594 research outputs found

    Enhancing physicochemical properties of coconut oil for the application of engine lubrication

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    Engine lubricants require specific physical and chemical properties to function effectively and extend the lifespan of engines. Coconut oil (CCO) is an abundant, renewable, and environmentally friendly bio-based stock that has the potential to be a viable alternative to conventional mineral oil-based lubricants. In this study, we investigated the potential of CCO as a lubricant and formulated different blends with additives to enhance its physicochemical characteristics. Polymethylmethacrylate (PMMA), styrenated phenol (SP) and potassium hydroxide (KOH) were used as additives in varying concentrations. We evaluated the formulations for low pour point (PP), high viscosity index (VI) and total base number (TBN) using differential scanning calorimetry (DSC), viscometry, and titration methods (following ASTM D2270 and ASTM D2896–21 respectively). The formulated CCO was also tested for thermal, oxidative, and shear stability using thermogravimetric analysis and rheometry. The optimal formulation exhibited a PP reduction from 21 °C to 6 °C, improved VI from 169 to 206, and a TBN adjustment from 0 to 4.14 mg KOH g-1. The formulated CCO also exhibited superior thermal, oxidative, and shear stability compared to unformulated CCO and reference oil (15W40). Our results suggest that blending CCO with additives can effectively enhance its suitability for engine lubrication, opening up new possibilities for environmentally sustainable and renewable lubricants

    Selenate-enriched urea granules are a highly effective fertilizer for selenium biofortification of paddy rice grain

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    Citation: Premarathna, Lakmalie, Mike J. McLaughlin, Jason K. Kirby, Ganga M. Hettiarachchi, Samuel Stacey, and David J. Chittleborough. “Selenate-Enriched Urea Granules Are a Highly Effective Fertilizer for Selenium Biofortification of Paddy Rice Grain.” Journal of Agricultural and Food Chemistry 60, no. 23 (June 13, 2012): 6037–44. https://doi.org/10.1021/jf3005788.We examined the effects of applied selenium (Se) species, time of application, method of application and soil water management regime on accumulation of Se in rice plants. Plants were grown to maturity in a temperature- and humidity-controlled growth chamber using three water management methods: field capacity (FC), submerged until harvest, and submerged and drained two weeks before harvest; two Se species: selenate (SeO[subscript 4] ˉ²) and selenite (SeO[subscript 3]ˉ²) applied at a rate equivalent to 30 g haˉ¹; and four application methods: i) Se applied at soil preparation, ii) Se-enriched urea granules applied to floodwater at heading iii) foliar Se applied at heading and iv) fluid fertilizer Se applied to soil or floodwater at heading. Total Se concentrations in rice grains, husks, leaves, culms and roots were measured, as well as Se speciation in grains from the Se-enriched urea granule treatment. Highest Se concentrations in the grain occurred with SeO[subscript 4] ˉ² and with fertilizer applied at heading stage; SeO[subscript 4]ˉ²-enriched urea granules applied at heading increased grain Se concentrations 5 to 6 fold (by 450-600 μg kgˉ¹) compared to the control (no fertilizer Se applied) in all water treatments. Under paddy conditions other Se fertilization strategies were much less effective. Drainage before harvesting caused Se to accumulate in/on rice roots, possibly through adsorption onto iron plaque on roots. Rice grains contained Se mainly in the organic form as selenomethionine (SeM) which comprised over 90 % of the total grain Se in treatments fertilized with SeO[subscript 4]ˉ² -enriched urea granules. The results of this study clearly show of the fertilizer strategies tested that biofortification of Se in rice grains can best be achieved in lowland rice by broadcast application of SeO[subscript 4]ˉ² -enriched urea granules to floodwater at heading stage

