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Experimental study on anti-slip performance of galvanized cable-clamped joint at elevated temperature
A study of fracture mechanics for compact tensile specimen of Al6061-SiC metal matrix composite
Abstract The main contribution of the present work is the display of the impact of the addition of SiC into the aluminum alloy Al6061. For this reason, the Mode I stress intensity factor KI and T-stress for compact tension CT specimen are evaluated using 3D finite element analysis (FEA). The material used here in the compact tension CT specimen is Al6061-SiC metal matrix composites reinforced with various volume fractions of 4%, 6%, 10%, 12%, and 14% of SiC particles. Three different crack lengths (a/H) ratios of 0.35, 0.43, and 0.5 are considered through the analysis. Only half of the model of the cracked compact tension CT specimen with a subjected load of a magnitude P = 603 N is analyzed, and KI, T11-stress, and T33-stress are computed. From the FEA results, it is observed that the KI, T11-stress, and T33-stress are mainly influenced by the volume fractions of reinforced SiC particles. A more significant decrease in the values of KI, T11-stress, and T33-stress is found in the Al6061-14vol.%SiC composite CT specimen. Where FEA results of KI for the Al6061-14vol.%SiC composite CT specimen exhibited reduction percentages of 5.4%, 5.6%, and 5.7%, respectively, for (a/H) = 0.35, 0.43, and 0.5, as compared to those of Al6061. FEA values of T11-stress for the Al6061-14vol.%SiC composite CT specimen reduced by 5.5%, 5.6%, and 5.7%, respectively, for (a/H) = 0.35, 0.43, and 0.5, respectively, over those of Al6061. Also, the decrement percentages of FEA results of T33-stress for the Al6061-14vol.%SiC composite CT specimen over those of Al6061 were found to be 17.1%, 16.6%, and 16.5%, respectively, for (a/H) = 0.35, 0.43, and 0.5, respectively. Overall, fracture mechanics properties are improved by the addition of SiC particulates into the Al6061 alloy.
Coalescence of concentrated emulsions in microfluidic constrictions through avalanches
Investigating the spatial distribution and influencing factors of traditional villages in Qiandongnan based on ArcGIS and geodetector
Tailored bimetallic Zn/Ni and Zn/Ag MCM-41 photocatalysts for enhanced visible-light photocatalytic tetracycline degradation
Abstract Novel bimetallic-doped-MCM-41(Mobil Composition of Matter No. 41) (Zn/Ni-MCM-41 (ZNM)) and (Zn/Ag-MCM-41 (ZAM)) catalysts were synthesized and characterized for their structural, textural, morphological, and optical properties. XRD analysis confirmed metal incorporation into the MCM-41 framework, while N2 adsorption-desorption isotherms indicated a decrease in specific surface area (1210 in pure MCM-41 to 722.86 and 700.36 m2/g for ZNM and ZAM, respectively) due to partial pore filling. TEM images verified this finding. Boosted absorption extending into the visible light region was detected in the metal incorporated (ZNM and ZAM) samples with additional band gaps, related to transitions in Zn2+, Ag+ and Ni2+ ions. Photoluminescence studies revealed efficient charge carrier separation in ZNM and ZAM. Both catalysts exhibited superior tetracycline (TC) removal from aqueous solution with efficiency (95.59% and 95.30% within one hour for ZNM and ZAM, respectively) with pronouncing visible light photocatalytic capability compared to pure MCM-41. The degradation process followed pseudo-first-order kinetics. The enhanced photocatalytic activity of ZNM and ZAM is attributed to the synergistic effects of metal incorporation, increased light absorption, and efficient charge carrier dynamics. Additionally, a possible photocatalytic mechanism for degradation of TC over ZNM and ZAM has been proposed and involvement of superoxide radicals (O2 •−) and holes (h+) as reactive species is elucidated by radical trapping experiments. A distinct pH-dependent trend was observed in TC degradation efficiency using the ZAM photocatalyst. The efficiency gradually increased with increasing pH until reaching a maximum at pH 7, followed by a decline at higher pH values. These results demonstrate the potential of ZNM and ZAM as promising materials for removal of tetracycline antibiotic from water.
Frequencies of enamel hypomineralisation in permanent and primary molars in a medieval and early-modern-age population (7th − 17th c.) in Sains-en-Gohelle (Pas de Calais, France)
Source reservoir configuration and geological geochemical control of coal and shale
Design and usability evaluation of an immersive virtual reality mirrored hand system for upper limb stroke rehabilitation
Development of abnormal diagnosis and factory evaluation standards for RV reducer based on vibration characteristics
Abstract Vibration characteristics are important reference indicators for reflecting the overall performance of RV reducers. At present, there is no factory testing standard for vibration characteristics applicable to production enterprises in the industry. This study conducted vibration characteristic tests on RV40E reducers at different speed ratios. Through a large number of sample comparisons, suitable vibration characteristic factory testing standards for production enterprises were provided. Detailed on-site inspection standards have been developed based on research and analysis results for defective products such as eccentricity, gear defects, and detection errors. This standard can cover 90% of defect types within the factory. The samples are specific and executable. This study solves the problem of the lack of clear vibration detection standards in the industry. For the first time, such a detailed sample set of internal data within a company has been provided. It has extremely practical engineering application value and provides data reference for the development of RV reducer industry.
An evolutionary prediction model for enterprise basic research based on knowledge graph
Association between ACTN3 (R577X), BDKRB2 (−9/+9) and AGT (M235T) polymorphisms and physical performance in Brazilian junior handball players
First experience in employing a complex digital support system accompanied by personal assistance to improve aftercare in patients with stroke or transient ischemic attack – results of the PostStroke-Manager feasibility study
Abstract Stroke aftercare is widely acknowledged as crucial yet challenging. Digital tools offer a promising strategy to improve aftercare and, thus, patients’ quality of life. However, it has not yet been investigated whether digital tools addressing different aspects of aftercare at the same time can be utilized in stroke patients. This study was intended to gain first experience in employing a complex patient-centered digital support system (i.e., the PostStroke-Manager) in individuals with stroke or transient ischemic attack (TIA) and thus examined its feasibility accompanied by personal assistance. This cohort study was carried out to enroll patients with stroke or TIA. Digital support was realized through an application installed on a tablet, a smartwatch, and a blood pressure monitor. Trained nurses, referred to as stroke pilots, provided personal assistance. After 6 or 12 months, patients were asked to evaluate the concept with digital and personal support as a whole and concerning single components of the program for individually experienced beneficial effects. Additional descriptive analyses comprised temporal courses of stroke-related impairments, quality of life, anxiety, depression, adherence, empowerment, blood pressure, LDL cholesterol, and HbA1c levels. Between January 2022 and December 2022, 815 patients were screened, and 43 were included in the study, of whom 36 completed follow-up assessments. The study met its predefined feasibility criterion, with at least 50% of program components receiving positive ratings from at least 75% of patients. The digital system as a whole (77.8%), personal assistance (75.0%), and interactions with stroke pilots (77.8%) received particularly positive ratings. Additionally, aspects such as vital sign monitoring, platforms for communication and medical records were rated positively. Longitudinal analyses revealed improvements in patients’ impairments, blood pressure, and LDL cholesterol levels, while most psychometric measurements remained stable. These findings indicate the feasibility of employing complex digital support systems for patient-centered aftercare in selected individuals with stroke or TIA. The challenge remains in extending benefits to those patients with more severe neurological impairments, highlighting the necessity for ongoing advancement in this field.