Unbound

For many years, I have been repeatedly trying to understand what the term “trauma” means to me. While invisible, my trauma is ever-present, and I have not been able to understand how it has trapped me and my inner feelings. At the same time, more recently I don’t feel helpless or abandoned. I have been trying to tap the potential of connecting with the world outside, thereby piecing together the broken bits and pieces and reconciling with my family, past sorrows and myself. In my thesis collection, I pay homage to a garden I often visited as a child. The garden was a refuge, a place where I felt safe and free. My garments depict and interpret elements of that garden in a wide range of applications, from felted fringe to printed silk. They play with varied forms of camouflage, protection, and reclamation. These garments recall memories and hardships that I experienced growing up as well as places where I found extreme warmth and comfort that helped me get through it all. They are meant to be wearable and in being worn, offer solace to all who may be stuck in a dark world and hoping to find peace and freedom someday

Strain-based tunable optical microresonator with an in-fiber rectangular air bubble

We demonstrate a strain-based fully tunable, near-lossless, whispering gallery mode (WGM) resonator made of an in-fiber rectangular air bubble, which is fabricated by splicing two segments of standard single-mode fibers. Such a resonator, with a 39 μm order radius and 1 μm order wall thickness, contributes to a high quality factor exceeding 106. The tuning in resonant wavelength is achieved by applying tensile strain to the resonator, and the voltage-tuning rate of the WGM resonance peaks is about 31.96 pm/V (strain-tuning rate ∼14.12 pm∕με), and the corresponding tuning accuracy is better than 0.03 pm. Since the tensile strain applied on the resonator can reach 1000 με, the achievable total tunable bandwidth of ∼14.12 nm is more than two times that of its azimuthal free spectral range

Tunable and Switchable Dual-Wavelength Single-Longitudinal-Mode Erbium-Doped Fiber Lasers

Two types of erbium-doped fiber lasers based on Sagnac interferometer incorporated with fiber grating are proposed and experimentally demonstrated, which effectively support tunable and switchable dual-wavelength single-longitudinal-mode laser operation. The mode selection is implemented by use of the Sagnac interferometer with fiber grating, an umpumped erbium-doped fiber, and a tunable fiber Bragg grating. The Sagnac interferometer with fiber grating plays the role as a narrowband comb filter, while the unpumped erbium-doped fiber together with the tunable fiber Bragg grating essentially forms a passive self-tracking filter to ensure a stable single-longitudinal-mode fiber laser operation. By use of the Sagnac interferometer with chirped fiber Bragg grating, tunable microwave signals can be generated by beating the dual wavelengths, within the frequency range between ∼9.8 and ∼14 GHz.Department of Electrical Engineerin

Simulation of Friction Fault of Lightly Loaded Flywheel Bearing Cage and Its Fault Characteristics

Because of the operating environment and load, the main fault form of flywheel bearing is the friction fault between the cage and the rolling elements, which often lead to an increase in the friction torque of the bearing and even to the failure of the flywheel. However, due to the complex mechanism of the friction fault, the characteristic frequencies often used to indicate cage failure are not obvious, which makes it difficult to monitor and quantitatively judge such faults. Therefore, this paper studies the mechanism of the friction fault of the flywheel bearing cage and establishes its fault feature identification method. Firstly, the basic dynamic model of the bearing is established in this paper, and the friction between the cage and the rolling elements is simulated by the variable stiffness. The influence law of the bearing vibration response reveals the relationship between the periodic fluctuation of cage-rolling element friction failure and the bearing load. After analyzing the envelope spectrum of the vibration data, it was found that when a friction fault occurred between the cage and the rolling element, the rotation frequency component of the cage modulated the rotational frequency component of the rolling element, that is, the side frequency components appeared on both sides of the characteristic frequency of the rolling element (with the characteristic frequency of the cage as the interval). In addition, the modulation frequency components of the cage and rolling element changed with the severity of the fault. Then, a modulation sideband ratio method based on envelope spectrum was proposed to qualitatively diagnose the severity of the cage-rolling element friction faults. Finally, the effectiveness of the presented method was verified by experiments

A New Container Throughput Forecasting Paradigm under COVID-19

COVID-19 has imposed tremendously complex impacts on the container throughput of ports, which poses big challenges for traditional forecasting methods. This paper proposes a novel decomposition–ensemble forecasting method to forecast container throughput under the impact of major events. Combining this with change-point analysis and empirical mode decomposition (EMD), this paper uses the decomposition–ensemble methodology to build a throughput forecasting model. Firstly, EMD is used to decompose the sample data of port container throughput into multiple components. Secondly, fluctuation scale analysis is carried out to accurately capture the characteristics of the components. Subsequently, we tailor the forecasting model for every component based on the mode analysis. Finally, the forecasting results of all the components are combined into one aggregated output. To validate the proposed method, we apply it to a forecast of the container throughput of Shanghai port. The results show that the proposed forecasting model significantly outperforms its rivals, including EMD-SVR, SVR, and ARIMA

