Case history investigations have shown that pile foundations are more critically damaged in liquefiable soils than non-liquefiable soils.This study examines the differences in seismic response of pile foundations in l...Case history investigations have shown that pile foundations are more critically damaged in liquefiable soils than non-liquefiable soils.This study examines the differences in seismic response of pile foundations in liquefiable and non-liquefiable soils and their sensitivity to numerical model parameters.A two-dimensional finite element(FE)model is developed to simulate the experiment of a single pile foundation centrifuge in liquefiable soil subjected to earthquake motions and is validated against real-world test results.The differences in soil-pile seismic response of liquefiable and non-liquefiable soils are explored.Specifically,the first-order second-moment method(FOSM)is used for sensitivity analysis of the seismic response.The results show significant differences in seismic response for a soil-pile system between liquefiable and non-liquefiable soil.The seismic responses are found to be significantly larger in liquefiable soil than in non-liquefiable soil.Moreover,the pile bending moment was mainly affected by the kinematic effect in liquefiable soil,while the inertial effect was more significant in non-liquefiable soil.The controlling parameters of seismic response were PGA,soil density,and friction angle in liquefiable soil,while the pile bending moment was mainly controlled by PGA,the friction angle of soil,and shear modulus of loose sand in non-liquefiable soil.展开更多
Vibration induced by shield construction can lead to liquefaction of saturated sand.Based on FLAC3D software,a numerical model of tunnel excavation is established and sinusoidal velocity loads with different frequenci...Vibration induced by shield construction can lead to liquefaction of saturated sand.Based on FLAC3D software,a numerical model of tunnel excavation is established and sinusoidal velocity loads with different frequencies are applied to the excavation face.The pattern of the excess pore pressure ratio with frequency,as well as the dynamic response of soil mass under different frequency loads before excavation,is analyzed.When the velocity sinusoidal wave acts on the excavation surface of the shield tunnel with a single sand layer,soil liquefaction occurs.However,the ranges and locations of soil liquefaction are different at different frequencies,which proves that the vibration frequency influences the liquefaction location of the stratum.For sand-clay composite strata with liquefiable layers,the influence of frequency on the liquefaction range is different from that of a single stratum.In the frequency range of 5-30 Hz,the liquefaction area and surface subsidence decrease with an increase in vibration frequency.The research results in this study can be used as a reference in engineering practice for tunneling liquefiable strata with a shield tunneling machine.展开更多
Direct coal liquefaction(DCL)is an important and effective method of converting coal into high-valueadded chemicals and fuel oil.In DCL,heating the direct coal liquefaction solvent(DCLS)from low to high temperature an...Direct coal liquefaction(DCL)is an important and effective method of converting coal into high-valueadded chemicals and fuel oil.In DCL,heating the direct coal liquefaction solvent(DCLS)from low to high temperature and pre-hydrogenation of the DCLS are critical steps.Therefore,studying the dissolution of hydrogen in DCLS under liquefaction conditions gains importance.However,it is difficult to precisely determine hydrogen solubility only by experiments,especially under the actual DCL conditions.To address this issue,we developed a prediction model of hydrogen solubility in a single solvent based on the machine-learning quantitative structure–property relationship(ML-QSPR)methods.The results showed that the squared correlation coefficient R^(2)=0.92 and root mean square error RMSE=0.095,indicating the model’s good statistical performance.The external validation of the model also reveals excellent accuracy and predictive ability.Molecular polarization(a)is the main factor affecting the dissolution of hydrogen in DCLS.The hydrogen solubility in acyclic alkanes increases with increasing carbon number.Whereas in polycyclic aromatics,it decreases with increasing ring number,and in hydrogenated aromatics,it increases with hydrogenation degree.This work provides a new reference for the selection and proportioning of DCLS,i.e.,a solvent with higher hydrogen solubility can be added to provide active hydrogen for the reaction and thus reduce the hydrogen pressure.Besides,it brings important insight into the theoretical significance and practical value of the DCL.展开更多
Various crosslinking agents can be added to the formulations of natural-based adhesives for wood bonding in order to achieve better durability and higher strength of the formed joints.In the present study,the effect o...Various crosslinking agents can be added to the formulations of natural-based adhesives for wood bonding in order to achieve better durability and higher strength of the formed joints.In the present study,the effect of hexamethylenediamine(HMDA)addition on the performance of liquefied wood(LW)adhesive for wood bonding is investigated.Differential scanning calorimetry showed the improved thermal stability and crosslinking of the LW adhesive with HMDA.The intensified presence of amide linkages(C–N bonds)was found in LW+HMDA with attenuated total reflection Fourier transform infrared spectroscopy.Analysis of the bonded joints using an automated bonding evaluation system showed that a higher press temperature resulted in stronger bonds for both types of adhesives.Moreover,the addition of HMDA to LW adhesive improved the bond strength of the joints and accelerated the crosslinking of the adhesive.However,with a tensile shear strength of(6.76±2.16)N×mm^(−2)(for LW)and(6.89±2.10)N×mm^(−2)(for LW+HMDA),both adhesives were found to be unsuitable for interior non-structural use.In addition,the acidity of LW resulted in relatively high wood failure(70%)in the adhesive joints tested.Improved crosslinking of LW with HMDA was reflected in improved resistance of LW+HMDA adhesive joints to water degradation.In conclusion,HMDA is a promising additive for improving the adhesive performance of LW adhesives.展开更多
