253 research outputs found
Piezoelectric effects on bone modeling for enhanced sustainability
© 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)Bone tissue possesses piezoelectric properties, allowing mechanical forces to be converted into electrical potentials. Piezoelectricity has been demonstrated to play a crucial role in bone remodelling and adaptability. Bone remodelling models that consider strain adaptation, both with and without piezoelectric effects, were simulated and validated in this study. This simulation help to better comprehend the interplay between mechanical and electrical stimulations during these processes. This study aimed to optimise the modelling of piezoelectric effects in bone modelling analysis. The connection between mechanical loads applied to bones and the resulting electrical charges generated by the piezoelectric effect was examined. Furthermore, mathematical modelling and simulation techniques were employed to enhance the piezoelectric effect and promote bone tissue growth and repair. The findings from this research have substantial implications for developing novel therapies for bone-related diseases and injuries. It was observed that electrically stimulated bone surfaces increased bone deposition. In some instances of physical disability or osteoporosis, therapeutic electrical stimulation can supplement the mechanical stresses of regular exercise to prevent bone loss. Consequently, the bone remodelling method on the software platform enables easy application and repetition of finite element analysis. This study significantly benefits bone tissue/biomedical engineering, particularly in bone remodelling, healing, and repair.Peer reviewe
Determinants of Attitudes of Oil and Gas Companies to Host Communities: A Social Responsibility Perspective
The study was designed to explore the social responsibility attitudes of oil and gas companies to host communities. It presumed that these determinants fall broadly into endogenous and exogenous factors. Three oil and gas companies were sampled from the twelve listed in the Nigeria Stock Exchange for the study. The study found that for Oando Plc., Return on Assets, Earnings size and Debt-Equity ratio were determinants of attitudes of oil and gas companies but not so with MRS Plc. and Seplat Plc. Exogenous factors were found to be largely responsible for the social responsibility attitudes of oil and gas companies towards their communities. Keywords: Oil and Gas Companies, Host Communities, Social Responsibility, Attitude
Shape memory polymer review for flexible artificial intelligence materials of biomedical
The self-healing and biocompatibility of polymer composites for biomedicine have made them a preferred approach for small-scale tissue engineering elements. By moving from static to dynamic pressure, 4D printing simulates the natural physical-mechanical changes of living tissue over time. A promising new platform with excellent controllability actuation is required to enhance the significance of 4D printing for biological applications. This study systematically analyses current 4D printing technologies for the flexible fabrication of artificial intelligence (AIM) materials. In addition, many potential applications of flexible 4D printing in composite biological engineering are thoroughly investigated. We found that knowledge about this new category of flexible AIM composites is relatively limited, and the potential for practical applications has not yet been demonstrated. Finally, we discuss the problems and limitations of flexible 4D printing technology, AIM, and future approaches and applications.</p
SOIL PHYSICO-CHEMICAL PROPERTIES AND MICROFLORA AS INFLUENCED BY PARAQUAT APPLICATIONS
A field experiment was conducted to investigate the effects of paraquat (1, 1â-di methyl-4,4â-biyridinium dichloride) at the recommended and twice the recommended field application rates on soil physicochemical properties and microorganisms. The effects of the herbicide on soil pH, organic carbon, nitrogen, phosphorus content and cation exchange capacity were analyzed along with microbial populations and the growth and distribution of representative soil microorganisms were obtained using standard procedures. There was no significant effect of paraquat on soil physicochemical properties at P>0.05. Paraquat applications at both concentrations caused reduction in the bacterial and fungal populations with twice the recommended rate having more adverse effect when compared with the control while the fungal populations were more adversely affected than the bacteria populations by herbicide treatment. Reduced number of predominant bacteria and fungi genera as well as the elimination of some secondary genera as observed in paraquat treated soils could be detrimental to the sustainability of soil fertility. These results are discussed in line with the soil management practices for sustainable crop productio
The effect of potash on liver function of wistar rats
