Reflective Teaching as a Practical Approach

Since the beginning of the 20th-century specialists have strived for ways that could comprise language teaching methods, which can ensure the best results in language training and teaching classes. And there are various methods, especially in the first half of this century. Some language teaching experts progressed further than methods with the hope of earning more results. Only some of teachers’ encouraged towards what is known as reflective teaching (RT).The process of bridging the gap between experience and learning is called Reflection. RT teacher requires a good self-observations of self-assessment, the need to go on patrol in a way to ensure that teachers understand their classes so that they make their own classroom process improvements where needed. RT is the process by which teachers reflect on their classroom procedures for collecting and analysing the descriptive facts that will be modified to show where the change can be made. RT gives teachers material and professional flexibility for teachers. This paper elaborates on the process of reflection practice and deliberates the effects for foreign/second language educators. Keywords: Reflective teaching, reflection in action, reflection on action, the reflective proces

Preparation of bulk and supported Co/Mo carbide catalysts for CO2 conversion

This thesis investigates the preparation and characterisation of Co/Mo bimetallic carbides and their stability and catalytic activity as bulk catalysts for the Dry Methane Reforming (DMR) reaction and as supported catalysts on alumina. The DMR reaction was chosen due to its importance in producing syngas, as a precursor for liquid fuels, from CO2 and CH4, two greenhouse gases. Bulk and supported bimetallic carbides were prepared by reductive carburization of the oxides with various hydrocarbons. The resultant carbides were characterized by X-Ray diffraction. Reactivity studies were undertaken by investigating the variable temperature reactivity of the catalysts on the DMR reaction. Characterization studies indicate that the oxides were transformed to the carbides successfully and these carbides had significant catalytic activity and were stable under the conditions used in the investigations.</p

Advanced cracking catalysts for the conversion of naphtha into light olefins

To meet the current global warming limit of 1.5℃ above pre-industrial levels, an urgent requirement is to develop advanced technologies fully- able to decarbonise the energy industry and other sectors. It is also expected that the demand for fossil of derived fuels will start declining in the coming years. Thereby, a significant fraction of the still vast resources of fossil hydrocarbons will be targeted towards the production of petrochemicals, notably to the production of light olefins, especially propene, and aromatics within an environmentally–friendly, climate-conscious perspective. The main scope of the project is to design and develop highly selective solid based catalysts and also to optimize the reaction conditions for converting the relatively high molecular weight hydrocarbons present in naphtha into the desired compounds. ZSM-5 is the most efficient catalyst for naphtha cracking to light olefins. Our initial studies reveal that, for these catalytic processes, the SiO2/Al2O3 ratio is not perhaps the primary criterion for the assessment of the performance of the zeolite catalyst. When compared to the catalyst formulation that was created by the impregnation approach, Cr2O3 loading on HZSM-5 (SiO2/Al2O3 = 80) zeolite using the mechanical mixing (MM) method results in a better n-heptane conversion (i.e., 95 wt.%) than the impregnation method (IMP). The inclusion of Cr had an effect on the physicochemical parameters of the catalysts, as well as their catalytic activity and selectivity. The optimum amount of Cr loading, which was 10% by weight, resulted in an increase in selectivity toward olefins, especially ethylene. In order to gain an understanding of the interaction mechanisms of the catalyst components and the role of support in the catalytic cracking of n-heptane over a hybrid of zeolite-matrix catalysts, it was investigated the effect of different matrix over ZSM-5 zeolite. The advance made in this thesis is based on the designed combination of HZSM-5 with kaolin, the latter being a highly versatile catalyst and support matrix. This inert, inexpensive and earth-abundant material significantly improves the catalyst's sustainable features alongside the effective production of light olefins from n-heptane (a model compound) and naphtha (the actual petrochemical feedstock). The matrix alters the texture, morphology, surface density and strength of acid sites of HZSM-5 zeolite hence, enhancing the production of light olefins, particularly propene, followed by ethene and in minor extension C4H8 compound. This work highlights the favourable impact of carefully tuning the strength and surface density of acid sites in HZSM-5 by combining it with a natural clay! This strategy enhances the production of light alkenes, particularly propene, and even aromatics via the catalytic cracking of naphtha

