641 research outputs found
Computational Analysis of Surgical Tool-Brain Tissue Interaction
This paper presents new surgical tool-brain tissue interactions models in three directional format considering the linear elastic, hyperelastic and viscoelastic properties of a brain tissue which are characterized by conducting stress-strain simulation on brain model. Brain tissues properties like a Neo-Hookean, Mooney-Rivlin Model and Prony Series are considered. Effects of adopting non-linear properties are discussed. After optimizing models in COMSOL Muiltiphysics 4.0, the models show that the brain tissues contain non-linear characteristic and the coefficients of the models are available to Open Inventor in order to initiate a visio-haptic simulation which will be used for doctors and surgical operation manipulators
CLIMATE CHANGE IMPACT, ITS ADAPTATION MEASURES ON FISHERMEN LIVELIHOOD STATUS IN COASTAL AREA OF SOUTHWEST NIGERIA
Climate change effect and adaptation measure on the livelihood deeds of artisanal Fishermen was carried out within the coastal areas of Southwest Nigeria. Multi-stage sampling technique was used to select 263 fishermen from Lagos, Ogun and Ondo States. Information obtained was with the use of structured interviewed schedule and subjected to descriptive and inferential statistics at 0.05 level of significance. Findings shows that majority (65.4%) of the Fishermen were between 45-64 years of age, 77.9% married, 67.7% had above 11 years of fishing experience across the Coastal area of Southwest, Nigeria. Also, 22.4% of Fishermen in the coastal area have access to extension services while 22.4% of them only had access to extension services. Major livelihood activities were fishing gathering (95.1%), fish processing (91.6%) and fish marketing (81.7%) in the selected area. the main effect of climate change on the fishermen activities were flooding (x̄= 2.43), while increased waves were (x̄ = 2.24), ocean surge (x̄ =2.23), rainfall intensity (x̄ = 2.07) and high temperature (x̄ = 2.06) respectively across the selected states respectively. Majority of the artisanal Fisherfolk utilized different adaptation measures/practices towards climate change. There were significant relationship (p < 0.05) between the respondent sex (c2 = 19.342, df = 1), educational level (c2 = 11.242, df = 4), ethnicity (c2 = 10.523) and climate change effect on livelihood deeds of artisanal Fishermen across selected states. Correlation result also reveals significant relationship (p < 0.05) between age (r = 0.872), household size (r = 0.653), years of fishing experience (r = 0.815) and the climate change effect on livelihood activities of artisanal Fishermen across selected States, Results also showed that there is significant difference in the effect of climate change on livelihood of artisanal Fishermen (F = 16.325; P = 0.001) across the selected states. The study realized that Artisanal Fishermen sampled experienced high effect of climate change in term of flooding, increased waves, ocean surges, rainfall intensity and high temperature across the selected States sampled. The study recommended that Artisanal Fishermen should be participating in policy and strategy formulation in mitigate climate change impacts on their fishing and livelihood activities so as to reduce the vulnerability of the effects caused by climate change in the coastal areas. Keywords: Artisanal, Climate change, Coastal communities, Fishermen, Livelihood activities, Southwest. DOI: 10.7176/JNSR/14-12-07 Publication date:September 30th 2023
PROCESS OPTIMIZATION OF OIL EXPRESSION FROM WATERMELON (CITRULLUS LANATUS) SEEDS
Watermelon fruit contains large quantities of seeds and these seeds are under-utilized. It contains reasonable amount of oil (22%) which if expressed will serve as vegetable oil for human consumption or biodiesel for powering agricultural machines and boost the income of the farmers. The main objective of this research work is to study the interaction effect of operating parameters on the mechanical oil expression from the seed. The variables considered include applied pressure (85.00, 90.00, 95.00, 100.00 and 105.00 kN/mm2), roasting temperature (70.00, 80.00, 90.00, 100 and 110 °C) and moisture content (6.00, 8.00, 10.00, 12.00 and 14.00 %). A total sum of 20 batch experiments were carried out and the maximum oil yield was 13.49% (at corresponding moisture content of 6.00%, roasting temperature of 85.00oC and applied pressure of 105.00 kN/mm2 respectively) and minimum oil yield obtained was 9.41%.(at corresponding moisture content of 14.00%, roasting temperature 80 °C and applied pressure of 85.00 kN/mm2 respectively). While the optimum oil yield of 12.42% was obtained from the expression at corresponding moisture content of 6.00%, roasting temperature of 80.00ºC, and applied pressure of 105.00 kN/mm2. The result showed that the three independent variables had significant effect on oil yield and regression model equation was developed to predict the oil yield from watermelon seeds at known variables
