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- Is it possible to calculate the degree of crystalline phase after laser heating by using DSC ? I am working on laser. I use laser to irradiate the amorphous material, then I would like to know how many percent of crystalline phase created in amorphous? Is it possible to calculate the degree of crystalline phase after laser heating by using DSC ?
Hi Nguyen, Yes it is possible to use DSC semi-quantitatively for the purpose in question.
If you want to determine the amount of crystalline phase, then you will need to generate a calibration curve. For this you will need to prepare a mixture of known quantities of the amorphous and crystalline material. There are two ways you can generate a calibration curve for your particular work; (1) you can use the step change in baseline at the glass transition upon heating for known quantities of the amorphous material in the mixture or (2) you can use the heat of fusion value for known quantities of the crystalline material in the mixture. You can then determine the amount of crystalline phase present in your treated samples using the equation from the calibration curve.
You may experience some challenges in generating a good calibration with this method e.g the crystalline content in the mixture may increase disproportionately if the amorphous material crystallizes past the Tg. Also the limit of detection/quantification of the DSC may not be very good. So for these reasons I think it would be better to use X-ray powder diffraction.Following
- Can science provide solutions for the main problems of the world?
Nowadays, there are some high priority problems at a global level, such as: poverty, limited energy resources, limited food and even drinking water (especially related to the population growth phenomenon), global warming and rapid climate changes, the gap between developed and undeveloped countries.
@ Eraldo, There is no doubt that science has provided so many things for mankind. But whatever science has provided, it has social implications. In my opinion a complete synergy is required in science and social science to have complete fruits of science. Science can affect in following ways:
i) Science can help in building scientific temper which is requirement of the day.
ii) A balancing act is required in science and social science wherein science can help in a quantifiable way.
iii) Skewed growth of science may be detrimental to society.
iv) However, as whole scientific innovations with human touch can solve much of the problems as both science and social science are complementary to each other.Following
- Has anyone experienced working with frozen PBMCs and loosing a great amount when thawing them (sometimes 50%)?
PBMCs are usually frozen in vials with 106-15x106 PBMCs/vial.
We use 10% DMSO in FBS as cryopreservation media.
This is an interesting question because many groups use fresh PBMCs due to concerns about the quality of cryopreserved PBMCs. We routinely use a 10% DMSO with 10% FBS protocol and obtain 50-65% PBMC viability by Trypan Blue exclusion. We use these cells in one way mixed lymphocyte cultures and they behave in a manner similar to fresh PBMCs. The protocol suggested by Andrei incorporates using human serum albumin, a thorough thawing protocol and slow dilution of the cryoprotectant solution. These are all excellent methods suggested by the literature for minimizing damage to cryopreserved PBMCs that are not necessarily needed for most of the relatively hardy cell lines that we work with. We will give this protocol a comparison trial next time we freeze back a batch of PBMCs.Following
- How do I compare two teacher training models on classroom pedagogy?
I am trying to compare the impact of two teacher training interventions on the teacher's classroom practice. In the first model, teachers are supported with face to face training and some print and ICT materials while the second one provide similar ICT materials with very limited face to face training and print materials. I was wondering if there is any theory could be used for such comparison.
In my opinion, the research design is determined by the aims of your research. If it is your purpose that you want to measure the impact of teacher training on teacher classroom pedagogy I believe classroom observation and stimulated recall would be appropriate. In case you want to find out which model of teacher training leads to greater improvement of teacher classroom pedagogy you need to observe them before providing any training then post-training observations. In either case, an experiment design, from my personal view, is not appropriate. Regarding the theory, again an appropriate theoretical framework is determined by your research focus.
- How do you measure the social impact of the Use of Renewable Energy Sources in electricity generation?
Many places are carrying out programs energizing communities, buildings and facilities, I would like to know how to measure social impact or measure the social impact of the energization.
Thanks for the comment, Nicola.Following
- What is the easiest and quickest (screening) method to evaluate the degree (mild, moderate or severe) of intellectual disability?
