Harsh Conditions Research Articles

Temporal-enhanced Radar and Camera Fusion for Object Detection

Recently, object detection methods based on multimodal fusion have gained widespread adoption in autonomous driving, proving to be valuable for detecting objects in dynamic environments. Among them, millimetre wave (mmWave) radar is commonly utilized as an effective complement to cameras, as it is almost unaffected by harsh weather conditions. However, current approaches that fuse mmWave radar and camera often overlook the correlation between the two modalities, failing to fully exploit their complementary features. To address this, we propose a temporal-enhanced radar and camera fusion network to explore the correlation between these two modalities and learn a comprehensive representation for object detection. In our model, a temporal fusion model is introduced to fuse mmWave radar features from different moments, thus mitigating the problem of mmWave radar point-object mismatch due to object movement. Moreover, a new correlation-based fusion strategy using the dedicated mask cross attention is proposed to fuse mmWave radar and vision features more effectively. Finally, we design a gate feature pyramid network that selects shallow texture information based on deep semantic information to obtain more representative features. The experimental results on the nuScenes benchmark demonstrate the effectiveness of our proposed method.

Fluorescent Protein PEGylation for Stable Photon Manipulation in Deep‐Red Light‐Emitting Devices

AbstractPEGylation is a classic strategy to reduce denaturation and immunogenicity in therapeutic proteins, bioimaging, and drug delivery. However, this concept has not been applied to incorporate biogenic materials as functional components in optoelectronics. Herein, PEGylation is rationalized as an effective tool to stabilize fluorescent proteins in solid‐state photon manipulation down‐converters integrated into bio‐hybrid light‐emitting diodes. In short, the archetypal red‐emitting protein mCherry is nonspecifically PEGylated with methoxypolyethylene glycols (mPEG) chains of different lengths (mPEG‐350/‐750/‐2000). These derivatives hold the same photoluminescence figures‐of‐merit of mCherry, but an improved resistance against organic solvents, pH, temperature, and polymers (in solution/dry‐coatings) upon increasing the mPEG length. Indeed, the best‐performing mCherry‐mPEG‐2000 adduct leads to deep‐red devices with threefold enhanced color stability (>300 h) under harsh operation conditions (150 mW cm−2) over the prior art. Different device architectures along with spectroscopic, thermocycling, and electrochemical impedance spectroscopy studies of the prepared coatings aid in rationalizing that PEGylation successfully reduces i) nonreversible thermal denaturation, ii) aggregation in solid‐state, and iii) photo‐induced oxidation and H+‐transfer deactivation of the chromophore, since oxygen diffusivity and H+‐reorganization across the protein skeleton are slowed down by strong H+‐bonding/hydrophobic mCherry‐mPEG interactions. Hence, this simple supramolecular modification is of utmost relevance for future advances in protein‐based optoelectronics.

ENHANCING MECHANICAL RELIABILITY OF SILVER SINTERED JOINTS WITH COPPER NANOWIRES IN HIGH-POWER ELECTRONIC DEVICES

Abstract This study investigated the mechanical reliability of silver-sintered die attachment under harsh operating conditions, and explored the advantages of adding copper nanowires to improve the bond's mechanical properties. Samples were prepared using a template-assisted electrochemical deposition process to coat the substrate surface with copper nanowires, and were subjected to thermal aging at various temperatures to assess their mechanical reliability. Results showed that the incorporation of copper nanowires in the substrate interface significantly reduced degradation in shear strength as a result of thermal aging, acting as mechanical reinforcement and improving the interfacial resilience against mechanical shear stress. The addition of copper nanowires also reduced the void formation in the thermal aging, resulting in a more robust and reliable bond. The study demonstrates the potential of using copper nanowires as a reinforcing agent to enhance the mechanical properties of silver-sintered die attachment, particularly for high-temperature applications.

