Relay System Research Articles

Maximizing Productivity and Profitability of Rice through Crop Establishment Methods and Weed Management Practices in Winter Rice-Garden Pea Relay Cropping System

A field experiment was conducted at the farmer’s field at Pirakata Brahmin Gaon under the jurisdiction of Krishi Vigyan Kendra, Jorhat to study resource conservation through crop establishment methods and weed management practices in winter rice (Oryza sativa. L.) - garden pea (Pisum sativum var. hortense) relay cropping system during 2019-20 & 2020-21. The treatment consisted of four crop establishment methods of winter rice (T) viz., T1: WDSR (Broadcasting), T2: WDSR (Modified Drum Seeder with furrow opener), T3: PTR (Farmers’ Practice), T4: PTR (Mechanized Transplanting by paddy transplanter) where WDSR: Wet Direct Seeded Rice, PTR: Puddled Transplanted Rice along with three weed management practices of rice (W) viz., W0: Weedy check, W1: Pretilachlor 0.75 kg/ha as pre-emergence fb bispyribac-sodium 0.025 kg/ha (20 DAS/DAT) as post-emergence, W2: Pretilachlor 0.75 kg/ha as pre-emergence fb manual weeding (30 DAS/DAT). The experiment was laid out in a factorial randomized block design with three replications. The soil of the experimental site was sandy clay loam in texture, medium acidic in reaction, medium in organic carbon and available N and low in available P2O5 and K2O. The study revealed that the establishment method that T2, T3 and T4 had higher growth and yield parameters of the crop as compared to T1: WDSR (B) which resulted in higher grain and straw yield of winter rice as well as uptake of nutrients. The highest grain yield of 49.79 and 50.13 q/ha of winter rice was recorded under T4: PTR (MTR) followed by 46.62 and 47.8 q/ha in T2: WDSR (Drum seeder) during 2019 and 2020, respectively. The percent increase in grain yield of winter rice in W1 and W2 as compared to W0 (control) was 82.97, 84.52 in 2019 and 81.62, 81.58, respectively in 2020. The treatment combination T4W2 recorded the highest grain and straw yield of winter rice which was statistically at par with T4W1, T2W1 and T2W2. The higher B:C of 2.27 and 2.14 was recorded in T2W1 with higher gross return and net return followed by T2W2 (2.18 and 2.08 during 2019 and 2020, respectively).

ER Oxidoreductin 1-Like Activity of Cyclic Diselenides Drives Protein Disulfide Isomerase in an Electron Relay System.

Disulfide formation generally involves a two-electron oxidation reaction between cysteine residues. Additionally, disulfide formation is an essential post-translational modification for the structural maturation of proteins. This oxidative folding is precisely controlled by an electron relay network constructed by protein disulfide isomerase (PDI), with a CGHC sequence as the redox-active site, and its family enzymes. Creating reagents that mimic the functions of these enzymes facilitates folding during chemical protein synthesis. In this study, we aimed to imitate a biological electron relay system using cyclic diselenide compounds as surrogates for endoplasmic reticulum oxidoreductin 1 (Ero1), which is responsible for the re-oxidation of PDI. Oxidized PDI (PDIox) introduces disulfide bonds into substrate proteins, resulting in its conversion to reduced PDI (PDIred). The PDIred is then re-oxidized to PDIox by a coexisting cyclic diselenide compound, thereby restoring the function of PDI as a disulfide-forming agent. The produced diselenol state is readily oxidized to the original diselenide state with molecular oxygen, continuously sustaining the PDI catalytic cycle. This artificial electron relay system regulating enzymatic PDI function effectively promotes the oxidative folding of disulfide-containing proteins, such as insulin-a hypoglycemic formulation-by enhancing both yield and reaction velocity.

Secrecy Analysis of Transmit Antenna Selection with Hybrid GSC/SC in AF-MIMO Relay Systems

Secrecy Analysis of Transmit Antenna Selection with Hybrid GSC/SC in AF-MIMO Relay Systems

A Joint Design for Full-Duplex OFDM AF Relay System With Precoded Short Guard Interval

A Joint Design for Full-Duplex OFDM AF Relay System With Precoded Short Guard Interval

Overview of Tensor-Based Cooperative MIMO Communication Systems—Part 2: Semi-Blind Receivers

