Signatures of nearly compensated magnetism and spin glass behavior in highly frustrated ß-Mn-type Mn50Fe25+xAl25-x Heusler alloys.

The present study examines the effect of Fe/Al concentration on the structural and magnetic properties of Mn-rich Mn50Fe25+xAl25-x (x = 5, 10, 15) Heusler alloys through x-ray diffraction, temperature- and field-dependent DC magnetization, thermoremanent magnetization, magnetic memory effect, AC susceptibility measurements, and DFT calculations. The samples crystallize in a cubic ß-Mn structure. The trend shows a reduction in lattice parameters (unit cell volume) with the increasing Fe proportion. These alloys exhibit strong antiferromagnetic interactions with large frustration parameters, indicating the presence of competing magnetic interactions. The DC magnetization data reveal spin glass-like features with a peak at spin glass freezing temperature (Tf). The observation of bifurcation in temperature-dependent zero-field-cooled and field-cooled magnetization curves, exponential dependence of the temperature variation of remanence and coercivity, magnetic relaxation, and magnetic memory effect below Tf support the spin-glass character of these alloys. The frequency dependence of Tf is also examined in the context of dynamic scaling laws, such as the Vogel-Fulcher law and critical slowing down model, which further supports the presence of spin glass behavior. In the theoretical DFT calculations, the electronic structure is found to be metallic and similar for both spin projections. Moreover, the antiferromagnetic arrangement of the magnetic moments, in line with the experimental observations, is stabilized by exchange interactions, resulting in an almost compensated total magnetic moment of 0.02-0.38 µB/f.u. This is probably caused by the frustrated structure and non-stoichiometric compositions of Mn50Fe25+xAl25-x.

Current Status and Future Perspectives on Distribution of Fungal Endophytes and Their Utilization for Plant Growth Promotion and Management of Grapevine Diseases.

Grapevine is one of the economically most important fruit crops cultivated worldwide. Grape production is significantly affected by biotic constraints leading to heavy crop losses. Changing climatic conditions leading to widespread occurrence of different foliar diseases in grapevine. Chemical products are used for managing these diseases through preventive and curative application in the vineyard. High disease pressure and indiscriminate use of chemicals leading to residue in the final harvest and resistance development in phytopathogens. To mitigate these challenges, the adoption of potential biocontrol control agents is necessary. Moreover, multifaceted benefits of endophytes made them eco-friendly, and environmentally safe approach. The genetic composition, physiological conditions, and ecology of their host plant have an impact on their dispersion patterns and population diversity. Worldwide, a total of more than 164 fungal endophytes (FEs) have been characterized originating from different tissues, varieties, crop growth stages, and geographical regions of grapevine. These diverse FEs have been used extensively for management of different phytopathogens globally. The FEs produce secondary metabolites, lytic enzymes, and organic compounds which are known to possess antimicrobial and antifungal properties. The aim of this review was to understand diversity, distribution, host-pathogen-endophyte interaction, role of endophytes in disease management and for enhanced, and quality production.

A Novel Spinel Ferrite-Hexagonal Ferrite Composite for Enhanced Magneto-Electric Coupling in a Bilayer with PZT.

The magnetoelectric effect (ME) is an important strain mediated-phenomenon in a ferromagnetic-piezoelectric composite for a variety of sensors and signal processing devices. A bias magnetic field, in general, is essential to realize a strong ME coupling in most composites. Magnetic phases with (i) high magnetostriction for strong piezomagnetic coupling and (ii) large anisotropy field that acts as a built-in bias field are preferred so that miniature, ME composite-based devices can operate without the need for an external magnetic field. We are able to realize such a magnetic phase with a composite of (i) barium hexaferrite (BaM) with high magnetocrystalline anisotropy field and (ii) nickel ferrite (NFO) with high magnetostriction. The BNx composites, with (100 - x) wt.% of BaM and x wt.% NFO, for x = 0-100, were prepared. X-ray diffraction analysis shows that the composites did not contain any impurity phases. Scanning electron microscopy images revealed that, with an increase in NFO content, hexagonal BaM grains become prominent, leading to a large anisotropy field. The room temperature saturation magnetization showed a general increase with increasing BaM content in the composites. NFO rich composites with x ≥ 60 were found to have a large magnetostriction value of around -23 ppm, comparable to pure NFO. The anisotropy field HA of the composites, determined from magnetization and ferromagnetic resonance (FMR) measurements, increased with increasing NFO content and reached a maximum of 7.77 kOe for x = 75. The BNx composite was cut into rectangular platelets and bonded with PZT to form the bilayers. ME voltage coefficient (MEVC) measurements at low frequencies and at mechanical resonance showed strong coupling at zero bias for samples with x ≥ 33. This large in-plane HA acted as a built-in field for strong ME effects under zero external bias in the bilayers. The highest zero-bias MEVC of ~22 mV/cm Oe was obtained for BN75-PZT bilayers wherein BN75 also has the highest HA. The Bilayer of BN95-PZT showed a maximum MEVC ~992 mV/cm Oe at electromechanical resonance at 59 kHz. The use of hexaferrite-spinel ferrite composite to achieve strong zero-bias ME coupling in bilayers with PZT is significant for applications related to energy harvesting, sensors, and high frequency devices.

