Review of Concepts, Quantities, Units and Termi Nology for Non-Ionizing Radiation Protection
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Radiant Heating with Infrared
W A T L O W RADIANT HEATING WITH INFRARED A TECHNICAL GUIDE TO UNDERSTANDING AND APPLYING INFRARED HEATERS Bleed Contents Topic Page The Advantages of Radiant Heat . 1 The Theory of Radiant Heat Transfer . 2 Problem Solving . 14 Controlling Radiant Heaters . 25 Tips On Oven Design . 29 Watlow RAYMAX® Heater Specifications . 34 The purpose of this technical guide is to assist customers in their oven design process, not to put Watlow in the position of designing (and guaranteeing) radiant ovens. The final responsibility for an oven design must remain with the equipment builder. This technical guide will provide you with an understanding of infrared radiant heating theory and application principles. It also contains examples and formulas used in determining specifications for a radiant heating application. To further understand electric heating principles, thermal system dynamics, infrared temperature sensing, temperature control and power control, the following information is also available from Watlow: • Watlow Product Catalog • Watlow Application Guide • Watlow Infrared Technical Guide to Understanding and Applying Infrared Temperature Sensors • Infrared Technical Letter #5-Emissivity Table • Radiant Technical Letter #11-Energy Uniformity of a Radiant Panel © Watlow Electric Manufacturing Company, 1997 The Advantages of Radiant Heat Electric radiant heat has many benefits over the alternative heating methods of conduction and convection: • Non-Contact Heating Radiant heaters have the ability to heat a product without physically contacting it. This can be advantageous when the product must be heated while in motion or when physical contact would contaminate or mar the product’s surface finish. • Fast Response Low thermal inertia of an infrared radiation heating system eliminates the need for long pre-heat cycles. -
NOISE-CON 2004 the Impact of A-Weighting Sound Pressure Level
Baltimore, Maryland NOISE-CON 2004 2004 July 12-14 The Impact of A-weighting Sound Pressure Level Measurements during the Evaluation of Noise Exposure Richard L. St. Pierre, Jr. RSP Acoustics Westminster, CO 80021 Daniel J. Maguire Cooper Standard Automotive Auburn, IN 46701 ABSTRACT Over the past 50 years, the A-weighted sound pressure level (dBA) has become the predominant measurement used in noise analysis. This is in spite of the fact that many studies have shown that the use of the A-weighting curve underestimates the role low frequency noise plays in loudness, annoyance, and speech intelligibility. The intentional de-emphasizing of low frequency noise content by A-weighting in studies can also lead to a misjudgment of the exposure risk of some physical and psychological effects that have been associated with low frequency noise. As a result of this reliance on dBA measurements, there is a lack of importance placed on minimizing low frequency noise. A review of the history of weighting curves as well as research into the problems associated with dBA measurements will be presented. Also, research relating to the effects of low frequency noise, including increased fatigue, reduced memory efficiency and increased risk of high blood pressure and heart ailments, will be analyzed. The result will show a need to develop and utilize other measures of sound that more accurately represent the potential risk to humans. 1. INTRODUCTION Since the 1930’s, there have been large advances in the ability to measure sound and understand its effects on humans. Despite this, a vast majority of acoustical measurements done today still use the methods originally developed 70 years ago. -
Plant Lighting Basics and Applications
