Machine learning-driven optimization of plasma-catalytic dry reforming of methane

This study investigates the dry reformation of methane(DRM)over Ni/Al_(2)O_(3)catalysts in a dielectric barrier discharge(DBD)non-thermal plasma reactor.A novel hybrid machine learning(ML)model is developed to optimize the plasma-catalytic DRM reaction with limited experimental data.To address the non-linear and complex nature of the plasma-catalytic DRM process,the hybrid ML model integrates three well-established algorithms:regression trees,support vector regression,and artificial neural networks.A genetic algorithm(GA)is then used to optimize the hyperparameters of each algorithm within the hybrid ML model.The ML model achieved excellent agreement with the experimental data,demonstrating its efficacy in accurately predicting and optimizing the DRM process.The model was subsequently used to investigate the impact of various operating parameters on the plasma-catalytic DRM performance.We found that the optimal discharge power(20 W),CO_(2)/CH_(4)molar ratio(1.5),and Ni loading(7.8 wt%)resulted in the maximum energy yield at a total flow rate of∼51 mL/min.Furthermore,we investigated the relative significance of each operating parameter on the performance of the plasma-catalytic DRM process.The results show that the total flow rate had the greatest influence on the conversion,with a significance exceeding 35%for each output,while the Ni loading had the least impact on the overall reaction performance.This hybrid model demonstrates a remarkable ability to extract valuable insights from limited datasets,enabling the development and optimization of more efficient and selective plasma-catalytic chemical processes.

Application of single neuron adaptive PID controller during the process of timber drying

The paper presents a method of using single neuron adaptive PID control for adjusting system or servo system to implement timber drying process control, which combines the thought of parameter adaptive PID control and the character of neural network on exactly describing nonlinear and uncertainty dynamic process organically. The method implements functions of adaptive and self-learning by adjusting weighting parameters. Adaptive neural network can make some output trail given hoping value to decouple in static state. The simulation result indicates the validity, veracity and robustness of the method used in the timber drying process

Experimental study on shrinkage and rehydration of seed during drying process

Biomaterial will shrink during the drying process. The characteristics of shrinkage and rehydration of fresh peas were studied. Drying curves, shrinkage and rehydration curves of peas without seed coats and whole peas were compared. In addition, different volumetric shrinkage coefficients were obtained and discussed. The results show that seed coats resist moisture movement not only from inside to outside but also from outside to inside during different drying conditions. During a seed’s drying process, the drying curve is similar to the shrinkage curve. The higher the heat flux is, the less drying time is needed, and in the meantime, volume would shrink more and more intensively. Dried media will break easily at high heat flux. When we create a drying regime, both drying speed and the quality of dried media should be considered.

Mathematical Modeling and Effect of Various Hot-Air Drying on Mushroom(Lentinus edodes)

An experimental study was performed to determine the characteristics and drying process of mushroom （Lentinus edodes） by 6 different hot-air drying methods namely isothermal drying, uniform raise drying, non-uniform raise drying, uniform intermittent drying, non-uniform intermittent drying and combined drying. The chemical composition （dry matter, ash, crude protein, crude fat, total sugars, dietary fiber, and energy）, color parameters （L, a＊, b＊, c＊, and h~） and rehydration capacities were determined. Among all the experiments, non-uniform intermittent drying reached a better comprehensive results due to the higher chemical composition, better color quality associated with high bright （26.381＋5.842）, high color tone （73.670＋2.975）, low chroma （13.349a：3.456） as well as the highest rehydration （453.76% weigh of dried body）. Nine kinds of classical mathematical model were used to obtained moisture data and the Midili-kucuk model can be described by the drying process with the coefficient （R2 ranged from 0.99790 to 0.99967）, chi-square （X2 ranged from 0.00003 to 0.00019） and root mean square error （RMSE ranged from 0.000486 to 0.0012367）.

Second-order difference scheme for a nonlinear model of wood drying process

A numerical simulation for a model of wood drying process is considered. The model is given by a couple of nonlinear differential equations. One is a nonlinear parabolic equation and the other one is a nonlinear ordinary equation. A difference scheme is derived by the method of reduction of order. First, a new variable is introduced and the original problem is rewritten into a system of the first-order differential equations. Secondly, a difference scheme is constructed for the later problem. The solvability, stability and convergence of the difference scheme are proved by the energy method. The convergence order of the difference scheme is secondorder both in time and in space. A prior error estimate is put forward. The new variable is put aside to reduce the computational cost. A numerical example testifies the theoretical result.

