DRIFT CONTROL OF HIGH-RISE BUILDINGS WITH UNIT LOAD METHOD

The use of displacement participation factors obtained by the unit load method provides an effective drift control tool for high-rise buildings. Structural sensitivity coefficients and displacement participation factors for members in a structure with respect to the lateral displacement to be controlled are computed and used for identifying active members and their corresponding displacement components. The drift control method using the displacement participation factors with a variable linking strategy is formulated into an optimization problem to determine the amount of material to be modified. Using the drift control method, a structural design model for a high-rise building is proposed and applied to one verifying example and two moment resisting frames. Time consuming trial-and-error processes related to the structural design of a high-rise building is avoided by the proposed structural design model. As demonstrated in the examples, the maximum lateral displacements of the examples are reduced by 57·05, 40·0 and 16·36% without changing the total weights of the structures. © 1997 John Wiley & Sons, Ltd.     

Adsorption and Desorption of Cholesterol in Continuous Supercritical Fluid Processing of Anhydrous Milk Fat

The adsorption breakthrough volume of adsorbent for cholesterol reduction of anhydrous milk fat (AMF) was determined by passing supercritical carbon dioxide (SC-CO₂) phase through an adsorption column with magnesium silicate at 40°C/241 bar. The breakthrough quantity for 76% cholesterol reduction was 2.0g fat/g adsorbent. With in-line adsorption on magnesium silicate, the cholesterol reduction in the extracts was 80 to 86%. Magnesium silicates saturated with cholesterol were regenerated with 10% ethanol in CO₂ at 40°C and 64°C/241 bar. The adsorption capacity of the magnesium silicate regenerated with 10% ethanol in SC-CO₂ at 40°C/241 bar was close to its original value. Its behavior was described by the Langmuir isotherm.     

Yield and Quality of Tofu as Affected by Soybean and Soymilk Characteristics. Calcium Sulfate Coagulant

Nine light hilum soybean (Glycine max (L.) Merr.) varieties were used to study the characteristics of soybeans and soymilk that affect the yield and quality of tofu coagulated with calcium sulfate. The yield of tofu was not affected by the size of soybeans. Soybean varieties high in protein, fat and phosphorus contents produce tofu with higher protein, fat and phosphorus contents. Two models for predicting the yield of tofu were proposed. According to model one, soymilk with higher pH and total solids gives a higher yield of tofu. According to model two, soybeans high in protein and ash and low in phosphorus give a higher yield of tofu.     

EVALUATION OF SWEET POTATO CULTIVARS AND HEATING METHODS FOR CONTROL OF MALTOSE PRODUCTION, VISCOSITY AND SENSORY QUALITY

Two varieties of sweet potato were subjected to four cooking temperature‐time combinations. A fifth treatment involved adding maltose syrup. Raw comminuted sweet potato mash and cooked sweet potato puree were evaluated for total solids, alcohol insoluble solids, commonly occurring sugars, viscosity (puree only) and for starch gelatinization temperatures. The uncooked Owairaka Red variety was higher in total solids and in alcohol insoluble solids than the Toka Toka Gold. With the exception of the cooked puree with added maltose, baking at 200C resulted in puree with the highest maltose levels. A very fast cooking procedure tended to result in puree with lower levels of maltose and high viscosity. Sensory studies revealed that the Owairaka Red variety produced puree with more viscous and adhesive mouth feel. It was concluded that cooking alone could not be used to optimize both maltose production and viscosity.     

ECONOMIC DESIGN OF REFRIGERATED AUTOMATED STORAGE AND RETRIEVAL SYSTEMS

The objective of this paper is the development of a design model for refrigerated automated storage and retrieval systems (R-AS/RS). Compared with ordinary unit-load AS/RS, the R-AS/RS under this study has several different design and operating characteristics: (I) greater emphasis is placed on the storage function and so it has a double-depth lane in the storage rack; (2) cooling units are required to maintain a cold temperature environment in the system; (3) the maximum number of storage orders handled per unit time is limited by the system capacity. Considering the above characteristics, the design problem is formulated as a non-linear mixed integer programming problem in which the cost of the system is minimized. The decision variables are the storage volume, the number of storage and retrieval (S/R) machines, the type and number of cooling units, and the physical configuration of the building. A case problem is solved to illustrate the model.     

改性六方氮化硼/水性聚氨酯防腐涂料制备与性能

以聚甘油-10(PG)作为稳定剂，在超声条件下对六方氮化硼(h-BN)进行剥离和改性。通过红外光谱(FT-IR)、热重分析(TG)、原子力显微镜(AFM)和透射电镜(TEM)对PG改性的h-BN纳米片(GB)进行了表征。将制备的PG纳米粒子用作水性聚氨酯(WPU)涂层的防腐填料，制备了GB质量分数分别0，0.5%，1.0%，2.0%的为复合涂层(PU/GB)。考察了不同涂层的水接触角、吸水率、附着力损失、热稳定性和机械性能。最后，通过电化学工作站研究了WPU、PU/GB0.5、 PU/GB1.0 和PU/GB2.0复合涂层在3.5%NaCl水溶液中的腐蚀行为。结果表明，GB纳米粒子可以显著增强水性聚氨酯涂层的耐水性、热稳定性、机械性能和耐腐蚀性能。     

Integral action in the optimal control of linear systems with some inaccessible state variables†

Optimal feedback control for linear systems with the usual quadratic performance index which penalizes the state and the magnitude of the control is often difficult to apply because of the requirement of complete state measurement and lack of integral mode. A technique is presented, which introduces integral mode into the optimal control law and does not require the measurement of all of the state variables during the dynamic period. The control produced is equivalent to the original optimal Kalman feedback when external disturbance is absent, and during the period of constant disturbance the method yields a trajectory which can be made arbitrarily close to the optimal trajectory without disturbance.     

Mean-square stability of stochastic differential time-lag systems

Two sets of sufficient conditions for the mean-square asymptotic stability of the equilibrium state of linear differential time-lag systems with non-stationary random coefficients are derived. Each of the sets of sufficient conditions is then shown to be equivalent to a corresponding unconstrained optimization problem. Hence, it can readily be solved by standard efficient optimization techniques. The usual trial-and-error method of finding the required parameters to satisfy the stability conditions can now be avoided.