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Abstract Background Butane is an aliphatic hydrocarbon used in various commercial products. While numerous reports of sudden cardiac-related deaths from butane inhalation have been described, butane-associated acute encephalopathy has rarely been reported. Case presentation A 38-year-old man presented with cognitive dysfunction after butane gas inhalation. Neuropsychological test results showed impairments in verbal and visual memory, and frontal executive function. Diffusion weighted MRI revealed symmetric high-signal changes in the bilateral hippocampus and globus pallidus. FDG-PET demonstrated decreased glucose metabolism in the bilateral precuneus and occipital areas and the left temporal region. At the 8-month follow-up, he showed still significant deficits in memory and frontal functions. Diffuse cortical atrophy with white matter hyperintensities and extensive glucose hypometabolism were detected on follow-up MRI and FDG-PET, respectively. Brain autopsy demonstrated necrosis and cavitary lesions in the globus pallidus. Conclusions Only a few cases of butane encephalopathy have been reported to date. Brain lesions associated with butane encephalopathy include lesions in the bilateral thalamus, insula, putamen, and cerebellum. To the best of our knowledge, this is the first report on bilateral hippocampal and globus pallidal involvement in acute butane encephalopathy. The pathophysiology of central nervous system complications induced by butane intoxication is not yet fully understood. However, the direct toxic effects of butane or anoxic injury secondary to cardiac arrest or respiratory depression have been suggested as possible mechanisms of edematous changes in the brain after butane intoxication.

This study experimentally investigates the integration of Fe-Co-Al @ BTC Metal-Organic Framework (MOF) into a double slope solar still (DSSS) to enhance the evaporation rate. Three configurations were tested: MOF as a nanofluid in the basin water (Case I), MOF as a nanofluid with an atomizer (Case II), and MOF for thin film evaporation (Case III). A comprehensive 4E analysis—Energy, Exergy, Economic, and Environmental—evaluated the performance of the DSSS relative to conventional solar still (CSS). The MOF improved DSSS performance through its superior thermal properties and large surface area. Performance results showed notable improvements. Energy efficiency increased significantly, with Case III improving by 103 %, Case II by 82.3 %, and Case I by 53.3 %. Exergy efficiency witnessed more dramatic enhancements, with Case III rising by 162 %, Case II by 137 %, and Case I by 70.6 %. Accumulated distillate followed a similar pattern, with Case III rising by 92.12 %, Case II by 68.54 %, and Case I by 34.66 %. Case III demonstrated the most promising outcomes, achieving the lowest freshwater cost at 0.0122 $/L—a 26.22 % reduction from CSS. Additionally, the MOF integration resulted in CO2 mitigation ranging from 1.49 to 2.2 tons annually, generating carbon credits between 37.13 and 54.94 $/year.

This paper represents an endeavor to review the advancements achieved in the topic of coupled radiation-free convection (CRFC) across various investigated models. Through detailed bibliometric analysis, the paper not only underscores the importance of CRFC publications but also highlights their frequency, signaling an increasing interest and significant contributions in this domain. The literature review is systematically structured, categorizing studies based on the types of cavities/enclosures with or without internal heating sources, thereby providing a comprehensive and structured overview of this field. It then delves into the crux of CRFC, giving the governing equations, assumptions, parameters, and variables, establishing a robust knowledge. Transitioning seamlessly to application, the paper explores simulated models, boundary conditions, and insightful result discussions. Notably, the proven influence of surface thermal radiation in enhancing free convection heat transfer throughout the reviewed studies underscores CRFC's transformative potential, paving the path for innovative advancements in thermal engineering systems.

The availability of carbon nanotube (CNT)-based polymer composites allows the development of surface-attached self-sensing crack sensors for the structural health monitoring of reinforced concrete (RC) structures. These sensors are fabricated by integrating CNTs as conductive fillers into polymer matrices such as polyurethane (PU) and can be applied by coating on RC structures before the composite hardens. The principle of crack detection is based on the electrical change characteristics of the CNT-based polymer composites when subjected to a tensile load. In this study, the electrical conductivity and electro-mechanical/environmental characterization of smart skin fabricated with various CNT concentrations were investigated. This was performed to derive the tensile strain sensitivity of the smart skin according to different CNT contents and to verify their environmental impact. The optimal CNT concentration for the crack detection sensor was determined to be 5 wt% CNT. The smart skin was applied to an RC structure to validate its effectiveness as a crack detection sensor. It successfully detected and monitored crack formation and growth in the structure. During repeated cycles of crack width variations, the smart skin also demonstrated excellent reproducibility and electrical stability in response to the progressive occurrence of cracks, thereby reinforcing the reliability of the crack detection sensor. Overall, the presented results describe the crack detection characteristics of smart skin and demonstrate its potential as a structural health monitoring (SHM) sensor.

