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  • Josef Chmelar added an answer in Vapor Pressure:
    How would you measure an adsorption isotherm of a VOC (e.g. benzene) on an adsorbent (e.g. MOF or zeolite)?

    How may i measure an adsorption isotherm of VOCs on adsorbents.

    The principle is clear for gases like N2. This may be done by a device from quantachrome or micromeritics. But this may not be applicable for analytes (e.g. VOCs) that have a vapor pressure of way below 1 atm at room temperature.

    I was thinking of placing the adsorbent in a headspace vial together with a certain atmosphere of analyte (e.g. 30 ppm of benzene in nitrogen). After some time one could determine the gasphase concentration of benzene via headspace-GCMS?

    Of course this measurement describes only one point of the isotherm. This is a time-consuming one ;)

    Any better ideas out there?

    Maybe from packed-bed chromatography? I was recording breakthrough curves recently...



    i found this one. similar to aboves ideas...

    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: Single and ternary solute gas phase adsorption isotherms were conducted in this study to evaluate the effectiveness of a simple constant volume method, which was utilized by using Tedlar gas sampling bags as a constant volume batch reactor. For this purpose, gas phase adsorption of toluene, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK) on two types of activated carbons, BPL-bituminous base and OVC--coconut base, were investigated. For the single solute adsorption, the experimental adsorption data were found to be well correlated with Freundlich and Myers adsorption equations. The pore size distribution of adsorbents was found to affect their adsorption capacities; its effect was dependant on the solute concentration. The ternary adsorption experimental isotherms were accurately predicted by using the well-known model, i.e., ideal adsorbed solution theory (IAST).
      Chemosphere 09/2006; 64(8):1362-8. DOI:10.1016/j.chemosphere.2005.12.044
    Josef Chmelar


    To the last comment. In the case of gravimetric methods, there is usually a pressure sensor directly inside the measuring cell, which provides the real pressure values. If pure substances are to be measured, which I think is the case here based on the original question, then this solution is sufficient, 



  • P.E. Saranya added an answer in Cyclic Voltammetry:
    How can I coat the working electrode sample on the Nickel substrate for taking electrochemical studies?

    How can I coat the working electrode sample on the nickel substrate for taking electrochemical studies?

    P.E. Saranya

    The substrate is nickel foil. I want to coat the nanoparticles which I have synthesised. By which method I can coat the sample on the substrate? In most of the articles, I have seen that 0.8 mg prepared sample, 0.1 mg pvdf and 0.1 mg activated carbon. By making these three as slurry using NMP they have coated. My doubt is that small quantity how can be coated equally on the substrate. 

  • Ujjwal Kumar added an answer in Abaqus:
    How could I visualize the POR output data in ABAQUS?

    Nice Greeting, 

       I am a new ABAQUS user, could you please assist me to figure out how could visualize the out put data in acrostic media (POR) ?

    Thanks in advance 


    Ujjwal Kumar


    This 'preselect' option will show you POR in abaqus ODB viewer. 

  • Doohyung Lee added an answer in 4T1 Tumor Model:
    How many cells of 4T1 is needes to develop subcutaneous tumor in Balb C mice?

    I want to develop 4T1 tumor model .  How many cell s are needed to develop subcutaneuos  tumor in Balb c mice ?

    Should I can use male balb c mice in place of female?

    If anyone have any clue about this , please guide me ASAP

    Doohyung Lee

    It might be OK to inject with at least 1X10^5 cells/site. 

  • Rafik Karaman added an answer in Specific Heat:
    How to calculate specific heat of a broth ?