Intergenerational Conflict in Contemporary Cuba: Rivalry within Las Congas Santiagueras

The current article reflects on the topic of intergenerational conflict between those Cubans who lived closer to the beginning of the Castro-led Revolution of 1959, and those who were born closer to the beginning of the 1990s, during the fall of the Soviet Union, now referred to as the Special Period in the Time of Peace. In the documentary Lázaro and the Shark: Cuba under the Surface (2022), Cuban exile director William Sabourin O'Reilly showcases this national conflict. Through the screen, O’Reilly highlights the beauty of the Afro-influence combined with the intimate and lively rivalry between Santiago’s local Conga groups in a country riddled by harsh conditions to dive deeper into the ever-growing intergenerational conflict. Within this current conflict, Cuba’s generations are separated into Fidelists and Oppositionalists; in opposition to the Pragmatist and the Disengaged generation (Krull and Kobayashi). With recent restrictive legislation for Cuban filmmakers, the director’s ability to make a controversial documentary of this nature is only possible from outside of Cuba as an exile.

An Improved Synthesis of 2,3-Diamino-5,6-dichloropyrazine: A Useful Heterocyclic Scaffold

Abstract2,3-Diamino-5,6-dichloropyrazine represents a valuable but underexplored heterocyclic building block. Due to the use of harsh conditions and lack of selectivity surrounding the known literature synthesis, we developed a more accessible and selective three-step route from 2-aminopyrazine. Challenging conditions are avoided by using a high-yielding dichlorination with N-chlorosuccinimide (NCS), which is followed by a regioselective amination. The installation of the last chlorine atom using 1-chloro-1,2-benziodoxol-3(1H)-one is rapid, enabling access to 2,3-diamino-5,6-dichloropyrazine in an improved overall yield (41%).

Autophagy Blockage Enhancing Photothermal and Chemodynamic Synergistic Therapy Based on HCQ/CuS Nanoplatform.

As an intracellular protective mechanism, autophagy has the potential to significantly impair the therapeutic effects of photothermal therapy (PTT) and chemodynamic therapy (CDT), which helps cancer cells survive under harsh conditions, such as high temperature and reactive oxygen species (ROS). In this study, an autophagy blockage enhanced PTT and CDT synergistic therapy nanoplatform is constructed by loading hydroxychloroquine (HCQ) with autophagy inhibitory effect into hollow copper sulfide (HCuS). Specifically, HCuS produces toxic ROS through Fenton-like reaction in the tumor microenvironment (TME). At the same time, PTT-mediated temperature elevation of the tumor region accelerates the Fenton-like reaction and ROS production, enhancing the therapeutic effect of CDT. Furthermore, the internal autophagy inhibitor HCQ significantly blocks the fusion of autophagosomes and lysosomes by deacidifying lysosomes, cutting off the self-protection mechanism of cancer cells, and amplifying the combined treatment of PTT and CDT. Both in vitro and in vivo results demonstrate that the combination of photothermal-enhanced chemodynamic therapy with inhibition of autophagy provides new insights into designing multifunctional therapeutic nanoagents.

Circumferential Crack Detection in Ultra-High-Pressure Tubular Reactors with Pulsed Eddy Current Testing.

Ultra-high-pressure tubular reactors are crucial pieces of equipment for polyethylene production. Long-term operation under high temperature, high pressure, and other extremely harsh conditions can lead to various defects, with circumferential cracks posing a major safety risk. Detecting cracks is challenging, particularly when they are under a protective layer of a certain thickness. This study designed a pulsed eddy current differential probe to detect circumferential cracks in ultra-high-pressure tubular reactors, with the lift-off distance acting as a protective layer. Detection models for traditional cylindrical and semi-circular excitation differential probes were established using finite element simulations. Corresponding experiments under different lift-off conditions were carried out, and the model's accuracy was verified by the consistency between the simulation results and experimental data. The distribution of the eddy current field under different conditions and the disturbances caused by cracks at various positions to the detection signal were then calculated in the simulations. The simulation results showed that the cracks significantly disturbed the eddy current field of the semi-circular excitation differential probe compared with that of the traditional cylindrical probe. The designed differential probe effectively detected circumferential cracks of specific lengths and depths using the difference in the voltage signals. The experimental results were in agreement with the simulation results, showing that the designed probe could effectively detect 20 mm-long circumferential cracks at a lift-off of 60 mm. The experimental results also show that the probe's detection coverage area in the axial direction varied with the lift-off height. The probe design and findings are valuable for detecting cracks in ultra-high-pressure tubular reactors with protective layers.

