Dr. SaMeH S. Ahmed

Civil and Environmental Engineering Department

Carbon dioxide


Carbon dioxide


Carbon dioxide is one of the major pollutants in the atmosphere produced mainly by fuelcombustion and deforestation


Carbon dioxide (chemical formula CO2) is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state, as atrace gas at a concentration of 0.039% by volume.

As part of the carbon cycle known as photosynthesisplantsalgae, and cyanobacteria absorb carbon dioxide, light, and water to produce carbohydrate energy for themselves and oxygen as a waste product.  But in darkness photosynthesis cannot occur, and during the resultant respiration small amounts of carbon dioxide are produced. Carbon dioxide is also produced by combustion of coal or hydrocarbons, the fermentation of liquids and the breathing of humans and animals. In addition it is emitted from volcanoeshot springsgeysers and other places where the earth’s crust is thin; and is freed from carbonate rocks by dissolution. CO2 is also found in lakes at depth under the sea, and commingled with oil and gas deposits.]

As of November 2011, carbon dioxide in the Earth's atmosphere is at a concentration of approximately 390 ppm by volume. Atmospheric concentrations of carbon dioxide fluctuate slightly with the change of the seasons, driven primarily by seasonal plant growth in the Northern Hemisphere. Concentrations of carbon dioxide fall during the northern spring and summer as plants consume the gas, and rise during the northern autumn and winter as plants go dormant, die and decay. Taking all this into account, the concentration of CO2 grew by about 2 ppm in 2009  Carbon dioxide is a greenhouse gas as it transmits visible light but absorbs strongly in the infrared and near-infrared, before slowly re-emitting the infrared at the same wavelength as what was absorbed.

Before the advent of human-caused release of carbon dioxide to the atmosphere, concentrations tended to increase with increasing global temperatures, acting as a positive feedback for changes induced by other processes such as orbital cycles. There is a seasonal cycle in CO2 concentration associated primarily with the Northern Hemisphere growing season.]

Carbon dioxide has no liquid state at pressures below 5.1 standard atmospheres (520 kPa). At 1 atmosphere (near mean sea level pressure), the gas deposits directly to a solid at temperatures below −78.5 °C (−109.3 °F; 194.7 K) and the solid sublimes directly to a gas above −78.5 °C. In its solid state, carbon dioxide is commonly called dry ice.

CO2 dissolves in water forming carbonic acid, which is a weak acid, because CO2 molecule ionization in water is incomplete. Thehydration equilibrium constant Kh (at 25 °C) of carbonic acid is [H2CO3]/[CO2] = 1.70×10−3: Hence, the majority of the carbon dioxide is not converted into carbonic acid, but remains as CO2 molecules not affecting the pH. It is an amphoteric substance that can act as an acid or as a base, depending on pH of the solution.

CO2 is an asphyxiant gas and not classified as toxic or harmful in accordance with Globally Harmonized System of Classification and Labelling of Chemicals standards of United Nations Economic Commission for Europe by using the OECD Guidelines for the Testing of Chemicals. In higher concentrations 1% (10,000 ppm) will make some people feel drowsy. Concentrations of 7% to 10% may cause suffocation, manifesting as dizziness, headache, visual and hearing dysfunction, and unconsciousness within a few minutes to an hour.


The Best Book

Prayer Times

Click here




Office hours

Sunday:      10-1

Monday:      12-1

Wednesday: 10-11

You are welcome to contact me by at any time

You  may also contact me via WhatsApp group

Ext. 2524

Time Table 2018-19S


Civil Eng. Students


DON'T miss!

Love your department and be proud of your field of study

As we approaching the second midterm exams..  Get ready and remember our offices are open to answer you . do not hesitate to .contact me if you have difficulties

For CE 370 students : Your second midterm exam will be on Wednesday 27 March 2019. In the surveying lab

Good Luck


Announcements


My Dear Students

Please visit the  announcement box for the relevant course and make sure that you can download and upload easily, otherwise

.contact me  to sort it out

There will be an orientation session in the midell of this term to help you select your track in Civil and Environmental Engineering

Special Event

Special Issue

Electrical Power Resources: Coal versus Renewable Energy



Published Online on January 2016


Mining Engineering


Mining engineering is an engineering discipline that involves practice, theory, science, technology, and the application of extracting and processing minerals from a naturally occurring environment. Mining engineering also includes processing minerals for additional value.

