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Reflection - Science topic

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I need to find this distance for complete the modeling of reflection-absorption of light in Si solar cell.
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Thank you very much for your comments, solution, and recommendations. I added one more loop into my code that includes the ratio of L1/L2 to check the approximate solution.
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Hello everyone, does anyone know any english language literature on reflection and team reflection in preschool/daycare?
Hallo an alle, kennt jemand englischsprachige Literatur zum Thema Reflexion und Team-Reflexion in der Preschool / Daycare?
Thanks for your support. Have a nice weekend :)
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Good morning
Toran, M. Politics and Practices of the New Normal: What are Preschool Teachers' Experiences during the COVID-19 Pandemic in Turkey?. In Early Childhood Education and Care in a Global Pandemic (pp. 170-180). Routledge.
Thompson, M. L. B. (2022). EFFECTS OF A PARENT-IMPLEMENTED INTERVENTION ON PRESCHOOL CHILDREN’S ENGAGEMENT IN CONSTRUCTIVE PLAY IN HOME SETTINGS.
Best regards
Ph.D. Ingrid del Valle Garcia Carreno
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In my problem, the plasmonic nanostructures are quite reflective.
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The results in the transmission monitor can be greater than 1 or less than 0 because of the following reasons.
  • Simulation auto-shutoff level is not small (i.e.>1e-5)
  • Simulation is terminating or finishing before reaching the auto-shutoff level (increase simulation time and making it large enough to make sure that the simulation runs until auto-shutoff level).
  • The nanostructures have high Q resonances which need small auto-shutoff levels (i.e. 1e-7 or smaller).
  • The source is too close to the nanostructure and the reflection from the nanostructures is interfering with the source that can result in the abnormal outcome in the transmission monitor. (Keep the source far away from the nanostructure. i.e. 1.5-2.5 um away from the nanostructure surface).
  • Use of standard stretched coordinate PML with maximum PML layers to avoid reflections from the PML layers. This works well for normal incidence but if you are simulating oblique angles then using steep angle PML instead of standard one.
  • Sometimes using too fine mesh sizing can also be problematic.
  • Use of broadband simulations
From my personal experience, 1D simulations are easier to work and troubleshoot as they don't take much time.
I hope this helps but if you have some specific problems or questions. You can mention in the question thread.
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What is the meaning of diffuse and specular reflectance in the case of UV VIS when we are recording in the form of powders (glasses)?
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You can check our paper
Synthesis, diffused reflectance and electrical properties of nanocrystalline Fe-doped ZnO via sol–gel calcination technique
Authors
C Aydın, MS Abd El-sadek, Kaibo Zheng, IS Yahia, F Yakuphanoglu
Publication date
2013/6/1
Journal
Optics & Laser Technology
Volume
48
Pages
447-452
Publisher
Elsevier
Description
The nanocrystalline ZnO:Fe semiconductor oxides were successfully synthesized via the sol–gel calcination method. Structural, optical and electrical properties of the investigated samples were characterized by various techniques such as atomic force microscopy (AFM), UV–vis absorption and electrical transport measurements. The optical band gap for undoped ZnO (3.19 eV) decreases (2.75 eV) with increasing Fe-doped ZnO (20%). The temperature dependences of the electrical conductivities of undoped ZnO and Fe-doped ZnO were measured and analyzed by Arrhenius equation. The electrical conductivity of the samples decreases with the increase of Fe doping ratio; hence, the electrical conductivity mechanism is controlled by thermally activated processes. To support the nanostructure of Fe-doped ZnO, AFM micrographs were performed.
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The publication of a research: OPTICAL GEOMETRY IN THE FORBIDDEN CITY, show after carefully analysis of the an metal alloy horse with concave eyes .The investigation show the horse was designed and realized by the Jesuit Painter -Architect:
Giuseppe Castiglione (1688-1766), during his 50th years of service under Nr.3 Qing Emperor , from 1715-1766. As explained in the report the intention of Castiglione was to convert the Emperor Qianlong (1711-1799) to Christianity, but due yo rigid protocol in place, he can't due directly, but realizing work of art with technology , in this case (physic concept of light). As he can't be discovered for eventually any questions arising from Emperor about this phenomenon, in particular the left eye, where a triangle is visible ( sign of trinity) , as well as in the link (inserted at the end of pag.1 of the here attached research , to the video of 28th seconds ( eyes became real in the last 12 seconds).
As apparently brain neuronal mechanism of the retina is involved, with calculation and knowledge Castiglione used to realized the virtual image? probably the first in the history.
Considering also that he keep in consideration daily light, as an alibi, as daylight don't show any affects.
Thanks
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People lose sight acuity with aging.
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While we can find versions of "pilot waves", and "collapsing waves" we learned in any way, that at last two waves must interfere to get the interference pattern. Two!
Also one can read "particles wave is interferencing with it self". As we know by experiment that even if between particles can be a time of any duration, the interference will occur. Mystic was added into quantum mechanics.
While physicians did give up to develope a vividly explanable model, we can present that new one for Your attention:
At the same time it explaines all optical effects too like transparency, reflection, absorption etc..
Very short: the interference is an interaction of two waves too, but the one wave of two is the wave of the atomar and electron mass particles of the surface material in the two splits. Both waves are of electromagentic nature, so we have positive and negative electric fields and nord and south magnetic fields alternating. The size of the slits is therefore to be in tha size range of the photons wave lengths to assure, that photon waves only which are near enough to the surface of material of slits are interacting. All other photon waves will be rejected and so tehy do not distorb the interference pattern. The size of wave lengths of the atomic electrons is very much shorter letsay at factor 500 approximately. The photons wave is attrackting and disattracting by electromagnetic forces and it is for very short time running around the bringe element in the middle of the double slit, but cannot be absorbed into the atomic electrons. This is called an "assiciation interaction", which ends up in a decoppling and this happens on different periodical locations with a slightly chengged moment. While photons are arounding the brindge element, the phases of them are overlapping, and so we get the locations with a periodicity which is shorter then photons wave, but larger then electron waves. The angle of the changed momenta depends on locations by the shape of the edge of bridge element. This explains how it is working with particles sended one by one after a time period which can be as long as one wishes. Only the sender source and the double slit must stay in same position during whole experiment.
Transparency is explained in same association interaction as defraction and reflection too: here instead of macroscopic bridge element atoms are arounded by photons waves many times, this times of interaction on each of atoms is slowing down the summary speed of photons through a transparent media. In between space photons do have a known speed of light in vacuum. So at last photons only have this speed and cannot have a lower one. Also it could be that the bridge element can be build by a group of atoms instead of a singleatom. The difference between optical reflection, defraction and transparency is just, that the association interaction has different durations on different atoms of the optical material.
