147 research outputs found

    Filtration properties of staple fibre thermo-bonded nonwoven fabrics

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    Thermal bonded polyester staple fibre nonwoven fabrics have been produced, considering different proportions of binder fibres, directions of web laid as variables, and bonding time and bonding temperature as constant. The influence of process variables on fabric properties, such as bursting strength, air permeability, bubble point diameter, mean flow pore diameter and filtration efficiency with three different particle (1, 0.5, and 0.3µ) along with the overall filtration efficiency have been tested and the results are compared with spun laced nonwoven fabrics. The fibres are oriented in cross and parallel directions, this arrangement of fibres leads to increase in bursting strength. The trend in air permeability of cross-laid web fabrics is found similar to spunlaced fabrics. The pore sizes of the thermal bonded fabrics have been minimized by laying the web in cross direction and increasing the binder fibre proportion; it has minimum variation with spunlaced fabrics. Aerosols of different particles are fed to the upstream of the filters with the face velocity of 16.6 cm/s which is then maintained as constant. The maximum filtration efficiency achieved is found to be 93.13% which is around 13% higher than that of the spunlaced fabric. For 80g/m2 fabrics with 0.3µ particles, the filtration efficiency of spun laced fabric is only 38% which is around one and a half time lesser than 80 g/m2 of thermal bonded fabric; 90g/m2 fabrics show equal and better properties than 100g/m2 fabrics

    Prediction of open-hole tensile strength of unidirectional flax yarn reinforced polypropylene composite by analytical and numerical models

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    Open-hole tensile strength of unidirectional flax yarn reinforced polypropylene composites has been predicted fordifferent laminates with varying lay-up through analytical and numerical models. Point stress criterion (PSC), modified PSCand finite element modeling (FEM) have been applied to examine the effect of different open-hole sizes on the stressbearing capacity. The characteristic length (d0) of the composites has been confirmed by PSC which depends on thespecimen geometry. The modified PSC has been used with stress concentration factor, notch sensitivity factor, andexponential parameter for evaluating the open-hole tensile strength. The stress distribution and the open-hole tensile strengthhave also been obtained by finite element simulation. The best correlations between the experimental and predicted resultshave been achieved from modified PSC model than with traditional PSC and FEM models

    Preparation and characterisation of Nylon/PEG/PAN composite membrane for liquid filtration

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    A novel method has been proposed to prepare a Nylon/PEG/PAN composite membrane for the improvement of electrospun PAN fibre properties and filtration efficiency. Polyacrylonitrile fibre has been prepared by electrospinning technique. Different proportions of blended mixture of Nylon and PEG are prepared separately. Blended mixture of Nylon and PEG is poured over the electrospun PAN to prepare a Nylon/PEG/PAN composite membrane. The prepared Nylon/PEG/PAN composite membrane and Nylon/PEG membrane are characterized by using optical microscope, porosimeter, X-ray diffractometer and thermogravimetric analysis. Filtration efficiency of the prepared Nylon/PEG/PAN composite membrane is studied using pure water flux and oil water emulsion methods. The 50/50 proportion of Nylon and PEG has been identified for getting uniform and evenly distributed pores and also it shows around 80% of solute rejection, whereas 60/40 proportion shows little bit higher percentage due to higher proportion of Nylon. Thus, the pure water flux of 60/40 and 50/50 PAN/PEG/Nylon membranes met with the recommended pure water flux

    4-[(Dieth­oxy­phosphino­yl)meth­yl]benzoic acid

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    In the title compound, C12H17N2O5P, the phospho­nate group is almost orthogonal to both the ethyl groups, with a dihedral angle of 83.75 (11)°. In the crystal, mol­ecules are linked into centrosymmetric dimers via pairs of O—H⋯O hydrogen bonds with an R 2 2(20) graph-set motif. The crystal structure is further consolidated by weak C—H⋯π inter­actions

    The role of ultra-low-dose computed tomography in the detection of pulmonary pathologies : a prospective observational study

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    Purpose: The aim of the study was to compare the image noise, radiation dose, and image quality of ultra-low-dose computed tomography (CT) and standard CT in the imaging of pulmonary pathologies. Material and methods: This observational study was performed between July 2020 and August 2021. All enrolled patients underwent both ultra-low-dose and standard CTs. The image noise, image quality for normal pulmonary structures, presence or absence of various pulmonary lesions, and radiation dose were recorded for each of the scans. The findings of standard-dose CT were regarded as the gold standard and compared with that of ultra-low-dose CT. Results: A total of 124 patients were included in the study. The image noise was higher in the ultra-low-dose CT compared to standard-dose CT. The overall image quality was determined to be diagnostic in 100% of standard CT images and in 96.77% of ultra-low-dose CT images with proportional worsening of the image quality as the body mass index (BMI) range was increased. Ultra-low-dose CT offered higher (> 90%) sensitivity for lesions like consolidation (97%), pleural effusion (95%), fibrosis (92%), and solid pulmonary nodules (91%). The effective radiation dose (mSv) was many times lower in ultra-low-dose CT when compared to standard-dose CT (mean ± SD: 0.50 ± 0.005 vs. 3.99 ± 1.57). Conclusions: The radiation dose of ultra-low-dose chest CT was almost equal to that of a chest X-ray. It could be used for the screening and/or follow-up of patients with solid pulmonary nodules (> 3 mm) and consolidation

    3,4-Dibromo-2,5-bis­[(dieth­oxy­phosphor­yl)meth­yl]-1-phenyl­sulfonyl-1H-pyrrole

