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Abstract Metro trains have non-linear load characteristics, which means that the power sent to them gets distorted. Problems are caused by changes in power, swells, harmonics, and other disturbances. In this research, an artificial intelligence-driven control method was used on a unified power quality conditioner (UPQC) to help reduce power quality problems and improve power quality. Three advanced control methods are built and compared using MATLAB Simulink. Some of these methods are the ANN Controller, the NARMA-L2 Controller, and the PI Controller, improved using the Adaptive Lizard Algorithm. The controls' usefulness is judged by how well they lower the total harmonic distortion (THD) in the source current. The results show that all three AI-based controls work much better than the system that was not paid for. The ANN Controller works the best, followed by the NARMA-L2 Controller, and the PI Controller improved with the Adaptive Lizard Algorithm. These AI-driven control methods can enhance power quality and ensure that metro rail systems run smoothly and efficiently, as shown by how well they work. Modern transportation networks need more advanced ways to handle power quality, and this research helps make those solutions come together.

Abstract This paper presents a novel, dual-band, four-port multi-input–multi-output (MIMO) antenna for 28/38 GHz millimeter wave 5G wearable applications. In the proposed work, we have used a novel design approach to get the dual-band behavior from a MIMO design with a small footprint of 18 × 8.5 × 0.25 mm3. For this purpose, each MIMO element is designed as a composite form of a circular and elliptical structure connected with a narrow strip and fed by a tapered feedline. The peak realized gains and total efficiencies of the antenna, evaluated in free space, are 4.15 dBi, 7.73 dBi and 80.13%, 85.44% at 28 GHz and 38 GHz frequencies, respectively. To appraise the thorough behavior of the MIMO antenna, we have evaluated all the parameters of the antenna: Envelope Correlation Coefficient (ECC), Diversity Gain (DG), Mean Effective Gain (MEG), Channel Capacity Loss (CCL), and Total Active Reflection Coefficient (TARC), and found them satisfactory. Channel capacity of the antenna at SNR = 20 dB is found to be 21.61 bps/Hz. For wearable applications, the proposed 4-port MIMO antenna is designed on a flexible Rogers 3003 substrate, and the performance is checked by evaluating bending analysis. The safety of the antenna is verified by analyzing the 1 g/10 g SAR at 28/38 GHz and the corresponding average SAR values are 0.11/0.08 W/kg and 0.05/0.04 W/kg, respectively. All the average SAR values for the proposed MIMO antenna are within the acceptable limits according to FCC/ICNIRP standards.

Abstract Modifying the coordination or local environments of single‐, di‐, tri‐, and multi‐metal atom (SMA/DMA/TMA/MMA)‐based materials is one of the best strategies for increasing the catalytic activities, selectivity, and long‐term durability of these materials. Advanced sheet materials supported by metal atom‐based materials have become a critical topic in the fields of renewable energy conversion systems, storage devices, sensors, and biomedicine owing to the maximum atom utilization efficiency, precisely located metal centers, specific electron configurations, unique reactivity, and precise chemical tunability. Several sheet materials offer excellent support for metal atom‐based materials and are attractive for applications in energy, sensors, and medical research, such as in oxygen reduction, oxygen production, hydrogen generation, fuel production, selective chemical detection, and enzymatic reactions. The strong metal–metal and metal–carbon with metal–heteroatom (i.e., N, S, P, B, and O) bonds stabilize and optimize the electronic structures of the metal atoms due to strong interfacial interactions, yielding excellent catalytic activities. These materials provide excellent models for understanding the fundamental problems with multistep chemical reactions. This review summarizes the substrate structure‐activity relationship of metal atom‐based materials with different active sites based on experimental and theoretical data. Additionally, the new synthesis procedures, physicochemical characterizations, and energy and biomedical applications are discussed. Finally, the remaining challenges in developing efficient SMA/DMA/TMA/MMA‐based materials are presented.

Natural debris floods travel in straight and meandering courses. The flow behaviour greatly depends on the volume fractions of solid and fluid, as well as on their dynamic interactions with the channel geometry. For the quasi three-dimensional simulations of flow dynamics and mass transport of these floods through meandering and straight channels, we employ a two-phase debris flow model to carry out simulations for debris floods within straight and sine-generated meandering channels of different amplitudes. The results for different sinuous meandering paths are compared with that in the straight one in terms of phase velocity, downslope advection and dispersion, depths of the maxima, deposition of mass, position of front and rear parts of the solid and fluid phases, and also the flow dynamics out of the conduits. The results reveal the slowing of the flow and increase of momentary deposition of the mixture mass in the vicinity of the bends along with the increasing sinuosity. The numerical experiments are useful to better understand the dynamics of debris floods down meandering channels as seen in the natural paths of the rivers as well as already existing channels like episodic rivers in hilly regions. The results can be extended to propose some appropriate mitigation strategies.

