Uniform Pattern Research Articles

Potensi dan Keragaman Bakteri Endofit sebagai Agens Pemacu Pertumbuhan dan Biokontrol Anggrek

Soft rot disease in orchid plants is a factor in decreasing orchid production. One way of biological control that has the potential to spur growth is to utilize endophytic bacteria. This study aims to describe the diversity of orchid endophytic bacteria that have the potential as growth promoters and biocontrol agents. Observation parameters include indole acetic acid (IAA) production, inorganic phosphate dissolution, ammonia production of orchid endophytic bacteria, and antagonism of endophytic bacteria to pathogenic bacteria that cause soft rot in vitro. The diversity of orchid endophytic bacteria was analyzed using rep-PCR with BOX-A1R primer. The results showed that 10 isolates of orchid endophytic bacteria were able to produce IAA with a concentration of 79–321 μg/mL, able to dissolve phosphate, and produce ammonia. In antagonism testing against soft rot-causing bacteria, all isolates were able to form an inhibitory zone with a diameter of 3–7.2 cm. Furthermore, diversity analysis using rep-PCR showed that isolates of endophytic bacteria DnPh5, BgCt2, BgVt10, DnLp7, DnBl1, and DnAr4 had a uniform DNA band pattern so that they were grouped together. Meanwhile, isolates of TbPh7, IbtPhm1, DnDr2, and AkOc1 showed different DNA band patterns, indicating that the four isolates were different species or subspecies of bacteria. In dendrogram analysis, DnPh5, BgCt2, BgVt10, DnLp7, DnBl1, and DnAr4 isolates have a similarity of 100%. The similarity of isolates IbtPhm1, DnDr2, and AkOc1 was 90%, 79%, and 68%, respectively, against the other six isolates. TbPh7 isolate is an isolate with a low level of similarity to other isolates, which is about 51%.
 
 Keywords: orchid, endophytic bacteria, growth promoter, biocontrol agent, rep-PCR

Risk analysis of rainfall erosion on upland adjacent to riparian zone of the Three Gorges Reservoir

The Three Gorges Reservoir (TGR) is an artificial riparian ecosystem and influenced on its soil erosion. However, the probability and magnitude of the erosion on upland adjacent to riparian zone and its impacts on the TGR are still unclear. In this research, we determined the relationship between minute-scale rainfall erosivity and soil erosion from three replicated upland bare plots (5 m × 20 m for each) in Zhong County, southwest of China, from 2017 to 2019 (short-term), and estimated the rainfall erosion based on the daily-scale rainfall erosivity from 1992 to 2015 (long-term). We performed generalized extreme value (GEV) modeling to quantify three risk elements (scenario, probability-magnitude relation, consequences) and predicted the erosion risks. The results indicated that, over the short-term, wet season increased the average runoff depth and soil loss by a factor of 1.6 (p < 0.01) and 1.4 (p < 0.01), respectively. Low and rare rainfall erosivity (5 years < return period ≤ 20 years) caused the erosion event with relative low occurrence probability (return period > 5 years) to dominantly contribute the total erosion (>65%) in dry season. Common and normal rainfall erosivity (return period ≤ 5 years) caused the common erosion events (return period ≤ 2 years) to contribute nearly 50% of the total erosion in wet season. Over the long-term, extreme rainfall erosivity (1621 MJ·mm·ha−1·h−1) in dry season was predicted to be more effective on upland erosion, but a uniform pattern of erosion contribution of incremental rainfall return periods was estimated in wet season. Our findings improve the understanding of the uncertainty of upland-surface hydrologic processes in the TGR, and could provide useful risk management or ecological restoration strategies for the soil and water conservationists.

Monolithic fiber/foam-structured catalysts: beyond honeycombs and micro-channels

ABSTRACT Heterogeneous catalysis plays a pivotal role in the current chemical and energy vectors production. Notably, to fully utilize the intrinsic activity and selectivity of a catalyst, the chemical reactor has to be designed and operated optimally to achieve enhanced heat/mass transfer, well-defined contact time of reactants, uniform flow pattern, and high permeability. Structured catalysts are a promising strategy to overcome the major drawbacks encountered in the traditional packed-bed reactor technology due to the improved hydrodynamics in combination with enhanced heat/mass transfer. Newly emerged fiber/foam-substrates, with an entirely open 3D network structure, bring distinct advantages over the honeycomb and micro-channel contacting methods, including free radial diffusion, eddy-mixing driven heat/mass transfer, large area-to-volume ratio, and high contacting efficiency. However, how to place the nanocatalysts onto the fiber/foam-substrates is a challenging problem because the commercial washcoating method has great limitations such as the nonuniformity and easy exfoliation of coatings. This review discusses the newly developed non-dip-coating methods for the fiber/foam-structured catalysts and their promising applications in the strongly exo-/endo-thermic and/or high throughput reaction processes.

