Exchange Points Research Articles

Numerical Simulations of Flow and Heat Exchange in Zigzag-Shaped Microchannels

Cooling of electronic components is of great importance currently. One of the most important methods of integrated circuit cooling is the use of microchannel heat sinks. The aim of this work is to analyze the cooling capacity of zigzag shaped microchannels. The heat exchange for four different microchannels was tested depending on the flow rate of the cooling liquid (water) and the temperature of the cooled element. The system of differential equations that describe fluid flow and heat transport is presented in the paper. The equations were solved using the finite volume method. The work showed that both the increase in the number of zigzag sections and the increase in the flow velocity cause an increase in the flow resistance. In contrast, an increase in the temperature of the cooled element causes a decrease in fluid viscosity, which results in a decrease in flow resistance. From the point of heat exchange, both the increase in the number of segments, the flow rate, and the temperature of the cooled element increase the cooling capacity of the microchannel. Research shows that zigzag shaped microchannels are excellent cooling elements, especially for geometrically small heat sources such as electronic components.

Phenomenon of Screen Dance in the Context of Dialogism of Choreographic and Audiovisual Arts

The purpose of the article is to reveal the peculiarities of the phenomenon of screen dance in the context of dialogism of choreographic and audiovisual art. Research methodology. The method of analysis and synthesis was applied (to study the scientific literature on the research topic and identify the main concepts of screen dance), the terminological method (to clarify the concept of "screen dance"); the typological method and the method of historical and cultural analysis (to identify the peculiarities of the interaction of choreographic and audiovisual art in historical retrospect), the method of generalisation. Scientific novelty. The phenomenon of screen dance is studied in the context of dialogism of choreographic and audiovisual art in historical retrospect; the concept of "screen dance" has been clarified; the properties of screen dance are understood, the points of common influence and mutual exchange between film and dance are considered, which define it as an autonomous practice; little-known and unknown sources, as well as the results of research by modern foreign scientists, were introduced into scientific circulation. Conclusions. The study found that there are no strict criteria for defining screen dance in the scientific literature. During the historical development, this art form was usually denoted by a number of terms limited by indications of materiality (video dance, film dance, dance film), but it is screen dance that formulates the common denominator between them. Within the problematics of dialogism of choreographic and audiovisual art, screen dance can be considered as a form of research that studies the relationships between composition, choreographic language, and the meanings of body, movement, space, and time in the context of contemporary debates about cultural practices. Screen dance can take many forms and features and cross genres, with no limits on how it can be produced, filmed, edited and distributed. The coexistence of choreographic and audiovisual in the concept of screen dance is characterised by a constant dynamic interaction, the specifics of which are determined by innovative technological inventions and trends in the socio-cultural space.

Watercraft as Overwater Ambulance Exchange Points to Enhance Air Medical Evacuation

Ambulance exchange points are preidentified sites where patients are transferred between evacuation platforms while en route to enhanced medical care. We propose a new capability for maritime medical evacuation, which involves co-opting underway watercraft as overwater ambulance exchange points to transfer patients between medical evacuation aircraft. We partnered with the US Army's 25th Combat Aviation Brigade to demonstrate the use of Army watercraft as overwater ambulance exchange points. A manikin was transferred between 2 HH-60M medical evacuation Black Hawk helicopters conducting hoist operations over Army Logistics Support Vessel 3, which was traveling south of Honolulu, HI. The demonstration was enabled by a decision support system for dispatching aircraft, hoist stabilization technology, commercial satellite internet, military geospatial infrastructure applications, and digital medical documentation tools, the benefits of which are all discussed. Three extensions of the overwater ambulance exchange point are introduced, and civilian applications are considered.

