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Journal of Environmental Sciences 2016年第7期28卷 240-247页

作者： Bo Zhang Zhaoping Zhong Qinglong Xie Shiyu Liu Roger Ruan Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education Southeast University Center for Biorefining and department of bioproducts and biosystems engineering University of Minnesota

A novel technology of two-step fast microwave-assisted pyrolysis（f MAP） of corn stover for bio-oil production was investigated in the presence of microwave absorbent（Si C） and HZSM-5catalyst. Effects of f MAP temperature and catalyst-to-biomass ratio on bio-oil yield and chemical components were examined. The results showed that this technology, employing microwave, microwave absorbent and HZSM-5 catalyst, was effective and promising for biomass fast pyrolysis. The f MAP temperature of 500°C was considered the optimum condition for maximum yield and best quality of bio-oil. Besides, the bio-oil yield decreased linearly and the chemical components in bio-oil were improved sequentially with the increase of catalyst-to-biomass ratio from 1：100 to 1：20. The elemental compositions of bio-char were also determined. Additionally, compared to one-step f MAP process, two-step f MAP could promote the bio-oil quality with a smaller catalyst-to-biomass ratio.

关键词： Two-step Microwave Pyrolysis HZSM-5 zeolite catalyst Catalytic upgrading

Oscillating droplet tribometer for sensitive and reliable wetting characterization of superhydrophobic surfaces

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Droplet 2022年第1期1卷 38-47页

作者： Muhammad Junaid Heikki A.Nurmi Mika Latikka Maja Vuckovac Robin H.A.Ras department of Applied Physics School of ScienceAalto UniversityEspooFinland department of bioproducts and biosystems School of Chemical EngineeringAalto UniversityEspooFinland

Accurate wetting characterization is crucial for the development of next‐generation superhydrophobic ***,wetting properties are measured with a contact angle goniometer(CAG)suitable for a broad range of ***,due to optical errors and challenges in baseline positioning,the CAG method suffers from inaccuracies on superhydrophobic *** we present an improved version of the oscillating droplet tribometer(ODT),which can reliably assess wetting properties on superhydrophobic surfaces by measuring the frictional forces of a water‐based ferrofluid droplet oscillating in a magnetic *** demonstrate that ODT has superior accuracy compared to CAG by measuring the wetting properties of four different superhydrophobic surfaces(commercial Glaco and Hydrobead coatings,black silicon coated with fluoropolymer,and nanostructured copper modified with lauric acid).We show that ODT can detect the small but significant changes in wetting properties caused by the thermal restructuring of surfaces that are undetectable by *** more,unlike any other wetting characterization technique,ODT features an inverse sensitivity:the more repellent the surface,the lower the error of measurement,which was demonstrated by experiments and simulations.

关键词： oscillating frictional wetting

BLUNT CRACK-TIP ELASTOPLASTIC ZONE OF MIXED MODE FRACTURE

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Acta Mechanica Solida Sinica 2014年第5期27卷 531-541页

作者： Mehdi Khojastehpour department of biosystems engineering Ferdowsi University of Mashhad

This article discusses the characterization of fracture process zone at the tip of a blunt crack in elastoplastic materials under mixed mode loading. The analysis includes the description of elastoplastic zone geometry around the blunt crack tip for predicting crack growth direction. The deformed zone appearing at the crack front is described by presenting a criterion based on the subloading surface concept falling within the framework of unconventional plasticity. The mixed mode crack propagates along the minimum value of the elastoplastic region. The present solutions are reduced to those previously reported in literature, when the elastic perfectly plastic material is considered.

关键词： crack fracture elastic plastic materials stress concentration

Effects of reaction temperature,time and particle size on switchgrass microwave pyrolysis and reaction kinetics

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International Journal of Agricultural and Biological engineering 2013年第1期6卷 53-61页

作者： Rui Zhou Hanwu Lei James L.Julson department of Agricultural and biosystems engineering South Dakota State UniversityBrookingsSouth Dakota 57007 USA bioproducts Sciences and Engineering LaboratoryDepartment of Biological Systems EngineeringWashington State UniversityRichlandWashington 99352 USA

This study investigated microwave pyrolysis of switchgrass with particle sizes from 0.5 mm to 4 mm and determined the effects of reaction temperature and time on the yields of bio-oil,syngas,and bio-char.A prediction model was satisfactorily developed to describe the bio-oil conversion yield as a function of reaction temperature and ***-order reaction kinetics was also developed to model the switchgrass *** with different particle sizes was found to be similarly pyrolyzed by microwave *** research results indicated that thermochemical conversion reactions can take place rapidly in large-sized switchgrass by using microwave ***-MS analysis indicates that the bio-oil contained a series of important and useful chemical compounds:phenols,aliphatic hydrocarbons,aromatic hydrocarbons,and furan *** chemical compounds evolved were related to the pyrolysis conditions.

