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  • Tawfiqur Rahman added an answer in Optimal Control:
    How can I simulate a time optimization problem in matlab using m code?

    Hello! Sorry for my english.

    I'm trying to simulate on Matlab using "m code" a time optimization problem for a non-linear system. I want to lead my system from my initial conditions to my final conditions(BPV) on the minimum time. Do you have any idea how to do that? or any example, or something?

    My first problem it's because I already know initial conditions and final conditions of my system, but my initial conditions for my co-state of Hamilton equations are were unaware and final time too. I attached my problem.

    Thank you so much in advance.

    Arturo Gil

    Tawfiqur Rahman · Bangladesh Air Force

    You can use 'fmincon' command in MATLAB for optimization.In order to model your problem go through the help documentation in MATLAB. To make it more easy to understand see the command:   x = fmincon(fun,x0,A,b,Aeq,beq,lb,ub). Here the system dynamic equations will be in the 'fun', x0 is the initial guess of the solution, the equality and non equality equations are in Aeq, beq and A, b. You may consult some papers on trajectory optimization using shooting method in MATLAB.

  • Peter Mwangi Macharia added an answer in ArcMap:
    Does anyone know an extension of AHP that works in ArcMap 10.2?

    The Analytic Hierarchy Process (AHP) was introduced by Saaty (1977) and is a very popular means to calculate the needed weighting factors by help of a preference matrix where all identified relevant criteria are compared against each other with reproducible preference factors.

    The extension AHP 1.1 - Decision support tool for ArcGIS, from 2009, performs a criteria weight determination and create a new raster as a weighted sum of the available rasters.

    I installed the ArcScript AHP 1.1 in ArcMap 10.2, and when I try to create a new raster as a weighted sum of the available rasters I obtain an error: "AddRastersMapAlgb: Automation error".

    Peter Mwangi Macharia · Jomo Kenyatta University of Agriculture and Technology

    I tried the same while calculating weights, the same error resulted. The alternative that I worked with was to calculate the weights and CR via a spreadsheet. The matrix so formed calculated Eigen Vectors and Eigen Values that are the weights and CR.

  • Nashwan Yousif added an answer in Oxidative Stress:
    Do antioxidants in topical formulation act on the surface of skin or do they need to penetrate the Stratum Corneum Layer?

    We know that there are lot of antioxidant topical creams in the market. These antioxidant help to reduce the radicals and prevents for oxidative stress and aging. But I am confused whether these antioxidants act on surface of skin or it need to penetrate into the skin (stratum corneum) to act. Anyone aware about this can help me out. Thanks in advance.

    Dear Ramkumar

    I think it depends on the physics-chemical properties of the Resveratrol including the polar groups and the number of active binding sites and the pKa and the affinity to bind different organic molecules that determines the extent of penetration because the penetration enhancers in general helps to cross the epidermis ,but later , it depends on the drug molecule itself and it's concentration in the  preparation whether to stay locally or reach systemic circulation. You may need some literature survey concerning the molecule. You can check using excised animal skin to find extent of diffusion using Franz diffusion cell. Any way your API is natural and non toxic even if small concentration is found in blood


  • Pavan Kumar Dumble added an answer in Pseudomonas:
    How can I identify Pseudomonas fluorescens isolates using markers?

    I have isolated different species of Pseudomonas in a specific medium.

    How can I identify them at species level by using universal primers or ITS primers?

    Do ITS primers help in identification at species level?  

    Pavan Kumar Dumble · University of Horticultural Sciences

    Dear Chirajyoti , 

    Thank you for reply , sir isolates which i have are pseudomonas for sure , the molecular detection is becoming difficult for me i wanted a primer which could identify at genus level  , later the sequencing will give me identification at species level sir please share if you have papers regarding to pseudomonas molecular based identification

    Thank you for your time    

  • How do I ensure that the sample I have is representative of a country?

