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  • Sudhir Bisen added an answer in Heat Exchangers:
    Does anyone know about designing a single row tube bundle for use in AEHS or ACSC application?

    Dear researches,

    I need help for a design of a single row tube bundle. 

    actually i'm struggling in a problem,  how to optimize the tube pitch of a single row elliptical tubes bundles. that are used in Air cooled heat exchange's or air cooled steam condenser application. 

    Anyone have related documents or any link please give me.

    Thank you

    Sudhir Bisen · Indian Institute of Technology Delhi

    Thank you, Ronan Grimes

    This paper close to my work. 

  • Brian D Green added an answer in Antigen Presentation:
    Is there a short amino acid sequence that I could add on to a peptide which would enable it to target the surface of a macrophage?

    Basically I want to target a therapeutic peptide so that its actions are mostly confined to macrophages.

    The shorter and more specific the sequence of amino acids the better. I had thought of targeting some of the surface antigens present on macrophages, but know relatively little about these. Also - it would be important that the targeting sequence does not exert any immunodulatory actions - i.e. is pretty much inert when it comes to the immune system.

    Thank you.

    Brian D Green · Queen's University Belfast

    Hi thanks for the answer but molecules like lipoproteins and polysaccharides were the sort of thing that I was hoping to avoid using. Some sort of protein-to-protein interaction is what I am hoping for.

  • Harald Osmundsen added an answer in Microarray:
    Can someone please look at it and tell me if it would be worthwhile pursuing this sample for hybridization for microarray?

    Is it prudent to use an RNA sample which has no RIN number, when analyzed using a Bio-analyzer (Agilent).

    The profile shows a good 18S peak. However, the 28S peak is very small.(probably the reason for the absence of the RIN number) 

    I am attaching the picture of the profile herewith.

    Can someone please look at it and tell me if it would be worthwhile pursuing this sample for hybridization for microarray?

    Even if the microarray can be done and is ok, how much reproducible the data would be?

    Harald Osmundsen · University of Oslo

    You did not mention how you isolated your sample of RNA. Did you use a method involving organic solvents or did you use a procedure using columns (e.g. Qiagen RNAeasy). The latter is vastly preferable if you will be using RNA samples for microarrays.

     Presumably your sample should be total RNA; a RIN number is therefore expected. In the absence if a RIN number we would certainly discard the sample.

    If the OD 260/230 ratio < 1 we would not use a sample for microarrays. Re-purification is certainly possible. Best solution is to get further samples as already suggested, and to use a column-based isolation kit. 

  • Idris Mohamed Saeed asked a question in LC-MS:
    What is the different between the MS library in LC-MS and GC-MS?

    I want know the different. 

  • Sansrity Sinha added an answer in Primer:
    Could anybody help in interpreting an abnormal qPCR melting curve for CD34 primer?

    I've got a melting curve showing tow peaks (attached file), a small one before the main one, which is seen in 3 cell lines very similarly while absent in the NTC (no template control). The problem that, the amount of detected gene expression is very low using this primer in a CD34+ cells. Is it necessary to change the primer? and is the CD34 gene is expressed in very low amount? Thanks.

    Sansrity Sinha · Indian Institute of Technology Madras

    it seems  like u have multiple amplicons with these set of primers. however since the amplitude of the peak in melt curve corresponding to non specific amplicon is less u need to optimize template concentration along with annealing temperature. 

  • Nina-Naomi Kreis added an answer in Cell Transfection:
    How do I determine protein half life with cycloheximide or cell cycle arrest?

    I'm trying to determine the half life of the protein that is expressed from the plasmid and has auto degradation loop. So supposedly it should degrade faster than its non-loop counterpart. I've done some reading about cycloheximide, Is it possible to do this with non radioactive method, and can this be applicable in this instance with cell transfection? Can the half life be determined by arresting the cell cycle in G0/G1 phase and performing the western?

    Nina-Naomi Kreis · Goethe-Universität Frankfurt am Main

    I use 25 µg/ml cycloheximide for HeLa or HCT116 cells. Add it to your cells and to a time course up to several hours.

  • Gert Nolze added an answer in XRD Analysis:
    Why does the XRD peak shift when I measure(400) silicon using 2theta scan ?

    I measured (400) silicon bulk sample by using k-alpha1 X-ray of Cupper.

    For theta/2theta scan, The angle of a peak of (400) silicon is about 70 degree. It obeys Bragg's law.

