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| 2. |
- Abb, Marcel J.S., et al.
(författare)
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Thermal Stability of Single-Crystalline IrO2(110) Layers : Spectroscopic and Adsorption Studies
- 2020
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 124:28, s. 15324-15336
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Tidskriftsartikel (refereegranskat)abstract
- The interaction of ultrathin single-crystalline IrO2(110) films with the gas phase proceeds via the coordinatively unsaturated sites (cus), in particular Ircus, the undercoordinated oxygen species on-top O (Oot) that are coordinated to Ircus, and bridging O (Obr). With the combination of different experimental techniques, such as thermal desorption spectroscopy, scanning tunneling microscopy (STM), high-resolution core-level spectroscopy (HRCLS), infrared spectroscopy, and first-principles studies employing density functional theory calculations, we are able to elucidate surface properties of single-crystalline IrO2(110). We provide spectroscopic fingerprints of the active surface sites of IrO2(110). The freshly prepared IrO2(110) surface is virtually inactive toward gas-phase molecules. The IrO2(110) surface needs to be activated by annealing to 500-600 K under ultrahigh vacuum (UHV) conditions. In the activation step, Ircus sites are liberated from on-top oxygen (Oot) and monoatomic Ir metal islands are formed on the surface, leading to the formation of a bifunctional model catalyst. Vacant Ircus sites of IrO2(110) allow for strong interaction and accommodation of molecules from the gas phase. For instance, CO can adsorb atop on Ircus and water forms a strongly bound water layer on the activated IrO2(110) surface. Single-crystalline IrO2(110) is thermally not very stable although chemically stable. Chemical reduction of IrO2(110) by extensive CO exposure at 473 K is not observed, which is in contrast to the prototypical RuO2(110) system.
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| 3. |
- Abbas, Nahlah, et al.
(författare)
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The Impacts of Sea Level Rise on Basrah City,Iraq : The Impacts of Sea Level Rise on Basrah City,Iraq
- 2020
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Ingår i: Open Journal of Geology. - USA : Scientific Research Publishing. - 2161-7570 .- 2161-7589. ; 10:12, s. 1189-1197
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Tidskriftsartikel (refereegranskat)abstract
- Sea Level Rise (SLR) above the Mean Sea Level (MSL) is more likely to cause a significant risk to the coastal regions. This research explores the potential impact of sea level rise, due to climate change, on coastal areas. It examines the impact of sea level rise on Basrah city and adjacent cities in Iraq. A digital elevation model (DEM) was used to create a model of Potentially Inundated Areas, manipulated and processed in Geographical Information System version 10.7 (ArcGIS 10.7). Through this model, the impact of sea level rise was assessed on the surface area. After the susceptible areas were delineated, it was estimated that at worst case scenario of 5 m sea level rise will impact Basrah city by losing 38 percent of its total surface area.
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| 4. |
- Abbas, Syed Adeel, et al.
(författare)
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Spinel-type Na2MoO4 and Na2WO4 as promising optoelectronic materials : First-principle DFT calculations
- 2020
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Ingår i: Chemical Physics. - : Elsevier. - 0301-0104 .- 1873-4421. ; 538
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Tidskriftsartikel (refereegranskat)abstract
- The mechanical, thermodynamic, electronic, and optical properties of Na2MoO4 (NMO) and Na2WO4 (NWO) spinels are elaborated by density functional theory (DFT) based full potential augmented plane wave method (FP-LAPW + lo). Our optimized lattice constants for the studied spinels are in good agreement with that obtained experimentally. The enthalpy of formation ensures the thermodynamic stability of NMO and NWO in the cubic phase. The Born mechanical stability criteria guarantees their mechanical stability, while Poisson ratio (ν) and Pugh's ratio (B/G) infer their brittle behavior. The Debye temperature (θD) is significant for NMO than NWO. The wide bandgap of 3.5 eV for NMO and 4.4 eV for NWO show the maximum absorption in the ultraviolet region that increases their importance for optoelectronic applications. The optical properties are explained in term of dielectric constant, refractive index, absorption of light, reflection, and optical loss factor.
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| 5. |
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| 6. |
- Abdollahi, Morteza, et al.
(författare)
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A process mineralogy approach to optimize molybdenite flotation in copper : molybdenum processing plants
- 2020
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Ingår i: Minerals Engineering. - : Elsevier. - 0892-6875 .- 1872-9444. ; 157
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Tidskriftsartikel (refereegranskat)abstract
- The Sungun copper-molybdenum operation in Iran uses a typical copper-molybdenum flowsheet to produce separate copper and molybdenum concentrates through flotation and regrinding of the rougher concentrates arising from the primary circuit. This site was used as a case study limited to the feed and products of the copper-molybdenum separation circuit, in which process mineralogy might improve the quality of the molybdenum concentrate thorough diagnostic analysis of key flowsheet streams. The undesirable presence of copper in the molybdenum concentrate was identified as a key focus for the investigation by process mineralogy, which has a history of successful process diagnosis. This is because it develops information on minerals, which is far more informative than chemical assays alone. Together with the assays, the mineralogical data inform the investigator of the type and quantity of minerals present, their state of liberation and textural associations, and metal recovery.A key finding was that the appearance of chalcopyrite in the molybdenum concentrate was due to the presence of a chalcopyrite-pyrite texture that avoided the chalcopyrite depression in the molybdenum circuit because of suitable pyrite flotation conditions. Recovery of liberated pyrite to this concentrate also diluted the molybdenum concentrate. The open-circuit format of the regrind circuit also contributed to the unnecessary production of ultrafine particles. This flaw expressed itself as ultrafine losses of molybdenite to the flotation tailings.
