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Investigation on the effect of carbon on clustering of defects in tungsten by first principles calculations

MATERIALS TODAY cOMMUNIcATIONS 2023年 35卷

作者： Wen, Shulong Lv, YiNi Pan, Min Huang, Zheng Wang, Jiaming Han, Lei Zhao, Yong Deng, Huiqiu Southwest Jiaotong Univ Sch Elect Engn Chengdu 610031 Peoples R China Hunan Univ Sch Phys & Elect Changsha 410082 Peoples R China

carbon (c) impurity would be inevitably introduced in the process of industrial-scale tungsten production. In this work, by using the first-principles density functional theory, the c atom behaviors in tungsten lattice and the effect of c atom on defects clustering have been studied systematically. calculation results show that c atom prefers to occupy the octahedral interstitial site of the tungsten lattice, the migration barrier energy of c atom is 1.46 eV along the optimal pathway. Both vacancy cluster and c atom can form stable complex structure according to the attractive interaction, and c atom promotes the nucleation of the vacancy cluster. The growth mechanism shows that vacancy clusters are more likely to grow by combining a cluster rather than a single vacancy, where c atom plays a positive role of promoting vacancy clusters nucleation. In addition, c atom can cause tungsten lattice distortion and lead to the formation of the potential well, which prompts SIA rapidly diffuse toward it and forms a SIA-c complex structure. The calculation results of the nucleation rate indicate that c atom can enlarge the effective radius of the 2SIA cluster, and enhance the nucleation rate of 3SIA cluster. Therefore, we conjecture that the c atom can inhibit the recovery of the Frenkel pair and weaken the self-repair of the tungsten materials under irradiation. These results are meaningful for further understanding the mechanism of the effect of c impurity for the defects evolution of irradiation defects of W-based material.

关键词： Tungsten Defects evolution First-principles calculations c

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Electron transport materials based on ZnO@carbon derived metal-organic framework for high-performance perovskite solar cell

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SOLAR ENERGY 2023年第1期253卷 453-461页

作者： Abd El-Lateef, Hany M. Khalaf, Mai M. Heakal, Fakiha El-Taib Taleb, Manal F. Abou Gouda, M. King Faisal Univ Coll Sci Dept Chem Al Hasa 31982 Saudi Arabia Sohag Univ Fac Sci Chem Dept Sohag 82524 Egypt Cairo Univ Fac Sci Chem Dept Giza 12613 Egypt Prince Sattam Bin Abdulaziz Univ Coll Sci & Humanities Dept Chem Al Kharj 11942 Saudi Arabia

ZnO is widely known as an excellent electron-transport material for perovskite solar cells. MOF-derived ZnO is anticipated for use as ideal electron transport material due to its greater exciton binding energy, higher visible spectrum transmittance, and comparable energy level with perovskite can boost light harvesting and improve perovskite interfacial contact. Therefore, ZnO/c composites were successively prepared and well characterized. ZnO/c materials are characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), as well as by N2 adsorption-desorption isotherm surface area. compared to traditional ZnO nanoparticles, MOF-derived, carbon-doped ZnO/c attains more effective extracting electrons resulting in a much higher fill factor and short-circuit current density in the cells. The power conversion efficacy (PcE) of MOF-derived ZnO/c-based perovskite solar cells is 19.6 %, with a fill factor (FF) of 0.77. In addition, the hysteresis impact becomes almost nonexistent.

关键词： MOF ZnO c Perovskite solar cell EIS Materials? characterization

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Unraveling of the laser drilling of carbon/carbon composites: Ablation mechanisms, shape evolution, and damage evaluation

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INTERNATIONAL JOURNAL OF MAcHINE TOOLS & MANUFAcTURE 2023年 184卷

作者： Qingliang, Shen Tiyuan, Wang Qiang, Song Fang, Ye Hejun, Li Fu, M. W. Hong Kong Polytech Univ Res Inst Adv Mfg Dept Mech Engn Hong Kong Peoples R China Northwestern Polytech Univ Shaanxi Key Lab Fiber Reinforced Light Composite M Xian 710072 Peoples R China

