IR Region Research Articles

The complete plastomes of thirteen Libanotis (Apiaceae, Apioideae) plants: comparative and phylogenetic analyses provide insights into the plastome evolution and taxonomy of Libanotis

BackgroundThe genus Libanotis Haller ex Zinn, nom. cons., a contentious member of Apiaceae, encompasses numerous economically and medicinally significant plants, comprising approximately 30 species distributed across Eurasia. Despite many previous taxonomic insights into it, phylogenetic studies of the genus are still lacking. And the establishment of a robust phylogenetic framework remains elusive, impeding advancements and revisions in the taxonomic system for this genus. Plastomes with greater variability in their genetic characteristics hold promise for building a more robust Libanotis phylogeny.ResultsDuring our research, we sequenced, assembled, and annotated complete plastomes for twelve Libanotis species belong to three sections and two closely related taxa. We conducted a comprehensive comparative analysis through totally thirteen Libanotis plastomes for the genus, including an additional plastome that had been published. Our results suggested that Libanotis plastome was highly conserved between different subclades, while the coding regions were more conserved than the non-coding regions, and the IR regions were more conserved than the single copy regions. Nevertheless, eight mutation hotspot regions were identified among plastomes, which can be considered as candidate DNA barcodes for accurate species identification in Libanotis. The phylogenetic analyses generated a robustly framework for Libanotis and revealed that Libanotis was not a monophyletic group and their all three sections were polygenetic. Libanotis schrenkiana was sister to L. sibirica, type species of this genus, but the remainders scattered within Selineae.ConclusionThe plastomes of Libanotis exhibited a high degree of conservation and was effective in enhancing the support and resolution of phylogenetic analyses within this genus. Based on evidence from both phylogeny and morphology, we propose the recognition of "Libanotis sensu stricto" and provide taxonomic recommendations for other taxa that previously belonged to Libanotis. In conclusion, our study not only revealed the phylogenetic position and plastid evolution of Libanotis, but also provided new insights into the phylogeny of the family Apiaceae and phylogenetic relationships within the tribe Selineae.

The first complete chloroplast genome sequences of Pistacia eurycarpa Yalt, a horticultural important rootstock and industrial tree

AbstractPistacia genus is botanically classified in the Sapindales order and the Anacardiaceae family, and the member of this genus P. eurycarpa is used as a rootstock for pistachio. Due to its rich oil content, various soaps are produced from the green peels of P. eurycarpa nuts and are used in the cosmetic industry as soap. In the current study, we aimed to release the complete chloroplast genome of P. eurycarpa to detect the relationship of the members of the Sapindales and also Pistacia genus. The length of the chloroplast genome of P. eurycarpa was identified 160,693 (bp) and consisted of the distinct parts of the genomic fragments such as LSC, SSC, and IR regions. The length of the LSC was 88,410 (bp), and SSC genomic range represented a total of 19,087 (bp). Inverted regions length was 26,598 (bp). A total of 125 genes were determined within the whole chloroplast genome of P. eurycarpa. The number of simple sequence repeats (SSRs) in the chloroplast genome was computed as 74. Three main clusters defined the dendrogram of all accessions. The closest pairs of species were identified among the P. eurycarpa and P. vera species. The farthest genetic relationship was calculated among the members of the Sapindales species Mangifera indica and the Fagales species Castanea mollissima. The sequences of the chloroplast genome of P. eurycarpa species can be evaluated for the construction of the basis of the complete evolution of the order, genera, and the development of the SSRs for species-specific markers for revealing the evolution of Pistacia species for future breeding research.

Bulk modified gravity from a thermal CFT by the conformal flow

We construct a bulk spacetime from a boundary conformal field theory, O(N) free scalar model, at finite temperature using a smearing technique, called a conformal flow. The bulk metric is constructed from the thermal two-point function of the smeared boundary elementary field in such a way that it can be interpreted as an information metric associated with the boundary thermofield double state. Near the boundary (UV region), an asymptotically anti–de Sitter (AdS) spacetime is obtained with a leading order perturbation of scalar mode. Based on the falloff behavior of the perturbations and the O(N) symmetry in the conformal field theory, we argue that the corresponding bulk theory is a modified gravity with scalar mode such as f(R) gravity rather than Einstein’s general relativity coupled minimally to matter fields. Moving to the Einstein frame, we show that the metric is asymptotically the same as the AdS black brane solution. On the other hand, deep in the bulk (IR region), the spacetime turns out to be conformally equivalent to the near horizon limit of AdS extremal black brane, though it is no longer a solution of f(R) gravity, and hence more general classes of modified gravity need to be considered. Published by the American Physical Society 2024

Comparative Analysis of Chloroplast Pan-Genomes and Transcriptomics Reveals Cold Adaptation in Medicago sativa.

