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The focus of this study was to develop technologies using chlorine dioxide (ClO2) gas to control postharvest stem-end rot of citrus caused by Lasiodiplodia theobromae. Mycelial growth of L. theobromae on potato dextrose agar (PDA) plugs was completely inhibited by a 24-h ClO2 exposure provided by 0.5 g of solid ClO2 generating granular mixture in a 7.7-liter sealed container. In vivo experiments were conducted on artificially inoculated Tango and naturally infected U.S. Early Pride mandarins. When ClO2 treatments were initiated 0 to 6 h after inoculation, decay development was significantly reduced as compared with the control, and higher ClO2 doses were more effective. A ClO2 treatment (using 3 g of generating mixture per 7.7-liter sealed container) administered 0 h after inoculation resulted in 17.6% Diplodia stem-end rot incidence compared with 95.6% in the control, whereas the same treatment administered 24 h after inoculation was much less effective, resulting in 63.0% incidence compared with 85.4% in the control. Diplodia stem-end rot incidence of naturally infected fruit after using 6 or 9 g of generating mixture per 24-liter sealed box was 23.8 or 25.7%, respectively, compared with 47.9% for control fruit. The ClO2 treatments had no negative effects on fruit quality characteristics including weight loss, firmness, puncture resistance, titratable acids (TAs), total soluble solids (TSSs), and rind color. Albedo pH at wounds was significantly reduced from 6.0 to 4.8 by the ClO2 treatments, whereas undamaged albedo remained at 5.8. In addition, no visible physiologic defects, such as peel browning and bleaching, were observed on ClO2-treated fruit. These results indicate that ClO2 gas has the potential to be developed as a component of an integrated citrus postharvest decay control system to minimize fruit losses.

Virtual water trade in a region is affected by both nature and by humans. To study the contribution of human activities on virtual water trade quantitatively, an innovative method of quantitative comparison and analysis is put forward. At first, climates are adjusted into a unified standard. Then the impacts of increment and reduction of foreign water are studied. Additionally, the impacts of water management policy are studied according to the comparable water quotas. Results show that with the development of the economy, an N-shaped trend and inverted U-shaped trend exist with regard to the net exports of agricultural and industrial virtual water, respectively. The net imports of virtual water have beneficial effects to water environments in water deficient areas, while net exports have negative effects. In 1997, the net exports of agricultural and industrial virtual water reduced by 20.13% and 49.67% respectively due to the cut-off of the Yellow River channel compared with that under average Yellow River water diversion. In 2017, they increased by 1.32% and 41.99% respectively because of the South-to-North Water Transfer (SNWT) project and reduced by 10.01% and 20.39% respectively under the effects of the most stringent water management policy.

To study the influences of sand and gravel layer and groundwater velocity of Yufuhe River on atrazine migration, adsorption-desorption and sand column experiments were carried out. Results show that the adsorption capacity of montmorillonite, raw sand and washed sand to atrazine sequentially weakens. In different media, the time for atrazine concentrations to peak in washed sand with montmorillonite (WSM), raw sand and washed sand is 60, 135 and 105 minutes respectively, and the peak concentration accounts for 84, 90 and 95% of the initial concentrations. Under different flow rates, the peak time in washed sand at flow rates of 100, 150 and 200 mL/min is 135, 105 and 75 minutes, and the peak time in WSM is 90, 60 and 45 minutes, respectively. Results from this study indicate that increasing flow velocity and suspended colloids concentrations can promote the migration of atrazine in aquifers, while the presence of clay minerals in sand and gravel layers can reduce atrazine migration. Thus, during Yellow River water recharging, the sand and gravel layer of Yufuhe River is helpful to protect the aquifer, but the colloids-associated migration of atrazine can contaminate groundwater in underlying karst aquifer. HIGHLIGHTS Migrations of atrazine in porous media are related to clay minerals and colloids.; Sand and gravel layer can retard the atrazine migration during managed aquifer recharge (MAR).; Increasing groundwater velocity would accelerate atrazine migration.; This study is significant to maintain the long-term operation of the MAR.

Camellia drupifera is a main tea-oil Camellia species, and understanding its genetic variation, origin and evolution will facilitate protection and utilization of its genetic resources. However, the differentiation, genetic variation, origin and evolution of C. drupifera remains unknown. Here, SRAP markers and chloroplast sequences of 32 C. drupifera populations were used to determine genetic variation and differentiation and infer the origin and evolutionary history of the species. Genetic diversity is low (H=0.200, Hd=0.861, Pi=0.00238), with obvious pedigree geographical structure among populations (Nst=0.612, Gst=0.117). Genetic differentiation is high (Gst=0.400, SRAP; Fst=0.68080, cpDNA), but gene exchange is low (Nm = 0.749 for nrDNA, Nm = 0.358 for cpDNA). The phylogenetic tree and PCA showed that this differentiation is mainly due to separation of the Hainan Island and mainland populations. Geographical isolation and island effects caused the pedigree structure, with large genetic differentiation, and reduced genetic diversity. STRUCTURE analysis revealed that compared with the Hainan Island population, the mainland population has a single genetic background. The TCS network showed that H17 was the original haplotype on Hainan Island; the H41 haplotype was important in the expansion of C. drupifera from Hainan Island to mainland China. Haplotype historical dynamics revealed expansion of the Hainan Island populations (Tajima’s D=-2.31467**, Fu’s Fs=-2.45270*). Comprehensive analysis suggests that C. drupifera originated on Hainan Island and expanded its range to mainland China. These results provide a scientific basis for the protection, development and utilization of C. drupifera resources and a good example of how geographic isolation and island effects can drive plant lineage differentiation.

