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This paper presents a novel spectrum sensing and resource allocation method for Cognitive Radio Networks (CRNs) using the Hazelnut Tree Search (HTS) algorithm in a frequency-hopping framework. CRNs enable secondary users (SUs) to utilize unused licensed spectrum without causing interference to primary users (PUs). The proposed Spectrum Sensing and Resource Allocation using Hazelnut Tree Search in CRN (SS-RA-HTS-CRN) method detects PU presence, prompting SUs to switch channels to avoid interference, guided by a designated guide node (GN). The HTS algorithm selects optimal sensing nodes and improves spectrum sensing, enhancing resource allocation reliability. Simulations in NS-3.26 show that SS-RA-HTS-CRN achieves delay reductions of 28.93%, 31.9%, and 22.45%, delivery ratio improvements of 28.21%, 17.41%, and 11.565%, and packet drop rate reductions of 35.4%, 44.3%, and 23.12% compared with Energy-Aware Resource Allocation with Backtracking Search Optimization (SS-RA-BSO-CRN), Spectrum Sensing with Hybrid Particle Swarm and Gravitational Search (SS-hybrid PSOGSA-CRN), and Spectrum Sensing using Modified Spider Monkey Optimization (SS-MSMO-CRN). The proposed SS-RA-HTS-CRN method significantly enhances efficiency, reliability, and adaptability in CRNs, making it a promising solution for dynamic spectrum management.

Understanding molecular interactions is essential for biologists to elucidate protein functions, behaviors, and predict related biological processes. Recent studies have concentrated on examining protein–nanoparticle interactions using various techniques to determine the biological effects of nanoparticles. Investigating dendrimers as potential drug delivery agents requires an understanding of their ability to bind small ligands. In this research, we thoroughly examined the interaction between human serum albumin (HSA) and biocompatible polymeric Phloroglucinol Succinic Acid (PGSA) dendrimers of different generations. Using spectroscopic analysis and molecular docking studies, we aimed to uncover the mechanisms behind PGSA dendrimer-HSA binding, which could enhance stability, half-life, and bio-distribution. Our results, obtained through UV-Visible spectroscopy, fluorescence spectroscopy, and molecular docking, indicate a predominantly ground state complex formation with a single binding site, mainly mediated by hydrogen bonding. This study highlights the importance of understanding polymeric nanoparticle–protein interactions in drug design to improve drug solubility and therapeutic efficacy. Additionally, our investigation into dendrimer-HSA interactions offers promising insights into bio-barrier permeability, potentially aiding in the treatment of brain tumors using dendritic structures.

Directed energy deposition (DED) is an additive manufacturing (AM) technology that builds components using laser melting and solidification. To manufacture components with a consistent microstructure, powder feeding mechanism in the DED process must be precisely managed. Powder flow is one of the crucial determinants contributing to the quality of DED component produced. Considering this, research in powder feeders becomes critical. The rate of mass flow of powder elements in a rotary vane feeder is explored in this work utilizing mathematical, computational, and experimental methods. In mathematical model, the rate of mass flow was computed using volume and particle-based approaches. The discrete-element method (DEM) was used to simulate particle flow in rotary vane feeder. The effect of rotor speed on mass flow rate (MFR) is evaluated experimentally for aluminum, iron, and lead in order to explore the effect of particle density in powder flow characteristics. The experiment is also replicated with three variants of lead particle sizes to infer more on the impact of particle diameter on rate of mass flow. The accuracy of the mathematical model is assessed by comparing the experimental results to the mathematical and simulation results. In volume-based approach, the results showed that the simulated outcomes were 77% accurate to the experimental results. In particle-based approach, the results showed that the simulated outcomes were 93% accurate to the experimental results. The simulated result of mass flow rate is approximately 92% accurate in comparison to experiments. Further, in determining mass flow rate, the particle-based approach is more accurate than the volume-based approach. The findings of this research contribute to the development of a precise powder feeder in metal additive laser manufacturing (MALM), which finds use in modern manufacturing.