The development of blood protein profiles in extremely preterm infants follows a stereotypic evolution pattern

BackgroundPreterm birth is the leading cause of neonatal mortality and morbidity. Early diagnosis and interventions are critical to improving the clinical outcomes of extremely premature infants. Blood protein profiling during the first months of life in preterm infants can shed light on the role of early extrauterine development and provide an increased understanding of maturation after extremely preterm birth and the underlying mechanisms of prematurity-related disorders.MethodsWe have investigated the blood protein profiles during the first months of life in preterm infants on the role of early extrauterine development. The blood protein levels were analyzed using next generation blood profiling on 1335 serum samples, collected longitudinally at nine time points from birth to full-term from 182 extremely preterm infants.ResultsThe protein analysis reveals evident predestined serum evolution patterns common for all included infants. The majority of the variations in blood protein expression are associated with the postnatal age of the preterm infants rather than any other factors. There is a uniform protein pattern on postnatal day 1 and after 30 weeks postmenstrual age (PMA), independent of gestational age (GA). However, during the first month of life, GA had a significant impact on protein variability.ConclusionsThe unified pattern of protein development for all included infants suggests an age-dependent stereotypic development of blood proteins after birth. This knowledge should be considered in neonatal settings and might alter the clinical approach within neonatology, where PMA is today the most dominant age variable.

Relationship of mangrove snail’s abundance (Cerithidea sp.) with mangrove density at mangrove ecosystem in Banda Aceh and Aceh Besar

Mangrove snails are aquatic biota that inhabit in the mangrove ecosystem, they lives attached to mangrove trees or scattered on the substrate surface. The purposes of this study were to identify the species, distribution pattern, the abundance of mangrove snails (Cerithidea sp.) and their correlation with mangrove density, water and soil characteristics in mangrove ecosystem, Banda Aceh and Aceh Besar. The research sampling was started in April to May 2022. The samples were collected from 5 stations, and purposive sampling method was applied in order to select the sampling station. The results discovered that the species of Cerithidea was Cerithidea cingulate, and the highest abundance was 18 individuals/m2 (station 1). Moreover, the lowest abundance was at station 5 as many as 10 individuals/m2, and other stations showed the abundance of C. cingulata was 15.67 individuals/m2 (station 2), 14.67 individuals/m2 (station 4), and 13 individuals/m2 (station 3) respectively, with a uniform distribution pattern at each station. There was no significantly correlation between mangrove density and the abundance of mangrove snails as well as the relationship between the abundance of mangrove snails with the characteristics of water and soil where PSig. > 0.05.

Hydrogen Peroxide (H2O2) Biosensor Based on the Conducting Polymer Using Self-Assembly Technique

Biosensors are in principle fabricated by immobilized biomaterials on a detector membrane and combining them with electrochemical equipment. The applications of enzyme-based biosensors can be explored such as in the process of gas detection, medicine, pathogen detection and detection of toxic levels of substances before and after bioremediation. In this study, H2O2 detection was performed using HRP/PANI, HRP/PPY, HRP/PT and HRP/PT/PPY/PANI layers. The HRP/PANI layer from Variable Pressure Scanning Electron Microscopy (VPSEM) image exhibited a dry surface. The HRP/PPY layer exhibited a surface with agglomerate molecules. The HRP/PT layer, on the hand, exhibited a layer surface with almost the same molecular size. This is confirmed by the higher surface roughness value for HRP/PPY compared to other layers obtained via characterization with Atomic Force Microscopy (AFM). The increasing current response for all three layers was arranged in HRP/PANI&gt; HRP/PT&gt; HRP/PPY. VPSEM and AFM images exhibited surfaces with molecules being in an agglomeration state after the H2O2 detection process. In terms of current response, the response rate of H2O2on the surface of the HRP/PT/PPY/PANI electrode caused the current response obtained to be fast. The roughness value increased with time due to the reaction that took place between the surface of the HRP/PT/PPY/PANI layer with H2O2. The day-based current response showed that day 1 to day 14 exhibited a uniform graph pattern but from day 21 to day 30 there was a change in the graph pattern due to the HRP/PT/PPY/PANI layer undergoing degradation. The activity of the HRP enzyme was studied by looking at its absorption effect for 30 days. From day 1 to day 14, there was a difference in the overall rate of absorption. However, from day 21 to day 30, the rate of absorption remained constant which explains the slowing down of HRP activity.