Alfalfa (Medicago sativa) is a perennial forage legume that is widely distributed all over the world; therefore, it has an extremely complex genetic background. Though population structure and phylogenetic studies have been conducted on a large group of alfalfa nuclear genomes, information about the chloroplast genomes is still lacking. Chloroplast genomes are generally considered to be conservative and play an important role in population diversity analysis and species adaptation in plants. Here, 231 complete alfalfa chloroplast genomes were successfully assembled from 359 alfalfa resequencing data, on the basis of which the alfalfa chloroplast pan-genome was constructed. We investigated the genetic variations of the alfalfa chloroplast genome through comparative genomic, genetic diversity, phylogenetic, population genetic structure, and haplotype analysis. Meanwhile, the expression of alfalfa chloroplast genes under cold stress was explored through transcriptome analysis. As a result, chloroplast genomes of 231 alfalfa lack an IR region, and the size of the chloroplast genome ranges from 125,192 bp to 126,105 bp. Using population structure, haplotypes, and construction of a phylogenetic tree, it was found that alfalfa populations could be divided into four groups, and multiple highly variable regions were found in the alfalfa chloroplast genome. Transcriptome analysis showed that tRNA genes were significantly up-regulated in the cold-sensitive varieties, while rps7, rpl32, and ndhB were down-regulated, and the editing efficiency of ycf1, ycf2, and ndhF was decreased in the cold-tolerant varieties, which may be due to the fact that chloroplasts store nutrients through photosynthesis to resist cold. The huge number of genetic variants in this study provide powerful resources for molecular markers.

Analyzing genetic diversity of chloroplast genomes in Liliales

AbstractLiliales is a monocotyledonous order and contains both photosynthetic and mycoheterotrophic species that distribute locally or worldwide. In this study, thegenetic diversity of chloroplast genomes in Liliales was explored regarding theirnucleotide diversity and repeated composition. The analysis of nucleotide diversity revealed various hotspots in large and small single-copy regions whereas the IR regions had low sequence divergence. Although each family has specific hotspots, the rps15-ycf1 region was commonly found as a highly variable area in the cpDNA of observed taxa. In the cpDNA of Liliales, mononucleotide simple sequence repeat (SSR) is the most common type. The majority of SSRs are located in non-coding regions. Similarly, more long repeats were found in non-coding areas than in coding sequences. Additionally, the complement repeat exceeds forward type in the cpDNA of Liliales. The highest number of long repeats was found in Corsia dispar whereas that of SSRswas detected in Smilax china. The results of nucleotide diversity and repeat analyses provided fundamental information for further studies on population genetics, molecular marker development and evolutionary history of Liliales.® 2022 Journal of Science and Technology - NTTU

Complete chloroplast genomes of 13 species of sect. Tuberculata Chang (Camellia L.): genomic features, comparative analysis, and phylogenetic relationships