    However for 2theta scan, I've got an angle at 40 degree, not 70 degree.

    I am almost sure that the angle is a shifted peak of (400) silicon.

    The situation is not obeying Bragg's law, because the incident beam angle cannot be 35( = 70/2) degree when using 2theta scan. 

    Is this situation really caused by shifting like I mentioned above? If this hypothesis is right, why does the shift occur? 

    Gert Nolze · Bundesanstalt für Materialforschung und -prüfung

    Maykel, I agree with you that in very special cases you will have surface relaxation which will certainly display the planar symmetry for the first atomic layers, but the assumption this happens down to a depth of 2.5µm appears to my highly speculative. A few nanometers...ok...but I investigated many times Si by EBSD and I've never seen such an effect. Even not the tendency. Therefore, from my point of view: nice idea, but not experimentally confirmed. 

    The term "rocking curve" only defines that one (doesn't matter which) axis is moved wheras everything else is fixed. So you can have omega (theta), 2theta, phi, Psi rocking curves. They all display specific properties. is this also your opinion, RavI?

  • Elzein Elhassan added an answer in Mobile Marketing and Advertising:
    What are the main factors of customer loyalty in telecom sector?
    Telecommunication services including broadband internet, voice, IPTV have been commoditized. Telecom providers use common technologies, and the quality of services is hardly distinguished, the low prices do not affect customers' decisions anymore. So, what are the loyalty factors in these conditions?
    Elzein Elhassan · Tribhuvan University

    It is all about the customer experience since all the companies provide nearly the same services; the main difference will be in experience of identifying the customer usages pattern and providing the suitable package.   

  • Bastiaan Keuning added an answer in Physical Therapy:
    Does an overview about red flags for physical therapy exist?

    In Germany actually there is no direct access for physical therapy. In other countries the patients can direct go to the physical therapist. Is there an an overview about red flags which the therapists must pay attention? I only can find red flags for low back pain.

    Bastiaan Keuning

    Dear Eric, 

    Take a look at the site of the Dutch Association of Physiotherapy: https://www.fysionet-evidencebased.nl/index.php/richtlijnen/richtlijnen. It is all in Dutch but, hey, thank Google Translate! ;-)



  • Ervin Mujkic asked a question in Elections:
    Could anyone recommend any literature regarding conditions and procedure for the election of judges of the Constitutional Courts in EU countries?

    Each country has a peculiar system of election of Constitutional Court judges and every one of these models has its weaknesses. Procedure for the election of constitutional judges is considered to be one of the guarantees of their independence. Even more interesting is the question of the conditions that candidates for judges of the Constitutional Court must meet in order to be appointed.

  • Mark D. Laing added an answer in Soil Analysis:
    Which is the most effective method of diagnosis of nutrient constraints in perennials?

    In perennial crops , identifying nutrient constraints is truly  a complex exercise. An entire range of diagnostic techniques are being used , starting from soil analysis , tissue analysis ( Using index plant parts ) , metallo-enzymes , deficiency symptoms as  morphological descriptors, juice analysis, trunk injection to floral analysis,  of late. None of them alone is sufficient  to identify the nutrient constraint precisely matching to field conditions. Every method has its own merits and demerits. With the result , it is  often questioned that the currently available methods of diagnosis of nutrient constraints , are more inclined to diagnosis for the next season , overlooking the problems in the current season  standing  crop . This kind of constraint in diagnosis is so rampant in perennial crops. I wanted to know from researchers across , how to solve this so complicated issue?.

    Mark D. Laing · University of KwaZulu-Natal

    A Practical Suggestion: use Mulches around the trees

    The use of 100mm thick mulches of organic matter (ideally lignitic material such as the shells of macademia nuts, because these last much longer than cellulosic mulches, which also suck up nitrogen as they compost) will encourage the development of a thick mat of feeder roots under tree crops, to be found at the interface of the soil and the mulch. These are the roots that can take up the foliar sprays best, as the ionic fertilizers wash off the waxy leaves onto the soil surface, and before they can get leached or bound to clay particles. Mulching helps a lot with the uptake of micro-elements such as zinc and iron, which citrus is often deficient in.

    Even old newspapers make a good enough mulch to enhance this effect, and you can lift up the newspaper to see the mat of feeder roots developing under it. Nice for measuring this effect also.

  • Sabahat Nadeem added an answer in Emotion Regulation:
    Is there any questionaire to evaluate emotion regulation in e-Learning environments ?

