Science topics: Engineering
Science topic

Engineering - Science topic

This research group is created with an intention of making an interaction among the research scholars, professors, scientists, engineers & technologists working in the field of Engineering, so that today’s novel ideas can become reality of tomorrow and these all can be implemented in a more constructive manner for the welfare of whole mankind
Questions related to Engineering
  • asked a question related to Engineering
Question
10 answers
Hi
I'm solving nonlinear second order equation by using finite difference method . finally for calculating value at any desired node, knowing three preceding nodes is required however by knowing boundary condition just one of these nodes becomes obvious and still knowing two other values is necessary. it must be noted there are plenty of guesses for values of these nodes which lead to compatible response.
Relevant answer
Answer
please write the ODE, not only the discretization You used.
however, for multi-step methods you need to create the starting values using a single-step method for all required nodes. Use a discretization of the same accuracy.
Note that the second order ODE could be written as system of two first order ODE.
  • asked a question related to Engineering
Question
3 answers
Hello everyone!
I‘m currently a master student and studying Software Design and Engineering and looking for master thesis topics in the field of Microservices. I‘m not sure actually about the current topics for research in this domain and I need your help.
thanks!
Relevant answer
Answer
I suggest to to read several new articles about your topic, then think what you can prepare. Regards
  • asked a question related to Engineering
Question
8 answers
USA lose trillions of treated drinking water annually (ASCE, 2017) and similar problems are highly observed in many urban water supply systems as well. In case of water distribution system there are several methodologies to find leakages such as using SONAR, sensors and UV rays. However, what would be the best alternative method in your suggestions to find the leakages quickly and effectively?
Relevant answer
Answer
I have heard about SmartBall used in gas and oil pipes to detect leakage. Its performance is based on a hydrophone.
  • asked a question related to Engineering
Question
10 answers
In a discussion, with an acquaintance, we found out that research is highest form of learning _
Important notes from the discussion are as follows :
Teaching :
- Manner in which a teacher (speaker) passes ( visual, textual, audio-Video, experimental demonstration etc.) on the information to the target audience.
Effective teaching is expressing the information based on the target audience, and not the teachers.
Training :
Manner in which a person is accustomed (trained) to given set of skills and it's practice (application) , does not matter, who is the individual.
Research :
Manner in which we teach ourselves the available information, train ourselves to identify the flaws in proper understanding of information, present the possible solution ( experimental, mathematical etc.) , based on our skillset.
Do you agree?
Relevant answer
Answer
Teaching was the past, coaching and training are the future, and now is a transition! In my humble opinion,
Best Regards.
  • asked a question related to Engineering
Question
5 answers
How can I import 2D sketches from CATIA into COMSOL Multiphysics?
The formats that COMSOL reads in 2D geometry are not available in CATIA.
Relevant answer
Answer
You can import your 2D model from CATIA software into AutoCAD software and write output DXF.
Good luck!
  • asked a question related to Engineering
Question
1 answer
I am looking for a lecturer job for engineering college in India. Since there are millions of websites available on Google, most of them look like false advertisements or outdated ones. Here is my question: can some one please suggest me which website is more genuine based on your experience for finding lecturer jobs in India?
Relevant answer
Answer
Times Ascent, you can get latest updates on the related jobs in your region.
Employment News
  • asked a question related to Engineering
Question
8 answers
To whom it may concern...
Case shown in pictures below need to stop in front of it...
What the mean of overload... What will be the meaning of calculated loading before design... and.... What really mean the structural design based on submitted data..
All, in general,.. knows that.. design start with converting functional use of the building to loading on structural element... then start design element by element ...
So, what might be the supposed loading to one story house... based on all adopted code... ? this is the first question..
Then what you think, .. or what the supervisor engineer might think the value of such loading on that slab shown in pictures attached... ? this is the second question...
Then at last... whom responsibility is that... if failure occur...? where that will be the most important question....
Limited education with low experiences causes such cases, ... or... we need to ask the supervised engineer if he care...
Relevant answer
Answer
Invariably the loading on one storey building roof with access is only `1.5 to 2 kN/m2 . and this is uni-formally distributed load. But if you pile up load in a small area more than the failure load of slab with concentrated load then the failure is imminent. this failure load can be calculated using yield line theory or by Hillerborg Strip method.
If you have this kind of loading then keep your props intact before you finish roof top work
  • asked a question related to Engineering
Question
2 answers
Not a mechanical engineer, but my understanding is that:
- the damping coefficient is defined by damping force divided by velocity.
- the mechanical impedance is defined by force divided by velocity.
What am I missing?
Relevant answer
Answer
Dear Brian Clause,
I'd like to give it a try and answer your question. Before I get to the point, it is important to emphasize that mechanical impedance is a complex quantity that provides the relationship between the velocity response and the force input of a linear system in the frequency domain.
Therefore, if we suppose an 'ideal damper' (with no inertia and stiffness effects), we realize that the corresponding mechanical impedance is given by the damping coefficient. Physically, it means that the damping force is in phase with velocity, and thus an ideal damper is a resistive element that dissipates energy.
However, for real systems in which inertia and stiffness effects must be taken into account, we conclude that the corresponding mechanical impedance is given by terms related to inertia, stiffness and damping of the system.
I've also attached a file from Prof. Mike Brennan if you want to search for more information about this topic. If you want to go deeper, check the reference below:
F. Fahy, P. Gardonio, Sound and structural vibration, second ed., Elsevier, 2007.
  • asked a question related to Engineering
Question
2 answers
Question-4: How mature are our computing platforms and programming languages for enabling autonomous software generation mostly at run-time?
Relevant answer
Answer
  • asked a question related to Engineering
Question
2 answers
Question-7: Are our mathematical means ready for rigorously expressing software system requirements? Is our computer’s inference power adequate for expressing real-time inexhaustive, indeterministic, and uncertain behaviors in SSE?
Relevant answer
  • asked a question related to Engineering
Question
3 answers
Hi everyone,
What do you think are the most important problems in computer science and computer engineering which if it will be solved would make a huge impact on technology?
what is it in your mind?
don't think that your idea might be stupid or not practical, just leave the message here, may be it help scientists and researchers to solve worlds problems and make our world a better place for everyone to live.
Best regards,
Yasin
Relevant answer
Answer
Dear Yasin,
I propose the following developmental and current research topic in the field of computer engineering: Analysis of the determinants of creating predictive simulation models for multi-faceted, complex economic, social, climate, natural, financial, pandemic, global problems, etc. based on large sets of information and data obtained from various sources including from publicly available websites and social media portals, including the use of Internet users' sentiment analysis, data analysis on Big Data Analytics and Business Intelligence platforms, and with the use of selected, various Industry 4.0 technologies, including cloud computing, artificial intelligence, teaching machines, multi-criteria simulation models, digital twins, etc.
Best wishes,
Dariusz
  • asked a question related to Engineering
Question
7 answers
I am chemical engineer working on the synthesis of two compounds (carbon compound along with polymer). What are the technologies/methods/ways on discovering or identifying the exact mixture that been synthesized?
