Double Hybrid Research Articles

Cyclic test evaluation of double skin composite hybrid coupled wall with frictional steel truss coupling beams

The seismic performance of double skin composite shear walls (DSCSWs) has significant superior to conventional reinforce concrete (RC) shear walls. Previous studies have neglected the changes of axial compressive forces and bending moments actting on the top of wall piers. In addition, behaviors hybrid coupled wall (HCW) under real boundary condition have not been fully investigated. Thus, in this study, a novel quasi-static test which incorporates the boundary conditions of substructures in a prototype building was preformed. And a cyclic test was carried out on a 2/3-scaled double skin composite (DSC) HCW with frictional steel truss coupling beams (FSTCBs) using the proposed method. The seismic behavior of specimen under reversed lateral cyclic loads was investigated. The failure modes of the wall piers mainly included local buckling of the steel faceplate, fracture of the side plate, and concrete crushing at the corners of walls. The force-displacement hysteresis curve of FSTCBs was obtainable from the attached instruments as the force transmission path of the steel truss could be clearly observed. DSCSW pier deformation was evaluated based on the deformative relationship between the wall pier and FSTCB. The FSTCB primarily dissipated 80% of the total energy input prior to damage occurring in the DSCSW. Strain distribution curves along the DSCSW showed that the pre-peak-resistance plane section assumption was still valid.

Regularized and Opposite Spin-Scaled Functionals from Møller-Plesset Adiabatic Connection─Higher Accuracy at Lower Cost.

Noncovalent interactions (NCIs) play a crucial role in biology, chemistry, material science, and everything in between. To improve pure quantum-chemical simulations of NCIs, we propose a methodology for constructing approximate correlation energies by combining an interpolation along the Møller-Plesset adiabatic connection (MP AC) with a regularization and spin-scaling strategy applied to MP2 correlation energies. This combination yields cosκos-SPL2, which exhibits superior accuracy for NCIs compared to any of the individual strategies. With the N4 formal scaling, cosκos-SPL2 is competitive or often outperforms more expensive dispersion-corrected double hybrids for NCIs. The accuracy of cosκos-SPL2 particularly shines for anionic halogen bonded complexes, where it surpasses standard dispersion-corrected DFT by a factor of 3 to 5.

Substitution effect on the adiabatic ionization potential, vertical ionization potential, electrophilicity, and nucleophilicity of some hydantoin drug derivatives: Computational study

AbstractIn the current paper, the adiabatic ionization potentials (AIP) for 29 hydantoin derivatives and hydantoin‐based drugs such as allantoin, phenytoin, mephenytoin, nilutamide, iprodione, nitrofurantoin, and ethotoin were calculated using the double hybrid ωB97XD density functional theory (DFT) in coupling with 6‐311+G(2df,2p) basis set at the B3LYP/6‐31+G(d,p) optimized geometry. The neutral and cationic radicals of the examined species were firstly optimized using the B3LYP/6‐31+G(d,p) level. Final energies were improved by single point calculation using 16 different DFT methods such as B3LYP, ωB97, B97D, TPSSTPSS, M06‐2X, …, and so forth, with 6‐311+G(2df,2p) basis. Statistical tools such as root mean square error (RMSE) was used to examine the accuracy of the DFT method with respect to the standard reference AIP values. These standard references were calculated, for 12 hydantoin derivatives with less than nine non‐hydrogen atoms, by taking the average values of the AIP computed using the G4, G3B3, and CBS‐QBS methods. The vertical ionization potentials (VIPs), the vertical electron affinity (VEA), and global quantum parameters such as electrophilicity and nucleophilicity of the 29 molecules were also calculated. Substitution effect on the AIP, VIP, VEA, fundamental gap, electrophilicity, and nucleophilicity of the species under probe was studied and discussed. The results reveal that substitution of electron withdrawing group (EWG) raises the AIP and VIP, electrophilicity, and the fundamental gap, while substitution of electron donating group (EDG) raises the VEA and the nucleophilicity. Furthermore, the condensed Fukui functions were used to identify the active centers for nucleophilic, electrophilic, and free radical attacks.

Development, Analytical Characterization, and Bioactivity Evaluation of Boswellia serrata Extract-Layered Double Hydroxide Hybrid Composites.

