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
  • Dear all, can anyone tell me something to obtain a lipid characterization in human tissues in-vivo?

    I would like to quantify the hydrophilic lipids (polar) and neutral hydrophobic lipids (neutral) fractions. In particular, if it would be possible, using Magnetic Resonance Imaging and/or Magnetic Resonance Spectroscopy techniques. Thanks in advance.

    Ernesto Roldan-Valadez · Médica Sur Clinic Foundation

    As far as I know there is scarce (if any) information about DTI and its diagnostic ability to detect lipid content. In my view, it would be a topic with clinical applicability specially in survival of patients with aggressive brain tumors like glioblastoma multiforme.

  • Alvin Vista added an answer in Linear Regression:
    How to perform a general stepwise linear regression model to identify a covariate for gene expression?

    I have b-actin (and several other gene) expression data for 4 different population groups. I want to know if age can be variate for b-actin expression in these 4 groups. Should I perform a general stepwise linear regression model to identify age as a covariate? And How do I do it for 4 groups?

    Alvin Vista · University of Melbourne

    are you trying to find out if age predicts the expression of b-actin (or any other gene)?

    if yes, then age is a predictor, rather than a covariate. 

    if you have other predictors and want to control for the effect of age, then you can treat age as a covariate.

    the type of analysis will depend on your research questions.

  • Does anyone know research on mathematical modeling of fluid circulation in deposits volcanogenic massive sulphide-type?

    I am looking for research on mathematical modeling of fluid circulation in deposits volcanogenic massive sulphide-type. Thanks

    Kasturi Bhattacharyya · IIT Kharagpur

    Fliud modeling can be done using PetroMod Basin Modeling software....

  • Kenneth M Towe added an answer in Plasma Membrane:
    Best protocol for plasma membrane preparation for electron microscopy ?

    What should be the best protocol for plasma membrane preparation from cultured mammalian cell lines ?

    My goal is to obtain large (micron) sheets of plasma membranes in their native state, for electron microscopy and cryomicroscopy. 

    Thanks for sharing your ideas.

  • Manuel Jimmy Saint-Cyr added an answer in QIAGEN:
    In DNA isolation from Stool using zirconia beads, would vortexing the samples be an alternative of using a bead beater?

    I am using the QIAGEN kit for DNA isolation from stool for bacteria detection. I am also using Zirconia beads for mechanical destruction of the bacterial cells as a step in DNA isolation. I don't have a bead beater , Omnilyser or similar instruments. Would vortexing the stool sample containing the beads be enough? If yes, then for how long do you suggest?

    Manuel Jimmy Saint-Cyr · École Nationale Vétérinaire, Agroalimentaire et de l'Alimentation Nantes-Atlantique

    Vortex can't replace a bead beater

  • John Jupe added an answer in 3D Computer Vision:
    Does visual art render visible the fundamentals of perceptual structure from which both explicit ‘what’ and implicit ‘where’ takes on reality develop?
    If so then to what extent can this ‘model’ of visual perception be used to direct the development of vision science?
    Is this proposition meaningful to a cross-disciplinary section of the research community?

    Vision-Space is a new form of illusionary space that's based on perceptual structure and not the fundamentals of optics (or central perspective). It models both the data-strcutures and the dynamic of information exchange taking place within phenomenal field (experiential vision). As such we believe that it starts to model visual awareness. At present the programming architecture for Vision-Space is 'illustrative' in nature. It transforms optical record to accord with our understanding of perceptual structure. Vision it appears, is almost entirely non-photographically rendered. While this software can at present generate Vision-Space moving image media, to move the project forwards we need to create an 'academic' programming architecture advancing a 'generative' programming architecture. This architecture must take account of aspects of neural processing. Such an architecture could obviate the the requirement for optical projection as the basis for image generation and produce stimuli for experimentation to probe perceptual structure in detail.
    John Jupe · Perceptual Awareness Centre

    Morning Louis!

