Shifts Of Carbons Research Articles

13C NMR investigations and order parameters of rod-like molecules with terminal phenyl and thiophene rings in mesogenic core✰

Rod-like mesogens with the rigid core constituted by a combination of phenyl and thiophene moieties reveal interesting orientational ordering behavior. In this article, four rod-like mesogens constructed with a terminal alkoxy chain on only one side of the mesogenic core with the other end terminated with either a phenyl or thiophene ring have been investigated using 13C NMR spectroscopy. The mesogen with the terphenyl moiety in the core exhibited polymesomorphism with nematic, smectic C, and smectic I mesophases with very high clearing temperatures. The replacement of terphenyl with terthiophene moiety resulted in suppression of polymesomorphism, with only nematic mesophase being observed. Mesogens with single terminal thiophene connected to two phenyl rings in the core also showed only the nematic mesophase for both the possibilities of linking the core to the thiophene ring at the 2- and 3- positions. One- and two- dimensional 13C NMR spectra have been obtained in the mesophases from which the alignment induced chemical shifts of the ring carbons and 13C-1H dipolar couplings, as well as the local order parameters, have been obtained. The considerable difference in 13C chemical shifts and the 13C-1H dipolar couplings of thiophene ring with change in position of the linking unit is attributed to the difference in the order parameters of the thiophene moiety between the two cases. The data obtained on the ordering of phenyl and thiophene rings in the core units offered information into the effect of replacing the phenyl ring with the thiophene ring. So also, the change of position of the link to the thiophene moiety provided important insights into the orientational behavior in the liquid crystalline phase and on the molecular structure.

Photoemission and photofragmentation of butanoic, hexanoic and octanoic acids in the gas phase

The valence and C 1 s core photoelectron spectra of three carboxylic acids (butanoic, hexanoic and octanoic) as well as the near-edge absorption fine structure spectra and photo-electron photo-ion coincidence spectra have been measured. Changes in the valence spectra are related to the lengthening of the aliphatic chains, and the core spectra have been assigned. Small shifts of the carboxylic carbon 1 s binding energy are related to screening of the core hole by the aliphatic group. The C K edge near-edge absorption fine structure spectra probe the unoccupied density of states and the main changes in the spectra are due to increasing length of the aliphatic chain and related Rydberg states. The coincidence spectra show that soft (near threshold) ionization of all compounds leads to parent ion formation for butanoic and octanoic acids. For hexanoic acid, both parent ions and fragments are produced for near threshold ionization. Fragmentation occurs at the C2C3 bond for all carboxylic acids at the lowest energies, and other channels open for higher internal energy.

Blooms of the harmful algae Margalefidinium polykrikoides and Alexandrium monilatum alter the York River Estuary microbiome

Harmful algal blooms (HABs) cause damage to fisheries, aquaculture, and human health around the globe. However, the impact of HABs on water column microbiomes and biogeochemistry is poorly understood. This study examined the impacts of consecutive blooms of the ichthyotoxic dinoflagellates Margalefidinium polykrikoides and Alexandrium monilatum on the water microbiome in the York River Estuary, Chesapeake Bay, USA. The samples dominated by single dinoflagellate species and by a mix of the two dinoflagellates had different microbiome compositions than the ones with low levels of both species. The M. polykrikoides bloom was co-dominated by Winogradskyella and had increased concentrations of dissolved organic carbon. The A. monilatum bloom had little impact on the prokaryotic portion of the whole community but was associated with a specific group of prokaryotes in the particle-attached (>3 µm) fraction including Candidatus Nitrosopumilus, Candidatus Actinomarina, SAR11 Clade Ia, Candidatus Bealeia, and Rhodobacteraceae HIMB11. Thus, blooms of these two algal species impacted the estuarine microbiome in different ways, likely leading to shifts in estuarine carbon and nutrient cycling, with M. polykrikoides potentially having a greater impact on carbon cycling in the estuarine ecosystem than A. monilatum.

