scholarly journals Desarrollo de una superficie de Fresnel tipo canal usando un LED de alta potencia para adaptarlo a un reactor fotoquímico

2019 ◽  
pp. 7-14
Author(s):  
Edgar Alfredo González-Galindo ◽  
Víctor Hugo Soriano-Hernández ◽  
Jorge Pérez-García ◽  
Guadalupe Hernández-Hernández
Keyword(s):  
Polynomial Interpolation ◽  
Cooling System ◽  
Dark Chamber ◽  
Focal Distance ◽  
Led Lighting ◽  
Low Energy Consumption ◽  
Molecular Reaction ◽  
Pharmaceutical Laboratories ◽  
Led Irradiation ◽  
Channel Type

A channel-type Fresnel surface was designed using the polynomial interpolation adjustment method. The experimental arrangement was composed of a metal complex, a high power LED lighting source, a cooling system and a Fresnel concentrator. The tests were done in a dark chamber, placing the compound at an effective focal distance from the reflected rays of the concentrator, for a time. By exposing the sample to the LED irradiation, its changes were registered in a UV-Vis spectrophotometer, obtaining an absorbance graph vs wavelength, the changes observed in the transition bands in displacement and intensity of the blue region to the red of the spectrum, confirmed the efficiency and usefulness of the Fresnel-type concentrator in the development of the photochemical reactor. This photochemical reactor has an advantage over commercial reactors, because it uses samples of compounds in small solutions, is portable, it can be implemented in university and pharmaceutical laboratories. The results were favorable, a low energy consumption was obtained, and a reduction of time in the molecular reaction process of the analyzed compound.

Thermal Performance of Domestic Replacement A19 LED Lighting Products

2016 ◽  
Author(s):  
Thomas Storey ◽  
Robin Rackerby ◽  
Heather Dillon ◽  
Lydia Gingerich
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Dissipation ◽  
Cooling System ◽  
Light Emitting Diode ◽  
Research Process ◽  
Light Emitting ◽  
Led Lighting ◽  
Proper Design ◽  
The Cost

In an effort to create a Light Emitting Diode (LED) lighting system that is as efficient as possible, the heat dissipation system must be accurately measured for proper design and operation. Because LED lighting technology is new, little optimization has been performed on typical cooling system required for most A19 replacement products. This paper describes the research process for evaluating the thermal performance of over 15 LED lighting products and compares their performance to traditional lighting sources, namely incandescent and compact fluorescent (CFL). This process uses radiation and convection to model typical cooling mechanisms for domestic A19 type replacement LED products. The A19 products selected for this investigation had input wattages ranging between 7 to 60 Watts, with outputs ranging from 450 to 1100 lumens. The average LED tested dissipated 43% (± 5%) of the total heat generated in the lighting product through the heat exchanger. The best thermal performance was observed in an LED product that dissipated approximately 58% of the total product heat through the heat exchanger. Results indicate that significant improvements to the current LED heat exchanger designs are possible, which will help lower the cost of future LED products, improve performance, and reduce the environmental footprint of the products.

scholarly journals Relap5 Analysis of Processes in Reactor Cooling Circuit and Reactor Cavity in Case of Station Blackout in RBMK-1500

2007 ◽  
Vol 2007 ◽  
pp. 1-9
Author(s):  
Algirdas Kaliatka ◽  
Eugenijus Uspuras ◽  
Sigitas Rimkevicius
Keyword(s):  
Cooling System ◽  
Severe Accident ◽  
Diesel Generator ◽  
Core Damage ◽  
Design Basis Accident ◽  
Station Blackout ◽  
Core Cooling ◽  
Key Events ◽  
Channel Type