    ''Visual indeterminacy'' is of some interests but don't forget the point of the visual system is to be determinate! '' Visual indeterminacy'' is certainly not a description of the nature of perpetual structure. It's also not linked to QM indeterminate state. Much of implicit field is based on probability resulting from texture analysis. Is this value greater than that?, can it be grouped?, or is the step change between adjacent values so denoting spatial discontinuity? etc. '' Visual indeterminacy'' is the fence-sit until a direction is forthcoming. When we are not sure of a form we in-fill (sift through memory)  and extrapolate. As a result of that we can 'see' a rabbit and keep seeing it until it fails to move in a way commensurate with the way a rabbit would move. We then abandon that strategy and 'see' a lump of mud. If we don't look at it we simply get a spatial cue that forms part of the implicit spatial field - no interest in rabbits or mud! I want to know about the structures of vision. It's easy to keep a moron in suspense………………………………………………………(that's a joke Louis!)

    As you appreciate well, we create the saliency of vision as much as we detect it. Either way, vision is 'one way' and diagnostic in nature. You won't be able to trace a picture back to the retina just as you won't be able to trace a 'picture' being transposed to 'mind'. This is why disorder is interesting as structure? You can't reverse engineer that either! 

    For me I think there has to 'a' perceptual structure through which we understand the world irrespective of modality (sense organ - ecology etc). Even touch is understood in terms of 'what' and 'texture -context'. The interesting thing is that fixation (explicit attention) in vision is the same device as that used to 'attend' to a particular sound. What's happens to the structures of vision when we are attending to a particular sound? This is what interests me. The implicit field of Vision would appear to become  body centred - set out from us as the locus so still providing spatial proximity cues but no explicit form cues. It's vital to first appreciate the field structure to sensory perception and then how we use it. This will tell us so much about what's going on in visual process.

    If we can 'crack' vision - the rest will follow. 

    This is why I think its essential to get VS up and running in a form that scientists can test, evaluate and develop (even if they don't want it!). We need VS stimuli and when we have investigated we need it deployed in our technologies.

    The new painting is going well and I think there will be a good deal to discuss when completed. I am rendering phenomenal vision outside of visual field as the body centred proximity field. So the live view in visual field centred around fiction sits within prior acquired information in the rest of phenomenal field that's body centred. 

    We have got this body centred (camera centred) algorithm set up in the Post Production Tool but haven't tested it yet. If we can just get some funding we can get it all operational.

    Best - J

  • How are microfosills used to resolve sedimentary basin analysis issues?

    Based on forams, nanofossils, palinomorphs and ostracords.

    Kasturi Bhattacharyya · IIT Kharagpur

    you can use microfossils that are index fossils to resove chronological issues in sedimentary basins..

  • Spiros Koutandos added an answer in Schrodinger:
    What is the significance of the harmonic oscillator in quantum mechanics?

    In an article I posted at www.gsjournal.net "About the dimensions of h bar" I noted that the time derivative of the radius squared is equal to velocity times radius and that in turn is proportional to the wavenumber times the radius. This is just the phase of the wave. So I believe the harmonic oscillator potential is inhereted in Schrodinger equation in some way and we may always transform our potential to harmonic at some cost. Does any body have an idea of how to do this?

    Spiros Koutandos · ESPERINO

    I think my finding has something to do with Feynman 's path integral where he puts in the phase harmonic oscillator potentials but I dont remember the exact formulation

  • How can one quantify the ionic as well as covalent character of a crystal structure?

    For example, Wurtzite structure can have a mixture of ionic as well as covalent character..but how can we understand how many percentage is covalent and ionic nature? Is there any experimental facility to determine? Or theoretical band structure analysis can predict? Please suggest a solution.

    Giovanni Ferraris · Università degli Studi di Torino

    If one is just looking at the covalent percentage of a bond the following formula given by Linus Pauling  (1960, The nature of the chemical bond) can be used. Given the difference in electronegativity (EN) between two atoms X and A, the degree of ionicity (ID) of an ionocovalent bond can be evaluated by the following equation

    ID = 1– exp[–0.25(ENA–ENX)**2]

    Electronegativity is the property of an atom to attract electrons when a chemical bond is formed. E.g., by using EN = 1.0, 0.9, 0.8, 4.0 and 3.0 for Li, Na, K, F and Cl, in the order,  ID = 0.67, 0.70 and 0.89 for NaCl, KCl and LiF is obtained, respectively.

  • Salvatore Nasisi added an answer in ANSYS Workbench:
    How can one merge nodes on two co planar faces in Ansys WB ?