9/18/2012 Keywords Plant Lighting Basics and Light (radiation): electromagnetic wave that travels through space and exits as discrete Applications energy packets (photons) Each photon has its wavelength-specific energy level (E, in joule) Chieri Kubota The University of Arizona E = h·c / Tucson, AZ E: Energy per photon (joule per photon) h: Planck’s constant c: speed of light Greensys 2011, Greece : wavelength (meter) Wavelength (nm) 380 nm 780 nm Energy per photon [J]: E = h·c / Visible radiation (visible light) mole photons = 6.02 x 1023 photons Leaf photosynthesis UV Blue Green Red Far red Human eye response peaks at green range. Luminous intensity (footcandle or lux Photosynthetically Active Radiation ) does not work (PAR, 400-700 nm) for plant light environment. UV Blue Green Red Far red Plant biologically active radiation (300-800 nm) 1 9/18/2012 Chlorophyll a Phytochrome response Chlorophyll b UV Blue Green Red Far red Absorption spectra of isolated chlorophyll Absorptance 400 500 600 700 Wavelength (nm) Daily light integral (DLI or Daily Light Unit and Terminology PPF) Radiation Photons Visible light •Total amount of photosynthetically active “Base” unit Energy (J) Photons (mol) Luminous intensity (cd) radiation (400‐700 nm) received per sq Flux [total amount received Radiant flux Photon flux Luminous flux meter per day or emitted per time] (J s-1) or (W) (mol s-1) (lm) •Unit: mole per sq meter per day (mol m‐2 d‐1) Flux density [total amount Radiant flux density Photon flux (density) Illuminance, • Under optimal conditions, plant growth is received per area per time] (W m-2) (mol m-2 s-1) Luminous flux density highly correlated with DLI. -
Far Infrared Radiation Exposure
INTERNATIONAL COMMISSION ON NON‐IONIZING RADIATION PROTECTION ICNIRP STATEMENT ON FAR INFRARED RADIATION EXPOSURE PUBLISHED IN: HEALTH PHYSICS 91(6):630‐645; 2006 ICNIRP PUBLICATION – 2006 ICNIRP Statement ICNIRP STATEMENT ON FAR INFRARED RADIATION EXPOSURE The International Commission on Non-Ionizing Radiation Protection* INTRODUCTION the health hazards associated with these hot environ- ments. Heat strain and discomfort (thermal pain) nor- THE INTERNATIONAL Commission on Non Ionizing Radia- mally limit skin exposure to infrared radiation levels tion Protection (ICNIRP) currently provides guidelines below the threshold for skin-thermal injury, and this is to limit human exposure to intense, broadband infrared particularly true for sources that emit largely IR-C. radiation (ICNIRP 1997). The guidelines that pertained Furthermore, limits for lengthy infrared exposures would to infrared radiation (IR) were developed initially with an have to consider ambient temperatures. For example, an aim to provide guidance for protecting against hazards infrared irradiance of 1 kW mϪ2 (100 mW cmϪ2)atan from high-intensity artificial sources and to protect work- ambient temperature of 5°C can be comfortably warm- ers in hot industries. Detailed guidance for exposure to ing, but at an ambient temperature of 30°C this irradiance longer far-infrared wavelengths (referred to as IR-C would be painful and produce severe heat strain. There- radiation) was not provided because the energy at longer fore, ICNIRP provided guidelines to limit skin exposure wavelengths from most lamps and industrial infrared to pulsed sources and very brief exposures where thermal sources of concern actually contribute only a small injury could take place faster than the pain response time fraction of the total radiant heat energy and did not and where environmental temperature and the irradiated require measurement. -
Applied Spectroscopy Spectroscopic Nomenclature
Applied Spectroscopy Spectroscopic Nomenclature Absorbance, A Negative logarithm to the base 10 of the transmittance: A = –log10(T). (Not used: absorbancy, extinction, or optical density). (See Note 3). Absorptance, α Ratio of the radiant power absorbed by the sample to the incident radiant power; approximately equal to (1 – T). (See Notes 2 and 3). Absorption The absorption of electromagnetic radiation when light is transmitted through a medium; hence ‘‘absorption spectrum’’ or ‘‘absorption band’’. (Not used: ‘‘absorbance mode’’ or ‘‘absorbance band’’ or ‘‘absorbance spectrum’’ unless the ordinate axis of the spectrum is Absorbance.) (See Note 3). Absorption index, k See imaginary refractive index. Absorptivity, α Internal absorbance divided by the product of sample path length, ℓ , and mass concentration, ρ , of the absorbing material. A / α = i ρℓ SI unit: m2 kg–1. Common unit: cm2 g–1; L g–1 