Ignalina NPP is equipped with channel-type boiling-water graphite-moderated reactor RBMK-1500. Results of the level-1 probabilistic safety assessment of the Ignalina NPP have shown that in topography of the risk, the transients with failure of long-term core cooling other than LOCA are the main contributors to the core damage frequency. The total loss of off-site power with a failure to start any diesel generator, that is station blackout, is the event which could lead to the loss of long-term core cooling. Such accident could lead to multiple ruptures of fuel channels with severe consequences and should be analyzed in order to estimate the timing of the key events and the possibilities for accident management. This paper presents the results of the analysis of station blackout at Ignalina NPP. Analysis was performed using thermal-hydraulic state-of-the-art RELAP5/MOD3.2 code. The response of reactor cooling system and the processes in the reactor cavity and its venting system in case of a few fuel-channel ruptures due to overheating were demonstrated. The possible measures for prevention of the development of this beyond design basis accident (BDBA) to a severe accident are discussed.

scholarly journals IMPROVEMENT OF CLONAL MICROPROPAGATION OF BERRY CROPS

2021 ◽  
Vol 16 (1) ◽  
pp. 39-44
Author(s):  
Marina Markova ◽  
Elena Somova
Keyword(s):  
Nutrient Medium ◽  
In Vitro Cultivation ◽  
Waste Products ◽  
Led Lighting ◽  
Clonal Micropropagation ◽  
Berry Crops ◽  
Reproduction Factor ◽  
Led Irradiation ◽  
Wax Moth

The aim of the study is to optimize the conditions for in vitro cultivation of blue honeysuckle, raspberry and strawberry. The work was carried out in 2012-2020. The Murasige-Skuga medium (1/2 MS) was the control for all cultures for the initiation of explants. Additionally, we used a modified nutrient medium 1/2 MS with a reduced NH4 content by 15 % compared to the base MS; and Woodi Plant Medium (1/2 WPM) for honeysuckle; for raspberries - Quoirin-Lepoivre (1/2 QL) and 1/2 Anderson; for strawberries - 1/2 MS. For micropropagation and rooting, the following media were used: honeysuckle - modified MS and WPM; raspberries - QL and Anderson; strawberries - MS modified by Siliplant and Boksyu; control for all - MS. The following growth regulators were added to the optimal each culture a nutrient medium: 6-benzylaminopurine (6-BAP), gibberellic acid (GA), waste products of the large wax moth larvae, indolyl-3-butyric acid (IBA), Siliplant, EcoFus, HB-101. The effect of LED-phytoirradiators with a combination of red, blue and white light in the spectrum 2: 1: 1, 1: 1: 1, 2: 1, respectively, and LED-irradiators with a changing spectrum and flashing were studied at the stages of micropropagation and rooting in all cultures. The survival rate of honeysuckle explants on 1/2 WPM medium was 62.2 % (control 27.9 %). The highest reproduction factor of 5.1 (control 2.6) was achieved when using LED 2 red : 1 blue : 1 white on MS modified + 6-BAP 1.0 mg/L + kinetin 0.5 mg/L, and high rooting rate of honeysuckle 89.0 % (76.0 % k) was achieved on MS modified + IBA 0.5 mg/L. Cultivation of red raspberries on QL + 6-BAP 1.0 mg/L + GA 0.5 mg/L and LED irradiation 2 red : 1 blue : 1 white provided a reproduction factor of 5.3 (control 2.7), addition of IBA 0.5 mg/L + HB-101 100 μL/L in QL and LED irradiation 1 red : 1 blue : 1 white contributed to 100 % rooting. The addition of 6-BAP 1.0 mg/L + IBA 0.2 mg/L + GA 0.5 mg/L in QL and LED lighting 1 red : 1 blue : 1 white increased the reproduction factor of remontant raspberries by 1.6 times (from 2, 6 to 4.1), and the use of QL + IBA 0.5 mg/L + HB-101 50 μL/L and LED 2 red : 1 blue : 1 white increased its rooting ability to 96 % (control 67 %). LED irradiation with a changing spectrum during cultivation of garden strawberries on MS + Siliplant + EcoFus at 0.5 ml/L provided a reproduction factor of 5.9 (control 3.8), and the reproduction factor of remontant strawberries on MS + HB-101 100 μl/L was 7.4 (control 5.6). The addition of IBA 0.5 mg/L + HB-101 100 μL/L to the MS promoted the rooting of garden strawberries of 100 % when using a LED irradiator with a changing spectrum, and remontant strawberries – with a blinking LED irradiator

