Q&A

ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.

Browse by research topic to find out what others in your field are discussing.

Browse Topics

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
  • Atta Ullah Khan asked a question in Refining:
    How to change the pattern marker style permanently in WinPlotr?

    I don't like the pattern style which appears after refinement. I want to change it permanently but whenever I make changes, these are only temporary. Could you please guide me how to change it permanently?

  • Adam Hughes added an answer in Refractive Index:
    How the reflectance from the thin film will behave if I will change the different parameters?

    If I have two layer thin film, for example the first layer is Si and the second layer is some other layer and I want change following parameters of this second layer :1) Real part of the refractive index, 2)Imaginary part of the refractive index,3)Width of the second layer. How the reflectance from the thin film will behave in this case?

    I want develop intuition in this field? Thank you in advance!

    Adam Hughes · George Washington University

    This is a nice web applet to do these calculations:

    https://www.filmetrics.com/reflectance-calculator

  • Wes Raikowski added an answer in Mathematics:
    What are “potential infinite” and “actual infinite”? Is there anything wrong with our understanding and the definitions to “infinite”?

    “Potential infinite” and “actual infinite” are really there in our mathematics and science, but it seems very difficult to understand and express these two concepts clearly and logically ever since.

    Why many researchers (such as researchers taking mathematics as a practical tool) refuse “potential infinite” but only accept “actual infinite”. Do we really need both “potential infinite” and “actual infinite” or just need “actual infinite”? Is there anything wrong with our understanding and the definitions to “infinite”?

    Wes Raikowski · Griffith University

    Dear Geng,

    As I argued in my previous entries, zero is part of the value notion but not of repetition. For example, zero level of water in the vessel; no activation of the sensory ending; shares of zero value, light of no intensity, empty set, etc. The shares might have zero value (no value), but it does not mean that there are no shares. The light might have no intensity, but to see that you still need the same eyes or detectors which can sense some intensity. The level of water might be zero, but you still need a container to express it. The set could be empty, but you still need the concept of the set for it to be empty. This is no different to the notion of an “empty basket” – the basket is there, real, tangible even though there are no more apples in it. You cannot say just “empty” because this makes no sense. Even when philosophers talk about “emptiness” they see it locally or temporally in the context of objects and something that contains those objects. Even your concept of “nothing” or “nothingness” requires something for it to be conceived.

    Repetition, on the other hand, does not have the notion of zero because it makes no sense, at least cognitively. “Not to repeat” is not the same as “repeat zero times”. You can repeat something 1 time, 2 times, 10 times, infinitely many times – but not zero times. Please accept that I argue this from the position of human cognition only. In mathematics you can multiply by zero without any problems if you define the multiplication in operational terms.

    I have an inkling that whenever I consider problems in terms of cognition you still interpret them in terms of mathematics, which leaves you with an impression that what I am saying does not make any sense.

    My best, Wes

  • Kunpeng Jia added an answer in ALD:
    How to clean oxide wafers, before entering an ALD system?

    When I use Si wafers, I use a three-step process; first, rinse with 99% HNO3 (for removing organics) and then wash with di-water; second, rinse with 70% HNO3 (for removing metal traces) and then di-water again; finally, rinse with 1% HF (for removing native oxide).

    Can I use the same first 2 steps, in case of oxide wafers? (my feeling is; why not?)

    Thanks!

    Kunpeng Jia · Chinese Academy of Sciences

    I don't catch the mean of oxide wafer. What kind of oxide? If your mean silicon dioxide, I think the first 2 steps are available and the third step also can be used to achieve fresh surface.

    But the RCA clean process is the common method to clean Si wafer. I think you can use it as backup solution.

    FYI:http://en.wikibooks.org/wiki/Microtechnology/Etching_Processes#RCA

  • Boon Chin Tan added an answer in Auxin:
    What are the differences between local auxin and auxin?

    Ethylene stimulates auxin biosynthesis and basipetal auxin transport toward the elongation zone, where it activates a local auxin response leading to inhibition of cell elongation

    Boon Chin Tan · University of Malaya

    You mean endo and exogenous auxins?

  • In management, research is shifting from quantitative to qualitative or mixed method. Can anyone provide articles relating to this?

    Scandinavian countries have shifted in a big way from quantitative to qualitative research in management. In US, too, this trend is visible but Asian countries are still wedded to quantitative research. It appears that the knowledge of qualitative research is lacking in these countries or appropriate softwares are still not available to process the data or researchers are not yet comfortable with these softwares.

