مواقع التدريسيينجامعة الكوفة
Hasan Mahdi Mohammed Al-Khateeb
Professor

Hasan Mahdi Mohammed Al-Khateeb

Engineering Civil Engineering
0Publications
0Lectures

About

Curriculum vitae
Personal information:
Sure Name Al-Khateeb
Given Names Hasan Mahdi Mohammed
Address Al-Ameer Nieghborhood – Najaf – Iraq
Phone 00964 33 210542
Mobile 00964 7801035385
Nationality Iraqi
Date of birth 14-9-1971
Marital status Married with three children
E-mail [email protected]; [email protected]

Web site www.emg.kufauniv.com/staff/hassanm

Qualification
1989 – 1994 B.Sc. of Civil Engineering, College of Engineering – University of Mustansiriyah
1994 – 1997 M.Sc. of Civil Engineering / Environmental Engineering, College of Engineering – University of Mustansiriyah
Aug – Sept 1997 Certificate of passing advanced training course in computer hardware / University of Mustansiriyah
1997 – 2002 Ph.D. of Civil Engineering / Environmental Engineering, College of Engineering – University of Mustansiriyah

Conferences
- Head of organizing committee for the 1st Environmental Conference of Najaf Province, Local Governance Project, Najaf Environment Directorate, and Najaf Environment Protection Agency, Al-Najaf, March 2004.
- Lecturer of Environmental Education training, WHO and Najaf Environment Directorate, Najaf, May 2007.
- Article "Evaluation of Environmental Status of Najaf Sustainable Development", Environmental Education Symposium, Najaf, 2008.
- Article "Evaluation and Proposed solutions for Groundwater High levels Problem in the center of Kerbala City", Symposium of groundwater problem in Kerbala, Waqf Al-Shiey and the Supervising Establishment of Abbasiyah Shrine, Kerbala, April 2007.
- Lecturer of the" 1st Training Course of Environment and Water Resources Protection", Training center, Faculty of Engineering, University of Kufa, March – April 2007.
- Scientific evaluation for (6) M.Sc. thesis and (1) PhD. dissertation, Examiner of (7) M.Sc thesis, Evaluation of 73 researches for publishing and 10 for scientific upgrading.
- Member of Scientific Committee of 2nd Environmental Conference of Najaf Province, Najaf Environment Protection Council in collaboration with Najaf Environment Protection Directorate, 26 – 27 Aug. 2007.
- Head of Scientific Committee of 3rd Environmental Conference of Najaf Province, Environment Protection Committee /Najaf Province Council in collaboration Local Governance Project of Najaf, 27 – 28 May 2008.
- Lecturer of 1st Occupational Health and Safety Training Course, Training Center, Faculty of Engineering, University of Kufa, 1 – 25 April, 2010.
- Lecturer of 2nd Occupational Health and Safety Training Course, Training Center, Faculty of Engineering, University of Kufa, 16 – 23 January 2011.
- Consultant for Environment and Public Health Committee in Najaf Province Council to prepare Local Law of "Hazardous Waste Management in Najaf Province".
- Co-chair of “International Conference on Civil and Environmental Engineering Technologies, ICCEET, 2021”.
- Co-chair of “International Conference on Civil and Environmental Engineering Technologies, ICCEET, 2022”.
- Keynote speaker, the first symposium of engineering in the Fourth International Scientific Conference for Medical, Engineering, and Sciences at Al-Kafeel University, Jan 2023.
- Keynote speaker, the second Regional Symposium of Innovation in Science and Technology, University of Ferdowsi – Mashhad, Iran, Jan. 2025.
- Keynote speaker, the Second International Scientific Conference on Environmental Technologies and Sustainable Development, held at Komar University of Science and Technology in Sulaymaniyah, Feb 2025.
- Keynote speaker, “Pollution Crisis in Iraq: Challenges and Solutions,” conference held in London, organized by the Association of Iraqi Academics in the United Kingdom, September 2025.