Recently, wind power has gained popularity as a sustainable energy source. Wind energy conversion systems (WECSs) can accept fixed speed and variable speed (VS) operations. VS-WECSs are preferable to conventional WECSs because of their higher electricity collection capacity. Maximum power point tracking (MPPT) systems are essential for maximizing the efficiency of wind energy generation in wind turbine (WT) installations linked to power grids. This study introduces a hybrid fuzzy logic controller-based MPPT (FLC-MPPT) for WTs connected to permanent magnet synchronous generators (PMSGs) to accurately determine the maximum power output of WTs. This study employs a three-phase back-to-back converter to link a PMSG to a utility grid. The reference signals for pulse width modulation controllers comprise two-phase system currents. It constructs a converter that can transfer electrical energy in both directions using insulated-gate bipolar transistor technology and is powered by a battery. The machine-side converter uses model predictive control for the present control loop. Given the generator’s susceptibility to changes in wind conditions, this factor is of the utmost importance. A WT simulation was conducted using MATLAB/Simulink and an FLC methodology was employed. The model used a PMSG. Measurements of rotor speed, power, induced voltage, and current were taken in relation to variations in wind speed. The simulation results show that the FLC-MPPT can maximize the output power over a wide range of wind speeds with a higher efficiency of 92.6% and performance of 95.7%.

Soft computing techniques are now frequently employed in the industrial sector for process parameter modelling and optimization. Soft computing approaches produce good projected values that match the experimental data. In this study, a prediction model for the mechanical parameters of friction-stir-welded AA7068-T6 was established, including microhardness and ultimate tensile strength at the weld nugget. The models were created using the adaptive fuzzy inference system approach. For microhardness and ultimate tensile strength of weld nuggets, the generalized bell membership function yields minimal training g errors of 2.0494 and 0.84327, respectively. To test the expected adaptive fuzzy inference system output, the validation experiment was carried out at a tool rotation speed of 1400 rpm and a welding speed of 60 mm/min. The observed values for ultimate tensile strength and microhardness of the weld nugget obtained after the validation experiment were closer to the expected adaptive fuzzy inference system output.

A compact and novel semi-elliptical defected ground structure (SE-DGS) tapered microstrip line fed UWB antenna with band-notched characteristics integrated with Ku and K band applications is proposed. The proposed SE-DGS UWB antenna is printed on a compact size of (15 × 18 mm2) and has radiation bandwidth of 25.66 GHz over a span of 4.11–29.77 GHz, a fractional bandwidth of 151.47%, and both the down link of X- and ITU-8 bands are completely notched over a span of 6.86–9.09 GHz using a single C-structured reflector. The proposed antenna has a fluctuating gain of 1.7–4.82 dBi except for the gain at the notched band frequency, which is −12.25 dBi. The proposed antenna has a high radiation efficiency of 96.23%, stable radiation patterns over the UWB range, and a high rejection capability of the notched band, which is noticed from the high value of VSWR of 23.15, making it a potential candidate for UWB, Ku, and K band wireless applications with effectively suppressed downlink of X and ITU-8 bands. The developed antenna design simulates breast cancer tissue detection by comparing S21results, and specific absorption rates with and without tumour scenarios. These results suggest that the proposed radiator and system detect breast tumours efficiently.

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Solid waste management processes and cleanliness have been complex challenges in India. The launch of Swachh Bharat Mission (Clean India Mission), a nationwide campaign aroused the interests of many researchers and practitioners in cleanliness and waste management. This is a perceptual study that analysed municipal officials' perceptions on solid waste management process and effectiveness of Swachh Bharat mission pertaining to Thanjavur, a district of rich cultural heritage in Tamil Nadu, India. This study assessed the respondents' perceptions on existing methods of waste collection and its disposal. This research work also examined the challenges in the solid waste management process and successful implementation of Swachh Bharat mission. Further, the influence of socio-demographic factors on solid waste management and clean India mission was explored. The findings of this study may be beneficial to researchers, authorities and policymakers to progress further in this area for ensuring effective solid management process and cleanliness.