Simulation of Wetting and Drying Processes in A Depth Integrated Shallow Water Flow Model by Slot Method

A particular porosity method named ＂slot method＂ is implemented in a depth-integrated shallow water flow model （DIVAST） to simulate wetting and drying processes. Discussed is the relationship between the shape factors of the ＂slot＂ and the preset depth used in ＂wetting-drying＂ algorithm. Two typical tests are conducted to examine the performance of the method with the effect of the shape factors of the ＂slot＂ being checked in detail in the first test. Numerical results demonstrate that： 1 ） no additional effort to improve the finite difference scheme is needed to implement ＂slot method＂ in DIVAST, and 2） ＂slot method＂ will simulate wetting and diying processes correctly if the shape factors of the ＂slot＂ being selected properly.

Bacterial Cellulose-Silver Antibacterial Composites：Effects of Drying Processes of Bacterial Cellulose

A type of antibacterial bacterial cellulose(BC) film was prepared for potential uses as wound dressing.In order to obtain a high antibacterial effect,some forms of BC films,including the wet and dried ones were utilized as the template to in situ synthesize silver nanoparticles(AgNPs).The effects of drying methods including freeze-drying,heat drying and air drying,on the microstructures and physical properties of BC,as well as the silver contents and the antibacterial performances of the BC/AgNPs composites were investigated.It was found that the AgNPs impregnated on the dried BC films were inclined to achieve a faster silver releasing rate than the wet one,which was suitable for acute traumas treatment.

Green and Effective Ammonium Carbonate-assisted Process for Drying Hemicellulose Obtained through Alkali Extraction of Bleached Bamboo Kraft Pulp

Hemicellulose has a wide range of applications,including that as an emulsifier for the food industry and raw material for the synthesis of bioethanol/biochemicals and biodegradable films.Hemicellulose is usually present as a spent liquor,such as the prehydrolysis liquor of the prehydrolysis kraft dissolving pulp production process and the alkali extraction liquor of the cold caustic extraction of pulp fibers.Due to its dilute nature,hemicellulose needs to be dried for practical utilization,and this is challenging.In this study,cellulose and hemicellulose in a bleached bamboo kraft pulp were separated using an alkali extraction process.Hemicellulose obtained from the extraction liquor was dried by an ammonium carbonate-assisted drying process.The effects of drying time and drying temperature were determined.Structure of the hemicellulose obtained by the ammonium carbonate-assisted drying process was similar to that of original hemicellulose,as revealed by detailed Fourier transform infrared and X-ray diffraction analyses.The novel drying method was more energy efficient and required a shorter drying time than the conventional freeze drying method,and the excellent solubility in alkaline solutions favored the chemical modification of hemicellulose.The dried hemicellulose can be used as a renewable raw material for the preparation of hydrogels and other substances such as bioethanol/biochemicals and biodegradable films.

Effect of Different Drying Processes on Active Ingredients of Rheum officinale Baill.

[Objectives]To determine the drying process of different functional rhubarbs.[Methods]The contents of tannins,bianthrone,free anthraquinones and combined anthraquinones in medicinal rhubarb were determined by HPLC.The results were analyzed by two-way analysis of variance.[Results]Under different drying conditions,the contents of tannins,bianthrone,free anthraquinones and combined anthraquinones in medicinal rhubarb were significantly different.Taking the tannins content as the index,the optimum drying condition of the rhizome is 1 cm thick,dried at 60℃,the root is cut 1 cm thick,and dried at 30℃;the bianthrone content is used as an indicator,the rhizome is optimally dried.The condition is to cut 1 cm thick,dry at 60℃,the root is cut to 5 cm thick,and dried at 40℃;the free anthraquinones content is used as an index,and the optimum drying condition of the rhizome is 3 cm thick and dried at 50℃.The root is cut to a thickness of 3 cm and dried at 30℃.The combine anthraquinones content is used as an indicator.The optimum drying conditions for the rhizome are 5 cm thick,dried at 40℃,and the root is cut to 5 cm thick and dried at 70℃.[Conclusions]Different functional components of rhubarb have different directional processing methods.The drying process can reduce the drying temperature or increase the thickness of the slice,and the directional processing of the diarrhea-type rhubarb can be processed.The drying process can be carried out by increasing the drying temperature or reducing the thickness of the slice directed processing of heat-clearing and purging-fire rhubarb.