Laser machining is promising in shaping the brittle carbon/carbon composites (c/cs) with deep holes, sharp edges, or thin walls. However, there are still many unknowns relating to the laser ablation of carbon materials, and the existing theory and practice is insufficient to guide the industrial machining of c/cs. Herein the laser drilling of c/cs was experimentally conducted and numerically modeled to probe into the mechanisms responsible for the material removal, surface formation, and damage evaluation. Firstly, the intrinsic correlations among the anisotropic hole feature, the fiber yarn alignment and the steady-state thermal conduction are revealed. The detailed characterizations of the ablated surface and the recast layer clearly prove that sublimation of the graphitic carbon dominates the material removal process under laser ablation. Furthermore, it is proposed that the greater portion of crystalized graphene layers enables the lower ablation rate of the pyrocarbon matrix than the carbon fibers. Secondly, the combination of the experimental and simulated results unravels that the continuously evolved surface slope and the redeposited recast layer are the decisive factors in the laser-carbon interaction, which affect the efficient absorption coefficient of the laser and result in the nonlinear drilling rate and the self-limiting of the drilling. Finally, the roles of the laser heating and the subsequent rapid cooling in damage initiation and propagation are identified: nanoscale splitting of the pyrocarbon occurs due to the growth and realignment of the graphene layers upon laser heating, and the tensile thermal stress induced by the cooling drives the further growth of high-density but discrete microcracks from these splitting sites. The load bearing capability of the carbon fibers, however, is retained in this severe thermal shock. As a result, the laser drilling induces only a slight degradation of the mechanical strength of the c/cs.

关键词： c c composite Laser drilling Residual stress Thermal conduction Drilling quality

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Investigation on pH influence for the effective transportation of coal water slurry using experimental design

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INTERNATIONAL JOURNAL OF cOAL PREPARATION AND UTILIZATION 2023年第12期43卷 2017-2030页

作者： Karthik, J. Purushottam Raguraman, c. M. Sasanka, c. Tara Annamalai Univ Dept Mech Engn Chidambaram India Dept Mech Engn RVR & JC Coll Engn Guntur India Annamalai Univ Dept Mech Engn Chidambaram 608002 Tamil Nadu India

The present study aims to identify the pH values in preparation of coal water slurry (cWS) that were evaluated. Rheological characteristics and stability of coal water slurry (cWS) were observed with two types of impellers at pH varying from 6.99 to 7.24. The results showed that the concentration of coal water slurry, rheological characteristics and stability of cWS for propeller and rushton impellers. The parameters that are most effected on the objectives are impeller speed (N) and ratio of clearance height with diameter of tank (c/T). The third parameter, ratio of slurry height with tank diameter (Z/T), is not effecting on output. The pH values of concentrated coal water slurry are favorable to transport to coal gasifier. For propeller impeller, the pH values vary from 6.99 to 7.15;for Rushton impeller pH values vary from 7.12 to 7.24 comparatively Rushton impeller having more base which is most favorable and obtain good cWS concentration. The influence of coal particle size is also investigated on pH values for optimal parameters of equipment.

关键词： coal water slurry Rushton impeller Propeller impeller Ph values impeller speed c T ratio Z

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Synergistic effects of ternary mixture formulation and process parameters optimization in a sequential approach for enhanced L-asparaginase production using agro-industrial wastes

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ENVIRONMENTAL ScIENcE AND POLLUTION RESEARcH 2023年第12期31卷 17858-17873页

作者： Sharma, Deepankar Mishra, Abha BHU Indian Inst Technol Sch Biochem Engn Varanasi 221005 India

A novel ternary mixture of inexpensive and nutrient-rich agro-substrates comprising groundnut de-oiled cake, corn gluten meal, and soybean meal has been explored to enhance the L-asparaginase production in solid-state fermentation. To achieve the aim, a hybrid strategy was implemented by utilizing a combination of a mixture design and artificial neural networks. The study initiated with the judicious selection of the agro-substrates based on their low c/N content in comparison to the control using the cHNS elemental analysis. The mixture composition of soybean meal (49.0%), groundnut de-oiled cake (31.5%), and corn gluten meal (19.5%) were found optimum using the simplex lattice mixture design. The agro-industrial substrates mix revealed synergistic effects on the L-asparaginase production than either of the substrates alone. The maximum L-asparaginase activity of 141.45 +/- 5.24 IU/gds was observed under the physical process conditions of 70% moisture content, autoclaving period of 30 min and 6.0 pH by adopting the machine learning-derived artificial neural network (ANN) methodology. The ANN modeling showed excellent prediction ability with a low mean squared error of 0.7, a low root mean squared error of 0.84, and a high value of 0.99 for regression coefficient. Moisture content (%) was assessed to be the most sensitive process parameter in the global sensitivity analysis. The net outcome from the two sequential optimization designs is the selection of the ideal mixture composition followed by the optimum physical process parameters. The application of the enzyme demonstrated significant cytotoxicity against leukemia cell line and therefore exhibited an anti-cancer effect. The present study reports a novel mixture combination and methodology that can be used to lower the cost and enhance the production of L-asparaginase using an agro-industrial substrate mixture.