关键词： switchgrass microwave pyrolysis kinetics bio-oil syngas bio-char

Flow-mode synthesis of biodiesel under simultaneous microwave–magnetic irradiation

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Chinese Journal of Chemical engineering 2019年第10期27卷 2551-2559页

作者： Behzad Khedri Mostafa Mostafaei Seyed Mohammad Safieddin Ardebili Mechanics of biosystems engineering department Razi UniversityKermanshahIran biosystems engineering department Shahid Chamran University of AhvazAhvazIran

In this study,aiming at optimization of a novel continuous biodiesel production system was developed by combining technologies based on microwaves and magnetic *** affecting microwave-assisted biodiesel(alkyl esters)production reaction were analyzed in this *** factors included magnetic field intensity(0,0.225 and 0.450 T),microwave power(400,821,and 1181 W),percentages of KOH and Na OH catalysts at constant concentrations of 1 wt%(0,50%and 100%),and percentages of ethanol and methanol at a constant molar ratio of 6:1(0,50%and 100%).Response Surface Methodology(RSM)was used to optimize the reaction ***-based analysis indicated that,all independent parameters had significant effects on the reaction *** of the investigations reveal that the largest effects on the conversion efficiency were due to type of alcohol and magnetic field *** optimized conditions were found to be a magnetic field intensity of 0.331 T,a microwave power of 677.77 W,catalyst percentages of 30.35%and 69.65%for KOH and Na OH,respectively,and alcohol percentages of 80.47%and 19.53%for methanol and ethanol,*** the optimal conditions,yield of the reaction was 96.2%.

关键词： Biodiesel Microwave Magnetic field Transesterification Waste cooking oil

In-depth observations of fermentative hydrogen production from liquid swine manure using an anaerobic sequencing batch reactor

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Journal of Integrative Agriculture 2017年第6期16卷 1276-1285页

作者： Xiao Wu Jun Zhu Hongjian Lin Southern Research and Outreach Center University of Minnesota MN 56093 USA Biological and Agricultural engineering department University of Arkansas AR 72701 USA department of bioproducts and biosystems engineering University of Minnesota MN 55108 USA

In this study,experiments were designed to reveal in-depth information of the effect of pH and hydraulic retention time（HRT）on biohydrogen fermentation from liquid swine manure supplemented with glucose using an Anaerobic Sequencing Batch Reactor（ASBR）*** values of HRT（8,12,16,20,and 24 h）were first tested and the best HRT determined was further studied at five p H levels（4.4,4.7,5.0,5.3,and 5.6）.The results showed that for HRT 24 h,there was a dividing H2 content（around 37%）related to the total biogas production rate for the ASBR System running at p H *** the H2 content went beyond 37%,an appreciable decline in biogas production rate was observed,implying that there might exist an H2 content limit in the *** other HRTs（8 through 20 h）,an average H2 content of 42%could be *** the second experiment（HRT 12 h）,the highest H2 content（35%）in the biogas was found to be associated with p H *** upswing of p H from 5.0 to 5.6 had a significantly more impact on biogas H2 content than the downswing of p H from5.0 to *** results also indicated good linear relationships of biogas and H2 production rates with HRT（r=0.9971 and0.9967,respectively）.Since the optimal ASBR operating conditions were different for the biogas/H2 production rates and the H2 yield,a compromised combination of the running parameters was determined to be HRT 12 h and pH 5.0 in order to achieve good biogas/H2 productions.

关键词： biohydrogen fermentation swine manure hydraulic retention time pH values anaerobic sequencing batch reactor

Non-thermal plasma assisted polymer surface modification and synthesis:A review

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International Journal of Agricultural and Biological engineering 2014年第2期7卷 1-9页

作者： Cheng Yanling Wang Yingkuan Paul Chen Shaobo Deng Roger Ruan China University of Mining and Technology Beijing 100083China department of bioproducts and biosystems engineering University of MinnesotaSaint PaulMN 55108USA Chinese Academy of Agricultural engineering Beijing 100125China

This article reviews the applications of plasma to polymer surface modification and polymer *** treatment causes changes in morphology,structure and properties of *** polymers are treated using plasma,certain monomers with functional groups can be copolymerized with backbone chain or be loaded on the surface,which would help couple reaction of existing polymer chains,graft monomers onto polymers,immobilize proteins,carry antimicrobial drugs,and enhance cell ***,non-thermal plasma process creates unique properties on polymers which allow improved and expanded applications of polymers in food packaging and biotechnology.

