Numerical Optimization of a Premixer for an Internal Combustion Engine using Producer Gas as a Fuel

269-275Gasification seems to be one of the sustainable green energy solutions to fulfill the current and future energy needs. For efficient utilization of producer gas on existing IC Engines, carburetor/premixer needs to be carefully designed and developed to achieve uniform mixing quality. A long radius nozzle type premixer has been designed for natural gas engine to be operated on producer gas as an alternate fuel. Different configurations of T – Type premixers with single air entry and twin air entry with different throat diameters and hole sizes are numerically analysed using ANSYS® CFX. Turbulence is modelled using RNG k - ε closure model. Mixer performance is compared in terms of constituents’ mass fraction, flow Uniformity Index (UI) and pressure penalty. Numerical analysis reveals that throat diameter, air entry type and air hole diameter governs mixing and pressure drop. Out of all configurations, twin air entry type premixer provides better mixing of producer gas and air. The optimized design of premixer shows that the absolute deviation in mass fraction of individual constituent lies in the range of ± 1.73% with respect to the actual mass fractions obtained. The average absolute deviation calculated is 1.37% with Uniformity Index 0.958 at the exit plane while the pressure drop across the premixer is 951 Pa

A project for future life—Swedish women's thoughts on childbearing lacking experience of giving birth and parenthood

A lifeworld hermeneutic approach was used in order to understand Swedish women's thoughts on childbearing. Nine women were interviewed, and they ranged in age from 22 to 28 years and represented diverse socioeconomic, educational, sexual, and fertility backgrounds. All women were similar in that they lacked experience of giving birth and parenthood. The analysis showed that childbearing includes dimensions of both immanence and transcendence. Immanence, as childbearing is seen as stagnant to women's freedom in present life. Transcendence, as childbearing is thought of as a project for future life, a part of female identity, and a conscious standpoint for which the woman wants to be prepared and for which she wants to create the best conditions

5-(4-Chlorophenyl)-7-(4-methylphenyl)-4-(pyrrolidin-1-yl)-7H-pyrrolo[2,3-d]pyrimidine

The title compound, C23H21ClN4, contains two molecules (A and B) in the asymmetric unit, which are related to one another by a pseudo-inversion center. The non-aromatic pyrrolidine ring in each independent molecule adopts a half-chair conformation; the ring puckering parameters are θ = 0.407 (3) Å and ϕ = 270.5 (4)°, and the pseudo-rotation parameters are ρ = 72.5 (3)° and τ = 42.2 (2)° for an N—C bond of molecule A, and the corresponding values are 0.415 (3) Å, 271.6 (4)°, 73.6 (3)° and 42.6 (2)° for molecule B. The dihedral angles between the central fused-ring system and the substituted chlorophenyl and methylphenyl rings are 66.35 and 45.59°, respectively, for molecule A, and 64.51 and 41.89° for molecule B. The geometry of all four intramolecular C—H...π interactions are of type III. π–π interactions involving the centroids of symmetry-related pyrrole rings of molecule B are 4.390 Å, contributing further to the stability of the molecule

Novel quinazolinone-thiazolidinone hybrid: Design, synthesis and <i style="mso-bidi-font-style:normal">in vitro </i>antimicrobial and antituberculosis studies

1169-1177To cure multi-drug resistant problem, a series of quinazolinone based 5-arylidene-2- ( (2- (2-methyl-4-oxoquinazolin-3- (4H)-yl) ethyl) amino) thiazol-4 (5H)-one <b style="mso-bidi-font-weight: normal">6a-j have been synthesized. Quinazoline and styryl thiazolidinones have been clubbed through ethyl linkage to get hybrid molecule. Final synthesized compounds are screened for their <i style="mso-bidi-font-style: normal">in vitro antimicrobial activity against bacterial and fungal strains i.e two Gram-positive bacteria (S. aureus, B. cereus), six Gram-negative bacteria (E. coli, P. aeruginosa,<i style="mso-bidi-font-style: normal"> K. pneumoniae, S. typhi, P. vulgaris, and S. flexneria) and two fungal species (A. niger,<i style="mso-bidi-font-style: normal"> and C. albicans) using broth dilution technique. In vitro antimycobacterial efficacy has also been studied against Mycobacterium tuberculosis H37Rv using BACTEC MGIT method. Antituberculosis results have pointed towards the equal potency of the lead compounds (MIC= 6.25 µg/mL) in comparison to the standard Pyrazinamide drug. Though compounds bearing-<i style="mso-bidi-font-style: normal">ortho and-meta chloro substitution have shown 99% strain inhibition, MIC of <span style="mso-bidi-font-weight: bold">6.25 µg/mL has proved its superiority over >6.25 µg/mL MIC. All the final synthesized compounds have been confirmed by FT-IR, 1H and 13C NMR, mass and elemental analysis. </span

