Dr. SaMeH S. Ahmed

Associate Prof. of Environmental Engineering

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.


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Sunday:     12-1

Monday:     12-1

Tuesday:     10-12

Wednesday: 10-11

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Civil Eng. Students

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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 : I do apologize for did not attend the extra lab session that proposed to be on Wednesday at 6 am.  Sorry

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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

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.

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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

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My Academic Pages

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

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Course 2016/17-1


  1. Computer Applications in Surveying  CE 473
  2. Surveying 1 CE 370
  3. Photogrammetry CE 474
  4. Surveying II  CE 371
  5. Design I  (round 4) CE 498




The Rules of Life

Rule #7

Latest

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

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

Participating in The Third International Conference on Water, Energy and Environment,(ICWEE) 2015 - American University of Sharjah, UAE 24-26 March 2015 with a Paper and Poster

New article

Recovery of Titania from Waste-Sludge of Majmaah Water Treatment Plant

"Production of Titania Nano-particles from Wast-

Sludge

Coming soon



Results of M2 CE311

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 -  CE 370 - 2016-2017-1




Power point


Sheets


Lecture notes


Second Midterm Exam



Results


Model Answer
Inside, please follow:

Student Performance Records

CE 371 Course

Surveying II - CE 371 - 2016-2017-1




Lectures





First midterm exam


Lab


Results

See Inside

Student Performance Records

CE473 Course

Computer Applications in Surveying

CE 473



Lecturers


Power point


Sheets


Exams + Quizzes


Results




CE 474 Course

2015-2016-2 - Photogrammetry  CE474




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 360 Course

Environmental Engineering 1



CE 360: Environmental Engineering 1

37-2

Y PP0-1-2-3,4 Power point
Y 1,2,3,4,5 Chapters

Water quality Poster + Climate Change Reports
will be announced (Quiz #2 will be using D2L- Online Quizzes

Y

Quizzez 2,3 and 4 with model answer and results Exams and results

GE 306 Course

Engineering Report Writing


GE 306: Engineering Report Writing

CE 499 Course

Senior Design 2 - CE 499

Meeting on 14-4-2015

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

CE 360-Summer Course

Environmental Engineering I


Welcome to CE360 second Term 2015-2016 

Engineering Practice

 Engineering Practice GE 307

What is your opinion

Contact me

Mobile: 00966598311652

s.mohamed@mu.edu.sa

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

Thank you

Your frequent visit to my website has helped  a lot to get the 2nd place in the university competition in the  year 1434-2013... Thanks very mush and please keep following my work

زيارتكم المتكررة لموقعي ساهمت في حصولي على المركز الثاني لاحسن المواقع الشخصية بجامعة المجمعة ...لكم جميعا خالص شكري وتقديري

CE 212 - Summer Course

Properties and Strength of Materials 1

CE 212

Y from PP0 to PP 6 + PDF Power points
Y Midterm #2 + Model Answer + results Exams
Y lab 3 Labs

Solution of Quiz 4 + Results HW


CE 311- Summer Course

Soil Mechanics and Foundation Engineering

CE 311

M2+ model Answer + PP 1-9 = PDF 1-9 all are available

Sheets 2 + 4 with model Answers

Results of M2



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