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Purpose As most thyroid cancer patients survive for more than ten years, it has become increasingly important to understand whether the different surgery types have any effect on the quality of life (QoL) of patients. Patients and Methods Using observational data from head and neck surgery at the Sichuan Cancer Hospital in China, three scoring methods – sum scoring, domain-based scoring and IRT-based scoring, were employed to measure the QoL in differentiated thyroid cancer (DTC) patients and a propensity score matched analysis performed to explore the impact of surgery type on QoL as measured by the Treatment of Cancer Quality of Life core Questionnaire version 3.0 (EORTC QLQ-C30) and a disease-specific health-related quality of life questionnaire (THYCA-QoL). Results No statistically significant patient QoL differences were found between the two surgery types regardless of which questionnaire was used and which scoring method was used (\documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $${\rm{ATE}} = - 0.400$$ \end{document}, \documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $$p = 0.834$$ \end{document} using the EORTC QLQ-C30 and the sum scoring; \documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $${\rm{ATE}} = - 0.4491$$ \end{document}, \documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $$p = 0.807$$ \end{document} using the EORTC QLQ-C30 and the domain-based scoring; and \documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $${\rm{ATE}} = - 0.442$$ \end{document}, \documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $$p = 0.114$$ \end{document} using the EORTC QLQ-C30 and the IRT-based scoring; \documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $${\rm{ATE}} = - 0.827$$ \end{document}, \documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $$p = 0.586$$ \end{document} using the THYCA-QoL and the sum scoring; \documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $${\rm{ATE}} = - 1.692$$ \end{document}, \documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $$p = 0.406$$ \end{document} using the THYCA-QoL and the domain-based scoring; and \documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $${\rm{ATE}} = - 0.032$$ \end{document}, \documentclass[12pt]{minimal} \usepackage{wasysym} \usepackage[substack]{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage[mathscr]{eucal} \usepackage{mathrsfs} \DeclareFontFamily{T1}{linotext}{} \DeclareFontShape{T1}{linotext}{m}{n} {linotext }{} \DeclareSymbolFont{linotext}{T1}{linotext}{m}{n} \DeclareSymbolFontAlphabet{\mathLINOTEXT}{linotext} \begin{document} $$p = 0.908$$ \end{document} using the THYCA-QoL and the IRT-based scoring). Conclusion This study confirmed that the surgery type (hemithyroidectomy or total thyroidectomy) for DTC patients did not appear to influence their general QoL.

The 100-m X-ray Test Facility of the Institute of High Energy Physics (IHEP) was initially proposed in 2012 for the test and calibration of the X-ray detectors of the Hard X-ray Modulation Telescope (HXMT) with the capability to support future X-ray missions. The large instrument chamber connected with a long vacuum tube can accommodate the X-ray mirror, focal plane detector and other instruments. The X-ray sources are installed at the other end of the vacuum tube with a distance of 105 m, which can provide an almost parallel X-ray beam covering 0.2∼60 keV energy band. The X-ray mirror modules of the Einstein Probe (EP) and the enhanced X-ray Timing and Polarimetry mission (eXTP) and pay-load of the Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) have been tested and calibrated with this facility. It has been also used to characterize the focal plane camera and aluminum filter used on the Einstein Probe. In this paper, we will introduce the overall configuration and capability of the facility, and give a brief introduction of some calibration results performed with this facility.

The 100-m X-ray Test Facility of the Institute of High Energy Physics (IHEP) was initially proposed in 2012 for the test and calibration of the X-ray detectors of the Hard X-ray Modulation Telescope (HXMT) with the capability to support future X-ray missions. The large instrument chamber connected with a long vacuum tube can accommodate the X-ray mirror, focal plane detector and other instruments. The X-ray sources are installed at the other end of the vacuum tube with a distance of 105 m, which can provide an almost parallel X-ray beam covering 0.2$$\sim$$ ∼ 60 keV energy band. The X-ray mirror modules of the Einstein Probe (EP) and the enhanced X-ray Timing and Polarimetry mission (eXTP) and payload of the Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) have been tested and calibrated with this facility. It has been also used to characterize the focal plane camera and aluminum filter used on the Einstein Probe. In this paper, we will introduce the overall configuration and capability of the facility, and give a brief introduction of some calibration results performed with this facility.