Epiphytic Microbial Diversity of Vitis vinifera Fructosphere: Present Status and Potential Applications.

Vineyard provides an apt environment for growth of different types of microorganisms. The microbial domain is greatly affected by changing climatic conditions, geographical region, water activity, agricultural practices, presence of different pathogens and various pests. Grapevine microbial diversity is also affected by different stages of plant growth. Epiphytic berry microflora is specifically influenced by developmental phases and plays an important role in winemaking which is studied extensively. However, very little information is available about microbial community associated with table grape berries, which are consumed as fresh fruits. Moreover, our knowledge about the important role played by these microbes is precise and their scope might be larger than what is existing in the public domain. A systematic study on effect of developmental stages of table grape berries on microbial diversity would provide new insights for exploring the applicability of these microbes in plant growth, crop protection and bioremediation. In this review, we propose an effort to relate the developmental stages of grape berry with microbial consortium present and at the same time discuss the possible applications of these microbes in plant protection and biodegradation.

Structural Polymorphism in Na4Zn(PO4)2 Driven by Rotational Order-Disorder Transitions and the Impact of Heterovalent Substitutions on Na-Ion Conductivity.

Solid electrolytes have regained tremendous interest recently in light of the exposed vulnerability of current rechargeable battery technologies. While designing solid electrolytes, most efforts concentrated on creating structural disorder (vacancies, interstitials, etc.) in a cationic Li/Na sublattice to increase ionic conductivity. In phosphates, the ionic conductivity can also be increased by rotational disorder in the anionic sublattice, via a paddle-wheel mechanism. Herein, we report on Na4Zn(PO4)2 which is designed from Na3PO4, replacing Na+ with Zn2+ and introducing a vacancy for charge balance. We show that Na4Zn(PO4)2 undergoes a series of structural transitions under temperature, which are associated with an increase in ionic conductivity by several orders of magnitude. Our detailed crystallographic study, combining electron, neutron, and X-ray powder diffraction, reveals that the room-temperature form, α-Na4Zn(PO4)2, contains orientationally ordered PO4 groups, which undergo partial and full rotational disorder in the high-temperature ß- and γ-polymorphs, respectively. We furthermore showed that the highly conducting γ-polymorph could be stabilized at room temperature by ball-milling, whereas the ß-polymorph can be stabilized by partial substitution of Zn2+ with Ga3+ and Al3+. These findings emphasize the role of rotational disorder as an extra parameter to design new solid electrolytes.

Analytical method validation, dissipation and safety evaluation of combination fungicides fenamidone + mancozeb and iprovalicarb + propineb in/on tomato.

Dissipation behavior and degradation kinetics of fenamidone + mancozeb (Sectin 60 WG) and iprovalicarb + propineb (Melody Duo 66.75 WP) in tomato were studied at recommended dose (RD) and double dose (DD) of application. The analysis of the field samples were carried out by employing liquid chromatography tandem mass spectrometry (LC-MS/MS) for fenamidone and iprovalicarb residues and gas chromatography mass spectrometry for mancozeb and propineb residues after thorough validation of the extraction methods. The dissipation of residues best followed 1st + 1st order for all the test fungicides. The half-life period for fenamidone, mancozeb, iprovalicarb and propineb were 2, 2, 1.5 and 2 days for RD and 3, 2.5, 2 and 3 days for DD, respectively. The pre-harvest intervals were not applicable for iprovalicarb, fenamidone and mancozeb (at RD) as the residues at 0 day were below maximum residue limit set by European Union, and it was 1 day for DD of iprovalicarb, 3.5 days for DD of fenamidone, 3 days for DD of mancozeb, 3 and 7 days for propineb at RD and DD, respectively. A PHI of 4 and 7 days are proposed for fenamidone + Mancozeb and iprovalicarb + propineb, respectively. Dietary exposure calculated for all the pesticides were safe on all the sampling days except for propineb residues for which it was safe after first day of the double dose application. The study will be useful for promoting effective residue management and safe use of these chemicals for controlling fungal diseases in tomato crop.

