9,387 research outputs found
Improved sterilizable multiplier phototubes Final report
Development of sterilizable multiplier phototube for scintillation counte
Sterilizable photomultiplier tubes Final report
Environment, static acceleration, vibration, shock, gas contamination, and life tests in development of sterilizable photomultipliers for space program
Electricity from photovoltaic solar cells: Flat-Plate Solar Array Project final Report. Volume III: Silicon sheet: wafers and ribbons
The Flat-Plate Solar Array (FSA) Project, funded by the U.S. Government and managed by the Jet Propulsion Laboratory, was formed in 1975 to develop the module/array technology needed to attain widespread terrestrial use of photovoltaics by 1985. To accomplish this, the FSA Project established and managed an Industry, University, and Federal Government Team to perform the needed research and development.
The primary objective of the Silicon Sheet Task of the FSA Project was the development of one or more low-cost technologies for producing silicon sheet suitable for processing into cost-eompetitive solar cells. Silicon sheet refers to high-purity crystalline silicon of size and thickness for fabrication into solar cells.
The Task effort began with state-of-the-art sheet technologies and then solicited and supported any new silicon sheet alternatives that had the potential to achieve the Project goals.
A total of 48 contracts were awarded that covered work in the areas of ingot growth and casting, wafering, ribbon growth, other sheet technologies, and programs of supportive research. Periodic reviews of each sheet technology were held, assessing the technical progress and the long-range potential. Technologies that failed to achieve their promise, or seemed to have lower probabilities for success in comparison with others, were dropped. A series of workshops was initiated to assess the state of the art, to provide insights into problems remaining to be addressed, and to support technology transfer.
The Task made and fostered significant improvements in silicon sheet including processing of both ingot and ribbon technologies. An additional important outcome was the vastly improved understanding of the characteristics associated with high-quality sheet, and the control of the parameters required for higher efficiency solar cells. Although significant sheet cost reductions were made, the technology advancements required to meet the Task cost goals were not achieved.
This FSA Final Report (JPL Publication 86-31, 5101-289, DOE/JPL 1012-125, October 1986) is composed of eight volumes, consisting of an Executive Summary and seven technology reports:
Volume I: Executive Summary.
Volume II: Silicon Material.
Volume III: Silicon Sheet: Wafers and Ribbons
Volume IV: High-Efficiency Solar Celis.
Volume V: Process Development.
Volume VI: Engineering Sciences and Reliability.
Volume VII: Module Encapsulation.
Volume VIII: Project Analysis and Integration.
Two supplemental reports included in the final report package are:
FSA Project: 10 Years of Progress, JPL Document 400-279. 5101-279, October 1985.
Summary of FSA Project Documentation: Abstracts of Published Documents, 1975 to 1986, JPL Publication 82-79 (Revision 1),5101-221, DOE/JPL-1 012-76, September 1986
Infrared light emission from atomic point contacts
Gold atomic point contacts are prototype systems to evidence ballistic
electron transport. The typical dimension of the nanojunction being smaller
than the electron-phonon interaction length, even at room temperature,
electrons transfer their excess energy to the lattice only far from the
contact. At the contact however, favored by huge current densities,
electron-electron interactions result in a nano hot electron gas acting as a
source of photons. Using a home built Mechanically Controlled Break Junction,
it is reported here, for the first time, that this hot electron gas also
radiates in the infrared range (0.2eV to 1.2eV). Moreover, in agreement with
the pioneering work of Tomchuk, we show that this radiation is compatible with
a blackbody like spectrum emitted from an electron gas at temperatures of
several thousands of Kelvin given by where ,
and are respectively a fitting parameter, the current flowing and the
applied bias.Comment: 13 pages, 5 figure
Is the way we're dieting wrong?