Also, that explaines how it is possible, that a broad spectra of photons is transparently or reflectively or defractively interactiong on same atoms and how the defraction happens for different wave lengths of photons. There is no explain in no theory about to explain that: that problem was never questioned. The mass particles are interacting in same manner, as they are also electromagnetic waves in the inner struckture.
This is the beginn of a new Quantum Mechanic of association interaction, which unites suddenky all optical effects.
Same article in German:
What is Your first impression?
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Seems that double split phenomena are solved; wave particle duality depends on the emiting source
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Good day experts,
I am currently designing a research project where my partners and I are investigating the difference in effectiveness of thermal regulation in a highly color variable ectotherm species. We wish to investigate how much of a difference coloration causes in the absorption and reflection of broad spectrum- and UV-light.
We are looking for a method that can be applied in a field situation with relatively high accuracy.
Are there anyone here who can point me in the right direction? Or do you know someone I should be talking to?
Cheers
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Hello Joe; In the 1960s through the mid -1970s studies in temp regulation in reptiles and amphibians were rapidly developing. Bayard Brattstrom, Ken Nagy and others published a number of papers. Some of the data was referred to as "beer can" data. They would put a thermistor in a water-filled beer can (readily available at the field sites) and watch the rates of temp change in various, biologically realistic situations. Nagy made accurate models of animals and followed similar protocols. If you aren't familiar with that ancient stuff, you might enjoy looking it up. You can contact Bayard at bayard@hughes.net Enjoy!! Jim Des Lauriers
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Describe the skills and attributes that are necessary to communicate with someone who is experiencing mental health problems.
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It is a CLINICAL relationship and praxis -not a coffee chat or between friends- that usually has a Psychodynamic basis, Support Therapy and Ventilation, Catharsis, Relationship of Help, or Counseling (and can be more than one of the at the same time) ... in the end, is to use THE WORD (the "LOGOS") as a therapeutic weapon; the Asclepiades -and Hippocrates was- already told us in Classical Greece that "the Sanitary heals with the knife, the poison and the word": the knife has given foot to Surgery, the poison to Pharmacotherapy and, the word , to Psychotherapy (and they do not have to be exclusive).
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Literature states that there are 5 different facets (A, B, C, D and E) of a latent construct (Y) which I am interested in.
I am developing a measurement instrument to measure that latent construct (Y). It will be conceptualized as second-order reflective construct and A, B, C, D and E as first-order reflective constructs.
Is my study exploratory or confirmatory, i.e., do I need to do EFA, or CFA only?
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Efa is done to judge if the items are measuring the given construct.CFA is used then to understand fhe relation among these constructs.
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Electromagnetic (EM) waves have invoked a lot of interest among scientists and engineers over centuries. And this interest seems to be on the rise, in view of new applications of EM waves being explored and developed, particularly at newer and higher frequencies.
Propagation characteristics of EM wave depend on its frequency (or wavelength), to a large extent. And when an EM wave interacts with an object/material, it undergoes reflection, refraction, scattering, attenuation, diffraction, and/or absorption. Each of these effects are dependent on the frequency of the EM wave(s) because the size of wavelength (relative to the object/material) assumes great significance.
And due to the huge range of frequencies of EM waves employed in various applications these days, they undergo a variety of different effects. This confuses the scientific community sometimes as it is often unclear as to which effect is more dominant at what frequency.
Thus a single mathematical formula (or a small set of formulae) would/could be of great help if different effects (as listed above) and their relative weights can be known at different frequencies. This may be of great boon to young scientists and engineers as it would simplify things particularly for those who are mathematically minded.
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Not all these phenomena can be summarized in the permittivity of the material. For a start there is the permeability, which is as basic as the permittivity, then whole areas that these two do not cover at all, such as fluorescence, ionisation, photo-electricity, Rayleigh and Raman scattering, interaction with (other) fundamental particles, interaction with gravity/space-time, and more.
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The past month or so has been super busy as I've moved my lectures from the classroom to the virtual video meeting "room" while naturally been concerned about student welfare. Yet, this new "Coronavirus condition" has forced me to pause for reflection. The result is that I appear to be less preoccupied with conceptual or theoretical questions than with more empirical questions that can demonstrate impact and help to combat suffering or social evils.
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If your observation that "people going crazy" is the current state of our world(s), then that could perhaps be a reality check in itself.
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IRS modify the phase and Backscatter device adjust the reflection coefficient. Backscatter device can modulate its information symbols over incident carriers by intelligently changing its load impedance and IRS can also modulate its own information. So, how they are different from each other ?
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IRS is getting a gradually wider meaning. Many people are considering the use case when the IRS acts as a relay that support the transmission from a source to a destination, by configuring how it reflects the incident signals towards the destination.
But if the IRS is also trying to convey its own information, by encoding it into how it varies the reflection properties over time, then it also performs backscattering communications.
So the topics are overlapping. Some people might say that backscattering is a special case (or use case) of IRS technology. Others might say that IRS technology is capable of performing backscattering communication, as an add-on to its primary use cases.
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Hi,
I have a question about reflection, transmission, and absorption of light.
Is there a material that can absorb (or reflect) a light in one-way?
For example, there is a substrate that has a cavity structure on the surface.
When light irradiation from the top of it, it absorbs (or reflects) all(100%) the light from the surface with the aid of the cavity structure.
Then, how about the light irradiated from the bottom of it (flat surface)?
Can the light be emissive into the air through the substrate? Or will it be absorbed(or reflected) like the light irradiated from the top?
Thanks.
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Generally every light propagation is reciprocal, that means that the same happens when you revert the direction of light. Non reciprocal effects are desperatly searched after, thy would provide very useful components. The practically single technically used effect is the polarization rotation in Faraday isolators. This rotation in the presence of a magnetic field is not reciprocal, it rotats in the same direction for both light directions. There are also materials (MGL glas) that have an intrinsic magnetic field and high Verdet constant to provide a component to work without an external magnet, but needs external polarizers.
There are investigations to use plasmon effects, topological effects or Goos-Hänchen effect to create components. Bot no, there is no simple component or coating that is non reciprocal.
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As there is no RF chain in the smart reflecting surface, how reflecting elements can change the angle of reflected signal? What are the limitations of IRS based wireless communication? What are difficulties that may occur during it's practical implementation? What is the possibility of its consideration beyond 5G?
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Hi!
I'm explaining this in two videos on the topic:
Here are some short answers. Each "reflecting element" is not changing the angle of the reflected signal, but it is creates a time delay. This is the same thing as a phase-shift if we consider a narrowband channel. It is the combination of different phase-shifts among the elements that creates reflected beams in particularly directions.
The main limitation is how to estimate which phase-shifts that are needed to reflect the signals in the right direction and how to tell the IRS to reconfigure itself.
