68 research outputs found
Mesoporous TiO
Mesoporous anatase TiO2 micro-nanometer composite structure was synthesized by solvothermal method at 180°C, followed by calcination at 400°C for 2 h. The as-prepared TiO2 was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectrum (FT-IR). The specific surface area and pore size distribution were obtained from N2 adsorption-desorption isotherm, and the optoelectric property of the mesoporous TiO2 was studied by UV-Vis absorption spectrum and surface photovoltage spectra (SPS). The photocatalytic activity was evaluated by photodegradation of sole rhodamine B (RhB) and sole phenol aqueous solutions under simulated sunlight irradiation and compared with that of Degussa P-25 (P25) under the same conditions. The photodegradation preference of this mesoporous TiO2 was also investigated for an RhB-phenol mixed solution. The results show that the TiO2 composite structure consists of microspheres (∼0.5–2 μm in diameter) and irregular aggregates (several hundred nanometers) with rough surfaces and the average primary particle size is 10.2 nm. The photodegradation activities of this mesoporous TiO2 on both RhB and phenol solutions are higher than those of P25. Moreover, this as-prepared TiO2 exhibits photodegradation preference on RhB in the RhB-phenol mixture solution
Retrospective analysis of 217 fatal intoxication autopsy cases from 2009 to 2021: temporal trends in fatal intoxication at Tongji center for medicolegal expertise, Hubei, China
This retrospective analysis of fatal intoxication case autopsies was performed at Tongji Center for Medicolegal Expertise in Hubei (TCMEH) from 2009 to 2021 to obtain up-to-date information on intoxication cases. The objective was to describe important data about evolving patterns in intoxication occurrences, enhance public safety policies, and assist forensic examiners and police in more efficient handling of such cases. Analyses based on sex, age, topical exposure routes, toxic agents, and mode of death were performed using 217 records of intoxication cases collected from TCMEH as a sample, and the results were compared with reports previously published (from 1999 to 2008) from this institution. Deaths from intoxications occurred at a higher rate in males than in females and were most common among individuals aged 30–39 years. The most frequent method of exposure was oral ingestion. The causative agents of deadly intoxications have changed when compared to the data from the previous 10 years. For instance, deaths from amphetamine overdoses are becoming more prevalent gradually, whereas deaths due to carbon monoxide and rodenticide intoxication have declined dramatically. In 72 cases, pesticides continued to be the most frequent intoxication cause. A total of 60.4% of the deaths were accidental exposure. Men died from accidents at a higher rate than women, although women were more likely to commit suicide. Particular focus is needed on the use of succinylcholine, cyanide, and paraquat in homicides
Enhanced performance of micro deep drawing through the application of TiO2 nanolubricant and graphene lubricants on SUS 301 stainless steel foil
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Open AccessArticle
Enhanced Performance of Micro Deep Drawing through the Application of TiO2 Nanolubricant and Graphene Lubricants on SUS 301 Stainless Steel Foil
by Di Pan 1ORCID,Guangqing Zhang 1,Fanghui Jia 1,Yao Lu 2,Jun Wang 2,Zhou Li 3,Lianjie Li 4,Ming Yang 5ORCID andZhengyi Jiang 1,*
1
School of Mechanical, Materials, Mechatronic and Biomedical Engineering, Wollongong, NSW 2522, Australia
2
Welding Engineering and Laser Processing Centre, Cranfield University, Bedfordshire MK43 0AL, UK
3
College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China
4
School of Intelligent Manufacturing and Control Engineering, Shanghai Polytechnic University, Shanghai 201209, China
5
Graduate School of System Design, Tokyo Metropolitan University, Hino, Tokyo 191-0055, Japan
*
Author to whom correspondence should be addressed.