    I am currently engaged with a research project on cross-cultural comparison of employee attitudes and behaviors. How do I ensure that the sample I have is representative of a country?  

    Thomas Antwi Bosiakoh · Macquarie University

    Statistical sampling requires certain percentage as minimum. Here you can consult with other nationally representative surveys, or nation-wide studies and borrow ideas regarding their sampling techniques. All the best.

  • What are adequate instruments for measuring Indoor Air Pollution (CO and PM) for only 1-2 hours during the combustion of biomass?

    We would like to measure Indoor Air Pollution, in particular CO and PM 2.5, in rural, poorly ventilated kitchens during the preparation of meals. This means that the measurement won't take longer than 1-2 hours. Do you know any measuring devices that would be suitable for our purpose and that are sensitive enough to capture pollution also during that short period of time? Can you recommend CO dataloggers? Or would you rather recommend CO diffusion tubes?

    Also, do you know a low-cost instrument for measuring PM that is easy to handle? As far as I know they are all quite expensive.

    Thank you.

    Anne Koerner · Georg-August-Universität Göttingen

    Thank you all very much for the responses. That is very helpful. I was also thinking about the TSI Dust Trak or TSI Side Pak monitors since they seem to be the gold standard of PM measurements in the field. However, they are both a little above our budget. So, do you know about a similar alternative or, by any chance, about the possibility of borrowing such devices from any institutions? Preferably in India. 

    Also, I was thinking about the EL-USB-CO by Sierra Control. Can you recommend this product? 

  • George Dowse added an answer in Forest Fires:
    Has anyone got knowledge on the timber quality of burnt trees, immediately after fires as well as after new growth on top of burnt wood?

    What are the effects on timber quality from trees that survived a forest fire at e.g. age 15 and were felled and processed at age 25? What in-field tests can be done to determine timber quality?

    George Dowse · Merensky Timber

    Hi Geoffrey, the question came from Pines actually, but the same question stand for eucs. W.r.t. eucalyptus appearance grade recovery would be of highest importance, while with the pines total volume recovery - influenced by visual strength and visual appearance for a mostly structural market.

  • Mehran Hariri added an answer in Habitat:
    In which paper or reference was the term "functionnal habitat loss" defined?

    The term has been used a lot but I've never found it referenced.

    Mehran Hariri · Islamic Azad University Tehran Science and Research Branch

    Dear Amelie

    You can find mentioned phrase in the following book

    " Wildlife-Habitat Relationships, Concepts  and applications" by Micael L. Morrison, Bruce G. Marcot, and R. William Mannan"

    This is a valuable reference book, enjoy.

    Happy reading


  • Tisham Mohammed added an answer in Education:
    If trying to find out the influence of the religion&language in Canadian education, what are some questions that can help you with the research?

    It could be anything that you think is significant for the research.

    Tisham Mohammed · University of Saskatchewan

    hi, Deborah,

  • Is there any free software to fit impedance spectra with any data form?

    Impedance spectroscopy.

    Masoud Zakeri · Ferdowsi University Of Mashhad

    you can use this software. it is very easy to use

  • How can one compare organic and conventional farms having different cropping pattern?

    Conventional farms are in general are monocropping based whereas organic agriculture is suppose to have a more diverse cropping system and these two systems may have a different cropping cycles. Most studies compare them on basis of single crop which seems unfair to the organic systems. I want to design an experiment to systematically compare  the yields and soil parameters in these systems. Can anyone suggest studies that are present or any ideas to compare these in common unit(besides money, I don't want to use money either as they do not reflect the true value).

    Arun K Sharma · Central Arid Zone Research Institute (CAZRI)

    Some of the points Kwamina  has  covered  I would suggest if it is only the yield comparison of two systems from first year you will get input response ( organic or chemicals) but in real sense if you would like to test both systems, first developed both systems in about one ha (10000 m 2) area for each,  accommodate perennials,  flowering plants  and crops in rotation. After 3-4 year you may compare both system in terms of yield , soil health, fauna diversity  and many more parameters.  I deliberately  suggested area of  on ha   to clearly see/estimate  the effect of agro and fauna diversity and better averagning.

