Harsh Environment Research Articles

Selective signatures in composite MONTANA TROPICAL beef cattle reveal potential genomic regions for tropical adaptation.

Genomic regions related to tropical adaptability are of paramount importance for animal breeding nowadays, especially in the context of global climate change. Moreover, understanding the genomic architecture of these regions may be very relevant for aiding breeding programs in choosing the best selection scheme for tropical adaptation and/or implementing a crossbreeding scheme. The composite MONTANA TROPICAL® population was developed by crossing cattle of four different biological types to improve production in harsh environments. Pedigree and genotype data (51962 SNPs) from 3215 MONTANA TROPICAL® cattle were used to i) characterize the population structure; ii) identify signatures of selection with complementary approaches, i.e. Integrated Haplotype Score (iHS) and Runs of Homozygosity (ROH); and iii) understand genes and traits related to each selected region. The population structure based on principal components had a weak relationship with the genetic contribution of the different biological types. Clustering analyses (ADMIXTURE) showed different clusters according to the number of generations within the composite population. Considering results of both selection signatures approaches, we identified only one consensus region on chromosome 20 (35399405-40329703 bp). Genes in this region are related to immune function, regulation of epithelial cell differentiation, and cell response to ionizing radiation. This region harbors the slick locus which is related to slick hair and epidermis anatomy, both of which are related to heat stress adaptation. Also, QTLs in this region were related to feed intake, milk yield, mastitis, reproduction, and slick hair coat. The signatures of selection detected here arose in a few generations after crossbreeding between contrasting breeds. Therefore, it shows how important this genomic region may be for these animals to thrive in tropical conditions. Further investigations on sequencing this region can identify candidate genes for animal breeding and/or gene editing to tackle the challenges of climate change.

Increasing SAR Imaging Precision for Burden Surface Profile Jointly Using Low-Rank and Sparsity Priors

The synthetic aperture radar (SAR) imaging technique for a frequency-modulated continuous wave (FMCW) has attracted wide attention in the field of burden surface profile measurement. However, the imaging data are virtually under-sampled due to the severely restricted scan time, which prevents the antenna being exposed to high temperatures and heavy dust in the blast furnace (BF) for an extended period. In traditional SAR imaging algorithm research, the insufficient accumulation of scattered energy in reconstructing the burden surface profile leads to lower imaging precision, and the harsh smelting increases the probability of distortion in shape detection. In this study, to address these challenges, a novel rotating SAR imaging algorithm based on the constructed mechanical swing radar system is proposed. This algorithm is inspired by the low-rank property of the sampled signal matrix and the sparsity of burden surface profile images. First, the sparse FMCW signal is modeled, and the position transform matrix, calculated according to the BF dimensions, is embedded into the dictionary matrix. Then, the low-rank and sparsity priors are considered and reformulated as split variables in order to establish a convex optimization problem. Lastly, the augmented Lagrange multiplier (ALM) is employed to solve this problem under double constraints, and the imaging results are obtained using the alternating direction method of multipliers (ADMM). The experimental results demonstrate that, in the subsequent shape detection, the root mean square error (RMSE) is 15.38% lower than the previous algorithm and 15.63% lower under low signal-to-noise (SNR) conditions. In both enclosed and harsh environments, the proposed algorithm is able to achieve higher imaging precision even under high noise. It will be further optimized for speed and reliability, with plans to extend its application to 3D measurements in the future.

Printed Electronics by Plasma Spraying: Case Study for High Temperature Sensors

AbstractTemperature sensors are critical components in many industrial and research applications, particularly in harsh environments where high temperatures, corrosion and mechanical stress are prevalent. In this paper, we investigate the use of plasma spray technique as a versatile and simple method to print multipoint thermocouples and resistance temperature detectors (RTDs) based on NiCr-NiAl coatings on steel and ceramic substrates using stencil masking and laser scribing. The thickness of alumina the dielectric layer was optimized using metal-insulator-metal test. The thermoelectric properties of the printed thermocouples were investigated up to 1000 °C. The thermal independency of printed thermocouples and the capability of multilocation measurement at the surface on the same substrate was demonstrated. The thermoelectric properties of the printed RTD were investigated up to 850 °C. The electrical resistance of the RTD sensor is linear with the temperature variation from room temperature to 500 °C. The oxidation effect of the printed sensor metallic layers at high temperature was investigated and discussed.