    I am working on a project that focuses on emotion regulation strategies in e Learning environments. Does there exist any Questionaire to evaluate whether my devised strategy had a positive impact on the learner.

    Sabahat Nadeem · COMSATS Institute of Information Technology

    Thanks for such helpful answers

  • Xuerun Li added an answer in Ball Milling:
    What is the suitable particle size range for a good XRD analysis?

    I am working on rock mineral sample and reduced particle size by ball milling. I wish to know the range of the particle sizes suitable for getting clear XRD results.

    Xuerun Li · École Polytechnique Fédérale de Lausanne

    The ideal average particle size of the XRD is 10~50um (P.302, Fundamentals of Powder Diffraction and Structural Characterization of Materials). If you are going to do the Rietveld analysis, it is better to decrease the particle size further to 1~5um (Snellings, R., et al. (2014). "The existence of amorphous phase in Portland cements: Physical factors affecting Rietveld quantitative phase analysis." Cement And Concrete Research 59(0): 139-146.).

    Good luck.

  • Dilek Cakiroglu added an answer in Supercapacitors:
    Which electrode's mass should I use in asymmetric supercapacitors?

    I have a question related to mass of the electrode in asymmetric supercapacitors. In asymmetric supercapacitorsi anod and cathode are different materials and have also different mass. To calculate specific capacitance of the supercapacitor from CV curve or GCD curve, which electrode's mass should I use in equations? 

    Dilek Cakiroglu · Sabanci University

    In the papers, it is written that only one electrode mass should be used in symmetric one so are those equations not correct for asymmetric one?

  • Zakaria Al-Qodah added an answer in Bioreactor Design:
    What is a chemostat?

    I see some research papers mentioning about 'chemostat'.

    What is a chemostat? Your help is appreciated..


    Zakaria Al-Qodah · Taibah University, Madina , Saudi Arabia

    A chemostat is a constant environment reactor where the operational parameters are constant and under control. These parameters include pH, substrate flow rate, mixing speed, temperatures and others. Other reactor is named turbidostat where the parameters are controlled by monitoring the optical density in the reactor.

  • Mohamed Elsheikh asked a question in Journalism:
    Do you publish a topic on small areas ?

    Do your journal publish topics about small area?

  • Friedrich Menges added an answer in Fluorescent Dye:
    Can anyone suggest some oil soluble fluorescent dyes?

    I´m searching for some oil soluble dyes, if anyone can recommend some, please let me know.

    Thanks in advance,


    Friedrich Menges · Tecan Austria GmbH

    Atto-647N? certainly not!


    gives this information: : "The product is soluble in polar solvents, e.g. dimethylformamide (DMF), dimethylsulfoxide (DMSO), or acetonitrile."

  • Kodati Pavan Kalyan asked a question in H Index:
    Does any one have the information about impact factor of Journal of Mines, Metals and Fuels?

    H-Index :7

    Indian Journal

  • Andrei A Novikov added an answer in Raman Spectroscopy:
    Is it possible to remove Raman background signal ?

    Trying to obtain characteristic Raman signal from semi pure samples, however, the background signal from 1000-2000 cm-1 was always very strong, and this might overlap some useful signal response. 

    Raman spectrometer used in this study is the Perkin-Elmer Raman spectroscopy, which employed a diode laser operating system at 785 nm with average power of 100mW at the sample and 100-micron spot size.

    I obtained the signal by transferring power samples onto glass slides under microscopy (20X). 

    This strong background signal also appeared in another SERS experiment employing nanofilm deposit onto glass slide performed on this instrument. Silver nanofilm substrate was deposit on glass slide and placed on same glass slide. 

    BG from bare glass slide ( without anything on it) 


    BG from SERS substrate ( with As III droplet on it )


    Question. what is the source of this background signal ( 1000-2000 cm-1), and how to eliminate it? 

    Thanks for your help and input!

    Andrei A Novikov · Gubkin Russian State University of Oil and Gas

    As it was mentioned above, glass, quartz and similar materials have fluorescence background. The simplest alternative to glass slides is aluminum foil (in case your samples are not corrosive), it has virtually no background. You can check out spectra in our paper (sorry, text in Russian): page 106, materials from above to below are 1) glass slide, 2) quartz slide, 3) PE, 4) PET, 5) PTFE, 6) Al foil.

