1,754 research outputs found
Evaluation of a two-phase extraction system of carbohydrates and proteins from chlorella vulgaris utex 1803
Microalgae are a valuable source of high-value products and biofuels, however the high-energy cost required for the extraction of their metabolites has kept questioning on possible industrial upgrading. The aim of this study was to evaluate the effect of temperature, solvent/biomass, NaOH concentration and thermal pretreatment of the biomass in a 2-cycle carbohydrate and protein extraction system. Results shown that best conditions for carbohydrates extraction are achieved at a solvent concentration of 3.67 M, 55°C and a solvent/biomass ratio of 30mL/g. On the other side, the best conditions for protein were 3 M, 85°C and 45 mL/g. The efficiencies achieved under these conditions were 95% for carbohydrates and 98% for proteins. Using the best extraction conditions for each metabolite a thermal pre-treatment was performed at 25°C, 75°C and 105°C. Results indicate that highest efficiencies were achieved with dry biomass pretreated at 105°C, with values of 95% for carbohydrates and 98% for proteins
One-Dimensional Modeling of Mechanical and Friction Losses Distribution in a Four-Stroke Internal Combustion Engine
[EN] As the road transport accounts between 15%-18% of worldwide CO2 emissions, the automotive sector has a deep commitment to mitigate global warming. Consequently, stricter regulations have been adopted by the European Union and worldwide to reduce that big impact. Approximately, 10% of the energy generated by fuel combustion in the engine is destined to the auxiliaries components activation and the movement of mechanical elements with relative motion between themselves. A reduction on that figure or alternatively a mechanical efficiency improvement can be directly translated on target alignment. The aim of this work is developing a model to predict the mechanical and friction losses and its distribution in a four-stroke direct injection-diesel engine and simulating different strategies, which increment the engine efficiency. A 1D model has been developed and fitted in GT-SUITE based on the experimental results of a 1.6-L diesel engine. Additionally, a description of the tribological performance has been realized in different parts of the engine where friction is present. Finally, the engine friction maps have been broken down in order to quantify the friction losses produced in the piston ring assembly, crankshaft bearings, and valvetrainTormos, B.; Martín, J.; Blanco-Cavero, D.; Jiménez-Reyes, AJ. (2020). One-Dimensional Modeling of Mechanical and Friction Losses Distribution in a Four-Stroke Internal Combustion Engine. Journal of Tribology. 142(1). https://doi.org/10.1115/1.4044856S142
Application assessment of UV-vis and NIR spectroscopy for the quantification of fuel dilution problems on used engine oils
[EN] Fuel dilution in engine oil is a frequent problem in internal combustion engines (ICE); its main consequence is the reduction of the oil viscosity, decreasing lubrication film strength, and causing a negative impact on friction and wear. The standard and more precise methods for assessing fuel content in oil are based on chromatographic analysis (e.g., ASTM D3524, ASTM D7593), requiring high-cost equipment and highly qualified personnel. This work performed a study to propose an alternative method for quantifying diesel fuel dilution in used engine oil by UV¿vis and NIR spectroscopy. The samples for the study were prepared from used oil from six different vehicles with various mileages. According to the results obtained in this study, NIR spectroscopy proved to be the most suitable method for the quantification of diesel fuel in used engine oils. Furthermore, the use of NIR spectroscopy combined with multivariate calibration methods could predict the fuel concentration of the samples used for validating the model. The best predictive model for the quantification was obtained by Partial Least Squares Regression, which achieved a Root Mean Squared Error of prediction of 0.436% and a coefficient of determination of 0.9435. In comparison, the parameters for Principal Component Regression were 1.049% and 0.8441, respectively.Acknowledgments This work has been partially supported by grant PID2020-119691RB-100 funded by MCIN/AEI/10.13039/501100011033.Macian Martinez, V.; Tormos, B.; García-Barberá, A.; Balaguer-Reyes, A. (2023). Application assessment of UV-vis and NIR spectroscopy for the quantification of fuel dilution problems on used engine oils. Fuel. 333. https://doi.org/10.1016/j.fuel.2022.12635033