Boosting Efficiency and UV Resistance in Perovskite Solar Cells via Sunscreen Ingredient Octinoxate

AbstractUV radiation presents a substantial challenge to the stability of perovskite solar cells (PSCs), limiting their applications in harsh environments such as outer space. Herein, UV‐resistant molecule octinoxate (OCT) is introduced to mitigate the adverse effects of UV irradiation. OCT additive demonstrates the capability to modulate the crystallization process, resulting in perovskite films with larger grains and enhanced crystallinity. Moreover, OCT doping also facilitates charge extraction in PSCs. The PSCs with OCT doping exhibit an enhanced efficiency, increasing from 22.46% to 24.64%, along with improved stability with a T85 of 1000 h under continuous light exposure. Functioning as a sunscreen material, OCT mitigates UV‐induced degradation by absorbing irradiation and hindering I2 escape. Even after continuous exposure to 18.7 kWh m−2 UV illumination, the OCT‐doped PSCs maintain over 92% of their initial efficiency, meeting the 15 kWh m−2 UV exposure requirement specified in the IEC:61215 PV robustness testing standard. This study offers a straightforward approach to enhance the durability of PSCs under UV radiation, opening avenues for their application in extreme environments.

A highly reliable and low-overhead quadruple-node-upset tolerant latch design

With the advancement of semiconductor technology and the continual reduction in the feature size of transistors within integrated circuits (ICs), ICs are becoming more and more vulnerable to soft errors induced by energetic particles in harsh radiation environments. To mitigate the impact of soft error on ICs. This paper proposes a quadruple-node-upset tolerant latch (LCQNUT), which consists of two parts: a storage module and a three-stage interception module. The storage module is composed of 12 dual-input inverters. The three-stage interception module is composed of 6 dual-input C-elements (CEs). Based on the CEs and dual-input inverters' blocking capability, the proposed LCQNUT latch can efficiently tolerate the simultaneous upset of any four internal node combinations. Simulation results indicate the proposed LCQNUT latch has the smallest power consumption, area overhead, and area-power-delay product (APDP) compared to the latches with the same soft tolerance ability (D-LATCH, HS-QNU, QNUTL). It has moderate sensitivity to process, voltage, and temperature (PVT).

Advancing differential susceptibility research: Development and validation of the temperamental sensitivity Q-scale.

Temperamental sensitivity (TS), which is a correlated suite of traits reflecting a lower threshold of environmental stimulation and heightened responsivity to a range of environmental contexts, is an empirically documented susceptibility factor that increases children's plasticity to supportive and harsh family environments. To expand the limited options for assessing TS, this article tested the psychometric properties of a new Q-set measure (i.e., TS Q-scale) derived from the California Child Q-Set (CCQ-Set) and completed by experimenters. Participants in Study 1 consisted of 243 mothers, their partners, and their preschool children (Mage = 4.60 years; 56% girls; 54% Black or multiracial; 16% Latinx). For Study 2, participants included 201 mothers and their young children (Mage = 2.25 years; 44% girls; 63% Black or multiracial; 11% Latinx). Both longitudinal studies utilized multimethod, multiinformant measurement batteries. The TS Q-scale evidenced satisfactory internal consistencies across both studies. Support for the convergent and discriminant validity in Study 1 was evident in its large, unique, and significantly stronger association with a standard, more extensive, observational assessment of TS when compared with conventional dimensions of temperament. In each study, the TS Q-scale significantly moderated the association between family functioning and latent change analyses of children's functioning for most of the forms of child adjustment. Supporting its predictive validity as a differential susceptibility attribute, children with higher scores on the TS Q-scale exhibited substantially better functioning than their peers in supportive socialization contexts and considerably worse functioning in harsh rearing conditions. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Durability life evaluation of marine infrastructures built by using carbonated recycled coarse aggregate concrete due to the chloride corrosive environment