Relevant answer
Answer
Dear Malini Kanapathy, you have to separate the two compound for accurate analysis. After that, the polymer and the carbon compound are subjected to characterization. These include, NMR, elemental analysis, FT-IR, viscometry/GPC, DSC, and so on. My Regards
  • asked a question related to Engineering
Question
3 answers
Dears,
The following questionnaire is a part of my Ph.D. Thesis Degree in Civil Engineering and Construction from University of Bolton, UK.
You are kindly requested to reply to the following questions with a level of accuracy. Thanks a lot for your highly appreciated support. Furthermore, please share the questionnaire with your communities.
Sincerely Ashraf Ibrahim Nasr Elhendawi
Relevant answer
Answer
Participated in the questionnaire survey, Asharf. Good Luck and best wishes for your thesis and letting me know your email address and so, I can also share the questionnaire that I will develop to you via emails for the data collection, Ashraf Elhendawi .
  • asked a question related to Engineering
Question
4 answers
Please Suggest any Unpaid Scopus indexed Journals for Fast track publication ( in 2 Months) for Computer Science and Engineering related areas
Relevant answer
Answer
  • International Journal of Mechanical Engineering - Q4.
  • Specialusis Ugdymas/ Special Education - Q4.
  • Journal of Positive Psychology and Wellbeing - Q2.
  • International Journal of Health Sciences (IJHS)
  • Webology - Q3.
  • AIP Conference Proceedings.
  • Turkish Journal of Physiotherapy and Rehabilitation.
  • asked a question related to Engineering
Question
7 answers
An intelligent planning of rooms based on Passive Solar design could effectively mitigate energy consumption and also promort the comfort. Anyways, what are the different methods used in the construction industry to implement passive solar design in rooms? Any scientific theories? Any case studies?
I would like to receive feedbacks from fellow researchers.
Relevant answer
Answer
Apart from suggestion received, you can study the SUN DIAGRAM for our location and according plan your design of rooms. Requirement of rooms need to be workout before you proceeds for planning. Architectural planning concepts need to adhere for better planning with respect to your requirement.
  • asked a question related to Engineering
Question
4 answers
Weather forecast has utmost importance in Aviation, Ship routing, safety measures, planning and designing of structures, urban areas, offshore maintenance, natural resources, coastal areas, Agriculture, pollutants management and in many more weather applications in world wide.
Relevant answer
Answer
A seven-day forecast can accurately predict the weather about 80 percent of the time and a five-day forecast can accurately predict the weather approximately 90 percent of the time. However, a 10-day—or longer—forecast is only right about half the time.
But Extreme Weather Prediction models are yet to reach accuracy
  • asked a question related to Engineering
Question
4 answers
As well known
In almost all papers the experimental section is so short and not detailed for instance no clear weights setup and so on
Where can we find expanded detailed narration of experiments and methods
Relevant answer
Answer
The same concerns will be shared here which means I agree. The supposed standard concept of ethical publishing and research were taught and still in practice. Direct communication to the author/ correspondent is necessary, and in this way, limited access or limited amount of the manuscript maybe shared, both parties protected, and continuum of knowledge is not compromise. Best wishes.@Mahamid
  • asked a question related to Engineering
Question
4 answers
The acceptable industry standards for water pressure is 140 kPa - 560 kPa. Domestic appliances operate under the intermediate pressure magnitudes. Topographic features and the increase of customer density cause deviations in water pressure throughout the supply system. In some cases, some water supply networks provide water in exaggerated high pressure to reach some customers in high altitude. This higher pressure accelerates the volume of water running out through unobserved leakages in supply system which results on microbursts of water pressure that may cause large scale failure and demands higher maintenance cost for water supply providers.
Dear researchers, what is your recommended solution to prevent these unnecessary pressure rise against transient scenarios?
Relevant answer
Answer
sometimes having a small pumping station for the high lat customers is beneficial.
  • asked a question related to Engineering
Question
4 answers
I am finding difficulties while publishing one of my manuscript related to Maintenance Engineering. I worked very hard through out entire Year on this, and I believe that this manuscript will be very helpful and informative to any readers belong to Maintenance Engineering domain. I have submitted this in to renowned Journals but it's not been accepted. I have also updated the information as per reviewer's, However I am not satisfied with their comments.
What should I do? Please advise me.
Relevant answer
Answer
You don't say the reasons why reviewers rejected your article. Even if you are not satisfied with their comments, it is advisable to correct your article according to the recommendations of the reviewers because you do not hold the truth or part of the truth.
If you give the exact reasons for the rejection, the readers of this platform can help you improve the quality of your article and give you the right advice.
Regards
  • asked a question related to Engineering
Question
5 answers
There is nothing worse for curb appearance than chipped and cracked concrete, particularly in steps. But you don’t have to put up with that blight any longer. By the result of weather changes exerted on an existing construction for prolonged time, it causes contraction and expansion those gradually results concrete steps cracks and break up with time.
Dear researchers, I would like to get expert opinions on how to fix this issue with,
optimum efficiency
low cost
prolonged sustainability .
Your answers are highly welcomed.
Relevant answer
Answer
En mi pais, hay material especial para tratar estos casos y otros mas; por ejemplo selladores, alquitranes, y otros.
  • asked a question related to Engineering
Question
1 answer
Question-9: How may a nondeterministic intelligent programming language be created in order to enable run-time intelligent behavior generation for handling indeterministic events and autonomous decision-making requirements in SSE?
Relevant answer
Answer
Perhaps using a quantum model.
Instead of a proposition of which to say whether it is true or false and to decide which branch to take, a quantum state function that precipitates with a measurement process into one of the component eigenstates and determines which case of a case statement is chosen.
The quantum computer could help.
  • asked a question related to Engineering
Question
6 answers
You only relate Architecture to Engineering or Computer. I work with Architectural History and Architectural Design and neither are contemplated in your "Disciplines" field. There is a great number of people working in these areas. If you don't have subjects like these, it's difficult to use your services as a place for grouping information.
Relevant answer
Answer
Yes, there should be a classification as "Architecture" seperately. Otherwise, the categorization would be placed in either engineering/ civil engineering/ construction or building acoustics, where there is little chances for readers to have a review on the specific articles in Architecture.
  • asked a question related to Engineering
Question
2 answers
Question-6: Are our programming languages sufficiently expressive for designing intelligent software? What would happen to a software system if an expected ‘if-then-else’ structures were indeterminable at design-time or exhausted at run-time?
Relevant answer
Answer
"What would happen . . .?"
A mature system would reset resp. enter some safe state (in the worst case once the maximum allowable execution time has been exceeded).
Any other system might ruin your day or blow-up the world :(
  • asked a question related to Engineering
Question
3 answers
Question-8: How may an intelligent software system be trusted and verified when its state space is infinitive in de facto, such as those of self-driving vehicles and mission-critical robots?
Relevant answer
Answer
Yingxu Wang The primary distinction between Level 3 and Level 4 automation is that Level 4 vehicles can act if something goes wrong or if the system fails. In this way, most of the time, these automobiles do not require human engagement. However, a person may still manually override the system.
  • asked a question related to Engineering
Question
7 answers
Question-2: Why have AI technologies been approached by data-driven neural networks rather than program-driven software engineering?
Relevant answer
Answer
Yingxu Wang Because all software systems have quality features such as availability, modifiability, performance, security and safety, testability, and usability, basic software principles give common methods or techniques to support those qualities.