Influence of Temperature-Driven Polymorphism and Disorder on Ionic Conductivity in Li6Zn(P2O7)2.

Ionic conductivity in a compound is rooted in a delicate interplay between its crystal structure and its structural defects (vacancies, interstitials, etc.). Hence, understanding this interplay is of utmost importance to design new solid state electrolytes. To shed some light on the above query, we investigated the rich crystal chemistry of Li6Zn(P2O7)2. This compound undergoes multiple structural transitions under the influence of temperature, which increases the conductivity by several orders and lowers the activation energy. We explained this jump in conductivity by the increased disorder associated with cation mixing. Our structural exploration indicates that both the room-temperature α-polymorph and the high-temperature ζ-polymorph crystallize in a C2/ c space group but with a much smaller unit cell volume for the latter. While their structural framework based on P2O74- is similar, the ζ-polymorph presents a fully disordered Li/Zn sublattice, while it is fully ordered for the α-polymorph. Furthermore, the bond valence energy landscape calculations show that in the α-polymorph, the Li+ conduction is two-dimensional, whereas because of Li+/Zn2+ site mixing, Li+ can hop three-dimensionally in the ζ-polymorph.

All-Solid-State Mechanochemical Synthesis and Post-Synthetic Transformation of Inorganic Perovskite-type Halides.

All-inorganic and hybrid perovskite type halides are generally synthesized by solution-based methods, with the help of long chain organic capping ligands, complex organometallic precursors, and high boiling organic solvents. Herein, a room temperature, solvent-free, general, and scalable all-solid-state mechanochemical synthesis is demonstrated for different inorganic perovskite type halides, with versatile structural connectivity in three (3D), two (2D), and zero (0D) dimensions. 3D CsPbBr3 , 2D CsPb2 Br5 , 0D Cs4 PbBr6 , 3D CsPbCl3 , 2D CsPb2 Cl5 , 0D Cs4 PbCl6 , 3D CsPbI3 , and 3D RbPbI3 have all been synthesized by this method. The all-solid-state synthesis is materialized through an inorganic retrosynthetic approach, which directs the decision on the solid-state precursors (e.g., CsX and PbX2 (X=Cl/Br/I) with desired stoichiometric ratios. Moreover, post-synthetic structural transformations from 3D to 2D and 0D perovskite halides were performed by the same mechanochemical synthetic approach at room temperature.

High Power Factor and Enhanced Thermoelectric Performance of SnTe-AgInTe2: Synergistic Effect of Resonance Level and Valence Band Convergence.

Understanding the basis of electronic transport and developing ideas to improve thermoelectric power factor are essential for production of efficient thermoelectric materials. Here, we report a significantly large thermoelectric power factor of ∼31.4 µW/cm·K2 at 856 K in Ag and In co-doped SnTe (i.e., SnAgxInxTe1+2x). This is the highest power factor so far reported for SnTe-based material, which arises from the synergistic effects of Ag and In on the electronic structure and the improved electrical transport properties of SnTe. In and Ag play different but complementary roles in modifying the valence band structure of SnTe. In-doping introduces resonance levels inside the valence bands, leading to a significant improvement in the Seebeck coefficient at room temperature. On the other hand, Ag-doping reduces the energy separation between light- and heavy-hole valence bands by widening the principal band gap, which also results in an improved Seebeck coefficient. Additionally, Ag-doping in SnTe enhances the p-type carrier mobility. Co-doping of In and Ag in SnTe yields synergistically enhanced Seebeck coefficient and power factor over a broad temperature range because of the synergy of the introduction of resonance states and convergence of valence bands, which have been confirmed by first-principles density functional theory-based electronic structure calculations. As a consequence, we have achieved an improved thermoelectric figure of merit, zT ≈ 1, in SnAg0.025In0.025Te1.05 at 856 K.

