Rapeseed Oil Monoester of Ethylene Glycol Monomethyl Ether as a New Biodiesel

A novel biodiesel named rapeseed oil monoester of ethylene glycol monomethyl ether is developed. This fuel has one more ester group than the traditional biodiesel. The fuel was synthesized and structurally identified through FT-IR and P1PH NMR analyses. Engine test results show that when a tested diesel engine is fueled with this biodiesel in place of 0# diesel fuel, engine-out smoke emissions can be decreased by 25.0%–75.0%, CO emissions can be reduced by 50.0%, and unburned HC emissions are lessened significantly. However, NOx emissions generally do not change noticeably. In the area of combustion performance, both engine in-cylinder pressure and its changing rate with crankshaft angle are increased to some extent. Rapeseed oil monoester of ethylene glycol monomethyl ether has a much higher cetane number and shorter ignition delay, leading to autoignition 1.1°CA earlier than diesel fuel during engine operation. Because of certain amount of oxygen contained in the new biodiesel, the engine thermal efficiency is improved 13.5%–20.4% when fueled with the biodiesel compared with diesel fuel

Endometrial microbiota in women with and without adenomyosis: A pilot study

IntroductionThe endometrial microbiota plays an essential role in the health of the female reproductive system. However, the interactions between the microbes in the endometrium and their effects on adenomyosis remain obscure.Materials and methodsWe profile endometrial samples from 38 women with (n=21) or without (n=17) adenomyosis to characterize the composition of the microbial community and its potential function in adenomyosis using 5R 16S rRNA gene sequencing.ResultsThe microbiota profiles of patients with adenomyosis were different from the control group without adenomyosis. Furthermore, analysis identified Lactobacillus zeae, Burkholderia cepacia, Weissella confusa, Prevotella copri, and Citrobacter freundii as potential biomarkers for adenomyosis. In addition, Citrobacter freundii, Prevotella copri, and Burkholderia cepacia had the most significant diagnostic value for adenomyosis. PICRUSt results identified 30 differentially regulated pathways between the two groups of patients. In particular, we found that protein export, glycolysis/gluconeogenesis, alanine, aspartate, and glutamate metabolism were upregulated in adenomyosis. Our results clarify the relationship between the endometrial microbiota and adenomyosis.DiscussionThe endometrial microbiota of adenomyosis exhibits a unique structure and Citrobacter freundii, Prevotella copri, and Burkholderia cepacia were identified as potential pathogenic microorganisms associated with adenomyosis. Our findings suggest that changes in the endometrial microbiota of patients with adenomyosis are of potential value for determining the occurrence, progression, early of diagnosis, and treatment oadenomyosis

Genome-wide characterization and expression analysis of the aldehyde dehydrogenase (ALDH) gene superfamily under abiotic stresses in cotton

In plants, aldehyde dehydrogenases (ALDHs) function as ‘aldehyde scavengers’ by removing reactive aldehydes and thus play important roles in stress responses. To date, 30 ALDHs have been identified in Gossypium raimondii, whereas ALDHs have not been studied in Gossypium arboreum or in tetraploid cotton. In this study, we identified 30, 59 and 59 aldehyde dehydrogenase (ALDH) genes from G. arboreum, G. hirsutum and G. barbadense, re- spectively. Gene structure analysis revealed that members of the same family exhibit similar exon–intron structures and structural domains, and all members of the ALDH18 family possess a distinct AA-kinase domain. Synteny analysis showed that segmental and tandem duplications have played an important role in the ex- pansion and evolution of ALDHs in cotton. Phylogenetic and synteny analysis between G. arboreum and G. raimondii demonstrated that all GaALDHs and GrALDHs are orthologous and that most GaALDHs are located in syntenic blocks corresponding to those of G. raimondii, implying that these genes appeared before the divergence of G. arboreum and G. raimondii and that no expansion of the ALDH superfamily has occurred in these two cotton species. Quantitative real-time PCR analysis revealed that the majority of GaALDHs and GhALDHs are up- regulated under conditions of high salinity and drought, indicating that these genes may be stress responsive. The findings of this study, based on genome-wide identification of ALDHs in Gossypium and analysis of their evolution and expression, provide a foundation for further analysis of ALDHs and suggest potential target genes for improving stress resistance in cotton

Global Prescribed-Time Stabilization of High-Order Nonlinear Systems with Asymmetric Actuator Dead-Zone

This paper is concerned with the global prescribed-time stabilization problem for a class of uncertain high-order nonlinear systems (HONSs) with an asymmetric actuator dead-zone. Firstly, a new state-scaling transformation (SST) is developed for high-order nonlinear systems to change the original prescribed-time stabilization into the finite-time stabilization of the transformed one. The defects of the conventional one introduced in Song et al. (2017), which is unable to ensure the closed-loop stability behind a prespecified convergence time and a closed-loop system, which is only driven to the neighborhood of destination, is successfully overcome by introducing a switching mechanism in our proposed SST. Then, by using the adding a power integrator (API) technique, a state feedback controller is explicitly constructed to achieve the requirements of the closed-loop prescribed time convergence. Lastly, a liquid-level system is utilized to validate the theoretical results