Tea-oil

The safety protection of elderly pedestrians has always been the focus of passive safety research in car collision accidents. Lower limb protection efficiency for pedestrians is lower than occupant...

Ultrasensitive and ultraselective detection of the gene requires emergency development to meet the medical demands and infectious disease control. Herein we report a versatile and scalable method based on electrochemical-chemical-cyclic amplification (EC-CA) and fluorescence detection for ultrasensitive gene sensing. The EC-CA is achieved by an electro-Fenton reaction (EFR). The hydroxyl radicals generated at EFR are trapped by terephthalic acid to form highly fluorescent 2-hydroxyterephthalic acid, which can be sensitively detected by a fluorescence spectrophotometer. The method is the first to be able to amplify the signal and reduce the noise simultaneously by using the conventional analytical methods directly. This described method can be used for reliable Fe3+ quantification in the range from 0.1 nM to 0.08 mM. The calculated limit of detection (LOD) is 0.02 nM. Then, hepatitis B virus (HBV) and p53 gene were detected by this proposed method through introducing the Fe3O4 nanoparticles into the gene hybridization system. The LODs for HBV and p53 gene even topped out at 2.6 pM and 1.7 fM, respectively. We demonstrated that the finally recorded signal was triply amplified through the EC cycle, Fe3O4 nanoparticles, and sensitive fluorescence detection. At the same time, the background signal arisen from matrix effects and readout noise was effectively suppressed. This method shows it is simple, convenient, and operational through the detection of Fe3+, HBV, and the p53 gene in blood samples, respectively. We believe our method will make a significant, near-term impact on the development of high-sensitivity methods that are versatile and scalable.

Water/steam direct injection is an effective method to lower emissions and improve the power of engines by using waste heat recovery (WHR). The parameters of water injection (WI) and steam injectio...

We propose a simple differential method and a refined Roonizi’s method to fit single Gaussian function and integro-differential method to fit two Gaussian functions. The conventional method for fitting Gaussian functions is an iterative procedure. The proposed methods, being linear in estimated parameters, alleviate the problem of critical initial guess needed in iterative procedures. The experimental results confirm the methods perform better or in a competitive manner compared to Caruana’s, Guo’s, Roonizi’s and FAS algorithm for single Gaussian case. It is found that the proposed integro-differential method to fit two Gaussian functions is stable and identifies Gaussian parameters in an efficient way.

Traditional metal–organic frameworks (MOFs), although have the ability to accumulate some chemicals from solution, are usually electrochemically inert. Here, spherical MIL-53(NiFe) MOFs have been synthesized via a simple solvothermal method. A series of characterization methods including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectrophotometry, energy dispersive X-ray spectroscopy (EDS), and element mapping were used to investigate this material. An MIL-53(NiFe)/AB/GCE-modified electrode was constructed using acetylene black (AB) as the conductive substrate, which can make up for the electrochemical inertness of metal in the MOFs to some extent. Moreover, the bimetallic center can coordinate with the azo functional group in Sudan I to some extent, which is beneficial to the binding of the molecules to the electrode. Thus, the sensitive and rapid detection of Sudan I can be realized. The quantitative determination of Sudan I was carried out via the differential pulse voltammetry (DPV) method in a wider linear range (0.005–10 μM) and lower detection limit (0.002 μM, S/N = 3). The developed method can be successfully applied to the detection of Sudan I in chilli powder and tomato paste with satisfactory results.

