Evaluación de apéndices para disminución de la resistencia al avance

This paper shows experimental and numerical results of three types of appendages on forward resistance reduction of displacement and semidisplacement hulls. Forward resistance results were obtained by using Computational Fluid Dynamics and towing tank tests. The appendages evaluated are stern flaps and interceptors for displacement hulls and spray railspray rails for a semiplaning hull. The experiments are independent from each other and no research was undertaken to include the combined effect of appendages on a single hull. The predicted reduction in forward resistance in all three tested devices is around 5-10%, showing potential for fuel saving through the evaluation of hydrodynamic effects of energy saving appendages.Este trabajo contiene resultados experimentales y numéricos del efecto de tres tipos de apéndices en la disminución de la resistencia al avance en cascos de desplazamiento y semidesplazamiento. Los resultados de resistencia al avance han sido obtenidos mediante Dinámica de Fluidos Computacional y experimentos de remolque en tanques de pruebas. Los apéndices evaluados son flap e interceptores de popa para cascos de desplazamiento y spray railspray rails para un casco de semiplaneo. Los casos estudiados son independientes entre sí y no se ha realizado un análisis que incluya el efecto combinado de ellos actuando conjuntamente en un casco. La reducción estimada de la resistencia al avance, en los tres apéndices experimentados, es alrededor de 5-10%, mostrando que existe potencial para ahorro de combustible por medio de la evaluación de los efectos hidrodinámicos de estos apéndices para ahorro de energía

Speaking in Tongues: Everyday Experience and Practice

Speaking in tongues is arguably one of the controversial and life-impacting experiences for Christian believers. Notably, it is a powerful experience often interpreted as a direct encounter with God when it first occurs. Despite the assumption by some Pentecostal-charismatic groups that they have a monopoly on it, the experience of speaking in tongues has remained sporadic, at the least, throughout Christian history, and has found recent entrance into various denominations. Yet although it is practiced by probably hundreds of millions of people worldwide, the phenomenon remains an elusive and under-researched field.We have conducted a series of interviews with tongue speakers to gauge how, at and after the initial event (usually called the Baptism in the Spirit), tongues continue to be experienced. We wanted to know what happens when people first speak in tongues; how, and how often, is speaking in tongues being practiced; what are the supposed benefits or effects of praying in tongues; what are reasons and applications for praying in tongues; is tongues used in private or also in public - possibly with interpretation? Does it perform in ways that perhaps conventional collective or individual prayer does not? Based on a questionnaire with several sets of questions grouped around the topics 1) initial experience; 2) subsequent usage; 3) personal experience; and 4) particular questions (e.g., theology, opinions), we interviewed 75 tongues speakers. The results demonstrate that for many Christians speaking in tongues continues to be an important part of their lives. Many report that praying in tongues has positive effects, such as enhancing their prayer lives or helping them pray for aspects they feel inadequate to address in their own language. Tongues empowers, calms, gives peace and is experienced as a form of prayer substantially different from praying in one’s own language. As such, we conclude that the practice is there to stay due to its perceived benefit

Combined effects of aldehyde dehydrogenase variants and maternal mitochondrial genes on alcohol consumption

Two lines of rats bred to differ in their voluntary alcohol consumption — the alcohol-abstaining UChA rats and the alcohol-drinking UChB rats — differ in how effectively toxic acetaldehyde is removed during alcohol metabolism. UChB animals carry efficient variants of the aldehyde dehydrogenase 2 (ALDH2) genes and have active mitochondria, resulting in fast removal of acetaldehyde. UChA animals, in contrast, carry less efficient ALDH2 variants and less active mitochondria, which result in transient elevations of acetaldehyde levels after alcohol ingestion. Cross-breeding studies have demonstrated that the presence of active mitochondria inherited from UChB females can fully abolish the reduction of alcohol consumption associated with the presence of less efficient ALDH2 variants — a phenomenon known as epistasis. These and other findings suggest that mitochondrial activity during alcohol metabolism should be considered a new modulator of alcohol consumption not only in rats but also in other species, including humans

Lithium-Ion Battery End-of-Discharge Time Estimation and Prognosis based on Bayesian Algorithms and Outer Feedback Correction Loops: A Comparative Analysis

Battery energy systems are currently one of the most common power sources found in mobile electromechanical devices. In all these equipment, assuring the autonomy of the system requires to determine the battery state-of-charge (SOC) and predicting the end-of-discharge time with a high degree of accuracy. In this regard, this paper presents a comparative analysis of two well-known Bayesian estimation algorithms (Particle filter and Unscented Kalman filter) when used in combination with Outer Feedback Correction Loops (OFCLs) to estimate the SOC and prognosticate the discharge time of lithium-ion batteries. Results show that, on the one hand, a PF-based estimation and prognosis scheme is the method of choice if the model for the dynamic system is inexact to some extent; providing reasonable results regardless if used with or without OFCLs. On the other hand, if a reliable model for the dynamic system is available, a combination of an Unscented Kalman Filter (UKF) with OFCLs outperforms a scheme that combines PF and OFCLs.Battery energy systems are currently one of the most common power sources found in mobile electromechanical devices. In all these equipment, assuring the autonomy of the system requires to determine the battery state-of-charge (SOC) and predicting the end-of-discharge time with a high degree of accuracy. In this regard, this paper presents a comparative analysis of two well-known Bayesian estimation algorithms (Particle filter and Unscented Kalman filter) when used in combination with Outer Feedback Correction Loops (OFCLs) to estimate the SOC and prognosticate the discharge time of lithium-ion batteries. Results show that, on the one hand, a PF-based estimation and prognosis scheme is the method of choice if the model for the dynamic system is inexact to some extent; providing reasonable results regardless if used with or without OFCLs. On the other hand, if a reliable model for the dynamic system is available, a combination of an Unscented Kalman Filter (UKF) with OFCLs outperforms a scheme that combines PF and OFCLs