BackgroundSect. Tuberculata belongs to Camellia, and its members are characterized by a wrinkled pericarp and united filaments. All the plants in this group, which are endemic to China, are highly valuable for exploring the evolution of Camellia and have great potential for use as an oil source. However, due to the complex and diverse phenotypes of these species and the difficulty of investigating them in the field, their complex evolutionary history and interspecific definitions have remained largely unelucidated.ResultsTherefore, we newly sequenced and annotated 12 chloroplast (cp) genomes and retrieved the published cp genome of Camellia anlungensis Chang in sect. Tuberculata. In this study, comparative analysis of the cp genomes of the thirteen sect. Tuberculata species revealed a typical quadripartite structure characterized by a total sequence length ranging from 156,587 bp to 157,068 bp. The cp.genome arrangement is highly conserved and moderately differentiated. A total of 130 to 136 genes specific to the three types were identified by annotation, including protein-coding genes (coding sequences (CDSs)) (87–91), tRNA genes (35–37), and rRNA genes (8). The total observed frequency ranged from 23,045 (C. lipingensis) to 26,557 (C. anlungensis). IR region boundaries were analyzed to show that the ycf1 gene of C. anlungensis is located in the IRb region, while the remaining species are present only in the IRa region. Sequence variation in the SSC region is greater than that in the IR region, and most protein-coding genes have high codon preferences. Comparative analyses revealed six hotspot regions (tRNA-Thr(GGT)-psbD, psbE-petL, ycf15-tRNA-Leu(CAA), ndhF-rpl32, ndhD, and trnL(CAA)-ycf15) in the cp genomes that could serve as potential molecular markers. In addition, the results of phylogenetic tree construction based on the cp genomes showed that the thirteen sect. Tuberculata species formed a monophyletic group and were divided into two evolutionarily independent clades, confirming the independence of the section.ConclusionsIn summary, we obtained the cp genomes of thirteen sect. Tuberculata plants and performed the first comparative analysis of this group. These results will help us better characterize the plants in this section, deepen our understanding of their genetic characteristics and phylogenetic relationships, and lay the theoretical foundation for their accurate classification, elucidation of their evolutionary changes, and rational development and utilization of this section in the future.

MRCI Study of the Electronic Structure and Transition Properties of a Tin Dimer.

The ground and excited states of Sn2 are calculated using the multireference configuration interaction method combined with Davidson correction (MRCI+Q). The influence of the spin-orbit coupling (SOC) effect on the electronic structure is also considered by the state interaction method of Breit-Pauli Hamiltonian. In the calculations, the potential energy curves and spectroscopic constants of 23 Λ-S states and 31 Ω states of Sn2 are obtained. The prominent spectral features in the visible region, new constants, and potential energy curves are discussed. The intensity of weak magnetic and quadrupole transitions in the near IR spectra is also calculated. From a computational point of view, we predict that the weak v'(0-2)-v″(0-5) bands of the magnetic b1Σg,0++-X3Σg,1(Ms=±1)- transition may be detected experimentally; the sub-bands (0, 0), (1, 0), and (2, 0) of the a1Δg,2-X3Σg,1(Ms=±1)- transition also may be observed in experiments since they are not overlapped by the strong electric dipole transition in the same IR region. According to the SOC matrix elements and contributions of the 15Πu0+, 15Πu1 (|Σ| = 0), and 15Πu1 (|Σ| = 2) states to the predissociation line width of the 13Σu- -X3Σg1- transition, the broading and other predissociation features of the 13Σu- state are analyzed. From our calculations, it follows that the strong coupling between the bound 13Σu- state and the repulsive 15Πu state causes the predissociation of the 13Σu- state at the vibrational levels v' ≥ 8. In addition, our results suggest that the previously observed bands of Sn2 in the visible range of 19000-20000 cm-1 should be reassigned into the mixing transitions among the X3Σg,1--23Σu,0-+ and X3Σg,0+--23Σu,1+ manifold. The results are expected to provide new comprehensive information for better understanding the spectra and dynamics of the electronic excited states of the Sn2 molecule.

Site dependent strategy for B/C/N homo and heteroatom co-doping in governing the optoelectronic behavior of MgO monolayers

Density functional theory calculations are carried out to investigate the effects of homo- and hetero-type co-doping of B, C and N on structural and electronic properties of MgO monolayers (MLs). The co-doping sites considered here are the possible equivalent and non-equivalent positions of a hexagon in a pristine MgO ML. The planarity of the monolayers is found to be governed by the site selectivity of the dopant atoms as well as the positions of doping. Planar monolayers have a higher likelihood of formation than the non-planar monolayers. In case of non-equivalent doping, the doping atoms always prefer positions that are closer. Stepwise substitution is more likely to occur than simultaneous substitution in formation of the co-doped monolayers. Most of the co-doping combinations introduce magnetism to the pristine MgO ML. Hetero-type monolayers prefer to be in magnetic states and even exhibit higher magnetic moments than homo-type MLs, with a maximum value of 4 μB for B–N co-doping. Almost all the monolayers are semiconducting with significantly reduced band gaps, while few hetero-type monolayers are metallic in nature. The electronic energy band gaps of the monolayers are compatible with the IR and visible regions of the electromagnetic spectrum. The overall tuning of the electronic properties renders the co-doped MgO monolayers effective for applications in spintronics and optoelectronics.