Causes of the Interannual Variation of Summer Precipitation in Eastern Southwest China

Using ERA5 reanalysis data, we conducted an EOF analysis of summer precipitation in the eastern part of southwestern China (ESWC) over the past 60 years. Our study aimed to investigate the spatial distribution characteristics and interannual variability of summer precipitation in the ESWC, as well as to reveal the possible physical mechanisms influencing its interannual variability. The results indicate that, at the interannual scale, the first two modes of summer precipitation in the ESWC exhibit a uniform pattern and a north–south dipole pattern, respectively. The maximum and minimum time coefficients of the first mode correspond to the severe flood and drought events in 1998 and 2006, respectively, indicating that their time coefficients reflect the typical events well. The tri-pole sea surface temperature anomaly in the North Atlantic, along with the sea ice anomaly near the Barents Sea, induces a quasi-zonal wave train in the upper troposphere. This wave train propagates from the tropical and mid-latitude Atlantic, traverses the mid-high latitudes of Eurasia, and reaches the eastern part of China. The wave train induces cyclonic (anticyclonic) anomalies in the north (south) of the ESWC, facilitating the convergence of high-latitude dry and cold air with warm and moist southwesterly winds from the tropical ocean. This convergence promotes increased summer precipitation in the ESWC. We provided valuable insights into the interannual variability of summer precipitation in the ESWC, shedding light on the physical mechanisms responsible for these variations.

Operation Gukurahundi: A Policy of Genocidal Rape and Sexual Violence in Zimbabwe 1983–1984

The International Criminal Tribunal for Rwanda’s historic judgment in the Akayesu Judgment established that rape and other forms of sexual violence can be an actus reus of genocide as defined by the United Nations Convention on Genocide Article II. The Akayesu Judgment therefore provides a logical framework to analyze a hidden episode of extreme post-colonial state violence in the newly independent Zimbabwe, namely a state policy of mass atrocities in Matabeleland and parts of the Midlands, targeting the minority Ndebele ethnic group during Operation Gukurahundi. The specific foci of this study are the patterns of mass rape and sexual violence in the military operation between 1983 and 1984 in Matabeleland. Drawing on 36 in-depth interviews with survivors from throughout Matabeleland, this study provides a critical new lens on Operation Gukurahundi through its identification of uniform systematic patterns of rape and other forms of sexual violence across Matabeleland. The article concludes that the patterns of rape and other forms of sexual violence identified in this study are indicative of a state policy of systematic genocidal rape between 1983 and 1984, deployed with the intent and effect to destroy, in part, a specific ethnic group, namely the minority Ndebele of Zimbabwe, thereby fulfilling every condition of the Genocide Convention principles of genocide.

Significant differences in black and brown carbon concentrations at urban and suburban sites

Light-absorbing carbonaceous particles (LAC) may cause and/or exacerbate non-communicable diseases, interfere with the Earth's radiative balance, darken urban buildings and impair vistas. In this study, we explored the temporal behaviour of LAC concentrations measured at wavelengths of 370 nm (brown carbon, BrC) and 880 nm (black carbon, BC) at two sites of a mid-sized city in Brazil. We observed sharp changes in LAC concentrations at the city centre site in response to variations in traffic volume. The highest concentrations were observed when winds originated from both the city core and from the direction of the bus terminal. The suburban site exhibited a notably uniform diurnal pattern and consistently lower LAC concentrations throughout the day. Nevertheless, substantial increases during the evening led to mean BrC and BC concentrations (2.6 and 2.2 μg m−3, respectively) comparable to daytime peaks observed in the city centre (3 μg m−3 and 2.5 μg m−3). This phenomenon was attributed to the burning of residential waste and overgrown vegetation in nearby vacant lots. Moreover, the highest concentrations coincided with periods of low wind speeds, usually linked to non-buoyant plumes from point sources. BrC concentrations surpassed BC concentrations, even at the city centre site. Not only was the Ångström absorption exponent (Å370/880) larger at the suburban site compared to the city centre (95th percentiles of 1.73 and 1.38, respectively), but it also exhibited a wider span. Overall, the combined LAC and Å370/880 data indicated that i) biomass burning is a major source of LAC at the suburban site; ii) at the city centre, bare BC particles may become internally mixed with BrC from biomass or fossil fuel emissions and enhance absorption at lower wavelengths. The occurrence of LAC peaks outside the evening rush hours suggests that other sources but on-road vehicular emissions may contribute to the deterioration of the air quality in the urban core. Tackling air quality across the urban perimeter requires targeting other potential sources but traffic emissions.