    Root uptake of lipophilic zinc-rhamnolipid complexes

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    This study investigated the formation and plant uptake of lipophilic metal-rhamnolipid complexes. Monorhamnosyl and dirhamnosyl rhamnolipids formed lipophilic complexes with copper (Cu), manganese (Mn), and zinc (Zn). Rhamnolipids significantly increased Zn absorption by Brassica napus var. Pinnacle roots in 65Zn-spiked ice-cold solutions, compared with ZnSO4 alone. Therefore, rhamnolipid appeared to facilitate Zn absorption via a nonmetabolically mediated pathway. Synchrotron XRF and XAS showed that Zn was present in roots as Zn-phytate-like compounds when roots were treated with Zn-free solutions, ZnSO4, or Zn-EDTA. With rhamnolipid application, Zn was predominantly found in roots as the Zn-rhamnolipid complex. When applied to a calcareous soil, rhamnolipids increased dry matter production and Zn concentrations in durum (Triticum durum L. cv. Balcali-2000) and bread wheat (Triticum aestivum L. cv. BDME-10) shoots. Rhamnolipids either increased total plant uptake of Zn from the soil or increased Zn translocation by reducing the prevalence of insoluble Zn-phytate-like compounds in roots

    The Impact of Greenery in the Window View on Visual Sustained Attention with Special Reference to Classrooms of Children with Down Syndrome

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    One in every 700 babies worldwide is born with an intellectual disability such as Down Syndrome (DS), Autism Spectrum disorders, Cerebral Palsy etc. Architecture significantly enhances users’ development skills by leveraging the environment to fulfill their mental and psychological needs, particularly by boosting sustained attention in learning spaces. Based on existing literature, this research focused on the impact of greenery in window view of the classroom on visual sustained attention (VSA) of children with DS. Data of 19 participants (10 male, 9 female) of a selected school in the ages of 9 – 16 years (mean age – 11.42 years) was collected on existing and introduced levels of greenery in window view using three dimensional simulations and analysed. The study revealed that the introduction of 40% to 60% of greenery at far view depth (Scenario B) has a positive impact on VSA over both the existing window view (Scenario A) and the window view with 80% to 100% greenery (Scenario C). However, scenario C did not show any positive impact over scenario B as assumed. One reason for this could be the inclusion of the sky view in scenario B, and the findings indicate that introduction of greenery in the window view has a positive impact on VSA of children with DS, if the sky view is maintained. These findings can be used towards a design framework for classrooms in the future contexts of education in Sri Lanka

    Placement and source effects of phosphate fertilizers on phosphorus availability and reaction products in two reduced-till soils: A greenhouse study

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    Citation: Khatiwada, Raju, et al. “Placement and Source Effects of Phosphate Fertilizers on Phosphorus Availability and Reaction Products in Two Reduced-Till Soils: A Greenhouse Study.” Soil Science, vol. 179, no. 3, Mar. 2014, pp. 141–152. journals.lww.com, doi:10.1097/SS.0000000000000055.Crop yields are limited primarily by unavailability of nutrients in agricultural soil. Adoption of reduced tillage and no-tillage systems leads to stratification of nutrients in surface soil, so management of phosphorus (P) in these systems is a major issue. The objective of this research was to understand the influence of placement (broadcast vs. deep-placed P) and fertilizer source (granular versus liquid P) on the reaction products of P under greenhouse conditions using soil columns. Phosphorus was added at a rate of 75 kg/ha to two soils: an acid soil from Manhattan, KS, and a slightly acid to neutral soil from Ottawa, KS. At 5 weeks after P application soil pH, resin-extractable P, and speciation of P in soils were determined at different distances from the point of fertilizer application. Scanning electron microscope with energy dispersive X-ray analysis(SEM-EDXA) and synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy were used to understand P speciation. Results for P fertilizer sources and placement with respect to resin-extractable P showed no clear differences between the treatments except for granular broadcast and granular deep-placed treatments in the Ottawa soil.Reaction products formed after application of P in two soils showed some clear differences. The XANES speciation revealed that Fe-P-like forms dominated in the acidic soil, whereas adsorbed and Fe and Ca-P-like forms dominated in the neutral to slightly acid soil. No clear trends in reaction products were detected with respect to P source or the P placement method. Furthermore, SEM-EDXA analysis of incubated fertilizer granules extracted from soils at 5 weeks showed enrichment of Al, Fe, and Ca in the zones of remaining P in incubated granules, indirectly indicating that these cations enter and or remaining in the granules and begin to react with P before the granules dissolve completely

