A palindromization map for the free group

We define a self-map Pal: F_2 --> F_2 of the free group on two generators a, b, using automorphisms of F_2 that form a group isomorphic to the braid group B_3. The map Pal restricts to de Luca's right iterated palindromic closure on the submonoid generated by a, b, and is continuous for the profinite topology on F_2. The values of Pal are palindromes and coincide with the elements g of F_2 such that abg is conjugate to bag.Comment: 14 pages. Introduction expanded. Two references added. Sections 3 and 6 of Version 1 have been restructured, now forming Sections 3-

Hexane isomers sorption on a functionalized metal-organic framework

A series of functionalized porous Zr terephthalate MOFs of the UiO-66(Zr) structure type bearing either Br, NH2 or NO2 groups have been synthesized at the multi-gram scale through an atmospheric pressure solvothermal route with the final aim of investigating the influence of functionalization on the separation of hexane isomers (22DMB, 23DMB, 3MP and nHEX). The studies performed in a fixed bed adsorption column with equimolar mixtures at temperatures between 343 and 423 K and partial pressure up to 10 kPa have shown that the Br, NO2 and NH3 forms exhibit an uptake reaching 15%, being the sorption selectivity hierarchy on the whole comparable to the bared UiO-66 solid: 22DMB approximate to 23DMB >> 3MP nHEX. The 22DMB/nHEX selectivity reaches approximately three at low uptake while the 22DMB/3MP selectivity of UiO-66_NO2 is nearly constant (1.3)

A Clebsch-Gordan formula for SL_3 and applications to rationality

If R, S, T are irreducible SL_3-representations, we give an easy and explicit description of a basis of the space of equivariant maps from R tensor S to T. We apply this method to the rationality problem for invariant function fields. In particular, we prove the rationality of the moduli space of plane curves of degree 34. This uses a criterion which ensures the stable rationality of some quotients of Grassmannians by an SL-action.Comment: 16 pages; 1 figure; Macaulay2 scripts used can be found at http://www.uni-math.gwdg.de/bothmer/ClebschGordan/ or at the end of the latex source fil

Functionalization of metal-organic frameworks for hexane isomers separation

This work shows the effect of incorporating three different organic ligands (NH2-H2BDC, NO2-H2BDC and Br-H2BDC) into UIO-66(Zr) framework viewing the separation of hexane isomers(22DMB, 23DMB, 3MP and nHEX)

Functionalization of metal-organic frameworks for hexane isomers separation

This work shows the effect of incorporating three different organic ligands (NH2-H2BDC, NO2-H2BDC and Br-H2BDC) into UIO-66(Zr) framework viewing the separation of hexane isomers(22DMB, 23DMB, 3MP and nHEX)

Is V̇O2peak a Valid Estimation of V̇O2max in Swimmers with Physical Impairments?

Peak and maximal oxygen uptake ([Formula: see text] and [Formula: see text], respectively) are used in assessing aerobic power. For swimmers with physical impairments, it is unclear whether the physiological variables obtained in 200-m and Nx200-m tests are similar. The objective of this study is to assess the validity of [Formula: see text] as an estimator of [Formula: see text] and complementary physiological variables, in particular, carbon dioxide production ([Formula: see text]), respiratory exchange ratio (RER), minute-ventilation ([Formula: see text] and absolute (HR) and relative (%HRmax) heart rates-which were obtained in a time trial test (200-m) and an incremental intermittent test (Nx200-m) performed by swimmers with physical impairments. Methods: Eleven well-trained swimmers with physical impairments performed 200-m all-out and Nx200-m from low to all-out (controlled by a visual pacer), both with a respiratory valve system and a portable gas analyzer. Results: A paired Student's t-test showed no statistical difference (p > .05) for all comparisons. The intraclass correlation coefficient (ICC) was 0.97 and 0.98 for [Formula: see text] in l/min and ml/kg/min, respectively; ICC = 0.75 to 0.9 for [Formula: see text] (l/min and ml/kg/min),[Formula: see text] (in l/min) and HR (beats/min); ICC = 0.5 and 0.75 for %HRmax; and ICC < 0.5 for RER. Passing-Bablok regression showed that the dispersions were acceptable, considering the proportionality, except for HR and %HRmax. Bland-Altman method showed a high level of agreement for all variables. Conclusions: The [Formula: see text] and [Formula: see text], as well as the physiological variables [Formula: see text] and HR obtained, respectively, by 200-m and Nx200-m tests in swimmers with physical impairment were not different.The study was approved by the local ethics committee (number 2.274.037) and was performed in accordance with the Declaration of Helsinki.info:eu-repo/semantics/publishedVersio

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Reverse shape selectivity in the adsorption of hexane and xylene isomers in MOF UiO-66

An adsorption study of hexane and xylene isomers mixtures was addressed in a rigid zirconium terephthalate UiO-66 (UiO for University of Oslo) with octahedral and tetrahedral cavities of free diameter close to 1.1 nm and 0.8 nm, respectively. Multicomponent equimolar breakthrough experiments show that the adsorption hierarchy of structural isomers in UiO-66 is opposite to the one observed in conventional adsorbents. For hexane isomers, it was found that the amount adsorbed increases with the degree of branching, being 2,2-dimethylbutane (22DMB) and 2,3-dimethylbutane (23DMB) the more retained molecules. Regarding the xylene isomers, the results show that the adsorption of the bulkier ortho-xylene(oX) is favoured compared to its homologues. The structural similarity between MOF UiO-66 and zeolite MCM-22 suggests that the reverse shape selectivity observed in the adsorption of hexane and xylene isomers might be attributed to the rotational freedom of the molecules inside the small cavities

Developing pressure swing adsorption process for biogas upgrading using shaped MIL-160(Al)

In this study, regarding the increasing interest on renewable sources of energy as well as considering the challenges of climate changes, the potential of shaped MOF MIL-160 (Al) for biogas upgrading has been evaluated. Accordingly, firstly the breakthrough assessments of CO2 and CH4 adsorption onto this sorbents were studied. Afterwards, a pressure swing adsorption (PSA) process to this end was designed and developed. The results showed MIL-160(Al) has an excellent potential for biogas upgrading concerning CO2 and CH4 separation.info:eu-repo/semantics/publishedVersio