Impact of the Mediterranean-Atlantic connectivity and the late Miocene carbon shift on deep-sea communities in the Western Alboran Basin

Integration of foraminiferal and geochemical data (stable isotope and elemental composition) from West Alboran Basin (WAB) ODP Site 976 allowed evaluation of the effects of the initial Mediterranean – Atlantic restriction event preceding the Messinian Salinity Crisis (MSC) in a context of late Miocene cooling and diminishing water – mass exchange close to Gibraltar Strait.

13C NMR Spectroscopic Studies of Intra- and Intermolecular Interactions of Amino Acid Derivatives and Peptide Derivatives in Solutions

13C NMR spectroscopic investigations were conducted for various amino acid derivatives and peptides. It was observed that 13C NMR chemical shifts of the carbonyl carbons are correlated with the solvent polarities, but the extent depends on the structures. The size of the functional groups and inter- and intra-molecular hydrogen bonding appear to be the major contributors for this tendency.

Transcriptome and Metabolome Profiling of a Novel Isolate Chlorella sorokiniana G32 (Chlorophyta) Displaying Enhanced Starch Accumulation at High Growth Rate Under Mixotrophic Condition.

Chlorella sorokiniana is one of the most productive microalgal species with a high potential for the production of biofuels and other high value-added molecules. Many studies have focused on its capability of mixotrophic growth using reduced organic carbon and growth pattern shift between autotrophic and mixotrophic conditions. In this study, we investigated growth patterns of a novel isolate, C. sorokiniana G32, under mixotrophic growth conditions supplemented with a low level (1.25 g L–1) and a high level (5 g L–1) of glucose. Physiological, transcriptomic (i.e., RNA-seq), and metabolomic (i.e., LC-MS/MS) methods were used. We showed that peak growth based on OD680nm absorbance is ∼4-fold higher with high glucose vs. low glucose supplementation. Photosynthetic efficiency (Fv/Fm) in G32 mixotrophic cultures with high or low glucose supplementation remains identical to that of G32 phototrophic growth. We also found that the conversion rate between absorbance-based cell density and cell dry weight with high glucose supplementation was lower than with low glucose. This suggests that more cell biomass is produced under high glucose treatment than with low glucose. The result was confirmed via sucrose density gradient centrifugation. It is likely that accumulation of high concentration of starch may account for this effect. Transcriptomic analysis of G32 cultures (i.e., via RNA-seq) in response to reciprocal change of glucose levels reveals that expression of a subset of differentially expressed genes (DEGs) is correlated with the amount of glucose supplementation. These DEGs are designated as glucose-specific responsive (GSR) genes. GSR genes are enriched for a number of energy metabolic pathways. Together with metabolomics data (i.e., LC-MS/MS), we show that under high-level supplementation, glucose is preferentially oxidized through an oxidative pentose phosphate pathway. Collectively, our results indicate the mechanism of regulation of glucose assimilation and energy metabolism in G32 under mixotrophic conditions with different levels of glucose supplementation revealed by transcriptomic and metabolomic analyses. We propose that C. sorokiniana G32 has the potential for the production of high value-added molecules.

Responses of Soil Insect Communities to Warming are Mediated by Shifts in Microbial Carbon and Nitrogen in a Subarctic Grassland

Responses of Soil Insect Communities to Warming are Mediated by Shifts in Microbial Carbon and Nitrogen in a Subarctic Grassland

THE EU ENVIRONMENTAL TAXATION INFLUENCE ON A SUSTAINABLE DEVELOPMENT

European policyand environmental taxation mayhave a significant impact on promoting sustain-able development in the whole world and Europein particular.Although, properly designed strategic plans and a set of wide policy measures should be shaped to meet national needs and capabilities.Sus-tainable development refers to a way of achieving economic growth and societal progress that meets the needs of the present generation without compromising the ability of future generations to meet their own needs. It recognizes that economic, social, and environmental considerations are interconnected and that sustainable development requires a balance between these three pillars. The 2030 Agenda forSustainable Developmentand its 17 Sustainable Development Goals (SDGs)adopted by the United Nations (UN) in September 2015, lay down as an intrinsic part of the European Commission’s work programme, are the roadmap for achieving a sustainable future. The framework for sustainable development embracespoverty reduction, zero hunger, good health, education, clean water, affordable and clean energy, decent work and economic growth, reduced inequalities, sustainable cities, responsible consumption, climate action, gender equality, life below water, life on land, peace, justice and strong institutions, partnerships for the goals. The European Green Dealandthe common agricultural policy (CAP), set ambitious goals for re-ducing greenhouse gas emissions and promoting renewable energy and circular economy practices.On the other hand, environmental taxation remains animportant tool for promoting a “green” future. Taxes on carbon emissions, for example, can incentivize companies and individuals to reduce their carbon foot-print and shift towards cleaner energy sources. Similarly, taxes on single-use plastics can discourage their use and promote more sustainable alternatives.Also, the revision of the Energy Taxation Directive (ETD) supports theEU's climate targets by ensuring that the taxation of motor and heating fuels and electricity in the EU reflects their impact on the environment and our health. Overall, the combination of well-thought and revised EUpolicies along withenvironmental taxation can create a more sustainable economic model. By incentivizing companies and individuals to adopt sustainable practices, and by setting ambitious tar-gets for reducing emissions and promoting sustainable development, European countries can help build amore sustainable future for generations to come

Unexpected NMR shieldings of sp- and sp2-hybridized carbon atoms in graphyne systems.

Graphynes (GYs) are two-dimensional alloptropic forms of carbon consisting of periodically arranged sp- and sp2-hybridized carbon atoms in a planar structure. Graphynes can be formally created from graphene by inserting sp-hybridized carbon links into selected points of the graphene lattice. Depending on where the links are introduced, several forms of graphynes have been proposed with properties that make them potential candidates for new generation electronics or for applications in chemical processes. Since the applications of each form of GY depend on its structure, it is of interest to experimentally distinguish different forms of graphynes. In this paper we propose nuclear magnetic resonance (NMR) as a potential method of choice for such distinction. We computationally investigate on the DFT level the 13C-NMR chemical shifts for α-, β-, γ-, rhombic, and 6,6,12-graphynes, and α- and γ-graphdiynes. We perform the calculations both in periodic systems and with approximate finite models. The results show that NMR chemical shifts in graphynes are dependent on the structure and reflect the local bonding around the carbon nucleus. Interestingly, NMR shifts of several graphynes show anomalous values, differing significantly from shifts found in typical sp2-hybridized systems. We analyze these results in terms of local structural parameters and qualitatively investigate the possible origins of these anomalous NMR shifts. The results show that NMR is a viable method for determining the structure of graphynes and their finite precursor molecules.

Experimentally probing the chiral recognition mechanism of 1,1′-bi-2-naphthol on a nitrogen enriched chiral metal-organic framework

In this article, a micropore CMOF structure with abundant nitrogen species, D-His-ZIF-L (DHZL), was synthesized in water according to the reference with a modification. The performance of DHZL was verified by enantioselective capture of S-1,1′-bi-2-naphthol (S-BINOL), with an enantiomeric excess (ee) value of 60.5% under optimal conditions. To experimentally elucidate the chiral recognition mechanism, the chemical shifts of carbon and nitrogen signals were investigated on the basis of CP MAS NMR spectroscopy by using DHZL (200 mg) with R/S-BINOL of 750 μg mL−1 in CH3CN at room temperature, in which DHZL acts as the chiral shift reagent. The peaks corresponding to the chiral carbon and one imidazole ring carbon resonances in the D-histidine moiety of DHZL exhibit obvious upfield and downfield shifts in the presence of S-BINOL, respectively, indicating that the the strong hydrogen bonding and π-π interactions existed. Clear nitrogen splitting further indicates the hydrogen-bond interaction site between the hydroxyl of the optical S-isomer and the amino of D-histidine in the chiral framework. In addition, the positive shift in the N 1 s peak of DHZL by X-ray photoelectron spectroscopy (XPS) analysis was also proved the described observations when loaded with S-BINOL in contrast with R-one. Furthermore, a control experiment was performed to identify the essential features of the chiral microenvironment in DHZL. Based on these results above, the chiral recognition mechanism was experimentally determined.

