A Fuzzy Logic Approach to Predict Tensile Strength in TIG Mild Steel Welds

Welding defects influence the desired properties of welded joints giving fabrication experts a common problem of not being able to produce weld structures with optimal strength and quality. In this study, the fuzzy logic system was employed to predict welding tensile strength. 30 sets of welding experiments were conducted and tensile strength data was collected which were converted from crisp variables into fuzzy sets. The result showed that the fuzzy logic tool is a highly effective tool for predicting tensile strength present in TIG mild steel weld having a coefficient of determination value of 99%.

Contributions of Engineering Geological Properties of Subgrade Soils to Premature Failure of Major Highways in Southwestern Nigeria:A Case Study of Akure-Ikere Ekiti Highway

Geotechnical analyses were carried out to examine the contributions of engineering geological properties of subgrade soils to the failure of the Akure-Ikere Ekiti road,Southwestern Nigeria.Field observations revealed that the road is in a very poor state of serious deformation and disrepair as most parts of the road alignment have failed.The alignment of the studied road is predominantly underlain by Granite,Charnockites,and Migmatites.Laboratory tests results showed that the natural moisture content ranges from 10.98 to 21.4%,liquid limit from 22.8 to 47.7%,plastic limit from 19.2 to 24.6,plasticity index 3.6 to 26.3%.The grain size analysis revealed that the amount of fines ranges from 15.9 to 49%.Others are linear shrinkage,between 1.4 and 10%,free swell between 25 and 46%,maximum dry density from 1593 to 2016 kg/m,and CBR between 5 and 48%.The specific gravity ranges from 2.64 to 2.74.With reference to AASHTO classification,5% of the samples was classified as A-4,15% classified as A-2-4,40% classified as A-6,while 40% classified as A-7-6.The dominance of fair-to-good California bearing ratio,fair to good maximum dry density,high linear shrinkage and A-7-6,A-6,and A-2-4 soil groups have combined to give fair-to-good geotechnical properties to the studied soils.Generally,the fair to good geotechnical properties of soil of the road under study is an indication that the contribution of subgrade soil to the failure of the highway is negligible.The total breakdown of the road can be traced to substandard engineering specifications which are complemented by a poor drainage system.

The Use of Microbial Biotechnology in Value Addition to Cassava Wastes as Feed for Pigs: Prospects and Challenges

Cassava peels were fermented through a combination of two lactic acid bacteria (Lactobacillus coryneformis and Lactobacillus delbrueckii) and a fungus (Aspergillus fumigatus) using solid substrate fermentation (SSF) technique for five consecutive days. The enhanced product designated as microbially fermented cassava peel (MFCP) was used at graded levels in the feed formulation for growing pigs. Four iso-nitrogenous and iso-caloric diets were formulated with MFCP at 0% (T1), 20% (T2), 40% (T3) and 60% (T4) inclusion levels. Twenty-four boarlings of an average initial weight of 37.15 kg were used in a fourteen-week trial to test the effect of these graded levels of MFCP on growth performance, digestive and reproductive physiology of the experimental animals. The result showed significant differences (P < 0.05) in mean daily feed consumption. Pigs in T3 had the highest feed intake (2.24 ± 0.05 kg), while pigs in T4 had the lowest (1.78 ± 0.04 kg). The final highest live weight was in T3 (72.00 kg) and the least in T4 (58.17 kg). The feed conversion ratios also showed significant differences (P < 0.05) among treatment means. The result obtained from gut morphometry showed that animals in T1 had the highest stomach weight (full and empty), while animals in T3 had the least rate of gastric emptying (81.50%). Animals in T3 and T4 had the longest small intestine (16.21 m and 15.35 m, respectively), while those in T4 had the longest colon (4.24 m). Animals in T1 and T2 had more numbers of gastric glands, while animals in T3 and T4 had more parietal cells. The reproductive indices revealed that animals in T1 were better in terms of the weight and relative weight of vesicular and Cowper’s gland, while animals in T4 had the highest value of the weight and relative weight of prostate gland. Proximate analyses of the ileal digesta revealed that the rate of nutrient absorption was highest in T3 and T1 and lowest in T4. Histological examination of the testes revealed normal testicular architecture in the control diet. The testes of animals fed 0%, 20% and 40% MFCP diets exhibited normal and intact lumen, Sertoli cells, and germ cells. However, animal fed 60% MFCP diet revealed massive disruption and degeneration of germinal epithelium, and complete erosion of the seminiferous tubules. It could be concluded that feeding pigs at 40% MFCP would enhance feed consumption, nutrient absorption and improve the growth rate of pigs. Using MFCP beyond 40% level on swine diet could compromise gut health through diarrhoeagenic disposition of the digesta in the distal colon and modification of the parietal and chief cells of the gastric glands. The hypertrophy of the prostate gland and vacuolization of the seminiferous tubules of pigs fed the 60% MFCP diet indicated a probable reduced reproductive performance.

