bluuebunny/crossref_metadata_2025 huggingface dataset:
Multifactorial Mechanical Properties Study on Rat Skin at Intermediate Strain Rates - Using Orthogonal Experimental Design
Authors: Yang Shuaijun , Song Xuewei , Zhao Hui , Qiu Jinlong , Wang Nan , Yu Tianming
Published: April 2024

Most of the skin injuries caused by traffic accidents, sports, falls, etc. are in the intermediate strain rate range (1-100s-1), and the injuries may occur at different sites, impact velocities, and orientations.

To investigate the multifactorial mechanical properties of rat skin at intermediate strain rates, a three-factor, three-level experimental protocol was established using the standard orthogonal table L9(34), which includes site (upper dorsal, lower dorsal, and ventral side), strain rate (1s-1, 10s-1, and 100 s-1), and sampling orientation (0°, 45°, and 90° relative to the spine). Uniaxial tensile tests were performed on rat skin samples according to the protocol to obtain stress-stretch ratio curves. Failure strain energy was selected as the index, and the influence of each factor on these indexes, the differences between levels of each factor, and the influence of errors on the results were quantified by analysis of variance (ANOVA).

The results show that the site factor has the greatest influence on the skin’s mechanical properties within the intermediate strain rate range, followed by the strain rate factor, and the sampling orientation factor has the least influence. The mechanical properties of the lower dorsal and ventral skin differ significantly, but there is no apparent difference in the mechanical properties between the upper dorsal and ventral skin. As the strain rate increases, the failure strain energy of the skin increases significantly. There are no significant differences in the mechanical properties of skin samples in the three sampling orientations.
Development, Application, and Implementation of Passenger Vehicle Wind Averaged Drag for Vehicle Development
Authors: Kaminski Meghan , Borton Zackery
Published: April 2024

A new methodology is discussed for the development and implementation of a wind-averaged drag analysis technique for the development of aerodynamic-driven surfaces for use in the automotive industry. Current methods of vehicle design focus on reducing the straight-line coefficient of drag using wind tunnel testing and computational fluid dynamics and quote this value as the vehicle's aerodynamic performance. It is suggested to transition passenger vehicle aerodynamic design to the methodology employed for Class-A vehicles and design with a focus on reducing the wind-averaged drag value. Based on the methods used in J1252, the wind averaged drag calculation method utilizes the average wind speed a vehicle will experience in the continental United States and assumes an equal probability of the wind coming from all directions relative to the vehicle. Wind-averaged drag will optimize vehicle design for real-world improvements of vehicle efficiency. The wind average drag developed herein modifies and adapts the current standards for Class-A vehicles and applies it to passenger vehicles. Additionally, this paper includes examples of similarities and differences during the design process of individual parts when designing to reduce the straight-line drag coefficient versus the wind-averaged drag coefficient.
Wind-Load and Surface-Pressure Measurements of the Aerodynamic Interactions of a Passenger Vehicle with Adjacent-Lane Vehicles
Authors: McAuliffe Brian , Barber Hali
Published: April 2024

The mutual aerodynamic influence of road vehicles in close proximity is known to alter significantly the drag performance of the vehicles. This paper presents an extended analysis from a study of two open-access road-vehicle shapes (a DrivAer Notchback model and an AeroSUV Estateback model) in close lateral proximity with each other, or with other vehicle shapes. Wind-tunnel measurements were conducted for a yaw-angle range of ±10°, for lateral distances representing 75%, 100%, and 125% of a typical highway lane spacing, and for longitudinal distances up to 2 vehicle lengths forward and back. The results of a previous analysis of the data, which examined aerodynamic force measurements only, showed changes in drag coefficient of ±20% or more depending on the relative locations and wind conditions. In this paper, the force-coefficient results reexamined, and surface-pressure measurements are introduced to investigate the sources of the performance changes.

The results suggest that the changes in aerodynamic performance of vehicles in close lateral proximity arise from three mechanisms: 1) from a combination of locally-reduced static pressure, due to the combined blockage effect of the two vehicles on the local flow field; 2) from local flow-angularity changes altering the effective yaw angle of each vehicle; and 3) from wake-body interactions. The results also demonstrate a small increase in proximity effect when a proximate Ahmed body is introduced instead, likely as a results of its larger internal volume, but with trends that match the DrivAer/AeroSUV results. Proximity-induced loads and pressures are shown to increase with reduced distance and with increased adjacent-body size.
Design and Development of Base Valve for a Semi-Active Damper
Authors: Chintala Paramesh , Patwa Aakash , Sankaran Shivanand
Published: April 2024