    Muhammad Rafique · NUST College of Electrical & Mechanical Engineering

    Hi Arun,

    i think qualitative portion can give you answers of why?  which is not sufficient  and complete as it first requires answers of what which comes from quantitative portion. yes mixed method is strongly recommended for new domains in research.

    regarding your question about qualitative portion first of all you dig about theories in following aspects:

    abstract theories

    middle age theories

    grounded theories

    i think  it will be self guidance for you as it pin points problems with references.

    regards

  • Manu Kumar asked a question in Gene Amplification:
    RT-PCR is not showing any amplification of gene however actin shows good band?

    RT-PCR is not showing any amplification of gene however actin shows good band.

    In the gene amplification the positive control (gDNA) shows band means the pcr rxn conditions are good. Actin bands show cDNA quality also good. So what may be the problem for no amplified band of the specific gene.

    Thank You.

  • Saidul Islam asked a question in C:
    Trapped particle UDF Help

    I am working with DPM and using UDF. Without UDF my model is working good. When I compiled my UDF I got a warning (image attached) but opened the file. After compilation when I run the simulation, it stopped with n fatal signal error. Here is my UDF

    /**************************************************************************************/
    /* UDF for computing cell co-ordinates */
    /**************************************************************************************/

    #include "udf.h"
    #include "sg.h"
    #include "prop.h"
    #include "dpm.h"
    #include "surf.h"
    #define WALL_ID 8

    DEFINE_DPM_SCALAR_UPDATE(particle_coords, c, ct, initialize, p)
    {
    real A[ND_ND];
    int n;
    face_t f;
    Thread *ft;
    c_face_loop(c, ct, n)
    {
    f=C_FACE(c, ct,n);
    ft=C_FACE_THREAD(c, ct, n);
    if (NNULLP(ft))
    {
    if (THREAD_ID(ft)== WALL_ID)
    {
    p->user[0] = p->state.pos[0];
    p->user[1] = p->state.pos[1];
    p->user[2] = p->state.pos[2];

    }
    }

    }
    }

    DEFINE_DPM_OUTPUT(Particle_coords_output, header, fp, p, thread, plane)
    {
    char name[100];
    if (header)
    {
    if (NNULLP(thread))
    fprintf(fp,"(%s %d)\n",THREAD_HEAD(thread)-> dpm_summary.sort_file_name,3);
    else
    fprintf(fp,"(%s %d)\n",plane->sort_file_name,3);

    fprintf(fp,"(%10s %10s %10s %s)\n",
    "X", "Y", "Z");
    }
    else
    {
    sprintf(name,"%s:%d",p->injection->name,p->part_id);
    fprintf(fp,
    "((%10.6g %10.6g %10.6g) %s)\n", p->state.pos[0], p->state.pos[1], p->state.pos[2]);
    }
    }

    Could you please help me?

    Saeed

  • Boon Chin Tan added an answer in TCA Precipitation:
    What is the best way to determine the protein concentration for colored plant protein sample?

    As cocoa derived proteins is containing color (dark brown to black) and even after acetone / TCA precipitation, it still carries light brown coloration due to which there is an interference in the protein concentration measurement.

    I have tried the methods like BCA; Bradford and Neuhoff but did not get a reliable concentration value.

    Could anyone please suggest me a way?

    Boon Chin Tan · University of Malaya

    Perhaps you could try the 2-D Quant kit? It  works by quantitatively precipitating proteins while leaving interfering substances in solution. More info: https://www.gelifesciences.com/gehcls_images/GELS/Related%20Content/Files/1314729545976/litdoc28954714AE_20110830215136.pdf

  • Rudra Upadhyay added an answer in Remote Sensing:
    For dams, what method is used for doing evaluation of concrete distress?

    Should we have to do continuous monitoring using remote sensors as we do the same for the bridges?

    Rudra Upadhyay · Arizona State University

    Main methods which are used can be non destructive testing to study the corrosion but else then that cameras are installed to see when cracks start develop and also its develop profile can be studied

  • Chung-Su Kim asked a question in Enzyme Activity Assay:
    How can I deal with initial high O.D in enzyme activity assay?

    Last week, I did experiment for GST assay by using dilution-changed liver homogenate.(double concentraion of previous one.) As a result, I got more clear significant difference in activity. However, I encountered another problem. It's starting absorbance is too high(initial O.D is close to 1.0 in 340nm, and over 2.3 after 5min). I afraid of this matter because it will be same for other assays, like SOD, CAT, GPx. For this reason, I seek to solve this problem, high initial absorbance. How can I deal with this problem?