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| 7. |
- Abdolmaleki, Mehdi, et al.
(författare)
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Exploration of IOCG Mineralizations Using Integration of Space-Borne Remote Sensing Data with Airborne Geophysical Data
- 2020
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Ingår i: XXIV ISPRS Congress, Commission III (Volume XLIII-B3-2020). - : International Society of Photogrammetry and Remote Sensing (ISPRS). ; , s. 9-16
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Konferensbidrag (refereegranskat)abstract
- Nowadays, remote sensing technologies are playing a significant role in mineral potential mapping. To optimize the exploration approach along with a cost-effective way, narrow down the target areas for a more detailed study for mineral exploration using suitable data selection and accurate data processing approaches are crucial. To establish optimum procedures by integrating space-borne remote sensing data with other earth sciences data (e.g., airborne magnetic and electromagnetic) for exploration of Iron Oxide Copper Gold (IOCG) mineralization is the objective of this study. Further, the project focus is to test the effectiveness of Copernicus Sentinel-2 data in mineral potential mapping from the high Arctic region. Thus, Inglefield Land from northwest Greenland has been chosen as a study area to evaluate the developed approach. The altered minerals, including irons and clays, were mapped utilizing Sentinel-2 data through band ratio and principal component analysis (PCA) methods. Lineaments of the study area were extracted from Sentinel-2 data using directional filters. Self-Organizing Maps (SOM) and Support Vector Machines (SVM) were used for classification and analysing the available data. Further, various thematic maps (e.g., geological, geophysical, geochemical) were prepared from the study area. Finally, a mineral prospectively map was generated by integrating the above mentioned information using the Fuzzy Analytic Hierarchy Process (FAHP). The prepared potential map for IOCG mineralization using the above approach of Inglefield Land shows a good agreement with the previous geological field studies.
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| 8. |
- Abdullah, Mukhalad, et al.
(författare)
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Floods and Flood Protection in Mesopotamia
- 2020
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Ingår i: Journal of Earth Sciences and Geotechnical Engineering. - UK : Scientific Press International Limited. - 1792-9040 .- 1792-9660. ; 10:4, s. 155-173
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Tidskriftsartikel (refereegranskat)abstract
- Mesopotamia is a land where floods have occurred very frequently. Many destructive floods had been registered by historians, who noted also the food control schemes used in those times. Over history, many structures were built and managed, but this work was taken up again by the General Directorate of Irrigation which was formed in 1917 to manage floods and reduce as much as possible losses, in addition to the development of irrigation works. Plans were made to build a sophisticated flood control and protection system. Several projects were proposed, and since the 1950s they were successfully implemented. Many multipurpose dams were built to mitigate flood conditions in addition to their other functions, such as Mosul Dam, Dokan Dam, Derbendikhan Dam and Haditha Dam. Other projects which were solely planned for flood protection include developing and using natural depressions such as Habbaniyah Lake on the Euphrates River and Tharthar Lake on the Tigris River, to protect Mesopotamia from floods. Moreover, the southern marshes in lower Mesopotamia may be utilized for flood protection. This paper deals only with these natural depressions leaving the dams at the time being.
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| 9. |
- Abdullah, Mukhalad, et al.
(författare)
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Irrigation Major Systems on Euphrates River within Mesopotamia
- 2020
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Ingår i: Journal of Earth Sciences and Geotechnical Engineering. - UK : Scientific Press International Limited. - 1792-9040 .- 1792-9660. ; 10:4, s. 199-219
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Tidskriftsartikel (refereegranskat)abstract
- Euphrates River is one of the two rivers where the civilization and irrigation had started, many major irrigation systems are still operating for centuries. The most important advancement of irrigation within this area happened after 1920s, where new structures were constructed, new canals excavated, new pumps installed, and salt affected lands were reclaimed. The major irrigation projects in along the reach of Euphrates within Mesopotamia are, Great Abu Ghraib, Great Musayab, Hilla Branch projects, Kifl-Shiniafiyah, in addition to many other medium and small size projects. Besides, some important Barrages have been built for controlling water levels of the Euphrates for proper operation, such as Fallujah and Hindiya Barrages. There is a great need for more reclamation in the lower parts of this territory, as well alternatives are needed to avoid discharging saline drainage water to the Euphrates in some projects.
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| 10. |
- Abdullah, Mukhalad, et al.
(författare)
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Major Irrigation Systems on Tigris River within Mesopotamia
- 2020
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Ingår i: Journal of Earth Sciences and Geotechnical Engineering. - UK : Scientific Press International Limited. - 1792-9040 .- 1792-9660. ; 10:4, s. 175-198
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Tidskriftsartikel (refereegranskat)abstract
- Several irrigation systems have been built at Tigris River basin within Mesopotamia plain. The upper part of Tigris at Mesopotamia is extensively exploited, and several major projects were constructed since the 1970s. These are Ishaqi, Khalis, Diyala Combined Reach, Nahrawan, Dujailya and Dalmaj. Other projects were partially developed, which are Middle-Tigris, Gharraf projects, Great Amarah and KutButaira. The important barrages in this part are Kut Barrage, as well, as the barrages in Amarah area which are of vital importance for irrigation and navigation. Shaat Al-Arab is one of the most important waterways in Iraq. This river has been suffered from water scarcity and riparian countries actions. Solutions for adaptation to adapt the situation were studied and planned carefully, but still there is need for more work to cope with the situation in Basra area.
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