extraction - Extract pixel values by points and convert to a table in Google Earth Engine

I am undertaking a project that is relating field measurements of fire severity to band values and spectral indices derived from Landsat imagery before and after the fire. I am currently using Google Earth Engine to extract surface reflectance values from a collection of Landsat images. The approach I am using imports my field site locations (point data) as a feature collection and uses the getRegion function to extract band values from a Landsat image collection at each point. The code is provided below://IMPORT SAMPLE POINTSvar pts = ee.F...Read more

Are there libraries to assist in AutoCAD structure extraction?

I need to query AutoCAD models to extract structures and connections (e.g., power, data) between them, for storage in a database. I know from experience and research that handling native AutoCAD .dwg is problematic due to the proprietary nature of the format. I see that AutoCAD features a .NET API, but still the problem looks daunting since I have essentially no knowledge a priori of the content of the models. The problem seems like a PhD thesis, as my initial googling hasn't yielded much in the way of tools support or examples. Are there tools...Read more

extraction - Extracting(Clipping) in Google Earth Engine

I am working with Google earth Engine and I am trying to extract/Filter (clip) pixels in a band using another image (band). I calculated NDVI and created a threshold value that rendered an image with NDVI > 0.3 but I wanted to extract the corresponding pixels in the visible an NIR bands.Here is snippet code.var s2 = ee.ImageCollection('COPERNICUS/S2');var s2_filtered = s2.filterDate('2017-01-01', '2017-12-31') .filterBounds(geometry) //custom Geometryvar calcNDVI = function(x){ var ndvi4 = x.normalizedDifference(["B5", "B4"])...Read more

Microsoft research on fact extraction from the web?

Some time ago I had accidentally found website which was apparently product of Microsoft research on fact extraction from the web, more specifically from the Wikipedia. Right now I would like to have better look into how it works, but the problem is i can't find it, maybe somebody knows what I am talking about and could give me directions or link to it?Thank you!...Read more

extraction - Are glycosides more soluble in dichloromethane than in water?

I'm designing an experiment to extract the amygdalin from apricot leaves and kernels. I want to steam the kernels and leaves, grind them, add water and then filter it using a filter paper. Then transfer the solution to a separatory funnel, add dichloromethane (DCM), shake and collect the bottom DCM layer that I'm hoping would contain the amygdalin.This is the process I used for extracting caffeine from coffee beans and it worked because caffeine is much more soluble in DCM than in water. However, I'm not sure about the solubility of glycosides ...Read more

extraction - Rule of Thumb for separatory funnel volumes

Is there a general rule of thumb in terms of how one chooses the volume of separatory funnel used for an extraction? It's my understanding that it is the amount of product that determines this as opposed to the volume of the solvent it is present in. If that is correct I was wondering if someone could post what the general ranges in grams of product would be appropriate for the following sep funnel sizes:250 mL, 500 mL, 1 L...Read more

lindane extraction from aqueous solution using hexane

I am studying the degradation of lindane using iron nanoparticles. I have prepared lindane solution with an acetone and water mixture (1:9 v/v). I tried to extract lindane after reaction with nanoparticles using hexane as a solvent. a viscous third layer has formed between the two layers. I have no idea why this happened. Can anyone please explain why this has happened?...Read more

Extraction of calcium carbonate from liquid

I'm using calcium carbonate ($\ce{CaCO3}$) in apple juice to reduce the acidity of the juice. Once the $\ce{CaCO3}$ reacts with the apple juice and raises the pH, the juice is left cloudy in color BUT has the desired pH of 3.4. I need a way to extract (separate) the $\ce{CaCO3}$ precipitate from the apple juice which leaves the resulting liquid (apple juice) drinkable still... The pure juice has an initial pH of 2.9. I want to reduce the acidity and be left with pH of say 3.4. Perhaps by blending with another drink? I did a test using the pH...Read more

How does one separate ethanol from acetic acid using aqueous extraction?

Would you add in $\ce{NaOH}$, deprotonating the acid, and then wash the mixture in water, thereby removing the $\ce{Na^+}$ and $\ce{CH3O^-}$ ions in an aqueous layer? But then wouldn't the ethanol be dissolved in the water as well, as it is polar? In general, how do you separate two polar substances from each other using extraction?If you don't use extraction, how else would you separate the two, aside from distillation?All answers are appreciated....Read more

Skipping the defatting stage in extraction of alkaloids

I am attempting to extract certain alkaloids from green plant matter, which is very high in waxes and fats.I understand that in this scenario it is common to first acidify and then use a non-polar solvent to de-fat the solution.I am curious though: say I were to basicify and extract alkaloids without any de-fatting. If I were then to add HCl solution to the non-polar solvent which now contains the alkaloids, wouldn't this in theory be equivalent to the de-fatting stage? Wouldn't the alkaloids would now be in the aqueous layer, and the lipids wo...Read more

extraction - Extracting herbs with grape juice

I tried searching my question on google and did not find anything. I am looking to extract herbs with pure 100%grape juice http://www.lakewoodjuices.com/product_detail/id-32/ ( it is pasteurized ) instead of using the old school method of extracting with a 50% alcohol solution.My theory as of now would be that it would be more beneficial and itwould ferment or extract the same plus the extra beneficial minerals of the juice. I am wonder what your opinion onthis is. Do you think it would extract the same and be just as beneficial as a tincture? ...Read more