    Oh, I think dilution is not the answer. I diluted, and I failed to get significant difference. 

  • How to identify and measure responsible leadership? Is any link between responsible leadership and competencies?

    I'm interested in research about the responsible leadership and I am looking for some references, research, surveys, case studies, and suggestions of methods. Thank all for any help;

    Marie Florence Desir Pierre · Université Quisqueya

    I will recommend you " The twenty-one irrefutables laws of leadership". This a great book written by John C.Maxwell. Every year,he adresses 250.000 people and influences the life of more than a million individuals bythe means of seminars,books and cassettes. This is a french book.

  • Joan Marques asked a question in Intuition:
    I have developed a brief questionnaire about ambition vs. acceptance for a new book. Please participate at https://lnkd.in/bm-XCJB ?

    I plan to evaluate the intuitive area between ambition and acceptance, that guides responsible leadership.

  • Organoclay Nanocomposite polymer?

    Please tell me about the thermally strengthening  role of Organoclay on different polymers? Other than Organoclay, which NPs have significant effect on thermal stability on polymers?

    Sridhar Vadahanambi · Global Core Research Center for Ships and Offshore Plants,

    In addition to MMT.. other clays like bentonite, sepiolite, hydroxyapatite and carbon nanomaterials like nano-graphite, graphene, CNT, CNF can also improve thermal stability.. 

    But the key in getting good properties is the quality of dispersion and distribution of nano-particles in the polymer matrix..  

  • Ariel Linden added an answer in Wound Dressings:
    How to test a Disease management Protocol?

    I'ld to test and validate a management protocol developed by me. These are Prevention of Disability (POD) basic techniques to be applied by nurses in the wound's dressing room...

    Ariel Linden · University of Michigan

    Enric's suggestion is the right direction, but much too comprehensive for the development stage. If you are in the beginning stages of testing your protocol, you can start with a small pilot study. This should be randomized, but I don't see why it needs to be clustered. I assume that the nurse follows the protocol and then you measure the outcome on the patient level. It would be sufficient in the pilot to follow a several cases and see if there is a significant effect and if the protocol is OK as is. That should guide you into a more comprehensive study. However, you may find that your protocol needs modification, based on your observation during the pilot. Thus, you can make the changes to the protocol and reassess via another small pilot. Once you feel confident that your protocol is designed appropriately, and that the nurses implementing the protocol are following according to specification, you can formally implement a randomized controlled trial.

  • Xianling Wang asked a question in Uterus:
    The orientation and location of uterus in the MRI and three-dimensional reconstruction?

    I want to know whether is the orientation and location of uterus same between  in the MRI and three-dimensional reconstruction ?

    why is the orientation of uterus is different in the following picture  ?

  • Adnan Muzaffar added an answer in PCR:
    How much DMSO should I add in a PCR reaction mixture?
    Protocol is telling that I need to add 5% DMSO in 50 microliter PCR reaction mixture? Can anybody guide me how much amount in micro liter of DMSO will make it 5%? I am using DMSO from Thermoscientific plant Direct PCR kit.
    Thanks.
    Adnan Muzaffar · University of the Punjab

    Stock conc. xVol. = Final conc. x total vol of reaction     S0 if you are making it in 20 then 

    100XVol= 5X20= 1 microleter 

  • Are there only two relativities possible-- the special and the general? Or are there more to come in future??

    We have two relativity theories so far-- Einstein's special and general theories dealing respectively with observers in inertial and non-inertial frames. There have been other relativity proposals like quantum relativity, scale relativity etc. I have made a classification of all possible relativity in general in a recent upload to RG. I find that there can be eight relativities in all -- four objective and four subjective. Do you have any more to add or is my classification exhaustive?

    Zafar Turakulov · Uzbekistan Academy of Sciences

    H. Weyl tried relativity of scales. He sketched a theory with scales changing from one point to another. The changes were specified by a vector field such that there is a change in a closed path. This theory was called gauge theory. Passage to quantum mechanics turned changes of scales into that of phase and was interpreted as electrodynamics by Fock and London.

  • Dawid Deneka added an answer in Fusion:
    How to direct a protein to be expressed as inclusion body?

    Dear all,

    are there known fusion partners or amino-acid-subsequences that provoke precipitation of the fusion protein in inclusion bodies?

