Machine Research Articles

Coupling adaptation mode and regulation strategy for the wind–thermal climate environment of vernacular dwellings in Jiangnan, China based on regional bioclimatic evaluation

ABSTRACT With the increasing reliance on mechanical devices and the diminishing connection with climate and region, architecture is falling into a paradigm of “isolation” from the environment. As native building types, vernacular dwellings present the mode of human – environment mutualism, which is an important reference for responding to low-carbon and sustainable development of buildings and reshaping regional architectural styles. This study choses vernacular dwellings in Jiangnan, China as the research objects, focusing on the wind – thermal climate environment coupling adaptation mode and regulation strategy under the hot-summer and cold-winter zone. First, by using bioclimatology methods, the theoretical range of passive climate control zones in Jiangnan area during the summer and winter seasons was anatomically analyzed with the actual range of passive climate conrrtrol zones of Jiangnan dwellings. Second, the wind-thermal climate adaptation mechanism was comprehensively interpreted from climatological situation, space configuring type, climate space gradient and climate regulation interface four perspectives. Finally, from the perspective wind – thermal environments are respectively synergistic and contradictory in summer and winter, the coupling adaptation mode and strategy of Jiangnan residential climate adaptation are proposed, as well as a passive building regulation paradigm for hot-summer and cold-winter climate type, which provides an important way to promote climate-responsive sustainable development.

Development of low-cost conventional milling fixture for micro-friction stir welding process

Fixtures are robust mechanical clamping devices used for precise machining. It is used to securely locate, hold and support the workpiece in a specific position during the machining operation. Fixtures for micro-friction stir welding (µFSW) are basically used to hold workpieces during welding operations. Using a conventional milling machine for µFSW operation with a simplified milling fixture is less expensive. This paper presents a simplified design of an adjustable milling fixture for µFSW, in which plates of different thicknesses can be welded. The low-cost fixture is designed using AutoCAD software, considering the transverse and lateral movement of tools and workpieces. Later, the developed milling fixture setup was tested in actual µFSW operations using the pinless tool of H13 material and 8 mm diameter. During operation, 0.8 mm thick Al6061-T6 plates were placed in lap and butt configuration and successful welding joints were obtained at a constant tool spinning speed of 2000 rpm and traverse speed of 100 mm/min. The maximum strength of the joint found 274.40 MPa for butt configuration and 201.25 MPa in lap configuration, which is about 87.34% and 64.10% of the parent material’s strength (314.19 MPa).

Intravascular lithotripsy in calcified left main coronary artery: Procedural success and 1-year clinical outcomes.

Intravascular lithotripsy (IVL) has an excellent efficacy and safety profile in the treatment of calcified coronary lesions during percutaneous coronary intervention (PCI). However, data regarding its use on left main (LM) lesions are still limited. We aimed to analyze the technical success and 1-year clinical outcomes in calcified LM lesions treated with IVL. Patients who underwent IVL from the ongoing prospective BENELUX registry were eligible for inclusion. Patients were divided into LM and non-LM groups based on the anatomical application of the IVL pulses. The primary technical endpoint was technical success, defined as the successful delivery of the IVL catheter across the target lesion, administration of IVL pulses without angiographic complications, and achieving a residual target lesion stenosis of less than 30 %. The primary safety endpoint was in-hospital major adverse cardiac events (MACE). The study included 509 patients (59 LM and 450 non-LM). Patients in the LM group were significantly older (79 years [75-82] vs. 73 years [68-81], p < 0.01). Left ventricular ejection fraction was slightly lower in the LM group (41 % [19-50] vs. 51 % [40-60], p = 0.053). Temporary mechanical circulatory support devices were more frequently used in the LM group, primarily as part of the "protected PCI" strategy (6.8 % in LM vs. 2.1 % in non-LM, p = 0.04). Technical success was comparable between the two groups (93.2 % in LM vs. 89.8 % in non-LM, p = 0.41). Cardiac death, MACE, and target vessel revascularization rates were also comparable at hospital discharge, 30 days, and 1-year follow-up. IVL in calcified LM lesions achieved comparable technical success and long-term clinical outcomes to non-LM lesions.