It is still uncertain what role an IRS might play in future networks. There are some suggested use cases, but no convincing evidence that IRS is so much better than alternative methods that it will be worth turning it into products.
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Hello everyone.
Please, which one of the following materials can reflect the visible light more efficiently :
semiconductors, insulators, metals or dielectric materials and why ?
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Hello Balsam,
the reflectivity of a material depends on the refractive index, the conductivity, the surface properties and the angle of incidence (k-vector) of light.
For smooth surfaces and vertical incidence, the reflection coefficient R in dielectric media (conductivity zero) is equal to
R = (n-1)2/(n+1)2. This means, for glass with an refractive index of n = 1,5, you get R = 0,04. With increasing n, R increases. For silicon with n = 3,4, you find R = 0,3. If you take into account the conductivity, the reflection increases, due to the effect of the high mobily electrons. In metals, the reflectivity lies near 1. If you deviate from vertical incidence, the reflectivity increases as a function of angle of incidence and polarization. For specular incidence, the reflectivity is 1. Generally, Fresnels equations describe the behaviour exactly. You must differ between s- and p-waves (polarization vertical or within the plane of incidence). For p-waves, the reflectivity has a minimum at the brewster angle teta = arctan (n2/n1). You can test this property using a laser pointer. Look for a dielectric medium (smooth plastic surface), calculate the angle and rotate the laser around his axis. Then you see a point of maximum (s-wave) and minimum (p-wave) brightness.
The effect of total reflection you can observe if you have a boundary with n1 > n2.
A very complex behaviour you have for rough surfaces. Every point of surface has another reflection coefficient because the angle of incidence is distributed randomly. You must integrate over all contributions but of course, the reflectivity is higher than for vertical incidence.
You see, the reflectivity can be well described but the number of influencing factors is high.
With regards
R. Mitdank
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I am very confused about Reflection losses of my material. is there any one who can guide me about Reflection losses and Could you provide me the exact Solved equation to calculate Reflection losses? Please any body can guide??
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The short version is that absorbance is a kind of artificial quantity that was (much later) introduced because of the results of Bouguer and Lambert according to which log (I/I0)=-a*d where "a" is some kind of constant and "d" the pathlength of the light. But Bouguer and Lambert measured the absorption of the atmosphere where reflectance is no big deal, since (basically) the index of refraction of air is practically not much different from that of (empty) space. As Beer did his experiments with liquids/solutions, he was aware of the fact that he has to correct for reflection. Under certain circumstances (thick cuvette, rationg of the transmittance of the solution to the transmittance of the solvent), you might be able to disregard reflectance, under all others the errors can be extremely large. You can get some guidance in https://www.researchgate.net/project/Book-Project-Wave-Optics-in-Infrared-Spectroscopy - Chapter 0... The overall problem is that the Bouguer-Beer-Lambert law is in general not compatible with electromagnetic theory...
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Example : Variable B & C together form A. To measure B we have reflective scale but C can be measured only with formative scale. 
Please provide any reference, if you have
For the model refer to the attachment 
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Hi, could you please let me know how have you done the calculations for this model? is it possible to use the "repeated indicators approach" for it? Thanks in advance.
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What is the highest critical frequency f0F2 ever recorded? Is anyone aware of a paper/reference or published ionogram for the reflection of 50 MHz (or higher) radio waves by the Ionosphere at incidence?
"At incidence, generally frequencies below 10 MHz are reflected but with active events frequencies up to 50 MHz and higher may also be reflected by the E-layer."
Thank you for your contributions in advance!
Best regards,
Alex
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To clarify, I am not looking for a theoretical maximum; ANY paper with a f0F2 greater than 50 MHz that is either measured or inferred from electron density measurements are welcome. These would likely come from some short-lived solar event.
I tried a back-of-envelop calculation based on the peak density (~2e12 electrons/m3) given for daytime solar maximum conditions given in Table 1 from Anderson & Fuller-Rowell [1999].
Anderson, D. & Fuller-Rowell, T. The Ionosphere NOAA Space Environment Topics, 1999, 14
I used the approximation
f0F2 =9xsqrt(nmF2)
where fp is the plasma frequency in Hz and nmF2 is the peak density in electrons per cubic cm [Schunk and Nagy, 2000]. Unfortunately this gives a value of 12.7 MHz, which does not agree with the range of maximum usable frequencies given in the table from Anderson & Fuller-Rowell [1999].
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Do you know the best commercial software for analysis of high resolution seismic profiles and low price software, but good quality?
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REQUEST:
Dear colleagues and friends, I need seismic reflection data for processing in a free software for master students. if there is someone who has some data, please send them.
Thank you for your helps
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HOPG is a good substrate for growth of h-BN. One major application of h-BN is single photon emission which can be used for telecom wavelength. Can anyone give me any insight about the absorption quality(if there is any) of HOPG at 1550 nm.
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HOPG is an unpolar substance, so it is not exactly great at absorbing infrared radiation which is why people usually characterize it by Raman spectroscopy. Here you can find extrapolated dielectric functions:
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We have fabricated a nano-structured surface recently. What is the best way of measuring it's scattering behavior? i.e. scattered power vs. angle. More specifically, we need to determine the Lambertian factor of this surface (1 when fully Lambertian, 0 when fully specular).
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You had better to mount your sample on an angle changing stage. The stage can be controlled by a computer. You may need to have a portable spectrophometer such as one from Ocean Optics Inc. to measure the scattering (reflection light intensity). The stage can be rotated for the angles whatever you need. Hope it helps.
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I am working on image processing getting through captured video from high speed camera but due to motion of target object, there is reflection of light on the some videos images. I used 2 high intensity light source which was focused on the moving object. Is anyone suggest, how to remove the reflection from my experiment.
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I don't know if it will work for you but if you want to get rid of reflections, you should NOT focus the light ON the target but use as mush as possible diffuse lights.
We had this problem while trying to reconstruct metallic object by photogrammetry and reflections were breaking the process. We add diffusers, turn the lights towards the white walls instead of the object and the results were much better!
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The transverse magneto-optical Kerr effect (TMOKE) can be measured for thin film with the usual configuration of reflection. I heard that it is possible to measure TMOKE in transmission configuration.
Please, I need a recommended book or article discuss this topic.
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I sent you in your RG inbox
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In the laboratory we use dominat mode for measuiring unknown impedence, reflection coeffecient ,VSWR . I want to know that why we prefer dominant mode of operation.
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Marcelo B. Perotoni nailed it. The uniqueness of the propagation mode with lowest cutoff lies in the purity of mode pattern for at least some bandwidth. The common use of waveguide is to carry information, not for transferring random power. So the signal integrity is one of the major concern. Dispersion is already a problem with waveguide let alone multimode coupling and resulting distortions. The higher order mode can be used for some specific applications like filters, power combiners and so on but not for normal signal transmission purpose.
