| 1. |
- Hilo, Salam J., et al.
(författare)
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Structural Performance of Internally Stiffened Double-Skinned Profiled Composite Walls with Openings
- 2023
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Ingår i: Buildings. - 2075-5309. ; 13:6
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Tidskriftsartikel (refereegranskat)abstract
- The double-skin profiled composite wall (DSPCW) system, filled with concrete material, is favorable in modern structures due to its high strength and ductility. Openings may be required within this composite wall (DSPCW) for various reasons, similar to a conventional bearing wall, which can lead to a reduction in bearing capacity. Therefore, to avoid changes in the geometry, materials, and thickness of this DSPCW wall, a new internally stiffening concept has been suggested by providing embedded cold-formed steel tube (CFST) columns. For this purpose, two full-scale DSPCW specimens were tested under static axial load, one of which was fabricated with a large opening size and stiffened with two octagonal CFST columns, while the other was designed without an opening and served as a control wall specimen. The results showed that the stiffened DSPCW with an opening achieved a slightly lower ultimate bearing strength (-9.4%) than the control wall specimen, with no reduction in the ductility behavior. Furthermore, several finite element models of DSPCW have been analyzed and designed to investigate additional parameters that were not experimentally tested, including the effects of the embedded CFST column's shape and different types of internal stiffeners longitudinally provided inside these columns. The numerical investigation confirmed that the embedded CFST column with an octagonal cross-section was more efficient compared to the hexagonal and rectangular shapes by about 11% and 18.4%, respectively. Furthermore, using internal steel stiffeners for embedded tubes with a T-shape improved the axial bearing capacity of the DSPCW with an opening slightly higher than the corresponding stiffened walls with other investigated stiffener shapes (V-shaped, U-shaped, and L-shaped).
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| 2. |
- Al-Mamoori, Sohaib Kareem, et al.
(författare)
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Horizontal and Vertical Geotechnical Variations of Soils According to USCS Classification for the City of An-Najaf, Iraq Using GIS
- 2020
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Ingår i: Geotechnical and Geological Engineering. - Switzerland : Springer. - 0960-3182 .- 1573-1529. ; 38:2, s. 1919-1938
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Tidskriftsartikel (refereegranskat)abstract
- The unified soil classification system (USCS) first proposed by Casagrande and subsequently developed by the Army Corps of Engineers. It widely used in many building codes and books. An-Najaf city is the most important city in Iraq due to its religious and spiritual value in the Muslim world, so it is fast expanding and continuous developing city in Iraq. The data from 464 boreholes in the study area for depths of 0–26 m have been used. 13 Soil samples were collected from each borehole with 13 depths level (0–26) m with 2 m intervals. The USCS was applied to the soil samples from 13 depth levels borehole. This research aims to create a geodatabase for soil properties for An-Najaf. The ArcGIS 10.5 software was used to interpolate the spatial data to produce 33 geotechnical maps for fine soil, coarse soil and USCS for 13 depth levels. For numerical soil data, Ordinary Kriging has been used for interpolation mapping of Fine and Coarse percentage data for each depth. For non-numerical (nominal) soil data (USCS class), the Indicator Kriging method is used. The results show that the coarse soil occupied 85–95% for depth 0–16 m and consist of (SP, SP-SM, SM) while fine soil occupied 5–15% consisting of (OL, CH, ML) subsequently, this soil when compacted has a permeability of pervious to semi impervious, good shearing strength, low to very low compressibility and acceptable workability as a construction material. The results also show that after 16 m depths until 26 m, the fine soil percentage increased to 40% with a coarse soil percentage of 60%, indicating changes in soil characteristics as the permeability became semi-pervious to impervious, fair shearing strength, medium compressibility and fair workability as a construction material. The study results will provide help and saving time, efforts and money in preliminary engineering designs.
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| 3. |
- Alsaffar, Abdul Kareem K., et al.
