32 research outputs found
Multilevel optimization of economic dispatching in active distribution network based on ADMM
With the continuous improvement of the penetration rate of renewable energy and the continuous integration of advanced network control technology and measurement equipment, the traditional distribution network is developing into an active distribution network (ADN) with the characteristics of flexible scheduling control, high user interaction, and high energy utilization. This article fully considers the economy of the overall operation of the distribution network, and proposes a hierarchical optimization economic dispatch method for active distribution networks based on the alternating direction multiplier method (ADMM). Firstly, a hierarchical optimization scheduling model of active distribution network is established with the goal of minimizing the overall operating cost of the distribution network. The alternating direction multiplier method algorithm is decomposed into upper and lower layers to solve. The upper layer is optimized with the goal of minimizing the overall operating cost of the distribution network, and the lower layer considers the distribution network. The distributed photovoltaic and energy storage units connected to the internal nodes of the network are optimized with the goal of minimizing the local energy storage operation cost and power purchase cost. The upper and lower layers, through the exchange of limited boundary information, iterate each other until the convergence conditions are met, and the optimal solution is obtained. Finally, a design example is tested to verify the effectiveness and feasibility of the proposed scheduling method
The KLF4–p62 axis prevents vascular endothelial cell injury via the mTOR/S6K pathway and autophagy in diabetic kidney disease
Introduction: Diabetic kidney disease (DKD) is a complication of systemic diabetic microangiopathy, which has a high risk of developing into end-stage renal disease and death. This study explored the mechanism underlying autophagy in DKD vascular endothelial cell injury.
Material and methods: DKD and vascular endothelial cell injury models were established using Sprague Dawley rats and human umbilical vein endothelial cells (HUVECs). HUVECs overexpressing Kruppel-like factor 4 (KLF4) were constructed by transient transfection of plasmids. Biochemical determination of urinary protein and blood urea nitrogen (BUN), superoxide dismutase (SOD), and creatinine (Scr) levels was performed. Renal pathology was observed by periodic acid–Schiff (PAS) staining. Cell Counting Kit-8 (CCK8), terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL), and immunocytochemistry (ICC) were used to analyse the growth and apoptosis of HUVECs. Microtubule-associated protein light chain 3 (LC3) expression was observed by immunofluorescence (IF). The reactive oxygen species (ROS) levels were measured using flow cytometry. Monocyte chemoattractant protein-1 (MCP-1), KLF4, and tumour necrosis factor alpha (TNF-α) levels were detected using enzyme-linked immunosorbent assay (ELISA). The expression of KLF4, p62 protein, and LC3 was analysed using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). S6 kinase (S6K), p70 ribosomal S6 kinase (p-S6K), Beclin1, ATG5, LC3, p62, Caspase-3, mammalian target of rapamycine (mTOR), and phsophorylated mTOR (p-mTOR) expressions were detected by western blotting.
Results: PAS-positive substances (polysaccharide and glycogen) and S6K protein levels increased, and LC3 protein expression decreased in DKD rats. The levels of urinary protein, BUN, and Scr increased, and KLF4 decreased in DKD rats. High glucose (HG) levels decreased the proliferation and increased the apoptosis rate of HUVECs. The expression of ROS, TNF-α, MCP-1, and p62 increased, while the expression of SOD, KLF4, Beclin1, ATG5, and LC3 decreased in HG-induced HUVECs. KLF4 overexpression significantly increased Beclin1, ATG5, and LC3 protein expression and decreased p62 protein expression compared to the oe-NC group in HG-induced HUVECs. KLF4 overexpression inhibits the expression of Caspase-3, p-mTOR, and p-S6K in HG-induced HUVECs.