Samples of Publications.
- "Land Treatment of Oily Sludge of Daura Refinery", First Engineering Conference, College of Engineering, University of Mustansiriyah, Baghdad, Iraq, 1997.
- "Soil Conditions Affected by Oily Sludge Land Treatment", First Conference of Pure and Applied Science, University of Kufa, Najaf, Iraq, 2008.
- "Pre-aeration and Transversal Baffling Effect on Aerated Grit Chamber Performance of Kufa Wastewater Treatment Plant، "International Journal of Science and Research (IJSR), 2016.
- "Evaluation of Local Scour Development around Curved Non-Submerged Impermeable Groynes", International Journal of Scientific & Technology Research, 2015.
- "Hydraulic Study Of Minimizing Energy Consumption In Storm Water Pumping Station Suction Side", International Journal of Engineering Research and Technology, 2016.
- "Investigating the Setting of the Entrance of Multiple Vertical Suction Pipes in Storm Water Pump Station", International Advanced Research Journal in Science, Engineering and Technology (IARJSET), 2017.
- “An experimental study of flow over V- shape crump weir crest”, International Conference on Civil and Environmental Engineering Technology (ICCEET 2019).
- “Air entrained vortex occurrence at sump for inclined multiple intake pipes using CFD”, Journal of Engineering Science and Technology, special issue, 2021.
- “Incineration alternative for municipal solid waste disposal of Najaf city, Iraq”, Journal of Engineering Science and Technology, special issue, Vol. 16, 2021.
- “Impact of Water Pollution on Aspects of Aquatic Life in the Euphrates at Kufa City”. International Advanced Research Journal in Science, Engineering and Technology Vol. 7, Issue, 2020.
- “Iraqi Code of Sewerage System, Networks – Pump stations – treatment plants”, Iraqi Ministry of Reconstruction, Housing and Municipalities, 2021, Bagdad, Iraq.
- Graphene-Based Important Carbon Structures and Nano-materials for Energy Storage Applications as Chemical Capacitors and Super-capacitor Electrodes: a Review, BioNanoScience volume 13, pages219–248, 2023.

Lecturing Experience
- Computer Programing, Fortran 77-90, two years (2000 – 2002), College of Engineering, University of Mustansiriyah, Baghdad, Iraq.
- Fluid Mechanics, five years 2004 – 2009, Civil Engineering Dep, 2nd year, Faculty of Engineering, University of Kufa, Najaf, Iraq.
- Sanitary Engineering, 2009 – 2022, Civil Engineering Dep, 4th year, Faculty of Engineering, University of Kufa, Najaf, Iraq.
- Research Methodology course, 2015 – 2022, postgraduate studies, Civil Eng. Dep., Faculty of Engineering, University of Kufa.
- Open Channel Flow, 2015, postgraduate studies, specialty of Hydraulic Structures, Civil Eng. Dep., Faculty of Engineering, University of Kufa.
- Research Methodology course, 2016 - 2023, postgraduate studies, Material Eng. Dep., Faculty of Engineering, University of Kufa.
- Research Methodology course, 2018 - 2023, postgraduate studies, Mechanical Eng. Dep., Faculty of Engineering, University of Kufa.
- Environmental Engineering, 2018, 4th year, Department of Ecology, Faculty of Science, University of Kufa.
- Wastewater Treatment Engineering Course, 2018, Post-graduate / M.Sc. of Ecology, Faculty of Science, University of Kufa.
- Building services, 2020 – 2021, Architectural Engineering Dep, 3rd year, Faculty of Engineering, University of Kufa, Najaf, Iraq.
- Advanced Water Treatment Engineering, 2023, Graduate Studies, Master of Environmental Engineering, Department of Civil Engineering, Faculty of Engineering, University of Kufa.
- Advanced Wastewater Treatment Engineering, 2023, Graduate Studies, Master of Environmental Engineering, Department of Civil Engineering, Faculty of Engineering, University of Kufa.

