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1answer
79 views

Does $R=\dfrac{4q^2}{\pi^2a^2gH^2}$ suggest a square root relationship?

I did an experiment involve how R scales with q (the other variables are constant), and I got a relationship like $R\ \propto \sqrt q$ I have been told to evaluate my findings with those in ...
4
votes
1answer
37 views

How do you measure neutron energy?

I think you can detect a neutron event with a scintillator (neutron to photon), photomultiplier tube (photon to electric signal) system, but how would a fusion neutron's energy (2.45 MeV) be typically ...
0
votes
2answers
34 views

Peak at zero in one device and not the other

I was wondering if anyone could shed some light on this problem. I have placed two accelerometers on an animal one sampling at 50 Hz the other at 100 Hz. They were placed in the same position. I then ...
0
votes
1answer
26 views

Nuclear explosion wavelength data

I am looking for data source (or chart) of spectral data that is being emitted on detonation of nuclear or thermonuclear explosion. Reason I am looking is to see if this data has specific signature ...
0
votes
1answer
44 views

Using Audacity to generate power spectral density

Say I record something with a sound recording program like Audacity (e.g. plucking a guitar string). How could I use that recording to plot a dB vs Frequency graph?
3
votes
1answer
58 views

Absorption line detected with a significance of $2.2\sigma$

What do we mean by the following statement? The SV $\lambda$ 786.46 line is detected with a equivalent width of $W = 22.7\pm10.2$ corresponding to a significance of $2.2\sigma$ How does one ...
0
votes
1answer
18 views

How to compute $L_{\rm eq}$ from temporal pressure data

I have pressure vs time data. how can I compute sound equivalence Level $L_{\rm eq}$ in decibels? can this be done from a frequency spectrum assuming that it is constant?
1
vote
0answers
56 views

Coherent Intermediate Scattering Function from Simulations

I want to calculate the coherent intermediate scattering function, $S_{\text{coh}} (\mathbf{Q},t)$, from a molecular dynamics trajectory, based on its definition. The definition of the function is: ...
0
votes
0answers
31 views

Open-source up-to-date cosmological datasets [duplicate]

Where could I find open-source up-to-date cosmological datasets? Are there any available as a data stream with an API? I already know about these: http://cas.sdss.org ...
2
votes
1answer
51 views

Decay/Counts/Number of Nuclei

I'm writing up a lab report and have a question about the following formula $$N = N_0e^{-\lambda t}$$ $N$ indicates the number of nuclei left after a time $t$ and $N_0$ indicates how much there was ...
1
vote
1answer
51 views

Looking for an Time Series Analysis Text [closed]

(Apologies, I could not think of a better title). Two days ago, I was in the Library at Köln (Those who know it, knows that the books are not ordered by subject - but by date of buying, and one has ...
2
votes
2answers
105 views

Franck and Hertz graph function [closed]

I need a function whom graph is the following (the Frank and Hertz experiment graph): Currently I wrote the following function: ...
1
vote
1answer
31 views

What is the correct way to handle significant figures when calculating compound uncertainties? [duplicate]

When processing experimental data, and calculating an uncertainty value in multiple steps, should intermediary uncertainties be used to a certain number of significant figures or kept to the full ...
0
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1answer
25 views

how find resonance in extrasolar planet? [closed]

I make this program, i have a 2xN matrix in which the columns are the ID of planets and their period, the rows are the number of planets, for istance something like that: ...
1
vote
2answers
212 views

NMR Analysis of Ethylene glycol [closed]

I have the spectrum obtained by an NMR analysis of Ethylene glycol : I would like to explain the number of peaks in this spectrum, and assign them to the proton spins present in the molecule. I ...
1
vote
1answer
46 views

Collection Efficiency of Photon

I am currently reading this paper: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.116802#references In the second column of text in page 2, the author makes various claims about the ...
1
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2answers
46 views

Data for binary systems

I am looking for binary systems data that can be used in the context of Kepler's laws. Masses, distances, periods, etc.
-1
votes
1answer
125 views

What are the problems in analyzing an experiment with non-ideal collisions? [closed]