Developing an accurate "Time Remaining" indication for downloads, backups, software installation, battery life, and other tasks is by far the most difficult job in computer science. Despite being a persistent cause of anger and shame, little progress has been made on this issue in decades.
  • asked a question related to Engineering
Question
15 answers
In recent years, there has been development of some innovative construction technologies that are changing the way we build. There are many new technologies that will have a significant impact on the future of the construction industry.
Today, construction companies are able to complete projects more quickly and efficiently than ever before. There are new technologies in demand for the future that will help with accuracy, sustainability and faster construction.
Based on your point of view, what are the types of construction that can be used in future?
Relevant answer
Answer
I suppose something like that would be a future:
So its all about local materials, somehow tranformed in structural elements.
Its probably not, what you are looking for, but I m working on several ideas, how to construct partially underground cities. Let me know, if you are interesting in such stuff. best regards. J.
  • asked a question related to Engineering
Question
33 answers
Human dynasty in its millennium era. We have identified fire from the friction of stones and now we are interacting with Nano robots. Once it was a dream to fly but today all the Premier league, La liga and Serie A players travel in airplane at least twice in a week due to the unprecedented growth of human science. BUT ONE THING IS STILL ELUDING IN THE GLITTERING PROFILE OF HUMAN DYNASTY.
Although we have the gravitation theory, Maxwell's theory of electromagnetism, Max Planck's Quantum mechanics, Einstein's relativity theory and in most recently the Stephen Hawking's Big bang concepts...… Why can't we still revert back and forth into our life?
Any possibilities in future?
if not..
Why? in terms of mathematics, physics and theology??
Relevant answer
Answer
Dear Shuraik Kader,
Given Albert Einstein's theory of relativity, cosmology regarding the development of the universe, quantum mechanics, future technologies for building interplanetary spacecraft, etc., time travel is theoretically possible. But in practice the building of a time machine by humans is impossible. Even if a man would achieve the required technological development in the next several hundred years, unfortunately he would not have enough time for it. First of all, a person must first solve other global problems, such as the necessary one is urgent, i.e. in the perspective of the next max. 2-3 decades of time, stopping or significantly slowing down the progressing global warming process, achieving zero-emission economy and avoiding a global climate catastrophe, which may occur at the end of the current 21st century. In order for man to be able to create new technologies of the future, to be able to build interplanetary manned spacecraft, etc., he must first save the planet's climate, biosphere and biodiversity from the risk of almost total degradation.
Best regards,
Dariusz
  • asked a question related to Engineering
Question
9 answers
Thermal mass is a property of construction materials to absorb, store, and release heat energy. It is an important element of passive solar house design and can be utilized for passive solar heating, passive solar cooling, or both. I would like to know, what is the most effective technique to quantify these kinds of thermal masses in an existing construction?
Relevant answer
Answer
The simple muiltiplication of the mass by the thermal capacity as Bachir Achour proposes, is valid only at thermal equilibrium. Since buildings are always in a thermally dynamic state, this method strongly overestimente the active thermla capacity. When the ambient temperature continuously changes, the calculation is more complex, and needs solving the equation of heat. Simple mathematical solutions to determine the thermal mass of a multilayer plane building component under dynamic conditions are indeed described in EN-ISO 13786 as mentioned by Edwin Rodriguez-Ubinas.
An experimental method to determine the dynamic thermal capacity of a room was proposed by Van der Maas (see attched paper). The apparent room effusivity can be measured by recording the increase of the indoor temperature after switching on a constant power heat source.
  • asked a question related to Engineering
Question
3 answers
Any Thesis idea for MS Project Management? .. I am now working as a structural engineer but I hope to shift to project control. what kind of thesis may be as an intro to my new career. NB I have graduated 1 year ago.
Relevant answer
Answer
Dear Bassel Hossam Eldin,
I propose the following research topic for your thesis on project management issues: Improving the processes of planning and implementation of construction investment projects and their implementation through the use of ICT and Industry 4.0 information technologies, including the use of digital twins of construction investment projects created in information systems.
Best wishes,
Dariusz
  • asked a question related to Engineering
Question
8 answers
I just completing my undergraduate degree in engineering and I want to be an independent scientist without joining any organisation or institute. I want to know, how to do research work and be an independent scientist and
how to open own engineering research lab and earn money.
Relevant answer
Answer
Post graduate degrees are not an absolute necessity for you to perform research as an independent scientist but they certainly help. This is because, unlike undergraduate degrees, they prepare you for independent and original work and offer specific courses on research methodology. However, you can also get informal exposure to research methodology by reading the research work of engineers in the journals they publish. In Shona there is this saying: To succeed you must see how others before you achieved their success (Kugara nhaka huona dzevamwe).
  • asked a question related to Engineering
Question
18 answers
If your answer is no; yes it is by thermal energy
Relevant answer
Answer
Riccardo Bernardini This is an interesting article. But search "neutron accelerator" on Google and you get many tens of thousands of entry points. The neutron has a magnetic moment, so is affected by any magnetic gradient. Actually by any energy density gradient of the right size and timing. But it is a well developed and valuable technique.
I have been following neutron control methods for many years, but I am looking at low cost methods for research and development groups. And for low and middle income countries. Neutron sources can be tuned, neutrons can be slowed, neutrons can be focused, neutron activation and scattering have many uses. Lots of useful things now. The same methods (and better ones) work on any particle of any size that has a permanent or induced magnetic or electric moment.
("accelerating neutrons" OR "neutron accelerator") has 102,000 entry points (Google, 11 Mar 2022).
If you search for "The development of a low energy neutron accelerator for rebunching pulsed neutrons" there are a few places the PDF is posted.
If you see their equation (1) it has the usual B^2 term that is a good indication that energy density gradient methods are the low cost way to handle it. I have been at this for just over 40 years now. Lots of times the original ideas and methods never amount to much, even if a lot of money gets spent. It is when it gets into "engineering" stage that new products, devices and applications for society happen. With more sensitive amplifiers and ADCs, with high sampling rates and low latency monitoring of real time data streams, many things that were "impossible" a year ago, are possible now. Every day I read the "old" books and papers from the 40's, 50's, 60's, 70's, 80's, 90's, 00's and 10's to see places they said "impossible", and what they should have said, "not economic or possible with our current sensors, computers and algorithms". And that has changed, dramatically, in the last year or so.
I try to track those things every day for the Internet Foundation. Because the methods of the Internet depend on those same technologies applied to problems in all parts of human society.
Richard Collins, The Internet Foundation
  • asked a question related to Engineering
Question
15 answers
Picture attached shows the case of complete reinforcement of raft foundation, but after sand storm, as appear, more than 20mm layer form from sand under the reinforcement.... on your opinion, what might do to continue with work...?
Relevant answer
Answer
excellent quesion
  • asked a question related to Engineering
Question
4 answers
Thank you to everyone who took the time to give an opinion on my PhD research. In this study, your professional advice is much appreciated. There are (5) FIVE parts in this questionnaire that need around 20-30 minutes of your time to complete.
Relevant answer
Answer
Done
  • asked a question related to Engineering
Question
7 answers
Dear researchers,
I am working on Mg composites fabricated by powder metallurgy. I have investigated the wear behavior of Mg-based composites with variation in temperature. I observed that wear rate increased with an increase in the wear temperature. Can anyone explain me in detail, why is it happening? What is the mechanism? I am looking for your responses.
