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Study of Hydrogen Adsorption on Pt/WO_3-ZrO_2 through Pt Sites

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Journal of Natural Gas Chemistry 2007年第3期16卷 252-257页

作者： sugeng Triwahyono Aishah Abdul Jalil Hideshi Hattori Ibnu Sina Institute for Fundamental Science Studies Faculty of SciencesUniversiti Teknologi Malaysia81310 UTM SkudaiJohorMalaysia Faculty of Chemical & Natural Resources Engineering Universiti Teknologi Malaysia81310 UTM SkudaiJohorMalaysia Center for Advanced Research of Energy Technology Hokkaido UniversityNishi 5Kita 8Sapporo060-0808Japan

The rate determining step and the energy barrier involved in hydrogen adsorption on Pt/WO3- ZrO2 were studied based on the assumption that the hydrogen adsorption occurs only through Pt sites. The rate of hydrogen adsorption on Pt/WOa-ZrO2 was measured in the adsorption temperature range of 323-573 k and an initial hydrogen pressure of 50 Torr. The rates of hydrogen uptake were very high for the initial few minutes and the adsorption continued for more than 5 h below 523 k. The hydrogen uptake far exceeded the H/Pt ratio of unity for all adsorption temperatures, indicating that the adsorption of hydrogen involved the dissociative adsorption of hydrogen on Pt sites to form hydrogen atoms, the spillover of hydrogen atoms onto the surface of the WO3-ZrO2 catalyst, the diffusion of spiltover hydrogen atom over the surface of the WO3-ZrO2 catalyst, and the formation of protonic acid site originated from hydrogen atom by releasing an electron in which the electron may react with a second hydrogen atom to form a hydride near the Lewis acid site. The rate determining step was the spillover with the activation energy of 12.3 kJ/mol. The rate of hydrogen adsorption cannot be expressed by the rate equation based on the assumption that the rate determining step is the surface diffusion. The activity of Pt/WO3-ZrO2 was examined on n-heptane isomerization in which the increase of hydrogen partial pressure provided positive-effect on the conversion of n-heptane and negative-effect on the selectivity towards iso-heptane.

关键词： Pt/WO3-ZrO2 Pt sites hydrogen adsorption spillover n-heptane isomerization

The Effect of Sulfate Ion on the Isomerization of n-Butane to iso-Butane

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Journal of Natural Gas Chemistry 2006年第4期15卷 247-252页

作者： sugeng Triwahyono Zalizawati Abdullah Aishah Abdul Jalil Ibnu Sina Institute for Fundamental Science Studies Faculty of Chemical and Natural Resources Engineering Universiti Teknologi Malaysia 81310 SkudaiJohorMalaysia

The effect of sulfate ion （SO4^2-） loading on the properties of Pt/SO4^2-ZrO2 and on the catalytic isomerization of n-butane to/so-butane was studied. The catalyst was prepared by impregnation of Zr（OH）4 with H2SO4 and platinum solution followed by calcination at 600 ℃. Ammonia TPD and FT-IR were used to confirm the distribution of acid sites and the structure of the sulfate species. Nitrogen physisorption and X-ray diffraction were used to confirm the physical structures of Pt/SO4^2-ZrO2. XRD pattern showed that the presence of sulfate ion stabilized the metastable tetragonal phase of zirconia and hindered the transition of amorphous phase to monoclinic phase of zirconia. Ammonia TPD profiles indicated the distributions of weak and medium acid sites observed on 0.1 N and 1.0 N sulfate in the loaded catalysts. The addition of 2.0 N and 4.0 N sulfate ion generated strong acid site and decreased the weak and medium acid sites. However, the XRD results and the specific surface area of the catalysts indicated that the excessive amount of sulfate ion collapsed the structure of the catalyst. The catalysts showed high activity and stability for isomerization of n-butane to iso-butane at 200 ℃ under hydrogen atmosphere. The conversion of n-butane to iso-butane per specific surface area of the catalyst increased with the increasing amount of sulfate ion owing to the existence of the bidentate sulfate and/or polynucleic sulfate species （（ZrO）2SO2）, which acts as an active site for the isomerization.