A semi-active suspension system provides superior safety, ride, and handling performance for a vehicle by continuously varying the damping based on vehicle motions, where semi-active hydraulic damper (SAHD) is the most critical component. Today, SAHD’s are standard in most of the premium segments of vehicles and optional extras in mid-size and compact vehicle segments. Electric vehicles require larger sized SAHD’s to meet heavier vehicle loads and meet ride and handling requirements. The aim of this paper is to highlight the design and development methodology of a base valve for larger bore-size for semi-active hydraulic damper. The workflow follows to present a process for base valve design to meet structural strength and, the key steps of design calculations of the hydraulic performance. The design of the base valve and suction disks architecture was engineered with the aid of Computer Aided simulations. The structural performance was analyzed using the Finite Element Analysis (FEA) and valve hydraulic performance factors were obtained by using Computational Fluid Dynamics (CFD) methods to simulate the physics of hydraulic fluid flow around the base valve assembly using the de-coupled fluid /structure interaction (FSI) method. In this effort, the analytical study was reinforced to identify the critical performance parameters such hydraulic pressure (P) - oil discharge (Q) curve generation and understand the base valve design performance. Furthermore, valve characterization using flow bench testing was conducted to validate and correlate the simulation predictions with prototype samples to increase the confidence level in computer aided simulations.
Hydrogen Engine Insights: A Comprehensive Experimental Examination of Port Fuel Injection and Direct Injection
Authors: Mohamed Mohamed , Longo Kevin , Zhao Hua , Hall Jonathan , Harrington Anthony
Published: April 2024

The environmental and sustainable energy concerns in transport are being addressed through the decarbonisation path and the potential of hydrogen as a zero-carbon alternative fuel. Using hydrogen to replace fossil fuels in various internal combustion engines shows promise in enhancing efficiency and achieving carbon-neutral outcomes. This study presents an experimental investigation of hydrogen (H2) combustion and engine performance in a boosted spark ignition (SI) engine. The H2 engine incorporates both port fuel injection (PFI) and direct injection (DI) hydrogen fuel systems, capable of injecting hydrogen at pressures of up to 4000 kPa in the DI system and 1000 kPa in the PFI operations. This setup enables a direct comparison of the performance and emissions of the PFI and DI operations. The study involves varying the relative air-to-hydrogen ratio (λ) at different speeds to explore combustion and engine limits for categorising and optimising operational regions.

Furthermore, load sweep tests are conducted at various engine speeds to evaluate the advantages of the H2 direct injection system over the PFI system and to analyse the characteristics of NOx emissions. Additionally, a matrix of inlet and exhaust valve timings is tested for each injection system to assess the valve timings and their interactions with injection setups on combustion, engine performance and emissions. The main findings of this study demonstrate that both PFI and DI hydrogen systems offer the benefit of zero carbon emissions and improved indicated thermal efficiency (ITE) when used in an engine designed and tuned for gasoline combustion. The DI hydrogen system, in particular, exhibits 2% higher ITE than PFI as well as producing higher power output. This enhancement can be attributed to the DI’s ability to operate under stoichiometric conditions, thanks to higher injection pressure and late injection timing during the intake stroke. This configuration mitigates backfire occurrences and prevents hydrogen from bypassing through the exhaust, thus enhancing combustion efficiency.
Methane Conversion in Stoichiometric Natural Gas Engine Exhaust
Authors: Karamitros Dimitrios , Ibraimova Adjer , Konstantinidis Konstantinos , Koltsakis Grigorios , Choi Sungmu , Cho Jiho
Published: April 2024

Stoichiometric natural gas (CNG) engines are an attractive solution for heavy-duty vehicles considering their inherent advantage in emitting lower CO2 emissions compared to their Diesel counterparts. Additionally, their aftertreatment system can be simpler and less costly as NOx reduction is handled simultaneously with CO/HC oxidation by a Three-Way Catalyst (TWC). The conversion of methane over a TWC shows a complex behavior, significantly different than non-methane hydrocarbons in stoichiometric gasoline engines. Its performance is maximized in a narrow A/F window and is strongly affected by the lean/rich cycling frequency. Experimental and simulation results indicate that lean-mode efficiency is governed by the palladium’s oxidation state while rich conversion is governed by the gradual formation of carbonaceous compounds which temporarily deactivate the active materials. Lean/rich cycling around stoichiometry enables a higher CH4 oxidation as the oxygen storage seems to balance the individual effects of Pd oxidation and rich deactivation. In this work, the catalytic reaction mechanisms involved in CH4, CO and NOx conversion were studied by means of a multi-scale experimental campaign and mathematical modeling. Initially, a detailed kinetic study was performed on the synthetic-gas bench to understand the underlying phenomena and formulate the appropriate reaction mechanisms. The model was then evaluated under transient reactor experiments while final validation was performed against driving cycle measurements on the engine bench.
Real-Time Cornering Stiffness Estimation and Road Friction State Classification under Normal Driving Conditions
Authors: Balaga Sanjay Raghav , labella Mario , Singh Kanwar Bharat
Published: April 2024