Employment and membership
July 1994- Feb 1995 Site Engineer (civil Engineer), Iraqi Ministry of Industry and Minerals, Establishment of Erection of New Tires and Rubber Factory, Civil works of the project.
July – Oct 1995 Site Engineer (Civil Engineer), State Establishment of Implementing Transportation Projects, construction of Public Parks and Garages in Baghdad.
Dec 1995 – May 1997 Iraqi Ministry of Oil, contract of research, Land treatment of Oily Sludge and its Effect on surface Water.
Oct 1999 – March 2002 Iraqi Ministry of Irrigation (now called Ministry of Water Resources), Contract of research, Modeling of groundwater in Kerbala.
May – Oct 2004 Lecturer in Civil Engineering Dep., Faculty of Engineering, University of Kufa.
Oct 2003 – Aug 2004 Environmental Sector Manager, Local Governance Project – RTI, Najaf Province.
Sep 2004 – May 2013 Vice Dean for Administrative Affairs, Faculty of Engineering, University of Kufa.
July – Aug 2005 Acting Dean, Faculty of Engineering, University of Kufa.
Feb – July 2006 Engineering Affairs Manager, University of Kufa.
Sept 2004 – Sept 2008 Member of Engineering Consulting Bureau, Faculty of Engineering, University of Kufa.
March 2005 –till now Member of Najaf Province Environment Protection Council.
June 2005 – Aug 2006 Consultant member of Sewerage Projects Follow up Committee, Najaf Province Council.
July 2005 – Sept 2007 Member of Engineering Consulting Committee of Imam Ali Shrine Extension, Imam Ali Holy Shrine Administrative Establishment.
May 2005 – Aug 2006 Consultant Member of Engineering Committee concerned in evaluation and treatment of groundwater shallow levels problem in Najaf city. Najaf Province Council.
Aug 2006 Acting Dean, Faculty of Engineering, University of Kufa.
April 2007 Member of consulting committee of studying Heritage and Archeology of Najaf.
Aug 2007 Acting Dean, Faculty of Engineering, University of Kufa.
July 2007 – Feb 2009 Consultant of Najaf Vice Governor for Sewerage and water supply services.
Nov 2007 – Jan 2008 Acting Dean, Faculty of Engineering, University of Kufa.
Sept 2008 – April 2010 Member of Scientific Committee of researches funding approval, Iraqi Ministry of Higher Education and Scientific Research.
Aug 2008 – Feb 2009 Member of Technical Committee for Sewerage Projects in Najaf Province, Headed by Najaf Governor.
April – May 2011 Acting Dean, Faculty of Engineering, University of Kufa.
May 2017 – Oct 2019 Member of Curriculum Review Experts, Ministry of Higher Education and Scientific Research, Iraq.
Dec 2019- Oct 2023 Acting Dean, Faculty of Engineering, University of Kufa.
October 2019 - Member of Consulting Board of Waqf Al-Shyeey, republic of Iraq

Engineering Consultancy Work with the Engineering Consulting Bureau, Faculty of Engineering, University of Kufa.
- Consultant Engineer of Design team of Najaf city sewerage networks, a contract with Sewerage General Directorate, Iraqi Ministry of Municipalities and Public Works.
- Consultant Engineer of Design team of Kerbala city sewerage networks, a contract with Sewerage General Directorate, Iraqi Ministry of Municipalities and Public Works.
- Designer of Meshkhab city sewerage networks, a contract with Sewerage General Directorate, Iraqi Ministry of Municipalities and Public Works.
- Member of designing team for Najaf and Kerbala wastewater treatment plants, a contract with Sewerage General Directorate, Iraqi Ministry of Municipalities and Public Works.
- Member of designing team for Hamzah City wastewater treatment plant, a contract with Sewerage General Directorate, Iraqi Ministry of Municipalities and Public Works.
- Member of designing team for wastewater treatment plants of Najaf districts and sub-districts, a contract with Najaf reconstruction establishment.
- Member of designing team for Najaf – Kufa storm water sewer line, a contract with Najaf Sewerage Directorate, Iraqi Ministry of Municipalities and Public Works.
- Member of designing team for Jame'eyah - Maysan storm water sewer line, a contract with Sewerage General Directorate, Iraqi Ministry of Municipalities and Public Works.
- Designer of water supply boosting station and network of Kufa University Campus.
- Designer of plumbing services of several Facultys at the University of Kufa, like Faculty of Nursing, Agriculture, and sports.
- Consultant Engineer for plumbing works of Al-Najaf Al-Ashraf Hotel new building, a contract with the Iraqi Ministry of work and social affairs.
- Designer of plumbing services of several medical centers in Najaf. A contract with Najaf Public Health Directorate.
- Designer of water trunk line with low lift station, Al-Khammasy village, Najaf Province.
- Designer of water trunk line with low lift station, Al-Ghasiyah village, Najaf Province.
- Designer of water trunk line with low lift station, Al-Hawzah Houses, Kufa, Najaf Province.
- Designer of water trunk line with low lift station, Al-Wahaby village, Kufa, Najaf Province.
- Consultant Engineer preparing the preliminary study of some treatment plants like those in Najaf, Kerbala, Najaf districts, and Babylon districts.
- Consultant engineer for consulting supervision of several sewerage projects like:-
- Al- Jame'ah neighborhood in Najaf City.
- Kindah neighborhood in Najaf City.
- Kufa city center.
- Diwaniyah trunk line; contracts 57 / 2008, 59/2008, 26/2008, 31/2008, total length of 13 km.
- Hamzah trunk line and main pump station.
- Shamiyah trunk line.
- Consultant engineer for consulting supervision of the complex of Iraqi Ministry of works and social affairs, Najaf, Iraq.
- Designer of fire fighting system of Babylon Federal court.
- Evaluation study of water sedimentation Basin at Kufa water treatment plant.
- Designer of Tajji area water supply boosting system, north of Baghdad.
- Head of design team of sewerage network of Jameyah neighborhoods in Najaf City.
- Head of design team of sewerage network of Shurtah neighborhoods in Najaf City.
- Head of design team of sewerage network of Nidaa and Meelad neighborhoods in Najaf City.
- Head of design team of sewerage network of Makrama neighborhoods in Najaf City.
- Head of design team of sewerage network of Bayti Residential Complex in Najaf City.
- Head of team preparing Iraqi Sewerage Code, contract with Iraqi Ministry of Reconstruction and Housing and Municipalities, 2016 -2019.