For a two-dimensional collision experiment, I must explain in one of the questions the problems in analyzing a non-ideal two-dimensional collision. As the question states: Suppose that the ...
1
vote
0answers
40 views

How to calculate tortuosity of a signal? [closed]

Not sure which stack exchange forum to put this in. Moderators feel free to migrate it. One definition of the tortuosity $T$ of a curve is: $$T=\frac{C}{L}$$ Where $C$ is the chord length ...
0
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2answers
70 views

Function for curved line in log-log-plot

I've done experiments on the thermo-viscoelasticity of liver tissue and the following results ...
4
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1answer
254 views

Calculating Lyapunov exponents from a multi-dimensional experimental time series

Wolf's paper Determining Lyapunov Exponents from a Time Series states that: Experimental data typically consist of discrete measurements of a single observable. The well-known technique of phase ...
8
votes
2answers
527 views

Does a muon detector on Earth's surface correctly measure the mean lifetime of a muon?

Just a simple question. Does a muon detector on Earth's surface correctly measure the mean lifetime of a muon? I would think the answer is no because most muons detected are created about 15 km above ...
0
votes
0answers
38 views

How to analyse data that is in four dimension?

I have obtained a series of data that is about density distribution of liquid in three dimensions, density$=f(x,y,z)$. How can I know the detail information about the way that density changes with $x$ ...
3
votes
1answer
91 views

Combining uncertainties - multiple measurements

I am trying to understand how to combine uncertainties when they are dependent and independent from each other. Using this formula : $$\delta z = \sqrt {\Biggl(\dfrac{\partial f}{\partial x} \delta ...
0
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0answers
106 views

What about assessing negative Limit of Detection for concentration

I recently came in a work-group discussion where I think some concepts are misused. After seeking for scientific articles on the subject I have found that part of the problem is definition (what ...
4
votes
1answer
121 views

How do I calculate the experimental uncertainty in a function of two measured quantities

I am performing an experiment where I'm measuring two variables, say $x$ and $y$, but I'm actually interested in a third variable which I calculate from those two, $$z=f(x,y).$$ In my experiment, of ...
2
votes
1answer
159 views

Rutherford Experiment - practical and theoretical questions

I performed the Rutherford experiment the other day, using Au thin foil of $2\,\mathrm{\mu{}m}$, a source/gun of α particles (241Am) and a detector/counter. α particles were shot from the source ...
5
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0answers
91 views

Textbook about the handiwork of a HEP analysis?

I'm wondering if there is a textbook that describes the handiwork of a particle physics analysis. There are a bunch of books about theory, about the experimental aspects like detectors, and about ...
5
votes
1answer
220 views

Advanced data analysis in Physics experiments

Before answering, please see our policy on resource recommendation questions. Please try to give substantial answers that detail the style, content, and prerequisites of the book or ...
3
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0answers
48 views

Converting impact speed to pressure magnitude

In explosive safety and stability testing, a drop test is commonly used to determine the sensitivity to impact. In the test, an impactor of known mass is dropped. The initial height varies throughout ...
1
vote
0answers
70 views

What could be the distribution of an explosion energy of a mining-grade and seismic exploration explosives?

Seismic exploration involves the excitation of seismic waves using the industrially made explosive charges. What could be the distribution of explosion energy of such a charges? My guess is that it ...
0
votes
2answers
168 views

1/r Counting Rate for Radiation Experiment

In an experiment performed in the lab, I want to justify that, when the width of the Geiger counter window is approximately the same size as the distance between the window and a mildly radioactive ...
2
votes
0answers
23 views

Expression for combining several probabilities in a single discriminator

I'm doing an analysis of some experiment. Details are not very important, but I've stumbled on an expression that I cannot make sense of. I have several simultaneous measurements of a certain ...
0
votes
0answers
36 views

What star catalog is suitable for a programmer wanting to model observable stars in 3D?