Made available in DSpace on 2021-06-25T11:48:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA) from Brazil Coatings are generally applied to fruit as microemulsions, but nanoemulsions are still experimental. 'Nova' mandarins (Citrus reticulata) were coated with shellac or carnauba (Copernica cerifera) microemulsions or an experimental carnauba nanoemulsion; these were compared with an uncoated control during storage for 7 days at 20 degrees C. Coatings were also tested on 'Unique' tangors (C. reticulata x C. sinensis) stored for 14 days at 10 degrees C followed by a simulated marketing period of 7 days at 20 degrees C. Fruit quality evaluations included weight loss, gloss, soluble solids (SS), titratable acidity (TA), pH, SS/TA ratio, internal CO2, O-2, fruit juice ethanol, and other aroma volatile content. Sensory visual shine and tangerine (C. reticulata) flavor rank tests after storage were conducted, followed by an off-flavor rating. The carnauba waxes resulted in less weight loss compared with the uncoated control and shellac coating during both experiments. There were no differences in gloss measurements of 'Nova' mandarins; however, shellac-coated fruit ranked highest for shine in a sensory test. For 'Unique' tangors, initially, shellac showed the highest gloss (shine) measurement; however, at the end of storage, the nanoemulsion exhibited the highest gloss, although it was not different from that of the microemulsion. Similarly, after storage, the nanoemulsion ranked highest for visual shine, although it was not different from that of the microemulsion. There were only minor differences in SS, TA, pH, and SS/TA among treatments. The internal CO2 gas concentration and juice ethanol content generally increased and internal O-2 decreased during storage. The highest levels of CO2 and ethanol were found for the shellac treatment, as was the lowest O-2, indicating anaerobic respiration. There were only minor differences among the other coating treatments; however, they were only sometimes different from those of the control, which generally had the highest O-2, lowest CO2, and lowest ethanol. Shellac and the carnauba microemulsion also altered the volatile profile more than the control and the nanoemulsion did, especially for 'Unique' tangors. For 'Unique' tangors, the control and nanoemulsion ranked highest for tangerine flavor and had the least off-flavor at the end of storage. Among the coatings tested, the carnauba emulsions demonstrated less water loss, imparted more sustainable gloss, and caused less ethanol production than shellac, with the nanoemulsion exhibiting higher gloss measurements, less modifications of the atmosphere and volatile profile, and, consequently, better flavor compared with the microemulsion. Sao Paulo State Univ, Sch Pharmaceut Sci, BR-14800901 Araraquara, SP, Brazil ARS, US Hort Res Lab, USDA, 2001 South Rock Rd, Ft Pierce, FL 34945 USA Embrapa Instrumentacao Brazilian Agr Res Corp, BR-13560970 Sao Carlos, SP, Brazil Sao Paulo State Univ, Sch Pharmaceut Sci, BR-14800901 Araraquara, SP, Brazil CAPES: PDSE/201688881.132643/2016-01 FAPESP: 2016/23419-5 CNPq: 407956/2016-6

The equivalent consumption minimization strategy (ECMS) is a promising energy management approach to low-fuel economy with the outstanding features of high efficiency. In this article, an optimal ECMS by Improved Genetic Algorithm (IGA) is proposed. To this end, we improved the genetic algorithm (GA) from the coding method, initialization mode, and cross and mutation process. And based on the comprehensive energy consumption and Pontryagin’s minimum principle, the equivalent factor was derived. The IGA was used to optimize the equivalent factor. To evaluate the performance of the proposed energy management strategy (EMS), the average efficiency of the engine and the motor was analyzed in an urban area, high-speed area, and the whole area. The comprehensive fuel consumption was used as the energy consumption index, and the battery capacity loss under the transient conditions was amplified to 10 years as the evaluation battery life index. The simulation results show that under the New European Driving Cycle (NEDC), the proposed strategy improves the fuel economy and battery life index by 14.64% and 36.76%, respectively, compared with the rule-based EMS.

Fresh-cut mango (Mangifera indica) slices and chunks garner an exotic image and are highly appreciated for their unique flavor and nutritional value. However, processors tend to use firm unripe mangoes to achieve shelf life of 10 to 14 days, which compromises eating quality. The post-processing life of ripe fresh-cut mangoes is limited by tissue softening, translucency, and browning. The current study was undertaken to investigate whether edible coatings can extend the shelf life of fresh-cut mangoes processed at an eating-ripe stage. Three edible coatings, carboxymethylcellulose (1% w/v), aloe (Aloe vera) powder (2% w/v), and whey protein isolate (2% w/v), supplemented with calcium ascorbate 2% w/v (firming agent) and the antioxidants citric acid (0.8% w/v) and acetyl-N-cysteine (0.4% w/v), were used. The mixture of antibrowning agents, whether applied alone or with the edible coatings, was the most effective at reducing slice browning up to 10 and 11 days at 5 °C for ‘Tommy Atkins’ and ‘Kent’, respectively. In general, there were no differences in firmness and flavor among the three edible coatings. Calcium ascorbate alone did not suppress browning consistently, whereas citric acid appeared to be the ingredient having the greatest antibrowning effect on slice quality. Citric acid can easily be used by processors of fresh-cut mangoes to prevent browning.

Liposome-encapsulated citral was prepared by means of a hot homogenization method. The microstructure, particle size, and zeta potential of the capsules were analyzed by transmission electron microscope and dynamic light scattering, respectively, in which the results showed a good dispersion stability of the citral-loaded liposome. In vitro tests showed that liposome-encapsulated citral significantly (P < 0.05) reduced the populations of Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Penicillium italicum more than free citral. In vivo tests conducted on fresh Shatangju mandarin showed that liposome-encapsulated citral-treated fruit exhibited a decay incidence of 56.67%, which is 42.04% lower than free citral-treated fruit (97.78%) after 26 days of storage at 25°C and 60 to 70% relative humidity. Additionally, fruit treated with citral-loaded liposome significantly reduced weight loss and viable yeast and mold during storage. In summary, liposome-encapsulated citral could be an effective antimicrobial agent to extend the shelf life of the Shatangju mandarin. HIGHLIGHTS

