Bayesian Analysis of Serial Dilution Assays. Mation method, which is used in numerous laboratories across the country and worldwide.Section 2 presents our model, which is based on those of Racine-Poon et al.(1991), Giltinan and Davidian (1994), and Higgins et al.(1998).Section 3 ex. However, in some situations, the dilution factor, which is equal to the final volume divided by volume of stock solution needed for the dilution, is too large. This makes parallel dilution impractical as the necessary volume of the stock solution would be too small to accurately measure. Learn serial dilution with free interactive flashcards. Choose from 169 different sets of serial dilution flashcards on Quizlet.
SATA hard drive connections are faster than older PATA hard drive connections and the same can be said for external cabling standards, but this is counter-intuitive: why wouldn’t the parallel transmission be faster?
Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.
The Question
SuperUser reader Modest is curious about the data transfer rates of parallel and serial connections:
Intuitively, you would think that parallel data transmission should be faster than serial data transmission; in parallel you are transferring many bits at the same time, whereas in serial you are doing one bit at a time.
So what makes SATA interfaces faster than PATA, PCI-e devices faster than PCI, and serial ports faster than parallel?
While it’s easy to fall into the reasoning that SATA is newer than PATA, there must be a more concrete mechanism at work than just age.
The Answer
SuperUser contributor Mpy offers some insight into the nature of the transmission types:
You cannot formulate it this way.
Parallel Dilution
Serial transmission is slower than parallel transmission given the same signal frequency. With a parallel transmission you can transfer one word per cycle (e.g. 1 byte = 8 bits) but with a serial transmission only a fraction of it (e.g. 1 bit).
The reason modern devices use serial transmission is the following:
So, even if you transfer less data per cycle with a serial transmission, you can go to much higher frequencies which results in a higher net transfer rate.
[1] This also explains why UDMA-Cables (Parallel ATA with increased transfer speed) had twice as many wires as pins. Every second wire was grounded to reduce crosstalk.
Scott Chamberlain echoes Myp’s answer and expands upon the economics of design:
Serial Vs Parallel Dilution Method In Wastewater Systems
The problem is synchronization.
When you send in parallel you must measure all of the lines at the exact same moment, as you go faster the size of the window for that moment gets smaller and smaller, eventually it can get so small that some of the wires may still be stabilizing while others are finished before you ran out of time.
By sending in serial you no longer need to worry about all of the lines stabilizing, just one line. And it is more cost efficient to make one line stabilize 10 times faster than to add 10 lines at the same speed.
Some things like PCI Express do the best of both worlds, they do a parallel set of serial connections (the 16x port on your motherboard has 16 serial connections). By doing that each line does not need to be in perfect sync with the other lines, just as long as the controller at the other end can reorder the “packets” of data as they come in using the correct order.
The How Stuff Works page for PCI-Express does a very good explination in depth on how PCI Express in serial can be faster than PCI or PCI-X in parallel.
TL;DR Version: It is easier to make a single connection go 16 times faster than 8 connections go 2 times faster once you get to very high frequencies.
Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.
READ NEXT
•••ValerieVS/iStock/GettyImages
By Sean Lancaster
To ensure the accuracy of your results, chemical analysis requires you to calibrate your instruments. Some techniques operate and are applicable to a wide range of concentrations of the species in question. Preparing a series of solutions to generate a calibration curve of instrument response is fairly labor intensive and provides many points where errors may occur.
TL;DR (Too Long; Didn't Read)
You can use serial dilutions of a solution of known concentration to calibrate lab equipment and ensure its accuracy.
Errors
Making multiple calibration standards for your lab equipment means measuring out a solution of known concentration and diluting it to make a series of lower concentrations. You must exercise care at each step; any errors will increase through multiple dilutions. Since the point is to calibrate your instruments, errors in this process will compromise your final results; in fact, you could have serious problems with your data.
Serial dilution only requires that you measure your solution of known concentration one time. Each calibration standard that follows comes from the previous one. The absolute size of the error in each standard becomes smaller and smaller as the concentration drops.
Easier and Faster Preparation of Calibration Standards
Each calibration standard solution is prepared based on the previous calibration standard. The process involves taking a portion of the previous standard and diluting it with the solvent to obtain the next calibration standard. The errors introduced with each successive dilution drops proportionately with the solution concentration. Preparing a series of calibration standards by this method reduces the amount of required time. Most calibration standards span a large range of concentrations, so the accuracy of the calibration standard prepared increases.
Calibrations Solutions More Evenly Spaced
The calibration standards should span the entire concentration range of the analysis. The more evenly spaced the calibration standards are over this range, makes the results of the analysis more reliable. Evenly spaced calibration standards are easier to prepare using serial dilution. Each successive standard uses a small portion of the previous standard, which is diluted by solvent to generate the next calibration standard in the series.
Greater Variability in Calibration RangeSerial Vs Parallel Dilution Method In Wastewater Management
The dilution factor chosen for the series of calibration standards is achievable by using serial dilution. The progression of calibration standard concentration is always a geometric series. Consider the example of making the first standard at 1/3 the concentration of the known, the next calibrant would be 1/9th the concentration of the known and the following two calibrants formed are 1/27th and 1/81st. This becomes a much greater advantage when the span of the calibration standards must cover several orders of magnitude in concentration.
Comments are closed.
|
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |