Close Distance Research Articles

Single-incision bone bridge lateral meniscus allograft transplantation: preserving neurovascular safety with promising results for posterior horn distortion and graft maturation.

This study aimed to investigate the graft maturation and safety of single-incision bone bridge lateral meniscus allograft transplantation (LMAT). This study involved 35 patients who underwent LMAT between 2019 and 2020. All patients completed at least 2years of follow-up (median 34months; range 24-43) and underwent preoperative magnetic resonance imaging (MRI) to assess the trajectory safety of the leading suture passer and all-inside suture instrument (Fast-Fix). Graft status was evaluated according to the Stoller classification. Based on preoperative MRI measurements, the expected trajectory of the leading suture passer did not transect the common peroneal nerve (CPN), with the closest distance between the expected trajectory and CPN being 1.4mm and the average distance being 6.8 ± 3.2mm. The average distance from the lateral meniscal posterior horn (LMPH) to the popliteal neurovascular bundle (PNVB) was 7.4 ± 2.6mm and the nearest was 4.8mm. The expected trajectory of the all-inside suturing instrument did not transect the PNVB when the distance was at least 12mm, from the most lateral margin of the posterior cruciate ligament (PCL). Grade 3 signal intensity in the posterior third of the allograft on MRI was observed in 6 of 35 (17.1%) patients. Amongst the grade 3 signal intensities in the posterior one-third of the allografts, 3 of the 35 (8.5%) LMATs had a distorted contour. The single-incision bone bridge LMAT technique introduced in this study is a convenient approach that preserves neurovascular safety and provides good results for the distortion of the posterior horn of the allograft and graft maturation. The safety zone for the penetrating devices during the procedure extended from 12mm laterally to the most lateral margin of the PCL to the medial margin of the popliteal hiatus. IV.

Mobilization of the blaKPC-14 gene among heterogenous plasmids in extensively drug-resistant hypervirulent Klebsiella pneumoniae.

Ceftazidime/avibactam (CZA) is an effective alternative for the treatment of infections caused by KPC-producing carbapenem-resistant Klebsiella pneumoniae (CRKP). However, KPC variants with CZA resistance have been observed in clinical isolates, further limiting the treatment options of clinical use. In this study, we isolated three KPC-14-producing CRKP from two patients in intensive care units without CZA therapy. The antimicrobial susceptibility was determined using the broth microdilution method. Three CRKP were subjected to whole-genome sequencing to analyze the phylogenetic relatedness and the carriage of antimicrobial resistance genes and virulence factors. Long-read sequencing was also performed to obtain the complete sequences of the plasmids. The horizontal transfer of the blaKPC-14 gene was evaluated by conjugation experiments. Three CRKP displayed resistance or reduced susceptibility to ceftazidime/avibactam, colistin, and tigecycline. Single-nucleotide polymorphism (SNP) analysis demonstrated the close phylogenetic distance between these strains. A highly similar IncFII/IncR plasmid encoding blaKPC-14 was shared by three CRKP, with blaKPC-14 located in an NTEKPC-Ib element with the core region of ISKpn27- blaKPC-14-ISKpn6. This structure containing blaKPC-14 was also observed in another tet(A)-carrying plasmid that belonged to an unknown Inc-type in two out of three isolates. The horizontal transferability of these integrated plasmids to Escherichia coli EC600 was confirmed by the cotransmission of tet(A) and blaKPC-14 genes, but the single transfer of blaKPC-14 on the IncFII/IncR plasmid failed. Three CRKP expressed yersiniabactin and carried a hypervirulence plasmid encoding rmpA2 and aerobactin-related genes, and were thus classified as carbapenem-resistant hypervirulent K. pneumoniae (hvKP). In this study, we reported the evolution of a mosaic plasmid encoding the blaKPC-14 gene via mobile elements in extensively drug-resistant hvKP. The blaKPC-14 gene is prone to integrate into other conjugative plasmids via the NTEKPC-Ib element, further facilitating the spread of ceftazidime/avibactam resistance.

Detection of Small Objects in Side-Scan Sonar Images Using an Enhanced YOLOv7-Based Approach

Deep learning-based object detection methods have demonstrated remarkable effectiveness across various domains. Recently, there has been growing interest in applying these techniques to underwater environments. Conventional optical imaging methods face severe limitations when operating in underwater conditions, restricting their ability to identify objects with good visibility and at close distances. Consequently, side-scan sonar (SSS) has emerged as a common equipment choice for underwater detection due to its compatibility with the characteristics of sound waves in water. This paper introduces a novel method, termed the Enhanced YOLOv7-Based Approach, for detecting small objects in SSS images. Building upon the widely-adopted YOLOv7 method, the proposed approach incorporates several enhancements aimed at improving detection accuracy. First, a dedicated detection layer tailored for small objects is added to the original network architecture. Additionally, two attention mechanisms are integrated within the backbone and neck components of the network, respectively, to strengthen the network’s focus on object features. Finally, the network features are recombined based on the BiFPN structure. Experimental results demonstrate that the proposed method outperforms mainstream object detection algorithms. In comparison to the original YOLOv7 network, it achieves a Precision of 95.5%, indicating a significant improvement of 4.8%. Moreover, its Recall reaches 87.0%, representing an enhancement of 5.1%, while the mean Average Precision (mAP) at an IoU threshold of 0.5 (mAP@.5) reaches 86.9%, reflecting a 6.7% improvement. Furthermore, the mAP@.5:.95 reaches 55.1%, a 4.8% enhancement. Therefore, the method presented in this paper enhances the performance of YOLOv7 for object detection in SSS images, providing a fresh perspective on small object detection based on SSS images and contributing to the advancement of underwater detection techniques.

Origin of Giant Rashba Effect in Graphene on Pt/SiC

Intercalation of noble metals can produce giant Rashba-type spin–orbit splittings in graphene. The spin–orbit splitting of more than 100 meV has yet to be achieved in graphene on metal or semiconductor substrates. Here, we report the p-type graphene obtained by Pt intercalation of zero-layer graphene on SiC substrate. The spin splitting of ∼200 meV was observed at a wide range of binding energies. Comparing the results of theoretical studies of different models with the experimental ones measured by spin-ARPES, XPS and STM methods, we concluded that inducing giant spin–orbit splitting requires not only a relatively close distance between graphene and Pt layer but also the presence of graphene corrugation caused by a non-flat Pt layer. This makes it possible to find a compromise between strong hybridization and increased spin–orbit interaction. In our case, the Pt submonolayer possesses nanometer-scale lateral ordering under graphene.

Subjective Wellbeing, Work Performance and Lived Experience of Zanzibari Women Entrepreneurs with Uncorrected Functional Presbyopia: A Pre-Post Mixed-Methods Study

ABSTRACT Purpose Uncorrected presbyopia has been shown to reduce Zanzibari women’s quality of life. In this mixed-methods study, we examined the subjective wellbeing and self-reported work performance among older women entrepreneurs with functional presbyopia before and shortly after correction, and how poor vision at close distance affected their daily lives. Methods Women entrepreneurs underwent eye examination to identify those with uncorrected functional presbyopia. Their subjective wellbeing and work performance were both measured in Cantril’s ladder. Ready-made glasses were then provided and 30 minutes to an hour later, their subjective wellbeing and work performance was remeasured. Twenty women entrepreneurs were interviewed to understand their lived experience with uncorrected presbyopia. Results Two-hundred-seventeen women entrepreneurs were included in the survey (mean age 51.6 years, SD 8.64). Women entrepreneurs had a mean subjective wellbeing score of 3.32 (SD 1.10) pre-correction and 5.99 (SD 1.13) post-correction (p < .001), and a mean self-rated current work performance score of 4.62 (SD 1.36) before correction and 5.47 (SD 1.35) post-correction (p < .001). One-hundred-and-ninety (87.6%) and 121 women entrepreneurs (55.8%) rated their current subjective wellbeing and work performance scores < 5, respectively. Around 1/4 of women entrepreneurs reported having severe difficulties with near tasks. Conclusion Poor vision at a close distance caused by uncorrected functional presbyopia negatively affected economic, physical and psychosocial aspects of women entrepreneurs’ lives. Subjective wellbeing and self-reported work productivity scores improved significantly shortly after presbyopia was corrected. More research with longer follow-up is needed to understand the full benefits of correcting presbyopia.

Towards Realistic 3D Models of Tumor Vascular Networks.

For reliable in silico or in vitro investigations in, for example, biosensing and drug delivery applications, accurate models of tumor vascular networks down to the capillary size are essential. Compared to images acquired with conventional medical imaging techniques, digitalized histological tumor slices have a higher resolution, enabling the delineation of capillaries. Volume rendering procedures can then be used to generate a 3D model. However, the preparation of such slices leads to misalignments in relative slice orientation between consecutive slices. Thus, image registration algorithms are necessary to re-align the slices. Here, we present an algorithm for the registration and reconstruction of a vascular network from histologic slices applied to 169 tumor slices. The registration includes two steps. First, consecutive images are incrementally pre-aligned using feature- and area-based transformations. Second, using the previous transformations, parallel registration for all images is enabled. Combining intensity- and color-based thresholds along with heuristic analysis, vascular structures are segmented. A 3D interpolation technique is used for volume rendering. This results in a 3D vascular network with approximately 400-450 vessels with diameters down to 25-30 µm. A delineation of vessel structures with close distance was limited in areas of high structural density. Improvement can be achieved by using images with higher resolution and or machine learning techniques.

Hemagglutinin 3 and 8 can be the most efficient influenza subtypes for human host invasion; a comparative in silico approach

The severity of the influenza virus infection is largely determined by its ability to invade the human host receptor. This critical step is conducted by utilizing hemagglutinin (HA) due to its binding with sialic acid 2,6 (SA). Though 18 subtypes (H1–H18) of HA have been identified, the most efficient one for conducting the host entry has not yet been resolved. This study aims to assess the severity of infections for HA variants by conducting a comparative docking of H1–H18 with the human SA receptor. Eighteen viral 3D structures were retrieved, minimized, and optimized for docking with human SA. In all retrieved structures, five conserved amino acid residues were selected for docking with human SA. Special protein grids were prepared by locating these five residues in the 18 selected subtypes. Results showed that H3 and H8 exerted the highest standard precision and extra precision docking scores, and the highest binding affinities with the human SA, respectively. Phylogenetic analyses confirmed the actual positioning of the selected 3D structures and showed these docked structures belonged to their usual classes due to the extremely close distances found in each docked subtype compared with its corresponding non-docked structures. H8-SA showed slightly better RMSD and SASA values than H3-SA, while H3-SIA showed more favourable radius of gyration scores than H8-SIA in the majority of the simulation period. Due to the highest affinity of binding of H3 and H8 with the human receptor, special caution should be exercised regarding any possible outbreak mediated by these subtypes in human populations. However, it is important to acknowledge a limitation inherent to the computational approach; it may hold relative rather than absolute significance. Further research is needed to deepen our understanding of the intricate interplay between HA variants and the host receptor, taking into account the broader context of viral infection dynamics. Communicated by Ramaswamy H. Sarma

Convex grid drawings of planar graphs with constant edge-vertex resolution

In this work, we continue the study of the area required for convex straight-line grid drawings of 3-connected plane graphs, which has been intensively investigated in the last decades. Motivated by applications, such as graph editors, we additionally require the obtained drawings to have bounded edge-vertex resolution, that is, the closest distance between a vertex and any non-incident edge in the drawing is lower bounded by a constant that does not depend on the size of the graph. We present a drawing algorithm that takes as input a 3-connected plane graph with n vertices and f internal faces, and computes a convex straight-line drawing with edge-vertex resolution at least 12 on an integer grid of size (n−2+a)×(n−2+a), where a=min⁡{n−3,f}. Our result improves the previously best-known area bound of (3n−7)×(3n−7)/2 by Chrobak, Goodrich and Tamassia.

