Construction is a general term meaning the art and science to form objects, systems, or organizations, and comes from Latin constructio (from com- "together" and struere "to pile up") and Old French construction. To construct is the verb: the act of building, and the noun is construction: how something is built, the nature of its structure.
In its most widely used context, construction covers the processes involved in delivering buildings, infrastructure and industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design, and continues until the asset is built and ready for use; construction also covers repairs and maintenance work, any works to expand, extend and improve the asset, and its eventual demolition, dismantling or decommissioning.
As an industry, construction accounts for more than 10% of global GDP (6-9% in developed countries) and employs around 7% of the global workforce - over 273m people. The output of the global construction industry was worth an estimated $10.8 trillion in 2017.
Maybe 1860s - 1870s tintype. Post processed heavily to reveal the image.
What do you think they are building?
I'm not student or engineer. I'm an archivist. (non-professional) I get lots of old photos and films that need some deciphering, so hope this group can help out.
The above was part of a conversation on ##\pi## and the implication seems to be that the more accurate the value of ##\pi## in our calculations in an engineering context, the more circular our construction.
Questions:
1. Is this true? More accurate values of ##\pi## allow for construction of...
On the book, it says, "Let ## f ## be defined by ## f(4n)=f(4n+1)=0, f(4n+2)=2 ## and ## f(4n+3)=1 ##, for all integers ## n ##". (Other answers are possible). But I don't understand, how does this work in the problem? I know that it must has something to do with the period, which is ## 4 ## in...
Hi all, I’m here to pick the brains of a people much smarter than myself. I cannot afford to nor can I justify a full education just to scratch my curiosity itch.
I work in construction and did coatings on concrete for 17 years, more recently I’ve transitioned to home remodeling. I barely...
There are lot of people on the Internet trying to build a cheap and sustainable house. Inspired by them I came with the idea of building external walls of Corrugated galvanised iron (CGI) and rebars and fill them with earth / sand. The basic element of the wall structure is this rebar trapeze...
Dear Engineers,
I hope this message finds you well. I'm reaching out to seek guidance on a new project that I am undertaking: the construction of an Internal Floating Roof (IFR) tank with a dome roof. As I am relatively new to this position, this project presents a significant learning...
Hello everyone,
I just joined the forum, after a bit of lurking on some various threads. It seems like a great forum. While I'm not a engineer, I am involved in various areas of construction, and I always try to back up my designs and work with as much science and engineering as I can. I hope...
I hope you folks can help.
I want to be able to pour a liquid from one container into two others in the absence of air. So I was thinking of making some sort of vacuum chamber out of 1/2" polycarbonate and some heavy duty plastic sleeving into which to place my hands and arms. Or am I being...
In Problem 3.7, Ballentine says:
The unitary operator ##U(v) = exp(iv·G)## describes the instantaneous ##(t = 0)## effect of a transformation to a frame of reference moving at the velocity ##v## with respect to the original reference frame. Its effects on the velocity and position operators are...
Hello,
Happy New Year 2023 !
Interested in spontaneous parametric down-conversion (SPDC), and the possibility of creating entangled photon pairs, I studied several possible configurations with type 1 and type 2 nonlinear crystals.
When using these crystals, the dominant phenomenon is second...
I am a client who bought a new house and the cavity in the wall was not insulated.
I can calculate the U value of the uninsulated wall and the U Value of the wall if it were insulated correctly.
front the two different U values I want to calculate how much extra energy is being lost through a...
The titular paper can be found here, https://doi.org/10.1088/1751-8121/ac6f2f, and on arXiv as https://arxiv.org/abs/2101.10931 (which is paginated differently, but the text and equation and section numbers are the same). Please see the abstract, but in part this 24 page paper argues that we...
