Performance analysis of an 80 (8 × 10) Gbps RZ-DPSK based WDM-FSO system under combined effects of various weather conditions and atmospheric turbulence induced fading employing Gamma–Gamma fading model

Free space optics (FSO) has the capacity to be a vital element for the design of ubiquitous and reliable systems for next-generation networks owing to its large bandwidth and high data rate support. The last-mile issue finds an efficient solution in FSO in scenarios where fiber deployment is not feasible. However the FSO link is prone to fluctuations in optical signal strength due to various weather conditions and atmospheric turbulence. In this paper, an 80 (8 × 10) Gbps RZ-DPSK based WDM-FSO system is analyzed based on its performance on weather conditions viz. very clear, drizzle, haze, thin fog, moderate fog and thick fog. Link-margin analysis is also done. The turbulence model employed is the Gamma–Gamma fading model. The system is simulated on OptiSystem 14.0.     

Damages to the extracellular matrix in articular cartilage due to cryopreservation by microscopic magnetic resonance imaging and biochemistry

To investigate the damages to the extracellular matrix in articular cartilage due to cryopreservation, the depth-dependent concentration profiles of glycosaminoglycans (GAGs) in 34 cartilage specimens from canine humeral heads were imaged at 13-μm pixel resolution using the in vitro version of the dGEMRIC protocol in microscopic MRI (μMRI). In addition, a biochemical assay was used to determine the GAG loss from the tissue to the solution where the tissue was immersed. For specimens that had been frozen at −20°C or −80°C without any cryoprotectant, a significant loss of GAG (as high as 56.5%) was found in cartilage, dependent upon the structural zones of the tissue and the conditions of cryopreservation. The cryoprotective abilities of dimethyl sulfoxide (DMSO) as a function of its concentration in saline and storage temperature were also investigated. A 30% DMSO concentration was sufficient in preventing the reduction of GAG in the tissue at the −20°C storage temperature, but a 50% concentration of DMSO was necessary for the −80°C cryopreservation. These imaging results were verified by the biochemical analysis.     

Kinetics of homogeneous hydrogenation of 1-pentene catalysed by bis(diphenylphosphinoethylamine) chlororhodium (I)

Catalytic homogeneous hydrogenation of 1-pentene catalyzed by bis(diphenylphosphinoethylamine) chlororhodium(I) [RhClHN(CH₂CH₂PPh₂)₂](1) was investigated over the temperature range 10–20°C under 1 atm of hydrogen pressure. The dependence of the rate of hydrogenation on temperature, catalyst and substrate concentration in solution is reported. The thermodynamic and activation parameters for the hydrogenation of 1-pentene catalyzed by1 were computed and compared with those of cyclohexene and 1-heptene.

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1-, () (I), [RhClHN(CH₂CH₂PPh₂)₂] (1), 10–20°C 1 . , . 1- 1 1-.

     

Theoretical study of hydrogen adsorption in Ti-decorated capped carbon nanotube

We present ab initio study using dispersion-corrected density functional theory calculations to investigate the hydrogen interaction with Ti-coated, one end closed, single-walled carbon nanotube (SWCNT). Our results demonstrate that a single Ti atom binds up to five hydrogen molecules on SWCNT cap top, whereas adsorption of four hydrogen molecules is energetically more favourable. The analyses from adsorption energy profile, highest occupied molecular orbital–lowest unoccupied molecular orbital gap and Mulliken charge distribution show contrast in first hydrogen molecule adsorption compared with the rest of four configurations. This is clearly due to the strongly different bonding nature of first hydrogen adsorption among others, between hydrogen molecules and Ti-coated SWCNT. These results not only support our understanding of adsorption nature of hydrogen in Ti-coated SWCNTs but also suggest new directions for smart storage techniques.     

Prediction and measurement of pollutant emissions in CNG fired internal combustion engine

In the present study, the detailed reaction mechanisms were developed and Chemkin 4.1.1 was implemented to predict the formation of pollutant species in compressed natural gas (CNG) fired internal combustion (IC) engine. The proposed mechanisms were developed by coupling the EXGAS (an automatic mechanism generation tool for alkane oxidation) mechanisms with the Leed's NOx mechanism (version 2.0). The simulation results of each proposed mechanism were validated by the experimental measurements for profiles of temperature, pressure and pollutant species (CO, NOx). The rate of production analysis of each mechanism identified the important reactions in each mechanism which contributed to the formation of pollutant species. In spite of some discrepancies, the experimental measurements indicate that Mechanism-IV (consisting of 208 reactions and 78 species) showed closer agreement for each of the predicted profiles of temperature, pressure and pollutant species (CO, NOx).     

