Mechanical properties and microstructure of fibre-reinforced clay blended with by-product cementitious materials

Clayey soils endure adverse changes in strength and volume due to seasonal changes in moisture content and temperature. It has been well recognised that high cement content has been successfully employed in improving the mechanical properties of clayey soils for geotechnical infrastructural purposes. However, the environmental setbacks regarding the use of high cement content in soil reinforcement have necessitated the need for a greener soil reinforcement technique by incorporating industrial by-product materials and synthetic fibres with a reduced amount of cement content in soil-cement mixtures. Therefore, this study presents an experimental study to investigate the mechanical performance of polypropylene and glass fibre-reinforced cement-clay mixtures blended with ground granulated blast slag (GGBS), lime and micro silica for different mix compositions and curing conditions. The unconfined compressive strength, linear expansion and microstructural analysis of the reinforced soils have been studied. The results show that an increase in polypropylene and glass fibre contents caused an increase in unconfined compressive strength but brought on the reduction of linear expansion of the investigated clay from 7.92% to 0.2% at fibre content up to 0.8% for cement-clay mixture reinforced with 5% Portland cement (PC). The use of 0.4–0.8% polypropylene and glass fibre contents in reinforcing cement-clay mixture at 5% cement content causes an increase in unconfined compressive strength (UCS) values above the minimum UCS target value according to American Society for Testing and Materials (ASTM) 4609 after 7 and 14 days curing at 20◦ C to 50◦ C temperature. Therefore, this new clean production of fibre-reinforced cement-clay mixture blended with industrial by-product materials has great potential for a wide range of applications in subgrade reinforcement

Biodegradation of crude petroleum by bacterial consortia from oil-contaminated soils in Ota, Ogun State, South-Western, Nigeria

Pollution from petroleum products is of public health concern because of its attendant health and environmental impacts. Biodegradation of Bonny light crude petroleum and other selected hydrocarbons by bacteria isolated from soils of three different mechanic workshops in Ota, Ogun State were studied. Species of bacteria were isolated by the enrichmentofthesoilsamplesinminimalsaltmediumsupplementedwith1%(v/v)crude petroleumasthesolecarbonandenergysource.Thepetroleumutilizingbacteriabelonging to the genera Bacillus sp. SB4, Pseudomonas sp. SC8, Serratia sp. SC11, and Acinetobacter sp. SC12 were screened and subjected for oil degradation using turbidity and total viable count,reductioninpHandresidualoilconcentrationasindices.GasChromatographic(GC) analysis was used to analyze the component and percentage of the petroleum utilized. Plasmidcuringandprofilingweredonetodeterminewhethertheabilitytoutilizecarbon isplasmidorchromosomallyencoded.Resultsrevealedthatfourbacteriastrainswereable to utilize petroleum as energy source. The GC fingerprints showed that both the aliphatic and aromatic components of crude petroleum were reduced to varying degree but the nonadecane C19 could not be reduced. Strain SC11 could not reduce anthracene, pyrene, benzo(a)pyrene and chrysene components. Strain SB4 depleted 24 to 57% aliphatics and 20to42%aromaticsandstrainSC8depleted38to67%aliphaticsand30to79%aromatics while strain SC11 depleted 12 to 46% aliphatics and 13 to 29% aromatics. All organisms harbored plasmid which could suggest that petroleum degradation capabilities could be plasmid encoded. This indicates that the petroleum utilizing bacteria are could be used bioremediationofthepetroleumpollutedenvironment

Estimation of the length of interactions in arena game semantics

We estimate the maximal length of interactions between strategies in HO/N game semantics, in the spirit of the work by Schwichtenberg and Beckmann for the length of reduction in simply typed lambdacalculus. Because of the operational content of game semantics, the bounds presented here also apply to head linear reduction on lambda-terms and to the execution of programs by abstract machines (PAM/KAM), including in presence of computational effects such as non-determinism or ground type references. The proof proceeds by extracting from the games model a combinatorial rewriting rule on trees of natural numbers, which can then be analyzed independently of game semantics or lambda-calculus.Comment: Foundations of Software Science and Computational Structures 14th International Conference, FOSSACS 2011, Saarbr\"ucken : Germany (2011

Trans-orbital sonographic assessment of optic nerve diameter in a sampled Nigerian population