Due to the harsh marine environment of chloride ion invasion and corrosion, the issues of long-term chloride transport and durability life evaluation for marine infrastructures constructed/maintained by recycled aggregate concrete (RAC) after enhancement remain poorly understood. For our studies, an accelerated carbonation modification method for recycled coarse aggregate (RCA) was adopted to prepare carbonated recycled coarse aggregate (CRCA) samples, and the macroproperties, i.e., apparent density and water absorption, of CRCA were enhanced by approximately 1.40-3.97% and 16.3-21.8%, respectively, compared with those of RCA. An in-door experiment for chloride transport into concrete specimens subjected to a simulated marine environment of alternating drying-wetting cycles was conducted. The chloride profiles and transport characteristics of carbonated recycled coarse aggregate concrete (CRCAC), recycled coarse aggregate concrete (RCAC), and natural coarse aggregate concrete (NCAC) were analysed and compared. The results indicated that the chloride penetration depths and concentrations of CRCAC were approximately 52.6-96.2% of those of RCAC, which highlighted the better chloride resistance of CRCAC. A chloride transport model for marine concrete structures with various coarse aggregate types in a corrosive marine environment was established. Taking a certain harbour wharf as an example, the durability life of this case considering the application of the CRCAC was evaluated based on the chloride transport model, and the durability life of the CRCAC structure was improved by approximately 28.10% compared with that of the RCAC. The CRCAC developed in this paper has improved mechanical performance and durability than those of RCAC, and it has the potential to replace the NCAC and further support the construction and maintenance of marine infrastructures.

Design of a high sensitivity and wide range angular rate sensor based on exceptional surface

Abstract It is found that when the parity time symmetry phenomenon is introduced into the resonant optical gyro system and it works near the exceptional point, the sensitivity can be significantly amplified at low angular rate in theory. However, in fact, the exceptional point is easily disturbed by external environmental variables, which means that it depends on harsh experimental environment and strong control ability, so it is difficult to move towards practical application. Here, we propose a new angular rate sensor structure based on exceptional surface, which have the advantages of high sensitivity and high robustness. The system consists of two fiber-optic ring resonators and two optical loop mirrors, and one of resonators contains a variable ratio coupler and a variable optical attenuator. We theoretically analyzed the system response and the effects of phase and coupling ratio on the system response, respectively. Finally, compared with conventional resonant gyro, the sensitivity of this exceptional surface angular rate sensor can be improved by about 300 times at low speed. In addition, by changing the loss coefficient in the ring resonator, it can achieve a wide range of 600 rad/s. This scheme provides a new approach for the development of ultra-high sensitivity and wide range angular rate sensors in the future.

Fatigue Life and Crack Initiation of K and N Type Jacket Structure Using 3D Fatigue FE Analysis

Jacket structures are widely used as foundation structures for offshore wind energy. The jacket structure as a truss shape structure is not deformed easily and has the advantage of keeping the structure stable under wind load. The offshore jacket structures are subjected to unstable repetitive loads such as wind, and wave loads in the deep sea. These harsh environments lead to the deterioration of material performance and fatigue failure with cracks in the structure. It is crucial to locate fatigue cracks since they might compromise a structure's overall stability.In this study, fatigue life and crack initiation for different braced jacket structures were investigated. First, 3D non-steady heat conduction analysis and thermal elastic-plastic analysis were performed to reproduce the initial state of the weld joint in the jacket structure. The heat history obtained from the 3D non-steady heat conduction analysis was enforced as an input in thermal elastic-plastic analysis to calculate welding deformation and residual stress. Next, the fatigue FE analysis of the jacket welding structure was carried out using the residual stress and welding deformation as initial values along with the external cyclic loadings. The 3D fatigue FE analysis employed cyclic hysteresis constitutive equations and fatigue damage theory to calculate the fatigue life and crack initiation. The 3D fatigue FE results were compared with the S-N curve by European code 3 and the hot spot stress (HSS) method. The results show that the 3D fatigue FE method effectively calculates the fatigue life and finds crack initiation.

Role of Genome Sequences of Major and Minor Millets in Strengthening Food and Nutritional Security for Future Generations

Millets are small-seeded cereals belonging to the family Poaceae. They are considered to be climate-resilient and future nutritional food cereals for humans. Millets are resistant to biotic and abiotic stressors compared to other major cereals and thrive in low-quality soils with little maintenance and less rainfall. The importance of millets is still not well known to many people due to the lack of popularity and cultivation in semi-arid tropics of Asia and Africa. The United Nations has declared 2023 as the International Year of Millets (IYM 2023) to promote millet cultivation and popularize their health benefits globally. A few years ago, the application of molecular biology was in its infancy in millets due to the unavailability of genome sequences. Genome sequences are available for most of the millets on NCBI and Phytozome databases. In this review, we discuss the details of genome sequences for millets, candidate genes identified from the native genome of millets. The current status of quantitative trait loci and genome-wide association studies in millets are also discussed. The utilization of millet genome sequences in functional genomics research and translating the information for crop improvement will help millet and non-millet cereals survive harsh environments in the future. Such efforts will help strengthen food security and reduce malnutrition worldwide in 2050.