Thank you so much.
Relevant answer
Answer
Thank you, sir. But I don't understand your language.
  • asked a question related to Engineering
Question
10 answers
Structural failures that cause the loss of life are argued by some to be because the engineers in charge were not licensed professional engineers by their respective government agencies.
Q1 of 2: What do you believe might reduce/eliminate the collapse of engineered structures?
Q2 of 2: Regardless of a professional engineers' license and a university engineering degree(s), what might be the "Root Cause" for such horrific failures?
Stay Healthy!
Cheers,
Bill
Relevant answer
Answer
I am about to complete a manuscript on this with Prof. John Campbell. It is our opinion that what Griffiths referred to as prior (preexisting) crack is an artifact of how we treat liquid metals, filling all engineering metals with invisible cracks that the current NDI techniques cannot detect. So even of the structures have been designed by licensed engineers with high factors of safety, our metallic structures will have invisible defects that open up under stress during failure. The forensic literature is full of these premture fatigue failure cases, although the engineering design seems to be impeaccable.
  • asked a question related to Engineering
Question
28 answers
Q. : Students asked me that "we only study about different forms of energy, one form of energy getting converted to another forms of energy. But no one knows what is energy."
Ans: No answer
Q. Sir Why do we have to call something by the name that a scientists used long back, can't we change it.
Ans: Science or engineering is field of perspective, how one looks at something matters. But everything that you read in a book can be changed. If you wish you can express it in a different manner.
It is the terminology, that we learn, in which people who observed certain phenomenon used to explain a particular concept we follow. Learn. To make world understand what you have to say you have to first make them ready to understand. Otherwise no one would know.
Relevant answer
Answer
Aditya Kumar Mishra Scientific answers are already cited by many experts aI can say depending upon the simplest form is that Energy is nothing but ability to do the work......
  • asked a question related to Engineering
Question
2 answers
Dear Colleagues,
Please, I need the doc template for Alexandria Engineering Journal.
I require it directly to download.
I appreciate any help you can provide.
Relevant answer
Answer
Hello,
If you use LaTeX then it is just the elsarticle.sty class. This is because the journal is published by Elsevier. You can find it here: https://www.elsevier.com/authors/policies-and-guidelines/latex-instructions
Otherwise, you can prepare your document in MS Word, and submit it through the editorial process. The final layout is done by the production house.
Regards,
  • asked a question related to Engineering
Question
13 answers
I have a simulation code for a Horizontal Washing Machine.
The code solves the equations of motions of the system by Matlab ode45 and plots the vibration response of the system at the transient state of performance.
In this code, the frequency (omega) is an exponential function of time, as it's stated below (and its diagram is attached to 'the question'):
-------------------------------------------------------------------------------------------------------------------------------------------------------
omega= (1-exp((-0.5)*t))*omega_0+(1-exp((-0.5)*heaviside(t-t1).*(t-t1)))*(omega_1-omega_0);
-------------------------------------------------------------------------------------------------------------------------------------------------------
ode command:
-----------------------------------------------------------------------------
[T,Y]=ode45(@snowa1,tspan1,initial_vector1);
plot(T,Y(:,1)-mean(Y(:,1)))
-----------------------------------------------------------------------------
The resulting displacement response is attached to the question.
It is desired to :
First, increase the frequency to omega_0 by exponential1
Then, increase it to omega_1 by exponential2
But 'the problem' is that:
the displacement response shows an unexpected increase in frequency at the beginning of the second exponential increase (it becomes 20 Hz, which is much larger than the maximum frequency in the simulation- 10 Hz).
Do you know what could be the reason for this response?
Any help would be gratefully appreciated.
Relevant answer
Answer
I understand that the 4DOF system for the washer can be quite lengthy. However, I'm unsure if your question is a control problem. If it is, and the 4DOF mathematical model can be expressed in such form:
x' = f(x) + g(xFc(ω)
where
  1. f(x) = [f1(x), f2(x), f3(x), f4(x)]T and g(x) are the nonlinear terms in column vector forms that you derived from the Lagrangian method,
  2. Fc(ω) is the control force that represents a function of ω in vector form, and
  3. ω (omega) is the control input,
then I think it is possible to design the spin speed profile for the control input, ω, so that the desired responses of x can be achieved. If you want to design the profile, you need to at least understand the mathematical equation for Fc(ω). Do you want to regulate the spin speed at 300 rpm, 600 rpm, or 1200 rpm? Because I see only the signal oscillates within the dimensionless amplitudes ± 4×10–3.
I have plotted the signal according to your suggestion, and compared it with Mahdi's original signal. Note that if t1 > 5/τ, then exp(–τ·θ(t – t1)·t) ≈ 0 after t1, because exp(–0.5·t) has decayed to almost zero.
  • asked a question related to Engineering
Question
13 answers
Greetings
It is very difficult for me to choose between these two majors for the master's degree
Although I think this is a question for many other students as well
Regardless of interest, which of these two disciplines do you think has a better future? Which has more job markets, in the US and Europe? Which one is more suitable for studying abroad? And which one has more income? Are jobs related to organic chemistry less than analytical chemistry?
Please share with me if you have information about these two fields and their job market.
Thanks
Relevant answer
Answer
The subject of specialisations does not depend on the feature income rather your subject if interest . Organic chemistry has too much scopes as a synthetic( R&D) chemist in multinational pharmaceutical houses like Chem biotech , Pfizer , DRL labs etc etc. Even in post doc level abroad from India very high scope in organic nano synthesis like CNT . So scope of income is naturally very high in organic chemistry indeed . But in analytical chemistry the scope is narrow compared to organic chemistry . Since analytical and quality control laboratories are also guided by organic chemists / phyto chemists / petrochemicals for mainly UV-Visible spectrophotometric analysis / Chromatography like GC , HPLC , HPTLC , GC-Mass spectrophotometer and fluroscence spectroscopy .Yes analyical chemists are useful in effluent treatment / waste water analysis as well as drinking water analysis of trace heavy metals like Cu , Cd, As , Pb , Hg ( II , I ) by AAS ( Atomic abs Spectrophotometry ) AES ( Atomic emission spectrophotometry. In drinking / waste water lab there are so many important analytical parameters like B.O.D , C.O.D , D.O , pH , TDS , TSS and limit tests for heavy metals in trace metals .
  • asked a question related to Engineering
Question
22 answers
Data science is a growing field of technology in present context. There have been notable applications of data science in electronic engineering, nanotechnology, mechanical engineering and artificial intelligence. What kind of future scopes available for data science at civil engineering aspects in the field of structural analysis, structural design, geotechnical engineering, hydrological engineering, environmental engineering and sustainable engineering?
Relevant answer
  • asked a question related to Engineering
Question
7 answers
Yesterday I have read a news stating that The embryo fossil, nicknamed “Baby Yingliang,” was discovered in Ganzhou, Jiangxi Province in southern China, and is believed to be at least 66 million years old. Researcher Dr. Fion Waisum Ma told the AFP news agency that the discovery is “the best dinosaur embryo ever found in history” (globalnews, 2021).