Panasonic is going to build an electric car battery factory plant in DeSoto, KS. Will hire 4000 jobs at the plant and another 4000 jobs throughout the state. IIRC, the factory will cost 4 billion dollars to build.
edit: corrected spelling of DeSoto
Hey everyone I am looking at an older home to buy and wondering how much of a pain in the butt it would be to extend the garage out wider vs just building a secondary garage? Attached is a picture for reference :smile:
It is there a gentle introduction to C*-algebras and the GNS construction that is readable for physicists? You know, a text with an emphasis on QM that is formal enough to not be sloppy but not too much as to require a Ph.D in functional analysis to be read.
In discussing flight mechanics with a (15 years younger) co-worker with a doctorate in Aerospace Engineering. We examined some angles and I happened to mention bisecting an angle. I told him in High School in the early 1970's we learned how to bisect an angle with compass, and straightedge...
7. Fruehauf Super Dump
The super dump has a load-bearing axle rated at as high as 13,000 pounds. The large distance between the first and last axles is in fact the maximum allowed under the federal bridge formula. Developed by Strong Industries, the super dump is renowned for its high payload...
So I have heard that IBM and Google have constructed Quantum computers, how does one actually construct a Quantum computer? I would like as much detail as possible on the construction of one of these devices and how it works exactly, I wanted to buy a Spin Q Quantum computer and I understand how...
A Construction is stiffened by a bottemplate with welded ribs. A flange welded to the inletpipe is bolted at the botomplate. I want to simulate the current situation. Therfore I need a handcalculation of the stresses in the ribs of the constuction. The forces and moments are working in the worst...
I'm reading the book QFT by Ryder, in the section where ##\rm{SU(2)}## is discussed.
First, he considered the group of ##2 \times 2## unitary matrices ##U## with unit determinant such that it has the form,
$$U =\begin{bmatrix}
a & b \\
-b^* & a^*
\end{bmatrix}, \qquad \xi =
\begin{bmatrix}...
Hi!
Is it possible to construct gamma matrices satisfying the Clifford algebra ##\{\gamma^\mu, \gamma^\nu \} = \eta^{\mu \nu}## that are *real*, for ##\eta = diag(-1,1,1)##?
I know that I can construct them in principle from sigma matrices, but I don't know how to construct real gamma...
In chapter 1, page 10, real numbers are found by confining them to an interval that shrinks to "zero" length (we consider subintervals ##I_0,\,I_1,...,\,I_n##). Basically, if ##x## is between ##c## and ##c+1##, then we can divide that interval into ten subintervals, and we can, then, have...
In all books about QFT I have seen I can not find anything about what a localized particle concept is. Suddenly I found this note in Zee's 'QFT in nutshell' page 4:
"As usual, we can form wave packets by superposing eigenmodes. When we quantize the theory, these wave packets behave like...
Larger telescopes collect more light and, thanks to modern adaptive optics, achieve a better resolution. After several telescopes with ~10 m diameter three projects aim at much larger telescopes:Giant Magellan Telescope (GMT), Chile, 24.5 m diameter, 368 m2 area
Thirty Meter Telescope (TMT)...
What are the ideal dimensions of a hyperboloid tower that would maximize the venturi effect started by thermal updraft from human body heat (assuming previous physical activity on a hot day)? Given a 40ft base, how large should the skirt be and how high off the ground? A vertically symmetrical...
In the link:
https://www.maa.org/external_archive/joma/Volume7/Aktumen/Polygon.html
Why the law of sines is permitted here? What are the goals of the author to use it?
I'm trying to understand the BMS formalism in General Relativity and I'm in doubt with the so-called Bondi Coordinates.
In the paper Lectures on the Infrared Structure of Gravity and Gauge Theories Andrew Strominger points out in section 5.1 the following:
In the previous sections, flat...
Am I right to say that an electron in the lowest level of an atom cannot fall into the nucleus because to do so requires it to give up energy in the process and it . does not possesses the energy at this atomic level.Electrons in higher levels can give up energy and fall to a lower level if...
One idea for a moon base would be reinforced concrete domes, but is pouring concrete in a total vacuum even possible? Wouldn't the water just evaporate, or is there another material we could use instead of water? Are the ingredients of concrete plentiful on the moon, or could we synthesize them...