Aging transitions of multimodal oscillators in multilayer networks

When individual oscillators age and become inactive, the collective dynamics of coupled oscillators is often affected as well. Depending on the fraction of inactive oscillators or cascading failures that percolate from crucial information exchange points, the critical shift toward macroscopic inactivity in coupled oscillator networks is known as the aging transition. Here, we study this phenomenon in two overlayed square lattices that together constitute a multilayer network, whereby one layer is populated with slow Poincaré oscillators and the other with fast Rulkov neurons. Moreover, in this multimodal setup, the excitability of fast oscillators is influenced by the phase of slow oscillators that are gradually inactivated toward the aging transition in the fast layer. Through extensive numerical simulations, we find that the progressive inactivation of oscillators in the slow layer nontrivially affects the collective oscillatory activity and the aging transitions in the fast layer. Most counterintuitively, we show that it is possible for the intensity of oscillatory activity in the fast layer to progressively increase to up to 100%, even when up to 60% of units in the slow oscillatory layer are inactivated. We explain our results with a numerical analysis of collective behavior in individual layers, and we discuss their implications for biological systems. Published by the American Physical Society 2024

2024 HRS perspective on advancing workflows for CIED remote monitoring

Cardiac implantable electronic devices (CIEDs) generate substantial data, often stored in image or PDF formats. Remote monitoring, now an integral component of patient care, places considerable administrative burdens on clinicians and staff, in large part due to the challenge of integrating these data seamlessly into electronic health records (EHRs). Since 2006, the Heart Rhythm Society, in collaboration with the CIED industry, has led an initiative to establish a unified standard nomenclature. This effort has harmonized terminology, aligning diverse terms with single terms approved by the Institute of Electrical and Electronics Engineers. With this foundational work complete, attention now turns to developing technical standards for interoperability, which would enable the smooth communication of CIED data between information technology systems used in clinical practice. In this manuscript, by leveraging Health Level 7 Fast Healthcare Interoperability Resources, we present a roadmap for the technical committee to guide this endeavor. We identify critical data exchange points between remote transceivers, EHRs, and third-party platforms commonly used for CIED patient data management. Our objective is to establish bidirectional communication among these resources, ensuring the accuracy, timeliness, and accessibility of clinical data for clinicians. We also anticipate substantial benefits for both clinical research and administrative efficiency through the implementation of this interoperability framework.

Enhanced recombination empowers the detection and mapping of Quantitative Trait Loci

Modern plant breeding, such as genomic selection and gene editing, is based on the knowledge of the genetic architecture of desired traits. Quantitative trait loci (QTL) analysis, which combines high throughput phenotyping and genotyping of segregating populations, is a powerful tool to identify these genetic determinants and to decipher the underlying mechanisms. However, meiotic recombination, which shuffles genetic information between generations, is limited: Typically only one to two exchange points, called crossovers, occur between a pair of homologous chromosomes. Here we test the effect on QTL analysis of boosting recombination, by mutating the anti-crossover factors RECQ4 and FIGL1 in Arabidopsis thaliana full hybrids and lines in which a single chromosome is hybrid. We show that increasing recombination ~6-fold empowers the detection and resolution of QTLs, reaching the gene scale with only a few hundred plants. Further, enhanced recombination unmasks some secondary QTLs undetected under normal recombination. These results show the benefits of enhanced recombination to decipher the genetic bases of traits.

Capture Beyond the Platforms: The Material and Infrastructural Conditions for Digital Journalism

News organisations are growing increasingly dependent on digital infrastructures for the distribution of news, AI implementation, and management of data. In this article, we argue that this dependency goes beyond the level of platforms, reaching into the internet backbone infrastructures that transmit, peer, deliver and host data on which journalism relies. Using Norway as a case, we map the actors involved in the subsea cable sectors, internet exchange points, content delivery networks and the data centres and cloud services that traffic, store and process digital journalism. Given the private, foreign nature of most of the actors involved in these infrastructures, we ask how these backbone infrastructures create interdependencies for the news industries in terms of data sovereignty, distribution control and regulatory jurisdiction. We discuss journalism’s dependency on each of these infrastructural sectors using sociotechnical theory, the contribution to which is to extend the range at which platform capture is considered in journalism scholarship.

“What it is exactly that circulates”: Affective value, re/production, and rhetorical exchange

Revising Marxist theories of circulation with affect theory, this article establishes a new model of rhetorical analysis that positions rhetorical exchange as a circulatory infrastructure of late capitalism. By measuring the value produced by rhetors and audiences in rhetorical exchange, we can see how the daily rhetorical activity of neoliberal subjects captures our behavior, positioning us a raw material for late capitalists. This new theory of rhetorical circulation is tested and revised by a qualitative study on the mundane communication of neoliberal subjects, in this case, the group chat of one fantasy football league. Fantasy football communication creates an ambient backdrop for its users, leading to quotidian rhetorical exchanges in clearly defined social networks. The study shows the contours of rhetorical exchange in one league's GroupMe chat. I found that, in exchange, subjects transform their investments into social and cultural capital (Bourdieu's capital forms). Ultimately, subjects can produce what I call affective capital, a uniquely neoliberal capital form. I find that the immense value of affective capital produced by league members in rhetorical exchange points to the reasons why neoliberal subjects repeatedly return to platforms that harvest our data.