Other Consultancy Works with other than Engineering Consulting Bureau, Faculty of Engineering, University of Kufa.
- Hydraulic and sanitary designer for industrial wastewater treatment plant of Kufa soft drink factory.
- Hydraulic and sanitary designer for raw water treatment plant of Kufa soft drink factory.
- Consulting supervision of two compact wastewater treatment plants with 20,000 population capacity each; first in Kufa city, second in Rumaitha, Samawah.
- Designer of storm water network in Hurriyah subdistrict, Kufa, Najaf.
- Designer of storm water network in Abbassiyah subdistrict, Kufa, Najaf.
- Designer of filtered manhole used to lower ground water level in Nassiriyah.
- Member of the team prepared the study and design of Haj Al-Barry road, engineering Consulting Bureau of Al- Mustansirayh University.
- Prepared over than 845 Environmental Impact Assessment reports of different activities like; industries and residential complexes in Iraq.
- Evaluation study to improve the performance of sedimentation basin in Kufa city water treatment plant.
- Consultant engineer for consulting supervision of several sewerage projects like:-
- Sewerage network of Al-Ansar neighborhood, Najaf.
- Sewerage network of 4th Judaidah neighborhood, Najaf.
- Sewerage network of Imam Ali neighborhood, Najaf.
- Prepared 19 feasibilty studies for different activities and projects (industries, workshops, residential complex and hotels, infrastructure services,..etc.
- Evaluation study of pressurized filters used in 18 water treatment compact units in Najaf.
- Designer of water supply trunk lines in Rumaythah, Samawa, Iraq.
- Designer of sewerage network for some neighborhoods in Kufa city (Mu'alimeen and Rashadiyah).
- Designer of sewerage network for Karamah neighborhood in Meshkhab – Najaf Province.
- Designer of eight sewage treatment plants of Babylon districts, 2019.

Publications

5
2018

Effect of Oily Sludge Land Treatment on Soil Conditions

AuthorsAssist.Prof. Dr. Hasan Mahdi M. AL-Khateeb, none
JournalEuropean Journal of Engineering Research and Science
Abstract

Land treatment is a method of handling wastes produced by the petroleum refining industry and others. This method allows the simultaneous treatment and final disposal of the waste. This study represent a fundamental filed investigation to follow the land treatment method for disposing of an oily sludge produce by Daura Refinery Wastewater Treatment Plant. The sludge typically consists of (84.5-86.2) %water, (4.7-5.3) %oils, and (8.4-9.25) %sediments. It is characterized by law contents of phenol, nitrogen, and heavy metals of environmental concern. Loamy sand soil land located inside Daura Refinery was selected and divided into a1-sq. meter plots. A range of sludge application rates was applied to add the sludge to (mix with) the upper 15 cm soil layer of 18 plots, whereas 6 plots left as control plots. The applications range included three applications ratios of (fresh sludge wt.,dry soil wt.) as (1:3), (1:6), and (1:10), each of them was applied in three application intervals: weekly, monthly, and seasonally. Selection of the best application rate was made with regard to sludge degradation and land area requirements. Soil samples were tested for oil residue, heavy metals, total nitrogen, electrical conductivity, pH, and aggregate stability. The results show that, monthly (1:10) application rate caused neither considerable downward oil migration in the soil nor significant accumulation of oil, heavy metals, or salts in the soil. However, it maintained neutral soil pH and improved soil aggregate stability. Oil biodegradation in the soil was encouraged by soil weakly tillage.