The impact of psychological distance and fintech on Chinese farmers’ willingness to make financing choices

ABSTRACT Using data from China’s 2017 national household survey, we examine the effect of psychological distance on Chinese farmers’ willingness to make financing choices. Our empirical results show that psychological distance has a statistically significant impact on farmers’ choice of finance. A close psychological distance increases farmers’ willingness to choose financial institutions by activating low-level construal representation. Fintech plays an intermediary role. The psychological distance between farmers and financial institutions affects farmers’ financing choices and is mediated by fintech. Our study offers the micro-level proof of the relationship between psychological distance and Chinese farmers’ financing preferences.

Development of Copper-based Catalysts for the Preparation of C2+ by Electrochemical Reduction of CO2

Electrocatalytic reduction of carbon dioxide involves the conversion of carbon dioxide (CO2) and water into fuels and other chemicals under mild conditions using electrical energy, thereby simultaneously enabling carbon recycling as well as renewable energy storage. The reaction produces a wide variety of products, of which C2+ products such as ethylene, ethanol and propanol have higher energy density and added value compared to C1+ products such as carbon monoxide and formic acid [1]. Electrochemical reduction of CO2 is carried out using a gas diffusion electrolytic cell, which has many advantages: 1. small size, easy operation, close electrode distance, etc., which can effectively improve the mass transfer efficiency between gas and liquid; 2. the advantage of close electrode distance is low potential and less electrolyte consumption; 3. the reactor is easy to install and dismantle, the reaction system is well-closed and does not leak; the electrolyte is circulated outside the body, and the flow rate is adjusted by a peristaltic pump, which is more convenient and easy to control. At present, a new type of catalyst preparation has been completed and has completed the effect of the test, the catalyst is by the copper iodide (CuI) and 4,4-bipyridine coordination reaction two obtained by the ratio of the amount of different substances of the two mixed as well as the reaction of different time to obtain different coordination form of the catalyst, and the effect of the test, that is, the catalyst mixed with organic solvents are sprayed together with the carbon paper, clamped into the electrolytic cell, the electrolyte is analyzed using various instruments. Various instruments were used to analyze the composition of the electrolyte to derive the percentage of product. Through the test, it was found that the color of the catalyst gradually became darker with the prolongation of the reaction time, and the color of the catalyst gradually became darker with the increase of the proportion of 4,4-bipyridine in the reactants. The catalytic effect of the darker catalysts was significantly better than that of the lighter catalysts, with the percentage of C2+ products such as ethylene and ethanol increasing by 10%-15%.

Can the Parker Solar Probe Detect a CME-flare Current Sheet?

A current sheet (CS) is the central structure in the disrupting magnetic configuration during solar eruptions. More than 90% of the free magnetic energy (the difference between the energy in the nonpotential magnetic field and that in the potential one) stored in the coronal magnetic field beforehand is converted into the heating and kinetic energy of the plasma, as well as accelerating charged particles, by magnetic reconnection occurring in the CS. However, the detailed physical properties and fine structures of the CS are still unknown, since there is no relevant information obtained via in situ detections. The Parker Solar Probe (PSP) may provide us with such information should it traverse a CS in an eruption. The perihelion of PSP’s final orbit is located at about 10 solar radii from the center of the Sun, so it can observe the CS at a very close distance, or even traverse the CS, which would provide us with a unique opportunity to look into the fine properties and structures of the CS, helping to reveal the detailed physics of large-scale reconnection that would have been impossible before. We evaluate the probability that PSP can traverse a CS, and examine the orbit of a PSP-like spacecraft that has the highest probability to traverse a CS.

