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A chiller is a machine that removes heat from a liquid via a vapor-compression or absorption refrigeration cycle. This liquid can then be circulated through a heat exchanger to cool air or equipment as required. As a necessary byproduct, refrigeration creates waste heat that must be exhausted...
The spectra of three diamonds
Although diamond has the simplest possible chemical formula, it can exhibit large variety of luminescence behaviours. I took three of the small diamonds from my collection and looked at their visible absorption and luminescence spectra.
The diamonds are labelled:
xtal: An octahedral crystal ~2mm on a side with small black (graphite?) inclusions
b: one of a set of small (1-2mm) diamonds given to me by Gérard Barmarin
green: A cut (0.12ct) diamond that has been irradiated in a nuclear reactor and appears a pale apple-green colour
The luminescence spectra of the three diamonds were obtained with excitation by a 50mW 406.9nm violet laser and a 300mW 532.2nm green laser. For the green laser measurement a BG38 filter was used between the laser and the sample to remove the ~800nm pumping signal and an OG570 filter used between the sample and the spectrometer input collimator to block the elastically scattered laser light but to include Raman lines beyond a shift of about 800cm-1.
The luminescent colours of the diamonds excited with a 384nm LED are shown in the image at the top right of two of the plots.
Most of the luminescence centres in diamond are related to nitrogen atoms since these have an atomic radius very close to that of carbon. The centres generallly consist of vacancies in the carbon lattice but can include other impurity atoms such as boron and nickel.
The spectral plot has been divided into overlapping blue and red sections that show the response of the three diamonds to 407 and 532 nm laser excitation. There is also an absorption spectrum of the green diamond which, in addition to the very broad absorption band centred at around 620nm and responsible for the green colour, shows two distinct but weak narrow absorption lines at 416 and 503nm arising from the self absorption in the zero-phonon lines of the N3 and H3 centre fluorescence respectively.
List of spectral features and their likely identification.
Centre----------------Wavelength (nm)
_______________________________________
N3 ZPL-------------------------415.8
N3 abs-------------------------415.8
N3-------------------------------429
Raman I ex 406.9nm-----430.2 (1332 cm-1)
N3-------------------------------439
N3-------------------------------452
N3-------------------------------465
S2-------------------------------489.9
S3-------------------------------496.7
H3-------------------------------503.2
H4-------------------------------505
H4-------------------------------513
H3+H4+S2 + abs ~523
H4-------------------------------529
S3-------------------------------537
Raman I ex 532.2nm-----572.8 (1332 cm-1)
N-V^0 ZPL--------------------576
Graphite xtal?---------------578.3 (1500 cm-1)
Raman II ex 532.2nm-----613 (2467 cm-1)
N-V^- ZPL---------------------639
N-V^- 1 phonon-------------660
?---------------------------------742
_______________________________________
Many of the diamond defects are associated with nitrogen atoms and vacancies in the carbon lattice and there is an extensive literature on the subject and much interest from solid state physicists and engineers. In particular the negatively charged nitrogen vacancy centre known as N-V^- has properties that are of great importance in the development of quantum computing since individual ionic vacancies can be addressed with lasers. The plots show the narrow zero-phonon lines (ZPL) from both the neutral defect, N-V^0 at 576nm and the negative defect, N-V^- at 639nm. These narrow lines (which are much stronger at low temperatures rather than the room temperature (293K) used here) are accompanied by a set of broader phonon sidebands that extend to longer wavelengths. The ZPL represents the electronic transition between the lowest vibrational levels of two electronic states. The phonon sidebands appear at shorter wavelengths in absorption and at longer wavelengths in emission in a manner determined by the Franck-Condon principles.
Other common defects are N3, consisting of three substitutional nitrogen atoms bound to a single vacancy or carbon atom: H3 and H4 that are connected with a pair of nitrogen atoms and a single vacancy in slightly different configurations; and S2 and S3, the first due to a single nitrogen atom associated with two vacancies and the second to a combination of several nitrogen atoms and a single vacancy. As far as I am aware, not all of the luminescence centres in diamond have yet been fully identified and understood.