This paper proposes a novel multi-band textile monopole antenna for patient tracking applications. The designed antenna has compact footprints (0.13λ02) and works in the narrow band-internet of things (NB-IoT) 1.8 GHz, radio frequency identification (RFID), and industrial, scientific, and medical (ISM) 2.45 GHz and 5.8 GHz bands. The impedance bandwidths and gain of the antenna at 1.8 GHz, 2.45 GHz, and 5.8 GHz are 310 MHz, 960 MHz, and 1140 MHz; 3.7 dBi, 5.3 dBi, and 9.6 dBi, respectively. Also, the antenna’s behavior is checked on different body parts of the human body in various bending scenarios. As per the evaluated link budget, the designed antenna can easily communicate up to 100 m of distance. The specific absorption rate values of the designed antenna are also within acceptable limits as per the (FCC/ICNIRP) standards at the reported frequency bands. Unlike traditional rigid antennas, the proposed textile antenna is non-intrusive, enhancing user safety and comfort. The denim material makes it comfortable for extended wear, reducing the risk of skin irritation. It can also withstand regular wear and tear, including stretching and bending. The presented denim-based antenna can be seamlessly integrated into clothing and accessories, making it less obtrusive and more aesthetically pleasing.

Abstract Copper Zinc Tin Sulphide (CZTS) is a propitious semiconductor for active absorber material in thin-film solar cells (SCs). Here, SC architecture comprising FTO/ZnS/CZTS/variable HTLs/Au is discussed. Fluorine-doped tin oxide (FTO) and gold (Au) are used as front and back contacts, respectively. Zinc sulphide (ZnS) is used as an active electron transport layer (ETL), while different Cu-based materials (Cu2O, CuO, CuI, and CuSCN) are used as hole transport layers (HTL). A one-dimensional solar cell capacitance simulator (SCAPS-1D) is utilized to simulate the SC structure. Among different Cu-based HTLs, Cu2O is preferred as a potential candidate for high cell performance of CZTS-based SC. The effects of various layer parameters such as thickness, doping density, and carrier concentrations, electron affinity of HTL and absorber, respectively, are also discussed. After optimization of the device, variation of operating temperature and the effect of series and shunt resistance are also taken into consideration. The optimized results of thickness and acceptor concentration (NA) of absorber material are 1.5 µm and approx. 1.0 × 1019 cm−3, respectively. In addition, the function of HTL (with and without) in the designed SC structure is also studied. Capacitance–voltage (C–V) characteristics are also discussed to get an insight of built-in potential. We have achieved cell performances viz. efficiency = 31.86%, short circuit current density = 32.05 mA/cm2, open circuit voltage = 1.19 V, and fill factor = 83.37%.

In this paper, we present the design of a millimeter-wave 1 × 4 linear MIMO array antenna that operates across multiple resonance frequency bands: 26.28–27.36 GHz, 27.94–28.62 GHz, 32.33–33.08 GHz, and 37.59–39.47 GHz, for mm-wave wearable biomedical telemetry application. The antenna is printed on a flexible substrate with dimensions of 11.0 × 44.0 mm2. Each MIMO antenna element features a modified slot-loaded triangular patch, incorporating ‘cross’-shaped slots in the ground plane to improve impedance matching. The MIMO antenna demonstrates peak gains of 6.12, 8.06, 5.58, and 8.58 dBi at the four resonance frequencies, along with a total radiation efficiency exceeding 75%. The proposed antenna demonstrates excellent diversity metrics, with an ECC < 0.02, DG > 9.97 dB, and CCL below 0.31 bits/sec/Hz, indicating high performance for mm-wave applications. To verify its properties under flexible conditions, a bending analysis was conducted, showing stable S-parameter results with deformation radii of 40 mm (Rx) and 25 mm (Ry). SAR values for the MIMO antenna are calculated at 28.0/38.0 GHz. The average SAR values for 1 gm/10 gm of tissues at 28.0 GHz are found to be 0.0125/0.0079 W/Kg, whereas, at 38.0 GHz, average SAR values are 0.0189/0.0094 W/Kg, respectively. Additionally, to demonstrate the telemetry range of biomedical applications, a link budget analysis at both 28.0 GHz and 38.0 GHz frequencies indicated strong signal strength of 33.69 dB up to 70 m. The fabricated linear MIMO antenna effectively covers the mm-wave 5G spectrum and is suitable for wearable and biomedical applications due to its flexible characteristics.