Although there were several discoveries of Dinosaur components such as:
Eggs
DNAs from thier remains
are frequently being discovered, Since the biotechnology development is in its Zenith at 2022, Why nobody has attempted to create a dinosaur?
What type of scientific constraints would be encountered in such a laboratory experiment?
Relevant answer
Answer
The science fiction book Jurassic Park and the movies based on it are about recreating dinosaurs by extracting their DNA from the guts of dinosaur-biting insects trapped in amber.
DNA is not sufficiently stable to survive for the necessary 65 million years or longer since dinosaurs roamed the Earth, so dinosaur DNA is not available. What you would do with it, if you could get it, in order to recreate dinosaurs is another issue.
The oldest DNA ever recovered was recently reported from 1.2 million year old mammoth teeth in Siberia.
It has been seriously proposed to recreate mammoths, which went extinct several thousand years ago. Mammoth DNA is available from animals preserved in permafrost.
  • asked a question related to Engineering
Question
2 answers
Complex graphical sketches are highly involved in Culmann's methods. Therefore, it is highly prone for getting deviations in magnitudes for resultant pressure on retaining wall. I would like to get suggestions from RG colleagues on why Culmann's graphical approach is mostly preferred in many research papers albeit Rankine's method is easy and precise in terms of equations and substitutions. I would welcome answers from both theoretical and practical perspectives.
Relevant answer
Answer
Perhaps this is due to the fact that the graphical method makes it possible to "see" the calculation. Psychological factor in choosing a method.
  • asked a question related to Engineering
Question
39 answers
Dear Research colleagues,
I have got some replies for my applications for postgraduate doctoral studies. While I analyze the replies, I have found the following issues:
1. Some replies are from good universities but the supervisors have less publications in my field of research.
2. Some replies are from universities with QS ranking below 1000 but the supervisors are with highly decorated profile with many editor positions and also with 150+ published peer review articles.
So which option do I need to chose to become a very good doctorate academic?
Relevant answer
Answer
I agree with Prof. Hans-Georg Petersen´s opinion, Dear Shuraik Kader, adding that sometimes good supervisors are responsible for the advanced courses taught to their students.
It is not only handling famous papers to students and disappear the rest of the term, as some do.
Best Regards and Good Luck.
  • asked a question related to Engineering
Question
20 answers
Dear colleagues,
I would like to request your collaboration to take part in the survey, available at the links: (EN): https://lnkd.in/djVdWne (IT): https://lnkd.in/dnvK3eJ (PT-BR): https://lnkd.in/dVGWmHv This questionnaire is part of the project aiming to analyze the transition from a linear economy to a circular economy, comparing developed and developing countries, at a macro level (nations, regions, cities). The project is a partnership between the University of Brasilia (Brazil), coordinated by Professor Patricia Guarnieri and the University of Bologna (Italy), coordinated by Professor Augusto Bianchini.
Your participation is very important to us. Please share with your network! Sincerely,
Patricia Guarnieri, Dr. Professor and Researcher Faculty of Economics, Business Administration, Accounting and Public Policies Management (FACE/UnB) - http://www.adm.unb.br/ University of Brasilia - UnB -  http://www.unb.br/ ORCID : http://orcid.org/0000-0001-5298-5348
Relevant answer
Answer
The transition to a circular economy is not uniform and varies depending on a series of factors such as the degree of industrialization, the level of technological development, the availability of qualified human resources and access to financing, among others.
  • asked a question related to Engineering
Question
4 answers
CO2 is used as raw material for chemical syntheses. It paves the opportunity to mitigate the greenhouse gas (GHG) emissions. However, it is not mathematically or logically proved yet that carbon capture benefits the environment in terms of resource efficiency. In my opinion, I believe that the life cycle assesment (LCA) would be the most suitable tool to quantify the resource-based benefits due to carbon based methane (CH4) production and to prove the resource efficacy of carbon capture.
I would like the researchers who read this discussion to provide their own ideas on whether LCA is the most suitable tool to identify the carbon capture resource efficacy or are there any methods better than LCA that can be applied on CO2 based methane production.
Relevant answer
Answer
"Life cycle assesment (LCA)" could be jointly addressed with the "circular economy (CE)" and the "ecosystem service valuation (ESV)", as an integrated tool to "quantify the resource-based benefits due to carbon based methane (CH4) production". Besides, this integrated approach can better control the excessive use of material, lowering the energy needs for new products, saving natural sources from overexploitation and environmental degradation, managing labour's capital, and proving the resource efficacy of carbon capture.
  • asked a question related to Engineering
Question
6 answers
Hello RG members,
Our team is engaged in preparing a comprehensive LCA tool that is freely available for any kind of users to facilitate the global warming potential calculation due to the building structures, pavement structures and hydraulic structures. In reference to this objective, I would like to get opinions from you on what type defects/failures/issues that you encounter with present life cycle assesment softwares such as Oneclick LCA, SimaPro and OpenLCA etc.
Your answers would help our team to develop a well structured LCA tool. Thank you
Relevant answer
Answer
The only weakness in my opinion is that all the software are proprietary and two different software cannot communicate with each other without compatibility issues.
  • asked a question related to Engineering
Question
4 answers
I am searching on standard books on secondary WW treatment options such as oxidation ditch and maturation ponds. I would like to know which books do you recommend for students.
Relevant answer
Answer
If you want to some basic ideas about that then you go for S k garg. And if you want to know deep knowledge about that then go for Metcalf and Eddy. It's clear all the concepts from basics to advance.
  • asked a question related to Engineering
Question
63 answers
Do we need to be specific?
Sometime I feel that if we become specific with more details when we ask the questions, we loose some potential researchers from other fields. So the number of answers reduce, then it is difficult to get attention of other researchers. So at the end we do not get many answers.
What is your experience and opinion on this? Please share your thoughts as well.
Relevant answer
Answer
Dear Amila Abeynayaka . I think the question must be highlighted social world issues (scientific &non scientific ) .
. Thank you.
  • asked a question related to Engineering
Question
4 answers
When running AVL, the program outputs derivative values, however I have not been able to find documentation on whether the derivatives are dimensional, or dimensionless based on the *.AVL input file.
Relevant answer
Answer
Pavel Zikmund yep - controls in degrees instead of radians for some reason! Interesting when CRRCsim uses AVL derivatives, the controls derivatives need to be back in [1/rad]
  • asked a question related to Engineering
Question
3 answers
Hi for everyone,
I would like to do a Life Cycle Assessment comparison for teak timbers from various geographical locations. Could you please share with me any data that you have for carbon footprint on timber with their corresponding information?
Relevant answer
Answer
Please have a look at enclosed PDF..
  • asked a question related to Engineering
Question
3 answers
I have prepared 6 manuscripts related to green roof substrates, 4 of them consist of experimental studies and 2 literature reviews. I have previously submitted some articles for 8 journals. But unfortunately I am continuously getting rejected due to "inappropriate content" for the corresponding journal. Meanwhile, some of the journals have facilitated me article transfer options and still I am getting rejected by those transferred journals with same reason of "inappropriate". I don't want to let my works in vain. Can anybody suggest me some suitable journals with high acceptance rate and have subscription options for publications?
It would be a tremendous help.