Numerical Optimization of a Premixer for an Internal Combustion Engine using Producer Gas as a Fuel

Gasification seems to be one of the sustainable green energy solutions to fulfill the current and future energy needs. For efficient utilization of producer gas on existing IC Engines, carburetor/premixer needs to be carefully designed and developed to achieve uniform mixing quality. A long radius nozzle type premixer has been designed for natural gas engine to be operated on producer gas as an alternate fuel. Different configurations of T – Type premixers with single air entry and twin air entry with different throat diameters and hole sizes are numerically analysed using ANSYS® CFX. Turbulence is modelled using RNG k - ε closure model. Mixer performance is compared in terms of constituents’ mass fraction, flow Uniformity Index (UI) and pressure penalty. Numerical analysis reveals that throat diameter, air entry type and air hole diameter governs mixing and pressure drop. Out of all configurations, twin air entry type premixer provides better mixing of producer gas and air. The optimized design of premixer shows that the absolute deviation in mass fraction of individual constituent lies in the range of ± 1.73% with respect to the actual mass fractions obtained. The average absolute deviation calculated is 1.37% with Uniformity Index 0.958 at the exit plane while the pressure drop across the premixer is 951 Pa

Coupling Continuous Positive Airway Pressure (CPAP) and MR-guided Radiation Therapy

Purpose/Objective(s): Continuous positive airway pressure (CPAP) is a cost effective and readily available device that increases lung volumes and has shown promise in conventional x-ray-based radiation therapy (RT). However, limited data are available to quantify the impact of CPAP on lung reproducibility due to the use of ionizing radiation during imaging. We propose a novel pilot study combining CPAP with the powerful soft tissue capabilities of MR-guided RT to reduce the amount of radiation exposure to organs at risk, with the overarching goals of quantifying the impact of CPAP on lung stability under free-breathing (FB) and deep inspiration breath-hold (DIBH) conditions and assessing feasibility. Materials/Methods: An MR-safe configuration was devised by affixing several CPAP breathing circuits and verifying pressure maintenance using a manometer. Six healthy volunteers (median age 38, range: 28-54) underwent MRIs of the thorax (25 second TrueFISP, 1.5×1.5×3 mm3 resolution) using a 0.35T MR-Linac. FB and 2 verbally coached DIBH acquisitions were performed at CPAP of 0, 6, 10, 12, and 15 cm H20. To define a mutual coordinate system between successive datasets, automated rigid registration was performed (translations only) based on bony anatomy to the reference condition (FB, CPAP 0 cm H20). To quantify the linear relationship between lung volume and pressure under FB conditions, R2 was estimated for each subject. To study positioning reproducibility that may depend on increased pressures in the setting of DIBH, a Spearman correlation coefficient was calculated based on the centroid differences in lung volume. A paired t-test was used to compare the difference between pressures of 0, 6, 10, 12, and 15 cm H20. Image quality with and without CPAP under FB conditions were assessed. Surveys about volunteer perceptions of CPAP were administered after initial CPAP tolerability screening and following the imaging session based on a ten-point scale (10 = least tolerable). Results: FB lung volumes increased as CPAP increased (R2 = 0.85 ± 0.13, range: 0.57 to 0.99) with visible reductions in motion artifacts. A significant negative correlation was observed between CPAP and the lung anterior/posterior centroid differences under DIBH, indicating a reduced difference on repeated measures (i.e., increased lung stability) as pressure increased. Paired t-tests showed significantly better reproducibility in lung volumes at pressures of 6, 10, 12, and 15 cm H20, as compared to 0 cm H20. Patient-reported difficulty tolerating CPAP was perceived to be lower after the study session (mean 2.0, range 1-4) than before (mean 2.83, range 1-5). Conclusion: This study confirms that integrating CPAP into MR-guided RT is feasible and well-tolerated. CPAP not only increases lung volumes under FB conditions, but also improves reproducibility of DIBH, offering potential for reducing treatment-related side effects regardless of treatment delivery platform

