Effect of paint-bake like treatment on mechanical properties of Mg-Zn-Ca alloy

Magnesium alloys are promising materials for the fabrication of automotive components due to their lightweight which could help car manufacturers reduce the amount of emissions generated per automobile and to meet present and future regulations of owning more environmentally friendly vehicles. However, the low strength of magnesium alloys compared to aluminium and steel have limited its usage and has necessitated the search for more potent strengtheningmechanism, like precipitation strengthening, to widen the application of magnesium alloys in the automotive industries. Precipitation hardening response of a Mg-4wt%Zn-0.3 wt%Ca(ZX40) alloy in an ageing process at 180oC temperature typical of those used during paint baking cycle in automotive industries were studied using optical microscopy, Scanning electron microscopy (SEM), micro - hardness and thermoelectric power machine (TEP). Prior to the ageing process, one alloy was subjected to a 30 minutes solution heat treatment while the other sample was without solution heat treatment. Although, an initial decrease in hardness and strength of the alloy was observed due to solution treatment prior to ageing. The overall results showed that the mechanical (strength and hardness) and microstructure (fracture surface and precipitate formation) properties were enhanced in the 30 minutes solution treated sample s, which further emphasizes the need for solution treatment for better properties in an alloy. Keywords: Paint baking, Magnesium alloys, Precipitation strengthening, scanning electron microscop

Production of Biodiesel from the Transesterification of Waste Cooking Oil using Biobased Sulphonated Catalyst prepared from Coconut Shells

This study investigated the effects of transesterification process factors on biodiesel yield from waste cooking oil using a biobased sulphonated catalyst made from waste coconut shells. The catalyst was characterized in terms of surface structure, elemental compositions, surface area, pore volume and pore size. Reaction duration was varied from 30 to 180 minutes, catalyst loading varied from 1 to 6 wt%, and reaction temperature varied from 45 to 65°C are among the transesterification process variables studied. The Box Behnken design (BBD) of response surface methods was used to design the transesterification reaction. The catalyst surface morphology revealed that it has an uneven pore structure while elemental composition revealed that it is mainly composed of CaO (17.32%), SiO2 (21.40%), SO3 (21.04%), and Al2O3 (13.68%). The catalyst surface area, pore volume, and pore size were determined to be 474.4 m2.g-1, 0.295 cm3.g-1, and 2.144 nm, respectively. Reaction time and temperature had significant effect on the biodiesel yield while the influence of catalyst dosage was minimal. After a reaction time of 147.73 minutes and a catalyst dosage of 2.18 wt % at a reaction temperature of 65°C, a maximum yield of 96.22 percent of biodiesel was produced. The predicted R2 (0.9541) and actual R2 (0.7705) values were found to be in good agreement. Due to the high output of biodiesel, waste cooking oil could be a low-cost biobased feedstock for biodiesel formulations. The characteristics of biodiesel made from waste cooking oil were comparable to those of conventional biodiesel

Hydrogen Production From catalytic reforming of greenhouse gases (CO2 and CH4) Over Neodymiun (III) oxide supported Cobalt catalyst

Hydrogen production from CO2 reforming of methane over 20wt%.Co/Nd2O3 has been investigated in a fixed bed stainless steel reactor. The 20wt%.Co/Nd2O3 catalyst was synthesized using wet impregnation method and characterized for thermal stability, textural property, crystallinity, morphology and nature of chemical bonds using techniques such as TGA, XRD, N2 adsorption-desorption, FESEM, EDX and FTIR. The CO2 reforming of methane was performed at feed ratio (CH4:CO2) between 0.1-1 and reaction temperature ranged 973-1023 K. The catalyst displayed good activity towards selectivity and yield of hydrogen as well as CO, a by product. The selectivity and yield of Hydrogen increases with feed ratio and reaction temperature. The 20wt%.Co/Nd2O3 catalyst displayed promising catalytic activity for hydrogen production with the highest yield and selectivity of 32.5% and 17.6% respectively.Keywords: Cobalt; Greenhouse gases; Hydrogen; Reforming;; Neodymium (III)Oxid

Impact of soil amendments on the early growth of Streculia setigera Del. in the nursery

There exists an inadequate research on the propagation and nutrient needs of most tropical tree species. Hence, this work involves the developmental impact of soil amendments on the early growth of Streculia setigera Del. in the nursery. Different soil amendments; poultry waste (F1), goat manure (F2), cow manure (F3) and the control, normal soil (F4) were applied to several viable seeds of Streculia setigera in the nursery. The seeds were subjected to the same routine nursery practices. The experiment was laid in a Completely Randomized Design (CRD) and lasted for ninety (90) days. Descriptive statistics and ANOVA were used in the data analysis. The findings revealed that the entire growth response of Streculia setigera seedlings were only sparely affected by the soil amendments (P<0.05). F3 was found to be the most preferred soil amendment for this species, followed by F2 and F4 consecutively. The result obtained from F1 was very poor and thus it is not ideal for this species

Development on inverted perovskite solar cells: A review

Recently, inverted perovskite solar cells (IPSCs) have received note-worthy consideration in the photovoltaic domain because of its dependable operating stability, minimal hysteresis, and low-temperature manufacture technique in the quest to satisfy global energy demand through renewable means. In a decade transition, perovskite solar cells in general have exceeded 25 % efficiency as a result of superior perovskite nanocrystalline films obtained via low temperature synthesis methods along with good interface and electrode materials management. This review paper presents detail processes of refining the stability and power conversion efficiencies in IPSCs. The latest development in the power conversion efficiency, including structural configurations, prospect of tandem solar cells, mixed cations and halides, films’ fabrication methods, charge transport material alterations, effects of contact electrode materials, additive and interface engineering materials used in IPSCs are extensively discussed. Additionally, insights on the state of the art and IPSCs' continued development towards commercialization are provided

A qualitative evaluation of racial disparities in glucose control.

OBJECTIVE: Type 2 diabetes is more prevalent and severe among African Americans than among Whites. To elucidate barriers to glucose control that are unique to African Americans with poor glucose control we conducted a qualitative study among veterans with diabetes in an academic Veterans Affairs medical center. METHODS: We enrolled African American and White veterans with diabetes; participants' glucose control was described as well controlled or poorly controlled, and groups were organized on the basis of ethnicity and glucose control. Discussions were conducted by using modified nominal group technique to define factors that aided or hindered glucose control. RESULTS: Well-controlled groups similarly reported that self-care, health care, and psychosocial factors were important in controlling glucose. Although poorly controlled African Americans cited self-care as important, they also noted difficulty following self-care practices and the interference of psychosocial factors with glucose control. Poorly controlled Whites were similar. Uniquely, poorly controlled African Americans were less likely to report positive healthcare experiences; their barriers were related to poor access and poor relationships with providers. CONCLUSIONS: Poorly controlled African Americans endorsed healthy self-care behaviors but found it difficult to follow through. Interventions targeting the management of stress, depression, mood, and temptation, as well as improved access to and communication with providers may help these patients better manage their glucose and minimize disparities in diabetes outcomes. (Ethn Dis. 2009; 19:121-127