A novel solution for hydrogen monitoring in fusion processes: 3D printed BaCe0.6Zr0.3Y0.1O3-α sensors

The control of tritium (3H) in liquid-based tritium breeding blankets (TBBs) is one of the key points to assure their correct performance to prove the 3H sufficiency. For that, electrochemical sensors are a good option for tritium quantification since they can perform in-situ and online measurements.One of the multiple challenges for hydrogen detection is to find suitable materials that can operate at high temperatures and in harsh environments. In this context, perovskite-type ceramics, such as BaCe0.6Zr0.3Y0.1O3-α (BCZY), have elevated proton conductivity and exceptional stability even in reducing atmospheres and at elevated temperatures, which make them strong contenders for high-temperature hydrogen sensing applications.In the present study, we describe the development of a dual-mode hydrogen sensors based on 3D-printed BCZY, which allows a high degree of design flexibility. Crucible geometries were tested and characterized using X-ray diffraction and scanning electron microscopy. Electrochemical sensors were constructed and characterized at 400, 450 and 500 °C in both, amperometric and potentiometric configuration. The results demonstrated the capability of 3D-printed BCZY sensors for hydrogen detection in fusion reactors, offering a breakthrough solution for monitoring fusion processes.

Computational Mechanics for Turbofan Engine Blade Containment Testing: Fan Case Design and Blade Impact Dynamics by Finite Element Simulations

The harsh environment during airplane take-off and flights with complex operating conditions require a high dynamic and impact resistance capability of airplane engines. The design, development, and performance evaluation of new turbofan engines are generally performed through numerical simulations before a full-scale model or prototype experiment for certification. Simulations of fan blade containment tests can reduce trial–error testing and are currently the most convenient and inexpensive alternative for design; however, certification failure is always a risk if the calibration of material models is not correctly applied. This work presents a three-dimensional computational model of a turbofan for designing new engines that meet the certification requirements under the blade containment test. Two calibrated Johnson–Cook plasticity and damage laws for Ti64 are assessed in a simulation of a turbofan blade containment test, demonstrating the ability of the models to be used in the safe design of aircraft engine components subjected to dynamic impact loads with large deformations and adequate damage tolerance.

High-pressure gallium seeder for atomic fluorescence measurements

This work presents the design and testing of a seeder based on laser ablation capable of introducing gallium particles into a gaseous flow at elevated pressures typical of that found in practical combustion devices. The ability to seed such a flow with gallium particles is required to apply Ga-TLAF, a spatially and temporally resolved thermometry imaging technique well suited to harsh combustion environments. The design criteria for this gallium particle seeder are first listed and all the necessary details required to understand and replicate it are then provided. Next, the efficiency of gallium ablation is verified as a function of the ablation laser's fluence and repetition rate and of the pressure using gallium laser induced fluorescence and laser scattering measurements at ∼403 nm. For the conventional 355-nm nanosecond, Nd:YAG laser used for ablation in this study, data show that the quantity of gallium seeded into the flow can be conveniently modulated by varying the fluence of the ablation laser and/or its repetition rate. Data also show that the efficiency of ablation is marginally better for solid gallium than for liquid gallium, but that ablation of liquid gallium should be preferred to avoid a loss of ablation efficiency after some time. The temperature of the liquid gallium feedstock is found to be unimportant. SEM, EDX, and SPMS analyses show that laser ablation yields pure gallium particles with a characteristic size ranging at least from 50 nm to 10 μm and that the size distribution is insensitive to the pressure and to the ablation laser's fluence. Also important for future applications of Ga-TLAF in high-pressure flames, data show that the gallium LIF intensity recorded at room temperature or in the hot products of a flame is not significantly affected by pressure.