An enhanced scanning technique for flexible power point tracking under partial shading condition

Flexible power point tracking (FPPT) terminology has recently emergedto support additional functionality for grid-connected systems. Despite having a well-developed operation under uniform irradiance conditions, the FPPT algorithm's operation under partial shading conditions(PSC) reveals substantial challenges. The presented article introduces a global FPPT (GFPPT) algorithm that can operate under the PSC with a fast-trackingspeed. The proposed GFPPT algorithm employs the conventional search-skip-judge global maximum power point trackingmethod and the essential strategic scheme. The method conducts on the left side of the power-voltage curve to avoid the less robust nature ofthe right-sideoperation. Simulation and experimental tests are employed to validate the adequacy of the proposed approach. The simulation and experimental study adopted an indirect control approach using a proportional-integral controller and a buck-boost dc-dc converter. The uniform irradiance condition and PSC patterns with various peaks are chosen, and the presented GFPPT method is applied underdistinct criteria. The proposed method's effectiveness has been adequately validated based on the simulation and experimental outcomes.

PA21 A rare case of diffuse infantile fibromatosis

Abstract Fibromatoses are a heterogeneous collection of tumours of the skin and soft tissue with a large variability in presentation. We present a case of diffuse infantile fibromatosis in a 17-day-old infant boy. He was born at 40 + 7 weeks gestation with a vacuum-assisted delivery following an uncomplicated pregnancy. On physical examination, there were two well-circumscribed circular plaques that coalesced centrally on his left elbow. The plaque measured 2 × 1 cm and was firm, nontethered and nontender. Full skin examination was otherwise normal. Histopathological examination showed hyperkeratotic skin with an attenuated epidermis overlying a dermally based bland-appearing spindle cell proliferation. The lesion was infiltrative throughout the dermis and was arranged in short fascicles and interdigitated with subcutaneous fat, which was extensively trapped by spindle cells. There was no significant atypia and mitotic activity was identifiable but not brisk. Immunohistochemical stains showed strong and diffuse reactivity for smooth muscle actin. Infantile fibromatosis is the childhood counterpart of musculoaponeurotic fibromatosis. It is a benign mesenchymal tumour of infancy and early childhood with diffuse proliferations of oval-to-spindled fibroblasts that infiltrate regional structures. There is a male predominance and in most cases is noted within the first 8 years of life. Clinically, it presents as an asymptomatic, white-yellowish mass that is nontethered to the overlying skin. Although any site may be involved, the majority of cases affect the upper limbs, head and neck region. Histological findings include a wide morphological spectrum. In infants, small oval cells appearing between primitive mesenchymal cells and fibroblasts are in a myxoid background. The cells are loosely arranged and infiltrate skeletal muscle and other regional structures. Peripheral lymphocytic inflammation blends with more cellular proliferation composed of spindle-shaped fibroblasts arranged in bundles and fascicles. There is no well-documented immunohistochemical profile. An important differential diagnosis to exclude is congenital/infantile fibrosarcoma, which, characteristically, has high cellularity, uniform herringbone pattern, high mitotic rate, and zones of haemorrhage and necrosis. In terms of management, as there is a high likelihood of local recurrence in 65% of cases, evidence supports complete excision with documented margins. Where the lesion is diffusely infiltrative, a partial resection to maintain the best postoperative function is recommended.

Texture Feature Extraction from 1H NMR Spectra for the Geographical Origin Traceability of Chinese Yam.