Preparation of bulk and supported Co/Mo carbide catalysts for CO2 conversion

This thesis investigates the preparation and characterisation of Co/Mo bimetallic carbides and their stability and catalytic activity as bulk catalysts for the Dry Methane Reforming (DMR) reaction and as supported catalysts on alumina. The DMR reaction was chosen due to its importance in producing syngas, as a precursor for liquid fuels, from CO2 and CH4, two greenhouse gases. Bulk and supported bimetallic carbides were prepared by reductive carburization of the oxides with various hydrocarbons. The resultant carbides were characterized by X-Ray diffraction. Reactivity studies were undertaken by investigating the variable temperature reactivity of the catalysts on the DMR reaction. Characterization studies indicate that the oxides were transformed to the carbides successfully and these carbides had significant catalytic activity and were stable under the conditions used in the investigations.This thesis is not currently available in ORA

The effect of lanthanum addition on the catalytic activity of γ-alumina supported bimetallic Co–Mo carbides for dry methane reforming

The effect of lanthanum addition to γ-alumina supported bimetallic carbides has been studied for the reaction of dry methane reforming using four different lanthanum loading levels of 1, 5, 10 and 15 wt% of lanthanum. It has been demonstrated that the addition of lanthanum to supported bimetallic carbides at low loading levels (1 wt%) results in smaller carbide crystallite sizes compared to catalysts containing either no lanthanum or higher lanthanum loading levels (5–15 wt%). Increased lanthanum loading results in increased carbon dioxide desorption at 500–700 °C. Reactions indicated that increased lanthanum loading resulted in significantly reduced product yields due to increased reverse water–gas shift activity. All materials exhibited degrees of sintering during the reaction. It was found that cobalt reacted with lanthanum species to form a LaCoO3 phase. The 1 wt% catalyst possessed superior catalytic properties for dry methane reforming and was tested for 100 h. After an initial loss of activity, the catalyst appeared to stabilise, however, a decrease of ~3 % in the H2:CO ratio, evidence of carbide crystallite growth and carbon deposition, indicated that a shift in the side reactions had occurred during the reaction

Ni–Sr/TiZr for H 2 from methane via POM: Sr loading &amp; optimization

Achieving remarkable H2 yield with significantly high H2/CO over Ni-based catalysts through partial oxidation of methane (POM) is a realistic approach to depleting the concentration of CH4 and using H2 and CO as synthetic feedstock. This study examined Ni catalysts on titania–zirconia for methane conversion via POM at 600 °C and atmospheric pressure. The addition of strontium to the catalyst was explored to improve its performance. Catalysts were characterized by X-ray diffraction, Raman-infrared-UV-vis spectroscopy, and Temperature-programmed reduction-desorption techniques (TPR, TPD). 2.5 wt% Sr addition induced the formation of the highest concentration of extreme basic sites. Interestingly, over the unpromoted catalyst, active sites are majorly generated by hardly reducible NiO species whereas upon 2.5 wt% promoted Sr promotional addition, most of active sites are derived by easily reducible NiO species. 45% CH4 conversion and 47% H2 yield with H2/CO = 3.5 were achieved over 2.5 wt% Sr promoted 5Ni/30TiO2 + ZrO2 catalyst. These results provide insight into the role of basic sites in enhancing activity through switching indirect pathways over direct pathways for POM. Further process optimization was carried out in the range of 10 000–22 000 SV, 0.35–0.75 O2/CH4, and 600–800 °C reaction temperature over 5Ni2.5Sr/30TiO2 + ZrO2 by using central composite design under response surface methodology. The optimum activity as high as ∼88% CH4 conversion, 86–87% yield of H2, and 2.92H2/CO were predicted and experimentally validated at 800 °C reaction temperature, 0.35O2/CH4 ratio, and 10 000 space velocity