Relevant answer
Answer
Dear Shuraik Kader
If your focus area is on building design-related research (with a green roof), you can submit built environment-related journals. However, If your focus area is on environmental engineering, you can submit physical environment-related journals.
For the Journal search, please follow Jochen Hack's suggestions.
Best of Luck.
  • asked a question related to Engineering
Question
4 answers
Hi
Do you know a journal or conference for publishing Book review in computer engineering ?
can you suggest me one?
thanks in advance
Relevant answer
Answer
FWIW: I used to submit such book reviews to the "Microelectronics Journal". Admittedly, when I did so was in the mid 1980s, and the editor in chief was my boss. You can probably find somewhere else more appropriate these days, so I will eagerly await how others reply to your question. Good luck.
  • asked a question related to Engineering
Question
18 answers
Excess of fluoride content in drinking water (more than 1.5mg/L) sourced from inland water bodies causes dental fluorosis and skeletal fluorosis. Although reverse osmosis (RO), electrodialysis, and distillation are available for deflouridating inland water bodies. However am not sure that how effective these methods can be used to deflouridate groundwater. I would like to hear some suggestions on the mechanisms effective at deflouridation of groundwater.
Relevant answer
Answer
Deflouridation techniques are simple and can be explained like Bone charcoal, contact precipitation, Algona, activated alumina, ion-exchange technology, membrane filtration, nanofiltration, and clay are all methods for defluoridating water that can be used. Reverse osmosis (RO), electrodialysis, and distillation are examples of cutting-edge treatment methods.
  • asked a question related to Engineering
Question
9 answers
Jerk is defined as the rate of change in acceleration. But I would like to know some practical applications of Jerk inorder to have better understanding. I kindly request to suggest me some examples.
Relevant answer
Answer
The application of jerk in physics have many instances and one of the example I can shot is simple that the jerk is nothing but it is all about the rate at which any objects acceleration changes with the time or with respect to time.
  • asked a question related to Engineering
Question
8 answers
Hi, I hope you all will be fine. I need the suggestions for the Dissertation Topic of my MSc Electrical Power and Control Engineering. Your cooperation will be highly appreciated.
I am Interested in Solar PV technologies.
Thank you
Relevant answer
Answer
Dear Muhammed:
You can benefit from these suggestions:
1_ Concentrated Photovoltaics:
Research focusing on the development of concentrating systems for solar photovoltaic devices began at the University of California, Merced in 2005. Through both funding and collaboration with public and private organizations, our research has led to the development of products that are currently entering the marketplace. These concentrating devices greatly enhance the efficiency of photovoltaic cells and permit the use of lower-cost materials in the fabrication of solar cell devices.
2- Solar Thermal:
Solar thermal systems operate by using sunlight to raise the temperature of an oil medium as high as 400° F or a molten salt to temperatures exceeding 1,800° F. The energy captured in this process is stored in the form of heat that can later be used in a number of applications ranging from large-scale electric power generation to simply heating water for home use. This capacity to store energy at a lower relative cost is a key advantage that solar thermal systems have over photovoltaic systems.
3- Contamination and Cleaning of Solar Collectors:
Soiling is the phenomena of accumulation of dirt on solar collectors, which blocks or deflects sunlight and significantly reduce the performance of the solar energy systems. We will systematically study soiling and cleaning processes and their effect on the performance of solar systems. Synergistic lab and field experiments and complementary numerical simulations will be conducted to investigate particle deposition, adhesion and mitigation under natural or artificial wind conditions, which will be applied for performance forecasting and optimal design of cleaning methods.
4- Nanopillar Photovoltaics:
Solar energy represents one of the most abundant and yet least-harvested source of renewable energy. In recent years, tremendous progress has been made in developing photovoltaics (PVs) that can be potentially mass employed.
5-Nanostructured Photovoltaics:
work on the design and development of solar cells and solar concentrators which will utilize nanoscale materials for converting solar energy into electrical power. The nanoparticles we use in our research are semiconducting quantum dots grown by chemical synthesis. These include dots of different materials and sizes, with optical and structural properties varying over a wide range. In particular, we are focusing on narrow band-gap semiconductor quantum dots with emission energies in the infra-red.
6- Daylighting:
You are probably reading this, sitting in a room, illuminated by several conventional lights which are all consuming an abundant amount of energy—with the sun glaring outside! The plan is to bring the free sunlight from outside, inside! Using our solar concentration technology we can direct daylight into buildings.
7- Thermoelectric Materials:
More efficient materials are needed to expand the commercial applications of thermoelectric devices. CoSb3 is the most promising thermoelectric material to replace PbTe-based alloys. The binary skutterudite compound cobalt triantimonide CoSb3 is particularly interesting because it displays remarkable electrical properties. The overall performance of this material remains however low due to an excessive value of its lattice thermal conductivity.
8- All-Carbon Solar-Driven Water Splitting:
The high-level goal of this research is to achieve high performance, all-carbon, solar-driven water splitting by understanding the synergistic co-assembly of earth abundant fullerenes (C60s), semiconducting single walled carbon nanotubes (SWCNTs) using graphitic nano-surfactants with engineered geometry-driven function. We employ novel experimental techniques and unconventional device architectures guided by fundamental modeling.
9- Minichannel-based Solar Collectors:
Solar thermal systems provide the capability of generating heat, electric power, and/or cooling in a sustainable way and for a variety of applications due to the relatively large range of temperatures that different collector configurations provide. Currently, a key issue that remains a subject of intense research relates to effectively transferring the energy obtained from the sun to the working fluid. Increasing the efficiency of solar water heaters has the potential to have a high impact on the consumption of natural gas and other fuels in the residential and commercial sector.
10- Solar Fuel Conversion:
Sunlight and seawater are the ultimate and sustainable energy sources on earth, and together they constitute a potential solution to the global energy crisis, which at the same time can reduce the carbon emission due to the use of fossil fuels. A photoelectrochemical (PEC) cell utilizes solar energy to directly split water and generate H2, which is clean and free of carbon emission. However, it is broadly recognized by the PEC community that there is no single material can be the perfect photoelectrode candidate for solar water splitting with respect to light absorption, water reduction, chemical stability.
11- Advanced Solution Processable Photovoltaics Research:
Solar is the most abundant renewable energy source. One hour of solar energy on earth is equivalent to the world annual energy consumption. The relatively high cost of solar energy conversion compared to that of fossil sources is still a major hurdle preventing the widespread adoption of PV technologies. Therefore, cost reduction is key. To reduce the cost of solar energy conversion, our work includes the development of polymer and solution process small molecule solar cells and the development of solution process inorganic solar cells.
12- Full-Spectrum Photovoltaic-Photothermal Concentrator System:
Using power from the sun to replace the current massive use of fossil fuel to power the planet is truly a modern day “Holy Grail” for future energy economies. At an average solar irradiance of 1.76 x 1017 watts, solar power is a near-infinite source of terrestrial power. If solar power could be economically and resourcefully converted to other useful energy and power sources, it would allow earth to migrate from generating a huge carbon footprint, due to fossil fuel use, to being carbon neutral.
I hope it will be helpful...
Best regards....
  • asked a question related to Engineering
Question
8 answers
Please help on that
Relevant answer
Answer
Firstly a design mix must be prepared to meet the strength specified by the consultant. When the required strength is achieved per what the consultant want then you deduce the ratio from the mix design to be used at site.