(författare)
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Development of eco-friendly wall insulation layer utilising the wastes of the packing industry
- 2023
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Ingår i: Heliyon. - : Elsevier. - 2405-8440. ; 9:11
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Tidskriftsartikel (refereegranskat)abstract
- Efficient thermal insulation materials considerably lower power consumption for heating and cooling of buildings, which in turn minimises CO2 emissions and improves indoor comfort conditions. However, the selection of suitable insulation materials is governed by several factors, such as the environmental impact, health impact, cost and durability. Additionally, the disposal of used insulation materials is a major factor that affects the selection of materials because some materials could be very toxic for humans and the environment, such as asbestos-containing materials. Therefore, there is a continuous research effort, in both industry and academia, to develop sustainable and affordable insulation materials. In this context, this work aims at utilising the packing industry wastes (cardboard) to develop an eco-friendly insulation layer, which is a biodegradable material that can be disposed of safely after use. Experimentally, wasted cardboard was collected, cleaned, and soaked in water for 24 h. Then, the wet cardboard was minced and converted into past papers, then cast in square moulds and left in a ventilated oven at 75 °C to dry before de-moulding them. The produced layers were subjected to a wide range of tests, including thermal conductivity, acoustic insulation, infrared imaging and bending resistance. The obtained results showed the developed material has a good thermal and acoustic insulation performance. Thermally, the developed material had the lowest thermal conductivity (λ) (0.039 W/m.K) compared to the studied traditional materials. Additionally, it successfully decreased the noise level from 80 to about 58 dB, which was better than the efficiency of the commercial polyisocyanurate layer. However, the bending strength of the developed material was a major drawback because the material did not resist more than 0.6 MPa compared to 2.0 MPa for the commercial polyisocyanurate and 70.0 MPa for the wood boards. Therefore, it is recommended to investigate the possibility of strengthening the new material by adding fibres or cementitious materials.
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| 4. |
- Al Maliki, Ali, et al.
(författare)
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Comparison between inductively coupled plasma and X-ray fluorescence performance for Pb analysis in environmental soil samples
- 2017
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Ingår i: Environmental Earth Sciences. - : Springer. - 1866-6280 .- 1866-6299. ; 76:12
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Tidskriftsartikel (refereegranskat)abstract
- Comparison of two conventional analytical techniques such as X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS) for measuring Pb concentrations in soil samples was achieved using field and laboratory work. Seventy-three samples were collected from urban areas surrounding the large lead smelter at South Australia, as an indicator of the environment impact of smelter activity. Soil Pb concentrations were determined using hand-held XRF analyser under laboratory conditions. ICP-MS analysis on digested soils (using a microwave-assisted nitric acid digestion-extraction) was applied to validate p-XRF data. The analysis showed that Pb concentrations determined by XRF correlated with high linearity with Pb concentrations determined by ICP-MS measurements (R2 = 0.89). Statistical test (t test) was applied to the data of both methods applied without any significant difference between the two techniques. These results indicated that ICP-MS corroborated XRF for Pb soil measurements and suggests that XRF was a reliable and quick alternative to traditional analytical methods in studies of environmental health risk assessment, allowing for much larger sampling regimes in relatively shorter times and could be applied in the field.
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| 5. |
- Al-Rawabdeh, Abdulla M., et al.
(författare)
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A GIS-based drastic model for assessing aquifer vulnerability in Amman-Zerqa groundwater basin, Jordan
- 2013
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Ingår i: Engineering. - : Scientific Research Publishing, Inc.. - 1947-3931 .- 1947-394X. ; :5, s. 490-504
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Tidskriftsartikel (refereegranskat)abstract
- Amman-Zerqa Basin (AZB) is a major basin in Jordan. The concentration of economic, agricultural and social activities within the basin makes it of prime importance to Jordan. Intensive agricultural practices are widespread and located close to groundwater wells, which pose imminent threats to these resources. Groundwater contamination is of particular concern as groundwater resources are the principal source of water for irrigation, drinking and industrial activities. A DRASTIC model integrated with, and GIS tool has been used to evaluate the groundwater vulnerability of AZB. The Drastic index map showed that only 1.2% of the basin’s total area of 3792 km2 lies in the no vulnerable zone and about 69% is classified as having low pollution potential. The results also revealed that about 30% of the catchment area is moderately susceptible to pollution potential and slightly 1% is potentially under high pollution risk. These results suggest that almost one third of the AZB is at moderate risk of pollution potential. These areas are mainly in the north-east and central parts of the basin where the physical factors like gentle slope and high water table well support the chances of getting shallow aquifer water polluted. Areas with high vulnerable pollution are mainly the central of Amman old city.