The Follow-up X-ray Telescope (FXT), a key payload onboard the Einstein Probe sallite (EP), is equipped with a Wolter-I x-ray focusing mirror system. We introduce the principle of such a mirror system and analyze the influence of the mirror gap in the multishell nested mirror of the FXT on the effective area, stray-light ratio, and vignetting. To ensure that no occlusion occurs within adjacent shells and minimize stray-light ratio, the size of the gap is set to a optimized value for corresponding shell. We finished a design of a 54-shell mirror system according to these results. The optical performance of the design was then simulated using a Monte Carlo algorithm and the ray-tracing principle. The simulation shows that the effective area is 414.5 ± 0.2 cm2 at 1.25 keV (considering the spider), and the field of view is 64 arcmin in diameter. These parameters meet the optical requirements of the FXT.

Spectroscopy focusing array (SFA) and Polarimetry focusing array (PFA) are the two major payloads of enhanced X-ray Timing and Polarimetry mission (eXTP). Nested Wolter-\RNum{1} X-ray mirror module is implemented in SFA and PFA to achive high effective area. When evaluating the properties of the mirror module, the alignment of the optical axis of the X-ray mirror module and a quasi-parallel X-ray beam is a prerequisite to ensure the accuracy of the results. Hence, to assist the alignment of the X-ray mirror module, an X-ray focal plane detector is designed based on the back-illuminated scientific Complementary Metal-Oxide-Semiconductor Transistor (sCMOS) sensor GSENSE6060BSI, one of the largest detection areas, is produced by \textit{Gpixel Inc}. Then the characteristics of readout noise, dark current, and split-pixel event properties of the detector are studied with the self-developed multi-target fluorescence X-ray source in a 100 m long X-ray test facility. The energy calibration is carried out with the single-pixel event and the energy non-linearity of the detector is also obtained. Eventually, the simulation of the eXTP mirror module based on the optical model is conducted and the alignment test of the Wolter-\RNum{1} X-ray mirror module designed for \textit{EP/FXT} (Einstein Probe/Follow-up X-ray Telescope) with "Burkert test" method is shown., Comment: 27 pages, 16 pages, submitted to NIM-A

The main scientific goal of the Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) is to monitor various types of Gamma-Ray Bursts (GRB) originated from merger of binary compact stars, which could also produce gravitational wave, and collapse of massive stars. In order to study the response of GECAM Gamma-Ray Detectors (GRDs) to high-energy bursts and test the in-flight trigger and localization software of GECAM before the launch, a portable GRB simulator device is designed and implemented based on grid controlled X-ray tube (GCXT) and direct digital synthesis (DDS) technologies. The design of this GRB simulator which modulates X-ray flux powered by high voltage up to 20 kV is demonstrated, and the time jitter (FWHM) of the device is about 0.9 $\mu$s. Before the launch in December, 2020, both two GECAM satellites were irradiated by different types of GRBs (including short and long bursts in duration) generated by this GRB simulator. The light curves detected with GECAM/GRDs are consistent with the programmed input functions within statistical uncertainties, indicating the good performance of both the GRDs and the GRB simulator., Comment: 15 pages, 12 figures, accepted to be published in Experimental Astronomy on 09 July 2021

The Einstein Probe (EP) is an X-ray astronomical mission mainly devoting to time-domain astronomy. There are two main scientific payloads onboard EP, the Wide Field X-ray Telescope (WXT) based on the lobster eye optics and the Follow-up X-ray Telescope (FXT). FXT contains two Wolter-1 mirrors with a pnCCD detector on each focus. The total effective area is about 600 cm2 and the energy range is 0.3-10 keV. The pnCCD detector cooled by a pulse tube cooler enables high-resolution spectroscopy and imaging combined with excellent time resolution. It will also have several working modes with time resolution ranging from tens of microseconds to 50 milliseconds. Currently, the FXT is in its qualification model phase. The mirror assemblies (STM and TCM) as well as the pnCCD EM module have been manufactured and tested.