The Entner-Doudoroff Pathway Contributes to Glycogen Breakdown During High to Low CO2 Shifts in the Cyanobacterium Synechocystis sp. PCC 6803.

Cyanobacteria perform plant-like oxygenic photosynthesis to convert inorganic carbon into organic compounds and can also use internal carbohydrate reserves under specific conditions. A mutant collection with defects in different routes for sugar catabolism was studied to analyze which of them is preferentially used to degrade glycogen reserves in light-exposed cells of Synechocystis sp. PCC 6803 shifted from high to low CO2 conditions. Mutants defective in the glycolytic Embden–Meyerhof–Parnas pathway or in the oxidative pentose-phosphate (OPP) pathway showed glycogen levels similar to wild type under high CO2 (HC) conditions and were able to degrade it similarly after shifts to low CO2 (LC) conditions. In contrast, the mutant Δeda, which is defective in the glycolytic Entner-Doudoroff (ED) pathway, accumulated elevated glycogen levels under HC that were more slowly consumed during the LC shift. In consequence, the mutant Δeda showed a lowered ability to respond to the inorganic carbon shifts, displayed a pronounced lack in the reactivation of growth when brought back to HC, and differed significantly in its metabolite composition. Particularly, Δeda accumulated enhanced levels of proline, which is a well-known metabolite to maintain redox balances via NADPH levels in many organisms under stress conditions. We suggest that deletion of eda might promote the utilization of the OPP shunt that dramatically enhance NADPH levels. Collectively, the results point at a major regulatory contribution of the ED pathway for the mobilization of glycogen reserves during rapid acclimation to fluctuating CO2 conditions.

Hydrogen bonding and crystalline structure of bio-based PA56

PA56 is a newly commercialized bio-based polyamide with excellent thermal, mechanical and processing properties. However, its hydrogen bonds and crystalline structures are not well investigated yet. In this study, PA56 films with γ form and α-like form crystalline phases were successfully prepared by melt-crystallization and solution casting, respectively. The hydrogen bond and crystalline structure were systematically studied with solid-state 13C NMR, variable temperature-FTIR and dynamic oscillatory rheological tests. 13C NMR and variable temperature-FTIR results indicate that the hydrogen bond strength of PA56 in α-like form crystal is higher than that in γ-form, while both are lower than that of PA66 in α-form. The chemical shifts of carbons in diamine units are highly dependent on the crystalline forms due to the molecular chain of PA56 adopts different conformations in γ-form and α-like form. The curve-fitting of variable temperature-FTIR spectra reveals that the melt crystallization results in γ-form regardless of the crystal form before melt. Dynamic oscillatory rheological tests demonstrate that the stronger hydrogen bond interactions endow α-like form of PA56 a higher dynamic storage modulus and complex viscosity than γ-form.

Molecular Characterization of NSO Compounds and Paleoenvironment Implication for Saline Lacustrine Oil Sands by Positive-Ion Mass Spectrometry Coupled with Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry.