Evaluation of Natural Fertilizer Potential of Neem Leaves Aqueous Extract for Irrigation Practices
A natural fertilizer relies on plant, mineral and animal sources for its nutrients. The objective of this paper is to evaluate the natural fertilizer potential of Neem leaves aqueous extract for irrigation practices by analyzing some physicochemical parameters using standard methods. Data obtained shows that the pH level were, 8.4, 7.2, 7.1, and 7.3 respectively   indicating a moderate alkalinity status suitable for irrigation. The electrical conductivity values were as 2.4, 2.2, and 1.8 mg/L for Neem aqueous extract while turbidity values were 334, 323, and 296 NTU respectively .These values are within the acceptable range according to FAO guidelines. SAR values were as 11.20, 10.04, and 10.81 and chloride levels were found to be; 22.1, 16.12, and 5.97 mg/L, posing no concerns for irrigation. Sodium levels were 35.7, 27.32 and 25.31 mg/L which also falls within the FAO guidelines and indicating moderate sodicity. Overall, the nutritional compositions of the Neem leaf extracts were within the FAO guideline limits for irrigation fluid, indicating their suitability for irrigation practices. This Neem leaf extract as an irrigation solution could provide a valuable insights for farmers and agricultural practitioners seeking to optimize crop productivity and quality
Flash vacuum pyrolysis of benzylidene halides, benzotrihalides and aryl halides over magnesium
This work was supported by B.P.Flash vacuum pyrolysis at 600 °C through glass wool coated with freshly sublimed magnesium is examined as a preparative method for dehalogenative coupling in organic synthesis. Substituted benzylidene chlorides give predominantly the corresponding stilbenes and in some cases these are readily isolated in pure form. With an ortho-halogen substituent, additional cyclisation gives phenanthrenes but the method is not compatible with the presence of several reactive groups. An ortho-methoxy substituent leads to unexpected formation of mono- and dimethyl products. With 1,4-bis(dihalomethyl)benzenes, halogenated polymers are deposited directly from the gas phase via generation of halogenated p-xylylenes. The 1,2- and 1,3-isomers lead respectively to benzocyclobutadiene, isolated as a dimer, and to pyrene. The 1,4-bis(trihalomethyl)benzenes give more highly halogenated polymers directly from the gas phase via halogenated p-xylylenes. While halobenzenes generally give the corresponding benzenes and biphenyls, 1,2-dihalobenzenes additionally produce triphenylene in preparatively useful yield by a process not involving intermediacy of free benzyne.PostprintPeer reviewe
Awareness of Cassava Peel Utilization Forms among Cassava Processors in Rural Communities of Southwest, Nigeria
Significant quantities of generated peels are been thrown on dumping sites in southwest, Nigeria thereby constituting a source of environmental pollution. This study assessed the awareness of cassava peel utilization forms among cassava processors in rural communities of southwest, Nigeria. Interview guide was used to elicit information from 200 cassava processors through a multistage sampling technique. Data were analyzed with both descriptive and inferential statistics. Result revealed that majority of the cassava processors were women (76.5%), married (75.0%), and members of cassava processing associations (89.5%) with 73.0% having at least primary education. The mean age and cassava processing experience were 53.01 and 22.76 years respectively. About 23.0% of the processed cassava tubers constituted peels. The study also revealed that 50% of the cassava processors discarded peels as waste, 26% sold generated peels while 24% fed the peels to their livestock. Also 93.5% of the cassava processors were not aware of any cassava peel utilization technology. Chi-square analysis revealed that significant association existed between existing practice on cassava peel utilization (χ2=17.341, p<0.05) and cassava processors’ awareness of cassava peel utilization forms. The study concluded that substantial quantity of peel been generated is discarded as waste due to lack of awareness of cassava peel utilization technologies in the study areas. The study therefore recommended that improved technologies on the utilization of cassava peel should be popularized through result demonstration among cassava processors in southwest, Nigeria