Background Lung cancer has the highest morbidity and mortality of cancers worldwide. Lung adenocarcinoma (LUAD) is the most common pathological subtype of lung cancer and surgery is its most common treatment. The dysregulated expression of DNA repair genes is found in a variety of cancers and has been shown to affect the origin and progression of these diseases. However, the function of DNA repair genes in surgically-treated LUAD is unclear. Methods We sought to determine the association between the signature of DNA repair genes for patients with surgical LUAD and their overall prognosis. We obtained gene expression data and corresponding clinical information of LUAD from The Cancer Genome Atlas (TCGA) database. The differently expressed DNA repair genes of surgically-treated LUAD and normal tissues were identified using the Wilcoxon rank-sum test. We used uni- and multivariate Cox regression analyses to shrink the aberrantly expressed genes, which were then used to construct the prognostic signature and the risk score formula associated with the independent prognosis of surgically-treated LUAD. We used Kaplan–Meier and Cox hazard ratio analyses to confirm the diagnostic and prognostic roles. Two validation sets (GSE31210 and GSE37745) were downloaded from the Gene Expression Omnibus (GEO) and were used to externally verify the prognostic value of the signature. OSluca online database verifies the hazard ratio for the DNA repair genes by which the signature was constructed. We investigated the correlation between the signature of the DNA repair genes and the clinical parameters. The potential molecular mechanisms and pathways of the prognostic signature were explored using Gene Set Enrichment Analysis (GSEA). Results We determined the prognostic signature based on six DNA repair genes (PLK1, FOXM1, PTTG1, CCNO, HIST3H2A, and BLM) and calculated the risk score based on this formula. Patients with surgically-treated LUAD were divided into high-risk and low-risk groups according to the median risk score. The high-risk group showed poorer overall survival than the low-risk group; the signature was used as an independent prognostic indicator and had a greater prognostic value in surgically-treated LUAD. The prognostic value was replicated in GSE31210 and GSE37745. OSluca online database analysis shows that six DNA repair genes were associated with poor prognosis in most lung cancer datasets. The prognostic signature risk score correlated with the pathological stage and smoking status in surgically-treated LUAD. The GSEA of the risk signature in high-risk patients showed pathways associated with the cell cycle, oocyte meiosis, mismatch repair, homologous recombination, and nucleotide excision repair. Conclusions A six-DNA repair gene signature was determined using TCGA data mining and GEO data verification. The gene signature may serve as a novel prognostic biomarker and therapeutic target for surgically-treated LUAD.

In order to meet the requirement of spintronic and optoelectronic, we have systematically investigated the effect of Mn doping and co-doping of Mn with C on the electronic, magnetic and optical properties of wurtzite zinc sulfide (ZnS) using first principle calculations. Our results find that single Mn doping alters the non-magnetic ZnS to a magnetic one and keeps its semiconducting and a semiconductor to half-metal transition is observed for Mn-C co-doping. Furthermore, an antiferromagnetic (AFM) and ferromagnetic (FM) ground states are favorable for Mn-doped and Mn-C co-doped system, respectively. Additionally, the optical properties of our studied configuration have been calculated in terms of real and imaginary parts of the complex dielectric function, absorption coefficient, and reflectivity. The absorption edge shifts slightly toward lower energy and intensity of the main peak become weak for single Mn doping, and a sharp peak at low energy is observed for the Mn-C co-doping. The analysis of optical absorption of Mn ions doped system shows the blue- and red-shifts of the d-d transition in the AFM and FM coupled of Mn ions doped configuration, respectively which is in good agreement with the experimental observations. The improved magnetic and optical properties of Mn-C co-doped ZnS shed light on the future application of such kind of materials in spintronic and optoelectronic devices such as remote sensing and photovoltaics.