A physical barrier woven by flexible, adiabatic and structurally stable high-entropy nanofiber sponges for efficient surface protection

The surface of equipment under harsh conditions often requires protection from adiabatic ceramic fibers. However, the structural stability and flexibility of fibers are frequently compromised. Here, (LaCeNdSmEu)2Zr2O7+δ, a defective high-entropy pyrochlore, was fabricated into flexible nanofiber sponges utilizing a simple saturated solution blow spinning method. The novel 3D lamellar sponges, containing numerous micropores woven by nanofibers, can achieve thermal insulation efficiently. Moreover, the defects and high-entropy effects inside nanofibers can further strengthen their structural stability. Furthermore, nanofiber sponges can remain flexible at -196–1350 °C. Even when burned by the flame, only 2-cm-thick sponges can reduce the heat source from 1350 to 285 °C. The smooth sintering process, low thermal conductivity (0.024–0.044 W/(m•K) at 28–500 °C), high long-term operation temperature (1350 °C), low density (14 mg/cm3), excellent compression flexibility, and remarkable structural stability under various harsh conditions can endow nanofiber sponges with powerful surface protection capability.

Microwave Assisted Williamson Synthesis: A Green Approach towards the Preparation of Ethers

Introduction: Microwave-assisted reactions align with the principles of green chemistry by significantly reducing synthesis time, avoiding high temperatures, and typically yielding high product quantities. Method: A catalyst was synthesized from waste banana peels, ensuring both availability and lowcost production. Ethers were synthesized using microwave irradiation at 300W, employing two different alkyl halide variants with both substituted and unsubstituted phenols. Results: The reaction proceeded efficiently without the need for corrosive bases such as caustic soda or caustic potash. Microwave irradiation facilitated reduced reaction times for ether formation. Additionally, the supported catalyst demonstrated the advantage of reusability. Conclusion: This protocol offers several benefits, including the use of a green solvent and the exclusion of phase transfer catalysts and harsh conditions. Consequently, an efficient and green synthesis of ethers has been achieved.

Combined endovascular interventions for pulmonary embolism at high altitude in Tibet.

Managing pulmonary embolism (PE) at extremely high altitudes poses unique challenges due to harsh environmental conditions and limited healthcare resources. This study retrospectively analyzed Tibetan PE patients in the Tibet Autonomous Region of China to evaluate the effectiveness and safety of combined endovascular interventional therapy in high-altitude areas. The average altitude of long-term residence for Tibetan patients was 3,863.4 ± 317.4 m, with an average age of 62.0 ± 16.0 years, and the time from computed tomography pulmonary angiography (CTPA) diagnosis to interventional treatment averaged 2.8 ± 2.2 days. The operation time for these patients was 106.1 ± 22.2 min, and the intraoperative dose of alteplase used was 23.3 ± 5.0 mg. All 9 patients reported profound remission of dyspnea and chest pain after endovascular interventions. The heart rate (p < 0.05) and respiratory rate (p < 0.001) of all enrolled patients were significantly decreased, and the peripheral capillary oxygen saturation (SpO2) was significantly increased (p < 0.05) after interventions. No severe complications, such as bleeding, occurred in any patient. This study demonstrated the potential clinical benefits and feasibility of combined endovascular interventional therapy for treating acute PE in extreme high-altitude regions.

Periodic dual-mixing method for fast and robust solving of ultra-thin fluid-structure interaction problems

This study proposes the periodic dual-mixing method (PDMM) that can rapidly and robustly solve ultra-thin fluid-structure interaction (UTFSI) problems, especially in severe mixed lubrication. The dual mixing denotes a two-step process: the first step is to mix the historical inputs and outputs separately according to optimal mixing weights; the obtained results are mixed with dynamic damping factors in the second step to predict the deformation of the next iteration. Meanwhile, the residual is injected into the predicted deformation periodically. The comparison study is carried out with the popular IQN-ILS method in general FSI, which shows the PDMM is 5.3 times faster and 5 times more robust. Furthermore, the advantages of the PDMM are more significant under harsh mixed lubrication conditions.