This study was aimed at investigating the effect of potash on liver function of wistar rats. Thirty two adult albino wistar rats divided into eight (8) groups were used for this study. Group A was the control, while B, C and D were test groups given 0.4g/ml, 0.6g/ml, and 0.8g/ml of potash respectively for 21 days. The weights of both the test animals and the control were monitored. The results on acute toxicity tests showed that LD50 was greater than 2.5g/kg body weight. The activities of GGT increased in group B (1.63 ± 0.54 U/L), C (3.20 ±0.92 U/L) and D (3.41 ±0.81 U/L) when compared with the control (1.00 ±0.36 U/L). The activities of AST increased in group B (0.83 ±0.09 U/L), C (0.90 ±0.05 U/L) and D (0.93 ±0.09 U/L) when compared with the control (0.76 ±0.13 U/L). ALT activities in group B (0.57 ±0.18 U/L), C (0.67 ±0.14 U/L) and D (0.87 ±0.07 U/L) increased in comparison with the control (0.55 ±0.17 U/L). ALP activities increased in group B (4.18 ±1.99 U/L), C (6.86 ±2.04 U/L) and D (6.00 ±1.34 U/L), in comparison with control (3.80 ±1.83 U/L). Our study revealed that Potash altered the functionality of the liver as well as the physical activity of the wistar rats and that the effect is dosage dependent.Keywords: Potash, Liver, Toxicity, Rats, Dos
Essai dâisolement de Campylobacter dans la viande de volaille en RĂ©publique du BĂ©nin
La viande de volaille importĂ©e occupe une place importante dans lâalimentation bĂ©ninoise. Elle est le plus souvent mise en cause dans les cas de toxi-infections alimentaires. De ce fait, elle devrait ĂȘtre sujette Ă uncontrĂŽle de tous les microorganismes de toxi-infections afin de prĂ©server la santĂ© des consommateurs. Mais il sâavĂšre que Campylobacter, qui de plus en plus est indexĂ©, ne fait pas partie de la gamme des bactĂ©riesrecherchĂ©es pour la qualification sanitaire des aliments au BĂ©nin. Cette situation serait due aux probables difficultĂ©s liĂ©es Ă lâisolement de ce germe. La prĂ©sente Ă©tude a essayĂ© dâisoler par culture cette bactĂ©rie afin de prouver que sa recherche en microbiologie alimentaire est possible. Cela pourrait permettre de commencer par lâinclure dans les diagnostics ultĂ©rieurs. Pour ce faire, 30 Ă©chantillons de viande de volaille importĂ©e ont fait lâobjet dâanalyse au Laboratoire de Microbiologie du MinistĂšre de la SantĂ©. Sur les 30 Ă©chantillons, Campylobacter a Ă©tĂ© isolĂ© dans 6, soit un taux de contamination de 20%. En somme, Campylobacter peut ĂȘtre isolĂ© par culture dans notre contexte.Mots clĂ©s : Campylobacter, viande de volaille, maladies alimentaires, BĂ©nin.
Genetic gains in yield and yield related traits under drought stress and favorable environments in a maize population improved using marker assisted recurrent selection
The objective of marker assisted recurrent selection (MARS) is to increase the frequency of favorable marker alleles in a population before inbred line extraction. This approach was used to improve drought tolerance and grain yield (GY) in a biparental cross of two elite drought tolerant lines. The testcrosses of randomly selected 50 S1 lines from each of the three selection cycles (C0, C1, C2) of the MARS population, parental testcrosses and the cross between the two parents (F1) were evaluated under drought stress (DS) and well watered (WW) well as under rainfed conditions to determine genetic gains in GY and other agronomic traits. Also, the S1 lines derived from each selection types were genotyped with single nucleotide polymorphism (SNP) markers. Testcrosses derived from C2 produced significantly higher grain field under DS than those derived from C0 with a relative genetic gain of 7% per cycle. Also, the testcrosses of S1 lines from C2 showed an average genetic gain of 1% per cycle under WW condition and 3% per cycle under rainfed condition. Molecular analysis revealed that the frequency of favorable marker alleles increased from 0.510 at C0 to 0.515 at C2, while the effective number of alleles (Ne) per locus decreased from C0 (1.93) to C2 (1.87). Our results underscore the effectiveness of MARS for improvement of GY under DS condition
Design, simulation and implementation of a PID vector control for EHVPMSM for an automobile with hybrid technology
This work proposes a Model design simulation and implementation of a novel engine of an Electric Hybrid Vehicle of Permanent Magnet Synchronous Motor (EHVPMSM) based on field oriented vector control. The experimental analysis was carried out using: automotive motor control MTRCKTSPS5604P, 3-Phase PMSM coded of a single Motor Control Kit with MPC5604P MCU and simulation with Simulink. Therefore, the direct torque control can be obtained by adjusting the magnitude and phase angle of the stator flux linkage to match the vector torque required by the load as fast as possible. This eradicates the stress of charging the vehicle battery. It automatically charges when it is connected to the main supply of the EHVPMSM. The electromagnetic torque can be increased from 0Â Nm to 6.7Â Nm in approximately 340Â ÎŒs. The response of speed transient was from â2100Â rpm to +2100Â rpm in 100Â ms of 6.7Â Nm torque limit. This is a novel way of conserving the energy consumption in a vehicle, which conserves space and weight and minimizes cost as it is simply done with low-cost materials. In this research, a new mathematical model is proposed for the direct and quadrature axis of the current to control the speed mechanism for the engine. Computer simulation ensures experimental validation of the system with a percentage error of 4.5%. The methodology employed to control the system was with the use of various sensors and software controller, this can be easily implemented in industry and institutional laboratory of learning. Keywords: Permanent magnet machines, PID, EHVPMSM, Vector control, Hybrid vehicl
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