The ratio will be used at site and samples will be taken to the lab for crushing. so if crushed and we are able get the same strength as specified by the consultant then that will be a means of ensuring that the specified grade of concrete is attain at the site.
other means is by using the maturity method.....
  • asked a question related to Engineering
Question
5 answers
Looking for power and control Engineering related answer
Relevant answer
Answer
I agree with the comments on the question being too generic. However, I have attempted to answer this question anyway (with some caveats) with the attached decision tree. This is an excerpt from my book; the PDF is available for free here:
  • asked a question related to Engineering
Question
3 answers
Which preprint server would you recommend for engineering and materials science field?
Relevant answer
Answer
I think https://arxiv.org/ is the best option.
  • asked a question related to Engineering
Question
4 answers
Hi everyone, Im looking for a word template for preparing a publication on the Journal of Building Engineering . Any help on this here?
Relevant answer
Answer
To Gabriel Felmer: Perhaps you may check Typeset (Research Writing Platform): https://typeset.io/
  • asked a question related to Engineering
Question
3 answers
Finding the seismic pressure is an important parameter to quantify the damages on structures during large earthquakes. Since soil force equilibrium in wedge approach can be used in site conditions there are no finite methods for laboratory experiments to study the seismic earth pressure behavior. A simple demonstration in this research area would help many students to understand its basic concept with good insight.
Relevant answer
Answer
There are different methods used to calculate bearing capacity in the laboratory.
It can be found through reading published papers.
best regards.
  • asked a question related to Engineering
Question
4 answers
What options available for Engineering students to get better Industrial exposure in India
Relevant answer
Answer
The question is narrowed down to Indian Engineering students who have exposure in India.
They can have tours for Industrial visits throughout India.
They can undergo Apprentinship in any one of the Industries.
Whatever they have studied in the classroom is only the Agreement Reality only.
Whatever they have done in the Industry practically is only the Experimental Reality.
The accumulated knowledge from books on a theoretical basis may not be sufficient enough for Engineering College students rather practical practices could support more.
India is one of the emerging countries globally to support Engineering Students.
  • asked a question related to Engineering
Question
4 answers
Hi,
I am currently working on my PhD in Control Engineering. I have run into a brick wall and it has consumed months of my time. I understand the following:
There are 4 types of configurations for a power converter:
Grid Forming
Grid Supporting Current
Grid Supporting Voltage
Grid Feeding
I am using the following paper to try and establish a microgrid of parallel converter:
1. When I establish a Grid Forming power converter, I set the w and v of the grid. I am then using a second Grid Supporting Current power converter, but the voltage of the grid become unstable. I have read in other threads that Grid Forming power converters cannot run in parallel with any other converters. I assume this is why this started.
2. I then try to establish 2 Grid Supporting Current power converters to run in parallel with each other. However, there doesn't really seem to be a way that I can synchronise them. I can get them to run when the power on the droop controller is the same, therefore the w are both the same and they synchronise. I tried to switch one of them for a Grid Feeding power converter, again this did the same as in part 1, it adjusted the voltage and it became unstable.
3. All of the models I have come across take the inner current loop voltage readers before the Capacitor but after the Inductor, as in the paper mentioned above. However, Simulink gives me an error about zero crossings, when I override it the AC output has major distortion in it.
How can I create a Simulink model with two parallel converters to run together ?
My goal is to create two or more parallel converters providing a single load so that I can create a controller that provides stability under actuator attacks.
The other papers I have based this off are:
You can see from these articles that the current reading is taken before the capacitor bank.
Relevant answer
Answer
Dear Sandford:
You can benefit from this valuable Link about your topic:
I hope it will be helpful...
Best regards....
  • asked a question related to Engineering
Question
5 answers
Dear colleagues, have you faced rejection from Alexandria Engineering Journal without any reason?
Relevant answer
Answer
Dear Ahmed,
It is a common thing for us, Iranian researchers theses days. Since many journals reject our manuscripts even before sending them out for review. For us, mostly politics can be at play- what a FAIR world!. For instance many journals, those with more fairness!, ask us to provide the a signed letter indicating that we are not working for our government (!). My research fields are orthopaedic and dental implants biomechanics, thus no connection between my work and nuclear weapons, etc. (!), but some journals, regardless, ask us to provide them a signed letter in order to make sure that we are working on the safe side!!!!. In my opinion, we, researchers, are being always tortured by both external and internal sources, since politics, with no doubt, is at play in science and technology these days. In other words, the main scope of research, i.e. discovering the true nature of each phenomenon, with no bias and no personal judgment, is not being really met. I personally believe that most problems in the world nowadays are caused by lack of purification in human beings. For instance, please see a PhD student's defense, if her/his supervisor is an influential person, the process goes quite easily and way much smoother than a student whose supervisor is doing pure research. I've unfortunately many examples in mind....anyways hope to see a better world in the future.
God bless All,
  • asked a question related to Engineering
Question
1 answer
Want to understand the options available for Engineering students to enhance their Industrial exposure while studying.
Relevant answer
Answer
Industry 4.0 - An excellent topic .
  • asked a question related to Engineering
Question
33 answers
Peer-reviewed (refereed or scholarly) journals - Articles are authored by specialists and vetted by numerous other experts in the subject before being published in the journal to assure the quality of the article. (The paper has a better chance of being scientifically sound, reaching reasonable findings, and so on.)
Because they have gone through the most rigorous review process, articles from scientific, peer-reviewed, academic, and refereed publications are more reputable than those from popular or trade journals ('magazines'). They also have the highest number of references or citations.
Relevant answer
Answer
Dear Linas Balciauskas thank you for your kind response and new question ("but it really matters if review process takes a year, and then you get rejection without any reviews?"). Yes, such a case is certainly a reason to worry, but it shows that the editor / journal / publisher are not doing their job professionally. I think that this varies very much with the different disciplines. In our field of research, chemistry, I did not experience such a case in over 40 years. In my personal experience the editors of all renowned journals are excellent chemists themselves. They are carefully selected by the publishers based on their scientific performance and leading skills. The same is true for the vast majority of reviewers who are selected based on their areas of expertise. Apparently in chemistry we as researchers are lucky that the publishing and reviewing process is largely fair and fact-based.
  • asked a question related to Engineering
Question
6 answers
Hello,
I am Yvon françois TSOLEFACK engineer in electrical and energy engineering of Cameroonian nationality, and promoter of a positive energy road project for Africa, and more particularly in Burkina Faso (pilot country for the experimentation of the project), project which has earned me to won a few brawls and rewards at the end of certain national and international challenges and innovation competitions in energy. I had to consult (carry out a bibliographic review) several works already carried out in the field, via certain open research thesis platforms, which were very interesting. A great thank to all researchers amongs all of you in the field who kindly accept to share their work with me. However, I would also like to do a thesis in co-supervision between the doctoral school of the 2iE institute in Ouagadougou in Burkina Faso, and a suitable school / university which has the expertise in the experimentation of positive energy road technologies. My project (my desired theme) consists of designing a thermo-piezoelectric block capable of simultaneously exploiting the mechanical stresses of road traffic, and the heat stored by the roadways, to produce electricity. It will therefore be a question of carrying out modeling and simulation work in order to determine the optimal structure of the block according to road traffic, vehicle weight, sunshine (temperature profile, humidity, etc.), depending on the context, etc. In short, I would like to have advice from you (the researchers community) regarding the best adapted and advanced doctoral school laboratories in these positive energy road technologies, through which I could carry out my research, in collaboration with the doctoral school of the 2iE institute in Ouagadougou.