NSO compounds mainly exist in geological bodies in the form of nonhydrocarbons and asphaltenes with abundant geological and geochemical information. Combined with the gas chromatography mass spectrometry (GC–MS) technology, positive-ion electrospray ionization Fourier-transform ion cyclotron resonance MS (FT-ICR MS) was used to understand the composition and distribution characteristics of NSO compounds in the oil sands of the Dongpu Depression and to explore their paleoenvironmental significance. The results show that n-alkanes are characterized by an even carbon number and phytane dominance, suggesting a saline lacustrine environment. Certain abundance of nC37 and β-carotane, high gammacerane content, and low diasterane content are detected in the analyzed samples, reflecting the saline-reducing paleoenvironment for the organic matter. Nine types of heteroatom compounds are detected: N1, N1O1, N1S1, O1, O1S1, O2, O2S1, S1, and S2. The main compounds are S1 and N1 compounds, followed by O1S1 compounds. The double-bond equivalent (DBE) value of S1 compounds is mainly distributed between 3 and 12, and the carbon number is mainly distributed between 18 and 35. The DBE value of N1 compounds is mainly distributed between 4 and 14, and the carbon number is mainly distributed in the range 15–35. Among the S1 compounds, DBE3 compounds (thiophenes) have relatively more sulfur-containing carotenoids (C40). The abundance of C40 S1 and the ratio of pyridine and its homologue DBE4–8/DBE9–12 N1 compounds show a good contrast with the paleoenvironment indicators of gammacerane/C30 hopane and diasterane/regular sterane. They can be used as a reference for the paleoenvironment index. Maturity is another factor affecting the distribution of NSO heteroatoms in the oil sands. NSO compounds are enriched in the DBE area with higher condensation, and the main peak carbon shifts forward. As the maturity increases, the relative abundance of N1 compounds increases, the aromatization intensifies, and carbon is broken into short chains. The research results shed light on the potential application of NSO compounds in petroleum exploration based on FT-ICR MS.

Rapid temporal decline of mercury in Greenland halibut (Reinhardtius hippoglossoides)

Mercury (Hg) pollution in the ocean is an issue of global concern, however bioaccumulation regimes of this ubiquitous pollutant in marine apex predators have important knowledge gaps. Our fish length and stable isotope (δ15N and δ13C) normalized data of Greenland halibut (GH) (Reinhardtius hippoglossoides) showed that Hg bioaccumulation in fillet tissue decreased by ~35–50 %, over a ten-year period from 2006 to 2015 (n = 7 individual sampling years). Hg was predominantly in the methylmercury form (>77 %). Results from a Bayesian information theoretic model showed that GH Hg concentrations decreased with time and its associated declines in Hg air emissions, estimated trophic position, and a potentially lower degree of demersal prey use as indicated by temporal trend shifts in nitrogen (δ15N) and carbon (δ13C) stable isotope values. GH trophic shifts accounted for about one third of the observed temporal reduction in Hg. Our study demonstrates the importance of simultaneously considering Hg emissions, food web dynamics and trophic shifts as important drivers of Hg bioaccumulation in a marine, deep water fish species and highlights the effectiveness of Hg regulations on ocean apex predator Hg concentrations and overall seafood safety.

The potential anticancer activities of platinum(II) complexes with tridentate N'N'N' pincer ligands

Treatment of cis/trans -[PtCl 2 (N≡CR) 2 ] 1 (R = CH 3 ( 1a ), C 2 H 5 ( 1b ), C 6 H 5 ( 1c ), CH 2 C 6 H 4 ( p -CH 3 ) ( 1d )) with 1,3-diiminoisoindoline 2 gives access to the corresponding symmetrical (1,3,5,7,9-pentaazanona-1,3,6,8-tetraenato) platinum(II) complexes [PtCl{ N H=C(R)N=C(C 6 H 4 ) N C=NC(R)= N H}] 3a-d , in good yields (65–77%). The compounds 3a-d have been characterized by IR, 1 H, 13 C and DEPT-135 NMR spectroscopies, ESI-MS and elemental analyses. GIAO/DFT studies have been performed to confirm the molecular structure of the platinum(II)-pincer 3d by comparing the experimental and theoretical 1 H and 13 C NMR chemical shifts, and it has shown good correlations between experimental and calculated chemical shifts for proton and carbon with correlation coefficients of 0.9947 and 0.9968, respectively. Molecular electrostatic potential is used to investigate the nucleophilic or electrophilic regions in the molecule 3d . The antimicrobial activities of compounds 3a-d are determined against different bacterial pathogens and yeasts. No toxicity is recorded against Artemia saline as a test organism for 3a-c , while moderate toxicity is found for 3d at 0.62 µM. Comparable antitumor activities are found for 3a-d against human colon HCT116 and human breast (MCF-7) cancer cell lines. The complexes 3a-d have shown good binding affinities to ct-DNA in the range of 6.00´10 5 to 8.33´10 5 and the conducted molecular docking studies suggest an intercalation mode of binding with DNA by the isoindole fragment of the ligands. Overall, this class of tridentate ligands have shown good potential in designing platinum(II) complexes with promising biological and anticancer activities. Moreover, the presence of the side chains on the ligands provides great design flexibility by introducing some chemical and/or physical characteristics.

