Insights into the relations between cell wall integrity and in vitro digestion properties of granular starches in pulse cotyledon cells after dry heat treatment

Natural foods,such as whole pulses,are recommended in the dietary guidelines of the US and China.The plant cell wall structure in whole pulses has important implications for the nutritional functionalities of starch.In this study,garbanzo bean cells with varying degrees of cell wall integrity were subjected to dry heat treatment(DHT)and used to elucidate the food structure-starch digestion properties of pulse food.The morphological features suggested that all cell samples do not exhibit remarkable changes after being subjected to DHT.Molecular rearrangement and the crystallite disruption of starch granules entrapped in cells occurred during DHT as assessed by the crystal structure and thermal properties.DHT decreased the inhibitory effects of enzymes of both the soluble and insoluble components,but the digestion rate and extent of slightly and highly damaged cell samples did not exhibit significant differences compared with their native counterparts.We concluded that the starch digestion of pulse cotyledon cells is primarily determined by the intactness of the cellular structure.This study reveals the role of food structure on the ability to retain the desirable nutritional properties of starch after subjection to physical modification.

Analysis of QTL for Seed Dormancy and Their Response to Dry Heat Treatment in Rice (Oryza sativa L.)

Quantitative trait loci (QTL) controlling seed dormancy in rice were identified usingrecombinant inbred lines (RILs) population derived from the cross between a japonicavariety Kinmaze and an indica variety DV85. Seeds of two parental cultivars and each RILwere harvested in 35d after heading. The germination percentage of these seeds at 30℃for 7 days were measured as the degree of seed dormancy. QTL analysis was performed withWindows QTL Cartographer 1.13a program by composite interval mapping. A total of four QTLfor seed dormancy were detected on chromosome 2 (two regions), 5 and 11, respectively.Phenotypic variation explained by each QTL ranged from 8.37 to 17.40%. Responses of suchloci to a dormancy-breaking treatment with dry heat were further detected. The resultsshowed that two alleles of qDOR-2-1 and qDOR-5 from DV85 as well as the allele of qDOR-11 from Kinmaze increased the seed dormancy, which seemed to be easily broken by dry heattreatment. Such loci of seed dormancy may be applied to rice genetic improvement. Theallele of qDOR-2-2 from DV85 increased the seed dormancy, which could not be broken bydry heat treatment.

Numerical Investigation of Heat and Mass Transfer in Nanofluid-Filled Porous Medium

In this work, we numerically study the laminar mixed convection of fluid flow in a vertical channel filled with porous media during the drying process. The porous medium, modeled as a vertical wall, consists of solid and nanofluid phase (Water-Al2O3 or Water-Cu), as well as a gas phase. The established model is developed based on Whitaker’s theory and resolved by our numerical code using Fortran. Results principally show the influence of various physical parameters, such as nanoparticle volume fraction, ambient temperature, and saturation on heat and mass transfer on the drying process. This study brings the effect of the presence of nanofluids in porous media. It contributes not only to our fundamental understanding of drying processes but also provides practical insights that can guide the development of more efficient and sustainable drying technologies. .

Effects of process parameters on pore structure of semi-coke prepared by solid heat carrier with dry distillation

The semi-coke was prepared by solid heat carrier with dry distillation in single factor method. The pore structures of raw coal and semi-coke were characterized by Brunauer-Emmett-Teller (BET) and scanning electron microscope (SEM). The results show that the adsorption and desorption isotherm of semi-coke are not coincident. There was a wide pore distribution on the semi-coke, in which mesopores and micropores account for a considerable proportion. Also there are many more secondary pores. With the increase of the final temperature of heat carrier and constant temperature, as well as the decrease of volume ratio of coal and hot carrier reactor, specific surface area and pore volume of semi-coke increased rapidly first and then decreased and finally increased, along with the rapidly reduction of average pore size. SEM photos show that the surface of semi-coke becomes increasingly rough and glossy.