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| 6. |
- Ehsan, Muhsan, et al.
(författare)
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Groundwater delineation for sustainable improvement and development aided by GIS, AHP, and MIF techniques
- 2024
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Ingår i: Applied water science. - : Springer Science and Business Media Deutschland GmbH. - 2190-5487 .- 2190-5495. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- Exploration of groundwater is an integral part of viable resource growth for society, economy, and irrigation. However, uncontrolled utilization is mainly reported in urban and industries due to the increasing demand for water in semi-arid and arid regions of the world. In the background, groundwater demarcation for potential areas is vital in meeting necessary demand. The current study applied an integrated method comprising the analytical hierarchy process (AHP), multiple influence factors (MIF), combined with a linear regression curve and observatory well data for groundwater prospects mapping. Thematic maps such as flow direction, flow accumulation, elevation map, land use land cover, slope, soil texture, hill shade, geomorphology, normalized vegetation index, and groundwater depth map were generated utilizing remote sensing techniques. The relative weight of each parameter was estimated and then assigned to major and minor parameters. Potential zones for groundwater were classified into five classes, namely very good, good, moderate, poor, and very poor, based on AHP and MIF methods. A spatially explicit sensitivity and uncertainty analysis method to a GIS-based multi-criteria groundwater potential zone model is presented in this research. The study addressed a flaw in the way groundwater potential mapping results are typically presented in GIS-based multi-criteria decision analysis studies, where discrete class outputs are used without any assessment of their certainty with respect to variations in criteria weighting, which is one of the main contributors to output uncertainty. The study region is categorized based on inferred results as very poor, poor, marginal, and very good in potential ground quality 3.04 km2 is considered extremely poor, 3.33 km2 is considered poor, 64.42 km2 is considered very good, and 85.84 km2 is considered marginal zones, which shows reliable and potential implementation. The outcomes of AHP and MIF were validated by linear regression curve and actual water table in a study area. The study results help to formulate the potential demarcation of groundwater zones for future sustainable planning and development of groundwater sources. This study may be helpful to provide a cost-effective solution to water resources crises. The current study finding may be helpful for decision-makers and administrative professionals for sustainable management of groundwater resources for present and future demands.
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| 7. |
- Tao, Hai, et al.
(författare)
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Global solar radiation prediction over North Dakota using air temperature : Development of novel hybrid intelligence model
- 2021
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Ingår i: Energy Reports. - Netherland : Elsevier. - 2352-4847. ; 7, s. 136-157
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Tidskriftsartikel (refereegranskat)abstract
- Accurate solar radiation (SR) prediction is one of the essential prerequisites of harvesting solar energy. The current study proposed a novel intelligence model through hybridization of Adaptive Neuro-Fuzzy Inference System (ANFIS) with two metaheuristic optimization algorithms, Salp Swarm Algorithm (SSA) and Grasshopper Optimization Algorithm (GOA) (ANFIS-muSG) for global SR prediction at different locations of North Dakota, USA. The performance of the proposed ANFIS-muSG model was compared with classical ANFIS, ANFIS-GOA, ANFIS-SSA, ANFIS-Grey Wolf Optimizer (ANFIS-GWO), ANFIS-Particle Swarm Optimization (ANFIS-PSO), ANFIS-Genetic Algorithm (ANFIS-GA) and ANFISDragonfly Algorithm (ANFIS-DA). Consistent maximum, mean and minimum air temperature data for nine years (2010–2018) were used to build the models. ANFIS-muSG showed 25.7%–54.8% higher performance accuracy in terms of root mean square error compared to other models at different locations of the study areas. The model developed in this study can be employed for SR prediction from temperature only. The results indicate the potential of hybridization of ANFIS with the metaheuristic optimization algorithms for improvement of prediction ccuracy.