The tire cornering stiffness plays a vital role in the functionality of vehicle dynamics control systems, particularly when it comes to stability and path tracking controllers. This parameter relies on various external variables such as the tire/ambient temperature, tire wear condition, the road surface state, etc. Ensuring a reliable estimation of the cornering stiffness value is crucial for control systems. This ensures that these systems can accurately compute actuator requests in a wide range of driving conditions. In this paper, a novel estimation method is introduced that relies solely on standard vehicle sensor data, including data such as steering wheel angles, longitudinal acceleration, lateral acceleration, yaw rate, and vehicle speed, among others. Initially, the vehicle's handling characteristics are deduced by estimating the understeer gradient. Subsequently, real-time estimates of the cornering stiffness values are derived by adapting the previously obtained parameters, all based on readily available vehicle sensor data. To enhance the robustness of the cornering stiffness model, a model for estimating vehicle mass is employed. The validity of the estimation method is confirmed through testing involving both low and high G excitation maneuvers, as well as real-world driving data on public roads, encompassing different road surface driving conditions. Additionally, the approach's robustness is assessed across various tire types and degrees of tire wear. Finally, the estimates of tire cornering stiffness are applied within a model to ascertain the classification of the road friction state.
System Level Modelling, Evaluation, and Trade-Off/Optimization of Solid-State & Hybrid DC Circuit Breakers for an EV Eco-System Using AI/ML in an MBSE Framework
Authors: Milind T. R. , Thomas Amal , Rastogi Sarthak , K Satyadeep
Published: April 2024

With the increasing demand for efficient & clean transport solutions, applications such as road transport vehicles, aerospace and marine are seeing a rise in electrification at a significant rate. Irrespective of industries, the main source of power that enables electrification in mobility applications like electric vehicles (EV), electric ships and electrical vertical take-off & landing (e-VTOL) is primarily a battery making it fundamentally a DC system. Fast charging solutions for EVs & e-VTOLs are also found to be DC in nature because of several advantages like ease of integration, higher efficiency, etc. Likewise, the key drivers of the electric grid are resulting in an energy transition towards renewable sources, that are also essentially DC in nature. Overall, these different business trends with their drivers appear to be converging towards DC power systems, making it pertinent. However, DC circuit protection poses serious challenges compared to AC due to the absence of natural zero-crossing points and the high rise rate of fault current demanding the need for fast-acting protective devices. Circuit breakers as protective devices are advantageous because of their resettable feature. This has prompted engineers to look beyond their conventional purview and explore developments in mechanical technologies of fast-acting switches & power electronics technologies to develop circuit protection solutions for DC systems. The result has been the development of solid-state circuit breakers (SSCB) and hybrid circuit breakers (HCB), making their design and analysis crucial.

Thus, this paper focuses primarily on the model-based analysis of SSCB & HCB used for DC circuit protection in mobility applications. System-level models of the breakers are developed and integrated with a DC power distribution system. Key critical to quality (CTQs) of the design like response time, power loss, temperature rise, rate of rise of fault current, current commutation, and drop in DC bus voltage are predicted. Also, sensitivity to design parameters is analyzed. As there are a variety of architectures for these breakers, a Model-Based System Engineering (MBSE) approach is adopted to have an ideal framework for tracking and evaluating different architectures. Further, a Machine Learning (ML) based Reduced-Order Model (ROM) is developed, embedded in the MBSE framework for quick model-based sensitivity and optimization studies for faster product-to-market without compromising on accuracy.
Fast CFD Diesel Engine Modelling Using the 1-Dimensional SprayLet Approach
Authors: Kurapati Vinaykumar Reddy , Anders Borg , Seidel Lars , Mauss Fabian
Published: April 2024

Spray modelling plays a key role in engine simulations to understand fuel propagation and mixing, combustion, pollutant formation and energy efficiency. The grid dependency, need of calibration of several spray parameters, complexity associated with validation and high computational demand associated with Spray modelling are addressed with 1-dimentional SprayLet model. This work focuses on enhancing the SprayLet model approach with a dual emphasis on computational efficiency and grid independence for advanced engine simulations. Key spray characteristics, such as vapor and liquid penetration lengths, have been systematically evaluated as they play pivotal roles in understanding fuel evaporation, spray-wall interactions, and mixture formation within engines. The SprayLet model has undergone substantial improvements, encompassing the integration of standard sub-models, multiple injector/nozzle handling capabilities, and extensions to the CONVERGE CFD code and Combustion Progress Variable (CPV) combustion model. A rigorous validation process has been implemented using various engine injection conditions as a benchmark. Through detailed comparisons with experimental data and the 3D Stochastic spray model, the validation phase underscores the SprayLet model's exceptional grid independence and computational efficiency. It demonstrates precise predictions of in-cylinder pressure, temperature distributions, and velocity profiles, along with substantial reductions of 95% in computational time. The subsequent verification phase explores the model's adaptability to diverse scenarios, with variations in Start of Injection (SOI) and injection rail pressure. The results confirm its robustness in handling distinct SOI and fuel characteristics while maintaining precise predictions of pressure and the Rate of Heat Release (RoHR). The model's capabilities extend to substantial reductions in computational time while ensuring accuracy. Its grid independence, simple calibration, ease of validation and computational efficiency position it as a promising spray model for optimizing engine performance and reducing emissions.
Vehicle Yaw Dynamics Safety Analysis Methodology based on ISO-26262 Controllability Classification
Authors: paik Scott , Almasri Hossam , Rao Medidha Neelakanta , Capobianco Anthony , Evans Andrew , Sevillano Yvette
Published: April 2024

Complex chassis systems operate in various environments such as low-mu surfaces and highly dynamic maneuvers. The existing metrics for lateral motion hazard by Neukum [13] and Amberkar [17] have been developed and correlated to driver behavior against disturbances on straight line driving on a dry surface, but do not cover low-mu surfaces and dynamic driving scenarios which include both linear and nonlinear region of vehicle operation. As a result, an improved methodology for evaluating vehicle yaw dynamics is needed for safety analysis.

