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Stereolithography Of Copper For 5G, 6G And Beyond
No full textNew mobile communication standards such as 5G, 6G and beyond require further miniaturisation of complex components such as waveguides or filters made of pure copper. Previous manufacturing methods for 3D components have reached their limits in terms of precision and productivity. As a new sinter-based additive process, lithography-based metal manufacturing (LMM) enables the economical and high-precision production of such components with structure widths of around 100 µm. Since only steels have been available in LMM so far, the material copper was developed for LMM for the first time in this work. The entire process chain from powder selection, paste formulation and printing process parameters to debinding and sintering was investigated. Special emphasis was focused on the achievable geometries and the material properties in order to achieve high purity, excellent debinding quality and high sintering density
Design Optimization by Virtual Prototyping Using Numerical Simulation to Ensure Thermomechanical Reliability in the Assembly and Interconnection of Electronic Assemblies
No full textA methodology is presented that allows the evaluation of the thermomechanical reliability of electronic packages using “virtual prototyping.” Here, a virtual flip chip ball grid array (FC-BGA) is examined in comparison to a reference chip scale package (CSP). The comparison is performed using finite element simulation. A combined measurement-simulation technique is used to calibrate the finite element simulations on a reference object. The adjustment is based on the in-plane deformation field obtained by both simulation and optical measurement. For the latter, an optical sensor is used for in-plane deformation and strain field analysis based on the gray-scale correlation method. The findings obtained can be extrapolated to alternative package types with different but similar design to evaluate their suitability for the desired application before physical fabrication.145
Evaluation and Selection of Supplier in Supply Chain with Fuzzy Analytical Network Process Approach
No full text6988One of the most important issues concerning the designing a supply chain is selecting the supplier. Selecting proper suppliers is one of the most crucial activities of an organization towards the gradual improvement and a promotion in performance. This intricacy is because suppliers fulfil a part of customer’s expectancy and selecting among them is multi-criteria decision, which needs a systematic and organized approach without which this decision may lead to failure. The purpose of this research is proposing a new method for assessment and rating the suppliers. We have identified several evaluation criteria and attributes; the selection among them was by the Simple Multi-Attribute Rating Technique (SMART) method, then we have specified the connection and the influence of the criteria on each other by DEMATEL method. After that, suppliers were graded by using the Fuzzy Analytical Network Process (FANP) approach and the most efficient one was selected. The innovation of this research is combining the SMART method, DEMATEL method, and Analytical Network Process in Fuzzy state which lead to more exact and efficient results which is proposed for the first time by the researchers of this study.2
Moving toward sustainable agriculture: The nexus between clean energy, ICT, human capital and environmental degradation under SDG policies in European countries
No full textThe United Nation's adaptation of the 2030 sustainable Development Goals (SDG) agenda has swung the attention toward sustainability. However, in achieving SDGs, this study investigates the nexus between agricultural productivity, renewable energy, ICT, human capital, CO2 emissions, and natural resources in a panel of ten European Union (EU) countries from 1996 to 2019. Our study uses the panel autoregressive distributed lag (ARDL) model of the Pool Mean Group (PMG) to estimate the long-run and short-run effects and heterogeneous causality approach. The empirical results ratify that a 1 % upsurge in the coefficient of renewable energy, ICT, and human capital increases agricultural productivity by 0.174 %, 0.030 %, and 2.158 % in the long run. Whereas, CO2 emission and natural resources decrease agricultural productivity. Finally, various causality exists among variables for EU countries. Our empirical results for the EU countries are notionally reliable and offer important policy implications accordingly.5
Impact of modularity as a circular design strategy on materials use for smart mobile devices
No full textThere is a huge variety of modular product designs for smartphones (concept studies, prototypes, products on the market), and a similarly high variety of circular economy aspects related to these different design approaches. Modularity requires initially more material input but pays off as the consumer is embracing the possibilities of modularity. Key materials for modularity features are gold, beryllium, and neodymium, etc. On the example of smartphones modularity as a strategy for circular design is analyzed in detail. Modularity of products is a design trend, which is supposed to facilitate reparability, recyclability, and/or upgradeability. However, modularity requires some design changes. The most evident design change is the need for connectors to provide mechanical and electrical contact between individual modules. Depending on the nature and use scenario of a connector reliability, robustness, wear resistance, and non-reactive surfaces are required. The paper explains different modularity approaches for smartphones, some of these being already available in the market, others are still in a conceptual phase. Analyzing technologies for modularity leads to a group of “modularity materials,” which are essential for such circular design approaches, but at the same time are among those materials with a large environmental footprint or limited recyclability. A life cycle assessment of a modular smartphone shows a roughly 10% higher environmental life cycle impact compared with a conventional design. This needs to be compensated by reaping the circular economy benefits of a modular design, i.e., higher likeliness of getting a broken device repaired, extending the lifetime through hardware upgrades and refurbishment.6
Development and characterization of precipitation hardening alloys in the Cu-Ni-Al system Entwicklung und Charakterisierung von ausscheidungshärtenden Legierungen im System Cu-Ni-Al
No full text3903937511-1
A semi-automated quality assurance tool for cardiovascular magnetic resonance imaging: application to outlier detection, artificial intelligence evaluation and trainee feedback
No full textBackground: Cardiovascular magnetic resonance (CMR) offers state-of-the-art volume, function, fibrosis and oedema imaging. Quality assurance (QA) tasks, such as quantitative parameter reproducibility assessments, the evaluation of AI methods, and the assessment of trainees have become essential to CMR. However, the explainability of how qualitative differences impact quantitative differences remains underexplored. Our aim is to demonstrate a semi-automated QA tool, Lazy Luna’s (LL) applicability to typical CMR QA application cases.
