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Previous studies have mainly focused on solar chimneys in single-chamber/zone or single-story buildings. Its theoretical development in multi-chamber or multi-story buildings is lagging, which hampers its practical applications in multi-storey buildings. This study investigated ventilation capacity characterized by volume flow rates numerically and theoretically for a multi-storey building with a solar chimney. Three mathematical methods based on simplified models were introduced to predict the ventilation rates for each floor. By comparing the three methods, Method 1, based on the bifurcation hypothesis, was found suitable for two-storey or single-storey cases; and Method 3, based on empirical flow equations, is practical for those cases greater than two-storey. To optimize the ventilation rate, a wider cavity gap and a higher stack height for a multi-storey solar chimney were the most effective ways compared to the single-zone/floor cases. A larger window area and air inlet size promoted the ventilation capacity, where the growth rate of volume flow was small and critical values exist. It was observed that the solar chimney dimensions show a more significant effect on the volume flow rates than the solar radiation intensity. The main contribution of this study is that it establishes the links between the single-zone and the multi-storey theoretical models and proposed practical mathematical methods to obtain acceptable prediction accuracy of ventilation rates for a solar chimney in a multi-storey building.

Silica aerogel is a unique three-dimensional nano-porous material and its characteristics have attracted much attention from both engineers and researchers. However, their structural behaviors under high temperature are not well known yet. The structure of silica aerogel under high temperature from 950°C to 1200°C was investigated based on pycnometry, scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET) analysis, Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction patterns (XRD). It was obtained that the structure of silica aerogels was strongly affected by heating temperature and time. It was known based on experimental results that the changes of silica aerogel during 950–1200°C can be divided into three steps: expansion of primary particles at sample surface (step I), atrophy and pore collapse of primary particles at the surface (step II), and atrophy and pore collapse of primary particles inside the sample (step III). Change rate was found significantly dependent on the moving rate of expansion region, while during the first two steps only limited changes were observed about three dimensional nanoporous structures. During Step III, the structure of silica aerogel was completely destructed, while the density can reach to about 1600kg/m3.

Rationale: Open eye injury is one of the commonest ophthalmic emergencies, and when accompanied by intraorbital foreign bodies, the condition carries a poor prognosis. Patient concerns: A 28-year-old man presented to the emergency department of our hospital complaining of sudden painful loss of vision in the left eye after he hammered an iron plate. Diagnosis: The ocular examination revealed a 4-mm full thickness scleral laceration with prolapsed uveal tissue, a traumatic cataract. Computed tomography (CT) demonstrated an orbital foreign body in the retrobulbar area. Interventions: The patient underwent emergency scleral suturing, severance of medial rectus muscle, and removal of the orbital foreign body. Twelve days after the emergency operation, pars plana lensectomy and pars plana vitrectomy were performed. Outcomes: After 3 months of follow-up, there was no immune response. Visual acuity in the left eye was the perception of hand motion. The retina remained mostly attached with normal intraocular pressure, and good cosmetic appearance. The globe anatomy was maintained, but the vision could not be restored due to the grave nature of the trauma. Lessons: Transconjunctival approach extraocular muscle severance may thus be a suitable approach to the removal of intraorbital metallic foreign body.

No abstract is provided for this article.

No abstract is provided for this article.

Several existing studies have been performed on the fire characteristics of traditional tunnel and enclosure models; however, these findings may not be applicable to a subway train with a special confined structure. Therefore, to investigate the smoke temperature distributions under conditions involving different fire locations and door statuses, a set of experiments were conducted by using a reduced-scale subway train model. The results indicated that the longitudinal and transverse temperature distributions correspond to the exponential decay law, although the transverse temperature does not exhibit a regular distribution under certain conditions. Furthermore, the previously developed empirical models were not applicable to the subway train considered in this work. Consequently, empirical models similar to those involving the exponential function were developed to predict both the longitudinal and transverse smoke temperature distributions. The corresponding results exhibited a reasonable fit with the experimental data. The powers of the exponential functions were noted to be proportional to the dimensionless heat release rate, with values of 0.4 and 0.3 for the longitudinal and transverse smoke temperature distributions, respectively. The research findings and empirical models provide a reference for the fire risk assessment of subway train or other similar frameworks.