Influence of Al addition on the microstructure and properties of Fe25Co25Ni25(Si0.3B0.7)25 high entropy metallic glass

This research work was focused on the development of a new series of high entropy metallic glasses (HE-MGs) combined with higher thermal stability, acceptable soft magnetic property, microhardness and good corrosion resistance by adding various Al content (1–8 at.%) on the basis of Fe25Co25Ni25(Si0·3B0.7)25 high entropy metallic glass using single-roller melt-spinning approach. It is found that the proper addition of Al can efficiently improve the anti-corrosion performance of high entropy metallic glasses, in particular, the corrosion current density is decreased from 7.61 μA/cm2 and 9.26 μA/cm2 for the 1 at.% and 2 at.% Al-added alloys to 5.11 μA/cm2 for the 5 at.% Al-added alloy. However, the improvement of Al content could deteriorate the soft magnetic property and thermal stability of HE-MGs. The saturation magnetization flux density and onset crystallization temperature reduce from 0.85 T to 766.15 K for the 1 at.% Al-added alloy to 0.53 T and 736.75 K for the 8 at.% Al-added alloy. Besides, the Vickers’ microhardness of all investigated alloy ribbons can reach 1124 HV0.2 or above. Therefore, this kind of senary new-type HE-MGs can be used as a promising magnetic shielding metal material with high hardness, superior thermal stability and good anti-corrosion performance for the surface protection of key component in harsh marine corrosive environment.

Pilot performance during simulated point and boundary avoidance tracking tasks

Abstract Helicopters are used in complex and harsh operational environments, such as search and rescue missions and firefighting, that require operating in ground proximity, tracking targets while avoiding impacting obstacles, namely a combination of point tracking (positive) and boundary avoidance (negative) objectives. A simulation task representing simplified helicopter dynamics is used to investigate point tracking and boundary avoidance tasks. The variance and regression analysis are used to study the effects of task conditions on participants’ tracking errors and input aggression. The overall tracking error shows a negative correlation with input aggression. The participants tend to have higher input aggression and lower tracking error near the boundaries, exposing the switching of manipulation input strategies under different task conditions. It also suggests a potential way of designing simulation tasks for human operators manipulating helicopters and a trigger for investigating pilots’ biodynamic feedthrough.

Enzyme-integrated metal-organic framework platform for cascade detection of α-amylase

As one of the most important industrial enzymes, α-amylase is widely used in food processing, such as starch sugar and fermentation, bringing high added value to industry of more than a trillion dollars. We developed a multi-enzyme system (Glu&Gox@Cu-MOF-74) prepared by embedding α-glucosidase (Glu) and glucose oxidase (Gox) into the biomimetic metal-organic framework Cu-MOF-74 using in situ encapsulation within 15 min at room temperature for efficient and sensitive detection of α-amylase activity. Benefitting from the remarkable peroxidase-mimicking property and rigid skeleton of Cu-MOF-74, the biocatalytic platform exhibited excellent cascade activity and tolerance in various extremely harsh environments compared to natural enzymes. On this basis, a cascade biocatalytic platform was constructed for the detection of α-amylase activity with wide linear range (5–100 U/L) and low limit of detection (1.45 U/L). The colorimetric cascade scheme is important for the sensitive and selective determination of α-amylase in complex fermentation samples, and the detection time is short (∼0.5 h). This work provides new ideas for the detection of α-amylase based on the cascade amplification method.

Robust design of reinforced superhydrophobic FEP-SiO2@PTFE hollow fiber membrane for waste lubricating oils treatment

The shortage of petroleum resources brings the regeneration of used lubricating oils (ULOs) to a major issue, and hence the superhydrophobic membranes attract extensive attention derived from lotus-effect and capillary forces. In this paper, a superhydrophobic FEP-SiO2@PTFE hollow fiber composite membrane (HFCM) based on a facile step-by-step adhesive bonding method with a water contact angle up to 154.1°. The multilayered structure with superhydrophobic separation layer, microporous structure transition layer, and high strength supporting layer could be constructed. The lubricant permeate flux of membrane was as high as 814.5 L·m−2·h−1·bar−1 at 100 °C, with separation efficiencies of 99.3 % and 98.9 % for lubricants containing activated carbon and SiO2, respectively. Meanwhile, the flux of the membrane was stabilized at 430.9 L·m−2·h−1·bar−1 after 200 h of operation, and showed an initial permeation of 680.1 L·m−2·h−1·bar−1 after 5 cycles. Prominent mechanical properties and thermal-resistance (breaking strength of about 165.0 MPa, thermal decomposition temperature was up to 380℃) are another excellent performance of the membrane. As a result, the membrane provided another preferred option for the recycling of heavy oils, such as ULOs, at high temperatures or in various harsh environments.