Control Strategy and Corresponding Parameter Analysis of a Virtual Synchronous Generator Considering Frequency Stability of Wind Power Grid-Connected System

The doubly-fed induction generator (DFIG) based on the control strategy of constant parameter virtual synchronous generator (VSG) can cause problems of sharp frequency variations in the grid-connected system, long adjustment times, and large overshoot of the active power output from the DFIG. Aiming at dealing with the above-mentioned problems, a VSG control strategy with an independent flexible link (IFLVSG) is proposed in this paper without changing the parameters and structure of the VSG, so that the moment of inertia and damping coefficient can be flexibly adjusted according to the change of the system frequency, so as to improve the system frequency stability. To form a complete selection scheme for control parameters in IFL, the state space equation including IFLVSG control is established, and the advantages of exponential IFL are highlighted by using the sensitivity calculation method. At the same time, in order to improve the analysis efficiency, the main control parameters affecting the frequency stability of the system are selected according to the sensitivity value. Finally, the root locus analysis method is used to reveal the influence law of the main control parameters on the frequency stability of the system. The formed scheme provides a theoretical basis for the selection of control parameters

Joint Fusion and Detection via Deep Learning in UAV-Borne Multispectral Sensing of Scatterable Landmine

Compared with traditional mine detection methods, UAV-based measures are more suitable for the rapid detection of large areas of scatterable landmines, and a multispectral fusion strategy based on a deep learning model is proposed to facilitate mine detection. Using the UAV-borne multispectral cruise platform, we establish a multispectral dataset of scatterable mines, with mine-spreading areas of the ground vegetation considered. In order to achieve the robust detection of occluded landmines, first, we employ an active learning strategy to refine the labeling of the multispectral dataset. Then, we propose an image fusion architecture driven by detection, in which we use YOLOv5 for the detection part, to improve the detection performance instructively while enhancing the quality of the fused image. Specifically, a simple and lightweight fusion network is designed to sufficiently aggregate texture details and semantic information of the source images and obtain a higher fusion speed. Moreover, we leverage detection loss as well as a joint-training algorithm to allow the semantic information to dynamically flow back into the fusion network. Extensive qualitative and quantitative experiments demonstrate that the detection-driven fusion (DDF) that we propose can effectively increase the recall rate, especially for occluded landmines, and verify the feasibility of multispectral data through reasonable processing

Control Strategy and Corresponding Parameter Analysis of a Virtual Synchronous Generator Considering Frequency Stability of Wind Power Grid-Connected System

The doubly-fed induction generator (DFIG) based on the control strategy of constant parameter virtual synchronous generator (VSG) can cause problems of sharp frequency variations in the grid-connected system, long adjustment times, and large overshoot of the active power output from the DFIG. Aiming at dealing with the above-mentioned problems, a VSG control strategy with an independent flexible link (IFLVSG) is proposed in this paper without changing the parameters and structure of the VSG, so that the moment of inertia and damping coefficient can be flexibly adjusted according to the change of the system frequency, so as to improve the system frequency stability. To form a complete selection scheme for control parameters in IFL, the state space equation including IFLVSG control is established, and the advantages of exponential IFL are highlighted by using the sensitivity calculation method. At the same time, in order to improve the analysis efficiency, the main control parameters affecting the frequency stability of the system are selected according to the sensitivity value. Finally, the root locus analysis method is used to reveal the influence law of the main control parameters on the frequency stability of the system. The formed scheme provides a theoretical basis for the selection of control parameters

A Review of the Developed New Model Biodiesels and Their Effects on Engine Combustion and Emissions

Biodiesel is regarded to be a renewable, CO2 neutral and thus sustainable biological alternative diesel fuel. With attention to the reduction of petroleum import, PM 2.5 aerosol particles and the greenhouse effect gas CO2, biodiesel has drawn great research interests and efforts in the past decade in China. Generally, biodiesel refers to fatty acid methyl ether (FAME) which has a proved effect in reducing diesel emission, particularly PM. However, FAME has a limited cetane number and oxygen content, to study the effects of elevated cetane number and oxygen content on fuel properties, engine combustion and emissions, ethylene glycol monomethyl ether is used to produce a series of new models of biodiesels by transesterification method. The feedstocks are rapeseed oil, soybean oil, peanut oil, palm oil and cottonseed oil. Ether group alcohols used in this study include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether. The molecular structure was proved by FT-IR and NMR analyses. Fuel properties were measured based on the corresponding standards. The developed new model biodiesels have cetane number (CN) over 70 and oxygen content over 17% by mass, which are higher than FAME (50 CN and 11% oxygen). They have the same level of lower heating value as FAME, but have a higher density, which helps to compensate the decrease of engine power. Meanwhile, the engine tests were carried out to investigate the effects of ether ester group on engine combustion and emissions. The test results show that FAME reduced smoke 30% to 50%, while the new model biodiesel fuels reduced engine smoke as high as 80% and have the potential to decrease engine HC, CO and NOx emissions 50% or more