2017

Investigating the Setting of the Entrance of Multiple Vertical Suction Pipes in Storm Water Pump Station

AuthorsAsst. Prof. Dr. Hasan Mahdi M. Al-Khateeb, Asst. Prof. Dr. Hayder Abdulameer K. AL-Thamiry Ali Hussein Athab
JournalInternational Advanced Research Journal in Science, Engineering and Technology
Abstract

Storm water pump stations are usually utilized to facilitate drainage of run-off water from segments of cities and neighborhoods. The velocity of inlet suction pipe (v) and the water depth from suction pipe onset to the water surface (submergence) represent important factors to avoid free and subsurface vortices at pump suction pipes. The present study set out to determine effect of submergence (s) and velocity of inlet suction pipe (v) on the hydraulic conditions of storm water pump station. Through this study, a physical model has been constructed to simulate a typical wet well side for multiple vertical suction pipes with the same diameter (d) and bell mouth out diameter (D). Many runs have been conducted through which effects of the pipe flow velocity, suction pipes spacing (b) and submergence were observed through the four glasses sided well model by means of naked eye, and detected by pressure gauge situated at suction side. Measurements were made for diameter and height of vortices formed. This study aims to determine the best arrangement of pumps intake suction pipes with respect to operational submergence to prevent the occurrence of any type of vortices using minimal wet well dimensions for a given flow rates. The results showed that, surface vortices do not formed when the submergence (s ≥ 1.75D) and spacing (b > 2D) for Fr (u) ≤ 1.

2016

Pre-aeration and Transversal Baffling Effect on Aerated Grit Chamber Performance of Kufa Wastewater Treatment Plant

AuthorsDr. Hasan Mahdi M. Al-Khateeb
JournalInternational Journal of Science and Research (IJSR)
Abstract

Abstract: This paper investigates solutions for a problem of heavy loads of grits and grease encountered in a 50,000 m3/day capacity municipal wastewater treatment plant of Kufa city located at 160 Km south of Baghdad in Iraq. Total suspended soli ds TSS concentrations in the influent were 410 – 780 ppm causing about 1 – 2 ton/day of grits to deposit in a reducing flow velocity basin located in between the fine screen and the aerated grit removal chamber. Oil and grease O&G were found with high concentrations 145 – 255 ppm in the raw sewage causing operational problems in secondary treatment. The solutions investigated were; using pre-aeration in the reducing flow velocity basin, installing effluent transversal baffle at the last 35.5 cm length section before end wall of the aerated grit chamber of 14.8m total length, and longitudinal diffused aeration condition near baffle location. Six operational cases were investigated with various installations of baffle submerged depth, pre-aeration and longitudinal chamber aeration conditions. For each of the six cases studied, three daily samples for each of influent, effluent and settled grits were collected and tested. Sampling was carried out for seven days period for each of the six cases at 9:00am, 12:00pm and 2:00 pm in order to cover quality possible variation. Influent and effluent samples were tested for TSS, and O&G, while grit samples were tested for total organic carbon TOC. Flow rate of the chamber was observed three times daily at the mean time of sampling by means of a Parshal Flume installed downstream the chamber. Longitudinal and transversal local flow velocity measurements were carried out by means of a flow velocity meter specially developed and calibrated for the field work. Three transversal sections were adopted along the chamber. First section was at 3.24m behind the inlet wall, second section was at 8.24m from inlet wall, corresponding to the center of the middle air diffuser, while third one was at 13.24m from inlet wall. Each of the three transversal sections was subdivided into five successive bays of 0.5m width each for the main channel of the chamber. At centerline of every bay, point (local) flow velocity was measured at water depths 0.25, 0.75, 1.25, 1.75, 2.25, 2.75 and 3.25m for both longitudinal (main) and transversal directions. Both longitudinal and transversal local velocities measured were divided by the main average flow velocity to get dimensionless relative flow velocity distribution along the chamber in both directions. The results showed that pre-aeration of 7.5 m 3 air/ hr . m 3 water increased TSS and O&G removal efficiencies of the grit chamber with 43% and 134%, respectively. Installing the transversal baffle with a depth corresponds to 50% of water entire depth beside the same pre-aeration have together greater effect to increase O&G removal efficiency with 209%. However, the best dual removal efficiency for both TSS and O&G was through installing the transversal baffle with submerged depth of 24% of entire water depth and the same pre-aeration. Such conditions increased TSS removal efficiency by 44.5% and increased O&G removal efficiency by 170%, and neither adversely effected the helical flow velocity distribution pattern nor the longitudinal flow. TOC results in dicated relatively long detention time adopted in the chamber causing considerable deposition of organic matters with the grits removed.