Venoarterial Membrane Oxygenation in Cardiogenic Shock Complicated from an Acute Myocardial Infarction: An Overview and Comprehensive Meta-Analysis.

Background: Cardiogenic shock remains a significant cause of mortality in patients with acute coronary syndrome, despite early interventions, such as coronary revascularization. Mechanical circulatory support devices, particularly venoarterial extracorporeal membrane oxygenation (VA-ECMO), are increasingly being utilized to address this issue. Limited randomized controlled trials (RCTs) exist to evaluate the efficacy of VA-ECMO in cardiogenic shock related to acute coronary syndrome. Methods: A meta-analysis was conducted to assess the effectiveness of VA-ECMO in adult patients with infarct-related cardiogenic shock. Trials were identified through database searches and selected based on specific inclusion criteria. The primary outcome was 30-day all-cause mortality, with secondary outcomes including bleeding and vascular complications. Results: A total of 24 studies met the inclusion criteria and were included in the meta-analysis, involving 4706 patients. The median age of the patients was 61.8 ± 4.1 years, with 76% of them being males. The analysis revealed that 30-day mortality rates for patients with cardiogenic shock receiving ECMO were still high, with a mortality of 63%. Vascular complications were identified as factors associated with a worse prognosis. Conclusions: The meta-analysis highlights the ongoing challenge of high mortality rates in cardiogenic shock patients despite the use of VA-ECMO. While VA-ECMO shows promise in providing circulatory support, further research is needed to explore ways to improve outcomes and reduce complications associated with the use of these devices. The complexity of patient management in cardiogenic shock cases underscores the need for a multidisciplinary approach to optimize treatment strategies and enhance patient outcomes.

Systemic Circulation in Advanced Heart Failure and Cardiogenic Shock: State-of-the-Art Review.

The integrative physiology of the left ventricle and systemic circulation is fundamental to our understanding of advanced heart failure and cardiogenic shock. In simplest terms, any increase in aortic stiffness increases the vascular afterload presented to the failing left ventricle. The net effect is increased myocardial oxygen demand and reduced coronary perfusion pressure, thereby further deteriorating contractile function. Although mechanical circulatory support devices should theoretically work in concert with guideline-directed medical therapy, cardiac resynchronization and inotropic and vasopressor agents designed to support myocardial performance and enhance left ventricle recovery, this does not always occur. Each therapy and intervention may result in vastly different and sometimes deleterious effects on vascular afterload. Although best described by a combination of both steady-state and pulsatile components, the latter is frequently overlooked when mean arterial pressure or systemic vascular resistance alone is used to quantify vascular afterload in advanced heart failure and cardiogenic shock. In this state-of-the-art review, we examine what is known about vascular afterload in advanced heart failure and cardiogenic shock, including the use of temporary and permanent mechanical circulatory support systems. Importantly, we outline 4 key components for a more complete assessment of vascular afterload. Unlike previous discussions on this topic, we set aside considerations of venous return and ventricular preload, as important as they are, to focus exclusively on the hydraulic load within the systemic circulation against which the impaired left ventricle must contract.

Preliminary development and evaluation of a mechanical handwriting assistive device to support individuals with movement disorders

Individuals with movement disorders often face challenges in writing independently due to factors such as spasticity, lack of precise motor control, muscle weakness, and tremors. This paper aims to develop a handwriting assistive device (HAD) for individuals with movement disorders, to stabilize the motion of user's hand, through initial needs assessment, iterative design, and a preliminary evaluation. The research is scoped to include only initial testing with a small user group, six potential users with movement disorders, providing foundational insights for future refinement. The findings from the initial needs assessment revealed that current assistive technologies do not fully meet handwriting challenges for individuals with motor impairments. The HAD prototype, developed with adjustable damping mechanism and customizable handles to suit different levels of motor control, enabled steadier handwriting in preliminary testing with six participants. Children drew shapes more accurately, and some traced letters they couldn't otherwise. The adult participant showed greater fluidity and legibility, completing tasks 4.81 times faster with the HAD. The qualitative feedback indicated the device's potential to enhance handwriting independence and usability across age groups. Future prospects for this study include developing an electronic version of the HAD, allowing real-time adjustable damping to better support users' voluntary movements while further stabilizing involuntary motions.

