VERTICAL IMPINGING STREAMS AND SPOUTED BED DRYERS COMPARISON AND PERFORMANCE CHARACTERISTICS

A comparison made between spouted-bed and two-impinging-streams reactors proved the superiority of the-impinging-streams dryer The latter device exhibited, on the one hand, relatively small energy requirements for pumping the phases through the reactor and, on the other hand, improved drying characteristics Thus the two-imping-streams reactor is recommended as a useful device for drying operations     

Optimization of Resource Allocation and Leveling Using Genetic Algorithms

Resource allocation and leveling are among the top challenges in project management. Due to the complexity of projects, resource allocation and leveling have been dealt with as two distinct subproblems solved mainly using heuristic procedures that cannot guarantee optimum solutions. In this paper, improvements are proposed to resource allocation and leveling heuristics, and the Genetic Algorithms (GAs) technique is used to search for near-optimum solution, considering both aspects simultaneously. In the improved heuristics, random priorities are introduced into selected tasks and their impact on the schedule is monitored. The GA procedure then searches for an optimum set of tasks' priorities that produces shorter project duration and better-leveled resource profiles. One major advantage of the procedure is its simple applicability within commercial project management software systems to improve their performance. With a widely used system as an example, a macro program is written to automate the GA procedure. A case study is presented and several experiments conducted to demonstrate the multiobjective benefit of the procedure and outline future extensions.     

Implosive compaction of homo- and copolymer PVC Powders

Four polymeric powders, ranging in average particle size from 75 to 170μm, were shock consolidated at pressures between 6.5 and 14 GPa. High green densities of the order of 95% of theoretical were obtained as a result of plastic deformation, particle comminution and interparticle bonding. Compressive strength to fracture of up to 60 MPa was attained and satisfactory post-shock creep properties were noted. Explosive compacating parameters are discussed and related to impact and material characteristics of direct, axisymmetric systems.     

Objective Site Characterization Using Clustering of Piezocone Data

Cluster analysis is a statistical method for grouping similar mathematical data sets and is used herein for delineating geostratigraphy from piezocone penetration test data. In terms of site characterization, clustering is an improvement over other statistical methods because no preliminary estimation of the inherent groups within the analyzed data is needed, and no overlapping is permitted between identified clusters. Clustering can accommodate single or multivariables and no data filtering is required. Its application to defining stratigraphic interfaces is illustrated using five case studies with layered profiles. Clustering is able to detect major changes within the stratigraphy not apparent by visually examining the trends of piezocone data or by available cone soil classification methods.     

An Environmentally Benign,Highly Efficient Catalytic Reduction of p‐Nitrophenol using a Nano‐Sized Nickel Catalyst Supported on Silica‐Alumina

A green and effective method is reported for the reduction of p‐nitrophenol to p‐aminophenol using a nano‐sized nickel catalyst supported on silica‐alumina in the presence of hydrazine hydrate as an alternative source of hydrogen. It was found that nickel loaded on a silica‐alumina support is a very effective catalyst in the hydrogenation of p‐nitrophenol to p‐aminophenol. Thus it attained 100% conversion in only 69 seconds instead of 260 seconds for commercial Raney nickel. In addition, the possibility to reuse it more than one time with great efficiency gives it another advantage over commercial Rainey nickel which cannot be used more than once. This economical and environmentally friendly method provides a potentially new approach for the synthesis of the intermediate product of paracetamol in industry, which overcomes the drawbacks of the known reduction methods. The prepared catalysts were fully characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray (EDX), and electron spin resonance (ESR) tehniques.     

Improvement and stabilization white of bread flavour

Effect of adding the model system mixture (D,L-lysine · HCl, L-proline and D-glucose) on the sensory properties and volatile components of fresh bread and bread stored for 3 days were investigated. The results showed that the model system mixture improved the crust colour and flavour of fresh bread and kept the freshness, retarded the staling and improved the quality of the bread samples stored for 3 days. Analysis of the crust aroma of the bread samples showed that 2-acetyl pyrazine, 2-acetyl pyridine and 2-methyl-3-ethyl pyrazine, which may be responsible for bread crust aroma, were determined at high concentration in the bread sample containing 0.24% model system mixture. The concentration of pyrazine derivatives increased during storage whereas the carbonyl, pyrrol and furan derivatives decreased.     

An improved method to create nitrocellulose particles suitable for the immobilization of antigen and antibody

A method is described for producing 1-3 microns sized particles of nitrocellulose (NC) which are able to absorb protein. Protein is absorbed onto preformed particles made by first dissolving a sheet of nitrocellulose paper in DMSO, and then precipitating it with sodium carbonate/bicarbonate buffer. The efficiency of binding is the same as that of an equivalent sheet of non-processed NC filter paper. Antibodies absorbed onto preformed particles are not exposed to DMSO and carbonate buffer and therefore retain a high antigen binding capacity. Antigen and antibody-absorbed NC preformed particles were used to capture antibody and antigen, respectively. Using lysis buffer, the captured antibodies and antigens were readily released from the NC particles. This makes the latter an appropriate matrix for immunoprecipitation assays either for an antigen or for specific antibody. Antigen-coated NC particles were specifically aggregated ('agglutinated') by specific antibodies and thus can be used in semi-quantitative tests.     

Partial discharge pulse pattern recognition using Hidden Markov Models

An approach for the classification of cavity sizes based on their maximum charge transfer characteristics, applied voltage partial discharge pattern using Hidden Markov Models, is described. In these models, the partial discharge patterns for different cavity sizes are represented by a sequence of events rather than by the actual curves. In the training phase, each cavity size represents a unique class, which emits its own eigen sequence. Vector Quantization is deployed to assign labels for this particular sequence of events. A Hidden Markov Model is trained for each class, using a set of training patterns consisting of the labels produced by Vector Quantization. During testing, the sequence of events to be recognized is quantized and then matched against all the developed models. The best-matched model pinpoints the cavity size class. Experimental results demonstrate the remarkable capability of the proposed algorithm.