an aquifer located within a petroleum processing plant in moín, costa rica, suffers hydrocarbon pollution. this study aimed to determine the ability of indigenous microorganisms from this site to degrade polycyclic aromatic hydrocarbons (pahs) to evaluate the feasibility of an eventual bioremediation process. aerobic conditions were found in the aquifer, while microbial analyses of the groundwa...

Preparative high pressure liquid chromatography on US-Y zeolite shape-selective molecular sieve was studied for carbon isotopic fractionation e€ects. We tested a standard mixture [17b, 21b(H)-hopane, 5a-cholestane] and complex natural hydrocarbon mixtures dominated by tetraand pentacyclic triterpenoids extracted from Oxford Clay shales. We con®rmed that steroids and hopanoids were separated on ...

The a-master functions of the mode coupling theory for a binary soft-sphere mixture are presented. They are directly determined by the static structure factors S,. The asymmetric stretching of the susceptibility spectra, which is mainly caused by the common von Schweidler high frequency asymptote, is well described by Kohlrausch fits. The stretching parameters and a-relaxation times for various...

We experimentally study one-dimensional, lattice-modulated Bose gases in the presence of an uncorrelated disorder potential formed by localized impurity atoms, and compare to the case of correlated quasidisorder formed by an incommensurate lattice. While the effects of the two disorder realizations are comparable deeply in the strongly interacting regime, both showing signatures of Bose-glass f...

A simple experiment such as the batch distillation of an ethanol–water binary mixture can be performed in a 3-h laboratory session using a very rudimentary apparatus consisting of a still pot and two thermocouples. Yet, the results can lead to very interesting insights to distillation and chemical engineering thermodynamics. The present article describes how one can exploit this simple laborato...

We develop a new method for building a hierarchical tree from binary sequence data. It is based on an ancestral mixture model. The sieve parameter in the model plays the role of time in the evolutionary tree of the sequences. By varying the sieve parameter, one can create a hierarchical tree that estimates the population structure at each fixed backward point in time. Application to the cluster...

Exploiting the mapping between a binary mixture and the Ising model we have analyzed the critical fluctuations by means of the density-matrix renormalization group technique. The calculations have been carried out for a two-dimensional Ising strip subject to equally strong surface fields. It was found that the critical Casimir force has significantly different behavior on opposite sides of the ...

Plastics are not easily biodegradable; and because of these characteristics they can remain under landfill and water for a very long period of time. All over the world only 6% of waste plastics are recycled and the rest of all waste plastics are dumped into landfills. An experiment was conducted in a laboratory scale batch process under Labconco’s fume hood utilizing low density polyethylene (L...

The thermal diffusion factor, aT, for a binary gas mixture is calculated on the basis of nonequilibrium thermodynamics. A new formula for aT is derived and this factor is given for several paris of gases according to this formula.

Some drugs have low bioavailability due to their poor aqueous solubility and/or slowdissolution rate in biological fluids. Stiripentol (STP) is a novel anticonvulsant drug that isstructurally unrelated to the currently available antiepileptics. It has poor aqueous solubilityand its solubility has to be enhanced accordingly. Polyethyleneglycol 6000 (PEG-6000) iscommonly utilized as a hydrophilic...