Dry Heat Treatment Reduces the Occurrence of Cladosporium cucumerinum, Ascochyta citrullina, and Colletotrichum orbiculare on the Surface and Interior of Cucumber Seeds

Dry heat treatment has been identifie as a method for disinfecting seed-borne pathogens in vegetable seeds. This study demonstrated that three seed-borne pathogens of cucumber(Cladosporium cucumerinum that causes scabs, Ascochyta citrullina that results in gummy stem blight,and Colletotrichum orbiculare that induces anthracnose) could be effectively eradicated from cucumber seeds by dry heat treatment. In vitro growth of these three pathogens was inhibited by dry heat treatment at 70 °C for 40 min. These pathogens were inactivated after exposing infected seeds to 70 °C dry heat for at least 90 min. Seed infection was significant y reduced by exposing the seeds to 70 °C dry heat for at least 40 min. Seed moisture content and germination were slightly reduced after 70 °C heat treatment for 40–120 min. Seed vigor remained at a high level after dry heat treatment at 70 °C for 90 min. In conclusion, 70 °C dry heat treatment for 90 min was determined to be the optimal method for eradication of C. cucumerinum, Didymella bryoniae, and C. orbiculare from cucumber seeds.

Effect of Heat Treatment on Silica Aerogels Prepared via Ambient Drying

Silica aerogels were prepared at ambient drying by using ethanol/trimethylchlorosilane （TMCS）/heptane solution as pore water exchange and surface modification of the wet gel before drying. The obtained silica aerogels exhibit a sponge-like structure with uniform pore size distribution. The effects of heat-treatment on the hydrophobicity, specific surface area and other properties were investigated. The results indicated that the hydrophobicity of silica aerogels could be maintained up to 350℃. With increasing heating temperature, hydrophobicity decreased, and became completely hydrophilic after heat-treatment at 500℃. Brunaueremmitt-teller （BET） surface area results indicated that the specific surface area of silica aerogels increased with increasing heating temperature in the range of 150-500℃. The effects of heat-treatment on the morphology and chemical bonding state of silica aerogels were investigated by scanning electron microscopy （SEM）, differential temperature analysis （DTA） and Fourier-transform infrared spectroscopy （FT-IR）.

AN ANALYSIS OF HEAT AND MASS TRANSFERPHENOMENON IN WOOD DURING DRYING

According to modeling simulation and experiments study, the heat and mass transtfer phenomenon.in wood during dring processes was analyzed. The results indicate: at initial stage of drying, moisture movement in wood is due to capillary force, heat transfer is major effect, at end stage, moisture movement in wood is due to diffusive transport, heat transfer is less

Experiment research on grain drying process in the heat pump assisted fluidized beds

A heat pump assisted fluidized bed grain drying experimental system wasdeveloped. Based on this system, a serial of experiments was performed under four kinds of air cycleconditions. According to the experimental analysis, an appropriate drying medium-air cycle for theheat pump assisted fluidized bed drying equipment was decided, which is different from the commonlyused heat pump assisted drying system. The experimental results concerning the drying operationperformance of the new system show that the averaged coefficient of performance (COP) can reach morethan 2.5. The economical evaluation was performed and the power consumption for removing a kilogramwater from grains was about 0.485 kW-h/kg (H_2O), which shows its reasonable commercial efficiencyand great application potentiality in future market.

Effect of friction heat on tribological behavior of M2 steel against GCr15 steel in dry sliding systems

The tribological behavior depends significantly on friction heat under high sliding velocity. Many factors influence the conduction rate of friction heat, such as thermophysical properties of the pairs, the formation components of interface-film, environment mediums, etc. Through theoretical and experimental studies on surface temperature, the heat partition approaches have been applied to the pairs of M2 steel against GCr 15 steel to compare and discuss their tribological behavior in dry sliding contact. The results indicate that the values of the contact pressure have little effect on the heat partition at a high sliding velocity of 40 m/s. Furthermore, the degree of correlation between the dynamic temperature and friction coefficient is obvious, and the correlation degree of parameters increases as the pressure grows. A close correlation exists among the temperatures measured from different points of the pin specimen. At last, X-ray diffraction analysis denotes that the carbides of secondary M6C are separated out during the process of friction.

