vehicle. Sensitivities of the vehicle to changes in specific impulse and sea-level thrust-to-weight ratio are examined. The results of a variety of vehicle/propulsion system trades performed on the near-term AMLS SSTO vehicle are also presented.

Characterization of glycoprotein biopharmaceutical products by Caliper LC90 CE-SDS gel technology.

PubMed

Chen, Grace; Ha, Sha; Rustandi, Richard R

2013-01-01

Over the last decade, science has greatly improved in the area of protein sizing and characterization. Efficient high-throughput methods are now available to substitute for the traditional labor-intensive SDS-PAGE methods, which alternatively take days to analyze a very limited number of samples. Currently, PerkinElmer(®) (Caliper) has designed an automated chip-based fluorescence detection method capable of analyzing proteins in minutes with sensitivity similar to standard SDS-PAGE. Here, we describe the use and implementation of this technology to characterize and screen a large number of formulations of target glycoproteins in the 14-200 kDa molecular weight range.

The Langley turbo-prop commuter design: A complete project description

NASA Technical Reports Server (NTRS)

Buttram, Greg; Horton, Keith; Keeter, Tim; Millhouse, Paul; Newberry, Kelli; Obyrne, Brian

1991-01-01

The primary objective of this project was to propose and prove the possibility of a new, advanced technology commuter aircraft design. Among the specifications were short to medium range capabilities, low seat per mile cost, fuel efficiency, and passenger comfort. Based on market evaluation, we found that the optimum size for new regional aircraft is around 50 passengers; we have designed our aircraft for this capacity. Turboprop engines provide substantial reductions in operating costs due to lower fuel consumption. We have therefore chosen an advanced turboprop engine. Composite materials, while more expensive to purchase and manufacture, result in decreased costs later through weight savings and ease of replacement.

Development and test of a 100 kVA superconducting transformer operated at 77 K

NASA Astrophysics Data System (ADS)

Kummeth, P.; Schlosser, R.; Massek, P.; Schmidt, H.; Albrecht, C.; Breitfelder, D.; Neumüller, H.-W.

2000-05-01

High-temperature superconducting (HTS) transformers are very promising candidates for application in electrical power engineering. Their main advantages are reduced size, weight, better efficiency and reduced potential fire and environmental hazards. We have designed, constructed and tested a 100 kVA HTS power transformer operated at 77 K. The nominal primary and secondary currents (voltages) are 18 A (5.6 kV) and 92 A (1.1 kV), respectively. No-load tests, short-circuit tests and load tests proved repeatedly that the transformer has the rated capacity. HTS winding losses of 20.6 W and iron losses of 403 W were measured.

Structural Analysis in a Conceptual Design Framework

NASA Technical Reports Server (NTRS)

Padula, Sharon L.; Robinson, Jay H.; Eldred, Lloyd B.

2012-01-01

Supersonic aircraft designers must shape the outer mold line of the aircraft to improve multiple objectives, such as mission performance, cruise efficiency, and sonic-boom signatures. Conceptual designers have demonstrated an ability to assess these objectives for a large number of candidate designs. Other critical objectives and constraints, such as weight, fuel volume, aeroelastic effects, and structural soundness, are more difficult to address during the conceptual design process. The present research adds both static structural analysis and sizing to an existing conceptual design framework. The ultimate goal is to include structural analysis in the multidisciplinary optimization of a supersonic aircraft. Progress towards that goal is discussed and demonstrated.

Compact instrument for fluorescence image-guided surgery

NASA Astrophysics Data System (ADS)

Wang, Xinghua; Bhaumik, Srabani; Li, Qing; Staudinger, V. Paul; Yazdanfar, Siavash

2010-03-01

Fluorescence image-guided surgery (FIGS) is an emerging technique in oncology, neurology, and cardiology. To adapt intraoperative imaging for various surgical applications, increasingly flexible and compact FIGS instruments are necessary. We present a compact, portable FIGS system and demonstrate its use in cardiovascular mapping in a preclinical model of myocardial ischemia. Our system uses fiber optic delivery of laser diode excitation, custom optics with high collection efficiency, and compact consumer-grade cameras as a low-cost and compact alternative to open surgical FIGS systems. Dramatic size and weight reduction increases flexibility and access, and allows for handheld use or unobtrusive positioning over the surgical field.

Heat exchangers in regenerative gas turbine cycles

NASA Astrophysics Data System (ADS)

Nina, M. N. R.; Aguas, M. P. N.

1985-09-01

Advances in compact heat exchanger design and fabrication together with fuel cost rises continuously improve the attractability of regenerative gas turbine helicopter engines. In this study cycle parameters aiming at reduced specific fuel consumption and increased payload or mission range, have been optimized together with heat exchanger type and size. The discussion is based on a typical mission for an attack helicopter in the 900 kw power class. A range of heat exchangers is studied to define the most favorable geometry in terms of lower fuel consumption and minimum engine plus fuel weight. Heat exchanger volume, frontal area ratio and pressure drop effect on cycle efficiency are considered.

Childhood obesity affects postural control and aiming performance during an upper limb movement.

PubMed

Boucher, François; Handrigan, Grant A; Mackrous, Isabelle; Hue, Olivier

2015-07-01

Obesity reduces the efficiency of postural and movement control mechanisms. However, the effects of obesity on a functional motor task and postural control in standing and seated position have not been closely quantified among children. The aim of this study is to examine the effects of obesity on the execution of aiming tasks performed in standing and seated conditions in children. Twelve healthy weight children and eleven obese children aged between 8 and 11 years pointed to a target in standing and seated position. The difficulty of the aiming task was varied by using 2 target sizes (1.0 cm and 5.0 cm width; pointing to the smaller target size needs a more precise movement and constitutes a more difficult task). Hand movement time (MT) and its phases were measured to quantify the aiming task. Mean speed of the center of pressure displacement (COP speed) was calculated to assess postural stability during the movement. Obese children had significantly higher MTs compared to healthy-weight children in seated and standing conditions explained by greater durations of deceleration phase when aiming. Concerning the COP speed during the movement, obese children showed significantly higher values when standing compared to healthy-weight children. This was also observed in the seated position. In conclusion, obesity adds a postural constraint during an aiming task in both seated and standing conditions and requires obese children to take more time to correct their movements due to a greater postural instability of the body when pointing to a target with the upper-limb. Copyright © 2015 Elsevier B.V. All rights reserved.

Impact of Low Molecular Weight Poly(3-hexylthiophene)s as Additives in Organic Photovoltaic Devices.

PubMed

Seibers, Zach D; Le, Thinh P; Lee, Youngmin; Gomez, Enrique D; Kilbey, S Michael

2018-01-24

Despite tremendous progress in using additives to enhance the power conversion efficiency of organic photovoltaic devices, significant challenges remain in controlling the microstructure of the active layer, such as at internal donor-acceptor interfaces. Here, we demonstrate that the addition of low molecular weight poly(3-hexylthiophene)s (low-MW P3HT) to the P3HT/fullerene active layer increases device performance up to 36% over an unmodified control device. Low MW P3HT chains ranging in size from 1.6 to 8.0 kg/mol are blended with 77.5 kg/mol P3HT chains and [6,6]-phenyl C 61 butyric acid methyl ester (PCBM) fullerenes while keeping P3HT/PCBM ratio constant. Optimal photovoltaic device performance increases are obtained for each additive when incorporated into the bulk heterojunction blend at loading levels that are dependent upon additive MW. Small-angle X-ray scattering and energy-filtered transmission electron microscopy imaging reveal that domain sizes are approximately invariant at low loading levels of the low-MW P3HT additive, and wide-angle X-ray scattering suggests that P3HT crystallinity is unaffected by these additives. These results suggest that oligomeric P3HTs compatibilize donor-acceptor interfaces at low loading levels but coarsen domain structures at higher loading levels and they are consistent with recent simulations results. Although results are specific to the P3HT/PCBM system, the notion that low molecular weight additives can enhance photovoltaic device performance generally provides a new opportunity for improving device performance and operating lifetimes.

Triolein-based polycation lipid nanocarrier for efficient gene delivery: characteristics and mechanism

PubMed Central

Zhang, Zhiwen; Fang, Xiaoling; Hao, Junguo; Li, Yajuan; Sha, Xianyi

2011-01-01

We proposed to develop a polycation lipid nanocarrier (PLN) with higher transfection efficiency than our previously described polycation nanostrucutred lipid nanocarrier (PNLC). PLN was composed of triolein, cetylated low-molecular-weight polyethylenimine, and dioleoyl phosphatidylethanolamine. The physicochemical properties of PLN and the PLN/DNA complexes (PDC) were characterized. The in vitro transfection was performed in human lung adenocarcinoma (SPC-A1) cells, and the intracellular mechanism was investigated as well. The measurements indicated that PLN and PDC are homogenous nanometer-sized particles with a positive charge. The transfection efficiency of PDC significantly increased with the content of triolein and was higher than that of PNLC and commercial Lipofectamine™ 2000. In particular, the transfection of PLN in the presence of 10% serum was more effective than that in its absence. With the help of specific inhibitors of chlorpromazine and filipin, the clathrin-dependent endocytosis pathway was determined to be the main contributor to the successful transfection mediated by PLN in SPC-A1 cells. The captured images verified that the fluorescent PDC was localized in the lysosomes and nuclei after endocytosis. Thus, PLN represents a novel efficient nonviral gene delivery vector. PMID:22114487

Triolein-based polycation lipid nanocarrier for efficient gene delivery: characteristics and mechanism.

PubMed

Zhang, Zhiwen; Fang, Xiaoling; Hao, Junguo; Li, Yajuan; Sha, Xianyi

2011-01-01

We proposed to develop a polycation lipid nanocarrier (PLN) with higher transfection efficiency than our previously described polycation nanostrucutred lipid nanocarrier (PNLC). PLN was composed of triolein, cetylated low-molecular-weight polyethylenimine, and dioleoyl phosphatidylethanolamine. The physicochemical properties of PLN and the PLN/DNA complexes (PDC) were characterized. The in vitro transfection was performed in human lung adenocarcinoma (SPC-A1) cells, and the intracellular mechanism was investigated as well. The measurements indicated that PLN and PDC are homogenous nanometer-sized particles with a positive charge. The transfection efficiency of PDC significantly increased with the content of triolein and was higher than that of PNLC and commercial Lipofectamine 2000. In particular, the transfection of PLN in the presence of 10% serum was more effective than that in its absence. With the help of specific inhibitors of chlorpromazine and filipin, the clathrin-dependent endocytosis pathway was determined to be the main contributor to the successful transfection mediated by PLN in SPC-A1 cells. The captured images verified that the fluorescent PDC was localized in the lysosomes and nuclei after endocytosis. Thus, PLN represents a novel efficient nonviral gene delivery vector.

The Series Connected Buck Boost Regulator Concept for High Efficiency Light Weight DC Voltage Regulation

NASA Technical Reports Server (NTRS)

Birchenough, Arthur G.

2003-01-01

Improvements in the efficiency and size of DC-DC converters have resulted from advances in components, primarily semiconductors, and improved topologies. One topology, which has shown very high potential in limited applications, is the Series Connected Boost Unit (SCBU), wherein a small DC-DC converter output is connected in series with the input bus to provide an output voltage equal to or greater than the input voltage. Since the DC-DC converter switches only a fraction of the power throughput, the overall system efficiency is very high. But this technique is limited to applications where the output is always greater than the input. The Series Connected Buck Boost Regulator (SCBBR) concept extends partial power processing technique used in the SCBU to operation when the desired output voltage is higher or lower than the input voltage, and the implementation described can even operate as a conventional buck converter to operate at very low output to input voltage ratios. This paper describes the operation and performance of an SCBBR configured as a bus voltage regulator providing 50 percent voltage regulation range, bus switching, and overload limiting, operating above 98 percent efficiency. The technique does not provide input-output isolation.

Truck size and weight enforcement technologies : implementation plan

DOT National Transportation Integrated Search

2009-06-01

The purpose of this Implementation Plan is to recommend strategies to encourage the deployment of roadside technologies to improve truck size and weight enforcement in the United States. The plan includes strategies that State practitioners can use t...

Low molecular weight polyethylenimine cross-linked by 2-hydroxypropyl-gamma-cyclodextrin coupled to peptide targeting HER2 as a gene delivery vector.

PubMed

Huang, Hongliang; Yu, Hai; Tang, Guping; Wang, Qingqing; Li, Jun

2010-03-01

Gene delivery is one of the critical steps for gene therapy. Non-viral vectors have many advantages but suffered from low gene transfection efficiency. Here, in order to develop new polymeric gene vectors with low cytotoxicity and high gene transfection efficiency, we synthesized a cationic polymer composed of low molecular weight polyethylenimine (PEI) of molecular weight of 600 Da cross-linked by 2-hydroxypropyl-gamma-cyclodextrin (HP gamma-CD) and then coupled to MC-10 oligopeptide containing a sequence of Met-Ala-Arg-Ala-Lys-Glu. The oligopeptide can target to HER2, the human epidermal growth factor receptor 2, which is often over expressed in many breast and ovary cancers. The new gene vector was expected to be able to target delivery of genes to HER2 positive cancer cells for gene therapy. The new gene vector was composed of chemically bonded HP gamma-CD, PEI (600 Da), and MC-10 peptide at a molar ratio of 1:3.3:1.2. The gene vector could condense plasmid DNA at an N/P ratio of 6 or above. The particle size of HP gamma-CD-PEI-P/DNA complexes at N/P ratios 40 was around 170-200 nm, with zeta potential of about 20 mV. The gene vector showed very low cytotoxicity, strong targeting specificity to HER2 receptor, and high efficiency of delivering DNA to target cells in vitro and in vivo with the reporter genes. The delivery of therapeutic IFN-alpha gene mediated by the new gene vector and the therapeutic efficiency were also studied in mice animal model. The animal study results showed that the new gene vector HP gamma-CD-PEI-P significantly enhanced the anti-tumor effect on tumor-bearing nude mice as compared to PEI (25 kDa), HP gamma-CD-PEI, and other controls, indicating that this new polymeric gene vector is a potential candidate for cancer gene therapy. (c) 2009 Elsevier Ltd. All rights reserved.

Maternal Weight Gain as a Predictor of Litter Size in Swiss Webster, C57BL/6J, and BALB/cJ mice.

PubMed

Finlay, James B; Liu, Xueli; Ermel, Richard W; Adamson, Trinka W

2015-11-01

An important task facing both researchers and animal core facilities is producing sufficient mice for a given project. The inherent biologic variability of mouse reproduction and litter size further challenges effective research planning. A lack of precision in project planning contributes to the high cost of animal research, overproduction (thus waste) of animals, and inappropriate allocation of facility resources. To examine the extent daily prepartum maternal weight gain predicts litter size in 2 commonly used mouse strains (BALB/cJ and C57BL/6J) and one mouse stock (Swiss Webster), we weighed ≥ 25 pregnant dams of each strain or stock daily from the morning on which a vaginal plug (day 0) was present. On the morning when dams delivered their pups, we recorded the weight of the dam, the weight of the litter itself, and the number of pups. Litter sizes ranged from 1 to 7 pups for BALB/cJ, 2 to 13 for Swiss Webster, and 5 to 11 for C57BL/6J mice. Linear regression models (based on weight change from day 0) demonstrated that maternal weight gain at day 9 (BALB/cJ), day 11 (Swiss Webster), or day 14 (C57BL/6J) was a significant predictor of litter size. When tested prospectively, the linear regression model for each strain or stock was found to be accurate. These data indicate that the number of pups that will be born can be estimated accurately by using maternal weight gain at specific or stock-specific time points.

Moment and maximum likelihood estimators for Weibull distributions under length- and area-biased sampling

Treesearch

Jeffrey H. Gove

2003-01-01

Many of the most popular sampling schemes used in forestry are probability proportional to size methods. These methods are also referred to as size biased because sampling is actually from a weighted form of the underlying population distribution. Length- and area-biased sampling are special cases of size-biased sampling where the probability weighting comes from a...

Photo series for quantifying natural forest residues: southern Cascades, northern Sierra Nevada

Treesearch

Kenneth S. Blonski; John L. Schramel

1981-01-01

A total of 56 photographs shows different levels of natural fuel loadings for selected size classes in seven forest types of the southern Cascade and northern Sierra-Nevada ranges. Data provided with each photo include size, weight, volumes, residue depths, and percent of ground coverage. Stand information includes sizes, weights, and volumes of the trees sampled for...

How does plate size affect estimated satiation and intake for individuals in normal‐weight and overweight groups?

PubMed Central

2017-01-01

Summary Objective Manipulating plate sizes could possibly introduce perceptual biases for judging food satiation and intake, which is thought to be related to the Delbeouf illusion – a visual illusion based on the perceived size of one object related to another. This study was to investigate whether an association exists between an individual's susceptibility to the plate‐size‐effect and their weight status (i.e. normal‐weight versus overweight). Methods The study assessed the effect of plate size amongst normal‐weight (N = 124) and overweight (N = 79) New Zealand Europeans. All participants were asked to rate estimated satiation (ES) and intake (EI) on Visual Analogue Scales for 20 food images, which comprised photographs of ten different dishes placed on large versus small plates. These responses were analysed by mixed‐model ANCOVA. Results The results showed that the plate size had significant effects on ES (F (1, 1986) = 19.14, p < 0.001) and EI (F (1,1986) = 5.25; p = 0.048), with the small plate associated with higher ES and lower EI than the large plate. Significant differences in ES and EI were also evident across the weight groups (ES: F (1,1986) = 4.26, p = 0.039; EI: F (1,1986) = 42.22, p < 0.001), with the normal‐weight group reported higher ES and lower EI than the overweight group. Furthermore, the weight group and the plate‐size‐effect were found to be involved in a significant interaction for EI. Post‐hoc tests showed that the plate size only had a significant effect for the normal‐weight group (p < 0.05), but not for the overweight group. Conclusions Overall, the study demonstrated that the normal‐weight and overweight group differed in their susceptibilities to the plate‐size‐effect (reflected by EI). This study revealed some potential moderators for the plate‐size‐effect, such as the type of dish, and its associated appeal and familiarity, and provided useful indications about the effectiveness of small plates for food reduction. PMID:29071104

Influence of particle size, an elongated particle geometry, and adjuvants on dendritic cell activation.

