Congratulation to recent Nepelese PhD graduates

We would like to congratulate recent graduates in chemistry and related fields for completing their doctorate study successfully. New Nepalese PhD chemists are as follows.

1. Dr. Lekh Nath Sharma: Dr. Sharma completed his PhD from Baylor University, TX, USA. He is currently a post-doc researcher at University of Georgia.
2. Dr. Rumi Chand: Dr. Chand did her doctorate study at Saga University, Japan.
3. Dr. Hom Nath Luitel: Dr. Luitel did his doctorate study at Saga University, Japan.
4. Dr. Santosh Gurung: Dr. Gurung finished his PhD from KangWon National University, South Korea.
5. Dr.Dambar Hamal: From Kansas State University, KS, USA
6. Dr.Tej B. Shrestha: From Kansas State University, KS, USA
   

All the best for your future career.

Chemistry Jokes: Humor Chemistry-I

1. What did one atom tell another? 

   - I think I lost an electron 

   - Are you sure? 

   - Yes, I'm positive. 

2. Heisenberg is out for a drive when he's stopped by a traffic cop. 

The cop says: " Do you know how fast you were going? 

Heisenberg replies: "No, but I know where I am".

 

3. A neutron walks into a bar; he asks the bartender: 

" How much for a beer?" 

The bartender looks at him and says: "For you, it's no charge". 

4. What do dipoles say in passing?
       - Have you got a moment?" 

 

5. What weapon can you make from the elements potassium, nickel and iron?
    - A KNiFe.

 

6. How do chemists do it?
         Chemists do it reactively
         Chemists do it on the bench
         Electrochemists have more potential
         Polymer chemists do it in chains

Selected from here 

Molecule of the Week: Rhodamine B

Rhodamine B  
CAS Number:509-34-2


Formula: C₂₈H₃₀N₂O₃

Molecular Weight:	442.55

IUPAC: 3',6'-Bbis(diethylamino)spiro[isobenzofuran-1(3h),9'-[9h]xanthene]-3-one

I use this dye to check electroosmotic flow (EOF) in microfluidic channels. EOF has to be  suppressed in the channels for many microfluidic experiments. Because of the charge developed on the surface of microfluidics channels buffer solution also moves when a voltage is applied. It moves from positive to negative electrode in glass microfluidic channel. RdB helps to monitor the EOF in the channel. Dye is injected into the positive electrode reservoir. Because it is a neutral dye any dye detected in the negative electrode side is due to EOF.

Rhodamine B, a neutral dye, is often used as a tracer to determine the rate and direction of flow and transport. This is fluorescent dye. It can thus be detected easily and inexpensively with instruments called fluorometers. Rhodamine dyes are used extensively in biotechnology applications such as fluorescence microscopy, flow cytometry, fluorescence correlation spectroscopy and ELISA.

Rhodamine B is used in biology as a staining fluorescent dye, sometimes in combination with auramine O, as the auramine-rhodamine stain to demonstrate acid-fast organisms, notably Mycobacterium.

Rhodamine B is tunable around 610 nm when used as a laser dye . Its luminescence quantum yield is 0.65 in basic ethanol, 0.49 in ethanol , and 0.68 in 94% ethanol. 

The solubility in water is ~50 g/l. However, the solubility in acetic acid solution (30 vol.%)  is ~400 g/l. Chlorinated tap water decomposes rhodamine B. Rhodamine B solutions adsorb to plastics and should be kept in glass. 

Other uses: Rhodamine B is being tested for use as a biomarker in oral rabies vaccines for wildlife, such as raccoons, to identify animals that have eaten a vaccine bait. The rhodamine is incorporated into the animal's whiskers and teeth.

http://en.wikipedia.org/wiki/Rhodamine_B