891 research outputs found

    Studies on hot-filament chemical vapor deposition grown graphene sheets

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    Graphene was grown on high purity Cu foils using hot-filament chemical vapor deposition method. The foils were kept directly below the tungsten filament and the whole assembly was kept inside a vacuum chamber. CH4 and H2 were used as precursor gases and were allowed to shower on a hot filament, which was kept at a predetermined temperature. The optimization of the process parameters such as gas flow rates, temperature, durations, etc. was done to grow single layer and multilayer graphene. The graphene was characterized using optical microscopy, field emission scanning electron microscopy and micro-Raman spectroscopy techniques. The graphene layers grown at different methane flow rates are shown in Figure 1. By varying the methane flow rates, graphene domains of different sizes and shapes were achieved and are clearly evident from Figures 1a-c. The curved white lines (Figure 1a) present in the FESEM micrographs correspond to Cu terraces. The graphene grown on Cu foils was successfully transferred to SiO2 substrate and the micrograph of which is shown in Figure 1d. The presence of D, G and G’ bands in the Raman spectrum confirmed the growth of graphene in the Cu foil (Figure 2)

    Doppler assessment of foetus with IUGR

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    INTRODUCTION: Intrauterine Growth Restriction (IUGR) or foetal growth restriction is defined as less than 10th percent of estimated foetal weight for gestational age. It is a serious condition in which the foetus is not growing adequately and is smaller than expected for its dates. The purpose of this study was to use Doppler indices of uterine artery PI, umbilical artery, middle cerebral arteries and ductus venosus in women with decrease symphysis fundal height at 20-22 weeks and to follow them until delivery to assess the relation with maternal and perinatal outcomes. METHODOLOGY: We selected 50 pregnant women who had a symphysis fundal height less than 10th percentile to the gestational age at 20 -22 weeks. The indices noted during Doppler velocimetry where Uterine artery –PI and diastolic notch, Umbilical artery end diastolic flow, Middle cerebral artery PI and Ductus venosus waveform and correlated with maternal and neonatal outcome like development of PIH, pre term delivery, IUGR, requirement of NICU admission, number of days stay and steroid requirement. RESULTS: In our study 26% were pre term delivery, 24% mothers developed PIH, 32% of babies had IUGR, 26% required neonatal admission and 24% required steroid. Coming to the Doppler indices in uterine artery diastolic notch was present in 26% and pulsatility index was high in 34% in scan. Umbilical artery end diastolic flow was abnormal in 26%, While in middle cerebral artery the PI was low in 28% and also abnormal waveform in ductus venosus was around 28%.All these indices had the positive influence on the outcomes which were also statistically significant. CONCLUSION: Doppler ultrasound is a must to pregnant women who have any complications to detect the IUGR, thus foetal problem could be avoided. Early screening of the UA Artery and MCA waveform should be performed along uterine artery and ductus venosus analysis as all indices have positive relation with maternal and neonatal outcomes particularly IUGR and a proper early diagnosis of IUGR and may decrease the foetal and maternal morbidity and mortality rate

    Concatenated batch and continuous flow procedures for the upgrading of glycerol-derived aminodiols via N-acetylation and acetalization reactions

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    An unprecedented two-step sequence was designed by combining batch and continuous flow (CF) protocols for the upgrading of two aminodiol regioisomers derived from glycerol, i.e., 3-amino-1,2-propanediol and 2-amino-1,3-propanediol (serinol). Under batch conditions, at 80-90 \ub0C, both substrates were quantitatively converted into the corresponding amides through a catalystfree N-acetylation reaction mediated by an innocuous enol ester as isopropenyl acetate (iPAc). Thereafter, at 30-100 \ub0C and 1-10 atm, the amide derivatives underwent a selective CF-acetalisation in the presence of acetone and a solid acid catalyst, to afford the double-functionalized (amideacetal) products

    Concatenated batch and continuous flow procedures for the upgrading of glycerol-derived aminodiols via N-acetylation and acetalization reactions

    Get PDF
    An unprecedented two-step sequence was designed by combining batch and continuous flow (CF) protocols for the upgrading of two aminodiol regioisomers derived from glycerol, i.e., 3-amino-1,2-propanediol and 2-amino-1,3-propanediol (serinol). Under batch conditions, at 80-90 °C, both substrates were quantitatively converted into the corresponding amides through a catalystfree N-acetylation reaction mediated by an innocuous enol ester as isopropenyl acetate (iPAc). Thereafter, at 30-100 °C and 1-10 atm, the amide derivatives underwent a selective CF-acetalisation in the presence of acetone and a solid acid catalyst, to afford the double-functionalized (amideacetal) products

    DEVELOPMENT AND VALIDATION OF PATIENT INFORMATION LEAFLET FOR HEART ATTACK PATIENTS

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    Objective: To prepare a validated heart attack patient information leaflet and to educate and promote the patient knowledge regarding the disease, lifestyle modification, and medication.Methods: The patient information leaflet was prepared by referring to the various literature. The content of the leaflet was validated by ensuring the quality information for patient's method. Baker able leaflet design has been applied to develop the layout and design of the PILS and readability by Flesch readability score.Results: The mean validity score by EQIP method achieved for the leaflet was 84.9%. Flesch readability score is 72.4. Scoring for the leaflet's layout and design criteria based on baker able leaflet design method was 24. The overall knowledge assessment means score was statistically significant with *P value 0.000.Conclusion: The validated heart attack PILs found to be effective in patients self management

