96 research outputs found
Elucidating thermochemical pretreatment effectiveness of different particle-size switchgrass for cellulosic ethanol production
Effects of switchgrass particle sizes (\u3c0.25 mm, 0.5–1.0 mm, and 2.0–4.0 mm) on the effectiveness of H2SO4 and NaOH pretreatments were investigated. As particle size increased, glucan, xylan, and lignin contents in raw switchgrass augmented from 30.32% to 32.02%, 18.44% to 19.03%, and 14.78% to 15.33%, respectively. Glucan and xylan (58.54–60.94% and 18.55–20.01%) contents in NaOH pretreated switchgrass and their recoveries (91.95–94.69% and 47.91–52.31%) increased. The highest glucan content (55.76%) and recovery (79.72%) in H2SO4 pretreated switchgrass were reached by middle particle size. The lowest (59.39% for H2SO4 and 58.99% for NaOH) and highest (65.23% for H2SO4 and 66.15% for NaOH) CrI values were obtained from middle and small particle sizes, respectively. SEM images and FTIR spectra showed no visible variations in microstructures and chemical bonds among different particle sizes under the same pretreatment conditions. On the basis of pretreated switchgrass, the highest ethanol concentration and efficiency were reached by big particle size for H2SO4 pretreated (7.03 g/L and 49.28%) switchgrass, while they were achieved by small particle size for NaOH pretreated (11.68 g/L and 72.37%) switchgrass. The highest ethanol yield based on raw switchgrass was attained by big particle size for untreated (29.54%), middle particle size for H2SO4 pretreated (30.60%), and small particle size for NaOH pretreated (62.36%) switchgrass. These findings indicate that the optimal ethanol conversion performance is the result of the interaction between the pretreatment method and biomass particle size
Zhang Taiyan\u27s Visim on East Asian Union
Normally, we know that Zhang Taiyan is the pioneer of anti-Man nation and an important founder of RPC; however, his idea on building an East-Asia Union has not been known. This article argues that Zhang initiates his theory on the East Asian Union after the Sino-Japanese War in 1894. Zhang actually completed this idea when he was in Taiwan; he escaped to there after the unsuccessful Hundred-Day Reform. In addition, Zhang\u27s idea on building the East Asia Union is showing in his 訄書, and that is different from related desires of Kang Youwei and Sun Yatsen. Therefore, Zhang is not a nationalist; his slogan of anti-Man nation was only a convenient method.文部科学省グローバルCOEプログラム 関西大学文化交渉学教育研究拠点東アジアの思想と構
Moisture content online detection system based on multi-sensor fusion and convolutional neural network
To monitor the moisture content of agricultural products in the drying process in real time, this study applied a model combining multi-sensor fusion and convolutional neural network (CNN) to moisture content online detection. This study built a multi-sensor data acquisition platform and established a CNN prediction model with the raw monitoring data of load sensor, air velocity sensor, temperature sensor, and the tray position as input and the weight of the material as output. The model’s predictive performance was compared with that of the linear partial least squares regression (PLSR) and nonlinear support vector machine (SVM) models. A moisture content online detection system was established based on this model. Results of the model performance comparison showed that the CNN prediction model had the optimal prediction effect, with the determination coefficient (R2) and root mean square error (RMSE) of 0.9989 and 6.9, respectively, which were significantly better than those of the other two models. Results of validation experiments showed that the detection system met the requirements of moisture content online detection in the drying process of agricultural products. The R2 and RMSE were 0.9901 and 1.47, respectively, indicating the good performance of the model combining multi-sensor fusion and CNN in moisture content online detection for agricultural products in the drying process. The moisture content online detection system established in this study is of great significance for researching new drying processes and realizing the intelligent development of drying equipment. It also provides a reference for online detection of other indexes in the drying process of agricultural products
Secondary frequency control of islanded microgrid considering wind and solar stochastics
As the high penetration of wind and photovoltaic distributed generation (DG)
in the microgrid, the stochastic and low inertia emerge, bringing more
challenges especially when the microgrid operates in isolated islands.
Nevertheless, the reserve power of DGs in deloading control mode can be
utilized for frequency regulation and mitigating frequency excursion. This
paper proposed a model predictive control (MPC) secondary frequency control
method considering wind and solar power generation stochastics. The extended
state-space matrix including unknown stochastic power disturbance is
established, and a Kalman filter is used to observe the unknown disturbance.
