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Influence of electronic wastes on the wear and corrosion properties of aluminum matrix composites
No full textIn this study, the influence of electronic waste reinforcement on the properties of aluminum was investigated. For this purpose, samples were produced with hot pressing at 600 °C. The reinforcement ratio for the composites was determined as 1 wt.%, 5 wt.%, and 10 wt.%. The wear and corrosion behavior of the samples were investigated by dry sliding wear test and electrochemical corrosion tests. The wear rate values indicated that the increasing reinforcement ratio reduced the wear rate. Moreover, it was determined that the increasing reinforcement ratio improved the corrosion behavior of the composites. The corrosion rate of the samples was reduced with an increasing reinforcement ratio, and a more stable surface was obtained in corrosion environment. In conclusion, it was deduced that Rh, Ag, Pt, and Sn containing electronic waste provided significant improvements in wear and corrosion behaviors
On basicity of some trigonometric system in Banach Function Spaces
No full textIn this paper it is considered the trigonometric system {1; cos nx; x sin nx}n∈N, which is a collection of eigenfunctions of one nonlocal spectral problem for an ordinary second order differential operator. Let X (-π, π) be a Banach Function Space (by Luxembourg classification) on (-π, π) with Lebesgue measure. A criterion is obtained for the trigonometric system{1/2; cosnt; sinnt}n∈N to have the Riesz Property in X (-π, π). It is proved that if the trigonometric system has the Riesz Property n∈N in X (-π, π), then the system (T) also forms a basis for X (-π, π). Some concrete spaces, such as the weighted Lebesgue space Lp;w (-π, π), the weighted grand Lebesgue space Lp);w (-π, π), Lebesgue space with variable exponent Lp(·) (-π, π), Morrey space Lp;λ (-π, π), symmetric space X (-π, π) with Boyd indices αX; βX ∈ (0, 1) are presented
KENT KİMLİĞİNİ YANSITACAK VE İKLİM DEĞİŞİKLİĞİNE UYUM SAĞLAYABİLECEK ODUNSU BİTKİLER: AYDIN
No full textModeling risk attitudes in picture fuzzy multi-objective linear programming with chance constraints
No full textPicture fuzzy sets provide a flexible framework for simultaneously modeling uncertainty, neutrality, and refusal. This study proposes a novel solution method for chance-constrained multi-objective linear programming within a picture fuzzy context. We introduce a comprehensive definition of generalized trapezoidal picture fuzzy numbers (GTPFNs), with particular attention to ensuring coherent and shape–preserving arithmetic operations. To enhance computational efficiency, we adopt a risk-based simplification guided by the selected risk attitude and cost–benefit classification. Specifically, it reduces the coefficients represented by GTPFNs to a generalized trapezoidal representation. This makes the proposed approach more practical for large-scale decision problems, where optimistic, pessimistic, and intermediate attitudes of decision-makers are captured through possibility, necessity, and credibility measures, respectively. The method has been applied to single- and multi-objective problems defined in intuitionistic and picture fuzzy environments, considering both single and multiple height levels, using benchmark cases from the literature. Numerical results on benchmark problems confirm that the proposed approach is computationally tractable and faithfully reflects the prescribed risk attitudes of the decision-makers. As the risk parameter increases, sensitivity analysis shows that the solutions systematically become more conservative, with lower optimal values of the maximization-oriented objective function and tighter possibility-, credibility-, or necessity-based satisfaction levels
Risk ratio assessment of key parameters affecting main engine starting system failures on container ships
No full textUltrahigh removal of toxic basic green 4 from wastewater by zinc cobaltite filled calcium alginate composite microbeads: Isotherm, kinetic, and thermodynamic studies
No full textSince dyes in water have become a common problem recently, the aim of the present study was to create a highly effective material using sodium alginate (SA) biopolymer and zinc cobaltite (ZC). ZC was added to the SA biopolymer gel at 10 %, 20 %, and 30 % by weight to form calcium alginate/ZC (CA/ZC) composite microbeads. Basic green 4 (BG4) dye was effectively adsorbed from contaminated water using these composites as a surface. SEM, FTIR-ATR, XRD, pHpzc, and BET studies were used to characterize the adsorbents. The pHpzc value was determined to be 6.70. From BET analysis, the surface area, pore diameter, and pore volumes of the ZC adsorbent were determined as 77.35 m2/g, 13.27 nm, and 0.2566 cm3/g, respectively, while those of the SA/ZC/30 were determined as 95.61 m2/g, 11.28 nm, and 0.3371 cm3/g, respectively. The effects of temperature (298–318 K), initial pH (2–10), treatment time (0–150 min), adsorbent mass (0.01–0.15 g/50 mL), initial concentrations (100–800 mg/L), and ionic strength on the dye removal efficiency were studied. The total water content of the prepared beads was determined as 97 %. Various nonlinear isotherm models, such as Langmuir, Freundlich, Temkin, Jovanovic, and Hill, were used to fit the raw adsorption data. Using the Langmuir model, the adsorption capacity of CA/ZC/30 was found to be 750.9 mg/g at 298 K. Pseudo-first order , pseudo-second order , and Elovich kinetic models were used to investigate the kinetics of dye removal. These kinetic studies determined that the process occurred via a chemical adsorption mechanism. Thermodynamic studies determined that the process was endothermic and spontaneous. All studies indicated that the prepared composite microbeads have a high surface area, are natural and sustainable, and have high performance. They can be used as a highly effective potential adsorbent for the removal of cationic pollutants from aqueous solutions