The complex chemical effects of air pollutants, meteorology and dust on the concentrations of criteria and non-criteria air pollution in Kuwait

Air pollution is the leading environmental health risk factor globally. A number of cities experienced improvements in air quality during the COVID-19 lockdown; however such changes depend on the contributions from natural and anthropogenic sources and meteorological factors pertaining to each city. This study investigated the effects of anthropogenic and meteorological factors on air quality in Kuwait during the COVID-19 lockdown (22 March–10 May 2020) using mixed-effect regression and machine learning models. Criteria (PM2.5, PM10, NO2, O3, SO2, CO) and non-criteria (C6H6, NH3, H2S, NMHC) air pollutants were compared between the lockdown period, and the same period in the preceding and the following years, 2019 and 2021, respectively. The results showed that during the lockdown three criteria air pollutants (PM2.5, NO2, CO) were reduced by 38, 40, 26%, respectively. All no-criteria air pollutants were reduced, except for H2S. The arid region’s harsh desert conditions have major contributions to particulate pollution. Although PM levels are overwhelmed by meteorological and natural dust, stringent abatement measures on oil/gas hydrocarbon and power plant emissions can significantly reduce PM and other pollutants. Abatement measures on traffic pollution can further reduce the NO2 levels. This study highlights Kuwait's ongoing struggle with elevated levels of particulate and gaseous pollution, driven by hydrocarbon emissions and dust. Effectively tackling air quality requires a nuanced understanding of the interplay between air pollutants, meteorological, and dust covariates.

Unveiling the Significance of tert-Butoxides in Transition Metal-Free Cross-Coupling Reactions.

The astounding reactivity of tert-butoxides in transition metal-free coupling reactions is driving the scientific community towards a new era of environmental friendly, as well as cost-effective, transformation strategies. Transition metal-catalyzed coupling reactions generate hazardous wastes and require harsh reaction conditions, mostly at elevated temperature, which increases not only costs but also environmental concerns regarding the methodology. Tert-butoxide-catalyzed/mediated coupling reactions have several advantages and potential applications. They can form carbon-carbon, carbon-heteroatom, and heteroatom-heteroatom bonds under mild reaction conditions. Mechanistic insights into these reactions include both ionic and radical pathways, with the fate of the intermediates depending on the reaction conditions and/or additives used in the reactions. Among all of the known tert-butoxides, potassium tert-butoxide has pronounced applications in transition metal-free coupling reactions as compared to other tert-butoxides, such as sodium and lithium tert-butoxides, because of the higher electropositivity of potassium compared to sodium and lithium. Moreover, potassium tert-butoxide can act as a source of base, nucleophile and single electron donors in various important transformations. In this review, we provide an extensive overview and complete compilation of transition metal-free cross-coupling reactions catalyzed/promoted by tert-butoxides during the past 10years.

DGRO: Doppler Velocity and Gyroscope-Aided Radar Odometry

A stable and robust odometry system is essential for autonomous robot navigation. The 4D millimeter-wave radar, known for its resilience in harsh weather conditions, has attracted considerable attention. As the latest generation of FMCW radar, 4D millimeter-wave radar provides point clouds with both position and Doppler velocity information. However, the increased uncertainty and noise in 4D radar point clouds pose challenges that prevent the direct application of LiDAR-based SLAM algorithms. To address this, we propose a SLAM framework that fuses 4D radar data with gyroscope readings using graph optimization techniques. Initially, Doppler velocity is employed to estimate the radar’s ego velocity, with dynamic points being removed accordingly. Building on this, we introduce a pre-integration factor that combines ego-velocity and gyroscope data. Additionally, leveraging the stable RCS characteristics of radar, we design a corresponding point selection method based on normal direction and propose a scan-to-submap point cloud registration technique weighted by RCS intensity. Finally, we validate the reliability and localization accuracy of our framework using both our own dataset and the NTU dataset. Experimental results show that the proposed DGRO system outperforms traditional 4D radar odometry methods, especially in environments with slow speeds and fewer dynamic objects.