Adulteration is widespread in the herbal and food industry and seriously restricts traditional Chinese medicine development. Accurate identification of geo-authentic herbs ensures drug safety and effectiveness. In this study, 1H NMR combined intelligent "rotation-invariant uniform local binary pattern" identification was implemented for the geographical origin confirmation of geo-authentic Chinese yam (grown in Jiaozuo, Henan province) from Chinese yams grown in other locations. Our results showed that the texture feature of 1H NMR image extracted with rotation-invariant uniform local binary pattern for identification is far superior compared to the original NMR data. Furthermore, data preprocessing is necessary. Moreover, the model combining a feature extraction algorithm and support vector machine (SVM) classifier demonstrated good robustness. This approach is advantageous, as it is accurate, rapid, simple, and inexpensive. It is also suitable for the geographical origin traceability of other geographical indication agricultural products.

P-785 Promising Reproductive Outcomes In Patients With Refractory Thin Endometrium After Autologous Bone Marrow Regenerative Cell Therapy (ABM-RCT) – A Case Series

Abstract Study question Does Autologous Bone Marrow Regenerative Cell Therapy (ABM-RCT) improve endometrial thickness and receptivity and restoration of fertility in refractory cases of thin endometrium? Summary answer Selective Autologous Bone Marrow Regenerative Cell Therapy from Seragen (ABM-RCT) improves endometrial thickness, pregnancy, and live birth rate in refractory cases of thin endometrium. What is known already The impaired endometrial function can limit implantation due to insufficient tissue regeneration. Clinical investigation has proved that stem cells existing in the endometrium might originate from bone marrow and provides evidence that bone marrow-derived cells have a non-hematopoietic physiologic contribution to decidual stroma and play a vital role in implantation and pregnancy maintenance and non-hematopoietic BMSCs are able to impact decidual molecular milieu and overcome implantation defects. ABM-RCT is the most commonly used cell therapy and its safety and efficacy are well-established and documented. This forms the basis for exploring and standardizing ABM-RCT in the management of refractory thin endometrium. Study design, size, duration Eleven patients (from age 29 to 43 with refractory thin endometrium resistant to conventional treatment modalities were recruited and obtained informed consent with detailed explanation that the therapy is still experimental and the risk of failure was given to the couple as part of gynec-oncology treatment. Five patients had asherman’s syndrome, two patients had genital tuberculosis, two patients had thin endometrium hypo-responsive/unresponsive to estrogens, with RIF and two patients underwent chemo and radiotherapy Participants/materials, setting, methods BM aspiration was performed under local anesthesia, from the iliac crest using a disposable BM aspiration needle (Jamshidi, 11 G) and collected in heparinized syringes. Progenitor cell enrichment was done by Seragen’s Selective Enrichment Protocol. Peripheral blood was collected to enrich growth factor concentrate. A 2.9mm Hysteroscope was used with an operating channel and egg pickup needle attached to it and cells were implanted in subendometrial zone in all four walls of the uterine cavity. Main results and the role of chance All patients presented to us with refractory thin endometrium in HRT cycle despite giving all possible medications. Hence the decision was taken for Autologous Bone Marrow Cell Concentrate Therapy.Post ABM-RCT, endometrial thickness showed increase 100% (11/11) of more than 8 mm in all cases on day of embryo transfer with average endometrial thickness improvement was 1.8 mm than previous cycles, with uniform triple layer pattern.10 out of 11 (91%) patients conceived after autologous stem cell injection. 9 Out of 10 (90%) patients conceived had delivered healthy babies and 1 patient (9%) had a miscarriage at 12th week of pregnancy. 1 patient did not conceive will be assessed for immunoprofiling and one more rejuvenation cycle. Limitations, reasons for caution Our study outcomes are consistent with several previous studies and the feasibility of treatment at an IVF setup and encouraging results. Well-planned study with more patients is warranted to evaluate safety, effectiveness, and cost of this modality before it becomes integrated in treatment of this frustrating condition during IVF procedures Wider implications of the findings Our results demonstrates selectively enriched ABM-RCT enhances endometrial thickness, tissue remodeling, uneventful gestation, improved pregnancy and live birth rate. Need for Surrogacy in Non-Responsive Thinendometrium May Be Re-Evaluated. Role of hematopoetic stem cell research and knowledge generated is representing reliable strategy in IVF that may be routinely used in clinicalpractice. Trial registration number Not applicable

High-gain printed monopole antenna with dual-band characteristics using FSS-loading and top-hat structure