Energy Audit Methodology of Sponge Iron Manufacturing Units Using DRI Process

Conducting complete energy audit (both process and utility) of a sponge iron unit is challenging as there is no laid down procedure to audit the process side. Further, the average heat to power ratio (kWth/kWe) of sponge iron plants ranges from (25:1) to (31:1). This shows that the manufacturing process mostly uses thermal energy and application of electrical energy is insignificant. The main & only source of thermal energy is coal and the entire coal is fed to the rotary kiln. Therefore we find that “Kiln” is the “Black-Box” of this industry and the success of energy efficiency is hidden in the kiln process chemistry. This article tries to establish detailed energy audit methodology of sponge iron manufacturing process or kiln operation with a view to finding out major energy saving potential of the unit. In the research work we find that it is the incomplete reaction of coal that causes the major energy inefficiency in the process. Substantial amount of un-reacted carbon comes out with the char (by-product) which has virtually zero commercial value. The article also puts a question mark on the justification of using high-grade imported coal in such energy inefficient industries.

Optimized Synthesis of Carbon Aerogels via Ambient Pressure Drying Process as Electrode for Supercapacitors

Carbon aerogels were synthesized via ambient pressure drying process using resorcinolformaldehyde as precursor and P123 to strengthen their skeletons. CO2 activation technology was implemented to improve surface areas and adjust pore size distribution. The synthesis process was optimized, and the morphology, structure, adsorption properties and electrochemical behavior of different samples were characterized. The CO2-activated samples achieved a high specific capacitance of 129.2 F/g in 6 M KOH electrolytes at the current density of 1 m A/cm^2 within the voltage range of 0-0.8 V. The optimized activation temperature and duration were determined to be 950 ℃ and 4 h, respectively.

Experimental Study of Drying Process of COLZA Seeds in Fluidized Bed Dryer by Statistical Methods

In this study the effect of initial parameters such as inlet gas temperature, initial particles temperature and gas velocity on temperature changes of solid particles and outlet gas temperature in a fluidized bed dryer was studied. For testing, an experimental setup was established. With combination of air and Colza seeds belonging to D groups of the Geldart classification (Geldart, 1986) fluidization regime was carried out. With five test series with maintaining the inlet gas temperature, solid particle temperature and outlet gas temperature during time were carefully measured. To analyze these data by using regression analysis to predict solid particle and outlet gas temperature, 2 correlations on initial pa-rameters were presented. The result has shown that temperature gradients in the beginning of fluidization, is very high and therefore the exponential functions in the regression model is used to predict the temperature changes.

Intensification of the Banana Drying Processes by Using EFL Electromagnetic Waves

Drying of the banana in the hot water has a negative impact on the quality of the product and drying effect. The purposes of this study are increasing the drying rate, using the relatively low temperature to improve the quality (40℃, 50℃ and 60℃) and investigate the use of electromagnetic waves to increase the drying speed. Therefore, experiments are performed using 5 kHz,10 kHz and 15 kHz low frequency electromagnetic waves in the air velocity values of 0.5 m/s, 1 m/s, 1.5 m/s and 2 m/s and 40℃, 50℃, 60℃ centigrade degrees of air blast in a special compartment. Mathematical model of the drying process has been created as using the electrical circuits methods and experimental results. As a result, a simple equation describing the drying process has been obtained. Nonlinear expression of the diffusion coefficient for a different situation in this equation has been identified for the first time. The obtained theoretical results and experimental results have been provided a good agreement. This study is considered to be useful for all studies in the drying area.

