Experimental and numerical studies of the effects of a rail vibration absorber on suppressing short pitch rail corrugation

The effects of a rail vibration absorber on suppressing short pitch rail corrugation are studied. Firstly, a rail vibration field test is carried out to analyze the vibration response of the rail with and without the vibration absorbers. Secondly, based on the hypothesis that friction-induced self-excited vibration of a wheel-rail system causes rail corrugation; two finite element models of a wheel-rail system and a wheel-rail-absorber system are established and analyzed. Both sets of rail vibration test results and theoretical results show that the rail absorbers can effectively reduce the friction-induced self-excited vibration of the wheel-rail system in the frequency range of 200-800 Hz, which corresponds to frequencies of short pitch rail corrugation. This may be a main reason that the rail vibration absorber can suppress the formation of short pitch rail corrugation

Physiological responses of Vallisneria spiraslis L. induced by different hydraulic conditions when exposed to copper and nitrogen

A two-flume experiment with submerged plant Vallisneria spiraslis L. was conducted to investigate the effects of different hydraulic conditions on physiological responses when exposed to water polluted with copper (Cu) and nitrogen (N). Plants were divided into two groups and grown for 120 h in hydrodynamic and hydrostatic flumes, respectively, using the same nutrient solution with fixed concentrations of 0.64 mg l–1 CuSO4 and 4.0 mg l–1 total N. Combined pollution with Cu and N resulted in rapid increase in chlorophyll in the first hour and relative growth rate of plants in hydrodynamic water increased from 0 to 0.073 in the first 8 h. Meanwhile, peroxidase (POD) activity in shoots sharply increased to alleviate supraoptimal oxidative stress. And proteolytic degradation in shoots was observed to be catalyzed as protein contents in shoots decreased. Persistent decline in total chlorophyll and relative growth rate was noticed in longer duration. In roots, POD activity increased only at 8 h and decreased after 24 h. Malonaldehyde (MDA) content in roots also increased only at 8 h and MDA content was lower (P < 0.01), while protein content was higher (P < 0.01) after prolonged exposure than those at 0 h. Comparison of different hydraulic groups indicated that hydrodynamic condition induced higher POD activity in shoots in the first hour to alleviate the toxicity resulted by Cu and N. Thus, relative growth rate of plants was significantly higher than that in hydrostatic group (P < 0.05). While roots in hydrodynamic condition were less influenced by water flow, its protein contents in hydrodynamic group were significantly higher (P < 0.01) than those in hydrostatic group at all durations. These results suggested that hydrodynamic condition alleviated combined toxicity of Cu and N in V. spiraslis L shoots and enhanced the accumulation of protein in roots.Key words: Physiological response, hydrodynamic, copper, nitrogen, Vallisneria spiraslis L

ChatCAD: Interactive Computer-Aided Diagnosis on Medical Image using Large Language Models

Large language models (LLMs) have recently demonstrated their potential in clinical applications, providing valuable medical knowledge and advice. For example, a large dialog LLM like ChatGPT has successfully passed part of the US medical licensing exam. However, LLMs currently have difficulty processing images, making it challenging to interpret information from medical images, which are rich in information that supports clinical decisions. On the other hand, computer-aided diagnosis (CAD) networks for medical images have seen significant success in the medical field by using advanced deep-learning algorithms to support clinical decision-making. This paper presents a method for integrating LLMs into medical-image CAD networks. The proposed framework uses LLMs to enhance the output of multiple CAD networks, such as diagnosis networks, lesion segmentation networks, and report generation networks, by summarizing and reorganizing the information presented in natural language text format. The goal is to merge the strengths of LLMs' medical domain knowledge and logical reasoning with the vision understanding capability of existing medical-image CAD models to create a more user-friendly and understandable system for patients compared to conventional CAD systems. In the future, LLM's medical knowledge can be also used to improve the performance of vision-based medical-image CAD models

Experimental and numerical studies of the effects of a rail vibration absorber on suppressing short pitch rail corrugation

The effects of a rail vibration absorber on suppressing short pitch rail corrugation are studied. Firstly, a rail vibration field test is carried out to analyze the vibration response of the rail with and without the vibration absorbers. Secondly, based on the hypothesis that friction-induced self-excited vibration of a wheel-rail system causes rail corrugation; two finite element models of a wheel-rail system and a wheel-rail-absorber system are established and analyzed. Both sets of rail vibration test results and theoretical results show that the rail absorbers can effectively reduce the friction-induced self-excited vibration of the wheel-rail system in the frequency range of 200-800 Hz, which corresponds to frequencies of short pitch rail corrugation. This may be a main reason that the rail vibration absorber can suppress the formation of short pitch rail corrugation