Mitochondrial regulation in the tumor microenvironment: targeting mitochondria for immunotherapy

Mitochondrial regulation plays a crucial role in cancer immunity in the tumor microenvironment (TME). Infiltrating immune cells, including T cells, natural killer (NK) cells, and macrophages, undergo mitochondrial metabolic reprogramming to survive the harsh conditions of the TME and enhance their antitumor activity. On the other hand, immunosuppressive cells like myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), mast cells, and tumor-associated macrophages (TAMs) rely on mitochondrial regulation to maintain their function as well. Additionally, mitochondrial regulation of cancer cells facilitates immune evasion and even hijacks mitochondria from immune cells to enhance their function. Recent studies suggest that targeting mitochondria can synergistically reduce cancer progression, especially when combined with traditional cancer therapies and immune checkpoint inhibitors. Many mitochondrial-targeting drugs are currently in clinical trials and have the potential to enhance the efficacy of immunotherapy. This mini review highlights the critical role of mitochondrial regulation in cancer immunity and provides lists of mitochondrial targeting drugs that have potential to enhance the efficacy of cancer immunotherapy.

Uncovering the Crucial Role of Chelating Structures in Cyano-Alkyl-Phosphate Electrolytes for High-Voltage Lithium Metal Batteries.

The inferior oxidative stability of commercial carbonate electrolytes and overgrowth of the electrode-electrolyte interphase (EEI) have largely hindered the development of high-voltage lithium metal batteries. In this study, these challenges are addressed by designing Li+-solvent chelating solvation structures to inhibit solvent decomposition using cyano-alkyl-phosphate as a demonstration. Theoretical and experimental studies confirm that the -P═O and -C≡N groups within diethyl (2-cyanethyl) phosphonate exhibit a comparable ability to coordinate with Li+, facilitating the formation of seven-membered chelating structures. This unique solvation structure contributes to the formation of anion-derived inorganic-rich EEI with high stability and robustness, hindering the further decomposition of the electrolyte. Additionally, the cyano group has a strong complexation with the transition metal (TM) in the cathode to inhibit TM dissolution, thereby ensuring the structural stability of the cathode particle. Utilizing this special chelating structure, the designed electrolyte demonstrates favorable Li plating/stripping reversibility and promising oxidative stability in high-voltage batteries. Consequently, the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode exhibits a high capacity retention (90%) after operating 300 cycles. Under harsh testing conditions, the 4.6 V Li||NCM811 pouch cell with a capacity of 1.4 Ah (∼295 Wh kg-1 based on the total mass of the cell) retains 70% capacity after 80 cycles. This work provides new insights into the correlation between the solvation structure and oxidative stability of electrolytes, contributing significantly to the advancement of high-voltage lithium metal batteries.

High dynamic performance based by sliding mod control of quadrotor MAV

The paper focuses on strong control of high dynamic performance based on the sliding mode in order to control the quadrotor MAV. The model used in the simulation is the Newton-Euler model, and also choose the Mambo Parrot quadrotor parameters, to improve the latter's performance in terms of accuracy and robustness in case the impedance control chosen by the manufacturer needs to be changed. The results of which gave effectiveness and efficiency compared to classical controls PID and sliding mode. High dynamic performance control (HDP) is a type of control system designed to provide the highest level of performance over a wide range of operating conditions. This control is not a regulator but an organizing technique. It uses a prediction-based approach to anticipate rapid variations in system states and disturbances and to generate real-time commands to correct tracking errors and maintain system stability. This approach allows HDP control to achieve high performance while maintaining system stability, even under harsh operating conditions.

Tetraphenylethene-Based Ni8-Pyrazolate Metal-Organic Framework for Photoredox/Nickel Dual Catalysis of C-S Cross-Coupling.

