Deacidification of passion fruit juice by ultrafiltration and ion-exchange processes

Deacidification of passion fruit juice by a combination of ultrafiltration (UF) and ion-exchange was studied. Prefiltering the juice by UF facilitated the ion-exchange process. At a feed rate of 700 ml h⁻¹, weakly basic resins removed nearly 95, 80 and 50% titrat-able acids from five, seven and twelve bed volumes of UF permeate, respectively, and did not cause significant sugar losses. UF retentate can be added back to the deacidified UF permeate to restore the suspended solids and some flavour components.     

以苯酚为溶剂用抽提蒸馏法从铂重整生成油中抽取纯甲苯的中型试验

为了提供以苯酚为溶剂用抽提蒸馏法从铂重整生成油中抽取纯甲苯的工业装置设计依据和操作条件,进行了日处理量为250公斤的中型试验。抽提蒸馏塔为一直径200毫米,拥有44个塔盘的泡帽塔。铂重整生成油先经预分馏切割成70—119℃馏份,其中苯含量为0.8%（重量）,甲苯含量为48%（重量）。然后将该馏分进行抽提蒸馏,合理操作条件为酚油比4:1（体积比）;回流比4.5;油进口温度120℃;酚进口温度130℃。精馏段塔盘数为19,汽提段塔盘数为20,酚回收段塔盘数为5。产品经酸碱洗涤和再蒸馏后为硝化级纯度的甲苯,抽提蒸馏的甲苯收率可达97—98%（重量）。如包括预分馏损失,则甲苯的收率为96%（重量）。酸碱洗涤和再蒸馏损失一般可按3%计,因此,纯甲苯净收率为93%（重量）。试验结果提供了工业装置的设计数据。     

Adaptive control systems with robustness optimization to non-linear time-varying unmodelled dynamics

In this paper, the robustness properties of adaptive controllers to non-linear time-varying unmodelled dynamics are presented. A new robust stability criterion will be derived for analysing the robustness of adaptive control in deterministic systems under non-linear time-varying model errors. The concept of the excess robustness of adaptive systems is introduced, and the theory of the minimum H^∞ norm will be employed to solve the problem of robustness optimization in adaptive control systems. The results of simulations, which display the good performance of the robust adaptive controller according to our design algorithm, are also presented.     

MULTITUNING FUZZY CONTROL SYSTEMS DESIGN

A multituning fuzzy control system structure that involves two simple, but effective tuning mechanisms, is proposed: one is called fuzzy control rule tuning mechanism (FCRTM); the other is called dynamic scalar tuning mechanism (DSTM). In FCRTM, it is used to generate the necessary control rules with a center extension method. In DSTM, it contains three fuzzy IF-THEN rules for determining the appropriate scaling factors for the fuzzy control system. In this paper, a method based on the genetic algorithm (GA) is proposed to simultaneously choose the appropriate parameters in FCRTM and DSTM. That is, the proposed GA-based method can automatically generate the required rule base of fuzzy controller and efficiently determine the appropriate map for building the dynamic scalars of fuzzy controller. A multiobjective fitness function is proposed to determine an appropriate parameter set such that not only the selected fuzzy control structure has fewer fuzzy rules, but also the controlled system has a good control performance. Finally, an inverted pendulum control problem is given to illustrate the effectiveness of the proposed control scheme.     

Chinese text classification by the Naïve Bayes Classifier and the associative classifier with multiple confidence threshold values

Each type of classifier has its own advantages as well as certain shortcomings. In this paper, we take the advantages of the associative classifier and the Naïve Bayes Classifier to make up the shortcomings of each other, thus improving the accuracy of text classification. We will classify the training cases with the Naïve Bayes Classifier and set different confidence threshold values for different class association rules (CARs) to different classes by the obtained classification accuracy rate of the Naïve Bayes Classifier to the classes. Since the accuracy rates of all selected CARs of the class are higher than that obtained by the Naïve Bayes Classifier, we could further optimize the classification result through these selected CARs. Moreover, for those unclassified cases, we will classify them with the Naïve Bayes Classifier. The experimental results show that combining the advantages of these two different classifiers better classification result can be obtained than with a single classifier.     