Vehicle yaw dynamics safety analysis is a methodical evaluation of the overall vehicle controllability with respect to its yaw motion and change of handling characteristic. The yaw dynamics safety analysis is crucial for understanding how a driver-vehicle system responds to disturbances (external forces such as failure modes) in various driving scenarios and maneuvers., and it plays a significant role in evaluating the overall safety and performance of vehicles.

In this paper, we are proposing a methodology for evaluating and performing vehicle yaw dynamics safety analysis, which considers definition of test maneuvers based on exposure, driver behavior model for assessment of controllability, and combining them to apply ISO-26262 approach to determine risk.
Investigation of Ammonia-Fueled SI Combustion in a High Tumble Engine
Authors: Yan Ziming , Peters Nathan , Harrington Anthony , Bunce Michael , Hall Jonathan
Published: April 2024

The use of ammonia (NH3), a low life-cycle carbon fuel, is an increasingly popular pathway towards decarbonization in the marine and other sectors. However, NH3 possesses low reactivity and flame speed, making its use in internal combustion engines challenging. Additionally, combustion of NH3 can produce incomplete combustion, combustion instability, and toxicity concerns related to fuel slip. Therefore, robustly igniting the fuel and promoting effective flame propagation is critical for NH3 usage in engines. In the present study, investigations of NH3 combustion in a 0.4-liter single-cylinder spark-ignited (SI) research engine are carried out experimentally over a range of operating conditions. 100% NH3 operation successfully covers 60% of the speed-load map, while other areas require aid from a secondary fuel. Compared to the gasoline baseline, 7 percentage points higher peak efficiency is realized by NH3, and nitrogen oxides (NOx) emissions are reduced by two thirds. Separately, computational fluid dynamics (CFD) investigations are used to understand the cyclic variability associated with NH3 SI combustion and passive pre-chamber combustion. The observed cyclic variability in Reynolds Averaged Navier-Stokes (RANS) CFD is introduced by the variability of turbulent kinetic energy (TKE) distribution and flow fields, combined with NH3’s less reactive flame chemistry that amplifies the sensitivity to this turbulence. It is concluded that the cyclic variability observed with RANS CFD is an effective measure of combustion robustness concerning fuel and flame sensitivity. The passive pre-chamber shows promising simulation results compared to SI, resulting in higher thermal and combustion efficiency and reduced combustion instability. These results illustrate the challenges associated with developing and simulating single-fuel NH3 combustion engines and indicate promising routes forward.
Experimental Study on Bendability of Advanced High Strength Steels
Authors: Shih Hua-Chu
Published: April 2024

Fracturing in a tight radius during bending is one of the major manufacturing issues in forming Advanced High Strength Steels (AHSS). The study investigated the bendability of AHSS under two forming conditions: bending with and without stretched over the die radius. The bendability was evaluated by conducting modified Bending Under Tension (BUT) test for stretch bending and 90o v bend test for bending without stretch. The study also examined the effect of material properties on the limiting bend ratio. Various strength high strength steels, range from 420 MPa to 1700 MPa tensile strength, were selected in the study. Results indicated that critical radius-to-thickness ratios between the two tests are different but correlated in a relationship which was depicted in the bendability diagram. The map and constitutive relation curve derived from limiting bend ratios identified the multiple bendability (stretched and no-stretch) of each strength grade of test steel, which is recommended as the guideline for design-evaluate the bendability performance of the AHSS. The determined limiting bending strains could serve as the die radius thinning criterion, while further field validations are needed to verify the robustness.
Generalized Alternating Projections on Manifolds and Convex Sets
Authors: Fält Mattias , Giselsson Pontus
Published: April 2024

In this paper, we extend the previous convergence results for the generalized
alternating projection method applied to subspaces in [arXiv:1703.10547] to
hold also for smooth manifolds. We show that the algorithm locally behaves
similarly in the subspace and manifold settings and that the same rates are
obtained. We also present convergence rate results for when the algorithm is
applied to non-empty, closed, and convex sets. The results are based on a
finite identification property that implies that the algorithm after an initial
identification phase solves a smooth manifold feasibility problem. Therefore,
the rates in this paper hold asymptotically for problems in which this
identification property is satisfied. We present a few examples where this is
the case and also a counter example for when this is not.
Impact of persistent cold stress on spectral characteristics of EEG alpha and theta rhythms in military academy cadets
Authors: Tolstoguzov SN , Fisher TA , Naida YuV , Lepunova ON
Published: April 2024