Background: Studies have reported variants in the dimensions of optic nerve diameter among different ethnic groups, just as other body anatomy differs from regions to regions.Aim: To establish normal range of optic nerve diameter in a sampled Nigerian population, sonographically.Materials and Method: A total of 725 apparently healthy adult subjects (362 males aged 32 to 65 years and 363 females aged 30 to 68 years) were recruited from the South South and South Eastern parts of Nigeria for this prospective descriptive study. The optic nerve diameter (OND) was measured using a high-resolution digital dedicated small-parts real time ultrasound machine (Sonoace 5500; Medicol, Medison, Miami, FL, USA) with a high frequency (10-MHz) linear array transducer. Subjects were in supine position and were asked to keep their eyes closed and still. Coupling gel was placed on the closed eye lid with the transducer softly placed over the upper temporal eyelid in an axial plane. The OND was measured perpendicular to the vertical axis of the scanning plane as a horizontal distance between the two walls of the nerve sheath. The height and weight of the subjects were determined using a meter rule and a weighing scale.Results: The mean optic nerve sheath diameter of males and females was 4.2 ± 0.13 mm. It ranged from 4.0 to 4.45 mm. The optic nerve sheath diameter of males was not significantly different from that of females (p = 0.345). No significant difference between the mean OND of both eyes (p = 0.345). Body mass index and age did not have any association with OND (r = 0.017, 0.034), the data were normally distributed.Conclusion: Optic nerve diameter of apparently normal Nigerian adults ranges from 4.0 to 4.5 mm. Values outside this range may demand further evaluation in the study population

Evaluation of different packaging types for adoption in safe handling and transportation of fresh tomato fruits in Nigeria

ABSTRACTThis work evaluated plastic, wooden and carton crates and compared the best of them to traditional basket for possible adoption in safe handling and transportation of fresh tomato fruits in Nigeria. This was achieved through laboratory experiments and analysis involving static tests, simulating storage conditions (at average temperature and humidity of 28.920C and 62.08% respectively) and dynamic tests, simulating handling and transportation conditions involving dropping from different heights and vibration at different amplitudes and frequency. Based on experimental results and economic considerations, carton crate was adjudged the best and a new modified design of it was developed. The performance of the designed crate and the traditional basket presently in use in Nigeria was compared. Results of comparative predictive analysis between the carton and the traditional basket revealed that losses that can be incurred using traditional basket while on transit is about 6.25-7.08%; which can be reduced to an average of 5.71% when carton crates are used. In case of accident, the traditional method can incur an average loss of 51.59%, which can be reduced to an average of 37.88% when carton crates are used. In case of delay in travel (2-3weeks), the traditional method may lose an average of 23.81-88.10%, but this can be reduced to 14-67% when carton crates are used

Phytochemical Screening and Antimicrobial Studies of Crateva adansonii Leaf Extract

Diverse challenges of microbial infections and upsurge of multi-drug resistant microbes informed the investigation into the phytochemical and antibacterial properties of Crateva adansonii. Cold extraction was carried out using methanol solvent. The crude extract of Crateva adansonii was fractionated into the n-hexane, methanol and chloroform layers successively. The phytochemical screening indicated the presence of alkaloids, saponins, terpenoids, flavonoids and cardiac glycosides. The antimicrobial assay showed that, for Bacillus spp, the organism was sensitive to the chloroform fraction of leaf extract at 1.562 mg/ml. For Microccocus varians, result showed organism was sensitive to the crude extract at 3.125 mg/ml. According to the result of antifungal screening, the n-hexane fraction and crude extract showed activity against Aspergillus niger at 12.500 mg/ml and 3.125 mg/ml respectively. From these results, the crude extract of the leaf of Crateva adansonii shows activity against both bacteria and Fungi; hence, it may might be a good source of new drug for treating infections caused by these pathogen

Change in Emotional and Theory of Mind Processing in Borderline Personality Disorder: A Pilot Study.

Changes in emotional processing (EP) and in theory of mind (TOM) are central across treatment approaches for patients with borderline personality disorder (BPD). Although the assessment of EP relies on the observation of a patient's self-criticism in a two-chair dialogue, an individual's TOM assessments is made based on responses to humorous stimuli based on false beliefs. For this pilot study, we assessed eight patients with BPD before and after a 3-month-long psychiatric treatment, using functional magnetic resonance imaging and behavioral tasks. We observed arousal increase within the session of the two-chair dialogue (d = 0.36), paralleled by arousal decrease between sessions (d = 0.80). We found treatment-associated trends for neural activity reduction in brain areas central for EP and TOM. Our exploratory findings using an integrative assessment procedure of changes in EP and TOM point toward evidence for treatment effects at the brain systems level related to behavioral modulation

Structural changes to the uterus of the dwarf ornate wobbegong shark (Orectolobus ornatus) during pregnancy

Embryos of the viviparous dwarf ornate wobbegong shark (Orectolobus ornatus) develop without a placenta, unattached to the uterine wall of their mother. Here, we present the first light microscopy study of the uterus of O. ornatus throughout pregnancy. At the beginning of pregnancy, the uterine luminal epithelium and underlying connective tissue become folded to form uterine ridges. By mid to late pregnancy, the luminal surface is extensively folded and long luminal uterine villi are abundant. Compared to the nonpregnant uterus, uterine vasculature is increased during pregnancy. Additionally, as pregnancy progresses the uterine epithelium is attenuated so that there is minimal uterine tissue separating large maternal blood vessels from the fluid that surrounds developing embryos. We conclude that the uterus of O. ornatus undergoes an extensive morphological transformation during pregnancy. These uterine modifications likely support developing embryos via embryonic respiratory gas exchange, waste removal, water balance, and mineral transfer