cm–1. (Not used: absorbancy index, extinction coefficient, or specific extinction.) Attenuated total reflection, ATR A sampling technique in which the evanescent wave of a beam that has been internally reflected from the internal surface of a material of high refractive index at an angle greater than the critical angle is absorbed by a sample that is held very close to the surface. (See Note 3.) Attenuation The loss of electromagnetic radiation caused by both absorption and scattering. Beer–Lambert law Absorptivity of a substance is constant with respect to changes in path length and concentration of the absorber. Often called Beer’s law when only changes in concentration are of interest. Brewster’s angle, θB The angle of incidence at which the reflection of p-polarized radiation is zero. -
Decibels, Phons, and Sones
Decibels, Phons, and Sones The rate at which sound energy reaches a Table 1: deciBel Ratings of Several Sounds given cross-sectional area is known as the Sound Source Intensity deciBel sound intensity. There is an abnormally Weakest Sound Heard 1 x 10-12 W/m2 0.0 large range of intensities over which Rustling Leaves 1 x 10-11 W/m2 10.0 humans can hear. Given the large range, it Quiet Library 1 x 10-9 W/m2 30.0 is common to express the sound intensity Average Home 1 x 10-7 W/m2 50.0 using a logarithmic scale known as the Normal Conversation 1 x 10-6 W/m2 60.0 decibel scale. By measuring the intensity -4 2 level of a given sound with a meter, the Phone Dial Tone 1 x 10 W/m 80.0 -3 2 deciBel rating can be determined. Truck Traffic 1 x 10 W/m 90.0 Intensity values and decibel ratings for Chainsaw, 1 m away 1 x 10-1 W/m2 110.0 several sound sources listed in Table 1. The decibel scale and the intensity values it is based on is an objective measure of a sound. While intensities and deciBels (dB) are measurable, the loudness of a sound is subjective. Sound loudness varies from person to person. Furthermore, sounds with equal intensities but different frequencies are perceived by the same person to have unequal loudness. For instance, a 60 dB sound with a frequency of 1000 Hz sounds louder than a 60 dB sound with a frequency of 500 Hz. -
CNT-Based Solar Thermal Coatings: Absorptance Vs. Emittance
coatings Article CNT-Based Solar Thermal Coatings: Absorptance vs. Emittance Yelena Vinetsky, Jyothi Jambu, Daniel Mandler * and Shlomo Magdassi * Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel; [email protected] (Y.V.); [email protected] (J.J.) * Correspondence: [email protected] (D.M.); [email protected] (S.M.) Received: 15 October 2020; Accepted: 13 November 2020; Published: 17 November 2020 Abstract: A novel approach for fabricating selective absorbing coatings based on carbon nanotubes (CNTs) for mid-temperature solar–thermal application is presented. The developed formulations are dispersions of CNTs in water or solvents. Being coated on stainless steel (SS) by spraying, these formulations provide good characteristics of solar absorptance. The effect of CNT concentration and the type of the binder and its ratios to the CNT were investigated. Coatings based on water dispersions give higher adsorption, but solvent-based coatings enable achieving lower emittance. Interestingly, the binder was found to be responsible for the high emittance, yet, it is essential for obtaining good adhesion to the SS substrate. The best performance of the coatings requires adjusting the concentration of the CNTs and their ratio to the binder to obtain the highest absorptance with excellent adhesion; high absorptance is obtained at high CNT concentration, while good adhesion requires a minimum ratio between the binder/CNT; however, increasing the binder concentration increases the emissivity. The best coatings have an absorptance of ca. 90% with an emittance of ca. 0.3 and excellent adhesion to stainless steel. Keywords: carbon nanotubes (CNTs); binder; dispersion; solar thermal coating; absorptance; emittance; adhesion; selectivity 1. -
Guide for the Use of the International System of Units (SI)