In addition to the fluorescent emission lines in the spectra that appear at a fixed energy/wavelength, diamonds exhibit a set of characteristic inelastically scattered (Raman) lines that appear at a fixed energy difference from that of the exciting (monochromatic) light source. The most famous of these is the strong, well-known line with a Raman shift of 1332cm-1 that arises from the fundamental vibrational mode of the carbon lattice. It is possible to see overtones of this line although these are faint and have a complex structure (see the lovely 1946 paper by Krishnan, one or Raman's colleagues: repository.ias.ac.in/30540/ ). All three of the spectra here show both the first order at 572.8nm and the second order Raman line at 613nm (2467cm-1) excited by the 532.2nm laser. In the blue, I see only the first order Raman line excited by the 406.9nm laser at 430.2nm and this is blended with the first phonon sideband of the N3 defect luminescence.
In one of my 532nm laser excited spectra of the diamond xtal, I see a narrow line at 578.3nm that does not show up in all spectra. This diamond contains a few small black inclusions which are most probably graphite. I tentatively identify this line with the raman line from graphite which can range from Raman shifts of 1335cm-1 for amorphous material to 1575cm-1 for crystalline graphite. The Raman shift I measure is 1500cm-1. However, I am not at all sure of this ID.
I hope this experiment will help orient people who are interested in diamond spectra to get started with this somewhat bewildering topic. I was certainly bewildered when I started! I can't present myself as an expert in this field and there may well be some mistakes and misunderstandings in this description but, if there are, I will correct them as I learn more. I made use of the books by Gaft et al. (2005, "Luminescence Spectroscopy of Minerals and Materials", Springer Verlag, Berlin Heidelberg, p100 and p187) and by Gorobets & Rogojine (“Luminescent Spectra of Minerals” Moscow, 2002) as well as some of the extensive journal literature.
Note: These measurement of the luminescence spectra were reduced with a new (Cal #9) radiative flux calibration based on the Solar (outside the atmosphere) flux from the Hubble Space Telescope Calibration Database and a transmission model of the Earth's atmosphere at the appropriate zenith distance. The actual calibration curve used for the measurements is from an observation of a halogen filament lamp which has been adjusted to fit the solar flux data. The result is a relative flux scale in energy units per nm which removes the fine pixel-to-pixel sensitivity variations from the spectrometer detector. The result is smooth flux spectra with photon (poisson) fluctuations being the dominant noise source.
The well-understood benefit of sunlight is the production of vitamin D. When skin is exposed to sunlight, a series of chemical reactions begin that converts precursors of vitamin D to the active form of vitamin D. Vitamin D is needed for the intestinal absorption of calcium and the maintenance of calcium and phosphate levels necessary for healthy bone formation. It is also important for proper immune function, cell growth, and nerve and muscle function. Some foods naturally supply vitamin D, such as fish and liver. Other foods, such as milk and cereal, are typically fortified with vitamin D.
1. Sunlight and whole foods send breast cancer into remission. The American physician Dr. Zane Kime used sunbathing and nutrition to cure his patients. Even in terminal cases, Dr. Kime was able to completely reverse the metastasized cancer.
2. The sun's light kills bad bacteria. The German solders after WWI knew of the discoveries that had been made in 1903 by the Nobel Prize winner, Niels Finsen. They used sunlight to disinfect and heal wounds.
3. Sunlight has a beneficial effect on skin disorders, such as psoriasis, acne, eczema and fungal infections of the skin.
4. Sunlight lowers cholesterol. The sun converts high cholesterol in the blood into steroid hormones and the sex hormones we need for reproduction. In the absence of sunlight, the opposite happens; substances convert to cholesterol.