Micromagnetic simulations of interacting dipoles on a fcc lattice: Application to nanoparticle assemblies
Micromagnetic simulations are used to examine the effects of cubic and axial
anisotropy, magnetostatic interactions and temperature on M-H loops for a
collection of magnetic dipoles on fcc and sc lattices. We employ a simple model
of interacting dipoles that represent single-domain particles in an attempt to
explain recent experimental data on ordered arrays of magnetoferritin
nanoparticles that demonstrate the crucial role of interactions between
particles in a fcc lattice. Significant agreement between the simulation and
experimental results is achieved, and the impact of intra-particle degrees of
freedom and surface effects on thermal fluctuations are investigated.Comment: 10 pages, 9 figure
LiFT: A Scalable Framework for Measuring Fairness in ML Applications
Many internet applications are powered by machine learned models, which are
usually trained on labeled datasets obtained through either implicit / explicit
user feedback signals or human judgments. Since societal biases may be present
in the generation of such datasets, it is possible for the trained models to be
biased, thereby resulting in potential discrimination and harms for
disadvantaged groups. Motivated by the need for understanding and addressing
algorithmic bias in web-scale ML systems and the limitations of existing
fairness toolkits, we present the LinkedIn Fairness Toolkit (LiFT), a framework
for scalable computation of fairness metrics as part of large ML systems. We
highlight the key requirements in deployed settings, and present the design of
our fairness measurement system. We discuss the challenges encountered in
incorporating fairness tools in practice and the lessons learned during
deployment at LinkedIn. Finally, we provide open problems based on practical
experience.Comment: Accepted for publication in CIKM 202
A review of wire arc additive manufacturing and advances in wire arc additive manufacturing of aluminium
The Novel Mouse Mutation Oblivion Inactivates the PMCA2 Pump and Causes Progressive Hearing Loss
Progressive hearing loss is common in the human population, but we have few clues to the molecular basis. Mouse mutants with progressive hearing loss offer valuable insights, and ENU (N-ethyl-N-nitrosourea) mutagenesis is a useful way of generating models. We have characterised a new ENU-induced mouse mutant, Oblivion (allele symbol Obl), showing semi-dominant inheritance of hearing impairment. Obl/+ mutants showed increasing hearing impairment from post-natal day (P)20 to P90, and loss of auditory function was followed by a corresponding base to apex progression of hair cell degeneration. Obl/Obl mutants were small, showed severe vestibular dysfunction by 2 weeks of age, and were completely deaf from birth; sensory hair cells were completely degenerate in the basal turn of the cochlea, although hair cells appeared normal in the apex. We mapped the mutation to Chromosome 6. Mutation analysis of Atp2b2 showed a missense mutation (2630C→T) in exon 15, causing a serine to phenylalanine substitution (S877F) in transmembrane domain 6 of the PMCA2 pump, the resident Ca2+ pump of hair cell stereocilia. Transmembrane domain mutations in these pumps generally are believed to be incompatible with normal targeting of the protein to the plasma membrane. However, analyses of hair cells in cultured utricular maculae of Obl/Obl mice and of the mutant Obl pump in model cells showed that the protein was correctly targeted to the plasma membrane. Biochemical and biophysical characterisation showed that the pump had lost a significant portion of its non-stimulated Ca2+ exporting ability. These findings can explain the progressive loss of auditory function, and indicate the limits in our ability to predict mechanism from sequence alone
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