Small Deviations Research Articles

Generalizable process monitoring for FFF 3D printing with machine vision

AbstractAdditive manufacturing has experienced a surge in popularity in both commercial and private sectors over the past decade due to the growing demand for affordable and highly customized products, which are often in direct opposition to the requirements of traditional subtractive manufacturing. Fused Filament Fabrication (FFF) has emerged as the most widely-used additive manufacturing technology, despite challenges associated with achieving contour accuracy. To address this issue, the authors have developed a novel camera-based process monitoring method that enables the detection of errors in the printing process through a layer-by-layer comparison of the actual contour and the target contour obtained via G-Code processing. This method is generalizable and can be applied to different printer models with minimal hardware adjustments using off-the-shelf components. The authors have demonstrated the effectiveness of this method in automatically detecting both coarse and small contour deviations in 3D-printed parts.

Skin-like and highly elastic optical fiber strain sensor based on a knot-bend shape for human motion monitoring.

A simply designed, highly sensitive, stretchable, compact wearable, and skin-like optical fiber sensing instrument is designed and demonstrated for joint motion monitoring. The fiber sensing scheme comprises only a section of single-mode fiber (SMF) deformed in the knot-like configuration, which performs as a Mach-Zehnder interferometer (MZI) based on a modal coupling mechanism between the core and cladding modes of the deformed SMF section. This proposed optical fiber sensor based on a knot-like configuration is mounted onto wearable woven fabric and then garments on the limbs of a healthy human's body. As the flexion angle of the human limb is varied, the interference fringe coding based on the spectral shift difference of the periodical transmission spectra is perceived. The proposed wearable optical fiber sensor exhibits excellent sensitivities from around -0.431 to -0.614n m/∘ realized for elbow and knee joint flexion between a range of motion around 0°-90°. Additionally, this sensor also displays high repeatability and stability and a fast response time of 1.4ms, combined with a small standard deviation of about 2.585%. The proposed sensor device possesses manufacturing simplicity, high processing accuracy, lightness, and elasticity, as well as certain improvements over other goniometers and optical fiber sensors. These attributes of the proposed sensor prove its applicability for human joint angle monitoring.

Wavelet Transforms of Microlensing Data: Denoising, Extracting Intrinsic Pulsations, and Planetary Signals

Wavelets are waveform functions that describe transient and unstable variations, such as noise. In this work, we study the advantages of discrete and continuous wavelet transforms (DWTs and CWTs) of microlensing data to denoise them and extract their planetary signals and intrinsic pulsations hidden by noise. We first generate synthetic microlensing data and apply wavelet denoising to them. For these simulated microlensing data with ideally Gaussian noise based on the Optical Gravitational Lensing Experiment (OGLE) photometric accuracy, denoising with DWTs reduces standard deviations of data from real models by 0.044–0.048 mag. The efficiency to regenerate real models and planetary signals with denoised data strongly depends on the observing cadence and decreases from 37% to 0.01% with increasing cadence from 15 min to 6 hr. We then apply denoising on 100 microlensing events discovered by the OGLE group. On average, wavelet denoising for these data improves standard deviations and of data with respect to the best-fit models by 0.023 mag and 1.16, respectively. The best-performing wavelets (based on the highest signal-to-noise ratio’s peak (), the highest Pearson’s correlation, or the lowest root mean squared error for denoised data) are from the Symlet and Biorthogonal wavelet families in simulated and OGLE data, respectively. In some denoised data, intrinsic stellar pulsations or small planetary like deviations appear that were covered with noise in raw data. However, through DWT denoising rather flattened and wide planetary signals could be reconstructed rather than sharp signals. CWTs and 3D frequency–power–time maps could inform about the existence of sharp signals.