Background: Perforated peptic ulcer disease (PPUD) has a prevalence of 0.004–0.014% with mortality of 23.5% (Tarasconi et al. in World J Emerg Surg 15(PG-3):3, 2020). In this single center study, we examined the impact associated with patient transfer from outside facilities to our center for definitive surgical intervention (exploratory laparotomy). Methods: Using EPIC report workbench, we identified 27 patients between 2018 and 2021 undergoing exploratory laparotomy with a concurrent diagnosis of peptic ulcer disease, nine of which were transferred to our institution for care. We queried this population for markers of disease severity including mortality, length of stay, intensive care unit (ICU) length of stay, and readmission rates. Manual chart reviews were performed to examine these outcomes in more detail and identify patients who had been transferred to our facility for surgery from an outside hospital. Results: A total of 27 patients were identified undergoing exploratory laparotomy for definitive treatment of PPUD. The majority of patients queried underwent level A operations, the most urgent level of activation. In our institution, a Level A operation needs to go to the operating room within one hour of arrival to the hospital. Average mortality for this patient population was 14.8%. The readmission rate was 40.1%, and average length of ICU stay post-operatively was 16 days, with 83% of non-transfer patients requiring ICU admission and 100% of transfer patients requiring ICU admission, although this was not found to be statistically significant. Average length of hospital stay was 27 days overall. For non-transfer patients and transfer patients, LOS was 20 days and 41 days, respectively, which was statistically significant by one-sided t-test (p= 0.05). Conclusion: Patients transferred for definitive care of PPUD in a population otherwise notable for high mortality and high readmission rates: their average length of stay compared to non-transfer patients was over twice the length, which was statistically significant. Transferred patients also had higher rates of ICU care requirement although this was not statistically significant. Further inquiry to identify modifiable variables to facilitate the care of transferred patients is warranted, especially in the context of improving quality metrics known to enhance patient outcomes, satisfaction, and value. Graphical abstract:

A highly compact dual-band power divider (PD) based on the HMSIW structure is investigated in this paper. The dual-band operation is achieved by incorporating an inner modified circular complementary split-ring resonator (MC-CSRR) and outer circular CSRR on the top metal layer of HMSIW. The operating frequency of the PD decreases due to evanescent mode propagation. This assists in miniaturizing the structure apart from the 50% size reduction offered by the HMSIW. By asymmetric placement of two output ports of a PD, it is possible to achieve an unequal PD with an arbitrary power division ratio. To exhibit the proposed idea, two dual-band PD prototypes, one with equal power division and the other with unequal power division are designed, fabricated and experimentally verified. The PD occupies a compact size of 0.128 λg× 0.122 λg, where λgbeing the guided wavelength at the first operating frequency. The proposed PD with advantages of lower insertion loss, better return loss, minimum amplitude and phase imbalance between the output ports is beneficial for 5G FR1 n78 (3.3- 3.8 GHz) and WLAN (5.17 GHz) communications.

PVA, Chitosan film containing metal oxide nanocomposites (MONC) or chalcone moiety, prepared with a thickness of around 0.03 cm. Different molecular weights of MONC are used for the preparation of different polymer composite films. FT-IR, XRD, XPS, EDX, and TGA techniques were used to characterise the prepared film. Semicrystalline (40–150 nm) behaviour is observed for prepared film, which is confirmed by XRD, and the film undergoes multistage decomposition on heating, confirmed by TGA. SEM analysis concludes the film has a blooming flower like structure on the surface. Different elements of the polymer and dopant were confirmed using XPS and EDX analysis. FT-IR analysis suggests that there is no chemical interaction between the polymer and the hosting materials. The film shows a AC conductivity value of 1.36 × 10−5 Scm−1, and it shows higher dielectric properties.

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Toiletry-based diseases play a major role in world hygiene. Lack of toilets and lack of proper toilet maintenance often cause fatalities. From the bus stands in interior villages, to the most sophisticated airports, toilets play a major role. Also, lavatories inside the train, plane or any other mode of transport are inclusive in the list. Improper maintenance of these would lead to many disastrous and dangerous diseases like, staphylococcus, escherichia and streptococcus. Often, children are the major targets. Hence, it is important to provide a technical solution to monitor their quality, so as to maintain them as and when required. Here, we aim at getting a frugal IoT-based solution to monitor the quality, gather feedback and alert the concerned about the cleanliness of lavatory. The system is tested for its functionality, and it is observed that, if implemented, it would be definitely add value for the users and would help in building healthy chain of lavatories.