    Hi,
    I am simulating a fracture problem. For that, I split a body into two bodies with slice by plane. That gives two faces at the same location (at intersection of bodies). Again, I split faces on each body at intersection into two faces with a sketch edge. Now, I have four faces at intersection (two faces on one body and two faces on other body). After meshing it I want to merge nodes on two faces (one face on one body and another face on another body). How can I merge nodes on two faces that exist in same location in ansys workbench?
    (For my problem I can't use form parts in DM)

    So, finally I need help on merging nodes on two geometrically similar faces at same location (coplanar faces).

    Salvatore Nasisi · Czech Technical University in Prague

    Excuse Saimohan..you say the problem is that "for new part" option creates a continuous mesh over the whole interface but this is what you don't want because you want a part of the interface with same nodes and other part with not same nodes. So, why don't you use for the whole interface the option "imprints" ? This creates a conformal mesh for only the part where you want same nodes, but does not create conformal mesh in the other part where you don't wanna share same nodes..the first problem occurs because you're using "share topology". This is what i see through the picture...

  • What would you do if you received a report from the reviewer of your paper asking for a major revision, with which you completely disagree?
    What would be your response? Would you appeal to the editor by asking him/her to make the final decision, would you be weak and amend what you believe is right, would you argue back with facts, would you re-submit the paper to another journal?
  • Can anyone help me to improve the following method for purification of acetylene using H2SO4 and NaOH

    Acetylene can be produced from the reaction of CaC2 and H2SO4:

    CaC2(s) + H2O ---> C2H2 (g) + Ca(OH)2

    Then, in the next step H2SO4 is used for the purification of acetylene to around 99%.
    I know if we produce acetylene according to the conventional method, using CaC2 and H2O, then we can purify the acetylene using different methods. There are different impurities in the produced gas. Moreover the N2 exists in the produced gas.

    May I know your suggestion for better purification of gas?

    Three columns were used for the acid wash step. In first column the weak acid is used for the washing at 45 C, in second column stronger acid is used at 45 C, and in the 3rd column NaOH is used for purification. During this procedure we are facing some problems as mentioned bellow. I need some suggestion to identify the following issues?
    1- The gelatinous brown material, in the top of the column that used for acid washing the gas.
    I think this was formed by the reaction of 98% H2SO4 at 40 to 60 degree C with acetylene.
    Under these conditions, I think the acetylene will polymerize forming tar like products.
    I am looking to confirm this theory- so is this jelly a mixture of polymerized acetylene and H2SO4? How can one prevent it?
    Is it correct to say that polymerization of C2H2 means longer chain hydrocarbons?
    As this is occurring in the presence of H2SO4, I guess there will be C4, C6, C8 compounds with SOx fragments. is it correct?

    What kine of characterization techniques can be used to confirm the existence of these products? FTIR, XPS, GC/MS are adequate for this purpose?

    2- The hard crystals
    These form in, and at the exit of, a tower containing 10% NaOH.
    I suspect they are the result of reaction of H2SO4 with NaOH. This crystal might be Na2SO4?

    I really appreciate your cooperation and guides.

    Best regards,
    Zahra

    Rastislav SOLÁR · University of Technology in Zvolen

    Dear Zahra,

    though I am not any expert in acetylene chemistry and purrification, I think you are right when guessing the gellatinous product on a top of the second column might be acetylene polymerization products. The reaction starts via addition of H+ on one of the two pee bonds of acetylene as follows: C2H2 + H+  =  CH2=CH+ carbcation which starts polymerization of acetylene. According to the reaction conditions linear by-products containing -SO3H, or aromatic - benzene and styrene  at high temperatures over 4OO oC may be formed.

    Maybe HPLC/MS,  CG/MS or PY-GC/MS could give you information concerning the "jelly". H1 NMR, FTIR or even UV spectroscopy can give you also intersting data, problem is quantification of the by-procucts

    I am of the opinion, that reduced washing temperature of the produced acetylene with H2SO4 and higher number of columns might supress formation of "polymeric unsaturated moieties".

    As for the crystals arising in the final alkali washing tower, they are posibly a mixture of Na2SO4 and H2C=CH-/CH=CH/n-CH=CH-SO3- Na+ salts.

    Best regards,

    R.S.

  • Please suggest a standard for carbon isotope analysis of bone extracted collagen?

    standard for mass spectromectric analysis

  • Do you know the concentration of TCEP for protein purification?

    I'm working with a zinc finger protein and we need to test TCEP in the step of purification.  I need some suggestions about the concentration of TCEP in the buffer that contains ZnCl2, considering that TCEP can chelate the zinc. Thank you very much in advance.

