Modeling and Analysis on Production Yield and Energy Consumption of Pelleting Process

The existing studies on the pelleting process were reviewed, and then the forming process of pelleting was introduced. Furthermore, the models describing the production yield and energy consumption of pelleting were presented. Based on the models, the influence of the pelleting structure parameters, die speed on the production yield and energy consumption were discussed. The results showed that larger pellet mill was preferred and the proper speed of the die should be selected to increase the production yield and reduce the energy consumption.

One-pot synthesis of hexagonal NaLuF_(4):Yb,Er microcrystals with enhanced upconversion emission and high production yield

In this work,monodisperseβ-NaLuF_(4):Yb,Er microcrystals with intense upconversion emission were synthesized via a modified hydrothermal method.With the increase of reactant concentration,their production yield is increased obviously,and the upconversion emission intensity inβ-NaLuF_(4):Yb,Er microcrystals is also enhanced significantly.The luminescence enhancement should be attributed to minimal internal OH defects,validated by a combination of analytical X-ray diffraction(XRD),energy dispersive spectrum(EDS),and Eu^(3+)structural probe measurements.We also reveal that high Na^(+):RE~(3+)ratio in theβ-NaLuF_(4):Yb,Er microcrystals prepared under Na^(~)+-rich reaction will arouse the increased repulsive energy ofβ-NaLuF_(4)microcrystals between F^(~)-and OH^(~)-anions and then facilitate the substitution of large OH^(-)ions by small F^(~)-ions under F^(~)--rich reaction conditions.Minimal OH^(-)concentrations can limit nonradiative relaxation and promote excitation energy harvesting for high upconversion efficiency.The presented results not only offer a facile method for the simultaneous production yield and luminescence intensity increase ofβ-NaREF_(4)microcrystals,but also uncover a better insight into the upconversion emission alterations,which is favorable to broaden their practical applications.

Verification of neutron-induced fission product yields evaluated by a tensor decompsition model in transport-burnup simulations

Neutron-induced fission is an important research object in basic science.Moreover,its product yield data are an indispensable nuclear data basis in nuclear engineering and technology.The fission yield tensor decomposition(FYTD)model has been developed and used to evaluate the independent fission product yield.In general,fission yield data are verified by the direct comparison of experimental and evaluated data.However,such direct comparison cannot reflect the impact of the evaluated data on application scenarios,such as reactor transport-burnup simulation.Therefore,this study applies the evaluated fission yield data in transport-burnup simulation to verify their accuracy and possibility of application.Herein,the evaluated yield data of235U and239Pu are applied in the transport-burnup simulation of a pressurized water reactor(PWR)and sodium-cooled fast reactor(SFR)for verification.During the reactor operation stage,the errors in pin-cell reactivity caused by the evaluated fission yield do not exceed 500 and 200 pcm for the PWR and SFR,respectively.The errors in decay heat and135Xe and149Sm concentrations during the short-term shutdown of the PWR are all less than 1%;the errors in decay heat and activity of the spent fuel of the PWR and SFR during the temporary storage stage are all less than 2%.For the PWR,the errors in important nuclide concentrations in spent fuel,such as90Sr,137Cs,85Kr,and99Tc,are all less than 6%,and a larger error of 37%is observed on129I.For the SFR,the concentration errors of ten important nuclides in spent fuel are all less than 16%.A comparison of various aspects reveals that the transport-burnup simulation results using the FYTD model evaluation have little difference compared with the reference results using ENDF/B-Ⅷ.0 data.This proves that the evaluation of the FYTD model may have application value in reactor physical analysis.

The heterotic effects on dry matter production and grain yield formation in hybrid rice

We studied the characteristics of dry matterproduction and matter partitioning in hybridrice and the relationships of them with heterot-ic effect in 1993. Two popular indica hybrids, Shanyou 63(Zhenshan 97A/Minhui 63 ) and Teyou 63(Longtepu A/Minhui 63), as well as theircommon restorer line, Minhui 63 (elite cultivar

The combined effects of farm yard manure and boron application on growth,and oil quality of Canola grown under newly reclaimed soils

Two field experiments were conducted during the main seasons of 2021/2022 at the Research and Production Station of National Research Centre in Egypt to investigate the effects of farmyard manure(FYM)and boron on Canola growth,yield,oil yield,and quality.The results unequivocally demonstrated that the combined application of FYM at a rate of 14.4 ton ha^(-1)with a foliar spray of boron at 100 ppm positively influenced plant characteristics,leading to enhanced growth rates and higher yields compared to the control group.Moreover,this integrated approach significantly improved nutrient content by enhancing levels of oil content,carbohydrates,proteins,phenolics,flavonoids,and total soluble sugars.These findings provide compelling evidence that utilizing farm manure along with boron can effectively enhance Canola properties in newly reclaimed soils while promoting sustainable agricultural practices.

