Simple Arrangement for Internal Audiomodulation of a He-Ne Laser

1970 ◽  
Vol 38 (7) ◽  
pp. 926-927
Author(s):  
Antonio Armando Carrá
Keyword(s):  
Simple Arrangement

Modeling of a Smart Heat Pump Made of Laminated Thermoelectric and Electrocaloric Materials

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Dudong Feng ◽  
Shi-Chune Yao ◽  
Tian Zhang ◽  
Qiming Zhang
Keyword(s):  
Heat Pump ◽  
Temperature Difference ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Laminated Structure ◽  
Heat Pump System ◽  
Simple Arrangement ◽  
Parametric Effects ◽  
Hybrid Heat Pump ◽  
Physical Features

In this study, a smart heat pump, which could be used for the cooling of electronics, made of laminated structure of thermoelectric (TE) and electrocaloric (EC) materials, is studied. A simple arrangement of two TE layers sandwiched with one EC layer is modeled. This smart heat pump utilized the newly developed EC materials of giant adiabatic temperature change and the TE materials of high figure of merit. The system has the advantages of no moving parts, made of solid state, operable over large working temperature difference, and can be formed into very small size. The operation of the device is numerically modeled considering the three major parametric effects: EC operation as a function of time, electric current applied on TE, and temperature difference between the hot and cold sinks. The results on coefficient of performance (COP) and heat flow per unit area are discussed. This study is performed as an early attempt of analyzing the basic physical features of TE–EC–TE laminated structure heat pump and extends the understanding by further discussing the tradeoff between lower COP and larger overall temperature difference coverage in the TE/EC hybrid heat pump system with multilaminated structure.

scholarly journals BIOMASSA E NUTRIENTES DE EUCALIPTO CULTIVADO EM SISTEMA AGROSSILVIPASTORIL

Nativa ◽  
2018 ◽  
Vol 6 ◽  
pp. 754
Author(s):  
Charlote Wink ◽  
Anderson Lange ◽  
Kamile Zompero Araújo ◽  
Ana Paula Silveira ◽  
Maurel Behling ◽  
...  
Keyword(s):  
Eucalyptus Grandis ◽  
Triple Line ◽  
Nutrient Content ◽  
Integration System ◽  
Line Arrangement ◽  
Residual Biomass ◽  
Technological Unit ◽  
Simple Arrangement ◽  
Nutrient Stock ◽  
Hybrid Eucalyptus

O objetivo foi quantificar a biomassa e o estoque de nutrientes do híbrido Eucalyptus grandis Hill ex Maiden x E. urophylla S. T. Blake (clone H13) aos 60 meses em sistema agrossilvipastoril. O estudo da biomassa residual (folhas e galhos finos), galhos grossos, madeira e casca e do estoque de nutrientes de eucalipto foi realizado na unidade de referência tecnológica de integração lavoura-pecuária-floresta em Nova Canaã do Norte, MT, cultivado em arranjo simples (2x20 m), duplo (3x2x20 m), triplo (3x2x20 m) e em monocultivo (4x3 m). Apenas a biomassa de galhos grossos, madeira e casca apresentaram diferenças significativas entre arranjos. Os nutrientes se acumularam em maior quantidade na madeira, e em ordem decrescente na casca, biomassa residual e nos galhos grossos. A biomassa residual, galhos grossos e casca correspondem a fração expressiva de nutrientes que permanece no sistema, e que contribuem para menor reposição na manutenção desses, após a colheita. O arranjo triplo apresentou maior acúmulo nutricional comparado ao arranjo simples e duplo. A eficiência nutricional é maior no arranjo de linha tripla devido a maior competição intraespecífica. O teor de nutrientes nas diferentes posições ao longo do fuste não apresentou variações nutricionais significativas para a madeira, diferentemente para a casca.Palavras-chave: sistema iLPF, nutrição florestal, compartimentos. BIOMASS AND NUTRIENTS OF EUCALYPTUS CULTIVATED IN AGROSSILVIPASTORAL SYSTEM ABSTRACT:The objective was to quantify the biomass and nutrient stock of the hybrid Eucalyptus grandis Hill ex Maiden x E. urophylla S. T. Blake, (clone H13) at 60 months in the agrosilvipastoril system. The study of the residual biomass (leaves and thin branches), thick branches, wood and bark and of the nutrient stock of eucalyptus was carried out in the technological unit of crop-livestock-forest integration in Nova Canaã do Norte, MT, cultivated in a simple arrangement (2x20 m), double (3x2x20 m), triple (3x2x20 m) and monoculture (4x3 m). Only the biomass of thick branches, wood and bark presented significant differences between arrangements. The nutrients accumulate in greater quantity in the wood, and in descending order in the bark, residual biomass and in the thick branches. Residual biomass, thick branches and bark correspond to the expressive fraction of nutrients that remain in the system, and which contribute to a lower replacement in the maintenance of these, after harvesting. The triple arrangement presented greater nutritional accumulation compared to the single and double arrangement. The nutritional efficiency is higher in the triple line arrangement due to greater intraspecific competition. The nutrient content in the different positions along the stem did not present significant nutritional variations for the wood, differently for the bark.Keywords: CLF integration system, forest nutrition, compartments.