    Looking for BHI broth

    Rafik Karaman

    Dear Shyam,

    Please read the following text:

    Intended Use
    Brain-Heart Infusion Broth is used for the cultivation of a wide variety of fastidious organisms.
    Product Summary and Explanation
    prepared a rich medium for culturing streptococci by combining dextrose broth and brain tissue.
    Hayden2 modified the original formula while working with dental pathogens. The current formula is a
    modification of Rosenow1
    and Hayden2
    , using dehydrated infusions of porcine brain and heart tissue.
    Brain-Heart Infusion Broth can be supplemented with antibiotics, varying amounts of sodium chloride, yeast
    extract, and serum to provide a rich medium for bacteria, yeasts and pathogenic fungi.3 The addition of 0.1%
    agar can be used to lower oxygen tension, providing an atmosphere to support the growth of aerobic,
    microaerophilic, and obligate anaerobic microorganisms.
    Brain-Heart Infusion Broth, abbreviated as BHI, is specified in many references for food and water testing.4-7
    NCCLS, National Committee for Clinical Laboratory Standards, cites Brain-Heart Infusion Broth for preparing
    the inoculum used in antimicrobial susceptibility tests.8
    Principles of the Procedure
    The nitrogen, vitamin, and carbon sources are provided by Brain-Heart Infusion and Enzymatic Digest of
    Gelatin in BHI Broth. Dextrose is the carbohydrate source, and Sodium Chloride maintains the osmotic
    environment. Disodium Phosphate is the buffering agent in this medium.
    Formula / Liter
    Brain Heart Infusion ............................................................. 17.5 g
    Enzymatic Digest of Gelatin.................................................... 10 g
    Dextrose.................................................................................... 2 g
    Sodium Chloride ....................................................................... 5 g
    Disodium Phosphate.............................................................. 2.5 g
    Final pH: 7.4 ± 0.2 at 25°C
    Formula may be adjusted and/or supplemented as required to meet performance specifications.
    1. For Laboratory Use.
    2. IRRITANT. Irritating to eyes, respiratory system, and skin.
    1. Dissolve 37 g of the medium in one liter of purified water.
    2. Heat with frequent agitation to completely dissolve the medium.
    3. Autoclave at 121°C for 15 minutes.
    Quality Control Specifications
    Dehydrated Appearance: Powder is homogeneous, free flowing, and light beige.
    Prepared Appearance: Prepared broth is brilliant to clear, with none to light precipitate, and light to medium
    amber in color.
    PI 7116, Rev 03, Nov. 2010
    Expected Cultural Response: Cultural response in Brain-Heart Infusion Broth incubated at 35 ± 2°C under
    aerobic atmosphere and temperature and examined for growth at 1 – 3 days.
    Microorganism Approx. Inoculum
    Expected Results
    Escherichia coli ATCC® 25922 10 - 300 Good to excellent
    Staphylococcus aureus ATCC® 25923 10 - 300 Good to excellent
    The organisms listed are the minimum that should be used for quality control testing.
    Test Procedure
    Refer to appropriate references for specific procedures using Brain-Heart Infusion Broth.
    Refer to appropriate references for test results.
    Store sealed bottle containing the dehydrated medium at 2 - 30°C. Once opened and recapped, place
    container in a low humidity environment at the same storage temperature. Protect from moisture and light by
    keeping container tightly closed.
    Refer to expiration date stamped on the container. The dehydrated medium should be discarded if not free
    flowing, or if the appearance has changed from the original color. Expiry applies to medium in its intact
    container when stored as directed.
    Limitation of the Procedure
    Due to nutritional variation, some strains may be encountered that grow poorly or fail to grow on this medium.
    Brain-Heart Infusion Broth Code No. 7116A 500 g
    7116B 2 kg
    7116C 10 kg
    1. Rosenow, E. C. 1919. Studies on elective localization. J. Dent. Research 1:205-249.
    2. Hayden, R. L. 1923. Elective localization in the eye of bacteria from infected teeth. Arch. Int. Med. 32:828-849.
    3. Atlas, R. M. 1993. Handbook of microbiological media, p. 147-153, CRC Press, Boca Raton, FL.
    4. Cunnif, P. (ed.). 1995. Official Methods of Analysis AOAC International, 16th ed. AOAC International, Gaithersburg, MD.
    5. U.S. Food and Drug Administration. Bacteriological analytical manual, 8th ed., AOAC International, Gaithersburg, MD.
    6. Vanderzant, C., and D. F. Splittstoesser (eds.). 1992. Compendium of methods for the microbiological examination of food., 3rd
    ed. American Public Health Association, Washington, D.C.
    7. Greenberg, A. E., L. S. Clesceri, and A.D. Eaton (eds.). 1995. Standard methods for the examination of water and wastewater,
    19th ed. American Public Health Association, Washington, D.C.
    8. National Committee for Clinical Laboratory Standards. 1994. M11-A3, Vol. 13, No. 26, Methods for antimicrobial susceptibility
    testing of anaerobic bacteria. National Committee for Clinical Laboratory Standards, Villanova, PA.
    Technical Information
    Contact Acumedia Manufacturers, Inc. for Technical Service or questions involving dehydrated culture media preparation or
    performance at (517)372-9200 or fax us at (517)372-2006.