Given a real-valued matrix ## \bar{B}_2=\begin{bmatrix}
\bar{B}_{21}\\
\bar{B}_{22}
\end{bmatrix}\in{R^{p \times m}}
##, I am looking for an orthogonal transformation matrix i.e., ##T^{-1}=T^T\in{R^{p \times p}}## that satisfies:
$$
\begin{bmatrix}
T_{11}^T & T_{21}^T\\
T_{12}^T...
Hi, it was suggested previously on PF by others that a way to solve a ODE where the domain of the operator in Hilbert space allowed a real solution, is through the construction of wavepackets.
The conditions for real solutions are according to Kreyszig's Functional Analysis that E, in the...
1.
The metric ##g_{\mu \nu}## of spacetime shall be constructed from tensor products of vectors (relevant are the unit vectors in the respective directions). One such vector shall be called ##A##.
Homework Equations
##g_{\mu \nu} = \lambda \frac{A_\mu A_\nu}{g^{\alpha \beta} A_\alpha A_\beta}...
I am trying to understand the construction of CVT Metal belts that are made up of steel elements and some rings. I do not understand the full construction details of the belt.
The most detailed information I have got ever is in this PDF on page 5...
What is cheaper,
the construction cost of 30 separate houses at ground level vs
that of a 30 storied building, with one house per floor and exactly same layout ?
Also, how about 10 or 20 instead of 30 ? Does it linearly scale ?
At present I am trying to understand the construction of the number systems ... natural, integers, rationals and reals ...
What do members of PFs think is the clearest, most detailed, most rigorous and best treatment of number systems in a textbook or in online notes ... ?
NOTE: I am currently...
At present I am trying to understand the construction of the number systems ... natural, integers, rationals and reals ...
What do members of MHBs think is the clearest, most detailed, most rigorous and best treatment of number systems in a textbook or in online notes ... ?
NOTE: I am...
Hello,
Using surface energy dependence on surface orientation it is possible to predict equilibrium crystal shape by applying Wulff construction. But I faced the problem when the surface energy depends not only on the surface orientation but also on the surface depth or surface termination and...
They're building new condos across from my parents house right now (adjacent neighborhood). I see this site everyday and it's growing. Right now, they've got a lot of the framework up for the condos and it's all wood (as far as I can tell).
It's also raining a lot here.
Question - why...
How does one depict R= 1 × 10-6 , and subsequently a y-intercept of y = 6 × 10-6 on a y-x diagram? I'm new to the concept and very confused.
From my understanding, this means that the reflux is essentially 0. It's also assumed that the distillate is purely vapour, so XD = 0 as there is no...
Hello,
I tried looking this up a lot and just could not find it. For four bar linkage, Klein's construction is used to find velocity and acceleration of piston and connecting rod. Here is a link for the procedure of the same...
Hi everyone.
I know that construction lines were used when drafting was done by hand. Now, we do everything on the computer. So, how are they used on the computer?
Also, how are guidelines used in autodesk? Were they not used in manual drafting also? How are they used in computer drafting...
I'm a high school junior and doing a project on ben franklin. specifically I'm making a model of his electric motor which used two Leyden jars to operate. I want to make it a working model but I cannot get the leyden jars work. can anyone explain to me how to construct a historically accurate...
This is a rough sketch, (Happy)
Now apart from constructing the triangle can you help me to located the point D & Obtain the location of point E on side AB such that ACDE is a trapezium ,only using an straight edge and a compass. (Crying)
Looks like this question is going to make a long thread. :) This is what the problem states
Using the pair of compass and a straight edge,
Then,
After That,
Thereafter,
Thereafter, The question states to mark the point where the tangent and AD produced as 'X'.Now can you help me...
I do not know if this is the proper rubric to ask this question, but I picked the one that seemed the most relevant.
I have noticed some superficial resemblance between the tensor product and the ultraproduct definitions. Does this resemblance go any further?
While I am on the subject of...