the adsorption of lead (11) and copper (11) in a fixed bed column using activated carbonprepared from nipa palm nut was investigated. thomas model and yoon and nelson kinetic models were used to analyze the column performance. the rate constant for thomas model increased with increase in flow rate and initial ion concentration but remained constant at varying bed height. adsorption capacity for...

a high performance liquid chromatographic method was developed for determination of aflatoxin b1 (afb1) in foods using a monolithic column with sample clean up on an immunoaffinity column. the method was validated for analysis of afb1 in rice, bread, puffed corn snack, wheat flour and peanut samples. the average recoveries for afb1 in different foods ranged from 94.4 to 102.5% with the coeffici...

The notion of a universal construction is central in computing science: the wheel has not to be reinvented for each new problem. In the context of n-process asynchronous distributed systems, a universal construction is an algorithm that is able to build any object defined by a sequential specification despite the occurrence of up to (n − 1) process crash failures. The aim of this paper is to pr...

Autoreducibility and mitoticity express weak forms of redundancy of information that a set might possess. We describe many results known about these concepts. Mitoticity always implies autoreducibility, but the converse holds in some situations and fails in others. Among the results we describe are that NP-complete sets are many-one autoreducible and that every many-one autoreducible set is man...

MDVSP k k p p k k p K k p k p k ip K k p k p k p k k k ip k k p k j ij i i ij i i p K k x K k n x N i x a x c K k n N i p a p c K k K N j i t d s t A j i A K N j i j i d N i s N i t N K k k k min depot at vehicles of number available : otherwise 0 ; task covers path if 1 path of cost : depot to and from paths of set : , for , if) , (arcs; of set : , for , node to node from go to time : for task...

This paper tells the story of Vectorwise, a high-performance analytical database system, from multiple perspectives: its history from academic project to commercial product, the evolution of its technical architecture, customer reactions to the product and its future research and development roadmap. One take-away from this story is that the novelty in Vectorwise is much more than just column-s...

Although the field of “parameterized complexity” has been around for several years and has generated a large and varied literature, the field is still unknown to a large segment of the theory community, and it is misunderstood by many who have only a vague notion of the field. The article below is not only entertaining and highly readable, but it also explains how the field of parameterized com...

Column-oriented database systems (column-stores) have attracted a lot of attention in the past few years. Column-stores, in a nutshell, store each database table column separately, with attribute values belonging to the same column stored contiguously, compressed, and densely packed, as opposed to traditional database systems that store entire records (rows) one after the other. Reading a subse...

Dear Readers: It is with pleasure that I present to you this month’s extensive issue of 16 excellent papers that show the range of subjects covered by J.UCS. The issue also shows the international flavour of our journal: the contributions come from 16 countries! Those are, in alphabetical order: Australia, Austria, China, Czech Republic, Egypt, Greece, India, Iran, Italy, Japan, New Zealand, Pa...

tion is the importance of random events in generating cell behavior. All biological processes, at the cellular as well as the organismal and evolutionary levels, rely on the energy-dependent reinforcement and perpetuation of random accidents to maintain and transmit information. We appreciate the overwhelming importance of random events in evolution, but randomness rules biology at the microsco...