PubMed

Mathaes, Roman; Winter, Gerhard; Siahaan, Teruna J; Besheer, Ahmed; Engert, Julia

2015-08-01

Modern subunit vaccines have many benefits compared to live vaccines such as convenient and competitive large scale production, better reproducibility and safety. However, the poor immunogenicity of subunit vaccines usually requires the addition of potent adjuvants or drug delivery vehicles. Accordingly, researchers are investigating different adjuvants and particulate vaccine delivery vehicles to boost the immunogenicity of subunit vaccines. Despite the rapidly growing knowledge in this field, a comparison of different adjuvants is sparsely found. Until today, little is known about efficient combinations of the different adjuvants and particulate vaccine delivery vehicles. In this study we compared three adjuvants with respect to their immune stimulatory potential and combined them with different particulate vaccine delivery vehicles. For this reason, we investigated two types of polyI:C and a CL264 base analogue and combined these adjuvants with differently sized and shaped particulate vaccine delivery vehicles. A high molecular weight polyI:C combined with a spherical nano-sized particulate vaccine delivery vehicle promoted the strongest dendritic cells activation. Copyright © 2015 Elsevier B.V. All rights reserved.

The role of underestimating body size for self-esteem and self-efficacy among grade five children in Canada.

PubMed

Maximova, Katerina; Khan, Mohammad K A; Austin, S Bryn; Kirk, Sara F L; Veugelers, Paul J

2015-10-01

Underestimating body size hinders healthy behavior modification needed to prevent obesity. However, initiatives to improve body size misperceptions may have detrimental consequences on self-esteem and self-efficacy. Using sex-specific multiple mixed-effect logistic regression models, we examined the association of underestimating versus accurate body size perceptions with self-esteem and self-efficacy in a provincially representative sample of 5075 grade five school children. Body size perceptions were defined as the standardized difference between the body mass index (BMI, from measured height and weight) and self-perceived body size (Stunkard body rating scale). Self-esteem and self-efficacy for physical activity and healthy eating were self-reported. Most of overweight boys and girls (91% and 83%); and most of obese boys and girls (93% and 90%) underestimated body size. Underestimating weight was associated with greater self-efficacy for physical activity and healthy eating among normal-weight children (odds ratio: 1.9 and 1.6 for boys, 1.5 and 1.4 for girls) and greater self-esteem among overweight and obese children (odds ratio: 2.0 and 6.2 for boys, 2.0 and 3.4 for girls). Results highlight the importance of developing optimal intervention strategies as part of targeted obesity prevention efforts that de-emphasize the focus on body weight, while improving body size perceptions. Copyright © 2015 Elsevier Inc. All rights reserved.

Albumin nanoparticles coated with polysorbate 80 as a novel drug carrier for the delivery of antiretroviral drug—Efavirenz

PubMed Central

Jenita, Josephine Leno; Chocalingam, Vijaya; Wilson, Barnabas

2014-01-01

Purpose of the study: The antiretroviral therapy (ART) has dramatically improved human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) treatment, prevention and also has been found to increase the lifespan of HIV/AIDS patients by providing durable control of the HIV replication in patients. Efavirenz is a non-nucleoside reverse transcriptase inhibitor of HIV-1. The purpose of this study is to formulate efavirenz-loaded bovine serum albumin nanoparticles to improve efavirenz delivery into various organs. Materials and Methods: Nanoparticles were prepared by desolvation technique and coated with polysorbate 80. Ethanol, glutaraldehyde, and mannitol were used as desolvating, cross linking agent, and cryoprotectant, respectively. Drug to polymer ratio was chosen at five levels from 1:2, 1:3, 1:4, 1:5, and 1:6 (by weight). The formulated nanoparticles were characterized for Fourier Transform Infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) studies, entrapment efficiency, particle size, surface charge, surface morphology, in vitro drug release, release kinetics, stability studies, and biodistribution studies. Results and Major Conclusion: The particle size of the prepared formulations was found below 250nm with narrow size distribution, spherical in shape and showed good entrapment efficiency (45.62-72.49%). The in vitro drug release indicated biphasic release and its data were fitted to release kinetics models and release pattern was Fickian diffusion controlled release profile. The prepared nanoparticles increased efavirenz delivery into various organs by several fold in comparison with the free drug. PMID:25126528

Influence of polymer size, liposomal composition, surface charge, and temperature on the permeability of pH-sensitive liposomes containing lipid-anchored poly(2-ethylacrylic acid).

PubMed

Lu, Tingli; Wang, Zhao; Ma, Yufan; Zhang, Yang; Chen, Tao

2012-01-01

Liposomes containing pH-sensitive polymers are promising candidates for the treatment of tumors and localized infection. This study aimed to identify parameters influencing the extent of contents release from poly(ethylacrylic acid) (PEAA) vesicles, focusing on the effects of polymer size, lipid composition, vesicle surface charge, and temperature. Anchored lipid pH-sensitive PEAA was synthesized using PEAA with a molecular weight of 8.4 kDa. PEAA vesicles were prepared by insertion of the lipid-anchored PEAA into preformed large unilamellar vesicles. The preformed liposomes were manipulated by varying the phosphocholine and cholesterol content, and by adding negative or positive charges to the liposomes. A calcein release assay was used to evaluate the effects of polymer size, liposome composition, surface charge, and temperature on liposomal permeability. The release efficiency of the calcein-entrapped vesicles was found to be dependent on the PEAA polymer size. PEAA vesicles containing a phosphatidylcholine to cholesterol ratio of 60:40 (mol/mol) released more than 80% of their calcein content when the molecular weight of PEAA was larger than 8.4 kDa. Therefore, the same-sized polymer of 8.4 kDa was used for the rest of study. The calcein release potential was found to decrease as the percentage of cholesterol increased and with an increase in the phosphocholine acyl chain length (DMPC DPPC DSPC). Negatively charged and neutral vesicles released similar amounts of calcein, whereas positively charged liposomes released a significant amount of their contents. pH-sensitive release was dependent on temperature. Dramatic content release was observed at higher temperatures. The observed synergistic effect of pH and temperature on release of the contents of PEAA vesicles suggests that this pH-sensitive liposome might be a good candidate for intracellular drug delivery in the treatment of tumors or localized infection.

Influence of polymer size, liposomal composition, surface charge, and temperature on the permeability of pH-sensitive liposomes containing lipid-anchored poly(2-ethylacrylic acid)

PubMed Central

Lu, Tingli; Wang, Zhao; Ma, Yufan; Zhang, Yang; Chen, Tao

2012-01-01

Background Liposomes containing pH-sensitive polymers are promising candidates for the treatment of tumors and localized infection. This study aimed to identify parameters influencing the extent of contents release from poly(ethylacrylic acid) (PEAA) vesicles, focusing on the effects of polymer size, lipid composition, vesicle surface charge, and temperature. Methods Anchored lipid pH-sensitive PEAA was synthesized using PEAA with a molecular weight of 8.4 kDa. PEAA vesicles were prepared by insertion of the lipid-anchored PEAA into preformed large unilamellar vesicles. The preformed liposomes were manipulated by varying the phosphocholine and cholesterol content, and by adding negative or positive charges to the liposomes. A calcein release assay was used to evaluate the effects of polymer size, liposome composition, surface charge, and temperature on liposomal permeability. Results The release efficiency of the calcein-entrapped vesicles was found to be dependent on the PEAA polymer size. PEAA vesicles containing a phosphatidylcholine to cholesterol ratio of 60:40 (mol/mol) released more than 80% of their calcein content when the molecular weight of PEAA was larger than 8.4 kDa. Therefore, the same-sized polymer of 8.4 kDa was used for the rest of study. The calcein release potential was found to decrease as the percentage of cholesterol increased and with an increase in the phosphocholine acyl chain length (DMPC DPPC DSPC). Negatively charged and neutral vesicles released similar amounts of calcein, whereas positively charged liposomes released a significant amount of their contents. pH-sensitive release was dependent on temperature. Dramatic content release was observed at higher temperatures. Conclusion The observed synergistic effect of pH and temperature on release of the contents of PEAA vesicles suggests that this pH-sensitive liposome might be a good candidate for intracellular drug delivery in the treatment of tumors or localized infection. PMID:23028220

Testicular size at weaning in tropically-adapted beef bulls as influenced by breed of sire and dam.

PubMed

Browning, R; Warrington, B G; Holloway, J W; Randel, R D

1997-07-15

This study was conducted to evaluate testicular size at weaning for bulls representing diverse tropically-adapted genotypes. Calves from 2 locations were weighed and castrated at weaning. In one herd, calves were born to Brahman dams and Angus, Tuli, and Brahman sires. Body weights and paired testes weights were heavier (P < 0.01) for Angus x Brahman (AB) genotype than for Tuli x Brahman (TB) and purebred Brahman (BB) genotype calves. The testes:body weight ratio was greater (P < 0.01) for AB than for TB and BB calves. In a second herd, calves were born to Angus cows and Brahman, Tuli, and Senepol sires. Means were similar between Brahman- (BA), Tuli-(TA), and Senepol-sired (SA) calves for body weight and testes:body weight ratio. Paired testes weight was heavier (P < 0.05) for SA than BA calves. Across locations, paired testes weights were heavier (P < 0.01) for TA than TB calves but their body weights were similar. Within-herd deviations were greater (P < 0.01) for AB than BA calves for paired testes weight and testes:body weight ratio. The correlation between the proportion of Bos indicus genetic contribution and testes:body weight ratio was significantly negative. Tropically-adapted calves differed in testicular size at weaning due to breed of sire and dam effects.

Case Studies in Physiology: Ventilation and perfusion in a giraffe-does size matter?

PubMed

Nyman, Görel; Röken, Bengt; Hedin, Eva-Maria; Hedenstierna, Göran

2016-12-01

The trachea in the giraffe is long but narrow, and dead space ventilation is considered to be of approximately the same size as in other mammals. Less is known about the matching between ventilation and lung blood flow. The lungs in the giraffe are large, up to 1 m high and 0.7 m wide, and this may cause considerable ventilation/perfusion (V A /Q) mismatch due to the influence of gravitational forces, which could lead to hypoxemia. We studied a young giraffe under anesthesia using the multiple inert gas elimination technique to analyze the VA/Q distribution and arterial oxygenation and compared the results with those obtained in other species of different sizes, including humans. V A /Q distribution was broad but unimodal, and the shunt of blood flow through nonventilated lung regions was essentially absent, suggesting no lung collapse. The V A /Q match was as good as in the similarly sized horse and was even comparable to that in smaller sized animals, including rabbit and rat. The match was also similar to that in anesthetized humans. Arterial oxygenation was essentially similar in all studied species. The findings suggest that the efficiency of V A /Q matching is independent of lung size in the studied mammals that vary in weight from less than 1 to more than 400 kg. Copyright © 2016 the American Physiological Society.

Canonical correlation analysis of infant's size at birth and maternal factors: a study in rural northwest Bangladesh.

PubMed

Kabir, Alamgir; Merrill, Rebecca D; Shamim, Abu Ahmed; Klemn, Rolf D W; Labrique, Alain B; Christian, Parul; West, Keith P; Nasser, Mohammed

2014-01-01

This analysis was conducted to explore the association between 5 birth size measurements (weight, length and head, chest and mid-upper arm [MUAC] circumferences) as dependent variables and 10 maternal factors as independent variables using canonical correlation analysis (CCA). CCA considers simultaneously sets of dependent and independent variables and, thus, generates a substantially reduced type 1 error. Data were from women delivering a singleton live birth (n = 14,506) while participating in a double-masked, cluster-randomized, placebo-controlled maternal vitamin A or β-carotene supplementation trial in rural Bangladesh. The first canonical correlation was 0.42 (P<0.001), demonstrating a moderate positive correlation mainly between the 5 birth size measurements and 5 maternal factors (preterm delivery, early pregnancy MUAC, infant sex, age and parity). A significant interaction between infant sex and preterm delivery on birth size was also revealed from the score plot. Thirteen percent of birth size variability was explained by the composite score of the maternal factors (Redundancy, RY/X = 0.131). Given an ability to accommodate numerous relationships and reduce complexities of multiple comparisons, CCA identified the 5 maternal variables able to predict birth size in this rural Bangladesh setting. CCA may offer an efficient, practical and inclusive approach to assessing the association between two sets of variables, addressing the innate complexity of interactions.

Correlation between Ribosome Biogenesis and the Magnitude of Hypertrophy in Overloaded Skeletal Muscle.

PubMed

Nakada, Satoshi; Ogasawara, Riki; Kawada, Shigeo; Maekawa, Takahiro; Ishii, Naokata

2016-01-01

External loads applied to skeletal muscle cause increases in the protein translation rate, which leads to muscle hypertrophy. Although some studies have demonstrated that increases in the capacity and efficiency of translation are involved in this process, it remains unclear how these two factors are related to the magnitude of muscle hypertrophy. The present study aimed to clarify the roles played by the capacity and efficiency of translation in muscle hypertrophy. We used an improved synergist ablation in which the magnitude of compensatory hypertrophy could be controlled by partial removal of synergist muscles. Male rats were assigned to four groups in which the plantaris muscle was unilaterally subjected to weak (WK), moderate (MO), middle (MI), and strong (ST) overloading by four types of synergist ablation. Fourteen days after surgery, the weight of the plantaris muscle per body weight increased by 8%, 22%, 32% and 45%, in the WK, MO, MI and ST groups, respectively. Five days after surgery, 18+28S rRNA content (an indicator of translational capacity) increased with increasing overload, with increases of 1.8-fold (MO), 2.2-fold (MI), and 2.5-fold (ST), respectively, relative to non-overloaded muscle (NL) in the WK group. rRNA content showed a strong correlation with relative muscle weight measured 14 days after surgery (r = 0.98). The phosphorylated form of p70S6K (a positive regulator of translational efficiency) showed a marked increase in the MO group, but no further increase was observed with further increase in overload (increases of 22.6-fold (MO), 17.4-fold (MI), and 18.2-fold (ST), respectively, relative to NL in the WK group). These results indicate that increases in ribosome biogenesis at the early phase of overloading are strongly dependent on the amount of overloading, and may play an important role in increasing the translational capacity for further gain of muscular size.

Polymeric nano-encapsulation of 5-fluorouracil enhances anti-cancer activity and ameliorates side effects in solid Ehrlich Carcinoma-bearing mice.

PubMed

Haggag, Yusuf A; Osman, Mohamed A; El-Gizawy, Sanaa A; Goda, Ahmed E; Shamloula, Maha M; Faheem, Ahmed M; McCarron, Paul A

2018-05-29

Biodegradable PLGA nanoparticles, loaded with 5-fluorouracil (5FU), were prepared using a double emulsion method and characterised in terms of mean diameter, zeta potential, entrapment efficiency and in vitro release. Poly (vinyl alcohol) was used to modify both internal and external aqueous phases and shown have a significant effect on nanoparticulate size, encapsulation efficiency and the initial burst release. Addition of poly (ethylene glycol) to the particle matrix, as part of the polymeric backbone, improved significantly the encapsulation efficiency. 5FU-loaded NPs were spherical in shape and negatively charged with a size range of 185-350 nm. Biological evaluation was performed in vivo using a solid Ehrlich carcinoma (SEC) murine model. An optimised 5FU-loaded formulation containing PEG as part of a block copolymer induced a pronounced reduction in tumour volume and tumour weight, together with an improved percentage tumour growth inhibition. Drug-loaded nanoparticles showed no significant toxicity or associated changes on liver and kidney function in tested animals, whereas increased alanine aminotransferase, aspartate aminotransferase and serum creatinine were observed in animals treated with free 5FU. Histopathological examination demonstrated enhanced cytotoxic action of 5FU-loaded nanoparticles when compared to the free drug. Based on these findings, it was concluded that nano-encapsulation of 5FU using PEGylated PLGA improved encapsulation and sustained in vitro release. This leads to increased anti-tumour efficacy against SEC, with a reduction in adverse effects. Published by Elsevier Masson SAS.

Separate and combined effects of exercise training and weight loss on exercise efficiency and substrate oxidation.

PubMed

Amati, Francesca; Dubé, John J; Shay, Chris; Goodpaster, Bret H

2008-09-01

Perturbations in body weight have been shown to affect energy expenditure and efficiency during physical activity. The separate effects of weight loss and exercise training on exercise efficiency or the proportion of energy derived from fat oxidation during physical activity, however, are not known. The purpose of this study was to determine the separate and combined effects of exercise training and weight loss on metabolic efficiency, economy (EC), and fat oxidation during steady-state moderate submaximal exercise. Sixty-four sedentary older (67 +/- 0.5 yr) overweight to obese (30.7 +/- 0.4 kg/m(2)) volunteers completed 4 mo of either diet-induced weight loss (WL; n = 11), exercise training (EX; n = 36), or the combination of both interventions (WLEX; n = 17). Energy expenditure, gross efficiency (GE), EC, and proportion of energy expended from fat (EF) were determined during a 1-h submaximal (50% of peak aerobic capacity) cycle ergometry exercise before the intervention and at the same absolute work rate after the intervention. We found that EX increased GE by 4.7 +/- 2.2%. EC was similarly increased by 4.2 +/- 2.1% by EX. The addition of concomitant WL to EX (WLEX) resulted in greater increases in GE (9.0 +/- 3.3%) compared with WL alone but not compared with EX alone. These effects remained after adjusting for changes in lean body mass. The proportion of energy derived from fat during the bout of moderate exercise increased with EX and WLEX but not with WL. From these findings, we conclude that exercise training, either alone or in combination with weight loss, increases both exercise efficiency and the utilization of fat during moderate physical activity in previously sedentary, obese older adults. Weight loss alone, however, significantly improves neither efficiency nor utilization of fat during exercise.

