A BIPV/T System Design Based on Simulation and its Application in Integrated Heating System

AbstractIn order to better master the internal airflow distribution characteristics of photovoltaic thermal (PV/T) collector on air source heat pump (ASHP) system heating performance, CFD software was applied in studying the building-integrated photovoltaic thermal (BIPV/T) sys-tem. A mathematical model of BIPV/T and ASHP integrated heating system was established. Numerical simulation of the system was conducted based on the typical meteorological data in Shenyang area. The influence of the inlet and outlet velocity, internal flow field distribution and temperature field distribution of the BIPV/T system were analyzed on the system thermal efficiency. The relationship between optimal COP and the inlet and outlet velocity of ASHP system was studied. The optimal inlet velocity of the BIPV/T – ASHP integrated system was determined to be 4 m/s, and the COP reached 4.6

High-Qf value and temperature stable Zn2+-Mn4+ cooperated modified cordierite-based microwave and millimeter-wave dielectric ceramics

Cordierite-based dielectric ceramics with a lower dielectric constant would have significant application potential as dielectric resonator and filter materials for future ultra-low-latency 5G/6G millimeter-wave and terahertz communication. In this article, the phase structure, microstructure and microwave dielectric properties of Mg2Al4–2x(Mn0.5Zn0.5)2xSi5O18 (0 ≤ x ≤ 0.3) ceramics are studied by crystal structure refinement, scanning electron microscope (SEM), the theory of complex chemical bonds and infrared reflectance spectrum. Meanwhile, complex double-ions coordinated substitution and two-phase complex methods were used to improve its Q×f value and adjust its temperature coefficient. The Q×f values of Mg2Al4–2x(Mn0.5Zn0.5)2xSi5O18 single-phase ceramics are increased from 45,000 [email protected] GHz (x = 0) to 150,500 [email protected] GHz (x = 0.15) by replacing Al3+ with Zn2+-Mn4+. The positive frequency temperature coefficient additive TiO2 is used to prepare the temperature stable Mg2Al3.7(Mn0.5Zn0.5)0.3Si5O18-ywt%TiO2 composite ceramic. The composite ceramic of Mg2Al3.7(Mn0.5Zn0.5)0.3Si5O18-ywt%TiO2 (8.7 wt% ≤ y ≤ 10.6 wt%) presents the near-zero frequency temperature coefficient at 1225 °C sintering temperature: εr = 5.68, Q×f = 58,040 GHz, τf = −3.1 ppm/°C (y = 8.7 wt%) and εr = 5.82, Q×f = 47,020 GHz, τf = +2.4 ppm/°C (y = 10.6 wt%). These findings demonstrate promising application prospects for 5 G and future microwave and millimeter-wave wireless communication technologies

Characteristics of Formaldehyde Pollution in Residential Buildings in a Severe Cold Area—A Case in Liaoning, China

The negative impact of indoor formaldehyde pollution has become a growing interest, especially in severe cold areas, since most residential buildings do not have enough ventilation and people are unwilling to open windows. In order to explore the status and the influencing factors of indoor formaldehyde pollution in severe cold areas and predict the formaldehyde concentrations in these areas, a study of 60 residential buildings in Liaoning, China, was carried out using the method of phenol reagent spectrophotometry. While testing the formaldehyde concentration, the infiltration air change rate of the room was also tested using CO2 as a tracer gas. The correlation between formaldehyde concentration and its influencing factors was analyzed by SPSS software. Multiple linear regression equations were established for the linear regression analysis. The measured data were used to assess the formaldehyde cancer risk of residents in Liaoning. The test results showed that the most serious rates of average formaldehyde pollution occurred in summer with a concentration of 0.097 mg/m3, and the bedroom was the room most seriously polluted by formaldehyde in autumn with a concentration of 0.104 mg/m3. According to the correlation analysis, the formaldehyde concentration was significantly correlated with the indoor temperature, years of decoration, and the infiltration ventilation rate. The linear regression equation for predicting the formaldehyde concentration was established. According to the risk assessment of the test results, residents in Liaoning are already at risk of cancer caused by formaldehyde

Robust Visual Ship Tracking with an Ensemble Framework via Multi-View Learning and Wavelet Filter

Maritime surveillance videos provide crucial on-spot kinematic traffic information (traffic volume, ship speeds, headings, etc.) for varied traffic participants (maritime regulation departments, ship crew, ship owners, etc.) which greatly benefits automated maritime situational awareness and maritime safety improvement. Conventional models heavily rely on visual ship features for the purpose of tracking ships from maritime image sequences which may contain arbitrary tracking oscillations. To address this issue, we propose an ensemble ship tracking framework with a multi-view learning algorithm and wavelet filter model. First, the proposed model samples ship candidates with a particle filter following the sequential importance sampling rule. Second, we propose a multi-view learning algorithm to obtain raw ship tracking results in two steps: extracting a group of distinct ship contour relevant features (i.e., Laplacian of Gaussian, local binary pattern, Gabor filter, histogram of oriented gradient, and canny descriptors) and learning high-level intrinsic ship features by jointly exploiting underlying relationships shared by each type of ship contour features. Third, with the help of the wavelet filter, we performed a data quality control procedure to identify abnormal oscillations in the ship positions which were further corrected to generate the final ship tracking results. We demonstrate the proposed ship tracker’s performance on typical maritime traffic scenarios through four maritime surveillance videos