Research and application of bionic robotic arms

The research on bionic robotic arms originates from the aspiration to imitate and replicate the structure and functions of the human arm. With advancements in technology, particularly in the rapid development of robotics, sensor technology, and materials science, robust technical support has been provided for the study of bionic robotic arms. Additionally, as people's demands for a higher quality of life increase, so does the need for mechanical devices that can undertake arduous, hazardous, or high-precision tasks in place of humans. Especially in fields such as industrial production, healthcare, and military security, the research and application of bionic robotic arms have become a focal point in today's technological landscape. This article presents a comprehensive overview of the research background, development trajectory, and future prospects of three specific areas: flexible robotic arms for confined space operations, bionic robotic arms for rotorcraft, and bionic jellyfish robotic arms. The aim is to provide theoretical support and technical references for research and engineering applications in related fields

Implications of mechanical circulatory support devices in a pregnant woman with cardiogenic shock

Data on the use of mechanical circulatory support devices in pregnant women are limited. A 27-year-old woman at 27 weeks and 6 days of gestation was supported by three different mechanical circulatory support devices due to cardiogenic shock. She came into spontaneous labor, which was complicated by major hemorrhage at the cannulation site, fetal distress, and transverse position, requiring emergency cesarean section. The postpartum period was complicated by intra-abdominal bleeding and arterial occlusion of lower extremity. When using mechanical circulatory support devices in pregnant women, a multidisciplinary approach is recommended.

Thermal Characteristics Analysis and Experimental Study of Magnetic Fluid in Sealing Gap

The widespread application of magnetic fluid seals in mechanical devices highlights the significant impact of temperature on the stability of these sealing systems. This paper investigates the magnetic field characteristics and thermal properties of magnetic fluid in sealing devices through both numerical simulations and experimental methods. The effects of rotational speed, magnetic fluid solid content, and heating power on the magnetic fluid temperature of the magnetic sealing device were analyzed. The numerical simulation findings indicate that the viscosity the of magnetic fluid significantly contributes to enhanced energy dissipation, while the temperature of the magnetic fluid rises with increasing rotational speed. The initial-phase transition point of the magnetic fluid and its correlation with phase transition volume relative to shaft rotational speed was determined. The experimental results show that the magnetic fluid temperature rises continuously and the time to reach stability increases with the increase in power, and the same is true for the magnetic fluid with a different solid content. Under the same power, the temperature variation is not large, and the magneto-liquid variation is consistent with that in the numerical simulation. This research provides theoretical insights for designing magnetic fluid sealing devices.

Optimization of the Liquid Mixing Process in a Vertical Capacitative Apparatus with Mechanical Mixing Devices

Optimization of the Liquid Mixing Process in a Vertical Capacitative Apparatus with Mechanical Mixing Devices

Mechanical circulatory support: when, how, and for whom.

Cardiogenic shock represents a critical condition in which the heart is unable to maintain adequate circulation leading to insufficient tissue perfusion and end-organ failure. Temporary mechanical circulatory support offers the potential to stabilize patients, provide a bridge-to-recovery, provide a bridge-to-decision, or facilitate definitive heart replacement therapies. Although randomized controlled trials have been performed in infarct-related cardiogenic shock and refractory cardiac arrest, the optimal timing, appropriate patient selection, and optimal implementation of these devices remain complex and predominantly based on observational data and expert consensus, especially in non-ischaemic shock. This review explores the details of 'when, how, and for whom' temporary mechanical circulatory support devices should be used, examining specific clinical scenarios, the mechanisms by which they operate, and the patient populations that may benefit. The review also highlights the many gaps in evidence and need for better understanding of the interaction between human biology and these devices.

Mechanical Circulatory Support in Patients Without Cardiogenic Shock Undergoing Percutaneous Coronary Intervention.

