Search Results (153)

Lithium-ion batteries are a promising type of energy storage for renewable energy applications owing to their high energy density. Extensive research has therefore been carried out, utilizing both experimental and computational methods to aid in a deeper understanding of these types of batteries. This research work presents an electrochemical–thermal computational model for lithium-ion battery cells that analyzes electrical behavior, chemical behavior and thermal behavior. This computational model is developed by implementing a finite volume solution of a set of partial differential equations that describe this behavior in the anode, separator and cathode. These differential equations are mass conservation, charge conservation and energy conversion. In addition, the Butler Volmer equation is used to describe the exchange of lithium ions between the solid electrodes and the electrolyte and empirical relationships are used to describe the equilibrium electrical potentials. The results obtained by the developed MATLAB program are validated against those published in the literature. On top of the comparisons, a number of additional results are generated using the developed computational tool such as profiles of the lithium-ion concentrations, profiles of the voltage and profiles of the temperature across the battery. In addition, the voltage output and temperature as a function of time for specified current flows are given. The effect of including a temperature simulating routine in the battery model is assessed. This work contributes toward the advancement of renewable and clean energy by providing a tool and results that can be used to better understand battery energy storage. Full article

This article reflects on six years of work that implemented various participatory research methods with young women linked to gangs in El Salvador. The reflection focuses on the fundamental role of emotions and trust in contexts marked by violence and social exclusion. From the Freirean perspective of popular education and the approaches of Haraway and Butler, it also analyzes how these participatory methodologies with an autobiographical focus contribute to the re-signification of identities, the construction of agency, and the creation of safe spaces for dialogue. Through methods such as the systematization of experiences, life narratives, and critical ethnography, not only was the complexity of the participants’ lived realities captured, but the investigative process also became a vehicle for empowerment and social transformation. This article highlights how the ethical management of emotions, combined with the construction of trust-based relationships and the use of an autobiographical approach in participatory methodologies, redefines research as a humanized and transformative practice in the study of stigmatized and excluded populations. The findings emphasize the recognition of the contribution participatory research makes in contexts of violence and exclusion for the design of public policies, programs, or reintegration strategies. This underscores the need to promote research lines and funding that advance such proposals from the social sciences, establishing them as key tools for structural transformation. Full article

In this article, I have tried to measure the distance that separates us from Kafka by trying to register both the things that we still have in common with him and his time, and the many things that have changed in between. The first section is an analysis of the story “A Visit to a Mine” in terms of the new accident prevention techniques instituted by the welfare state at the turn of the nineteenth to the twentieth centuries. The second section deals with the new concepts of time and space that emerged in the age of electric and electro-magnetic media. And the third section is an attempt to write a short history of imitation from Descartes to Darwin, Kafka, Turing, and, finally, to the Large Language Models that we now call Artificial Intelligence. Full article

The pine caterpillar (Dendrolimus spectabilis Bulter, Lepidoptera: Lasiocampidae) is a destructive insect threatening forest communities across Eurasia. The pest is polyvoltine, and under global warming, more favorable temperatures can lead to additional generations. Here, we simulated the pine caterpillar voltinism under current and future climatic scenarios based on insect thermal physiology and cumulative growing degree day (CGDD) model. Subsequently, we revealed the future change patterns of the voltinism along elevational and latitudinal gradients. The results showed that both CGDD and pine caterpillar voltinism are increasing. The current voltinism of pine caterpillar ranges from 1.26 to 1.56 generations (1.40 ± 0.07), with an increasing trend of 0.04/10a. Similar trends are expected to continue under the future climate scenarios, with values of 0.01/10a, 0.05/10a, 0.07/10a, and 0.09/10a for the SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios, respectively. At the elevation and latitudinal gradients, voltinism increases across all ranges, peaking at 500–1000 m and latitudes of 34–34.5° N. This study highlights that the increase in voltinism is not limited to low-elevation and -latitude regions but is predicted across various elevations and latitudes. These findings can enhance our understanding of how climate change affects pine caterpillar voltinism and contribute to forest pest management strategies, although this study assumes a linear relationship between temperature and voltinism, without considering other ecological factors. Full article