Egg production of turbot, Scophthalmus maximus, in the Baltic Sea

NASA Astrophysics Data System (ADS)

Nissling, Anders; Florin, Ann-Britt; Thorsen, Anders; Bergström, Ulf

2013-11-01

In the brackish water Baltic Sea turbot spawn at ~ 6-9 psu along the coast and on offshore banks in ICES SD 24-29, with salinity influencing the reproductive success. The potential fecundity (the stock of vitellogenic oocytes in the pre-spawning ovary), egg size (diameter and dry weight of artificially fertilized 1-day-old eggs) and gonad dry weight were assessed for fish sampled in SD 25 and SD 28. Multiple regression analysis identified somatic weight, or total length in combination with Fulton's condition factor, as main predictors of fecundity and gonad dry weight with stage of maturity (oocyte packing density or leading cohort) as an additional predictor. For egg size, somatic weight was identified as main predictor while otolith weight (proxy for age) was an additional predictor. Univariate analysis using GLM revealed significantly higher fecundity and gonad dry weight for turbot from SD 28 (3378-3474 oocytes/g somatic weight) compared to those from SD 25 (2343 oocytes/g somatic weight), with no difference in egg size (1.05 ± 0.03 mm diameter and 46.8 ± 6.5 μg dry weight; mean ± sd). The difference in egg production matched egg survival probabilities in relation to salinity conditions suggesting selection for higher fecundity as a consequence of poorer reproductive success at lower salinities. This supports the hypothesis of higher size-specific fecundity towards the limit of the distribution of a species as an adaptation to harsher environmental conditions and lower offspring survival probabilities. Within SD 28 comparisons were made between two major fishing areas targeting spawning aggregations and a marine protected area without fishing. The outcome was inconclusive and is discussed with respect to potential fishery induced effects, effects of the salinity gradient, effects of specific year-classes, and effects of maturation status of sampled fish.

Seasonally different reproductive investment in a medium-sized rodent (Cavia aperea).

PubMed

Rübensam, K; Hribal, R; Jewgenow, K; Guenther, A

2015-09-01

Pronounced seasonal variations in day length, temperature, and resource availability characterize the temperate regions and strongly influence the animals living in these environments. To survive and reproduce successfully, animals must allocate resources among competing physiological systems, and they usually adjust their time of breeding to the most adequate season. Here, we examined whether reproductive investment in the wild guinea pig (Cavia aperea) differs across seasons. We kept animals in combined indoor-outdoor enclosures under natural light and temperature year-round. We measured littering probability, litter size, and birth weight, as well as maternal weight loss during lactation. In addition, we measured ovulation rate as a parameter to adjust reproductive investment prenatally. Our data reveal strong seasonal variations in reproductive traits despite the fact that the animals reproduced year-round. The results show a reduced reproductive investment in winter, indicated by a lower litter size and birth weight of pups, whereas investment was highest in warm seasons (summer and autumn) with higher litter size and birth weight. Maternal weight loss in lactation was highest in cold seasons even if the litter size was lower. Furthermore, we found the regulation on the proximate level of the reproductive investment, the ovulation rate, to differ significantly between the seasons. Copyright © 2015 Elsevier Inc. All rights reserved.

Sound Symbolic Patterns in Pokémon Names.

PubMed

Kawahara, Shigeto; Noto, Atsushi; Kumagai, Gakuji

2018-04-11

This paper presents a case study of sound symbolism, cases in which certain sounds tend to be associated with particular meanings. We used the corpus of all Japanese Pokémon names available as of October 2016. We tested the effects of voiced obstruents, mora counts, and vowel quality on Pokémon characters' size, weight, strength parameters, and evolution levels. We found that the number of voiced obstruents in Pokémon names correlates positively with size, weight, evolution levels, and general strength parameters, except for speed. We argue that this result is compatible with the frequency code hypothesis of Ohala. The number of moras in Pokémon names correlates positively with size, weight, evolution levels, and all strength parameters. Vowel height is also shown to have an influence on size and weight - Pokémon characters with initial high vowels tend to be smaller and lighter, although the effect size is not very large. Not only does this paper offer a new case study of sound symbolism, it provides evidence that sound symbolism is at work when naming proper nouns. © 2018 S. Karger AG, Basel.

Designing Waveform Sets with Good Correlation and Stopband Properties for MIMO Radar via the Gradient-Based Method

PubMed Central

Tang, Liang; Zhu, Yongfeng; Fu, Qiang

2017-01-01

Waveform sets with good correlation and/or stopband properties have received extensive attention and been widely used in multiple-input multiple-output (MIMO) radar. In this paper, we aim at designing unimodular waveform sets with good correlation and stopband properties. To formulate the problem, we construct two criteria to measure the correlation and stopband properties and then establish an unconstrained problem in the frequency domain. After deducing the phase gradient and the step size, an efficient gradient-based algorithm with monotonicity is proposed to minimize the objective function directly. For the design problem without considering the correlation weights, we develop a simplified algorithm, which only requires a few fast Fourier transform (FFT) operations and is more efficient. Because both of the algorithms can be implemented via the FFT operations and the Hadamard product, they are computationally efficient and can be used to design waveform sets with a large waveform number and waveform length. Numerical experiments show that the proposed algorithms can provide better performance than the state-of-the-art algorithms in terms of the computational complexity. PMID:28468308

Designing Waveform Sets with Good Correlation and Stopband Properties for MIMO Radar via the Gradient-Based Method.

PubMed

Tang, Liang; Zhu, Yongfeng; Fu, Qiang

2017-05-01

Waveform sets with good correlation and/or stopband properties have received extensive attention and been widely used in multiple-input multiple-output (MIMO) radar. In this paper, we aim at designing unimodular waveform sets with good correlation and stopband properties. To formulate the problem, we construct two criteria to measure the correlation and stopband properties and then establish an unconstrained problem in the frequency domain. After deducing the phase gradient and the step size, an efficient gradient-based algorithm with monotonicity is proposed to minimize the objective function directly. For the design problem without considering the correlation weights, we develop a simplified algorithm, which only requires a few fast Fourier transform (FFT) operations and is more efficient. Because both of the algorithms can be implemented via the FFT operations and the Hadamard product, they are computationally efficient and can be used to design waveform sets with a large waveform number and waveform length. Numerical experiments show that the proposed algorithms can provide better performance than the state-of-the-art algorithms in terms of the computational complexity.

Effects of leptin replacement alone and with exendin-4 on food intake and weight regain in weight-reduced diet-induced obese rats

PubMed Central

Haver, Alvin; Chelikani, Prasanth K.; Apenteng, Bettye; Perriotte-Olson, Curtis; Anders, Krista; Steenson, Sharalyn; Blevins, James E.

2012-01-01

Weight loss in obese humans produces a relative leptin deficiency, which is postulated to activate potent orexigenic and energy conservation mechanisms to restrict weight loss and promote weight regain. Here we determined whether leptin replacement alone or with GLP-1 receptor agonist exendin-4 attenuates weight regain or promotes greater weight loss in weight-reduced diet-induced obese (DIO) rats. Forty percent restriction in daily intake of a high-fat diet in DIO rats for 4 wk reduced body weight by 12%, body fat by 29%, and plasma leptin by 67% and normalized leptin sensitivity. When food restriction ended, body weight, body fat, and plasma leptin increased rapidly. Daily administration of leptin [3-h intraperitoneal (ip) infusions (4 nmol·kg−1·h−1)] at onset and end of dark period for 3 wk did not attenuate hyperphagia and weight regain, nor did it affect mean daily meal sizes or meal numbers. Exendin-4 (50 pmol·kg−1·h−1) infusions during the same intervals prevented postrestriction hyperphagia and weight regain by normalizing meal size. Coadministration of leptin and exendin-4 did not reduce body weight more than exendin-4 alone. Instead, leptin began to attenuate the inhibitory effects of exendin-4 on food intake, meal size, and weight regain by the end of the second week of administration. Plasma leptin in rats receiving leptin was sevenfold greater than in rats receiving vehicle and 17-fold greater than in rats receiving exendin-4. Together, these results do not support the hypothesis that leptin replacement alone or with exendin-4 attenuates weight regain or promotes greater weight loss in weight-reduced DIO rats. PMID:22510712

Metabolism, food consumption and growth of plaice ( Pleuronectes platessa) and flounder ( Platichthys flesus) in relation to fish size and temperature

NASA Astrophysics Data System (ADS)

Fonds, M.; Cronie, R.; Vethaak, A. D.; Van Der Puyl, P.

Daily rates of oxygen consumption, food consumption and growth of plaice ( Pleuronectes platessa) and flounder ( Platichthys flesus) have been measured in the laboratory at various constant temperatures. Oxygen consumption was related to body weight of the fish as a power function, with a weight exponent of between 0.71 and 0.85. No significant effects of temperature or feeding on this exponent were found. Flounder showed a significantly higher metabolic rate and a higher temperature coefficient for metabolism than plaice. Maximum daily rates of food consumption and the weight increment of fish fed with excess rations of fresh mussel meat could also be related to fish weights by means of power functions. For plaice these exponents decreased from about 0.9 at low temperatures (2-6 C°) to about 0.7 at high temperatures (18-22°C). Such a temperature effect on the weight exponent indicates that small juvenile fish eat more and grow faster at higher temperatures than do large older fish, and that large fish do better at low temperatures. After scaling of daily food consumption and growth in proportion to metabolic weights of the fish (W 0.78), feeding and growth at different fish sizes and temperatures can be compared and temperature-growth rate models can be used for investigations of feeding in natural populations. Compared to plaice, young flounder ate more and grew faster at higher temperatures (> 14°C). This may partly explain the preference of flounder for the shallower parts of coastal areas and estuaries, where summer temperatures and food densities are higher. Energy budgets of young plaice and flounder fed with excess rations of mussel meat indicate that at least 29% of the food energy is used for metabolism while about 37% of the food energy is converted into growth. The net conversion efficiency was estimated at 0.45 for food and growth in units of ash-free dry weight, and at 0.53 for food and growth in energy units. Analysis of the energy budget showed that the assimilated physiologically useful food energy is divided almost equally over metabolism (42-47%) and growth (53-55%). It is suggested that flatfish spend relatively less energy in swimming and therefore convert more food energy into growth than (pelagic) roundfish.

Emission characteristics for gaseous- and size-segregated particulate PAHs in coal combustion flue gas from circulating fluidized bed (CFB) boiler.

PubMed

Wang, Ruwei; Liu, Guijian; Sun, Ruoyu; Yousaf, Balal; Wang, Jizhong; Liu, Rongqiong; Zhang, Hong

2018-07-01

The partitioning behavior of polycyclic aromatic hydrocarbons (PAHs) between gaseous and particulate phases from coal-fired power plants (CFPPs) is critically important to predict PAH removal by dust control devices. In this study, 16 US-EPA priority PAHs in gaseous and size-segregated particulate phases at the inlet and outlet of the fabric filter unit (FFs) of a circulating fluidized bed (CFB) boiler were analyzed. The partitioning mechanisms of PAHs between gaseous and particulate phases and in particles of different size classes were investigated. We found that the removal efficiencies of PAHs are 45.59% and 70.67-89.06% for gaseous and particulate phases, respectively. The gaseous phase mainly contains low molecular weight (LMW) PAHs (2- and 3-ring PAHs), which is quite different from the particulate phase that mainly contains medium and high molecular weight (MMW and HMW) PAHs (4- to 6-ring PAHs). The fractions of LMW PAHs show a declining trend with the decrease of particle size. The gas-particle partitioning of PAHs is primarily controlled by organic carbon absorption, in addition, it has a clear dependence on the particle sizes. Plot of log (TPAH/PM) against logD p shows that all slope values were below -1, suggesting that PAHs were mainly adsorbed to particulates. The adsorption effect of PAHs in size-segregated PMs for HMW PAHs is more evident than LMW PAHs. The particle size distributions (PSDs) of individual PAHs show that most of PAHs exhibit bi-model structures, with one mode peaking in the accumulation size range (2.1-1.1 μm) and another mode peaking in coarse size range (5.8-4.7 μm). The intensities of these two peaks vary in function of ring number of PAHs, which is likely attributed to Kelvin effect that the less volatile HMW PAH species preferentially condense onto the finer particulates. The emission factor of PAHs was calculated as 3.53 mg/kg of coal burned, with overall mean EF PAH of 0.55 and 2.98 mg/kg for gaseous and particulate phase, respectively. Moreover, the average emission amount of PAHs for the investigated CFPP was 1016.6 g/day and 371073.6 g/y, respectively. Copyright © 2018 Elsevier Ltd. All rights reserved.

Transmission of linear regression patterns between time series: From relationship in time series to complex networks

NASA Astrophysics Data System (ADS)

Gao, Xiangyun; An, Haizhong; Fang, Wei; Huang, Xuan; Li, Huajiao; Zhong, Weiqiong; Ding, Yinghui

2014-07-01

The linear regression parameters between two time series can be different under different lengths of observation period. If we study the whole period by the sliding window of a short period, the change of the linear regression parameters is a process of dynamic transmission over time. We tackle fundamental research that presents a simple and efficient computational scheme: a linear regression patterns transmission algorithm, which transforms linear regression patterns into directed and weighted networks. The linear regression patterns (nodes) are defined by the combination of intervals of the linear regression parameters and the results of the significance testing under different sizes of the sliding window. The transmissions between adjacent patterns are defined as edges, and the weights of the edges are the frequency of the transmissions. The major patterns, the distance, and the medium in the process of the transmission can be captured. The statistical results of weighted out-degree and betweenness centrality are mapped on timelines, which shows the features of the distribution of the results. Many measurements in different areas that involve two related time series variables could take advantage of this algorithm to characterize the dynamic relationships between the time series from a new perspective.

Transmission of linear regression patterns between time series: from relationship in time series to complex networks.

PubMed

Gao, Xiangyun; An, Haizhong; Fang, Wei; Huang, Xuan; Li, Huajiao; Zhong, Weiqiong; Ding, Yinghui

2014-07-01

The linear regression parameters between two time series can be different under different lengths of observation period. If we study the whole period by the sliding window of a short period, the change of the linear regression parameters is a process of dynamic transmission over time. We tackle fundamental research that presents a simple and efficient computational scheme: a linear regression patterns transmission algorithm, which transforms linear regression patterns into directed and weighted networks. The linear regression patterns (nodes) are defined by the combination of intervals of the linear regression parameters and the results of the significance testing under different sizes of the sliding window. The transmissions between adjacent patterns are defined as edges, and the weights of the edges are the frequency of the transmissions. The major patterns, the distance, and the medium in the process of the transmission can be captured. The statistical results of weighted out-degree and betweenness centrality are mapped on timelines, which shows the features of the distribution of the results. Many measurements in different areas that involve two related time series variables could take advantage of this algorithm to characterize the dynamic relationships between the time series from a new perspective.

Comparison of Two Multidisciplinary Optimization Strategies for Launch-Vehicle Design

NASA Technical Reports Server (NTRS)

Braun, R. D.; Powell, R. W.; Lepsch, R. A.; Stanley, D. O.; Kroo, I. M.

1995-01-01

The investigation focuses on development of a rapid multidisciplinary analysis and optimization capability for launch-vehicle design. Two multidisciplinary optimization strategies in which the analyses are integrated in different manners are implemented and evaluated for solution of a single-stage-to-orbit launch-vehicle design problem. Weights and sizing, propulsion, and trajectory issues are directly addressed in each optimization process. Additionally, the need to maintain a consistent vehicle model across the disciplines is discussed. Both solution strategies were shown to obtain similar solutions from two different starting points. These solutions suggests that a dual-fuel, single-stage-to-orbit vehicle with a dry weight of approximately 1.927 x 10(exp 5)lb, gross liftoff weight of 2.165 x 10(exp 6)lb, and length of 181 ft is attainable. A comparison of the two approaches demonstrates that treatment or disciplinary coupling has a direct effect on optimization convergence and the required computational effort. In comparison with the first solution strategy, which is of the general form typically used within the launch vehicle design community at present, the second optimization approach is shown to he 3-4 times more computationally efficient.

SU-F-18C-12: On the Relationship of the Weighted Dose to the Surface Dose In Abdominal CT - Patient Size Dependency

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

Zhou, Y; Scott, A; Allahverdian, J

2014-06-15

Purpose: It is possible to measure the patient surface dose non-invasively using radiolucent dosimeters. However, the patient size specific weighted dose remains unknown. We attempted to study the weighted dose to surface dose relationship as the patient size varies in abdominal CT. Methods: Seven abdomen phantoms (CIRS TE series) simulating patients from an infant to a large adult were used. Size specific doses were measured with a 100 mm CT chamber under axial scans using a Siemens Sensation 64 (mCT) and a GE 750 HD. The scanner settings were 120 kVp, 200 mAs with fully opened collimations. Additional kVps (80,more » 100, 140) were added depending on the phantom sizes. The ratios (r) of the weighted CT dose (Dw) to the surface dose (Ds) were related to the phantom size (L) defined as the diameter resulting the equivalent cross-sectional area. Results: The Dw versus Ds ratio (r) was fitted to a linear relationship: r = 1.083 − 0.007L (R square = 0.995), and r = 1.064 − 0.007L (R square = 0.953), for Siemens Sensation 64 and GE 750 HD, respectively. The relationship appears to be independent of the scanner specifics. Conclusion: The surface dose to the weighted dose ratio decreases linearly as the patient size increases. The result is independent of the scanner specifics. The result can be used to obtain in vivo CT dosimetry in abdominal CT.« less

RGD/TAT-functionalized chitosan-graft-PEI-PEG gene nanovector for sustained delivery of NT-3 for potential application in neural regeneration.

