Reaction of certain tomato (Lycopersicon esculentum L.) cultivars to damping-off disease

Five fungal isolates were isolated from infected tomato seedlings showing dampingoff which collected from several tomato nurseries of Assiut and New Valley Governorates, Egypt. These isolates were Rhizoctonia solani Kühn, Fusarium oxysporum f.sp. lycopersici Schlechtendahl, Fusarium semitectum Berk. & Rav., Setosphaeria rostrata Leonard and Alternaria alternata (Fries) Keisler. Also, six tomato cultivars and hybred, namely Castle Rock, Super marmande, Super Strain B, Enz 10F1, 0240F1 and Dream Hybrid were evaluated for their susceptibility to damping-off disease. All tested tomato cultivars were susceptible to damping-off disease, Castle Rock cv. showed the highest percentage of pre and post emergence damping-off disease severity followed by Super marmande and Super Strain B cvs. then Dream Hybrid and Enz 10F1 Hybrid. 0240 F1 Hybrid gave the lowest ones. Each tested tomato cultivars showed higher amount of total phenolic and total protein content in infected plants with the tested pathogenic fungal isolates than uninfected plants (control). The highest amount of total phenol and total protein was found in infected plant of tomato Enz 10F1cv. followed by 0240F1cv. while the lowest amount of total phenol and total protein were found in infected plant of castel Roke cv. then super marmande cv

ECONOMIC GROWTH AND INCOME INEQUALITY IN SUB-SAHARAN AFRICA

Economies of Sub-Saharan African (SSA) countries have been growing slowly in recent time. Economic growth is thought to affect inequality but not much is known about the nature of such relationship in SSA and there is no concordance among the few available. This paper examined the relationship between economic growth and inequality in the region using data from 1990 to 2017estimated with the Panel Autoregressive Distributed Lag (ARDL) Model and Granger Causality. Hausman’s test suggested the superiority of the Pooled Mean Group (PMG) over the Mean Group (MG) Model. The PMG results showed that economic growth had significant and negative effect on income inequality (proxy by GINI-coefficient) in the long run suggesting a state of the later part of the Kuznet curve. This is in addition to the negative effect in the short run which is contrary to the theory. Furthermore, the result of the Granger Causality test revealed evidence of unidirectional relationship running from economic growth to income inequality in the region. Therefore, the study recommended that governments of Sub-Saharan African countries should implement policies and programmes capable of sustaining and improving inclusive growth in order to avoid high income inequality in the region.     &nbsp

Rearrangements and Dilatancy for Sheared Dense Materials

Constitutive equations are proposed for dense materials, based on the identification of two types of free-volume activated rearrangements associated to shear and compaction. Two situations are studied: the case of an amorphous solid in a stress-strain test, and the case of a lubricant in tribology test. Varying parameters, strain softening, shear thinning, and stick-slip motion can be observed.Comment: 4 pages, 3 figure

Investigation Of The Suitability Of Polyphosphoric Acid In Reducing The Degree Of Thermal Aging Of Agabu Natural Bitumen

Bitumen otherwise known as asphalt is a complex mixture of hydrocarbons which are naturally occurring or obtained from crude oil distillation. Bitumen when used as a binder in road pavement deteriorates with time as result of traffic load and contact of the pavement with environmental factors. The degradation of bitumen causes a rapid aging of the asphalt based pavement leading to road problems such as rutting, potholes etc. This deterioration is attributed to oxidative degradation of molecules of bitumen by factors such as heat, moisture and sunlight. This study investigates the viability of using polyphosphoric acid (PPA) to reduce the oxidative degradation effect of heat (at 60oC) on constituents of Agbabu Natural Bitumen (ANB) with a view to making it more durable when used for road pavement. Modification of ANB with PPA was carried out at 160oC using melt blend technique. Thereafter, the PPA modified and neat ANB samples were thermally aged in a hot air oven at 60oC. Fourier Transform Infrared (FTIR) Spectroscopy was used to validate the changes in the structure of ANB and aging indexes of neat and PPA modified samples of ANB calculated. The result showed that aging indexes of PPA modified samples of ANB were lower compared with that of the neat or unmodified samples of ANB. This implies that the rate of aging (at 60oC) of the unmodified ANB was faster than that of PPA modified ANB. Thus, a good potential for reducing thermal aging in ANB was found in PPA

Efficacy of Polyphosphoric Acid in Reducing the Degree of Thermal Aging of Agbabu Natural Bitumen