The study was focused on the features of spectral characteristics of the EEG alpha and theta ranges in the military academy cadets undergoing specific training to improve cold resistance (cold exposure training). The study was aimed to assess the impact of the military academy cadets’ incremental exposure to the graduated cold stress (cold exposure training) on spectral characteristics of the EEG alpha and theta rhythms. Students of the civil higher educational institution and military academy cadets were assessed (58 individuals in total). Cadets underwent a specific program focused on improving cold resistance (cold exposure training). Background EEG in the alpha and theta frequency ranges was recorded. Statistical data processing involved nonparametric comparison using the Mann–Whitney U test. The results were obtained suggesting that there were significant differences in spectral characteristics of alpha and theta rhythms between the group of foreign cadets and the controls. The cold exposure training program was effective in the group of Russian cadets, which had an effect on the cerebral homeostasis stability with some degree of instability of neurodynamic processes in the CNS. In foreign cadets, regular cold exposure training resulted in the pronounced disintegration of cortical-subcortical and intracortical interactions, as well as in the formation of binary alpha-theta structure of background EEG.
Decision Factors Which the Company Makes Transfer Pricing
Authors:   Accounting Study Program, Faculty of Economics and Business, Universitas Muhammadiyah Palembang, Jl. General A. Yani 13 Ulu Palembang, Indonesia, Astrina Fenty , Yanti Darma ,   Accounting Study Program, Faculty of Economics and Business, Universitas Muhammadiyah Palembang, Jl. General A. Yani 13 Ulu Palembang, Indonesia, Ningsih Nurul Hutami ,   Accounting Study Program, Faculty of Economics and Business, Universitas Muhammadiyah Palembang, Jl. General A. Yani 13 Ulu Palembang, Indonesia, Afrida Anggrelia ,   Accounting Study Program, Faculty of Economics and Business, Universitas Muhammadiyah Palembang, Jl. General A. Yani 13 Ulu Palembang, Indonesia
Published: April 2024

The practice of transfer pricing initially it was carried out solely to evaluate company performance, but as time goes by, practice transfer pricing it is also used to minimize the amount of tax that the company must pay. This research aims to find out the influence of taxes, company size and Good Corporate Governance (GCG) Regarding Decisions Transfer Pricing. The data collection technique is by using documentation. The type of research used is associative research. The data used is secondary data. The population in this study was 30 companies, and the sample was 16 manufacturing companies in the food and beverage sub-sector listed on the Indonesia Stock Exchange during the 2019-2022 period using the method purposive sampling. The data analysis method used is quantitative analysis. The analysis technique used in this research is logistic regression. The research results show that partially, taxes and firm size have a significant positive effect on decisions transfer pricing where as good corporate governance has no influence on the decision transfer pricing.
Enhancing Mechanical Characteristics of PETG Carbon Fiber Composite through Various Shell Thickness in FDM Processing
Authors: Deivasikamani S M  , Mathiyazhagan.K  , Mugeshkannan.G  , Sridhar.D  , Pranesh.M
Published: April 2024

The utilization of PETG (Polyethylene Terephthalate Glycol) carbon fiber composites in Fused Deposition Modelling (FDM) processes has gained significant attention due to their enhanced mechanical properties compared to traditional PETG filaments. This study focuses on investigating the impact of varying shell thickness on the mechanical characteristics of PETG carbon fiber composites fabricated through FDM. The objective is to optimize the shell thickness to achieve superior mechanical performance while maintaining printing efficiency. A series of PETG carbon fiber composites with different shell thicknesses were manufactured using an FDM 3D printer. Mechanical tests, including tensile strength, flexural strength, and impact resistance, were conducted to evaluate the performance of the fabricated specimens. Additionally, micro-structural analysis was performed to understand the influence of shell thickness on the interfacial bonding between PETG matrix and carbon fibers. Preliminary results indicate that increasing shell thickness positively affects the mechanical properties of PETG carbon fiber composites. Tensile and flexural strength show a noticeable improvement with an increase in shell thickness, attributed to enhanced interlayer adhesion and improved load-bearing.
God's Exiles and English Verse
Authors: Niles John
Published: April 2024

This monograph is a critical study of the medieval manuscript held in Exeter Cathedral Library, popularly known as ‘The Exeter Book’. Recent scholarship, including the standard edition of the text, published by UEP in 2000 (2 ed’n 2006), has re-named the manuscript ‘The Exeter Anthology of Old English Poetry’. The book gives us intelligent, sensitive literary criticism, profound readings of all of the poems of the Anthology. God’s Exiles and English Verse is the first integrative, historically grounded book to be written about the Exeter Book of Old English poetry. By approaching the Exeter codex as a whole, the book seeks to establish a sound footing for the understanding of any and all of its parts, seen as devout yet cosmopolitan expressions of late Anglo-Saxon literary culture. The poems of the Exeter Book have not before been approached primarily from a codicological perspective. They have not before been read as an integrated expression of a monastic poetic: that is to say, as a refashioning of the medium of Old English verse so as to serve as an emotionally powerful, intellectually challenging vehicle for Christian doctrine and moral instruction. Part One, consisting of three chapters, introduces certain of the book’s main themes, addresses matters of date, authorship, audience, and the like, and evaluates hypotheses that have been put forth concerning the origins of the Exeter Anthology in the south of England during the period of the Benedictine Reform. Part Two, the main body of the book, begins with a long chapter, divided into seven sections, that introduces the contents of the Exeter Anthology poem by poem in a more systematic fashion than before, with attention to the overall organization of the Anthology and certain factors in it that have a unifying function. The five shorter chapters that follow are devoted to topics of special interest, including the volume’s possible use as a guide to vernacular poetic techniques, its underlying worldview, its reliance on certain thematically significant keywords, and its intertextual versus intratextual relations. The riddles, especially those of a sexual content, receive attention in a chapter of their own. In addition, there is a translation of the popular poem The Wanderer into modern English prose, a folio-by-folio listing of the contents of the Exeter Anthology, and a listing of a number of the poems of the Anthology with notes on their genre, according to Latin generic terms familiar to educated Anglo-Saxons. This book is the first of its kind - an integrative, book-length critical study of the Exeter Anthology.
Craneotomía guiada por estereotaxia en lesiones cerebrales
Authors: Vázquez Soto Pedro , Lecaros Nicolás , Méndez Emmanuel , Baabor Marcos , Zomosa Gustavo
Published: April 2024