Synthesis, Growth, and Characterization of Structural, Optical, and Nonlinear Optical Properties of L‐Proline Tartrate Added by Lanthanum Chloride Single Crystal

L‐proline tartrate (LPT), 1 and 2 mol% of lanthanum chloride‐ (LaCl3‐) doped LPT single crystals have been synthesized and grown using a slow evaporation solution method at room temperature. The crystals have undergone different characterization studies to test their suitability for device fabrication. The single crystal X‐ray diffraction studies have revealed that both 1 and 2 mol% of LaCl3‐doped LPT single crystals have been crystalized monoclinic crystal structure and space group P21. The UV‐Vis‐NIR spectrum analysis has shown that pure, 1, and 2 mol% of LaCl3‐doped LPT single crystals have good optical transparency in the entire visible and near IR region. The optical band gap energy for pure, 1 and 2 mol% of LaCl3‐doped LPT single crystals to be 4.9, 5, and 5.1 eV, respectively. The energy dispersive X‐ray analysis confirmed that LaCl3 has been incorporated into LPT crystal. The second harmonic generation (SHG) efficiency for 1 and 2 mol% of LaCl3‐doped LPT single crystals has been tested and found to be 1.27 and 1.6 times greater than that of the reference KDP crystal, respectively.

Recent progress in atomically precise metal nanoclusters for photocatalytic application.

Photocatalysis is a widely recognized green and sustainable technology that can harness inexhaustible solar energy to carry out chemical reactions, offering the opportunity to mitigate environmental issues and the energy crisis. Photocatalysts with wide spectral response and rapid charge transfer capability are crucial for highly efficient photocatalytic activity. Atomically precise metal nanoclusters (NCs), an emerging atomic-level material, have attracted great interests owing to their ultrasmall size, unique atomic stacking, abundant surface active sites, and quantum confinement effect. In particular, the molecule-like discrete electronic energy level endows them with small-band-gap semiconductor behavior, which allows for photoexcitation in order to generate electrons and holes to participate in the photoredox reaction. In addition, metal NCs exhibit strong light-harvesting ability in the wide spectral UV-near IR region, and the diversity of optical absorption properties can be precisely regulated by the composition and structure. These merits make metal NCs ideal candidates for photocatalysis. In this review, the recent advances in atomically-precise metal NCs for photocatalytic application are summarized, including photocatalytic water splitting, CO2 reduction, organic transformation, photoelectrocatalytic reactions, N2 fixation and H2O2 production. In addition, the strategy for promoting photostability, charge transfer and separation efficiency of metal NCs is highlighted. Finally, a perspective on the challenges and opportunities for NCs-based photocatalysts is provided.

Phylogenomic Analysis of Dichrocephala benthamii and Comparative Analysis within Tribe Astereae (Asteraceae).

Dichrocephala benthamii C. B. Clarke has long been used as traditional Chinese medicine. However, the chloroplast (cp) genome of D. benthamii is poorly understood so far. In this study, we sequenced and analyzed the cp genome of D. benthamii. The results showed that the cp genome is 152,350 bp in length, with a pair of inverted repeat regions (IRa and IRb, each 24,982 bp), a large single-copy (LSC) region comprising 84,136 bp, and a small single-copy (SSC) region comprising 18,250 bp. The GC content of the cp genome was 37.3%. A total of 134 genes were identified, including 87 protein-coding genes (CDS), 38 tRNA genes, 8 rRNA genes, and 1 pseudogene (ycf1). Expansion or contraction of IR regions were detected in D. benthamii and other species of the tribe Astereae. Additionally, our analyses showed the types of sequence repeats and the highly variable regions discovered by analyzing the border regions, sequence divergence, and hot spots. The phylogenetic analysis revealed D. benthamii is the basal group of Astereae. The results of this study will be a significant contribution to the genetics and species identification related to D. benthamii.