I have searched around the web and looked at Wiki entries and I am overcome by the number of catalogs available. What I want is a catalog that includes all objects you might conceivably see with ...
1
vote
1answer
70 views

Curve Fitting and Multiple Experiments

Say I do an an experiment 5 times, each of which gives you a list of data points. Do I fit a curve to each one separately and then average the parameters and their uncertainties? Or do I take the ...
1
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0answers
45 views

Where can I get latest full updated list of supernovae candidates from the SDSS-II Supernova Survey?

I am doing a project where I need the list of supernovae candidates from the Sloan Digital Sky Survey II (SDSS-II) supernova survey. One list is available as part of the data-release-7 (DR7) website. ...
1
vote
1answer
22 views

Choice of color for graphs with filled area [closed]

I am writing an article and the central results are summarized in a graph so I want it to be very beautiful and physically intuitive. It has 3 regions in which a certain quantity is conserved, ...
2
votes
1answer
88 views

What are anticipated events and experimental uncertainty?

I am working on this lab that involved gathering data from two different sources. It involved gathering reaction times from a device and from a web application which was put into our data sets. It is ...
0
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0answers
58 views

Where can I find how to do data analysis for a magnetic hysteresis loop?

I am given a data set that has a hysteresis loop but there's a diamagnetic signal that I understand needs to be subtracted, but I don't know the how this is done. I remember finding the slope of the ...
3
votes
1answer
42 views

Asymmetry in muon energies of public CMS dimuon event data

CMS published for educational purposes (caveat) 100.000 dimuon events: https://cms-docdb.cern.ch/cgi-bin/PublicDocDB//ShowDocument?docid=11583 As one easily sees, column 4 shows the first muon's ...
5
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0answers
118 views

Statistical analysis of data in Physics

Analysis of data is integral in bridging the gap between theory and experiment. My question is about the two major methods of approaching the analysis - Bayesian and Frequentist. How much do the ...
0
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0answers
2k views

How to calculate lattice parameter of wurtzite struture

I am trying to calculate lattice parameter of ZnO (wurtzite). I have found out the formula for calculating lattice parameter of this system from a research article. $\frac{1}{^{d^{2}}}=\frac{H ^{2}+ ...
1
vote
1answer
293 views

gaussian fitting of xrd peaks

I am reading a paper regarding the nano crystalline material with hexagonal crystal structure. In that paper in order to find out lattice parameter of hexagonal crystal structure they have fitted a ...
3
votes
3answers
1k views

What does a curved natural log graph suggest?

Sorry if this is rather simple, but I've only just started learning about using logarithms in experimental physics. I did an experiment to test the amount of time it would take for an amount of ...
0
votes
0answers
102 views

Short term track of a hand held sensor (gyro, accelerometer) data with rough precision

I have acceleration and attitude data for the movement of a device in 3d space. what transformations, before numerical integration, are required, in order to produce a 3D track of the the movement in ...
3
votes
1answer
95 views

Galaxy Kinematic Fitting: How to deal with Point Spread Function (PSF)

The past few months I have been studying astronomy and Integral Field Spectroscopy (IFS). What I want to do is to fit a galaxy kinematic model to data (ie: estimate the model parameters that give the ...
1
vote
1answer
66 views

Interpreting the results

I have preformed the muon lifetime experiment at my uni's lab, and got the data. It's text file with 8190 numbers. My TDC unit was set so that the time gates were at 10 $\mu s$, and it has 8192 ...
3
votes
0answers
158 views

Production vs. Collection, and Contaminants vs. Depositions, what might be missing in cold fusion research

I though cold fusion and LENR were discredited, but just a few days ago I found out that NASA is claiming LENR is real. So I thought if they're detecting something, what could it be, and why wasn't it ...
3
votes
1answer
240 views

How to determine frequency components present in distorted signal, with the set of possible components already known?

I am trying to choose the best approach to digitally analyse a signal, which is a mix of an unknown number (but less than 16) fundamental signals at specific frequencies (e.g., sines). The goal is ...
1
vote
1answer
1k views

Uncertainty in Acceleration given the uncertainty in position

I had a motion detector record the position of a dynamics cart and automatically plot Position vs Time and Velocity vs Time plots in Logger Pro on the computer. If the instrument uncertainty in ...