Cooperative MIMO communication systems play an important role in the development of future sixth-generation (6G) wireless systems incorporating new technologies such as massive MIMO relay systems, dual-polarized antenna arrays, millimeter-wave communications, and, more recently, communications assisted using intelligent reflecting surfaces (IRSs), and unmanned aerial vehicles (UAVs). In a companion paper, we provided an overview of cooperative communication systems from a tensor modeling perspective. The objective of the present paper is to provide a comprehensive tutorial on semi-blind receivers for MIMO one-way two-hop relay systems, allowing the joint estimation of transmitted symbols and individual communication channels with only a few pilot symbols. After a reminder of some tensor prerequisites, we present an overview of tensor models, with a detailed, unified, and original description of two classes of tensor decomposition frequently used in the design of relay systems, namely nested CPD/PARAFAC and nested Tucker decomposition (TD). Some new variants of nested models are introduced. Uniqueness and identifiability conditions, depending on the algorithm used to estimate the parameters of these models, are established. Two families of algorithms are presented: iterative algorithms based on alternating least squares (ALS) and closed-form solutions using Khatri–Rao and Kronecker factorization methods, which consist of SVD-based rank-one matrix or tensor approximations. In a second part of the paper, the overview of cooperative communication systems is completed before presenting several two-hop relay systems using different codings and configurations in terms of relaying protocol (AF/DF) and channel modeling. The aim of this presentation is firstly to show how these choices lead to different nested tensor models for the signals received at destination. Then, by capitalizing on these models and their correspondence with the generic models studied in the first part, we derive semi-blind receivers to jointly estimate the transmitted symbols and the individual communication channels for each relay system considered. In a third part, extensive Monte Carlo simulation results are presented to compare the performance of relay systems and associated semi-blind receivers in terms of the symbol error rate (SER) and channel estimate normalized mean-square error (NMSE). Their computation time is also compared. Finally, some perspectives are drawn for future research work.

Under Voltage Relay System for Battery and DC Load Safety Using Arduino Nano

The quality of the electric power supply in an electrical system is very necessary. One of the important things that need to be considered is the quality of the voltage supply. The disturbance in the electrical system is under voltage. Undervoltage is an electrical system disturbance that will affect the performance of connected electrical equipment and reduce the life of the equipment, including battery components in DC voltage source electrical systems such as solar power plants. To anticipate this occurrence, Under Voltage Relay equipment is needed which can be used to protect batteries and DC equipment from under voltage conditions by using a potentiometer as a voltage divider and IC 7809 to reduce the voltage from the battery input, Relays to disconnect the load, LCD for monitoring and using Arduino Nano microcontroller control. The method used is a development method or Research and Development. This method is used as a basis for designing and manufacturing Low Voltage Relay devices to protect batteries and DC equipment. From the results of the tests carried out, it can disconnect the DC load when detecting low voltage conditions with an accuracy of ± 99.795%. for the normalized execution test for under voltage relay at voltages of 12 V and 24 V, there is a difference value of ± 0.096V and an error of ± 0.554%.

Transmit Power Optimization in Multihop Amplify-and-Forward Relay Systems with Simultaneous Wireless Information and Power Transfer

In this paper, we study a multi-hop amplify-and-forward (AF) simultaneous wireless information and power transmission (SWIPT) relay system. Each relay node harvests power using a power split (PS) method from a portion of the received signal, amplifies the remaining received signal, and passes it to the next relay. Based on this system model and signal flow, we derived and solved the convex power minimization problem with the optimal PS ratio. In this case, it was found that using the optimal PS ratio consumed a lower amount of power than when using a fixed PS ratio (0.5). We then investigated the impact of processing cost on the AF-SWIPT system using decoding and forwarding SWIPT as benchmarks, and found that AF-SWIPT was superior.

Evaluation of the performance and stability of early maturing orange-fleshed sweetpotato genotypes in selected areas in Ethiopia.

Orange-fleshed sweetpotato varieties that mature and harvest sooner play an important role in addressing food and nutrition demands in areas where irregular rainfall makes sustainable production challenging. A national variety trial was conducted in 2021 and 2022 during the main cropping season using ten OFSP genotypes in three locations in Sidama, South, and Oromia regions of Ethiopia, namely Hawassa, Arbaminch, and Koka, respectively. The objective of this study was to develop and select early-maturing and high-yielding OFSP genotypes for short-term harvesting (3-4 months). The field trial was conducted in a randomized complete block design with three replications. Data were collected on root yield and yield-related traits, sweetpotato virus disease reactions (SPVD), root dry matter (DMC), and beta-carotene contents (BCC) and were subjected to analysis of variance. A genotype plus genotype by environment interaction (GGE) bi-plot was also used to determine genotype stability. The results showed the presence of highly significant (p<0.001) differences among locations and genotypes, reflecting the existence of differential responses among genotypes in varied locations. Based on combined analysis, G3 (13NC9350A-9-3) outperformed the other genotypes for most of the traits considered, except for DMC, i.e., which has an equivalent to the check variety (Alamura) and showed a yield advantage of 41.4% over it. The GGE biplot also revealed that the G3 was the vertex genotype with the consistent performance in all environments. It had a low score of 1.39 on the 1-9 scoring scale, indicating that it falls within the resistant range, with adequate levels of BCC (5.5 mg/100 g) and DMC (30.0%). Furthermore, G3 is an early-maturing variety, which allows other crops to be grown in double and relay cropping systems. Therefore, based on its outstanding performance, G3 is recommended for verification and release for cultivation in mid- to low-land areas in Ethiopia.