    Nanostructured Al2O3/Graphene Additive in Bio-Based Lubricant: A Novel Approach to Improve Engine Performance

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    Personal and industrial use of internal combustion engines (ICEs) is projected to continue until 2050 and beyond. Yet demands to reduce global dependence on petrochemicals and fossil fuel-derived lubricants are increasing and environmentally necessary. New strategies for maintaining and enhancing ICE performance by reducing friction, wear, fuel consumption, and exhaust emissions will reduce the depletion of mineral and fossil fuel reserves and environmental pollution. This paper reports the tribological enhancement of nano-bio lubricants formulated using 2D nanocomposites of Al2O3/graphene as novel additives in coconut oil, whose performance as a lubricant compares favourably with the mineral-based engine oil 15W40. Structural, compositional, and morphological characterization of an Al2O3/graphene nanocomposite synthesized via thermal annealing revealed an ultra-fine particle size (<10 nm) with spherical/laminar morphology and a rich sp2 domain, exhibiting a consistent colloidal stability when formulated as nanofluid. Through the use of various characterisation techniques, including friction and wear analysis we gained valuable insight into the tribological mechanism. Our optimisation of 2D tribological system using coconut oil formulation resulted significant reductions in the coefficient of friction (28%), specific fuel consumption (8%), and exhaust pollutants (CO, SO2, and NOx) emissions. This work demonstrates the benefits of using nano-bio lubricant formulated using coconut oil and 2D based hybrids as base stock and additives, delivering solutions to global challenges such as improving fuel consumption while reducing environmental pollution; solutions that can be transferred to other areas where lubricants are a necessity

    CREEP OF SMALL DIAMETER TIMBER POLES

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    It has become necessary to encourage the use of small diameter timber poles (plantationthinnings) as building timber particularly in roof construction, as the supply of betterknown indigenous species can no longer meet the increasing demand for constructiontimber. Eucalyptus and Pinus species were introduced to Sri Lanka some years ago and atpresent there exists a large area under their plantation. While the larger diameter trees areused in pole form for transmission poles or are processed for furniture, the thinnings havehad little use. Preliminary studies were carried out to assess the feasibility of using thethinnings as roof timber. The mechanical properties were found to be adequate. Boththese species however need to be preservative treated to increase their durability. Borondiffusion was considered a cost effective method of treatment provided the poles are usedwhile still green. Previous studies have shown that the poles removed from a Boronpreservative tank took 3 to 4 months to reach equilibrium moisture content. Thus theymust be allowed to dry out under load.The limiting of deflection often controls the design of seasoned timber beams. It is thusexpected that limiting deflection, will be more the controlling design requirement for thegreen poles drying out under load. The magnitude of long term or creep deflection thatoccurs as the poles dry out under load is thus significant and needs to be determined.This paper describes an investigation into the creep behaviour of initially green smalldiameter timber poles drying out under load. The magnitude of a factor that can be appliedto instantaneous elastic deformation to evaluate long term deformation is determinedexperimentally for timber poles of Eucalyptus and Pinus species of different diametersdrying out under a range of bending stresses.

    ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES OF LEAVES, SKIN, FLESH AND SEEDS OF SRI LANKAN VARIETY OF CUCURBITA MOSCHATA

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    Reactive oxygen species are continuously produced by normal physiological activities of the human body and these cause damage to the cell membrane and biomolecules and thereby resulting chronic diseases. Antioxidants are scavengers of such free radicals and could combat oxidative stress. In spite of the advances in modern medicine, plant based remedies are increasingly sort after due to their lesser side effects. The antioxidants capacity and antimicrobial properties of ethyl acetate, acetone and methanol extracts of seeds, leaves, flesh and skin of the Sri Lankan variety of Cucerbita moschata were investigate. The ethyl acetate extracts of leaves gave the highest rate of change of reducing power with concentration (0.1625 ml/mg) in Fe3+ reducing power assay and the highest hydroxyl radical activity (72.8±3.8%). The acetone extract of leaves gave the highest rate of change of radical scavenging activity with concentration (7.016 ml/mg) during DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay. Ethyl acetate extract of leaves also showed the highest phenolic content (42.4±2.4 mg (PGE/g)) and highest flavonoid content (40.2±0.6 mg (QE)/g). All extracts of skin and seeds as well as the methanol extract of leaves and acetone extract of flesh showed antibacterial activity against Bacillus subtilis. The three extracts of skin and the acetone extract of leaves showed antibacterial activity against the Escherichia coli

    Ticarcillin hypersusceptibility in pseudomonas aeruginosa in cystic fibrosis

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    Background: A subpopulation of Pseudomonas aeruginosa (PsA) exists in cysticfibrosis (CF) patients that&nbsp; is&nbsp; hypersusceptible&nbsp; to&nbsp; ticarcillin,&nbsp; a&nbsp; carboxypenicillin,&nbsp; in&nbsp; vitro (Tichs strain)&nbsp; defined&nbsp; as&nbsp; a minimum inhibitory concentration (MIC) ≤4μg/ml. Methods: In a retrospective cohort study, isolates of PsA from CF (23),&nbsp; non-cystic fibrosis bronchiectasis (NCFB) (17) and control (18) patients were analysed. MICs for each isolate were determined using agar dilution against six antibiotics and interpreted using EUCAST breakpoints. Prevalence of Tichs in&nbsp; each&nbsp; cohort&nbsp; was&nbsp; calculated.&nbsp; A&nbsp; point&nbsp; prevalence&nbsp; survey&nbsp; was&nbsp; conducted&nbsp; in&nbsp; CF&nbsp; to&nbsp; review&nbsp; the&nbsp; patients’ clinical progress following PsA isolation. Results: Prevalence of the Tichs strain in PsA was 48%, 76% and 0% in the CF, NCFB and control cohorts respectively. A statistically significant difference in geometric mean MIC was seen between the Tichs and non-Tichs&nbsp; cohorts in CF for ticarcillin (as expected) and temocillin (p=0.041and p=0.036 respectively). A similar trend was observed in NCFB for ticarcillin (p=0.038) and temocillin (p=0.067), although statistical significance was not reached for the latter.In&nbsp; CF,&nbsp; the&nbsp; Tichs&nbsp; strain&nbsp; demonstrated&nbsp; lower&nbsp; MICs&nbsp; to&nbsp; all antibiotics&nbsp; tested&nbsp; apart&nbsp; from&nbsp; gentamicin compared&nbsp; to&nbsp; their&nbsp; non-Tichs counterparts. Those&nbsp; who&nbsp; had the Tichs strain&nbsp; in&nbsp; CF&nbsp; had&nbsp; fewer&nbsp; antibiotics (13.9&nbsp; days&nbsp; versus&nbsp; 23.5&nbsp; days,&nbsp; Tichs&nbsp; and&nbsp; non-Tichs respectively)&nbsp; although&nbsp; this&nbsp; result&nbsp; was&nbsp; not&nbsp; statistically significant p=0.202. Conclusion: Our&nbsp; data&nbsp; supports&nbsp; the&nbsp; existence&nbsp; of&nbsp; a&nbsp; Tichs strain&nbsp; of&nbsp; PsA&nbsp; in&nbsp; our&nbsp; CF&nbsp; and&nbsp; NCFB&nbsp; patient populations. This strain correlated with reduced MICs to temocillin in CF, to which PsA would normally be resistant, which may be of clinical relevance.</p
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