Metal/composite hybrid thin-walled structure is the most preferential approach to achieve dual contradictive objectives of high crashworthiness and lightweight of auto body. Its collapse with regard to different fiber layup patterns is one of the governing mechanisms of energy dissipation, which is yet to be explored. Especially, the effect of different fiber layup angles and layup sequences on bending collapse, which is one of the most significant performance indicators, has received little attention. To this gap, this study investigates experimentally and numerically the bending characteristics of aluminum/carbon fiber reinforced plastic (Al/CFRP) hybrid structures with different layup angles and layup sequences. To start with, three-point bending tests are carried out on specimens to derive the bending failure behavior and crashworthiness, and the internal section damage is observed by CT scan. Finite element model is then constructed and benchmarked against the test results to be proficient. On this basis, the effects of Al thickness, number of CFRP layers and CFRP wrapping range on the bending performance of hybrid tube are analyzed numerically. The simulation results show that layup angle has greater effect on the bending performance than layup sequence. Increasing Al thickness and the number of CFRP layers can effectively improve the bending resistance of structure, and appropriate partial wrapping of CFRP can increase the specific energy absorption (SEA) by 10.92% compared with that of complete wrapping. The revelation from this study provides sound reference for the crashworthiness design of metal/composite hybrid thin-walled structure.

The surrogate fuel chemical reaction kinetic mechanism is widely used in computational fluid dynamics (CFD) model to improve the simulation accuracy. The present work developed a new surrogate fuels of heavy fuel oil. The new surrogate fuel includes eight components: C14H16, C16H34, C20H42, C21H44, C5H10, C7H8, C10H8, and C14H10, which were employed according to HFO's measured chemical composition. The newly developed mechanism includes 113 species and 418 reactions. The mechanism was validated with experimental data in shock tube. The surrogate fuel of HFO was chose by comparing heat release rate in fuel ignitability analyzer (FIA). The different ratios of components were researched in surrogate fuel. The surrogate fuel S6 was used as surrogate fuel of HFO. The surrogate fuel S6 of HFO was validated with experimental data in visual constant volume combustion chamber (VCVCC) and marine engine. Satisfactory prediction of spray and combustion development by the present model was shown by comparison with flame images from VCVCC experiments. Last, simulated in-cylinder pressure for a three-dimensional (3D) marine engine CFD model was consistent with experimental and one-dimensional (1D) results. Overall, the S6 mechanism can accurately simulate HFO combustion, bringing the simulation of marine engine a step closer.

Carvacrol is a natural phenolic compound that has received great attention for its high antimicrobial activity. However, the applications of this compound are limited due to its high volatility and low water solubility. In this research, the use of food grade polymers for microencapsulation of carvacrol in a pectin-alginate matrix using a spray drying method was studied. The physical properties, encapsulation efficiency, stability, and the microstructure of the microcapsules were analyzed as well as the products’ antimicrobial and antioxidant properties. The microcapsules were regularly spherical particles with 4.51% moisture content, 0.33 g cm−3 bulk density, 4.55 min wettability, and a hygroscopicity of 34.44 g 100 g−1. The microcapsules also showed high encapsulation efficiency (76.98%) and stability. The microencapsulation process did not significantly affect the antimicrobial activity against Escherichia coli K12 (minimum inhibitory concentration (MIC) = 0.25 mg mL−1) and antioxidant activity (DPPH percentage inhibition (PI) = 89.96%) of carvacrol. The results indicated that the carvacrol microcapsule product can potentially be used as a controlled-release decontaminator in food and nutraceutical processing industries.

By density functional theory of quantum chemistry, the gas reaction mechanism in GaN HVPE growth is extensively studied, especially the reaction of GaCl with NH3, the elimination of H2 or Cl2 from GaCl3:NH3, and the formation of H radicals caused by the evaporation of liquid gallium and its subsequent reactions. By calculations of Gibbs free energies and energy barriers at different temperatures, the reaction probabilities are determined both thermodynamically and kinetically. The results show that Δ G >0 for the whole six possible reactions between GaCl and NH3, which indicates that those reactions are unfavorable. For the three reactions with elimination of H2 or Cl2 from GaCl3:NH3, the reactions are also unfavorable. By thermodynamic calculation of Ga phase change, when T >1200 K, the Ga vapor pressure rises rapidly. Thus, the gaseous Ga in gas phase reaction cannot be neglected. The gaseous Ga reacts with HCl to form GaCl and H radicals, and H radicals will finally result in the amino compounds GaClNH2 and GaCl(NH2)2, which are also unfavorable to further react with NH3. Thus, we conclude that, in addition to GaCl, GaClNH2 and GaCl(NH2)2 are also the most likely Ga-containing molecules in the HVPE reactor, which will provide both GaN surface growth and nanoparticles.

