Mede, Cuthy (1949--)

Born in Zimbabwe in 1949 to Malawian parents, Cuthbert (Cuthy) Mede grew up on Likoma Island, Lake Malawi. Internationally, Mede is considered the most well known Malawian artist. Known for his cubist forms and pointillist style, Mede unites modern art techniques with traditional Malawian subjects, and his work is inspired by his religious beliefs and local imagery. With a single dot giving perspective to his pointillism paintings, Mede’s most well recognized style emerges in wavy lines of white light over portraits of local people, or vivid primary colors of dancing, celebrations, and movement. His subjects are distinctly local: a woman with snuff; a witchdoctor; a mother and child; traditional instruments; cooking pots; images of imaginary spirit forms in reds, oranges and blues. Cuthy Mede taught modern art in Chancellor College as a young man, but soon became a successful artist. Mede opened the first art gallery in Malawi, the Gallerie Africaine in the city center, in Lilongwe in the early 1980s, and exhibited his works throughout Malawi from 1970s on, finding success worldwide. In recent years Mede is known for his fluorescent tube white garden and his purely white artworks.

GENERATION OF LIGHT THROUGH PLASMA USING RADIO FREQUENCY SOURCE IN DISUSED FLUORESCENT TUBE

Light has been generated through Plasma using radio frequency source in 4Ft 40W disused fluorescent tube. As against the thermionic and incandescence source of running a fluorescent tube which is actually difficult to get started due to the resistance of the gases enclosed inside, a Radio Frequency signal of 30MHz generated using a designed Hartley Oscillator is employed. The power of the signal generated is amplified from 231mW to 197.8W using a modeled inverter. The coupled Hartley oscillator and the inverter form an ionizing circuit. The gases inside fluorescent tube consist of mercury Vapor, argon, krypton or Neon. When sufficient energy is supplied to these gases, by the ionizing circuit, ionization and excitation takes place which makes otherwise neutral gases, to change state to a cloud of ionized gas called Plasma. When excited electrons in the gases return to the ground state they lose energy in packets called Photon. This Photon is ultraviolet light which is not visible to the human eye but when it strikes the walls of the tube coated with Phosphor it glows whereby light is generated. The high electric field Radio frequency circuit designed has generated light in a fluorescent tube without the use of starter and ballast. It has also generated light in otherwise “dead” or disused fluorescent bulbs.

Effect of Artificial Light Conditions on Local and Systemic Resistance Response of Tobacco to TMV Infection

Systemic acquired resistance (SAR) is effectively inducible in greenhouse and certain artificial light sources cause non-optimal growth of tobacco plants. Therefore, the morphological characteristics, local and systemic resistance response of N. tabacum cv. ‘Xanthi’ nc plants (harbouring NN resistance genes) to tobacco mosaic virus (TMV) infection under three artificial light sources with different spectral distribution were compared with greenhouse conditions. Statistical analysis of data was carried out by R package (R Core Team, 2015). Generally, artificial light sources (especially fluorescent tube, and halogen lamp) decreased the local resistance response and caused substantial morphological and developmental differences as compared to greenhouse conditions when plants were kept during their entire life (lifelong experimental regime) under these conditions. On the contrary, no or much less differences were found when plants were transferred from greenhouse to artificial light sources only at six leaf stage (short experimental regime). While induction of systemic acquired resistance (SAR) frequently decreased TMV lesion size by about 50-60% under greenhouse conditions, two of the three artificial light sources, fluorescent tube and halogen lamp were substantially and significantly less effective under short experimental regime conditions (25-35%). A metal halide light source with similarity to sunshine’s spectral distribution, however, partially mimicked the effect of greenhouse conditions indicating the importance of light spectrum among other factors in SAR induction and prevention of distorted growth of plants. Consequently, the optimization of the effect of artificial light sources is an important factor in experimental design studying signal transduction and biochemistry of SAR.

Modeling the Effect of Temperature-Induced Surface Tension Gradient in Coating Processes

The coating of the fluorescent-lamp material inside the fluorescent tube is prone to defect such as dark line formation. A one-dimensional mathematical model based on Navier-Stokes equation, which describes the flow of drying coating on horizontal planar substrates, was developed to investigate the defect formation. The effect of temperature distribution on surface tension gradient was incorporated into the model, to quantify defect formation in drying coating. The results showed that, temperature-induced surface tension gradient plays a major role in defect formation while the effect of pressure gradient is insignificant. The evaporation rate and viscosity affect the defect thickness and spread, and also the defect formation time. The temperature gradient seems to have the largest influence on surface tension gradient, thus defect formation. The model developed can be used as a process analysis tool in industrial applications of fluorescent tube coating.