In this study,a model of combined cooling,heating and power system with municipal solid waste(MSW)and liquefied natural gas(LNG)as energy sources was proposed and developed based on the energy demand of a large commun...In this study,a model of combined cooling,heating and power system with municipal solid waste(MSW)and liquefied natural gas(LNG)as energy sources was proposed and developed based on the energy demand of a large community,andMSW was classified and utilized.The systemoperated by determining power by heating load,and measures were taken to reduce operating costs by purchasing and selling LNG,natural gas(NG),cooling,heating,and power.Based on this system model,three operation strategies were proposed based on whether MSW was classified and the length of kitchen waste fermentation time,and each strategy was simulated hourly throughout the year.The results showed that the strategy of MSW classified and centralized fermentation of kitchen waste in summer(i.e.,strategy 3)required the least total amount of LNG for the whole year,which was 47701.77 t.In terms of total annual cost expenditure,strategy 3 had the best overall economy,with the lowest total annual expenditure of 2.7730×108 RMB at LNG and NG unit prices of 4 and 4.2 RMB/kg,respectively.The lower heating value of biogas produced by fermentation of kitchen waste from MSW being classified was higher than that of MSW before being classified,so the average annual thermal economy of the operating strategy of MSW being classified was better than that of MSW not being classified.Among the strategies in which MSW was classified and utilized,strategy 3 could better meet the load demand of users in the corresponding season,and thus this strategy had better thermal economy than the strategy of year-round fermentation of kitchen waste(i.e.,strategy 2).The hourly analysis data showed that the net electrical efficiency of the system varies in the same trend as the cooling,heating and power loads in all seasons,while the relationship between the energy utilization efficiency and load varied from season to season.This study can provide guidance for the practical application of MSW being classified in the system.展开更多
Fluidization mechanism of liquefiable cargo is similar to that of sand liquefaction.But the cargo is subjected to more complex external loads during sea transportation.Based on two different constitutive models,numeri...Fluidization mechanism of liquefiable cargo is similar to that of sand liquefaction.But the cargo is subjected to more complex external loads during sea transportation.Based on two different constitutive models,numerical predictions were conducted in this study.And the effects of ship motions including motion acceleration,frequency and relative density of cargo on fluidization was investigated.By comparing with available the experimental data,validation is carried out.Results show that the roll motion is the most important one related to cargo fluidization.When the motion acceleration increases,the possibility of cargo fluidization increases.The higher of the cargo density the lower of the possibility of cargo fluidization.The effect of frequency on cargo fluidization is not unique,and it exists a critical value.The fluidization behavior of cargo could be described both by UBCSAND and FINN models.And the comparisons were discussed and summed up.展开更多
Oxide-Zeolite(OX-ZEO) bifunctional catalyst design concept has been exemplified in several processes to direct conversion syngas to value-added chemicals and fuels such as mixed light olefins, ethylene, aromatics and ...Oxide-Zeolite(OX-ZEO) bifunctional catalyst design concept has been exemplified in several processes to direct conversion syngas to value-added chemicals and fuels such as mixed light olefins, ethylene, aromatics and gasoline.Herein we demonstrate that the product can be steered toward liquefied petroleum gas(LPG) with a selectivity up to 89% in hydrocarbons especially propane selectivity reaching 80% at CO conversion of 63% using ZnCrOx-H-SSZ-39 catalyst.Interestingly, the quantity of the acid sites of SSZ-39 does not influence obviously the hydrocarbon distribution but the strength is crucial for selective formation of propane.This finding provides an alternative route of LPG synthesis from a variety of carbon resources via syngas.展开更多
The performance of four formulated solvents(labeled as UDS-I, UDS-II, UDS-III, and UDS-IV) for removing methyl mercaptan from liquefied petroleum gas was predicted based on a two-dimensional solubility parameter theor...The performance of four formulated solvents(labeled as UDS-I, UDS-II, UDS-III, and UDS-IV) for removing methyl mercaptan from liquefied petroleum gas was predicted based on a two-dimensional solubility parameter theory. The calculation results show that UDS-IV has the closest solubility parameter to that of methyl mercaptan as compared with other tested solvents, indicating the strongest affinity and the highest solubility for methyl mercaptan. The industrial tests at a plant for desulfurization of LPG produced from the delayed coker have shown that the UDS solvents have the excellent performance for removal of organosulfur compounds(mainly methyl mercaptan). Although the sulfur loading dramatically increases, the total sulfur content of LPG treated with UDS-IV can be reduced by about 50% in comparison with N-methyl diethanolamine. In addition, UDS-IV has superior regeneration performance and selectivity for sulfur compounds over hydrocarbons. The industrial test and the solubility parameter calculation results are in good agreement with each other.展开更多
One of the basic ways to reduce polluting emissions of ship power plants is application of innovative devices for on-board energy generation by means of secondary energy resources.The combined gas turbine and diesel e...One of the basic ways to reduce polluting emissions of ship power plants is application of innovative devices for on-board energy generation by means of secondary energy resources.The combined gas turbine and diesel engine plant with thermochemical recuperation of the heat of secondary energy resources has been considered.It is suggested to conduct the study with the help of mathematical modeling methods.The model takes into account basic physical correlations,material and thermal balances,phase equilibrium,and heat and mass transfer processes.The paper provides the results of mathematical modeling of the processes in a gas turbine and diesel engine power plant with thermochemical recuperation of the gas turbine exhaust gas heat by converting a hydrocarbon fuel.In such a plant,it is possible to reduce the specific fuel consumption of the diesel engine by 20%.The waste heat potential in a gas turbine can provide efficient hydrocarbon fuel conversion at the ratio of powers of the diesel and gas turbine engines being up to 6.When the diesel engine and gas turbine operate simultaneously with the use of the LNG vapor conversion products,the efficiency coefficient of the plant increases by 4%–5%.展开更多
The detonation of an explosive atmosphere from liquefied petroleum gas disseminated in air in a confined space is studied using numerical modeling with software product ANSYS AUTODYN.