Rolling route for refining grains of super light Mg-Li alloys containing Sc and Be

Pioneering work on Sc or/and Be added Mg-Li alloys with refined grains was initiated.Various rolling-based thermo-mechanical treatments on these Mg-Li alloys were carried out.Four Mg-Li alloys were prepared by vacuum melting process.A unique route for producing fine grains was applied which concluded solution treatment at 350°C,cold rolling with 60% thickness reduction and 250°C annealing,successively.     

一种基于连续线性规划技术的在线静态安全校正算法

提出了一种电力系统在线静态安全校正算法.该算法基于连续线性规划技术,将安全校正问题分解为非线性潮流和线性控制灵敏度计算子问题以及基于灵敏度的线性规划控制子问题.在线性规划控制子问题中采用了扩大参与约束集策略、主导约束预测策略、筛选参与控制集策略和限制部分控制的有效可控区间策略等来提高在线计算的效率.对3个大型实际系统进行的数值分析表明文中所提算法是十分有效的.     

Production of clear guava nectar

Three fining methods were tested for use in producing clarified guava nectar. The enzyme hydrolysis method, especially treating the guava purée with 1000ppm of pectinase at 50°C for 3 h, accomplished satisfactory clarification but caused severe losses in volatile components, pre-treating the purée with 100ppm of pectinase for 1 h greatly facilitated the subsequent bentonite or ultrafiltration clarification processes, and both the bentonite treatment and the ultrafiltration process yielded clarified product, but the ultrafiltered product had less loss of volatiles. However, to achieve storage stability, a membrane of lower than 100000 dalton molecular weight cut-off should be used.     

Heat Curing of Whey Protein Films

Heat curing of edible whey protein isolate (WPI) films was studied as a means of improving mechanical and water vapor barrier properties. Curing temperature and relative humidity (RH) effects on the rate of change of maximum tensile stress (TS), elongation at break (E), Young's Modulus (Y_m), and water vapor permeability (WVP) were investigated. Cure time linearly affected TS and Y_m, while influencing E and WVP exponentially. Increased cure temperature and reduced RH accelerated TS increase, E and Y_m decrease, and increased improvement in WVP barrier properties. These data support the hypothesis that heat curing may elicit additional cross-linking of protein, yielding increased TS and decreased E and WVP; however, further work is required to confirm this hypothesis.     

POTENTIAL USES OF MECHANICALLY DEBONED BULLFROG (RANA CATESBEIANA) MEAT TO PARTIALLY REPLACE LEAN PORK TO PRODUCE EMULSIFIED MEATBALLS

ABSTRACT

The objective of this study was to evaluate the qualities of emulsified meatballs where part of the lean pork was substituted with mechanically deboned bullfrog (Rana catesbeiana) meat (MDBM) during manufacturing and subsequently stored at 4C. Meatballs were manufactured by adding 0, 7.5, 15, 22.5 or 30% MDBM. The meatballs had higher moisture, lower protein and fat contents, darker color, lower water‐holding capacity, higher cooking loss and softer texture as the MDBM usage level increased. The thiobarbituric acid and volatile basic nitrogen values of the products significantly (P < 0.05) increased, and the shear values, springiness and fracturability decreased as the MDBM usage level increased (P < 0.05). The products containing 7.5% MDBM had higher acceptable sensory characteristics than those samples containing more MDBM. In conclusion, emulsified meatballs that had 7.5% mechanically deboned bullfrog meat, substituted with equal quantities of the lean pork, were acceptable based on their physicochemical and sensory qualities.

PRACTICAL APPLICATIONS

Many animal by‐products which are produced during processing are edible and valuable. How to utilize these by‐products has become a great issue for the industry. In this study, high‐quality proteins which were obtained from mechanically deboned bullfrog meat (MDBM) resulted in emulsified meatballs with acceptable qualities. More specifically, this information could make MDBM a possible material to substitute for part of the added lean meat in many emulsion‐type meat products and increase products marketability because of lower raw ingredients' cost. This finding may be useful for both marine and domestic animal industries to make better use of this by‐product. Lastly, this information can be used to enhance the potential reduction of animal wastes, which might pollute the environment.