Role of Recreational Facilities in Community Well-Being in India

Purpose: The aim of the study was to assess the role of recreational facilities in community well-being in India. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: The study revealed that, ranging from parks and playgrounds to community centers and sports complexes, serve as focal points for social interaction, physical activity, and cultural exchange within neighborhoods. Studies indicate that access to such amenities correlates with improved mental and physical health outcomes, reduced stress levels, and increased community cohesion. Furthermore, recreational facilities often contribute to crime prevention by providing safe spaces for leisure activities and fostering a sense of belonging among residents. Their presence can also enhance property values and attract businesses, thus contributing to overall community development. As vital components of urban planning and public infrastructure, investing in and maintaining recreational facilities is essential for fostering healthier, happier, and more connected communities. Implications to Theory, Practice and Policy: Social capital theory, place attachment theory and ecological systems theory may be used to anchor future studies on assessing the role of recreational facilities in community well-being in India. Design and implement community-driven initiatives to enhance the accessibility, inclusivity, and quality of recreational facilities, ensuring that they meet the diverse needs and preferences of residents across different demographic groups and geographic contexts. Advocate for policies and funding mechanisms that prioritize investments in recreational infrastructure as integral components of urban planning and development strategies, recognizing their essential role in promoting public health, social cohesion, and economic vitality.

Numerical study of solar evaporation in 3D-printed structures

In this study, we used three-dimensional (3D) printed concave geometries filled with activated carbon to create a unique 3D solar evaporator for clean water production. The evaporation process was modeled considering airflow and solar radiation to investigate the advantages of 3D concave geometries. This work encompasses a series of studies, focusing on mass transfer inside the concavity and around the structure, to elucidate specific exchange points. Additionally, the research explores the effects of air velocity and the incorporation of additional holes within the structure, with the aim of improving evaporation.

A novel harmonic movable tooth drive with almost surface contact conjugate tooth profiles: Parametric design, modification and analysis

This paper focuses on a novel harmonic movable tooth drive as an alternative of currently used harmonic gear drives. Different from the harmonic gear drives, the novel drive removes small module teeth from thin-walled flexible rim, instead, adopts several rigid movable teeth with logarithmic spiral tooth profile. Such tooth geometry makes almost surface contact possible under load condition, in comparison with the conventional involute tooth profile creating a linear contact. Aiming at the issue of cusp meshing between movable tooth and ring gear during the meshing process, this paper proposes a modification design method for the conjugate tooth profiles. First, the radial motion law of movable tooth is modified, in order to avoid rigid impacts at the exchange point of the rise travel and return travel. Then, the tooth profile of ring gear is generated by the envelope of the modified profile of movable tooth. Based on the formulated modification scheme, the equations of the conjugate tooth profiles are derived, and the influences of spiral angle and modification parameters on the meshing characteristics are systematically investigated. Finally, the wave generator cam profile and pivoted segment profile are established considering the strength consistency. The outcomes can provide significance guidance for the parametric design and optimization of this novel drive.

Hybrid nanofluids flow over a Riga plate surrounded by a variable porous medium for heat transfer optimization

Enhancing the heat transfer rate in hybrid nanofluids is significantly aided by a porous medium. The nanofluid’s heat transfer to the surrounding medium is more efficient due to the presence of a porous medium. The porous space also provides additional surface contact points for heat exchange and an intricate network of interconnected pores. This article elaborates on the incorporation of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) into water to perform hybrid nanofluids. The flow is considered over a Riga plate surrounded by a variable porous space. Various applications, including thermal management systems, microelectronics cooling, and energy conversion devices, benefit greatly from the study of hybrid nanofluid flow on a Riga plate. The similarity equations of the flow problem are easily tackled with the homotopy analysis method (HAM) built on fundamental homotopy mapping. Furthermore, with the increments in paramount parameters, the skin friction coefficient and heat transfer rate are remarkably meliorated under a higher modified Hartmann number. All reverberations are illustrated in graphs and Tables. From the obtained results it is observed that flow control capabilities are enabled by the variations in permeability in the case of hybrid nanofluids. It is also observed that hybrid nanofluids are more capable to enhance the thermal capabilities of the traditional fluids as compared to the mano nanofluids.

