Methodology to implement fresh water bunkering procedures in the SGS of any vessel. Practical application to the vessel “Martin i Soler”

El presente trabajo consiste en el diseño de un procedimiento genérico de toma de agua dulce, así como una metodología para implantarlo en cualquier buque o naviera. La aplicación práctica consistirá en incorporar el procedimiento diseñado en la metodología tanto en el buque “Martin i Soler” como en el Sistema de Gestión de la Seguridad de la compañía BaleariaThe present work consists of the design of a generic freshwater bunkering procedure, as well as a methodology to implement it in any ship or shipping company. The practical application will consist of incorporating the procedure designed into the methodology on both the “Martin i Soler” ship and the Balearia company's Safety Management SystemMáster en Ingeniería Náutica y Gestión Marítim

Exploring and correcting the bias in the estimation of the Gini measure of inequality

The Gini index is probably the most commonly used indicator to measure inequality. For continuous distributions, the Gini index can be computed using several equivalent formulations. However, this is not the case with discrete distributions, where controversy remains regarding the expression to be used to estimate the Gini index. We attempt to bring a better understanding of the underlying problem by regrouping and classifying the most common estimators of the Gini index proposed in both infinite and finite populations, and focusing on the biases. We use Monte Carlo simulation studies to analyse the bias of the various estimators under a wide range of scenarios. Extremely large biases are observed in heavy-tailed distributions with high Gini indices, and bias corrections are recommended in this situation. We propose the use of some (new and traditional) bootstrap-based and jackknife-based strategies to mitigate this bias problem. Results are based on continuous distributions often used in the modelling of income distributions. We describe a simulation-based criterion for deciding when to use bias corrections. Various real data sets are used to illustrate the practical application of the suggested bias corrected procedures.Regional Government of Andalusia and the European Regional Development Fund (project P18-RT-576)Grants of the University of Granada (Unidad Científica de Excelencia “Desigualdad, Derechos Humanos y Sostenibilidad – DEHUSO” del Plan Propio; and Programa de Ayudas a la revisión de textos científicos de la Facultad de Ciencias Económicas y Empresariales

Single Imputation Methods and Confidence Intervals for the Gini Index

This research has been partially supported by the Ministry of Economy, Industry and Competitiveness, the Spanish State Research Agency (SRA) and European Regional Development Fund (ERDF) (project reference ECO2017-86822-R). This research has been partially supported by the Ministry of Economy, Industry and Competitiveness, the Spanish State Research Agency (SRA) and European Regional Development Fund (ERDF) (project reference ECO2017-84138-P).The problem of missing data is a common feature in any study, and a single imputation method is often applied to deal with this problem. The first contribution of this paper is to analyse the empirical performance of some traditional single imputation methods when they are applied to the estimation of the Gini index, a popular measure of inequality used in many studies. Various methods for constructing confidence intervals for the Gini index are also empirically evaluated. We consider several empirical measures to analyse the performance of estimators and confidence intervals, allowing us to quantify the magnitude of the non-response bias problem. We find extremely large biases under certain non-response mechanisms, and this problem gets noticeably worse as the proportion of missing data increases. For a large correlation coefficient between the target and auxiliary variables, the regression imputation method may notably mitigate this bias problem, yielding appropriate mean square errors. We also find that confidence intervals have poor coverage rates when the probability of data being missing is not uniform, and that the regression imputation method substantially improves the handling of this problem as the correlation coefficient increases.Ministry of Economy, Industry and Competitiveness Spanish State Research Agency (SRA)European Commission ECO2017-84138-

An alternative expression for the constant c4[n] with desirable properties

The constant c4[n] is commonly used in the construction of control charts and the estimation of process capability indices, where n denotes the sample size. Assuming normal distribution, the unbiased estimator of the population standard deviation is obtained by dividing the sample standard deviation by the constant c4[n]. An alternative expression for c4[n] is proposed and the mathematical induction technique is used to prove its validity in the present paper. Some desirable properties are described. First, the suggested expression provides the exact value of c4[n]. Second, it is not a recursive formula in the sense it does not depend on the previous sample size. Finally, the value of c4[n] can be directly computed for large sample sizes. Such properties suggest that the proposed expression may be a convenient solution in computer programming and it has direct applications in statistical quality control