Analisis Faktor Pemlihan Alat Kontrasepsi IUD Pasca Persalinan DI Wilayah Puskesmas Rawalo

The high population growth in developing countries and the high birth rate in Indonesia are currently important problems that require extra attention in their management to achieve birth control. According to the Head of BKKN Hasto, there is Postpartum Family Planning Data in 2022 which is still very low at 15.8% so that there are still 85% of mothers who have not used Postpartum Family Planning. Success Rate Postpartum IUD is a contraceptive method that is safe to use for almost all women with an effectiveness rate of 99.94%, Postpartum IUD installation is done immediately after giving birth in less than 48 hours. Based on this, this study aims to explore the use of postpartum IUD contraception in the Rawalo Health Center area. A comparative study was carried out using documentation of delivery registers at the Rawalo Health Center for 8 postnatal IUD acceptors in the Rawalo Health Center area using a purposive sampling technique with a phenomenological approach.The results showed that the characteristics of the primary informants were 8 acceptors aged 20-35 (75%), while those aged &gt; 35 years (25%). The informants of this research are acceptors. This research was conducted in-depth interviews and observations. The results of this study prove that the factor analysis for choosing a postpartum IUD contraceptive device in the Rawalo Health Center area is the reason acceptors choose a postpartum IUD contraceptive device, husband/family support after using a postpartum IUD, KIE that is not carried out optimally and access to health services that have been quite good and for a fairly close distance of about 10 minutes.

Research on the coupled support technology of a composite rock beam-retained roadway roof under close coal seams

IntroductionThe technology of gob-side entry retaining without coal pillars in close (distance) coal seams is still immature, and the roof control and support technology in this case is not perfect.MethodsIn this paper, the coupled support technology of a composite rock beam roof under close coal seams is systematically studied by using theoretical analysis, numerical simulation and field test.ResultsBoth the floor slip calculation results and numerical simulations indicate that the vertical failure depth in the plastic zone of the #8 coal seam has not penetrated the roof of the #9 coal seam after mining, which is consistent with the field electronic imaging results. A theoretical formula for a composite rock beam model anchored by high-prestressed anchor cables was derived, and a formula for the optimal spacing of anchor cables under noncompressive shear failure of the roof was obtained. Identification of the internal stress hazard region of the rock beam provides a basis for determining the locations of vertical support. Through numerical simulation of different support schemes, including roof cutting, arrangement of high-prestressed anchor cables, and setting up of vertical supports, roof cutting was found to effectively reduce the stress of supporting structure and roof pressure. Setting up of vertical supports can reduce the roof convergence by 25.2%, and coupling with anchor cables can reduce the convergence by more than 49.1%. The feasibility of this support scheme was verified through field tests, with a maximum convergence of 99 mm between the roof and floor.DiscussionThis two-way verification approach, in which the damage degree of the roof of a close coal seam is analyzed through multiple means, targeted support plans are proposed, the support mechanisms are explored, and feedback is conducted through field tests, plays a certain guiding role in solving roof control of the gob-side entry retaining under similar geological conditions.

Marine distribution and habitat use by Snow Petrels Pagodroma nivea in East Antarctica throughout the non-breeding period

The relationships between flying Antarctic seabirds and their at-sea environments remain poorly understood, particularly outside of the breeding season. Improving our knowledge of how these marine predators use their habitat is a critical step towards conservation of these species. We tracked 27 adult Snow Petrels from two large breeding colonies in East Antarctica during the Austral winter (non-breeding period) – when they are primarily at sea away from their nesting sites. During this time, Snow Petrel habitat use was most associated with bathymetry (&amp;gt; 5000 m), low sea-surface height, relatively close distance to the southern boundary of the Antarctic Circumpolar Current, relatively close distance to the ice-edge, relatively high sea-ice concentration, and low sea-surface temperature. Individuals displayed various movement patterns: 20 birds occupied overlapping winter areas that ranged broadly (up to 2000 km) from their breeding sites. The remaining birds ventured far beyond their breeding sites – reaching a maximal distance from the colony of 5,268 km. One individual circumnavigated Antarctica. Daily activity patterns were related to day length, with peak activity occurring near dawn and dusk. Nocturnal activity increased from March until August/September. Key results reveal and depict Snow Petrel habitat maps for the non-breeding period in the East Antarctic region.

