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The correct use of a child restraint system (CRS) is an effective internationally recognized measure to protect the safety of child occupants which can reduce the probability of child road traffic accident deaths by 54–80%. Finite element (FE) analysis is one important method with which to study the protection of child occupants. The aim of this study was to investigate thoracic and abdominal injuries and the protective effect of CRS on child occupants in 6-year-old (6YO) children in a frontal sled test using different computational models. In this study, a verified FE model of a 6YO child occupant was placed in the FE model of a CRS with a three-point safety belt. In the simulation setup phase, the frontal sled simulation of the 6YO FE model was reconstructed by applying the AAMA pulse. Based on the simulation data of the Q6 dummy FE model (Q6) and the 6YO child Virthuman model (V6) from previous studies, the frontal sled test simulation of a verified 6YO child FE model with detailed anatomical structures (TUST IBMs 6YO) was carried out to analyze pediatric thorax and abdomen injuries under the same experimental conditions. According to the simulation results, the variation tendencies of the simulation responses such as chest acceleration and compression are consistent with each other, which can provide effective information for the design of a CRS. In addition, the simulation results of the TUST IBMs 6YO can provide a variety of simulation data, such as the maximum first principal strain value and nephogram, of the internal organs of the chest and abdomen, providing a theoretical basis for the performance analysis and later development of a CRS.

Nanoscale zero-valent iron (NZVI) was first assembled on magnetic carbon/Fe3O4 (CM) with a combination of hydrothermal and liquid phase reduction methods. The novel NZVI@CM magnetic nanocomposites have the merits of large surface area, unique magnetic property, low cost and environmental friendliness. They can be used for Pb(II) removal in aqueous solution. The materials were characterized by using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) adsorption. The various parameters, such as reaction time, dosage of catalyst, solution pH and acid ions concentrations were studied. The removal efficiency of Pb(II) can be obviously increased by the combination of appropriate CM and NZVI. The removal efficiency of Pb(II) is 99.7% by using 60 mg of NZVI@CM at pH 7. The kinetics study indicates that the Pb(II) removal accords to pseudo-second-order kinetics model.

The novel, stable, and environmentally friendly Ag 2 O/g-C 3 N 4 /Fe 3 O 4 nanocomposites were firstly synthesized with a combination of calcination and co-precipitation methods. The material was characterized by using transmission electron microscopy (TEM), Energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–Vis) diffuse reflectance spectroscopy, thermogravimetric analysis (TGA), and vibrating sample magnetometry (VSM). The nanocomposites were applied in the photodegradation of Rhodamine B (RhB) under visible light. The effects of the catalyst component ratio, catalyst dosage, solution pH, RhB concentration and catalyst reusability on the degradation were explored. 10 mg/L RhB can be degraded by 98.3% after 60 min under 500 W of visible light. In addition, the photodegradation kinetics and the possible reaction mechanism were investigated.

Children are the vulnerable groups in traffic accidents, so understanding injury mechanism based on their physiological anatomy characteristics is very important for more effective prevention. The post-mortem human subjects are rarely used for biomechanical experiments due to regulatory and ethical concerns. Therefore, finite element (FE) modeling becomes a significant approach to inform tissue-level mechanical responses by exporting the strain or stress. This study provides a high biofidelity FE model of a 3-year-old child abdomen and it could be used to parametrically study the injury mechanism, which is very valuable to developing protection devices and proposing the injury criteria of children abdomen. In this research, a 3-year-old child abdominal finite element model with detailed anatomy structure is developed which consists of 273,322 nodes, 194,684 hexahedral solid elements, and 118,549 shell elements. A simulation test is implemented to validate the FE model according to the child cadaver tests conducted by Ouyang et al. The results show that the simulation curve of impact force-abdominal deformation is inside the corridor obtained from cadaveric experiment, which suggests a validity of FE Model. And then, the FE model is used to analyze the injury mechanism through rotating the impactor 30 degrees clockwise (-30°) and counterclockwise (+30°) respectively along the vertical direction of its velocity. The results indicate the sensitivity of internal organs to blunt impact through comparing the strains of different visceral organs and analyze their injury threshold when the crash by the impactor happens head-on or from the rotating angle of ±30°. Human abdomen is asymmetric so that the deformation location and degrees of damage will be different when it is struck from different directions. If the impactor strikes the child on the right side, the liver is much easier to get injured; if the abdomen is struck on the left side, the stomach and the spleen become most vulnerable. While if the impact happens head-on, the child's abdomen can bear the force evenly to effectively reduce the injury risks of different visceral parts.

Child pedestrian was vulnerable group in traffic accident, and the type of pedestrian traffic accident was side impact. This paper aims to study the relationship between the injury biomechanical responses of pediatric thoracic tissues and the lateral impact angle. A finite element model of a six-year-old child pedestrian thorax with real anatomical structural muscles was developed, according to medical CT scan images, and verified by reconstructing lateral and oblique impact experiments. Simulation results showed that the force-deformation curves under the lateral and oblique conditions were in good agreement with that of experiments. The results showed that maximum force was inversely proportional to the oblique impact angle, and maximum deformation was proportional to the angle of oblique impact. Maximum first principal strain of the lung and heart increased with the increasing of the oblique impact angle. The validated child thorax model can be used to study the biomechanical impact response and injury mechanism for child pedestrian.

Biomechanically, one of the important roles of the cerebrospinal fluid playing is to provide effective damping against sudden intracranial brain motion during head impact. Thus, the mesh density of cerebrospinal fluid in finite element model needs to be studied because of its significant impact on the brain's biomechanical responses, such as relative displacement. This study based on a previous finite element head model of a 6 years old child developed and validated by the Tianjin University of Science and Technology. The effects of different mesh density of the cerebrospinal fluid on the relative displacement of the brain were studied. The thickness of cerebrospinal fluid remained unchanged but constructed into three layers and one layer of hexahedral elements. The results indicate that the relative displacements of skull-brain in two cases react to impact differently. Relative displacement is higher in the three layers CSF case than that of one layer. Rotational acceleration caused higher relative displacement than translational acceleration for both cases.

The molecular electronegativity-distance vector (MEDV) is employed to describe the chemical structure of organic pollutants. Quantitative linear relationships between the molecular descriptors and BCF values are developed by best subset regression and partial least square regression analysis. The main structural factors influencing the bioactivities are -CH2, -X, -C≮, -C≮, -O-. The high values of r2 and q2LOO present good estimation ability and stability of models. The prediction power for external samples is validated by the model developed from the training set.