This paper presents a novel microwave-assisted hydrothermal technique for synthesizing tin(II) oxide nanoparticles. This technique can be used for producing large quantities of homogeneous nanoparticles in a short time. The effect of the solution molarity, final pH, hydrothermal processing time and microwave power were studied. The tin(II) oxide structure verified from XRD...

This paper studies the optimization of hydrothermal systems. We shall use Pontryagin’s Minimum Principle as the basis for proving a necessary condition for the stationary functions of the functional, setting out our problem in terms of optimal control in continuous time, with the Bolza-type functional. This theorem allows us to elaborate the optimization algorithm that leads to determination of...

Recently published data on the precipitation of Ni–Zn ferrite powders prepared by the hydrothermal method have been analysed in a manner consistent with Avrami theory. The results indicate that the value of the time exponent is due to the growth of spherical particles in a solution which becomes progressively depleted of reactants. The analysis also indicates that the process can be considered ...

The utilization of renewable energy resources is desirable owing to several issues, including the depletion of petroleum resources and global warming1). Among many kinds of renewable resources, marine biomass (macroalgae) could be a promising feedstock for bioproduct and biofuel production2),3). However, appropriate pretreatment is needed prior to its effective utilization. Owing to the high wa...

UNLABELLED Sulfur is an important element in sustaining microbial communities present in hydrothermal vents. Sulfur oxidation has been extensively studied due to its importance in chemosynthetic pathways in hydrothermal fields; however, less is known about sulfate reduction. Here, the metagenomes of hydrothermal chimneys located on the ultraslow-spreading Southwest Indian Ridge (SWIR) were pyro...

Data from a dual-frequency GPS network operated continuously from May 1998±October 1999 on Taal volcano, Philippines, were processed on a daily basis to monitor processes of crustal deformation associated with volcanic activity. During the 16-month period of observations, displacements totaled nearly 30 mm in the horizontal and 50 mm in the vertical over 2.7 and 5.8 km baselines. Relative site ...

Polypropylene (PP) has been one of the most widely used polymers due to the versatility and cost benefits obtained with this material. In this work, composites of PP modified with nanostructured ZSM-5 zeolite were prepared and their thermal and mechanical properties were evaluated. Zeolites were synthetized by hydrothermal method and the crystallization time was modified to evaluate the effect ...

The diversity associated with a microbial mat sample collected from a deep-sea hydrothermal vent on the Southern East Pacific Rise was determined using a molecular phylogenetic approach based on the comparison of sequences from the small subunit ribosomal RNA gene (16S rDNA). The DNA was extracted from the sample and the 16S rDNA was amplified by PCR. Sixteen different phylotypes were identifie...

We report the synthesis of nanoapatite crystals via a hydrothermal reaction of hydroxyapatite precipitates. The impact of the reaction conditions on the properties of the crystals obtained were evaluated. The hydrothermal reaction that takes place markedly affected the crystallinity, morphology, and size of the nanoapatite crystals formed. High crystallinity and large crystal size were obtained...