A two-dimensional sand tank experiment was designed to explore the mechanism of water distribution and silt clogging of Yellow River water whilst replenishing groundwater in ‘open window’ reach of the piedmont river and strong seepage area consisting of a gravel and karst layer from top to bottom. Water released through the reach was divided into surface, pore and fracture karst water, of which karst water was an effective recharge from the surface water. A reasonable released water plan is necessary in recharging to avoid invalid recharge. The karst water accounted for 60–70% of the amount of water released before clogging, and this value was reduced to approximately 10–20% whilst a thin clay layer formed from suspended particles on the surface layer of the medium after clogging. The removal rate of suspended solids along vertical and lateral directions in the medium can reach over 96%. The retained amount of suspended particles was mainly distributed on the surface and upper layer region of the medium. A rubber dam can improve effective infiltration whilst promoting suspended solid deposition in the medium. The fitting degree of the numerical simulation and measured results was above 0.9, which proves the reliability of the sand tank model results.

Florida orange trees have been affected by huanglongbing (HLB) for more than a decade. To alleviate disease-caused tree decline, maintain fruit productivity, and reduce disease transmission, enhanced foliar spray programs combining vector control and nutritional supplementation have been applied to healthy and diseased trees. The aim of this research was to discover if the various foliar sprays affect fruit peel oil chemical components. In this study, “Valencia” orange trees, with or without HLB (HLB±), were treated with the grower standard program (control, C) or one of four proprietary enhanced foliar spray programs (N1, N2, N3, and N4) over 16 months. Compared with HLB−, HLB+ samples had lower concentrations of typical peel oil components, including valencene, octanal, and decanal, and were abundant in oxidative/dehydrogenated terpenes, such as carvone and limonene oxide. However, limonene, the dominant component, was not affected by any treatment. Control and three out of four enhanced foliar spray programs, N2, N3, and N4, had very little influence on the chemical profiles of both HLB− and HLB+ samples, while N1 treatment greatly altered the chemical profile of HLB+ samples, resulting in peel oil similar to that of HLB− samples.

Many methods have been developed to reduce emissions from marine heavy-fuel oil (HFO) engines. The effects of exhaust gas recirculation (EGR), Miller cycle, humid air motor (HAM), and start...

Huanglongbing (HLB) is one of the most devastating diseases of citrus, which is associated with Candidatus Liberibacter asiaticus (Las) in the United States. To date, no effective antimicrobial compound is commercially available to control the disease. In this study, we investigated the effects of different antimicrobial chemicals with suitable surfactants on HLB-affected matured citrus trees with emphasis on the fruit yield and quality. Each treatment was applied three times in a 2-week interval during the spring flush period, one time in summer and three times during the autumn flushing period. We extensively examined different parameters such as pathogenic index, disease index, tree canopy, fruit yield, quality, and nutritional status. The results showed that among the treatments, penicillin (PEN) with surfactant was most effective in suppressing Las titer in infected citrus trees, followed by Fosetyl-Al (ALI), Carvacrol (CARV), and Validamycin (VA). Fruit quality analysis revealed that PEN treatment increased the soluble solids content (SSC), whereas Oxytetracycline (OXY) treatment significantly reduced titratable acidity (TA) level and increased the SSC/TA ratio compared to the control. Nutrient analysis showed increased N and Zn levels in ALI and PEN treatments, and OXY treatment increased leaf P, K, S, and Mg levels compared to untreated control. Furthermore, B, Ca, Cu, Fe, and Mn in leaves were reduced in all chemical treatments than that of the untreated control. These findings revealed that some of the chemical treatments were able to suppress Las pathogen, enhance nutritional status in leaves, and improve tree growth and fruit quality of HLB-affected trees.

The objectives of this research were to microencapsulate tangeretin, and to evaluate the basic characteristics of the microcapsule products. Tangeretin is a polymethoxyflavone (PMF) which has been revealed to possess various health benefits and is abundant in tangerine and other citrus peels. Microencapsulation technology is widely employed in the food and pharmaceutical industries to exploit functional ingredients, cells, and enzymes. Spray drying is a frequently applied microencapsulation method because of its low cost and technical requirements. In this research, tangeretin dissolved at different concentrations in bergamot oil was microencapsulated in a citrus pectin/sodium alginate matrix. The resulting microcapsule powder showed promising physical and structural properties. The retention efficiency of tangeretin was greater at a concentration of 2.0% (98.92%) than at 0.2% (71.05%), probably due to the higher temperature of the emulsion during the homogenizing and spray-drying processes. Encapsulation efficiency was reduced with increased concentration of tangeretin. Our results indicate that tangeretin could be successfully encapsulated within a citrus pectin/sodium alginate matrix using bergamot oil as a carrier.

Multi-walled carbon nanotubes (MWCNTs) were used as conductive carrier on the glassy carbon electrode (GCE), and the hybrid of metal organic framework [NH2-MIL-53(Fe)] and horseradish peroxidase (HRP) was prepared by simple physical mechanical mixture. The GCE modified by the above material with immobilization, namely NH2-MIL-53(Fe)/HRP/MWCNTs/GCE, was used to construct an electrochemical biosensor toward H2O2. The results indicated that the addition of NH2-MIL-53(Fe) had a good synergistic effect on the electron transfer of HRP and the detection of H2O2. Under the optimized condition, the biosensor exhibited excellent electrochemical performances such as low detection limit, high sensitivity, good stability and so on. The H2O2 biosensor showed two linear ranges of 0.1 – 1 μM and 1 – 600 μM with a calculated detection limit of 0.028 μM (signal-to-noise ratio, S/N = 3). In addition, the stability of the hybrid of NH2-MIL-53(Fe) and HRP were discussed by SEM, XRD and UV–vis methods. Furthermore, the reported biosensors were practically used in direct detection of H2O2 released from HeLa and HepG2 cells successfully. Thus, this work provides a new strategy to fabricate electrochemical biosensors using MOFs and biomolecules.