Few-Layer Nanosheets of n-Type SnSe2.

Layered p-block metal chalcogenides are renowned for thermoelectric energy conversion due to their low thermal conductivity caused by bonding asymmetry and anharmonicity. Recently, single crystalline layered SnSe has created sensation in thermoelectrics due to its ultralow thermal conductivity and high thermoelectric figure of merit. Tin diselenide (SnSe2 ), an additional layered compound belonging to the Sn-Se phase diagram, possesses a CdI2 -type structure. However, synthesis of pure-phase bulk SnSe2 by a conventional solid-state route is still remains challenging. A simple solution-based low-temperature synthesis is presented of ultrathin (3-5 nm) few layers (4-6 layers) nanosheets of Cl-doped SnSe2 , which possess n-type carrier concentration of 2×1018  cm-3 with carrier mobility of about 30 cm2 V-1 s-1 at room temperature. SnSe2 has a band gap of about 1.6 eV and semiconducting electronic transport in the 300-630 K range. An ultralow thermal conductivity of about 0.67 Wm-1  K-1 was achieved at room temperature in a hot-pressed dense pellet of Cl-doped SnSe2 nanosheets due to the anisotropic layered structure, which gives rise to effective phonon scattering.

Extraordinary Changes in the Electronic Structure and Properties of CdS and ZnS by Anionic Substitution: Cosubstitution of P and Cl in Place of S.

Unlike cation substitution, anion substitution in inorganic materials such as metal oxides and sulfides would be expected to bring about major changes in the electronic structure and properties. In order to explore this important aspect, we have carried out first-principles DFT calculations to determine the effects of substitution of P and Cl on the properties of CdS and ZnS in hexagonal and cubic structures and show that a sub-band of the trivalent phosphorus with strong bonding with the cation appears in the gap just above the valence band, causing a reduction in the gap and enhancement of dielectric properties. Experimentally, it has been possible to substitute P and Cl in hexagonal CdS and ZnS. The doping reduces the band gap significantly as predicted by theory. A similar decrease in the band gap is observed in N and F co-substituted in cubic ZnS. Such anionic substitution helps to improve hydrogen evolution from CdS semiconductor structures and may give rise to other applications as well.

Bioefficacy, residue dynamics and safety assessment of the combination fungicide trifloxystrobin 25% + tebuconazole 50%-75 WG in managing early blight of tomato (Lycopersicon esculentum Mill.).

This paper reports the in vitro and in vivo bioefficacy of a combination fungicide trifloxystrobin (25%) + tebuconazole (50%) against early blight disease of tomato (Lycopersicon esculentum Mill.) caused by Alternaria solani and their corresponding pre-harvest intervals (PHI) with reference to the maximum residue limits (European Union). Bioefficacy of the test fungicide combination revealed that in vitro conditions manifested the best control (75.1%) at 350 mg kg(-1) against 76.2% control under field conditions. A sample preparation method based on ethyl acetate extraction and estimation by LC-MS multiple reaction monitoring (MRM) was validated in tomato fruits at 0.01 mg/kg and dissipation studies were conducted in field at single and double doses. The residues of both the compounds on all the sampling days were below the European Union maximum residue limits (EU-MRLs) and the maximum permissible intakes (MPIs) were calculated on the basis of prescribed acceptable daily intake (ADI). The combined bioefficacy and residue dynamics information will support label-claim of this fungicide combination for the management of early blight in tomato.

Biocontrol potential of endophytic fungi originated from grapevine leaves for management of anthracnose disease caused by Colletotrichum gloeosporioides.

In the present study, 51 fungal endophytes (FEs) were isolated, purified and identified from the healthy leaf segments of ten grapevine varieties based on the spore and colony morphologies and ITS sequence information. The FEs belonged to the Ascomycota division comprising eight genera viz., Alternaria, Aspergillus, Bipolaris, Curvularia, Daldinia, Exserohilum, Fusarium and Nigrospora. The in vitro direct confrontation assay against Colletotrichum gloeosporioides revealed that six isolates viz., VR8 (70%), SB2 (83.15%), CS2 (88.42%), MN3 (88.42%), MS5 (78.94%) and MS15 (78.94%) inhibited the mycelial growth of test pathogen. The remaining 45 fungal isolates showed 20-59.9% growth inhibition of C. gloeosporioides. Indirect confrontation assay manifested that the isolates MN1 and MN4a showed 79.09% and 78.18% growth inhibition of C. gloeosporioides followed by MM4 (73.63%) and S5 (71.81%) isolates. Isolate S5 and MM4 were found to produce azulene and 1,3-Cyclopentanedione, 4,4-dimethyl as antimicrobial volatile organic compounds, respectively. The 38 FEs showed PCR amplification using internal transcribed spacer universal primers. The BLAST search revealed highest similarity with the existing sequences in the database. The phylogenetic analysis revealed the occurrence of seven distinct clusters each corresponding to single genus. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03675-z.