关键词： Solid-state fermentation c N ratio Mixture design Machine learning Artificial neural network (ANN) Mean squared error (MSE) Sensitivity analysis

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Special color change mechanism of Disperse Red 60 in alkaline dyeing system

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TEXTILE RESEARcH JOURNAL 2023年第3-4期93卷 807-816页

作者： Ai, Li Zhu, Yawei Wuhan Text Univ Hubei Key Lab Biomass Fibers & Ecodyeing & Finish Wuhan Peoples R China Soochow Univ Coll Text & Clothing Engn Suzhou Peoples R China

color Intex (c.I.) Disperse Red 60 is a bright red anthraquinone dye, but it is easy to produce dyeing defects (a kind of discoloration phenomenon, the partial color is random blue patches) in the polyester dyeing process, and the mechanism of blue patches is unknown, resulting in a low right-one-time of dyeing. To investigate the mechanism of this particular color change, the interaction between c.I. Disperse Red 60 and borax was investigated by absorbance, and samples with blue patches were prepared;the presence of B-N bonds was confirmed by testing the X-ray Photoelectron Spectroscopy (XPS) of the dyed samples. The functional additive LV200 (a polymer containing polyester and polyether) was selected to control the interaction between the Disperse Red 60 and LV200. The results showed the co-existence of the red component (1-amino-2-phenoxy-4-hydroxy-9,10-anthraquinone) and the blue component (1-amino-2-phenoxy-10-hydroxy-4,9-anthraquinone) of Disperse Red 60 was the main reason for the random blue patches (dye defects) during the dyeing process of c.I. Disperse Red 60. By using the functional auxiliary LV200 and the H-bonding of the polar group of the dye, the conversion of the red and blue components of the reciprocal isomers can be controlled, and both bright red polyester-dyed fabrics and purplish red polyester-dyed fabrics can be produced. This provides a theoretical guide to improving the dyeing authentic rate of c.I. Disperse Red 60.

关键词： Polyester fiber disperse dyes c I Disperse Red 60 1-amino anthraquinone isomers dyeing defects

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NITROGEN SEQUESTRATION DURING SEWAGE SLUDGE cOMPOSTING AND VERMIcOMPOSTING

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JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDScAPE MANAGEMENT 2023年第2期31卷 157-163页

作者： Zigmontiene, Ausra Sereviciene, Vaida Vilnius Gediminas Tech Univ Dept Environm Protect & Water Engn Vilnius Lithuania

composting is the oldest and most natural form of organic material recycling. Technological parameters are very important because when the process is unbalanced, other gases are produced, some of which have objectionable odours (NH3). Sewage sludge is a valuable material that has accumulated large amounts of nitrogen and phosphorus, which can contribute to improving soil quality. Optimal composting and vermicomposting conditions (c/N ratio, pH, and moisture) can reduce the emissions of gaseous pollutants in the environment. Experimental studies have shown that the volume of ammonia emitted into the environment during vermicomposting of sewage sludge is significantly lower (3 mg/m3 concentration was reached on the 28th day) than that resulting from traditional composting (3 mg/m3 concentration was reached on the 56th day). Vermicomposting of sewage sludge preserves higher amounts of total nitrogen (12.52 mg/kg) compared to traditional composting (10.35 mg/kg).

关键词： sewage sludge treatment composting vermicomposting earthworms Kjeldahl nitrogen c N ratio ammonia

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Anaerobic co-digestion of sludge, sugarcane leaves, and corchorus stalks in Egypt

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BIOMASS cONVERSION AND BIOREFINERY 2023年第3期13卷 2177-2191页

作者： Elsayed, Mahmoud Hassany, Ramadan Soliman, Mohamed Aswan Univ Fac Engn Civil Engn Dept Aswan 81542 Egypt CNRS UMR 6144 GEPEA IMT Atlantique 4 Rue Alfred Kastler F-44307 Nantes 3 France Aswan Univ Fac Engn Civil Engn Dept Aswan 81542 Egypt Aswan Univ Fac Engn Civil Engn Dept Aswan 81542 Egypt

This paper mainly introduces the potential of methane yield from co-digestion of primary sludge (PS) and the proposed new waste materials of sugarcane leaves (SL) and corchorus stalks (cS) in Egypt. This paper includes three parts. In the first part, anaerobic co-digestion of PS, SL, and cS at different carbon-to-nitrogen (c/N) ratios was studied to determine the best c/N ratio. The results indicated that the maximum cumulative methane yields (cMYs) were observed at a c/N ratio of 18, which was associated with the highest volatile solid (VS) removal rate (74.41%). In the second part, the effect of using two types of inoculum (fresh cow manure (cM) and rumen content from slaughterhouses (RS)) on increasing the production of methane was investigated. clearly, using cM as inoculum showed a superiority of the production of methane from co-digestion of PS, SL, and cS. The maximum cMYs were observed using the cM as inoculum from co-digestion of PS, SL, and cS. It was higher about 1.26 times more cMY using RS as inoculum. In the third part, the possibility of enhancing biogas yields from semi-continuous co-digestion of PS, SL, and cS using different organic loading rates (OLR) of 0.5, 1.0, and 2.0 was conducted. The highest biogas production rate was observed at an OLR of 1.0 gVS/(L-reactor.d) that coincided with the optimum VS removal rate. Statistical analysis of the results was conducted using analysis of variance (ANOVA) test, and the c/N ratio of 18 is statistically the best enhanced ratio. Overall, the feasibility of maximizing the methane productivity considering the anaerobic co-digestion of PS, SL, and cS under the optimal operating conditions and configuration was proved.