2016

Evaluation of Local Scour Development Around Curved Non-Submerged Impermeable Groynes

AuthorsDr. Hasan Mahdi M. Al - Khateeb, Dr. Hayder Abdulameer K. AL - Thamiry and Huda Hadi Hassan
JournalINTERNATIONAL JOURNA L OF SCIENTIFIC & TE CHNOLOGY RESEARCH
Abstract

Abstract : Groynes are man - made hydraulic structures constructed for a variety of pu rposes. They extend outside the bank in the depth of streams. Local scour usually occurs around groynes resulting in problems of interest to hydraulic engineers. In this study, laboratory experiments were conducted to evaluate the local scour around differ ent number of groynes distributed on different spacing with different shapes. Physical models have been developed for groynes installed in a straight hydraulic channel grounded with uniform cohesionless (soil) as bed material wit h medium grain size (d50 = 0.69 mm). The experiments were conducted under subcritical flow and Clear - water conditions. Three different numbers of groynes (single, double and triple) were used to indicate the impact of the numbers on the local scour; such impact have been observed t o be as reverse relationship, specially, for the intermediate groynes. Different spacing between groynes as (1, 1.5, and 2) times the length of groynes were used in this study. For the range tested, it has been observed that for each spacing decrease by (0 .5 Lg) there was a decrease in scour depth about (20%). Also, several lengths of groynes (13, 10, and 7) cm were used, and it has been observed that scour depth is decreased about (20 - 53)% by decreasing the ratio of groyne length to main flow width (Lg/B ) by (7.5%). Two different shapes of curved groynes, namely as, quadrant (quarter of a cylinder) and semi - parabolic shaped groynes were used to indicate the effect of groyne shape on the local scour. Generally, scour is decreased about (75) % in quadrant s hape groynes as compared with that of semi - parabolic shape groynes

2014

Hydraulic Study Of Minimizing Energy Consumption In Storm Water Pumping Station Suction Side

AuthorsDr . Hasan Mahdi M. Al-khateeb, Dr. Hayder Abdulameer K. Al-thamiry and Eng. Riyadh Mahdi L. Albonassiriya
Journal International Journal of Engineering Research & Technology
Abstract

One of the important factors effecting the efficiency of pumped-storage power stations is the losses induced at the hydraulic waterways. One part of the hydraulic waterways is the intake-inlet structure at the wet basin of the station. Through this study, a physical hydraulic model was constructed with typical relative dimensions derived from common design guidelines, to simulate storm water pumping stations adopted in Iraq. Sensitive and accurate measurement devices were used in the model to measure water flow, power and pressure. This research aims to determine the hydraulic effect of suction pipe size and inlet configuration as provided with bell-mouth end. This effect was investigated through observing the saving in energy consumed by the pump, and pressure reduction detected at the inlet section. Variables considered in the experiments curried out during this study were; suction pipe position (90º elbows), suction pipe diameters (5.08cm, 7.62cm and 10.16cm), and using bell-mouth inlet with different flow velocities. The results, generally, indicate that there is energy saving when using bell-mouth and when increasing suction pipe diameter. The best installation was through using bell-mouth with (10.16) cm pipe diameter were give best specific energy (power /flow rate) . On the other hand, The Largest energy saving of bell-mouth effect is recorded when using bell-mouth with (5.08)cm pipe diameter .

Lectures

17
View details