Guide for the Use of the International System of Units (SI) m kg s cd SI mol K A NIST Special Publication 811 2008 Edition Ambler Thompson and Barry N. Taylor NIST Special Publication 811 2008 Edition Guide for the Use of the International System of Units (SI) Ambler Thompson Technology Services and Barry N. Taylor Physics Laboratory National Institute of Standards and Technology Gaithersburg, MD 20899 (Supersedes NIST Special Publication 811, 1995 Edition, April 1995) March 2008 U.S. Department of Commerce Carlos M. Gutierrez, Secretary National Institute of Standards and Technology James M. Turner, Acting Director National Institute of Standards and Technology Special Publication 811, 2008 Edition (Supersedes NIST Special Publication 811, April 1995 Edition) Natl. Inst. Stand. Technol. Spec. Publ. 811, 2008 Ed., 85 pages (March 2008; 2nd printing November 2008) CODEN: NSPUE3 Note on 2nd printing: This 2nd printing dated November 2008 of NIST SP811 corrects a number of minor typographical errors present in the 1st printing dated March 2008. Guide for the Use of the International System of Units (SI) Preface The International System of Units, universally abbreviated SI (from the French Le Système International d’Unités), is the modern metric system of measurement. Long the dominant measurement system used in science, the SI is becoming the dominant measurement system used in international commerce. The Omnibus Trade and Competitiveness Act of August 1988 [Public Law (PL) 100-418] changed the name of the National Bureau of Standards (NBS) to the National Institute of Standards and Technology (NIST) and gave to NIST the added task of helping U.S. -
Direct Insolation Models
SERI/TR-33S-344 UC CATEGORY: UC-S9,61,62,63 DIRECT INSOLATION MODELS RICHARD BIRD ROLAND L. HULSTROM JANUARY 1980 PREPARED UNDER TASK No. 3623.01 Solar Energy Research Institute 1536 Cole Boulevard Golden. Colorado 80401 A Division of Midwest Research Institute Prepared for the U.S_ Department of Energy Contract No_ EG-77-C-01-4042 , '. Printed in the United States of America Available from: National Technical Information Service U.S. Departm ent of Commerce 5285 Port Royal Road Springfi e1dt VA 22161 Price: Microfiche $3.00 Printed Copy $ 5.25 NOTICE This report was prepared as an account of work sponsored by the United States Govern ment. Neither the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process dis closed, or represents that its us e would not infringe privately owned rights. S=�I TR-344 FOREWORD This re port documents wo rk pe rforme d by the SERI Energy Resource Assessment Branch for the Division of Solar Energy Technology of the U.S. De pa rtment of Energy. The re po rt compares several simple direct insolation models with a rigorous solar transmission model and describes an improved , simple, direct insolation model. Roland L. Hulstrom , Branch Chief Energy Resource Assessment , \ Approved for: SOLAR ENERGY RE SEARCH INSTITUTE for Research iii S=�I TR-344 TABLE OF CONTENTS 1.0 Introduction •••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1 2.0 Description of Models •••••••••••• . -
Lighting: the Principles
TECHNICAL GUIDE Cross Sector AHDB Fellowship CP 085 Dr Phillip Davis, Stockbridge Technology Centre Lighting: The principles Filmed over 3 weeks at Stockbridge Technology Centre SCAN WITH LAYAR APP 2 TECHNICAL GUIDE Lighting: The principles CONTENTS SECTION ONE LIGHT AND LIGHTING SECTION THREE LEDS IN HORTICULTURE 1.1 What is light? 6 3.1 Crop growth under red and blue LEDs 21 1.2 The natural light environment and its 3.2 The influences of other colours of impact on plant light responses 6 light on crop growth 22 1.3 The measurement of light 6 3.3 End of day, day extension and night interruption lighting 23 1.3.1 Photometric light measurement – lumens and lux 6 3.4 Interlighting 23 1.3.2 Radiometric light measurement – Watts per 3.5 Propagation 24 metre squared or Joules per metre squared 8 3.6 Improving crop quality 24 1.3.3 Photon counts – Moles 8 3.6.1 Improving crop morphology and reducing 1.3.4 Daily light integrals (DLI) 10 the use of plant growth regulators 24 1.4 Conversions between different 3.6.2 Improving pigmentation 25 measurement units 10 3.6.3 Improving flavour and aroma 26 1.5 Assessing light quality 10 3.7 Lighting strategies 26 1.6 Overview of light