In order to get the excitation forces of the vehicle powertrain, a six-degree-of-freedom model of the powertrain mounting system is established. Two different identification methods are presented. Through the test of mount dynamic response, the powertrain excitations identified through these two methods are compared. The results show that the powertrain excitations identified through two methods are basically the same, since the mount accelerations at the body side are really small. The identified excitation is verified by comparing the deformation of torque strut. The robustness analysis of the mount acceleration phase affecting the identification results is also proposed. Improving the accuracy of phase in test input is helpful to improve the accuracy of identification results.

In this study, the effect of direct water injection (DWI) was investigated on the performance of marine diesel engine based on the three-dimensional simulation model. The water injection quantity, temperature and timing were researched on the in-cylinder pressure and temperature, indicated power and NOx emissions. Then, the DWI strategies were compared with the exhaust gas recirculation (EGR). The results showed that the in-cylinder pressure, temperature, indicated power and NOx emissions decrease with increasing of water quantity. Reductions in NOx emissions up to 55.6% were obtained after applying DWI to the engine at the compression stroke. The water injection temperature has a little effect on the combustion and emissions of marine engine. The indicated power decreased when the water injection timing in the compression stroke. However, the indicated power increased when the water injection timing in the late combustion phase. The water injection timing in the compression stroke has more potential in reduction NOx emissions. The NOx emissions with water injection in the compression stroke decreased by 40% compared to the value with water injection in the later combustion phase. The ability of DWI and EGR were researched on the solve the trade-off between power and NOx emissions. The results showed that the DWI strategy can reduce NOx emissions at the higher indicated power compared with the results of EGR.

In order to develop a biodegradable agent for food preservation, β-cyclodextrin (β-CD) inclusion complexes containing p-Anisaldehyde (PAA) were prepared using co-precipitation method. Physical properties including moisture content, bulk density, hygroscopicity, entrapment efficiency and loading capacity of the inclusion complexes showed considerable results for food applications. SEM and particle size test showed notably difference between the prepared inclusion complexes and the other formulations including the raw β-CD, physical mixture, and the recrystallized β-CD in both shape and size distribution. FTIR, XRD, TGA and DTA were also carried out and confirmed the formation of inclusion complexes and inhibition of the volatility of encapsulated PAA. As a potential preservation agent, inclusion complexes demonstrated a sustained released behavior in phosphate buffer saline (PBS). Comparing with pure PAA, the inclusion complexes presented a better storage stability in low humidity environment, a higher antioxidant activity, and equal MICs against Escherichia coli and Staphylococcus aureus.

Two major winter melon (Benincasa hispida) cultivars, waxy ‘Large Round’ and non-waxy ‘Southern Dark Skin’ were used for comparison of the physical, chemical and sensory properties of processed juice. Two types of juice were processed by using non-waxy fruits: non-waxy juice without peel (NW) and non-waxy juice with peel (NWP). For waxy fruit, the juice was prepared without peel (W) only. Peel tissues contributed firm particles, and more primary and secondary metabolites. The total tyrosine, phenylalanine, and dietary fiber content in NWP were 12.14 mg L−1, 11.78 mg L−1 and 1.04% respectively, which were significantly higher than in W and NW. However, NWP had more off-flavor, such as hexanal and (E)-2-hexenal, less stability, and higher pulpy mouthfeel. W samples were more stable than NW and NWP during storage without visible sedimentation. The glucose, fructose and TA content of W were 0.58%, 0.58 and 0.23% respectively, which were significantly lower than in NW and NWP. The W juice also had less dimethyl disulfide, and hexanal, and was better rated by the sensory panel for having lower sour, salty, bitter, grassy and cooked vegetable characteristics. The results indicate that the waxy ‘Large Round’ melons are a viable candidate for juice processing.

As a promising non-thermal decontamination technique, γ-irradiation has been practically used to ensure microbial safety of meat and meat products, but its effects on the properties of meat have not yet been fully understood. So, this study mainly investigated the effects of different doses irradiation (0, 3, 5 and 7 kGy) on the muscle protein conformation, surface hydrophobicity, solubility, particle size, turbidity and thermal stability. The results of CD spectroscopy showed that 3 kGy disrupted the beta-sheet to form unordered structures in SP while increasing dose level recovered the ordered structures in SP, especially the increased alpha-helix content of SP after 7 kGy irradiation. In case of MP, beta-turn exhibited a dose-dependent reduction and 7 kGy irradiation resulted in a dramatic increase in beta-sheet compared with MP control (P