Beam-switching technology is critical for fifth-generation (5G) Frequency Range 1 (FR1) base stations, yet existing odd-number Butler matrix designs often struggle to achieve compact size, low complexity, and efficient performance. Although a few studies have investigated 5 × 5 Butler matrices, their reliance on waveguide structures or multilayer implementations leads to larger footprints and greater fabrication complexity. This work introduces a novel 5 × 5 Butler matrix integrated with a five-element dipole antenna array for 3.3–3.7 GHz applications, offering notable improvements in beam-switching efficiency and overall system design. The proposed matrix generates five distinct beams at −144°, −72°, 0°, 72°, and 144° by employing precise phase progression, while eliminating crossovers and power dividers to simplify the layout. With a compact footprint of 2.67 × 0.80 × 0.02 cubic wavelength—94.4% smaller than waveguide-based designs—the matrix achieves a bandwidth of 3.32–3.62 GHz and consistently covers the target beams. The integrated system attains measured gains up to 11.4 dBi and half-power beamwidths ranging from 7.96° to 23.66°, with sidelobe levels comparable to those of state-of-the-art configurations. By employing a low-loss substrate, the gain can be further enhanced by as much as 6.81 dB, highlighting the potential for additional performance gains. These innovations establish the proposed design as a compact, low-complexity, and high-performance solution for 5G base station applications. Full article

A compact and wideband beamforming antenna array based on a substrate-integrated coaxial line (SICL) Butler matrix at 60 GHz is proposed in this paper. The cavity-backed patch antenna loading double-ridged horn antenna is designed to enhance a gain of 5.4 dB and a bandwidth of 2.7 GHz. Different phase centers of double-ridged horn elements are formed into a non-uniform array to reduce sidelobes by −7.9 dB. By introducing the defected ground structure (DGS) for a broadband coupler, a rotationally symmetric SICL Butler matrix is designed with a 55–70 GHz bandwidth and compact dimensions of 63 × 65 × 0.512 mm³. To validate the design, a prototype was fabricated and measured. The experimental results show a wideband −10 dB impedance bandwidth of 23.3% (55.4–70 GHz) with measured gains ranging from 15 to 16.1 dBi at 62 GHz. The one-dimensional beam scanning covers ±32°. The simulation and measurement results are in good agreement. Full article

This paper explores the intersection of tourism and environmental theories, highlighting how sustainability serves as a critical bridge between the two disciplines. Tourism theories such as Butler’s Tourism Area Life Cycle (TALC) and the Theory of Planned Behavior (TPB) provide insights into destination development and tourist behavior but often lack an ecological perspective. The environmental framework, including Ecological Modernization Theory (EMT) and Common-Pool Resource (CPR) Theory, emphasizes sustainable resource management and the interconnectedness of human activities and natural systems. This paper examines common concepts such as carrying capacity, sustainable development, and behavioral insights while also identifying tensions between economic growth and environmental preservation. Case studies from Costa Rica, Hawaii, and Thailand illustrate practical applications of these theories in real-world settings, revealing how tourism can be both a threat and a tool for conservation. My paper concludes that integrating environmental impact assessment (EIA) and community-based tourism (CBT) models into tourism planning can lead to better long-term resource management. It recommends the adoption of stricter regulations on tourism development in fragile ecosystems, the implementation of eco-certifications, and the promotion of locally governed tourism initiatives. These strategies will ensure the sustainability of both tourism activities and the ecosystems on which they depend. Full article

The underground mining industry faces significant challenges in maintaining reliable communication due to multipath fading and physical obstructions, leading to weak signals and dead spots. This study addresses these issues by proposing a smart antenna system with circular polarization and beam steering capabilities. The system utilizes a four-element square patch array and a Butler matrix for beamforming, enabling directional signal transmission. The antenna was designed and optimized using CST simulations. The experimental results demonstrate the antenna’s ability to steer beams in four directions, significantly reducing signal interference and improving coverage. The antenna achieved a bandwidth of 400 MHz (5.52–5.99 GHz) and a gain of up to 9.69 dBi, effectively mitigating polarization mismatches. The novelty of this study lies in the integration of circular polarization and beam steering into a compact, cost-effective system, specifically designed to enhance communication in underground mining environments. This solution improves both safety and operational efficiency by providing reliable communication in harsh conditions. Full article