Development of Methods for Identifying BAS Exhibiting Anticoagulant Activity

Introduction. Vascular pathologies associated with thromboembolism are common complications and the leading cause of morbidity and mortality among patients of various nosological groups. Previously, we obtained water-soluble 2-hydroxy-4-oxo-4-R-2-butenoates of hetarylammonium, which exhibit a significant pharmacological effect on the blood coagulation system». A compound with a pronounced anticoagulant effect was found in various routes of administration. It was of interest to study various methods of confirming the authenticity of a potential anticoagulant.Aim. Development of methods for identification of a potential anticoagulant 2-hydroxy-4-oxo-(4-chlorophenyl)-2-butenoate of thiazolinammonium.Materials and methods. The studies were carried out on three series of the substance 2-hydroxy-4-oxo-(4-chlorophenyl)-2-butenoate of thiazolinammonium obtained in laboratory conditions. The melting point of BAS was measured by the capillary method according to GF XV OFS.1.2.1.0011 "Melting point". The solubility of the substance was determined in accordance with GF XV of the OFS.1.2.1.0005 "Solubility". The absorption spectra in the IR region were taken in accordance with GF XV of the OFS.1.2.1.1.0002 "Spectrophotometry in the middle infrared region". Absorption spectra in the UV region were taken in accordance with GF XV of the OFS.1.2.1.1.0003 "Spectrophotometry in the ultraviolet and visible regions". In carrying out qualitative reactions, reagents prepared in accordance with GF XV of the OFS were used.1.3.0001 "Reagents. Indicators".Results and discussion. A description of the substance has been carried out. The melting point and solubility of the compound were determined. Spectra in the IR and UV regions of the spectrum were taken. Methods were selected, and qualitative reactions of authenticity of a potential anticoagulant were carried out.Conclusion. The studied characteristics of the new BAS can be used in the standardization of the substance according to the indicators "Description", "Solubility", "Identification", "Melting point". These indicators characterize the physico-chemical properties of 2-hydroxy-4-oxo-(4-chlorophenyl)-2-butenoate of thiazolinammonium, and will be included in the draft regulatory documentation for the substance in the future.

Wavelength Tunable Infrared Perfect Absorption in Plasmonic Nanocrystal Monolayers.

The ability to efficiently absorb light in ultrathin (subwavelength) layers is essential for modern electro-optic devices, including detectors, sensors, and nonlinear modulators. Tailoring these ultrathin films' spectral, spatial, and polarimetric properties is highly desirable for many, if not all, of the above applications. Doing so, however, often requires costly lithographic techniques or exotic materials, limiting scalability. Here we propose, demonstrate, and analyze a mid-infrared absorber architecture leveraging monolayer films of nanoplasmonic colloidal tin-doped indium oxide nanocrystals (ITO NCs). We fabricate a series of ITO NC monolayer films using the liquid-air interface method; by synthetically varying the Sn dopant concentration in the NCs, we achieve spectrally selective perfect absorption tunable between wavelengths of two and five micrometers. We achieve monolayer thickness-controlled coupling strength tuning by varying NC size, allowing access to different coupling regimes. Furthermore, we synthesize a bilayer film that enables broadband absorption covering the entire midwave IR region (λ = 3-5 μm). We demonstrate a scalable platform, with perfect absorption in monolayer films only hundredths of a wavelength in thickness, enabling strong light-matter interaction, with potential applications for molecular detection and ultrafast nonlinear optical applications.

Attenuated Total Reflection Infrared and Far-Infrared, and Raman Spectroscopy Studies of Minerals, Rocks, and Biogenic Minerals.

Attenuated total reflection infrared (ATR-IR, 4000-400 cm-1), ATR-far-IR (ATR-FIR, 400-50 cm-1), and Raman spectra (4000-10 cm-1) were measured for calcium carbonate, three kinds of minerals (calcite, aragonite, and quartz), two kinds of rocks (obsidian and pumice), and four kinds of biogenic minerals, i.e., coral (aragonite), Ruditapes philippinarum (aragonite), Meretrix lusoria (aragonite), and Corbicula japonica (aragonite), to investigate the polymorphism of minerals and biogenic minerals, differences in the crystal structure among aragonite and aragonite biogenic minerals, water in the minerals and biogenic minerals, Boson peaks of obsidian and pumice, very small amounts of carotenoids in the three kinds of shells, and so on. In this study, we put some emphasis on the low-frequency region of IR (FIR) and Raman spectra. ATR-FIR spectra were measured down to 50 cm-1 and Raman spectra were obtained down to 10 cm-1. Second derivative spectra were calculated for the FIR spectra. It has been found from the present study that the FIR spectra are the most powerful for exploring polymorphism and differences in the crystal structure among aragonite and aragonite biogenic minerals. A Boson peak, which is a characteristic low-frequency Raman band for amorphous materials, was observed at around 40 cm-1 in the Raman spectra of obsidian and pumice. The Boson peak of pumice is located at a lower frequency by 12 cm-1 than that of obsidian, indicating that the mean atomic volume of pumice is larger than that of obsidian. The present study has revealed that IR spectra are useful to investigate the amounts and structure of fluid and bound water. Moreover, it has also been found that Raman spectra can detect a very tiny amount of carotenoids in the shells due to the resonance Raman effect.