Coupling analysis method of grouting construction with deformation response of adjacent existing tunnel

In the new tunnel under close distance through the existing tunnel risk source, the grouting scheme developed to compensate for stratum losses is still based on empirical methods, relying on the overburden thickness of existing tunnels. This can potentially lead to an excessively high or low probability of uplift of existing tunnels. Proposing a coupled deformation analysis method between the grouting construction and adjacent existing tunnels is of great theoretical significance for developing grouting schemes. In order to reasonably limit the design parameters of grouting construction, based on the theory of fluid–solid coupling elastic pore-column expansion and the theory of random media, the calculation method of stratum displacement which simultaneously considers the coexistence of grout compaction expansion and permeability diffusion mode is derived, and the accuracy of the calculation method is verified by engineering examples. The accuracy of this calculation method was verified through engineering examples. Combined with the deformation coordination condition, the existing tunnel is regarded as an elastic Euler-Bernoulli continuous beam, and the finite element coupling balance equation of the interaction between the existing tunnel and the surrounding soil is obtained. Based on this, a coupling calculation model of the grouting construction and the deformation response of the adjacent existing tunnel is established. Combined with three times of grouting construction examples in the shield tunneling project of Beijing Metro Line 12 under the existing airport line, the reliability of the coupling calculation model to determine the grouting construction parameters is verified. The calculation parameters in the coupling calculation model have clear physical meanings, which can provide a theoretical basis for the grouting design of similar risk source projects.

Voice Warning to Identify Distance to Obstacles on Smart Cane for Blind People

Blind people are often hampered in their mobility, while currently available assistive technology includes manual sticks and electronic mobility devices. Currently, the development of smart canes is still being carried out in many studies. Smart cane works by detecting the distance of the cane to obstacles in front of you. From detecting this distance, the response the user gets is generally in the form of vibrations and sounds from the buzzer. The sound provided by the buzzer cannot differentiate the distance between obstacles. Therefore, this study proposes the existence of additional sound playback responses to differentiate far, middle, and near obstacles. Apart from that, the design of the prototype refers to the shape of a flashlight. The smart cane is designed using an Arduini UNO microcontroller with a rechargeable battery power supply with three response components, namely two ISD 1820 modules connected to a speaker to detect long distances (201-300 cm) with a "Hati-hati" sound and medium distances (101-200 cm) with an "Awas" sound, as well as a buzzer and piezoelectric component in the form of a "beep" sound and vibration for close distances (1-100 cm) to obstacles. The result is that both the ultrasonic sensor and response components work according to design. Apart from that, the rechargeable battery supply feature and the implementation of the prototype design make it easier for users to store and use for daily activities.

Combining Force Fields and Neural Networks for an Accurate Representation of Chemically Diverse Molecular Interactions.

A key goal of molecular modeling is the accurate reproduction of the true quantum mechanical potential energy of arbitrary molecular ensembles with a tractable classical approximation. The challenges are that analytical expressions found in general purpose force fields struggle to faithfully represent the intermolecular quantum potential energy surface at close distances and in strong interaction regimes; that the more accurate neural network approximations do not capture crucial physics concepts, e.g., nonadditive inductive contributions and application of electric fields; and that the ultra-accurate narrowly targeted models have difficulty generalizing to the entire chemical space. We therefore designed a hybrid wide-coverage intermolecular interaction model consisting of an analytically polarizable force field combined with a short-range neural network correction for the total intermolecular interaction energy. Here, we describe the methodology and apply the model to accurately determine the properties of water, the free energy of solvation of neutral and charged molecules, and the binding free energy of ligands to proteins. The correction is subtyped for distinct chemical species to match the underlying force field, to segment and reduce the amount of quantum training data, and to increase accuracy and computational speed. For the systems considered, the hybrid ab initio parametrized Hamiltonian reproduces the two-body dimer quantum mechanics (QM) energies to within 0.03 kcal/mol and the nonadditive many-molecule contributions to within 2%. Simulations of molecular systems using this interaction model run at speeds of several nanoseconds per day.