  • Azwan Bakri asked a question in Electric Vehicles:
    How to determine energy consumed in battery banks based on State of Charge for an Electric Vehicle?

    SoC for EV and not stationary application.

  • Ivan Brukner asked a question in CFX:
    Does CFX Bio-Rad 96 qPCR have to have ROX normalisation for monoplex reaction?

    is there fundamental need for CFX-96 well Bio-Rad assay to use Rox day for qualitative assay?  thanks in advance


  • Edward Coetzee added an answer in Medicine:
    What makes it difficult for guidelines to be followed?

    Benefits of restricted transfusion vs. liberal in certain patient groups; No role of renal dose dopamine; No role of FFP to increase serum albumin levels; Voluven (starch) predisposes to increased bleeding post-cardiac surgery, etc.  Such and many others.  Inspite of adequate proof, what are the factors that you think or may have encountered which make non-compliance/hesitance/reluctance with the published studies?

    Edward Coetzee · Groote Schuur Hospital

    Simplicity and brevity are the key components for guidelines. The evidence can be provided in a linked document for those who wish to follow it up.

    However I totally agree with Mark Noble, guidelines are not rigid protocols and we should apply guidelines with thought to each individual patient

  • Julien Bergoz added an answer in Instrument Development:
    How can I choose the material for electrical feedthrough pins?

    I have the options of Cu and stainless steel. It will operate with 30kV, 10mA under vacuum. I will appreciate if you share any ideas about which material to go for...

    Many thanks,


    Julien Bergoz · Bergoz Instrumentation

    Are you concerned with radiations where the feedthrough will be installed?

    PTFE (Teflon) should be avoided if exposure >200 Grays.  Generally any halogen-containing dielectric will cause copper corrosion (long ugly green needles) when the halogen is liberated by radiations.

  • Titus Sobisch added an answer in Nicotine:
    I have to do UV analysis of nictone in millipore water to find its absorbance peak, how can I proceed?

    Sample- Nicotine

    Solvent-Millipore water

    I have done UV directly of the sample( nicotine dissolved in water) .But no peak is coming. So, what can be done to make Nicotine UV sensitive

    Titus Sobisch · LUM GmbH

    From Wikipedia: 'Nicotine is a hygroscopic, colorless oily liquid that is readily soluble in alcohol, ether or light petroleum. It is miscible with water in its base form between 60 °C and 210 °C.' I would suspect that your problem is aqueous solubility. You need a suitable solvent to determine spectra in solution.

  • Frédéric Rychen added an answer in Diffusion of Innovation:
    Have you used the diffusion of innovations model of Rogers to understand the adoption of new technologies?

    I would like to know if you have used this model to investigate the possibility that a new technology would be adopted in an educational setting - and what did you find? I believe the model is quite useful as a framework, but that the content needs to be adapted ....

    Frédéric Rychen · Aix-Marseille Université

    Rogers model can provide a good understanding of the mechanics of the diffusion process in a simple setting. But it is not well suited for innovations that rely on network effects because of the non linearity and the multiple equilibria (indeterminacy) they create. The chasm that many firms face in trying to access to the mass market is good example of difficulty to adopt a continuous diffusion process approach.

  • Muthuswamy Jaikumar asked a question in Seaweeds - Culture:
    Is the any other reason other than temp and pollutant will diminish seaweed culture.?

    Is the any other reason other than temp and pollutant will diminish seaweed culture.Any seaweed associated fauna will shrink the growth of seaweed culture Species Kappaphycus sp 

  • Deniz Karadurmus added an answer in sgRNA:
    How to obtain sgRNA in order to generate floxed mice using CRISPR/Cas9?

    Hi everybody,

    I would like generate a floxed mouse. I have found information about how to design sgRNA and clone it into cas9 expressing plasmid, but what are the next steps? I mean, how to purify the sgRNA before microinjection into the zygote?

    Thanks in advance

    Deniz Karadurmus · Université Libre de Bruxelles

    Thank you very much for your answer!

  • Rakesh Konkumalla asked a question in Boiling Point:
    Which is a better working fluid in organic rankine cycle toluene or acetone?

    Latent Heat of Evaporation of acetone 518(kJ/kg) , toluene 351(kJ/kg) according to this data toluene makes less load on boiler than acetone.

    but boiling point of acetone is 56 degrees centigrade is much lesser than boiling point of toluene 111 degrees centigrade.

    toluene is dry fluid and acetone is isentropic fluid.