The use of mechanical circulatory support devices for high-risk percutaneous coronary intervention (PCI) has increased over the past decade despite limited data of benefit. We sought to examine the association between intravascular microaxial left ventricular assist device (LVAD) versus intra-aortic balloon pump use in patients without cardiogenic shock (CS) undergoing PCI. This retrospective study analyzed claims data from a large, insured population who underwent PCI without CS from April 1, 2016 to July 31, 2022. Using inverse probability treatment weighting, we assessed for the association between device type and clinical outcomes. The primary outcome was all-cause mortality. Secondary outcomes included stroke, bleeding, incident dialysis, repeat revascularization, and total health care costs during the index admission and at 30 days. We identified 2879 patients without CS who underwent PCI with either an intra-aortic balloon pump or microaxial LVAD. The mean±SD age was 68.2±12.5 years, and 27% (n=764) were women. After propensity weighting, intravascular LVAD use was not associated with a significant difference in either in-hospital (odds ratio [OR] 1.30 [95% CI, 0.88-1.91]; P=0.19) or 30-day mortality (OR, 1.19 [95% CI, 0.84-1.69]; P=0.33) compared with intra-aortic balloon pump use. Compared with those receiving an intra-aortic balloon pump, the mean total costs for the index admission ($96 716 versus $71 892; P<0.001) and at 30 days (+$16 671 [95% CI, $6639-$28 103]; P=0.001) were significantly higher in those receiving an intravascular LVAD. There was no significant association between device type and stroke, bleeding, incident dialysis, and repeat revascularization at any time point (all P>0.05). In patients without CS undergoing PCI, intravascular LVAD use was associated with higher costs but not associated with lower mortality. Randomized data are needed to improve device selection for patients without CS undergoing PCI.

De Novo Assembly of the Polyhydroxybutyrate (PHB) Producer Azohydromonas lata Strain H1 Genome and Genomic Analysis of PHB Production Machinery.

Polyhydroxybutyrate (PHB) is a biodegradable natural polymer produced by different prokaryotes as a valuable carbon and energy storage compound. Its biosynthesis pathway requires the sole expression of the phaCAB operon, although auxiliary genes play a role in controlling polymer accumulation, degradation, granule formation and stabilization. Due to its biodegradability, PHB is currently regarded as a promising alternative to synthetic plastics for industrial/biotechnological applications. Azohydromonas lata strain H1 has been reported to accumulate PHB by using simple, inexpensive carbon sources. Here, we present the first de novo genome assembly of the A. lata strain H1. The genome assembly is over 7.7 Mb in size, including a circular megaplasmid of approximately 456 Kbp. In addition to the phaCAB operon, single genes ascribable to PhaC and PhaA functions and auxiliary genes were also detected. A comparative genomic analysis of the available genomes of the genus Azohydromonas revealed the presence of phaCAB and auxiliary genes in all Azohydromonas species investigated, suggesting that the PHB production is a common feature of the genus. Based on sequence identity, we also suggest A. australica as the closest species to which the phaCAB operon of the strain H1, reported in 1998, is similar.

Hybrid quantum neural networks: harnessing dressed quantum circuits for enhanced tsunami prediction via earthquake data fusion

Tsunami is one of the deadliest natural disasters which can occur, leading to great loss of life and property. This study focuses on predicting tsunamis, using earthquake dataset from the year 1995 to 2023. The research introduces the Hybrid Quantum Neural Network (HQNN), an innovative model that combines Neural Network (NN) architecture with Parameterized Quantum Circuits (PmQC) to tackle complex machine learning (ML) problems where deep learning (DL) models struggle, aiming for higher accuracy in prediction while maintaining a compact model size. The hybrid model’s performance is compared with the classical model counterpart to investigate the quantum circuit’s effectivity as a layer in a DL model. The model has been implemented using 2-6 features through Principle Component Analysis (PCA) method. HQNN’s quantum circuit is a combination of Pennylane’s embedding (Angle Embedding (AE) and Instantaneous Quantum Polynomial (IQP) Embedding) and layer circuits (Basic Entangler Layers (BEL), Random Layers (RL), and Strongly Entangling Layers (SEL)), along with the classical layers. Results show that the proposed model achieved high performance, with a maximum accuracy up to 96.03% using 4 features with the combination of AE and SEL, superior to the DL model. Future research could explore the scalability and diverse applications of HQNN, as well as its potential to address practical ML challenges.

