10 research outputs found
Optimization of synthesis condition for carboxymethyl cellulose-based hydrogel from rice straw by microwave-assisted method and its application in heavy metal ions removal
No full textUnderstanding Participation in Online Courses
No full textThis chapter reports the results of the case study of online interaction. Prior to conducting the case study, the author conducted a pre-study to understand how students and instructors view the problems they face in online courses. After that, the author used Hillman et al. and Moore’s four types of interaction and Henri’s analytical model as a framework to guide the investigation in order to understand the nature of interaction in an online course. The results of this study showed that combination three of the types of interaction and the analytical model help teaching and learning become more effective. Furthermore, this study provides recommendations and practices that would be helpful for online instructors to design and deliver online courses effectively.</jats:p
Understanding Participation in Online Courses
No full textThis chapter reports the results of the case study of online interaction. Prior to conducting the case study, the author conducted a pre-study to understand how students and instructors view the problems they face in online courses. After that, the author used Hillman et al. and Moore’s four types of interaction and Henri’s analytical model as a framework to guide the investigation in order to understand the nature of interaction in an online course. The results of this study showed that combination three of the types of interaction and the analytical model help teaching and learning become more effective. Furthermore, this study provides recommendations and practices that would be helpful for online instructors to design and deliver online courses effectively. </jats:p
Influence of the Calcination Technique of Silica on the Properties and Performance of Ni/SiO<sub>2</sub> Catalysts for Synthesis of Hydrogen via Methane Cracking Reaction
No full textDeactivation
of catalysts due to rapid blocking of active surfaces
and pores is a major problem for methane cracking. The removal of
the template using different calcination methods contributes to the
different characteristics of catalyst support. Therefore, silica supports
were prepared with the sol–gel method, where sodium silicate
and chitosan are a silica source and a template, respectively. Calcination
using a microwave muffle furnace (MWF) was preferred over the conventional
electric muffle furnace at the heating rates of 2 and 17 °C/min
(CEF2 and CEF17, respectively) in order to remove the chitosan template.
A nickel nitrate precursor was loaded onto the obtained silica supports
by the incipient wetness impregnation method. The properties of the
silica support and the Ni/SiO2 catalysts were characterized
by means of N2-sorption, X-ray diffraction, scanning electron
microscopy–energy-dispersive X-ray, field emission transmission
electron microscopy, and H2 temperature-programmed reduction.
The catalytic activity was evaluated using a fixed-bed reactor at
550 °C with a CH4/N2 ratio of 1:4 in the
feed. The amount and the allotropes of carbon deposited on the spent
catalysts were investigated using thermogravimetric/differential thermal
analysis. The results showed that the SiO2-MWF support
had a higher surface area and a larger pore volume of a mesoporous
structure with larger interparticle channels than that of the SiO2-CEF supports. This leads to the higher dispersion of Ni metal
particles over and inside the interparticle channels of the SiO2-MWF support. This provided a higher metal–support
interaction, resulting in lower rates of methane conversion and carbon
deposition on the catalyst surface than those of Ni/SiO2-CEF catalysts. However, it displayed a lower bed pressure. It was
found that the carbon fibers deposited on all the catalysts were multiwalled
carbon nanotubes (MWCNTs). Additionally, the base-growth mechanism
of MWCNTs was only exhibited by the Ni/SiO2-MWF catalyst
Low Temperature Methanation of CO2 on High Ni Content Ni-Ce-ZrO delta Catalysts Prepared via One-Pot Hydrothermal Synthesis
No full textNi-Ce-Zr-O-delta catalysts were prepared via one-pot hydrothermal synthesis. It was found that Ni can be partially incorporated into the Ce-Zr lattice, increasing surface oxygen species. The catalysts possess high surface areas even at high Ni loadings. The catalyst with Ni content of 71.5 wt.% is able to activate CO2 methanation even at a low temperature (200 degrees C). Its CO2 conversion and methane selectivity were reported at 80% and 100%, respectively. The catalyst was stable for 48 h during the course of CO2 methanation at 300 degrees C. Catalysts with the addition of medium basic sites were found to have better catalytic activity for CO2 methanation
Influence of drying technique on physicochemical properties of bimodal meso-macropore structure of silica support