Liquefied natural gas(LNG)is regarded as one of the cleanest fossil fuel and has experienced significant developments in recent years.The liquefaction process of natural gas is energy-intensive,while the regasificatio...Liquefied natural gas(LNG)is regarded as one of the cleanest fossil fuel and has experienced significant developments in recent years.The liquefaction process of natural gas is energy-intensive,while the regasification of LNG gives out a huge amount of waste energy since plenty of high grade cold energy(-160℃)from LNG is released to sea water directly in most cases,and also sometimes LNG is burned for regasification.On the other hand,liquid air energy storage(LAES)is an emerging energy storage technology for applications such as peak load shifting of power grids,which generates 30%-40%of compression heat(-200℃).Such heat could lead to energy waste if not recovered and used.The recovery of the compression heat is technically feasible but requires additional capital investment,which may not always be economically attractive.Therefore,we propose a power plant for recovering the waste cryogenic energy from LNG regasification and compression heat from the LAES.The challenge for such a power plant is the wide working temperature range between the low-temperature exergy source(-160℃)and heat source(-200℃).Nitrogen and argon are proposed as the working fluids to address the challenge.Thermodynamic analyses are carried out and the results show that the power plant could achieve a thermal efficiency of 27%and 19%and an exergy efficiency of 40%and 28%for nitrogen and argon,respectively.Here,with the nitrogen as working fluid undergoes a complete Brayton Cycle,while the argon based power plant goes through a combined Brayton and Rankine Cycle.Besides,the economic analysis shows that the payback period of this proposed system is only 2.2 years,utilizing the excess heat from a 5 MW/40 MWh LAES system.The findings suggest that the waste energy based power plant could be co-located with the LNG terminal and LAES plant,providing additional power output and reducing energy waste.展开更多
Enlarging the fleet of gas carriers would make it possible to respond to the growing demand for hydrocarbon gases,but it will increase carbon dioxide emissions.The International Maritime Organization(IMO)has developed...Enlarging the fleet of gas carriers would make it possible to respond to the growing demand for hydrocarbon gases,but it will increase carbon dioxide emissions.The International Maritime Organization(IMO)has developed the energy efficiency design index(EEDI)with the objective of carbon emission reduction for new ships.In this paper,thirty gas carriers transporting liquefied natural gas(LNG)and liquefied petroleum gas(LPG)and equipped with various types of main engines are considered.As shown by the calculation of the attained EEDI,2 of the 13 LPG carriers and 6 of the 17 LNG carriers under study do not comply with the EEDI requirements.To meet the stringent EEDI requirements,applying thermochemical regenerators(TCRs)fed by main engine exhaust gases is suggested.Mathematical modeling is applied to analyze the characteristics of the combined gas-turbine-electric and diesel-electric power plant with thermochemical recuperation of the exhaust gas heat.Utilizing TCR on gas carriers with engines fueled by syngas produced from boil-off gas(BOG)reduces the carbon content by 35%and provides the energy efficiency required by IMO without the use of other technologies.展开更多
Underground storage in rock caverns is widely used in Norway for many different petroleum products,such as crude oil,fuel,propane and butane.Basically,the caverns for such storages are unlined,i.e.containment is ensur...Underground storage in rock caverns is widely used in Norway for many different petroleum products,such as crude oil,fuel,propane and butane.Basically,the caverns for such storages are unlined,i.e.containment is ensured without using any steel lining or membrane.The main basis for the storage technology originates from the extensive hydropower development in Norway.As part of this activity,about 4500 km of tunnels and shafts have been excavated,and around 200 large powerhouse caverns have been constructed.The hydropower tunnels are mainly unlined,with hydrostatic water pressure on unlined rock of up to 1000 m.Some of the projects also include air cushion chambers with volumes of up to 1×10^(5)m^(3)and air pressure up to 7.7 MPa.Many lessons which are valuable also for underground oil and gas storage have been learnt from these projects.For a storage project to become successful,systematic,well planned design and ground investigation procedures are crucial.The main steps of the design procedure are first to define the optimum location of the project,and then to optimize orientation,shape/geometry and dimensions of caverns and tunnels.As part of the procedure,ground investigations have to be carried out at several steps integrated with the progress of design.The investigation and design procedures,and the great significance of these for the project to become successful will be discussed.Case examples of oil and gas storage in unlined rock caverns are given,illustrating the relevancy of experience from high-pressure hydropower projects for planning and design of unlined caverns for oil and gas storage.展开更多
