Search

Ti-10%Zr-2%Sn-8%Mo alloy and Ti-10%Zr-2%Sn-8%Ta alloy were manufactured using the technique of powder metallurgy. The corrosion of the two alloys was performed after 1 h, 24 h, and 48 h immersion in 3.5% NaCl solution using electrochemical impedance spectroscopy (EIS), cyclic polarization (CPP), and the measurement of current over time. EIS (Nyquist and Bode) data indicated that the Ti-10%Zr-2%Sn-8%Ta alloy has higher polarization resistance compared to the Ti-10%Zr-2%Sn-8%Mo alloy. CPP results revealed that the Ti-10%Zr-2%Sn-8%Ta alloy has higher corrosion resistance and lower corrosion currents. The experiments of measuring the change of current over time at 500 mV showed that both the Ti-10%Zr-2%Sn-8%Mo alloy and the Ti-10%Zr-2%Sn-8%Ta alloy do not show pitting corrosion, which confirms the CPP results. Extending the time to 24 h and 48 h increased the corrosion resistance for both alloys. The surface of the alloys after being corroded in NaCl solution were investigated using scanning electron microscopy and energy dispersive spectroscopy. All investigations confirmed that the Ti-10%Zr-2%Sn-8%Ta alloy is more passivated than the Ti-10%Zr-2%Sn-8%Mo alloy and the increase of exposure time to 48 h enhances the passivation of both alloys, which recommends that these alloys are best choice in the biomedical applications.

The analysis of the squeezing nanofluid flow across bounded domains received great attention from researchers and engineers due to its tremendous application in automobiles, energy exchangers, and aerodynamics. In the current analysis, we are using double Riga plates parallel to each other, in order to induce the squeezing nanofluids flow with the significances of chemical reaction, thermal radiation, and heat source/sink. The nanoliquid has been prepared by the dispersion of Copper (Cu) nanoparticles (NPs) in kerosene oil (C12H26C15H32) and water (H2O). The nanofluid flow has been modeled in form of nonlinear partial differential equations, which are further convert into the dimensionless form of ordinary differential equations. The obtained set of non-dimensional equations is numerically resolved by using the Matlab built-in package bvp4c. The results are compared to another numerical technique for accuracy purposes. The detailed results are presented in Figures. It has been detected that the energy field of nanofluid is enriched with the effect of heat source/sink component. Moreover, the velocity curve magnifies with the variation of the squeezing parameter of Riga plates, whereas declines with the accumulation of Cu-NPs in both types of base fluid (C12H26C15H32and H2O).

Experts and different companies are always attempting to use composites in place of traditional materials to build designs that are more robust, lighter, more corrosion resistant, and other necessary qualities. Composites are being utilised in a growing number of products and applications. Increasing enterprise performance requirements, such as aerospace, automobiles, and other frameworks, require broader mechanical and hands-on testing. Mechanical test equipment has been developed using many of the equipment created to provide different ways to test composites based on the properties of the material and its expected end use. This article details various strategies for testing composites of composition (0.6 wt.% cobalt and fiberglass) for application to excavator engine hoods. Long glass fiber tensile and flexural strength were available at 97.22N/mm2and 120.28N/mm2, respectively, while tensile and flexural strength of the reinforced short fiber was combined found in 94.12 N/mm2and 110.23N/mm2. Also, the energy absorbed by long fiber is (7.21 Kgm) which is more than the short fiber i.e. (5 Kgm). Additionally, this article offers a source of information on these test methods that enable composites to be assessed at a high degree in order to obtain satisfactory results in terms of tension and impact.

Purpose: This paper aims to integrate control systems to minimize vibration in rotating machinery, specifically focusing on propulsion shaft systems. The effectiveness of magnetorheological (MR) dampers in reducing vibration across various operational scenarios is assessed. Methods: The research paper involves the development and validation of numerical models for both the propulsion shaft system and MR dampers, followed by experimental validations to verify model accuracy. These validated models are integrated to simulate controlled propulsion shaft systems equipped with MR dampers. A state-space formulation and Linear Quadratic Gaussian (LQG) control law are employed to devise a propulsion shaft system controller that coordinates the operation of MR dampers for vibration mitigation and improved dynamic performance. Results: Simulation outcomes reveal notable decreases in vibration levels at varying rotational speeds, with higher speeds exhibiting more pronounced reductions. At lower speeds (50 rpm), vibration reduction indices show decreases of about 12.47% at 25 Hz and 18.75% at 175 Hz. At higher speeds (100 rpm and 150 rpm), substantial decreases in vibration levels are observed, with corresponding vibration reduction indices reaching 28.86% and 36.53%, respectively. Conclusion: Frequency domain analysis highlights the enhanced dynamic performance achieved through control interventions. The study offers valuable insights for improving the efficiency and reliability of industrial machinery by demonstrating the efficacy of MR dampers in vibration reduction across various operational scenarios.