Get PDF[EN] Drying process directly affect in structure of the silica support for catalysts. Therefore, we herein prepared bimodal meso-macropore structure of silica by sol-gel method and investigated the silica support obtained from various drying techniques, namely, hot air drying (HA), microwave drying(MW)and freeze drying (FD)by means of BET and BJH N2-sorption, and SEM. The results showed a significant effect of drying technique on the textural properties of the dried bimodal porous silica support. In addition, it was found that freeze drying could enhance surface area of silica support with higher than 500 m2/g.The authors express their sincere appreciation to the Kasetsart University Research and Development Institute (KURDI) and the Center of Excellence on Petrochemical and Materials Technology, National Science and Technology Development Agency ( NSTDA) for supporting the study financially.Panchan, N.; Niamnuy, C.; Chukeaw, T.; Seubsai, A.; Devahastin, S.; Chareonpanich, M. (2018). Influence of drying technique on physicochemical properties of bimodal meso-macropore structure of silica support. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1935-1942. https://doi.org/10.4995/IDS2018.2018.8369OCS1935194
พื้นฐานการพัฒนาโรงงานขนาดกลางและขนาดย่อมสู่การเป็นส่วนหนึ่งของเมืองอุตสาหกรรมเชิงนิเวศFundamental Development of Medium and Small-Scale Industries Towards Becoming Part of an Eco-Industrial Town
No full textบทความวิชาการนี้นำเสนอแนวทางการพัฒนาสู่การเป็นโรงงานอุตสาหกรรมเชิงนิเวศสำหรับโรงงานขนาดกลางและขนาดย่อม ตามเกณฑ์ข้อกำหนดต่าง ๆ ของสภาอุตสาหกรรมแห่งประเทศไทย และชี้ให้เห็นประโยชน์ของการเป็นโรงงานอุตสาหกรรมเชิงนิเวศ ที่นอกจากจะช่วยให้บรรลุผลประโยชน์ทางเศรษฐกิจ สังคม และสิ่งแวดล้อมแล้ว ยังช่วยสร้างความยั่งยืนในการดำเนินกิจการของโรงงานอุตสาหกรรมขนาดกลางและขนาดย่อม เพื่อก้าวไปสู่การเป็นส่วนหนึ่งของเมืองอุตสาหกรรมเชิงนิเวศต่อไปอย่างยั่งยืนได้ในอนาคตThis article presents development guidelines for medium and small-scale industrial factories based on the criteria according to the Federation of Thai Industries. It highlights the benefits of being an eco-factory, which helps to achieve economic, social, and environmental benefits, in addition to contributing to sustainable operations of medium and small size factories, pursuing to be part of the eco-industrial town that is sustainable in the future
Synthesis of Dimethyl Ether via CO<sub>2</sub> Hydrogenation: Effect of the Drying Technique of Alumina on Properties and Performance of Alumina-Supported Copper Catalysts
No full textThermal
treatment during catalyst preparation is one of the important
factors affecting the characteristics and performance of a catalyst.
To improve the catalytic performance of an alumina-supported copper
catalyst prepared by an impregnation method for dimethyl ether (DME)
synthesis from CO2, the effects of the use of hot air and
infrared drying as well as calcination at 600 and 900 °C to prepare
alumina supports were investigated. Infrared drying could shorten
the required drying time by 75% when compared with hot air drying.
Infrared drying could also help maintain the pore size and pore volume
of the supports, leading to their larger surface areas. Different
drying techniques were additionally noted to result in different sizes
and shapes of the pores as well as to different copper distributions
and intensities of acid sites of the catalyst. An increase in the
calcination temperature resulted in a decrease in the surface area
of the supports because of particle aggregation. The drying technique
exhibited a more significant effect than calcination temperature on
the space-time yield of DME. A catalyst utilizing the support prepared
by infrared drying and then calcined at 600 °C exhibited the
highest yield of DME (40.9 gDME kgcat–1 h–1) at a reaction temperature of 300 °C.
Stability of the optimal catalyst, when monitored over a 24 h period,
was noted to be excellent
Approaching low liver iron burden in chelated patients with non-transfusion-dependent thalassemia: the safety profile of deferasirox
Get PDFObjective: Patients with non-transfusion-dependent thalassemia (NTDT) often develop iron overload and related complications, and may require iron chelation. However, the risk of over-chelation emerges as patients reach low, near-normal body iron levels and dose adjustments may be needed. In the THALASSA study, the threshold for chelation interruption was LIC <3 mg Fe/g dw (LIC<3); 24 patients receiving deferasirox for up to 2 yr reached this target. A post hoc analysis was performed to characterize the safety profile of deferasirox as these patients approached LIC<3. Methods: THALASSA was a randomized, double-blind, placebo-controlled study of two deferasirox regimens (5 and 10 mg/kg/d) versus placebo in patients with NTDT. Patients randomized to deferasirox or placebo in the core could enter a 1-yr extension, with all patients receiving deferasirox (extension starting doses based on LIC at end-of-core and prior chelation response). The deferasirox safety profile was assessed between baseline and 6 months before reaching LIC<3 (Period 1), and the 6 months immediately before achieving LIC<3 (Period 2). Results: Mean ± SD deferasirox treatment duration up to reaching LIC<3 was 476 ± 207 d, and deferasirox dose was 9.7 ± 3.0 mg/kg/d. The exposure-adjusted AE incidence regardless of causality was similar in periods 1 (1.026) and 2 (1.012). There were no clinically relevant differences in renal and hepatic laboratory parameters measured close to the time of LIC<3 compared with measurements near the previous LIC assessment. Conclusions: The deferasirox safety profile remained consistent as patients approached the chelation interruption target, indicating that, with appropriate monitoring and dose adjustments in relation to iron load, low iron burdens may be reached with deferasirox with minimal risk of over-chelation
Clinical profiles of multiple myeloma in Asia-An Asian Myeloma Network study
No full text10.1002/ajh.23731American Journal of Hematology897751-756AJHE
