Durability, Mechanical, and Corrosion Characteristics of Recycled Aggregate Concrete Utilizing Locally Sourced Waste and Ultrafine Cerium Oxide

This study seeks to identify an environmentally sustainable method for utilizing the synergetic effects of window glass (WG), ceramic powder (CP), and ultrafine cerium oxide (UFC) in developing concrete containing 25% coarse ceramic aggregate. Four different mixtures were formulated. The first represents control, consisting of 100% ordinary Portland cement (OPC), two other mixtures were composed of 10% WG, 10% CP and 80% OPC, and the fourth mixture consisted of four compositions of 79.5% OPC, 10% WG, 10% CP, and 0.5% UFC. The effect of these additives on recycled ceramic concrete (RA) properties, including workability and setting time, compressive strength, total water absorption, permeable pore ratio, electrical resistivity, and corrosion resistance, was studied. The results showed that when 10% WG and 0.5% UFC were combined, the components' synergistic effect was more noticeable. It had a compressive strength of 44.53, 48.83, and 56.17MPa after 28, 90, and 180 days, which is higher than the ternary mixtures of Portland cement, ultrafine cerium oxide, and ceramic powder, as well as the quaternary mixtures of Portland cement, WG powder, CP, and UFC. Moreover, it recorded a lower corrosion rate than the reference mix (RA-C), ternary mix (RA-CP10UFC0.5), and quaternary mixes (RA-CP10WG10UFC0.5) mixes. Meanwhile, the quaternary mix (RA-CP10WG10UFC0.5) showed 40% and 45% lower porosity and water absorption than the control mixture and 54% higher electrical resistivity values compared to the control mixture and ternary mixtures (RA-WG10UFC0.5 and RA-CP10UFC0.5) at 180 days

Improving the Mechanical, Corrosion Resistance, Microstructural and Environmental Performance of Recycled Aggregate Concrete Using Ceramic Waste Powder as an Alternative to Cement

This study investigates the effectiveness of replacing the cement with 0, 5, 10, 15, and 20 wt.% of ceramic waste powder (HCCP) to improve the performance of recycled aggregate concrete (RCA) prepared using 25 wt.% wall tile ceramic coarse aggregates. The slump, initial and final setting time, compressive strength, splitting tensile strength, flexural strength, electrical resistivity, bulk density, porosity, total and surface water absorption, pH level, ultrasonic pulse velocity, dynamic elastic modulus, chloride ion diffusion coefficient, chloride penetration depth, microstructure analysis, and environmental assessment properties were investigated. The results showed that replacing cement with HCCP by 5 to 20 wt.% prolonged the setting time and improved all hardened properties. The highest improvements in mechanical properties were observed at 5 wt.% HCCP, with increasing rates of 26.5%, 22%, and 22.4% at 90 days for compressive strength, tensile strength, and flexural strength, respectively. On the other hand, the optimum enhancement for the durability, microstructural, and environmental efficiency properties was recorded at a 20 wt.% HCCP replacement rate. However, the strength at this ratio tended to decrease but remained higher than that of the control RAC. For instance, the total water absorption, surface water absorption, void ratio, chloride penetration depth, and migration coefficient were reduced by 47%, 45%, 38%, 62.3%, and 55.52%, respectively, compared to the reference sample

Fresh and hardened properties of self-compacting high performance concrete containing nano-metakaolin as a partial replacement

Abstract In this study, the effect of partial substitution of cement material with nano-materials represented by nano-metakaolin(NMK) has been studied on the fresh and hardening properties of High-Performance Self-Compacting concrete (SCHPC), where the substitution was made in different proportions, namely (1.25, 2.5 and 3.75). Four mixtures were made, the first reference and the remaining three mixtures in which the cement was partially replaced by the above mentioned proportions. Fresh characteristics represented by the Slump flow, T5 0 c m, the L- box and the V- funnel were studied. As for the hardening properties, the compression and tensile strengths were examined. We observed through practical results that the Slump flow and L- box values decrease as the percentage of partial substitution of cement to nano-metakaolin increases. Whereas, T5 0 cm and T v It increases with the increase in the partial substitution rate for cement with nanometakaolin. As for compressive strength and tensile strength, it increases with the increase in the percentage of partial replacement of cement with nano-metakaolin.</jats:p

The effect of changing the wavelength on some of the optical properties of copper nitrate water

Abstract In this work, some of optical properties for ( Cu(NO3)2.6H2O), such as (transmission, reflectance, absorbance, damping coefficient, refractive index, Brewster angle and critical angle ) have been calculated with (0.1-0.9)gm/ml concentration at (242,449,631,978) nm wave length at 250c. the results showed the optical properties were increased with concentration and wave length have been used, except transmission and critical angle which decreased with the same concentration and wave length when as, the same optical properties have higher values, while the transmission and critical angle were decreased at the case wave length.</jats:p

The Effect Of Active Warm -Up Exercises On Flexibility And Achievement Among Effectiveness High Jump Players