Effect of High-Anisotropic Co2+ Substitution for Ni2+ on the Structural, Magnetic, and Magnetostrictive Properties of NiFe2O4: Implications for Sensor Applications.

This work reports on the effect of substituting a low-anisotropic and low-magnetic cation (Ni2+, 2µB) by a high-anisotropic and high-magnetic cation (Co2+, 3µB) on the crystal structure, phase, microstructure, magnetic properties, and magnetostrictive properties of NiFe2O4 (NFO). Co-substituted NFO (Ni1-xCoxFe2O4, NCFO, 0 ≤ x ≤ 1) nanomaterials were synthesized using glycine-nitrate autocombustion followed by postsynthesis annealing at 1200 °C. The X-ray diffraction measurements coupled with Rietveld refinement analyses indicate the significant effect of Co-substitution for Ni, where the lattice constant (a) exhibits a functional dependence on composition (x). The a-value increases from 8.3268 to 8.3751 Å (±0.0002 Å) with increasing the "x" value from 0 to 1 in NCFO. The a-x functional dependence is derived from the ionic-size difference between Co2+ and Ni2+, which also induces grain agglomeration, as evidenced in electron microscopy imaging. The chemical bonding of NCFO, as probed by Raman spectroscopy, reveals that Co(x)-substitution induced a red shift of the T2g(2) and A1g(1) modes, and it is attributed to the changes in the metal-oxygen bond length in the octahedral and tetrahedral sites in NCFO. X-ray photoelectron spectroscopy confirms the presence of Co2+, Ni2+, and Fe3+ chemical states in addition to the cation distribution upon Co-substitution in NFO. Chemical homogeneity and uniform distribution of Co, Ni, Fe, and O are confirmed by EDS. The magnetic parameters, saturation magnetization (MS), remnant magnetization (Mr), coercivity (HC), and anisotropy constant (K1) increased with increasing Co-content "x" in NCFO. The magnetostriction (λ) also follows a similar behavior and almost linearly varies from -33 ppm (x = 0) to -227 ppm (x = 1), which is primarily due to the high magnetocrystalline anisotropy contribution from Co2+ ions at the octahedral sites. The magnetic and magnetostriction measurements and analyses indicate the potential of NCFO for torque sensor applications. Efforts to optimize materials for sensor applications indicate that, among all of the NCFO materials, Co-substitution with x = 0.5 demonstrates high strain sensitivity (-2.3 × 10-9 m/A), which is nearly 2.5 times higher than that obtained for their intrinsic counterparts, namely, NiFe2O4 (x = 0) and CoFe2O4 (x = 1).

Y-type hexagonal ferrite-based band-pass filter with dual magnetic and electric field tunability.

This work is on the design, fabrication and characterization of a hexagonal ferrite band-pass filter that can be tuned either with a magnetic field or an electric field. The filter operation is based on a straight-edge Y-type hexagonal ferrite resonator symmetrically coupled to the input and output microstrip transmission lines. The Zn2Yfilter demonstrated magnetic field tunability in the 8-12 GHz frequency range by applying an in-plane bias magnetic field H0 provided by a built-in permanent magnet. The insertion loss and 3 dB bandwidth within this band were 8.6 ± 0.4 dB and 350 ± 40 MHz, respectively. The electric field E tunability of the pass-band of the device was facilitated by the nonlinear magnetoelectric effect (NLME) in the ferrite. The E-tuning of the center frequency of the filter by (1150 ± 90) MHz was obtained for an input DC electric power of 200 mW. With efforts directed at a significant reduction in the insertion loss, the compact and power efficient magnetic and electric field tunable Zn2Y band-pass filter has the potential for use in novel reconfigurable RF/microwave devices and communication systems.

Electric field tuning of a nickel zinc ferrite resonator by non-linear magnetoelectric effects.

