We establish a numerically explicit version of the Pólya–Vinogradov inequality for the sum of values of a Dirichlet character on an interval. While the technique of proof is essentially that of Landau from 1918, the result we obtain has better constants than in other numerically explicit versions that have been found more recently. – Dedicated to Mel Nathanson on his 65th birthday

A finite subset A of an abelian group G is said to be zero-free if the identity element of G cannot be written as a sum of distinct elements from A. In this article we study the structure of zero-free subsets of Z/pZ, the cardinalities of which are close to the largest possible. In particular, we determine the cardinality of the largest zero-free subset of Z/pZ, when p is a sufficiently large p...

this experiment was conducted to increase the resistance of tiger barb (capoeta tetrazona ) against environmental stress by feeding brackish water gammarus sp. powder as supplementary diet in three levels (25%, 50% and 75%) and three replicates pe group compared to control group for 60 days. fishes was fed with 4 diet treatment containea of: 100% artificial diet (control group), 25% brakish wat...

the concentrations of cadmium, nickel, lead, and zinc in the four commercial species; silver pomfret(pampus argenteus), king mackerel. (sc0l1l,beromorous commerson), (pomaclasys kaakan), and green tiger prawns (penaeus semisulcatus) were determined in the persian gulf all were collected from the bushir coast. the samples were digested by ultrapure .nitric acid, and then analyzed using the atomi...

in order to evaluate the intercropping of corn (zea mays l.) and bean cultivars (phaseolus spp.) an experiment was carried out in a randomized complete block design with three replicaties at sari agricultural sciences and natural resources university during growing season of 2010. the experimental treatments consisted of sole cropping of corn, white bean, bush bean, red bean, pinto bean and swo...

We present Tiger, a visual environment to design visual language (VL) specifications based on meta models, graph grammars and layout definitions. A VL specification serves as basis to generate a visual editor for VL diagrams as Eclipse plug-in. Introduction. Domain specific modeling languages are of growing importance for software and system development. Meta tools are needed to support the rap...