Effects of pigeon pea and plantain starches on the compressional, mechanical, and disintegration properties of paracetamol tablets

A study has been made of the effects of pigeon pea starch obtained from the plant Cajanus cajan (L) Millisp. (family Fabaceae) and plantain starch obtained from the unripe fruit of Musa paradisiaca L. (family Musaceae) on the compressional, mechanical, and disintegration properties of paracetamol tablets in comparison with official corn starch BP. Analysis of compressional properties was done by using density measurements, and the Heckel and Kawakita equations, whereas the mechanical properties of the tablets were evaluated by using tensile strength (T--a measure of bond strength) and brittle fracture index (BFI--a measure of lamination tendency). The ranking for the mean yield pressure, P(y), for the formulations containing the different starches was generally corn < pigeon pea < plantain starch while the ranking for P(k), an inverse measure of the amount of plasticity, was pigeon pea < plantain < corn starch, which indicated that formulations containing corn starch generally exhibited the fastest onset of plastic deformation, whereas those formulations containing pigeon pea starch exhibited the highest amount of plastic deformation during tableting. The tensile strength of the tablets increased with increase in concentration of the starches while the Brittle Fracture Index decreased. The ranking for T was pigeon pea > plantain > corn starch while the ranking for BFI was corn > plantain > pigeon pea starch. The bonding capacity of the formulations was in general agreement with the tensile strength results. The disintegration time (DT) of the formulation increased with concentration of plantain and corn starches but decreased with concentration of pigeon pea starch. The general ranking of DT values was plantain < pigeon pea < corn starch. Notably, formulations containing pigeon pea starch exhibited the highest bond strength and lowest brittleness, suggesting the usefulness of pigeon pea starch in producing strong tablets with minimal lamination tendency. Plantain starch, on the other hand, would be more useful where faster disintegration of tablet is desired. The results show that the starches could be useful in various formulations depending on the intended use of the tablets with the implication that the experimental starches can be developed for commercial purposes.     

On developing a prospecting tool for wind industry and policy decision support

This paper presents the rudiments of a Wind Prospecting Tool designed to inform private and public decision makers involved in wind industry development in reducing transaction costs associated with identifying areas of mutual focus within a state. The multiple layer decision support framework has proven to be valuable to industry, state government and local decision makers. Information on wind resources, land availability, potential land costs, potential NIMBYism concerns and economic development potential were integrated to develop a framework for decision support. The paper also highlights implications for decision support research and the role of higher education in providing anticipatory science to enhance private and public choices in economic development.     

Assessment of the Oxidation Behavior of a Pt-Based Alloy for High Temperature Applications

Pt-based alloys are being developed as a possible future replacement for Ni-based superalloy components in the hottest section of turbine engines. The critical properties of these alloys are their ability to withstand higher thermal and mechanical stresses as well as to resist aggressive corrosive and oxidizing environments in applications. Oxidation properties of these alloys were investigated between 1150 and 1350 °C. The surface roughness of the as-polished samples was determined using atomic force microscopy, while the microstructures of both the as-polished and oxidized samples were examined using scanning electron microscopy. The alloy was found to be composed of a two-phase gamma/gamma prime microstructure, while the average surface roughness decreased from 5.78 nm after 1 μm diamond paste polishing to 4.13 nm with 0.25 μm diamond paste polishing. Microstructure examination of the oxidized alloy samples revealed the formation of compact and protective external oxide scale composed of α-alumina, as confirmed by the XRD and Raman spectroscopy. The results also showed that the oxide scale thickens with increased exposure time and temperatures according to parabolic kinetics. It was concluded from the results that the Pt-based alloys possess good oxidation resistance and thus will be suitable for high temperature applications, such as turbine engines.     

Raman investigation of the ageing of Ni-BaTiO<Subscript>3</Subscript> multilayer ceramic capacitors

Ni-BaTiO₃ multilayer ceramic capacitors (MLCC) have been aged at 121 °C and 100% Relative Humidity for 2,600 h. Raman and energy dispersive spectral measurements have been made on both aged and unaged samples. Raman spectra indicate the presence of a coating of substoichiometric SnO _x (1 < x < 2) in the aged samples. Morphological and elemental changes occurring in the MLCC were examined by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Preliminary, frequency dependent dielectric measurements indicate that ageing causes a substantial decrease (about 50%) of the capacitance, even if only surfaces are affected by the ageing phenomenon.     