scholarly journals Active Stabilization of the Beam Pointing of a High- Power KrF Laser System

2015 ◽  
Vol 22 (1) ◽  
pp. 165-172 ◽  
Author(s):  
A. Barna ◽  
I. B. Földes ◽  
J. Bohus ◽  
S. Szatmári
Keyword(s):  
High Power ◽  
Laser System ◽  
Spot Size ◽  
Electric Signal ◽  
Simple Arrangement ◽  
Krf Laser ◽  
Active Stabilization ◽  
Directional Change ◽  
Position Sensitive Detectors

Abstract An active beam-pointing stabilization system has been developed for a high-power KrF laser system to eliminate the long-term drift of the directional change of the beam in order to have a stable focusing to a high intensity. The control of the beam direction was achieved by a motor-driven mirror activated by an electric signal obtained by monitoring the position of the focus of the output beam. Instead of large sized UV-sensitive position sensitive detectors a simple arrangement with scatter plates and photodiodes are used to measure the directionality of the beam. After the beam stabilization the long-term residual deviation of the laser shots is ~14 μrad, which is comparable to the shot-to-shot variation of the beam (~12 μrad). This deviation is small enough to keep the focal spot size in a micrometer range when tightly focusing the beam using off-axis parabolic mirrors.

Development of a Combined Scanning Ion-Conductance and Nearfield Optical Microscope to Image Living Cells

1999 ◽  
Vol 5 (S2) ◽  
pp. 976-977
Author(s):  
M. Raval ◽  
D. Klenerman ◽  
T. Rayment ◽  
Y. Korchev ◽  
M. Lab
Keyword(s):  
Optical Microscopy ◽  
Biological Samples ◽  
Near Field ◽  
Sample Surface ◽  
Optical Microscope ◽  
Ion Conductance ◽  
Simultaneous Generation ◽  
Simple Arrangement ◽  
Wavelength Resolution ◽  
Sub Wavelength

It is important to be able to image biological samples in a manner that is non-invasive and allows the sample to retain its functionality during imaging.A member of the SPM (scanning probe microscopy) family, SNOM (scanning near-field optical microscopy), has emerged as a technique that allows optical and topographic imaging of biological samples whilst satisfying the above stated criteria. The basic operating principle of SNOM is as follows. Light is coupled down a fibre-optic probe with an output aperture of sub-wavelength dimensions. The probe is then scanned over the sample surface from a distance that is approximately equal to the size of its aperture. By this apparently simple arrangement, the diffraction limit posed by conventional optical microscopy is overcome and simultaneous generation of optical and topographic images of sub-wavelength resolution is made possible. Spatial resolution values of lOOnm in air and 60nm in liquid[1,2] are achievable with SNOM.

A Simple Method for Simultaneous Projection of a Schlieren Image on a Viewing Screen and into a Camera

1963 ◽  
Vol 67 (631) ◽  
pp. 454-454 ◽  
Author(s):  
C. Nebbeling
Keyword(s):  
Light Beam ◽  
Time Lag ◽  
Visual Observation ◽  
Schlieren Image ◽  
Steady Flows ◽  
Knife Edge ◽  
Simple Method ◽  
Schlieren System ◽  
Simple Arrangement ◽  
Viewing Screen

The toepler schlieren system of wind tunnels is usually designed in such a way that an image of the flow in the test section can be formed in a camera for taking flow pictures. For visual observation, a mirror is inserted in the light beam and the image is projected on a screen. When a photograph or film record of the flow is desired, the mirror is removed by some quick-acting mechanism to allow the light beam to enter the camera. Especially in the case of non-steady flows, the time lag involved in removing the mirror can prove to be a drawback. An interesting pattern observed upon the screen may have vanished by the time the light beam is switched over to the camera. At the same time the image disappears from the screen, leaving the operator in doubt whether or not the pattern lasted long enough to be recorded by the camera. In this note a very simple arrangement of the schlieren system is described, which gives simultaneously an image on the viewing screen and in the camera. So far as the author knows, it is not applied elsewhere. The method consists of the use of a mirror knife edge instead of the usual knife edge.

A simple arrangement and notation of the thirty-two classes of symmetry based on the symmetry of zone-axes

1907 ◽  
Vol 14 (67) ◽  
pp. 360-364 ◽  
Author(s):  
John W. Evans
Keyword(s):  
Zone Axis ◽  
Cyclic Symmetry ◽  
Crystal Face ◽  
Straight Line ◽  
Simple Arrangement ◽  
Complete Revolution ◽  
Pass Through

If a straight line making an angle with a zone-axis of a crystal be rotated about the zone-axis while the crystal remain fixed, the physical characters of that line will pass through a cycle of changes. If these changes repeat themselves n times during the course of a complete revolution, the zone-axis is said to have an nth-turn or n-fold cyclic symmetry. If the line be at any time normal to a crystal-face it will be normal to a face with the same physical characters n times during such a revolution.

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