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In my experiment, I need to track the amplitude change of the peaks in my spectrum.
I have two spectrometers, one with 0.5nm resolution and the other one with 0.05nm.
In the spectrum taken by high-resolution spectrometer I'm seeing some oscillatory behavior which are actually wasting 10 data points that I will get more in comparison to the low-resolution spectrometer.
Does anybody know a trick to get rid of these oscillations?
The spectrometer has an (SMA-FC/APC) patch cable which is connected to the sample (a single mode fiber with FC/APC connector) using fiber mating sleeves
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If VL's assumption (above) is correct, I don't have an explanation but more likely, NP (above) is right about a weak reflection occurring between connectors or elsewhere in your system. Here's an article that uses such spectral features (and actually, the Fourier transform of such features) to uncover various Fabry-Perot resonant cavities that are visible, as you point out, as 'oscillations' in a spectrum. "Characterizing residual reflections within semiconductor lasers, integrated sources, and coupling optics," IEEE Journal of Quantum Electronics, vol. 34, 7, pp 1224-1230, Jul, 1998. As a guess -- when your measurement system is free of residual reflections, the spectrum of the laser or other source you are examining will be free of these artifacts.
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In my experimental work, I am studying the photothermal conversion of nanofluids which exposed to incident light from a solar simulator. The insulation layers around the nanofluid glass container (sides and bottom) is white and reflects the transmitted light from the container bottom back to the nanofluid. This light reflection will increase the photothermal conversion efficiency of nanofluid more than its real value. The question now, if I insert a black layer in-between the bottom of glass container and the white insulation underneath to prevent that light reflection, in the same time the transmitted light will be absorbed by the black layer inserted and converted to heat, however this heat won't be lost because of the existence of the insulation underneath the black layer. I am not sure if this will be the right solution or not, so please let me what you think or any alternative suggestions. Thanks
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In fact, the black layer can reduce the light reflection, but you need to ensure that temperature of the bottom surface will not increase due to radiation absorption, since thermal energy could be returned to the working fluid by convection, consequently, you cannot measure the efficiency of photo-thermal energy conversion without considering the temperature of bottom surface.
If temperature of the black layer increased unproportionally to the temperature working fluid, you can think about a transparent bottom surface, although this concept will suffer thermal losses without insulation. If you can use double glass layers with vacuum gap, it will be great. Or,
Another option to design the test section in a way that prevent the light beam from penetrating the full depth of fluid; you can increase height of the container or increase the loading of nanoparticles.
Best regards!
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Dear Community,
I am currently working on a project envolving the data extraction of the spectral charateristics of plants under artifical light for quality optimisation in PFAL Systems.
Therefore I have to access the Chlorophyll Fluorescence Yield (ChlFY) without the possibility of PAM AC signal filtering.
My tool is a simple spectrometer, with which I can acess the Raw Readings, the absolute PPFD readings and the Calibrated relative Reflection from 400 to 880nm. The sample speed is 1,2Hz. So short pulse modulation (PAM) is not possible.
But the system is designed to work with artificial light sorces (white LEDs + RGB LED) only. Therefore light intensity and spectra can be adjusted.
How can I acess Information abouth The ChlFY with this setup? Should I modulate some low frequency AC Light intensity change and check the ChlF change? Or is there some Index like NDVI/PRI to acess ChlFY?
Or did I missunderstand the Concept or difference between ChlF and ChlFY?
Thank you for your Help!
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Chlorophyll fluorescence is measured by a fluorimeter .
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I have another question regarding the relation between the thickness of the substrate and reflection phase of FSS.I have observed different results for different thickness i.e. the thickness of 1.6mm phase is changing  +180 to -180 and extends more than -200 by adding the phase progressively, whereas with the thickness of 0.8mm it is changing from +180 to +100  and then suddenly rises to +235 degrees at the resonance frequency.Then after again decreasing as the frequency increases,  but overall this value is having positive phase.
Can anyone explain the reason?
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I recommend you to read this paper:
Best regards
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A wave landing on a plane surface and reflected, obeys the law that the angle of the incident wave with the normal, θincident is equal with the angle of the reflected wave with the normal, θreflected.
But why does is happen? The incoming wave meets in fact the atoms of the material on which they land. If each atom would reflect what comes on it in an arbitrary directions, the reflected wave would consist of beams crossing one another under different phases, and the result would be extinction because of destructive interference. Thus, the reflected wave should be a bundle of parallel beams.
But why the reflected wave choose a reflection angle equal with the incident one? What would have happened if θreflected ≠ θincident ?
Note that the same law is valid for rigid bodies kicking a plane wall, s.t. it doesn't seem to be a quantum effect in this behavior.
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Joerg Fricke,
Yes, Joerg, you are right. It is a simple geometrical fact. The picture below illustrates what you explained.
The front incident wave does not reach the reflecting surface at one single time but at a series of times t1 < t2 < t3 < t4, etc. From each point 1, 2, 3, 4, etc., evolves a circle, and since the circles C1, C2, etc., appear one before the other, their radiuses at a given time T are R1 > R2 > R3 > R4, etc. - see the figure. The envelope of these circles (which is tangent to all the circles) forms the reflected front wave at the time T. Geometrically, there results that this tangent is symmetrical to the incident front-wave.
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We are working on reflection-in-action. More precisely, how junior doctors engage in reflection during the action and we are using shadowing as a data collection method. Of course, this is different from reflection-on-action (Schon), in which practitioners reflect after they have taken decision and actions. There is much more evidence on reflection-on-action.
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I agree that it is about time - which is a reflection of prioritisation - what an organisation values to invest time in. While there is little understanding about the value of reflective praxis, an organisation is unlikely to make time for it. And a couple of the key threats to this way of working being valued is a) it makes the invisibilised and unheard present, which can be threaten peoples' standing in many ways and b) it makes decision making distributed which threatens explicit and tacit power systems and cultures in organisations. So until the practice that requires reflection in action is related to an issue that is compelling enough to the organisation to learn about and support this transformative shift in how change is done, it is unlikley to be invested in. Added to this is that to do it well, we have to learn to learn which requires a formalised learning culture to built into an organisation or discipline - so the preproduction investment is also significnat.
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For hyperspectral image, each spectral curve represents the reflectance of a region, but there are several endmembers in the region, I can get the ratio value of each endmember, I want to obtain the reflection of each endmemer.