Processes 2023, 11(10), 3042; https://doi.org/10.3390/pr11103042
Received: 2 September 2023 / Revised: 17 October 2023 / Accepted: 20 October 2023 / Published: 23 October 2023
(This article belongs to the Special Issue Processing, Manufacturing and Properties of Metal and Alloys)
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Abstract
In recent years, the quest for effective lubrication in micro deep drawing (MDD) has seen promising advancements. In this study, the influence of TiO2 nanolubricants and graphene lubricants on the performance of 301 stainless steel foil in MDD is examined. The MDD undergoes an extensive evaluation of various lubrication conditions, including dry, TiO2 nanolubricant, graphene lubricant at concentrations of 2.5 mg/mL, 5.0 mg/mL, and 10.0 mg/mL, as well as combined applications of TiO2 and graphene lubricants. Utilising a 5.0 mg/mL graphene lubricant together with TiO2 nanolubricants led to a significant reduction in drawing force, highlighting the synergistic efficacy of this combined lubricant. A pronounced enhancement in the consistency of the produced microcups was also attained. These results emphasise the promise of TiO2 nanolubricant and graphene lubricants in optimising the MDD process
Exploring the use of graphene lubricant and TiO2 nanolubricants in micro deep drawing of stainless steel SUS301
This study investigates the effects of different lubrication conditions on drawing force and microcup formation during micro deep drawing (MDD). Results show that graphene lubricant, in combination with TiO2 nanolubricants, has the potential to reduce friction during MDD. The peak drawing force was reduced by 15.39% when both lubricants were used together, while the use of TiO2 nanolubricant and 10.0 mg/ml graphene lubricant reduced it by 6.03% and 14.52%, respectively. The study also reveals that lubricants reduce wrinkling during the formation of microcups by minimising energy consumption during the primary formation. However, the combination of TiO2 nanolubricant and graphene lubricant can cause inhomogeneous formation on the upper part of the blank, leading to more apparent wrinkling. Overall, the study highlights the potential of TiO2 nanolubricant and graphene lubricant in reducing friction and improving microcup formation during MDD.Open Access funding enabled and organized by CAUL and its Member Institutions. This research received funding from the Australian Research Council (ARC) through the project designated as DP190100738
Research on the Seismic Performance of the Prefabricated Reinforced Concrete Column with Steel Mortise and Tenon Connections
In this study, 6 prefabricated reinforced concrete columns with different lengths of connectors and thicknesses of the steel plate used in connectors and 1 cast-in-place reinforced concrete column were made, and then these specimens were tested under the low cycled reversed loading experiment to study the seismic performance of the prefabricated reinforced concrete columns with steel mortise and tenon connections. The failure mode, bearing capacity, ductility, stiffness degradation, and energy dissipation of the specimens were analyzed. The results show that compared with the cast-in-place specimens, the bearing capacity of the fabricated specimen is reduced by 5.77%–16.67%, but the ductility is increased by 11.28%–26.69%, and the cumulative energy consumption is increased by 3.40%–30.29%; the stiffness, bearing capacity degradation, and hysteretic behavior of the fabricated specimen under different displacement angles are less different from those of the cast-in-place specimens. When the length of the connector is 100 mm and the thickness of the steel plate used in the connector is 4 mm, the weld fracture may occur in the connection area of the fabricated specimen. The test results show that when the connector with a length of 100 mm is used, the thickness of the steel plate of the connector should not be less than 6 mm
Experimental Study on Cumulative Damage Behavior of Steel-Reinforced Concrete Columns
The cumulative damage behavior of SRC columns under far-field long-period ground motions was simulated and studied by quasi-static tests with the same displacement for 10 times. Quasi-static tests of 8 SRC columns were conducted under the horizontal cyclic loading with the same displacement for 10 times or 3 times, and then the effects of steel ratio, stirrup ratio, axial compression ratio, and number of cyclic loading on the cumulative damage of SRC columns under the far-field long-period ground motions were studied. The results showed that the number of cyclic loading had little effect on the peak load of the specimens, but had a significant effect on the deformation capacity, stiffness degradation, and energy dissipation capacity. Compared with the specimens after 3 cycles, the displacement ductility coefficient of specimens after 10 cycles was reduced by about 20%–26%, the ultimate hysteresis energy dissipation was reduced by 35%–48%, while the stiffness degradation rate was accelerated. After the peak load, the cumulative damage caused by multiple cyclic loading with the same displacement was more significant, which aggravated the reduction of bearing capacity and stiffness degradation. The smaller the steel ratio and stirrup ratio, the larger the axial compression ratio, and the greater the reduction of the bearing capacity and stiffness of specimens. However, accumulated damage caused by multiple cyclic loading with the same displacement had a slight impact on the energy dissipation capacity. Increasing the steel ratio and stirrup ratio can effectively improve the deformation capacity and energy dissipation capacity of the specimens and reduce the bearing capacity and stiffness degradation caused by cumulative damage