  • Ravi Kant Upadhyay added an answer in DMSO:
    For how long do the leaf samples remain stable while anaysing the total chlorophyll content using DMSO method?

    mentioned in some work..for 52 weeks if kept at 400C, not sure though

    Ravi Kant Upadhyay · Deen Dayal Upadhyaya Gorakhpur University

    Destructive method is used for measurement of chlorophyll content in plant tissues. Dimethyl sulfoxide solvent (DMSO) is used for chlorophyll extraction from five leaf disc in dark accodring to method by Hiscox and Israelstam (1979). Absorbance of extracts is read by Beckman gratin  spectrophotometer (model U-1100, ltitach, Ctd, tokyo, Japan) at 645 and 663 nm. Chlorophyll a (mg/cm-2) Chlorophyll  b (mg/cm-2) and total chlorophyll content (mg/cm-2) is calculated from absorbance at 663 nm and 645 nm according to Arnonʹs (1949) equations: Chlorophyll a = (ml solvent)[(0.0127 Absorbance 663) - (0.00269 Absorbance 645)]/Leaf area (cm²) , chlorophyll b = (ml solvent) [(0.0229 ×Absorbance 645) - (0.00468 Absorbance 663)]/Leaf area(cm²) , Total chlorophyll content = (ml solvent)(0.0202 ×Absorbance 645) + (0.00802 Absorbance 663)]/ Leaf area(cm²)

  • Why is the corrosion rate calculated from EIS different from LPR?

    I am wondering why the corrosion rates calculated from Linear polarization resistance is different from electrochemical impedance spectroscopy? Is that because EIS  uses AC while LPR is a DC technique? or are there more reasons?

    Masoud Zakeri · Ferdowsi University Of Mashhad

    the difference between EIS and LPR results is quite natural and type of current which is applied (AC or DC) is considered as the reason of this difference. if you select very low sweep rate for your LPR test, these values are become close.

  • Fatemeh Ejeian asked a question in SH-SY5Y:
    is there anybody had experience with getting a stable cell line from SH-SY5Y cells?

    Dear all
    I want to produce a stable cell line of SH-SY5Y by lentiviral system to express a gene in inducible format (with dox) and assess its neuroprotictive role.
    I have two questions:
    1-as I passaged these cells for 10 times, their morphology became epithelial-like. So how should i manage to get a line?
    2- Have you any other recommendation for selecting a line?
    I attach a picture from cells in a high passage number.
    With great thanks

  • David Stoler added an answer in Quantum Mechanics:
    What's the interpretation of single photon interference in a double slit experiment?

    I want to know what are the reasons of this interference.

    How does quantum mechanics look for this interference? Does the photon interfere with itself or are the waves accompanied with it interfering with each other?

    What's the relation of wave particle duality with this experiment?

    What are the most acceptable interpretations of this experiment?

    David Stoler · DSA

    Let me add that it is the wave function that displays the interference.  The photon is not its wave function. The photon just does what its wave function tells it to do (statistically).

    I know that this partially begs the question but then it partially doesn't.

  • Keven L. Ates added an answer in Stream Data:
    Is it possible that the Space Saving Algorithm [1] to track frequent elements in data stream can handle negative updates?

    By negative update I mean elements with negative weights (frequencies)  in data stream.

    Is there any other algorithm for finding frequent elements in data stream, which can handles negative updates.

    [1] A. Metwally, D. Agrawal, A.E. Abbadi. Efficient Computation of Frequent and Top-K Elements in Data Streams 

    Keven L. Ates · University of Texas at Dallas

    There are other algorithms that can handle negative patterns (if this is what you mean by elements).  See the SUBDUE system and VEGGIE.  These systems deal with graph patterns and compete with Agrawal.  Streams are a subset of graphs.  Particularly, SUBDUE is used to induct frequent subsets.  Negative graphs can be specified to direct induction away from those patterns.  This area of research may not be what you are specifically pursuing, but may give you a broader understanding of pattern matching w.r.t. competing research.

