Effect of konjac glucomannan addition on aroma release in gels containing potato starch

The present study aimed to measure the retention of aroma compounds (ethyl acetate, ethyl hexanoate and carvacrol) in dispersions based on konjac glucomannan and/or potato starch, and to highlight the influence of konjac glucomannan on the mechanisms involved in aroma retention. Publications on the effect of konjac glucomannan on aroma release are scarce. Konjac glucomannan is a polysaccharide used as a food additive for its viscous and emulsifying properties. Retention of aroma compounds in dispersions was calculated from partition coefficients which were measured using the phase ratio variation method. This method, consisting of analyses of the headspace at equilibrium, enables the determination of the partition coefficient of volatile compounds in a gas/liquid system without external or internal calibration. The three aroma compounds chosen for this study behave differently toward amylose. Prior to the release study, the complexing behavior of carvacrol with starch, hitherto unknown, was investigated by X-ray diffraction: V_6III amylose complexes were formed with carvacrol. Our results showed no specific interaction between ethyl hexanoate and potato starch or konjac glucomannan. Ethyl acetate retention seemed to be due to trapping in the complex network of polysaccharides and to the density of this network. Retention of carvacrol was influenced by the nature of polysaccharides present in the dispersion, and was mainly governed by specific interaction with starch. Additionally, the addition of konjac glucomannan to potato starch dispersions decreased the retention of volatile compounds complexing starch, but had little effect on the retention of the other aroma compounds.     

Path planning of nanorobot: a review

Microsystem Technologies - Efficient and accurate path planning in a complex biological environment have become a challenge for nanorobot research. This paper first reviews the current path...     

The effect of solvent and ionomer on agglomeration in fuel cell catalyst inks: Simulation by the Discrete Element Method

We simulate agglomeration in different fuel cell catalyst ink solutions using Discrete Element Method. Carbon support is modelled as particles in various inks with ionomer and various solvents. The particles interact with particle-pair forces resulting in agglomerate build-up. The classical colloidal theory with van der Waals and electric double layer forces underestimates the ink stability, which motivates the development of a new model of polymer force between particles. The force is activated when there is a bridging of polymer between the carbon black particles, and the strength is dependent on the ionomer interaction with the solvent by the dielectric constant. A critical dielectric constant was defined for which ionomer form a web-like polymer network that increases the ink stability. This modification can explain the trend of the ink stability, and the model can simulate the effect of different solvents on the agglomerate size distribution with good agreement with experimental results.     

大型整体式修边模的堆焊工艺与应用

大型整体式修边模的堆焊是以普通铸铁为基体,通过选用新型堆焊焊条在模具刃口部位堆焊,替代传统的、采用镶拼修边刃块的修边模制造大型整体式修边模的工艺。通过实践和总结,得出了合理的堆焊工艺参数和预防焊接缺陷的具体措施。实践表明,堆焊刃口的组织和硬度均满足使用要求,具有生产效率高、经济耐用的特点,明显优于传统镶拼修边刃块的制造工艺,特别适用于改型车的模具开发与制造。     

电加热管式炉的优化设计

为节省生产及维修成本,对电加热管式炉进行优化设计。采用浇注料代替常规的耐火砖,设计了新型搁管砖、搁丝砖和透孔砖;炉膛结构由常规拱形改为方形,大砌块烧结搁管砖、搁丝砖的应用使炉膛稳定性增加,避免了更换不锈钢管和炉丝时导致炉体保温性能的下降;对炉体进行优化设计,炉体保温性能好,安装更加方便快捷。实际应用表明,该炉型Dv值可达40 mm·m/min;炉温温度恒定,炉温的波动在±1℃以内,炉两侧温度不超过室温30℃;生产直径1.45 mm高压胶管半成品钢丝,批次抗拉强度波动在±20 MPa内。     

炉温测定过程中问题产生的原因及解决方法

描述了某新建工厂涂装车间烘干炉炉温测定过程中遇到的若干问题及问题的解决。     

豆腐果苷及其代谢产物时辰药动学研究

目的：研究不同时辰给药对豆腐果苷及其代谢产物药代动力学行为的影响。方法：建立并验证豆腐果苷及其3种Ⅰ相代谢产物高效液相色谱-质谱联用同时检测方法。分别在8∶00,14∶00及0∶00灌胃给予大鼠豆腐果苷50 mg/kg,眼底静脉丛采集血样,测得其血药浓度,对比在不同时间给药后原药及代谢产物的药物代谢动力学行为。结果：所建立的高效液相色谱串联质谱检测方法成功应用于灌胃给药后的大鼠血浆豆腐果苷及其3种代谢产物的同时检测。以AUC(0-t)做为吸收程度评价指标,原药、氧化产物、还原产物均为8∶00给药组>0∶00给药组>14∶00给药组;同一时间点原药与代谢产物比较,8∶00给药组、14∶00给药组、0∶00给药组均为：原药>还原产物>氧化产物。Cmax原药0∶00给药组>8∶00给药组>14∶00给药组,还原产物与氧化产物为8∶00给药组>14∶00给药组>0∶00给药组;Tmax原药与还原产物8∶00给药组>14∶00给药组>0∶00给药组,氧化产物8∶00给药组>0∶00给药组>14∶00给药组;以CLz/F为表征的清除情况,原药、还原产物与氧化产物均为14∶00给药组>0∶00给药组>8∶00给药组。 结论：本研究所选择的三个特定时间点,大鼠体内豆腐果苷原药及代谢产物在吸收与代谢过程显示出明显差异。8∶00给药吸收程度要大于其他两个时间点（P<0.01）,14∶00给药原药及代谢产物体内清除快于其他时间点（P<0.01）。     

稀土复合微合金化对A356.2铝合金组织与性能的影响

通过光学显微镜、扫描电镜和拉伸试验机等分析手段研究了多元稀土元素复合添加对A356.2铝合金微观组织及力学性能的影响,并与添加Al-Ti-B和Al-Sr的A356.2微观组织及力学性能进行了对比。结果表明,在多种元素复合添加后,A356.2铝合金的细化和变质效果均较添加Al-Sr、Al-Ti-B时要好,含Fe相也从针状转变成细小的颗粒状。且多元稀土元素复合添加后,合金的伸长率为6.26%,较添加前的4.40%提升了42.38%。     

基于LCC管理的变电站主接线的风险评估

全寿命周期成本(life-cycle Cost,LCC)管理是资产全寿命周期管理(life-cycle management,LCM)的基础和技术手段。Petri网具有图形化表达方式,可以对故障树分析、马尔可夫方程等进行改进并补充更多特征和信息,提高了整个风险评估系统的速度和准确性。采用基于LCC管理的风险评估的方法,在变电站主接线运行分析过程中建立四状态模型。讨论了元件发生计划检修事件和断路器拒动现象,提出利用Petri网的基本方程确定系统状态并计算相应概率,定量分析变电站主接线运行的断供成本,寻求最佳效益下的运行方式。在算例中讨论计算了不同主接线方案的风险指标断供成本,计算结果验证了所提算法的可行性。     

地源热泵的发展现状及新方法研究

简要的介绍了地源热泵的发展情况,对土壤源泵地埋管换热量及土壤热物性测试技术中存在的问题进行了分析,针对土壤热物性测试方法的不足,提出了改进方法,并指出高效节能的地源热泵系统具有良好的发展前景。