Currently, cancer is one of the main research topics, due to its high incidence and drug resistance to existing anti-cancer drugs. Formononetin, a natural product with phytoestrogenic properties and diverse biological functions, has attracted the attention of researchers working on anticancer drugs. Formononetin emerges as an intriguing bioactive substance compared to other isoflavones as it exhibits potent chemotherapeutic activity with less toxicity. Formononetin effectively plays a significant role in inhibiting cell proliferation, invasion, and metastatic abilities of cancer cells by targeting major signaling pathways at the junction of interconnected pathways. It also induces apoptosis and cell cycle arrest by modulating mediator proteins. It causes upregulation of key factors such as p-AKT, p38, p21, and p53 and downregulation of NF-κB. Furthermore, formononetin regulates the neoplastic microenvironment by inactivating the ERK1/2 pathway and lamin A/C signaling and has been reported to inactivate JAK/STAT, PKB or AKT, and mitogen-activated protein kinase pathways and to suppress cell migration, invasion, and angiogenesis in human cancer cells. To assist researchers in further exploring formononetin as a potential anticancer therapeutic candidate, this review focuses on both in vitro and in vivo proof of concept studies, patents, and clinical trials pertinent to formononetin's anticancer properties. Overall, this review discusses formononetin from a comprehensive perspective to highlight its potential benefits as an anticancer agent.

The present investigation recommends some major modifications for performance improvement in the conventional solar still (CSS). Five different configurations have been analysed viz: (1) still with no wick, (2) still with a wick at 15° (3) still with a wick at 30°, (4) still with a wick at 45°, and (5) blackened basin solar still (BBSS) with a wick at 30°. Experiments were conducted in March because of favourable climatic conditions. The flow rate of water passing through the basin and the wick was kept constant for all the configurations (0.2 gram/m2sec). Experiments were conducted to calculate the distillate yield and to carry out 5E analysis (energy, exergy, energy metrices, exergo-economic analysis, enviro-economic analysis). The results explore that the BBSS had the highest productivity of 4.372 kg/m2 among all configurations. However, the distillate yield obtained in CSS with 30° wick is quite close to the BBSS yield i.e., 4.25 kg/m2. Distillate yield obtained in the remaining case of CSS with 15°, 45° and without wick is about 3.802 kg/m2, 3.925 kg/m2, and 4.102 kg/m2, respectively. Energy output for modified CSS was observed to be highest for BBSS i.e., 2.31 kWh/day. The embodied energy was also found to be highest for BBSS i.e., 457.15 kWh with a minimum energy payback time (EPT) of 1.11 years. In addition, CO2 mitigated/year was found to be highest for the BBSS (energy basis -2.01 tones and exergy basis -0.25 tones) compared with the CSS (energy basis -1.88 tones and exergy basis -0.21 tones). The cost of distillate yield was found to be lowest for BBSS, which is found to be ₹ 1.38/L along with the payback period of 91 days.

Data from 242 ozonesondes launched from ARIES, Nainital (29.40∘ N, 79.50∘ E; 1793 m elevation), are used to evaluate the Atmospheric Infrared Sounder (AIRS) version 6 ozone profiles and total column ozone during the period 2011–2017 over the central Himalayas. The AIRS ozone products are analysed in terms of retrieval sensitivity, retrieval biases/errors, and ability to retrieve the natural variability in columnar ozone, which has not been done so far from the Himalayan region, having complex topography. For a direct comparison, averaging kernel information is used to account for the sensitivity difference between the AIRS and ozonesonde data. We show that AIRS has more minor differences from ozonesondes in the lower and middle troposphere and stratosphere with nominal underestimations of less than 20 %. However, in the upper troposphere and lower stratosphere (UTLS), we observe a considerable overestimation of the magnitude, as high as 102 %. The weighted statistical error analysis of AIRS ozone shows a higher positive bias and standard deviation in the upper troposphere of about 65 % and 25 %, respectively. Similarly to AIRS, the Infrared Atmospheric Sounding Interferometer (IASI) and the Cross-track Infrared Sounder (CrIS) are also able to produce ozone peak altitudes and gradients successfully. However, the statistical errors are again higher in the UTLS region, which are likely related to larger variability in ozone, lower ozone partial pressure, and inadequate retrieval information on the surface parameters. Furthermore, AIRS fails to capture the monthly variation in the total column ozone, with a strong bimodal variation, unlike unimodal variation seen in ozonesondes and the Ozone Monitoring Instrument (OMI). In contrast, the UTLS and the tropospheric ozone columns are in reasonable agreement. Increases in the ozone values of 5 %–20 % after biomass burning and during events of downward transport are captured well by AIRS. Ozone radiative forcing (RF) derived from total column ozone using ozonesonde data (4.86 mW m−2) matches well with OMI (4.04 mW m−2), while significant RF underestimation is seen in AIRS (2.96 mW m−2). The fragile and complex landscapes of the Himalayas are more sensitive to global climate change, and establishing such biases and error analysis of space-borne sensors will help us study the long-term trends and estimate accurate radiative budgets.