The magnetic excitons in diluted magnetic semiconductor (DMS) have varied formats due to the inhomogeneous phases out of doping concentration and/or structural relaxations or defects. Here the high quality cobalt-doped zinc blende ZnSe nanoribbons (NRs) were synthesized, showing bright and color-variable emissions from blue, yellow to a little mixed white colors. Their power and temperature dependent micro-photoluminescence (PL) spectra have been obtained in which two emission bands, one magnetic exciton band near the band-edge and a Co2+ high-level d–d transition emission band at 550 nm out of their ferromagnetic (FM) coupled aggregates in ZnSe lattice, both bands could also be reflected by a nonlinear optical absorption enhancement. The easy formed stacking fault defects in a chemical vapor deposition (CVD) grown ZnSe zincblende NR took part in the above optical processes out of magnetic polaronic excitons (PXs). The femtosecond (fs) laser pulse pumping on single ZnSe:Co NR produces obvious lasing behavior but with profile of a complicated magnetic exciton interactions with indication of a crossover from collective exciton magnetic polarons (EMP) to bound magnetic polaron (BMP) scattering in Co doped ZnSe NR. These findings indicate the complication of the magnetic coupling natures in varied DMS structures, whose optical properties have been found to be highly nonlinear, due to the involvement of the spin–spin, spin–exciton and spin–phonon interactions, verified by the theoretic calculation in Yang X-T et al (2019 Interstitial Zn-modulated ferromagnetism in Co-doped ZnSe Mater. Res. Express 6 106121).

e21013 Background: Immunoglobulin G (IgG) is produced by B lymphocytes which is an important effector molecule of human immunity. However,our collaborators in China Peking University have found that malignant tumor cells can also express IgG (cancer-IgG). This study was designed to investigate the relationship between cancer-IgG and radiosensitivity and to explore its possible mechanisms in NSCLC. Methods: First, the expression of IGHG1 (immunoglobulin heavy constant gamma 1, IGHG1) and cancer-IgG in NSCLC and their relationship with clinicopathological features and prognosis were analyzed by TCGA(The Cancer Genome Atlas, TCGA), GEO(Gene Expression Omnibus, GEO) databases and immunohistochemistry. Secondly, after silencing the expression of cancer-IgG, cell scratch test, transwell, clone formation and apoptosis experiments were performed to observe the changes of EMT and radiation sensitivity of tumor cells after irradiation. Finally, the key proteins of PI3K/Akt signaling pathway and EMT-related proteins were detected by western blot and real-time PCR. Results: 1. The expression levels of IGHG1 and cancer-IgG in NSCLC were significantly higher than those in normal lung tissues, and high expression of IGHG1 and cancer-IgG were factors of poor prognosis. And cancer-IgG was closely related to clinical stage (P = 0.042), T stage (P = 0.044) and metastasis (P = 0.007). 2. Cell scratches and transwell experiments showed that the cell migration and invasion ability of si-control+IR group were significantly enhanced, but in si-Cancer-IgG+IR group were significantly lower than si-control+IR group. 3. Cloning formation experiments showed that the number of cell clones formed in the si-cancer-IgG group was significantly less than that in the control group under 2-6 Gy irradiation. Apoptosis results showed that the apoptosis rates of si-control group, si-Cancer-IgG group, si-control+IR group and si-Cancer-IgG group were 6.36±1.69%, 21.33±1.21%, 23.31±0.96% and 52.69±2.33% respectively. The apoptotic cells in the Si-cancer-IgG group were significantly more than the si-control group. (P < 0.01). 4. Western blot results showed that p-AKT, p-GSK3β, bcl2 and Vimentin were significantly decreased in si-Cancer-IgG+IR group compared with si-control+IR, and the expression levels of BAD and E-cadherin were increased. Conclusions: Cancer-IgG may mediate radiation-induced EMT and radiotherapy resistance through the PI3K/AKT pathway.

The objective of this paper is to investigate the effect of free tissue flap colorimetric card in the postoperative flap management for tumors of oral and maxilla-facial region. Through observing 42 patients who used free tissue flap colorimetric card after operation, it was found that twelve patients had vascular disease, three had insufficient arterial infusion, and nine had venous return obstruction. Among them, one patient who had insufficient arterial infusion and two had venous return obstruction received re-anastomosis of vascular surgery and hemostasis surgery, and then all patients recovered well. The paper conclude that the free tissue flap colorimetric card is a simple, timely, accurate and effective tool for the observation of flaps, and it is suitable for clinical application.