Introducción: La craneotomía y microcirugía guiada por estereotaxia se realiza a través de un sistema guiado por ordenador donde se adquieren imágenes neurorradiologicas para luego representarlas en tres dimensiones, optimizando la resección de lesiones ubicadas en localizaciones complejas.Objetivo: Describir la experiencia en la aplicación de la craneotomía guiada por estereotaxia en 33 pacientes con lesiones cerebrales.Materiales y métodos: Estudio descriptivo-retrospectivo, revisando fichas clínicas, protocolos y biopsias de pacientes entre los años 2005 y 2010 en el Hospital Clínico de la Universidad de Chile.Resultados: Pacientes del sexo masculino fueron 54,5%. La edad promedio fue de 49,8 años. La mayoría de las lesiones se situaron en el lóbulo frontal con un 49%. La cefalea fue el síntoma más frecuente con un 46,8. Según tipo histológico la mayoría correspondieron a tumores, dentro de los que destacan los meningiomas con un 21%. De las lesiones no tumorales los cavernomas alcanzan un 15%. No se registro en éste estudio mortalidad.Discusión: La reaparición de las técnicas estereotácticas con marco ha impulsado el desarrollo de la cirugía guiada por imágenes, adquiriendo gran importancia en el manejo de lesiones cerebrales de difícil acceso. Además la localización precisa de lesiones permite minimizar incisiones al realizar craneotomías centradas disminuyendo al mínimo la retracción cerebral.Conclusiones: Técnica efectiva y segura, con una resección precisa de lesiones bajo una visión directa, apertura ósea pequeña y trayecto transcortical planeado. Minimiza la morbilidad postoperatoria, la estadía hospitalaria, optimizando los recursos de los pacientes y los centros hospitalarios.
Genetics-guided therapy in neuroendocrine carcinoma: response to BRAF- and MEK-inhibitors
Authors: Falkman Lovisa , Sundin Anders , Skogseid Britt , Botling Johan , Bernardo Yvette , Wallin Göran , Zhang Liang , Welin Staffan , Lase Ieva , Mollazadegan Kazhan , Crona Joakim
Published: April 2024

Background: Metastatic neuroendocrine carcinoma (NEC) is associated with short survival. Other than platinum-based chemotherapy, there is no clear standard regimen. Current guidelines suggest that combination treatment with BRAF-inhibitors should be considered for patients with BRAF V600E-mutated NEC. However, since only eight such patients have been reported in the literature, our object was to confirm the validity of this recommendation.
Methods: This was a single-center retrospective cohort study conducted at Uppsala University Hospital. The included patients 1) had a histopathologically confirmed diagnosis of NEC, 2) were diagnosed between January 1st, 2018 and December 31st, 2023, 3) had tumor tissue genetically screened by a broad next-generation sequencing (NGS) panel, and 4) showed a tumor mutation for which there is a currently available targeted therapy.
Results: We screened 48 patients diagnosed with NEC between January 1st, 2018 and December 31st, 2023. Twelve had been analyzed with a broad NGS-panel, and two had a targetable mutation. Both these patients harbored a BRAF V600E-mutated colon-NEC and were treated with BRAF- and MEK-inhibitors dabrafenib and trametinib in second-line. At first radiological evaluation (RECIST 1.1), both patients had a reduction of tumor size, which decreased by 31 and 40%. Both had short response periods, and their overall survival was 12 and 9 months.
Conclusions: BRAF-mutated NEC is sensitive to treatment with BRAF- and MEK-inhibitor combination. These results further support that DNA sequencing should be considered as standard of care in NECs to screen for potential treatment targets.
BIOMARCADORES INFLAMATÓRIOS NOS PACIENTES COM DOENÇA RENAL CRÒNICA EM HEMODIÁLISE
Authors: Oliveira Fabiano Santana de , Morais Mauro José de Deus , Deus Maura Bianca Barabry de , Ferreira Carlos Roberto Teixeira , Leitão Francisco Naildo Cardoso , Pérez-Riera Andrés Ricardo
Published: April 2024