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See the paper for basic hyperspectral data processing and analysis
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Hello everyone. I have been doing a FTIR stup to measure the reflectance at grazing incidences by using parabolic mirrors. So I prepared a sketch of it, and attached. Could you tell me if this setup works or not? If you think this setup works, I need to learn what will be the beam diameter on the surface and what will be the angle range between sample and beam. This sketch is prepared for using parabolic mirrors (Thorlabs MPD249-M03 Off axis, RFL:101.6 mm ). I have setted the incident angle at 10 degree by taking consideration RFL, as a result X:100.0565mm and Y:17.64265mm. Could you give me advices on this setup please? I know I am not good at optics and I need some advices.
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In the special reflection of IR beam, the incident angle must be the same as the reflection angle. In your diagram, those two are very different as Dr. Irizawa properly pointed out.
You can calculate the size of the beam on the sample by knowing the initial beam diameter of the spectrometer, which is often 11 mm at the sample location in the case of transmission set-up, and using these beam size and the focal point of the mirror. The easiest way is to draw optics exactly the same way as the real system and measure it on the diagram.
The size of the mirror has two important consequences. When you use a large mirror, the angle spread is large and therefore, angular error is large. In case you are thinking of reflection-absorption spectroscopy to measure the molecular orientation, the orientation determined will have errors according to this angle spread. However, because of the large mirror, the energy throughput is also large, allowing the signal-to-noise ratio to be good. This can be important for surface studies (if you are interested in studying very thin film on a metallic substrate using reflection-absorption spectroscopy). So, there is a trade-off between these two quantities.
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I have a multi-layer structure of length 700 nm with a refractive index of approximately 1.5, and I am trying to view at different angles. I have observed from the plot which is attached here, the peak reflection has shifted to lower wavelengths as the viewing angle is increased. But as per the relation,       length = lambda/(2*refractive index), the peak reflection has to shift to higher wavelengths, since the effective length increases with respect to increase in viewing angle. 
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Dear Dr. Daniel,
Thank you for your response.
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I was asked to reflect on my experiences as a member of a clinical team. and to answer these questions: What makes a team effective in terms of achieving expected outcomes for patients and agencies? What situations or conditions make it difficult for teams to work together?
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I am looking for method/s for measuring the reflectance spectrum of phytoplankton in laboratory settings.
Please provide me reference with the most up-to-date method.
Thanks. 
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I want to plot the time domain reflections for bi-static antenna configuration using S21 in MATLAB, what is the development procedure?
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@Paiboon Yoiyod I am doing the same but problem is time axis, I am not getting proper results on required time, second for unknown distance how to know the time delay.
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I have data reflectance vs incident angle for different wavelengths
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This is might be useful. Please read the attached file.
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Intellectual Capital
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Just to add on these elements, there is the typical moral hazard problem. Suppose banks provide loans to a firm. In case of problems, the banks are entitled to the collateral (assets) before the owners are. If intangible assets are capitalized, these results in profits which may be dictributed to the owners, and in this way, these possible future revenues can to some extent be distributed to owners. It is questionable whether it is a valuable collateral in case of default leaving the banks with less certainty. Some of these may not be sufficiently hard for the bank to serve as collateral so that allowing firms to capitalize will actually result in higher interest rates (as the risk for the lender increases). This is even more so because of the fact that valuation of these is often subjective (which indeed can lead to earnings management). So it is questionable whether it is preferable for firms. Actually, more conservative accounting may reduce interest rates on loans (see the paper of Zhang 2008 'The contracting benefits of conservatism to lenders and borrowers').
[As a note in addition: for valuation, you may think of the Ohlson framework (1995) in which the value of a firm is written as the book value of the firm (book value of equity) plus the present value of residual income. The latter is income in excess of the return on capital. If you realize that capital is indeed estimated 'too' low (as intangibles are not included), then return on this capital is low which implies that in expectation earnings will exceed this return on the (low) book value. This is the residual income (or abnormal earnings). If you earn money based on e.g. the value of your brand name, this leads to higher earnings than just return on capital. This is included in the value of the firm as the present value of this future residual income.]
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Dear All,
I am using Mini-IPIP Questionnaire which was developed by Donnellan et al. (2006) to check Big Five Personality Traits . I have emailed the author several times but he never reply!!!
I have 2 questions and i appreciate if you can help.
1. Are the questions formative or reflective? 
2. Should i reverse code some items which are negative? (as it is personality questionnaire i am not sure to reverse code or not)
I have attached the questionnaire.
Thanks
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Hello,
Regarding whether you should reverse code some of the items, yes you will need to. For instance, just looking at two items of the Extraversion scale, if someone indicated that the following item, "Am the life of the party" described them well (and chose a score of "5") and indicated that the item,  "Don’t talk a lot" does not describe them well (and chose a score of "1") then this indicates that they are high on Extraversion, but if you did not reverse score the second item, the total Extraversion score would not reflect high Extraversion.  In the Appendix of the original article, the authors identify which items should be reverse-coded (marked with an "R" next to the items)...
Good luck.
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I am interested in finding suitable outlet for sharing my reflections on leadership style theory and Butlerian performativity theory.
Would appreciate any suggestions.
Rgds,
I.
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Thank you all for replies!
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Does light change phase when reflecting off a metal surface?
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thank you very much Rituraj Verma
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I am doing a narrative research
My reserch questions are about whether technology could help pre- teachers to reflect on thier practice?
and how they canbenefit from reflecting using technology on improving their self-efficacy?
It is clear that my research covers two subjects, reflection and technology, and does so not in a single phenomenon approach.
Do you think that I may need to analysis data in various ways to answer the research questions?
Can you please advice me how can I analyize my data as I really get stuck
Many thanks
Shtaha
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There is a major difference between collecting your data with narratives (which is what almost all qualitative interviewing does), versus concentrating on the detailed nature of those stories as the basis for analyzing your data (which is what is meant by "narrative analysis").
If you are indeed interested in narrative analysis as a specific technique, then the biggest challenge is that there are a wide number of different approaches to this method. Indeed, Holstein and Gubrium have a 300 page edited collection titled, Varieties of Narrative Analysis.
Alternatively, if you want to concentrate on the substantive content of your data (rather than ways that the stories are told), then you could use a much more general method, such as Braun and Clarke's (2006) Thematic Analysis.
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Hi I am having trouble accurately finding the refractive index of a structure I simulate in HFSS.