The effect of vacancy defects on optoelectronic and magnetic properties of Mn-doped ZnS have been systematically investigated using first principle approaches. A single Mn substitution at Zn site induces a spin-polarized ground state in pure ZnS with total magnetization 5 [Formula: see text]. Our results for magnetic coupling show that the coupling between Mn spins in pure Mn doped ZnS is antiferromagnetic under the super-exchange mechanism. The existence of native defects has a great influence on the magnetic ground state of Mn-doped ZnS. In particular, a p -type defect such as Zn vacancy play a crucial role in stabilizing ferromagnetic ground state while n-type defect, such as S vacancy, has no effect on the magnetic ground state i.e. the interaction between two Mn spins with S-vacancy remain antiferromagnetic. Furthermore, optical properties such as dielectric functions, absorption coeffiecients, reflectivity and transmissitivity for Mn doped systems with and without vacancy defect were also studied, and we found that an absorption peak was obtained in the infrared region which is attributed to the defect states introduced by Zn vacancy in the system. In a S-vacancy defect system, the peaks in the near infrared and visible region are due to donor states introduced by S vacancy defect and these peaks are produced by electrons flipping from a spin up state to a spin down state. Finally, we also correlated the magnetic interactions with the d-d optical transition in pure Mn-doped ZnS and found that the d-d transitions during optical absorptions are red shifted and blue shifted in FM and AFM coupled Mn ions pair, which is in good agreement with the experimental observations. This study may help to understand the behavior of optical and magnetic properties of DMS under vacancy defects.

Using first-principles method, we studied systematically the structural and electronic properties of ZB/WZ superlattices of ZnSe. The band offsets are calculated by Heyd–Scuseria–Ernzerhof (HSE) hybrid functional which can give a good prediction on the relative band positions. The band alignment at ZB/WZ interface is found to be type-II with holes localized in wurtzite region and electrons in zinc-blende region, which is suitable for optoelectronic and solar energy conversion. The origin of type-II character and the carrier localization are investigated in detail.

The integrated cold box and demethanizer system as one of the most critical production sections in an ethylene plant couples multistage refrigeration and cryogenic separation to extract hydrogen and methane from the cracked gas feed. Ethylene and the heavier components are liquefied for recovery in the downstream process. During separation, ethylene contained in the methane and hydrogen streams is accounted as the product loss which in reality is significant. To reduce the ethylene loss with energy consumption consideration, a systematic methodology has been developed to optimize the process operation of the integrated cold box and demethanizer system. It covers rigorous simulation model development and validation, sensitivity analysis, operational optimization, and result analysis. The optimization results demonstrate the significant economic benefits of the proposed methodology.

Crude oil blending is a very common practice in petroleum refineries, where the main focus is to minimize the total purchase cost of crude oils under specified blending oil properties. Crude oil blending actually has significant impacts on energy consumption from heating furnaces during crude oil processing. Conceivably, furnace energy consumption from burning fuels such as natural gas, fuel oil, or propane causes huge amounts of CO2 emissions. In this paper, a methodology framework for crude oil blending and processing with simultaneous consideration of energy, emission, and economic profit (E3) is developed. It includes four stages of work: steady-state modeling, heating energy consumption calculation, emission model development, and economic evaluation. With Aspen HYSYS simulation, the developed methodology provides a quantitative support for refinery to identify an optimal E3 operating strategy. A case study is implemented to demonstrate the efficacy of this methodology.

Epoxy resin nanocomposites reinforced with three different ionic liquid functionalized carbon nanotubes (f-CNTs) were fabricated by an in situpolymerization method. The influence of the anions on the curing process was studied through differential scanning calorimetry (DSC) and normalized Fourier transform infrared (FTIR) spectroscopy. The composition of the nanocomposites was analyzed by X-ray photoelectron spectroscopy. Two different mechanisms are proposed to explain the curing process of the neat epoxy and its composites. The electric conductivity and mechanical properties of the nanocomposites are also reported. The tensile strength was increased dramatically due to the insertion of f-CNTs. Scanning electron microsopy fracture surface analysis indicates a strong interfacial bonding between the carbon nanotubes and the polymer matrix.

