What is good strength training for a regular cyclist?

I am a cyclist that averages about 100 miles per week(mpw) between my commuting (50 mpw) and fun rides (varies 50-100 mpw). I want to build up my upper body strength and add some mass.

What sort of exercises and/or routines should I consider for general upper body strength and some increased mass?

If it will benefit my cycling that is great, but I am looking for more functional upper body strength and less specialized for my cycling.

For some context, I’m 31 years old, 5′10″, 190lbs. I carry a little extra pudge because I enjoy food, but I’m still decently athletic. I recently did a 60 miles bike ride averaging 19mph. This was a pleasure ride and not what I would call “race pace” for me.

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Relation between layer height and bond strength

I’ve seen many references to a FDM print being weakest in the Z axis, due to poor bonding between layers compared to the extruded walls.

Thinking about optimising this for a specific material (excluding temperature and geometry), is there an optimum layer height? It seems obvious that too thick a layer will give less compression and maybe less heat transfer into the layer below (so 0.3 with a 0.4mm nozzle might be expected to be a bit weak). Is there a single break point (i.e. less than half the nozzle is good), or are super fine layers either good or bad?

I’m specifically using PLA at the moment, in case different materials have different behaviour in this respect.

I am not asking how to model the strength of layer bonds or how to take that into account when designing a part.

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Using approximate signal strength at a distance to estimate reception strength of a radio station

I have some historical data on radio stations, but unfortunately, the dataset only has these variables:

  • the power of the transmitter, in watts

  • the coordinates of the radio tower

Unfortunately, I don’t have any data on the characteristics of the antenna(s) or the radio towers themselves, e.g. their height. I asked a similar question on the physics.SE and was told that, with an example of a 500 W transmitter, I can very roughly estimate the strength at a distance of, say, 10 km, as

At a distance of $10km$, that power is uniformly distributed over a sphere of radius $10km$. In other words, the power per $m^2$ will be

$frac{500}{4 pi r^2}$ in units of $frac{watt}{m^2}$.

In this example, this gives me approximately $4 times 10^{-7} frac{text{watts}}{m^2}$, or -33.98 dBm per square meter.

With that number in hand, is there anything I can say about a receiver’s ability to pick up that signal? As in, a standard household radio receiver in the 1920s could, on average, audibly receive signals down to strength -25 dbm, so it probably wouldn’t be able to pick up this signal?

Or is the more appropriate way to convert this power into $V/m$ and use an approximation of the audible area like in this article?

(Yes, I know this is an overly simplistic approximation; I’m trying to do the best I can with the extremely limited data that I have. It was recommended that I ask here, so any information is most welcome!)

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Calculating entropy within xkcd 936: Password Strength

When I calculate entropy for the XKCD password advise (936) I don’t get nearly the amount of entropy stated in the comic.

So why doesn’t the the first password “Tr0ub4dor&3” have an entropy of around 50 bits? And why doesn’t the passphrase sentence “correcthorsebatterystaple” represent > 100 bits of entropy?

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Untyped strength bonus in Herolab

I am trying to create an object in Herolab for pathfinder that grants an untyped strength bonus. What I am starting from is


 
 
 
 
 
 #enhancementbonus[hero.child[aSTR], 2]
 

This gives an enhancement bonus. The commented line is my attempt to convert it to an untyped bonus, which gives an error.

How do I convert this to an untyped bonus?

As a more general question, is there a document that says “these are the expressions that you can put into a script for hero lab?

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How can I know the impact strength of someone falling from 0.5 meter?

My coffee table has to resist to a 100Kg guy falling from 0.5 meters on it.

I explained to the client that I had absolutely no idea of the elasticities to take in account… I would prefer to make a test. He prefer to have some calculus before to avoid making several prototypes.

Do you have an idea about the methods that could be used ?

I can only run my finite elements software with static strenghs.

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coupling strength g in various contexts

I’ve come across the term coupling strength $g/2pi$ in various contexts (transmon, quantum dots, optomechanics etc)

Also, I’ve come across coupling term J (exchange coupling) a lot.

I think in some sense, these coupling terms mean the same thing but I have a very cloudy view of all these coupling terms.

More specifically, I would like to know have intuitive understanding of $g/2pi$(inter-qubit capacitive coupling strength) in this paper.

Also, why are they all in the units of frequency and the higher the value, the stronger the coupling? (Intuitively, I suppose higher numbers mean higher frequency of interaction… but i still have lingering discomfort with my understanding)

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Why does the strength of a sheet of material under strain increase with thickness?

For instance, why is a thick plywood table able to bear heavier loads than a thin plywood table?

I am aware of the concept of tensile strength but, seeing as that only says things about the strength of cross-sectional areas of material, I don’t see why greater thickness of materials tends to result in greater “practical” strength when the thickness of a sheet increases (after all, doesn’t cross-sectional area stay the same in that case)?

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Why does the strength of a material under strain increase with thickness?

For instance, why is thick plywood able to bear heavier loads than thin plywood?

I am aware of the concept of tensile strength but, seeing as that only says things about the strength of cross-sectional areas of material, I don’t see why greater thickness of materials tends to result in greater “practical” strength.

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Can Yang-Mills field strength be defined as covariant derivative squared?

In Yang-Mills theory the field strength tensor $F_{mu nu}$ can be calculated as
$$
begin{equation}
F_{munu} equiv frac{i}{g} [D_mu,D_nu] = partial_mu A_nu – partial_nu A_mu -ig[A_mu,A_nu],
end{equation}
$$

where covariant derivative is defined as
$$
D_mu = partial_mu -ig A_mu.
$$

Can Yang-Mills field strength be defined as covariant derivative squared instead, rather than as the non-commutatibity of the covariant derivatives? The two definitions are essentially the same, but the former affords an alternative way of deriving the covariance properties of field strength (see below).

It’s easier to demonstrate the idea in terms of differential forms. The field strength 2-form $F$ (also called curvature 2-form) is defined as (here the coupling constant and $i$ are absorbed into the definition of $A$ and $F$)
$$
F = F_{mu nu}dx^muwedge dx^nu = dwedge A + Awedge A,
$$

gauge field 1-form $A$ is defined as
$$
A = A_mu dx^mu,
$$

and the covariant derivative of the Dirac fermion field $psi$ (spinor) is defined as
$$
Dpsi = (d+A)psi.
$$

Now the covariant derivative squared $Dwedge D$ of a spinor is
$$
Dwedge D psi = (d+A)wedge (d+A)psi
$$

$$
= (dwedge d + dwedge A + A wedge d + Awedge A) psi
$$

$$
= 0 + dwedge (A psi) + A wedge (d psi) + (Awedge A) psi
$$

$$
= (dwedge A) psi – A wedge (d psi) + A wedge (d psi) + (Awedge A) psi
$$

$$
= (dwedge A + Awedge A) psi
$$

$$
= F psi,
$$

or in short
$$
F = Dwedge D,
$$

where we have used the fact that $dwedge d = 0$ and 1-forms $d$ and $A$ anti-commute in wedge (outer) $wedge$ product.

The beauty of the covariant derivative squared definition is that the covariance of field strength 2-form $F$
$$
F rightarrow F’ = gFg^{-1}
$$

is an automatic outcome, since by definition of the covariant derivative we have
$$
Fpsi = Dwedge D psi rightarrow g Dwedge D psi = g F psi = g F g^{-1}gpsi = F’psi’,
$$

where
$$
psi rightarrow psi’ = gpsi.
$$

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