Boswellia serrata Roxb. extract (BSE), rich in boswellic acids, is well known as a potent anti-inflammatory natural drug. However, due to its limited aqueous solubility, BSE inclusion into an appropriate carrier, capable of improving its release in the biological target, would be highly desirable. Starting with this requirement, new hybrid composites based on the inclusion of BSE in a lamellar solid layered double hydroxide (LDH), i.e., magnesium aluminum carbonate, were developed and characterized in the present work. The adopted LDH exhibited a layered crystal structure, comprising positively charged hydroxide layers and interlayers composed of carbonate anions and water molecules; thus, it was expected to embed negatively charged boswellic acids. In the present case, a calcination process was also adopted on the LDH to increase organic acid loading, based on the replacement of the original inorganic anions. An accurate investigation was carried out by TGA, PXRD, FT-IR/ATR, XPS, SEM, and LC-MS to ascertain the nature, interaction, and quantification of the active molecules of the vegetal extract loaded in the developed hybrid materials. As a result, the significant disruption of the original layered structure was observed in the LDH subjected to calcination (LDHc), and this material was able to include a higher amount of organic acids when its composite with BSE was prepared. However, in vitro tests on the composites' bioactivity, expressed in terms of antimicrobial and anti-inflammatory activity, evidenced LDH-BSE as a better material compared to BSE and to LDHc-BSE, thus suggesting that, although the embedded organic acid amount was lower, they could be more available since they were not firmly bound to the clay. The composite was able to significantly decrease the number of viable pathogens such as Escherichia coli and Staphylococcus aureus, as well as the internalization of toxic active species into human cells imposing oxidative stress, in comparison to the BSE.

Status and prospects for the development of mobile power sources

The physicochemical foundations of the basic structures and technologies for the production of promising electrolytic cells for the accumulation of electrical energy with a specific energy intensity for reusable cells of 350–500 W ⋅ h/kg at the first stage and 1000 W ⋅ h/kg at the second stage have been developed. Along with traditional chemical current sources and ionistors, supercapacitive capacitor structures with a thin dielectric in a double electric layer and hybrid capacitors appear, in which energy is accumulated both in a double electric layer and due to electrochemical processes. This approach makes it possible to reduce the internal resistance of electrolytic cells, which leads to a decrease in heat generation during operation and, accordingly, an increase in specific energy consumption, operational safety, a decrease in charging time, and an increase in specific power. A promising anode is a nanostructured electrode material, which is a carbon-based matrix filled with a nanostructured reactive material. Promising materials for filling the carbon matrix are Li and its alloys, Si, Al, Na, Sn, Mg, Zn, Ni, Co, Ag, and a number of other materials and their compounds. The influence of the specific area of the carbon material, dielectric constant, addition of a chemically active substance on the specific energy consumption has been studied. The theoretical values of the specific energy capacity of hybrid capacitors with a metal-air system are calculated. A thin-film technological complex has been developed that ensures the creation of a new generation of electrode materials, the design of which is a carbon matrix with a highly developed surface, in which there is a tunnel-thin dielectric, on the surface of which a chemically active material is placed.

Guide for the development and evaluation of supercapacitors with the proposal of a novel design to improve their performance

Supercapacitors, as an energy storage device, have shown great potential as a tool to help solve today's energy problems. There are currently three types of supercapacitors: electrochemical double layer, pseudocapacitors and hybrid supercapacitors. They have aroused great interest due to their high-power density, fast charging and discharging and good cyclic behaviour, and nowadays, it is necessary to continue their study in order to extend their capabilities. This work proposes a design and fabrication method for supercapacitors with a materials guide that, firstly, guides researchers in the development of supercapacitors and, secondly, proposes an improvement of the current supercapacitor design to ensure parallelism of the collectors, avoid corrosive processes of the collectors using graphite and avoid pad breakage. All this is carried out with 3D design and additive manufacturing or 3D printing technologies, which means a reproducible solution with low available resources. In addition, the model proposed here avoids the breakage of the pads that act as electrodes by designing an intermediate body that prevents the Swagelok® cell thread from being consumed.