Meso-scopically homogeneous superelastic transformation and related elastocaloric effect in a textured Ti-based shape memory alloy

Homogeneous superelastic behavior in shape memory alloys (SMAs) has been confirmed to be crucial for functional and structural fatigue properties, and more importantly, for stable elastocaloric effect (eCE). Here, the Ti–22Nb–4Zr–2Ta plate was prepared by successive cold rolling at 98.5%, followed by annealing at 1023 K for 30 min, forming a strong recrystallized texture, denoted as {112}β < 110>β. Such favorable texture contributed to a completely recoverable superelastic strain of ∼2.4% with narrow hysteresis of 35/45 MPa under isothermal/quasi-adiabatic conditions, which resulted in homogeneous martensitic transformation (MT) and adiabatic temperature changes (ΔTadi) of 4.8 K upon loading and 4.4 K upon unloading. The observation on the evolution of space-resolved strain and temperature throughout the sample revealed that the intrinsic feature of diffuse transformation along with favorable texture contributed to meso-scopically homogeneous transformation and related eCE. A standard deviation of strain was determined to be only 0.05%, corresponding to a small temperature deviation of 0.2–0.3 K, which quantitatively demonstrated the homogeneity, potentially high solid-state cooling performance efficiency, and long structural and functional fatigue life in Ti-based SMAs.

Evaluation of Reliability of the Luna EMG Rehabilitation Robot to Assess Proprioception in the Upper Limbs in 102 Healthy Young Adults.

BACKGROUND Proprioception, the body's ability to perceive its own position and movement, is fundamental for motor control and coordination. Reliable assessment tools are essential, particularly for conditions affecting proprioceptive function. This study aimed to evaluate the external and internal compliance of the Luna EMG -multifunction robotic device in assessing proprioception. MATERIAL AND METHODS The study involved 102 healthy students (31 men and 71 women; mean age 22.2±1.46 years), assessing proprioception using the Luna EMG for the upper limbs. Two investigators conducted measurements, which were repeated after 2 weeks under identical conditions. RESULTS Based on the identified values of the interclass correlation coefficient (ICC) (ICC=0.969-0.997), which is a key measure of agreement between 2 assessments, the study shows a high agreement of measurements both between investigators (for right hand: P=0.3484 [Exam 1]; P=1.0000 [Exam 2]; for left hand: P=0.1092 [Exam 1]; P=0.7706 [Exam 2]) and between the examinations (for right hand: 0.1127 [Investigator 1]; 0.2113 [Investigator 2]; for left hand: P=0.0087 [Investigator 1]; P=0.1466 [Investigator 2]). The Bland-Altman analysis showed very small inter-rater deviations, approximately 0.05° in the first examination for the left side and 0.04° for the right side. The highest deviation between the examinations, amounting to 0.08°, was identified for the left side. CONCLUSIONS The study shows that the Luna EMG multifunction robotic device enables a reliable evaluation of upper limb proprioception. Measurements performed using this device show high internal and external consistency in the assessment of the proprioceptive senses of the upper limb in 102 healthy young adults.

Accuracy of Photo-Optical Timber Measurement Using a Stereo Camera Technology

Harvested timber requires efficient and accurate measurements for timber trade. Recently, the amount of timber that is harvested for industrial purposes is growing and methods for roundwood measurements are under constant development. Some of these solutions are with certification confirming its accuracy, some of them are proposed for general use without certification. The aim of this paper was to select the best and most useful electronic solution for timber volume masurement and calculation, and to recommend the most effective and accurate solution for future timber trade. Three photo-optical systems were tested: LogStackPro, iFovea and Timbeter. Each system was used to measure 71 stacks of pine and oak roundwood, which amounted to 3481.15 cubic meter stacked. Timber volumes obtained from the manual measurements were used as reference. Volumes obtained from the photo-optical systems were larger in comparison with the volume from manual measurements, by 3.37, 8.07 and 9.08%, in LogStackPro, iFovea and Timbeter, respectively. It was concluded from the tested systems that, currently, the most recommended solution for timber measurement will be LogStack Pro, which also presented, in most cases, the smallest deviations from the volume obtained in manual measurements.