We aim to investigate the prevalence of mental disorder in individuals with intellectual disability in Portugal, and it would be important to administer a simple screening tool to divide the sample into mild, moderate and severe impairment, prior to administering the Mini-PAS-ADD.Following
- Can anyone give me some information about -t option of Linux Perf tool?
I have two questions about Linux Perf tool. I would be very thankful if you answer me.
1- As you now perf stat has an option called -t which is used to attach perf stat to a thread. I want to know whether this option can be used by two or more than one thread? for example: perf stat -t x,y (x and y are the ids of two active threads).
2- when you attach perf stat to a thread using -t option, perf stat is not terminated when the attached thread is finished, and perf stat continues its execution. May I know how I can solve the problem?
- Do you know of a 'biomarker' of the activity of protein synthesis (translation)?
I observed markedly different weights of a specific organ in my animal model upon treatment. My hypothesis is that this change is largely driven by protein. I would like to examine if the translational activity is changed. How would you adress this? Do you know of any well established markers of protein synthesis activity? I was thinking about eIFs, but this would also relate to ER stress, right?
How about a Western blot to analyze phosphorylation of S6k1 and 4EBP1? That would be an indication of increased protein synthesis.Following
- Can anyone please explain why the magnetoresistance may be negative?
I am investigating the magnetoresistance in 2-D quantum wells and superlattices. The magnetoresistance is both positive and negative but I do not understand why it is negative. Please explain this for me if you can.
Thank you in advances!
Thanks for Profs. Ernesto Medina Dagger and Aseel B Al-Zubaidi answers very much!Following
- What is the minimum number of participants in a study?
Suppose we have an EEG study with 3 groups. The recorded numbers of participants for each group were 7, 3, and 7, respectively. The reviewer correctly claimed that this is not enough statistically significant to study the differences among the groups. I quote: "aiming for a medium effect size of Cohen’s f= 0.25 (#=0.05) and a power of 0.85 for condition x group interaction effects, one would need a total sample size of 48 subjects, thus at least 16 subjects per group." Which equation led to that conclusion? Suppose we reduce the number of groups to two. How would that change the minimum total number of subjects?
Thank you very much for your reply.
In my opinion there is no answer to this question. In general you first have to perform a power calculation based on pilots or previous experiments. Then you can calculate how many subnjects theoretically are necessary to demeonstrate a statistical difference between groups.Following
- How to add equality constrain to the objective function in the Matlab simulated annealing optimization functions?
I am using Simulated Annealing matlab functions. I need to add equality constrain for the parameters. How can this be done.
There are many constraint handling methods, for example if you have an equality constraint you can reduce the number of variables by the number of equality constraints you have. Consider a minimization problem with objective function being f(x1,x2,...,xn), and suppose you have an equality constraint given by a1x1+a2x2+...anxn=b, from this xn=b-a1x1-a2x2+...an-1xn-1. From this your objective function will be f(x1,x2,...,xn-1) and no more equality constraint.
you can also use penalty method, or feasibility check at each run of the algorithm (here you have to make sure your initial solutions are feasible)Following
- How do I get the latest elderly population data?
I am doing one research project so i need elderly population
You may get ans from following links.Following
- Is a second-step lectotypification appropriate after the original lectotype was destroyed?
For several taxa in the group that I work on (Passiflora sect. Dysosmia), the lectotype that was originally chosen was destroyed in the 1943 fire at the Berlin-Dahlem Herbarium (B). When picking new lectotypes for these names, do I go through a "second-step lectotypification", or are they just simply "new" lectotypes?
There is a tiny blurb in the Melbourne Code about second-step lectotypification (Art. 9.17, Ex. 12), but it looks like this deals only with situations where the original (= "first-step") lectotype is too ambiguous in some way; so one may need to "further narrow down" the lectotype using the second-step clause. It doesn't say anything about a lectotype being destroyed, however.
Perhaps this point is a little trivial (because either way I'll be referencing the destroyed lectotype), but I just want to make sure I don't misuse the term if I'm not in fact performing a second-step lectotypification.