Molecular Diversity of Fusarium oxysporum and Geotrichum candidum Isolated from Two Tomato Varieties Commonly Consumed in Some Southwestern Town in Nigeria

Fusarium oxysporum and Geotrichum candidum, which are among important pathogens of Solanum lycopersicum L. (Tomato), are sometimes misidentified during morphological misidentification. The study was carried out to evaluate molecular diversity of F. oxysporum and G. candidum isolated from two tomato varieties obtained from Akure, Ilorin and Ibadan, Nigeria. The tomato samples were collected and brought back to the laboratory for fungal isolation. Isolation of the pathogens were done following standard procedures. DNA extraction from pure cultures of the pathogens was done at the Centre Laboratory of University of Ibadan. Genetic relationships among the organisms were also estimated by constructing a Dendrogram through UPGMA using the Mega6 Software and genetic distance was computed also using the Mega6 Software. Five strains of F. oxysporum and seven strains of G. candidum were identified. Percentage similarity of the pathogens with those in GenBank was 99.17% - 100.00% for F. oxysporum and 98.48% - 100.00% for G. candidum. The T-01 marker showed the lowest major allele frequency of 0.0833, while T-10 marker has the highest value for major allele frequency of 0.6667 and an average value of 0.3958. Evolutionary relationship showed that the two strains of G. candidum (MN650247 and MN650250) were similar. The three strains of F. oxysporum (MN650246 and MN650248, MN650245 and MN650253) were also similar. Genetic distances among pairs of the fungal strains ranged from 0.12 to 6.30 in pairwise fashion, with an average of 1.32. Evolutionary relationship or closeness among strains of a fungal species can thus be said not to depend on location.

Groundwater Evolution, Hydrochemical Facies and Quality Evaluation for Irrigation Use in Akure, Ondo State, Nigeria

Hydrochemical facies, groundwater evolution, and physicochemical reactions between soil or rock and water are of considerable importance when evaluating or predicting the nature of anthropogenic impacts on groundwater quality. In this respect a total of 67 ground water samples were collected randomly in Akure, southwestern, Nigeria from hand pump/dug wells and analyzed for major cations and anions. The domination of cations and anions was in the order of Ca2+ > K+ > Na+ > Mg2+ and ?> Cl- > ?> ?respectively. The pH and Eh of the water samples show an acidic condition, with low salinity hazard (generally less than 250 μS/cm). The Piper classification for hydrogeochemical facies indicates carbonate hardness (secondary alkalinity) exceeds 50% that is by alkaline earths and weak acids, with Ca2+ + Mg2+ + ?water-type. This also suggests a meteoric origin of water quality caused by rock-water interaction. The ratio of ?and Cl- is greater than 1 and implies recharge area or upper water flow course of carbonate rocks (interaction of water with aquifer material). The Na+:Cl- is less than 0.7 signifying loss of Na+ through precipitation of evaporating water;the water is Ca2+ rich and Na+ depleted with Mg2+:Ca2+ less than 0.5 and Na+:K+ less than 15. The Na+:Ca2+ (<1) indicates reverse ionic exchange. The Ca2+:?+ ?for the samples is less than 1.0 suggestive of flow of water through the normal hydrological cycle. The calculated range of values of sodium absorption ratio (1.89 - 26.42), permeability index (42.67 - 170.24), residue sodium carbonate (-1 to 5), magnesium ratio (4 - 53), Kelly ratio (0.04 - 0.84), percent sodium (0.41 - 3.45) suggest good water suitable for irrigation purposes. In addition, the Wilcox plot shows that 98% of the water samples belong to “good to permissible category” for irrigation use.