THERMODYNAMIC IMPERATIVES THE MODERNIZATION OF THE ELECTRIC DRIVE OF PUMP UNITS OF THE CENTRALIZED HEAT SUPPLY NETWORK IN THE CONTEXT OF INCREASEING ENERGY EFFICIENCY

The relationship between thermodynamic and hydraulic parameters of the heat supply network has been established. The dependence of the electric power consumed by the electric drive of the pump unit on the pressure and supply of the coolant was determined. It is proved that the regulated electric drive system has advantages over the non-regulated electric drive system in the context of energy efficiency of the pumping unit and the district heating network in general. Approaches and criteria for the synthesis of a regulated electric drive system, including its automatic control system, were determined, regulation methods were analyzed, and the most acceptable version of the electric drive was chosen: a controlled frequency converter - an asynchronous motor with a short-circuited rotor, taking into account the above, an energy-saving mechanical system of a centralized heat supply network was synthesized. The peculiarity of this system is that the protection of parameters of hydraulic and temperature regimes in the network of centralized heat supply is ensured with the help of extreme automatic control systems. At the same time, the assignment of mode parameters is provided by the temperature controller of the heat exchange point of the network. Regulation of the pressure and productivity of the pumping unit is carried out by changing, according to a certain law, the frequency and power supply of the asynchronous motor.

Determination of Zinc and Magnesium in Food Samples via Cloud Point Extraction using Brilliant Green as a Reagent

In this article, we present a sensitive and efficient method for the separation and determination of Zinc (II) and Magnesium (II) ions using a combination of liquid ion exchange and cloud point extraction (CPE). The process includes converting these ions into metal ion complexes by using EDTA at pH 10. These complexes are then bound electrostatically with Brilliant Green (BG) to form ion pair association complexes, which are subsequently transferred into a cloud point layer. The study involved optimizing the extraction conditions, including the EDTA concentration, temperature, heating duration, and surfactant volume. The concentration of EDTA for achieving higher extraction efficiency is 1×10-4 M in the presence of 100 μg of Zn(II) and Mg(II) per 10 mL of aqueous solution using 1×10-4 M of BG. The solutions should be heated at 85°C for Zn(II) and 80°C for Mg(II) for 20 minutes. The optimal volume of surfactants is 0.5 mL of Triton X-100 for Zn(II) and 0.6 mL for Mg(II). The study also includes an analysis of the impact of electrolytes and interferences and the spectrophotometric identification of Zn(II) and Mg(II) in various samples.

Optimization of Network Management Resource in Internet Exchange Point (IXP) Implementation: Case Study of PT. Cloud Hosting Indonesia

Internet Exchange Point (IXP) is vital for global network development, supporting cloud computing and IoT trends. However, managing IXP networks is increasingly complex, impeding internet network growth. This research optimizes IXP network management by utilizing IXP Manager as the central infrastructure. Qualitative methods reveal limitations in BIRD configuration, confined to the Chief Technology Officer without a management platform. IXP Manager enables automation, empowering all technicians with performance graphs for evaluation, centralized management, improved employee performance, and enhanced device functionality. This approach fosters cost savings and supports the expansion of the internet network.

Enhanced Mechanism for Link Failure Rerouting in Software-Defined Exchange Point Networks

Enhanced Mechanism for Link Failure Rerouting in Software-Defined Exchange Point Networks