Innovative lightweight flexibility test platform for RV reducer with topology optimization and 3-D printing

Abstract The majority of existing mechanical devices are only capable of measuring a single parameter. They are constructed primarily from metal processing, resulting in a substantial weight, elevated manufacturing costs, and a fixed and inflexible accuracy and assembly methodology. Accordingly, this paper presents the design of a lightweight RV reducer test platform, which enhances the flexibility of high-precision measurement. The test platform employs topology optimization lightweight structure design and 3D printing technology. Static simulation is used to lightweight the structure and add an adjustable structure. It significantly reduces cost and weight while having an adjustable self-connection structure and a wide range of application scenarios. It improves the flexibility of high-precision measurement while ensuring sufficient strength. In order to verify the measurement performance of the platform, the wavelet threshold method with excellent denoising effect was used to analyze the acceleration power spectral density of each part of the test platform at different rotation speeds. The results show that the wavelet threshold method could effectively filter noise and extract key experimental data. The accelerometer results show that the test bench has superior stability at both 0.5 r min−1 and 120 r min−1 speeds, and has practical application value. The simulation also verifies that the test platform has sufficient rigidity to meet the working conditions.

Design and Development of Green Trash Compactor for Recyclable Waste Management

A trash compactor is a mechanical device invented to reduce the volume of trash, making it suitable for use in various scenes such as domestic, public, and industries. Utilizing this kind of machine provides significant benefits in the waste accumulation system, as it allows for more efficient waste management by compacting the trash, enabling larger quantities to be collected at once. In this study, a Green Trash Compactor is designed and developed as an innovative semi-automated machine to efficiently reduce the size and volume of recyclable materials such as plastics, paper cups, and PET bottles. The project focuses on optimizing the sensor layout to minimize the impact during the compaction process, thereby reducing the requirement for heavy load cells or weight sensors. The working output is achieved by recording different input commands through buttons, where the system employs load cells to identify the detected force, and the microcontroller makes corresponding decisions. The results indicated that the Green Trash Compactor successfully operated with its mechanical and programmed codes, demonstrating impressive volume reduction during the compaction process. This substantial reduction in volume contributes to lowering transportation costs for the trash, making the compactor a highly efficient waste management solution.

A Methodology for Rapid Deployment of Diagnostic Applications for Human Gait &amp;amp; Posture Analysis and Exoskeleton Configurations, Combining AI with a Biomimetic Rig

Research has shown that certain simple, yet valuable gait and posture diagnostic tests can be conducted without the involvement of human experts using optical detection software employing Artificial Intelligence (AI), either on par with some physicians or, in some cases, even better in terms of availability, productivity, ease, and cost. The purpose of the current paper is to propose a methodology that uses dedicated AI models for partial body frames instead of full-body pose trackers. To achieve this, we obtain training dataset (photos/ videos) using a biomimetic rig instead of humans. In this research, we also study existing applications using already available AI pose trackers, their methodology, limitations regarding partial body views, and limitations in detecting mechanical devices and systems. Finally, to support our study, we present stand2squatAI_biorig software as an example of an AI-automated, diagnostic, real-time test that does not require physicians to complete the examination. We developed this software as a proof-of-concept to illustrate the proposed methodology and confirm our findings. Software applications developed in this manner can be used to study and diagnose various human conditions. The value of the proposed approach, which includes a biomimetic rig, is that it increases precision, reduces costs, and increases human safety; for example, during the application of mechanical aids while ensuring personal data privacy and overcoming ethical issues. Received: 16 June 2024 | Revised: 20 September 2024 | Accepted: 16 October 2024 Conflicts of Interest The authors declare that they have no conflicts of interest to this work. Data Availability Statement The Teachable machine AI model used in this study is openly available in figshare at http://doi.org/10.6084/m9.figshare.27894876. Author Contribution Statement Christos Kampouris: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation, Writing – original draft, Writing – review &amp; editing, Visualization, Project administration, Funding acquisition. Philip Azariadis: Supervision.