Flavor quality is import for determining consumer perception and acceptance of tomato products. In this study, ‘Fendou’ tomato fruit were harvested at six ripening stages and sampled to investigate the development of flavor-relevant compounds during vine ripening. Results showed that upon the initiation of ripening there was an increase in respiration rate and concomitant ethylene evolution that was associated with increased membrane permeability. In accordance with these physiological changes, flavor-relevant compounds demonstrated different expression patterns as fruit ripened, which contributed to ‘red-ripe’ flavor characteristics of red-ripe fruit. Based on correlation analysis between ethylene evolution and the flavor-relevant compounds during ‘Fendou’ tomato ripening and the other researchers’ reports, the activation of System 2-dependent autocatalytic ethylene production plays an important role in the development of most flavor-relevant compounds during tomato vine ripening. Overall, our results suggested that most flavor-relevant compounds that accumulated the most during tomato fruit ripening at red stage could be under ethylene regulation and were among the most important contributors to the ‘red-ripe’ flavor. Due to the development of these compounds, the flavor quality at late ripening stages is different from that of fruit at early ripening stages.

This work assessed two types of two-stage injection strategies for the operation of a diesel engine: pilot and early injection. The effects of the two-stage injection interval and the first-stage fuel injection proportion on the combustion and emission characteristics when employing these two injection strategies were investigated by numerical modeling, dividing the in-cylinder zone into three different regions. Variations in the NOx, soot, HC and CO emissions in each region were determined at various values of two-stage injection interval and first-stage fuel injection proportion for both strategies. The results demonstrate that, considering both the engine combustion and emission characteristics, a two-stage injection strategy in conjunction with an injection interval of 30–40°CA and a first-stage fuel injection proportion of 30–60% is advisable.

A reduced n-tetradecane-toluene mechanism was developed as a surrogate fuel for marine diesel engines. The new mechanism includes 85 species and 317 reactions. The mechanism was used in a computational fluid dynamics model to investigate the performance of marine diesel engine. The new mechanism was validated with experimental data from experiments with a shock tube, flow reactor, jet-stirred reactor and marine diesel engine. The effect of toluene content on the performance of marine diesel engines was also investigated. The results showed that the calculated ignition delay times of n-tetradecane and toluene species were consistent with the experimental data. The errors in the mole fractions of main middle species of toluene were in an acceptable range. The calculated in-cylinder pressure of the marine diesel engine was consistent with the experimental data. The calculated quantity of NOx was also close to the experimental data. The physical properties of toluene significantly affected the performance of the marine diesel engine. The n-tetradecane-toluene mechanism including 30% mass fraction toluene is most suitable as a surrogate fuel for a marine diesel engine, considering the comparisons of calculated and experimental data of power, brake specific fuel consumption, and the quantities of NOx and CO2.

Fouling and corrosion of heat exchanger and pipeline caused by geothermal water is one of the bottlenecks that restrict the efficient utilization of geothermal energy. To mitigate fouling and corrosion of heat transfer surfaces in hot-dry-rock geothermal water with the temperature of 423.15 K, SiO2, SiO2-FPS and TiO2 coatings on AISI304 stainless steel substrates were respectively prepared by sol-gel and liquid phase deposition methods. The effects of surface morphology, roughness and surface free energy on fouling deposition rate were studied. Based on the characteristics of two-dimension roughness profiles of surfaces, surfaces were classified into rough surface and microscopic rough surface. For microscopic rough surface, roughness coefficient was defined, which could preferably describe the characteristic of the microscopic roughness degree. The fouling and corrosion behaviors of different coatings and AISI304 stainless steel substrate in simulated hot-dry-rock geothermal water at about 423.15 K were investigated systematically under forced convection heat transfer. The results showed that the liquid phase deposition TiO2 and sol-gel TiO2 coatings had favorable antifouling property in the calcium bicarbonate type simulated geothermal water. The sol-gel SiO2 and SiO2-FPS coatings had better performances of antifouling and anticorrosion in moderately corrosive hot-dry-rock geothermal water with total dissolved solids (TDS) of about 7000 mg/L.

Peracetic acid (PAA) is commonly used as the strong oxidant in many areas. However, high concentration of PAA can be harmful to health of people. The quantitative determination of PAA is of great significance. Here, a metal–organic framework (MOF) is introduced into the electrochemical sensor for PAA detection. The influence of common transition metal centers on the performance of electrochemical detection of PAA was investigated and the results showed the Cu-1,3,5-trimesic acid (Cu-BTC) was the best original MOF. Ag nanoparticles were decorated in the Cu-BTC to further improve the electrocatalytical activity. The concentration of the added Ag salt and the quality of the reducing agent tannic acid (TA) had a great impact on the performance. The final sample optimized for the synthesis conditions was named as Ag NPs/Cu-BTC. The electrochemical sensor based on Ag NPs/Cu-BTC/GCE was fabricated for sensing PAA with a wide linear range (0.1–5000 μM), low detection limit (0.046 μM, S/N = 3) and high sensitivity (1013.4 μA mM−1 cm−2). The water stability of Ag NPs/Cu-BTC and the anti-interference ability of the sensor were good. The electrochemical sensor could be applied in detecting the concentration of PAA in the commercially available peracetic acid, suggesting the practical application value.