How Elemental Stoichiometric Ratios in Microorganisms Respond to Thinning Management in Larix principis-rupprechtti Mayr. Plantations of the Warm Temperate Zone in China

The stoichiometric ratios of elements in microorganisms play an important role in biogeochemical cycling and evaluating the nutritional limits of microbial growth, but the effects of thinning treatment on the stoichiometric ratio of carbon, nitrogen, and phosphorus in microorganisms remain unclear. We conducted research in a Larix principis-rupprechtti Mayr. plantation to determine the main factors driving microbial carbon (C): nitrogen (N): phosphorus (P) stoichiometry following thinning and the underlying mechanisms of these effects. The plantation study varied in thinning intensity from 0% tree removal (control), 15% tree reduction (high density plantation, HDP), 35% tree reduction (medium density plantation, MDP), and 50% tree reduction (low density plantation, LDP). Our results indicated that medium density plantation significantly increased litter layer biomass, soil temperature, and other soil properties (e.g., soil moisture and nutrient contents). Understory vegetation diversity (i.e., shrub layer and herb layer) was highest in the medium density plantation. Meanwhile, thinning had a great influence on the biomass of microbial communities. For example, the concentration of phospholipid fatty acids (PLFA) for bacteria and fungi in the medium density plantation (MDP) was significantly higher than in other thinning treatments. Combining Pearson correlation analysis, regression modeling, and stepwise regression demonstrated that the alteration of the microbial biomass carbon: nitrogen was primarily related to gram-positive bacteria, gram-negative bacteria, soil temperature, and soil available phosphorus. Variation in bacteria, actinomycetes, gram-positive bacteria, gram–negative bacteria, and soil total phosphorus was primarily associated with shifts in microbial biomass carbon: phosphorus. Moreover, changes in microbial biomass nitrogen: phosphorus were regulated by actinomycetes, gram-negative bacteria, and soil temperature. In conclusion, our research indicates that the stoichiometric ratios of elements in microorganisms could be influenced by thinning management, and emphasizes the importance of soil factors and microbial communities in driving soil microbial stoichiometry.

Changes in carbon and nitrogen metabolism during seawater-induced mortality of Picea sitchensis trees.

Increasing seawater exposure is causing mortality of coastal forests, yet the physiological response associated with seawater-induced tree mortality, particularly in non-halophytes, is poorly understood. We investigated the shifts in carbon and nitrogen (N) metabolism of mature Sitka-spruce trees that were dying after an ecosystem-scale manipulation of tidal seawater exposure. Soil porewater salinity and foliar ion concentrations increased after seawater exposure and were strongly correlated with the percentage of live foliated crown (PLFC; e.g., crown 'greenness', a measure of progression to death). Co-occurring with decreasing PLFC was decreasing photosynthetic capacity, N-investment into photosynthesis, N-resorption efficiency and non-structural carbohydrate (soluble sugars and starch) concentrations, with the starch reserves depleted to near zero when PLFC dropped below 5%. Combined with declining PLFC, these changes subsequently decreased total carbon gain and thus exacerbated the carbon starvation process. This study suggests that an impairment in carbon and N metabolism during the mortality process after seawater exposure is associated with the process of carbon starvation, and provides critical knowledge necessary to predict sea-level rise impacts on coastal forests.

Atomistic Insight into Nitrogen-Terminated Diamond(001) Surfaces by the Adsorption of N, NH, and NH2: A Density Functional Theory Study.

