85 research outputs found

    (E)-2-[(2-Hydr­oxy-5-nitro­phen­yl)iminiometh­yl]phenolate

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    In the title mol­ecule, C13H10N2O4, the dihedral angle between the mean planes of the benzene and phenolate rings is 21.6 (4)°. The nitro O atoms are twisted slightly out of the plane of the ring to which the nitro group is attached [dihedral angle 8.4 (3)°]. The amine group forms an intra­molecular hydrogen bond with both nearby O atoms. An extended π delocalization throughout the entire mol­ecule exists producing a zwitterionic effect in this region of the mol­ecule. The shortened C—O bond [1.2997 (15) Å] in concert with the slightly longer C—OH bond [1.3310 (16) Å] provide evidence for this effect. The crystal packing is influenced by strong inter­molecular O—H⋯O hydrogen bonding. As a result, mol­ecules are linked into an infinite zigzag chain running along the b axis. A MOPAC PM3 calculation provides support to these observations

    2-(4-Hy­droxy­phen­yl)-3-(trimethyl­sil­yl)propanaminium chloride

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    In the title crystal structure, C12H22NOSi+·Cl−, anions and cations are linked via O—H⋯Cl, N—H⋯Cl and N—H⋯O hydrogen bonds to form a two-dimensional network parallel to (101). Within the hydrogen-bonded network, R 4 2(22) ring motifs are stacked along [010]

    Towards the Development of a Capability Assessment System for Flood Risk Management

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    Having in place adequate levels of emergency management capabilities (EMCs) underpins a managed civil emergency response, especially during a flooding event(s). Good EMC is either built on having the right internal capabilities or by exploiting existing emergency capabilities from other responders. In some countries, such as Saudi Arabia, there is a noted lack of decision‐making in the Civil Defence (CD) Authority about generating effective mutual‐aid requests. Three core areas of EMC include having the right types and levels of response equipment to hand, ensuring sufficient Human Resources, can be maintained throughout a sustained event, and developing adequate Training capabilities. Other factors impacting on Saudi Arabia include both stress and a lack of work experience. In this chapter, we examine the effectiveness of a prototype IT System in the case of Saudi CD Authority as a tool for addressing the availability and adequacy of mutual‐aid for EMC, Human Resources (HR), and training capabilities against scalable levels of flood risk event(s). The proposed IT System is built using the ‘fuzzy expert system’ approach

    Effect of Carbamate Insecticide, Lannate, on the Gonads of Mice

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    The effect of the carbamate insecticide, lannate, on the gonads of mice was studied. Treating mice with lannate at a dose level of 10mg/kg body weight daily for 3-6 weeks had induced degenerative effects in the gonads, as follows, first in testis, a significant reduction in the diameter of the seminiferous tubules and germinal epithelial height. Histological examination of the testis showed that the seminiferous tubules were elongated and contained reduced spermatogenic cells. The number, of mature sperms was markedly reduced and after 3 weeks the sperm bundles were completely absent. On the other hand, the effect on the ovarian structure showed that, decrease in the number of secondary ovarian follicles and corpora lutea was recorded, while, the number of atretic follicles showed a significant increase. It is speculated that it may be resulted from the inhibition of RNA synthesis due to the effect of lannate

    3-(2,6-Dioxopiperidin-3-yl)-3-aza­bicyclo­[3.2.0]heptane-2,4-dione

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    The title mol­ecule, C11H12N2O4, consists of a 3-aza­bicyclo­[3.2.0]heptane group containing a nearly planar cyclo­butane ring (r.m.s. deviation of fitted atoms is 0.0609 Å), fused to a pyrrolidine ring, bonded to a 2,6-dioxopiperidine ring at the 3-position. The angle between the mean planes of the cyclo­butane and fused pyrrolidine ring is 67.6 (6)°. The dihedral angles between the mean planes of the pyrrolidine and cyclo­butane rings and the dioxopiperidine ring are 73.9 (2) and 62.4 (4)°, respectively. The pyrrolidine and dioxopiperidine rings are twisted about the 3-yl group [torsion angles = −55.0 (1) and 115.0 (1)°] in a nearly perpendicular manner. Crystal packing is influenced by extensive inter­molecular C—H⋯O and N—H⋯O inter­actions between all four carbonyl O atoms and H atoms from the cyclo­butane and dioxopiperidine rings, as well as between the N atom and an H atom from the cyclo­butane ring. In addition, weak π-ring interactions also occur between H atoms from the cyclobutane ring and the five-membered pyrrolidine ring. As a result, mol­ecules are linked into infinite chains diagonally along the [101] plane of the unit cell in an alternate inverted pattern

    Forming of miniature components from powders by combining field-activated sintering and micro-forming