Chickpea is widely grown in rainfed areas of developing countries because of its nutritional abundance and adaptability. To overcome the environmental effect of drought on yield, a characteristic-linked selection strategy is proved as well-thought-out and advantageous for the development of drought-tolerant cultivars. To precisely understand the contribution of various physio-biochemical and yield-attributing traits toward drought tolerance in chickpea (Cicer arietinum L.), forty chickpea genotypes were evaluated in the years 2020–2021 and 2021–2022 under normal irrigated as well as drought-stressed conditions. Among the studied genotypes, genotype ICC4958 retained the highest chl content (0.55 mg g−1 FW), minimal electrolyte leakage, and superoxide dismutase (1.48 U/mg FW) and peroxidase (2.21 µmol/min/g FW) activities while cultivar JG11 maintained the maximum relative water content and proline accumulation. The principal-component-based biplots prioritized the physio-biochemical and yield-accrediting characteristics based on their association significance and contribution to terminal drought tolerance. Under drought stress, grain yield per plant was depicted to have a strongly positive association with canopy temperature depression, catalase, superoxide dismutase, and peroxidase activities as well as total soluble sugar, proline, and chlorophyll content, along with the numbers of pods and biological yield per plant. These identified physio-biochemical and yield-attributing traits can be further deployed to select drought-tolerant chickpea genotypes for the breeding of climate-smart chickpea genotypes.

Equilibrium status among 226Ra and radon daughters was studied in soil samples around Rawatbhata, Rajasthan. It was found that the increase in radioactivity of 214Bi (radon daughter) due to complete radon buildup in the sealed container is within 15% which establishes that 226Ra remains in equilibrium with radon daughter in soil of Rawatbhata. Radioactivity of 238U was estimated from the radioactivity of 235U using natural uranium isotopic radioactivity ratio (238U/235U) of 21.5. 238U radioactivity in soil was found in the range 25.8–49.5 Bq/kg with an average of 36.7 Bq/kg which is comparable to the global average of 35 Bq/kg.

Chickpea production is seriously hampered by drought stress, which could be a great threat in the future for food security in developing countries. The present investigation aimed to screen the drought-tolerant response of forty desi chickpea genotypes against drought stress through various physio-biochemical selection indices and yield-attributing traits. Principle component-based biplot analysis recognized PG205, JG2016-44, JG63, and JG24 as tolerant genotypes based on physiological selection indices. These genotypes retained higher relative water content, stomatal conductance, internal CO2 concentration, and photosynthetic rate. ICC4958, JG11, JAKI9218, JG16, JG63, and PG205 were selected as tolerant genotypes based on biochemical selection indices. These genotypes sustained higher chlorophyll, sugar and proline content with enhanced antioxidant enzyme activities. With respect to yield trials, JAKI9218, JG11, JG16, and ICC4958 had higher seed yield per plant, numbers of pods, and biological yield per plant. Finally, JG11, JAKI9218, ICC4958, JG16, JG63, and PG205 were selected as tolerant genotypes based on cumulative physio-biochemical selection indices and yield response. These identified drought-tolerant genotypes may be further employed in climate-smart chickpea breeding programs for sustainable production under a changing climate scenario.

The formation and growth of dendrites in solid-state lithium metal batteries is a common cause of failure. Here, thin-film amorphous Li-La-Zr-O shows high resistance to lithium penetration, making it promising for thin-film solid-state batteries and as a coating for bulk ceramic electrolyte.

This work aims at extending the understanding of the formation processes of (Cs0.07FA0.93)PbI3 perovskite layers deposited by a two-step vapour method. In a first step, an inorganic CsI/PbI2 precursor stack is deposited by thermal evaporation (TE). A chemical vapour deposition (CVD) is then used to convert the precursor into the perovskite layer by reaction with a chemical vapour of formamidinium iodide (FAI). Here we show how crystallinity and morphology of the TE precursor layer are both influenced not only by the substrate surface properties but also by the thermal treatment in the initial phase of the CVD process. Furthermore, we provide insights on the evolution of perovskite film formation and show how a uniform elemental composition is achieved by the diffusion of cesium through PbI2 during the CVD conversion reaction.