Illuminating the path to high-precision dual-mode optical thermometry: A Mn4+-activated oxyfluoride single crystal for a portable optical fiber thermometric platform

Multifunctional ratiometric and lifetime-technology dual-mode sensing plays a pivotal role in optical thermometry, yet poses substantial challenges in Mn4+-doped oxyfluorides/fluorides. Especially, despite of higher sensitivity, the applicability of lifetime-mode optical thermometers is generally restricted to large volume, highly integrated spectrometers. Here, a Mn4+-doped oxyfluoride single crystal Na2NbOF5:Mn4+ (NNOFM) is demonstrated as accurate dual-mode optical temperature sensor and developed into a portable optical fiber thermometric platform. Homogeneous NNOF shell is grown to improve the moisture resistant for extending operational lifespan. Under blue light excitation, two different temperature-sensitive sharp line vibrational transitions endow ratiometric mode temperature sensor. Importantly, rapidly decaying lifetime of Mn4+ produces high relative sensitivity Sr of 5.36 % K−1 at 448 K among Mn4+-based phosphors. Integrating NNOFM core–shell single crystal into optical fiber and coupling pulsed laser and oscilloscope, a portable optical fiber thermometric platform is realized. Accurate measurement result of boiling water being 373.33 K with quite small relative standard deviation to 0.04 % shows great potential of this fabricated thermometric platform for practical applications. This study not only enlightens the design of high-precision dual-mode optical thermometers in Mn4+-doped oxyfluorides/fluorides, but also illuminates the path to create portable optical fiber thermometric platforms.

PSXI-19 A Novel Calculation Method in the Difference Procedure for Determining Energy Digestibility of Ingredients for Pigs

Abstract The objective was to suggest a novel calculation method in the difference procedure for determining the apparent total tract digestibility (ATTD) of gross energy (GE) of ingredients for pigs. This procedure involves formulating a basal diet (BD) and a test diet (TD) which contains a test ingredient (TI), feeding these diets to pigs, determining ATTD of GE in the diets, and calculating ATTD of GE in a TI by extrapolation. To calculate ATTD of GE in a TI, it is necessary to calculate the proportional contribution of GE in the BD (PBD) and the TI (PTI) to the TD using the following equations: PBD = (analyzed GE of BD × inclusion rate of BD)/analyzed GE of TD; PTI = (analyzed GE of TI × inclusion rate of TI)/analyzed GE of TD. One of the assumptions for the difference procedure is that GE values in a BD and a TI are additive (PBD + PTI = 1). However, the analyzed GE in the TD is not always exactly equal to the calculated value based on analyzed GE values in the BD and the TI. To investigate the influence of non-additivity of GE in a TD on the ATTD of GE in a TI, 33 observations were collected from 9 studies that determined ATTD of GE using the difference procedure. A ratio of analyzed GE in TD to calculated GE in TD (GEAnalyzed:GECalculated, %) ranged from 98.7 to 101.3%. The following relationship was established: PTD = PTI + PBD = (GEAnalyzed:GECalculated)–1. Corrected PBD and PTI were calculated: corrected PBD = PBD × (GEAnalyzed:GECalculated)–1; corrected PTI = PTI × (GEAnalyzed:GECalculated)–1; and corrected PTD = corrected PBD + corrected PTI = 1. Four values for the ATTD of GE in TI were obtained or calculated: 1) presented in the literature (ATTDLiterature), 2) calculated based on the PTI (ATTDNon-corrected), 3) calculated based on the corrected PTI (ATTDCorrected), and 4) calculated based on the calculated GE in TD (ATTDCalculated). Three ratios (%) for each observation were computed, namely, ATTDLiterature:ATTDCalculated, ATTDNon-corrected:ATTDCalculated, and ATTDCorrected:ATTDCalculated. The GEAnalyzed:GECalculated was used as an independent variable against the ratios as dependent variable. Results indicated that a 1 percentage unit increase in GEAnalyzed:GECalculated led to 3.47% (r2 = 0.67) and 4.28% (r2 = 0.92) increases in ATTDLiterature:ATTDCalculated and ATTDNon-corrected:ATTDCalculated, respectively. However, for the ATTDCorrected:ATTDCalculated, a 1 percentage unit increase in GEAnalyzed:GECalculated only increased the value by 0.54% (r2 = 0.88). Overall, even a small deviation between analyzed and calculated GE can cause large errors in the digestibility of TI, but the use of corrected proportional contributions suggested in the present work can mitigate the problem.