Trade-offs and synergies between ecosystem services in Yutian County along the Keriya River Basin,Northwest China

The Keriya River Basin is located in an extremely arid climate zone on the southern edge of the Tarim Basin of Northwest China,exhibiting typical mountain-oasis-desert distribution characteristics.In recent decades,climate change and human activities have exerted significant impacts on the service functions of watershed ecosystems.However,the trade-offs and synergies between ecosystem services(ESs)have not been thoroughly examined.This study aims to reveal the spatiotemporal changes in ESs within the Keriya River Basin from 1995 to 2020 as well as the trade-offs and synergies between ESs.Leveraging the Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)and Revised Wind Erosion Equation(RWEQ)using land use/land cover(LULC),climate,vegetation,soil,and hydrological data,we quantified the spatiotemporal changes in the five principal ESs(carbon storage,water yield,food production,wind and sand prevention,and habitat quality)of the watershed from 1995 to 2020.Spearman correlation coefficients were used to analyze the trade-offs and synergies between ES pairs.The findings reveal that water yield,carbon storage,and habitat quality exhibited relatively high levels in the upstream,while food production and wind and sand prevention dominated the midstream and downstream,respectively.Furthermore,carbon storage,food production,wind and sand prevention,and habitat quality demonstrated an increase at the watershed scale while water yield exhibited a decline from 1995 to 2020.Specifically,carbon storage,wind and sand prevention,and habitat quality presented an upward trend in the upstream but downward trend in the midstream and downstream.Food production in the midstream showed a continuously increasing trend during the study period.Trade-off relationships were identified between water yield and wind and sand prevention,water yield and carbon storage,food production and water yield,and habitat quality and wind and sand prevention.Prominent temporal and spatial synergistic relationships were observed between different ESs,notably between carbon storage and habitat quality,carbon storage and food production,food production and wind and sand prevention,and food production and habitat quality.Water resources emerged as a decisive factor for the sustainable development of the basin,thus highlighting the intricate trade-offs and synergies between water yield and the other four services,particularly the relationship with food production,which warrants further attention.This research is of great significance for the protection and sustainable development of river basins in arid areas.

Analysis and calculation model of energy consumption and product yields of delayed coking units

Delayed coking is an important process consumption and light oil yield are important factors used to convert heavy oils to light products. Energy for evaluating the delayed coking process. This paper analyzes the energy consumption and product yields of delayed coking units in China. The average energy consumption shows a decreasing trend in recent years. The energy consumption of different refineries varies greatly, with the average value of the highest energy consumption approximately twice that of the lowest energy consumption. The factors affecting both energy consumption and product yields were analyzed, and correlation models of energy consumption and product yields were established using a quadratic polynomial. The model coefficients were calculated through least square regression of collected industrial data of delayed coking units. Both models showed good calculation accuracy. The average absolute error of the energy consumption model was approximately 85 MJ/t, and that of the product yield model ranged from 1 wt% to 2.3 wt%. The model prediction showed that a large annual processing capacity and high load rate will result in a reduction in energy consumption.

The effects of aeration and irrigation regimes on soil CO_2 and N_2O emissions in a greenhouse tomato production system

Aerated irrigation has been proven to increase crop production and quality, but studies on its environmental impacts are sparse. The effects of aeration and irrigation regimes on soil CO2 and N2O emissions in two consecutive greenhouse tomato rotation cycles in Northwest China were studied via the static closed chamber and gas chromatography technique. Four treatments, aerated deficit irrigation（AI1）, non-aerated deficit irrigation（CK1）, aerated full irrigation（AI2） and non-aerated full irrigation（CK2）, were performed. The results showed that the tomato yield under aeration of each irrigation regime increased by 18.8% on average compared to non-aeration, and the difference was significant under full irrigation（P〈0.05）. Full irrigation significantly increased the tomato yield by 23.9% on average in comparison to deficit irrigation. Moreover, aeration increased the cumulative CO2 emissions compared to non-aeration, and treatment effects were significant in the autumn-winter season（P〈0.05）. A slight increase of CO2 emissions in the two seasons was observed under full irrigation（P〉0.05）. There was no significant difference between aeration and non-aeration in soil N2O emissions in the spring-summer season, whereas aeration enhanced N2O emissions significantly in the autumn-winter season. Furthermore, full irrigation over the two seasons greatly increased soil N2O emissions compared to the deficit irrigation treatment（P〈0.05）. Correlation analysis indicated that soil temperature was the primary factor influencing CO2 fluxes. Soil temperature, soil moisture and NO3^- were the primary factors influencing N2O fluxes. Irrigation coupled with particular soil aeration practices may allow for a balance between crop production yield and greenhouse gas mitigation in greenhouse vegetable fields.