The submarine pipelines that are buried in the Yellow River subaqueous delta can be subject to fluctuant local-liquefied soil caused by storm wave action, possibly causing pipeline damage. An experimental investigatio...The submarine pipelines that are buried in the Yellow River subaqueous delta can be subject to fluctuant local-liquefied soil caused by storm wave action, possibly causing pipeline damage. An experimental investigation was carried out in a wave flume to study the horizontal normal force on buried rigid pipelines in fluctuant liquefied soil. In this experiment, the soil bed was made of silt from the Yellow River Delta, whereas a steel pipe served as pipeline. Under the experimental conditions, the normal force range on the pipeline in fluctuant liquefied soil was several times higher than that in stable soil, specifically on the side of the pipeline exposed to the wave direction. The resultant force of the horizontal normal forces on the buried pipeline grew by about one order of magnitude after soil liquefaction.展开更多
AIM: To analyze and identify the proteomic differences between liquefied after-cataracts and normal lenses by means of liquefied chromatography-tandem mass spectrometry(LC-MS/MS).METHODS: Three normal lenses and three...AIM: To analyze and identify the proteomic differences between liquefied after-cataracts and normal lenses by means of liquefied chromatography-tandem mass spectrometry(LC-MS/MS).METHODS: Three normal lenses and three liquefied after-cataracts were exposed to depolymerizing reagents to extract the total proteins. Protein concentrations were separated using two-dimensional gel electrophoresis(2-DE). The digitized images obtained with a GS-800 scanner were then analyzed with PDQuest7.0 software to detect the differentially-expressed protein spots. These protein spots were cut from the gel using a proteome work spot cutter and subjected to in-gel digestion with trypsin. The digested peptide separation was conducted by LC-MS/MS.RESULTS: The 2-DE maps showed that lens proteins were in a p H range of 3-10 with a relative molecular weight of 21-70 kD. The relative molecular weight of the more abundant proteins was localized at 25-50 kD, and the isoelectric points were found to lie between PI 4-9. The maps also showed that the protein level within the liquefied after-cataracts was at 29 points and significantly lower than in normal lenses. The 29 points were identified by LC-MS/MS, and ten of these proteins were identified by mass spectrometry and database queries: beta-crystallin B1, glyceraldehyde-3-phosphate dehydrogenase, carbonyl reductase(NADPH) 1, cDNA FLJ55253, gamma-crystallin D, GAS2-like protein 3, sorbitol dehydrogenase, DNA FLJ60282, phosphoglycerate kinase, and filensin. CONCLUSION: The level of the ten proteins may play an important role in the development of liquefied aftercataracts.展开更多
The work is a case study of a cruise ship supplied by liquefied natural gas(LNG)and equipped with a solid oxide fuel cell(SOFC).It is supposed that a 20 MW SOFC plant is installed on-board to supply hotel loads and as...The work is a case study of a cruise ship supplied by liquefied natural gas(LNG)and equipped with a solid oxide fuel cell(SOFC).It is supposed that a 20 MW SOFC plant is installed on-board to supply hotel loads and assisting three dual-fuel(DF)diesel/LNG generator sets.LNG consumption and emissions are estimated both for the SOFC plant and DF generator sets.It results that the use of LNG-SOFC plant in comparison to DF generator sets allows to limit significantly the SO_(x),CO,NO_(x),PM emissions and to reduce the emission of CO_(2)by about 11%.A prediction of the weight and volume of the SOFC plant is conducted and a preliminary modification of the general arrangement of the cruise ship is suggested,according to the latest international rules.It results that the SOFC plant is heavier and occupies more volume on board than a DF gen-set;nevertheless,these features do not affect the floating and the stability of the cruise ship.展开更多
Tourmaline was modified with cerous nitrate and lanthanum nitrate by coprecipitation method. Through characterization by differential thermal analysis, transmission electron microscopy, X-ray diffraction, and Fourier ...Tourmaline was modified with cerous nitrate and lanthanum nitrate by coprecipitation method. Through characterization by differential thermal analysis, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy, it was found that the tourmaline modified with La-doped nano-CeO_2 had a better far infrared emitting property than the tourmaline modified with CeO2, which depended on La enhancing the redox properties of CeO_2, leaded to much more oxidation of Fe2+ to Fe3+ in the tourmaline. Based on the results of the water boiling test, it was found that the tourmaline modified with La-doped nano-CeO_2 could decrease the consumption of liquefied petroleum gas, which resulted from the tourmaline modified with La-doped nano-CeO_2 decreasing the molecular clusters volume of liquefied petroleum gas and combustion-supporting air.展开更多