Exponentially weighted moving average control charts for monitoring increases in Poisson rate
The Exponentially Weighted Moving Average (EWMA) control chart has been widely studied as a tool for monitoring normal processes due to its simplicity and efficiency. However, relatively little attention has been paid to EWMA charts for monitoring Poisson processes. This article extends EWMA charts to Poisson processes with an emphasis on quick detection of increases in Poisson rate. Both cases with and without normalizing transformation for Poisson data are considered. A Markov chain model is established to analyze and design the proposed chart. A comparison of the results obtained indicates that the EWMA chart based on normalized data is nearly optimal
Effects of locational accessibility on firm diffusion characteristics: the case of Sino-Europe Economic Corridor
Regional mobility of economic production factors accelerates the globalization of the associated economies and impacts firm diffusion trends. The Belt and Road Initiative aims to facilitate the orderly flow of economic production factors along the Sino-Europe Economic Corridor. However, little is known about the effects of locational accessibility on firm relocations with such an initiative. Conceptualizing locational accessibility based on elementary production factors, this paper proposed a methodological framework to analyze the potential firm diffusion trends by applying the percolation theory in a multimodal freight supernetwork. The empirical analysis concerns two typical manufacturing industries along the Sino-Europe Economic Corridor. The results show that the percolation transition happens during the diffusion of the two manufacturing industries considering land rent, labor cost, and freight transport cost as the elementary production factors. It is found that the improvement in transport accessibility accelerates the diffusion trends of the manufacturing industries, although the bottleneck regions for the diffusion of both industries do not change comparatively. The proposed methodological framework acts as an efficient testbed for analyzing the regional diffusion trends of different types of industries
An Adaptive CUSUM Procedure for Signaling Process Variance Changes of Unknown Sizes
Similar to the CUSUM location chart, the traditional CUSUM dispersion chart can be designed to optimize the detection of specified variance changes. However, this optimality property requires that the magnitude of the out-of-control variance is known exactly a priori. To get away from this requirement, this paper suggests an adaptive CUSUM procedure for signaling changes in the process variance of unknown sizes. The basic idea is to first estimate the current process variance and then dynamically adjust the CUSUM chart to match the variance estimate. A two-dimensional Markov chain model is developed to analyze the chart performance. The comparison results with the traditional CUSUM dispersion chart and other competitive procedures favor the proposed one
Comparative Study on Advanced Nitrogen Removal of Landfill Leachate Treated by SBR and SBBR
In order to achieve advanced nitrogen removal from landfill leachate without the addition of external carbon sources, a Sequencing Batch Reactor (SBR) and a Sequencing Biofilm Batch Reactor (SBBR) were proposed for the treatment of actual landfill leachate with ammonia nitrogen (NH4+-N) and chemical oxygen demand (COD) concentrations of 1000 ± 100 mg/L and 4000 ± 100 mg/L, respectively. The operating modes of both systems are anaerobic–aerobic–anoxic. After 110 days of start-up and biomass acclimation, the effluent COD and the total nitrogen (TN) of the two systems were 650 ± 50 mg/L and 20 ± 10 mg/L, respectively. The removal rates of COD and total nitrogen could reach around 85% and above 95%, respectively. Therefore, advanced nitrogen removal was implemented in landfill leachate without adding any carbon sources. After the two systems were acclimated, nitrogen removing cycles of SBR and SBBR were 24 h and 20 h, respectively. The nitrogen removing efficiency of SBBR was improved by 16.7% in comparison to SBR. In the typical cycle of the two groups of reactors, the nitrification time of the system was the same, which was 5.5 h, indicating that although the fiber filler occupied part of the reactor space, it had no significant impact on the nitrification performance of the system. At the end of aeration, the internal carbon source content of sludge of SBBR was equivalent to that of the SBR system. However, the total nitrogen concentration of SBBR was only 129 mg/L, which is 33.8% lower than that of SBR at 195 mg/L. The main reason was that biofilm enhanced the simultaneous nitrification and denitrification (SND) effect of the system
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