Traffic accidents caused by road icing are a serious global problem, and conventional de-icing methods like spraying chemicals have several limitations, including excessive manpower management, road damage, and environmental pollution. In this study, the carbon nanotubes reinforced de-icing coating for the road system with a self-heating function was developed as part of the development of a new system to prevent accidents caused by road icing. The electrical characteristics of the fabricated coating were analyzed, and the carbon nanotube coating heating performance experiment was conducted to measure the temperature increments by applying a voltage to the coating at a sub-zero temperature using an environmental chamber. In addition, the coating was installed on the road pavement and the applicability was investigated through a heating test in winter. As a result of the experiment, the coating made with the higher carbon nanotube concentration presented higher heating owing to its higher electrical conductivity. In addition, the coating showed sufficient heating performance, although the maximum temperature by Joule heating decreased for the entire coating at sub-zero temperatures. Finally, field tests demonstrated the potential of electrically conductive coatings for de-icing applications.

Passive wireless sensing systems, particularly passive antenna sensors, offer a viable alternative to traditional wired and active sensors for long-term structural health monitoring due to their simplicity, easy installation and maintenance, and ability to measure strain without an external power supply. Customization of antenna shape can also adapt to various structural geometries. However, sensor fabrication using chemical etching is expensive and time-consuming, which is unsuitable for limited-quantity production. To address this, this study explores the potential of extrusion-based additive manufacturing to produce cost-effective passive wireless antenna strain sensors. The study investigates polylactic acid’s mechanical and electromagnetic properties for substrate design and uses multi-physics simulation to estimate strain-sensing performance. The obtained results show similar strain-sensing performance to sensors produced through chemical etching, making the manufacturing process a promising alternative.

In the construction and machinery industry, heat is a major factor causing damage and destruction. The safety and efficiency of most machines and structures are greatly affected by temperature, and temperature management and control are essential. In this study, a carbon nanotube (CNT) based temperature sensing coating that can be applied to machines and structures having various structural types was fabricated, and characteristics analysis and temperature sensing performance were evaluated. The surface coating, which detects temperature through resistance change is made of a nanocomposite composed of carbon nanotubes (CNT) and epoxy (EP). We investigated the electrical properties by CNT concentration and temperature sensing performance of CNT/EP coating against static and cyclic temperatures. In addition, the applicability of the CNT/EP coating was investigated through a partially heating and cooling experiment. As a result of the experiment, the CNT/EP coating showed higher electrical conductivity as the CNT concentration increased. In addition, the CNT/EP coating exhibits high sensing performance in the high and sub−zero temperature ranges with a negative temperature coefficient of resistance. Therefore, the proposed CNT/EP coatings are promising for use as multi-functional coating materials for the detection of high and freezing temperatures.

Exactly 50 years ago, the first article on electrochromism was published. Today electrochromic materials are highly popular in various devices. Interest in nanostructured electrochromic and nanocomposite organic/inorganic nanostructured electrochromic materials has increased in the last decade. These materials can enhance the electrochemical and electrochromic properties of devices related to them. This article describes electrochromic materials, proposes their classification and systematization for organic inorganic and nanostructured electrochromic materials, identifies their advantages and shortcomings, analyzes current tendencies in the development of nanomaterials used in electrochromic coatings (films) and their practical use in various optical devices for protection from light radiation, in particular, their use as light filters and light modulators for optoelectronic devices, as well as methods for their preparation. The modern technologies of “Smart Windows”, which are based on chromogenic materials and liquid crystals, are analyzed, and their advantages and disadvantages are also given. Various types of chromogenic materials are presented, examples of which include photochromic, thermochromic and gasochromic materials, as well as the main physical effects affecting changes in their optical properties. Additionally, this study describes electrochromic technologies based on WO3 films prepared by different methods, such as electrochemical deposition, magnetron sputtering, spray pyrolysis, sol–gel, etc. An example of an electrochromic “Smart Window” based on WO3 is shown in the article. A modern analysis of electrochromic devices based on nanostructured materials used in various applications is presented. The paper discusses the causes of internal and external size effects in the process of modifying WO3 electrochromic films using nanomaterials, in particular, GO/rGO nanomaterials.