    I want to provoke inclusion body formation, caused solely by the aggregation-prone fusion partner and independent of the second, interchangeable partner. So in fact a reversion of the usual strategy of using fusion partners (such as Maltose-Binding-Protein) to enhance solubility.

    thanks a lot in advance,
    regards,
    peter

    Dawid Deneka · University of Chicago

    "Leukotriene BLT2 Receptor Monomers Activate the Gi2 GTP-binding Protein More Efficiently than Dimers" J Biol Chem. Feb 26, 2010; 285(9): 6337–6347. 

    In this paper you can find some info about aggregation- enhancing fusion partners. I used one of them, human α5 integrin for my GPCR expression. It worked well.

    Best

    Dawid

  • Kathleen D Toohey added an answer in Archaeology:
    Is there any kind of literature and e-source associated with archaeological evidence for hittite iron processing?

    Right now i only found some mentions of hittite iron, products, and biblical mentions of the iron using hittites. So no real archaeological evidence for now.

    Everything could help like evidence for products, ovens, productionplaces and traces of ressource exploitation.

    Kathleen D Toohey · International Arthurian Society (North American Branch)

    You may find some useful references in Chapter 5 of The End of the Bronze Age: Changes in Warfare and the Catastrophe CA. 1200 B.C., by Robert Drews, pp. 73 - 76.

    While Drews holds that iron did not come into regular use until after the collapse of the Hittite civilisation, some of the works cited in his footnotes might be helpful to you, such as Jane C. Waldbaum: From Bronze to Iron. The Transition from the Bronze Age to the Iron Age in the Eastern Mediterranean; Studies in Mediterranean Archaeology, LIV.  1978.

    There may also be something of value in the following link:

    http://www.claytoncramer.com/unpublished/Iron2.pdf

    But I have not read the article, and don't know the author's credentials.

    Good luck

  • Tianlong Qiu added an answer in Reverse Osmosis:
    How can I remove algae from raw water ponds to be used as feed water for a reverse osmosis plant?

    I am looking the chemical method to remove the algae from raw water pond to be used as feed water for a reverse osmosis plant. As the algae is making problem in the cartridge filters. So what chemical in what ratio should be poured in pond's water to avoid the growth of algae colonies. Thanks & regards.

    Tianlong Qiu · Chinese Academy of Sciences

    I donnot think chemical method is good. it introduces pollution again. How about some simple method, like to cover the pond with shading net? If there is not enough sunshine, the algae will dissaper some days latter.

  • What is thermal equilibrium and how much time it takes to be established?

    Many experts say "It doesn,t make sense to calculate the time of thermal equilibrium establishing since its time is infinity"  (see exponential law of cooling or heating). On the other hand, the main postulate of thermodynamics says that the thermal equilibrium establishes within the finite period of time, and it is a basis for the next three laws of thermodynamics. How should be the time of thermal equilibrium existence in different systems easily and correctly calculated?   

    Nikolai I. Kobasko · IQ Technologies Inc., Akron, USA and Intensive Technologies Ltd, Kyiv, Ukraine

    Samvel, thank you very much for your comments ! Thanks also to All for interesting discussion. Hope for more discussion when a manuscript "Universal correlation for heating (cooling) time calculation suitable for steel parts of any configuration during  their hardening".

  • Can anyone express the mathematical equation for love?
    Although many believe love is a subjective expression, is there an objective mathematical function for it?
    Subhash C. Kundu · Guru Jambheshwar University of Science & Technology

    Love can not be expressed in equation. Rather it is an emotional feeling and state of mind.

  • Pankaj Kumar added an answer in Plant Biology:
    Morphological identification of Orchids to species
    I have few orchids of my own which are indigenous to my state (Mizoram) as a hobby. I don't have any idea on their morphological identification to species. I have photographs of the flowers. Can I have some help?
    PS: I have uploaded thirteen (13) photos if you scroll down the comments.
    Pankaj Kumar · Kadoorie Farm and Botanic Garden

    You can send me the pics on pkumar@kfbg.org

  • Saemee Song added an answer in Silver Staining:
    What are these streaks on silver stained polyacrylamide gels?

    Any good ideas as to what is causing these streak would be helpful. Thanks

    Details:

    Second step of a taptag purification

    Bis-Tris Precast Polyacrylamide gels

    Ran at 165 volts

    1ul sample/20ul H2O/7ul 4x loading dye/ ~37mM DTT

    heat and spin samples before loading between 4-10ul to gel

    Saemee Song · Seoul National University

    I think, It might be due to a high voltage during electrophoresis. It is helpful to decrease the voltage and use a fresh running buffer. 

  • Afaq Ahmad added an answer in Logic Gates:
    Does the "wired OR" really implement OR... or AND... or some else logic function?