Seti Space Missions

1997 ◽  
Vol 161 ◽  
pp. 761-776 ◽  
Author(s):  
Claudio Maccone
Keyword(s):  
Electromagnetic Waves ◽  
Space Missions ◽  
Gravitational Lens ◽  
The Sun ◽  
Space Antenna ◽  
Focal Distance ◽  
Large Space ◽  
The Earth ◽  
Space Antennas ◽  
New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

A High Angle, Double Tilting Cold Stage for the AEI EM7

1974 ◽  
Vol 32 ◽  
pp. 450-451
Author(s):  
P.R. Swann ◽  
A.E. Lloyd
Keyword(s):  
Habit Plane ◽  
Temperature Control ◽  
Tilt Angle ◽  
Cooling System ◽  
Thermal Drift ◽  
High Angle ◽  
Cold Stage ◽  
High Degree ◽  
Better Than

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.

An improved magnetic prism design for a transmission electron microscope energy filter

1978 ◽  
Vol 36 (1) ◽  
pp. 40-41 ◽  
Author(s):  
John W. Andrew ◽  
F.P. Ottensmeyer ◽  
E. Martell
Keyword(s):  
Energy Resolution ◽  
Symmetry Plane ◽  
Fringe Field ◽  
Focal Distance ◽  
Electron Trajectories ◽  
Focusing Effect ◽  
Transmission Electron ◽  
Path Lengths ◽  
Electron Microscopes ◽  
Focusing Properties

Energy selecting electron microscopes of the Castaing-Henry prism-mirror-prism design suffer from a loss of image and energy resolution with increasing field of view. These effects can be qualitatively understood by examining the focusing properties of the prism shown in Fig. 1. A cone of electrons emerges from the entrance lens crossover A and impinges on the planar face of the prism. The task of the prism is to focus these electrons to a point B at a focal distance f2 from the side of the prism. Electrons traveling in the plane of the diagram (i.e., the symmetry plane of the prism) are focused toward point B due to the different path lengths of different electron trajectories in the triangularly shaped magnetic field. This is referred to as horizontal focusing; the better this focusing effect the better the energy resolution of the spectrometer. Electrons in a plane perpendicular to the diagram and containing the central ray of the incident cone are focused toward B by the curved fringe field of the prism.

A conduction-cooled stage for high-resolution Cryo-SEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1282-1283
Author(s):  
John G. Sheehan
Keyword(s):  
High Resolution ◽  
Liquid Nitrogen ◽  
Mechanical Stability ◽  
Cooling System ◽  
Cold Trap ◽  
Nitrogen Gas ◽  
Particulate Suspensions ◽  
Advantages And Disadvantages ◽  
Convection Cooling ◽  
Styrene Butadiene

The goal is to examine with high resolution cryo-SEM aqueous particulate suspensions used in coatings for printable paper. A metal-coating chamber for cryo-preparation of such suspensions was described previously. Here, a new conduction-cooling system for the stage and cold-trap in an SEM specimen chamber is described. Its advantages and disadvantages are compared to a convection-cooling system made by Hexland (model CT1000A) and its mechanical stability is demonstrated by examining a sample of styrene-butadiene latex.In recent high resolution cryo-SEM, some stages are cooled by conduction, others by convection. In the latter, heat is convected from the specimen stage by cold nitrogen gas from a liquid-nitrogen cooled evaporative heat exchanger. The advantage is the fast cooling: the Hexland CT1000A cools the stage from ambient temperature to 88 K in about 20 min. However it consumes huge amounts of liquid-nitrogen and nitrogen gas: about 1 ℓ/h of liquid-nitrogen and 400 gm/h of nitrogen gas. Its liquid-nitrogen vessel must be re-filled at least every 40 min.

XRMF applications of a monolithic, polycapillary, focusing x-ray optic

1996 ◽  
Vol 54 ◽  
pp. 240-241
Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla
Keyword(s):  
Trace Elements ◽  
Point Source ◽  
Focal Spot ◽  
Fluorescence Analysis ◽  
X Rays ◽  
Focal Distance ◽  
Spot Diameter ◽  
X Ray ◽  
Focal Spot Diameter

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.

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