Environmental Engineering


Environmental engineers are the technical professionals who identify and design solutions for    environmental problems. Environmental engineers provide safe drinking water, treat and properly dispose of wastes, maintain air quality, control water pollution, and remediate sites contaminated due to spills or improper disposal of hazardous substances. They monitor the quality of the air, water, and land. And, they develop new and improved means to protect the environment.

Proverb

Actions speak louder than words

Tawasl


College of Eng. MU

http://mu.edu.sa/ar


Univeristies

Universities I've worked in


Assuit University (Home University), Egypt


Imperial College, London, UK


Faculty of Engineering, Al-Mergeb University, Libya


King Saud University, KSA

,Majmaah University


Majmaah University has a very nice web page that provide  all information regarding deanships, colleges, activities,  campuses and many others. Search your request in
http://mu.edu.sa/en

Also visit

My Academic Pages

https://www.researchgate.net/profile/Sameh_Ahemd

and give me


Think


??

Sports

Ahly vs Zamalek, 30 March 2019

Africa Nation Cup, June 2019


Course 2018/19-2


  1. Surveying 1 CE 370
  2. Surveying II  CE 371
  3. Senior Design II  (round 6) CE 499




The Rules of Life

Rule #1


Latest

Member of the Editorial Board: " Journal of Water Resources and Ocean Sciences"  2013 till now

https://www.researchgate.net/profile/Sameh_Ahmed5/?ev=hdr_xprf

Participating in The Third International Conference on Water, Energy and Environment,(ICWEE) 2019 - American University of Sharjah, UAE 26-28 March 2019 with a Paper and Poster

New article


Coming soon



2nd Midterm Exams on 3/4/2019

Student Conference



Participation  in the 6Th Student Conference

With a paper and oral presentation

From the Senior Design Project CE499 -35

See inside, the paper, and presentation

CE 370 Course

Surveying I

2018-2019S




Power point


Sheets


Lecture notes
15

3-4-2019

:Second Midterm Exam



Results


Model Answer
Inside, please follow

Working  marks is available -Click on Surveying I

CE 371 Course

Surveying II

2018-2019-2




Lectures





First midterm exam


Lab


Results

See Inside

Working marks out of 60 is  available- Click on Surveying 2

CE 474 Course

Photogrammetry

2018-2019-1



Available 0-1-2-3-4 Power point

Available

Quizzes 2 and 3 with model Answer

Quizzes
Available Chapter 1,2,3,4,5 Lecture notes

Report 1  Cameras Report

Y

60 marks Exams

See Inside

Student Performance Records


CE 499 Course

Senior Design 2


Second Best paper from Senior Design Projects in 2015

Paper title:

Evaluation of Groundwater Quality Parameters using Multivariate Statistics- a case Study of Majmaah, KSA

Students:

Abdullah A. Alzeer

Husam K. Almubark

Maijd M. Almotairi

Engineering Practice


A must for Engineer

Useful Links

Google

See what can you get from Google!! more than translation and locations

http://www.googlealert.com/

http://blogsearch.google.com/

http://books.google.com/

http://earth.google.com/

http://finance.google.com/finance


?What is your opinion

Email me in:  [email protected]


Saudi Vision 2030

Sustainability

Learn more about it


Riyadh Metro

A job opportunity 

Safe Fly


Surveying 2-19-3

JEAS

Conversion-Hegira to AD

Conversion


SDL

Saudi Digital Library

Research-gate

Visit me in RG

Success


Contact me

Mobile: 00966598311652

[email protected]

Civil and Environmental Engineering Department
College of Engineering, Majmaah University
Majmaah, P.O. 66, 11952, KSA

Thank you

خالص شكري وتقديري

إحصائية الموقع

عدد الصفحات: 2066

البحوث والمحاضرات: 2042

الزيارات: 69621