Abstract The sintering of alumina (Al2O3) traditionally occurs at high temperatures (up to ca. 1700 °C) and in significantly long times (up to several hours), which are required for the consolidation of the material by diffusion processes. Here we investigate the photonic sintering of alumina particles using millisecond flash lamp irradiation with extreme heating rates up to 108 K/min. The limitation of the low visible light absorption of alumina is resolved by adding colored α-Fe2O3 nanoparticles, which initiated the grain growth during sintering. After the millisecond-long light pulses from a xenon flash lamp, a bimodal mixture of α-Al2O3 precursor particles was sintered and iron segregation at the grain boundaries was observed. The proposed photonic sintering approach based on doping with colored centers may be extended to other refractory ceramics with low absorption in the visible light range once appropriate high-absorbing dopants are identified.

Las lombrices (Clitellata, Moniligastridae) del río Chaliyar de Malappuram, el Parque Nacional de Eravikulam, el refugio de especies silvestres de Neyyar, la reserva de tigres de Parambikulam, el refugio de especies silvestres de Peppara, el Parque Nacional de Periyar, el refugio de especies silvestres de Shendurney y el bosque de Wayanad, en Kerala, que son una parte de la elevada diversidad de Western Ghats, en la India, se estudiaron mediante el método convencional de taxonomía, y su código de barras del ADN utilizando el gen de la oxidasa I del citrocromo c (COI). El estudio representa 11 especies de lombrices de la familia Moniligastridae, a saber: Drawida brunnea Stephenson, Drawida circumpapillata Aiyer, Drawida ghatensis Michaelsen, Drawida impertusa Stephenson, Drawida nilamburensis (Bourne), Drawida robusta (Bourne), Drawida scandens Rao, Drawida travancorense Michaelsen, Moniligaster aiyeri Gates, Moniligaster deshayesi Perrier y Moniligaster gravelyi (Stephenson). En el análisis filogenético, todas las especies se recuperaron tanto en los árboles producidos mediante el método de unión de vcinos como en los árboles basados en la máxima verosimilitud, con un elevado apoyo de los clados. La distancia media calculada con el modelo K2P dentro de una misma especie y entre especies fue del 1,2 % y el 22 %, respectivamente, mientras que el análisis de deficiencias del código de barras (BGA) de las especies estudiadas sugirió una brecha del 2–5 %, lo que refleja la precisión de la caracterización. En el estudio se presenta el primer paso en la caracterización molecular de la familia de lombrices Moniligastridae, autóctona de la India. Datos publicados en GBIF (Doi: 10.15470/l2nlhz)

Time-resolved photoluminescence (TRPL) is applied to determine an effective lifetime of minority charge carriers in semiconductors. Such effective lifetimes include recombination channels in the bulk as well as at the surfaces and interfaces of the device. In the case of Cu(In,Ga)Se2 absorbers used for solar cell applications, trapping of minority carriers has also been reported to impact the effective minority carrier lifetime. Trapping can be indicated by an increased temperature dependence of the experimentally determined photoluminescence decay time when compared to the temperature dependence of Shockley–Read–Hall (SRH) recombination alone and can lead to an overestimation of the minority carrier lifetime. Here, it is shown by technology computer-aided design (TCAD) simulations and by experiment that the intentional double-graded bandgap profile of high efficiency Cu(In,Ga)Se2 absorbers causes a temperature dependence of the PL decay time similar to trapping in case of a recombinative front surface. It is demonstrated that a passivated front surface results in a temperature dependence of the decay time that can be explained without minority carrier trapping and thus enables the assessment of the absorber quality by means of the minority carrier lifetime. Comparison with the absolute PL yield and the quasi-Fermi-level splitting (QFLS) corroborate the conclusion that the measured decay time corresponds to the bulk minority carrier lifetime of 250 ns for the double-graded CIGS absorber under investigation.

We explore the feasibility of Ag fiber meshes as electron transport layer for high-efficiency flexible Cu(In,Ga)Se2 (CIGS) solar cells. Woven meshes of Ag fibers after UV illumination and millisecond flash-lamp treatment results in a sheet resistance of 17 Ω/sq and a visible transmittance above 85%. Conductive Ag meshes are integrated into flexible CIGS cells as transparent conductive electrode (TCE) alone or together with layers of Al-doped ZnO (AZO) with various thickness of 0…900 nm. The Ag mesh alone is not able to function as a current collector. If used together with a thin AZO layer (50 nm), the Ag mesh markedly improves the fill factor and cell efficiency, in spite of the adverse mesh shadowing. When Ag mesh is combined with thicker (200 nm or 900 nm) AZO layers, no improvements in photovoltaic parameters are obtained. When comparing a hybrid TCE consisting of 50 nm AZO and Ag fiber mesh with a thick 900 nm reference AZO device, an improved charge carrier collection in the near-infrared range is observed. Regardless of the AZO thickness, the presence of Ag mesh slows down cell degradation upon mechanical tensile stress, which could be interesting for implementation into flexible thin film CIGS modules.