Novel Double Hybrid-Type Bone Cements Based on Calcium Phosphates, Chitosan and Citrus Pectin.

In this work, the influence of the liquid phase composition on the physicochemical properties of double hybrid-type bone substitutes was investigated. The solid phase of obtained biomicroconcretes was composed of highly reactive α-tricalcium phosphate powder (α-TCP) and hybrid hydroxyapatite/chitosan granules (HA/CTS). Various combinations of disodium phosphate (Na2HPO4) solution and citrus pectin gel were used as liquid phases. The novelty of this study is the development of double-hybrid materials with a dual setting system. The double hybrid phenomenon is due to the interactions between polycationic polymer (chitosan in hybrid granules) and polyanionic polymer (citrus pectin). The chemical and phase composition (FTIR, XRD), setting times (Gillmore needles), injectability, mechanical strength, microstructure (SEM) and chemical stability in vitro were studied. The setting times of obtained materials ranged from 4.5 to 30.5 min for initial and from 7.5 to 55.5 min for final setting times. The compressive strength varied from 5.75 to 13.24 MPa. By incorporating citrus pectin into the liquid phase of the materials, not only did it enhance their physicochemical properties, but it also resulted in the development of fully injectable materials featuring a dual setting system. It has been shown that the properties of materials can be controlled by using the appropriate ratio of citrus pectin in the liquid phase.

Self-reinforced aluminum phosphate framework/bismaleimide composites with double cross-linking hybrid structures

In this work, aluminum phosphate framework (APF)/ bismaleimide (BMI) hybrid composites with the double cross-linking hybrid (DCH) structures are successfully fabricated in right conditions. Herein, the three-dimensional (3D) structures of APF play the critical role in the reinforced effects of mechanical properties. Aim to strengthen the APF/BMI composites, the lamellar aluminum phosphate (LAP) particles are chosen by self-reinforced effects. From the perspective formation of the LAP-APF complex, the structures of the LAP-APF/BMI composites are investigated and the mechanical and dielectric properties are evaluated. Finally, the reinforced mechanism is also analyzed. The maximum flexural strength can approximately reach up to 170.46 MPa, and the dielectric constant further decreased after the addition of LAP particles. There are helpful for designing the higher performance inorganic/organic hybrid composites and expanding their applications.

Structural and catalytic investigations of the novel carbon foam composites containing double hybrid nano reinforcements

Recently many attempts were conducted to enhance the structural morphology and properties of pitch-derived carbon foam (CF) by dispersing different additives in the CF matrix. But unfortunately, these additives enhance one property at the cost of another one. Herein, this work mainly considered the collaborated effect of multi-walled carbon nanotubes (MWCNTs) and functionalized nanodiamonds (FNDs) in the CF matrix phase was studied and compared with coupled CF/MWCNTs and CF/MWCNTs-FNDs hybrid composites. Coal tar pitch (CTP), a raw substance was applied to synthesize pretreated CF pitches via forming, carbonization, and graphitization techniques. Both types of nanocomposites were checked for various structural and morphological characterizations. Investigations revealed that the upgradation of microstructure, pore size, and uniform dispersion of samples can be made possible with the incorporation of nanofillers. However, between two different types of reinforcement materials, FNDs proved more influential to maximize the mechanical, thermal, and electrical attributes of CF nanocomposites. Different samples including pure CF, 1, 2, and 4 wt% CF/MWCNTs and CF/MWCNTs-FND were investigated. It was observed that with an increment in the amount of nanofiller, properties showed different variations. The best thermal, mechanical, and electrical properties were offered by 2 and 4 wt% CF/MWCNTs-FNDs hybrid samples respectively. Furthermore, the photocatalytic activity of the CF samples was investigated against Alizarin red (AR) dye. Results show that a hybrid sample of CF/MWCNTs-FND (4 wt%) is the most effective and sustainable as well as it almost decolorized about 88 % AR dye. Furthermore, it was also noticed that the dye decolorization increases with increasing catalyst dosage and pH of the medium and decreasing initial dye concentration.