Application of Analytic Hierarchy Process in Selection of an Appropriate Drying Platform for Maize Drying in a Solar Bubble Dryer

The solar bubble dryer (SBD) is a convenient and better option to traditional open sun drying commonly practiced by smallholder farmers in Ghana and other developing countries. However, to operate the SBD, one is faced with the challenge of frequent mixing of grains using a rake to enhance uniform drying and prevent over-heating of the top-layer exposed to the sun. Additionally, condensation in the SBD can compromise the quality of grains during drying under humid conditions. In the present study, the Analytical Hierarchy Process (AHP) was used to select an appropriate drying platform, tarpaulin, or elevated drying rack for maize drying in the SBD. Using the AHP, the elevated drying rack was chosen as a suitable platform for drying maize in the SBD. The SBD with the elevated drying racks was used to dry 270 kg of maize from a moisture content of 18.2% to 12.6% (w.w.b) within 6 hours compared to 11 hours for the same quantity of grains dried on the tarpaulin of the SBD to reach an MC of 12.5% (w.w.b). An average drying rate and moisture extraction rate of 0.93%/h and 2.88 kg/h were achieved with the elevated drying rack system compared to 0.52%/h and 1.60 kg/h when drying on the tarpaulin of the SBD. An average temperature of 44.6°C recorded in the SBD was 9°C more compared to the ambient temperature. The thermal efficiency of the SBD collector was determined as 36.2%. Drying grains with the elevated racks showed advantages of reduced drying time, improved airflow through the drying bed, and prevention of condensation, which occurs when drying on the tarpaulin of the SBD.

Feasibility Analysis of Drying Process Habanero Chili Using a Hybrid-Solar-Fluidized Bed Dryer in Yucatan, M^xico

Drying processing of Habanero chili was improved, through solar energy usage. Habanero chili is a notable seasonal product being drying such important for Mexican producers; this process is expensive and wasteful of energy. A feasibility analysis was developed, to determine the market tendency and the optimal drying conditions for redesign Habanero chili drying process, through a hybrid solar-electric energy usage. The new drying process would be held in two stages： （a） an open solar dryer was used; （b） an existing pilot fluidized bed dryer was adapted with a low temperature solar collector for air heating. Habanero chili was dehydrated from 90% to 5% moisture in 10.3 h, with good quality product, available for commercialization. A reduction in the average drying time of 50% was obtained, also, in the energy usage of 77% in the fluidized bed dryer, with an energy saving of 0.52 kg of natural gas per kg of fresh Habanero chili. An innovative sustainable efficient drying process was developed, and will be strategic to expand the market for Habanero chili with low energy cost.

Nitrogen application levels based on critical nitrogen absorption regulate processing tomatoes productivity, nitrogen uptake, nitrate distributions, and root growth in Xinjiang, China

The unreasonable nitrogen(N)supply and low productivity are the main factors restricting the sustainable development of processing tomatoes.In addition,the mechanism by which the N application strategy affects root growth and nitrate distributions in processing tomatoes remains unclear.In this study,we applied four N application levels to a field(including 0(N0),200(N200),300(N300),and 400(N400)kg/hm^(2))based on the critical N absorption ratio at each growth stage(planting stage to flowering stage:22%;fruit setting stage:24%;red ripening stage:45%;and maturity stage:9%).The results indicated that N300 treatment significantly improved the aboveground dry matter(DM),yield,N uptake,and nitrogen use efficiency(NUE),while N400 treatment increased nitrate nitrogen(NO_(3)^(-)-N)residue in the 20–60 cm soil layer.Temporal variations of total root dry weight(TRDW)and total root length(TRL)showed a single-peak curve.Overall,N300 treatment improved the secondary root parameter of TRDW,while N400 treatment improved the secondary root parameter of TRL.The grey correlation coefficients indicated that root dry weight density(RDWD)in the surface soil(0–20 cm)had the strongest relationship with yield,whereas root length density(RLD)in the middle soil(20–40 cm)had a strong relationship with yield.The path model indicated that N uptake is a crucial factor affecting aboveground DM,TRDW,and yield.The above results indicate that N application levels based on critical N absorption improve the production of processing tomatoes by regulating N uptake and root distribution.Furthermore,the results of this study provide a theoretical basis for precise N management.