In this paper, a printed monopole antenna with high-gain and dual-band characteristics for applications in wireless local area networks and the internet of things sensor networks is presented. The proposed antenna consists of a rectangular patch with multiple matching stubs surrounded to improve the impedance bandwidth of the antenna. The antenna incorporates a cross-plate structure which is seated at the base of the monopole antenna. The cross-plate consist of metallic plates aligned perpendicularly which enhances the radiations from the edges of the planar monopole to maintain uniform omnidirectional radiation patterns within the antenna’s operating band. Furthermore, a layer of frequency selective surface (FSS) unit cells and a top-hat structure is added to the antenna design. The FSS layer consist of three unit cells printed at the back side of the antenna. The top-hat structure is placed on top of the monopole antenna and comprises of three planar metallic structures arranged in a hat-like configuration. The coupling of both the FSS layer and the top-hat structure presents a large aperture to increase the directivity of the monopole antenna. Thus, the proposed antenna structure realizes a high gain without compromising the omnidirectional radiation patterns within the antenna’s operating band. A prototype of the proposed antenna is fabricated where good agreement is achieved between the measured and full-wave simulation results. The antenna achieves an impedance bandwidth |S11| < − 10 dB and VSWR ≤ 2 for the L and S band at 1.6–2.1 GHz and 2.4–2.85 GHz, respectively. Furthermore, a radiation efficiency of 94.2% and 89.7% is realized at 1.7 and 2.5 GHz, respectively. The proposed antenna attains a measured average gain of 5.2 dBi and 6.1 dBi at the L and S band, respectively.

Radon transform of image monotonic rearrangements as feature for noise sensor signature

Source camera identification represents a delicate, crucial but challenging task in digital forensics, especially when an image has to be used as a proof in a court of law. This paper investigates some properties of the Photo Response Non Uniformity (PRNU) pattern noise that represents the fingerprint of any acquisition sensor. The main goal is to define specific and distinctive features for this noise source that enable the identification of the acquisition sensor by simply analysing a few images. These features are required to be independent of image size, modifications, storage mode, etc. The discrimination power of the decreasing rearrangement of a function, combined with the Radon transform, has been investigated in this paper. Preliminary tests show that a proper rearrangement of PRNU image provides specific and device-dependent geometric structures that can be properly coded through the Radon transform. In particular, the empirical distribution of the Radon Transform of rearranged Flat Field images alone is capable to correctly characterize each device with high accuracy, showing robusteness to some standard image modifications, such as quantization and blurring; in addition, it guarantees independence of image size.

Measuring the Cosmic X-Ray Background in 3–20 KeV with Stray Light from NuSTAR

By characterizing the contribution of stray light to large data sets from the CXB Measurement X-ray observatory collected over 2012–2017, we report a measurement of the cosmic X-ray background (CXB) in the 3–20 keV energy range. These data represent ∼20% sky coverage while avoiding Galactic ridge X-ray emission and are less weighted by deep survey fields than previous measurements with CXB Measurement. Images in narrow energy bands are stacked in detector space and spatially fit with a model representing the stray light and uniform pattern expected from the CXB and the instrumental background, respectively. We establish baseline flux values from Earth-occulted data and validate the fitting method on stray-light observations of the Crab, which further serve to calibrate the resulting spectra. We present independent spectra of the CXB with the focal plane module FPMA and FPMB detector arrays, which are in excellent agreement with the canonical characterization by HEAO 1 and are 10% lower than most subsequent measurements: and . We discuss these results in light of previous measurements of the CXB and consider the impact of systematic uncertainties on our spectra.

Textile and metasurface integrated wide-band wearable antenna for wireless body area network applications

Wireless Body Area Network (WBAN) enhances the quality of life through personal health and remote healthcare monitoring. In this work, we present a numerical model, which is based on CST Microwave Studio simulations, and a fabrication process to achieve a wideband, low-profile, and flexible wearable antenna by integrating textiles with a metasurface (MTS). The performance of the developed antenna was investigated in free space and on a human body (chest, arm, and leg) both numerically and experimentally. The results showed that by incorporating a metasurface structure on the antenna, the simulated gain was improved from 6.1 dBi to 9.08 dBi, while the measured gain was increased from 6.63 dBi to 8.49 dBi. The increased gain in a specific direction is related to more power concentration in that direction. The antenna operates in a bandwidth ranging from 6 to 12 GHz, which is preferred for WBAN applications. The antenna with an MTS structure displayed a more uniform radiation pattern with greater directivity and a Front-to-Back Ratio (FBR) of approximately 15 dB from both numerical and measured results, which is essential for WBAN to avoid back radiation from the body while worn and to increase the wireless signal distance. Additionally, numerical analysis of the bending evaluation for different diameters revealed that its reflection coefficient is not much altered. We believe that the developed structure could assist in the fabrication of unique WBANs and healthcare monitoring devices.