The possibility to manufacture perovskite solar cells (PSCs) at low temperatures paves the way to flexible and lightweight photovoltaic (PV) devices manufactured via high-throughput roll-to-roll processes. In order to achieve higher power conversion efficiencies, it is necessary to approach the radiative limit via suppression of non-radiative recombination losses. Herein, we performed a systematic voltage loss analysis for a typical low-temperature processed, flexible PSC in n-i-p configuration using vacuum deposited C60 as electron transport layer (ETL) and two-step hybrid vacuum-solution deposition for CH3NH3PbI3 perovskite absorber. We identified the ETL/absorber interface as a bottleneck in relation to non-radiative recombination losses, the quasi-Fermi level splitting (QFLS) decreases from ~1.23 eV for the bare absorber, just ~90 meV below the radiative limit, to ~1.10 eV when C60 is used as ETL. To effectively mitigate these voltage losses, we investigated different interfacial modifications via vacuum deposited interlayers (BCP, B4PyMPM, 3TPYMB, and LiF). An improvement in QFLS of ~30–40 meV is observed after interlayer deposition and confirmed by comparable improvements in the open-circuit voltage after implementation of these interfacial modifications in flexible PSCs. Further investigations on absorber/hole transport layer (HTL) interface point out the detrimental role of dopants in Spiro-OMeTAD film (widely employed HTL in the community) as recombination centers upon oxidation and light exposure.

The sluggish kinetics of the oxygen evolution reaction (OER) is the main obstacle in water splitting which is generally catalyzed by precious metals. Here, authors report a DFT predicted non-precious bimetallic phosphate electrocatalyst that displays high OER activity and stability.

Cyanobacterial strains were isolated, and identified from rhizospheric soil and plant parts of rice varieties from Ludhiana, Punjab during kharif 2018. Out of the total 18 strains, 16 were heterocystous and 2 were non-hetercocystous. Seven were isolated from rice variety PB-1121 while 11 were from variety Parman-126. These belonged to four genera, Nostoc (13), Anabaena and Phormidium (2 each); and Trichormus (one).These were characterized for cell dry weight, pigments and total soluble proteins which showed a significant variation. Pigments ranged from 1.51 μg/ml to 11.63 μg/ml (chlorophyll), 0.41 μg/ml to 11.06 μg/ml (carotenoids), 1.13 μg/ml to 26.28 μg/ml (phycocyanin), 0.15 μg/ml to 33.23 μg/ml (phycoerythrin), 0.16 μg/ml to 11.18 μg/ml (allophycocyanin). Total phycobili proteins varied from a highest of 54.31 μg/ml to the lowest of 2.95 μg/ml, whereas, total soluble proteins ranged as 0.29 mg/ml to 0.70 mg/ml. Nitrogenase activity was measured as Acetylene Reduction Assay and this parameter also varied amongst the strains. Extracellular ammonia release varied as lowest of 11.10 μmole NH4 +/ml to the highest of 229.70 μmole NH4 +/ml, whereas, indole acetic acid production ranged from 7.45 μg/ml to 66.00 μg/ml.On the basis of efficient plant growth promoting parameters, these cyanobacterial strains can be studied for their possible positive influence on the performance of rice crop, which may, in turn, help in nitrogen economy after testing under pot culture and field evaluations as per required procedure and guidelines.

The excessive use of digital platforms with rapidly increasing users in the wireless domain enforces communication systems to provide information with high data rates, high reliability and strong transmission connection quality. Wireless systems with single antenna elements are not able to accomplish the desired needs. Therefore, multiple-input multiple-output (MIMO) antennas are getting more attention in modern high-speed communication systems and play an essential part in the current generation of wireless technology. However, along with their ability to significantly increase channel capacity, it is a challenge to achieve an optimal isolation in a compact size for fifth-generation (5G) terminals. Portable devices, automobiles, handheld gadgets, smart phones, wireless sensors, radio frequency identification and other applications use MIMO antenna systems. In this review paper, the fundamentals of MIMO antennas, the performance parameters of MIMO antennas, and different design approaches and methodologies are discussed to realize the three most commonly used MIMO antennas, i.e., ultra-wideband (UWB), dual-band and circularly polarized antennas. The recent MIMO antenna design approaches with UWB, dual band and circularly polarized characteristics are compared in terms of their isolation techniques, gain, efficiency, envelope correlation coefficient (ECC) and channel capacity loss (CCL). This paper is very helpful to design suitable MIMO antennas applicable in UWB systems, satellite communication systems, GSM, Bluetooth, WiMAX, WLAN and many more. The issues with MIMO antenna systems in the indoor environment along with possible solutions to improve their performance are discussed. The paper also focuses on the applications of MIMO characteristics for future sixth-generation (6G) technology.