The nature of nonlinear magnetoelectric (NLME) effect has been investigated at room-temperature in a single-crystal Zn substituted nickel ferrite. Tuning of the frequency of magnetostatic surface wave (MSSW) modes under an applied pulsed DC electric field/current has been utilized to probe the effect. The frequencies of the modes at 8-20 GHz were found to decrease by ~ 400 MHz for an applied DC power P of ~ 100 mW and the frequency shift was the same for all of the MSSW modes and linearly proportional to P. A model is proposed for the effect and the NLME phenomenon was interpreted in terms of a reduction in the saturation magnetization due to the DC current. The decrease of magnetization with applied electric power, estimated from data on mode frequency versus P, was - 2.50 G/mW. The frequency tuning efficiency of the MSSW modes due to NLME effects in the ferrite resonator was found to be 4.1 MHz/mW which is an order of magnitude higher than the shift reported for M-type strontium and barium hexaferrite resonators investigated earlier. The spinel ferrite resonator discussed here has the potential for miniature, electric field tunable, planar microwave devices for the 8-20 GHz frequency range.

Aluminum Doping and Nanostructuring Enabled Designing of Magnetically Recoverable Hexaferrite Catalysts.

We demonstrate an approach based on substituting a magnetic cation with a carefully chosen isovalent non-magnetic cation to derive catalytic activity from otherwise catalytically inactive magnetic materials. Using the model system considered, the results illustratively present that the catalytically inactive but highly magnetic strontium hexaferrite (SrFe12O19; SFO) system can be transformed into a catalytically active system by simply replacing some of the magnetic cation Fe3+ by a non-magnetic cation Al3+ in the octahedral coordination environment in the SFO nanocrystals. The intrinsic SFO and Al-doped SrFe12O19 (SrFe11.5Al0.5O19; Al-SFO) nanomaterials were synthesized using a simple, eco-friendly tartrate-gel technique, followed by thermal annealing at 850 °C for 2 h. The SFO and Al-SFO were thoroughly characterized for their structure, phase, morphology, chemical bonding, and magnetic characteristics using X-ray diffraction, Fourier-transform infrared spectroscopy, and vibrating sample magnetometry techniques. Catalytic performance evaluated toward 4-nitrophenol, which is the toxic contaminant at pharmaceutical industries, reduction reaction using NaBH4 (mild reducing agent), the Al-doped SFO samples exhibit a reasonably good performance compared to intrinsic SFO. The results indicate that the catalytic activity of Al-SFO is due to Al-ions occupying the octahedral sites of the hexaferrite lattice; as these sites are on the surface of the catalyst, they facilitate electron transfer. Furthermore, surface/interface characteristics of nanocrystalline Al-SFO coupled with magnetic properties facilitate the catalyst recovery by simple, inexpensive methods while readily allowing the reusability. Moreover, the activity remains the same even after five successive cycles of experiments. Deriving the catalytic activity from otherwise inactive compounds as demonstrated in the optimized, engineered nanoarchitecture of Al-doped-Sr-hexaferrite may be useful in adopting the approach in exploring further options and designing inexpensive and recyclable catalytic materials for future energy and environmental technologies.

A Comparative Analysis of Microbe-Based Technologies Developed at ICAR-NBAIM Against Erysiphe necator Causing Powdery Mildew Disease in Grapes (Vitis vinifera L.).

