Biodiesel Produced from Catalyzed Transesterification of Triglycerides Using ion-Exchanged Zeolite Beta and MCM-22

AbstractIn this work, biodiesel production from catalyzed transesterification of triglycerides with excess methanol was studied by using ion-exchanged Zeolite Beta and MCM-22 as heterogeneous catalysts. Zeolite Beta and MCM-22 were synthesized with hydrothermal processes and, subsequently, modified by ion-exchanged with alkali ions. These as-obtained zeolite catalysts could yield a high conversion of triglycerides to biodiesel. The conversion efficiency was largely affected by crystallinity and frameworks of zeolite support, pH value of alkali ion-exchange solutions and alkali loadings onto the zeolite support. Furthermore, the effects of the duration of the sodium ion-exchange process on the final conversion efficiency of triolein to biodiesel, both the as-prepared Zeolite MCM-22 and Zeolite Beta catalysts were used. The effect of the duration of the sodium ion-exchange process is insignificant in transesterification using Na-ion-exchanged Zeolite MCM-22 catalysts from 0.5 to 4h. In contrast, the conversion efficiency of triolein to biodiesel reached ca. 95% in 0.5hours of transesterification using Zeolite Beta ion-exchanged with 3 mmol-eq. Na+/g cat for 0.5hours

Kinematic strategies for obstacle-crossing in older adults with mild cognitive impairment

IntroductionMild cognitive impairment (MCI) is considered a transitional stage between soundness of mind and dementia, often involving problems with memory, which may lead to abnormal postural control and altered end-point control when dealing with neuromechanical challenges during obstacle-crossing. The study aimed to identify the end-point control and angular kinematics of the pelvis-leg apparatus while crossing obstacles for both leading and trailing limbs.Methods12 patients with MCI (age: 66.7 ± 4.2 y/o; height: 161.3 ± 7.3 cm; mass: 62.0 ± 13.6 kg) and 12 healthy adults (age: 67.7 ± 2.9 y/o; height: 159.3 ± 6.1 cm; mass: 61.2 ± 12.0 kg) each walked and crossed obstacles of three different heights (10, 20, and 30% of leg length). Angular motions of the pelvis and lower limbs and toe-obstacle clearances during leading- and trailing-limb crossings were calculated. Two-way analyses of variance were used to study between-subject (group) and within-subject (obstacle height) effects on the variables. Whenever a height effect was found, a polynomial test was used to determine the trend. A significance level of α = 0.05 was set for all tests.ResultsPatients with MCI significantly increased pelvic anterior tilt, hip abduction, and knee adduction in the swing limb during leading-limb crossing when compared to controls (p < 0.05). During trailing-limb crossing, the MCI group showed significantly decreased pelvic posterior tilt, as well as ankle dorsiflexion in the trailing swing limb (p < 0.05).ConclusionPatients with MCI adopt altered kinematic strategies for successful obstacle-crossing. The patients were able to maintain normal leading and trailing toe-obstacle clearances for all tested obstacle heights with a specific kinematic strategy, namely increased pelvic anterior tilt, swing hip abduction, and knee adduction during leading-limb crossing, and decreased pelvic posterior tilt and swing ankle dorsiflexion during trailing-limb crossing. The current results suggest that regular monitoring of obstacle-crossing kinematics for reduced toe-obstacle clearance or any signs of changes in crossing strategy may be helpful for early detection of compromised obstacle-crossing ability in patients with single-domain amnestic MCI. Further studies using a motor/cognitive dual-task approach on the kinematic strategies adopted by multiple-domain MCI will be needed for a complete picture of the functional adaptations in such a patient group

Orderly arranged NLO materials on exfoliated layeredtemplates based on dendrons with alternating moietiesat the periphery†

Nonlinear optical dendrons with alternating terminal groups of the stearyl group (C18) and chromophorewere prepared through a convergent approach. These chromophore-containing dendrons were used asthe intercalating agents for montmorillonite via an ion-exchange process. An orderly exfoliatedmorphology is obtained by mixing the dendritic structure intercalated layered silicates with a polyimide.As a result, optical nonlinearity, i.e. the Pockels effect was observed for these nanocomposites withoutresorting to the poling process. EO coefficients of 9–22 pm V 1 were achieved despite that relativelylow NLO densities were present in the nanocomposites, particularly for the samples comprising thedendrons with alternating moieties. In addition, the hedging effects of the stearyl group on the selfalignmentbehavior, electro-optical (EO) coefficient and temporal stability of the dendron-intercalatedmontmorillonite/polyimide nanocomposites were also investigated

An Algorithm for Cold Patch Detection in the Sea off Northeast Taiwan Using Multi-Sensor Data

Multi-sensor data from different satellites are used to identify an upwelling area in the sea off northeast Taiwan. Sea surface temperature (SST) data derived from infrared and microwave, as well as sea surface height anomaly (SSHA) data derived from satellite altimeters are used for this study. An integration filtering algorithm based on SST data is developed for detecting the cold patch induced by the upwelling. The center of the cold patch is identified by the maximum negative deviation relative to the spatial mean of a SST image within the study area and its climatological mean of each pixel. The boundary of the cold patch is found by the largest SST gradient. The along track SSHA data derived from satellite altimeters are then used to verify the detected cold patch. Applying the detecting algorithm, spatial and temporal characteristics and variations of the cold patch are revealed. The cold patch has an average area of 1.92 × 104 km2. Its occurrence frequencies are high from June to October and reach a peak in July. The mean SST of the cold patch is 23.8 °C. In addition to the annual and the intraseasonal fluctuation with main peak centered at 60 days, the cold patch also has a variation period of about 4.7 years in the interannual timescale. This implies that the Kuroshio variations and long-term and large scale processes playing roles in modifying the cold patch occurrence frequency

Molecular Imaging, Pharmacokinetics, and Dosimetry of 111In-AMBA in Human Prostate Tumor-Bearing Mice

Molecular imaging with promise of personalized medicine can provide patient-specific information noninvasively, thus enabling treatment to be tailored to the specific biological attributes of both the disease and the patient. This study was to investigate the characterization of DO3A-CH2CO-G-4-aminobenzoyl-Q-W-A-V-G-H-L-M-NH2 (AMBA) in vitro, MicroSPECT/CT imaging, and biological activities of 111In-AMBA in PC-3 prostate tumor-bearing SCID mice. The uptake of 111In-AMBA reached highest with 3.87 ± 0.65% ID/g at 8 h. MicroSPECT/CT imaging studies suggested that the uptake of 111In-AMBA was clearly visualized between 8 and 48 h postinjection. The distribution half-life (t1/2α) and the elimination half-life (t1/2β) of 111In-AMBA in mice were 1.53 h and 30.7 h, respectively. The Cmax and AUC of 111In-AMBA were 7.57% ID/g and 66.39 h∗% ID/g, respectively. The effective dose appeared to be 0.11 mSv/MBq−1. We demonstrated a good uptake of 111In-AMBA in the GRPR-overexpressed PC-3 tumor-bearing SCID mice. 111In-AMBA is a safe, potential molecular image-guided diagnostic agent for human GRPR-positive tumors, ranging from simple and straightforward biodistribution studies to improve the efficacy of combined modality anticancer therapy