  • Francesca Cansani added an answer in Philosophy:
    Can ethics be measured objectively?
    Ethics, ethical committee, ethical approval and other ethical related words are extensively used on Researchgate and other places. How to define and measure ethics in objective bases?
    Francesca Cansani · University of Applied Sciences and Arts of Southern Switzerland

    Sorry for adding. I've also said that the Lack of Ethics can be measured. Ethics is about Unity, it is what makes me similar to you, or you to me, us to them, and them to us.

    While Morality is about cultural Habits, which makes me different to you, you to me, us to them and them to us. The Difference between let's say, Moralities, can be measured [the Morality of one could be amoral or immoral for another, and the other Way 'round is true as well].

    I've also asked to reason around a Couple of concrete Themes, referring to Ethics and its objective Measurement or else: Pornography and genial Mutilation [feminine and masculine (callled Circumcision) included].

    Ethics is about the Golden Rule, which is, applying one's Sensitivity to Others, and know, that what hurts me, might very much hurt another as well, and therefore, as much as one avoids to hurt himself/herself, an ethical Person avoids to hurt another.

    Here we're at the Level of Ethics [see above] not about the Level of cultural Indoctrination, mental Manipulation, political Ideologies and institutional Habits [which belong to the Domain of Morality, ''Moeurs'' from French, Habits, Way to socially behave].

    Ethics belongs to every spiritual Path; Philosophy is a spiritual Path [Love for Wisdom]. It is about Wisdom, not Knowledge.

    Today's Societies are so plenty of Knowledge, but so void of Wisdom, which on the other hand can be, let's say, possessed or expressed even by People who have little, so to call it, formal Education [Sholarship].

    The Question by Ahed implies Ethics [and therefore the Discipline called Love for Wisdom] and the Question whether it can be measured or not.

    I see no Ground to state that I'm in the wrong Topic. Not at all.

    Do you believe that Ethics can be discussed only by so called knowleadgeable People, or do you think that it can be discussed by anyone?

    Here is a first or main or ... essential, basic, original [which lies Beyond ...] Question or Reasoning around the very main Theme of this Topic by Ahed.

    Honestly speaking, apart of the so called most well known Authors' Names, WHAT DO YOU THINK about Ethics [the ... Essence] of ourselves?

    And about Objectivity, WHAT DO YOU THINK?

    Let me know. I'm in the right Topic. As much as you are.

    Jiddu Krishnamurti stated that we've technologically developed, but not psychologically [Soul, Psychè (this is the Domain of Philosophy), Consciousness], and he was right. The Point is, to develop psychologically as well.

    Therefore, there is the Need to take actively Part to Discussions, reasoning, and expressing our Reasoning, and possibly, look around to see whether Evolution has occurred or not.

    About Objectivity, we might consider whether Today's World appears to objectively be ethical enough, or not, or to have developed or to express Ethics enough: where, when, how.

    ''Ethics for a whole World'' says a Lot about the present Day's Situation [...].

    In the End, Ahed was asking about the ethical Committees: I state that Today there is little Ethics within the political [atheist or theist] Domain, and that Lobbies, or Mafias, rule the World and ourselves [certain of us realizing it, being conscious of it, and liking or disliking it, certain other of us ignoring it, and feeling comfortable or discomfortable].

    The Committee must be made of spiritual Masters not of Businessmen. This has already been suggested by Gandhi, which has obviously been disregarded by the so called West or MiddleEasternized West. They're the only Persons who have grasped the Wisdom and know what is Ethics, not intellectually or according to Knowledge only, but essentially, with the Wholeness of their Being [that's why they spread certain Values and Virtues].

    Ethics is the Core and lies at the Core.