A novel multi-functional road surface system is designed to improve safety, the efficiency of traffic flow, and environmental sustainability for future transportation systems. The surface coating, preforming temperature detection with heating element and hydrophobic features, were fabricated with a nanocomposite consisting of carbon nanotube (CNT) modified polyurethane (PU). The CNT/PU coating showed higher electrical conductivity as well as enhanced hydrophobic properties as the CNT concentration increased. The multifunctional properties of CNT/PU coatings were investigated for use in freezing temperature sensing and heating. The CNT/PU coatings showed high temperature sensitivity in the freezing temperature range with a negative temperature coefficient of resistance. In addition, the CNT/PU coatings had excellent heating performance due to the Joule heating effect. Therefore, the proposed CNT/PU coatings are promising for use as multifunctional road coating materials for detection of freezing temperature and deicing by self-heating.

Background: Cerebral embolism in patients with non-valvular atrial fibrillation (NVAF) is mainly caused by thrombus formation in the left atrial appendage. D-dimer is known to reflect the thrombogenic activity of the left atrium in NVAF patients. This study aimed to investigate the relationship between D-dimer levels and infarct pattern in ischemic stroke patients with NVAF. Methods: We enrolled 255 patients who developed cardioembolic stroke caused by NVAF and presented to the hospital within 7 days. We divided the infarct pattern into two groups: single lesions (SL) and multiple lesions (ML). The infarct pattern was also classified into two groups: ischemic lesions involving a single vascular territory (ST) and multiple vascular territories (MT). We analyzed the relationship between the infarct pattern and D-dimer levels. Results: Of the 255 patients, 79 (31.0%) and 176 (69.0%) were in the SL and ML groups, respectively. In addition, 207 (81.2%) and 48 (18.8%) patients were classified into the ST and MT groups, respectively. Compared with the SL group, a higher D-dimer level was observed in the ML group (p=0.006). Similarly, the MT group had higher D-dimer levels than the ST group (p=0.001). Logistic regression analysis showed that elevated D-dimer levels were significantly and independently associated with the presence of multiple ischemic lesions (p=0.021) and the involvement of multiple vascular territories (p=0.020). Conclusions: This study showed that elevated D-dimer levels were independently associated with multiple ischemic lesions involving multiple vascular territories in ischemic stroke patients with NVAF. [ABSTRACT FROM AUTHOR]

Global warming, one of the most serious aspects of climate change, can be expected to cause rising sea levels. These, in turn, have been linked to unprecedentedly large typhoons that can cause flooding of low-lying land, coastal invasion, seawater flows into rivers and groundwater, rising river levels, and aberrant tides. To prevent loss of life and property damage caused by typhoons, it is crucial to accurately estimate storm surge related risk. This study therefore develops a statistical model for estimating probability model, based on surge data pertaining to Typhoon Maemi, which struck South Korea in 2003. Specifically, estimation of non-exceedance probability models of the typhoon-related storm surge was achieved via clustered separated peaks-over-threshold simulation, while various distribution models were fitted to the empirical data for investigating the risk of storm surge height. The result of this process found that the result of Weibull distribution was better than other distribution model for Typhoon Maemi's peak total water level. [ABSTRACT FROM AUTHOR]

Carbon nanotube-reinforced polymer composites were fabricated by high shear mixing. The microstructure and the electrical properties of the carbon nanotube--polymer composites were investigated by scanning electron microscopy and electrical resistance measurement. We found that the carbon nanotube composites showed high electrical conductivity (1.5 S m-1) at 7.0 wt% of carbon nanotubes, and the increase in thickness enhanced the electrical conductivity of the composites. The multifunctional properties of the carbon nanotube composites were also investigated for use in sensing the freezing temperature and also in deicing by self-heating. The results showed that the carbon nanotube--polymer composites had high temperature sensitivity in the freezing temperature range from -5 to 5 C and an excellent heating performance due to the Joule heating effect. The carbon nanotube composites are promising to be used as smart coating materials for deicing by self-heating as well as by detection of the freezing temperature. [ABSTRACT FROM AUTHOR]

This article presents a soft pneumatic bending actuator using a magnetically assisted bilayer composite composed of silicone polymer and ferromagnetic particles. Bilayer composites were fabricated by mixing ferromagnetic particles to a prepolymer state of silicone in a mold and asymmetrically distributed them by applying a strong non-uniform magnetic field to one side of the mold during the curing process. The biased magnetic field induces sedimentation of the ferromagnetic particles toward one side of the structure. The nonhomogeneous distribution of the particles induces bending of the structure when inflated, as a result of asymmetric stiffness of the composite. The bilayer composites were then characterized with a scanning electron microscopy and thermogravimetric analysis. The bending performance and the axial expansion of the actuator were discussed for manipulation applications in soft robotics and bioengineering. The magnetically assisted manufacturing process for the soft bending actuator is a promising technique for various applications in soft robotics. [ABSTRACT FROM AUTHOR]