Investigation of ordering phenomenon in Me–Pt (Me=Fe,Ni) liquid alloys

The phase diagrams of Fe–Pt and Ni–Pt liquid alloy systems show the existence of FePt and NiPt intermetallic compounds, respectively, in their solid intermediate states, and the associative tendency between unlike atoms in these liquid alloys has been analysed using the self-association model. The concentration dependences of mixing properties such as the free energy of mixing, G_M; the concentration fluctuations, S_cc(0), in the long-wavelength limits; the chemical short-range order (CSRO) parameter, α₁; as well as the chemical diffusion, enthalpy and entropy of the mixing of Fe–Pt and Ni–Pt liquid alloys have been investigated to determine the nature of ordering in the liquid alloys. The results show that heterocoordination occurs in the alloys at all concentrations. The effect of CSRO on S_cc(0), chemical diffusion, D, and the order parameter, α₁, has been considered. The ordering phenomenon in the liquid alloys is also related to the effect of the atomic size mismatch volume on S_cc(0).     

Evaluation of the Mechanical Properties of Reinforcing Steel Bars from Collapsed Building Sites

Mechanical properties of reinforcing steel bars obtained from three different collapsed building sites in Lagos, Nigeria were examined. An optical emission spectrometer was used for chemical composition analysis while the tensile test was carried out using a Universal Testing Machine. The yield strength of the steel bars was found to be higher than BS4449 (GRADE 460B), Nst.65-Mn, and ASTM A706 standards, while their percentage elongations were lower than most of the standards. The steel bars used at the Sango collapse site have higher UTS compared with the standards, while those used at Ilesanmi and Ewuntun collapse sites have UTS values that are in close range with the standards. The reinforcing bar obtained from Ilesanmi collapsed site has higher percentage elongation than ASTM A706 standard but lower than Nst.65-Mn and BS4449 (GRADE 460B) standards. The bars obtained from Sango and Ewuntun collapse sites displayed lower percentage elongation compared with that from Ilesanmi site. All the investigated reinforcing bars possessed reasonably high strength with low ductility. Thus, these bars are susceptible to brittle fracture, which might have contributed to the collapse of the building structures.     

Critical review of recent development in fiber reinforced adobe bricks for sustainable construction

This paper presents a state-of-the-art review of research on the utilization of fibers (predominantly derived from waste materials) as reinforcement in adobe brick production. Recycling of these wastes provides sustainable construction materials and helps to protect the environment. Specimen preparation and test procedures are outlined. The effects of addition of these wastes on the physical and mechanical properties of adobe bricks as presented in the literature, are investigated. The main results for each additive are presented and discussed. It is concluded that improved adobe brick properties can be expected with the addition of combination of waste additives. The use of waste materials in the construction industry is generally of interest and useful for engineers and designers seeking sustainable solutions in construction. It is also of interest to researchers actively seeking to develop methodical approaches to quantifying, optimising and testing the performance in use of such waste material additives.     

Renewable energy potential on brownfield sites: A case study of Michigan

Federal priorities are increasingly favoring the replacement of conventional sources of energy with renewable energy. With the potential for a federal Renewable Electricity Standard (RES) legislation, many states are seeking to intensify their renewable energy generation. The demand for wind, solar, geothermal and bio-fuels-based energy is likely to be rapidly expressed on the landscape. However, local zoning and NIMBYism constraints slow down the placement of renewable energy projects. One area where land constraints may be lower is brownfields; whose development is currently constrained by diminished housing, commercial, and industrial property demand. Brownfield sites have the potential for rapid renewable energy deployment if state and national interests in this area materialize. This study investigates the application of renewable energy production on brownfield sites using Michigan as a case study. Wind and solar resource maps of Michigan were overlaid with the brownfield locations based on estimates of brownfield land capacity. The total estimated energy potential available on Michigan’s brownfield sites is 4320 megawatts (MW) of plate capacity for wind and 1535for solar, equating to 43% of Michigan’s residential electricity consumption (using 30% capacity factor). Estimated economic impacts include over $15 billion in investments and 17,500 in construction and long-term jobs.     

Recent developments in the application of oil palm fibers in cement composites

Fibers obtained from different parts of the oil palm tree (Elaeis guineensis) have been under investigation for possible use in construction. Studies have been carried out investigating the engineering properties and possible applications of these fibers. However, the experimental methods employed and the values of mechanical and physical properties recorded by various authors are inconsistent. It has therefore become necessary to organize information which would be useful in the design of oil palm fiber cement composites and help researchers and engineers make informed decisions in further research and application. This review provides information about fibers from different parts of the oil palm, their properties, enhancement techniques, current and potential application in cement composites.