方竹笋笋干无硫护色关键技术研究

为降低方竹笋笋干加工过程中褐变程度,提升其外观品质,以新鲜方竹笋为原料,对其蒸煮工艺进行优化,分析抗坏血酸、柠檬酸、植酸及浸泡时间对方竹笋外观品质的影响。单因素试验及正交试验结果表明,将方竹笋清洗后先用蒸汽蒸60 min,再用流水冷却至室温,辅以抗坏血酸添加量0.05%,柠檬酸添加量0.50%,植酸添加量0.15%制成的护色剂,于室温下浸泡60 min所制备方竹笋笋干外观品质最佳,其中柠檬酸添加量对护色效果影响最大,植酸影响最小。该研究结果可为方竹笋笋干的外观品质提升提供理论基础。

基于改进YOLOv7-ByteTrack的干制哈密大枣缺陷检测与计数系统

针对目前无法同时对随机多列排布干制哈密大枣进行快速缺陷检测和统计计数问题,该研究设计了一款干制哈密大枣在线检测与计数系统。以干制哈密大枣为研究对象,利用工业相机拍摄传送带上随机排列的多类别缺陷干制哈密大枣视频为数据源,采用改进的YOLOv7模型进行干制哈密大枣多类别缺陷检测并将检测结果作为后续多目标跟踪算法的输入;考虑到传送带上干制哈密大枣的外观相似性高以及排列密集等特点,该研究结合ByteTrack多目标跟踪算法的思想,设计了一种多类别干制哈密大枣的画线计数方法,实现了随机排布多类别干制哈密大枣的缺陷检测、准确定位及计数。试验结果表明:1)改进的YOLOv7模型浮点计算量为64.6 G,在干制哈密大枣目标检测数据的测试集上的平均检测精度、召回率、F_(1)平衡分数分别达到了98.03%、93.43%和95.00%,相比YOLOv7模型分别提高了4.40、6.88和7.00个百分点,浮点计算量下降了38.6%;2)基于改进YOLOv7为目标检测器开发的ByteTrack算法计数模型对干制哈密大枣计数的准确率为90.12%。该研究可为干制哈密大枣检测计数和分选分级提供技术支持。

晒青绿茶加工过程香气物质及其部分前体变化分析

为探究晒青绿茶特征香气成分在加工过程中的变化规律,以云南大叶种为原料制作晒青绿茶,利用溶剂风味辅助蒸发萃取和气相色谱-质谱联用技术测定鲜叶、杀青叶、揉捻叶和晒青叶的挥发性物质,并结合气味活度值(odor activity value,OAV)表征晒青绿茶活性香气。结果显示,共检测出67种挥发性化合物,以醇类、酯类、醛类物质为主,从鲜叶至杀青结束后挥发物总量增加,晒青叶挥发物质总量较鲜叶略有下降,但种类数增加。晒青绿茶中OAV>1的活性香气成分共计23种,主要为芳樟醇、香叶醇、壬醛等呈花香型和青香型的化合物,各加工工序中以醛类最为突出。采用气相色谱-火焰离子化检测器和高效液相色谱-二极管阵列检测器分别测定其香气前体脂肪酸和类胡萝卜素组分含量,共检测出7种脂肪酸,以饱和脂肪酸为主。共检测出13种类胡萝卜素,其中黄体素在各加工工序中含量都为最高。在晒青绿茶加工过程中,脂肪酸和类胡萝卜素总量持续下降,亚油酸、亚麻酸尤为明显,与其主要降解产物己醛含量变化趋势相反;类胡萝卜素降解转化生成的萜烯酮、紫罗酮及其衍生氧化物,如β-紫罗酮、5,6-环氧-β-紫罗兰酮等含量显著上升。晒青绿茶加工过程中脂肪酸和类胡萝卜素前体变化趋势与其关联香气产物均有一定相关性。本研究结果可为定向改良晒青绿茶香气提供理论指导。

醒发工艺对挂面品质及风味的影响

挂面加工当前多以精制面粉为原料,使用中温干燥工艺,易造成其营养和风味损失。为探究醒发工艺对挂面品质及风味的影响,对不同醒发方式、时间的挂面进行力学特性、蒸煮品质、质构特征、菌落总数、感官评价和挥发性风味物质的测定。结果表明,挂面的最佳醒发工艺为:面絮醒发1.0 h,复合压延4次后面带醒发1.0 h。此工艺条件下,挂面柔韧性高,吸水率高,蒸煮损失率低,硬度小,拉断距离大,检测出风味物质37种,其中醇、醛、酯、酚类化合物总含量达80%以上,具有良好的风味品质。该研究可为提升工业化挂面产品的品质和风味特性提供理论和技术支持。