Experimental study on impact toughness of multi-combination hybrid fiber-reinforced magnesium phosphate cement-based materials

In order to improve the brittleness of magnesium phosphate cement-based materials (MPC) and overcome the limitations of single fiber-reinforced cement-based materials, this study investigated the mechanical properties of hybrid fiber-reinforced magnesium phosphate cement-based composite materials (HFRMPC) by incorporating four types of fibers: hooked-end steel fiber (HSF), micro steel fiber (MSF), polyvinyl alcohol fiber (PVAF), and basalt fiber (BF). Cylindrical specimens were prepared by single and double hybridization of the fibers and subjected to drop hammer impact tests to analyze the effects of different fiber hybridization methods on the impact resistance of these materials. The two-parameter Weibull distribution was used to analyze the test results to predict failure probabilities and to investigate the fiber reinforcement and toughening mechanisms in MPC through microscopic structural analysis. The results showed that the impact resistance of the fiber hybridization group was much better than that of the single fiber group, and the impact resistance increased continuously with increasing fiber content. The fibers' impact resistance enhancement effects were in the following order: MSF > PVAF > BF. The fiber combination methods were ranked as follows from best to worst: HSF + PVAF > HSF + BF > HSF + MSF > PVAF + BF. The 1.5% HSF+0.6% PVAF hybridization had the best impact resistance performance, with an increase in initial cracking and impact energy dissipation at the failure of 7748.6% and 8921.2%, respectively, compared to the M0. The probability distribution of impact number of initial cracking (N1) and failure (N2) of the specimens followed the double-parameter Weibull distribution well. The multiscale strengthening and toughening zone composed of fibers with different geometric dimensions and elastic modulus was crucial to the material's performance, as the fibers acted in progressive briding under external impact loads, dissipating impact energy through the failure morphology of pull-out and breaking, significantly improving the HFRMPC's impact toughness. A comprehensive evaluation of the four indicators of impact resistance and manufacturing costs for various hybrid fiber compositions found that the combination of 1.5% HSF and 0.6% PVAF exhibits the most outstanding overall performance.

Accurate Structures and Spectroscopic Parameters of Guanine Tautomers in the Gas Phase by the Pisa Conventional and Explicitly Correlated Composite Schemes (PCS and PCS-F12).

A general strategy for the accurate computation of structural and spectroscopic properties of biomolecule building blocks in the gas phase is proposed and validated for tautomeric equilibria. The main features of the new model are the inclusion of core-valence correlation in geometry optimizations by a double hybrid functional and the systematic use of wave-function composite methods in conjunction with cc-pVnZ-F12 basis sets with separate extrapolation of MP2 and post-MP2 contributions. The resulting Pisa composite scheme employing conventional (PCS) or explicitly correlated (PCS-F12) approaches is applied to the challenging problem of guanine tautomers in the gas phase. The results are in remarkable agreement with the experimental structures, relative stabilities, and spectroscopic signatures of different tautomers. The accuracy of the results obtained at reasonable cost by means of black-box parameter-free approaches paves the way toward systematic investigations of other molecular bricks of life also by non-specialists.

Joint Optimization of Jamming Type Selection and Power Control for Countering Multifunction Radar Based on Deep Reinforcement Learning

Developing intelligent jamming methods to combat the multi-function radar (MFR) has become a vital task in electronic warfare, because the MFR can tune into different working modes according to surrounding environment information. In this paper, we present a solution to the limitations of conventional jamming methods, including strong prior knowledge dependence and inaccurate selection strategies.Specifically, we study a joint optimization of jamming type selection and power control task (JO-JTSPC) for a general radar countermeasure scenario. In particular, we first model the sequential decision-making task JO-JTSPC as a Markov Decision Process (MDP). Subsequently, considering the differences in the designed action space, we accordingly develop two algorithms, i.e., dueling double deep Q-learning (D3QN) and hybrid proximal policy optimization (HPPO), to solve the optimization problem. Taking into consideration the threat level of various MFR working modes and the corresponding required jamming effect, we elaborately design the reward function of MDP as a weighted summation of the mode switching factor, jamming performance factor and jamming power factor. Further, the learned polices of these algorithms are derived based on the designed reinforcement learning (RL) elements. Extensive simulation results demonstrate that the proposed algorithms can learn highly adaptive polices in the radar countermeasure scenarios and achieve good jamming performance.