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    In the title compound, C20H29Br2NO8P2S, the pyrrole ring is essentially planar, with a maximum deviation of 0.013 (3) Å for a C atom. The pyrrole ring is almost orthogonal to the sulfonyl-bound phenyl ring, with a dihedral angle 88.5 (2)°. Both P atoms exhibit distorted tetra­hedral configurations with O—P—O angles widened and O—P—C angles narrowed from the ideal tetra­hedral value. In the crystal, mol­ecules are linked into centrosymmetric dimers via C—H⋯O inter­actions, resulting in R 2 2(10) graph-set motifs which are further consolidated by R 2 2(13) graph-set ring motifs via C—H⋯O inter­actions, further resulting in chains of mol­ecules running parallel to the c axis; a phosphono O atom is involved in bifurcated hydrogen bonding. All the eth­oxy groups are disordered over two positions each with unequal site-occupancy factors

    2-Azido­methyl-3-methyl-1-phenyl­sulfonyl-1H-indole

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    In the title compound, C16H14N4O2S, the plane of the indole ring is twisted by 70.4 (2)° with respect to the plane of the azidomethyl­ substituent. As a result of the electron-withdrawing character of the phenyl­sulfonyl groups, the N—C bond lengths are slightly longer than the anti­cipated value of approximately 1.355 Å for an N atom with a planar configuration. The indole ring is essentially planar, with a maximum deviation of 0.0296 Å. The azide group is almost linear, the N—N—N angle being 171.4 (3)°. The methyl group on the azide-substituted C atom is in a flagpole position. The phenyl ring of the sulfonyl substituent makes a dihedral angle of 87.07 (10)° with the best plane of the indole moiety. The crystal packing is stabilized by inter­molecular C—H⋯O inter­actions, which link the mol­ecules into infinite chains running parallel to the b axis. The crystal packing is further stabilized by C—H⋯π inter­actions

    Regulation of B cell linker protein transcription by PU.1 and Spi-B in murine B cell acute lymphoblastic leukemia

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    B cell acute lymphoblastic leukemia (B-ALL) is frequently associated with mutations or chromosomal translocations of genes encoding transcription factors. Conditional deletion of genes encoding the E26-transformation-specific transcription factors, PU.1 and Spi-B, in B cells (ΔPB mice) leads to B-ALL in mice at 100% incidence rate and with a median survival of 21 wk. We hypothesized that PU.1 and Spi-B may redundantly activate transcription of genes encoding tumor suppressors in the B cell lineage. Characterization of aging ΔPB mice showed that leukemia cells expressing IL-7R were found in enlarged thymuses. IL-7R-expressing B-ALL cells grew in culture in response to IL-7 and could be maintained as cell lines. Cultured ΔPB cells expressed reduced levels of B cell linker protein (BLNK), a known tumor suppressor gene, compared with controls. The Blnk promoter contained a predicted PU.1 and/or Spi-B binding site that was required for promoter activity and occupied by PU.1 and/or Spi-B as determined by chromatin immunoprecipitation. Restoration of BLNK expression in cultured ΔPB cells opposed IL-7-dependent proliferation and induced early apoptosis. We conclude that the tumor suppressor BLNK is a target of transcriptional activation by PU.1 and Spi-B in the B cell lineage. Copyright © 2012 by The American Association of Immunologists, Inc

    Diethyl [(3-cyano-1-phenyl­sulfonyl-1H-indol-2-yl)meth­yl]phospho­nate

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    In the title compound, C20H21N2O5PS, the indole ring is essentially planar, with a maximum deviation of −0.0083 (18) Å. The methyl C atom of the methyl­phospho­nate group and the S atom lie 0.104 (2) and −0.2158 (6) Å, respectively, from the indole mean plane. The sulfonyl-bound phenyl ring is almost perpendicular to the indole ring system, with a dihedral angle of 82.30 (8)°. The ethyl side chains are disordered over two sets of sites, with occupancy factors of 0.737 (5)/0.263 (5) and 0.529 (11)/0.471 (11). In the crystal, mol­ecules are linked into centrosymmetric dimers via C—H⋯O hydrogen bonds, resulting in an R 2 2(18) graph-set motif. The crystal structure is further stabilized by C—H⋯π inter­actions

    Pathological Characteristics of Primary Bladder Carcinoma Treated at a Tertiary Care Hospital and Changing Demographics of Bladder Cancer in Sri Lanka

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    Objectives. The aim was to compare demographics and pathological features of bladder carcinoma treated in a urology unit with findings of previous studies done in Sri Lanka. Materials and Methods. Data of newly diagnosed patients with bladder cancer in a tertiary referral centre from 2011 to 2014 were analysed. Data on bladder cancers diagnosed from 1993 to 2014 were obtained from previous publications and Sri Lanka Cancer Registry. Results. There were 148 patients and mean age was 65 years. Male to female ratio was 4.1 : 1. Urothelial carcinoma (UC) was found in 89.2% of patients. Muscle invasion was noted in 35% of patients compared to 48.4% two decades ago. In patients with UC, 16.5% were found to have pT1 high grade tumour. It was 5.3% from 1993 to 2000. Pure squamous cell carcinoma was found in 8.1% of patients while primary or de novo carcinoma in situ (not associated with high grade pT1 tumours) was seen in one patient only. Conclusions. The percentage of squamous carcinoma is higher among Sri Lankan patients while primary carcinoma in situ is a rarity. The percentage of muscle invasive disease has decreased while the percentage of pT1 high grade tumours has increased during the last two decades in Sri Lanka
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