The characteristics of the welding molten pool of AZ91 magnesium alloy were studied and the welding interface model was built using metallographic observation and scanning electorn microscope(SEM) composition analysis...The characteristics of the welding molten pool of AZ91 magnesium alloy were studied and the welding interface model was built using metallographic observation and scanning electorn microscope(SEM) composition analysis.The welding area was divided into heat affected zone(HAZ),liquefaction zone(LZ),rich poly zone(RPZ),sparse zone(SZ) and weld zone(WZ).The analyses of the microstructure and composition of each region show that optimizing the welding process can improve mechanical properties of weld zone.While for LZ,its tensile properties can be strengthened only by improving the composition of the parent metal and the second phase distribution.And the way to improve the tensile properties of LZ,RPZ,and SZ is to give priority to improve the parent metal composition and the second phase distribution,improving welding technology as the complementary method.Furthermore,based on the results above and the analyses of the microstructure and composition of welding cracks,it is found that the tensile fracture is mainly caused by the stress cracking rather than composition crack.展开更多
基金National Science Foundation for Excellent Young Scholars of China under Grant No.51722801National Natural Science Foundation of China under Grant Nos.51808006 and 52078016。
文摘Case history investigations have shown that pile foundations are more critically damaged in liquefiable soils than non-liquefiable soils.This study examines the differences in seismic response of pile foundations in liquefiable and non-liquefiable soils and their sensitivity to numerical model parameters.A two-dimensional finite element(FE)model is developed to simulate the experiment of a single pile foundation centrifuge in liquefiable soil subjected to earthquake motions and is validated against real-world test results.The differences in soil-pile seismic response of liquefiable and non-liquefiable soils are explored.Specifically,the first-order second-moment method(FOSM)is used for sensitivity analysis of the seismic response.The results show significant differences in seismic response for a soil-pile system between liquefiable and non-liquefiable soil.The seismic responses are found to be significantly larger in liquefiable soil than in non-liquefiable soil.Moreover,the pile bending moment was mainly affected by the kinematic effect in liquefiable soil,while the inertial effect was more significant in non-liquefiable soil.The controlling parameters of seismic response were PGA,soil density,and friction angle in liquefiable soil,while the pile bending moment was mainly controlled by PGA,the friction angle of soil,and shear modulus of loose sand in non-liquefiable soil.
基金Research Grants for Returned Students of China under Grant No.2020-038the National Natural Science Foundation of China under Grant No.51408392。
文摘Vibration induced by shield construction can lead to liquefaction of saturated sand.Based on FLAC3D software,a numerical model of tunnel excavation is established and sinusoidal velocity loads with different frequencies are applied to the excavation face.The pattern of the excess pore pressure ratio with frequency,as well as the dynamic response of soil mass under different frequency loads before excavation,is analyzed.When the velocity sinusoidal wave acts on the excavation surface of the shield tunnel with a single sand layer,soil liquefaction occurs.However,the ranges and locations of soil liquefaction are different at different frequencies,which proves that the vibration frequency influences the liquefaction location of the stratum.For sand-clay composite strata with liquefiable layers,the influence of frequency on the liquefaction range is different from that of a single stratum.In the frequency range of 5-30 Hz,the liquefaction area and surface subsidence decrease with an increase in vibration frequency.The research results in this study can be used as a reference in engineering practice for tunneling liquefiable strata with a shield tunneling machine.
基金the financial support from the National Key Research and Development Program of China(2022YFB4101302-01)the National Natural Science Foundation of China(22178243)the science and technology innovation project of China Shenhua Coal to Liquid and Chemical Company Limited(MZYHG-22-02).
文摘Direct coal liquefaction(DCL)is an important and effective method of converting coal into high-valueadded chemicals and fuel oil.In DCL,heating the direct coal liquefaction solvent(DCLS)from low to high temperature and pre-hydrogenation of the DCLS are critical steps.Therefore,studying the dissolution of hydrogen in DCLS under liquefaction conditions gains importance.However,it is difficult to precisely determine hydrogen solubility only by experiments,especially under the actual DCL conditions.To address this issue,we developed a prediction model of hydrogen solubility in a single solvent based on the machine-learning quantitative structure–property relationship(ML-QSPR)methods.The results showed that the squared correlation coefficient R^(2)=0.92 and root mean square error RMSE=0.095,indicating the model’s good statistical performance.The external validation of the model also reveals excellent accuracy and predictive ability.Molecular polarization(a)is the main factor affecting the dissolution of hydrogen in DCLS.The hydrogen solubility in acyclic alkanes increases with increasing carbon number.Whereas in polycyclic aromatics,it decreases with increasing ring number,and in hydrogenated aromatics,it increases with hydrogenation degree.This work provides a new reference for the selection and proportioning of DCLS,i.e.,a solvent with higher hydrogen solubility can be added to provide active hydrogen for the reaction and thus reduce the hydrogen pressure.Besides,it brings important insight into the theoretical significance and practical value of the DCL.