DFT Meets Wave-Function Composite Methods for Characterizing Cytosine Tautomers in the Gas Phase.

A general strategy for the accurate computation of structural and spectroscopic properties of biomolecule building blocks in the gas phase has been further improved and validated with a special reference to tautomeric equilibria. The main improvements concern the use of the cc-pVTZ-F12 basis set in both DFT and CCSD(T)-F12 computations, the inclusion of core-valence correlation in geometry optimizations by double hybrid functionals, and the use of the cc-pVQZ-F12 basis set for complete basis set extrapolation at the MP2-F12 level. The resulting model chemistry is applied to the challenging problem of cytosine tautomers in the gas phase. The results are in remarkable agreement with experiment concerning both rotational and vibrational spectroscopic parameters and permit their unbiased interpretation in terms of structural and thermochemical features. Together with the intrinsic interest of the studied molecule, the accuracy of the results obtained at reasonable cost without any empirical parameter suggests that the proposed composite method can be profitably employed for accurate investigations of other molecular bricks of life.

Evaluation of elite bivoltine mulberry silkworm (Bombyx mori L.) double hybrids suitable for North West India

Nine bivoltine silkworm double hybrids along with control were developed and evaluated at Central Sericultural Research and Training Institute, Central Silk Board, Pampore, Jammu and Kashmir (J&K) during summer (July-August) and autumn (August-September) 2020. The main aim is to develop silkworm double hybrids locally by utilising the silkworm breeds developed by different research Institutes. The bivoltine silkworm breeds developed by CSB research institutes were procured initially for preparation and evaluation of foundation crosses. Based on the performance, out of twenty four foundation crosses three oval and three constricted foundation crosses were shortlisted for further development of 09 double hybrids. On the basis of the evaluation index (E.I) values 05 double hybrids during summer and 05 double hybrids during autumn recorded E.I value above 50. During summer 05 silkworm double hybrids viz., (CSR50×PAM114) X (PAM117×APS4), (CSR50×PAM114) X (PAM117× SK7), (PAM114× CSR27) X (PAM117×APS4), (PAM114×CSR50) X (PAM117 ×APS4) and (PAM114×CSR50) X (SK6×SK7) recorded E.I values 50.09, 55.86, 57.95, 61.35 and 52.88, respectively over control FC2× FC1 (60.67) whereas in autumn 05 silkworm double hybrids viz., (CSR50×PAM114) X (SK6×SK7), (CSR50×PAM114) X (PAM117× SK7), (PAM114× CSR27) X (PAM117×APS4), (PAM114×CSR50) X (PAM117 ×APS4) and (PAM114×CSR50) X (SK6×SK7) recorded E.I values 56.20, 53.13, 54.62, 55.52 and 59.80, respectively over control FC2× FC1 (57.65). Based on results one double hybrid (PAM114×CSR50) X (PAM117 ×APS4) for summer and one double hybrid (PAM114× CSR50) X (SK6×SK7) for autumn identified for North West India.

Evaluation of elite bivoltine mulberry silkworm (Bombyx mori L.) double hybrids suitable for North West India

Nine bivoltine silkworm double hybrids along with control were developed and evaluated at Central Sericultural Research and Training Institute, Central Silk Board, Pampore, Jammu and Kashmir (J&K) during summer (July-August) and autumn (August-September) 2020. The main aim is to develop silkworm double hybrids locally by utilising the silkworm breeds developed by different research Institutes. The bivoltine silkworm breeds developed by CSB research institutes were procured initially for preparation and evaluation of foundation crosses. Based on the performance, out of twenty four foundation crosses three oval and three constricted foundation crosses were shortlisted for further development of 09 double hybrids. On the basis of the evaluation index (E.I) values 05 double hybrids during summer and 05 double hybrids during autumn recorded E.I value above 50. During summer 05 silkworm double hybrids viz., (CSR50×PAM114) X (PAM117×APS4), (CSR50×PAM114) X (PAM117× SK7), (PAM114× CSR27) X (PAM117×APS4), (PAM114×CSR50) X (PAM117 ×APS4) and (PAM114×CSR50) X (SK6×SK7) recorded E.I values 50.09, 55.86, 57.95, 61.35 and 52.88, respectively over control FC2× FC1 (60.67) whereas in autumn 05 silkworm double hybrids viz., (CSR50×PAM114) X (SK6×SK7), (CSR50×PAM114) X (PAM117× SK7), (PAM114× CSR27) X (PAM117×APS4), (PAM114×CSR50) X (PAM117 ×APS4) and (PAM114×CSR50) X (SK6×SK7) recorded E.I values 56.20, 53.13, 54.62, 55.52 and 59.80, respectively over control FC2× FC1 (57.65). Based on results one double hybrid (PAM114×CSR50) X (PAM117 ×APS4) for summer and one double hybrid (PAM114× CSR50) X (SK6×SK7) for autumn identified for North West India.