Methods: A software feature error-tracing is designed that allows for quickly pinpointing qualitative reasons for quantitative differences and outliers. Three QA application cases were designed. First, LL was applied to perform outlier detection for inter- and intraobserver analyses to detect failure cases and provide qualitative explanations. Outlier detection was performed on several typical images types. Second, LL supported an Artificial intelligence (AI) evaluation, in which an AI method was compared to a CMR-expert of 144 patients. LL assessed the acceptability of AI biases for left and right ventricular (LV, RV) end-systolic, -diastolic, and stroke volumes (ESV, EDV, SV), ejection fractions (EF) and the myocardial mass (LVM). Annotations were examined to explain the qualitative differences that resulted in good and poor parameters. The AI investigation was recorded as a video. Third, LL was used to provide a Trainee Feedback to a CMR beginner. The trainee was compared to an expert on several imaging techniques to investigate outliers.
Results: For the outlier detection, LL detected segmentation differences that caused parameter differences on multiple sequences. For the AI evaluation calculated clinical parameter biases to be: LVESV:-3.1 ml, LVEDV:2.1 ml, LVSV:6.5 ml, LVEF:3.0 ml, RVESV:0.3 ml, RVEDV:-3.8 ml, RVSV:-4.2 ml, RVEF:-1.4 ml, LVM:-2 g. Inspecting the causes for outlier differences revealed that juxtaposed basal slice failures caused unacceptable LVSV deviations between AI and expert. For the trainee assessment, LL showed that trainee parameters exceeded tolerance ranges. The segmentations could be improved to better mirror expert segmentations and close the parameter gaps.
Conclusion: Lazy Luna, as a semi-automated quality assurance tool, is applicable to several quality assurance application cases in CMR.25
Historical and future learning for the new era of multi-terawatt photovoltaics
No full text3846Solar photovoltaics (PV) is entering a new era of multi-terawatt deployment, with 2 TW already in service and more than 75 TW predicted in many scenarios by 2050. This next era has been enabled by over five decades of cumulative advances in PV module cost reduction, performance and reliability. The current scale of deployment also introduces new needs, opportunities and challenges. In this Perspective we frame a path forwards based on learning, broadly defined as a combination of expansion of knowledge and advances through research and development, experience and collaboration. We discuss historical topics where learning has driven PV deployment until now, and emerging areas that are required to sustain high levels of future deployment. We expect progress to continue in terms of module price, performance and reliability, driven by advances in PV cell and module design, the emergence of tandem devices and increased focus on extending module lifetimes. Large-scale deployment also means large-scale sustainability and responsibility. We therefore posit that additional metrics, such as the impact on global CO2 emissions, resource consumption and design for reuse and recycling, will become increasingly important to the PV industry and provide opportunities for further learning.1
5G New Radio in Nonlinear Satellite Downlink: A Physical Layer Comparison with DVB-S2X
No full text499504This paper assesses the 5G New Radio (NR) physical layer for satellite downlink transmission requiring power amplification (PA) with low backoff, thereby suffering significant nonlinear distortion. State-of-the-art single-carrier (SC) transmission used in satellite digital video broadcasting (DVB-S2X) is used as a baseline. Subject to nonlinear PA, out-of-band emissions, modulation quality, and degradation in block error rate performance are compared between data transmission with the DVB-S2X waveform and the 5G NR ones, namely, CP-OFDM (cyclic prefix orthogonal frequency-division multiplexing) and its transform-precoded SC variant called DFT-s-OFDM (discrete Fourier transform-spread OFDM)
Differential diagnosis between urticarial vasculitis and chronic spontaneous urticaria: An international Delphi survey
No full textBackground: Urticarial vasculitis (UV) should be differentiated from chronic spontaneous urticaria (CSU) in patients initially presenting with recurrent wheals, although criteria for differential diagnosis remain ill-defined. Objectives: To set the goals, define criteria and unmet needs in UV diagnosis and differential diagnosis with CSU, and explore the possibility of coexistence of both diseases. Methods: Thirteen experts experienced in UV research participated in a Delphi survey of European Academy of Allergy and Clinical Immunology taskforce. This Delphi survey involved three rounds of anonymous responses to n = 32 questions with the aim to aggregate the experts' opinions and to achieve consensus. Urticaria specialists (n = 130, most from Urticaria Centers of Reference and Excellence) evaluated the consensus statements and recommendations in the fourth and final round. Results: The panel agreed that essential criteria to guide a skin biopsy in patients with recurrent wheals should include at least one of the following features: wheal duration >24 h, bruising/postinflammatory hyperpigmentation, and systemic symptoms. Leukocytoclasia and fibrin deposits were identified as a minimum set of UV histological criteria. As agreed by the panel members, CSU and normocomplementemic UV (NUV) may coexist in some patients. Conclusions: The use of established criteria for the diagnosis and differential diagnosis of UV in patients with recurrent wheals can help guide the diagnostic approach and prompt earlier treatment. Further studies should investigate whether CSU and NUV are different entities or part of a disease spectrum.131