I have been using chapter 3 of optical metamaterials (Wenshan Cai Vladimir Shalaev) to aid me in creation of a script to define mu and epsilon from scatter parameters S11 and S21. Where Z and then the real and imaginary components of N are calculated and combined where
Epsilon = n/Z
and 
Mu = n*Z
My script.
clear all;
close all;
disp('test extraction routing');
%Known parameters d = thickness l = frequency k = wave number
%frequency adjusted to wavelength. d remains constant. For now using speed
%of light and freq to calculate wavelength
d=200e-9;
freqraw=load('freqs.csv');
freq=freqraw;
lambda=(2.99792458*10^8)./(freq*10^12);
k=(2.*pi)./lambda;
%Outputs S11 (r) and S21 (t) and phase variables
S11=load('magS11m2.csv');
S21=load('magS21m2.csv');
PhaseS11=load('phaseS11m2.csv');
PhaseS21=load('phaseS21m2.csv');
r = S11.*exp(j*PhaseS11);
t = S21.*exp(j*PhaseS21);
figure
hold on
plot(freq,abs(r),'r.')
plot(freq,abs(t),'b.')
title('reflection and transmission over frequency')
xlabel('freq')
ylabel('tranmission (red) and reflection (blue) over frequency')
for gh=1:length(freq);
% Impedance - Z - The route much be chosen which leads to the real
% component of Z being positive
q(gh)=1;
z(gh)=q(gh)*(sqrt(((1+r(gh)).^2-t(gh).^2)/((1-r(gh)).^2-t(gh).^2)));
if real(z(gh))<0;
q(gh)=-1;
end
%refractive index - n
%The route must be chosen where the imaginary component is positive
xx(gh)=-1;
nimag(gh)=xx(gh)*(1/(k(gh)*d))*imag(acos((1-r(gh).^2+t(gh).^2)/(2*t(gh))));
if nimag(gh)<0;
xx(gh)=xx(gh)*-1;
end
%M is apparently used the find the correct branch of the real component.
%This has never really been an issue. When used it is an integer which
%makes the real component contiuous over a large spectrum
M=0;
%Shares the same route as the imag component
nreal(gh)=xx(gh)*(1/(k(gh)*d))*real(acos((1-r(gh).^2+t(gh).^2)/(2*t(gh))))+((2*pi*M)/(k(gh)*d));
%n
n(gh)=nreal(gh)+i*nimag(gh);
end;
% Permittivity
epsilon=n./z;
% Permeability
mu=n.*z;
% Graphs
%figure
%hold on;
%plot(freq,nimag,'r.')
%plot(freq,nreal1,'g.')
%plot(freq,n1,'b.')
%plot(freq,nreal3,'k.')
%title(' refractive index over freq')
%xlabel('freq')
%ylabel('Alternative n (imaginary red and real green)')
%Refractive index
figure
hold on;
plot(freq,nimag,'r.')
plot(freq,nreal,'g.')
title(' refractive index over freq')
xlabel('freq')
ylabel('n (imaginary red and real green)')
%both over freq
figure
plot(freq,real(mu),'b')
hold on
plot(freq,real(epsilon),'r')
title('both')
xlabel('freq')
ylabel('(Eps red) (mu Blue)')
%epsilon over freq
figure
plot(freq,imag(epsilon),'b')
hold on
plot(freq,real(epsilon),'r')
title('epsilon over freq')
xlabel('freq')
ylabel('epsilon (Real red) (Imag Blue)')
%mu over freq
figure
plot(freq,imag(mu),'b')
hold on
plot(freq,real(mu),'r')
title('mu over freq')
xlabel('freq')
ylabel('mu (Real red) (Imag Blue)')
%impedance over freq
figure
hold on
plot(freq,real(z),'r.')
plot(freq,imag(z),'b.')
title('impedance over freq')
xlabel('freq')
ylabel('Z (Real red) (Imag Blue)')
%absorption over freq
figure
absorption=1-S11.^2-S21.^2;
plot(freq,absorption)
title('absorption over freq')
xlabel('freq')
ylabel('absorption')
Sorry its a bit messy. I have no real experience with matlab or HFSS before beginning this project. Any advice welcome. Thanks for your time.
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Hi Azita Gudarzi
I'm not sure about my code. There are some unbreakable rules which seem to be broken when I run the script.
For example my main concern:
Sometimes the imaginary component of the refractive index is negative.
This should never happen.
I'm fairly sure I'm using the software correctly I think its just my code.
Could you possibly point me to a script youd use or a paper where I could find some more information? (Obviously its important that the script is for optical wavelength)
Thank you 
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Reflectance standard 90 - 100 %
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Does the packing method matter?
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Why small angle XRD pattern shows peaks for hexagonal and cubic symmetric structure like SBA-15, MCM-41.
Reflection at 100, 110 and 200
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Dear Christian,
I want to know how these intense reflection are coming at low angle for such periodicity
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as i am very new to this field and i need to design a simple piece of reflective silencer plate(perforation max 60%)
is there any rule/equation that can help me to decide/calculate:
the position of inlet/outlet (distance between them ect.)
thickness of the silencer
diameter/ arrangement/spacings of the holes for perforation
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Dear Al Lw,
There are not rules for this geometry definition because its performance depends on the travelling waves in the premises of the secion and they depends on the geometry of the muffler and the acosutic source as a whole. The problem that you want to tackle is difficult but probably you want to check a text book writen by Dr. Munjan that describes the mathematics of muffler attenuation:
See:
A good read to this work will be very revealing.
Best regards
Juan
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How to confine range of surface reflectance Landsat image data between 0 to 1?
hello
I have got a surface reflectance image of Landsat TM5 by downloading of USGS website. Range of surface reflectance of the image is not confined between 0 to 1. please help me converting the surface reflectance data to 0 to 1 range.
and where can I find scale factor of the image?
what is scale factor basically?
thank you.
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Check the table present on page 21 from the attached product guide for the valid range and scale factors. For the 'how' question refer to a similar discussion. But bear in mind that 'Landsat Surface Reflectance products are considered provisional'.
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I'm doing research in PBRT and trying to carry out experiments with a lambertian sphere (small size, almost diffuse, near 100% reflectance). I searched the Internet and found no where to get such a sphere. Can anyone tell me where to buy one?
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I belive the standard approach is to paint a sphere with lambertian paint, which you can buy.
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Is there any valid measurement tool for reflection?
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Anna,
I was looking through old questions, and this one from you in 2013 appeared to me.  
In case you are still interested, please see the attached rubric that my colleagues and I use.
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Hi,
We are planning to build a high finesse(>2000) FP cavity in which mirror reflectivity is 99.93%, in order to stabilize the ECDL. These FP cavity will be used in PDH locking in the later stage and we would like to know the AR coating necessary for the rear side of mirror since we are planning to order the mirrors.