5. The sun's rays lower blood pressure. Even a single exposure significantly lowers blood pressure in individuals with high blood pressure. On the other hand, pharmaceutical drugs such as Statins have side effects, such as robbing the body of Coenzyme Q10. CoQ10 is essential for cellular and heart energy
6. Sunlight penetrates deep into the skin to cleanse the blood and blood vessels. Medical literature published in Europe showed that people with atherosclerosis (hardened arteries) improved with sun exposure.
7. Sunlight increases oxygen content in human blood. And, it also enhances the body's capacity to deliver oxygen to the tissues; very similar to the effects of exercise. The sun has a great effect on stamina, fitness and muscular development.
8. Sunlight builds the immune system. The white blood cells, which increase with sun exposure, are called lymphocytes, and these play a major role in defending the body against infections.
9. Regular sunlight exposure increases the growth and height of children, especially babies. Many cultures throughout history have recognized this fact. Studies have shown the amount of sun exposure in the first few months has an effect on how tall the person grows.
10. Sunlight can cure depression. The noon sunshine can deliver 100,000 lux. When we sit in offices for the best part of the day, out of the sun, under neon and artificial lights (150-600 lux), we are depriving ourselves of the illumination of nature. Sunlight deprivation can cause a condition called seasonal affective disorder (SAD), a form of depression. It is more common in winter months, but also common in people who work long hours in office buildings .Exposure to the sun should be done SLOWLY! If you are not used to the sun, then your skin will be more sensitive to it. Avoid sunburn by building up your tolerance SLOWLY. There are many known benefits of sunlight on mood and health, but regular sunlight exposure also can have long-lasting, positive effects on bone health, heart health, immunity and disease prevention. Sunlight often serves to encourage exercise, physical activity, travel and social interactions.
To know more visit www.yogagurusuneelsingh.com Pic By Addy
Chlorophyll (ˈklɔːrəfɪl):
A green pigment, present in all green plants and in cyanobacteria, which is responsible for the absorption of light to provide energy for photosynthesis.
A variety of furniture styles and colours make this an inviting location for informal study. Easy access to power is provided from the ceiling mounted extension cables. Wireless access the the world wide web is also provided. Flexible screens for reconfiguration of space give students some privacy and help absorb sound.
A prototype of an acoustic absorption movable panel passed here in the early stages of development. I had to say that it worked very well, hope to try a more definitive and well finished piece in the future.
Amsterdam
June 2012
THe Netherlands
Urban life in the Netherlands
Ricoh GRD IV
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The setting Sun on June 30, 2014 as it set into a hazy or dusty sky and turned deep red/magenta, above the horizon clouds. I shot this through the 66mm William Optics apo refractor with the Canon 60Da camera at ISO 100. This is a composite of two exposures: longer for the sky and shorter for the Sun and details on the disk. A large sunspot group is on the eastern limb. This was shot without a filter -- atmospheric extinction dimmed the Sun enough naturally.
Liquids from the in-use compost chamber of our toilet flow into the slotted pipe that is bedded in a rubble trench. It's kind of wasting precious nutrients, especially nitrogen, so we will be planting a lemon tree nearby this winter. Trench part constructed and prior to filling.
The Briar carbine is a firearm designed for close and medium-range combat, in settings such as urban locations.
It utilizes the 4.8mm caseless round, giving it a high rate of fire, coupled with the weapon's even weight distribution and recoil-absorption system, makes full-automatic shooting more accurate.
Timberland 6 Inch Premium Waterproof Boots, Menâs Size 12, Wide, Wheat, Nubuck, TB010061, 100613640, Premium leather uppers, waterproof construction, Leather lining for comfort and durability, Rustproof hardware, anti-fatigue technology, 400 grams of PrimaLoft® insulation, Padded collar for a comfortable fit around the ankle, Anti-fatigue midsole and removable footbed for all-day comfort, lightweight cushioning and shock absorption, Rubber lug outsole is made with 10% plant-based materials, reddealsonline, redd3413,
Assembled using methane absorption band (CB2, MT2, MT3) images taken by Cassini on January 13 2008.