Responses of water productivity to irrigation and N supply for hybrid maize seed production in an arid region of Northwest China

Water and nitrogen（N） are generally two of the most important factors in determining the crop productivity. Proper water and N managements are prerequisites for agriculture sustainable development in arid areas. Field experiments were conducted to study the responses of water productivity for crop yield（WP_（Y-ET）） and final biomass（WP_（B-ET）） of film-mulched hybrid maize seed production to different irrigation and N treatments in the Hexi Corridor, Northwest China during April to September in 2013 and also during April to September in 2014. Three irrigation levels（70%–65%, 60%–55%, and 50%–45% of the field capacity） combined with three N rates（500, 400, and 300 kg N/hm^2） were tested in 2013. The N treatments were adjusted to 500, 300, and 100 kg N/hm^2 in 2014. Results showed that the responses of WP_（Y-ET） and WP_（B-ET） to different irrigation amounts were different. WP_（Y-ET） was significantly reduced by lowering irrigation amounts while WP_（B-ET） stayed relatively insensitive to irrigation amounts. However, WP_（Y-ET） and WP_（B-ET） behaved consistently when subjected to different N treatments. There was a slight effect of reducing N input from 500 to 300 kg/hm^2 on the WP_（Y-ET） and WP_（B-ET）, however, when reducing N input to 100 kg/hm^2, the values of WP_（Y-ET） and WP_（B-ET） were significantly reduced. Water is the primary factor and N is the secondary factor in determining both yield（Y） and final biomass（B）. Partial factor productivity from applied N（PFP_N） was the maximum under the higher irrigation level and in lower N rate（100–300 kg N/hm^2） in both years（2013 and 2014）. Lowering the irrigation amount significantly reduced evapotranspiration（ET）, but ET did not vary with different N rates（100–500 kg N/hm^2）. Both Y and B had robust linear relationships with ET, but the correlation between B and ET（R^2=0.8588） was much better than that between Y and ET（R^2=0.6062）. When ET increased, WP_（Y-ET） linearly increased and WP_（B-ET） decreased. Taking the indices of Y, B, WP_（Y-ET）, WP_（B-ET） and PFP_N into account, a higher irrigation level（70%–65% of the field capacity） and a lower N rate（100–300 kg N/hm^2） are recommended to be a proper irrigation and N application strategy for plastic film-mulched hybrid maize seed production in arid Northwest China.

Optimizing N fertilizer use for sesame under rain fed and irrigation conditions in Northern Ethiopia

Inappropriate use of fertilizers is one of the major production constraints in sesame. Studies on N fertilizer optimization on sesame were conducted at Humera Agricultural Research Center(Hu ARC) under rain fed and irrigation conditions. Thirteen(13) N doses were evaluated in a Randomized Complete Block Design(RCBD)during 2016–2018 for rainfed conditions and 2017 to 2019 for irrigation conditions. The study was conducted with objective to optimize N fertilizer use for sesame. In the rainfed condition, the results demonstrated a prolonged duration to reach 50% flowering with higher nitrogen(N) application rates. The application of 52.5–110kg N ha^(-1) resulted in significantly higher seed yield, while lower(18 kg N ha^(-1)) and higher(156 kg N ha^(-1)) doses of N led to reduced seed yield. Under irrigation conditions, superior seed weights and maximum seed yield were observed at 64 and 75 kg N ha^(-1), whereas lower N doses resulted in diminished seed yield. The agronomic efficiency of N fertilizer(N-AE) was found to be highest at the rate of 64 kg N ha^(-1) under both growing conditions.The partial budget analysis revealed that applying 64 kg N ha^(-1) for rainfed cultivation and between 64 and 75 kg N ha^(-1) for irrigated sesame production yielded greater net profit, MRR, and residual ranking. Therefore, it is recommended to apply a rate of 64 kg N ha^(-1) for rainfed sesame cultivation and between 64 up to 75 kg N ha^(-1) for the irrigated sesame inorder to increase the productivity of this crop.