Layer-by-layer construction of diamond devices for spin-sensing calls for the atomistic understanding of the nitrogen species on diamond surfaces. Motivated by recent experiments, we used density functional theory simulations to examine the adsorption of nitrogen species (N, NH, and NH2) on bare and hydrogenated diamond(001) surfaces. On the bare substrate, we find that nitrogen species favor to attack the C═C dimers at low coverages, forming N(ad) and NH(ad) in a bridge configuration and NH2(ad) in a terminal configuration. At increasing coverages up to one full monolayer, the computed adsorption geometries and energetics suggest that the adsorbate-adsorbate interactions are attractive for N(ad), but repulsive for NH(ad) and NH2(ad). On the hydrogenated substrate, the adsorbed nitrogen species are subject to structural modification, as resulted from the weakened adsorbate-substrate interactions. Further, we calculated the vibration of nitrogen species and the 1s core-level shift of surface carbons, providing atomistic insights into the nature of surface bonding. Lastly, we simulated images of representative nitrogen species adsorbed on diamond(001), guiding future work using scanning tunneling microscopy.

NLO mechanism evaluation by Z-Scan, opto-electronic properties interpretation and chemical potential cavity investigation of 1,8-anthracenedimethanol using quantum computations

The crystal for organic compound; 1,8-anthracenedimethanol was grown using slow evaporation method. The crystal was characterized morphologically, structurally, optically, spectroscopically and their results were validated by obtaining theoretical data from standard HF and DFT-B3LYP/6311++G(d,p) calculations. The molecular space group for organic phase was determined and respective crystal lattice was to be orthorhombic. The anthracene crystal property was enhanced by adopting couple of methanol groups in suitable places of core ring and all the parameters associated with Z-Scan technique are calculated. The crystal was examined optically by observing dispersed linear and nonlinear refractive indices and it was found to be controlled electrically called electro-optic effect. The Mulliken charge dispersion was rated by molecular charge scale and required chemical potential distribution was measured to enable stable crystal activity. The optical role of polarization dipole bonds was identified for recognizing dielectric susceptibility. The chemical shifts for core carbons nuance the chemical potential displacement noted for intimating restoring chemi-kinetics. The UV-Visible trans-absorption curves were raced out to find band gap, charge transfer complex, optical transparency and optical mechanism. The direct and indirect band gap was measured on first and second order HOMO: LUMO and the use crystal material for laser utility were studied. The NLO activity was keenly observed from the first order and second order hyperactive polarizability.

Nannoplankton and 13C and 13O stable isotope stratigraphy record of the mid Cretaceous sequences, Zagros Basin (western Iran)

Deposition of black shales and dark argillaceous limestones across the Cenomanian to Turonian interval has been recorded in many parts of the world. In this regard, a stratigraphic section in the Iran's hydrocarbon field in the Kermanshah region in the Zagros Basin has been studied in detail to reconstruct palaeoceanographic conditions under a reliable biostratigraphic framework. Biostratigraphy based on calcareous nannofossils integrated with high resolution carbonate and oxygen stable isotope analyses were carried out on the Cenomanian-early Turonian interval of the upper part of Garau Formation. In this formation, 24 species of calcareous nannofossils were identified in the pelagic marine deposits. Our study allowed the definition of nannoplankton bio zones from the upper part of Eiffellithus turriseiffelii Zone to the lower part of Quadrum gartneri Zone in the mid Cretaceous. This research first recorded the upper part of the Garau Formation at site and it is consistent with the previous bio zones identified in the Tethyan domain in the region. The middle Cretaceous events of calcareous nannofossils proposed here correlate with the isotope global profile for the early Cenomanian-earliest Turonian interval and with those, reported for the southeastern France and south England reference curves, represented by the positive Cenomanian to Turonian δ13C excursion. Thus, the sequences of dark argillaceous limestone rich in organic matter in Kermanshah region can be considered as a continuation of the global trend in the Tethyan domain, where the Cenomanian-Turonian Oceanic Anoxic Event constrained to about 91.5 ± 8.6 millions of years, occurred in an anoxic pelagic sedimentary environment correlates with both, global and local sea-level rises, represented in this study by the characterization of the nannoflora assemblage reflected in a variety of widespread paleoenvironmental changes that coincides with significant shifts in the stable carbon and oxygen isotope signature.