Компетeнтностные несоответствия: аспект менеджмента человеческих ресурсов
Статья посвящена аспекту подготовки в менеджменте человеческих ресурсов в качестве отражения перспективы ситуации молодых работников. Существует значительный приток рабочих мест, которым молодые люди не соответствуют по своей квалификации. Ситуация становится головоломкой, в которой отдельные компоненты не соответствуют друг другу; экономический рост, с одной стороны, и компетенции работников, с другой стороны, не коррелируют адекватно с потребностями производственного сектора в современных обществах. Необходимо новое понимание конкурентных компетенций.The article deals with training aspect of human resources management as it reflects the perspective situation of young employees. There is a high supply of jobs that young people cannot afford because they are not qualified for them. This situation turns to a puzzle in which the pieces do not fit for each other; the economy growth, on one side and the skills of workers on the other side do not correlate adequately with the needs of key productive sectors in modern societies. A new comprehension of skills that are competitive is highly wanted
Evaluation of the bioaccessibility of antioxidant bioactive compounds and minerals of four genotypes of Brassicaceae microgreens
Microgreens constitute an emerging class of fresh, healthy foods due to their nutritional composition. In this study the content of minerals and antioxidant bioactive compounds, and for the first time bioaccessibility, were evaluated in broccoli (Brassica oleracea L. var. italica Plenck), green curly kale (Brassica oleracea var. sabellica L.), red mustard (Brassica juncea (L.) Czern.) and radish (Raphanus sativus L.) hydroponic microgreens. Macro- (K, Ca, Mg) and oligo-elements (Fe, Zn), ascorbic acid, total soluble polyphenols, total carotenoids, total anthocyanins, total isothiocyanates and total antioxidant capacity (Trolox Equivalent Antioxidant Capacity and Oxygen Radical Absorbance Capacity) were determined before and after the standardized simulated gastrointestinal digestion process. All microgreens provided relevant amounts of vitamin C (31-56 mg/100 g fresh weight) and total carotenoids (162-224 mg β-carotene/100 g dry weight). Mineral content was comparable to that normally found in hydroponic microgreens and the low potassium levels observed would allow their dietetic recommendation for patients with impaired kidney function. Both total soluble polyphenols and total isothiocyanates were the greatest contributors to the total antioxidant capacity after digestion (43-70% and 31-63% bioaccessibility, respectively) while macroelements showed an important bioaccessibility (34-90%). In general, radish and mustard presented the highest bioaccessibility of bioactive compounds and minerals. Overall, the four hydroponic Brassicaceae microgreens present a wide array of antioxidant bioactive compounds
Finite axisymmetric charged dust disks in conformastatic spacetimes
An infinite family of axisymmetric charged dust disks of finite extension is
presented. The disks are obtained by solving the vacuum Einstein-Maxwell
equations for conformastatic spacetimes, which are characterized by only one
metric function. In order to obtain the solutions, it is assumed that the
metric function and the electric potential are functionally related and that
the metric function is functionally dependent of another auxiliary function,
which is taken as a solution of Laplace equation. The solutions for the
auxiliary function are then taken as given by the infinite family of
generalized Kalnajs disks recently obtained by Gonz\'alez and Reina (MNRAS 371,
1873, 2006), which is expressed in terms of the oblate spheroidal coordinates
and represents a well behaved family of finite axisymmetric flat galaxy models.
The so obtained relativistic thin disks have then a charge density that is
equal, except maybe by a sign, to their mass density, in such a way that the
electric and gravitational forces are in exact balance. The energy density of
the disks is everywhere positive and well behaved, vanishing at the edge.
Accordingly, as the disks are made of dust, their energy-momentum tensor it
agrees with all the energy conditions.Comment: Submitted to PR
Androgen receptor gene and sociosexuality. Does fighting ability moderate the effect of genetics in reproductive strategies?