Comparative Analysis of Six Chloroplast Genomes in Chenopodium and Its Related Genera (Amaranthaceae): New Insights into Phylogenetic Relationships and the Development of Species-Specific Molecular Markers.

Species within the genus Chenopodium hold significant research interest due to their nutritional richness and salt tolerance. However, the morphological similarities among closely related species and a dearth of genomic resources have impeded their comprehensive study and utilization. In the present research, we conduct the sequencing and assembly of chloroplast (cp) genomes from six Chenopodium and related species, five of which were sequenced for the first time. These genomes ranged in length from 151,850 to 152,215 base pairs, showcased typical quadripartite structures, and encoded 85 protein-coding genes (PCGs), 1 pseudogene, 37 tRNA genes, and 8 rRNA genes. Compared with the previously published sequences of related species, these cp genomes are relatively conservative, but there are also some interspecific differences, such as inversion and IR region contraction. We discerned 929 simple sequence repeats (SSRs) and a series of highly variable regions across 16 related species, predominantly situated in the intergenic spacer (IGS) region and introns. The phylogenetic evaluations revealed that Chenopodium is more closely related to genera such as Atriplex, Beta, Dysphania, and Oxybase than to other members of the Amaranthaceae family. These lineages shared a common ancestor approximately 60.80 million years ago, after which they diverged into distinct genera. Based on InDels and SNPs between species, we designed 12 pairs of primers for species identification, and experiments confirmed that they could completely distinguish 10 related species.

Self-driven, stable broadband photodetector based on GaAs:CdS heterojunction with ultrahigh on/off ratio and detectivity

In this study, a CdS film was successfully coated on GaAs wafer by the facile and easy method of close-spaced sublimation and a high performance visible-UV-IR, self-driven GaAs:CdS photodetector was obtained. Morphological and elemental analysis of the CdS film was performed by SEM, XRD and EDAX, respectively. The fabricated device exhibited an excellent rectification ratio of 4.90×107 in the dark, at ± 2 Vs. Furthermore, GaAs:CdS photodetector showed a superior photoresponse at zero bias, both in visible and in the UV and IR regions, due to the built-in electrical potential. The maximum photodetector parameters of the fabricated heterojunction in visible light were R = 16.91 mA/W (150 mW, V= -2.0 V), D*=8.99×1012 (150 mW, V = 0.0 V) Jones and on/off ratio = 4.27×105 (V = 0.0 V). Furthermore, R = 0.107 A/W (365 nm), R = 0.083 A/W (395 nm), R = 0.104 A/W (850 nm) were obtained at V= -2.0 Volts, while D* values ​​ of 1.972×1013 Jones (365 nm), 1.566×1013 Jones (395 nm), and 1.972×1013 Jones (850 nm) were determined for V = 0.0 Volts. Furthermore, the on/off ratios determined for 365 nm, 395 nm and 850 nm, were 1.79×105, 1.43×105 and 1.54×105, respectively at V = 0.0 V. In addition, after about 40 days, almost no significant degradation of the GaAs:CdS photodetector performance was observed.