Bioaugmentation to enhance anaerobic digestion of food waste: Dosage, frequency and economic analysis

This study investigated whether bioaugmentation can improve the anaerobic digestion (AD) performance of food waste (FW), as well as the effects of addition dosage and frequency on the bioaugmentations performance and economic feasibility. The findings demonstrated that all the bioaugmented digesters, regardless of dosage and frequency, performed more effectively in biogas production than the non-bioaugmentation control. Furthermore, relatively higher dosages or frequencies increased AD performance. Introducing 0.25 g L-1 d(-1) of bioaugmentation seed every three days increased OLR and volumetric biogas production 8-fold and 12-fold, respectively, compared to the non-bioaugmentation control. Whole-genome sequencing analysis showed that bioaugmentation enhanced the population of the acetoclastic Methanothrix (belong to the order Methanosarcinales). Moreover, high abundance of Methanothrix (exceeding 80%) contributed to a better AD performance. Economic analysis of an up-scale biogas plant suggested that an appropriate bioaugmentation process increased income, thus increasing the profit to 3696 CNY d(-1) if treated at 21 t FW

Topological structures for microchannel heat sink applications – a review

The microchannel heat sink (MCHS) has the advantages of small heat transfer resistance, high heat transfer efficiency and small size, which exhibits good heat transfer performance in the field of active heat dissipation of electronic devices integrated with high heat flux density. In this paper, the application of MCHS in thermal management is reviewed in recent years, and the research progress of microchannel topology on enhancing heat transfer performance is summarized. Firstly, the research progress on the cross-sectional shape of the microchannel shows that the heat transfer area and fluid flow dead zone of the microchannel is the keys to affecting the heat transfer performance; Secondly, the microchannel distribution and the bionic microchannel structure have a great role in enhancing heat transfer performance, especially in microchannel temperature uniformity; Thirdly, the disturbing effect caused by interrupted structures in microchannels such as ribs and concave cavities has become a hot topic of research because it can weaken the thermal boundary layer and increase heat dissipation. Finally, the commonly used MCHS materials and cooling media are summarized and introduced. Based on the above reviews of MCHS research and applications, the future trends of MCHS topologies are presented

Experimental analysis of isothermal adsorption and desorption characteristics of gas in coal samples with multi grain sizes: A case study on No.3 coal in Sihe Coal Mine

In order to study influence of adsorption pressure and grain size of coal sample on coal gas desorption, the No.3 coal in Sihe Coal Mine was selected as samples, and variety characteristics of gas desorption amount and desorption speed of coal samples with 0.17-0.25, 0.25-0.50, 1-3 mm grain sizes were analyzed at 1, 1.5, 3 MPa adsorption pressure by use of a gas isothermal adsorption and desorption experiment system. The experimental results show that under different adsorption pressure conditions, the gas desorption amount of the coal samples and initial desorption speed increase with the increase of adsorption on the whole. However, the influence of adsorption pressure on gas desorption amount and desorption speed of coal samples with 0.25-0.50 mm grain size is smaller than the other two grain sizes. The initial gas desorption amount of coal samples with smaller grain sizes is more than the one of the coal sample with bigger grain size under different adsorption pressure conditions, and the initial desorption speed is faster. But the gas desorption amount of the coal sample with 1.0-3.0 mm grain size is more than the one of the others under 1.5, 3 MPa adsorption pressure condition. Therefore, increasing adsorption pressure of coal sample or reducing grain size would cause increase of gas desorption amount and desorption speed

Development and optimization of an immunoassay for the detection of Hg(II) in lake water

Abstract In this paper, an indirect competitive enzyme‐linked immunosorbent assay (IC‐ELISA) has been developed and optimized to detect Hg(II) in tap water and lake water based on a monoclonal antibody (mAb‐A24). Some stabilizing additives (Gelatin, bovine serum albumin [BSA], polyvinyl alcohol [PVA], and polyvinyl pyrrolidone [PVP]) and surfactant (Tween‐20) have been investigated thoroughly in the optimization process. Under the optimal condition, the 50% half maximal inhibitory concentration (IC50) and limit of detection (LOD) were 1.68 and 0.079 ng/ml, respectively. These anti‐Hg mAbs also have some affinity with methyl mercury (CH3Hg) and with no cross‐reactivity with other thirteen metal ions. The developed method has shown satisfactory recovery of Hg(II), ranged between 91% and 116%, from tap water and lake water. Therefore, this immunoassay can be used to detect trace Hg(II) in environment water