The method for the estimation of fracture toughness of thin-walled metallic tube considering the effect of crack orientation

Thin-walled metallic tubes are very susceptible to axial or circumferential cracks in harsh environments such as high temperature, high pressure, and severe corrosion, which seriously endangers the service safety of thin-walled tubes. Fracture toughness is an essential mechanical property index for evaluating the service safety of thin-walled metallic tubes, and its special thin-walled structure cannot be tested by using the specimens with standard configuration. In this work, based on the principle of energy density equivalence, the load–displacement and J-integral expressions of thin-walled metallic tubes with axial and circumferential cracks are proposed, and the fracture toughness test method of thin-walled metallic tubes with axial and circumferential cracks is established. Typical zircaloy cladding tubes were selected to complete the fracture test, and the influence of crack orientation on their fracture properties was investigated. The results show that the fracture toughness of circumferential cracks is lower than that of axial cracks, the circumferential cracks also face the risk of fracture failure, and the estimation of fracture properties of the cladding tubes with circumferential cracks cannot be simply replaced by axial cracks.

High Hydrogen Storage in Trigonal Prismatic Monomer-based Highly Porous Aromatic Frameworks.

Hydrogen storage is crucial in the shift toward a carbon-neutral society, where hydrogen serves as a pivotal renewable energy source. Utilizing porous materials can provide an efficient hydrogen storage solution, reducing tank pressures to manageable levels and circumventing the energy-intensive and costly current technological infrastructure. Herein, we report two highly porous aromatic frameworks (PAFs), C-PAF and Si-PAF, prepared through a Yamamoto C-C coupling reaction between trigonal prismatic monomers. These PAFs exhibited large pore volumes and BET areas, 3.93 cm3 g-1 and 4857 m2 g-1 for C-PAF, and 3.80 cm3 g-1 and 6099 m2 g-1 for Si-PAF, respectively. Si-PAF exhibited a record-high gravimetric hydrogen delivery capacity of 17.01 wt% and a superior volumetric capacity of 46.5g L-1 under pressure-temperature swing adsorption conditions (77 K, 100bar → 160 K, 5bar), outperforming benchmark hydrogens storage materials. By virtue of the robust C-C covalent bond, both PAFs showed impressive structural stabilities in harsh environments and unprecedented long-term durability. Computational modeling methods were employed to simulate and investigate the structural and adsorption properties of the PAFs. These results demonstrate that C-PAF and Si-PAF are promising materials for efficient hydrogen storage. This article is protected by copyright. All rights reserved.

A flue gas velocimeter based on the hyperbolic chirp modulation method of acoustic source signal

Accurate measurement of flue gas velocity is of great significance for the safe production, energy saving, and emission reduction of coal-fired power plants. In this paper, a method of flue gas velocimetry based on a hyperbolic chirp-modulating acoustic source was proposed, and its superiority was verified by numerical simulations and field experiments. For an acoustic velocimeter, it is crucial to ensure the accuracy of the acoustic Time-of-Flight (TOF), which directly affects the flue gas velocity measurements. The improvement of the accuracy of estimation of the TOF directly determines the accuracy of the flue gas velocity measurement. Simulation on the different types of acoustic sources at different signal-to-noise ratios (SNRs) was conducted, and the results proved that the hyperbolic chirp signal is more accurate in the measurement of TOF. In the strong noise range of − 10 dB to − 20 dB, the average relative root mean square error (RRMSE) obtained using this hyperbolic chirp modulating acoustic source is 0.60 dB and 0.36 dB lower than obtained using the linear and logarithmic modulating modes, respectively. The average relative error (RE) is approximately 0.87 times that of the linear chirp. Power plant flue field experiments show that the measurement error using this hyperbolic modulating mode is about 0.52 times and 0.74 times that of using linear and logarithmic modulating modes, respectively. In harsh measurement environments with strong noise, the proposed acoustic source modulation scheme can significantly improve the measurement SNR and effectively enhance the accuracy and robustness of flue gas velocimetry.