High production-yield solid-state carbon dots with tunable photoluminescence for white/multi-color light-emitting diodes

Plastic waste is generally resistant to natural degradation and has become a major environmental pollution problem globally. The pollution of ecosystems seriously affects the health and survival of organisms,including humans. Much attention has been paid to finding suitable ways to convert plastic waste into high-value-added carbon materials. To this end, we report the high production yield(60%–85%) of carbon dots(CDs) for solid-state fluorescence(SSF) obtained by a one-step solvothermal method using waste expanded polystyrene as the precursor. The SSF mechanism of the CDs was also explored. Their emission wavelength, with a large full width at half maximum of 150–200 nm, exhibited tunable photoluminescence from white to yellow and orange. CDs powder was used to fabricate single-component white and multi-colour light-emitting diodes on UV chips. Overall, plastic waste was converted into tunable solid-state fluorescent CDs powder, which has promising applications in carbon-based lighting, by a simple solvothermal method that provides a viable method for recycling plastic waste.

Theoretic heat sink simulation and experimental investigation of the pyrolysis of substituted cyclohexanes

Reaxgen program for the pyrolysis mechanism of cycloalkanes was adopted to simulate the heat sink of substituted cyclohexanes. Thermal cracking of cyclohexanes was performed to examine the cracking performance, wherein the substituent effects were detailedly discussed under supercritical condition. It was found that Reaxgen program played a good part in the screening and optimization of cyclohexanes. A good agreement with the experimental data for the mono-substituted and bi-substituted cyclohexanes was demonstrated, however, some deviation for the tri-substituted cyclohexanes were observed. The experiment results indicated that the gaseous product yield increased sharply for mono- substituted cyclohexanes with short substituents containing no more than two carbons. Nevertheless, continuous increase in the alkyl chain depressed the gaseous product yield smoothly. The cyclic substituent dramatically inhibited the pyrolysis of cyclohexanes. All the substituents but cyclohexyl had no obvious effect on the yield of hydrogen and olefins （≤C4）. For bi-substituted cyclohexanes, the more close the distance between the two substituents, the higher the gaseous product yield was obtained. However, opposite result on the selectivity to hydrogen and olefins （≤C4） was generally obtained except 1,3-dimethylcyclohexane. The position of tri-substituents acted little significance on the gaseous product yield, as well as the selectivity to hydrogen and olefins （≤C4）.

Preparation of lithium carbonate by microwave assisted pyrolysis

Investigations were conducted to purify crude Li_(2)CO_(3)via direct carbonation with CO_(2)at atmospheric pressure and pyrolysis with both water bath heating method and microwave heating method.The reaction kinetics of LiHCO_(3)pyrolysis was studied and the effect of different operating conditions including initial concentration of LiHCO_(3)solution,pyrolysis temperature and stirring speed on the purity of Li_(2)CO_(3)was investigated to obtain the optimal operating conditions.Results showed that the effect law is similar in the two pyrolysis processes.The purity of the Li_(2)CO_(3)increases firstly and then decreases with the increase of the initial concentration of LiHCO_(3)solution and the stirring speed,while the purity of Li_(2)CO_(3)first decreases and then increases with the increase of pyrolysis temperature.The product yield increases with the increase of initial concentration of LiHCO_(3)solution and pyrolysis temperature and is essentially unaffected by the stirring speed.Under the optimal operating conditions,the purity of Li_(2)CO_(3)can reach up to 99.86%and 99.81%in water bath heating and microwave heating process,respectively.In addition,the pyrolysis rate of microwave assisted pyrolysis is 6 times that of water bath heating process,indicating that the microwave heating technology can significantly improve pyrolysis efficiency and reduce energy consumption.