Sıcak presleme yöntemiyle üretilen alüminyum matrisli B4C takviyeli kompozitlerin özelliklerine sıcak presleme sıcaklığının ve takviye oranının etkisi
No full textPredicting Visitors’ Digital Footprints Using Spatial Features and Synthetic Pedestrian Data
No full textAssessing digital footprints of visitors has often depended on a pedestrian count data representing the human density in urban environment. The data is commonly generated via sensor, cellular phone network, or CCTV technologies, which involves high costs and raises concerns regarding personal data protection. This study presents a novel approach for predicting visitor ratings of eating and drinking out venues in Bakırköy, Istanbul, without relying on a real pedestrian counting system. In our work, a synthetic pedestrian count measure is generated by interpolating the overall review volume data extracted from a complete set of points-of-interest data via Google Maps API. This measure is aggregated to streets, and additional spatial measures are used to further describe the urban environment. Some street geometric features (i.e., sinuosity and street length) that showed limited predictive value in earlier studies were removed from the analysis. A random forest machine learning model was applied to predict visitors’ high/low ratings, achieving a 76% F1-score. The results suggest that digital traces left by visitors can be effectively predicted through alternative spatial measures and synthetic data. The proposed approach provides a cost-effective and privacy-respecting method that can support business decision-making in the context of digital consumer behavior
EffEctiveness of Prophylactic fOam dressings in the prevention of saCral pressure injuries in at-risk hospitalised patients (EEPOC): A randomised control trial
No full textBackground: Hospital-acquired pressure injuries are a serious patient safety issue with the sacrum the most common location. Silicone foam border dressings are increasingly used in hospitalised patients, yet their clinical and cost-effectiveness in preventing pressure injuries is unclear in some patient cohorts. Objective: To determine the clinical and cost-effectiveness of a silicone foam border dressing in preventing sacral hospital acquired pressure injuries in at-risk medical-surgical patients. Methods: A prospective, multi-site, parallel group, pragmatic, superiority randomised controlled trial was conducted in Southeast Queensland, Australia. Medical-surgical adult patients (≥ 18 years) at-risk of pressure injury were recruited and randomly allocated to either an intervention (sacral dressing plus routine care) or control (routine care only) group. The Primary outcome was development of a new sacral pressure injury. Daily, blinded, and independent outcome assessments were conducted off-site for up to 14 days using edited photographs of deidentified participants' sacra. Intention-To-Treat analyses were performed using both best-case and worse-case scenarios. Additional complete case analyses were conducted as part of sensitivity analyses. Secondary outcomes comprised time to onset of hospital-acquired sacral pressure injury, severity, incidence rates per 1000 trial days (days patients were in the trial), incidence rates per 1000 hospital days (days patients were in hospital), and cost-effectiveness that compared the difference in pressure injury incidence between groups. Results: Of the 1121 eligible patients approached, 958 agreed to participate. There were no significant differences in baseline characteristics between intervention and control groups. Cumulative incidence of sacral pressure injury was 1.67 % (8/478) and 1.25 % (6/480) in the intervention and control groups respectively (p = 0.592). There was an increased risk of pressure injury for those in the intervention group (Relative Risk: 1.34 (95 % CI 0.47–3.83)), but the effect was not statistically significant and confidence intervals wide. Distribution of secondary outcomes was also similar in both the intervention and control groups. The intervention was more costly than the control showing an incremental cost of 74.10–$125.60) associated with using the dressings. Conclusions: The study did not provide evidence that silicone foam border dressings reduced the incidence of sacral hospital acquired pressure injuries in adult medical-surgical patients at risk of pressure injuries. Additionally, the silicone foam dressings incurred higher incremental costs than routine care. Trial registration number: ACTRESN12619000763145, Registered 22/05/2019, first recruitment 10/07/2020