NASA/JPL-Caltech/SSI/Kevin M. Gill
Line graph showing the relative amounts of light absoption at different light wavelengths of the photosynthetic pigments, Chlorophyll A and Chlorophyll B. Feel Free to use the photo but please don't forget to give credit to www.ledgrowlightshq.co.uk.Thanks!
My shop time is my therapy. I love the creativity of building something of beauty (hopefully) with my hands, and the total absorption necessary to keep from screwing it up or hurting myself is healthy for my head. I've taken up building bigger things lately. This Shaker table is my first "official" piece of furniture. It is made of cherry that I milled and dimensioned myself from rough cut lumber. I even turned the knob for the drawer.
Normally, I would post several other photos of the details (the top, dovetails in the drawer, etc.) in the comments below, but with the new flickr interface, I don't think it will tell the story as well as it used to. If I posted them in my photostream, your home page would clogged with just my photos, right? What happens if a contact posts a hundred photos?
So... no, I don't care for the new flickr interface and I feel a need to voice my opinion. But I think upsetting new interface is serving to distract many of us from something even more important... more important to me, at least. The bigger deal to me is the community we've built. You people are important to me! I love getting to know you and know your stories through your photos and comments. I could get used to just about any interface if it was only about looking at photos, but this new design (and the encouraging everyone to ditch Pro accounts) make it much harder to make and see our comments, connections, and conversations around our photos.
I understand some things about business. Yahoo is not in business to make their customers happy, they are in business to make money. (Seems like the two would go hand in hand, but that isn't the corporate take on things these days.) Apparently they feel they will make more money through advertisers than through Pro accounts. Apparently they feel they will make more money by having a huge high-res photo database. I don't take their business decisions personally, and I would have been surprised had they asked me what direction they should take in redesigning their site for achieving their goal of making more money. I know my community means very little to the Yahoo corp.
Even though I "get" all that, I fear it will wreak havoc on my flickr community. I think flickr has been dying a slow death the last few years anyway... so many have left or disappeared or stopped posting as much. Clearly, something needed to be done to rejuvenate the site. Unfortunately, Yahoo is doing what they think is in their best interests, not ours.
It's too early to tell what will finally happen, but I am hanging on to my Pro account as long as I hang around here. I can't imagine looking at ads on top of the already atrocious new flicker look. And... since they so clearly want to do away with the Pro accounts, I may just keep re-upping simply because I'm an ornery, cantankerous, contrary old woman!! Long-winded, too!
Hope you like the table and love my little Angie.
Meanwhile, my energy has to go what I love. Like my Angie here, and the rest of my menagerie, and you, my friends. Love and big ol' hugs to y'all. And thanks to you, too.
Soldiers practicing rescuing possibilities in a missile absorption exercise in Tel Nof, February 2010.
Photo by: Carmel Horowitz.
חיילים מתרגלים אפשרויות חילוץ בתרגיל ספיגת טילים בתל נוף, פברואר 2010.
צילום: כרמל הורוביץ.
ALE won the contract to receive and transport a 184te absorption tower from Richards Bay port to the Omnia Fertilizer plant in Sasolburg.
Bus
Beijing, China
July 2012
A long and hot ride from Sanyanqiao to Sanlitun
Candid shots in and around Public Transport
Ricoh GRD IV
Please do not reproduce or use this picture without my explicit permission.
If you ask nicely I will probably say yes, just ask me first!
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Please no glossy awards, scripted comments and big thumbnails back to your own work.
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Transmission path ~3.5mm. The fluorescence is an average of a range of wavelengths between 354 and 407nm. The apparent 'noise' in the visible-nir spectrum is due to the interference fringing between different paths through this rough sample.