Abstract The knowledge of minority carrier lifetime of a semiconductor is important for the assessment of its quality and design of electronic devices. Time-resolved photoluminescence (TRPL) measurements offer the possibility to extract effective lifetimes in the nanosecond range. However, it is difficult to discriminate between surface and bulk recombination and consequently the bulk properties of the semiconductor cannot be estimated reliably. Here we present an approach to constrain systematically the bulk and surface recombination parameters in semiconducting layers and reduces to finding the roots of a mathematical function. This method disentangles the bulk and surface recombination based on TRPL decay times of samples with different surface preparations. The technique is exemplarily applied to a CuInSe2 and a back-graded Cu(In,Ga)Se2 compound semiconductor, and upper and lower bounds for the recombination parameters and the mobility are obtained. Sets of calculated parameters are extracted and used as input for simulations of photoluminescence transients, yielding a good match to experimental data and validating the effectiveness of the methodology. A script for the simulation of TRPL transients is provided.

A comparative study of the electrical and photodetection properties of ZnO and Cr doped ZnO thin films are being reported here. The films were deposited using magnetron sputtering. X-ray diffraction (XRD) revealed hexagonal crystal structure of the films with (002) preferred orientation. Pt/ZnO/Pt and Pt/Cr doped ZnO/Pt Schottky diodes were fabricated for photodetection studies. The Schottky barrier height was lowered for Cr doped ZnO film as compared to ZnO film. The ideality factor was improved upon Cr doping. Pt/ZnO/Pt diode was unresponsive to visible light, however, Pt/Cr doped ZnO/Pt diode showed response to visible light with short response and recovery times. The response of the Pt/Cr doped ZnO/Pt diodes to visible light is attributed to the reduction in band gap of the Cr doped ZnO thin film. Keywords: Chromium-doped Zinc oxide, Thin films, Sputtering, Schottky contact, Photodetectors

Multi-junction solar cells show the highest photovoltaic energy conversion efficiencies, but the current technologies based on wafers and epitaxial growth of multiple layers are very costly. Therefore, there is a high interest in realizing multi-junction tandem devices based on cost-effective thin film technologies. While the efficiency of such devices has been limited so far because of the rather low efficiency of semitransparent wide bandgap top cells, the recent rise of wide bandgap perovskite solar cells has inspired the development of new thin film tandem solar devices. In order to realize monolithic, and therefore current-matched thin film tandem solar cells, a bottom cell with narrow bandgap (~1 eV) and high efficiency is necessary. In this work, we present Cu(In,Ga)Se2 with a bandgap of 1.00 eV and a maximum power conversion efficiency of 16.1%. This is achieved by implementing a gallium grading towards the back contact into a CuInSe2 base material. We show that this modification significantly improves the open circuit voltage but does not reduce the spectral response range of these devices. Therefore, efficient cells with narrow bandgap absorbers are obtained, yielding the high current density necessary for thin film multi-junction solar cells.

Structural defects such as voids and compositional inhomogeneities may affect the performance of Cu(In,Ga)Se2 (CIGS) solar cells. We analyzed the morphology and elemental distributions in co-evaporated CIGS thin films at the different stages of the CIGS growth by energy-dispersive x-ray spectroscopy in a transmission electron microscope. Accumulation of Cu-Se phases was found at crevices and at grain boundaries after the Cu-rich intermediate stage of the CIGS deposition sequence. It was found, that voids are caused by Cu out-diffusion from crevices and GBs during the final deposition stage. The Cu inhomogeneities lead to non-uniform diffusivities of In and Ga, resulting in lateral inhomogeneities of the In and Ga distribution. Two and three-dimensional simulations were used to investigate the impact of the inhomogeneities and voids on the solar cell performance. A significant impact of voids was found, indicating that the unpassivated voids reduce the open-circuit voltage and fill factor due to the introduction of free surfaces with high recombination velocities close to the CIGS/CdS junction. We thus suggest that voids, and possibly inhomogeneities, limit the efficiency of solar cells based on three-stage co-evaporated CIGS thin films. Passivation of the voids’ internal surface may reduce their detrimental effects.