While waiting for a favorable result from you, please receive my sincere admirations and considerations.
Best regards,
Yvon François TSOLEFACK
Electrical and energy engineer
Tel: +226 62 64 77 10(Whatsapp)
Relevant answer
Answer
The following RG link is very helpful:
  • asked a question related to Engineering
Question
4 answers
Hello
With you, engineer/ Ahmed Mohamed El-Sayed
Teaching assistant at the Department of Construction and Building Engineering - Faculty of the Arab Academy for Science, Technology and Maritime Transport, South Valley Branch in Aswan
Attached to you is a survey related to the research point and the factors affecting the partnership between the public and private sectors. The survey time will not exceed ten minutes.
Thanks for your time
Relevant answer
Answer
Dear Mr. Elsayed!
I submitted my answers. This is a very interesting project with a relevant topic! Hope YOU the best, Yours sincerely, Bulcsu Szekely
  • asked a question related to Engineering
Question
6 answers
Hello, Im currently in an Engineering module of Fluid Mechanics, and I was hoping if anyone could assist me in the process with these 2 questions while my Professor is absent. I feel my process is correct, but i keep getting answers only close to what the real answer is. I wont be reanswering these questions, so anyone who can properly get through it and arrive at the answer would be appreciated
Q1
'A fluid of density 807 kg/m3 flows through a sudden contraction into to a pipe of diameter 17 mm, with final mean velocity 2.4 m/s.
If the total pressure loss is 401 Pa, calculate the diameter of the vena contracta, in mm to 1 decimal place'
Answer: 14.3 ± 0.05
Q2
'Two sealed tanks, whose total pressures differ by 3,764 Pa, a are connected by a pipe of length 82 m and diameter 22.8 cm. A fluid of density 897 kg/m3 flows through from one tank to the other at a steady rate. Calculate the mass flow rate in SI units, to 3 s.f., when
  • the contraction loss coefficient is 0.5 at the entry to the pipe
  • the friction factor for the pipe = 0.05(1+(20x10^3 / d)
  • the downstream tank can be assumed to be infinte.
Answer: 23.1 ± 0.05 (kg/s)
Thank you
Relevant answer
Answer
Q1:
I assume that you are familiar with the expression for the contraction loss:
Loss in total pressure = P_loss = k * rho * v2^2/2, where k = (1/Cc-1)^2, Cc being the ratio of the cross-sectional areas of the vena contracta and the downstream pipe.
If you haven’t learned this, then you may do a google search on the topic of pressure loss during sudden contraction. For instance, you might watch the YouTube videos:
Now, look at the information given in the problem statement:
P_loss = 401 Pa
rho = 807 kg/m^3, v2 = 2.4 m/s  rho * v2^2/2 = 2324.16 Pa
Using this information with the expression for the pressure loss, you can find:
k = 401/2324.16 = 0.17253545366,
and, therefore,
1/Cc-1 = sqrt(k) = 0.41537387215, i.e., Cc = 1/(1+sqrt(k)) = 0.7065271019
For a circular pipe, the area ratio is proportional to square of the respective diameters. Thus, the diameter at the vena contracta is given by:
Dc = sqrt(Cc) * D2 = 14.2893783087 = 14.3 ± 0.05, when truncated to a single significant digit.
Q2:
I am unable to help you with Q2 due to multiple issues related to the empirical expression for the friction factor:
1. The expression “0.05(1+(20x10^3 / d)” includes the symbol “d” which is not explained in the problem statement.
2. If d happens to refer to the pipe diameter, the units for d will need to be given
3. As you can see, the above expression for the friction factor involves unbalanced parentheses. Therefore, it's not clear whether or not the problem statement is missing any information.
In brief, however, the total head loss between the two tanks equals the sum of the losses due to sudden contraction and expansion, respectively, and the friction loss along the length of the pipe. The first two components can be evaluated along similar lines as Q1 above. Then you can use the correct expression for the friction loss to determine the mass flow through the pipe.
  • asked a question related to Engineering
Question
16 answers
In the past two decades, many robust structural reliability methods have been presented that we may not even have heard their name. For a reliability researcher, it is very difficult to read all manuscripts, write their code and properly examine their efficiency/accuracy. On the other hand, it seems that some efficient/robust ones are being forgotten.
The purpose of this discussion is to create a space for the exchange of experience and expression of reliability researchers' views/opinions about the structural reliability methods. I hope this could help us to save time and learn more.
Suppose that you have a real-world structural reliability problem without any information about its limit state function, geometry of the performance function and the safety level of the problem (i.e. the performance function can be estimated by a finite element method-based software).
Among the existing reliability methods, which one is your choice? Why?
Let us discuss about this. Share your experiences to help others.
Relevant answer
Answer
I have not received any response from Sajad Saraygord Afshari.
So, just an update for interested readers: "The popular structural reliability analysis is meaningless for safety analysis of an existing structure!". Why? the reason is that an "existing structure" is mathematically placed in safe domain! Resistance of an existing structure is not a random variable. Resistance could be a random variable in the design phase. We may use current structural reliability methods to design a new structure (not to evaluate safety of an existing structure).
For an existing structure, "useful remaining life" and/or "time dependent reliability analysis" is rational. Otherwise, just load parameters should be considered das random variable and the reliability problem becomes a "conditional probability" problem.
Easy but important.
  • asked a question related to Engineering
Question
6 answers
'A hospital ventilator is fed by an oxygen supply at 177 g/s mixed with ambient air, density 1.295 kg/m3, at a rate of 0.69 m3/s. The gas mixture is humidified by the addition of 0.161 kg/s of water. Calculate the total mass flow of fluid supplied by the ventilator in kg/s, to 3 d.p.'
Hello, I am a First Year at my University taking Engineering, and need some help understanding this question.
The answer to it is 1.232kg/s
Thank you to anyone who can help!
Relevant answer
Answer
I admit all the calculations considering mass flow rate , moisture content . I just add additional link for the same type of calculation in volimmetric flow rate - https://www.hamilton-medical.com/en_IN/E-Learning-and-Education/Knowledge-Base/Knowledge-Base-Detail~2020-06-30~Calculating-oxygen-consumption-for-Hamilton-Medical-ventilators~c1b09f7f-3224-45b9-aa12-4cfd37e6d5ff~.html
  • asked a question related to Engineering
Question
3 answers
Hospitals design evaluation
Relevant answer
Answer
Check DOAJ directory: https://doaj.org/
There you can browse the journals by discipline https://doaj.org/subjects
Check the SJR website too:
  • asked a question related to Engineering
Question
6 answers
I have prepared magnesium green compacts from powders of different particle sizes. I observed that the green strength of compacts produced from fine powder was very low. Green compact splitted in two parts in the vertical plane during removal of green compact from the powder compaction dies. I repeated the experiment so many times and observed the same behavior. What can be the possible reason? Please explain.
Relevant answer
Answer