Relaxation method for Mie–Grüneisen type equations of state

Mie–Grüneisen type equations of state (EOS) are widely used to describe the thermodynamics of solids, liquids, and gases in a variety of physics problems, including shock wave dynamics in condensed materials and the thermodynamic behavior of dense gases generated by detonation waves. The Jones–Wilkins–Lee (JWL), Cochran–Chan, and original Mie–Grüneisen EOSs are relevant examples. However, these EOSs present several major difficulties. First, their range of validity is limited because these EOSs are fitted to a reference curve and tolerate only small deviations from that curve. The second difficulty lies in the complexity of the mathematical formulations, affecting the efficiency of pressure relaxation solvers. These two difficulties give rise to a third. Under extreme flow conditions, computational failures are quite common. Methods for “extending” the equations of state are often used to continue the computations. For example, below a certain arbitrary density, the JWL EOS is sometimes extended to the ideal-gas EOS. A fundamentally new method is presented in this work. It consists of using the much simpler Noble–Abel-stiffened-gas EOS as a predictor, to close the corresponding flow model. A thermodynamic relaxation step follows the prediction step. The solution is projected onto the target EOS, in this case the Mie–Grüneisen EOS, with the help of additional transport equations. Therefore, the flow model is an extended version, much more efficient for numerical resolution. This method solves the three problems above by extending the validity domain of the thermodynamic formulation, making the relaxation solvers much faster, and dramatically increasing the robustness of computations.

Effects of Welding Parameters on Droplet Transfer and Bead Geometry in Laser Welding with Aluminum and Stainless Steel Filler Wires

Laser welding is increasingly used in industries because it allows high production cycle time and single-sided welding, but is characterized by a high sensitivity to joint preparation. By inserting filler wires, the sensitivity to joint preparation can be suppressed. In this study, the effect of welding variables on the bead geometry and melted droplet transfer were investigated. Two wires with different thermal diffusivities and densities were selected: stainless steel (STS) and aluminum (Al) wires. According to the wire feeding angle, the melting area tended to differ between the STS and Al wires. This implied that the wire feeding angle had to consider the absorption rate of the material for the laser wavelength. With an increase in the distance between the wire tip and the substrate, the dominant force acting on the droplet was changed from surface tension to gravity. Therefore, the distance was considered as a major factor in determining the droplet transfer mode. In all cases, the droplet transfer period exhibited relatively small deviation when the wire feeding direction was leading. Furthermore, the focal length effects on droplet transfer were irrelevant.

Inverse Problem Algorithm-Based Time-Resolved Imaging of Head and Neck Computed Tomography Angiography Contrast Kinetics with Clinical Testification.