PubMed

Wu, Dongni; Zhang, Yongnu; Xu, Xiaoting; Guo, Ting; Xie, Deming; Zhu, Rong; Chen, Shengfeng; Ramakrishna, Seeram; He, Liumin

2018-05-01

In this study, we prepared a multifunctional gene delivery nanovector containing a chitosan (CS) backbone and polyethylenimine (PEI) arms with arginine-glycine-aspartate (RGD)/twin-arginine translocation (TAT) conjugated via polyethylene glycol (PEG). Branched PEI, with a molecular weight of 2000 Da, was used to achieve a balance between biocompatibility and transfection efficiency, whereas RGD/TAT peptides were conjugated for enhanced targeting ability and cellular uptake. Synthesis of the copolymers was confirmed by characterizing the chemical structure with 1 H nuclear magnetic resonance and Fourier Transform Infrared Spectroscopy (FTIR). The nanovector was biocompatible with cells and showed excellent capability for DNA condensation; the resulting complexes with DNA were well-formed, and possessed small particle size and reasonable positive charge. Higher gene transfection efficiency, compared to that achieved with PEI (25 kDa), was confirmed in tumor (HeLa cells) and normal cells (293T and NIH 3T3 cells). More importantly, the cells transfected with the chitosan-graft-PEI-PEG/pCMV-EGFP-Ntf3 complex produced sustained neurotrophin-3 with a linear increase in cumulative concentration, which induced neuronal differentiation of neural stem cell and promoted neurite outgrowth. These findings suggested that our multifunctional copolymers might be ideal nanovectors for engineering cells via gene transfection, and could potentially be applied in tumor therapy and regenerative medicine. We successfully prepared a multifunctional gene delivery nanovector containing branched PEI with a molecular weight of 2000 Da to balance between biocompatibility and transfection efficiency, and RGD/TAT peptides for enhanced targeting ability and cellular uptake. The well-formed CPPP/DNA complexes of small particle size and reasonable positive charges potentially enhanced gene transfection in both tumor and normal cells. More importantly, the CPPP/pCMV-EGFP-Ntf3 complex-transfected 293T cells could produce sustained NT-3 with a constant ratio, which induced neuron differentiation of NSC and promoted neurite outgrowth. Therefore, our study provided an effective strategy for producing neurotrophins by engineering cells with gene delivery, which deserved wide investigation and potential application in regenerative medicine. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

NV-CMOS HD camera for day/night imaging

NASA Astrophysics Data System (ADS)

Vogelsong, T.; Tower, J.; Sudol, Thomas; Senko, T.; Chodelka, D.

2014-06-01

SRI International (SRI) has developed a new multi-purpose day/night video camera with low-light imaging performance comparable to an image intensifier, while offering the size, weight, ruggedness, and cost advantages enabled by the use of SRI's NV-CMOS HD digital image sensor chip. The digital video output is ideal for image enhancement, sharing with others through networking, video capture for data analysis, or fusion with thermal cameras. The camera provides Camera Link output with HD/WUXGA resolution of 1920 x 1200 pixels operating at 60 Hz. Windowing to smaller sizes enables operation at higher frame rates. High sensitivity is achieved through use of backside illumination, providing high Quantum Efficiency (QE) across the visible and near infrared (NIR) bands (peak QE <90%), as well as projected low noise (<2h+) readout. Power consumption is minimized in the camera, which operates from a single 5V supply. The NVCMOS HD camera provides a substantial reduction in size, weight, and power (SWaP) , ideal for SWaP-constrained day/night imaging platforms such as UAVs, ground vehicles, fixed mount surveillance, and may be reconfigured for mobile soldier operations such as night vision goggles and weapon sights. In addition the camera with the NV-CMOS HD imager is suitable for high performance digital cinematography/broadcast systems, biofluorescence/microscopy imaging, day/night security and surveillance, and other high-end applications which require HD video imaging with high sensitivity and wide dynamic range. The camera comes with an array of lens mounts including C-mount and F-mount. The latest test data from the NV-CMOS HD camera will be presented.

Why Barbie Feels Heavier than Ken: The Influence of Size-Based Expectancies and Social Cues on the Illusory Perception of Weight

ERIC Educational Resources Information Center

Dijker, Anton J. M.

2008-01-01

In order to examine the relative influence of size-based expectancies and social cues on the perceived weight of objects, two studies were performed, using equally weighing dolls differing in sex-related and age-related vulnerability or physical strength cues. To increase variation in perceived size, stimulus objects were viewed through optical…

Comprehensive Truck Size and Weight Study : volume 1 : executive summary

DOT National Transportation Integrated Search

2000-08-01

This report presents results of a comprehensive examination of issues surrounding current Federal truck size : and weight (TS&W) limits and potential impacts of changes to those limits. This is the first comprehensive : TS&W study by the Department s...

Comparison of selected analytical techniques for protein sizing, quantitation and molecular weight determination.

PubMed

Goetz, H; Kuschel, M; Wulff, T; Sauber, C; Miller, C; Fisher, S; Woodward, C

2004-09-30

Protein analysis techniques are developing fast due to the growing number of proteins obtained by recombinant DNA techniques. In the present paper we compare selected techniques, which are used for protein sizing, quantitation and molecular weight determination: sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), lab-on-a-chip or microfluidics technology (LoaC), size exclusion chromatography (SEC) and mass spectrometry (MS). We compare advantages and limitations of each technique in respect to different application areas, analysis time, protein sizing and quantitation performance.

ZResponse to selection, heritability and genetic correlations between body weight and body size in Pacific white shrimp, Litopenaeus vannamei

NASA Astrophysics Data System (ADS)

Andriantahina, Farafidy; Liu, Xiaolin; Huang, Hao; Xiang, Jianhai

2012-03-01

To quantify the response to selection, heritability and genetic correlations between weight and size of Litopenaeus vannamei, the body weight (BW), total length (TL), body length (BL), first abdominal segment depth (FASD), third abdominal segment depth (TASD), first abdominal segment width (FASW), and partial carapace length (PCL) of 5-month-old parents and of offspnng were measured by calculating seven body measunngs of offspnng produced by a nested mating design. Seventeen half-sib families and 42 full-sib families of L. vannamei were produced using artificial fertilization from 2-4 dams by each sire, and measured at around five months post-metamorphosis. The results show that hentabilities among vanous traits were high: 0.515±0.030 for body weight and 0.394±0.030 for total length. After one generation of selection. the selection response was 10.70% for offspring growth. In the 5th month, the realized heritability for weight was 0.296 for the offspnng generation. Genetic correlations between body weight and body size were highly variable. The results indicate that external morphological parameters can be applied dunng breeder selection for enhancing the growth without sacrificing animals for determining the body size and breed ability; and selective breeding can be improved significantly, simultaneously with increased production.

Relative importance of expertise, lifting height and weight lifted on posture and lumbar external loading during a transfer task in manual material handling.

PubMed

Plamondon, André; Larivière, Christian; Delisle, Alain; Denis, Denys; Gagnon, Denis

2012-01-01

The objective of this study was to measure the effect size of three important factors in manual material handling, namely expertise, lifting height and weight lifted. The effect of expertise was evaluated by contrasting 15 expert and 15 novice handlers, the effect of the weight lifted with a 15-kg box and a 23-kg box and the effect of lifting height with two different box heights: ground level and a 32 cm height. The task consisted of transferring a series of boxes from a conveyor to a hand trolley. Lifting height and weight lifted had more effect size than expertise on external back loading variables (moments) while expertise had low impact. On the other hand, expertise showed a significant effect of posture variables on the lumbar spine and knees. All three factors are important, but for a reduction of external back loading, the focus should be on the lifting height and weight lifted. The objective was to measure the effect size of three important factors in a transfer of boxes from a conveyor to a hand trolley. Lifting height and weight lifted had more effect size than expertise on external back loading variables but expertise was a major determinant in back posture.

Generalized weighted likelihood density estimators with application to finite mixture of exponential family distributions

PubMed Central

Zhan, Tingting; Chevoneva, Inna; Iglewicz, Boris

2010-01-01

The family of weighted likelihood estimators largely overlaps with minimum divergence estimators. They are robust to data contaminations compared to MLE. We define the class of generalized weighted likelihood estimators (GWLE), provide its influence function and discuss the efficiency requirements. We introduce a new truncated cubic-inverse weight, which is both first and second order efficient and more robust than previously reported weights. We also discuss new ways of selecting the smoothing bandwidth and weighted starting values for the iterative algorithm. The advantage of the truncated cubic-inverse weight is illustrated in a simulation study of three-components normal mixtures model with large overlaps and heavy contaminations. A real data example is also provided. PMID:20835375

Cleavage of the main carbon chain backbone of high molecular weight polyacrylamide by aerobic and anaerobic biological treatment.

PubMed

Song, Wenzhe; Zhang, Yu; Gao, Yingxin; Chen, Dong; Yang, Min

2017-12-01

High molecular weight partially hydrolyzed polyacrylamide (PAM) can be bio-hydrolyzed on the amide side group, however, solid evidence regarding the biological cleavage of its main carbon chain backbone is limited. In this study, viscometry, flow field-flow fractionation multi-angle light scattering (FFF-MALS), and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) analysis were used to investigate the biodegradability of PAM with a nominal molecular weight of 2 × 10 7  Da (Da) in two suspended aerobic (25 and 40 °C) and two upflow anaerobic blanket reactors (35 and 55 °C) operated for 470 d under a hydraulic residence time (HRT) of 2 d. Both anaerobic and aerobic biological treatment reduced the viscosity from 2.02 cp in the influent to 1.45-1.60 cp, and reduced the molecular weight of PAM using FFF-MALS from 2.17 × 10 7  Da to less than one-third its original size. The removals of both the amide group and carbon chain backbone in the PAM molecule were further supported by the FTIR analysis. In comparison with the other conditions, thermophilic anaerobic treatment exhibited higher efficiency for PAM biodegradation. Batch test excluded the influence of temperature on the molecular weight of PAM over the range 25-55 °C, suggesting that cleavage of the main carbon chain backbone was attributed to biological degradation. Our results suggested that high molecular weight PAM was biodegradable, but mineralization did not occur. Copyright © 2017 Elsevier Ltd. All rights reserved.

STIMULI-RESPONSIVE POLYMERS WITH ENHANCED EFFICIENCY IN RESERVOIR RECOVERY PROCESSES

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

Charles McCormick; Roger Hester

This sixth and final progress report for DOE Award Number DE-FC26-01BC15317 describes research during the period March 01, 2004 through August 31, 2004 performed at the University of Southern Mississippi on ''Stimuli Responsive Polymers with Enhanced Efficiency in Reservoir Recovery'' processes. Significantly, terpolymers that are responsive to changes in pH and ionic strength have been synthesized, characterized, and their solution properties have been extensively examined. Terpolymers composed of acrylamide, a carboxylated acrylamido monomer (AMBA), and a quaternary ammonium monomer (AMBATAC) with balanced compositions of the latter two, exhibit increases in aqueous solution viscosity as NaCl concentration is increased. This increasemore » in polymer coil size can be expected upon injection of this type of polymer into oil reservoirs of moderate-to-high salinity, leading to better mobility control. The opposite effect (loss of viscosity) is observed for conventional polymer systems. Additionally polymer mobility characteristics have been conducted for a number of hydrophilic copolymers utilizing an extensional flow apparatus and size exclusion chromatography. This study reveled that oil recovery enhancement through use of polymers in a water flood is due to the polymer's resistance to deformation as it flows through the reservoir. Individual polymers when in aqueous solution form coils. The larger the polymer's coil size, the greater the polymer's resistance to extensional flow and the more effective the polymer is in enhancing oil recovery. Large coil sizes are obtained by increasing the polymer molecular weight and having macromolecular structures that favor greater swelling of the coil by the aqueous solvent conditions (temperature, pH and electrolyte concentration) existing in the reservoir.« less

Cluster randomised crossover trials with binary data and unbalanced cluster sizes: application to studies of near-universal interventions in intensive care.

PubMed

Forbes, Andrew B; Akram, Muhammad; Pilcher, David; Cooper, Jamie; Bellomo, Rinaldo

2015-02-01

Cluster randomised crossover trials have been utilised in recent years in the health and social sciences. Methods for analysis have been proposed; however, for binary outcomes, these have received little assessment of their appropriateness. In addition, methods for determination of sample size are currently limited to balanced cluster sizes both between clusters and between periods within clusters. This article aims to extend this work to unbalanced situations and to evaluate the properties of a variety of methods for analysis of binary data, with a particular focus on the setting of potential trials of near-universal interventions in intensive care to reduce in-hospital mortality. We derive a formula for sample size estimation for unbalanced cluster sizes, and apply it to the intensive care setting to demonstrate the utility of the cluster crossover design. We conduct a numerical simulation of the design in the intensive care setting and for more general configurations, and we assess the performance of three cluster summary estimators and an individual-data estimator based on binomial-identity-link regression. For settings similar to the intensive care scenario involving large cluster sizes and small intra-cluster correlations, the sample size formulae developed and analysis methods investigated are found to be appropriate, with the unweighted cluster summary method performing well relative to the more optimal but more complex inverse-variance weighted method. More generally, we find that the unweighted and cluster-size-weighted summary methods perform well, with the relative efficiency of each largely determined systematically from the study design parameters. Performance of individual-data regression is adequate with small cluster sizes but becomes inefficient for large, unbalanced cluster sizes. When outcome prevalences are 6% or less and the within-cluster-within-period correlation is 0.05 or larger, all methods display sub-nominal confidence interval coverage, with the less prevalent the outcome the worse the coverage. As with all simulation studies, conclusions are limited to the configurations studied. We confined attention to detecting intervention effects on an absolute risk scale using marginal models and did not explore properties of binary random effects models. Cluster crossover designs with binary outcomes can be analysed using simple cluster summary methods, and sample size in unbalanced cluster size settings can be determined using relatively straightforward formulae. However, caution needs to be applied in situations with low prevalence outcomes and moderate to high intra-cluster correlations. © The Author(s) 2014.

Brazilian Maternal Weight Perception and Satisfaction With Toddler Body Size: A Study in Primary Health Care.

PubMed

Duarte, Luciane Simões; Fujimori, Elizabeth; Minagawa Toriyama, Aurea Tamami; Palombo, Claudia Nery Teixeira; Borges, Ana Luiza Vilela; Kurihayashi, Aline Yukari

2016-01-01

Maternal perception and satisfaction with child's weight status are important to detect early and to successfully treat the extremes in weight, especially during early childhood, when the child is more dependent on maternal care. To assess the inaccuracy of maternal perception of toddler body size and its associated factors and to analyze maternal dissatisfaction with toddler body size. Cross-sectional study with 135 mother-toddler dyads attending Primary Health Care Facilities, São Paulo, Brazil. Children's actual weight status was classified using body mass index-for-age. Inaccuracy and dissatisfaction were assessed using an image scale. We used logistic regression to identify the factors associated with inaccuracy of maternal perception of toddler body size. Inaccuracy in maternal perception was observed in 34.8% of participants. Mothers of excessive weight children were more likely to have inaccurate perceptions (OR=4.6; 95% CI 2.0-10.7), and mothers of children who attended well-child care were less likely to have inaccurate perceptions (OR=0.3, 95% CI 0.1-0.9). More than half of mothers (52.6%) were dissatisfied with their toddler's size and desired a larger child (75.0% of mothers of underweight children, 25.0% of mothers whose children were at risk for overweight and 23.0% of mothers of overweight children). The majority of mothers were inaccurate in their perception and was dissatisfied with their toddler's body size. Maternal inaccuracy and dissatisfaction differed by the weight status of the toddler. Attendance at well-child visits was an effective way to decrease maternal inaccuracy, which reinforces the importance of the influence of health professionals. Copyright © 2016 Elsevier Inc. All rights reserved.

Associations between maternal exposure to air pollution and traffic noise and newborn's size at birth: A cohort study.

PubMed

Hjortebjerg, Dorrit; Andersen, Anne Marie Nybo; Ketzel, Matthias; Pedersen, Marie; Raaschou-Nielsen, Ole; Sørensen, Mette

2016-10-01

Maternal exposure to air pollution and traffic noise has been suggested to impair fetal growth, but studies have reported inconsistent findings. Objective To investigate associations between residential air pollution and traffic noise during pregnancy and newborn's size at birth. From a national birth cohort we identified 75,166 live-born singletons born at term with information on the children's size at birth. Residential address history from conception until birth was collected and air pollution (NO2 and NOx) and road traffic noise was modeled at all addresses. Associations between exposures and indicators of newborn's size at birth: birth weight, placental weight and head and abdominal circumference were analyzed by linear and logistic regression, and adjusted for potential confounders. In mutually adjusted models we found a 10μg/m(3) higher time-weighted mean exposure to NO2 during pregnancy to be associated with a 0.35mm smaller head circumference (95% confidence interval (CI): 95% CI: -0.57; -0.12); a 0.50mm smaller abdominal circumference (95% CI: -0.80; -0.20) and a 5.02g higher placental weight (95% CI: 2.93; 7.11). No associations were found between air pollution and birth weight. Exposure to residential road traffic noise was weakly associated with reduced head circumference, whereas none of the other newborn's size indicators were associated with noise, neither before nor after adjustment for air pollution. This study indicates that air pollution may result in a small reduction in offspring's birth head and abdominal circumference, but not birth weight, whereas traffic noise seems not to affect newborn's size at birth. Copyright © 2016 Elsevier Ltd. All rights reserved.

MATERNAL HEIGHT AND PRE-PREGNANCY WEIGHT STATUS ARE ASSOCIATED WITH FETAL GROWTH PATTERNS AND NEWBORN SIZE.