Proactive Eavesdropping in Relay Systems via Trajectory and Power Optimization

Proactive Eavesdropping in Relay Systems via Trajectory and Power Optimization

Covert Communications in a Hybrid DF/AF Relay System.

In this paper, we study covert communications in a hybrid decode-and-forward (DF)/ amplify-and-forward (AF) relay system. The considered relay in normal operation forwards messages from a source node to a destination node in either DF or AF mode on request. Meanwhile, the source and destination nodes also attempt to secretly exchange covert messages such as confidential or sensitive information and avoid detection by the covert message detector embedded on the relay. We first establish an optimal DF/AF mode selection criterion to maximize the covert rate based on the analyses of delay-aware achievable covert rates of individual DF and AF modes. To further reduce the time complexity, we propose a low-complexity selection criterion as well for practical use. The numerical results demonstrate the covert rate gain as high as 50% and running time gain as high as 20% for particular system parameters, which verify the effectiveness of the proposed criteria.

AcpAS: An Advanced Circularly Polarized Antenna Structure for an Airborne Relay Communication System

The airborne relay system is an important support for improving the stability of communication systems in complex electromagnetic environments. As a key component of the airborne relay system, the antenna needs to have characteristics such as high gain, dual circular polarization, wide beam coverage, and miniaturization. Based on the septum circular polarizer, this paper proposes a high-performance circularly polarized antenna structure suitable for airborne relay systems, named AcpAS. The structure consists of a coaxial feed port, a coaxial-to-waveguide transition, a septum circular polarizer, and a parabolic metal housing. Based on this structure, two antennas operating at 19.6 GHz to 21.6 GHz and 29.2 GHz to 31.2 GHz are designed in this paper. Simulated and measured results show that the two antennas have dual circular polarization characteristics, with beam coverage range of more than ±55° for gains higher than 0 dBi, and the radiation patterns exhibit good symmetry and wide-beam coverage characteristics.

Impact of conservation tillage practices in rice-blackgram cropping system

Field experiments were conducted with two tillage practices in rice (Puddled and Non- puddled) during rainy season and three seed priming methods (Bio- seed priming with Rhizobium, hydropriming and no seed priming) and two foliar spray (2% DAP and 2% urea) during post rainy seasons in blackgram. The results indicated that the soil penetration resistance was found to be lesser in the soils of non-puddled tillage. The rice yield reduction due to NPTR was non-significant (less than 3 per cent). However, the soil penetration resistance was higher with the soils of blackgram sown as succeeding crop in the PTR. The blackgram yield obtained under NPTR was 10.6 per cent higher than PTR system. Bio seed priming with Rhizobium increased the yield by 26.0 per cent over no seed priming. The study indicated that NPTR showed a positive impact on the yield in the rice-blackgram relay cropping system. Bangladesh J. Bot. 53(3): 519-525, 2024 (September)

Understanding Bacillus response to salt stress: Growth inhibition, enhanced EPS secretion, and molecular adaptation mechanisms

This study investigates the secretion pattern of extracellular polymeric substances (EPS) by Bacillus sp. under varying salt concentrations and elucidates the molecular mechanisms governing EPS synthesis and secretion. Salt stress inhibited cell proliferation, while optimal salt stimulation promoted EPS secretion, resulting in increased viscosity of the culture medium and the formation of bacterial clusters. Fourier infrared spectrum analysis revealed functional groups such as C-O-C and N-H within the EPS. Soluble-EPS (S-EPS) contained sulfur and phosphorus groups associated with heavy metal ions adsorption. The study also identified a novel polysaccharide formed through bonding EPS (B-EPS). High salt concentrations correlated with elevated levels of tryptophan protein and its derivatives, increased tyrosine polysaccharide derivatives, and decreased aromatic polysaccharides. B-EPS exhibited higher levels of aromatic polysaccharides, with Na+ promoting detachment of B-EPS from the cell surface. Transcriptome sequencing (RNA-seq) analysis under salt stress revealed significant expression of spore kinase (KinD) and response regulatory protein Spo0A in the phosphoric acid relay system. Key transcriptional regulatory factors, including OmpR and exopolysaccharide biosynthesis, were closely associated with EPS synthesis and secretion. This study establishes a theoretical foundation for the industrial production and practical application of EPS by elucidating the molecular mechanisms underlying Bacillus' response to salt stress.