In view of the problem of laser dizzy interference of medium-wave infrared seeker detector in the field of photoelectric confrontation, there is a lack of equidistant distance test to verify the problem. In this paper, a medium-wave infrared seeker for short-range precision guided missile CCD detector was used as the subject, and the 3.8 μm wavelength medium wave laser was used as the laser source to study the calibration of the laser. In the experiment, two locations with a viewing distance of 14.5 km were selected to place the laser and missile seeker detectors respectively. The atmospheric transmittance was estimated using the MODTRAN software based on the meteorological parameters provided by the simple meteorological monitoring tool. Under the different target power density conditions, the simulation of the missile seeker head of the interference of the dizzy effect. By analyzing the interference images in the tracking state, the corresponding qualitative and quantitative dizziness interference results are obtained. After the calculation and analysis, it is considered that the laser energy output from the mid-wave infrared laser is 0.08 mW/m2 when the power density of the target surface of the detector is 0.08 mW/m2, respectively, under medium meteorological conditions with a visibility of 0.625. Box cannot lock the original target, there cannot effectively extract the target dizzy effect. The experimental results show that the anti-jamming ability of the anti-jamming capability of the medium-wave infrared precision guidance probe is verified by the photoelectric countermeasure, and it is considered that the dodge power density is smaller when the interference laser wavelength matches the wavelength of the seeker detector. The experimental data can provide theoretical guidance for the inversion and determination of parameters in the study of the medium wave infrared photoelectric countermeasure.

The latex mattress is usually accompanied by fire risk due to its coating material and multi-layer structure. The fire behaviors of multi-layer (with a total thickness of 5 cm) latex foam coated with different fabric layer under bottom ventilation conditions were investigated experimentally. Experimental results showed that fabric coated on the surface of the multi-layer sample could significantly affect the fire behaviors. The combustion duration and peak mass loss rate of single layer sample were obtained 30% shorter and 25% larger than that of the coated samples, respectively. The effects of blending coated from the latex foam surface on the fire behaviors were found larger than those from the cotton coated sample. The total combustion duration and average fuel regression rate of cotton coated samples reduced by 34%, 43.2% when compared to those of the blending coated samples, respectively. With the increase of the number of latex foam layers, the fuel regression rate in the depth direction of the sample increases.

Polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFRs) have been extensively investigated in the terrestrial environment of China. However, little is known about how PBDEs and NBFRs burdens in agricultural soils altered over time. In this study, agricultural soils from different regions of China were collected from 2011 to 2021 to investigate the contamination levels and temporal variation of PBDEs and NBFRs. The concentrations of ∑26PBDEs and ∑5NBFRs ranged from 0.144 to 215 ng/g dry weight (d.w.) and 0.186–144 ng/g (d.w.), with a mean value of 9.27 ng/g (d.w.) and 8.22 ng/g (d.w.), respectively. Among PBDEs and NBFRs, BDE-209 and decabromodiphenylethane (DBDPE) were the most predominant compounds. The PBDE concentrations did not vary significantly during the past decade, whereas the lower brominated congeners increased with time (doubling times ranged from 5.46 to 8.56 years). Meanwhile, NBFR concentrations increased over time, with concentrations significantly higher in 2021, 2016, and 2013 than in 2011 (p < 0.05). Additionally, DBDPE, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), and hexabromobenzene (HBB) had doubling times of 6.84, 11.2, and 7.37 years, respectively. Total organic matter (TOC) impacted the distribution and variation of PBDEs (particularly lower-brominated congeners), with soil organic matter (SOM)-sorption showing an increasing and then decreasing trend. Health risk assessment suggested that PBDEs and NBFRs did not pose non-carcinogenic risks to humans. Nevertheless, the long-term health risk of BFRs should be considered. Overall, this is the first study to comprehensively analyze the contamination burdens and temporal trends of PBDEs and NBFRs in Chinese agricultural soils over a long period, providing a fundamental basis for future BFR management.