Fruit seeds are often an underutilized side-stream of fruit processing. The most common approach to seed valorization is oil extraction due to the relative simplicity of the process. The partially or fully defatted seed meal is rarely further processed, even though seeds generally contain more protein and fiber than oil. The present study used single-screw extrusion (oil press), supercritical CO₂ extraction, and a combination of the two, to defat Japanese quince (Chaenomeles japonica) seeds, and evaluated the defatted meals as sources of functional protein. Defatting with oil press and CO₂ extraction proved similarly effective (reduced seed flour fat content from 11.75% to 6.40% and 5.32%, respectively); combining the two methods reduced fat content to 0.90%. The yield was minimally affected, but protein extract purity was defined by defatting efficiency (65.05% protein from non-defatted versus 82.29% protein from a combination-defatted meal). Defatting did not significantly affect amino acid composition but had a significant effect on every tested functional property (solubility, water, and oil binding capacity, apparent viscosity, foaming capacity, and emulsifying activity index). Of the tested defatting methods, supercritical CO₂ extraction and the combination provided the best results from most aspects. Full article

Aerospace fasteners are a ubiquitous component within the aerospace, air-frame, and aero-engine industries due to the essential role they play in structural integrity. Ti-6Al-4V is a common material for fasteners to be manufactured from, owing to the excellent strength-to-density ratio the material possesses, allowing for weight-saving in an application where weight is penalised by loss of fuel efficiency. The manufacture of aerospace pins sees a solid-state lubricant applied over the surface of the bar stock, at the titanium manufacturers, which aids forging processing; however, this lubricant layer must be fully removed post-forging to allow for solution heat treatment operations to achieve the desired mechanical properties. Whilst the exact composition of the lubricant is proprietary to the titanium producers, this can make understanding the removal via salt bath processing difficult. As such, the lubricant has been analysed and characterised to understand the primary chemical composition of the lubricant. Furthermore, the salt bath process has been studied to understand the efficacy of the cleaning process and the impact that variation in the salt bath hold time has or that adding some method of agitation to the molten salt in the bath as it cleans the surface lubricant off the Ti-6Al-4V fastener has. The salt bath cleaning process can cause a bottleneck to the full manufacturing route for the aerospace fasteners. Results suggest that there is some margin to reduce the hold time, or that by adding in a dipping process to increase agitation, it can also allow for lower hold times. Full article

Metal corrosion poses a significant challenge for industries by decreasing the lifespan of materials and escalating maintenance and replacement costs. This study is critically important, as it assesses the corrosion resistance properties of annealed steel wire electrodes coated with manganese, employing chronoamperometry and linear voltammetry techniques. The electrodes were immersed in an electrolyte solution and subjected to chronoamperometry at various voltages (−0.55 V, −0.60 V, and −0.70 V) and durations (60 s and 1800 s). Subsequently, linear voltammetry was performed over a potential range from −0.8 V to 0.8 V to generate Tafel plots. The Butler–Volmer equation was applied to the data obtained to determine the corrosion current density. The results indicate that the optimal conditions for forming a highly effective protective manganese layer occur at a potential of −0.70 V for 1800 s. Under these conditions, the electrodes exhibited superior corrosion resistance. This study also revealed that shorter durations and less negative potentials led to less-effective manganese coatings, with higher corrosion rates and reduced stability. These findings are significant for developing efficient corrosion protection methods in industrial and research applications, providing clear parameters for optimizing the manganese electrodeposition process on annealed steel. Full article

Thelyphonida Blanchard, 1852, also known as vinegaroons or whip-scorpions, is a small arachnid order with 140 described species contained in a single family, Thelyphonidae Lucas, 1835. Despite being conspicuous and widely distributed across the tropics and subtropics on four continents, knowledge of the order has been slow to advance. Hypoctoninae Pocock, 1899, one of four subfamilies currently recognized and one of two represented in the New World, comprises five genera. Since its inception, Thelyphonellus Pocock, 1894 has remained the only hypoctonine genus occurring in South America, with only four species described prior to the present contribution. The first detailed morphological study and phylogenetic analysis of Thelyphonellus is presented herein. The morphological phylogenetic analysis—the first for Thelyphonida—includes all except one of the previously described species of Thelyphonellus in addition to two new species described herein; the species of Ravilops Víquez and Armas, 2005 (from the Caribbean island of Hispaniola); and the monotypic Old World genus Etienneus Heurtault, 1984 (from West Africa) scored for 45 morphological characters. A single, most parsimonious phylogenetic hypothesis revealed that Thelyphonellus is paraphyletic with respect to Ravilops. The New World Hypoctoninae comprises four clades with disjunct distributions and well supported by a combination of morphological characteristics, on the basis of which four genera, two of which are new, are recognized: Ravilops, with two species, endemic to Hispaniola; Thelyphonellus, herein restricted to Thelyphonellus amazonicus (Butler, 1872) and Thelyphonellus ruschii Weygoldt, 1979, occurring in Guyana, Suriname, French Guiana, and northern Brazil; Wounaan, gen. n., containing Wounaan vanegasae (Giupponi and Vasconcelos, 2008), comb. n. and Wounaan yarigui, sp. n. from Colombia; and Yekuana, gen. n., containing Yekuana venezolensis (Haupt, 2009), comb. n. and Yekuana wanadi, sp. n. from Venezuela. The two new species are described and illustrated. A key to the identification of the Neotropical genera of Hypoctoninae and a map plotting the known distribution of its species are also presented. Full article