关键词： plasma modification synthesis NTP polymers functional groups

Prediction of shelled shrimp weight by machine vision

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第8期10卷 589-594页

作者： Peng-min PAN Jian-ping LI Gu-lai LV Hui YANG Song-ming ZHU Jian-zhong LOU department of biosystems engineering School of Biosystems Engineering and Food Science Zhejiang University Hangzhou 310029 China

The weight of shelled shrimp is an important parameter for grading *** weight prediction of shelled shrimp by contour area is not accurate enough because of the ignorance of the shrimp *** this paper,a multivariate prediction model containing area,perimeter,length,and width was established.A new calibration algorithm for extracting length of shelled shrimp was proposed,which contains binary image thinning,branch recognition and elimination,and length reconstruction,while its width was calculated during the process of length *** model was further validated with another set of images from 30 shelled *** a comparison purpose,artificial neural network(ANN) was used for the shrimp weight *** ANN model resulted in a better prediction accuracy(with the average relative error at 2.67%),but took a tenfold increase in calculation time compared with the weight-area-perimeter(WAP) model(with the average relative error at 3.02%).We thus conclude that the WAP model is a better method for the prediction of the weight of shelled red shrimp.

关键词： Shelled shrimp Image Feature Length extracting Weight prediction Weight-area-perimeter (WAP) model

Biofilter:a promising tool for mitigating methane emission from manure storage

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Journal of Arid Land 2011年第1期3卷 61-70页

作者： Nazim CICEK Danny MANN department of biosystems engineering University of Manitoba

Liquid manure storage may contribute to methane （CH4） emission and this emission can be greatly reduced if appropriate management practices are applied. Biofiltration has been used in other fields for mitigating greenhouse gas （GHG） emission （e.g., landfill） and shown promise for mitigation OH4 emis- sion from liquid manure storage. It has been reported that biofilter was capable of reducing 80% of CH4 emissions from manure storage. The OH4 removal efficiency is influenced by many factors, including OH4 and 02 concentrations, temperature, moisture, composition of the filter bed, nutrient, and empty bed resi- dency time （EBRT）. Biological conversion of methane of a biofilter is a slow process due to the low water solubility of methane. The residence times （EBRT） between 5 min and 5 h have been used, whereas a typical EBRT of 25 s is used for common biofilter applications. Temperature at which methanotrophic bac- teria are active ranges from 10℃ to 45℃. The maximum activity is found at around 30℃. The optimal filter bed water content depends on both the gas flow rate and the type of filter bed （soil, compost, etc.） and ranges from 30%-70% of the water holding capacity. Compost is the best material for filter bed. The optimal pH for methanotrophic bacteria is neutral to slightly acidic. Copper and nitrogen compounds especially nitrate are important nutrients to methanotrophic bacteria but their optimal concentrations have not been founded. Phosphorus and other elements such as potassium and manganese are reported to affect the performance of methanotrophic bacteria but need further confirmation.

关键词： biofilter greenhouse gas methane manure storage

Determination of key soil characteristic parameters using angle of repose and direct shear stress test

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International Journal of Agricultural and Biological engineering 2023年第3期16卷 143-150页

作者： Qizhi Yang Lei Shi Aiping Shi Mingsheng He Xiaoqi Zhao Li Zhang Min Addy School of Agricultural engineering Jiangsu UniversityZhenjiang 212013JiangsuChina China Wine Industry Technology Institute Yinchuan 750021China department of bioproducts and biosystems engineering University of MinnesotaMN 55108USA

Discrete element modelling(DEM)is a numerical method for examining the dynamic behavior of granular *** order to build an accurate simulation model and provide more comprehensive soil characteristic parameters for the design and optimization of various soil contact machinery,in this paper,the discrete element simulation method(EDEM)combined with experimental approach is used to investigate the soil contact characteristic parameters in East *** this study,Hertze-Mindlin(no slip)was used as a particle contact model by taking particle contact parameters and soil JKR(Johnson-Kendall-Roberts)surface energy as determinants,and repose angle,internal friction angle,and cohesive force as evaluation *** method of Plackett-Burman,Stepest ascent,and Box-Behnken were used to gradually reduce the range of parameters needed for simulation until the most accurate value was *** results show that the restitution coefficient,static friction coefficient,and rolling friction coefficient between soil particles have significant effects on the DEM model,and their value of them are 0.596,0.725,and 0.16,*** on these parameters used for the repose angle test and direct shear stress test,the value of repose angle is 31.97°,the internal friction angle is 27.61°,and the cohesive force is 33.06 *** relative errors with the actual measured values are 9.54%,1.87%,and 2.31%,*** order to further test whether the simulation parameters of soil obtained by repose angle test and direct shear stress test are consistent with the real soil,comparison test between field test and discrete element simulation was *** results show that the error in height of ridge between the simulated soil and the actual soil is 4.06%,which is within the acceptable *** also indicates that the calibrated and optimized soil simulation model can accurately represent the real *** research provides theoretical basis and technical support for the study of soil

关键词： soil characteristic parameters calibration repose angle direct shear stress discrete element