文摘Various crosslinking agents can be added to the formulations of natural-based adhesives for wood bonding in order to achieve better durability and higher strength of the formed joints.In the present study,the effect of hexamethylenediamine(HMDA)addition on the performance of liquefied wood(LW)adhesive for wood bonding is investigated.Differential scanning calorimetry showed the improved thermal stability and crosslinking of the LW adhesive with HMDA.The intensified presence of amide linkages(C–N bonds)was found in LW+HMDA with attenuated total reflection Fourier transform infrared spectroscopy.Analysis of the bonded joints using an automated bonding evaluation system showed that a higher press temperature resulted in stronger bonds for both types of adhesives.Moreover,the addition of HMDA to LW adhesive improved the bond strength of the joints and accelerated the crosslinking of the adhesive.However,with a tensile shear strength of(6.76±2.16)N×mm^(−2)(for LW)and(6.89±2.10)N×mm^(−2)(for LW+HMDA),both adhesives were found to be unsuitable for interior non-structural use.In addition,the acidity of LW resulted in relatively high wood failure(70%)in the adhesive joints tested.Improved crosslinking of LW with HMDA was reflected in improved resistance of LW+HMDA adhesive joints to water degradation.In conclusion,HMDA is a promising additive for improving the adhesive performance of LW adhesives.
基金support provided by the Nature Science Foundation of Shandong Province(ZR201709180049)the Shandong Key Research and Development Program(2019GSF109023).
文摘In this study,a model of combined cooling,heating and power system with municipal solid waste(MSW)and liquefied natural gas(LNG)as energy sources was proposed and developed based on the energy demand of a large community,andMSW was classified and utilized.The systemoperated by determining power by heating load,and measures were taken to reduce operating costs by purchasing and selling LNG,natural gas(NG),cooling,heating,and power.Based on this system model,three operation strategies were proposed based on whether MSW was classified and the length of kitchen waste fermentation time,and each strategy was simulated hourly throughout the year.The results showed that the strategy of MSW classified and centralized fermentation of kitchen waste in summer(i.e.,strategy 3)required the least total amount of LNG for the whole year,which was 47701.77 t.In terms of total annual cost expenditure,strategy 3 had the best overall economy,with the lowest total annual expenditure of 2.7730×108 RMB at LNG and NG unit prices of 4 and 4.2 RMB/kg,respectively.The lower heating value of biogas produced by fermentation of kitchen waste from MSW being classified was higher than that of MSW before being classified,so the average annual thermal economy of the operating strategy of MSW being classified was better than that of MSW not being classified.Among the strategies in which MSW was classified and utilized,strategy 3 could better meet the load demand of users in the corresponding season,and thus this strategy had better thermal economy than the strategy of year-round fermentation of kitchen waste(i.e.,strategy 2).The hourly analysis data showed that the net electrical efficiency of the system varies in the same trend as the cooling,heating and power loads in all seasons,while the relationship between the energy utilization efficiency and load varied from season to season.This study can provide guidance for the practical application of MSW being classified in the system.
基金supported by the National Natural Science Foundation of China(Grant No.51809237)the Fundamental Research Funds for the Provincial Universities(Grant No.2021J017).
文摘Fluidization mechanism of liquefiable cargo is similar to that of sand liquefaction.But the cargo is subjected to more complex external loads during sea transportation.Based on two different constitutive models,numerical predictions were conducted in this study.And the effects of ship motions including motion acceleration,frequency and relative density of cargo on fluidization was investigated.By comparing with available the experimental data,validation is carried out.Results show that the roll motion is the most important one related to cargo fluidization.When the motion acceleration increases,the possibility of cargo fluidization increases.The higher of the cargo density the lower of the possibility of cargo fluidization.The effect of frequency on cargo fluidization is not unique,and it exists a critical value.The fluidization behavior of cargo could be described both by UBCSAND and FINN models.And the comparisons were discussed and summed up.
基金supported by the Ministry of Science and Technology of China (No.2017YFB0602201)the Chinese Academy of Sciences (XDA21020400)+2 种基金the National Natural Science Foundation of China (Grant nos.91645204, 21425312 and 21621063)the Youth Innovation Promotion Association of Chinese Academy of Sciences (2019184)the INCOE (International Network of Centers of Excellence) project coordinated by BASF SE
文摘Oxide-Zeolite(OX-ZEO) bifunctional catalyst design concept has been exemplified in several processes to direct conversion syngas to value-added chemicals and fuels such as mixed light olefins, ethylene, aromatics and gasoline.Herein we demonstrate that the product can be steered toward liquefied petroleum gas(LPG) with a selectivity up to 89% in hydrocarbons especially propane selectivity reaching 80% at CO conversion of 63% using ZnCrOx-H-SSZ-39 catalyst.Interestingly, the quantity of the acid sites of SSZ-39 does not influence obviously the hydrocarbon distribution but the strength is crucial for selective formation of propane.This finding provides an alternative route of LPG synthesis from a variety of carbon resources via syngas.
基金the financial support from the National Key Science and Technology Project of China (2011ZX05017-005)
文摘The performance of four formulated solvents(labeled as UDS-I, UDS-II, UDS-III, and UDS-IV) for removing methyl mercaptan from liquefied petroleum gas was predicted based on a two-dimensional solubility parameter theory. The calculation results show that UDS-IV has the closest solubility parameter to that of methyl mercaptan as compared with other tested solvents, indicating the strongest affinity and the highest solubility for methyl mercaptan. The industrial tests at a plant for desulfurization of LPG produced from the delayed coker have shown that the UDS solvents have the excellent performance for removal of organosulfur compounds(mainly methyl mercaptan). Although the sulfur loading dramatically increases, the total sulfur content of LPG treated with UDS-IV can be reduced by about 50% in comparison with N-methyl diethanolamine. In addition, UDS-IV has superior regeneration performance and selectivity for sulfur compounds over hydrocarbons. The industrial test and the solubility parameter calculation results are in good agreement with each other.