This study mitigated the challenge of head and neck CT angiography by IPA-based time-resolved imaging of contrast kinetics. To this end, 627 cerebral hemorrhage patients with dizziness, brain aneurysm, stroke, or hemorrhagic stroke diagnosis were randomly categorized into three groups, namely, the original dataset (450), verification group (112), and in vivo testified group (65), in the Affiliated BenQ Hospital of Nanjing Medical University. In the first stage, seven risk factors were assigned: age, CTA tube voltage, body surface area, heart rate per minute, cardiac output blood per minute, the actual injected amount of contrast media, and CTA delayed trigger timing. The expectation value of the semi-empirical formula was the CTA number of the patient's left artery (LA). Accordingly, 29 items of the first-order nonlinear equation were calculated via the inverse problem analysis (IPA) technique run in the STATISTICA 7.0 program, yielding a loss function and variance of 3.1837 and 0.8892, respectively. A dimensionless AT was proposed to imply the coincidence, with a lower AT indicating a smaller deviation between theoretical and practical values. The derived formula was confirmed for the verification group of 112 patients, reaching high coincidence, with average ATavg and standard deviation values of 3.57% and 3.06%, respectively. In the second stage, the formula was refined to find the optimal amount of contrast media for the CTA number of LA approaching 400. Finally, the above procedure was applied to head and neck CTA images of the third group of 65 patients, reaching an average CTA number of LA of 407.8 ± 16.2 and finding no significant fluctuations.

Unimodular Theory of Gravity in Light of the Latest Cosmological Data

The unimodular theory of gravity is an alternative perspective to the traditional general relativity of Einstein and opens new possibilities for exploring its implications in cosmology. In this paper, we investigated Unimodular Gravity (UG) with the cosmological data from the Pantheon sample of Type Ia Supernovae (SNs) (2018), Baryon Acoustic Oscillations (BAOs), and the observational H(z) data from the Differential Age method (DA). We also used the Cosmic Microwave Background (CMB) distance priors from the Planck 2018 results. We considered a model consisting of a generalized cosmological constant, radiation, and a dark matter component along with normal matter. The considered theory respects only unimodular coordinate transformations. We first fit our model with low-redshift data from SNs and DA and determined the value of the model parameters (ξ,H0). We found the best-fit value of parameter ξ=6.03±0.40, which deviates slightly from 6, for which the theory becomes the standard general theory of relativity. We observed a small deviation in the value of the Hubble constant (H0=72.6±3.5 km s−1 Mpc−1) in the UG model compared with the standard ΛCDM model (H0=72.2±1.2 km s−1 Mpc−1). Using the BAO + CMB constraint in the UG model, we obtained H0=68.45±0.66kms−1Mpc−1, and ξ is ∼6.029. For the combined datasets (SN + DA + BAO + CMB), the estimated H0=69.01±0.60kms−1Mpc−1 with ξ∼6.037, and in standard gravity, H0=68.25±0.40kms−1Mpc−1.

A new step forward in realistic cluster lens mass modelling: analysis of Hubble Frontier Field Cluster Abell S1063 from joint lensing, X-ray, and galaxy kinematics data

ABSTRACT We present a new method to simultaneously and self-consistently model the mass distribution of galaxy clusters that combines constraints from strong lensing features, X-ray emission, and galaxy kinematics measurements. We are able to successfully decompose clusters into their collisionless and collisional mass components thanks to the X-ray surface brightness, as well as use the dynamics of cluster members, to obtain more accurate masses exploiting the fundamental plane of elliptical galaxies. Knowledge from all observables is included through a consistent Bayesian approach in the likelihood or in physically motivated priors. We apply this method to the galaxy cluster Abell S1063 and produce a mass model that we publicly release with this paper. The resulting mass distribution presents different ellipticities for the intra-cluster gas and the other large-scale mass components as well as deviation from elliptical symmetry in the main halo. We assess the ability of our method to recover the masses of the different elements of the cluster using a mock cluster based on a simplified version of our Abell S1063 model. Thanks to the wealth of mutliwavelength information provided by the mass model and the detected X-ray emission, we also found evidence for an ongoing merger event with gas sloshing from a smaller infalling structure into the main cluster. In agreement with previous findings, the total mass, gas profile, and gas mass fraction are all consistent with small deviations from the hydrostatic equilibrium. This new mass model for Abell S1063 is publicly available, as the lenstool extension used to construct it.