    Hoping this will be helpful,


  • Shivani Dhall added an answer in Pt Nanoparticles:
    Can anyone tell me why attachment of Pt nanoparticles on TiO2 shows metallic behavior when record temperature dependent electrical characteristics?

    In case of TiO2, behavior is semiconducting, but in case of TiO2/Pt, it become metallic.  

    Shivani Dhall

    In my case, the size and concentration of Ant. TiO2 is very large as compared to the Pt metal NPs. 

  • Thanusha Av Ajay asked a question in Gelatin:
    How to remove water bubbles or foam before casting in to petridish, if it is viscous?

    I prepared a hydrogel which is composed of gelatin and due to nitrogen purging, it is forming full bubbled and uneven gel is forming..

    how to reduce this?

  • Sushrisangita Sahoo added an answer in Dielectrics:
    What is single relaxation time in Debye model of dielectric and its role in dielectric studies?

    Dielectric studies in solids ( basically in polymers) related to Relaxation time i.e single relaxation time in Debye theory and distribution of relaxation time in cole cole theory....

    Sushrisangita Sahoo

    Single relaxation time means there is a single relaxation process associated with the dielectric study. distribution of relaxation time means multiple relaxation mechanism are involved in the dielectric relaxation. It can be described briefly from the frequency dependent loss tangent , imaginary part of the impedance and from the Nyquist plot. 

  • Muhammad Khattab added an answer in OriginLab:
    How can I plot a 3D graph using originlab or any other software?

    I need to plot excitation (x-axis), emission (y-axis) and Intensity (z-axis). I am confused because for every excitation wavelength, there is a certain intensity and the same for emission. Which means i have 4 columns not 3 to draw. Please explain in a simple way what i should do.


    Muhammad Khattab

    Thanks, Harish! 

    unfortunately, i don't use matlab and i have very weak mathematics background. that's why i think originlab is easier solution for me. 

  • Ujjwal Kumar asked a question in Abaqus:
    Material force: please suggest post processing steps (In abaqus) for calculating material force as durability indicating parameter?

    I am working on steel wire reinforced rubber.

  • Thanusha Av Ajay asked a question in Cultural Studies:
    Which stem cells are best to do cell culture studies on wound healing?

    I need to know whether co-culture is the best way or only one cell culture on the prepared scaffolds is a way to do for wound healing?

  • Seema Trivedi added an answer in Heat Maps:
    Can anyone refer me to a good heat map program for epitopes?

    The data sheet produced affinities of 4800 consecutive segments of 15 amino acids, each overlapping by one single amino acid progressing downstream to cover the entire length of the 188 AA mucin-like domain of the Ebola Glycoprotein.

  • Sudiksha Sridhar added an answer in Microbubbles:
    What are the two microbubbles behavior compared to one microbubble?

    When the bubbles in one and two interaction. what will happen to the bubbles behaviour. Then in two microbuubles, what will happen.