technologies 10 3.8 Other lighting techniques 27 1.6.1 Incandescent and halogen bulbs 10 3.9 Insect management under LEDs 27 1.6.2 Fluorescent tubes 10 3.10 Plant pathogens and their interactions 1.6.3 High intensity discharge lamps 11 with light 28 1.6.4 Plasma and sulphur lamps 12 3.11 Conclusions 28 1.6.5 LED technology 12 SECTION FOUR OTHER INFORMATION SECTION TWO PLANT LIGHT RESPONSES 4.1 References 30 2.1 Photosynthesis 15 2.2 Light stress – Photoinhibition 15 2.3 Sensing light quality 18 2.4 UVB light responses 18 2.5 Blue and UVA light responses 18 2.6 Green light responses 18 2.7 Red and far-red light responses 19 2.8 Hormones and light 19 3 TECHNICAL GUIDE Lighting: The principles GLOSSARY Cryptochrome A photoreceptor that is sensitive to blue and UVA light. -
Glossary of Terms
GLOSSARY OF TERMS Terminology Used for Ultraviolet (UV) Curing Process Design and Measurement This glossary of terms has been assembled in order to provide users, formulators, suppliers and researchers with terms that are used in the design and measurement of UV curing systems. It was prompted by the scattered and sometimes incorrect terms used in industrial UV curing technologies. It is intended to provide common and technical meanings as used in and appropriate for UV process design, measurement, and specification. General scientific terms are included only where they relate to UV Measurements. The object is to be "user-friendly," with descriptions and comments on meaning and usage, and minimum use of mathematical and strict definitions, but technically correct. Occasionally, where two or more terms are used similarly, notes will indicate the preferred term. For historical and other reasons, terms applicable to UV Curing may vary slightly in their usage from other sciences. This glossary is intended to 'close the gap' in technical language, and is recommended for authors, suppliers and designers in UV Curing technologies. absorbance An index of the light or UV absorbed by a medium compared to the light transmitted through it. Numerically, it is the logarithm of the ratio of incident spectral irradiance to the transmitted spectral irradiance. It is unitless number. Absorbance implies monochromatic radiation, although it is sometimes used as an average applied over a specified wavelength range. absorptivity (absorption coefficient) Absorbance per unit thickness of a medium. actinometer A chemical system or physical device that determines the number of photons in a beam integrally or per unit time. -
The Human Ear Hearing, Sound Intensity and Loudness Levels
UIUC Physics 406 Acoustical Physics of Music The Human Ear Hearing, Sound Intensity and Loudness Levels We’ve been discussing the generation of sounds, so now we’ll discuss the perception of sounds. Human Senses: The astounding ~ 4 billion year evolution of living organisms on this planet, from the earliest single-cell life form(s) to the present day, with our current abilities to hear / see / smell / taste / feel / etc. – all are the result of the evolutionary forces of nature associated with “survival of the fittest” – i.e. it is evolutionarily{very} beneficial for us to be able to hear/perceive the natural sounds that do exist in the environment – it helps us to locate/find food/keep from becoming food, etc., just as vision/sight enables us to perceive objects in our 3-D environment, the ability to move /locomote through the environment enhances our ability to find food/keep from becoming food; Our sense of balance, via a stereo-pair (!) of semi-circular canals (= inertial guidance system!) helps us respond to 3-D inertial forces (e.g. gravity) and maintain our balance/avoid injury, etc. Our sense of taste & smell warn us of things that are bad to eat and/or breathe… Human Perception of Sound: * The human ear responds to disturbances/temporal variations in pressure. Amazingly sensitive! It has more than 6 orders of magnitude in dynamic range of pressure sensitivity (12 orders of magnitude in sound intensity, I p2) and 3 orders of magnitude in frequency (20 Hz – 20 KHz)! * Existence of 2 ears (stereo!) greatly enhances 3-D localization of sounds, and also the determination of pitch (i.e.