The article presents a feasibility study on jojoba - a vegetable oil - as a candidate base oil mixed with and without molybdenum disulfide nano-particles (nMoS2) in hard-machining with minimum ...quantity lubrication (MQL). The jojoba oil is benchmarked against commercially available mineral oil (LRT 30) for machining of Ti–6Al–4V alloy. The machining performance in terms of cutting force, tool wear, and surface roughness is assessed under five cutting environments, namely, dry turning, MQL (jojoba oil and LRT 30), nanofluid MQL (jojoba oil + nMoS2 and LRT 30 + nMoS2) is evaluated applied with different concentrations of nanoparticles (0.1, 0.5, and 0.9% by weight). The results show that jojoba oil, in pure and nano-fluidic condition as well, presents itself as a strong and sustainable replacement for commercially available mineral oil for MQL turning. The improvement in performance with jojoba oil is attributed to long chain fatty acidic structure (monoesters), excellent thermal oxidative stability, high viscosity index, and lamellar structure of nMoS2. The MQL turning with jojoba oil + nMoS2(0.1%) is found to have a reduction in cutting force, surface roughness, and tool wear in the range 35–47%. The overall results show that jojoba oil, as well as jojoba oil with an optimum concentration of MoS2 nanoparticles, emerged as a sustainable machining alternative.
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•Gas oil HDS on a NiMo/Al2O3 catalyst was not affected by the vegetable oil presence.•Gaseous and liquid phase analysis showed the same selectivity of the HDO ...reactions.•Hydrodeoxygenation pathway is promoted more by NiMo/γ-Al2O3 than CoMo/γ-Al2O3.•The presence of vegetable oil does not affect catalyst deactivation.
The effect of the refined and acidic vegetable oil content on the catalytic co-hydroprocessing of their mixtures with gasoil was studied in the presence of a NiMo/Al2O3 catalyst. The experiments were carried out in a bench-scale trickle-bed reactor at T=310–350°C and total pressure P=33bar. The content of the vegetable oils in the liquid feed varied from 0 to 30wt%. For the determination of the hydrodeoxygenation (HDO) selectivity both gas and liquid phase analyses were conducted. The results obtained by the two approaches are in good agreement and it was estimated that the decarboxylation/decarbonylation pathways were followed by 52±3% of the ester bonds either of the refined or acidic vegetable oil. Decarboxylation cannot be distinguished from decarbonylation mechanism by either method. To estimate the effect of the presence of vegetable oils on the hydrotreater effectiveness, the hydrodesulphurization (HDS) reaction was also studied and the influence of the vegetable oil concentration on gasoil HDS was evaluated. For the NiMo catalyst this effect was found to be negligible. A comparison with the CoMo catalyst’s performance, previously tested, is given.
This paper evaluates the effect of the production process and storage on the quality of extra virgin olive oil used as a covering medium for vegetable preserves. Acidity, peroxide value, ...spectrophotometric indices (K232, K270 and ??) and total polyphenols were evaluated for 6 to 12 months in the oil drained from vegetable preserves hand-canned in extra virgin olive oil. Our results showed that many oil-vegetable interactions occurred in the preserves, and the extra virgin olive oil's chemical characteristics experienced significant variation after processing and during conservation. Polyphenols compounds showed a dramatic drop after pasteurisation and remained almost stable during the period of conservation, whereas significant changes during the entire period were revealed in the oxidative status of the oil, as measured by peroxide levels and spectrophotometric indices. The most important changes were found in K270, which, after a few months, reached values that were not compatible with those required for classification as an extra virgin olive oil. These results make the parameters normally used for assessing the quality and genuineness of extra virgin olive oil inadequate when they are used for vegetable preservation. PUBLICATION ABSTRACT
In this study we estimated shelf life of canned marinated hearts of artichoke (Cynara scolymus L.) which had the major sensory preference in color and flavor evaluated by a semi trained panel ...conformed by 15 judges. Also omega 3 and omega 6 content was determined (28.69 g/100g y 43.26 g/100g of fat respectively) which are within the limit approved by the World Health Organization. It was done the estimation of the shelf life by accelerated testing, the samples were incubated at 37ºC, 49ºC and 55ºC, evaluating the kinetic of deterioration of the fat in function of the peroxide index that followed a reaction of order zero. The temperature effect was evaluated with the equation of Arrhenius, and the activation energy was 96115.6 J/mol. At a storage temperature of 20 ºC, the estimation of shelf life was 892 days.
In this study we estimated shelf life of canned marinated hearts of artichoke (Cynara scolymus L.) which had the major sensory preference in color and flavor evaluated by a semi trained panel ...conformed by 15 judges. Also omega 3 and omega 6 content was determined (28.69 g/100g y 43.26 g/100g of fat respectively) which are within the limit approved by the World Health Organization. It was done the estimation of the shelf life by accelerated testing, the samples were incubated at 37ºC, 49ºC and 55ºC, evaluating the kinetic of deterioration of the fat in function of the peroxide index that followed a reaction of order zero. The temperature effect was evaluated with the equation of Arrhenius, and the activation energy was 96115.6 J/mol. At a storage temperature of 20 ºC, the estimation of shelf life was 892 days. DOI: 10.17268/sci.agropecu.2010.04.04
Vegetable oils may be used with dilution modification technique as an alternative diesel fuel. In this study, a used sunflower oil-diesel fuel blend (20:80 v/v%) was investigated in a Pancar Motor ...E-108-type diesel engine to observe engine characteristics and exhaust emission. The effect of the compression ratio on ignition delay characteristics and smoke emissions of blend fuel was determined in this CFR engine. The results of fuel blends were compared with the reference grade No. 2-D diesel fuel.
Vegetable oils may be used directly as an alternative diesel fuel in compression-ignition engines. Within the scope of this work, employment of sunflower oil in a diesel engine during short- and ...long-term engine tests were studied, and the fuel characteristics of sunflower oil with its positive and negative aspects are put forward along with our recommendations.
O governo e a sociedade brasileira têm debatido a matriz energética do país com a intenção de identificar alternativas que diminuam a sua dependência dos derivados de petróleo. O biodiesel tem sido o ...produto considerado mais promissor para substituir parte do diesel fóssil consumido no Brasil para reduzir a emissão de carbono. Este trabalho procurou analisar os dois mercados (biodiesel e óleo vegetal), identificar a mistura de biodiesel para cada região brasileira e caracterizar a produção de biodiesel e as processadoras de óleo vegetal. Os resultados mostram que o consumo do biodiesel está concentrado nas regiões Sul e Sudeste. Já as fábricas esmagadoras de óleos vegetais estão estruturadas para processarem soja e se concentram nas regiões Centro-oeste e Sul---The Brazilian government had discussed about alternative energetic matrix to reduce petroleum dependence and carbon emission at atmosphere. Thus, the biodiesel had been main product to replace part of diesel consuming in Brazil. The present paper looked for analysis two markets and to identify the bland of biodiesel each region of Brazil, to describe de biodiesel production and to locate crushing oil vegetable. The results shows that biodiesel consume is concentrated in south and southeast region of Brazil, and the crushing of vegetable oil is structured to process soybean and the main regions are center ester and south of Brazil.
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