关键词： Anaerobic co-digestion c N ratio corchorus stalks Semi-continuous co-digestion Sugarcane leaves

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Effect of Process Parameters on chitosan-mediated Microalgae Flocculation

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cHEMIcAL AND BIOcHEMIcAL ENGINEERING QUARTERLY 2023年第2期37卷 97-105页

作者： Akis, S. Inan, B. Ozcimen, D. Balkanli Yildiz Tech Univ Fac Chem & Met Bioengn Dept TR-34220 Istanbul Turkiye

Today, microalgae have received considerable interest as an alternative feedstock for biofuel, animal feed, human food, and pharmaceuticals because they possess valuable oils and biomolecules. The main problem of the cost of microalgae production is generally associated with the harvesting process. Flocculation is an effective method to harvest microalgal biomass and minimize the operating cost. In this study, the effect of the chitosan solution, different pH conditions, and flocculation time on flocculation process of chlorella minutissima and Nannochloropsis oculata were investigated, and the obtained data were evaluated statistically. Flocculation efficiency of c. minutissima and N. ocula-ta were the highest under the conditions of 10 pH, 100 mg L-1 chitosan concentration, and flocculation time of 60 min, and found as 97 % and 85 %. It was also found that chitosan flocculation could be improved with pH increase. This study showed that chitosan is a favorable flocculant because of its high efficiency, being non-toxic, and enabling the reusability of the growth medium after flocculation.

关键词： N oculata c minutissima flocculation chitosan microalgae

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Antimicrobial photodynamic therapy with Ligularia fischeri against methicillin-resistant Staphylococcus aureus infection in caenorhabditis elegans model

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APPLIED BIOLOGIcAL cHEMISTRY 2023年第1期66卷 19页

作者： Ha, Ngoc Minh Hwang, Hoseong Alam, Seemi Tasnim Nguyen, Uyen Tran Tu Lee, Soon Kwang Park, Jin-Soo Kim, Jin-chul Kwon, Hak cheol Kwon, Jaeyoung Kang, Kyungsu Korea Inst Sci & Technol Gangneung Inst Nat Prod Nat Prod Informat Res Ctr 679 Saimdang ro Kangnung 25451 Gangwon Do South Korea Univ Sci & Technol UST KIST Sch Div Biomed Sci & Technol Kangnung 25451 Gangwon Do South Korea Korea Inst Sci & Technol Gangneung Inst Nat Prod Nat Prod Res Ctr Kangnung 25451 Gangwon Do South Korea

The high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infection threatens the effectiveness of current clinical settings. Antimicrobial photodynamic therapy (APDT) is a promising alternative to antibiotics for treating infections due to its low resistance. This study aimed to evaluate the antibacterial properties of APDT with L. fischeri extract (LFE) against MRSA and various skin and oral pathogens in vitro and its photopharmaceutical actions in caenorhabditis elegans. The antimicrobial activities of APDT with LFE against pathogens were evaluated using plate counting method. The chemical profile was characterized using high-performance liquid chromatography and spectrophotometry. The growth rate assay, lifespan assay, and bacterial attachment on worms were performed to assess the therapeutics effects in c. elegans. The swab method was used for the detection of pathogens on the micropig skin surface. The APDT treatment with L. fischeri extract (LFE, 20 mu g/mL) and red light (intensity of 120 W/m(2)) reduced 4.3-4.9 log (colony forming unit/mL) of Staphylococcus aureus, MRSA, cutibacterium acnes, Streptococcus mutans;and 2.4 log (cFU/mL) of candida albicans. chemical analysis revealed that LFE enriched three active photosensitizers. APDT reduced bacterial populations on worms, recovered growth retardation, and improved lifespan in MRSA-infected c. elegans without causing severe side effects. The surface eradication of MRSA after exposure to LFE with red light was demonstrated on micropig skin. These findings highlight the significance of L. fischeri as a natural resource for the safe phototreatment of MRSA infection in the biomedical and cosmeceutical industries.

关键词： Antimicrobial photodynamic treatment c elegans Ligularia fischeri Pheophorbide MRSA Staphylococcus aureus

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