    The diet of post-breeding Marbled Teal Marmaronetta angustirostris and Mallard Anas platyrhynchos in the Göksu Delta, Turkey

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    Faecal analysis was used to study the diet of the Marbled Teal Marmaronetta angustirostris and the Mallard Anas platyrhynchos in the Goksu Delta, Turkey from 13 July to 5 August 1995. Potential food items were netted at Marbled Teal feeding sites, enabling the identification of invertebrate fragments in the faeces and a study of food selection by this species. Marbled Teal faeces were dominated by Scirpus seeds (95 % of dry weight), and seven families of invertebrates (from orders Heteroptera, Diptera, Coleoptera and Ostracoda) were identified. ln contrast, 93 % of Mallard faeces (dry weight) was green plant matter, which was dominated by Potamogeton pectinatus and Chara vulgaris vars. Seeds (5 % by dry weight) and 10 families of invertebrates (from orders Heteroptera, Diptera, Coleoptera and Ostracoda) were also present. The combination of faecal analysis with invertebrate sampling can give information about the feeding areas used by Marbled Teal. Although based on a small number of samples, this is the first detailed study of the diet of this globally threatened speciesL'analyse des fèces a été utilisée pour étudier le régime alimentaire de la Sarcelle marbrée Marmaronetta angustirostris et du Colvert Anas platyrhynchos dans le delta de Gôksu, Turquie, du 13 juillet au 5 août 1995. Les aliments potentiels ont été récoltés sur les sites d'alimentation de la Sarcelle marbrée, permettant l'identification des fragments d'invertébrés et une étude des préférences alimentaires de l'espèce. Les graines de Scirpus dominaient (95 % du poids sec) dans les fèces de la Sarcelle marbrée et sept familles d'invertébrés (appartenant aux Hétéroptères, Diptères, Coléoptères et Ostracodes) ont été identifiées. En revanche, 93 % (en poids sec) des fèces du Colvert consistaient en végétaux verts où dominaient Potamogeton pectinatus et Chara vulgaris vars ; des graines (5 % en poids sec) et 10 familles d'invertébrés (également des Hétéroptères, Diptères, Coléoptères et Ostracodes) étaient aussi présentes. La combinaison de l'analyse des fèces et des échantillonnages d'invertébrés donne des informations sur les sites d'alimentation fréquentés par la Sarcelle marbrée. Bien que basée sur de petits échantillons, il s'agit de la première étude un peu précise du régime alimentaire de cette espèce globalement menacée

    reactions of p coumaryl alcohol model compounds with dimethyl carbonate towards the upgrading of lignin building blocks

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    Cinnamyl alcohol 1 and 4-(3-hydroxypropyl)phenol 2, two compounds resembling the lignin building block p-coumaryl alcohol, can be selectively transformed into different products by catalytic methodologies based on dimethyl carbonate (DMC) as a green solvent/reagent. Selectivity can be tuned as a function of the reaction temperature and of the nature of the catalyst. Basic catalysts such as K2CO3, trioctylmethylphosphonium methylcarbonate ([P8881][CH3OCOO]), and CsF/αAl2O3 promote selective transesterification of the aliphatic hydroxyl group at 90 °C. However, amphoteric solids such as alkali metal-exchanged faujasites, NaX and NaY, selectively yield the corresponding alkyl ethers at higher temperatures (165–180 °C). The phenolic hydroxyl group of 2 can be methylated similarly with the faujasites at high temperatures. This preliminary screening for selectivity illustrates reactivity trends and delineates some of what might be among the most promising synthetic pathways to upgrade lignin-derived chemical building blocks

    A Bootstrapped Modularised method of Global Sensitivity Analysis applied to Probabilistic Seismic Hazard Assessment

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    Probabilistic Seismic Hazard Assessment (PSHA) evaluates the probability of exceedance of a given earthquake intensity threshold like the Peak Ground Acceleration, at a target site for a given exposure time. The stochasticity of the occurrence of seismic events is modelled by stochastic processes and the propagation of the earthquake wave in the soil is typically evaluated by empirical relationships called Ground Motion Prediction Equations. The large uncertainty affecting PSHA is quantified by defining alternative model settings and/or model parametri-zations. In this work, we propose a novel Bootstrapped Modularised Global Sensitivity Analysis (BMGSA) method for identifying the model parameters most important for the uncertainty in PSHA, that consists in generating alternative artificial datasets by bootstrapping an available input-output dataset and aggregating the individual rankings obtained with the modularized method from each of those.The proposed method is tested on a realistic PSHA case study in Italy. The results are compared with a standard variance-based Global Sensitivity Analysis (GSA) method of literature. The novelty and strength of the proposed BMGSA method are both in the fact that its application only requires input-output data and not the use of a PSHA code for repeated calculations
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