Flexibility is one of the elements of fitness that contributes to others, such as strength, speed, and endurance in building and developing the motor performance of the player. Also, mathematical forms need this important element. And the athlete, which has good flexibility, will help him to use the rest of the other fitness elements with a little effort and a short time to improve the achievement and its development. Also, the weak flexibility in the player leads to a weak level of sports achievement. Exaggeration in the flexibility of the joints leads to its relaxation and sometimes it reaches the state of infection, and exaggeration in it affects a harmful effect on strength. So it is necessary to pay attention when training to develop it. It is considered an important basic element among the jumping in the effectiveness of high jumping, as the player must have the flexibility of all joints in order to be able to reach a good result as well as active specialized warmth. The researchers used the experimental curriculum to suit the nature of the research. The research sample was from Al -Qurna Sports Club for Higher Jump in Basra Governorate. The tests for flexibility and achievement were applied to the high jump. Tribal tests and post -tests for the research sample, extracting results and processing them statistically, were the most important recommendations: -The necessity of paying attention to flexibility in choosing the appropriate exercises in the training curricula in jumping activities, especially high jumping in the atmosphere to achieve good achievement. The necessity of paying attention to the varied active and corresponding warm -up with the nature of the performanc

Synthesis and Investigation of Metals Oxide Pastes Used as Semiconductors Electrode for Dye-sensitized Solar Cells

The aim of this research is to prepare some of metal oxides pastes to be used as semi-conductors electrode to manufacture of solar cells devices (third generation). The efficiency of these cells were tested by using these pastes to determine the response and susceptibility of these pastes for adsorbing of photosensitive pigments on their surfaces and pores, Three types of metal oxides such as Titanium oxide, Zinc oxide and Aluminium oxide, were prepared in this research. These pastes were identified by measuring UV-visible spectra and also by microscope instrument. The experiments which have been demonstrated approved the susceptibility and adsorption of these pastes to the photosensitive dyes on their surface and gave conversion efficiency up to 1.64%. In this research, a comparison was made between the pastes that were prepared in laboratory and the imported commercial paste in terms of efficiency.</jats:p

Pancreatic surgery outcomes: multicentre prospective snapshot study in 67 countries

Background: Pancreatic surgery remains associated with high morbidity rates. Although postoperative mortality appears to have improved with specialization, the outcomes reported in the literature reflect the activity of highly specialized centres. The aim of this study was to evaluate the outcomes following pancreatic surgery worldwide. Methods: This was an international, prospective, multicentre, cross-sectional snapshot study of consecutive patients undergoing pancreatic operations worldwide in a 3-month interval in 2021. The primary outcome was postoperative mortality within 90 days of surgery. Multivariable logistic regression was used to explore relationships with Human Development Index (HDI) and other parameters. Results: A total of 4223 patients from 67 countries were analysed. A complication of any severity was detected in 68.7 per cent of patients (2901 of 4223). Major complication rates (Clavien–Dindo grade at least IIIa) were 24, 18, and 27 per cent, and mortality rates were 10, 5, and 5 per cent in low-to-middle-, high-, and very high-HDI countries respectively. The 90-day postoperative mortality rate was 5.4 per cent (229 of 4223) overall, but was significantly higher in the low-to-middle-HDI group (adjusted OR 2.88, 95 per cent c.i. 1.80 to 4.48). The overall failure-to-rescue rate was 21 per cent; however, it was 41 per cent in low-to-middle- compared with 19 per cent in very high-HDI countries. Conclusion: Excess mortality in low-to-middle-HDI countries could be attributable to failure to rescue of patients from severe complications. The authors call for a collaborative response from international and regional associations of pancreatic surgeons to address management related to death from postoperative complications to tackle the global disparities in the outcomes of pancreatic surgery (NCT04652271; ISRCTN95140761)

Pancreatic surgery outcomes: multicentre prospective snapshot study in 67 countries

Background: Pancreatic surgery remains associated with high morbidity rates. Although postoperative mortality appears to have improved with specialization, the outcomes reported in the literature reflect the activity of highly specialized centres. The aim of this study was to evaluate the outcomes following pancreatic surgery worldwide.Methods: This was an international, prospective, multicentre, cross-sectional snapshot study of consecutive patients undergoing pancreatic operations worldwide in a 3-month interval in 2021. The primary outcome was postoperative mortality within 90 days of surgery. Multivariable logistic regression was used to explore relationships with Human Development Index (HDI) and other parameters.Results: A total of 4223 patients from 67 countries were analysed. A complication of any severity was detected in 68.7 percent of patients (2901 of 4223). Major complication rates (Clavien-Dindo grade at least IIIa) were 24, 18, and 27 percent, and mortality rates were 10, 5, and 5 per cent in low-to-middle-, high-, and very high-HDI countries respectively. The 90-day postoperative mortality rate was 5.4 per cent (229 of 4223) overall, but was significantly higher in the low-to-middle-HDI group (adjusted OR 2.88, 95 per cent c.i. 1.80 to 4.48). The overall failure-to-rescue rate was 21 percent; however, it was 41 per cent in low-to-middle-compared with 19 per cent in very high-HDI countries.Conclusion: Excess mortality in low-to-middle-HDI countries could be attributable to failure to rescue of patients from severe complications. The authors call for a collaborative response from international and regional associations of pancreatic surgeons to address management related to death from postoperative complications to tackle the global disparities in the outcomes of pancreatic surgery (NCT04652271; ISRCTN95140761)