Temperature and Humidity Control System Identification Based on Neural Network in Heating and Drying System

Artificial neural network has unique advantages for massively parallel processing, distributed storage capacity and self-learning ability. The paper mainly constructs neural network identifier and neural network controller for system identification and control on temperature and hmnidity of heating and drying system of materials. And the paper introduces the structure and principles of neural network, and focuses on analyzing learning algorithm, training algorithm and limitation of the most widely applied multi-layer feed-forward neural network （ BP network） , based on which the paper proposes introducing momentum to improve BP network.

Energy Analysis of Pid Controlled Heat Pump Dryer

In this experimental study, a heat pump dryer was designed and manufactured, in which drying air temperature was controlled PID. Manufactured heat pump dryer was tested in drying kiwi, avocado and banana from among tropical fruits and energy and exergy analyses were made. Drying air temperature changed between 40 oC - 40.2 oC while drying the tropical fruits. Before the drying process in heat pump dryer, initial moisture contents were determined as 4.31 g water / g dry matter for kiwi, 1.51 g water / g dry matter for avocado and 4.71 g water / g dry matter for banana. Then tropical fruits were dried separately in heat pump dryer. Drying air temperature was kept unchanged with the error of +0.2 oC. Drying air velocity changed between 0.3 and 0.4 m/s in a period of 310 min. COPws of the heat pump dryer was calculated as 2.49 for kiwi, 2.47 for banana and 2.41 for avocado during the experiments. EUR changed between 13 % and 28 % for kiwi, 18% and 33% for avocado and 13% and 42% for banana in heat pump dryer.

Weakened carbon and nitrogen metabolisms under post-silking heat stress reduce the yield and dry matter accumulation in waxy maize

Post-silking high temperature is one of the abiotic factors that affects waxy maize(Zea mays L. sinensis Kulesh) growth in southern China. We conducted a pot trial in 2016–2017 to study the effects of post-silking daytime heat stress(35°C) on the activities of enzymes involved in leaf carbon and nitrogen metabolisms and leaf reactive oxygen species(ROS) and water contents. This study could improve our understanding on dry matter accumulation and translocation and grain yield production. Results indicated that decreased grain number and weight under heat stress led to yield loss, which decreased by 20.8 and 20.0% in 2016 and 2017, respectively. High temperature reduced post-silking dry matter accumulation(16.1 and 29.5% in 2016 and 2017, respectively) and promoted translocation of pre-silking photoassimilates stored in vegetative organs, especially in leaf. The lower leaf water content and chlorophyll SPAD value, and higher ROS(H2O2 and O2^-·) content under heat stress conditions indicated accelerated senescent rate. The weak activities of phosphoenolpyruvate carboxylase(PEPCase), Ribulose-1,5-bisphosphate carboxylase(Ru BPCase), nitrate reductase(NR), and glutamine synthase(GS) indicated that leaf carbon and nitrogen metabolisms were suppressed when the plants suffered from a high temperature during grain filling. Correlation analysis results indicated that the reduced grain yield was mainly caused by the decreased leaf water content, weakened NR activity, and increased H2O2 content. The increased accumulation of grain weight and post-silking dry matter and the reduced translocation amount in leaf was mainly due to the increased chlorophyll SPAD value and NR activity. Reduced PEPCase and Ru BPCase activities did not affect dry matter accumulation and translocation and grain yield. In conclusion, post-silking heat stress down-regulated the leaf NR and GS activities, increased the leafwater loss rate, increased ROS generation, and induced pre-silking carbohydrate translocation. However, it reduced the post-silking direct photoassimilate deposition, ultimately, leading to grain yield loss.