PubMed

Pölzlberger, Eva; Hartmann, Beda; Hafner, Erich; Stümpflein, Ingrid; Kirchengast, Sylvia

2017-05-01

The impact of maternal height, pre-pregnancy weight status and gestational weight gain on fetal growth patterns and newborn size was analysed using a dataset of 4261 singleton term births taking place at the Viennese Danube Hospital between 2005 and 2013. Fetal growth patterns were reconstructed from three ultrasound examinations carried out at the 11th/12th, 20th/21th and 32th/33th weeks of gestation. Crown-rump length, biparietal diameter, fronto-occipital diameter, head circumference, abdominal transverse diameter, abdominal anterior-posterior diameter, abdominal circumference and femur length were determined. Birth weight, birth length and head circumference were measured immediately after birth. The vast majority of newborns were of normal weight, i.e. between 2500 and 4000 g. Maternal height showed a just-significant but weak positive association (r=0.03: p=0.039) with crown-rump length at the first trimester and with the majority of fetal parameters at the second trimester (r>0.06; p0.09; p0.08; p0.17; p0.13; p0.13; p<0.001), were significantly positively associated with newborn size. Some of these associations were quite weak and the statistical significance was mainly due to the large sample size. The association patterns between maternal height and pre-pregnancy weight status with fetal growth patterns (p<0.001), as well as newborn size (p<0.001), were independent of maternal age, nicotine consumption and fetal sex. In general, taller and heavier women gave birth to larger infants. This association between maternal size and fetal growth patterns was detectable from the first trimester onwards.

Analytical and experimental study of structurally efficient composite hat-stiffened panels loaded in axial compression

NASA Technical Reports Server (NTRS)

Williams, J. G.; Mikulus, M. M., Jr.

1976-01-01

Structural efficiency studies were made to determine the weight saving potential of graphite/epoxy composite structures for compression panel applications. Minimum weight hat-stiffened and open corrugation configurations were synthesized using a nonlinear mathematical programming technique. Selected configurations were built and tested to study local and Euler buckling characteristics. Test results for 23 panels critical in local buckling and six panels critical in Euler buckling are compared with analytical results obtained using the BUCLASP-2 branched plate buckling program. A weight efficiency comparison is made between composite and aluminum compression panels using metal test data generated by the NACA. Theoretical studies indicate that potential weight savings of up to 50% are possible for composite hat-stiffened panels when compared with similar aluminum designs. Weight savings of 32% to 42% were experimentally achieved. Experience suggests that most of the theoretical weight saving potential is available if design deficiencies are eliminated and strict fabrication control is exercised.

Effects of floc and bubble size on the efficiency of the dissolved air flotation (DAF) process.

PubMed

Han, Mooyoung; Kim, Tschung-il; Kim, Jinho

2007-01-01

Dissolved air flotation (DAF) is a method for removing particles from water using micro bubbles instead of settlement. The process has proved to be successful and, since the 1960s, accepted as an alternative to the conventional sedimentation process for water and wastewater treatment. However, limited research into the process, especially the fundamental characteristics of bubbles and particles, has been carried out. The single collector collision model is not capable of determining the effects of particular characteristics, such as the size and surface charge of bubbles and particles. Han has published a set of modeling results after calculating the collision efficiency between bubbles and particles by trajectory analysis. His major conclusion was that collision efficiency is maximum when the bubbles and particles are nearly the same size but have opposite charge. However, experimental verification of this conclusion has not been carried out yet. This paper describes a new method for measuring the size of particles and bubbles developed using computational image analysis. DAF efficiency is influenced by the effect of the recycle ratio on various average floc sizes. The larger the recycle ratio, the higher the DAF efficiency at the same pressure and particle size. The treatment efficiency is also affected by the saturation pressure, because the bubble size and bubble volume concentration are controlled by the pressure. The highest efficiency is obtained when the floc size is larger than the bubble size. These results, namely that the highest collision efficiency occurs when the particles and bubbles are about the same size, are more in accordance with the trajectory model than with the white water collector model, which implies that the larger the particles, the higher is the collision efficiency.

Design study of steel V-Belt CVT for electric vehicles

NASA Technical Reports Server (NTRS)

Swain, J. C.; Klausing, T. A.; Wilcox, J. P.

1980-01-01

A continuously variable transmission (CVT) design layout was completed. The intended application was for coupling the flywheel to the driveline of a flywheel battery hybrid electric vehicle. The requirements were that the CVT accommodate flywheel speeds from 14,000 to 28,000 rpm and driveline speeds of 850 to 5000 rpm without slipping. Below 850 rpm a slipping clutch was used between the CVT and the driveline. The CVT was required to accommodate 330 ft-lb maximum torque and 100 hp maximum transient. The weighted average power was 22 hp, the maximum allowable full range shift time was 2 seconds and the required lift was 2600 hours. The resulting design utilized two steel V-belts in series to accommodate the required wide speed ratio. The size of the CVT, including the slipping clutch, was 20.6 inches long, 9.8 inches high and 13.8 inches wide. The estimated weight was 155 lb. An overall potential efficiency of 95 percent was projected for the average power condition.

An IPv6 routing lookup algorithm using weight-balanced tree based on prefix value for virtual router

NASA Astrophysics Data System (ADS)

Chen, Lingjiang; Zhou, Shuguang; Zhang, Qiaoduo; Li, Fenghua

2016-10-01

Virtual router enables the coexistence of different networks on the same physical facility and has lately attracted a great deal of attention from researchers. As the number of IPv6 addresses is rapidly increasing in virtual routers, designing an efficient IPv6 routing lookup algorithm is of great importance. In this paper, we present an IPv6 lookup algorithm called weight-balanced tree (WBT). WBT merges Forwarding Information Bases (FIBs) of virtual routers into one spanning tree, and compresses the space cost. WBT's average time complexity and the worst case time complexity of lookup and update process are both O(logN) and space complexity is O(cN) where N is the size of routing table and c is a constant. Experiments show that WBT helps reduce more than 80% Static Random Access Memory (SRAM) cost in comparison to those separation schemes. WBT also achieves the least average search depth comparing with other homogeneous algorithms.

On the Hardness of Subset Sum Problem from Different Intervals

NASA Astrophysics Data System (ADS)

Kogure, Jun; Kunihiro, Noboru; Yamamoto, Hirosuke

The subset sum problem, which is often called as the knapsack problem, is known as an NP-hard problem, and there are several cryptosystems based on the problem. Assuming an oracle for shortest vector problem of lattice, the low-density attack algorithm by Lagarias and Odlyzko and its variants solve the subset sum problem efficiently, when the “density” of the given problem is smaller than some threshold. When we define the density in the context of knapsack-type cryptosystems, weights are usually assumed to be chosen uniformly at random from the same interval. In this paper, we focus on general subset sum problems, where this assumption may not hold. We assume that weights are chosen from different intervals, and make analysis of the effect on the success probability of above algorithms both theoretically and experimentally. Possible application of our result in the context of knapsack cryptosystems is the security analysis when we reduce the data size of public keys.

An Expressive, Lightweight and Secure Construction of Key Policy Attribute-Based Cloud Data Sharing Access Control

NASA Astrophysics Data System (ADS)

Lin, Guofen; Hong, Hanshu; Xia, Yunhao; Sun, Zhixin

2017-10-01

Attribute-based encryption (ABE) is an interesting cryptographic technique for flexible cloud data sharing access control. However, some open challenges hinder its practical application. In previous schemes, all attributes are considered as in the same status while they are not in most of practical scenarios. Meanwhile, the size of access policy increases dramatically with the raise of its expressiveness complexity. In addition, current research hardly notices that mobile front-end devices, such as smartphones, are poor in computational performance while too much bilinear pairing computation is needed for ABE. In this paper, we propose a key-policy weighted attribute-based encryption without bilinear pairing computation (KP-WABE-WB) for secure cloud data sharing access control. A simple weighted mechanism is presented to describe different importance of each attribute. We introduce a novel construction of ABE without executing any bilinear pairing computation. Compared to previous schemes, our scheme has a better performance in expressiveness of access policy and computational efficiency.

Thermal to Electric Energy Conversion for Cyclic Heat Loads

NASA Astrophysics Data System (ADS)

Whitehead, Benjamin E.

Today, we find cyclic heat loads almost everywhere. When we drive our cars, the engines heat up while we are driving and cool while parked. Processors heat while the computer is in use at the office and cool when idle at night. The sun heats the earth during the day and the earth radiates that heat into space at night. With modern technology, we have access to a number of methods to take that heat and convert it into electricity, but, before selecting one, we need to identify the parameters that inform decision making. The majority of the parameters for most systems include duty cycle, total cost, weight, size, thermal efficiency, and electrical efficiency. However, the importance of each of these will depend on the application. Size and weight take priority in a handheld device, while efficiency dominates in a power plant, and duty cycle is likely to dominate in highly demanding heat pump applications. Over the past decade, developments in semiconductor technology has led to the creation of the thermoelectric generator. With no moving parts and a nearly endlessly scalable nature, these generators present interesting opportunities for taking advantage of any source of waste heat. However, these generators are typically only capable of 5-8% efficiency from conversion of thermal to electric energy. [1]. Similarly, advancements in photovoltaic cells has led to the development of thermophotovoltaics. By heating an emitter to a temperature so it radiates light, a thermophotovoltaic cell then converts that light into electricity. By selecting materials that emit light in the optimal ranges of the appropriate photovoltaic cells, thermophotovoltaic systems can potentially exceed the current maximum of 10% efficiency. [2]. By pressurizing certain metal powders with hydrogen, hydrogen can be bound to the metal, creating a metal hydride, from which hydrogen can be later re-extracted under the correct pressure and temperature conditions. Since this hydriding reaction is exothermic, and dehydriding is endothermic, we can use the reaction to control temperature and store or release energy as desired. Connecting the liberated hydrogen gas to a hydrogen/air or hydrogen/oxygen fuel cell can then generate useful electrical power. A fuel cell operates by flowing hydrogen and oxygen over a membrane that only allows protons through. This process creates a voltage through the separation of the negatively charged electrons and positively charged water. Typical fuel cells operate at 30-40% efficiency with research aiming to increase that number to 65% with solid oxide fuel cells. [3]. In this thesis, I develop several models to size metal hydride systems, identify the critical design parameters of a metal hydride system, and predict hydrogen production for a given heat source. The first model consists of a lumped parameter treatment that analyzes how the effects of varying metal hydrides and heat source values change the dehydriding process. The second model uses COMSOLRTM Multiphysics to create a higher fidelity simulation of the heat transfer within a metal hydride bed by calculating the spatial heat transfer as well as the porous nature of the system. The Comsol model shows that thermal conductivity is the highest sensitivity parameter of those studied, and therefore should be the primary focus for system design. The model also shows that the efficiency of the system is relatively independent of the duty cycle of the heat source.

Algebraic solution for the forward displacement analysis of the general 6-6 stewart mechanism

NASA Astrophysics Data System (ADS)

Wei, Feng; Wei, Shimin; Zhang, Ying; Liao, Qizheng

2016-01-01

The solution for the forward displacement analysis(FDA) of the general 6-6 Stewart mechanism(i.e., the connection points of the moving and fixed platforms are not restricted to lying in a plane) has been extensively studied, but the efficiency of the solution remains to be effectively addressed. To this end, an algebraic elimination method is proposed for the FDA of the general 6-6 Stewart mechanism. The kinematic constraint equations are built using conformal geometric algebra(CGA). The kinematic constraint equations are transformed by a substitution of variables into seven equations with seven unknown variables. According to the characteristic of anti-symmetric matrices, the aforementioned seven equations can be further transformed into seven equations with four unknown variables by a substitution of variables using the Gröbner basis. Its elimination weight is increased through changing the degree of one variable, and sixteen equations with four unknown variables can be obtained using the Gröbner basis. A 40th-degree univariate polynomial equation is derived by constructing a relatively small-sized 9´9 Sylvester resultant matrix. Finally, two numerical examples are employed to verify the proposed method. The results indicate that the proposed method can effectively improve the efficiency of solution and reduce the computational burden because of the small-sized resultant matrix.

Highly fluorescent and superparamagnetic nanosystem for biomedical applications

NASA Astrophysics Data System (ADS)

Cabrera, Mariana P.; E Cabral Filho, Paulo; Silva, Camila M. C. M.; Oliveira, Rita M.; Geraldes, Carlos F. G. C.; Castro, M. Margarida C. A.; Costa, Benilde F. O.; Henriques, Marta S. C.; Paixão, José A.; Carvalho, Luiz B., Jr.; Santos, Beate S.; Hallwass, Fernando; Fontes, Adriana; Pereira, Giovannia A. L.

2017-07-01

This work reports on highly fluorescent and superparamagnetic bimodal nanoparticles (BNPs) obtained by a simple and efficient method as probes for fluorescence analysis and/or contrast agents for MRI. These promising BNPs with small dimensions (ca. 17 nm) consist of superparamagnetic iron oxide nanoparticles (SPIONs) covalently bound with CdTe quantum dots (ca. 3 nm). The chemical structure of the magnetic part of BNPs is predominantly magnetite, with minor goethite and maghemite contributions, as shown by Mössbauer spectroscopy, which is compatible with the x-ray diffraction data. Their size evaluation by different techniques showed that the SPION derivatization process, in order to produce the BNPs, does not lead to a large size increase. The BNPs saturation magnetization, when corrected for the organic content of the sample, is ca. 68 emu g-1, which is only slightly reduced relative to the bare nanoparticles. This indicates that the SPION surface functionalization does not change considerably the magnetic properties. The BNP aqueous suspensions presented stability, high fluorescence, high relaxivity ratio (r 2/r 1 equal to 25) and labeled efficiently HeLa cells as can be seen by fluorescence analysis. These BNP properties point to their applications as fluorescent probes as well as negative T 2-weighted MRI contrast agents. Moreover, their potential magnetic response could also be used for fast bioseparation applications.

Optimized zein nanospheres for improved oral bioavailability of atorvastatin

PubMed Central

Hashem, Fahima M; Al-Sawahli, Majid M; Nasr, Mohamed; Ahmed, Osama AA

2015-01-01

Background This work focuses on the development of atorvastatin utilizing zein, a natural, safe, and biocompatible polymer, as a nanosized formulation in order to overcome the poor oral bioavailability (12%) of the drug. Methods Twelve experimental runs of atorvastatin–zein nanosphere formula were formulated by a liquid–liquid phase separation method according to custom fractional factorial design to optimize the formulation variables. The factors studied were: weight % of zein to atorvastatin (X1), pH (X2), and stirring time (X3). Levels for each formulation variable were designed. The selected dependent variables were: mean particle size (Y1), zeta potential (Y2), drug loading efficiency (Y3), drug encapsulation efficiency (Y4), and yield (Y5). The optimized formulation was assayed for compatibility using an X-ray diffraction assay. In vitro diffusion of the optimized formulation was carried out. A pharmacokinetic study was also done to compare the plasma profile of the atorvastatin–zein nanosphere formulation versus atorvastatin oral suspension and the commercially available tablet. Results The optimized atorvastatin–zein formulation had a mean particle size of 183 nm, a loading efficiency of 14.86%, and an encapsulation efficiency of 29.71%. The in vitro dissolution assay displayed an initial burst effect, with a cumulative amount of atorvastatin released of 41.76% and 82.3% after 12 and 48 hours, respectively. In Wistar albino rats, the bioavailability of atorvastatin from the optimized atorvastatin–zein formulation was 3-fold greater than that from the atorvastatin suspension and the commercially available tablet. Conclusion The atorvastatin–zein nanosphere formulation improved the oral delivery and pharmacokinetic profile of atorvastatin by enhancing its oral bioavailability. PMID:26150716

Removal of micropollutants from Sakarya River water by ozone and membrane processes.

PubMed

Yaman, Fatma Büşra; Çakmakcı, Mehmet; Yüksel, Ebubekir; Özen, İsmail; Gengeç, Erhan

2017-09-01

The removal of some pollutants in the Sakarya River was investigated in this study. Sakarya River located in Turkey flows from the northeast of Afyonkarahisar City to the Black Sea. Nineteen different micropollutants including trihalomethanes (THMs), haloacetic acids (HAAs), endocrine disrupting compound (EDC) and pharmaceuticals personal care product (PPCP) groups, and water quality parameters such as dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm wavelength (UV 254 ), hardness, and conductivity values were examined. To remove the micropollutants and improve the water quality, the treatment was performed with ozone, microfiltration (MF), and ultra-filtration (UF) membranes. The highest treatment efficiency was obtained with 1 mg/L ozone dosage and UP005 UF membrane. The trihalomethan formation potential (THMFP) and haloacetic acid formation potential (HAAFP) decreased with ozone + membrane at a concentration of 79 and 75%, respectively. After the treatment with ozone + membrane, the concentration of the micropollutants in the EDC and PPCP group remained below the detection limit. It was found that by using only membrane and only ozone, the maximum DOC removal efficiency achieved was 46 and 18%, respectively; and with ozone + membrane, this efficiency increased up to 82%. The results from the High-Pressure Size Exclusion Chromatography (HPSEC) analyses pointed that the substances with high molecular weight were converted into substances with low molecular weight after the treatment. The Fourier Transform Infrared (FTIR) analysis results showed that the aromatic and aliphatic functional groups in water changed after the treatment with ozone and that the peak values decreased more after the ozone + membrane treatment.

Yield and size of oyster mushroom grown on rice/wheat straw basal substrate supplemented with cotton seed hull.