The performance improvement of conventional CdTe solar cells is mainly limited by doping concentration and minority carrier life time. Alloying CdTe with an isovalent element changes its properties, for example its band gap and behaviour of dopants, which has a significant impact on its performance as a solar cell absorber. In this work, the structural, optical, and electronic properties of CdTe1-xSex films are examined for different Se concentrations. The band gap of this compound changes with composition with a minimum of 1.40 eV for x = 0.3. We show that with increasing x, the lattice constant of CdTe1-xSex decreases, which can influence the solubility of dopants. We find that alloying CdTe with Se changes the effect of Cu doping on the p-type conductivity in CdTe1-xSex, reducing the achievable charge carrier concentration with increasing x. Using a front surface CdTe1-xSex layer, compositional, structural and electronic grading is introduced to solar cells. The efficiency is increased, mostly due to an increase in the short-circuit current density caused by a combination of lower band gap and a better interface between the absorber and window layer, despite a loss in the open-circuit voltage caused by the lower band gap and reduced charge carrier concentration.

Cu(In,Ga)Se2 -based solar cells have reached efficiencies close to 23%. Further knowledge-driven improvements require accurate determination of the material properties. Here, we present refractive indices for all layers in Cu(In,Ga)Se2 solar cells with high efficiency. The optical bandgap of Cu(In,Ga)Se2 does not depend on the Cu content in the explored composition range, while the absorption coefficient value is primarily determined by the Cu content. An expression for the absorption spectrum is proposed, with Ga and Cu compositions as parameters. This set of parameters allows accurate device simulations to understand remaining absorption and carrier collection losses and develop strategies to improve performances.

Background & objectives: There is an urgent need of introducing new insecticide molecules with novel modes of action to counter the ever growing insecticide-resistance in mosquito vectors. In the present study, a new insecticide molecule, SumiShield 50 WG (clothianidin 50%, w/w) was investigated for its efficacy as an indoor residual spray along with its residual action in comparison to deltamethrin, pirimiphos-methyl and bendiocarb. Methods: The study area included three villages in Almatti Dam catchment area in Bagalkot district, Karnataka, India. Spraying was done using Hudson sprayers with the following dosages—Clothianidin, 300 mg AI/m2; deltamethrin, 25 mg AI/m2; bendiocarb, 400 mg AI/m2; and pirimiphos-methyl, 1 g AI/m2. Cone bioassays were conducted on cement and mud plastered surfaces at fortnightly intervals to assess the bioefficacy and residual activity. Mosquito densities in the sprayed houses were recorded at regular intervals for assessment of the insecticidal efficacy. Filter paper samples collected from the sprayed houses were analyzed for insecticide content sprayed on different wall surfaces at the Walloon Agricultural Research Institute, Gembloux, Belgium. Results: Chemical content analysis of filter paper samples revealed that the applied to target ratios were in the acceptable range (1 + 0.5) for all the treatment types. Duration of persistence of effectiveness of bendiocarb (≥80% mortality in cone bioassays) was 19 to 21 wk on cement plastered surfaces and 15 to 19 wk on mud plastered surfaces. Duration of persistence of effectiveness of deltamethrin was 17 to 21 wk on both mud and cement plastered surfaces and that of pirimiphos-methyl was 15 to 19 wk. For SumiShield, it was 17 to 25 wk on both types of surfaces, indicating slow action of SumiShield. The densities of Anopheles culicifacies were lower in bendiocarb sprayed houses throughout the observation period, followed by pirimiphos methyl, deltamethrin and clothianidin sprayed houses. In case of other mosquitoes also, similar trend was observed. Interpretation & conclusion: Considering the persistence of effectiveness of SumiShield on sprayed surfaces, effectiveness in reducing the density of mosquitoes, operational feasibility, safety and community acceptance, the formulation of clothianidin is a better option for IRS for the control of insecticide-resistant mosquito vectors.

Purpose: To compare the visual outcomes and higher order aberrations (HOAs) following wavefront optimized (WFO) laser in situ keratomileusis (LASIK) versus topography-guided customized ablation (TCAT) LASIK for myopia and myopic astigmatism. Methods: Patients who underwent femtosecond-assisted LASIK for myopic correction between August 2016 and October 2017 were included in this interventional prospective case series. The following parameters were evaluated preoperatively and at 3 months' postoperative visit: uncorrected distance vision acuity (UDVA) and corrected distance vision acuity (CDVA), manifest refraction, and HOAs. Results: Two hundred eyes of 100 patients were included in the study. At 3 months' postoperative visit, 92% and 90% eyes in the TCAT and WFO groups, respectively, demonstrated a UDVA of 20/20 or better (P = 0.90). A residual manifest spherical equivalent within 0.5 D was achieved in 100% and 95% of the eyes in the TCAT and WFO groups, respectively (P = 0.10). No significant difference was observed in the HOAs induced in both the groups, with slightly lower induction of trefoil and horizontal coma in the TCAT group. Conclusion: Both groups demonstrated similar refractive efficacy and predictability, with greater gain of CDVA following TCAT ablation. HOAs induced were not significantly different between the two groups. Further studies are needed to validate the superiority of one procedure over the other.