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Questions related from Hamed Khodadadi T.
Carbonate deposits resulting from a microbial process in a solution containing required nutrients for bacterial growth, 0.1M CaCl2, 0.78M urea and 50% seawater (composed of 0.055M Mg2+, no Sr)...
05 May 2015 1,118 9 View
I am looking for someone, who is expert and interested in investigation of caco3 polymorphs formation through microbial activity, for cooperation in writing a research paper (as an co-author). I...
03 March 2015 7,911 3 View
I have the XRD patterns of two samples which mainly contains calcite and aragonite (S1 and S2, see the attachments). How can I just roughly say that S2 has more amount of aragonite than S1?
02 February 2015 1,463 12 View
It is known that the urea will be degraded to NH4+ and CO2 within a hydrolysis process. In higher concentration of urea, [NH4+] increases till the point at which the solution is supersaturated...
02 February 2015 2,830 3 View
I recorded the concentrations of a product during a reaction. There was an enzyme producing bacteria as catalyzer. Then I plotted the concentration changes versus time and fitted a modified...
01 January 2015 9,149 9 View
I analyzed a sample contained calcite using XRD. The pattern attached. It was identified as nitratine by the related software searching the database of XRD patterns. As nitratine is isostructural...
01 January 2015 5,580 10 View
How much a model with: - Model p-value < 0.05 - Lack of fit p-value > 0.1 - R2=0.99, Adj. R2= 0.99, Pred. R2=0.99 - normal probability plot attached (residuals do not follow a straight...
10 October 2014 5,257 2 View
I did a two-level full factorial design in order to find the significance of three factors (A, B, C) and their interactions on a response (R). Due to interaction between minimum level of A and...
09 September 2014 7,403 5 View
I did the following full factorial experiments to find the significance of variables and fit model. I analyzed the data using the standard least squares model and generalized linear model (normal...
09 September 2014 2,654 6 View
I did a 2-level full factorial design with 3 factors in order to find the significance of each factor and their interactions on a response. After ANOVA on non-transformed response, I found no...
09 September 2014 398 11 View
I am going to define an inverse polynomial (quadratic) model in "Fit Model" platform in JMP. How can I do it? I am using 30-days trial version of JMP.
09 September 2014 603 2 View
For instance, there is no growth when the initial concentration of bacteria in a medium with high ionic strength is adjusted to 10^6 cell/ml, but the growth happens when it is adjusted to 10^8 in...
06 June 2014 2,316 9 View
We obtained a powder through a precipitation process in solution. The powder is expected to be mainly CaCO3 (and sometimes CaCO3 and gypsum). XRD, XRF, FTIR, and EDS ( on the SEM) are...
06 June 2014 8,760 7 View
Is it just for making nutrients easily available for the bacteria? If so, does it mean that there is no need to shake if it is assumed that the bacteria never settle on the flask bottom and each...
04 April 2014 9,998 29 View
I have results of the experiments designed as you can see below (or in the attached file). What is your suggestion for analysis of such designed experiments? Actually my problem is with center...
02 February 2014 1,592 2 View
I want to do 2^4 (+ 3 center points) experiments in order to find the effect of 4 factors on a goal at two levels. One of the factors is temperature. If i want to run the experiments randomly it...
01 January 2014 4,336 6 View
We have two solutions with known volume and pH. We want to mix them together and then adjust its pH to a specific value using 1M HCl which also has a known pH. Without any trial we want to exactly...
12 December 2013 1,667 5 View
In order to enrich soil ureolytic bacteria, I poured 1g soil into a solution containing Yeast Extract, urea and some other salts. Then I added 1mL (10^7 cell) of the prepared bacteria solution...
12 December 2013 6,376 7 View
I know that urea will be decomposed to NH3 and CO2 when it is heated (NH2COONH4(s) 2NH3(g) + CO2(g)). But if we add urea to the solution containing enough concentration of NH3 (e.g. solution with...
12 December 2013 4,961 7 View
Assume that we have 8 factors and want to design experiments using 2-level fractional factorial design. At the same resolution for 1/8 fraction and 1/16 fraction, we can run partly a same number...
11 November 2013 7,927 8 View
I read the solubility of CaCl2 is about 75% but when I prepared 2M solution it contains some suspended particles and is not clear. It seems it is not that much soluble. What is the problem you think?