Ingeniería Naval y Oceánica: más que Buques y Offshore

Traditionally, Naval and Oceanic Engineering has been focused on research in surface and submarine ships; and fixed and floating offshore structures. More than 90% of world trade is transported by sea, so it is not surprising that most research efforts have been focused on making merchant ships more efficient and safer. Something similar is happening in the offshore industry driven by the demand for energy. Despite the evident need to perform research in the traditional fields of Naval and Oceanic Engineering, new challenges have caused universities and research centers to tackle new fields of research. This paper presents some of the research and innovations developed at the Institute of Naval and Maritime Sciences (ICNM) of the Austral University of Chile (UACH). These new frontiers for research address problems as diverse as the capturing of energy from waves and currents [1], the development of structures and systems for aquaculture [2], the design of autonomous underwater vehicles [3], the use of solar energy for the propulsion of small boats [4] and the design of floating ports for remote areas [5].Tradicionalmente la Ingeniería Naval y Oceánica ha estado enfocada a la investigación en naves de superficie y submarinas; y estructuras offshore fijas y flotantes.  Más del 90% del comercio mundial es transportado vía marítima por lo que no es de sorprender que la mayoría de los esfuerzos de investigación hayan sido enfocados a hacer los buques mercantes más eficientes y seguros. Algo similar ocurre en la industria offshore impulsada por la demanda de energía.  No obstante la evidente necesidad de investigar en los campos tradicionales de la Ingeniería Naval y Oceánica, nuevos desafíos han hecho que las universidades y centros de investigación aborden nuevos campos de investigación. Este trabajo presenta algunas de las investigaciones e innovaciones desarrolladas en el Instituto de Ciencias Navales y Marítimas (ICNM) de la Universidad Austral de Chile (UACH). Estas nuevas fronteras para la investigación abordan problemas tan diversos como la captación de energía de olas y corrientes [1], el desarrollo de estructuras y sistemas para  la acuicultura [2], el diseño de vehículos autónomos submarinos [3], el aprovechamiento de la energía solar para propulsión de pequeñas embarcaciones [4] y el diseño de puertos flotantes para zonas remotas [5]

Maximizing the greenhouse gas reductions from biomass: The role of life cycle assessment

Biomass can deliver significant greenhouse gas reductions in electricity, heat and transport fuel supply. However, our biomass resource is limited and should be used to deliver the most strategic and significant impacts. The relative greenhouse gas reduction merits of different bioenergy systems (for electricity, heat, chemical and biochar production) were examined on a common, scientific basis using consistent life cycle assessment methodology, scope of system and assumptions. The results show that bioenergy delivers substantial and cost-effective greenhouse gas reductions. Large scale electricity systems deliver the largest absolute reductions in greenhouse gases per unit of energy generated, while medium scale wood chip district heating boilers result in the highest level of greenhouse gas reductions per unit of harvested biomass. However, ammonia and biochar systems deliver the most cost effective carbon reductions, while biochar systems potentially deliver the highest greenhouse gas reductions per unit area of land. The system that achieves the largest reduction in greenhouse gases per unit of energy does not also deliver the highest greenhouse gas reduction per unit of biomass. So policy mechanisms that incentivize the reductions in the carbon intensity of energy may not result in the best use of the available resource. Life cycle assessment (LCA) is a flexible tool that can be used to answer a wide variety of different policy-relevant, LCA “questions”, but it is essential that care is taken to formulate the actual question being asked and adapt the LCA methodology to suit the context and objective

A Server-Based Mobile Coaching System

A prototype system for monitoring, transmitting and processing performance data in sports for the purpose of providing feedback has been developed. During training, athletes are equipped with a mobile device and wireless sensors using the ANT protocol in order to acquire biomechanical, physiological and other sports specific parameters. The measured data is buffered locally and forwarded via the Internet to a server. The server provides experts (coaches, biomechanists, sports medicine specialists etc.) with remote data access, analysis and (partly automated) feedback routines. In this way, experts are able to analyze the athlete’s performance and return individual feedback messages from remote locations

Remaining energy estimation for lithium-ion batteries via Gaussian mixture and Markov models for future load prediction