Analysis of news communication strategies in the era of full media based on data mining

Abstract In this paper, we first study the representation of news text, build the content tree using the CTWE text method, and combine the word vector with the interrelationship between words in the content tree. Then, a feature word extraction technique is applied to filter key information, and Single-pass hierarchical clustering algorithm is used to classify the news content, and a data mining algorithm is applied to realize news delivery. Finally, the impact of information’s initial value and credibility on the transmission process is examined, and the model’s feasibility and practicality are assessed. The results show that the RMSE value of the data mining model is 0.0408, the Pearson correlation coefficient is 0.9334, and the cosine similarity is 0.9596, and the model in this paper has the smallest deviation from the real data and the greatest similarity compared with other models. This study confirms the unique advantages of the data mining model in news dissemination.

Statistics and effect evaluation of college students’ participation in Civic Education based on multiple linear regression method

Abstract This paper first designs the study of college students’ ideological and political participation behaviors and determines the independent, dependent, mediating, and control variables of multiple linear regression based on ideological and political participation behaviors. Then, the original data were obtained using questionnaires, the Cronbach’s Alpha coefficient was selected to test the reliability of the questionnaires, and the logical structure of the multiple linear regression model was used to explore the participation degree of college students in ideological and political education and the evaluation of teaching effectiveness based on the multiple linear regression model. The results showed that the relationship between the three dimensions of intrinsic ideological and political efficacy and ideological and political participation behavior was significant and positive regarding the participation degree of ideological and political education. In terms of teaching effectiveness, the regression coefficient R is 0.507, which indicates that the independent variable influences the dependent variable, i.e., 50.7% of the variation of the dependent variable “college students’ evaluation of Civics class”, with a small standard deviation, which indicates that college students’ evaluation of Civics teaching effectiveness and Civics teachers are the same. This paper aims to improve students' awareness of ideological and political participation, as well as their ability to participate and promote the cultivation of qualified citizens in the new era.

Study of quality indicators of sour cream products enriched with extracts of tea drinks

The decline in household income against the backdrop of rising food prices has led to a decrease in their demand. Among fermented milk products, the smallest deviation in purchasing demand can be noted for sour cream. It is possible to reduce the cost of this product line by producing sour cream products. The use of herbal prescription components in sour cream products allows you to expand their range, adjust properties, and give a functional focus. Tea extracts are used as natural dyes and flavors, structure-forming additives. Biologically active substances of tea raw materials and products of its processing exhibit various types of physiological activity: antioxidant, anti-inflammatory, antiseptic, antispasmodic, vasoconstrictive action, etc. To give sour cream products a pleasant color and improved taste properties, it is of interest to use extracts of green tea and hibiscus tea drink. Studies of the obtained sour cream products have been carried out. The mass fraction of the introduced extracts was determined by evaluating the total significance coefficient for the following indicators: harmony of taste; consistency; color. The optimal dosage of green tea extracts and hibiscus tea drink is 10%. Flavor components (a mixture of cinnamon and sugar), a stabilizer were additionally added to the composition of sour cream products. The products were stored at a temperature of 4±2 ºС, the organoleptic, physicochemical and microbiological parameters of the latter were studied. Viscosity studies were carried out in the control and test samples. It has been established that the samples of sour cream products have a high viscosity index, well restore the structure after mixing. Sour cream products with extracts of tea drinks can be consumed as an independent product, as well as a prescription ingredient for baked goods.

Growth of large-sized relaxor ferroelectric PZN-PT single crystals by modified flux growth method