Springer Nature remains neutral with regard to juris dictional claims in published maps and institutional affiliations.Sociosexuality is a reliable proxy to evaluate the trade-off between short-term and long-term human mating strategies. The androgen receptor (AR) gene CAG-repeats polymorphism regulates the effect of testosterone and the expression of testosterone-related traits commonly associated with short-term mating strategies. According to the strategic pluralism hypothesis, a more effective receptor would prompt a short-term mating strategy to maximize the number of sexual partners, but studies are inconclusive and contradictory. The effect of a particular gene in behavior is frequently small and affected by the social environment and other variables, particularly psychological and personality traits. In the current study we propose the effect of the AR gene polymorphism in sociosexuality to be moderated by self-perceived fighting ability, a psychological attribute relevant in intrasexual competition. Our objective is to reveal if the CAG polymorphism is associated with a short-term strategy as expected from the strategic pluralism hypothesis, or conversely with long-term investments to maximize parental care. We fail to find any effect of the CAG polymorphism over mating strategies. However, self-perceived fighting ability is related to short-term mating orientation but not to the number of past sexual partners. In conclusion, we find no clear evidence about the potential role of CAG polymorphism of the AR gene over sociosexual attitudes and behavior. However, results from other studies suggest that there is evidence that genetic factors influence sociosexuality, but it is necessary to consider simultaneously more than a single genetic polymorphism and other psychological and physiological variablesThis study was supported by a postdoctoral proj ect from Universidad del Desarrollo for author Nohelia T. Valenzuela and funded by the project BIOUAM03-2019 of the Departmento de Biología of the Universidad Autónoma de Madri
Effect of Company-Driven Disability Diversity initiatives: A multi-case study across industries
OBJECTIVE: In this article, we share insights emerging from case studies conducted across seven companies.We illustrate the motives, processes, and outcomes of these initiatives. METHODS: This study is built on the previously published case studies conducted across seven companies. We applied elements of consensual qualitative research (CQR) for the data collection and analyses before performing an in-depth qualitative content analysis using the data coded for each company, looking for commonalities and differences. RESULTS: Although practices differed, all companies experienced noted benefits. Committed leadership and complementary company values facilitated successful outcomes for initiatives. The strength or salience of disability-inclusive actions and practices appeared to moderate outcomes related to company performance, employee perceptions of the company, and cohesiveness. CONCLUSION: Company disability initiatives can yield positive impacts on company performance and culture. The practices we identified and their positive outcomes serve as beacons to other organizations that recognize disability as a valued part of company diversity
Safety monitoring of cytostatic handling
Context: The Institute of Oncology and Radiobiology (INOR) is the leading institution for the diagnosis, treatment and follow up of cancer in Cuba. Cancer treatment is mainly by three methods: surgery, radiotherapy and chemotherapy. Pharmacological treatments involve the use of dangerous substances such as cytostatics, the handling of which threat the health of the occupationally exposed staff.
Aims: To evaluate a biomarker of genotoxicity indicative of DNA damage in the biomonitoring of occupational risks associated with the administration of antineoplastic drugs to hospitalized patients.
Methods: The determination of the frequency of micronuclei, in cells of the exfoliated oral mucosa was determined (Micronucleus test) in subjects who administer cytostatic drugs at the institute and a control group formed by administrative personal.
Results: Present results evidenced that all exposed subjects possess the same DNA damage that non-exposed-ones. Such results are in concordance with the proper use of primary protection barriers and the adhesion to normalized operational procedures.
Conclusions: The frequency of micronuclei is a useful biomarker for assessing DNA damage associated with the administration of antineoplastic drugs. The risk perception analysis (RISKPERCEP) in occupationally exposed subjects complements the occupational safety monitoring
Design, development, and scientific performance of the Raman Laser Spectrometer EQM on the 2020 ExoMars (ESA) Mission
The Raman Laser Spectrometer (RLS) is one of the three Pasteur Payload instruments located within the rover analytical laboratory drawer (ALD), for ESA’s Aurora exploration programme, ExoMars 2020 mission. The instrument will analyse the crushed surface and subsurface samples that are positioned below the Raman optical head by the ALD carousel. The RLS engineering and qualification model (EQM) was delivered to ESA at the end of 2017, after a wide technical and scientific test characterization campaign. The scientific campaign comprised instrument calibration and detailed evaluation of the scientific requirements and overall performance. For spectral calibration, continuous emission standard lamps (such as Hg-Ar, Ne, and Xe) were utilized, as well as Raman spectra of pure liquids typically used as standards (cyclohexane and carbon tetrachloride (CCl4)). In addition, Raman spectra of the RLS calibration target (CT), a small disc of polyethylene terephthalate (PET) were obtained at various temperatures. This target, placed inside the rover, will be used for both Instrument health checks and calibration activities throughout Mars operations. For the scientific requirements and performance evaluations, several liquid and solid samples were analysed under a wide range of ambient conditions. The obtained spectral band parameters (peak position, relative peak intensity, peak width, and peak profile) were evaluated. Also, the instrument response (in terms of SNR) was characterized at different integration times and detector operating temperatures. In this paper, we provide a description of the development, verification, functional test, and overall scientific performance of the RLS instrument developed for ExoMars. Particular attention is placed on the performance of the EQM, which is the most representative instrument, in terms of engineering and functionality, of the flight model (FM) and in addition is used for performing all the mechanical, thermal, and radiation tests necessary for space qualification (for planetary applications). The data presented and analysed here, comprise part of the overall dataset obtained during the full instrument characterization campaign conducted at INTA before and during delivery and integration of the EQM in the rover ALD at TAS-I facilities (Torino, Italy). The results obtained confirm that the full functionality and scientific performance of the RLS instrument was maintained after integration.Proyecto MINECO Retos de la Sociedad. Ref. ESP2017-87690-C3-1-
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