A simple carbon dioxide injection system has been developed for the maintenance of CO(2) concentrations in semiclosed cuvette systems suitable for photosynthesis and gaseous pollutant studies. The device injects small volumes of pure carbon dioxide into the cuvette in response to a signal from an infrared gas analyzer.

Let $R = bigoplus_{n in mathbb{N}_{0}} R_{n}$ be a standardgraded ring, $M$ be a finitely generated graded $R$-module and $J$be a homogenous ideal of $R$. In this paper we study the gradedstructure of the $i$-th local cohomology module of $M$ defined by apair of ideals $(R_{+},J)$, i.e. $H^{i}_{R_{+},J}(M)$. Moreprecisely, we discuss finiteness property and vanishing of thegraded components $H^...

Vancomycin-resistant Enterococcus faecium strains (VRE) were isolated from human wastewater but not swine fecal waste from a semiclosed agri-food system in Texas. Forty-nine VRE isolates possessed vanA, and one possessed vanB. Twenty-one pulsed-field gel electrophoresis types were identified and segregated into three groups. There was evidence of clonal dissemination among geographically separa...

let $r$ be a commutative noetherian ring with non-zero identity, $fa$ an ideal of $r$, and $x$ an $r$--module. here, for fixed integers $s, t$ and a finite $fa$--torsion $r$--module $n$, we first study the membership of $ext^{s+t}_{r}(n, x)$ and $ext^{s}_{r}(n, h^{t}_{fa}(x))$ in the serre subcategories of the category of $r$--modules. then, we present some conditions which ensure the exi...

The objective of this study is to investigate the fuzzy subhypernear-modules over hypernear-ring by using a triangular norm, which T-fuzzy are generalization submodules hyper near-modules, and some related properties discussed. Idempotent subhypernear-module hypernear-module suggested. relation between level subset presented. Also, image inverse under mapping introduced. direct product i...

Let $R$ be a commutative Noetherian ring and let $fa$, $fb$ be two ideals of $R$ such that $R/({fa+fb})$ is Artinian. Let $M$, $N$ be two finitely generated $R$-modules. We prove that $H_{fb}^j(H_{fa}^t(M,N))$ is Artinian for $j=0,1$, where $t=inf{iin{mathbb{N}_0}: H_{fa}^i(M,N)$ is not finitelygenerated $}$. Also, we prove that if $DimSupp(H_{fa}^i(M,N))leq 2$, then $H_{fb}^1(H_{fa}^i(M,N))$ i...

we introduce the notions of t-dual rickart and strongly t-dual rickart modules. we provide several characterizations and investigate properties of each of these concepts. it is shown that every free (resp. finitely generated free) $r$-module is t-dual rickart if and only if $overline{z}^2(r)$ is a  direct summand of $r$ and end$(overline{z}^2(r))$ is a semisimple (resp. regular) ring. it is sho...