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| 8. |
- Zaki, Zaki I., et al.
(författare)
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Combustion synthesis of NbC/ZrO2 composites : Influence of Cr additives on the microstructure and mechanical properties
- 2021
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Ingår i: International Journal of Applied Ceramic Technology. - : John Wiley & Sons. - 1546-542X .- 1744-7402. ; 18:5, s. 1502-1509
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Tidskriftsartikel (refereegranskat)abstract
- Composites of NbC/ZrO2 reinforced with different weight ratios of Cr metal were prepared by dynamic compaction combustion from a blend of Nb2O5-Zr-Cr powders. Factors controlling the synthesis process, the microstructure and the mechanical properties of the samples, such as Cr wt% and the compression loads were studied. The samples were characterized by XRD, SEM, porosity and hardness measurements. The porosity value of sample with no additives was high and reached 31.6 vol%. A sudden decrease in the sample porosity to 2.4 vol % was noticed for sample containing 3.0 wt% of Cr. A high density sample with less than 2.0 vol % porosity and a maximum hardness of 1038 HV was produced using 5.0 wt% Cr under 300 MPa compression load. Detailed thermodynamic calculations for the effect of Cr additives on the physico-chemical properties of the system were introduced.
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| 9. |
- Al-Mubarak, Ahmed H., et al.
(författare)
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Preventing voltage collapse by large SVCs at power system faults
- 2009
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Ingår i: 2009 IEEE/PES POWER SYSTEMS CONFERENCE AND EXPOSITION, VOLS 1-3. - : IEEE. ; , s. 1967-
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Konferensbidrag (refereegranskat)abstract
- This paper shows how the performance of a power grid in Saudi Arabia is improved by using SVCs to reduce the risk for voltage collapse at short circuits. Full SVCs capacity is needed during faults and for a short time following fault clearing for system recovery. It is shown that SVCs can handle the phase Jumps at fault inception and clearing. The paper also deals With control stability for large SVCs in weak networks.
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| 10. |
- Ahsan, Amimul, et al.
(författare)
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Modeling the impacts of best management practices (BMPs) on pollution reduction in the Yarra River catchment, Australia
- 2023
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Ingår i: Applied water science. - : Springer. - 2190-5487 .- 2190-5495. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Pollution of a watershed by different land uses and agricultural practices is becoming a major challenging factor that results in deterioration of water quality affecting human health and ecosystems. Sustainable use of available water resources warrants reduction of Non-Point Source (NPS) pollutants from receiving water bodies through best management practices (BMPs). A hydrologic model such as the Soil and Water Assessment Tool (SWAT) can be used for analyzing the impacts of various BMPs and implementing of different management plans for water quality improvement, which will help decision makers to determine the best combination of BMPs to maximize benefits. The objective of this study is to assess the potential reductions of sediments and nutrient loads by utilizing different BMPs on the Yarra River watershed using the SWAT model. The watershed is subdivided into 51 sub-watersheds where seven different BMPs were implemented. A SWAT model was developed and calibrated against a baseline period of 1998–2008. For calibration and validation of the model simulations for both the monthly and annual nutrients and sediments were assessed by using the Nash–Sutcliffe efficiency (NSE) statistical index. The values of the NSE were found more than 0.50 which indicates satisfactory model predictions. By utilizing different BMPs, the highest pollution reduction with minimal costs can be done by 32% targeted mixed-crop area. Furthermore, the combined effect of five BMPs imparts most sediments and nutrient reductions in the watershed. Overall, the selection of a BMP or combinations of BMPs should be set based on the goals set in a BMP application project.
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