Mechanistic study on the synergy of cold plasma and sulfate radical in the degradation of azo and triarylmethane dyes using density functional theory

The activation of persulfate using cold plasma and the synergy of plasma-generated reactive species and SO4•− in mineralization of organic dyes were assessed. In this regard, solutions of crystal violet (CV) as a triarylmethane dye and methyl orange (MO) as an azo dye, were treated with cold plasma, UV-C-activated sulfate radicals, and their combination. The achieved results showed 95% TOC removal, a synergy factor of 1.3 and an energy yield of 1.68 (g kWh−1) for the combined system. The contribution of oxidant species in CV (SO4•− > O2•- > •OH) and MO (SO4•−> O2•- >1O2) degradation was explored. Moreover, analysis of degradation products and density functional theory (DFT) calculations were adopted to find the degradation mechanism based on the minimum energy pathway. Experimental and DFT results revealed that while radical and nucleophilic pathways were the drivers of CV degradation, the electrophilic attack of oxidants was a more plausible mechanism for MO degradation. Additionally, a comparison of the results of different DFT methods with experimental values showed that the Kohn–Sham DFT yielded more accurate results compared to recommended double hybrid methods. Analysis of a treated real wastewater revealed that the background constituents had negligible effects on MO and CV degradation. The high TOC removal efficiency of the combined system suggests its feasibility for treating wastewater from fertilizer and pharmaceutical production facilities.

A facile strategy for constructing lightweight, fire safety and compression resistance poly(vinylalcohol) aerogels with highly-efficient expansible graphene oxide/layered double hydroxides hybrid synergistic flame retardant

Poly(vinyl alcohol) (PVA) aerogels with excellent environmentally friendly properties have been considered to replace undegradable polymer foams. However, due to highly flammable, hydrophilic, and worse compression resistance performance, PVA aerogels have always been excluded from practical. Herein, a fire safety and compression resistance PVA/expansible graphene oxide (EGO)/Layered double hydroxides (LDHs) (PGL) aerogel was prepared via the freeze-drying method and electrostatic adsorption of flame retardant. The ice crystals from aerogels were sublimated and left a mass of tree-like pore tunnel structures. Meantime, the compound of EGO and LDHs rendered PGL aerogels high compressive strength of 6.0917 MPa (at 80% of strains), a high specific modulus of 19.16 m2/s2, and an ultra-low density of 0.059 g/cm3. Especially, the as-prepared PGL aerogels showed heat release reduced by 55.4%, smoke release reduced by 54.3%, and the limiting oxygen index reaching up to 31%. Moreover, LDHs also enhanced the interface with PVA/EGO resulting in hydrophobic performance improvement. The proposed enhancements mechanism suggested that (i) chemical reactions between EGO and PVA matrix; (ii) a mass of negative potential sites from the interface of PVA/EGO composites made LDHs sheets easily adsorbing; (iii) oxygen-containing groups from EGO and LDHs absorbed mass of heat during combustion; (iv) the compact char residues on the surface of aerogels acting as barriers suppressed smoke and prevented PVA matrix from further combustion. Therefore, electrostatic adsorption as a facile production process was paved for meeting the compression resistance, flame-retardant, heat-insulating, and smoke-suppressed requirements of PVA aerogels in this work.