    Misha Soskine · University of Leuven

    It depends on how efficient is TCEP in extracting Zn from zinc finger.

     I would mix the protein and TCEP and findout what happens to the zinc finger.

    (My guess - not much since it has nM affinity to Zn)

  • Gerhard Leichtfried added an answer in Rhenium:
    Does (densely) sintered W-Re or Mo-Re have a certain ductility or does it have to be worked and heat-treated?

    Does (densely) sintered tungsten-rhenium or molybdenum-rhenium have a certain ductility at room temperature or does it have to be worked and heat-treated first? If the first is the case, is there a minimum rhenium content to achieve a considerable elongation? Thanks!

    Gerhard Leichtfried · Plansee

    Dear Christian,

    in the paper Leichtfried, G., Schneibel, J., Heilmaier, M.: „Ductility and Impact Resistance of P/M Molybdenum-Rhenium Alloys“,Metall. Mater. Trans. 37A (2006), 2955-2961 (for downloadung see https://www.researchgate.net/profile/Gerhard_Leichtfried) tensile elongation, reduction in area and Charpy Impact energy in dependence on Re-content, testing temperature and microstructure are given. Sintered fine grained Mo-41Ma%Re with a density of 97% has ductility values comparable to the values for coarse grained recrystallized material. HIPed Mo-41Ma%Re has ductility values close to those of fine grained recrystallized material, if grain coarsening is avoided during HIPing.

    Best regards

    Gerhard

  • Which open-source software do you prefer for measuring cortical brain thickness and volumetry?

    Several open-source software allow measurements of brain gyri, some of them are FreeSurfer, Siena (FSL), SPM, MIPAV (NIH). Which one do you think is better accepted by the scientific community?

    Ernesto Roldan-Valadez · Médica Sur Clinic Foundation

    Thank you Paulo. I guess we have a winner software here :-)

  • Behrouz Ahmadi-Nedushan added an answer in Shyness:
    How to increase the group discussion skills of the students?

    Dear Professor/RG members/friends,

    Some of the class toppers don’t speak in the structured or in the unstructured mock group discussion. They don’t shed away their shyness.
    Some of them may be good in class seminar presentation . But they don’t make their contributions in discussion. Even though we educate them on

    What should be done and what should not be in the GD,
    on the various tips (internet sources)
    collected from management experts ;and
    arranging guest lectures by corporate sector managers.
    At the same time some of the average students make their best contributions in the GD. I used to appreciate them.

    Dr. Shanmugasudnaram P

    Behrouz Ahmadi-Nedushan · University of Yazd

    Several points should be kept in mind to develop group discussion skills.

    • During conversation, observe yourself and how others in the group react to you.
    • Pause and restate your point differently if the reaction is not what you expected.
    • Listen to others and ask clarifying questions.
    • When you do not agree with others, express your views politely without interrupting.
    • Express your views by giving examples to substantiate your point of view.
    • Listen to their clarifications and ask questions to clarify your doubts if any.
    • When you agree with someone else’s point of view, express your agreement and the reasons for your agreement.
    • Summarize your and the other person’s views and elicit the understanding of all the participants on the views expressed.
  • Hugh J Byrne added an answer in Doppler Effect:
    Why do we get broadened peaks in Raman Spectroscopy?

    Ideally one should get single lines corresponding to different vibrational excitation in a sample for Raman Spectroscopy. But we do not observe the same in an experiment. One of the arguments given in its favor is Doppler effect. We can easily perceive this in liquids or gases but for solid powder samples I find it hard to visualize. One reason that I can think about is instrument resolution. But I am not sure if this is the only reason. Hence, I want to know the reason behind Raman peak broadening in solid powder samples.

    Hugh J Byrne · Dublin Institute of Technology

    In general in spectroscopy, the line shape is determined by the intrinsic properties, and can be further homogeneously or inhomogeneously broadened. Doppler, collisional, thermal are often classified amongst the former (although at any moment in time, different species in an ensemple are broadened differently). Inhomogeneous broadening is usually more extreme in solids, particularly in amorphous, chemically and physically inhomogeneous samples, in which the chemical composition, crystal size, molecular chain length, morphology or local environment can vary significantly for different parts of the sample. Each variation has a slightly different specrtum (each of which has the homogeneous linewidth), and so the integrated spectrum of the ensemble can be sugnificantly broadened.