Progress in personalized medicine is now being translated to personalized nutrition. A recent proof-of-concept study shows that the increase in blood glucose levels after a meal is highly variable between individuals, but can be predicted by using a computational model that combines information from gut microbiome profiles and dietary questionnaires. This study raises questions about the usefulness of universal diet recommendations, and suggests we might need to move on to personalized diets
Impact of knee marker misplacement on gait kinematics of children with cerebral palsy using the Conventional Gait Model — a sensitivity study
Clinical gait analysis is widely used in clinical routine to assess the function of patients with motor disorders. The proper assessment of the patient’s function relies greatly on the repeatability between the measurements. Marker misplacement has been reported as the largest source of variability between measurements and its impact on kinematics is not fully understood. Thus, the purpose of this study was: 1) to evaluate the impact of the misplacement of the lateral femoral epicondyle marker on lower limb kinematics, and 2) evaluate if such impact can be predicted. The kinematic data of 10 children with cerebral palsy and 10 aged-match typical developing children were included. The lateral femoral epicondyle marker was virtually misplaced around its measured position at different magnitudes and directions. The outcome to represent the impact of each marker misplacement on the lower limb was the root mean square deviations between the resultant kinematics from each simulated misplacement and the originally calculated kinematics. Correlation and regression equations were estimated between the root mean square deviation and the magnitude of the misplacement expressed in percentage of leg length. Results indicated that the lower-limb kinematics is highly sensitive to the lateral femoral epicondyle marker misplacement in the anterior-posterior direction. The joint angles most impacted by the anterior-posterior misplacement were the hip internal-external rotation (5.3° per 10 mm), the ankle internal-external rotation (4.4° per 10 mm) and the knee flexion-extension (4.2° per 10 mm). Finally, it was observed that the lower the leg length, the higher the impact of misplacement on kinematics. This impact was predicted by regression equations using the magnitude of misplacement expressed in percentage of leg length. An error below 5° on all joints requires a marker placement repeatability under 1.2% of the leg length. In conclusion, the placement of the lateral femoral epicondyle marker in the antero-posterior direction plays a crucial role on the reliability of gait measurements with the Conventional Gait Model
Declarative process modeling in BPMN
Traditional business process modeling notations, including the standard Business Process Model and Notation (BPMN), rely on an imperative paradigm wherein the process model captures all allowed activity flows. In other words, every flow that is not specified is implicitly disallowed. In the past decade, several researchers have exposed the limitations of this paradigm in the context of business processes with high variability. As an alternative, declarative process modeling notations have been proposed (e.g., Declare). These notations allow modelers to capture constraints on the allowed activity flows, meaning that all flows are allowed provided that they do not violate the specified constraints. Recently, it has been recognized that the boundary between imperative and declarative process modeling is not crisp. Instead, mixtures of declarative and imperative process modeling styles are sometimes preferable, leading to proposals for hybrid process modeling notations. These developments raise the question of whether completely new notations are needed to support hybrid process modeling. This paper answers this question negatively. The paper presents a conservative extension of BPMN for declarative process modeling, namely BPMN-D, and shows that Declare models can be transformed into readable BPMN-D models. © Springer International Publishing Switzerland 2015
Lutte contre les cercosporioses du bananier aux Antilles françaises Banatrace, un système d'information géographique multi-acteurs pour la gestion et la traçabilité des épandages aériens
[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]INSPIREBanatrace est un système d'information intégrant les tâches de gestion des épandages aériens qui incombent aux opérateurs dans le cadre de la lutte contre la cercosporiose de la banane en Guadeloupe et en Martinique. Cet outil multi-acteurs est l'aboutissement d'un travail d'analyse-conception réalisé par le Cemagref. En combinant une base de données répartie et des fonctions d'information géographique, il répond aux différents besoins de traçabilité imposée par la réglementation récente sur les épandages aériens. Il assure l'interface entre le gestionnaire, les opérateurs aériens, les planteurs, les groupements de producteurs, et l'administration. Au-delà de l'efficacité obtenue dans les taches de gestion, il contribue à améliorer la sécurité des personnes et la protection des cours d'eau et de l'environnement. / " Banatrace " is an information system integrating the European rules and regulations relative to the aerial spraying of pesticide over the banana plantations. It helps to the fight against the cercosporia contamination in the French West Indies. This tool aims to fulfill the information needed by the different parties involved in this process: user manager, planters, aerial treatment companies, planters' cooperatives and administration. It includes DBMS and GIS functionalities in order to program the treatments and to record all events, leading to a better traceability. Moreover carrying out treatment management, it contributes to improve people security and environment protection
Compositional characterisation of the Themis family
Context. It has recently been proposed that the surface composition of icy
main-belt asteroids (B-,C-,Cb-,Cg-,P-,and D-types) may be consistent with that
of chondritic porous interplanetary dust particles (CPIDPs). Aims. In the light
of this new association, we re-examine the surface composition of a sample of
asteroids belonging to the Themis family in order to place new constraints on
the formation and evolution of its parent body. Methods. We acquired NIR
spectral data for 15 members of the Themis family and complemented this dataset
with existing spectra in the visible and mid-infrared ranges to perform a
thorough analysis of the composition of the family. Assuming end-member
minerals and particle sizes (<2\mum) similar to those found in CPIDPs, we used
a radiative transfer code adapted for light scattering by small particles to
model the spectral properties of these asteroids. Results. Our best-matching
models indicate that most objects in our sample possess a surface composition
that is consistent with the composition of CP IDPs.We find ultra-fine grained
Fe-bearing olivine glasses to be among the dominant constituents. We further
detect the presence of minor fractions of Mg-rich crystalline silicates. The
few unsuccessfully matched asteroids may indicate the presence of interlopers
in the family or objects sampling a distinct compositional layer of the parent
body. Conclusions. The composition inferred for the Themis family members
suggests that the parent body accreted from a mixture of ice and anhydrous
silicates (mainly amorphous) and subsequently underwent limited heating. By
comparison with existing thermal models that assume a 400km diameter
progenitor, the accretion process of the Themis parent body must have occurred
relatively late (>4Myr after CAIs) so that only moderate internal heating
occurred in its interior, preventing aqueous alteration of the outer shell.Comment: 9 pages, 5 figures, accepted for publication in A&
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