Recent progress and development prospects of mobile current sources

Physicochemical fundamentals have been developed for the basic design solutions and fabrication technologies of prospective electrolytic power cells with a reusable cell capacity of 350–500 W·h/kg at the first stage and 1000 W·h/kg at the second stage. Along with conventional chemical current sources and ionistors, there are emerging high-performance supercapacitor structures with thin dielectric in the double electric layer and hybrid capacitors in which energy is accumulated in the double electric layer and due to electrochemical processes. This approach reduces the internal resistance of the electrolytic cells thus decreasing the heat emission during operation and therefore providing for a higher specific energy capacity and operation safety, shorter charging time and an increase in specific power. Prospective anode is a nanostructured electrode material in the form of a carbon matrix filled with a nanostructured chemically active material. Promising carbon matrix fillers are Li and its alloys, Si, Al, Na, Sn, Mg, Zn, Ni, Co, Ag, as well as a range of other materials and their compounds. The effect of carbon material specific surface area, dielectric permeability and chemically active material addition on the specific energy capacity has been studied. Theoretical specific energy capacity of metal/air hybrid capacitors has been calculated. Thin-film technological system has been designed for new generation electrode materials in the form of carbon matrices with highly developed surface containing thin tunneling dielectrics and chemically active materials on dielectric surface.

HETEROSIS AND LINE-BY-TESTER COMBINING ABILITY ANALYSIS FOR GRAIN YIELD AND PROVITAMIN A IN MAIZE

Developing a high-yielding and provitamin A-rich maize variety is one of the best approaches to reduce malnutrition and increase production, especially in regions where maize is a staple food, such as, the former Katanga Province in the Democratic Republic of the Congo. However, it requires a good knowledge of combining ability and heterosis for grain yield and provitamin A. Thus, evaluating grain yield, provitamin A content and other agronomic traits of eight lines, four testers, and their 32 hybrids occurred during the 2015-2016 and 2016-2017 cropping seasons. The results showed that genetic parameters related to combining ability and heterosis among various F1 hybrids influenced all the studied traits except plant height. The parental genotypes P6 and P10 were suitable for improving 100-kernel weight, grain yield, stature at ear insertion, and provitamin A content. The parental genotypes P7, P4, and P2 were promising for provitamin A content, while the parental genotype P3 was leading for grain yield. Five hybrids (P10 × P5, P10 × P6, P10 × P7, P10 × P8, and P11 × P5) showed distinction as the best specific combinations for improving productivity and provitamin A content. The F1 hybrid P10 × P6 with desirable specific combining ability revealed that it is helpful as the best combination in producing double and triple hybrids with the highest yield and provitamin A potential. Crosses P10 × P5 and P11 × P5 can serve as the best cross combinations for grain yield, while hybrids P10 × P7 and P10 × P8 showed promising for provitamin A content. The presented results could benefit future breeding programs to develop maize genotypes with high yield and provitamin A elements, alleviating food insecurity and malnutrition.

Structural and lattice dynamics investigation of double luminescent nanosized hybrid Gd2O3

A series of cubic Yb3+/Eu3+ co-doped Gd2O3 using melamine as a complexing ligand have been prepared by low-temperature treatment at 200 °C. Structural and lattice dynamics have been done using XRD and Raman analysis. Photoluminescence analysis of the co-doped Gd2O3 samples is performed at 220, 275, and 980 nm excitations and the plausible mechanism is discussed in detail. The Eu3+ ions asymmetric ratio is calculated as 2.254 in Yb3+ co-doped Gd2O3 lattice. Luminescence lifetimes oscillate between 3.83 and 739 µs. Spectral parameters and J-O intensity parameters are calculated for all co-doped Gd2O3 NPs. Electric-multipole interaction is the energy transfer mechanism responsible for concentration quenching with a critical distance of 11.45 Å in Gd2O3: Yb3+(20 mol%), Eu3+(5 mol%) nanoparticles (NPs) on 980 nm excitation. The sample emits near-white, blue, and orange-red light emissions and can be utilized for bio-labeling applications. Temperature-dependent studies on Gd2O3: Yb3+ (20 mol%), Eu3+ (5 mol%) NPs are performed in the temperature range of 303–478 K. The developed NPs exhibit paramagnetism with a value of 1.580 emu/g owing to Gd3+ intrinsic magnetic moments.