A coupled CFD simulation approach for investigating the pyrolysis process in industrial naphtha thermal cracking furnaces

In the steam thermal cracking of naphtha,the hydrocarbon stream flows inside tubular reactors and is exposed to flames of a series of burners in the firebox.In this paper,a full three-dimensional computational fluid dynamics(CFD)model was developed to investigate the process variables in the firebox and reactor coil of an industrial naphtha furnace.This comprehensive CFD model consists of a standard k-εturbulence model accompanied by a molecular kinetic reaction for cracking,detailed combustion model,and radiative properties.In order to improve the steam cracking performance,the model is solved using a proposed iterative algorithm.With respect to temperature,product yield and specially propylene-toethylene ratio(P/E),the simulation results agreed well with industrial data obtained from a mega olefin plant of a petrochemical complex.The deviation of P/E results from industrial data was less than 2%.The obtained velocity,temperature,and concentration profiles were used to investigate the residence time,coking rate,coke concentration,and some other findings.The coke concentration at coil exit was1.9×10^(-3)%(mass)and the residence time is calculated to be 0.29 s.The results can be used as a scientific guide for process engineers.

Synthesis of Urea by Ammonolysis of Propylene Carbonate

Studying urea formation by ammonolysis of propylene carbonate in a liquid phase showed that this process is two-stage, and proceeds through preferred formation of 2-hydroxypropyl carbamate, besides, the rate of the first stage is much higher than the rate of the second stage （urea formation）. With the aid of the HPLC and HPLC/MS methods found some other intermediate products and offered consecutive-parallel scheme of the process. The obtained results explain the composition of impurities obtained during the production of the 13C-urea for diagnostic breath tests.

Seedless Synthesis of Gold Nanorods with 5–10 nm in Diameters:a Comprehensive Study

Small gold nanorods(AuNRs),namely AuNRs with less than 10 nm in diameter,possess a high absorption-to-scattering ratio,a large surface area-to-volume ratio,as well as high cellular uptake behaviors.In this study,we systematically investigate seedless synthesis of AuNRs with diameters ranging from 5 nm to 10 nm.It has been found that several experimental conditions,including the chain length of the used cationic surfactants,and the concentrations of ascorbic acid,NaBH4,and AgNO_(3)can profoundly affect the obtained products.Under optimal conditions,the production yields of the obtained several AuNRs with different diameters can exceed 90%and even reach almost 100%.The conversion of gold precursors to AuNRs was estimated to be 70%–77%as measured by absorption spectroscopy and inductively coupled plasma mass spectrometry.

Challenges in Photocatalytic Carbon Dioxide Reduction

An energy crisis and significant anthropogenic CO_(2)emissions as a result of rising fossil fuel consumption have caused a rapid increase in global temperature.One of the best solutions to these two issues is thought to be the photocatalytic reduction of CO_(2)into value-added carbon-containing products.In this aspect,the main challenges mainly include the photocatalytic mechanism,reaction activity,and product selectivity,especially in ambiguous reaction pathways and product selectivity,an unclear charge transfer mechanism,and an overestimate of product yield.Therefore,in this perspective,we attempt to exhibit the discussion and in-depth analysis of the possible reaction pathways and product selectivity,the specific charge transfer mechanism,and the origin of carbon-containing products in phtocatalytic CO_(2)reduction.Besides,the fundamentals for photocatalytic CO_(2)reduction are also illustrated.Finally,the state-of-the-art challenges and perspectives in CO_(2)photoreduction are highlighted and discussed in detail.This perspective is expected to evoke more research attention for the photocatalytic reduction of CO_(2)into value-added products.

A mixed acid methodology to produce thermally stable cellulose nanocrystal at high yield using phosphoric acid

Cellulose nanocrystal(CNC)with distinctive shape-morphology,enhanced thermal stability and dispersibility is essential for overcoming the challenges in processing polymer/CNC nanocom-posites through melt compounding at elevated temperatures.This study shows a mixed acid hy-drolysis method to produce CNC with improved thermal stability and high productivity.The use of phosphoric acid(H_(3)PO_(4)),as a mild acid,in combination with a strong acid either sulphuric acid(H_(2)SO_(4))or hydrochloric acid(HCl)leads to reduced use of strong acids and low impact on our environment.The influences of acid combination and sequence of addition on the production yield were investigated by retaining the proportion of H_(3)PO_(4)to corrosive acid(H_(2)SO_(4)and HCl)4 to 1,and solid to liquid ratio 1꞉75.This methodology has enabled to isolate CNC with higher thermal stability,dispersibility and productivity in terms of amount acid used 1 g of CNC,as compared with single acid hydrolysis.The CNC produced using the combination of H_(3)PO_(4)and HCl exhibits high thermal stability,dispersibility and rod-like shape morphology with length and width of(424±86)and(22±3)nm,respectively.Moreover,this approach has reduced H_(3)PO_(4)consumption by 54%as compared with single acid hydrolysis method for the production of same amount of CNC.