Азербайджанский цифровой центр: стратегия в действии

The article explores the digital transformation landscape under pandemic and post-pandemic conditions. As global internet traffic continues to surge, nations worldwide are prioritizing digital strategies to keep pace with this rapid transformation. Azerbaijan, an oil-rich country seeking economic diversification, has taken a strategic approach to become a key player in the digital landscape. Neqsol Holding, utilizing its capital from the oil and gas industry, initiated the Azerbaijan Digital Hub, a comprehensive program comprising the Digital Silk Road, a Regional Data Center, an Internet Exchange Point, and the development of a digital ecosystem. The hub aims to reshape the internet map along the Silk Way and thrive amidst disruptive changes through three consecutive stages: ideation, incubation, and scaling. The article highlights the strategic choices made by Azerbaijan in establishing the Digital Hub and its potential impact on the nation's economy. It presents the shift from the «Castles» quadrant to the «Connectors» quadrant, adopting new power models and values for sustainable growth. The dynamic capabilities of the Digital Hub are explored, emphasizing its transformative nature and adaptability to rapid technological advancements. In conclusion, the article suggests that the success of the Azerbaijan Digital Hub depends on effective management of continuous change, fostering a culture of innovation, and leveraging strategic advantages through mergers, alliances, and investments. By navigating a complex and uncertain environment, the Digital Hub can solidify its position as a crucial player in the digital era.

Traditional Knowledge Evolution over Half of a Century: Local Herbal Resources and Their Changes in the Upper Susa Valley of Northwest Italy.

Susa Valley, located in the Italian Western Alps, has served as a meeting point for cultural, spiritual, and commercial exchange for a long period of history. The valley's role as one of the main connecting routes between south and southwestern Europe resulted in its acquisition of a rich traditional ecological knowledge. However, like other Italian mountainous valleys, this valley has suffered from abandonment and depopulation in the past 50 years. Our study aims to investigate the current ethnobotanical medicinal knowledge in the valley and to compare our findings with a study conducted over 50 years ago in the same area. In 2018, we conducted 30 in-depth semi-structured interviews on medicinal plants and food-medicines used in the Susa Valley. We documented 36 species, of which 21 species were used for medical purposes and 15 species were used as food-medicine. The comparison with the previous study on medicinal herbs conducted in 1970 in the valley demonstrated a significant decrease in both the knowledge and use of medicinal plants, which could be attributed to socioeconomic, cultural, and possibly environmental changes that occurred in the past half-century. Our study highlights several promising species for future use as nutraceuticals, food, and medicinal products, such as Taraxacum officinale, Urtica dioica, and Artemisia genipi.

DDoS2Vec: Flow-Level Characterisation of Volumetric DDoS Attacks at Scale

Volumetric Distributed Denial of Service (DDoS) attacks have been a severe threat to the Internet for more than two decades. Some success in mitigation has been achieved based on numerous defensive techniques created by the research community, implemented by the industry, and deployed by network operators. However, evolution is not a privilege of mitigations, and DDoS attackers have found better strategies and continue to cause harm. A key challenge in winning this race is understanding the various characteristics of DDoS attacks in network traffic at scale and in a realistic manner. In this paper, we propose DDoS2Vec, a novel approach to characterise DDoS attacks in real-world Internet traffic using Natural Language Processing (NLP) techniques. DDoS2Vec is a domain-specific application of Latent Semantic Analysis that learns vector representations of potential DDoS attacks. We look into the link between natural language and computer network communication in a way that has not been previously studied. Our approach is evaluated on a large-scale dataset of flow samples collected from an Internet eXchange Point (IXP) in one year. We evaluate the performance of DDoS2Vec via multi-label classification in a Machine Learning (ML) scenario. DDoS2Vec characterises DDoS attacks more clearly than other baselines - including NLP-based approaches inspired by recent networks research and a basic non-NLP solution.

Evaluating E. coli genome-scale metabolic model accuracy with high-throughput mutant fitness data.

The Escherichia coli genome-scale metabolic model (GEM) is an exemplar systems biology model for the simulation of cellular metabolism. Experimental validation of model predictions is essential to pinpoint uncertainty and ensure continued development of accurate models. Here, we quantified the accuracy of four subsequent E. coli GEMs using published mutant fitness data across thousands of genes and 25 different carbon sources. This evaluation demonstrated the utility of the area under a precision-recall curve relative to alternative accuracy metrics. An analysis of errors in the latest (iML1515) model identified several vitamins/cofactors that are likely available to mutants despite being absent from the experimental growth medium and highlighted isoenzyme gene-protein-reaction mapping as a key source of inaccurate predictions. A machine learning approach further identified metabolic fluxes through hydrogen ion exchange and specific central metabolism branch points as important determinants of model accuracy. This work outlines improved practices for the assessment of GEM accuracy with high-throughput mutant fitness data and highlights promising areas for future model refinement in E. coli and beyond.