文摘One of the basic ways to reduce polluting emissions of ship power plants is application of innovative devices for on-board energy generation by means of secondary energy resources.The combined gas turbine and diesel engine plant with thermochemical recuperation of the heat of secondary energy resources has been considered.It is suggested to conduct the study with the help of mathematical modeling methods.The model takes into account basic physical correlations,material and thermal balances,phase equilibrium,and heat and mass transfer processes.The paper provides the results of mathematical modeling of the processes in a gas turbine and diesel engine power plant with thermochemical recuperation of the gas turbine exhaust gas heat by converting a hydrocarbon fuel.In such a plant,it is possible to reduce the specific fuel consumption of the diesel engine by 20%.The waste heat potential in a gas turbine can provide efficient hydrocarbon fuel conversion at the ratio of powers of the diesel and gas turbine engines being up to 6.When the diesel engine and gas turbine operate simultaneously with the use of the LNG vapor conversion products,the efficiency coefficient of the plant increases by 4%–5%.
文摘The detonation of an explosive atmosphere from liquefied petroleum gas disseminated in air in a confined space is studied using numerical modeling with software product ANSYS AUTODYN.
基金partial support of UK EPSRC under grants EP/V012053/1,EP/S032622/1,EP/P004709/1,EP/P003605/1 and EP/N032888/1the British Council under 2020-RLWK12-10478 and 2019-RLWK11-10724。
文摘Liquefied natural gas(LNG)is regarded as one of the cleanest fossil fuel and has experienced significant developments in recent years.The liquefaction process of natural gas is energy-intensive,while the regasification of LNG gives out a huge amount of waste energy since plenty of high grade cold energy(-160℃)from LNG is released to sea water directly in most cases,and also sometimes LNG is burned for regasification.On the other hand,liquid air energy storage(LAES)is an emerging energy storage technology for applications such as peak load shifting of power grids,which generates 30%-40%of compression heat(-200℃).Such heat could lead to energy waste if not recovered and used.The recovery of the compression heat is technically feasible but requires additional capital investment,which may not always be economically attractive.Therefore,we propose a power plant for recovering the waste cryogenic energy from LNG regasification and compression heat from the LAES.The challenge for such a power plant is the wide working temperature range between the low-temperature exergy source(-160℃)and heat source(-200℃).Nitrogen and argon are proposed as the working fluids to address the challenge.Thermodynamic analyses are carried out and the results show that the power plant could achieve a thermal efficiency of 27%and 19%and an exergy efficiency of 40%and 28%for nitrogen and argon,respectively.Here,with the nitrogen as working fluid undergoes a complete Brayton Cycle,while the argon based power plant goes through a combined Brayton and Rankine Cycle.Besides,the economic analysis shows that the payback period of this proposed system is only 2.2 years,utilizing the excess heat from a 5 MW/40 MWh LAES system.The findings suggest that the waste energy based power plant could be co-located with the LNG terminal and LAES plant,providing additional power output and reducing energy waste.
文摘Enlarging the fleet of gas carriers would make it possible to respond to the growing demand for hydrocarbon gases,but it will increase carbon dioxide emissions.The International Maritime Organization(IMO)has developed the energy efficiency design index(EEDI)with the objective of carbon emission reduction for new ships.In this paper,thirty gas carriers transporting liquefied natural gas(LNG)and liquefied petroleum gas(LPG)and equipped with various types of main engines are considered.As shown by the calculation of the attained EEDI,2 of the 13 LPG carriers and 6 of the 17 LNG carriers under study do not comply with the EEDI requirements.To meet the stringent EEDI requirements,applying thermochemical regenerators(TCRs)fed by main engine exhaust gases is suggested.Mathematical modeling is applied to analyze the characteristics of the combined gas-turbine-electric and diesel-electric power plant with thermochemical recuperation of the exhaust gas heat.Utilizing TCR on gas carriers with engines fueled by syngas produced from boil-off gas(BOG)reduces the carbon content by 35%and provides the energy efficiency required by IMO without the use of other technologies.
文摘Underground storage in rock caverns is widely used in Norway for many different petroleum products,such as crude oil,fuel,propane and butane.Basically,the caverns for such storages are unlined,i.e.containment is ensured without using any steel lining or membrane.The main basis for the storage technology originates from the extensive hydropower development in Norway.As part of this activity,about 4500 km of tunnels and shafts have been excavated,and around 200 large powerhouse caverns have been constructed.The hydropower tunnels are mainly unlined,with hydrostatic water pressure on unlined rock of up to 1000 m.Some of the projects also include air cushion chambers with volumes of up to 1×10^(5)m^(3)and air pressure up to 7.7 MPa.Many lessons which are valuable also for underground oil and gas storage have been learnt from these projects.For a storage project to become successful,systematic,well planned design and ground investigation procedures are crucial.The main steps of the design procedure are first to define the optimum location of the project,and then to optimize orientation,shape/geometry and dimensions of caverns and tunnels.As part of the procedure,ground investigations have to be carried out at several steps integrated with the progress of design.The investigation and design procedures,and the great significance of these for the project to become successful will be discussed.Case examples of oil and gas storage in unlined rock caverns are given,illustrating the relevancy of experience from high-pressure hydropower projects for planning and design of unlined caverns for oil and gas storage.