PubMed

Yang, Wenjie; Guo, Fengling; Wan, Zhengjie

2013-10-01

Oyster mushroom (Pleurotus ostreatus) was cultivated on rice straw basal substrate, wheat straw basal substrate, cotton seed hull basal substrate, and wheat straw or rice straw supplemented with different proportions (15%, 30%, and 45% in rice straw substrate, 20%, 30%, and 40% in wheat straw substrate) of cotton seed hull to find a cost effective substrate. The effect of autoclaved sterilized and non-sterilized substrate on growth and yield of oyster mushroom was also examined. Results indicated that for both sterilized substrate and non-sterilized substrate, oyster mushroom on rice straw and wheat basal substrate have faster mycelial growth rate, comparatively poor surface mycelial density, shorter total colonization period and days from bag opening to primordia formation, lower yield and biological efficiency, lower mushroom weight, longer stipe length and smaller cap diameter than that on cotton seed hull basal substrate. The addition of cotton seed hull to rice straw and wheat straw substrate slowed spawn running, primordial development and fruit body formation. However, increasing the amount of cotton seed hull can increase the uniformity and white of mycelium, yield and biological efficiency, and increase mushroom weight, enlarge cap diameter and shorten stipe length. Compared to the sterilized substrate, the non-sterilized substrate had comparatively higher mycelial growth rate, shorter total colonization period and days from bag opening to primordia formation. However, the non-sterilized substrate did not gave significantly higher mushroom yield and biological efficiency than the sterilized substrate, but some undesirable characteristics, i.e. smaller mushroom cap diameter and relatively long stipe length.

Chinese Version of the EQ-5D Preference Weights: Applicability in a Chinese General Population

PubMed Central

Wu, Chunmei; Gong, Yanhong; Wu, Jiang; Zhang, Shengchao; Yin, Xiaoxv; Dong, Xiaoxin; Li, Wenzhen; Cao, Shiyi; Mkandawire, Naomie; Lu, Zuxun

2016-01-01

Objectives This study aimed to test the reliability, validity and sensitivity of Chinese version of the EQ-5D preference weights in Chinese general people, examine the differences between the China value set and the UK, Japan and Korea value sets, and provide methods for evaluating and comparing the EQ-5D value sets of different countries. Methods A random sample of 2984 community residents (15 years or older) were interviewed using a questionnaire including the EQ-5D scale. Level of agreement, convergent validity, known-groups validity and sensitivity of the EQ-5D China, United Kingdom (UK), Japan and Korea value sets were determined. Results The mean EQ-5D index scores were significantly (P<0.05) different among the UK (0.964), Japan (0.981), Korea (0.987), and China (0.985) weights. High level of agreement (intraclass correlations coefficients > 0.75) and convergent validity (Pearson’s correlation coefficients > 0.95) were found between each paired schemes. The EQ-5D index scores discriminated equally well for the four versions between levels of 10 known-groups (P< 0.05). The effect size and the relative efficiency statistics showed that the China weights had better sensitivity. Conclusions The China EQ-5D preference weights show equivalent psychometric properties with those from the UK, Japan and Korea weights while slightly more sensitive to known group differences than those from the Japan and Korea weights. Considering both psychometric and sociocultural issues, the China scheme should be a priority as an EQ-5D based measure of the health related quality of life in Chinese general population. PMID:27711169

Obstructive Sleep Apnea: Differences between Normal-Weight, Overweight, Obese, and Morbidly Obese Children.

PubMed

Scott, Brian; Johnson, Romaine F; Mitchell Md, Ron B

2016-05-01

The severity of obstructive sleep apnea in children determines perioperative management and is an indication for postoperative polysomnography. The relationship between increasing weight and sleep apnea severity in children remains unclear. To compare demographic, clinical, and polysomnography parameters in normal-weight, overweight, obese, and morbidly obese children, as well as identify demographic factors that predict sleep apnea severity. Case series with chart review. Academic children's hospital. A retrospective chart review of 290 children aged 2 to 18 years who underwent polysomnography at an academic children's hospital was performed. Demographics, clinical findings, and polysomnographic parameters were recorded. Children were categorized as normal weight, overweight, obese, or morbidly obese. Differences were assessed using linear and logistical regression models. Significance was set at P < .05. Morbidly obese were older than normal-weight children (mean, 8.0 ± 0.5 years vs 5.8 ± 0.3 years; P < .001) and less likely to have a normal polysomnogram (16% vs 48%; P = .02). There were no differences in sex, ethnicity, birth status (term or preterm), or tonsil size between normal-weight, overweight, obese, and morbidly obese children. Sleep efficiency and percentage of time in rapid eye movement were decreased in morbidly obese compared with other children (P < .05). The apnea-hypopnea index was positively correlated with increasing body mass index z score only as a function of increasing age (P < .001). Obstructive sleep apnea severity is correlated with a combination of increasing age and weight but not with either variable independently. This study suggests that obese and morbidly obese older children are most likely to have severe obstructive sleep apnea. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Timing of Gestational Weight Gain on Fetal Growth and Infant Size at Birth in Vietnam

PubMed Central

Young, Melissa F.; Hong Nguyen, Phuong; Addo, O. Yaw; Pham, Hoa; Nguyen, Son; Martorell, Reynaldo; Ramakrishnan, Usha

2017-01-01

Objective To examine the importance of timing of gestational weight gain during three time periods: 1: ≤ 20 weeks gestation), 2: 21–29 weeks) and 3: ≥ 30 weeks) on fetal growth and infant birth size. Methods Study uses secondary data from the PRECONCEPT randomized controlled trial in Thai Nguyen province, Vietnam (n = 1436). Prospective data were collected on women starting pre-pregnancy through delivery. Maternal conditional weight gain (CWG) was defined as window-specific weight gains, uncorrelated with pre-pregnancy body mass index and all prior body weights. Fetal biometry, was assessed by ultrasound measurements of head and abdomen circumferences, biparietal diameter, and femoral length throughout pregnancy. Birth size outcomes included weight and length, and head, abdomen and mid upper arm circumferences as well as small for gestational age (SGA). Adjusted generalized linear and logistic models were used to examine associations. Results Overall, three-quarters of women gained below the Institute of Medicine guidelines, and these women were 2.5 times more likely to give birth to a SGA infant. Maternal CWG in the first window (≤ 20 weeks), followed by 21–29 weeks, had the greatest association on all parameters of fetal growth (except abdomen circumference) and infant size at birth. For birth weight, a 1 SD increase CWG in the first 20 weeks had 3 times the influence compared to later CWG (≥ 30 weeks) (111 g vs. 39 g) and was associated with a 43% reduction in SGA risk (OR (95% CI): 0.57 (0.46–0.70). Conclusion There is a need to target women before or early in pregnancy to ensure adequate nutrition to maximize impact on fetal growth and birth size. Trial Registration ClinicalTrials.gov, NCT01665378 PMID:28114316

Timing of Gestational Weight Gain on Fetal Growth and Infant Size at Birth in Vietnam.

PubMed

Young, Melissa F; Hong Nguyen, Phuong; Addo, O Yaw; Pham, Hoa; Nguyen, Son; Martorell, Reynaldo; Ramakrishnan, Usha

2017-01-01

To examine the importance of timing of gestational weight gain during three time periods: 1: ≤ 20 weeks gestation), 2: 21-29 weeks) and 3: ≥ 30 weeks) on fetal growth and infant birth size. Study uses secondary data from the PRECONCEPT randomized controlled trial in Thai Nguyen province, Vietnam (n = 1436). Prospective data were collected on women starting pre-pregnancy through delivery. Maternal conditional weight gain (CWG) was defined as window-specific weight gains, uncorrelated with pre-pregnancy body mass index and all prior body weights. Fetal biometry, was assessed by ultrasound measurements of head and abdomen circumferences, biparietal diameter, and femoral length throughout pregnancy. Birth size outcomes included weight and length, and head, abdomen and mid upper arm circumferences as well as small for gestational age (SGA). Adjusted generalized linear and logistic models were used to examine associations. Overall, three-quarters of women gained below the Institute of Medicine guidelines, and these women were 2.5 times more likely to give birth to a SGA infant. Maternal CWG in the first window (≤ 20 weeks), followed by 21-29 weeks, had the greatest association on all parameters of fetal growth (except abdomen circumference) and infant size at birth. For birth weight, a 1 SD increase CWG in the first 20 weeks had 3 times the influence compared to later CWG (≥ 30 weeks) (111 g vs. 39 g) and was associated with a 43% reduction in SGA risk (OR (95% CI): 0.57 (0.46-0.70). There is a need to target women before or early in pregnancy to ensure adequate nutrition to maximize impact on fetal growth and birth size. ClinicalTrials.gov, NCT01665378.

23 CFR 657.7 - Objective.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of an enforcement process which identifies vehicles of excessive size and weight and provides a... 23 Highways 1 2010-04-01 2010-04-01 false Objective. 657.7 Section 657.7 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS CERTIFICATION OF SIZE AND WEIGHT...

Trucking and Size and Weight Regulations in the Mid-Continent Corridor

DOT National Transportation Integrated Search

1996-11-01

This thesis is an empirical analysis of trucking and truck size and weight (TS&W) regulations in the Mid-continent corridor. Based on this analysis, it compares and contrasts plausible near term TS&W policy options relating to this corridor. The appr...

[Influence of wall polymer and preparation process on the particle size and encapsulation of hemoglobin microcapsules].

PubMed

Qiu, Wei; Ma, Guang-Hui; Meng, Fan-Tao; Su, Zhi-Guo

2004-03-01

Methoxypoly (ethylene glycol)- block-poly (DL-lactide) (PELA) microcapsules containing bovine hemoglobin (BHb) were prepared by a W/O/W double emulsion-solvent diffusion process. The P50 and Hill coeffcient were 3466 Pa and 2.4 respectively, which were near to the natural bioactivity of bovine hemoglobin. The results suggested that polymer composition had significant influence on encapsulation efficiency and particle size of microcapsules. The encapsulation efficiency could reach 90% and the particle size 3 - 5 microm when the PELA copolymer containing MPEG 2000 block was used. The encapsulation efficiency and particle size increased with the concentration of PELA. Increasing the concentrations of NaCl in outer aqueous solution resulted in the increase of encapsulation efficiency and the decrease of particle size. As the concentration of stabilizer in outer aqueous solution increased in the range of 10 g/L to 20 g/L, the particle size reduced while encapsulation efficiency was increased, further increase of the stabilizer concentration would decrease encapsulation efficiency. Increasing of primary emulsion stirring rate was advantageous to the improvement of encapsulation efficiency though it had little influence on the particle size. The influence of re-emulsion stirring rate was complicated, which was not apparent in the case of large volume of re-emulsion solution. When the wall polymer and primary emulsion stirring rate were fixed, the encapsulation efficiency decreased as the particle size reduced.

Accounting for body size deviations when reporting bone mineral density variables in children.

PubMed

Webber, C E; Sala, A; Barr, R D

2009-01-01

In a child, bone mineral density (BMD) may differ from an age-expected normal value, not only because of the presence of disease, but also because of deviations of height or weight from population averages. Appropriate adjustment for body size deviations simplifies interpretation of BMD measurements. For children, a bone mineral density (BMD) measurement is normally expressed as a Z score. Interpretation is complicated when weight or height distinctly differ from age-matched children. We develop a procedure to allow for the influence of body size deviations upon measured BMD. We examined the relation between body size deviation and spine, hip and whole body BMD deviation in 179 normal children (91 girls). Expressions were developed that allowed derivation of an expected BMD based on age, gender and body size deviation. The difference between measured and expected BMD was expressed as a HAW score (Height-, Age-, Weight-adjusted score). In a second independent sample of 26 normal children (14 girls), measured spine, total femur and whole body BMD all fell within the same single normal range after accounting for age, gender and body size deviations. When traditional Z scores and HAW scores were compared in 154 children, 17.5% showed differences of more than 1 unit and such differences were associated with height and weight deviations. For almost 1 in 5 children, body size deviations influence BMD to an extent that could alter clinical management.

Body image and weight control in South Africans 15 years or older: SANHANES-1.

PubMed

Mchiza, Zandile J; Parker, Whadi-Ah; Makoae, Mokhantso; Sewpaul, Ronel; Kupamupindi, Takura; Labadarios, Demetre

2015-09-30

South African studies have suggested that differences in obesity prevalence between groups may be partly related to differences in body image and body size dissatisfaction. However, there has never been a national study that measured body image and its relationship to weight control in the country. Hence, the main aim of the study was to examine body image in relation to body mass index and weight control in South Africa. A cross-sectional survey and a secondary analyses of data were undertaken for 6 411 South Africans (15+ years) participating in the first South African National Health and Nutrition Examination Survey. Body image was investigated in relation to weight status and attempts to lose or gain weight. Data were analysed using STATA version 11.0. Descriptive statistics are presented as counts (numbers), percentages, means, standard error of means, and 95 % confidence intervals. Any differences in values were considered to be significantly different if the confidence intervals did not overlap. Overall, 84.5 % participants had a largely distorted body image and 45.3 % were highly dissatisfied about their body size. Overweight and obese participants under estimated their body size and desired to be thinner. On the other hand, normal- and under-weight participants over estimated their body size and desired to be fatter. Only 12.1 and 10.1 % of participants attempted to lose or gain weight, respectively, mainly by adjusting dietary intake and physical activity. Body mass index appears to influence body image and weight adjustment in South Africa. South Africans at the extreme ends of the body mass index range have a largely distorted body image and are highly dissatisfied by it. This suggests a need for health education and beneficial weight control strategies to halt the obesity epidemic in the country.

Seed weight variation of Wyoming sagebrush in northern Nevada.

PubMed

Busso, Carlos A; Perryman, Barry L

2005-12-01

Seed size is a crucial plant trait that may potentially affect not only immediate seedling success but also the subsequent generation. We examined variation in seed weight of Wyoming sagebrush (Artemisia tridentata ssp. wyomingensis Beetle and Young), an excellent candidate species for rangeland restoration. The working hypothesis was that a major fraction of spatial and temporal variability in seed size (weight) of Wyoming sagebrush could be explained by variations in mean monthly temperatures and precipitation. Seed collection was conducted at Battle Mountain and Eden Valley sites in northern Nevada, USA, during November of 2002 and 2003. Frequency distributions of seed weight varied from leptokurtic to platykurtic, and from symmetry to skewness to the right for both sites and years. Mean seed weight varied by a factor of 1.4 between locations and years. Mean seed weight was greater (P < 0.05) in 2003 than in 2002 at both sites. This can partially be attributed to 55% greater precipitation in 2003 than 2002, since mean monthly temperatures were similar (P > 0.05) in all study situations. Simple linear regression showed that monthly precipitation (March to November) explained 85% of the total variation in mean seed weight (P = 0.079). Since the relationship between mean monthly temperature (June-November) and mean seed weight was not significant (r2 = 0.00, P = 0.431), this emphasizes the importance of precipitation as an important determinant of mean seed weight. Our results suggest that the precipitation regime to which the mother plant is exposed can have a significant effect on sizes of seeds produced. Hence, seasonal changes in water availability would tend to alter size distributions of produced offspring.

Perceptions relating to body size, weight loss and weight-loss interventions in black South African women: a qualitative study.

PubMed

Draper, Catherine E; Davidowitz, Kesiah J; Goedecke, Julia H

2016-02-01

A higher tolerance for a larger body size has been associated with obesity in black South African (SA) women. The aim of the present study was to explore perceptions regarding body size and weight loss in a sample of black women from a low-income community in Cape Town, SA. Qualitative pilot study including five focus groups. Data were analysed using thematic analysis. Khayelitsha, Cape Town, SA. Twenty-one black SA women. The majority of participants had positive perceptions of overweight/obesity, which were influenced by community and cultural perceptions, but some inconsistencies were observed as overweight/obesity was also associated with ill health. Participants identified many benefits to weight loss, but due to the association with sickness, they were concerned about being stigmatised in their community. Although participants had knowledge about healthy eating, the main barrier to eating healthily included the perceived higher cost of healthier food and food insecurity. All participants saw exercise as a strategy to lose weight and improve health, and were interested in participating in a community-based exercise intervention, but negative community perceptions and conflicting views regarding who should lead the intervention were identified as barriers. These findings highlight the complexities surrounding participants' perceptions regarding body size, weight loss and weight-loss interventions, and emphasise low socio-economic status as a barrier to change. The study also highlights the strong influence of cultural ideals and community perceptions on personal perceptions. These findings underscore the necessity for culturally appropriate weight-loss interventions in low-income, transitioning communities.

46 CFR 160.077-21 - Approval Testing-Type I and Commercial Hybrid PFD.

Code of Federal Regulations, 2012 CFR

2012-10-01

... this test. (2) In-water removal, UL 1517, section S9 for Adult and Youth sizes. The Small Child size is... paragraph S7.1.A apply to all subjects regardless of their in-water weight. For Type V adult-size devices the requirements of paragraph S7.1.A apply to all adult subjects having an in-water weight of 13 lb or...

46 CFR 160.077-21 - Approval Testing-Type I and Commercial Hybrid PFD.

Code of Federal Regulations, 2014 CFR

2014-10-01

... this test. (2) In-water removal, UL 1517, section S9 for Adult and Youth sizes. The Small Child size is... paragraph S7.1.A apply to all subjects regardless of their in-water weight. For Type V adult-size devices the requirements of paragraph S7.1.A apply to all adult subjects having an in-water weight of 13 lb or...

46 CFR 160.077-21 - Approval Testing-Type I and Commercial Hybrid PFD.

Code of Federal Regulations, 2010 CFR

2010-10-01

... this test. (2) In-water removal, UL 1517, section S9 for Adult and Youth sizes. The Small Child size is... paragraph S7.1.A apply to all subjects regardless of their in-water weight. For Type V adult-size devices the requirements of paragraph S7.1.A apply to all adult subjects having an in-water weight of 13 lb or...

46 CFR 160.077-21 - Approval Testing-Type I and Commercial Hybrid PFD.

Code of Federal Regulations, 2013 CFR

2013-10-01

... this test. (2) In-water removal, UL 1517, section S9 for Adult and Youth sizes. The Small Child size is... paragraph S7.1.A apply to all subjects regardless of their in-water weight. For Type V adult-size devices the requirements of paragraph S7.1.A apply to all adult subjects having an in-water weight of 13 lb or...