11 November 2013 8,563 5 View
We were using Ammonium Chloride (Molecular Biology Grade; Merck brand, Product No.168320) and Sodium Hydrogen Carbonate (EMPROVE® bio Ph Eur, BP, JP, USP Sodium hydrogen carbonate suitable for the...
11 November 2013 4,417 3 View
I am going to design some experiments with one response and 4 factors to find response surface. I can not do three level full factorial design due to some shortages. Just around 27 experiments are...
10 October 2013 1,660 6 View
I am using JMP in order to find a relation between response (Y) and factors (B, CU, T, pH), with the following details: Y (Product of a biochemical reaction): I don't want neither...
10 October 2013 7,279 8 View
In the brochure of the "Standard I Nutrient Broth" has been mentioned that it is for cultivation of fastidious bacteria. Does it mean that it can not be used for non-fastidious or less fastidious...
10 October 2013 4,763 2 View
Assume that we have baterial solution with concentration of 10^6 cell/ml. If we centrifuge 2ml of the solution, pour off the supernatant and replace the old solution with the new one, do we still...
10 October 2013 9,002 4 View
If there is filter or other set, please let me know the specification and how we can find it.
10 October 2013 8,559 0 View
Nutrient Agar.......................10g Urea.........................5g 1M tris buffer solution................1L (All the material should be sterilized separately and then mixed...
10 October 2013 7,229 10 View
If not, how can it be sterilized?
10 October 2013 7,348 2 View
Today when I was trying to measure OD of a bacterial solution I obtained very strange readings. The OD was always same for every diluted solution and even for the same solution as control...
10 October 2013 8,364 6 View
As I found we should have a transmitter piezo sensor connected with signal generator (waveform producer) and a receiver piezo sensor connected with oscilloscope. Is it true? If so, where can i buy...
10 October 2013 520 5 View
I need to add a dye in a bacterial solution to monitor a solid precipitation due to bacterial activity.
09 September 2013 2,132 2 View
Yielding of a chemical product (Y) is a function of concentration of 3 ingredients (X1, X2, X3), temperature (T), and pH. I want to find a fitting model which relates Y with all the factors (X1,...
09 September 2013 5,000 7 View
I prepared culture media in Na2CO3-NaHCO3 buffer solution in order to adjust the pH of the media to 9. But after 36hrs, there was not any growth in the petries. So I measured the pH of media and I...
09 September 2013 1,939 9 View
I found bacterial concentration of a culture solution with serial dilution method (e.g. 10^7 cell/ml). Now, I want to transfer a given amount of the solution (e.g. 1ml) to the same but fresh...
09 September 2013 9,856 3 View
I am preparing a culture media containing nutrient agar, ammonium sulfate and 0.13M tris buffer pH9 solution, for a ureas active bacteria where its optimum growth pH is 9. I read in a paper in...
09 September 2013 9,855 4 View
I am going to establish a small home biology laboratory for isolation and culture of bacteria (usually soil bacteria). I don't want to pay that much to buy biological safety cabinet (hood), so how...
06 June 2013 591 10 View
Actually I wanted to know that whether UV degrades or changes the nutrient agar?
06 June 2013 6,110 18 View
In order to be sure about contamination on my work desk, I prepared Nutrient Agar plates on the desk and then put some of them in incubator at 37C for 48hrs. There were not any contamination when...
06 June 2013 8,539 14 View
Actually I am looking for a biological technique by which nano-meshes with adjustable hole size can be produced.
04 April 2013 6,868 1 View
I am investigating the effect of different culture media (with different amounts of ingredients) on the urease activity of the S.pasteurii. In order to prevent the effect of the initial...
03 March 2013 3,166 21 View
Ultramicrobacteria are certain species of bacteria that when starved shrink to approximately one-hundredth their normal size as a survival mechanism.
03 March 2013 7,872 2 View
In order to investigate the effect of various growth media on urease activity of S.pasteurii, I want to culture the bacteria in 64 different liquid media. Then I should add a given amount of each...
02 February 2013 5,698 2 View
The minimum temperature we can prepare in our lab is -20°C.
02 February 2013 1,792 6 View
I want to draw a growth curve for an urease active bacteria cultivated in a urea contained medium, but the color of culture solution changes by decomposition of urea due to bacterial activity. How...
02 February 2013 9,789 10 View
For instance, assume that the cell concentration of S.pasteurii cultivated in an Ammonium YE medium is estimated by the expression 8.59* 10^7(Z^1.363) where Z is the reading at OD600. Now, if I...
02 February 2013 3,209 90 View