Synthesis, characterizations, molecular structure and DFT studies of 4-benzylidene-2-(2-chloro-phenyl)-5-methyl-2,4-dihydro-pyrazol-3-one

819-826The title molecule 4-benzylidene-2-(2-chloro-phenyl)-5-methyl-2,4-dihydro-pyrazol-3-one, C17H13N2OCl (I) is synthesized and characterized by IR, NMR and X-ray single crystal diffraction analysis. Molecular geometry, vibrational wave numbers, frontier molecular orbitals and Mulliken charges of the title compound have been calculated using density functional method B3LYP at 6-311g* basis set. Title compound crystallizes in the monoclinic space group P21/c with a = 10.343 (3) Å, b = 11.321 (3) Å, <i style="mso-bidi-font-style: normal">c = 12.486 (4) Å, β = 92.380 (5)°, V = 1460.8 (7) Å3 and Z = 4. The dihedral angles between the mean plane of chloro phenyl ring, phenyl ring with the mean plane of pyrazole ring are 65.91(15)° and 21.75(17)°, respectively. After optimization by DFT method, the twisting of the central pyrazole ring with chloro phenyl ring and phenyl ring turns out to be 51.96(16)° and 1.26(14)°, respectively. The drastic differences observed in the dihedral angle calculated after treating the molecule by DFT method support our observations that molecular packing is influenced by the collective effect of weak but significant C-H..N, C-Cl…π, C-H…Cl, C-H…O and π-π interactions in the solid state which are otherwise lacking in isolated state. The optimized geometric bond lengths, bond angles and torsional angles obtained by density function theory (DFT) show good agreement with experimental data. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Pyrazole oxygen O7 and chloro phenyl carbon C13 act as bifurcated donor and acceptor in half a dozen intermolecular interactions, thereby strengthening the molecular packing. </span

Fatal complications after stereotactic body radiation therapy for central lung tumors abutting the proximal bronchial tree

PURPOSE: Stereotactic body radiation therapy (SBRT) is associated with excess toxicity following treatment of central lung tumors. Risk-adapted fractionation appears to have mitigated this risk, but it remains unclear whether SBRT is safe for all tumors within the central lung zone, especially those abutting the proximal bronchial tree (PBT). We investigated the dependence of toxicity on tumor proximity to PBT and whether tumors abutting the PBT had greater toxicity than other central lung tumors after SBRT. MATERIALS AND METHODS: A total of 108 patients receiving SBRT for central lung tumors were reviewed. Patients were classified based on closest distance from tumor to PBT. Primary endpoint was SBRT-related death. Secondary endpoints were overall survival, local control, and grade 3+ pulmonary adverse events. We compared tumors abutting the PBT to nonabutting and those ≤1 cm and \u3e1 cm from PBT. RESULTS: Median follow-up was 22.7 months. Median distance from tumor to PBT was 1.78 cm. Eighty-eight tumors were primary lung and 20 were recurrent or metastatic; 23% of tumors were adenocarcinoma and 71% squamous cell. Median age was 77.5 years. Median dose was 4500 cGy in 5 fractions prescribed to the 100% isodose line. Eighteen patients had tumors abutting the PBT, 4 of whom experienced SBRT-related death. No other patients experienced death attributed to SBRT. Risk of SBRT-related death was significantly higher for tumors abutting the PBT compared with nonabutting tumors (P \u3c .001). Two patients with SBRT-related death received anti-vascular endothelial growth factor therapy and experienced pulmonary hemorrhage. Patients with tumors ≤1 cm from PBT had significantly more grade 3+ events than those with tumors \u3e1cm from PBT (P = .014). CONCLUSIONS: Even with risk-adapted fractionation, tumors abutting PBT are associated with a significant and differential risk of SBRT-related toxicity and death. SBRT should be used with particular caution in central-abutting tumors, especially in the context of anti-vascular endothelial growth factor therapy