    See for exaple Laser Spectroscopy, by Demtroeder

    http://books.google.ie/books/about/Laser_spectroscopy.html?id=5vuqvvb9YxkC&redir_esc=y

  • Why do particle suspensions exhibit shear thickening behaviour?

    Flow curves which I have obtained for 1% (w/v) suspensions of kaolinite clay, montmorillonite clay and silica microspheres all reveal shear thickening behaviour (an increase in viscosity) at higher shear rates. As I understand it, this is to be expected but I would like to know why it happens.

    Aroon Shenoy · SAICO

    You are essentially dealing with a two-phase system in which there is a dispersed phase that lives inside a suspending medium which acts as a continuous phase.  Spatial arrangement and distribution, agglomeration and de-agglomeration during shear are responsible for shear-thickening and shear-thinning behavior. The basic knowledge on such type of systems can be got from the book

    Aroon V. Shenoy, Rheology of Filled Polymer Systems, Kluwer Academic Publishers, Netherlands (1999).

    There is a chapter on constitutive theories and equations of suspensions where the effects of shape, concentration, dimensions, and size distributions of the particles have been discussed. 

  • Stella Helten added an answer in Physisorption:
    Could anybody suggest how to discriminate between physisorption and chemisorption of CO2 onto activated carbons?

    Is chemisorption kinetic slower?

    I've measured the CO2 sorption onto some activated carbons by using TGA. My samples exhibited different sorption kinetics. In particular virgin carbons show quite fast kinetic, while functionalized (e.g. amino groups) samples take longer to reach the plateau. Is it a reasonable behavior?

    Also, according to the literature, the "isosteric heat of adsorption" gives a reliable indication about the interactions between the sorbent and the adsorbate (e.g. CO2), thus suggesting which type of sorption (i.e. physisorption or chemisorption) process is actually occurring. 

    How can I calculate this parameter? Should I use the Clausius Clapeyron equation? Do I need CO2 isotherms data (V vs P/P0) measured at different temperature values?

    Stella Helten · Technische Universität Dresden

    Please do be careful with the Clausius-Clapeyron equation: A requirement for being able to apply the equation is complete reversibility, meaning in the evaluated pressure range the adsorption branch has to be the same as the desorption branch. So, if you have chemisorption, that is probably not the case. Is your isotherm reversible? The slower kinetics seem reasonable, both due to possible reaction and some temporary pore blocking due to your functionalization. Don't you have access to a volumetric adsorption apparatus? Many of them offer chemisorption measurement modes, also temperature variation is easily achievable by using ice, dry ice mixtures, external thermostats for room temperature etc

  • Does anybody know about a specific tool for evaluating end-of-life in nursing homes?
    Looking for experiences of evaluating quality of end-of-life in nursing homes or similar.
    Rafael Montoya-Juarez · University of Granada

    Thanks Bojana. I am afraid I have been very disconnected to the network, but those are interstisting results. I will take a look 

  • Andrey Zhiglo added an answer in Photons:
    Do single photons propagate at the same speed as beams of light?

    When we measure the speed of light, we measure a beam or pulse. Are we correct to extrapolate this speed to single photons?  Are we correct to infer that single photons have any definite speed, at all?

    In QED, a definite speed is assumed.

    Andrey Zhiglo · National Science Center Kharkov Institute of Physics and Technology

    Photon is a quantum of perturbation of EM field. Such perturbations propagate with the speed of light, c. The space-time dependence of the photon operator \hat{A} is exp{i(kx - \omega t)} for a photon propagating in x direction. Its frequency and wave-vector absolute value are related as \omega = kc, which is one way to say (and know) that the photon speed is c. It's precisely the phase velocity of EM waves. A "beam" or "pulse" in your question probably refer to a EM wave that is a superposition of flat waves, which [superposition] has a discernible front or whatever other spatial feature that can be used for its speed measurement. At least this is my interpretation of your

    > When we measure the speed of light, we measure a beam or pulse.

    -- that you refer to measuring the speed of such a feature, i.e. essentially refer to measuring the group velocity. The latter is still c, as in empty space EM waves are dispersionless. With all this sophisticism -- I believe it's clear in what sense single photons "have a definite speed"; and that speed is c.

  • Kelly Cohen added an answer in Intelligence:
    Where is the intelligence in AI?