This article seeks to examine a new trend in Arabic women’s literature that not only aims to forge women’s communities but also creates resistance. Digital media is the mechanism that some Arab women authors employ to implement and foster a self-authority that acknowledges flexible identities in an age of revolutions and search for freedom. As a case study, I examine Ahlam Mosteghanemi’s Nessayne com and Rajaa Alsanea’s novel Girls of Riyadh, which originally appearing as compendiums, and Ibrahim Alsaqir’s novel Girls of Riyadh: The Complete Picture that comes as a literary response to the resistance of cultural and gender establishments. I suggest that the digital realm provides an arena for women to resist oppressing social establishments and that literary works and digital practices like Alsanea’s create spaces of and for resistance. Moreover, Alsanea’s and Mosteghanemi’s works are committed to promoting change in Arab societies, bridging the public and the private sphere by means of digital content. Arab women writers’ sites and blogs address subjects that challenge prevalent gendered structures in the Arab world, deconstruct cultural norms, give visibility and focus on the implications of gender on memory, love, masculinity and femininity, and sexuality. They do so by employing chats as a narrative technique that engages readers and women’s communities in the characters’ experiences and thereby inviting them to participate in making their work a site of challenge to gender and cultural establishments. As Alsanea’s representations of women subjectivities are uncommon and her characters defy the notion of the universality of woman as a shared gender, they are prohibited, criticized, and challenged. Those who defy gender performativity, such as Alsanea and Mosteghanemi, enact feminist resistance. The study engages with MENA gender and masculinity literature. It is also informed by Judith Butler’s notion of performativity, the construction of gender, and the demystification of the universalistic notion of “woman”. Full article

We present a corrosion internal state variable (ISV) damage model based upon the integrated computational materials engineering (ICME) hierarchical multiscale paradigm. Structure–property experiments for magnesium alloys were used where the only inputs were the volume fractions of each element of the periodic table. This macroscale ISV corrosion model finds its basis in Horstemeyer’s mechanical damage model, which includes three separate ISVs for damage nucleation, growth, and coalescence, as well as Walton’s inclusion of corrosion, which introduces five new ISVs for pit nucleation, growth, and coalescence, along with general corrosion and intergranular corrosion. While Walton’s corrosion ISVs are phenomenological in nature, herein we develop a multiscale physical basis for the corrosion ISVs. The parameters for the macroscale corrosion ISVs were garnered from the mesoscale Butler–Volmer equations. Pure magnesium with differing amounts of aluminum were used in corrosion tests to exemplify the different pitting, general corrosion, and intergranular corrosion rates, and the macroscale ISV model was calibrated with said data, in which the only inputs to the model are the volume percentages of the elements magnesium and aluminum. Although magnesium alloys were used to motivate and calibrate the model, the model is abstract enough to possibly capture other material systems as well. Full article

Microgravity has been shown to be an excellent tool for protein crystal formation. A retrospective analysis of all publicly available crystallization data, including many that have not yet been published, clearly demonstrates the value of the microgravity environment for producing superior protein crystals. The parameters in the database (the Butler Microgravity Protein Crystal Database, BμCDB) that were evaluated pertain to both crystal morphology and diffraction quality. Success metrics were determined as improvements in size, definition, uniformity, mosaicity, diffraction quality, resolution limits, and B factor. The proteins in the databases were evaluated by molecular weight, protein type, the number of subunits, space group, and Mattew’s Coefficient. Compared to ground experiments, crystals grown in a microgravity environment continue to show improvement across all metrics evaluated. General trends as well as numerical differences are included in the assessment of the BμCDB. The microgravity environment improves crystal formation across a spectrum of metrics and the datasets utilized for this investigation are excellent tools for this evaluation. Full article