46 CFR 160.077-21 - Approval Testing-Type I and Commercial Hybrid PFD.

Code of Federal Regulations, 2011 CFR

2011-10-01

... this test. (2) In-water removal, UL 1517, section S9 for Adult and Youth sizes. The Small Child size is... paragraph S7.1.A apply to all subjects regardless of their in-water weight. For Type V adult-size devices the requirements of paragraph S7.1.A apply to all adult subjects having an in-water weight of 13 lb or...

Size and Composition of the Lexicon in Prematurely Born Very-Low-Birth-Weight and Full-Term Finnish Children at Two Years of Age

ERIC Educational Resources Information Center

Stolt, Suvi; Klippi, Anu; Launonen, Kaisa; Munck, Petriina; Lehtonen, Liisa; Lapinleimu, Helena; Haataja, Leena

2007-01-01

This paper focuses on the aspects of the lexicon in 66 prematurely born very-low-birth-weight and 87 full-term Finnish children at 2;0, studied using the Finnish version of the "MacArthur Communicative Developmental Inventory". The groups did not differ in vocabulary size. Furthermore, the female advantage in vocabulary size was not seen…

Maternal and child awareness and expectations of child overweight.

PubMed

Brødsgaard, Anne; Wagner, Lis; Peitersen, Birgit; Poulsen, Ingrid; Sørensen, Thorkild I A

2011-01-01

We investigated mothers' and children's assessments of body weight and their expectations about perceived body size in relation to overweight of the children. We performed a case-control study of 111 cases of overweight children and 149 controls of non-overweight children (mean age 8.1 years) and their mothers. All were examined and interviewed about their assessment of body weight and their perception of a normal, attractive and acceptable body size. Case children were less able than control children to correctly assess their own body weight (p < 0.001), as were mothers of overweight children (MOC) to assess their children's body weight (p < 0.001). The majority of mothers from both groups wished their children to have a normal body size, but 18% of MOC wished their children to have an overweight body size (p < 0.013). The majority of case children, control children and mothers found a normal body size for boys and girls to be the most attractive and socially acceptable, but more MOC found overweight among boys to be the most attractive (p = 0.006). Overweight children and their mothers show increased uncertainty in the assessment of overweight and obesity, but the perception of a normal, attractive and socially acceptable body size is not distorted. Copyright © 2011 S. Karger AG, Basel.

Separation of both fibrous and globular proteins on the basis of molecular weight using high-performance size exclusion chromatography.

PubMed

Barden, J A

1983-11-01

A high-performance size exclusion liquid chromatographic system has been used to separate proteins with different shapes solely on the basis of their molecular weights. After the effects of ionic and hydrophobic interactions with the stationary phase have been overcome, protein elution is normally governed by their effective size in solution. Conditions are described under which proteins, with isoelectric points within the normal operating pH range of the columns, are eluted independent of their Stokes' radii. Even fibrous proteins with axial ratios of 50 elute according to their known molecular weights over the range 2000-2,000,000.

Effects of electrical field on hatchability performance of eggs from a layer-type breeder.

PubMed

Shafey, T M; Al-Batshan, H A; Ghannam, M M

2007-04-01

1. Eggs from a layer-type breeder flock (Baladi, King Saud University) between 50 and 63 weeks of age were used in three trials to study the effects of electrical field (EF) during incubation on albumen and yolk heights, incubation temperature, egg weight loss and hatchability traits. The effects of egg size and eggshell characteristics on hatchability traits of eggs incubated under EF were investigated. 2. Eggs were weighed and graded into three weight classes (small, medium, and large). The physical dimensions, eggshell characteristics, and conductance of eggs were examined. The incubator was divided into two compartments for the control and EF treatments. Two aluminium plates were fitted on the inside walls of the EF compartment, face to face, and connected to a step up electric transformer. Eggs were exposed constantly to the EF during the first 18 d of incubation at the level of 30 kV/m, 60 Hz. 3. Egg size influenced the physical dimensions and eggshell characteristics of eggs. Large eggs had higher egg weight, egg surface area, egg volume, eggshell conductance, and eggshell weight and lower yolk weight percentage than medium or small size eggs. Small eggs had lower egg length and higher egg density than large or medium size eggs. Large eggs had higher eggshell thickness than small size eggs. 4. EF incubation of eggs raised incubation temperature by 0.06 degrees C, and increased the percentage of egg weight loss, hatchability, and weight of hatching chicks and reduced the early embryo deaths, and length of incubation by approximately 9.8, 19.6, 1.7, 62.1 and 2.1%, respectively. 5. There was no significant difference between the two incubation treatments in the heights of albumen and yolk of incubated eggs, percentages of late embryo deaths, and pips with live and dead embryos. Hatchability traits were not significantly influenced by egg size. 6. It was concluded that EF incubation of eggs increased hatchability, chick-hatching weight, and reduced the length of incubation of Baladi eggs. Differences in the physical dimensions and eggshell characteristics of eggs did not influence hatchability traits of eggs under EF incubation.

Performance of a 1380-foot-per-second-tip-speed axial-flow compressor rotor with a blade tip solidity of 1.3

NASA Technical Reports Server (NTRS)

Hager, R. D.; Janetzke, D. C.; Reid, L.

1972-01-01

Aerodynamic design parameters are presented along the overall and blade element performance, of an axial flow compressor rotor designed to study the effects of blade solidity on efficiency and stall margin. At design speed the peak efficiency was 0.844 and occurred at an equivalent weight flow of 63.5 lb/sec with a total pressure ratio of 1.801. Design efficiency, pressure ratio, and weight flow 0.814, 1.65, and 65.3(41.1 lb/sec/sq ft of annulus area), respectively. Stall margin for design speed was 6.4 percent based on the weight flow and pressure ratio values at peak efficiency and just prior to stall.

Realistic weight perception and body size assessment in a racially diverse community sample of dieters.

PubMed

Cachelin, F M; Striegel-Moore, R H; Elder, K A

1998-01-01

Recently, a shift in obesity treatment away from emphasizing ideal weight loss goals to establishing realistic weight loss goals has been proposed; yet, what constitutes "realistic" weight loss for different populations is not clear. This study examined notions of realistic shape and weight as well as body size assessment in a large community-based sample of African-American, Asian, Hispanic, and white men and women. Participants were 1893 survey respondents who were all dieters and primarily overweight. Groups were compared on various variables of body image assessment using silhouette ratings. No significant race differences were found in silhouette ratings, nor in perceptions of realistic shape or reasonable weight loss. Realistic shape and weight ratings by both women and men were smaller than current shape and weight but larger than ideal shape and weight ratings. Compared with male dieters, female dieters considered greater weight loss to be realistic. Implications of the findings for the treatment of obesity are discussed.

The relative efficiency of nylon and cotton gill nets for taking lake trout in Lake Superior

USGS Publications Warehouse

Pycha, Richard L.

1962-01-01

The change from cotton to nylon twine for gill nets in 1949–52 resulted in a sharp increase in the efficiency of the most important gear used for taking lake trout in Lake Superior, and, consequently, biased estimates of fishing intensity and abundance severely.From early May to the end of September 1961, short gangs (2000 or 4000 linear feet) of cotton and nylon nets were fished in parallel sets for lake trout. A total of 343,000 feet of gill netting was lifted. Nylon nets were 2.25 times as efficient as cotton nets for taking legal-sized fish and 2.8 times as efficient for undersized lake trout. The average lengths of legal, undersized, and all lake trout taken in nets of the two materials did not differ greatly. The percentage of the catch which was undersized (less than 1.25 lb, dressed weight) was 20.8 in nylon nets and 17.7 in cotton. The relative efficiency of cotton and nylon nets showed no trend during the season. The efficiency ratio determined in this study was closely similar to that obtained by earlier workers.Correction of estimates of fishing intensity and abundance for the greater efficiency of the nylon nets used since 1951 has not been attempted. The drastic decline of the lake trout fishery has forced fishermen to make changes in fishing practices in the past few years that cause new bias of an unknown extent to estimates of fishing intensity.

Comprehensive Truck Size and Weight Study : summary report, phase 1

DOT National Transportation Integrated Search

1995-03-01

This is the Summary Report of Phase I of the Comprehensive Truck Size and Weight (TS&W) Study announced by the Federal Highway Administrator in June 1994. It summarizes 13 working papers prepared during Phase I. Phase I--Synthesis of TS&W Studies and...

The relative efficiency of modular and non-modular networks of different size

PubMed Central

Tosh, Colin R.; McNally, Luke

2015-01-01

Most biological networks are modular but previous work with small model networks has indicated that modularity does not necessarily lead to increased functional efficiency. Most biological networks are large, however, and here we examine the relative functional efficiency of modular and non-modular neural networks at a range of sizes. We conduct a detailed analysis of efficiency in networks of two size classes: ‘small’ and ‘large’, and a less detailed analysis across a range of network sizes. The former analysis reveals that while the modular network is less efficient than one of the two non-modular networks considered when networks are small, it is usually equally or more efficient than both non-modular networks when networks are large. The latter analysis shows that in networks of small to intermediate size, modular networks are much more efficient that non-modular networks of the same (low) connective density. If connective density must be kept low to reduce energy needs for example, this could promote modularity. We have shown how relative functionality/performance scales with network size, but the precise nature of evolutionary relationship between network size and prevalence of modularity will depend on the costs of connectivity. PMID:25631996

Effects of two commercially available feline diets on glucose and insulin concentrations, insulin sensitivity and energetic efficiency of weight gain.

PubMed

Coradini, M; Rand, J S; Morton, J M; Rawlings, J M

2011-10-01

A low-carbohydrate, high-protein (LCHP) diet is often recommended for the prevention and management of diabetes in cats; however, the effect of macronutrient composition on insulin sensitivity and energetic efficiency for weight gain is not known. The present study compared the effect in adult cats (n 32) of feeding a LCHP (23 and 47 % metabolisable energy (ME)) and a high-carbohydrate, low-protein (HCLP) diet (51 and 21 % ME) on fasting and postprandial glucose and insulin concentrations, and on insulin sensitivity. Tests were done in the 4th week of maintenance feeding and after 8 weeks of ad libitum feeding, when weight gain and energetic efficiency of each diet were also measured. When fed at maintenance energy, the HCLP diet resulted in higher postprandial glucose and insulin concentrations. When fed ad libitum, the LCHP diet resulted in greater weight gain (P < 0.01), and was associated with higher energetic efficiency. Overweight cats eating the LCHP diet had similar postprandial glucose concentrations to lean cats eating the HCLP diet. Insulin sensitivity was not different between the diets when cats were lean or overweight, but glucose effectiveness was higher after weight gain in cats fed the HCLP diet. According to the present results, LCHP diets fed at maintenance requirements might benefit cats with multiple risk factors for developing diabetes. However, ad libitum feeding of LCHP diets is not recommended as they have higher energetic efficiency and result in greater weight gain.

Effect of body image on pregnancy weight gain.

PubMed

Mehta, Ushma J; Siega-Riz, Anna Maria; Herring, Amy H

2011-04-01

The majority of women gain more weight during pregnancy than what is recommended. Since gestational weight gain is related to short and long-term maternal health outcomes, it is important to identify women at greater risk of not adhering to guidelines. The objective of this study was to examine the relationship between body image and gestational weight gain. The Body Image Assessment for Obesity tool was used to measure ideal and current body sizes in 1,192 women participating in the Pregnancy, Infection and Nutrition Study. Descriptive and multivariable techniques were used to assess the effects of ideal body size and discrepancy score (current-ideal body sizes), which reflected the level of body dissatisfaction, on gestational weight gain. Women who preferred to be thinner had increased risk of excessive gain if they started the pregnancy at a BMI ≤26 kg/m(2) but a decreased risk if they were overweight or obese. Comparing those who preferred thin body silhouettes to those who preferred average size silhouettes, low income women had increased risk of inadequate weight gain [RR = 1.76 (1.08, 2.88)] while those with lower education were at risk of excessive gain [RR = 1.11 (1.00, 1.22)]. Our results revealed that body image was associated with gestational weight gain but the relationship is complex. Identifying factors that affect whether certain women are at greater risk of gaining outside of guidelines may improve our ability to decrease pregnancy-related health problems.

Radiation-induced controlled polymerization of acrylic acid by RAFT and RAFT-MADIX methods in protic solvents

NASA Astrophysics Data System (ADS)

Sütekin, S. Duygu; Güven, Olgun

2018-01-01

The kinetic investigation of one-pot synthesis of poly(acrylic acid) (PAA) prepared via gamma radiation induced controlled polymerization was reported. PAA homopolymers were prepared by Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization in the presence of trithiocarbonate-based chain transfer agent (CTA) 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT) and also by Reversible Addition-Fragmentation/Macromolecular Design by Inter-change of Xanthates (RAFT/MADIX) polymerization in the presence of a xanthate based CTA O-ethyl-S-(1-methoxycarbonyl) ethyl dithiocarbonate (RA1). The polymerizations were performed at room temperature by the virtue of ionizing radiation. Protic solvents were used for the RAFT polymerization of AA considering environmental profits. The linear first-order kinetic plot, close control of molecular weight by the monomer/CTA molar ratio supported that the polymerization proceeds in a living fashion. The linear increase in molecular weight with conversion monitored by Size Exclusion Chromatography (SEC) is another proof of controlling of polymerization. [Monomer]/[RAFT] ratio and conversion was controlled to obtain PAA in the molecular weight range of 6900-35,800 with narrow molecular weight distributions. Reaction kinetics and effect of the amount of RAFT agent were investigated in detail. Between two different types of CTA, trithiocarbonate based DDMAT was found to be more efficient in terms of low dispersity (Đ) and linear first-order kinetic behavior for the radiation induced controlled synthesis of PAA homopolymers.

Development and Testing of an Inflatable, Rigidizable Space Structure Experiment

DTIC Science & Technology

2006-03-01

successful, including physical dimension, weight , and cost. Inflatable structures have the potential to achieve greater efficiency in all of these...potential for low cost, high mechanical packaging efficiency, deployment reliability and low weight (13). The term inflatable structure indicates that a...back-up inflation gas a necessity for long term success. This addition can be very costly in terms of volume, weight , and expense due to added or

Effect of obesity treatments on eating behavior: psychosocial interventions versus surgical interventions. A systematic review.

PubMed

Moldovan, Adela R; David, Daniel

2011-08-01

(1) To use available research data to estimate the amount of change in eating behavior following obesity treatment; (2) To examine how this change relates to the amount of change in weight loss after treatment and at follow up. A meta-analysis was conducted in September 2009. Studies were identified through a computer search of articles in the PubMed and PsychInfo databases. Key terms entered were obesity, treatment, and eating behavior. Effect sizes (Glass d) were calculated according to published procedures. Eighteen studies met the inclusion and exclusion criteria, grouped into two categories: psychosocial interventions and surgical interventions. For psychosocial interventions, we found a medium effect size on eating behavior (d=.73, CI=(.66, .90)), and a low effect size on weight (d=.32, CI=(.28, .36)) at posttreatment and a low effect size for both outcomes at follow-up (for eating behavior d=.47, CI=(.45, .49), for weight d=.37, (CI=.18, .56)). For surgical interventions we found large effect sizes on both outcomes (for eating behavior d=1.84, CI=(1.26, 2.42); for weight d=1.40, CI=(1.25, 1.65)). Surgical interventions have superior results to psychosocial interventions, on both weight loss and eating behavior. Implications for treatment of obesity are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Attrition and changes in size distribution of lime sorbents during fluidization in a circulating fluidized bed absorber. Double quarterly report, January 1--August 31, 1993

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

Lee, Sang-Kwun; Keener, T.C.; Cook, J.L.

1993-12-31

The experimental data of lime sorbent attrition obtained from attriton tests in a circulating fluidized bed absorber (CFBA) are represented. The results are interpreted as both the weight-based attrition rate and size-based attrition rate. The weight-based attrition rate constants are obtained from a modified second-order attrition model, incorporating a minimum fluidization weight, W{sub min}, and excess velocity. Furthermore, this minimum fluidization weight, or W{sub min} was found to be a function of both particle size and velocity. A plot of the natural log of the overall weight-based attrition rate constants (ln K{sub a}) for Lime 1 (903 MMD) at superficialmore » gas velocities of 2 m/s, 2.35 m/s, and 2.69 m/s and for Lime 2 (1764 MMD) at superficial gas velocities of 2 m/s, 3 m/s, 4 m/s and 5 m/s versus the energy term, 1/(U-U{sub mf}){sup 2}, yielded a linear relationship. And, a regression coefficient of 0.9386 for the linear regression confirms that K{sub a} may be expressed in Arrhenius form. In addition, an unsteady state population model is represented to predict the changes in size distribution of bed materials during fluidization. The unsteady state population model was verified experimentally and the solid size distribution predicted by the model agreed well with the corresponding experimental size distributions. The model may be applicable for the batch and continuous operations of fluidized beds in which the solids size reduction is predominantly resulted from attritions and elutriations. Such significance of the mechanical attrition and elutriation is frequently seen in a fast fluidized bed as well as in a circulating fluidized bed.« less

Blocking carbohydrate absorption and weight loss: a clinical trial using a proprietary fractionated white bean extract.

PubMed

Udani, Jay; Singh, Betsy B

2007-01-01

A proprietary fractionated white bean extract of Phaseolus vulgaris has been shown in vitro to inhibit the digestive enzyme alpha-amylase. This may prevent or delay the digestion of complex carbohydrates, potentially resulting in weight loss. A 4-week randomized, double-blind, placebo-controlled study of 25 healthy subjects consuming 1000 mg of a proprietary fractioned white bean extract or an identical placebo twice a day before meals in conjunction with a multi-component weight-loss program, including diet, exercise, and behavioral intervention, was conducted. Both groups reduced their weight and waist size significantly from baseline. The active group lost 6.0 lbs (P=.0002) and 2.2 in (P=.0050), and the placebo group lost 4.7 lbs (P=.0016) and 2.1 in (P=.0001). The differences between groups were not significant (weight P=.4235, waist size P=.8654). Through subsequent exploratory analysis to investigate group findings further, subjects were stratified by total dietary carbohydrate intake. This probative analysis revealed that the tertile of subjects who had consumed the most carbohydrates demonstrated significant reductions in both weight (8.7 lbs vs 1.7 lbs, P=.0412) and waist size (3.3 in vs 1.3 in P=.0100) compared with placebo subjects in the same tertile of carbohydrate intake. Subjects who adhere to a program including dietary modification, exercise, and behavioral intervention can significantly reduce their weight and waist size in a short period of time. In an exploratory analysis of data, the tertile of subjects who ate the most carbohydrates experienced a significant reduction in both weight and waist size with the addition of the white bean extract compared to the placebo group of the same tertile of carbohydrate consumption. Longer studies with a larger pool of subjects are required to validate these findings.