Simulations of Compression Ramp Shock Wave/Turbulent Boundary Layer Interaction Controlled via Steady Jets at High Reynolds Number

Shock wave/turbulent boundary layer interaction (SBLI) is one of the most common physical phenomena in transonic wing and supersonic aircraft. In this study, the compression ramp SBLI (CR-SBLI) was simulated at a 24° corner at Mach 2.84 using the open-source OpenFOAM improved delayed detached eddy simulation (IDDES) turbulence model and the “Rescaling and Recycling” method at high Reynolds number 1.57×106. The results of the control effect of the jet vortex generator on CR-SBLI showed that the jet array can effectively reduce the length of the separation zone. The simulation results of different jet parameters are obtained. With the increasing jet angle, the reduction in the length of the separation zone first increased and then decreased. In this work, when the jet angle was 60°, the location of the separation point was x/δ=−1.48, which was smaller than other jet angles. The different distances of the jet array also had a great influence. When the distance between the jet and the corner djet=70 mm, the location of the separation point x/δ=−1.48 was smaller than that when djet=65/60 mm. A closer distance between the jet hole and the corner caused the vortex structures to squeeze each other, preventing the formation of a complete vortex structure. On the other hand, when the jet was farther away, the vortex structures could separate effectively before reaching the shock wave, resulting in a better inhibition of SBLI. The simulation primarily focused on exploring the effects of the jet angle and distance, and we obtained the jet parameters that provided the best control effect, effectively reducing the length of the CR-SBLI separation zone.

LoRa and IoT-based Heart Rate and Temperature Monitoring Tool Using MQTT Protocol

Heart rate is one of the most important organs in the human body as it plays a role in the circulatory system. Body temperature is the result of the body's metabolic processes and is influenced by external and internal factors. In this research, we design a monitoring tool that uses LoRa and IoT technology to monitor heart rate and human body temperature. This tool aims to provide real-time health monitoring and can communicate remotely. MQTT allows efficient data transmission between connected devices in the network. Pulse heart rate sensor and temperature sensor MLX90614 The data obtained from these two sensors is sent through the LoRa network to the LoRa gateway. The LoRa gateway functions as a link between the monitoring device and the MQTT server. The gateway receives data from the monitoring device via the LoRa network and forwards it to the MQTT server via an internet connection. The MQTT server sends the data to an application that can be accessed via a smartphone. The test results show that the RSSI value of -72.5 dBm is obtained when the minimum distance is 5 metres. The lowest value for RSSI, which is -93.5 dBm, is obtained at the maximum testing distance of about 55 metres. For the results of the packet loss value is 0% occurs at a closer distance, but at a distance of 50m (5%) and at a distance of 55m (20%) indicates that the signal begins to weaken or experience interference at a greater distance

Enhancement of flame spread and droplet dynamics behavior of biodiesel constituents with ethanol and MWCNT-OH additions

The interactive droplet combustion between three adjacent droplets of biodiesel constituents was investigated to obtain flame spread and droplet dynamics behavior enhancement with ethanol and hydroxyl-functionalized multi-walled carbon nanotubes (MWCNT-OH) additives. The experiment was conducted at atmospheric pressure and under normal gravity using spatial and temporal tracking. This study found that ethanol effectively increases flame spread velocity and shortens droplet heating time at a close droplet distance. Meanwhile, MWCNT-OH shortens flame spread induction time at a large droplet distance when thermal conduction time mainly controls the flame spread. Both additives improve the volatility and thermal conductivity of fuel blends, extending the flame spread limit distance with strong reciprocal interaction between droplets and accelerating combustion with a higher burning rate. Different flame spread mechanisms were observed and determined by the fuel additives. Child droplet ejection and microburst flame encourage rapid ignition and flame spread to the next unburned droplet. The puffing and microexplosion mechanisms of the fuel blends were determined by the nucleation type preceding the child droplet ejection. Combining ethanol and MWCNT-OH as fuel additives is the most effective way to improve combustion and flame spread performance because ethanol induces nanoparticle burns at the earlier combustion stage.