A novel bottom-cooling high-temperature solution growth technique is developed for growing large-sized relaxor ferroelectric 0.91Pb(Zn1/3Nb2/3O3)-0.09PbTiO3 (PZN-PT) single crystals. During the growth, an inverse temperature gradient is maintained in the crucible base by flowing air at a controlled rate. This method restricts the number of spontaneously nucleated crystals at crucible bottom, reduces loss of volatile PbO component and favours the growth of large-sized PZN-PT single crystals. Large-sized PZN-PT single crystals of dimensions ∼ 22 × 20 × 14 mm3 are reproducibly grown by the proposed method. The electrical characteristics of the PZN-PT wafers oriented along the 〈100〉, 〈010〉 and 〈001〉 directions are investigated. PZN-PT wafers oriented along the 〈001〉 direction exhibited superior piezoelectric coefficient (d33) of ∼ 2221 pm/V. The homogeneity of the physical parameters is analysed by preparing 10 elements with dimensions of ∼ 5 × 2.5 × 2.5 mm3 which were cut from single wafer oriented along the 〈001〉 direction. The ferro-, piezo- and dielectric characteristics of these wafers were found to be highly uniform with small standard deviation. The observation of d33 value with less than 2 % deviation from mean value confirms the growth of highly quality PZN-PT single crystals.

An evaluation of the psychometric properties of the strengths and difficulties scale in Turkey: Implications for other non‐WEIRD countries

AbstractThe Strengths and Difficulties Questionnaire (SDQ) is a very widely used scale in which parents, teachers or the child rate various aspects of the child's well‐being. It is widely used in the Western world and is translated into 80+ languages. It is also used in countries that do not classify as WEIRD (Western, educated, industrialized, rich and democratic). However, unlike WEIRD countries, some studies indicate that the psychometric properties of the SDQ when used in non‐WEIRD countries are questionable. Therefore, we gave the SDQ to the mothers and teachers of 310 3‐ to 5‐year‐olds in urban centres of Turkey and examined its psychometric properties. Turkey is not a WEIRD country because it is not Western, although the participants in our study were well educated, living in an industrialized area, rich relative to others in Turkey (although poor relative to Westerners) and democratic. As such, it is not drastically different from WEIRD countries and our question was whether even relatively small deviations from standard WEIRD criteria could result in questionable psychometric properties for the SDQ.

Portable Smart Door base on Arduino and Artifical Neural Network for Temperature and Face Mask Detection

Temperature checks and wearing masks are an effort to reduce the transmission of Covid-19. Manual checking is impractical and spent time screening many people in public areas. This work propose a portable smart door that simultaneously detects the body temperature and mask of the people. Temperature detection uses MLX90614 sensor and Arduino, while mask recognition uses digital camera with artificial neural network (ANN). Component test and completion test are conducted to examine the smart door performance involving 20 volunteers. The door was tested to measure the body temperature of the volunteers with and without a mask. The measured temperature was compared with measurements of a thermal gun. The door will open automatically if the temperature is below 37.2°C and wearing a mask, while remaining closed if above 37.2°C or not wearing a mask. The temperature sensor works properly with a small deviation and saving time almost half of thermalgun response time. The accuracy of mask detection by the ANN is also at a high level of confidence. These findings demonstrate the applicability of the smart door for screening body temperature and mask in public areas for faster and precise.

Electroanalytical sensor based on CuInSe2/carbon sphere towards the non‐invasive determination of dopamine

AbstractDopamine (DA) is known as a crucial neurotransmitter synthesized and secreted by dopaminergic neurons and plays a role in regulating human emotions and behaviors. The determination of DA content is of great significance in clinical application and physiological function research. An electroanalytical sensor based on the ternary semiconductor material copper indium selenide (CuInSe2) coated carbon spheres functionalized glassy carbon electrode (CuInSe2@CS/GCE) towards the non‐invasive determination of DA was constructed in this study. The performances of the sensor were characterized using cyclic voltammetry, impedance method, and differential pulse voltammetry. The results show that wrinkled CuInSe2 completely coated on CS. The sensor exhibits good electrochemical kinetics and response signal towards DA, which results from the good electrochemical activity and excellent electroconductibility of transition metal centers of the composite. The determination limit of the proposed sensor towards DA is 0.59 μM (S/N=3), and the linear measuring range is between 1–800 μM. In addition, the sensor exhibits desirable long‐term robustness, reproducibility, repetitiveness, and interference immunity. In the non‐invasive determination towards real samples of human urine and sweat, the sensor provides good recovery rate and small determination deviation.