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Hi Muhammed,
I assume you mean HR coating if you want to obtain a 99.93% reflection on the back mirror? I don't know which wavelength you're aiming at but these HR coatings normally consist of combinations of high and low index coatings (e.g. SiO2-Si3N4, SiO2-Ta2O5). There is good software to calculate these coatings for your specific wavelength (TF_calc, Filmstar, McLeod). Very often the commercial companies who deliver you the mirrors will use this software if you give them the specs (wavelength, reflectance, polarisation, etc). For a 99.93% reflectance my guess is you will need 5-6 stacks of the material combinations I mentioned. For AR coatings the same software is used and there you probably need a single thin film (e.g SiO2) or a single combination of SiO2 and Ta2O5, depending on central wavelength and wavelength window. 
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I'd like to measure the bandgap of a 4-stack layers of Poly-Si/SiC embedded alternately onto quartz substrate. I read one article (J. Appl. Phys. 106, 103505 (2009)), where it is mentioned that they used integrating sphere to measure reflectance at 0 deg. I'd like to know why they used integrating sphere. Any suggestions would be appreciated
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Dear Debra Sharon Ferdinand,
Thank you very much for your useful link! 
Best regards,
Zaman
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Can somebody suggest an up-to-date method to transform reflectance measurements into variables of hue, chroma and brightness? Thank you!
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Since the road from reflectance data to subjective colour attributes has severals stations inbetween, I wondered for which step you seek an "up-to-date" method. While CIECAM02 is the latest development in colour appearance models, it starts with the tristimulus values of a colour sample, which thus have to be calculated first. 
Assuming that you are talking about *spectral* reflectance values you first must know the spectrum of the light source that is reflected from your patch. In a nutshell you first have to multiply those two spectra with each other, then you have to apply three different weighting functions to the result, and finally you have to integrate (sum up) these latter three results in order to find the tristimulus values X,Y,Z of your colour sample under the given illuminant. Only then you can proceed with the CIECAM model.
You might know all this, but since the exact method of calculation has always been a matter of debate, I thought I could mention that there is a standard from 1994 available detailing the procedure (see attached file).
ps "brightness" is often understood to be the subjective correlate of the luminace of a light source. It may be that "lightness" is what you are after, which is an attribute of a coloured object that varies between the extremes of black and white
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I am using cary 100 UV-VIS diffuse reflectance spectroscopy with 70mm integrating sphere.when I place the standard in the sample port and measure the reflectance the value I am getting is around 40%.
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It's ok since ther is incomplete light collection of light even by integrating sphere. You will get 100% after baseline recording. The reflectsnce of your samples will then calculated relative to your standard.
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1 how to calculate? Is it the ratio of the amplitude of the reflected wave to the incident wave?
2 use which device to measure it? Is it accurate enough?
3  Is there any simple method to measure the wall reflectance? I just want to be sure that the recommended value of 0.5 for simulation is not far from the fact.
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I agree with Tobias. We should distinguish between reflection coefficient and reflection factor or reflectance. The former relates the reflected amplitude of the electric field to that impinging in a surface. The reflection factor or irradiance deals with the irradiance reflected. Both parameters are related.
As most instruments measure reflected irradiance, you should calculate the electric field amplitude. However, please, be advised that you could loose the information about the reflection phase change if needed when measuring irradiance. Polarimetry could help you.
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I could use the conversion software to automatically convert the data, but I want to confirm what I'm actually measuring.
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This could be the "reflectance absorbance" defined by A = -lg (R/R0). Using internal reflection, having very weak absorption bands and with obeying some more conditions it can resemble "transmittance absorbance" = -lg  (T/T0).
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By convention single item measures are reflective in PLS path model. what about use behavior measured with a single item usage frequency . Should i measure it formatively or reflectively?
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You can do it reflectively as you may get a richer amount data for your measuring the behaviour.
Many thanks,
Debra
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How can we determine Fresnel complex transmission and reflection coefficients between any two layers. For example the transmission and reflection coefficients between AlGaAs and GaAs layers of solar cells.
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I find the result in this paper, while the details are not illustrated. Have you got any helpful papers, please pass a copy to me. Thank you!
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If it is assumed that having a clearer skin, should reflect more short-wave radiation, i.e. should have a higher albedo than people with dark skin. I look forward to your answer. Skin reflectance increases with latitude, i.e. people with fair light reflect more radiation, and then I wonder why they burn faster than dark skin? Thank you in advance.
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Most likely, you mean albedo of visible range of light range 400-760 nm. But it is not dangerous for the skin, unlike the UV radiation (100-400 nm), which little reacts to a white surface. The biologically more important in absence of the white skin of some important enzymes which protect the DNA from the direct damage. Perhaps the material below will be useful.
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Are they easy to handle and work with? Any word of advice for the newbie? Any comparison with plane reflection gratings in terms of temperature stability, efficiency and ghosts?
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"Are they easy to handle and work with?"
That depends on your application. Typically, concave aberration corrected gratings are used for flat field spectrometers. Since these gratings combine dispersive and imaging optics with low astigmatism, coma and field curvature, such spectrometers usually posess the easiest possible setup: an entrance slit, the grating and a CCD/CMOS detector. Their assambly however requires some alignment.
"Any comparison with plane reflection gratings in terms of temperature stability,"
I don't think that there should be a huge difference. It depends on the substrate and coating materials (concave gratings on Zerodur should be available) and dimensions. If your application comprises high temperatures >60°C, resin replica gratings might be unsuitable and you have to use more expansive master gratings.
"efficiency,"
Concave, aberration corrected gratings are to my best knowledge always manufactured holographically. In literature, it is often stated that holographic (plane and concave) gratings are inferiour to ruled plane gratings regarding efficiency, since blazed profiles are more difficultly achieved. However, I can't confirm this: blazed gratings can indeed be holographically manufactured with nice profiles and hence blazed efficiency behaviour, so no big difference, when it's done correctly.
"ghosts"
If the holographic setup for mastering was optimized in terms of stray light, there can be literally no ghosts orders and overall least possible scatter (grass). Holographic gratings should always be superiour to ruled gratings, if the recording setup was good.
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i am calculated albedo according to the way that is mentioned in SEBAL manual and my result has very much pixels that above 1 while albedo should be between 0 and 1.
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As well known, glass has reflection.What about lens? is it 100% light will transmit or still have reflectance?
If yes, how to calculate the reflectance? Any idea ?
Thanks..
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Tjhe Fresnel equations tell you how much light will be reflected from the surface of a lens. The amount of light reflected depends on the index of refraction of the glass, and on the angle of the incoming light. The higher the index and the shallower the angle, the more that will reflect.
For glass, a reflectance of about 4% or 5% is typical. I don't know where the 10% number in your diagram comes from, except that there is also light that reflects when exiting the lens.
There is nothing inherent in a Fresnel lens that changes this 4% reflectance. But, a Fresnel lens will often allow for curvature that a normal lens would never have. This will increase the amount of light that comes in at a shallow angle to the surface, so it will increase the surface reflectance.