UV filters and high refractive index materials based on carboxymethyl cellulose sodium and CuO@ZnO core/shell nanoparticles

Nanoparticles have substantially contributed to the field of skincare products with ultraviolet (UV) filters to preserve human skin from sun damage. Thus, the current study aims to develop new polymer nanocomposites for the efficient block of UV light that results from the stratospheric ozone layer loss. Co-precipitation method was used to successfully synthesis CuO@ZnO core/shell NPs with a well-crystalline monoclinic CuO core and wurzite ZnO shell. Using the casting method, core/shell NPs were successfully introduced to carboxymethyl cellulose sodium (CMC). The CMC nanocomposites displayed considerably broader optical response extending from near-ultraviolet to visible light, which was likely due to heterojunction between the p-CuO core and n-ZnO shell and defects originating from the synthetic process. The transmittance of pure CMC in the UV, visible, and near IR regions is significantly reduced with the addition of 2 and 4 wt% of CuO@ZnO core/shell NPs to CMC. 99% of UV light is absorbed when 4 wt% of CuO@ZnO core/shell NPs are added. The addition of different concentrations of CMC nanocomposite to one of the sunblock in Egyptian market were studied and showing the highest Sun Protection Factor of 22. Moreover, optical dispersion parameters and refractive index were improved strongly with core/shell NPs addition.

K5Eu1-xHox(MoO4)4: Structures and luminescence properties

The palmierite-type matrix with lanthanides is capable of producing customizable multicolored emission, and has characteristics such as long service life and high energy efficiency. This research explored the impact of synthesis method and composition on structural and luminescence properties of K5Eu1-xHox(MoO4)4 with the palmierite-type structure. Two modifications with space group (SG) R3¯m (α- phase) and C2/m (β-phase) were observed and characterized. This study underscores the critical role of co-doping of Eu3+ and Ho3+ cations in manipulating charge transfer and luminescence efficiency in visible and IR region. The existence of 5D0→7F0 transition in the PL spectra indicates stable local environment of Eu3+ cations regardless of synthesis conditions.

The potentials of Si-doped magnesium oxide nanotubes for decontamination of pollutants

This work investigated the potential of the silicon-doped magnesium oxide nanotubes (Si: MgONT) to serve as a photocatalyst for the treatment of pollutants. The analysis of the photocatalytic properties of the Si: MgONT was carried out based on considering structural, electronic and optical properties at Si concentrations of 3.12% and 6.25%, respectively. We performed ground state analysis and ionic interactions using density functional theory (DFT) via quantum ESPRESSO and Yambo codes. The results of structural property analysis showed that pristine single-walled magnesium oxide nanotubes (SWMgONT) were stable to the introduction of Si impurities at a concentration of up to 6.25%. The highest binding energy value of −288.66 eV for 3.12% Si-doped SWMgONT showed that photons can be bound more strongly in this system than for 6.25% Si-doped and pure SWMgONT. 3.12% Si-doped SWMgONT exhibited indirect band gaps of 2.36 eV, which is well above the standard overpotential for pollutant degradation, while 6.25% SWMgONT had no bandgap. Analysis of the optical absorption spectra showed that 3.12% SWMgONT absorbs light very well in the visible region and reflects it in the IR region, while pristine and 6.25% MgONT showed poor light absorption in the visible region. On this basis, this work recommended 3.12% Si-doped SWMgONT semiconductor as a better material for dye degradation, CO2 reduction and hydrogen evolution.

Experimental Study of Evaporation of Nanofluid Droplets on Substrates under Solar Radiation

This work is devoted to the experimental study of evaporating droplets of titania-, silica-, and diamond-based nanofluids on a substrate under solar radiation. The influence of various factors, including the type of a material, concentration of nanocomponents, irradiation direction, droplet volume, and substrate material, on the droplet evaporation has been investigated. As a result, the critical concentrations of nanoparticles, at which the evaporation rate reaches a stable level, have been determined for droplets of the studied nanofluids. The regimes and stages of the droplet evaporation process have been analyzed for the cases of the subcritical and critical nanoparticle concentrations. The efficiency of droplet evaporation under solar radiation has been shown to strongly depend on radiation direction. The effects of droplet volume and substrate material on the evaporation rate have been studied. In addition to the evaporation efficiency, the morphology of the structures deposited from the droplets has been analyzed. It has been shown that these structures depend on the concentration and material of nanoparticles, as well as on the regime of droplet evaporation. The results of this study enable one to gain a deeper insight into the behavior of the droplets during evaporation under irradiation especially in the IR region and confirm the promise of application of nanofluids in the solar thermal energy systems.