Unfortunately, drawing or the photo often happen very poor quality and not always represent necessary diagnostic signs. I think that to start to really check yourself herbarium "B". If there really is no original material, then it is preferable to choose a neotype. The neotype has to be not necessarily connected with initial material, it can be a collection of other authors, it is desirable from the локус classicus.Following
- Is it is fine to define the natural carbon cycle in terms of carbon sequestration?
I'm totally confused with the term carbon sequestration potential of any biomass (plant or animal) and carbon accumulation potential in the form of biomass.
Is carbon sequestration is natural process or something effort-ed by human beings (anthropogenically)?
In forestry systems, the stored carbon is that which is contained in the soil, forest floor, understory and tree layer. For example, in a newly established plantation, the stored carbon is one that can quantify at this time, while the carbon potential is one that might accumulate at the end of the production cycle.
Regarding your question I think is a natural process altered by anthropological activity.Following
- How to measure feasibility of implementing / integrating PLM manufacturing ?
How to measure the feasibility of implementing PLM Manufacturing into an existing organisation ?Following
- How the difference in mole affect the shape of the nano-particle? I made nickel nano-particles with surfactant, having 0.05M concentration of nickel acetate salt but did the process in 20 ml of water and 50 ml of water, rest all conditions are the same. Hydrazine hydrate was the reducing agent used. One has a thorny rod shape structure while the other doesn't have the rods but they kind of both spherical and thorny (totally uneven). I used between 80 as the surfactant and I am struggling to find its role in the synthesis process and also this structure difference due to moles. Without surfactant it also gave the same results so I feel there is no role played by the surfactant.
Hai Deepa, how are you? First i congratulates you. This is very good research. I think that the change due to Size dependence of the dispersion.
Have a nice dayFollowing
- How do I prepare 9k medium to grow bacteria?
I will have to use 9k medium to grow my bacteria. I already have the composition of the medium, but I am really confussed in the process of making it. some papers says that I should mix both solutions together and autoclave them and some other papers suggest to only autoclave the first solution ((NH4)2SO4, KCL, K2HPO4, MgSO4, Ca(NO3)2 and DI water and after this one is autoclaved I should add my FeSO4 solution which I will filter.
Im really confussed about How to prepare my medium.
In advance thank you very much
(NH4) 2SO4 3.0 g
KCl 0.1 g
K2HPO4 0.5 g
MgSO4. 7H2O 0.5 g
Ca(NO3) 2 0.01 g
Distilled water 700.0 ml
FeSO4. 7H2O 44.22 g
H2SO4 (1N) 10.0 ml
Distilled water 290.0 ml
Solution A & B should be sterilized separately and then mixed asceptically.Following
- Can anyone suggest some keys for identification of marine and mangrove fungi in India?
Fungi colonizing on wood debris and twigs of Mangroove plants like Rhizopora sp Avicennia sp, sonnerita sp
Thank u sir That text book will be more usefulFollowing
- Are there reports of malaria cases in the Pampa biome (Argentina and Rio Grande do Sul)?
In the 1940s and 1950s there have been cases of malaria in the south of the Atlantic Forest biome, however, never read anything about the Pampa biome.
Thank U! Did not know the existence of such maps.Following
- How can I measure COD of pure fruit juice puree/pulp?
Can anyone suggest a suitable way to measure COD of pure fruit juice puree/pulp to be used in MFC analysis?
Dilute the pulp with MilliQ or distilled water to uniform solution in proper COD concentration range, and mearure it with standard method.Following
- How can I calculate the speed at which a player moves in a badminton court?
I am trying to measure plantar pressure in badminton players when they make the shift to the net for linking with lower body injuries and need to have speed variable at which they are shifting around the court. Does anyone have a similar laboratory study with which to help me?
Thanks in advance
Hi Raul, As far as I remember, Lafayette Instrument Corporation had a system (way back in 2005, when I met them in NASPSPA Conference in Florida). That system works with simple videography. From the videography of any reaction-movement, reaction-movement time could be analyzed by employing simple markers attached to any body part, which could be identified by a cheaper software (it was only USD 840 then), that enables the researcher to obtain info. w.r.t the RT & MT of the players.Following
- How should I represent the charge and spin multiplicity of an Acid-Base reaction in Gaussian?