    Sudiksha Sridhar

    When there is a system that has more than one bubble , there is possibility of mass transfer between the bubbles.The transfer of gas can be considered a two step process.Firstly from the bubble to the surrounding and then to another bubble according to the direction of the concentration gradient. Population balance equation would be needed to define how populations of separate microbubbles would develop in specific properties over time.

    For details refer the paper :

    http://www.sciencedirect.com/ science/article/pii/ S0927775715303046  

  • Cedric D Cheong asked a question in Essential Oils:
    Anyone done any research or trials on the cleaning efficacy of essential oils on surfaces?

    Am looking at the efficacy of oils such as thieves, cloves, tea tree etc on bacteria and fungi.

  • Sita Sharan Patel added an answer in Dietary Carbohydrates:
    What is the evidence that insulin resistance in type 2 diabetes and in metabolic syndrome is NOT caused by hyperinsulinemia?

    When I was a medical student at McGill in the late 1970s, we learned a straightforward explanation for the cause of Type 2 diabetes, the most common form of diabetes in adults, accounting for about 90 per cent of all diabetes cases. We were told the insulin resistance responsible for Type 2 diabetes was caused by high levels of insulin. Hyperinsulinemia–increased insulin levels in the blood–was said to “downregulate” insulin receptors, making cells with those receptors less responsive to the insulin message. From a physiology point of view, this makes perfect sense. It’s analogous to the development of tolerance that can happen with regular heroin use when a person no longer responds to the drug in the way they did initially.

    Sometime in the 1980s this explanation for the cause of insulin resistance was abandoned. Instead, the medical community adopted a new theory that insulin resistance comes first, and is behind high insulin levels in Type 2 diabetes. To overcome insulin resistance, the pancreas secretes larger-than-normal amounts of insulin, resulting in so-called “reactive hyperinsulinemia.” The cause of this insulin resistance is never clearly explained, although obesity, chronic inflammation, and genes are all said to contribute.

    When I ask prominent endocrinologists about how insulin resistance comes about in this new paradigm, they say, sometimes condescendingly: “It’s too complicated for a psychiatrist to understand.” That may be. But I’m also an engineer, and when I studied at the University of Waterloo the saying was “BBB”, short for “Bulls**t Baffles Brains.” I consider myself to be a critical thinker, so if the new explanation for what causes insulin resistance is incomprehensible to me, that’s probably because it’s nonsense.

    Why did the medical community make a 180-degree reversal of its theory for the cause of Type 2 diabetes? Why discard a nice, coherent, easy-to-test explanation and replace it with a theory no one seems able to describe in terms that an engineer and physician can understand? Time to apply another useful saying: “Follow the money.”

    Who profits from this paradigm shift? To answer this question, let’s compare the consequences of diabetes management approaches under the old paradigm and the new one. If we follow the old theory that high insulin levels cause insulin resistance, then treatment involves lowering insulin levels, assuming that insulin resistance is reversible. Since the main stimulus to insulin secretion is the level of glucose in the blood, we can get the pancreas to release less insulin by decreasing the amount of glucose going into the bloodstream. For people who eat regularly, that main source of blood glucose is carbohydrates in the diet, i.e., sugars and starches.

    Treatment options for lowering blood glucose include medications such as acarbose, which reduces the absorption of dietary carbohydrates in the small bowel. Metformin, the first-line treatment of choice for Type 2 diabetes, is believed to have a similar effect and may also contribute to weight loss. Traditional and folk remedies for obesity and Type 2 diabetes, including yerba maté tea and the gourd bitter melon, may act in the same way. An easier route for some would be to lower the amount of carbohydrates in the diet, and/or pick foods with a low glycemic index. Research demonstrates a low-carb diet can reduce or even eliminate the need for medication to control blood sugar, in effect, curing diabetes in some patients, and, more importantly,  showing that Type 2 diabetes is likely caused by diet for people with susceptible genes.