Skeletal Growth Dysregulation in Australian Male Infants and Toddlers With Autism Spectrum Disorder.

PubMed

Green, Cherie C; Dissanayake, Cheryl; Loesch, Danuta Z; Bui, Minh; Barbaro, Josephine

2018-06-01

Recent findings suggest that children with Autism Spectrum Disorder (ASD) are larger in size for head circumference (HC), height, and weight compared to typically developing (TD) children; however, little is known about their rate of growth, especially in height and weight. The current study aimed to: (a) confirm and extend upon previous findings of early generalized overgrowth in ASD; and (b) determine if there were any differences in the rate of growth between infants and toddlers with ASD compared to their TD peers. Measurements of HC, height, and weight were available for 135 boys with ASD and 74 TD boys, from birth through 3 years of age. Size and growth rate in HC, height, and weight were analyzed using a linear mixed-effects model. Infants with ASD were significantly smaller in size at birth for HC, body length, and weight compared to TD infants (all P < 0.05); however, they grew at a significantly faster rate in HC and height in comparison to the TD children (P < 0.001); there was no significant difference between the groups in growth rate for weight (P > 0.05). The results confirmed that male infants and toddlers with ASD exhibit skeletal growth dysregulation early in life. Autism Res 2018, 11: 846-856. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. Recent findings suggest that infants with Autism Spectrum Disorder (ASD) are smaller in size at birth compared to typically developing infants but grow larger than their peers during the first year. Little is known about their rate of growth, especially for height and weight. Our findings confirmed that infants with ASD are smaller in size at birth for head circumference (HC), height, and weight, but grow at a faster rate in HC and height than their peers from birth to 3 years. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

Gestational age and newborn size according to parental social mobility: an intergenerational cohort study.

PubMed

Gigante, Denise P; Horta, Bernardo L; Matijasevich, Alicia; Mola, Christian Loret de; Barros, Aluisio J D; Santos, Ina S; Barros, Fernando C; Victora, Cesar G

2015-10-01

We examined the associations between socioeconomic trajectories from birth to adulthood and gestational age and birth size in the next generation, using linked data from two population-based birth cohorts carried out in a Brazilian city. By comparing socioeconomic trajectories of mothers and fathers, we attempted to identify-specific effects of maternal and paternal socioeconomic trajectory on offspring birth weight, birth length, head circumference and gestational age at birth. 2 population-based birth cohort studies were carried out in 1982 and 2004 in Pelotas (Brazil); 156 mothers and 110 fathers from the earlier cohort had children in 2004. Gestational age and birth length, weight and head circumference were measured. Analyses were carried out separately for mothers and fathers. Mediation analyses assessed the role of birth weight and adult body mass index (BMI). Among mothers, but not for fathers, childhood poverty was strongly associated with smaller size in the next generation (about 400 g in weight and 1.5 cm in height) and shorter gestations (about 2 weeks). Adult poverty did not play a role. For mothers, the associations with gestational age, birth length and weight-but not with head circumference-persisted after adjusting for maternal birth weight and for the height and weight of the grandmother. Maternal birth weight did not mediate the observed associations, but high maternal BMI in adulthood was partly responsible for the association with gestational age. Strong effects of early poverty on gestational age and birth size in the next generation were observed among mothers, but not among fathers. These findings suggest a specific maternal effect of socioeconomic trajectory, and in particular of early poverty on offspring size and duration of pregnancy. 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.

Linking actions and objects: Context-specific learning of novel weight priors.

PubMed

Trewartha, Kevin M; Flanagan, J Randall

2017-06-01

Distinct explicit and implicit memory processes support weight predictions used when lifting objects and making perceptual judgments about weight, respectively. The first time that an object is encountered weight is predicted on the basis of learned associations, or priors, linking size and material to weight. A fundamental question is whether the brain maintains a single, global representation of priors, or multiple representations that can be updated in a context specific way. A second key question is whether the updating of priors, or the ability to scale lifting forces when repeatedly lifting unusually weighted objects requires focused attention. To investigate these questions we compared the adaptability of weight predictions used when lifting objects and judging their weights in different groups of participants who experienced size-weight inverted objects passively (with the objects placed on the hands) or actively (where participants lift the objects) under full or divided attention. To assess weight judgments we measured the size-weight illusion after every 20 trials of experience with the inverted objects both passively and actively. The attenuation of the illusion that arises when lifting inverted object was found to be context-specific such that the attenuation was larger when the mode of interaction with the inverted objects matched the method of assessment of the illusion. Dividing attention during interaction with the inverted objects had no effect on attenuation of the illusion, but did slow the rate at which lifting forces were scaled to the weight inverted objects. These findings suggest that the brain stores multiple representations of priors that are context specific, and that focused attention is important for scaling lifting forces, but not for updating weight predictions used when judging object weight. Copyright © 2017 Elsevier B.V. All rights reserved.

How coupling affects closely packed rectenna arrays used for wireless power transmission

NASA Astrophysics Data System (ADS)

Walls, Deidra; Choi, Sang H.; Yoon, Hargsoon; Geddis, Demetris; Song, Kyo D.

2017-04-01

The development of power transmission by microwave beam power harvesting attracts manufactures for use of wireless power transmission. Optimizing maximum conversion efficiency is affected by many design parameters, and has been mainly focused previously. Combining several rectennas in one array potentially aides in the amount of microwave energy that can be harvested for energy conversion. Closely packed rectenna arrays is the result of the demand to minimize size and weight for flexibility. This paper specifically focuses on the coupling effects on power; mutual coupling, comparing sparameters and gain total while varying effective parameters. This paper investigates how coupling between each dipole positively and negatively affects the microwave energy, harvesting, and the design limitations.

Status of flexible CIS research at ISET

NASA Technical Reports Server (NTRS)

Basol, B. M.; Kapur, V. K.; Minnick, A.; Halani, A.; Leidholm, C. R.

1994-01-01

Polycrystalline thin film solar cells fabricated on light-weight, flexible substrates are very attractive for space applications. In this work CulnSe2 (CIS) based thin film devices were processed on metallic foil substrates using the selenization technique. CIS deposition method involved reaction of electron-bean evaporated Cu-In precursor layers with a selenizing atmosphere at around 400 C. Several metallic foils such as Mo, Ti, Al, Ni, and Cu were evaluated as possible substrates for these devices. Solar cells with AM1.5 efficiencies of 9.0-9.34 percent and good mechanical integrity were demonstrated on Mo and Ti foils. Monolithic integration of these devices was also demonstrated up to 4 in x 4 in size.

Substitution of ceramics for high temperature alloys. [advantages of using silicon carbides and silicon nitrides in gas turbine engines

NASA Technical Reports Server (NTRS)

Probst, H. B.

1978-01-01

The high temperature capability of ceramics such as silicon nitride and silicon carbide can result in turbine engines of improved efficiency. Other advantages when compared to the nickel and cobalt alloys in current use are raw material availability, lower weight, erosion/corrosion resistance, and potentially lower cost. The use of ceramics in three different sizes of gas turbine is considered; these are the large utility turbines, advanced aircraft turbines, and small automotive turbines. Special consideration, unique to each of these applications, arise when one considers substituting ceramics for high temperature alloys. The effects of material substitutions are reviewed in terms of engine performance, operating economy, and secondary effects.

Anthropometric measurements in the diagnosis of pelvic size: an analysis of maternal height and shoe size and computed tomography pelvimetric data.

PubMed

Awonuga, Awoniyi O; Merhi, Zaher; Awonuga, Modupe T; Samuels, Terri-Ann; Waller, Jennifer; Pring, David

2007-11-01

To determine whether measurements of maternal height and shoe size are predictors of pelvic size, using erect lateral computerized tomography (CT) pelvimetry as gold standard. Three hundred and fifty three obstetric patients out of a sequential population of 6112 (5.8%) had CT pelvimetry performed between January 1990 and December 1991 at the Department of Obstetrics and Gynecology, York District Hospital, United Kingdom. Multivariable logistic regression models were built using maternal height (n = 322), shoe size (314) and weight at last clinic visit (n = 318). The reference standard for pelvic size was CT Pelvimetry. Pelvic adequacy was defined as an anterior-posterior diameter of the inlet of > or =11 cm and an anterior-posterior diameter of the outlet > or =10 cm on erect lateral CT pelvimetry. Women with values lower than these were regarded as having an inadequate pelvis. The diagnostic accuracy of the models was determined by the area under the receiver operating characteristic curve (AUC). The area under the curve (AUC) for maternal height (0.768) was not significantly greater than that for shoe size (0.686, p = 0.163 for the difference in AUC's) and weight at the last clinic visit (0.655, p = 0.057 for the difference in the AUCs). The change in the AUC for each of the models (the full model with height, shoe size and weight [0.769]; model for height and shoe size [0.767] model for just height [0.768]) was also not significantly different. Measurements of maternal height, shoe size and weight at the last clinic visit are not useful for the identification of women with inadequate pelvis.

Body size satisfaction and physical activity levels among men and women.

PubMed

Kruger, Judy; Lee, Chong-Do; Ainsworth, Barbara E; Macera, Caroline A

2008-08-01

Body size satisfaction may be an important factor associated with physical activity. We analyzed data from the 2002 National Physical Activity and Weight Loss Survey (NPAWLS), a population-based cross-sectional telephone survey of US adults. Multiple logistic regression models were used to examine the association of body size satisfaction on being regularly active. Participants were aged > or =18 years with complete data on weight, race/ethnicity, physical activity level, and body size satisfaction (n = 10,021). More than half of men (55.8%) and women (53.3%) who reported being very satisfied with the body size were regularly active. After adjustment for covariates, participants who reported being somewhat or not satisfied with their body size had a 13 and 44% lower odds of being regularly active, respectively, compared with those very satisfied with their body size. When stratified by race/ethnicity, this association remained in whites (P for trend <0.001), but became weaker and nonsignificant in blacks, Hispanics, or other racial/ethnic groups. Irrespective of actual weight, those who were satisfied with their body size were more likely to engage in regular physical activity than those less satisfied. Further research is needed to explore predictors of physical activity to reduce health disparities.

Small Size at Birth or Abnormal Intrauterine Growth Trajectory: Which Matters More for Child Growth?

PubMed Central

Hutcheon, Jennifer A.; Jacobsen, Geir W.; Kramer, Michael S.; Martinussen, Marit; Platt, Robert W.

2016-01-01

Small size at birth is linked with lifelong adverse health implications. However, small size is only a proxy for the pathological process of interest, intrauterine growth restriction. We examined the extent to which information on intrauterine growth patterns improved prediction of childhood anthropometry, above and beyond birth weight alone. We obtained fetal weights estimated via serial ultrasound for 478 children in the Scandinavian Successive Small-for-Gestational-Age Births Study (1986–1988). Size at birth was classified using birth weight-for-gestational-age z scores and conditional fetal growth z scores (reflecting growth between 25 weeks’ gestation and birth) using internal references. Conditional z scores were also expressed as residuals of birth weight z scores. Growth measures were linked with age-5-years anthropometric characteristics using linear regression. In univariable analyses, conditional fetal growth z scores were positively associated with z scores for child height, body mass index, total skinfold thickness, and head circumference (β = 0.24 (95% confidence interval (CI): 0.18, 0.31), β = 0.16 (95% CI: 0.09, 0.23), β = 0.08 (95% CI: 0.01, 0.16), and β = 0.37 (95% CI: 0.22, 0.52), respectively). However, conditional z scores were highly correlated with birth weight z scores (r = 0.9), and residuals explained minimal additional variation in anthropometric factors (null coefficients; adjusted R2 increases < 0.01). Information on the intrauterine trajectory through which birth weight was attained provided little additional insight into child growth beyond that obtained from absolute size at birth. PMID:27257112

Robust and efficient estimation with weighted composite quantile regression

NASA Astrophysics Data System (ADS)

Jiang, Xuejun; Li, Jingzhi; Xia, Tian; Yan, Wanfeng

2016-09-01

In this paper we introduce a weighted composite quantile regression (CQR) estimation approach and study its application in nonlinear models such as exponential models and ARCH-type models. The weighted CQR is augmented by using a data-driven weighting scheme. With the error distribution unspecified, the proposed estimators share robustness from quantile regression and achieve nearly the same efficiency as the oracle maximum likelihood estimator (MLE) for a variety of error distributions including the normal, mixed-normal, Student's t, Cauchy distributions, etc. We also suggest an algorithm for the fast implementation of the proposed methodology. Simulations are carried out to compare the performance of different estimators, and the proposed approach is used to analyze the daily S&P 500 Composite index, which verifies the effectiveness and efficiency of our theoretical results.

"Whatever average is:" understanding African-American mothers' perceptions of infant weight, growth, and health.

PubMed

Thompson, Amanda L; Adair, Linda; Bentley, Margaret E

2014-06-01

Biomedical researchers have raised concerns that mothers' inability to recognize infant and toddler overweight poses a barrier to stemming increasing rates of overweight and obesity, particularly among low-income or minority mothers. Little anthropological research has examined the sociocultural, economic or structural factors shaping maternal perceptions of infant and toddler size or addressed biomedical depictions of maternal misperception as a "socio-cultural problem." We use qualitative and quantitative data from 237 low-income, African-American mothers to explore how they define 'normal' infant growth and infant overweight. Our quantitative results document that mothers' perceptions of infant size change with infant age, are sensitive to the size of other infants in the community, and are associated with concerns over health and appetite. Qualitative analysis documents that mothers are concerned with their children's weight status and assess size in relation to their infants' cues, local and societal norms of appropriate size, interactions with biomedicine, and concerns about infant health and sufficiency. These findings suggest that mothers use multiple models to interpret and respond to child weight. An anthropological focus on the complex social and structural factors shaping what is considered 'normal' and 'abnormal' infant weight is critical for shaping appropriate and successful interventions.

Nanosized soy phytosome-based thermogel as topical anti-obesity formulation: an approach for acceptable level of evidence of an effective novel herbal weight loss product

PubMed Central

El-Menshawe, Shahira F; Ali, Adel A; Rabeh, Mohamed A; Khalil, Nermeen M

2018-01-01

Purpose Herbal supplements are currently available as a safer alternative to manage obesity, which has become a rising problem over the recent years. Many chemical drugs on the market are designed to prevent or manage obesity but high cost, low efficacy, and multiple side effects limit its use. Nano lipo-vesicles phytosomal thermogel of Soybean, Glycine max (L.) Merrill, was formulated and evaluated in an attempt to investigate its anti-obesity action on body weight gain, adipose tissue size, and lipid profile data. Methods Three different techniques were used to prepare phytosome formulations including solvent evaporation, cosolvency, and salting out. The optimized phytosome formulation was then selected using Design Expert® (version 7.0.0) depending on the highest entrapment efficiency, minimum particle size (PS), and maximum drug release within 2 hours as responses for further evaluation. The successful phytosome complex formation was investigated by means of Fourier-transform infrared spec troscopy and determination of PS and zeta potential. Phytosome vesicles’ shape was evaluated using transmission electron microscope to ensure its spherical shape. After characterization of the optimized phytosome formulation, it was incorporated into a thermogel formulation. The obtained phytosomal thermogel formulation was evaluated for its clarity, homogeneity, pH, and gel transformation temperature besides rheology behavior and permeation study. An in vivo study was done to investigate the anti-weight-gain effect of soy phytosomal ther mogel. Results EE was found to be >99% for all formulations, PS ranging from 51.66–650.67 while drug release was found to be (77.61–99.78) in range. FTIR and TEM results confirmed the formation of phytosome complex. In vivo study showed a marked reduction in body weight, adipose tissue weight and lipid profile. Conclusion Concisely, soy phytosomal thermogel was found to have a local anti-obesity effect on the abdomen of experimental male albino rats with a slight systemic effect on the lipid profile data. PMID:29391791

Relationships between maternal engorgement weight and the number, size, and fat content of larval Ixodes scapularis (Acari: Ixodidae)

USGS Publications Warehouse

Ginsberg, Howard; Lee, Chong; Volson, Barry; Dyer, Megan C.; LeBrun, Roger A.

2017-01-01

The relationship between engorgement weight of female Ixodes scapularis Say and characteristics of offspring was studied using field-collected females fed on rabbits in the laboratory. The number of eggs laid was positively related to maternal engorgement weight in one trial, and larval size (estimated by scutal area) was positively related to maternal engorgement weight in the other. These results suggest a trade-off in number of eggs produced versus average size of offspring, possibly determined during late engorgement. The adults for the two trials were collected from different sites in southern Rhode Island and in different seasons (the fall adults were newly emerged, while the spring adults had presumably lived through the winter), so it is not clear whether these results reflect genetic differences or subtle environmental differences between trials. Percent egg hatch and average fat content of larvae were not related to female engorgement weight. We present a modified method to measure lipid content of pooled larval ticks.

Comprehensive Truck Size and Weight (TS&W) Study. Phase 1-synthesis, working paper 7 : truck costs and truck size and weight regulations

DOT National Transportation Integrated Search

2012-07-01

This report presents the Cost Benefit Analysis Test Plan for the national evaluation of the Los Angeles County Congestion Reduction Demonstration (LAC CRD) under the United States Department of Transportation (U.S. DOT) Congestion Reduction Demonstra...