石墨烯低温远红外辐射干燥稻谷干燥特性与品质研究

为研究稻谷的石墨烯低温远红外干燥特性及其对稻谷干燥品质的影响,以辐射温度、排粮流量和除湿风量为影响因素,以整精米率和应力裂纹指数增值为评价指标,用自制的循环式石墨烯低温远红外干燥机进行稻谷干燥试验,通过BBD(Box-Behnken设计)响应面法,分析了低温远红外干燥对稻谷干燥品质的影响以及工艺参数优化。结果表明:影响稻谷干燥特性和品质的最主要因素是辐射温度,其次是排粮流量和除湿风量。随着辐射温度的升高,稻谷干燥速率和应力裂纹指数增值逐步增大,整精米率则逐步降低。与同温度的热风干燥相比,石墨烯低温远红外干燥平均干燥速率和干燥品质均有显著提高。经优化后,稻谷最佳石墨烯低温远红外干燥工艺条件为:辐射温度43℃、排粮流量4 kg/min、除湿风量193 m^(3)/h,此时应力裂纹指数增值为9,整精米率为79.75%,稻谷干燥品质最佳。这说明利用石墨烯低温远红外干燥稻谷,可以明显提高干燥速率并改善稻谷干燥品质。

Research on vacuum drying process and internal heat conduction of Li-ion battery core

In this research, an innovative cylindrical automatic battery core oven was designed to avoid the structural deformation that frequently occurs in traditional ovens. The oven could be automatically connected with the electrolyte injection process after baking, achieving improvement in a battery's baking consistency. This contributed to the feasibility of studying the internal heat conduction process of batch battery cores during actual baking processes. A mathematical model of a certain plate battery cell during the baking process was established. The simulation results of the temperature change inside the battery core during the baking process were consistent with the calculation results of the mathematical model. The temperature distribution at each point inside the battery core could be fitted through the thermal conductivity at different temperatures and the temperature distribution between the layers of the battery core.Finally, based on the thermodynamic balance energy conservation method, the relationship between the temperature change inside the battery core and the entire baking process was established. A feasible algorithm for studying the thermal conduction of complex material and internal structure objects in the baking process was obtained.

基于机器学习的空气源热泵干燥能耗回归预测

为了降低空气源热泵干燥过程能耗,研究了空气源热泵干燥能耗特性,采用多元线性回归模型(multivariate linear regression model, MLRM)和BP神经网络(back propagation neural network, BPNN)模型来预测干燥工艺能耗。在分析干燥能耗影响特征参数的基础上,提出将干燥工艺过程进行切分处理的方法以降低数据获取难度。选取烘房设定温度、烘房设定湿度、烘房初始温度、烘房初始湿度、环境平均温度、环境平均湿度、物料质量和初始含水率8个特征参数作为模型输入,能耗和物料结束含水率作为模型输出。使用MLRM模型、BPNN模型和其他机器学习模型进行能耗预测,MLRM模型对能耗拟合的决定系数为0.739,对物料结束含水率拟合的决定系数为0.931;BPNN模型使用Sigmoid函数作为激活函数时对能耗拟合的决定系数最高,为0.828,使用Identity函数作为激活函数时对物料结束含水率拟合的决定系数最高,为0.942,拟合效果优于其他机器学习模型,能够满足实际生产需求。以复水豌豆为干燥对象设计加载物料65 kg、持续时间4 h的完整变温变湿干燥工艺进行验证试验,结果表明:试验总能耗为15.066 kW·h,MLRM模型和BPNN模型的预测总能耗分别为14.476 kW·h、15.183 kW·h,预测精度分别为96.08%、99.23%;试验结束含水率为8.541%,MLRM模型和BPNN模型的预测结束含水率分别为9.560%、8.889%,预测精度分别为88.07%、95.93%。该研究提出了一种使用MLRM模型和BPNN模型对空气源热泵干燥能耗进行分段精准预测的有效手段,对于优化干燥工艺和降低干燥能耗具有实际意义。

太阳能-空气源热泵牧草干燥系统制热性能研究

以太阳能-空气源热泵牧草干燥系统为研究对象,通过系统不同工作模式的温升、恒温制热试验及带载试验,分析了温升速率、单位温升能耗、COP及除湿效率。研究结果表明:联合制热模式与太阳能单独制热相比,单位温升耗电量降低了86.2%,温升速率提高了99~112倍。联合制热模式与热泵单独制热试验相比,在温升过程中温升速率降低了7.7%~17.6%,单位温升耗电量降低8.0%;在恒温制热过程中,前者COP比后者提高了6.5%~11.1%,耗电量降低了5.8%~10.7%;在升温制热过程中前者COP比后者提高了6.0%~10.4%,耗电量降低了6.6%~11.1%。联合干燥模式比热泵单独干燥模式的SMER值高19.8%~36.2%。