A review of potential fault detection methods for traditional collector stations and sensor fault diagnosis in wind farm doubly-fed generator converters

Collector stations sometimes face situations where existing relay protection systems may fail, making potential fault monitoring technology increasingly important. This technology plays a critical role in ensuring the stability of power supply and enhancing economic benefits. Simultaneously, in response to the nation's "dual carbon goals," the construction and operation of large-scale renewable energy power stations are booming. Therefore, potential fault monitoring technology for new power stations should not be overlooked. For traditional power stations, the application and development trends of infrared thermal imaging technology, vibration analysis and acoustic detection technology, chemical analysis, and oil quality detection technology will be compared and discussed. Regarding new power stations, methods for diagnosing sensor faults in doubly-fed generator converters in wind power will be analyzed and discussed.

Anchoring ultrafine Au nanoclusters on sulfonate groups functionalized carbon matrix for efficient catalytic reduction of nitrophenol

Despite immense research efforts in the field of Au supported on carbon matrix, the rational design and fabrication of ultrafine Au/carbon matrix nanocatalysts with effective reactivity and high stability are still challenging. The main obstacles are faced with adjusting the size of Au nanoclusters and strengthening the bond of Au and carbon. In this work, sulfonate groups (−SO3H) introduced onto activated coke (AC) matrix was prepared for steadily anchoring ultrafine Au nanoclusters (∼2 nm). The obtained Au/SO3H-AC exhibited superior reactivity for 4-nitrophenol reduction within 3 min using NaBH4 as reducing agent. The superior performance and stability are attributed to the − SO3H groups with hydrophilic property, benefiting for substrates readily dispersion and for Au species (including oxidized Au+ and Au3+) bind and stabilization, possibly by tightly interacting with the O atoms bound to S atom of − SO3H. In addition, several lines of evidence demonstrate the oxidized Au species can serve as electron relay system, ensuring the sustained reaction. Given that the Au nanoclusters in this study have superior reactivity and stability, this work proposes a novel strategy for preparing other supported metal nanocomposites.

Impact of camptothecin exposures on the development and larval midgut metabolomic profiles of Spodoptera frugiperda

Spodoptera frugiperda is an economic agricultural pest that has invaded many countries around the world and caused huge losses in grain production. Camptothecin (CPT) is one of the botanical compounds with insecticidal activity and has the potential for pest control. However, the effects of CPT on development and metabolism of S. frugiperda remain unknown. In this study, we have investigated the adverse effects of 1.0 and 5.0 mg/kg CPT exposures on the growth and development of S. frugiperda. Our results found that 1.0 and 5.0 mg/kg CPT treatments altered the parameters of the life cycle, including inducing larval mortality, altering the weight of larvae, pupae, and adults, the larval duration, and decreasing the pupation rate and emergence rate. In addition, comparative metabolomics analysis was performed in the larval midgut of S. frugiperda to explore the toxicity mechanism of CPT. A total of 261 and 348 differential metabolites were identified in the groups with 1.0 and 5.0 mg/kg CPT treatments, respectively. Further analysis found that pantothenate and CoA biosynthesis, sulfur relay system, selenocompound metabolism, and fatty acid biosynthesis pathways were significantly altered by 5.0 mg/kg CPT exposure. Our results provided new insight into the toxicological mechanisms of CPT against S. frugiperda and laid the foundation for the field application of CPT in pest control.

Examining the efficiency of D2D communication employing DF-enabled multiple relay systems amid co-channel interference

Device-to-device (D2D) communication is emerging as a potential paradigm in contemporary wireless communication systems. Enabling D2D communication in the mmWave range has numerous challenges that must be overcome. The biggest concern is the introduction of interference from several sources. This study investigates the impact of co-channel interference (CCI) on D2D communication when energy harvesting (EH) and decode-and-forward (DF) techniques are used across several relay nodes. It includes mathematical equations for the cumulative distribution function (CDF) of the Signal-to-Interference-Plus-Noise ratio (SINR), as well as formulas for calculating the network's outage probability (OP), throughput (TP), and availability rate (AR). Furthermore, it produces an asymptotic expression for analyzing the probability density function (PDF) of the instantaneous SINR, providing a simple and complete approach to understanding its OP, TP, and AR properties. The analytical results are supported by Monte Carlo simulations and MATLAB implementation.