    Pornography and genital Mutilation are unethical, maybe moral for certain People, or for certain ethical [sigh!] Committees, and certainly amoral or immoral for many living sentient Beings <-- this is a subjective/objective Measurement, plenty of Freedom or Liberty of Reasoning [might discuss about the Nature of Reasoning or what's Reasoning].

    Happiness inside/outside to Every1, Everywhere, Anytime.

  • Which equipment is used to measure polymer blended film?

    In my knowledge, there are two pieces of equipment to measure film thickness i.e. micrometer and dial gauge.  

    Can I use either of these two to measure polymer thickness? Is there any alternative to these two?

    Ahmed Mohamed El-Hadi · Umm Al-Qura University

    There are many methods to check the plastic film blends like DSC, XRD, FT-IR, POM, SEM, TEM and others

  • Ravi Kant Upadhyay added an answer in Bioassays:
    Can you help with the estimation of terpenoids and glycosides?
    Do you have a protocol for total estimation of terpenoids and glycosides using UV spec methodology? I only have a protocol for their estimation using TLC.
    Ravi Kant Upadhyay · Deen Dayal Upadhyaya Gorakhpur University

    Terpenes and terpenoids are primary constituents of essential oils of different type of plants and flowers. 1) T Salkowski Test is applied for estimation of terpinoids. For which plant extract is mixed with 2ml of chloroform and concentrate H2SO4 (3ml) is carefully added to form a layer. A reddish brown coloration of the interface is formed to show positive result of the presence of terprnoids.

  • Sunil Bhaskar asked a question in Alloys:
    Is AA6061 has any significant application in the field of wear resistant material?or is any relevance in the tribological study AA6061?

    Recently AA6061 using as the base alloy for the MMC's production.But its hardness and mechanical properties are better than the other base alloys.

  • Shinsmon Jose added an answer in Lenti:
    How does the Cignal Lenti Viral reporter system integrates into the host genome?

    I am doing GFP transfection using Cignal Lenti viral reporter system for the purpose of tracking my cells  (bmMSC and Fibroblast). The reporter system is said to provide a stable transfection upon transduction followed by clonal selection. However, I am not clear about the insertion of the expression system into host genome? How does it work? is it a random insertion? I am bit concerned about losing the natural function of these cells (becoz of a random insertion into any of the vital genes) upon transduction.

    Leave your comments here, any sorts of related discussion will be appreciated.


    Shinsmon Jose · National University of Malaysia

    Thank you for your answer. it definitely helps! Will look into the functions of desired genes once I am done with the clonal selection.

  • Dr. Nizar Matar added an answer in Solvents:
    Do poly(L-lactide)s and poly(D-Lactide)s behave differently in solution?

    I am curious to know if chiral polymers interact differently with the solvent i.e. does one enantiomer bind/interact differently with a solvent than the other?

    Dr. Nizar Matar · An-Najah National University

    In a given achiral solvent, poly(L-lactide) & poly(D-Lactide) will display the same behavior in terms of intermolecular attractions. However as dear professor Gyorgy Banhegyi has mentioned, if you use a chiral solvent then you will see differences in "normal" non-chiral properties i.e. there will be variations in the properties of  the 2 solutions.   

  • Majidreza Salehi asked a question in Condensation:
    How is the effect of volume flow rate of fan with evaporator and condenser coil Dimension in air conditioner with cooling capacity 500 W?

    I know in HVAC ,for example a condenser coil 1 cubic foot almost is suitable for 1 hp(horsepower)cooling capacity. but i don't know relationship between evaporator and condenser size with change in volume flow rate of fans!

  • Nadia Rezaei added an answer in Plant Extracts:
    How to induce diabetes using streptozotin to rats?

    I want to evaluate the effect of plant extracts against diabetes in animal models. I need protocol for this experiment. Please help me by giving me the protocol. Thanks for the time given to read and putting your effort to this question.

