Hydrogen production by sorption-enhanced steam reforming of glycerol

Catalytic steam reforming of glycerol for H(2) production has been evaluated experimentally in a continuous flow fixed-bed reactor. The experiments were carried out under atmospheric pressure within a temperature range of 400-700 degrees C. A commercial Ni-based catalyst and a dolomite sorbent were used for the steam reforming reactions and in situ CO(2) removal. The product gases were measured by on-line gas analysers. The results show that H(2) productivity is greatly increased with increasing temperature and the formation of methane by-product becomes negligible above 500 degrees C. The results suggest an optimal temperature of approximately 500 degrees C for the glycerol steam reforming with in situ CO(2) removal using calcined dolomite as the sorbent, at which the CO(2) breakthrough time is longest and the H(2) purity is highest. The shrinking core model and the 1D-diffusion model describe well the CO(2) removal under the conditions of this work

Romeríes del 1320

"Aquestes romeries faeren En P. Riber he En R. Torner en lany de nostre Senyor. M. CCCXX. que anaren a la perdonança de monsenyer sen Ffrancesch de Sis". Transcripció d'aquest manuscrit que es conserva en l'Arxiu de la Comunitat de Santa Maria de Ma

Enhancement of Critical Current Density in low level Al-doped MgB2

Two sets of MgB2 samples doped with up to 5 at. % of Al were prepared in different laboratories using different procedures. Decreases in the a and c lattice parameters were observed with Al doping confirming Al substitution onto the Mg site. The critical temperature (Tc) remained largely unchanged with Al doping. For 1 - 2.5 at.% doping, at 20K the in-field critical current densities (Jc's) were enhanced, particularly at lower fields. At 5K, in-field Jc was markedly improved, e.g. at 5T Jc was enhanced by a factor of 20 for a doping level of 1 at.% Al. The improved Jcs correlate with increased sample resistivity indicative of an increase in the upper critical field, Hc2, through alloying.Comment: 17 pages, 4 figures, to be published in Superconductor Science and Technolog

Robust high-temperature magnetic pinning induced by proximity in YBa2Cu3O7-8/La0.67Sr0.33MnO3 hybrids

An elaborately designed bilayer consisting of superconducting YBa2Cu3O7-6 (YBCO) and ferromagnetic La0.67Sr0.33MnO3-6 (LSMO) was prepared on a single crystal LaAlO3 substrate by pulsed laser deposition (PLD), with a view to understanding the mechanism behind the influence of superconductor/ferromagnet proximity on the critical current density, Jc. The present bilayer system shows significant modifications in Jc, as evidenced by the suppressed decay of its temperature dependence, as well as the crossing behavior of the magnetic field dependence of Jc at high temperatures. This indicates that enhanced flux pinning emerges at high temperatures, and it is believed to arise from the special magnetic inhomogeneity, i.e., the ferromagnet/antiferromagnet clusters caused by phase separation due to the epitaxial stress between LSMO and the substrate

The double Ringel-Hall algebra on a hereditary abelian finitary length category

In this paper, we study the category $\mathscr{H}^{(\rho)}$ of semi-stable coherent sheaves of a fixed slope $\rho$ over a weighted projective curve. This category has nice properties: it is a hereditary abelian finitary length category. We will define the Ringel-Hall algebra of $\mathscr{H}^{(\rho)}$ and relate it to generalized Kac-Moody Lie algebras. Finally we obtain the Kac type theorem to describe the indecomposable objects in this category, i.e. the indecomposable semi-stable sheaves.Comment: 29 page

Percutaneous Transforaminal Endoscopic Lumbar Foraminotomy in Stable Degenerative Lumbar Isthmic Spondylolisthesis with Radicular Leg Pain: A Retrospective Study

Rongbo Yu, Yiliu Xiang, Haoduan Dou, Hewen Li, Yuyang Zheng, Bin Chen Department of Minimally Invasive Spine Surgery, Chengde Medical University Affiliated Hospital, Chengde, Hebei, 067000, People’s Republic of ChinaCorrespondence: Bin Chen, Department of Minimally Invasive Spine Surgery, Chengde Medical University Affiliated Hospital, Chengde, Hebei, 067000, People’s Republic of China, Tel +8615633142760, Fax +863142279598, Email [email protected]: Endoscopic surgery is a minimally invasive option for effectively addressing lumbar degenerative diseases. This study aimed to describe the specific technology of percutaneous transforaminal endoscopic lumbar foraminotomy (PTELF) as a therapeutic intervention for managing radicular leg pain (RLP) resulting from stable degenerative lumbar isthmic spondylolisthesis (DLIS) and to present the associated clinical results.Methods: From March 2022 and April 2023, 25 patients were diagnosed with single-level stable DLIS with RLP and underwent PTELF. Clinical assessments utilized the visual analog scale (VAS), Oswestry Disability Index (ODI), and modified MacNab criteria. All endoscopic surgery videos were reviewed to interpret the pathology associated with DLIS.Results: The mean age of the cohort was 65.3 ± 11.0 years. The mean preoperative ODI score, VAS score for low back, and VAS score of the leg were 64.1 ± 8.2, 7.0 ± 0.7, and 7.3 ± 0.8, respectively. These scores significantly improved to 16.3 ± 10.4, 2.0 ± 0.6, and 1.7 ± 1.0 at the final follow-up, respectively (P< 0.01). The modified MacNab criteria indicated “good” or “excellent” outcomes in 92.0% of cases. Analysis of 23 surgical videos revealed 15 patients with disc herniation, nine with lower vertebral endplate involvement, consistent presence of uneven bone spurs (at the proximal lamina stump and around the foramen), and accumulated scars. Two patients experienced postoperative dysesthesia, and one encountered a recurrence of RLP.Conclusion: PTELF emerges as a potentially safe and effective procedure for alleviating RLP in patients with stable DLIS. However, additional evidence and extended follow-up periods are imperative to evaluate the feasibility and potential risks associated with PTELF.Keywords: radicular leg pain, lumbar isthmic spondylolisthesis, transforaminal, foraminotomy, local anesthesi