U.S. Department of Agriculture (USDA) Food and Nutrition Service (FNS) provides commodities for these Genesee County Community Action Resource Department (GCCARD) staff and Michigan government employee volunteers (on their own time) to assemble hundreds of Commodity Supplemental Food Program (CSFP) and The Emergency Food Assistance Program (TEFAP) packages, on Wednesday, October 5, 2016, in Flint, Michigan. From the finished palletizing end of the line, CSFP bulk commodities are on the right, and TEFAP bulk commodities are on the left. These USDA Foods are being packaged and delivered to, or picked up by 17,000 eligible households in the Flint area to help address the ongoing water crisis. CSFP works to improve the health of low- income elderly persons at least 60 years of age by supplementing their diets with nutritious USDA Foods. In addition to the CSFP foods, TEFAP packages are an additional 14 pounds of nutrient-targeted foods that are rich in calcium, iron, and Vitamin C â which are believed to help limit the absorption of lead in the body. This number of TEFAP boxes will be distributed each month for four months. The food is in addition to the regular allotment that recipients currently receive. Once packaged, the USDA Foods are palletized and taken to warehouse shelves for later use in the storefront pickup area, or loaded into delivery vans for household distribution to those who are unable to pick it up distribution center. USDA photo by Lance Cheung.
For more information about USDA -- www.usda.gov
For more information about FNS -- www.fns.usda.gov
For more information about Disaster Nutrition Assistance Programs, including DHHDP -- www.fns.usda.gov/sites/default/files/disaster/Disaster-Br...
For more information about CSFP -- www.fns.usda.gov/csfp/commodity-supplemental-food-program...
For more information about TEFAP -- www.fns.usda.gov/tefap/emergency-food-assistance-program-...
@USDA
Following my investigations of the visible and infrared transmission (absorbance) and visible fluorescence spectra of iolite (cordierite), I became intrigued by the presence of the strong, broad absorption band centred at about 1µm and stretching from about 800-1400nm. Since essentially no light was detected in the region of overlap of the JAZ (Vis) and NIRQUEST (IR) spectrometers, it was difficult to match the transmission scales in these two wavelength regions. What is the origin of this absorption and does it appear in other minerals?
A search through my own mineral visible spectra showed that peridot (olivine) also has essentially zero transmission at 1µm. Also, the spectrum of garnet (pyrope/alamandine) is decreasing rapidly towards the IR.
The compositions of these silicate minerals are:
Iolite: (Mg_2 Al_4 Si_5 O_18) with some Mg replaced by ferrous iron (Fe^2+) and manganese, and Al by ferric iron (Fe^3+)
Peridot: (Mg, Fe)_2 SiO_4
Garnet: 3MgO/3FeO Al_2O_3 3SiO_2, Mg -> pyrope; Fe -> alamandine
I then measured the infrared transmissions of peridot (a tumble-polished fragment) and garnet (a light purple/red rough pebble) to produce these transmission and absorbance spectra. Due to the nature of the specimens, the transmission measurement have a somewhat arbitrary scale due to refraction and scattering effects and so should be considered only representative of true absorbance measurements. The relative transmission scale of the peridot in the Vis and IR is not well-determined but that of the garnet is better.
The two plots here show the result of these and the previous iolite measurements for a sample ~.8mm deep. They show the transmission vs. wavelength (in nm) and the absorbance (=-Log_10(transmission) called optical density) vs. wavenumber (with the scale reversed to keep blue on the left). The peridot has a similar - but stronger - 1µm absorption (actually centred closer to 1.1µm) stretching from ~ 700-1600nm but with very low absorption at longer wavelengths. The garnet has the characteristic complex iron spectrum in the visible but very low transmission beyond 1100nm
The common feature of these three minerals is that they are all idiochromatic (self-coloured) due to iron as part of their basic structure. Most of the absorption features are due to ferric or ferrous iron. The peridot has the 1µm feature attributed to a ligand field transition in Fe2+ (Farrell and Newnham, 1965, The American Mineralogist, 50 1972; www.minsocam.org/ammin/AM50/AM50_1972.pdf ).