Rescaled bootstrap confidence intervals for the population variance in the presence of outliers or spikes in the distribution of a variable of interest

Confidence intervals for the population variance in the presence of outliers or spikes in the distribution of a variable of interest are topics that have not been investigated in depth previously. Results derived from a first Monte Carlo simulation study reveal the limitations of the customary confidence interval for the population variance when the underlying assumptions are violated, and the use of alternative confidence intervals is thus justified. We suggest confidence intervals based on the rescaled bootstrap method for many reasons. First, this is a simple technique that can be easily applied in practice. Second, it is free of probabilistic distributions. Finally, it can be easily applied to the cases of finite populations and samples selected from complex sampling designs. Results derived from a second Monte Carlo simulation study indicate that the suggested confidence intervals have desirable coverage rates with smaller average widths. Accordingly, an advantage of the suggested confidence intervals is that they offer a good compromise between simplicity and desirable properties. The various simulation studies are based on different scenarios that may arise in practice, such as the presence of outliers or spikes, and the fact that the underlying assumptions of the customary confidence interval are violated

Characterization of humic acids from low-rank coals by 13C-NMR and pyrolysis-methylation. Formation of benzenecarboxylic acid moieties during the coalification process

Instituto de Recursos Naturales y Agrobiologia de Sevilla, C.S.I.C., P.O. Box 1052, 41080-Seville, Spain; E-mail address: [email protected] acid (HA) fractions isolated from a peat and lignite deposit were studied by CP/MAS 13C-NMR and pyrolysis-methylation. Loss of carbohydrates, removal of methoxyls and formation of catechols during the coalification process was evident. Pyrolysis-methylation released a great variety of components, the lignin-derived monomers being the most prominent. A very striking feature was the release of benzenecarboxylic moieties after pyrolysis-methylation which have not been observed previously by pyrolytic techniques. These moieties were released in higher amounts from the lignite HA, suggesting that the content in carboxylic groups increase with coalification, at least up to the lignite stage. Oxidation of the C-3 side chain of the lignin structure would produce these benzenecarboxylic acids and benzylic ketones.We wish to thank the Comision Interministerial de Ciencia y Tecnologia (CICyT) for providing financial support (Project PB91-0074) and Professor H.-D. Lüdemann for recording NMR spectra.Peer reviewe

Thermally assisted hydrolysis and alkylation of lignins in the presence of tetra-alkylammonium hydroxides

Three different milled lignins isolated from bamboo, pine and beech, corresponding to the three different structural groups, have been subjected to pyrolysis in the presence of tetramethylammonium hydroxide (TMAH) and tetrabutylammonium hydroxide (TBAH). Pyrolysis of the lignins in the presence of TMAH releases the methyl esters and methyl ethers of the different lignin monomers. Several moieties bearing carboxylic acid groups, not previously detected using pyrolytic techniques, could be released from the three lignins, suggesting that the presence of these moieties in the lignin structure have been underestimated.The authors wish to thank the CICyT (Spanish Direction General de Investigation Cientifica y Tecnica; Project PB91-0074) for financial support.Peer Reviewe

First report of Cerithium scabridum Philippi, 1848 (Gastropoda:Cerithiidae) in the Iberian Peninsula

En el presente artículo se dan a conocer las primeras citas para la península ibérica de Cerithium scabridum, especie lessepsiana de molusco ampliamente distribuida en el Mediterráneo central y oriental.In this paper the first citation for the Iberian Peninsula of Cerithium scabridum, a lessepsian mollusc species widely distributed along the Eastern and Central Mediterranean Sea, are reported

