Innovation in milk powder technology

Global trade in preserved milks is on the increase as new markets open up in regions of the world that have not been traditionally associated with milk consumption. Equally, a rise in world milk production is forecasted to continue, and the indications are that significant quantities of the extra milk produced will be converted to commodity products such as butter and powders. Consequently, on-going investment in new spray drying capability is likely to track geographical shifts in milk production. Successful application of advanced process control to the operation of large scale drying plant is both a priority and a challenge.
  Meanwhile, opportunities for the exploitation of milk as a source of functional ingredients are being availed of by the dairy industry as it continues to achieve added value and unique key selling points. Recent research on the role of spray drying, along with other processes in the development of dairy ingredients for applications in chocolate and the preparation of microencapsulated powders, is reviewed.     

Thick bone section preparation using a silicon-rubber-based sealant

A method has been developed, using a silicon-rubber-based sealant, which allows 2–3-mm-thick specimens to be maintained in a protected fluid environment for a number of months, without risk of dehydration. Following this, the specimen can be retrieved, stained, embedded and sectioned further. For example, 2-mm-thick sections of fixed unstained bone are easily examined by means of epi-illuminated polarized light and fluorescence microscopies using either conventional or confocal optics. The method could easily be extended to other tissues, for example brain tissue.     

Clay-Particle Dispersion by Ultrasons

The dispersion of 1.0% kaolin suspensions in water was studied utilizing ultrasonic vibrational energy. The effect of time of exposure to ultra-sons was examined microscopically and turbidi-metrically by means of a spectrophotometer. Complete deagglomeration and dispersion were accomplished in 10 minutes of exposure to ultra-sons without any apparent deleterious effects on the primary particle size of the kaolin. The effects of two accepted methods of dispersion were compared with the ultrasonic method.     

The role of MRP in repetitive manufacturing

This paper discusses the findings of a study of production planning and control systems in nine repetitive manufacturers in the southeast United States. The purpose of the study was to identify the methods used by repetitive manufacturers to plan and control production. The companies in the study were selected so that three companies were noted for their use of MRP, three others were noted for their use of JIT, and three others were noted for their use of theory of constraints (TOC) (formerly OPT). The principle finding from the study was that all nine companies used a blend of production planning techniques using MRP as a framework to accomplish production planning. This finding was especially surprising when the companies had been specifically selected upon the recommendation of a panel of experts because some companies were known to be superior in the application of JIT and TOC methods     

A comparative study of priority dispatching rules in a hybrid assembly/job shop

This paper reports on research conducted on the use of priority dispatching rules in a hybrid assembly/job shop which manufactures both single-component and multiple-component products. A simulation model was constructed and a large stale experiment performed. Statistical analysis of the simulation results indicated significant impact of both the priority rules tested, and the product-mix considered on shop performance.

Among the 12 priority rules tested, the SPT (shortest processing time) rule and the ASMF-SPT (assembly jobs first with SPT as tie-breaker) rule performed very well with respect to measures like lateness, flow time, tardiness, staging time, and percent of jobs tardy. These findings lead to further investigation of a combined priority rule, MIXED, which implements the ASMF-SPT rule at all machine centres that process components of assembly jobs, and the SPT rule at the remaining machine centres which process non-component jobs. The additional research results yielded evidence that the MIXED rule can reduce the staging time of the SPT rule, and yielded betrer results than the ASMF-SPT rule with regard to other performance measures.

The most interesting finding, however, was the small variation in flow time distribution resulting from use of the MIXED rule when there were more assembly jobs. In an MRP environment, it is especially desirable to have a priority dispatching rule resulting in minimum variation in individual flow times which allows the replenishment lead times to be estimated with greater accuracy.     

Analysis of material and capacity requirements with Q-GERT

The purpose of this paper is to report on research conducted to develop a simulation model which incorporates the basic MRP logic into the modelled production process. The objective of the modelling effort is to provide information necessary for planning and controlling of the material and capacity requirements of a production process that includes stochastic processes. The modelling and analysis procedure exploits the fact that the structure of the production process can be logically modelled as a network flow process. The technique employed to facilitate the network modelling is Q-GERT (Graphical Evaluation and Review Technique) modelling and simulation language. A case application is presented to demonstrate a prototype model, followed by a report of the simulation results. The model is designed to provide answers and insights to the following questions: (1) how long must each production centre operate to yield the specified quantities of finished products, (2) what is the expected lead time required to complete the production of finished products, (3) what are the utilization rates for various processing stations, and/or percentage idle times due to lack of preprocess inventories, and (4) where do bottlenecks occur in the production process, as evidenced by large queues of materials or subassemblies prior to the machine centres.     

SENSITIVITY ANALYSIS AND OPTIMIZATION OF ELASTIC-PLASTIC STRUCTURES

Elastic-plastic analysis problems formulated as quadratic programming problems involve energy functional and equilibrium and yield constraints that depend on the design, material and loading. In this paper we consider the problem of determining the variation of structural response with respect to variations of these parameters. A general result for discrete structures is presented and implications for optimal design are discussed.     

More questions than answers: an examination of “To drill or not to drill: a synthesis of experts’ judgments”

The original paper by Nezhad and Baharlou (1991) employed the analytic hierarchy process to estimate the volume of recoverable oil available from a reservoir. The method has undoubted strengths, in particular the rapidity with which it may be employed and the limited resources required to perform the calculations. It is argued here that more information could have been obtained from the original calculation. In addition, it is suggested that modifying some factors in the procedure could affect the outcome. Simple approximate algorithms are presented that are helpful in interpreting the final results     

CRA'S “BLIND SPOTS”: COMMUNITY REINVESTMENT AND CONCENTRATED SUBPRIME LENDING IN DETROIT

ABSTRACT: As the mortgage crisis took shape by 2007, the Community Reinvestment Act of 1977 emerged at the center of a debate over whether community reinvestment regulations were perverse incentives promoting high‐risk lending, or whether those regulations had become outmoded in the face of concentrated subprime lending. This paper weighs those arguments by examining the market behavior of lenders subjected to Community Reinvestment Act (CRA) as the subprime lending boom took shape after 2004. Using Detroit as an illustrative case, it empirically examines the market structure of high‐cost lending, as well as the role played by CRA‐covered lenders in the critical market segments most prone to concentrated subprime lending. The results suggest that several “blind spots” in CRA regulations weakened the Act's ability to counter the firm‐ and neighborhood‐level segmentation that characterized the growth of concentrated subprime lending in Detroit during the peak years of the housing boom.