Multifunctional polymer-based composites have been widely used in various research and industrial applications, such as flexible and stretchable electronics and sensors and sensor-integrated smart structures. This study investigates the influence of particle coalescence on the mechanical and electrical properties of spherical nickel powder (SNP)/polydimethylsiloxane (PDMS) composites in which SNP was aligned using an external magnetic field. With the increase of the volume fraction of the SNP, the aligned SNP/PDMS composites exhibited a higher tensile strength and a lower ultimate strain. In addition, the composites with aligned SNP showed a lower percolation threshold and a higher electrical conductivity compared with those with randomly dispersed SNP. However, when the concentration of the SNP reached a certain level (40 vol. %), the anisotropy of the effective material property became less noticeable than that of the lower concentration (20 vol. %) composites due to the change of the microstructure of the particles caused by the coalescence of the particles at a high concentration. This work may provide rational methods for the fabrication of aligned composites. [ABSTRACT FROM AUTHOR]

Given the continued challenge of dispersion, for practical purposes, it is of interest to evaluate the impact of multi-walled carbon nanotubes (MWCNTs) at different states of clustering on the eventual performance properties of cement paste. This study evaluated the clustering of MWCNTs and the resultant effect on the mechanical and electrical properties when incorporated into cement paste. Cement pastes containing different concentrations of MWCNTs (up to 0.5% by mass of cement) with/without surfactant were characterized. MWCNT clustering was assessed qualitatively in an aqueous solution through visual observation, and quantitatively in cement matrices using a scanning electron microscopy technique. Additionally, the corresponding 28-day compressive strength, tensile strength, and electrical conductivity were measured. Results showed that the use of surfactant led to a downward shift in the MWCNT clustering size distribution in the matrices of MWCNT/cement paste, indicating improved dispersion of MWCNTs. The compressive strength, tensile strength, and electrical conductivity of the composites with surfactant increased with MWCNT concentration and were higher than those without surfactant at all concentrations. [ABSTRACT FROM AUTHOR]

We investigated the acoustic performance of electrostatic sound-generating devices consisting of bi-layer graphene on polyimide film. The total sound pressure level (SPL) of the sound generated from the devices was measured as a function of source frequency by sweeping, and frequency spectra were measured at 1/3 octave band frequencies. The relationship between various operation conditions and total SPL was determined. In addition, the effects of changing voltage level, adding a DC offset, and using two pairs of electrodes were evaluated. It should be noted that two pairs of electrode operations improved sound generation by about 10 dB over all frequency ranges compared with conventional operation. As for the sound-generating capability, total SPL was 70 dBA at 4 kHz when an AC voltage of 100 Vpp was applied with a DC offset of 100 V. Acoustic characteristics differed from other types of graphene-based sound generators, such as graphene thermoacoustic devices and graphene polyvinylidene fluoride devices. The effects of diameter and distance between electrodes were also studied, and we found that diameter greatly influenced the frequency response. We anticipate that the design information provided in this paper, in addition to describing key parameters of electrostatic sound-generating devices, will facilitate the commercial development of electrostatic sound-generating systems. [ABSTRACT FROM AUTHOR]

The electrical characteristics of NAND flash memories with an asymmetric interpoly-dielectric (IPD) structure and a conventional IPD structure were simulated by using a technology computer-aided sentaurus simulation tool to enhance their device performance. The floating gate potential and the on-current level of the NAND memory devices with an asymmetric IPD structure were higher than those with a conventional IPD structure. The maximum electric field formed at the rounding boundary area of the floating gate and the blocking oxide layer in an asymmetric IPD structure was 34% smaller than that in a conventional IPD structure. The trapped charges in the floating gate layer of NAND flash memories with an asymmetric IPD structure increased owing to an increase in the saturation voltage during programming and erasing operation. [ABSTRACT FROM AUTHOR]

As the shrinkage of devices accelerates and the vertical layers increase, beam angle spread of carbon ion implantation (C IIP) for the silicon selective epitaxial growth (Si-SEG) areas in V-NAND is one of the most critical parameters related with bin map defects. The roles of C IIP in Si-SEGs are that it can suppress channeling effect of boron IIP and diffusion limitation of boron dopants during subsequent annealing processes. In this study, beam angle spread was reduced by 36% and the center-to-edge beam angle skew of wafer was reduced to less than 1° by optimizing the specification of tracking magnet and the beam angle mean. After applying the improved process conditions and effective interlocks, the bin defective rate was controlled less than 0.5% successfully.