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types of commercial grade stainless steel

Type 304 : Aside from having a higher content of chromium than most other types of stainless steel, type 304 also contains nickel; this enables it to withstand most ordinary corrosion in architecture, is durable in typical food processing environments, and resists most chemicals. Type 316 : Similar to type 304, but also contains a small amount of molybdenum, which is an alloy element #304 does not contain (but one that provides even stronger resistance to some deterioration). Types 304 and 316 are grades of stainless steel that are most often used in plumbing , as well as in the manufacturing of kitchen utensils and sinks . Type 409 : Does not contain virtually any nickel at all, but also is the stainless steel that contains the least amount of chromium. Type 409 is more suitable for high temperature applications, which is why it's often used in automotive trim and exhaust systems , or hot water tanks . Type 410 : Also does not contain any significant nickel; its primary difference

Messier M11 wild duck cluster

Messier M44 beehive cluster

30 Dec 2017 near Virgo and Corvus

ISO800 60 secs x 25 subs 135mm APS-C seems can be improved by: longer exposure better polar alignment new location, new challenge

Howard Marks - The oaktree investment philosophy

Negative art  37:57 The Most Important Thing - Origins and Inspirations Negative art (37:57) Taleb says the future consists of a range of possibilites with the outcome significantly influenced by randomness Galbraith says forcasting is futile Ellis says if the game isn't controllable, it's a better to work to avoid losers than to try for winners Oaktree's Investment Philosophy (38:13) The primacy of risk control Emphasis on consistency The importance of market inefficiency The benefits of specialization Macro-forecasting not critical to investing Three Adages: What the wise does in the beginning, the fool does in the end     ( the innovator, the imitator, the idiot) Never forget the six-foot-tall man who drowned crossing the stream that       was five feet deep on average Being too far ahead of your time is indistinguishable from being wrong race at the bottom(1:06:57): There's a race to the bottom going on, reflecting a

Boosting Near infrared sensitivity using pyramid surfaces

From Sony: OCL: On Chip Lens PSD: Pyramid Shaped Diffractor (lightguide) DTI: Deep Trench Isolation Near-infrared Sensitivity Enhancement of a Back-illuminated Complementary Metal Oxide Semiconductor Image Sensor with a Pyramid Surface for Diffraction Structure, I. Oshiyama, S. Yokogawa, H. Ikeda, Y. Ebiko, T. Hirano, S. Saito, T. Oinoue, Y. Hagimoto, H. Iwamoto, Sony Semiconductor Boosting Near-Infrared Sensitivity in CMOS Imagers: Backside-illuminated CMOS image sensors are ubiquitous in camera phones, and there is a growing demand for them to be able to handle near-infrared (NIR) light frequencies so that they can be used in iris scanning, facial recognition and motion-sensing applications. However, the NIR-sensitivity of silicon CMOS image sensors has been inadequate. The simplest way to enhance it would be to make the photo-absorption layer thicker, but that would require substantial capital investment in manufacturing equipment like high-energy ion implanters to be ab

24 Dec 2017 M42

ISO800 20 secs x 25 subs Canon 760D 135mm f/5.6 Post processing DSS stacked with darks and bias frames fitworks flatten and smaller stars MS photo crop and enhance

debayering - removing the CFA (color filter array)

 work flow after the camera was disasembled and  the CMOS sensor module taken out: 1 remove front cover glass 2 protect the thin wires and two sides with epoxy resin 3 scratch away the microlens layer and CFA layer From stargazerslounge and petapixel don’t remove the color filter layer to the four edges of the frame, since there are important little wires on top and bottom, and invisible circuity on left and right side

atik 414EXC vs ASI1600MC

using M82 for comparison, here is the picture from ATIK414 EXC ( CCD) colour and ASI 1600MC(CMOS) both are cropped and re-sized to make them to same pixel sizes as close as possible ATIK414EXC: ASI1600MC: If at 100 % magnification, ATIK414EXC is definitely better. By getting the statistics using AstroImageJ, histogram on ASI1600MC shows truncation on values, not sure if it is due to stacking.  ATIK414EXC: ASI1600MC If the scale is reduced, then they are closer in image quality this is histogram of ASI1600MC after reducing the picture size: Noise level on background: ATIK414EXC is better Dynamic range: ASI1600MC is better The galaxy is more prominent on ASI1600MC,and thus higher contrast to the eye. But the stars on ATIK414EXC looks more natural in brightness. Might be ASI1600MC's stacking is bit overdone So ATIK414EXC, though a CCD at a much lower resolution ( 1384 x 1032) , but based on ExView HAD, is still very competent overall, if you can

my first fpga

by following the online tutorial from Altera, My first FPGA Design tutorial,  I added some adjustments to my Mars-EDA-s board The Quartus II that I am using is version 11.0 P11  Project Wizard:  p19, adding symbol 13. from icons bar, click "logic gate" symbol 14. in Symbol window, click Project directory to expand it 15. select newly created simple_counter by clicking it's icon  P22, speed setting As the FPGA in use is EP1C3T144C 8 N, using below part number description as an example, speed grade is 8 the crystal oscillator on board is 40 MHz  p24 p27: clock division cycle : 2 >> actual settings 20MHz p41, before doing "start Analysis & Elaboration", make sure the settings is as below From menu bar, Assignments >> Settings >> Top-level entity: my_first_fpga_top Analysis & Elaboration ok: now you can proceed to Pins Planner The Node Name <> locations are as follows

CMOS sensor trends and astrophotography, from amateur astronomers perspective

Nowadays, even in low light conditions, digital camera can quality pictures with higher ISO, noise and hot pixels have been gradually reduced. Sony has introduced back illumination process for consumer market. Sony BSI sensors evolved  from Exmor to now Exmor RS( stacked) technology. This stacked technology allows further chip size reduction, which has strong demands in smartphone camera market. Digital astrophotography is also benefited from such advances, utilising Back Side Illumination technology Exmor: Within the CMOS sensor, it outputs low-noise digital signals by "on-chip column AD conversion" and "dual noise reduction" to suppress noise in the first half of the process In low light conditions, when a wide aperture is desirable to collect as much light as possible. At apertures wider than f/2.0, back-illuminated Exmor R sensors are significantly more efficient at collecting light than conventional, front-illuminated sensor