Ethylene plant upsets usually lead to flaring of off-spec products, resulting in significant losses of raw material and energy as well as to air emission problems. Under the premise of plant safe operation, establishing process recycles connecting off-spec streams to their upper-stream process can help to reduce flaring during plant upsets. Operational strategies for recycling the potential flaring sources, i.e., effluents from the acetylene reactor and ethylene tower overhead, under various process upsets are developed and analyzed based on rigorous plant-wide dynamic simulations. Safety considerations on the compressor system performance have been addressed by quantitative comparison of the effectiveness of various recycling strategies. Case studies demonstrate that the safety-considered flare minimization strategies can proactively reduce the flaring emission amount and upset time and thus have great potentials of economical and environmental benefits to ethylene plants.

Flaring is an important but passive method in ethylene plants to protect plant personnel, facilities, and the ambient environment. However, excessive flaring emits huge amounts of CO, CO 2 , NO x , and hazardous volatile organic compounds (VOCs), which may cause locally transient air pollution problems and negative societal impacts. Flaring may also cause high losses of raw material and energy that could generate more desired products for the industry. Thus, flare minimization has great benefits to environmental, societal, and industrial sustainability. Based on current industrial practices, a general strategy for flare minimization under various ethylene plant events is presented.

Ethylene oxide (EO) is an important chemical intermediate for the production of various chemical products. The manufacturing of EO involves critical exothermic reactions at high temperature and high pressure, whose failure may cause catastrophic personal injury, severe air pollution, and tremendous economic loss. Thus, an EO plant must be well controlled under various situations, especially during its start-up operations. In this paper, a general methodology for improving chemical plant start-up operations through plant-wide dynamic simulation has been developed. It undergoes modeling and validations for steady-state, dynamic, and historian start-up operations. On the basis of the validated dynamic simulation model, the original plant start-up strategy is further examined and optimized to speed-up the plant start-up operation with enhanced safety considerations. A case study on an EO plant start-up has demonstrated the significant operational and economic benefits of the proposed methodology.

Multistage compression systems (MSCS) are the most important and valuable facilities in chemical plants, whose failure may cause severe accidents and/or tremendous economic loss. Thus, operation for MSCS needs sufficient care under various situations, especially during plant startup. This paper employs rigorous pressure-driven dynamic simulations to examine and improve operation safety of the cracked gas compression system during an ethylene plant startup. For safety consideration, antisurge process design and control strategies are dynamically evaluated along with startup procedures. Operating point trajectory for each compressor and their potential safety problems are identified. Assisted by the rigorous dynamic simulation, the plant startup procedure is improved with better safety performance.

Flaring is crucial to chemical plant safety. However, excessive flaring, especially the intensive flaring during the chemical plant start-up operation, emits huge amounts of volatile organic compounds (VOCs) and highly reactive VOCs, which meanwhile results in tremendous industrial material and energy loss. Thus, the flare emission should be minimized if at all possible. This paper presents a general methodology on flare minimization for chemical plant start-up operations via plantwide dynamic simulation. The methodology starts with setup and validation of plantwide steady-state and dynamic simulation models. The validated dynamic model is then systematically transformed to the initial state of start-up and thereafter virtually run to check the plant start-up procedures. Any infeasible or risky scenarios will be fed back to plant engineers for operation improvement. The plantwide dynamic simulation provides an insight into process dynamic behaviors, which is crucial for the plant to minimize the flaring w...

ABST R AC T Flaring emission during chemical plant turnaround operations generates huge amounts of air pollutants and also results in tremendous raw material and energy loss. This paper addresses near-zero aring studies for chemical plant turnaround operation to advance current endeavors on are minimization. Since off-spec products are inevitable during plant turnaround operations, they must be either recycled to the upstream process for online reuse or stored somewhere temporarily for future reprocessing when the plant manufacturing becomes stable, such that the off-spec products can be saved instead of being ared. A dynamic simulation based general methodology framework has been developed. The efcacies of the development are demonstrated by a virtual plant startup test.