The gaschromatographic determination of CO in blood has been simplified by using carbon molecular sieve columns for separation of gases. Regeneration of the columns is necessary only after 1000 and more analyses. Moreover, a more simple procedure for evaluating the CO concentration was developed. This procedure is suitable for routine determination in the sensitivity range of 0.2—100 % COHb in ...

The phloem unloading pathway remains unclear in fleshy fruits accumulating a high level of soluble sugars. A structural investigation in apple fruit (Malus domestica Borkh. cv Golden Delicious) showed that the sieve element-companion cell complex of the sepal bundles feeding the fruit flesh is symplasmically isolated over fruit development. 14C-autoradiography indicated that the phloem of the s...

On axonal surfaces that flank the node of Ranvier and in overlying glial paranodal loops, proteins are arranged within circumscribed microdomains that defy explanation by conventional biosynthetic mechanisms. We postulate that the constraint of proteins to these loci is accomplished in part by discriminative membrane-embedded molecular sieves and diffusion barriers, which serve to organize and ...

In a previous work we studied the influence of heat treatment on the molecular sieve properties of activated carbons prepared by chemical activation of lignin [1]. The thermal treatment modified the porous structure of the activated carbons, giving rise to solids that separate C6H6 from C6H12, CO2 from CH4 and O2 from N2 with a relative high selectivity. However, the heat treatment drastically ...

The study's primary purpose is to simulate the adsorption and desorption of volatile organic components on activated carbon bed using python. model was verified with experiments for separation methane (55 mol %) - dioxide (45 mixture vacuum pressure swing an molecular sieve. For a six-component (methane, ethane, propane, butane, nitrogen), Aspen Adsorption flowsheet simulator experimental resul...

Nitrogen is very difficult to remove from natural gas. Most specifications require no more than 4% nitrogen or total inerts in the interstate pipeline system. With about 15% of the raw natural gas produced in the United States having nitrogen contents over 4%, technology is needed to economically bring the gas to pipeline quality. Cryogenic distillation, the current state-of-the-art technology,...

Carbon membrane can be produced using a wide variety of polymer precursor materials via heat treatment process. A general concept route of precursor selection-preparation-modification-performance analysis platform for the carbon membrane has been proposed to promote the development of carbon membrane material for a wide range of application. The current review considers the recent progress of c...

The Front Cover shows the molecular sieve effect by carbon shell coated on metal surface. To suppress reverse current flow generated due to H2/O2 boundary formation under shut-down/start-up conditions during fuel cell operation, selective H2 permeation through allows high HOR activity while effectively inhibiting ORR. More information can be found in Research Article K. Ko, J. Min et al.

Phytoplasmas, biotrophic wall-less prokaryotes, only reside in sieve elements of their host plants. The essentials of the intimate interaction between phytoplasmas and their hosts are poorly understood, which calls for research on potential ultrastructural modifications. We investigated modifications of the sieve-element ultrastructure induced in tomato plants by 'Candidatus Phytoplasma solani,...