    If we follow the new paradigm and believe obesity, inflammation and genes cause insulin resistance, what can we do? Lose weight? Many find this impossible. Reduce inflammation? Difficult if we don’t know its cause. Change our genes? Maybe in the future. Typically the victim is blamed for overeating and not exercising enough. In the absence of effective ways to reduce insulin resistance in this paradigm, the usual solution is medication to control blood sugar levels.

    Some commonly prescribed anti-diabetic medications stimulate the pancreas to produce more insulin, while others act at the level of the insulin receptor to decrease insulin resistance. And of course, insulin itself, typically given in amounts way larger than what the pancreas secretes in normal individuals, can help people overcome insulin resistance. Yes, blood sugar levels will decrease. But there are side effects: insulin itself, and many of the medications that increase insulin or increase its effectiveness, may cause weight gain. And if obesity is a cause of insulin resistance, there is no way these treatments can stop a patient’s diabetes. Instead, for many victims, the diabetes just gets worse.

    So let’s follow the money. If today’s treatment approaches don’t cure diabetes and may even make it worse, who benefits? Drug companies, who gain customers for life due to diabetes and its many complications, including vascular disease, dementia, kidney and eye problems, even cancer. Medical device manufacturers profit when diabetic patients need cardiac pacemakers, artificial valves, and prosthetic limbs. Kidney failure requires expensive machines, products and dialysis facilities. Many professions, including physicians, pharmacists, dietitians, physiotherapists, social workers, occupational therapists, and others are called upon to provide care and diabetics need hospitals, clinics, blood test labs, MRI machines, offices, exercise machines, and more. Simply put, the new paradigm is good for the economy. It’s too bad that patients must suffer.

    If the theory that high insulin levels cause insulin resistance has no scientific basis, where is the research disproving this hypothesis? And why aren’t the current treatment approaches truly helping Type 2 diabetics fight a disease that has huge health consequences? I don’t mind being wrong. Show me the evidence!

    Sita Sharan Patel

    More insulin: some pills stimulate the pancreas to produce more insulin i.e. glyburide, glipizide, glimepiride, tolazamide, chlorpropamide and tolbutamide. These insulin secretagogues stimulate pancreas to produce more insulin. 

  • Helen Kas added an answer in Nanomaterials Characterization:
    How can we avoid agglomeration of nanomaterials?

    How to avoid agglomeration of nano materials especially for powder samples.If we having samples more days after synthesis that also reason for this,how to overcome it

    Any alternative for this problem and what is the various reason for this agglomeration,Actually my materials are ceramic powders

    Helen Kas

    Which i attached are with PEG only but same agglomeration occurred. And please give some of capping agents that we can use with hydroxyapatite

  • Oscar De Jesús May Tzuc asked a question in Solar Tracking System:
    Hello, can anybody help me give me information about gearbox and motors for solar tracking systems?

    I´m realinzing a proyect for the construction of parabolic trough collector system and I nedd the kind of motors and gearbox to implement the tracking system. I would be greatful if anybody could give information about providers or campanies where I can purchase it. 

  • Mohd Yusof Mohamad asked a question in PicoGreen:
    How to troubleshoot fluorescence standard curve result for picogreen assay?

    I have problem with picogreen assay since my blank has a high value and my standards showed slight increment but poor R-squared value

    How to troubleshoot? 

    Is it due to the contamination of TE buffer?

    Is it problem with the picogreen solution (since it is more than 1 year stored in -20 celcius and repeated thaw)?

    Is it due to the 520nm of emission instead of 528? 

    Please do help


  • Abir Shib asked a question in Classification:
    Components of zoological classification?

    please tell me  what are the components of zoological classification

  • H S Guruprasad added an answer in Internet of Things:
    Can anyone suggest me a journal paper for security related to internet of things ?

    can anyone suggest me a journal paper for security related to internet of things

    H S Guruprasad

    Dear Mr. Palani,

                      Please find the attached Research Paper which may be useful to you.