基金funded by the National Natural Science Foundation of China (No. 41576039)
文摘The submarine pipelines that are buried in the Yellow River subaqueous delta can be subject to fluctuant local-liquefied soil caused by storm wave action, possibly causing pipeline damage. An experimental investigation was carried out in a wave flume to study the horizontal normal force on buried rigid pipelines in fluctuant liquefied soil. In this experiment, the soil bed was made of silt from the Yellow River Delta, whereas a steel pipe served as pipeline. Under the experimental conditions, the normal force range on the pipeline in fluctuant liquefied soil was several times higher than that in stable soil, specifically on the side of the pipeline exposed to the wave direction. The resultant force of the horizontal normal forces on the buried pipeline grew by about one order of magnitude after soil liquefaction.
基金Supported by National Natural Science Foundation of China(No.81370996)
文摘AIM: To analyze and identify the proteomic differences between liquefied after-cataracts and normal lenses by means of liquefied chromatography-tandem mass spectrometry(LC-MS/MS).METHODS: Three normal lenses and three liquefied after-cataracts were exposed to depolymerizing reagents to extract the total proteins. Protein concentrations were separated using two-dimensional gel electrophoresis(2-DE). The digitized images obtained with a GS-800 scanner were then analyzed with PDQuest7.0 software to detect the differentially-expressed protein spots. These protein spots were cut from the gel using a proteome work spot cutter and subjected to in-gel digestion with trypsin. The digested peptide separation was conducted by LC-MS/MS.RESULTS: The 2-DE maps showed that lens proteins were in a p H range of 3-10 with a relative molecular weight of 21-70 kD. The relative molecular weight of the more abundant proteins was localized at 25-50 kD, and the isoelectric points were found to lie between PI 4-9. The maps also showed that the protein level within the liquefied after-cataracts was at 29 points and significantly lower than in normal lenses. The 29 points were identified by LC-MS/MS, and ten of these proteins were identified by mass spectrometry and database queries: beta-crystallin B1, glyceraldehyde-3-phosphate dehydrogenase, carbonyl reductase(NADPH) 1, cDNA FLJ55253, gamma-crystallin D, GAS2-like protein 3, sorbitol dehydrogenase, DNA FLJ60282, phosphoglycerate kinase, and filensin. CONCLUSION: The level of the ten proteins may play an important role in the development of liquefied aftercataracts.
文摘The work is a case study of a cruise ship supplied by liquefied natural gas(LNG)and equipped with a solid oxide fuel cell(SOFC).It is supposed that a 20 MW SOFC plant is installed on-board to supply hotel loads and assisting three dual-fuel(DF)diesel/LNG generator sets.LNG consumption and emissions are estimated both for the SOFC plant and DF generator sets.It results that the use of LNG-SOFC plant in comparison to DF generator sets allows to limit significantly the SO_(x),CO,NO_(x),PM emissions and to reduce the emission of CO_(2)by about 11%.A prediction of the weight and volume of the SOFC plant is conducted and a preliminary modification of the general arrangement of the cruise ship is suggested,according to the latest international rules.It results that the SOFC plant is heavier and occupies more volume on board than a DF gen-set;nevertheless,these features do not affect the floating and the stability of the cruise ship.
基金the Key Technologies R &D Programme of Tianjin (06YFGZGX02400)
文摘Tourmaline was modified with cerous nitrate and lanthanum nitrate by coprecipitation method. Through characterization by differential thermal analysis, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy, it was found that the tourmaline modified with La-doped nano-CeO_2 had a better far infrared emitting property than the tourmaline modified with CeO2, which depended on La enhancing the redox properties of CeO_2, leaded to much more oxidation of Fe2+ to Fe3+ in the tourmaline. Based on the results of the water boiling test, it was found that the tourmaline modified with La-doped nano-CeO_2 could decrease the consumption of liquefied petroleum gas, which resulted from the tourmaline modified with La-doped nano-CeO_2 decreasing the molecular clusters volume of liquefied petroleum gas and combustion-supporting air.
基金National Natural Science Foundation of China(No.51274092)Science Research of Hunan Provincial Department of Education,China(No.15C0710)
文摘The characteristics of the welding molten pool of AZ91 magnesium alloy were studied and the welding interface model was built using metallographic observation and scanning electorn microscope(SEM) composition analysis.The welding area was divided into heat affected zone(HAZ),liquefaction zone(LZ),rich poly zone(RPZ),sparse zone(SZ) and weld zone(WZ).The analyses of the microstructure and composition of each region show that optimizing the welding process can improve mechanical properties of weld zone.While for LZ,its tensile properties can be strengthened only by improving the composition of the parent metal and the second phase distribution.And the way to improve the tensile properties of LZ,RPZ,and SZ is to give priority to improve the parent metal composition and the second phase distribution,improving welding technology as the complementary method.Furthermore,based on the results above and the analyses of the microstructure and composition of welding cracks,it is found that the tensile fracture is mainly caused by the stress cracking rather than composition crack.