Analyzing error probability in aerial full-duplex relay systems: Exact formulations and optimization techniques

In this study, we investigate the performance of aerial full-duplex relay (AFDR) systems. In particular, we examine two practical scenarios: one where there is no direct link between the transmitter and user, and another where such a link exists. For both scenarios, we develop mathematical models to calculate the closed-form expressions of symbol error probabilities (SEPs) for AFDR systems, using a realistic channel aligned with the fifth generation (5G) and beyond yardsticks. To take care of residual self-interference (RSI) in AFDR, we propose an optimal power allocation strategy. Our numerical findings indicate that the performance in the case with a direct link is considerably higher than that in the case without this link. Additionally, we analyze thoroughly the effects of key parameters such as transmit power, RSI levels, carrier frequencies, and AFDR positions. The effect of RSI is significantly strong, and our proposed optimal power allocation method substantially improves system performance, especially in high transmit power scenarios where error floors may occur. Importantly, the optimal power level is dramatically lower than the conventional value where the optimal power cannot be found. Thus, besides reducing the SEPs, optimal power also helps to prolong the time of operation of AFDR. Monte-Carlo simulations are performed to confirm the accuracy of our derived expressions and demonstrate the efficacy of the proposed approaches in practical scenarios.

Dual-Prodrug-Based Hyaluronic Acid Nanoplatform Provides Cascade-Boosted Drug Delivery for Oxidative Stress-Enhanced Chemotherapy.

Insufficient drug accumulation in tumors severely limits the antitumor efficiency of hyaluronic acid (HA) nanomedicine in solid tumors due to superficial penetration depth, low cell uptake, and nonspecific drug release. Hence, we constructed a dual NO prodrug (alkynyl-JSK) and doxorubicin prodrug (cis-DOX)-conjugated HA nanoparticle (HA-DOX-JSK NPs), which achieved cascade-boosted drug delivery efficiency based on a relay strategy of NO-mediated deep tumor penetration─HA target CD44 tumor cell uptake─tumor microenvironment (TME)-responsive drug release. The nanoparticle demonstrated sustained and locoregionally GSH/GST-triggered NO release and GSH/pH-responsive DOX release in the tumor. The released NO first mediated collagen degradation, causing deep tumor penetration of nanoparticles in the dense extracellular matrix. Immediately, HA was relayed to enhance CD44-targeted tumor cell uptake, and then, the nanoparticles were finally triggered by specific TME to release DOX and NO in the deep tumor. Relying on the relayed delivery strategy, a significant improvement of DOX accumulation in tumors was realized. Moreover, NO depleted GSH-induced intracellular reactive oxygen species, enhancing DOX chemotherapy. Based on this strategy, the tumor inhibition rate in breast cancer was up to 87.8% in vivo. The relay drug-delivery HA system would greatly cascade-boost drug accumulation in deep tumors for efficient solid tumor therapy.

Blockchain-Based Spectrum Sharing Algorithm for UAV-Assisted Relay System

Unmanned aerial vehicles (UAVs) are promising tools in mobile communication due to their flexibility. However, the rapid development of mobile communications further intensifies the challenge of spectrum scarcity, necessitating spectrum sharing with other systems. We suggest a Spectrum Sharing Algorithm for a UAV-Assisted Relay System. The utility function of secondary users (SUs) is defined by their communication rate, rewards from relay primary users (PUs), and spectrum leasing expenses. The utility function of PUs consists of their communication rate and revenue from spectrum leasing. We propose a joint optimization algorithm for the positioning and power allocation of UAVs, maximizing the frequency spectrum utilization rate of users. Spectrum trading between PUs and SUs is modeled as a Stackelberg game, and the problem is solved by using Lagrange multipliers and KKT conditions. To enhance the security of spectrum trading, a reputation-based spectrum sharing blockchain consensus algorithm is designed. We utilize Shamir’s secret sharing method to reduce computational complexity. Additionally, we design a smart contract to optimize the functionality of transaction transfers. The findings demonstrate that the proposed algorithm enhances the benefits for both participants in spectrum sharing, while safeguarding the security of spectrum transactions.