红肉火龙果粉的发泡微波冷冻干燥制备与质量评价

制备浆果粉末产品是延长其货架期的有效手段。为降低干燥过程能耗和保留产品营养成分,该研究以平均含水率(87.03±1.26)%的新鲜红肉火龙果果浆为原料,采用冷冻干燥和喷雾干燥两种方法制备了火龙果粉末。以残余湿含量、色泽和典型生物活性成分甜菜红素、芦丁和总酚保留率为指标对产品质量进行了评价。用质量比为3%(w/w)的分离乳清蛋白和2.5%(w/w)的果胶为添加剂制备了未发泡和发泡2种样品,进行了传统和微波冷冻干燥试验。结果表明,使用石英底盘,在30˚C、20 Pa下,发泡样品比未发泡样品冷冻干燥时间缩短了39.06%;施加1 W微波功率时,未发泡和发泡样品微波冷冻干燥时间比无微波时分别缩短了18.75%和12.82%。用碳化硅底盘替代石英底盘,在30˚C、20 Pa和1 W下,发泡样品微波冷冻干燥时间比未发泡和发泡样品传统无微波冷冻干燥分别缩短了65.62%和43.59%。分别以5.5%(w/w)的分离乳清蛋白和15.6%(w/w)的麦芽糊精为添加剂,进行了喷雾干燥试验。工艺参数为进风温度150˚C、出风温度85˚C、进料速度28 mL/min。冷冻干燥产品的甜菜红素、芦丁和总酚保留率分别在72%、84%和75%以上,而喷雾干燥产品的保留率显著降低。该研究采用的冷冻干燥方法能够大幅缩短干燥时间、提高产品质量,为浆果类粉末产品的制备提供工业解决方案。

不同干燥方式对灵芝子实体干燥品质的影响

采用热风干燥、热泵干燥、微波热泵耦合干燥、热泵梯度升温干燥、热泵梯度降温干燥等干燥方式,探究不同干燥方式对灵芝子实体感官、营养及理化品质的影响。结果表明,微波12 min+60℃热泵干燥脱水效率最高,较单一热风干燥至少缩短180 min;微波4 min+60℃热泵干燥色泽保持相对较好;微波12 min+60℃热泵干燥粗多糖含量最高,较60℃热风干燥提高了63.26%;热泵梯度降温干燥对DPPH自由基的清除能力最强;60℃热泵干燥水溶性指数最高。从提高生产效率和营养成分保留率角度考虑,优先选择微波12 min+60℃热泵干燥方式;从产品良好色泽角度考虑,优先选择微波4 min+60℃热泵干燥方式;从产品良好功能活性角度考虑,优先选择热泵梯度降温干燥、60℃热泵干燥方式,为灵芝子实体干燥方式的选择提供理论依据。

干热地区高校夏季室外热环境研究——以石河子市某高校为例

高校校园是师生室外活动的主要场所,其室外热环境直接影响了师生的舒适程度,尤其在干热地区更加显著。因此,对干热地区高校校园进行热环境研究分析具有重要意义。以干热地区新疆石河子市内典型高校石河子大学北苑新区为研究对象,选取校园内人流量较大且功能性明显的5个区域作为典型点位探究室外热环境。从建筑空间形态、典型点位物理环境参数等角度进行实测数据分析。研究结果表明,点位周边的建筑形态以及是否存在绿化植被对其热环境产生了显著影响,从而为干热地区高校校园热环境的研究与改善提供理论基础,具有一定的参考价值。

新疆克州地区学校建筑供暖系统设计研究

研究了新疆克州地区某中学供暖系统设计的思路和流程,包括热源的选择、供暖系统设计,换热站设计等,深入探讨和分析了调试过程中出现的问题,对设计和施工阶段需要关注的设计调研、施工规范等关键环节进行了总结与反思,并提出了解决方案。