关键词： sulfate ion strong acid site isomerization n-butane Zr Pt

Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheimer porous medium

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 193-208页

作者： k.MUHAMMAD M.SARFRAZ Department of Humanities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology Department of Mathematics Quaid-i-Azam University

This article presents a mathematical model addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate remains stationary, while the other moves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheimer porous medium. A mixture of water-based fluid with gold(Au) and silicon dioxide(Si O2) nanoparticles is formulated. In contrast to the conventional Fourier's heat flux equation, this study employs the Cattaneo-Christov heat flux equation. A uniform magnetic field is applied perpendicular to the flow direction, invoking magnetohydrodynamic(MHD) effects. Further, the model accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem is solved via NDSolve in MATHEMATICA. Numerical and statistical analyses are conducted to provide insights into the behavior of the nanomaterials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling systems and optimizing thermal management strategies. It is observed that the squeezing motion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed more vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less time in the region between the plates. The thermal relaxation, however, abruptly changes the temperature, leading to a decrease in the temperature fluctuations.

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Particle formation of hydroxyapatite precursor containing two components in a spray pyrolysis process

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Frontiers of Chemical Science and Engineering 2014年第1期8卷 104-113页

作者： W. Widiyastuti Adhi Setiawan sugeng Winardi Tantular Nurtono Heru Setyawan Department of Chemical Engineering Institut Teknologi Sepuluh Nopember Kampus ITS Sukolilo Surabaya 60111 Indonesia Politeknik Perkapalan Negeri Surabaya Kampus ITS Sukolilo Surabaya 60111 Indonesia

The particle formation mechanism of hydroxyapatite precursor containing two components, Ca（OOCCH3）2 and （NH4）2HPO4 with a ratio of Ca/P = 1.67, in a spray pyrolysis process has been studied by computational fluid dynamics （CFD） simulation on the transfer of heat and mass from droplets to the surrounding media. The focus included the evaporation of the solvent in the droplets, a second evaporation due to crust formation, the decomposition reaction of each component of the precursor, and a solid-state reaction that included the kinetic parameters of the precursor regarding its two components that formed the hydroxyapatite product. The rate of evaporation and the reacted fraction of the precursor both increased with temperature. The predicted average size of the hydroxyapatite particles agreed well with the experimental results. Therefore, the selected models were also suitable for predicting the average size of particles that contain two components in the precursor solution.

关键词： droplet hydroxyapatite particle CFD tubular furnace spray pyrolysis

Effects of P301L-TAU on post-translational modifications of microtubules in human iPSC-derived cortical neurons and TAU transgenic mice

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Neural Regeneration Research 2025年第8期20卷 2348-2360页

作者： Mohamed Aghyad Al kabbani Christoph köhler Hans Zempel Institute of Human Genetics Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany Center for Molecular Medicine Cologne(CMMC) University of CologneCologneGermany Center Anatomy Department ⅡMedical FacultyUniversity of CologneCologneGermany

TAU is a microtubule-associated protein that promotes microtubule assembly and stability in the *** is missorted and aggregated in an array of diseases known as *** are essential for neuronal function and regulated via a complex set of post-translational modifications,changes of which affect microtubule stability and dynamics,microtubule interaction with other proteins and cellular structures,and mediate recruitment of microtubule-severing *** impairment of microtubule dynamics causes neuronal dysfunction,we hypothesize cognitive impairment in human disease to be impacted by impairment of microtubule *** therefore aimed to study the effects of a disease-causing mutation of TAU(P301L)on the levels and localization of microtubule post-translational modifications indicative of microtubule stability and dynamics,to assess whether P301L-TAU causes stability-changing modifications to *** investigate TAU localization,phosphorylation,and effects on tubulin post-translational modifications,we expressed wild-type or P301L-TAU in human MAPT-kO induced pluripotent stem cell-derived neurons(i Neurons)and studied TAU in neurons in the hippocampus of mice transgenic for human P301L-TAU(p R5 mice).Human neurons expressing the longest TAU isoform(2N4R)with the P301L mutation showed increased TAU phosphorylation at the AT8,but not the p-Ser-262 epitope,and increased polyglutamylation and acetylation of microtubules compared with endogenous TAU-expressing neurons.P301L-TAU showed pronounced somatodendritic presence,but also successful axonal enrichment and a similar axodendritic distribution comparable to exogenously expressed 2N4R-wildtype-TAU.P301L-TAU-expressing hippocampal neurons in transgenic mice showed prominent missorting and tauopathy-typical AT8-phosphorylation of TAU and increased polyglutamylation,but reduced acetylation,of microtubules compared with non-transgenic *** sum,P301L-TAU results in changes in micr

关键词： human induced pluripotent stem cell microtubules P301L pR5 mice TAU tauopathy tubulin code

Effect of iridium loading on HZSM-5 for isomerization of n-heptane

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Journal of Natural Gas Chemistry 2011年第5期20卷 477-482页