Deciphering the constrained total energy expenditure model in humans by associating accelerometer‑measured physical activity from wrist and hip

Thanks to Dr. Herman Pontzer (Duke University) for his valuable feedback. We also thank the following agencies for their funding: Fondo Nacional de Desarrollo Científico y Tecnológico (11180361 to R.F.-V.); Spanish Ministry of Education, Culture and Sport (FPU15/04059 to J.M.A.A.; FPU15/02645 to J.H.M.; FPU14/04172 to F.J.A.-G.); University of Granada (Plan Propio de Investigación 2019 [Programa Contratos-Puente] to F.J.A.-G.; Plan Propio de Investigación 2016 [Excellence actions: Unit of Excellence on Exercise and Health UCEES]); Spanish Ministry of Economy and Competitiveness (ACTIBATE study; ACTIVEBRAINS study); Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (PI13/01393 to ACTIBATE study); Junta de Andalucía, Consejería de Conocimiento, Investigación y Universidades and European Regional Development Funds (FEDER: ref. SOMM17/6107/UGR to ACTIBATE study); Redes Temáticas de Investigación Cooperativa RETIC (Red SAMID RD16/0022 to ACTIBATE study); EXERNET Research Network on Exercise and Health in Special Populations (DEP2005-00046/ACTI); Fundación Iberoamericana de Nutrición (ACTIBATE study); AstraZeneca HealthCare Foundation (ACTIBATE study); PTA 12264-I to FIT-AGEING study.Supplementary Information The online version contains supplementary material available at https://doi. org/10.1038/s41598-021-91750-x.The constrained total energy expenditure (TEE) model posits that progressive increases in physical activity (PA) lead to increases in TEE; but after certain PA threshold, TEE plateaus. Then, a compensatory reduction in the expenditure of non-essential activities constrains the TEE. We hypothesized that high PA levels as locomotion associate with a compensatory attenuation in arm movements. We included 209 adults (64% females, mean [SD] age 32.1 [15.0] years) and 105 children (40% females, age 10.0 [1.1] years). Subjects wore, simultaneously, one accelerometer in the non-dominant wrist and another in the hip for ≥ 4 days. We analyzed the association between wrist-measured (arm movements plus locomotion) and hip-measured PA (locomotion). We also analyzed how the capacity to dissociate arm movements from locomotion influences total PA. In adults, the association between wrist-measured and hip-measured PA was better described by a quadratic than a linear model (Quadratic-R2 = 0.54 vs. Linear-R2 = 0.52; P = 0.003). Above the 80th percentile of hip-measured PA, wrist-measured PA plateaued. In children, there was no evidence that a quadratic model fitted the association between wrist-measured and hip-measured PA better than a linear model (R2 = 0.58 in both models, P = 0.25). In adults and children, those with the highest capacity to dissociate arm movements from locomotion—i.e. higher arm movements for a given locomotion—reached the highest total PA. We conclude that, in adults, elevated locomotion associates with a compensatory reduction in arm movements (probably non-essential fidgeting) that partially explains the constrained TEE model. Subjects with the lowest arm compensation reach the highest total PA.AstraZeneca HealthCare Foundation PTA 12264-IEXERNET Research Network on Exercise and Health in Special Populations DEP2005-00046/ACTIFundación Iberoamericana de NutriciónFondo Nacional de Desarrollo Científico y Tecnológico 11180361 FONDECYTMinisterio de Economía y Competitividad MINECOInstituto de Salud Carlos III PI13/01393 ISCIIIUniversidad de Granada UGREuropean Regional Development Fund RD16/0022,SOMM17/6107/UGR ERDFConsejería de Conocimiento, Investigación y Universidad, Junta de AndalucíaVicerrectorado de Investigación y Transferencia, Universidad de Granada Health [UCEES]),Plan Propio de Investigación 2016 (Excellence actions: Unit of Excellence on Exercise,Plan Propio de Investigación 2019 (Programa Contratos-Puente