    "Wired-OR" circuits are sometimes called "wired-AND" circuits. Then а question arises, "What are they actually - OR or AND?" Here is my speculation why the "wired OR" really represents the OR logic function.

    There is nothing special in this connection; actually it is the primary and most elementary OR gate. Only to see the OR logic function here, we have to think in terms of resistances, conductances or switch states.

    From this point of view, the primary OR gate consists of elements (resistors, conductors or switches) connected in parallel that are driven by the input logical variables so that "conduct" (closed switch) represents "logical 1". It is obvious that, in this arrangement, the equivalent network will conduct (output logical 1) if only one of the elements conducts (input logical 1).

    Dually, an AND gate consists of such elements connected in series. Now the equivalent network will conduct (output logical 1) if both the elements conduct (input logical 1).

    Only electronic circuits use voltages (or more rarely, currents) as input and output variables. So, we should first convert the input voltages into resistances by some "electrically-controlled resistors" (FET, BJT, etc.), and then - the equivalent output resistance to voltage, by passing a current through it. The role of the pull-up resistor is just to provide this current.

    NMOS logic gates are implemented exactly in this way. For example, an NMOS OR gate consists of NMOS transistors in parallel and a pull-up drain resistor. So, in this case we think of the whole combination as of an (N)OR gate including the transistors. The same is true in the case of the RTL gate (the picture below).

    But what do we think in the case of a "wired OR"? What is the gate itself? In this case we do not consider the transistors as belonging to the logic gate... we consider them as external (belonging to the previous gates). And also, we do not consider the pull-up resistor as belonging to the logic gate... we consider it as external (belonging to the next gate).

    But wait... what has remained then from our logic gate? Only a point, node, joined wires... that is why it is named "wired OR"...

    Afaq Ahmad · Sultan Qaboos University

    Dear Dr. Cyril Mechkov,

    It is exactly the NOR gate. The NOR and NAND gates are universal gates. Using DeMorgan's theorem and positive and negative logics we can interchange the logics.

  • Dr A. Kumar added an answer in Shape Memory Alloys:
    What is the significance of the peak in DSC?

    I am working on NiTi shape memory alloys. Very recently I have conducted DSC (Differential Scanning Calorimetry) on my specimens. The enthalpy of transformation (Austenite (B2) ↔Martensite (B19’)) was different. The enthalpy of transformation is related to the area under the peak. Could someone tell me the significance of lower enthalpy? Does lower enthalpy (lower peak) indicates phase transformation is difficult. What is then, when no peak is detected or the peak is too shallow? 

    Dr A. Kumar · Harcourt Butler Technological Institute

    Sharp and intense peak may represent fast transformation with larger enthalpy changes. On the other hand, broad and shallow peak may represent slow transformation along with less enthalpy changes the area of the peak 

  • How do you evaluate general protein quality in lysate?

    I would like to use relatively old lysate in an experiment (10 years old lysate).

    Because some of my antibodies are reconizing full length proteins, but also fragments and oligomers, I want to evaluate the general quality of my samples looking at the protein quality. That would allow me to be sure that my group is homogeneous in term of storage condition.

    Arutchelvan Rajamanikam · University of Malaya

    If the lysate was stored in -80C through out that 10 years, I think it shouldn't be a prob. But if there was thawing along the way, degradation would have happened. You can check on it  through SDS-PAGE. However, I doubt it would be plausible for functional analysis of proteins in that lysate. 

  • Alexandria Costin added an answer in Art:
    What is the role of street art in adaptive reuse in architecture, urban planning and design?

    Street art can encourage and /or assist adaptive reuse of buildings, post-industrial buildings, underprivileged places, urban streets and lane ways. This can be to assist and improve way finding, maintaining a sustainable city, beautifying and softening the built environment and

    Also, street art can be used as a tool to bring awareness to social, economic and political issues and cheerful and entertaining visual art.
        For example: bringing awareness of sustainable living in cities that need to improve in this area; social issues such as smoking, racism, drugs, healthy living; political art is the voice of the people;  cheerful art can help people focus just on the art piece helping people to delve into their imagination with positive, emotional and 'feel good' characteristics.

    Alexandria Costin · Deakin University

    Valparaiso in Chile is a great example of an urban community that embraces and even promotes street art in the city. The artists express social issues and political views in the form of colourful artworks spray painted on the sides of buildings, laneways and brickwalls. These artworks give the city a colourful and vibrant aesthetic and consequently it has become a tourist hotspot in Chile. I have attached a link below that gives a little insight into city.

    Cheers - Allie