    Nadia Rezaei · Shiraz University of Medical Sciences

    Dear   Zaheer Ahmad  please read attached paper.

  • Is smallholder agriculture a relevant economic development strategy in today's Africa?

    I have read a lot of literature on the important role of agriculture in development. In today's Africa, specifically Malawi, agriculture is mostly being done at a subsistence level by smallholder farmers.

    My question is, will smallholder agriculture still be enough to effectively and efficiently lead an economy such as Malawi to sustainable economic growth and development, with regards to the fact that the world is a very different place today than it used to be years ago, facing a lot of challenges with a lot of advancements in technology.

    What are your views? In what literature can I read more on this subject?

    Célestin Bucekuderhwa · Catholic University of Bukavu

    Since subsistence agriculture still continues to represent the primary source of income for many of smallholder in Africa, the development of this contient will depend on thegrowth agricultural sector.  As you agricultural sector represents an important source of employment and contributes more than 50% to the African GDP.

  • Prashant Rathee added an answer in ANSYS:
    Is anyone familiar with CALCULIX and ANSYS?

    I am planning to move to open source FEA softwares. I found out that CALCULIX is one very good software with almost all the capabilities. Though I don't know about the accuracy of it. Can anyone compare its accuracy with ANSYS or other good FEA packages? And are there any demerits or flaws in CALCULIX? (Recently I came to know that one can only use linear elements at the slave surface while defining MPC contacts)

    Prashant Rathee · VIT University

    Hi @Awani Bhushan. 

    Thanks for the reply. I also know ANSYS and have performed contact problems in it. My question is can I perform it in Calculix with the same ease? And what is the accuracy of Calculix compared with ANSYS or COSOLE?

  • What are the refractive errors problems after enucleation or evisceration of one of the eyes?

    I wants to know the refractive errors problems after enucleation or evisceration of one of the eyes.

    Nasiru Muhammad · Usmanu Danfodiyo University Sokoto

    Yeah I agree with Karen. The pre-existing error remains. Apart from the expected change in refractive state in children up to 16-20 years, which can be large in pathological states e.g. myopia. Stereopsis is lost but this is not a refractive error.

  • Which is environmentally more toxic among the following, Cr3+ or Cr6+ ?

    I guess Cr6+.  However in practical, we using it more in laboratories.  How to avoid it.

    Ravi Kant Upadhyay · Deen Dayal Upadhyaya Gorakhpur University

    Chromium 3+ is  not toxic and essentially need for life in traces.These are oxidizing properties of chromium which makes it toxic that depends on valance. hexavalent Cr is highly dangerous and toxic for both acute and chronic exposures  to man.

  • Keven L. Ates added an answer in Design Patterns:
    Can someone show me how to identify design patterns?

    We have 3 types of design patterns, create, structural and behavioral design patterns. In each type contains few of the patterns, 23 different patterns in total. 

    How do I find the identical patterns?

    Keven L. Ates · University of Texas at Dallas

    There has been some research in this area using Graph Grammars and Trace Diagrams.  The trace diagrams can be used to find strong and weak patterns within program execution if you want to induce pattern recognition.  Even without trace diagrams, a tree graph from the parser can be used to find (induct) general patterns in a program.  However, for existing, or known, patterns, you may simply wish to use or develop a know set of grammar patterns and use a parser, such as SGG or VEGGIE, to "fit" the program's parse tree to the grammar.  This may involve some generalization of the program's tree graph since specific implementation and language requirements will include many low level details in the parse tree that may not be very important to design pattern matching.  Generalization of a parse tree can be automated, but you will probably need to develop a system that targets your specific needs.

  • Arash Zibaee added an answer in Molecular Biology:
    Do you prefer blind review process of your research paper?

    Some journals get their research reviewed after hiding the names of the authors. What is your preference and why? What is the fair review process: blind or open

    Arash Zibaee · University of Guilan


           depending to attitude of the referees or even authors it might be different but I personally prefer blind review.