When you set up the initial geometry of a TS in Gaussian, should I be modelling the charge and spin multiplicity of the TS itself or either the product/reactant? For example, in the case of the dissociation of acetic acid in aqueous solution (see link), I assume the H is between the H3O(+) and acetic acid. What charge would I give the water molecule as the third hydrogen is technically being shared with the carbonyl group for a fraction of time?
The multiplicity is considered for the total system including all molecules participating in the reaction.Following
- Could value added be a proxy for economic growth?
Economic growth usually has as proxies GDP growth or Home income growth. The dependent variables in my studies are gross value added or value added at factor costs.
Thank you for your answer!
- Optimal CO2/O2 concentration to culture human iPS cells?
I would be grateful if some of you could tell us about optimal CO2 and O2 conditions for human induced pluripotent stem cells (IPSC). We would like to cultivate these cells in pluripotent state, and also try to differentiate them into neurons.
Thansk in advance,
Thanks a lot, Another question 5% CO2 in air, or do you balance levels of O2 by N2?Following
- Which are suitable methods to isolate fungi from decaying wood debris or twigs of mangrove forest?
I had worked following methods to isolate fungi
- Single spore isolation
- Direct isolation
- Serial dilution
Is there any methods other than this? Please suggest a good articles regarding these methods.Following
- Circulating micro-RNA isolation - which method do you prefer?
I am new to the field of circulating nucleic acid detection. I would like to search for microRNA down/upregulation in blood samples from patients suffering from certain type of cancer. I have never tried to isolate and quantify extracellular micro-RNA. Have you tried it? Maybe there is a good kit you can recommend? Is the 30-5-5 min serum centrifugation necessary?
Hi Filip. We are using this kit http://www.mn-net.com/tabid/11246/default.aspx (nucleospin miRNA plasma) from Macheney-Nagel with very good results. We use plasma, not serum for microRNA purification.
The small amount of small RNA in plasma samples makes quantification in nanodrop unsatisfactory, and therefore, we use directly 4 µl of the eluted RNA for the RT.
For relative quantification we are using a endogenous reference control (miR-16). From non-degraded plasma samples you will obtain Ct for this microRNA ~20.
You can obtain similar results using this kit from EXIQON: miRCURY RNA Isolation Kit - Biofluids.
- What is your idea about "negative intercept" in calibration curve in HPLC? Can you recommend a good book on this subject? What is your idea about "negative intercept" in calibration curve in HPLC? Can you recommend a good book on this subject?
Thanks for all the replies. Actually the plot was constructed with current vs Concentration by standard addition method and linear curve was obtained but with a value of negative (-y intercept). like
- About the partial deletion of the KANSL1 in DGV database?
The article "Mutations in the chromatin modifier gene KANSL1 cause the 17q21.31 microdeletion syndrome" is very nice work. But I have a question about the pathogenicity of the KANSL1(KIAA1267).
In the database DGV(Database of Genomic Variants,http://dgv.tcag.ca/gb2/gbrowse/dgv2_hg19/), this deletion of KANSL1 can be found in the healthy control samples.So, the loss-of-function carrier of KANSL1 maybe healthy. And how can we confirm that the relationship between the loss-of-function of KANSL1 and the disease phenotype?
Actually, the deletion falls within a highly polymorphic region. This region can undergo duplication in general population, mostly of european ancestry. You can make a confirmation of these results with different tecniques (e.g., qPCR, FISH), evaluate carefully clinical manifestations in carriers, and finally analyze KANSL1 at a mRNA level. Moreover, compound heterozygous mutation (deletion plus point mutation) is always a possibility to lead to the clinical phenotype. Keep in mind the platforms used to evaluate such deletion in DGV, because previously one used aCGH with "controls" harbouring the same region duplicated. I hope this make sense to you. Greetings.Following
- Which is the correct resonance form of Nitrate ion?
I attach the a file containing two sets of resonance structures. Can you please identify which is the correct resonance form of Nitrate ion?
Both I and II can be identified as resonance, since the configurations involved correspond to energetically degenerate states.Following