Why we calculate difference between precipitation and potential evapotranspiration?

Hi in SPEI drought Index, we calculate difference between precipitation and potential evapotranspiration, why? who Knows?

12 November 2019 7,833 4 View

Flood Inundation in HEC-RAS?

Hi, I am using HEC-RAS 5.0.7 to create Inundation Boundary, however, it seems HEC-RAS extends flood inundation boundaries up to Edge Lines (two sides of cross sections) and then shows the vertical...

27 October 2019 5,722 10 View

What is time, t or ct?

One of the consequences of relativistic physics is the rejection of the well-known concepts of space and time in science, and replacing them with the new concept of Minkowski space-time or simply...

16 August 2019 4,563 85 View

Is there any effect of dark matter on the orbital speed of the Sun around the centre of the Milky way?

I have found two different results for the effect of dark matter on the orbital speed of the Sun. One from Wikipedia suggests there is no effect while another one from astronomynotes suggests...

15 February 2019 9,533 23 View

What is the best Machine Learning tool for time series analysis of physical-based simulations?

I am looking for a Machine Learning tool for Time series analysis. I have tried MATLAB (ANFIS tool) and ANN in R, but the error is more than my expectation in testing step. Furthermore, MATLAB...

07 December 2018 6,306 4 View

How long does it take for an OMG particle to travel one light year?

The obvious answer is one year as the speed of the oh-my-God (OMG) particle was calculated to be about 0.999,999,999,999,999,999,999,995,1c. However, at this speed, from the frame of the...

21 August 2018 5,636 49 View

Dose any one know that why the different papers have used different concentration of paraformaldehyde (0.5%, 4%, ...) for blastocysts fixation?

We are going to assay apoptosis in mice blastocysts with TUNEL assay kit, but we observed that different papers have used different concentration of PFA such as 0.4%, 0.5%, 2%, 3.7%, 4% with...

13 July 2018 1,733 2 View

How many fundamental mistakes a theory must have before it is forever banned from the classrooms?

In reference to the three attached articles in which it is shown that The theory of length contraction and time dilation are based on a simple oversight. When analyzing the Michelson & Morley...

08 May 2018 2,010 7 View

Does Michelson and Morley experiment support length contraction?

24 September 2017 7,272 86 View

Whould you please help me and say the best way for extraction RNA from panonychus citri by trizol?

I wanna to extract RNA in best way from Panonychus citri by trizol please say me what is the best way for good result?

03 June 2017 8,744 1 View

What is the most Operating System (OS) which can be INSTALL on Tiny hard devices like Raspberry Pi (RPi) hardware ?

I'm targeting to deploy a mesh network and manually configure MANET routing protocols. I'm preparing scenarios, architectures, and hard devices needed to do that. Are there some step-by-step...

03 March 2021 1,931 5 View

Can we classify HV and LV lines based on line length?

I have dataset which shows the length of power lines. I need to classify the lines based on the line length. Is there a rule to classify the High voltage (HV) and low voltage (LV) lines based on...

03 March 2021 4,116 4 View

Is there a classification scheme for rock cavities or caverns with respect to their size and shape?

The range of forms and sizes of cavities in rock is very big. Is there a classification scheme for rock cavities regarding their size and shape?

02 March 2021 4,511 3 View

Is there a powerful system for the security of the systems distributed on IoT systems?

Is there a powerful system for the security of the systems distributed on IoT systems?

02 March 2021 3,858 10 View

How can I integrate a routing protocol in a tiny device (e.g. Raspberry Pi)?

Hi Community, I'm facing the issue of integration/compiling a new routing protocol in a WSN simulator. The final goal is to successfully add, configure this routing protocol in hardware devices...

01 March 2021 9,332 6 View

Which is suitable for use with Python? MySQL or SQL Server?

Which is suitable for use with Python? MySQL or SQL Server? What is your suggestion?

01 March 2021 3,422 3 View

Isolates of Hymenoscyphus fraxineus?

Dear Dr. Cai, my name is Simone Prospero and I work in the team of Phytopathology at the Swiss Federal Institute for Forest Snow and Landscape Research (WSL;...

01 March 2021 1,133 1 View

How to eliminate Steady state error from Reinforcement learning genetic algorithm code?

The following code (see 1st 2 images attached) is used to produce PID controller values that are designed to control the system (G). The code finds the PID controller values (noted as k) by using...

28 February 2021 6,560 14 View

How to Eliminate cosine error and abbe error in LASER measurement system(for example Rhenishaw XL80)?

I like to do project in laser measurement system. My objective is to eliminate or reduce the cosine error, abbe error in Laser measurement system. I have Rhenishaw XL80 system. Please tell the...

28 February 2021 4,890 3 View

I need dataset for recommandation system?

Hi every body I need to collect datasets from different source to work on recommendation system algorithms, could you advise me how collect data?

27 February 2021 7,063 7 View