As a prototypical aggregation-induced emission luminogen (AIEgen), the tetraphenylethene (TPE) moiety has been judiciously modified as organic linkers for constructing various functional metal-organic frameworks (MOFs). However, these AIEgen-based MOFs have rarely received research attention in photocatalytic applications due to their limited stability in harsh reaction conditions. In this work, we report a robust Ni8-pyrazolate-based MOF (denoted as TPE4Pz-Ni) under the guidance of reticular chemistry, which is assembled by an AIE-active tetratopic linker of 1,1,2,2-tetrakis(4-(1H-pyrazol-4-yl)phenyl)ethane (H4-TPE4Pz) with a 12-connected Ni8-cluster of [Ni8(OH)4(H2O)2Pz12] (Pz = pyrazolate) in a (4,12)-connected ftw-a topological network. Notably, MOF TPE4Pz-Ni exhibits excellent stability in a wide range of solvents and even in a saturated NaOH solution. Moreover, its luminescent emission is effectively quenched via a ligand-to-metal charge transfer (LMCT) process originating from the TPE-cored linker to the Ni8 cluster, which enables TPE4Pz-Ni to act as an efficient photoredox/nickel dual catalyst for light-mediated C-S cross-coupling reactions between various aryl iodides and thiols.

Unyielding Tenacity: The Power of Establishing Occupational Legitimacy

ABSTRACT This study examines the pursuit of occupational legitimacy by Korean tattooists, a profession considered illegal in South Korea. Based on in-depth interviews with 10 Korean tattooists, it explores how they navigate legal and cultural challenges, developing their skills and identities through practice. The process of professional specialization among institutionally marginalized tattooists manifests itself in an unusual form of professional skill development that inevitably requires the relentless refinement of manual skills. The author introduces the concept of unyielding tenacity, which refers to the tattooists’ attitude of persistent practice in the face of harsh conditions created by social constraints. Repetitive practice immerses them in their actions, helping them understand their work, address shortcomings, and question the injustice of the social constraints they face. This points out that before tattooists can adopt the strategy of gaining occupational legitimacy through the artification of their work, a prerequisite is the repetitive performance of their craft.

Facile preparation of photothermal and superhydrophobic melamine sponge for oil/water separation and anti-icing

The preparation of superhydrophobic sponges with excellent physiochemical performance, affordability, and versatility is still a big challenge. Herein, a photothermal and superhydrophobic melamine sponge has been successfully achieved by decorating lignin particles (LPs)@MXene composite onto the skeletons of melamine sponge (MS) via the self-polymerization of dopamine. The obtained superhydrophobic MS (labeled as MS@PDA/LPs@MXene) shows a water contact angle of 153.7°, and maintains surface superhydrophobicity under harsh conditions (i.e., acidic, alkaline environments, high temperatures, frictional damage, and icing/de-icing cycles). Notably, the MS@PDA/LPs@MXene exhibits an exceptional oil adsorption capacity of carbon tetrachloride up to 143.6 times of its own weight, a high separation efficiency of 99.3 %, and a retained separation efficiency of 98.9 % after 15 cyclic adsorption processes, respectively. Owing to a synergistic photothermal effect of PDA and LPs@MXene, the MS@PDA/LPs@MXene possesses a maximum surface temperature of 62.8 °C under solar irradiation (1.0 kW/m2, 1 sun), and realizes the ice-free property at a low temperature of −17.9 °C (relative humidity, 90 %) on a continuous cooling stage under solar irradiation (0.5 sun). Furthermore, the LPs@MXene composite coating can be applied on various substrates (i.e., Al sheet, Cu sheet, filter paper, carbon cloth, steel mesh and NdFeB magnet) to obtain surface superhydrophobicity, showing excellent anti-corrosion property for the permanent NdFeB magnet. Thus, this paper proposes a facile and cost-effective strategy to prepare superhydrophobic melamine sponge with multifunctional properties, and provides new insights into the rational design of high-performance superhydrophobic sponges for their applications in oil/water separation and anti-icing.