The maximum available power of wind and solar DGs is estimated for establishing
real-time variable constraints that prevent DGs output power from exceeding the
limits. Through setting proper weight coefficients, wind and photovoltaic DGs
are given priority to participate in secondary frequency control. The
distributed restorative power of each DG is obtained by solving the quadratic
programming(QP) optimal problem with variable constraints. Finally, a microgrid
simulation model including multiple PV and wind DGs is built and performed in
various scenarios compared to the traditional secondary frequency control
method. The simulation results validated that the proposed method can enhance
the frequency recovery speed and reDGce the frequency deviation, especially in
severe photovoltaic and wind fluctuations scenarios.Comment: Accepted by Acta energiae solaris sinica [In Chinese
Model predictive control strategy in waked wind farms for optimal fatigue loads
With the rapid growth of wind power penetration, wind farms (WFs) are
required to implement frequency regulation that active power control to track a
given power reference. Due to the wake interaction of the wind turbines (WTs),
there is more than one solution to distributing power reference among the
operating WTs, which can be exploited as an optimization problem for the second
goal, such as fatigue load alleviation. In this paper, a closed-loop model
predictive controller is developed that minimizes the wind farm tracking
errors, the dynamical fatigue load, and and the load equalization. The
controller is evaluated in a mediumfidelity model. A 64 WTs simulation case
study is used to demonstrate the control performance for different penalty
factor settings. The results indicated the WF can alleviate dynamical fatigue
load and have no significant impact on power tracking. However, the uneven load
distribution in the wind turbine system poses challenges for maintenance. By
adding a trade-off between the load equalization and dynamical fatigue load,
the load differences between WTs are significantly reduced, while the dynamical
fatigue load slightly increases when selecting a proper penalty factor.Comment: Accepted by Electric Power Systems Researc
NEW LATE JURASSIC PALEOMAGNETIC RESULTS FROM SHARILYN FORMATION, SOUTHERN MONGOLIA, AMURIA BLOCK, AND THEIR IMPLICATIONS FOR THE TECTONIC EVOLUTION OF THE MONGOL–OKHOTSK SUTURE
The Amuria block occupies the eastern part of the Central Asian Orogenic Belt between the Siberia craton and the North China block (NCB) and bears important information to understand the evolution of the MongolOkhotsk suture and the amalgamation of East Asia. However, the paleomagnetic database of Amuria remains very poor.The Amuria block occupies the eastern part of the Central Asian Orogenic Belt between the Siberia craton and the North China block (NCB) and bears important information to understand the evolution of the MongolOkhotsk suture and the amalgamation of East Asia
Effects of hypersplenism on the outcome of hepatectomy in hepatocellular carcinoma with hepatitis B virus related portal hypertension
BackgroundAlthough hepatectomy plus splenectomy is not regularly recommended for hepatocellular carcinoma (HCC) with portal hypertension related hypersplenism due to the high risk accompanied with surgical procedures for now. Many researchers still believe that hypersplenism is a controversial adverse prognostic factor for HCC patients. Thus, the primary objective of the study was to determine the effects of hypersplenism on the prognosis of these patients during and after hepatectomy.MethodsA total of 335 patients with HBV-related HCC who underwent surgical resection as primary intervention were included in this study and categorized into three groups. Group A consisted of 226 patients without hypersplenism, Group B included 77 patients with mild hypersplenism, and Group C contained 32 patients with severe hypersplenism. The influence of hypersplenism on the outcome during the perioperative and long-term follow-up periods was analyzed. The independent factors were identified using the Cox proportional hazards regression model.ResultsThe presence of hypersplenism is associated with longer hospital stays, more postoperative blood transfusions, and higher complication rates. The overall survival (OS, P = 0.020) and disease-free survival (DFS, P = 0.005) were significantly decreased in Group B compared to those in Group A. Additionally, the OS (P = 0.014) and DFS (P = 0.005) were reduced in Group C compared to those in Group B. Severe hypersplenism was a significant independent prognostic variable for both OS and DFS.ConclusionSevere hypersplenism prolonged the hospital stay, increased the rate of postoperative blood transfusion, and elevated the incidence of complications. Furthermore, hypersplenism predicted lower overall and disease-free survivals
Automated Grading of Radiographic Knee Osteoarthritis Severity Combined with Joint Space Narrowing
The assessment of knee osteoarthritis (KOA) severity on knee X-rays is a
central criteria for the use of total knee arthroplasty. However, this
assessment suffers from imprecise standards and a remarkably high inter-reader
variability. An algorithmic, automated assessment of KOA severity could improve
overall outcomes of knee replacement procedures by increasing the
appropriateness of its use. We propose a novel deep learning-based five-step
algorithm to automatically grade KOA from posterior-anterior (PA) views of
radiographs: (1) image preprocessing (2) localization of knees joints in the
image using the YOLO v3-Tiny model, (3) initial assessment of the severity of
osteoarthritis using a convolutional neural network-based classifier, (4)
segmentation of the joints and calculation of the joint space narrowing (JSN),
and (5), a combination of the JSN and the initial assessment to determine a
final Kellgren-Lawrence (KL) score. Furthermore, by displaying the segmentation
masks used to make the assessment, our algorithm demonstrates a higher degree
of transparency compared to typical "black box" deep learning classifiers. We
perform a comprehensive evaluation using two public datasets and one dataset
from our institution, and show that our algorithm reaches state-of-the art
performance. Moreover, we also collected ratings from multiple radiologists at
our institution and showed that our algorithm performs at the radiologist
level.
The software has been made publicly available at
https://github.com/MaciejMazurowski/osteoarthritis-classification
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