The high transmission of peridot (olivine) in the IR is thought to have a significant effect on heat transfer in the Earth's mantle by providing a channel for radiative transfer.
Note that the term 'pebble' in the legend of the lower plot refers to the garnet.
Infrared measurements of water absorption (1450nm, 1950nm and >2500nm) in the brownish edges and through the blue central regions of a sample of fluorite exhibiting disulphide fluorescence (see previous post). This suggests that the water resides principally in the discoloured regions near the edges of the crystals.
The actual pathlengths through the crystals were 33mm (brown) and 24mm (blue).
Summerpalace, Beijing Juli 2012
China
en.wikipedia.org/wiki/Summer_Palace
Canon 550D
Please do not reproduce or use this picture without my explicit permission.
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Please no glossy awards, scripted comments and big thumbnails back to your own work.
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Technology: NFO
Dark Blue / Blue
Top: Mesh + Sythentic leather
Top: Beathable Mesh
TPU injection support
Out Sole:
Magnetic Shock Absorption.
RB with good traction
TPU Support Plate
Shock Absorption and high Density Eva
Magnectic shock absortion function
Recommended price £81.99
Our price £77.89
Prices include 20% VAT
No.SSA400
The Adidas adiZero Feather Mens Tennis Shoe is part of the 2011 Adidas Spring collection which is presented by several top tennis players at the 2011 Australian Open. The shoe is alternatively available in the colour black: UK clients please choose SSA401, all other international clients please choose SSA401.
Upper
The upper part is made of a synthetic material mix with perforations for dry comfort. The upper EVA tongue provides additional comfort. Includes adiTUFF on the medial toe protects from abrasions during athletic movements.
Outsole
The non-marking outsole is featured with adiWEAR 6 with stability claws that offer the ultimate in high-wear durability.
Midsole
The midsole contains an adiPRENE heel insert for comfort and shock absorption and an adiPRENE + for forefoot propulsion and efficiency.
Adidas EXTENDED TORSION for midfoot and forefoot integrity and improved surface adaptation/stability.
Technology
adiWear 6: Extremely durable, non-marking rubber used for adidas sport shoe outsoles in high abrasion areas to avoid wear and tear.
adiPRENE: Highly shock absorbent material that cushions and protects the heel at impact.
adiPRENE+: Resilient cushioning used to protect the forefoot and provide a responsive, dynamic toe-off.
TORSION: Lightweight arch support that allows the forefoot and rearfoot to move independently for better surface adaptation and stability.
adiTUFF: An abrasion-material used in the toe and/or lateral forefoot area of a shoe's upper to protect the upper from excessive wear.
Surface
The tennis shoes pattern allows for ideal traction on multiple surfaces.
Colour
The official colour of the tennis shoe is white/green.
Maintanance
Take your tennis shoes out of your tennis bag to air dry.
This is a figure used in my M.Sc. thesis which provides the spectral characteristics of the cyanine dye, CY3, in emission and absorption (excitation) along with the filter set (dichroic mirror in the filter cube, excitation filter, & emission filter) used in fluorescence microscopy experiments using our in situ spectroelectrochemical cell. (Created in Inkscape)
Note: the original figure is a PNG file, and uses transparency; this does not convert very well in the small version displayed. Full size is 1400x1540. Click the "magnifying glass"... middle top icon to access it.
Creative Commons: Attribution-Noncommercial 2.5 Canada
creativecommons.org/licenses/by-nc/2.5/ca/
For attribution in academic or publishing contexts, you may cite my thesis:
Murphy, Jeffrey N. Electrochemical in situ investigation of thiolate DNA monolayers on gold with fluorescence imaging. M.Sc. Thesis, University of British Columbia, Vancouver, BC, 2008.
If you would like a SVG version of this, send me a message.