Introdução: A doença renal crônica (DRC) tem aumentado nos últimos anos de forma epidêmica. Fatores como obesidade, hipertensão arterial, diabetes melito tipo 2 (DM2), senescência, doença cardiovascular, histórico familiar com DRC e medicações nefrotóxicos aumentam a suscetibilidade e a instalação e progressão da DRC. Além desses fatores, existem evidências de inflamação na fisiopatologia da DRC. Objetivo: Avaliar os biomarcadores inflamatórios mais examinados em pacientes portadores de doença renal crônica hemodialisados. Material e Métodos: Trata-se de uma revisão sistemática nos motores de busca National Library of Medicine (PubMed) e Biblioteca Virtual em Saúde (BVS) pelos descritores ((hemodialysis) AND (inflammation)) AND (chronic kidney disease). Para a seleção dos artigos foram incluídos aqueles que seguiam os critérios: (1) população do estudo com diagnóstico doença renal crônica, (2) população da amostra ≥ de 18 anos. (3) aqueles que foram avaliados IL-6, TNF alfa, PCR ou VHS. Resultados: 98 artigos foram encontrados realizados em diversos países, 20 completaram os critérios de inclusão. A maior parte dos estudos eram compostos predominantemente por homens. Conclusão: Pacientes hemodialíticos apresentam aumento dos níveis de biomarcadores inflamatórios, principalmente TNF-α e IL-6.
Comentarios sobre el artículo Dengue con signos de alarma: características clínicas
Authors: Pinedo-Saravi Jimena , Arango-Huaman Adhari
Published: April 2024

Una de las preocupaciones màs severas es la aparición de signos de alarma en el dengue que indican una complicación grave, signos que pueden ser difíciles de reconocer para los médicos y/o pacientes lo que realza la importancia de una mayor concientización y reconocimientosde estos, por ello resaltamos que se hizo una correcta identificación de los casos en pacientes hospitalizados del Hospital Tarapoto-MINSA,y consideramos realizar un mayor énfasis en los puntos sobre la relación de los serotipos del dengue con la frecuencia de presentar signos de alarma y la edad como factor de riesgo que determina gravedad, para brindar un mejor enfoque de entendimiento a los lectores.
The dynamics of marsh-channel slump blocks: an observational study using repeated drone imagery
Authors: Yang Zhicheng , Alexander Clark , Alber Merryl
Published: April 2024

Abstract. Slump blocks are widely distributed features along marsh shorelines that can disturb marsh edge habitats and affect marsh geomorphology and sediment dynamics. However, little is known about their spatial distribution patterns or their longevity and movement. We employed an unoccupied aerial vehicle (UAV) to track slump blocks in 11 monthly images (March 2020–March 2021) of Dean Creek, a tidal creek surrounded by salt marsh located on Sapelo Island (GA, USA). Slump blocks were observed along both convex and concave banks of the creek in all images, with sizes between 0.03 and 72.51 m2. Although the majority of blocks were categorized as persistent, there were also new blocks in each image. Most blocks were lost through submergence, and both decreased in area and moved towards the center of the channel over time. However, some blocks reconnected to the marsh platform, which has not been previously observed. These blocks were initially larger and located closer to the marsh edge than those that submerged, and they increased in area over time. Only 13 out of a cohort of 61 newly created blocks observed in May 2020 remained after 5 months, suggesting that most blocks persist for only a short time. When taken together, the total area of new slump blocks was 886 m2, and that of reconnected blocks was 652 m2. This resulted in a net expansion of the channel by 234 m2 over the study period, accounting for about 66 % of the overall increase in the channel area of Dean Creek, and this suggests that slump block processes play an important role in tidal creek channel widening. This study illustrates the power of repeated UAV surveys to monitor short-term geomorphological processes, such as slump block formation and loss, to provide new insights into marsh eco-geomorphological processes.
A dynamical process-based model AMmonia–CLIMate v1.0 (AMCLIM v1.0) for quantifying global agricultural ammonia emissions – Part 1: Land module for simulating emissions from synthetic fertilizer use
Authors: Jiang Jize , Stevenson David S. , Sutton Mark A.
Published: April 2024

Abstract. Ammonia (NH3) emissions mainly originate from agricultural practices and can have multiple adverse impacts on the environment. With the substantial increase of synthetic fertilizer use over the past decades, volatilization of NH3 has become a major loss of N applied to land. Since NH3 can be strongly influenced by both environmental conditions and local management practices, a better estimate of NH3 emissions from fertilizer use requires improved understanding of the relevant processes. This study describes a new process-based model, AMmonia–CLIMate (AMCLIM), for quantifying agricultural NH3 emissions. More specifically, the present paper focuses on the development of a module (AMCLIM–Land) that is used for simulating NH3 emissions from synthetic fertilizer use. (Other modules, together termed as AMCLIM-Livestock, simulate NH3 emissions from agricultural livestock, are described in Part 2). AMCLIM–Land dynamically models the evolution of N species in soils by incorporating the effects of both environmental factors and management practices to determine the NH3 emissions released from the land to the atmosphere. Based on simulations for 2010, NH3 emissions resulting from the synthetic fertilizer use are estimated at 15.0 Tg N yr-1, accounting for around 17 % of applied fertilizer N. Strong spatial and seasonal variations are found. Higher emissions typically occur in agricultural intensive countries (such as China, India, Pakistan and US), and mostly reach the maximum in the summer season. Volatilization rates indicate that hotter environments can result in more N lost due to NH3 emissions, and show how other factors including soil moisture and pH can greatly affect volatilization of NH3. The AMCLIM model also allows estimation of how application techniques and fertilizer type have impacts on the NH3 emissions, pointing to the importance of improving management practice to tackle nutrient loss and of appropriate data-gathering to record management practices internationally.
Fifty years of firn evolution on Grigoriev ice cap, Tien Shan, Kyrgyzstan
Authors: Machguth Horst , Eichler Anja , Schwikowski Margit , Brütsch Sabina , Mattea Enrico , Kutuzov Stanislav , Heule Martin , Usubaliev Ryskul , Belekov Sultan , Mikhalenko Vladimir N. , Hoelzle Martin , Kronenberg Marlene
Published: April 2024