In order to evaluate the potential of developed β-cyclodextrin (β-CD)/p-Anisaldehyde (PAA) inclusion complexes as a fumigation agent for the postharvest decay control in strawberry, both in vitro and in vivo tests were conducted. According to the colony morphology analysis on PDA media, inclusion complexes showed activity on inhibiting the mycelial growth of the fungi including Rhizopus stolonifer, Aspergillus niger and Penicillium. The effect of inclusion complexes on controlling postharvest decay in fresh strawberry was also confirmed by in vivo test, in which the inclusion complexes-treated fruit displayed significantly lower incidence and severity than control, β-CD-treated and free PAA-treated fruit. Moreover, evaluations of fruit qualities including color, weight loss, firmness and TSS, as well as the sensory indexes including appearance, color, texture and flavor were carried out in turn, showing there was no significant difference between inclusion complexes-treated fruit and the other groups.

Since gas sensor drift is a main limitation for the application of an electronic nose, and a reference standard is necessary for shelf management of litchi fruit, a modified mean deviation threshold function based on fast Fourier transform (MDFF–FFT) for electronic nose drift elimination and a new concept the rest storage life (RSL) for litchi fruit shelf situation evaluation have been constructed in this study. Three commonly used threshold acquisition methods, unbiased estimator, fixed threshold, and mini-max principle were evaluated to instead of selecting threshold value randomly for present MDFF–FFT. A PEN3 portable electronic nose was applied to recognize the RSL of litchi during storage across room temperature (RT), refrigerator environment (RE) and controlled-atmosphere (CA) environments. Linear discriminant analysis (LDA), probabilistic neural network (PNN), and partial least squares regression (PLSR) were used to compare the RSL classification effect, recognition accuracy, and predict ability of litchi stored in the three environments based on electronic nose with the drift elimination of different threshold acquisition methods using MDTF–FFT. The results showed that an electronic nose has the potential to recognize the RSL of litchi stored in different environments. Unbiased estimator method can provide better threshold than other threshold acquisition methods for MDTF–FFT. After drift elimination by unbiased estimator method combined with MDTF–FFT, litchi RSL can be classified, recognized and predicted by electronic nose effectively, the accuracy of which was higher than control (no drift elimination) and drift elimination with other methods.

The effect of controlled-release chlorine dioxide (ClO2) gas on the food safety and quality of cherry/grape tomatoes was investigated. Whole grape tomatoes artificially inoculated with either Escherichia coli or Alternaria alternata, or whole cherry tomatoes inoculated with Salmonella enterica Newport, were packed in 1-lb clamshells, and stored at 20 °C for 14 days. ClO2 pouches were attached under the lids with the following four dosages/release rates: single dose slow-release (S), single dose fast-release (F), fast/slow-release combination (FS), and double dose fast-release (FF). The corresponding equilibrium ClO2 concentration in the headspace was about 2, 4, 6 and 8 ppm, respectively. Treatment with F reduced populations of E. coli and A. alternata by 2.9–4.7, and 1.6 to 4.0 log CFU/g, respectively, within 14 days storage at 20 °C. FS and FF treatments showed little benefit over F. The F and FF treatments reduced population of S. enterica for inoculated cherry tomatoes by 3.28 and 3.80 log CFU/g, respectively, compared to control after 14 days’ storage at 20 °C. ClO2-treated grape tomatoes retained higher firmness and had less weight loss compared to the control. The results indicate that 2 ppm of ClO2 (S) in the clamshells did not adequately control microbial populations; the minimum effective concentration of ClO2 was 4 ppm (F). Higher concentrations provided a small but incremental improvement in ability to control microorganisms. ClO2 released into packages of cherry tomatoes during storage reduced weight loss, while maintaining firmness.

The component of marine diesel fuel is complex. The muti-component mechanism with aromatic hydrocarbon can more accuracy the combustion of marine diesel engine. The new reduced n-tetradecane-toluene mechanism of marine diesel engine has been developed in this paper. The established model consists of 85 species and 317 reactions without cross reaction. This paper discuss the cross reaction on the effect of marine diesel engine for different mechanism, the new mechanism and the mechanism with 15% toluene content. The results show that the computed ignition delay time with the new mechanism was agreement with the data of mechanism with cross reaction. The in-cylinder pressure are almost same for all case. However, the heat release rate is higher at the end of for the mechanism with cross reaction. The error of CO2 and NOx is minimum using the mechanism with 15% toluene content added cross reaction. The cross reactions has large effect on the emission of marine diesel engine.

The physical properties and chemical mechanisms have direct relationship with combustion. The physical properties of different alternative fuels are researched on the effect of performance of marine diesel engine in this paper. The effect of in-cylinder pressure, emission products and the main species are compared. It can provides a direction for the researchers in established the CFD model. The results show that the in-cylinder pressure and temperature have large difference for different alternative fuels. The in-cylinder pressure and temperature are lower for the heavy oil. Due to the worse combustion, the soot mass has maximum value for heavy oil. The C14H30 and O2 mass have higher value at the start of combustion for the heavy oil. It also explains the combustion process of heavy oil.