On the other hand, Fresnel lenses are often made of plastic. Most plastics (with the exception of "high index" plastics that are used in glasses) have a somewhat lower index than glass. This means that there is less reflection.
It is possible to add an anti-reflective coating to reduce this reflection. MgF is one such coating that has a lower index. Another way to reduce reflection is to add an interference filter to the surface. If you are looking at solar cells (as implied by your drawing) then neither of these are practical. They are expensive for large areas, and prone to scratching.
Another thing to consider is to put "goop" on the underside of the Fresnel lens, so that you do not have an air gap between the bottom of the lens and the top of the "plate". This will significantly reduce the lower surface reflectance.
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material that can absorb or reflect up to this frequency.
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THanks Alfonso...Looks interesting. I will look into it.
RG
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Why are Microwaves reflected by metals and passed through by glass? Can mirrors reflect EM waves? Is Skin depth the reason?
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In order to easily understand the behavior of the different materials concerning their interaction with an incident electromagnetic wave with specific wavelength, the material is modeled as a transmission line having a characteristic impedance Z0. 
If we have two materials with different Z0, then  by definition the reflection coefficient roh= (Z02-Zo1)/ Z02+Z01), iF  the two impedances are equal the reflection coefficient will be zero the two materials are matched. The characteristic impedance depends on the dielectric constant, the permeability and the resistivity of the material on both sides of the interface. . In case of metal air interface because of the high conductivity of the metal its characteristic impedance will be very different from that of the air and total reflection occurs from a relatively thin metal thickness. One can said if the metal is an ideal conductor it will make the electric field component equals zero. This is as if you short circuit the transmission line. The wave will be bounced back.
In case of partial reflection the refracted part will be partly absorbed in the material and the rest will be transmitted out of the materiel. The absorption depends on the interaction between the photos of the wave and the electrons in the material. It depends specifically on the energy band structure of the material,
wish you success
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I have downloaded the SR products directly for EVI, which has gaps due to SLC error. The gap filling method is defined by USGS as: http://landsat.usgs.gov/ERDAS_Approach.php has been utilized for DN values Landsat 7 bands.
Can we use these same methods for the SR products, like on EVI?
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Hi Atiqa.
First, you really need to understand how Focal Analysis works -- that's the function used by USGS in filling the gaps. Once you understand the theory behind it, you will know that the function can be applied to any type of image, since its purpose is to reduce noise and other imperfection of the image.
You notice in one of the figures in the USGS guide that you have to specify the window size (e.g. 3x3) and where you want to apply the function (e.g. mean). In this case, you need to apply it at the specified value of zero (e.g. gap).
Kindly check the link below.  And to answer your question, yes, the Focal Analysis function can be applied to any image.  However, I cannot assure you of the quality of the output.
I also posted a couple of links to previous discussions that might be of help to you.
Regards.
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I want to analyze documents to infer rules that define the relationship of precedence between activities that are reflected in the text.
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You can use DIRT – Discovery of Inference Rules from Text. For more details you can look at the attached paper.
best regards
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Reflection problems are usually defined for AC transmission lines. I would like to know whether DC lines can have this problem. And I also would like to know whether the length of the transmission lines have an influence on the reflection problems either for AC or DC lines.
Is the DC an electromagnetic wave?
Thank you very much,
Antonio Faggio
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The DC signal can induce an `electromagnetic wave' until steady state. This is due to transients caused by switching process. DC isn't truly DC for those few microseconds. A DC excitation cannot cause an electromagnetic wave to travel down the transmission line after steady state. Thus a charged transmission line does not have any EM waves propagating in the line. However, the transients in the DC switching process contain sinusoidal signals which in fact result in alternating electric and magnetic fields (electromagnetic fields) to travel down the line.
Reflection problems can thus be used for analyzing transients in both the AC and DC excitation case. The length of the transmission line  will change the impedance which will change the reflection coefficients. So the length of transmission lines will definitely influence reflections.
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The AR coating reduce the reflected power mean destructive interference. So, the reflected power is low, in some cases less than 0.1%, but this indicate that transmitted power is 99.9%? Or the transmitted power is unaffected by the ar coating?
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Jorge:
Not my area of expertise, but here's what is available in RG to include several 2015 articles that can help you find answers to your question:
Best regards,
Debra
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Normally, transmission or absorption data as a function of wavelength is used to calculate optical band gap of semiconductor. Can we get the same from reflection data alone?
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Dear sir,
By using UV-DRS we can find both direct and indirect band gap. Not only band gap optical constants like refractive index, absorption coefficient, extinction coefficient , optical conductivity also measured. I hope the following article helpful for you 
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reflection prob on plane wave in fibre-reinforced elastic medium.
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Depending on the layout of panel, you may get quasi-isotropic laminates that are actually isotropic in terms of velocity for certain wave modes.
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What is the explanation behind the difference in NDVI values when calculated from DN, radiance and reflectance?
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The wavelengths are 400 to 1000 nm.
I would like to know not the particle's absolute absorbance value just how they relate to each other; which of these particles reflect the most light.
is it  correct assumption that the bigger the area of the spectrum is the more löight is being reflexted 
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Dear Aras, the curve is like that, it is just flat at a certain wavelength range, higher values could be detected.
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Could anyone help with the instrument using for reflectance measurement?
Our Lab has JASCO V-670 instrument and ISV-723 60mm integrating sphere.
But no one knows how to use those things..
And I want take reflectance spectrum using this instrument.
Please help me ;)
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Not to be confused with REFLECTIVITY - not my area of expertise
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I have images from a Specim SWIR terrestrial hyperspectral camera, and I have converted them to radiance.  I also have FODIS data, which can be used to convert to reflectance, I'm just not quite sure how to do this.  
image: n lines, 291 samples, 256 bands.
FODIS data: n lines, 1 sample, 256 bands.
Any suggestions would be greatly appreciated.
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Hi Lukas!
Consider the following:
Reflectance is equal to the ratio of the reflected radiance and the incident radiance. The SPECIM radiance measurements correspond to the reflected radiance, while the FODIS measurements to the indicent radiance. Thus, to estimate the at-sensor reflectance you have to calculate the SPECIM/FODIS ratio for each one of the available spectral bands. Moreover, because the FODIS measurements are point data, the same FODIS measurement will be used for all the samples of each SPECIM line.
It is important that you pay attention to the following points:
  • The retrieved reflectace values will still carry the atmospheric influence (i.e. using this method you will estimate the at-sensor directional reflectance and not the at-surface directional reflectance).
  • Before applying this method you have to correct the FODIS measurements for the roll, pitch and yaw movement of the aircraft.
  • the SPECIM and FODIS radiance measurement units should be compatible.
  • Be very careful if clouds where present during the image acquisition.
Hope this will help,