Abstract. Grigoriev ice cap, located in the Tien Shan mountains of Kyrgyzstan, has a rich history of firn and ice core drilling starting as early as 1962. Here we extend the exceptional record and describe an 18 m firn core, drilled in February 2018 on the summit of Grigoriev ice cap, at 4600 m a.s.l. The core has been analyzed for firn stratigraphy, major ions, black carbon, water stable isotope ratios and total β activity. We find that the core covers 46±3 years and overlaps by 2 to 3 decades with legacy cores. A good agreement is found in major ion concentrations for the overlapping period. Concentrations of black carbon and major ions are reduced since the early 2000s, indicating the onset of meltwater runoff. Nevertheless, general concentration trends of these species are consistent with observations and Central Asian ice core records, since emissions were highest during periods when melt influence was negligible. The record of water stable isotopes does not reflect the strong increase of air temperatures during the last decades, implying that water stable isotope ratios ceased to be proxies of temperature variations at this site. Apart from runoff evidence, however, the firn's thermal regime appears remarkably unchanged. Firn temperatures in 2018 were the highest on record (∼-1.6 °C at ∼17 m depth). However, temperatures in 2023 are again similar to the early 2000s at ∼-2.5 °C. Furthermore, we find little change in net accumulation since the 1980s. We hypothesize (i) that firn temperatures are stabilized by the removal of latent heat through lateral meltwater runoff, and (ii) that mass loss by runoff is compensated by an increase in accumulation. Data from a nearby weather station support the latter hypothesis.
A rigorous approach to the specific surface area evolution in snow during temperature gradient metamorphism
Authors: Braun Anna , Fourteau Kévin , Löwe Henning
Published: April 2024

Abstract. Despite being one of the most fundamental microstructural parameters of snow, the specific surface area (SSA) dynamics during temperature gradient metamorphism (TGM) have so far been addressed only within empirical modeling. To surpass this limitation, we propose a rigorous modeling of SSA dynamics using an exact equation for the temporal evolution of the surface area, fed by pore-scale finite-element simulations of the water vapor field coupled with the temperature field on X-ray computed tomography images. The proposed methodology is derived from the first principles of physics and thus does not rely on any empirical parameter. Since the calculated evolution of the SSA is highly sensitive to fluctuations in the experimental data, we quantify the impact of these fluctuations within a stochastic error model. In our simulations, the only poorly constrained physical parameter is the condensation coefficient α. We address this problem by simulating the SSA evolution for a wide range of α values and estimate optimal values by minimizing the differences between simulations and experiments. This methodology suggests that α lies in the intermediate range 10-3<α<10-1 and slightly varies between experiments. Also, our results suggest a transition of the value of α in one TGM experiment, which can be explained by a transition in the underlying surface morphology. Overall, we are able to reproduce very subtle variations in the SSA evolution with correlations of R2=0.95 and 0.99, respectively, for the two TGM time series considered. Finally, our work highlights the necessity of including kinetic effects and of using realistic microstructures to comprehend the evolution of SSA during TGM.
La dialéctica eticidad-moralidad-acción en la formación universitaria: el esfuerzo de la negación
Authors: Yurén Camarena Teresa
Published: April 2024

El objetivo de este artículo es aportar razones para sostener que hacer efectiva la formación socio-moral requiere considerar la dialéctica eticidad-moralidad-acción, en la que es indispensable el “esfuerzo de la negación”. Se clarifican los términos que incluye esa tesis, construida con base en autores clásicos y actuales, y se ponen de manifiesto algunas implicaciones paradójicas de esa dialéctica, así como los aspectos en los que se requiere el esfuerzo de la negación. Se muestra la necesidad de hacer la crítica de la eticidad hegemónica en la que se entretejen valores y seudo-valores; se discute la idea de que la incertidumbre brinde mayor libertad y se propone la superación de la conciencia caprichosa y la pretensión de la autonomía absoluta. Se sostiene que el sujeto moral, para ser tal, ha de salir al encuentro del otro(a), mediante el reconocimiento, y superar el presentismo, el antropocentrismo, el androcentrismo y el pensamiento colonial.