Interrogating the Contending Issues in Nigeria-Ghana Relations: Reciprocity of Consequences or Constructive Engagement

The objective of this paper is to offer theoretical,analytical,and methodological investigations into the character of Nigeria’s relations and reactions towards Ghana on how it has been able to get to the level of reciprocity over trade disputes,political differences/relevance and superiority of influence in West Africa,Africa,and the world.In recent times,the counter measurers over demolition of Nigeria’s High Commission building in Accra and here conducts against the Ghana’s moves while it opted for constructive engagement and downplay the call for retaliatory or regulatory steps on Ghana.It also investigated how Nigeria has been able to use its constructive dialogue skills/diplomacy over reasons of reciprocity on other matters of national interest in relation to Ghana as citizens of both states have been deeply affected while businesses shutdown in both capitals at critical stages.The paper posits to examine the point of departure and seek ways for diplomatic intervention,and calls for leadership political will,factoring in the case of African Continental Free Trade Area Agreements,National and Strategic interests of both states,and the establishment of a compensation fund to Nigeria and Nigerians in Ghana.The paper makes use of secondary data while it adopts theories of interdependence and reciprocity as theoretical frameworks for the study.

Indoor Particulate Matter Assessment in a Northern Nigerian Abattoir and a Residential Building

Indoor air pollution in buildings puts people at risk of developing respiratory and cardiovascular diseases.Particulate matter(PM)exposure is known to cause these health issues.Preliminary efforts were made in this study to assess the quantity and quality of PM1.0,PM_(2.5),and PM_(10)present in an abattoir and a residential building in northern Nigeria.Canree A1 low-cost sensor was used to monitor the locations,8 hourly for two weeks.The results showed that the aver­age values(μg/m^(3))of PM1.0,PM_(2.5),and PM_(10)in an abattoir were 62.74,161.94,and 199.08,respectively,and in a residential building were 28.70,83.31,and 103.71.The average Air Quality Index(AQI)of the abattoir office was Very Unhealthy,while the living room of the residential building was unhealthy.The PM_(2.5),and PM_(10)levels were higher than the international(WHO)and national(FMEnv)standard limits,indicating a potential danger to building occupants.It is expected that the indoor environment of the locations will be improved by the use of good ventilators(adequate windows and doors)and the provision of good extractors.

Potential use of Clerodendrum capitatum extracts and its formulation for control of three major stored product beetles

Objective:Insecticidal activity of Clerodendrum capitatum extracts against the stored product insect pest,Sitophilus oryzae(L.),Rhyzopertha dominica(F.),and Tribolium castaneum(Herbst)were investigated.Materials and Methods:Hundred grams of C.capitatum powder was sequentially extracted with a series of solvents of increasing polarity in a Soxhlet apparatus and the extracts were concentrated on rotary evaporator to make it solvent free and the residue dissolved in a known volume of methanol and the solution was assayed for insecticidal activity by the fumigant toxicity.Hexane extract which showed maximum activity was selected for the preparation of herbal formulation and for its insecticidal properties and phytotoxicity.The herbal formulation obtained from leaves of C.capitatum was investigated by GCMS and GC/FID.Results:Clerodendrum capitatum ethyl extract had a very strong repellent activity to adults of all three major stored grain insects and was significantly repellent at a 1.58 mg/cm^(2).The hexane extract(oil)had high fumigant activity with LC_(50) values in the range between 25 and 32μg/L.A total of 14 components representing 97.8%of the formulation were identified and the main compounds in the formulation were found to be 2-Heptanone,3-methyl(33.9%)and Hexahydrofarnesyl acetone(25.3%)followed by 3-Dodecen-1-al(10.2%)and 8-Methyl-1-undecene(4.9%).Further,herbal formulation was found to be highly toxic to mixed age cultures of all three major stored grain insect pests which recorded 80%-90%mortality at dose of 200μg/L in 24 h exposure,where as 100%mortality achieved at dose of 200μg/L in 72 h exposure,respectively.Conclusion:The results indicate that extracts and formulation of C.capitatum has the potential to be developed in to a natural insecticide or repellent for controlling of stored product beetles.