Bitumen is a complex mixture of hydrocarbons which occurred naturally or obtained from crude oil distillation. The degradation of bitumen causes its rapid aging leading to deterioration of asphalt based pavement readily induced by cracking, rutting, potholes etc. Aging in bitumen is attributed to chemical oxidation of its molecules and exposure to environmental factors, such as heat, moisture and sunlight. This study therefore investigates the viability of using polyphosphoric acid (PPA) to reduce the oxidative degradation effect of heat (60 o C) on constituents of Agbabu natural bitumen (ANB) with a view to making it more durable when used for road pavement. Modification of ANB with PPA was carried out at 150-55 o C using melt blend technique. Thereafter, the PPA modified and neat (unmodified) ANB samples were thermally aged in a hot air oven at 60 o C. Fourier Transform Infrared (FTIR) Spectroscopy was used to evaluate the changes in the structure of ANB and aging indexes of neat and PPA modified samples of ANB were calculated. The neat and PPA modified ANB samples aged as a result of their exposure to temperature at 60 o C. However, the aging indexes of PPA modified samples of ANB were found to be lower compared with that of the neat sample of ANB. This implies that the rate of aging (60 o C) of the neat ANB was faster than that of PPA modified ANB samples. Thus, a good potential for reducing thermal aging in ANB was found in PPA

Hadron Production in Neutrino-Nucleon Interactions at High Energies

The multi-particle production at high energy neutrino- nucleon collisions are investigated through the analysis of the data of the experiment CERN-WA-025 at neutrino energy less than 260GeV and the experiments FNAL-616 and FNAL-701 at energy range 120-250 GeV. The general features of these experiments are used as base to build a hypothetical model that views the reaction by a Feynman diagram of two vertices. The first of which concerns the weak interaction between the neutrino and the quark constituents of the nucleon. At the second vertex, a strong color field is assumed to play the role of particle production, which depend on the momentum transferred from the first vertex. The wave function of the nucleon quarks are determined using the variation method and relevant boundary conditions are applied to calculate the deep inelastic cross sections of the virtual diagram.Comment: 6 pages PDF forma

Characterisation of Agbabu Natural Bitumen and Its Fractions Using Fourier Transform Infrared Spectrometry

Physico-chemical characterization of bitumen is very germane to its applications. There have been many physico-chemical investigations on Agbabu natural bitumen (ANB), but there appears to be some discrepancies in the results of some of the findings. Thus, the need to re-examine some of the physico-chemical parameters of the ANB. Raw sample of ANB was obtained from one of the observatory wells in Agbabu, Ondo State, Nigeria. The sample was dehydrated, purified and asphaltene component precipitated through addition of n-pentane to the sample. The maltene component was fractionated into saturate, aromatics and resin using column chromatographic method. The purified ANB sample and its fractions were each subjected to infrared analysis. In addition, the elemental composition and trace metals in the whole purified ANB were quantified using CHNS-O Analyzer (FlashEA® 1112) and Atomic Absorption Spectrometer (AAS) respectively. Infrared spectral features obtained for the whole bitumen and its fractions bear a good degree of resemblance to the results of earlier workers on the subject with some minor differences. The values obtained for structural indexes from Infrared (IR) spectra showed that all the fractions contained branch and straight chain hydrocarbons. The structural indexes also showed that asphaltenes and resin fractions are strongly polar, both of which contain hetero–atomic compounds. Results of compositional analysis are: C (86.62%), H(10.98%), S (0.92%) N (0.48%), O (0.83%), Maltene (78.34%) aand Asphaltene (21.67%). The concentrations of the trace metals are: Mg (792.00 ppm), Mn (28.40 ppm), Fe (3633.10 ppm), Ca (1082.10 ppm), Zn (17.50 ppm), Cu (17.90 ppm), Cr (153.90 ppm), Pb (93.78 ppm), Ni (103.65 ppm), V (156.53 ppm) and Na (3740.00 ppm). Results of compositional and trace metals analyses of this study are at variance with the earlier results on characterization of ANB in the literatures. The differences in the results might be attributed to variation in the method of sample preparation especially the inclusion of dehydration of the raw ANB in the purification step prior to characterization as introduced in this study. Keywords: Aromatics, Asphaltenes, Agbabu Natural Bitumen, IR, Resins, Saturate

Layer by Layer Silver Acetate based Coating on Glass and Cement Substrates to Tailor Reflectance and Conductance

Tailoring reflectance and conductance was achieved through layer by layer assembly of a silver acetate based multilayer coating. The coating was applied over glass and cement substrates by sol-gel spin coating and by brush painting, respectively. The structural, optical and electrical characteristics and the composition of the coating were studied. The diffraction peaks for all films revealed that the face-centered cubic lattice of the silver crystal structure and the films with more layers had a higher degree of crystallinity. The optical characteristics showed that having more layers leads to decreasing transmittance and increasing reflectance. The I-V characteristics of all samples showed typical ohmic contacts in a voltage range of -1 to 1 V. The conductance increased drastically as the coating developed into multiple layers. The eight-layer coated glass and cement based substrates had very low surface resistance, at 4 Ω and 2 Ω at 1 V, respectively. The study also revealed that the resistance behavior of a multilayered film generally is thermally stable for annealing up to 400 °C. The coating resistance was significantly increased by further increasing the post-annealing beyond 500 °C. The studied multilayered coating can be used to tailor the reflectance and conductance of dielectric substrate surfaces for various optoelectronics and sensor device applications

Flame/stretch interactions of heavy-hydrocarbon/O/N premixed flames

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76511/1/AIAA-1999-321-776.pd