Background: Manual total knee arthroplasty (TKA) has been documented several times for their safety and complications data. In contrast, there is a limited evidence-based analysis for safety and complications of autonomous robotic-assisted (RA)-TKA. This study aimed to evaluate the safety features and intra-operative surgical complications associated with the use of Cuvis Joint™ autonomous robotic system for TKA. Methods: The study included 500 consecutive patients who underwent TKA using the Cuvis Joint™ autonomous robotic system from November 2020 to November 2021. All surgeries were performed by a senior surgeon. Patients in whom the surgery was abandoned midway due to technical errors, were excluded from the analysis. In case of unilateral abandonment of the robotic arm during a bilateral RA-TKA, data of the side on which the surgery was completed with robotic assistance was recorded. Results: There was no incidence of neurological injury, vascular injury, extensor mechanism disruption, or medial collateral ligament injury. There was one case of superficial abrasion of the patellar tendon; however, it did not require any intervention. There were no cases of midway abandonment due to threatened soft tissue injury. There was no intra-operative pin loosening or stress-related fractures at the pin sites. There was one case of Steinmann pin breakage and another case of drill bit breakage, which were removed without any damage to the bone. Conclusion: The Cuvis Joint™ autonomous robotic system for TKA is safe with no significant intra-operative complications.

The main goal of the paper is to establish the solvability of the 3D acid-mediated tumor growth model combined with the Dirichlet and Neuman boundary conditions in the fractional-order Sobolev spaces using the Schauder fixed point theorem. Further, the uniqueness of solutions is also proved using the duality approach and Gronwall’s lemma.

In this letter, a low-profile dual-band frequency selective surface (FSS) is designed as a polarizer for satellite communication. This single-layered FSS with a meandered open loop intersected by a metallic strip behaves as a dual sense polarizer. It converts linearly polarized (LP) EM waves of frequency range 2.01–2.64 GHz into left-hand circularly polarized (LHCP) EM waves. Similarly, the LP waves in the frequency range of 3.26–3.68 GHz are converted into right-hand circularly polarized (RHCP) EM waves. The unit cell dimension of the compact polarizer is $0.075\lambda _{0} \times 0.075\lambda _{0} \times 0.005\lambda _{0}$ , where $\lambda _{0}$ stands for free space wavelength at the lowest cut-off frequency. This study explores the structural design evolution of the proposed polarizer and verifies the frequency behavior of the structure using a circuit model. The simulated performance of the dual-band polarizer is experimentally tested. Good concordance is observed between the simulated and measured results.

Fuel cell electric vehicles offer a potential solution for achieving the objectives of the energy transition currently underway, which entails replacing combustion vehicles with vehicles that are low in environmental impact. Thus, this market is expected to grow rapidly in the future. Today, there are a plethora of fuel cell types available on the market with a wide range of applications, including transportation, and stationary, portable, and emergency backup power. Among these fuel cells, Proton Exchange Membrane Fuel Cells (PEMFC) have the potential for use in automotive applications due to their low operating temperatures as well as high power density. Furthermore, these PEMFC power sources are also available in various power ranges and capacities for diverse vehicle applications. However, selection of optimized configurations for truck applications is a challenging task due to cost-sensitivity and competitiveness in the Indian market. Therefore, considering the above scenario, a simulation study for PEMFC performance with vehicle operating conditions is necessary to finalize the suitable fuel cell power capacity for truck applications. Based on this study, a fuel cell electric vehicle model for trucks with > 30–40 tonnage applications is developed for the simulation study in this paper. Furthermore, steady state and transient simulations are conducted using GT-Suites version 2021 software on a 100 kW PEM fuel cell system. The developed model of fuel cell was found to be capable of supplying sufficient power for two lower steady-state cycles in regions with low power demand, and slightly more power was required for the third steady-state cycle. On the other hand, during the transient cycle run, the fuel cell in consideration was able to perform adequately and meet the required power demands. This study has kept other parameters constant in addition to temperature, pressure, and humidity. On the basis of this analysis, PEMFCs may find applications in automotive applications due to their low operating temperatures and high power density.

Objective To assess neurocognitive impairment after the off-pump and on-pump techniques for coronary artery bypass graft surgery in patients with triple vessel disease. Design Randomised controlled trial. Setting University Hospital [...]