•Best weight percentage was identified by WASPAS method.•From WASPAS, 5 wt% fly ash was added to the vinyl ester resin.•BV2 composites with basalt fibers displayed superior tensile, compression and flexural strength than other composites.•Slight escalation in impact strength of all the fabricated composites.•Addition of basalt with fly ash and vinyl ester has a constructive character on the mechanical data.

Cosmolaelaps simplex Berlese was collected from soil samples including leaf litter under citrus trees at Lake Alfred, Polk County, Florida. The adult female is redescribed and the male is described and illustrated for the first time.

The larvae, protonymphs, deutonymphs, adult females, and adult males of Proprioseiopsis rotundus (Muma) and Proprioseiopsis asetus (Chant) are described and illustrated. Ontogenetic development of the idiosomal setae is discussed.

Effects on development, survivorship and reproduction of Euseius mesembrinus (Dean) were studied in the laboratory using nine different plant pollens: ice plant, Malephora crocea (Jacquin); live oak, Quercus virginiana Miller; castor bean, Ricinus communis L.; cattail, Typha latifolia L.; Spanish needle, Bidens pilosa L.; grapefruit, Citrus paradisi (L.) Osbeck; 'Sunburst' tangerine, C. reticulata Blanco (hybrid); 'Hamlin' orange, C. sinensis (L.) Osbeck; and pummelo, C. grandis (L.) Osbeck. Following eclosion, 100% of adults developed in 7.6 to 7.9 days when pollen of ice plant, live oak, castor bean or cattail was provided as single food sources at 27 ± 1°C. A total of 30.8 and 30.4 eggs per female were obtained when ice plant and live oak pollens, respectively, were provided compared to 23.0 and 19.2 eggs per female when castor bean and cattail pollens were used. Life table parameters were: mean generation time (T) = 12.38; net reproductive rate (Ro) = 17.17; intrinsic rate of natural increase (rm) = 0.2296 and finite rate of increase (λ) = 1.258 when live oak pollen was used as the food source compared with T = 12.47, Ro = 17.79, rm = 0.2308 and λ = 1.260 for ice plant pollen. Castor bean and cattail pollens are available as potential food sources for E. mesembrinus, but they are not as effective as ice plant or live oak pollens. Larvae of E. mesembrinus required 8.5 days to develop to adults, while only 72% of the larvae survived when B. pilosa pollen was used as the food source. Each female deposited an average of 0.45 eggs per day during the first 5 days of oviposition. Citrus pollens including C. paradisi, C. reticulata, C. sinensis and C. grandis are available as food sources for E. mesembrinus, and survivorship ranged from 64 to 84%. Developmental time was prolonged (8.8 to 12.5 days) and fecundity was also very low (0.10 to 0.67 eggs/female/day) during the first 5 days of oviposition compared with both ice plant and live oak pollens.

The biology of Typhlodromalus peregrinus (Muma) was studied in the laboratory at 26°C. Each of the following organisms was evaluated as suitable diet: all stages of Tetranychus urticae Koch; immature stages of Panonychus citri (McGregor) (Acari: Tetranychidae); and pollens of Malephora crocea (Jaquin), Quercus virginiana Miller, and Typhalatifolia (L.). The combination of T. urticae with each pollen was also tested. Total developmental time ranged between 5.73 and 7 d for females and between 5.67 and 6.93 d for males. The percentage of females in the total population ranged between 53 and 61%. A diet of T. urticae provided the shortest generation time (G), greatest female longevity, and mean total fecundity (F) which resulted in the highest net reproductive rate (R0) value (25.31 expected females per female), intrinsic rate of increase (rm = 0.224), and finite rate of increase (erm = 1.25) per day for T. peregrinl1s. Diets of only P. citri or M. crocea resulted in close values of G = 8.67, 8.91; F = 47.11, 49.47; R0 = 24.00, 26.65; rill = 0.210, 0.219; and erm = 1.23, 1.24, respectively. Q. virginiana and Typha latifolia were the least favorable food sources, with results of G = 8.78, 9.41; F = 30.38, 24.25; R0 = 14.20, 12.04; rm = 0.193, 0.170, and er = 1.21, 1.18, respectively. The rm values were highly affected by generation time and mean total fecundity (R2 = 0.947).