DESIGN AND OPTIMIZATION OF HEAT EXCHANGERS FOR BATCH HEATING BY THE NTU-EFFECTIVENESS METHOD

A design method has been developed for sizing external heat exchangers for batch processes based on the effectiveness-NTU method. The method is applicable to any heat exchanger configuration and design. Based on the specified process conditions a solution is obtained which directly specifies the required batch circulation rate and the associated heat exchanger effectiveness. This approach is particularly useful for those types of heat exchanger designs which permit explicit sizing.     

A TECHNIQUE FOR ESTABLISHING INSTRUMENTAL CONDITIONS FOR MEASURING FOOD FIRMNESS TO SIMULATE CONSUMER EVALUATIONS*

Abstract. A method is described for measuring the force and the rate at which it is applied to fruits and vegetables by the consumer's hands in judging firmness. Halves of the product were mounted on a force transducer, squeezed and the forces recorded. Preliminary results from an untrained panel indicated that the rates and maximum forces used by males and females are different and depend on the firmness of the product. The data also suggest that the rate of force application in sensory testing is significantly greater than that customarily used in instrumental tests. Limitations of the technique and its potential usefulness in establishing more rational conditions for objective firmness tests are discussed.     

NEED TYPE AND JOB SATISFACTION AMONG INDUSTRIAL SCIENTISTS.

NEED-FULFILLMENT THEORIES OF JOB SATISFACTION ASSUME THAT INDIVIDUALS DIFFER IN THE OUTCOMES THEY PREFER (NEED) TO OBTAIN FROM JOBS, AND THAT THE RELATIONSHIP BETWEEN THE OUTCOMES RECEIVED ON THE JOB AND SATISFACTION IS DEPENDENT UPON THESE PREFERENCES. IT WAS HYPOTHESIZED THAT THE PATTERN OF PREFERENCES FOR JOB OUTCOMES MODERATES THE RELATIONSHIP BETWEEN PREFERENCE FOR AND SATISFACTION WITH AN OUTCOME. QUESTIONNAIRES WERE EMPLOYED TO ASSESS PREFERENCE AND SATISFACTION ON 30 DIFFERENT JOB OUTCOMES WITH 113 INDUSTRIAL RESEARCH SCIENTISTS WORKING IN 1 FACILITY. PREFERENCE (NEED) RATINGS WERE SUBJECTED TO Q CLUSTER ANALYSIS. 2 "NEED" TYPES WERE IDENTIFIED. NEED TYPE MODERATED THE RELATIONSHIP BETWEEN PREFERENCE FOR AND SATISFACTION WITH THAT OUTCOME ONLY ON THOSE OUTCOMES MOST CLOSELY RELATED TO THE COMPANY ITSELF. IT IS PROPOSED THAT THESE 2 NEED TYPES REFLECT THE 2 TYPES OF RESEARCH AND DEVELOPMENT PERSONNEL THAT DIFFER PRIMARILY IN ORIENTATION TOWARD THE COMPANY ITSELF. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The critical distance theory for fatigue analysis of notched aluminium specimens subjected to repeated bending

This paper provides new insights in the use of the critical distance method for fatigue analysis of notched aluminium components subjected to constant amplitude bending loading. A straightforward test setup was developed to load test samples with different stress concentrations in repeated bending at high test frequency. The mean values of the local endurable stress amplitudes are determined with the staircase method and the Dixon and Mood theory using a minimum amount of test samples. The critical distance is determined using these fatigue limits and the corresponding stress gradients determined by means of finite element analysis. The results indicate a unique critical distance of 0.22 mm for fatigue crack initiation. Consequently, the critical distance theory can be successfully applied for fatigue analysis of notched specimens or engineering components of aluminium EN AW 7075 T7351 with geometrical features of various size and shape subjected to fluctuating loading in bending.     

A Rapid Method for the Determination of Soluble and Insoluble Dietary Fiber: Comparison with AOAC Total Dietary Fiber Procedure and Englyst's Method

Total dietary fiber (TDF) was measured in 16 foods by three methods: a rapid enzyme-NDF (neutral detergent fiber) procedure supplemented with a separate procedure for soluble (SOL) fiber, the AOAC TDF method and the comprehensive Englyst's procedure. The NDF+SOL method needed less operator time than the AOAC method and its TDF values were in agreement with the AOAC method (y = 0.98 -0.39; r = 0.997) and with the Englyst's method (y = 1.17 -0.19; r = 0.996). The constituent sugars of polysaccharides in NDF+SOL residues were similar to those by the Englyst's method, indicating an adequate estimation of dietary fiber in foods and food products.