Conclusions: KLF4–p62 axis improved vascular endothelial cell injury by regulating inflammation and the mTOR/S6K pathway in DKD
Yanghe Decoction Suppresses the Experimental Autoimmune Thyroiditis in Rats by Improving NLRP3 Inflammasome and Immune Dysregulation
Inflammation is an important contributor to autoimmune thyroiditis. Yanghe decoction (YH) is a traditional Chinese herbal formulation which has various anti-inflammatory effects. It has been used for the treatment of autoimmune diseases such as ankylosing spondylitis In this study we aimed to investigate the effects of YH on autoimmune thyroiditis in a rat model and elucidate the underlying mechanisms. The experimental autoimmune thyroiditis (EAT) model was established by thyroglobulin (pTG) injections and excessive iodine intake. Thyroid lesions were observed using hematoxylin and eosin (H and E) staining and serum TgAb, TPOAb, TSH, T3, and T4 levels were measured by enzyme-linked immunosorbent assay IL-35 levels were evaluated using real-time polymerase chain reaction (RT-PCR) and Th17/Treg balance in peripheral blood mononuclear cells (PBMCs) was determined by flow cytometry and RT-PCR. Changes in Wnt/β-catenin signaling were evaluated using Western blot. Immunofluorescence staining and western blot were employed to examine NLRP3 inflammasome activation in the thyroid. YH minimized thyroid follicle injury and decreased concentrations of serum TgAb, TPOAb, TSH, T3, and T4 in EAT model. The mRNA of IL-35 was increased after YH treatment. YH also increased the percentage of Treg cells, and decreased Th17 proportion as well as Th17/Treg ratio in PBMCs. Meanwhile, the mRNA levels of Th17 related cytokines (RORγt, IL-17A, IL-21, and IL-22) were suppressed and Treg related cytokines (FoxP3, TGF-β, and IL-10) were promoted in PBMCs. Additionally, the protein expressions of Wnt-1 and β-catenin were unregulated after YH treatment. NLRP3 immunostaining signal and protein levels of IL-17, p-NF-κB, NLRP3, ASC, cleaved-Caspase-1, cleaved-IL-1β, and IL-18 were downregulated in the thyroid after YH intervention. Overall, the present study demonstrated that YH alleviated autoimmune thyroiditis in rats by improving NLRP3 inflammasome and immune dysregulation
Optimization of 4-( N -Cycloamino)phenylquinazolines as a Novel Class of Tubulin-Polymerization Inhibitors Targeting the Colchicine Site
The 6-methoxy-1,2,3,4-tetrahydroquinoline moiety in prior leads 2-chloro- and 2-methyl-4-(6-methoxy-3,4-dihydroquinolin-1(2H)-yl)quinazoline (1a and 1b) was modified to produce 4-(N-cycloamino)quinazolines (4a–c and 5a–m). The new compounds were evaluated in cytotoxicity and tubulin inhibition assays, resulting in the discovery of new tubulin-polymerization inhibitors. 7-Methoxy-4-(2-methylquinazolin-4-yl)-3,4-dihydroquinoxalin- 2(1H)-one (5f), the most potent compound, exhibited high in vitro cytotoxic activity (GI50 1.9–3.2 nM), significant potency against tubulin assembly (IC50 0.77 μM), and substantial inhibition of colchicine binding (99% at 5 μM). In mechanism studies, 5f caused cell arrest in G2/M phase, disrupted microtubule formation, and competed mostly at the colchicine site on tubulin. Compound 5f and N-methylated analogue 5g were evaluated in nude mouse MCF7 xenograft models to validate their antitumor activity. Compound 5g displayed significant in vivo activity (tumor inhibitory rate 51%) at a dose of 4 mg/kg without obvious toxicity, whereas 5f unexpectedly resulted in toxicity and death at the same dose
Battery management and energy control in hybird grid I
This project is to fabricate building blocks used to connect the DC grid and battery to control the energy flow.Bachelor of Engineerin
Coordination control of hybrid AC/DC building microgrid
Advantages such as environmental friendliness and flexibility have made microgrid an attractive option for in modern power systems. Microgrid is a localized grouping of distributed generators, storages and loads. Microgrid integrates with sustainable energy sources could reduce carbon emission. A microgrid can serve specific purposes, such as to enhance reliability, diversification of energy sources, and cost reduction. Therefore, microgrid has been introduced into building distributed networks as it makes both power generation and consumption more efficient. In order to obtain better power conversion and utilization efficiency, the configuration, control strategy, and energy management of building microgrid need to be further studied. This thesis introduces the overall configuration of building microgrid and the specific subsystem controllers in a building microgrid.