Other than upgrading the energy storage technology employed within electric vehicles (EVs), improving the driving range estimation methods will help to reduce the phenomena, known as range anxiety. The remaining discharge energy (RDE) of the battery affects the remaining driving range of the vehicle directly and its accurate calculation is crucial. In this paper a novel approach for the RDE calculation of the battery is proposed. First a stochastic load prediction algorithm is prepared via a Markov model and Gaussian mixture data clustering. Then, the load prediction algorithm is connected to the battery second order equivalent circuit model (ECM) coupled with a bulk parameter thermal model. Based on the extrapolated load and the battery dynamics, the battery future temperature conditions, future parameter variations and its internal states are predicted. Finally, the battery end of discharge time is prognosed and its RDE is calculated iteratively. In order to prove the proposed concept, lithium-ion battery cells are selected and the performance of the method is validated experimentally under real-world dynamic current charge/discharge profiles

The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and its Implications for Structure Growth

We present new measurements of cosmic microwave background (CMB) lensing over $9400$ sq. deg. of the sky. These lensing measurements are derived from the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB dataset, which consists of five seasons of ACT CMB temperature and polarization observations. We determine the amplitude of the CMB lensing power spectrum at $2.3\%$ precision ($43\sigma$ significance) using a novel pipeline that minimizes sensitivity to foregrounds and to noise properties. To ensure our results are robust, we analyze an extensive set of null tests, consistency tests, and systematic error estimates and employ a blinded analysis framework. The baseline spectrum is well fit by a lensing amplitude of $A_{\mathrm{lens}}=1.013\pm0.023$ relative to the Planck 2018 CMB power spectra best-fit $\Lambda$CDM model and $A_{\mathrm{lens}}=1.005\pm0.023$ relative to the $\text{ACT DR4} + \text{WMAP}$ best-fit model. From our lensing power spectrum measurement, we derive constraints on the parameter combination $S^{\mathrm{CMBL}}_8 \equiv \sigma_8 \left({\Omega_m}/{0.3}\right)^{0.25}$ of $S^{\mathrm{CMBL}}_8= 0.818\pm0.022$ from ACT DR6 CMB lensing alone and $S^{\mathrm{CMBL}}_8= 0.813\pm0.018$ when combining ACT DR6 and Planck NPIPE CMB lensing power spectra. These results are in excellent agreement with $\Lambda$CDM model constraints from Planck or $\text{ACT DR4} + \text{WMAP}$ CMB power spectrum measurements. Our lensing measurements from redshifts $z\sim0.5$--$5$ are thus fully consistent with $\Lambda$CDM structure growth predictions based on CMB anisotropies probing primarily $z\sim1100$. We find no evidence for a suppression of the amplitude of cosmic structure at low redshiftsComment: 45+21 pages, 50 figures. Prepared for submission to ApJ. Also see companion papers Madhavacheril et al and MacCrann et a

The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters

We present cosmological constraints from a gravitational lensing mass map covering 9400 sq. deg. reconstructed from CMB measurements made by the Atacama Cosmology Telescope (ACT) from 2017 to 2021. In combination with BAO measurements (from SDSS and 6dF), we obtain the amplitude of matter fluctuations $\sigma_8 = 0.819 \pm 0.015$ at 1.8% precision, $S_8\equiv\sigma_8({\Omega_{\rm m}}/0.3)^{0.5}=0.840\pm0.028$ and the Hubble constant $H_0= (68.3 \pm 1.1)\, \text{km}\,\text{s}^{-1}\,\text{Mpc}^{-1}$ at 1.6% precision. A joint constraint with CMB lensing measured by the Planck satellite yields even more precise values: $\sigma_8 = 0.812 \pm 0.013$, $S_8\equiv\sigma_8({\Omega_{\rm m}}/0.3)^{0.5}=0.831\pm0.023$ and $H_0= (68.1 \pm 1.0)\, \text{km}\,\text{s}^{-1}\,\text{Mpc}^{-1}$. These measurements agree well with $\Lambda$CDM-model extrapolations from the CMB anisotropies measured by Planck. To compare these constraints to those from the KiDS, DES, and HSC galaxy surveys, we revisit those data sets with a uniform set of assumptions, and find $S_8$ from all three surveys are lower than that from ACT+Planck lensing by varying levels ranging from 1.7-2.1$\sigma$. These results motivate further measurements and comparison, not just between the CMB anisotropies and galaxy lensing, but also between CMB lensing probing $z\sim 0.5-5$ on mostly-linear scales and galaxy lensing at $z\sim 0.5$ on smaller scales. We combine our CMB lensing measurements with CMB anisotropies to constrain extensions of $\Lambda$CDM, limiting the sum of the neutrino masses to $\sum m_{\nu} < 0.12$ eV (95% c.l.), for example. Our results provide independent confirmation that the universe is spatially flat, conforms with general relativity, and is described remarkably well by the $\Lambda$CDM model, while paving a promising path for neutrino physics with gravitational lensing from upcoming ground-based CMB surveys.Comment: 30 pages, 16 figures, prepared for submission to ApJ. Cosmological likelihood data is here: https://lambda.gsfc.nasa.gov/product/act/actadv_prod_table.html ; likelihood software is here: https://github.com/ACTCollaboration/act_dr6_lenslike . Also see companion papers Qu et al and MacCrann et al. Mass maps will be released when papers are publishe