oxidative coupling of methane has been studied over (mn+a+w)/sio2 catalysts in a continuous–flow microreactor, where a represents an alkali ion of li, na, k or cs having different weight percents. the main aim of this study is to find the role of alkali ions in interaction between mn and w species with sio2 to make a proper structure for catalyzing oxidative coupling of methane (ocm) reaction. ...

At ambient conditions, lithium and sodium behave as free-electron metals and adopt highly symmetric close-packed structures. Under high pressure, however, these simple metals undergo a series of complex phase transitions to structures of lower symmetry, along with significant changes of their physical properties. In this review we provide a comprehensive description of these light alkali metals...

Aggregates containing certain constituents can react with alkali hydroxides in concrete. The reactivity is potentially harmful only when it produces significant expansion (Mather 1975). This alkali-aggregate reactivity (AAR) has two forms—alkali-silica reaction (ASR) and alkali-carbonate reaction (ACR, sometimes called alkali-carbonate rock reaction, or ACRR). ASR is more often a concern than A...

Aggregates containing certain constituents can react with alkali hydroxides in concrete. The reactivity is potentially harmful only when it produces significant expansion (Mather 1975). This alkali-aggregate reactivity (AAR) has two forms—alkali-silica reaction (ASR) and alkali-carbonate reaction (ACR, sometimes called alkali-carbonate rock reaction, or ACRR). ASR is more often a concern than A...

Three alkali swelling methods were used to treat two kinds of kraft pulp fibers. The morphological and chemical properties of the treated fibers were elucidated in terms of alkali concentration, with the aim of developing bulky paper and conserving wood resources. The effects of beating before and after alkali swelling were examined. The water retention value of fibers increased when higher con...

Ground granulated blast furnace slag (ggbs), can reduce the alkali load in concrete, despite its relatively high alkali content. Most research has been devoted to the efficacy of slag with an alkali content of less than 1.0% and this is reflected in guidance documents. A comparative assessment was made of the effect, if any, of the alkali level of ggbs on potential alkali-silica reactivity. Exp...

The changes in cell surface properties associated with alkali stress can significantly disrupt cell metabolism and structures, preventing effective interactions between bacterial cells and their environment. Listeria monocytogenes is known to display an adaptive response to alkali stress that enhances its capacity to more effectively survive subsequent severe alkali challenge. In this study, we...