Effect of extraction system, stage of ripeness, and kneading temperature on the sterol composition of virgin olive oils

Comparative extraction trials were carried out among a classical pressing, a dual-, and a three-phase centrifugation system using olive crops of Koroneiki variety. Two different kneading temperatures, 30 and 45°C, were tested at three stages of ripeness for two consecutive years of harvest, 1995–1996 and 1996–1997. Composition of the sterol fraction was determined in the resulting olive oil samples (n=72). Stigmasterol was found to be affected by the extraction system; it was obtained in the highest amount in the pressing system. The ratio campesterol/stigmasterol was significantly higher in oils extracted by dual- and three-phase centrifugation. Sterols were significantly affected by the ripening stage of the fruit. During December, the ratio campesterol/stigmasterol reached the maximal and β-sitosterol the minimal values; this appears to be the optimal period for harvesting the olives. Comparison of the different kneading temperatures showed that at 30°C, Δ⁵-avenasterol and campesterol/stigmasterol ratio reached higher values than at 45°C.     

高岭土填料的表面改性及其应用

高岭土作为填料,已广泛应用于许多行业,但由于不同高岭土表面性能有很大差别,使得应用范围具有局限性.研究、开发不同的表面改性方法,适应高岭土在不同行业中的应用要求,是扩大高岭土应用范围及改善应用效果的重要手段.介绍了高岭土改性的方法、改性高岭土的效果评价以及改性高岭土填料的应用,提出了高岭土改性存在的问题及发展建议.     

Enhanced dissolution and bioavailability of grapefruit flavonoid Naringenin by solid dispersion utilizing fourth generation carrier

Context: Naringenin (NRG), the aglycone flavonoid present in grapefruits, possesses anti-inflammatory, anti-carcinogenic, anti-lipid peroxidation and hepato-protective effects. However, it is poorly soluble in water and exhibits slow dissolution after oral ingestion, thus restricting its therapeutic efficacy.

Objective: With the aim to enhance the dissolution rate and oral bioavailability of NRG, solid dispersion technique has been applied using Soluplus® as carrier.

Methods: Solid dispersions of NRG were prepared by solvent evaporation and kneading methods using various ratios (1:4, 3:7, 2:3 and 1:1) of NRG:Carrier. Characterization of the optimized formulations was performed using Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis. The in vivo behavior of the optimized formulations was also investigated in Wistar Albino rats.

Results: NRG solid dispersion showed a significantly higher solubility and drug dissolution rate than pure NRG (p?Conclusion: Based on these results, it was concluded that solid dispersion technique markedly enhances the in vitro drug release and in vivo behavior of the grapefruit flavonoid NRG.     

立式捏合机桨叶转矩分析

建立了立式捏合机桨叶传动关系和转矩力学模型，应用ANSYS—CFX仿真软件，进行捏合机桨叶在混合高粘度流体时的受力数值模拟，得出了桨叶在捏合工作状态下，单输入多输出的各轴转矩分配定量结果，为捏合机桨叶和传动系统设计提供理论依据。     

平行双螺杆挤出机捏合盘元件设计方法深入探讨

对捏合盘元件设计方法进行了深入研究.利用有限元数值模拟的方法从产量、齿轮箱轴承受力、比能耗、停留时间和力学性能等方面量化对比了中心距修正法和法向等间隙修正法设计的捏合盘元件的加工性能和力学性能.研究内容对平行双螺杆挤出机捏合盘元件设计具有一定的帮助.     

啮合同向双螺杆捏合块元件混合效果的数值模拟分析与实验研究

对啮合同向双螺杆捏合块元件的动态流场进行了流场模拟与统计学分析，并对分析结果进行了实验验证。通过宽、窄捏合块两种螺杆元件的动态流场模拟，应用统计学分析方法计算了两种流场的停留时间分布、最大剪切速率分布以及固定百分比粒子经受的剪切速率分布随时间的变化。得出了宽捏合块元件的分散混合能力高于窄捏合块的结论，这一结论与实验结果较为一致。     

Preparation and Evaluation of Inclusion Complexes of Commercial Sunscreens in Cyclodextrins and Montmorillonites: Performance and Substantivity Studies

Herein we describe inclusion complexes of commercial sunscreens in cyclodextrins and montmorillonites to generate new sunscreen derivatives with optimized functional properties such as water resistance and skin adherence. Four cyclodextrins (α-, β-, and γ-cyclodextrin, and β-dimethyl cyclodextrin) and two montmorillonites (sodium and alkylammonium) were investigated for encapsulating some commercial sunscreens. Our results reveal a good yield and inclusion products with functional properties obtained by using kneading technique on Eusolex® 2292 and Eusolex® 6007 in β-cyclodextrin and solubilization method on Eusolex® 6007 and NeoHeliopan® MA in montmorillonite. In addition, molecular modeling studies indicated flexibility as important for the intercalation of the host molecule.     

浅谈2万t／a预焙阳极工程工艺设计

叙述了某乡镇企业预焙阳极工程的工艺设计特点，体现了既要技术先进又要节约投资的设计思想，为今后相同规模工程的设计提供借鉴和参考     

立式混合机温控系统分析与设计

按照大型立式混合机生产工艺与设备要求，介绍大型立式混合机在进行物料混合生产工艺时的温度自动控制系统的工作特点与设计方法，设计出了满足生产实际要求的结构简单性能优良的温度自动控制系统。     

捏合机恒温供水系统的研究

本文分析了捏合机生产过程的特殊性，并结合温度控制要求，提出一种恒温供水系统解决方案。在该方案中，恒温供水系统用一个控制水箱对捏合锅夹套进行水循环，达到控制被混合物料反应温度的目的。实施结果表明：恒温供水系统可以简化结构，降低故障发生率，并取得良好的温度控制效果，