  • Monu Mishra added an answer in Ultraviolet Photoelectron Spectroscopy:
    How to estimate valance band of semiconductor from UPS spectra?

    How to estimate valance band of semiconductor from UPS spectra?

    Monu Mishra

    Dear Huslen,

    UPS gives you the density of states and the information about the hybrization of valnece states.

    Now, what actually you want to know form that?

  • Manish Kumar added an answer in Bisulfite Sequencing:
    What method is suitable for flanking region upstream and downstream for primer binding?

    Hello everyone

    I am planning to do Bisulfite sequencing but my samples  lacks the flanking region upstream and downstream for primer binding. So can anyone  help me with possible solutions? 

    Manish Kumar

    Thank you sir

  • Mohsan Saeed added an answer in Virus:
    In cross neutralization, after mormalisation of homologous titre to 100, what should be the threshold to call a strain cross neutrlizing?

    Two virus strains were used, say A and B, and serum raised from each virus were tested against themselves (homologous) and the other strain (heterologous). The ND50 titre was calculated by Karber formula. The homologous titres were normalized to 100 and the heterologous titre was calculated accordingly. The titre of serum A against virus B after normalization is 40 and Serum B against virus A is 120. Now my question is, after normalization, at what percentage should I call the strain as cross neutralizing? Like in this case, serum B is showing higher heterologous neutralization than serum A, so it is definitely cross neutralizing. But in case of serum A, what should be my threshold to call serum A as cross neutralizing? Please provide reference.

    Mohsan Saeed

    Hi Sonal, I am not sure if cross-neutralization is a strictly qualitative feature. To me it is more of a quantitative thing, where an antibody can be strongly cross-neutralizing to one strain, while weakly cross-neutralizing to the other. If you agree with this, your serum A is weakly cross-neutralizing to strain B.  

  • Liting Ji added an answer in RNAse:
    For in situ hybridization how can I prepare RNase free buffers? Just use RNase free water and regular powdered reagents to make the buffer?

    For in situ hybridization how can I prepare RNase free buffers? Just use RNase free water and regular powdered reagents to make the buffer?

    Liting Ji

    Thank you over much. I will make all the reagents with RNase free water. And can I put RNase inhibitor?

  • Visalatchi k c asked a question in Forest:
    Hough forest transform for text detection ?

    madam/ sir

    can any one tell me about hough forest transform for text detection?

  • Sujoy Bepari asked a question in Metal Oxides:
    Can I get exact weight percentage of any metal from EDS analysis for a catalyst sample?

    If the catalyst contains different metal oxide. Then is it possible to know exact weight percentage of the metals? If not, then what is the exact technique to know that percentage?

  • Robyn Munford added an answer in Disabled Children:
    There are plenty of articles about moral distress in nurses; are there any articles on moral distress in parents of a child with disability?

    My research is on the needs of rural parents that have a son/daughter born with disability.

    Robyn Munford

    If you look at our article in Disability and Society - Munford et al you may find some interesting ideas.

  • Riza Arief Putranto asked a question in sgRNA:
    Does anyone understand what happen to the rest of the all-in-one plasmid carrying sgRNA and Cas9 such as selection antibiotic, etc in the cell?

    I am curious about the discussion of organism edited by CRISPR/Cas9 for being considered as non-transgenic material. However, if the plasmid used to carry sgRNA and Cas9 with all antibiotic selection sequence are inserted using Agrobacterium transformation, where they go after the transformation? Can the organism still not considered as transgenic? 

  • Sai Sudeep Dwarka asked a question in ANSYS Workbench:
    How to give give different thickness for different sections of a model in ANSYS workbench?

    Researchers working in the field of Finite element analysis

  • Narendiran Sivakumar asked a question in DSpace:
    How can i make Neural network and ANFIS controllers for MPPT in Dspace using MATLAB?

    I am cooming across memory problem in Dspace when I dump ANN and ANFIS based MPPT controllers for generating PWM pulses for DC-DC converter in Dspace.