作者： Herma Dina Setiabudi sugeng Triwahyono Aishah Abdul Jalil Nur Hidayatul Nazirah kamarudin Muhammad Arif Ab Aziz Department of Chemical Engineering Faculty of Chemical Engineering Universiti Teknologi Malaysia Ibnu Sina Institute for Fundamental Science Studies Faculty of Science Universiti Teknologi Malaysia

The effect of iridium loading on the properties and catalytic isomerization of n-heptane over Ir-HZSM-5 is studied. Ir-HZSM-5 was prepared by impregnation method and subjected to isomerization process in the presence of flowing hydrogen gas. XRD and BET studies show that the presence of iridium stabilizes the crystalline structure of HZSM-5, leading to more ordered framework structure and larger surface area. TGA and FTIR results substantiate that iridium species interacts with OH group on the surface of HZSM-5. Pyridine FT-IR study verifies the interaction between iridium and surface OH group slightly increased the Bro¨nsted and Lewis acid sites without changing the lattice structure of HZSM-5. The presence of iridium and the increase of strong Lewis acid sites on HZSM-5 were found to bring an increase about 4.1%, 33.2% and 11.8% in conversion, selectivity and yield of n-heptane isomerization, respectively.

关键词： Ir-HZSM-5 n-heptane isomerization Lewis acid sites protonic acid sites

Human endogenous retrovirus type-W and multiple sclerosis–related smoldering neuroinflammation

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Neural Regeneration Research 2025年第3期20卷 813-814页

作者： Joel Gruchot Laura Reiche Andrew Chan Robert Hoepner Patrick küry Department of Neurology Medical Faculty and University Hospital DüsseldorfHeinrich Heine University DüsseldorfDüsseldorfGermany Department of Neurology InselspitalBern University Hospital and University of BernBernSwitzerland

Introduction to human endogenous retrovirus type-W(HERV-W): Genomic inheritance from the past includes retroviral sequences that have been stably incorporated into our genomes and account for up to 8% of human DNA.

关键词： endogenous inflammation Human

Nucleoside modified mRNA-lipid nanoparticles as a new delivery platform for the repair of the injured spinal cord

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Neural Regeneration Research 2025年第8期20卷 2311-2312页

作者： krisztián Pajer Tamás Bellák Antal Nógrádi Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary

Spinal cord injury and treatment opportunities:The adult mammalian spinal cord has a very limited capacity for spontaneous regeneration due to various intrinsic molecular and cellular *** the spinal cord neurons have the capacity to regenerate their axons,the expression of growth inhibitory factors,lack or suppression of proper guidance cues,and profound inflammatory responses do not permit successful regeneration(khyeam et al.,2021).

关键词： injured capacity modified

Effect of PEG Incorporation on Physicochemical and in vitro Degradation of PLLA/PDLLA Blends:Application in Biodegradable Implants

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Journal of Renewable Materials 2023年第7期11卷 3043-3056页

作者： Mochamad Chalid Gifrandy Gustiraharjo Azizah Intan Pangesty Alyssa Adyandra Yudan Whulanza sugeng Supriadi Department of Metallurgical and Material Engineering Faculty of EngineeringUniversity of IndonesiaDepok City16424Indonesia Department of Mechanical Engineering Faculty of EngineeringUniversity of IndonesiaDepok City16424Indonesia

Polyethylene glycol(PEG)was added at different concentrations to the blend of poly(L-lactic acid)(PLLA)and poly(D,L-lactic acid)(PDLLA)to tailor the *** differential scanning calorimetry(DSC)measurement showed that all blends were miscible due to shifting a single glass transition temperature into a lower temperature for increasing PEG *** DSC,FTIR,and XRD results implied the crystallinity enhancement for PEG content until 8 wt%,then decreased at 12 wt%*** XRD result indicated the homo crystalline phase formation in all blends and no stereocomplex *** in vitro degradation study indicated that PEG content is proportional to the degradation *** highest weight loss after 28 days was achieved at 12 wt%*** FTIR analysis showed a structural evolution overview during hydrolytic degradation,*** and decreasing crystallinity during 14 days for the blend without and with PEG,*** conclusion,the PEG addition increased crystallinity and degradation rate of the PLLA/PDLLA mixture,but PEG higher amounts led to a decrease in crystallinity,and the weight loss was *** can be useful for tuning PLA-based biomaterials with the desired physicochemical properties and appropriate degradation rates for applications in drug delivery/tissue engineering.

关键词： PLLA PDLLA PEG crystallinity degradation