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    Micro-FAST is a process concept which scales down conventional FAST to the micro-scale process (dealing with miniature an micro-sized components) and it combines the sintering process with a micro-forming process to enable shaping components under coupled multi-fields actions and hence, to achieve high-density, near-net-shaped components with high efficiency. The main techniques developed for overcoming the barriers for the applications of FAST at the miniature/micro-scales include: (i). Directly pressing/forming loose powders in the die without using binders; (ii). Combining heating and shaping to enable complex shapes/features; and (iii). Dedicatedly controlling fusion bonding and material’s plastic flow to enable high-quality forming. Forming from powders without using binders significantly shortened the process cycle, which also led to high-purity of the parts formed; Combining forming and sintering has led to high-density components produced as well as achieving complex-shaped components; Large current density (e.g., >100~400 KA/cm-2) enables very high heating rates and using small volumes of materials results in high cooling rates, leading to much shorter forming/sintering cycles which enables consolidation of micro/nanocomposites into bulk-sized components while also preserving their micro/nanostructures

    3-Aminopyridine Salicylidene: A Sensitive and Selective Chemosensor for the Detection of Cu(II), Al(III), and Fe(III) with Application to Real Samples

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    Interest in developing selective and sensitive metal sensors for environmental, biological, and industrial applications is mounting. The goal of this work was to develop a sensitive and selective sensor for certain metal ions in solution. The goal was achieved via (i) preparing the sensor ((E)-2-((pyridine-3-ylimino)methyl)phenol) (3APS) using microwave radiation in a short time and high yield and (ii) performing spectrophotometric titrations for 3APS with several metal ions. 3APS, a Schiff base, was prepared in 5 min and in a high yield (95%) using microwave-assisted synthesis. The compound was characterized by FTIR, XRD, NMR, and elemental analysis. Spectrophotometric titration of 3APS was performed with Al(III), Ba(II), Cd(II), Co(II), Cu(II), Fe(III), Mn(II), Ni(II), and Zn(II). 3APS showed good abilities to detect Al(III) and Fe(III) ions fluorescently and Cu(II) ion colorimetrically. The L/M stoichiometric ratio was 2:1 for Cu(II) and 1:1 for Al(III) and Fe(III). Low detection limits (μg/L) of 324, 20, and 45 were achieved for Cu(II), Al(III), and Fe(III), respectively. The detection of aluminum was also demonstrated in antiperspirant deodorants, test strips, and applications in secret writing. 3APS showed high fluorescent selectivity for Al(III) and Fe(III) and colorimetric selectivity towards Cu(II) with detection limits lower than corresponding safe drinking water guidelines.This work was made possible by NPRP grant # 7-495-1-094 from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors. The authors also acknowledge the support of Qatar University through grant # QUCG-CAS-20/21-1

    (E)-2-[(2-Hydr­oxy-5-nitro­phen­yl)iminiometh­yl]-4-nitro­phenolate

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    The title mol­ecule, C13H9N3O6, consists of a 2-hydr­oxy-5-nitro­phenyl­iminio group and a 4-nitro­phenolate group bonded to a methyl­ene C atom with both of the planar six-membered rings nearly in the plane of the mol­ecule [dihedral angle = 1.3 (4)°]. Each of the nitro O atoms is twisted slightly out of the plane of the mol­ecule. The amine group forms an intra­molecular hydrogen bond with both nearby O atoms, each of which has partial occupancy of attached H atoms [0.36 (3) and 0.64 (3)]. An extended π-delocalization throughout the entire mol­ecule exists producing a zwitterionic effect in this region of the mol­ecule. The shortened phenolate C—O bond [1.2749 (19)°], in concert with the slightly longer phenol C—O bond [1.3316 (19) Å], provides evidence for this effect. The crystal packing is influenced by extensive strong inter­molecular O—H⋯O hydrogen bonding between the depicted phenolate and hydr­oxy O atoms and their respective H atoms within the π-delocalized region of the mol­ecule. As a result, mol­ecules are linked into an infinite polymeric chain diagonally along the [110] plane of the unit cell in an alternate inverted pattern. A MOPAC AM1 calculation provides support for these observations

    (3aR,8aR)-2,2,6,6-Tetra­methyl-4,4,8,8-tetra­phenyl­tetra­hydro-1,3-dioxolo[4,5-e][1,3,2]dioxasilepine

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    The title compound, C33H34O4Si, is a dioxasilepine compound, an effective chiral dopant for the determination of high helical twisting powers in liquid crystals. Its structure consists of a five-membered dioxolo ring fused to a seven-membered dioxasilepine ring which contains two sets of phenyl rings in a twisted butterfly shape attached to the two Csp 3 atoms in the ring opposite each other. Two methyl groups are attached to the Si atom in the ring and two additional methyl groups are attached to the Csp 3 atom in the dioxolo ring (one of which is disordered) and which lies in an envelope pattern. The dihedral angles between the mean planes of the phenyl ring pairs are 85.9 (2) and 83.5 (1)°. The dihedral angles between the mean planes of the dioxolo ring and the two pairs of butterfly shaped phenyl rings are 46.2 (1), 67.7 (1), 35.6 (7) and 83.5 (1)°
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