Residue depletion of albendazole and its metabolites in the muscle tissue of large mouth and hybrid striped bass after oral administration

The residue depletion profiles of albendazole (ABZ) and its major metabolites: albendazole sulfoxide (ABZ-SO), albendazole sulfone (ABZ-SO₂) and albendazole aminosulfone (ABZ-2-NH₂SO₂) were studied in the muscle tissues of large mouth (LMB) and hybrid striped bass (HSB). A single oral dose of 10 mg/kg albendazole was given to the two fish species via intra-gastric tube. The muscle tissues with adhering skin were collected at 8, 16, 24, 48, 72, 96 and 120 h post dose from both species. The samples were homogenized in dry ice and subjected to extraction and cleanup procedures. The final sample extracts were analyzed by high performance liquid chromatography. The results indicate that both ABZ and its pharmacologically active metabolite ABZ-SO were retained longer in LMB than in HSB after oral treatment. Albendazole was detectable until 8 h or 6.7 degree days (°D) and 48 h (40 °D) in HSB and LMB, respectively. However, ABZ-SO was detectable up to 48 h (40 °D) and 96 h (80 °D) in HSB and LMB, respectively. Among the inactive metabolites, ABZ-SO₂ was present in both fish species; however, ABZ-2-NH₂SO₂ was detected only in LMB.     

Synthesis of isoniazid-1,2,3-triazole conjugates: Antitubercular,antimicrobial evaluation and molecular docking study

In the present study, a series of new isoniazid-1,2,3-triazole conjugates ( 5a-k ) was synthesized via click chemistry approach. The newly synthesized compounds were assessed for their in vitro antitubercular and antimicrobial activities. The compound 5g has displayed potent antitubercular activity against Mycobacterium tuberculosis H37Rv (Mtb) with MIC value 1.56 μg/mL. The active compounds were screened for their cytotoxicity profile by MTT assay against RAW 264.7 cell line. The four compounds have shown good in vitro antimicrobial activities against both antibacterial and antifungal pathogens. A molecular docking study was accomplished to identify the probable mode of action of synthesized derivatives. These compounds have shown excellent binding affinity toward Enoyl-acp reductase (INHA) and DNA gyrase.     

Complexes of Pt(II) and Pt(IV) with disubstituted purines

Mixed-ligand complexes of Pt(II) and Pt(IV) with 2,6-diaminopurine and 6-thioguanine were synthesized and characterised. The complexes were prepared in acidic and basic media. The binding of the ligands to the metal ion varies according to the pH of the medium. Thus, in the complexes of 6-thioguanine, the ligand acts as a monodentate ligand coordinating through the neutral C₆-SH group in the acidic medium and in the basic medium as a bidentate ligand binding to the metal ion through C₆S^? and N₇, forming a five-membered chelate ring. In an acidic medium 2,6-diaminopurine forms mononuclear complexes with Pt(II) and Pt(IV) binding through N₇. In a basic medium binuclear hydroxobridged complexes are formed with Pt(IV) and the ligand is monodentate, coordinating through N₇.     

Triterpenoidal constituents of the leaves of Carissa carandas

Studies undertaken on the fresh leaves of Carissa carandas have led to the isolation of four pentacyclic triterpenoids (1-4) including one new constituent carissin (1) and two hitherto unreported compounds 2 and 3. The structure of the new triterpenoid has been elucidated as 3beta-hydroxy-27-E-feruloyloxyurs-12-en-28-oic acid. Compelete assignment of the protons of 2 has also been made based on 2D NMR studies.     

Kinetics of homogeneous hydrogenation of cyclohexene catalyzed by complexes of rhodium and iridium with a terdentate ligand

Complexes of the composition MC1HN (CH₂CH₂AsPh₂)₂ (M= =Rh(I), Ir(I) were used as catalysts for the homogeneous hydrogenation of cyclohexene over the temperature range 20–50 °C and 0.4 to 1 atm hydrogen partial pressure. The dependence of rate of hydrogenation on temperature, hydrogen concentration, catalyst concentration and substrate concentration is reported. The activation parameters of the reaction, H* and S* have been evaluated.

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MC1HN (CH₂CH₂AsPh₂)₂ (M=Rh(I) Ir(I) 20–50°C 0,4 1 atm. , , . H^* S^*.