abstract nitrogen is a key nutrient in plant growth and it is necessary for amino acid synthesis. sulfur has very important role in the biosynthesis of the alliums flavor and pungency precursors and potassium improve crop yield and quality. in order to study the effect of ammonium nitrate and potassium sulfate on concentration some of the mineral elements in onion (allium cepa l. azar shahr cv....

Keyword extraction attracts much attention for its significant role in various natural language processing tasks. While some existing methods for keyword extraction have considered using single type of semantic relatedness between words or inherent attributes of words, almost all of them ignore two important issues: 1) how to fuse multiple types of semantic relations between words into a unifor...

In recent years, many private corporations and government organizations have digitized corpuses of legacy paper documents. Often, these organizations hope to take advantage of digital representations to transform costly manual tasks associated with paper archives into less-costly computer-assisted tasks. The most common approach toward automated information extraction is through inverted indexi...

This paper examines the differences between author generated keywords and automatically generated keywords in one area of scientific and technical literature. Using inverse frequency, keywords produced using both methods are examined using a maximum likelihood algorithm. By reducing the scope and size of the corpus of literature examined, this study more closely emulates the information gatheri...

This work evaluated caffeine removal in a vertical flow constructed wetland (VFCW), planted with Vetiveria zizanioides. The feeding was continuous (synthetic influent: mineral medium and caffeine) to reduce the concentration variations bed. Two influent concentrations (0.75 ± 1.0 mg·L−1 1.5 mg·L−1) were used constant hydraulic load (100 10 L·m−2·d−1). Plant growth monitored weekly, characteriza...

Comparative studies of the pyroelectric properties and structural features sodium niobate sodium-potassium ceramics obtained under different technological conditions for synthesis have been carried out. X-ray phase analysis revealed existence an additional with chemical formula NaNb 10 O 18 in ceramic samples that do not exhibit ferroelectric properties. It is shown temperature material determi...