Globally, Erysiphe necator causing powdery mildew disease in grapevines (Vitis vinifera L.) is the second most important endemic disease, causing huge economic losses every year. At present, the management of powdery mildew in grapes is largely dependent upon the use of chemical fungicides. Grapes are being considered as one of the high pesticide-demanding crops. Looking at the residual impact of toxic chemical pesticides on the environment, animal, and human health, microbe-based strategies for control of powdery mildew is an emerging technique. It offers an environment-friendly, residue-free, and effective yet safer approach to control powdery mildew disease in grapes. The mode of action is relatively diverse as well as specific to different pathosystems. Hence, the aim of this study was to evaluate the microbe-based technologies, i.e., Eco-pesticide®, Bio-Pulse®, and Bio-Care 24® developed at the Plant-Microbe Interaction and Rhizosphere Biology Lab, ICAR-NBAIM, Kushmaur, against grape powdery mildew and to integrate these technologies with a safer fungicide (sulfur) to achieve better disease control under organic systems of viticulture. The experiments were conducted at four different locations, namely, the vineyards of ICAR-NRCG, Rajya Draksha Bagayatdar Sangh (MRDBS), and two farmers' fields at Narayangaon and Junnar in the Pune district of Maharashtra. A significantly lower percent disease index (PDI) was recorded on the leaves of grape plants treated with Eco-Pesticide®/sulfur (22.37) followed by Bio-Pulse®/sulfur (22.62) and Bio-Care 24®/sulfur (24.62) at NRCG. A similar trend was observed with the lowest PDI on bunches of Eco-pesticide® /sulfur-treated plants (24.71) followed by Bio-Pulse®/sulfur (24.94) and Bio-Care®/sulfur (26.77). The application of microbial inoculants singly or in combination with sulfur has a significant positive impact on the qualitative parameters such as pH, total soluble solids (TSS), acidity, berry diameter, and berry length of the grapes at different locations. Among all the treatments, the Bio-Pulse®/sulfur treatment showed the highest yield per vine (15.02 kg), which was on par with the treatment Eco-Pesticide®/sulfur (14.94). When compared with the yield obtained from the untreated control, 2.5 to 3 times more yield was recorded in the plants treated with either of the biopesticides used in combination with sulfur. Even in the case of individual inoculation, the yield per vine was approximately two times higher than the untreated control and water-treated plants across the test locations. Results suggested that microbial technologies not only protect grapevines from powdery mildew but also enhance the quality parameters with increased yield across the test locations.

Analytical Approach to Screen Semiconducting MOFs Using Bloch Mode Analysis and Spectroscopic Measurements.

A rapid and simple analytical approach is developed to screen the semiconducting properties of metal organic frameworks (MOFs) by modeling the band structure and predicting the density of state of isoreticular MOFs (IRMOFs). One can consider the periodic arrangement of metal nodes linked by organic subunits as a 1D periodic array crystal model, which can be aligned with any unit-cell axis included in the IRMOF's primitive cubic lattice. In such a structure, each valence electron of a metal atom feels the potential field of the entire periodic array. We allocate the 1D periodic array in a crystal unit cell to three IRMOFs-n (n = 1, 8, and 10) of the Zn4O(L)3 IRMOF series and apply the model to their crystal lattices with unit-cell constants a = 25.66, 30.09, and 34.28 Å, respectively. By solving Schrödinger's equation with a Kronig-Penney periodic potential and fitting the computed energy spectra to IRMOFs' experimental spectroscopic data, we model electronic band structures and obtain densities of state. The band diagram of each IRMOF reveals the nature of its electronic structures and density of state, allowing one to identify its n- or p-type semiconducting behavior. This novel analytical approach serves as a predictive and rapid screening tool to search the MOF database to identify potential semiconducting MOFs.

Novel biodegradable low-κ dielectric nanomaterials from natural polyphenols.

Biodegradable natural polymers and macromolecules for transient electronics have great potential to reduce the environmental footprint and provide opportunities to create emerging and environmentally sustainable technologies. Creating complex electronic devices from biodegradable materials requires exploring their chemical design pathways to use them as substrates, dielectric insulators, conductors, and semiconductors. While most research exploration has been conducted using natural polymers as substrates for electronic devices, a very few natural polymers have been explored as dielectric insulators, but they possess high dielectric constants. Herein, for the first time, we have demonstrated a natural polyphenol-based nanomaterial, derived from tannic acid as a low-κ dielectric material by introducing a highly nanoporous framework with a silsesquioxane core structure. Utilizing natural tannic acid, porous "raspberry-like" nanoparticles (TA-NPs) are prepared by a sol-gel polymerization method, starting from reactive silane unit-functionalized tannic acid. Particle composition, thermal stability, porosity distribution, and morphology are analyzed, confirming the mesoporous nature of the nanoparticles with an average pore diameter ranging from 19 to 23 nm, pore volume of 0.032 cm3 g-1 and thermal stability up to 350 °C. The dielectric properties of the TA-NPs, silane functionalized tannic acid precursor, and tannic acid are evaluated and compared by fabricating thin film capacitors under ambient conditions. The dielectric constants (κ) are found to be 2.98, 2.84, and 2.69 (±0.02) for tannic acid, tannic acid-silane, and TA-NPs, respectively. The unique chemical design approach developed in this work provides us with a path to create low-κ biodegradable nanomaterials from natural polyphenols by weakening their polarizability and introducing high mesoporosity into the structure.