Fabrication of micro patterns on BaTiO3:Er3+/Yb3+ perovskite films by femtosecond laser micromachining

Femtosecond lasers currently show much promise as potential sources for the fabrication of optical and photonic devices, displaying high performance due to their high resolution, excellent geometric flexibility, and low collateral damage. In particular, devices displaying high performance based on BaTiO3:Er3+/Yb3+ (BTEY) films have been widely investigated, promising for the innovation of perovskite patterning applications. Herein, we fabricated BTEY perovskite films by spin coating at room temperature. XRD pattern and Raman spectroscopy analysis of the BTEY films revealed a tetragonal crystal structure. The study of Williamson-Hall's method calculated the strain and crystallite size for the BTEY film. Different parameters in the exploiting cylindrical focusing of an fs-laser were adopted to modulate the crater cavity of patterning, which gives the opportunities to evaluate their impact on the energy ablation threshold (Eth). It was found that cavity radius is proportional to the energy cross-section, thus providing wide range dependence of damaged spot size versus pulse energy. The Eth was measured using Liu's method, determining a value of Eth that decreased from 33.4 nJ to 22.4 nJ when the number of applied laser pulses per spot increased. It is found that the number of pulses per spot low possesses the best performance, successfully producing highly uniform patterning. Moreover, the evolution with the number of pulses also revealed changes in the surface morphology of the crater cavity via AFM and scanning confocal fluorescence microscopy (SCFM) analysis. These results are crucial for determining the Eth required to damage the material, understating the driving mechanism of formations of cavity profile surfaces, and changes in their optics properties in the edges owing to the balling effects and structural defects.

U-slot Loaded Half-Circled Microstrip Patch Antenna Analysis Using XGBOOST Machine Learning Algorithm

Half-circled U-slot loaded antenna is studied using the HFSS and Machine Learning (ML) algorithm. The proposed work is for predicting the resonance frequency of the U-slot loaded antenna by providing the dimensions of the antennas.The proposed antenna is designed for Wi-MAX application with operating frequency of 3.4 GHz.The HFSS tool is being used for designing and analyzing fractal antennas and generating the training data. Parametric analysis of the designed U-slot-loaded half-circled antenna is developed by altering the half-circle radius, length of the U-slot and width. The data set is then given to the XGBoost ML algorithm for training the model. The XGBoost contains remarkably high processing speed and contains features like parallelization, cache optimization, and out-of-core computation which makes the perfect algorithm for predicting the resonance frequencies.U-slot loaded half-circled antenna offers a substantial size reduction, a wide impedance bandwidth, and a uniform radiation pattern on all sides.

Laser-synthesis of conductive carbon-based materials from two flexible commercial substrates: A comparison

One of the key challenges in the field of flexible electronics relies on finding conductive materials that can withstand bending and stretching stresses while maintaining their performance. In this context, this work presents a comparative study of laser-induced conductive materials from the direct laser-scribing of two commercial flexible films: the benchmark Kapton® HN polyimide (PI) precursor and the UltemTM 1000 polyetherimide (PEI) alternative contender. The synthesis process on both materials is optimized in terms of electrical conductivity using a high-performance galvanometric laser with a wavelength of 532 nm for the fabrication of multiple samples at different laser powers and speeds. The samples are structurally characterized using Scanning Electron Microscopy (SEM), Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS), and Fourier-Transform Infrared Spectroscopy (FTIR) aiming at understanding the chemical and physical changes of the ablated material. The results demonstrate that the proposed setup is feasible for the synthesis of uniform and reliable conductive patterns on the surface of both substrates with high reproducibility. In particular, it is proved that PEI is more suitable precursor for flexible electronics applications which demand high electrical conductivity, leading to a sheet resistance of 3.62 ± 0.35 Ω/sq at 0.8 W and 5 mm/s once the laser-synthesis process is optimized (against the 6.04 ± 0.63 Ω/sq at 0.6 W and 5 mm/s offered by the LIG on PI). The performance of both laser-induced patterns as electrodes for the fabrication of electrochemical capacitors is also studied and compared in terms of areal specific capacitance.