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Although it is relevant to understand spine and lower body motions in healthy individuals for a variety of applications, such as clinical diagnosis, implant design, and the analysis of treatment outcomes, proper assessment and characterization of normative gait symmetry in healthy individuals remains unclear. The purpose of this study was to investigate the in vivo 3-dimensional (3D) spine and lower body gait symmetry kinematics during treadmill walking in healthy individuals. Sixty healthy young adults (30 males and 30 females) were evaluated during normal and fast treadmill walking using a motion capture system approach. Statistical parametric mapping and the normalized symmetry index approaches were used to determine spine, pelvis, and lower body asymmetries during treadmill walking. The spine and pelvis angular motions associated with the left and right lower limb motions, as well as the left and right lower extremity joint angles were compared for normal and fast treadmill walking. The lower lumbar left-right rotation (5.74±0.04°) and hip internal rotation (5.33±0.18°) presented the largest degrees of asymmetry during normal treadmill. Upper lumbar left-right lateral flexion (1.48±0.14°) and knee flexion (2.98±0.13°) indicated the largest asymmetries and during fast treadmill walking. Few asymmetry patterns were similar between normal and fast treadmill walking, whereas others appeared either only during normal or fast treadmill walking in this cohort of participants. These findings could provide insights into better understanding gait asymmetry in healthy individuals, and use them as reference indicators in diagnosing and evaluating abnormal gait function.

in Wiley Online Library (wileyonlinelibrary.com) HZSM-5 (SiO 2 /Al 2 O 3 5280 mol/mol) is used to produce hydrocarbons from reagent-grade isopropanol and mixed alcohols made from lignocellulosic biomass (waste office paper and chicken manure) using the MixAlco TM process. All studies were performed at 101 kPa (abs). The experiments were conducted in two sets: (1) vary temperature (300-T max C) at weight hourly space velocity (WHSV)51.31 h -1 , and (2) vary WHSV (0.5-11.5 h -1 ) at T5370 C. For isopropanol, T max 5450 C and for mixed alcohols T max 5520 C. For isopropanol, higher temperatures produced more gaseous products and more aromatics. High WHSV gives high concentration of C61 olefins, whereas low WHSV gives high concentrations of C9 aromatics. For mixed alcohols, changes in temperature affected the product distribution similar to isopropanol. In contrast, WHSV did not affect the concentration of reaction products; only dehydration products were observed.

This study employed HZSM‐5 (SiO2/Al2O3 = 280 mol/mol) to produce hydrocarbons from reagent‐grade isopropanol and mixed alcohols made from lignocellulosic biomass (waste office paper and chicken manure) using the MixAlco™ process. All studies were performed at P = 5000 kPa (abs). The experiments were conducted in two sets: (1) vary temperature (300–450°C) at weight hourly space velocity (WHSV) = 1.92 h−1, and (2) vary WHSV (1.92–11.52 h−1) at T = 370°C. For isopropanol at higher temperatures, the olefins undergo more cracking reactions to produce smaller molecules and more aromatics. At low temperatures, the molecules have less energy so they do not crack and therefore form larger molecules. At T = 300°C, the carbon distribution is bimodal at C9 and C12, which shows trimerization and tetramerization of propene. At 300°C, propene was the only gas produced, cracking did not occur and therefore preserved high‐molecular‐weight molecules. For mixed alcohols, higher temperatures show significant catalyst deactivation; however, isopropanol did not show any catalyst deactivation. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1707–1715, 2016

This work presents the thermochemical analysis of a packed-bed reactor via multi-dimensional CFD modeling using FlexPDE and COMSOL Multiphysics. The temperature, concentration, and reaction rate profiles for methane production following the Fischer–Tropsch (F-T) synthesis were studied. To this end, stationary and dynamic differential equations for mass and heat transfer were solved via the finite element technique. The transport equations for 1-D and 2-D models using FlexPDE consider dispersion models, where the fluid and the catalyst can be treated as either homogeneous or heterogenous systems depending on the gradient extents. On the other hand, the 3-D model obtained in COMSOL deems the transport equations incorporated in the Porous Media module. The aim was to compare the FlexPDE and COMSOL models, and to validate them with experimental data from literature. As a result, all models were in good agreement with experimental data, especially for the 2-D and 3-D dynamic models. In terms of kinetics, the predicted reaction rate profiles from the COMSOL model and the 2-D dynamic model followed the temperature trend, thus reflecting the temperature dependence of the reaction. Based on these findings, it was demonstrated that applying different approaches for the CFD modeling of F-T processes conducts reliable results.