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Cytotoxicity and effect of extraction methods on the chemical composition of essential oils of Moringa oleifera seeds

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2015年第8期16卷 680-689页

作者： rowland monday ojo kayode Anthony Jide AFOLAYAN Medicinal Plant and Economic Development Research Centre Department of BotanyUniversity of Fort Hare

Renewed interest in natural materials as food flavors and preservatives has led to the search for suitable essential oils. Moringa oleifera seed essential oil was extracted by solvent-free microwave and hydrodistillation. This study assessed its chemical constituents. Cytotoxicity of the oils was investigated using hatchability and lethality tests on brine shrimps. A total of 16 and 26 compounds were isolated from the hydrodistillation extraction （HDE） and solvent-free microwave extraction （SME） oils, respectively, which accounted for 97.515% and 97.816% of total identifiable constituents, respectively. At 24 h when the most eggs had hatched, values of the SME （56.7%） and HDIE （60.0%） oils were significantly different （P〈0.05） from those of sea water （63.3%） and chloramphenicol （15.0%）. Larva lethality was different significantly （P〈0.05） between HDE and SME oils at different concentrations and incubation periods. The median lethal concentration （LC50） of the oils was 〉 1000 mg/ml recommended as an index for non-toxicity which gives the oil advantage over some antioxidant, antimicrobial, therapeutic, and preservative chemicals.

关键词： Moringa oleifera seed Extraction methods Essential oil Cytotoxicity

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Design and Development of Grip for Circular Test Piece Inuniversal Tensile Testing Machine

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Journal of Minerals and Materials Characterization and Engineering 2013年第6期1卷 331-335页

作者： ojo Jeremiah Akinribide Adetunji Kolawole Ogunkoya Itopa monday Momoh Olasupo Daniel Ogundare Ba’aku Emmanuel AttahDaniel Samuel Olugbenga Oloruntoba Olusunle Engineering Materials Development Institute Akure Nigeria

The design and development of jaw grip for circular tensile test samples in a universal mechanical tester were undertaken in this work. In developing economies, the cost of acquiring laboratory testing equipment and accessories is huge, thereby depriving most of the supposedly advanced laboratories of most of this necessary research equipment. Where the equipment is available, they are either non-functional due to inadequate maintenance know-how or non-availability of necessary accessories. The developed grip in this work is part of an effort at providing accessories as their need arises. Advanced design and manufacturing tools were deployed to develop the jaw grip by using austenitic stainless steel. The developed jaw grip was used on the test equipment to conduct tensile tests on steel samples and the results were found to conform to international standard. Consequently, replacement of worn-out accessories has been carried out in resent time, which eventually saves idle time of equipment or otherwise importation for replacement.

关键词： Mechanical Testing Tensile Test Jaw Grip

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Assessment of Noise Exposure of Sawmill Workers in Southwest,Nigeria

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Sound & Vibration 2021年第1期55卷 69-85页

作者： Abiola O.Ajayeoba Adewoye A.Olanipekun Wasiu A.Raheem Oluwaseun O.ojo Ayowumi R.Soji-Adekunle Department of Mechanical Engineering Ladoke Akintola University of TechnologyOgbomosoNigeria Department of Civil Engineering Ladoke Akintola University of TechnologyOgbomosoNigeria Department of Systems Engineering University of LagosLagosNigeria Department of Mechanical Engineering Adeleke UniversityEdeNigeria

Economic wood processing employs the use of industrial machines for cutting,shaping,milling,and sawing timber,thereby leading to the generation of high levels of *** data from empirical studies have categorized noise as an environmental hazard of global ***,noise exposure limits for different industries and all the industrial machines available has not been formally established as it presently exists in developed nations around the ***,this study assessed the daily exposure of sawmills workers to noise in Southwestern *** surveys were first carried out in Osun,Oyo,Ondo,Ekiti,Lagos,and Ogun States to select sawmills that were fully operational and fit for the *** fully functional sawmills in two cities of each State were eventually selected for data collection,making a total of 24 sawmills,while the Circular Machines(CM),Planer Machines(PM),and Band-saw Machines(BM)were the machines in each sawmill *** machines each of CM,PM,and BM were considered in each sawmill,making a total of forty-eight(48)machines each of CM,PM,and *** data were collected between 7 am and 7 pm each day for six days(between monday and Saturday)using Extech 407732 sound level meter and all stabilized measurements were taken three times at different *** data collected were in three different periods:Machine No-work Period(NPm),Machine Idle Period(IPm),and Machine Working Period(WPm).A two–way Analysis of Variance(ANOVA)was carried out at P<0.05 to determine whether there is a significant difference in the sound level average before and after the break,for both the idle and working periods of the three machines *** was also done to determine whether there is a signifi-cant difference between the sound level average of the results collected during idle and working periods of the three *** Pollution Levels(Lnp)ranged from 83.20 dB(PM)to 107.65(BM)and 93.42(CM and PM)–116.00(BM)resp

关键词： Sawmills machines noise exposure pollution wood

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