    Like many others, I am very enthusiastic about artificial intelligence, but the more I studied the AI, the less intelligence I found in it. What I found was classification, pattern recognition, and regression. Is there any hope for real AI to be developed in the future? Is it still correct to call AI AI?

    Kelly Cohen · University of Cincinnati

    I suggest that you explore some bio-inspired techniques such as artificial neural networks, genetic algorithms, fuzzy logic, swarming. I have found that these approaches provide interesting insights.

  • Do you have experience in and are interested in a possible collaboration in research on "approaches to learning"/ "approaches to teaching"?

    Dear colleagues, 

    I am interested in conducting research on the "approaches to learning" (SAL, Students' Approaches to Learning, Biggs, Marton, etc.), or "approaches to teaching" (Trigwell, etc.) line of research  with international partners, or maybe participating in a project already underway. So far I have analysed the approaches to teaching of secondary education trainee teachers in my home country (Spain), but would like to broaden my horizons. Would anyone be interested in a possible collaboration?

    Ralph Adon Córdova · University of Missouri - St. Louis

    Greetings, sounds like many are interested in your call. For the past decade my research community www.ourCoLab.org has been studying how transformative teaching & learning communities form, how to intentionally shape them, and, how to nurture intentional collaborative approaches among teachers and schools  around a  process we developed called the Inquiry into My Practice (IMP).

  • Please suggest names of institutes where one can send samples for peptide mass fingerprinting in India?
    What preliminary processing is required?
    Kanwaki Patwari · Tezpur University

    Ma'am do you have any labs in India that offer PMF

  • What are the legal mesasures for vulnerable (energy) consumers protection and fighting energy poverty in your country?

    Are they effective? Examples and references are welcome.

    Eraldo Banovac · Croatian Energy Regulatory Agency

    Dear Mariusz, It seems that ensuring subsidies as general social measures, including those intended for energy poverty, are reality regardless of their questionable response to the considered problem. From my point of view, an efficient response to such a situation could be a hypothetical long/term economic growth (to achieve much higher GDP per capita). However, implementation of resonable social measueres could be indispensably even in such a case. 

  • Jacob Lim asked a question in Dielectric Constant:
    What is the effect of concentration of salt in DI water on the overall dielectric constant?

    Testing a self made capacitor with changeable dielectric solution.

  • Sandrine Joachim asked a question in Fish Health:
    How can some bacteria affect fish health?

    Hello,

    The following colonies of bacteria were found in our mesocosms :

    Microbacterium aurantiacum
    Serratia  fonticola

    Brevundimonas mediterranea
    Enterobacter amnigenus
    Lysinibacillus sphaericus

    Does anyone know if these bacteria can effect fish health. I have found literature on Lysinibacillus sphaericus but not the other microorganisms.

    Thanks!

  • Is there any other property other than absorption, emission and scattering of light can be used for spectroscopy?

    It is known that Absorption, Emission and scattering property of light can be used in spectroscopy.  Is there any other property of light can be used for spectroscopy.

    Maddali V S Murali Krishna · Chaitanya Bharathi Institute of Technology

    Spectroscopy pertains to the dispersion of an object's light into its component colors (i.e. energies). By performing this dissection and analysis of an object's light, astronomers can infer the physical properties of that object (such as temperature, mass, luminosity and composition). Hence physical properties of an object plays an important role apart from wave length and frequency of light wave

  • Petr Mrak added an answer in TiO2:
    How can I determine concentration of TiO2 in aqueous solution by titration?

    I have TiO2 aqueous suspension (pH3) with unknown concentration. Due to some technical issue, I can’t use UV.VIS spectroscopy for determining the concentration. Can I determine concentration of TiO2 by titration?

    Petr Mrak · DOMA, Ltd.

    Dear Maryam,

    As I understood, the TiO2 concentration is more less than 50 mg TiO2 in 1000 mg of suspension? (about 30 mg Ti/g suspension). As you can't use UV-VIS and even ETA-AAS(?), try, please, to search "(micro)determination of Ti by chelatometric titration" by a browser (Google, sciencedirect...). Regardless of other simultaneously present (Al, Fe....?) ions to be "blocked" conveniently, I am not sure if Ti-concentration is not very low for this determination. May be after preconcentration (e.g.by oxine?). Good luck!

    Regards, Petr, alias Karel FIALA.