A Methodology for Rapid Deployment of Diagnostic Applications for Human Gait &amp;amp; Posture Analysis and Exoskeleton Configurations, Combining AI with a Biomimetic Rig

Research has shown that certain simple, yet valuable gait and posture diagnostic tests can be conducted without the involvement of human experts using optical detection software employing Artificial Intelligence (AI), either on par with some physicians or, in some cases, even better in terms of availability, productivity, ease, and cost. The purpose of the current paper is to propose a methodology that uses dedicated AI models for partial body frames instead of full-body pose trackers. To achieve this, we obtain training dataset (photos/ videos) using a biomimetic rig instead of humans. In this research, we also study existing applications using already available AI pose trackers, their methodology, limitations regarding partial body views, and limitations in detecting mechanical devices and systems. Finally, to support our study, we present stand2squatAI_biorig software as an example of an AI-automated, diagnostic, real-time test that does not require physicians to complete the examination. We developed this software as a proof-of-concept to illustrate the proposed methodology and confirm our findings. Software applications developed in this manner can be used to study and diagnose various human conditions. The value of the proposed approach, which includes a biomimetic rig, is that it increases precision, reduces costs, and increases human safety; for example, during the application of mechanical aids while ensuring personal data privacy and overcoming ethical issues. Received: 16 June 2024 | Revised: 20 September 2024 | Accepted: 16 October 2024 Conflicts of Interest The authors declare that they have no conflicts of interest to this work. Data Availability Statement The Teachable machine AI model used in this study is openly available in figshare at http://doi.org/10.6084/m9.figshare.27894876. Author Contribution Statement Christos Kampouris: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation, Writing – original draft, Writing – review &amp; editing, Visualization, Project administration, Funding acquisition. Philip Azariadis: Supervision.

Boundaries and cross-linking densities modulate domain sizes of polydomain nematic elastomers.

When nematic liquid crystal elastomers (LCEs) crosslinked at their isotropic phase are quenched to the nematic phase, they show polydomain patterns, in which nematic microdomains with different orientations self-organize into a three-dimensional mosaic with characteristic correlation patterns. The orientational correlation length of the domain, which is usually in the micrometer range, is believed to emerge as a result of a competition between liquid crystalline ordering and frozen network inhomogeneity. Although polydomain patterns show potentials as the basic platform for optical, memory, and mechanical devices, no study exists regarding how they are modulated by experimentally accessible parameters. Here, using confocal polarized fluorescence microscopy, we study the effects of a solid-wall or open boundary on the domain size in conjunction with effects of cross-linking density. The LCE bounded by solid glass shows reduced domain size near the boundary. In contrast, increased domain size appears at the free surface. With increasing cross-linking density, the domain size decreases, also exhibiting the boundary effects. Guided by theoretical considerations, the results are explained by a picture that the effective strength of the inhomogeneity frozen in the polymer network, i.e., the effective disorder strength, varies depending on the cross-linking density and constrained states at boundaries. The results offer the first experimental approach to global and local modulation of the polydomain pattern in nematic LCEs.

Plugging synthetic DNA nanoparticles into the central dogma of life.

Synthetic DNA nanotechnology has emerged as a powerful tool for creating precise nanoscale structures with diverse applications in biotechnology and materials science. Recently, it has evolved to include gene-encoded DNA nanoparticles, which have potentially unique advantages compared to alternative gene delivery platforms. In exciting new developments, we and others have shown how the long single strand within DNA origami nanoparticles, the scaffold strand, can be customized to encode protein-expressing genes and engineer nanoparticles that interface with the transcription-translation machinery for protein production. Remarkably, therefore, DNA nanoparticles - despite their complex three-dimensional shapes - can function as canonical genes. Characteristics such as potentially unlimited gene packing size and low immunogenicity make DNA-based platforms promising for a variety of gene therapy applications. In this review, we first outline various techniques for the isolation of the gene-encoded scaffold strand, a crucial precursor for building protein-expressing DNA nanoparticles. Next, we highlight how features such as sequence design, staple strand optimization, and overall architecture of gene-encoded DNA nanoparticles play a key role in the enhancement of protein expression. Finally, we discuss potential applications of these DNA origami structures to provide a comprehensive overview of the current state of gene-encoded DNA nanoparticles and motivate future directions.