Microgrid configuration, operation and control have been investigated for many years. Various microgrid configurations for building distributed networks have been proposed with each claiming some aspects of improvements. To achieve better energy efficiency, a novel hybrid building microgrid is introduced in this thesis. A building photovoltaic system (BPVS), a building motor drive system (BMDS) and a hybrid building energy storage system (HBES) are introduced respectively based on the common features among PV systems, motor driving circuits and various energy storages. The objective of the building hybrid microgrid (BHMG) is to improve building’s energy efficiency through reducing multiple reverse conversion loss in conventional building distributed networks (CBDN), to achieve more efficient connection of subsystems, and to reduce building energy consumption and peak power demand through power generation from BPVS and power regeneration in BMDS.
In building microgrid, motor drives are essential devices and widely used in lifts, air-conditioning and water pumping systems. In a high rise commercial building, lift motors not only consume energy but also regenerate energy. A building’s lift system is proposed to classify and integrate all lifts together to improve the efficiency in the building’s energy utilization. A novel distributed lift control approach based on fuzzy logic and DTC is proposed in this chapter to integrate lift operating system optimization and motor control. The objective of the novel control system is to choose the lift which makes the waiting & riding time shorter and consumes less power, and it can even regenerate power and channel back into energy storage. The motor controller with self-tuning has a smaller ripple and shorter response and recovery time. By using this controller, the power efficiency in high rise multi story building can be improved.
Another essential component in building microgrid is energy storage. Different types of energy storages with high power density and high energy density have to operate under different modes like voltage regulation and power exchange. An adaptive area droop control approach has been proposed to demonstrate an autonomous mode change and a stable operating performance for energy storage converters. The coordination control is introduced to reduce the battery charging/discharging times of miner cycle and discharge depth.
Plug-in hybrid electric vehicle (PHEV) is gaining popularity in today's automotive market and more charge stations for PHEV are installed in commercial buildings. The conventional charge circuit can only produce an output DC voltage that is higher than the peak AC input voltage. An efficient single-phase PFC converter that features sinusoidal input current, three-level output characteristic and flexible output DC voltage is introduced to cater for variable voltage levels of the battery pack (50V-600V). The charging efficiency is improved since it is partially contributed by the reduced switching voltage in the PFC stage, and also partially by the reduced power conversion in the DC/DC buck stage.
All design configurations and control algorithms have been thoroughly verified in MATLAB/Simulink and PLECS. Suitable experimental prototypes have been built in the laboratory for validating the practicalities of all theoretical findings.Doctor of Philosophy (IGS
Bi-directional energy flow grid-tied inverter
A hybrid DC-AC smart grid system has been designed and setup in the Water and Energy
Research Laboratory (WERL). The hybrid DC-AC grid system consists of an AC grid
and a DC grid and operates in both grid-tied and autonomous mode. In this hybrid grid,
various renewal energy sources are connected to the de grid while the ac grid is
connected to the public grid. The bi-directional grid-tied inverter bridges the gap in the
hybrid system where it is used to convert power from dc to ac as well as from ac to dc
depending on the power supply and demand profile.
Based on different requirements of system, some strategies should be considered in the
controller. At normal operating condition, the global power sharing strategy is needed to
transfer the power and also this strategy could make the transfer more stable. If there is
something wrong in DC grid or the battery is fully charged or discharged, which makes
the DC bus voltage unstable, DC bus voltage regular strategy is needed to maintain the
DC bus voltage. If the load power requirement is larger than the power that DC and AC
source could supply, it should shed the non-priority load and supply the priority load first.
So load shedding strategy is needed. Choosing control strategies for the algorithm should
be designed by detecting the system operating conditions and selecting the correct
strategy, hence, the objective is to design the controller which could meet this
requirement.Master of Science (Power Engineering
Safety management of specialized equipments in medical academic institutes
As a common type of equipment used in laboratories of universities and research institutes, especially medical academic institutes, special equipment can lead to safety accidents if used and managed improperly. To address the problems in the institutional framework, personnel management, equipment maintenance, and management methods of special equipment in laboratories, this article proposes a targeted solution based on practical management experience and literature research. This solution not only standardizes the safety management system of special equipment, enhances the efficiency of management departments, but also promotes safety awareness among users, providing a new insight for the safety management of special equipment in academic institutes and effectively preventing safety accidents