4,697 research outputs found

    1H NMR and kinetics studies of the reaction of 4-methyl, 4-bromo and 3-trifluoromethyl benzyltriflones with aromatic nitro-compounds

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    AbstractRate measurements are reported for the reactions in methanol of carbanions derived from benzyltriflones, 2a–c, with 4-nitrobenzofurazan derivatives, 4a and 4b, to give anionic σ-adducts. 1H NMR studies in DMSO-d6 of the reaction of benzyltriflones, 2, and 4-nitrobenzofurazan, 4a, in the presence of triethylamine are consistent with products formed by the elimination of trifluoromethyl sulfinic acid from σ-adducts initially formed by carbanion attack at the 5-position of 4a. Evidence for the high steric requirements of the benzyltriflone anions come from the low value of β; the slope of the linear plot of values of logk5 versus pKa

    A Marketplace for Efficient and Secure Caching for IoT Applications in 5G Networks

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    As the communication industry is progressing towards fifth generation (5G) of cellular networks, the traffic it carries is also shifting from high data rate traffic from cellular users to a mixture of high data rate and low data rate traffic from Internet of Things (IoT) applications. Moreover, the need to efficiently access Internet data is also increasing across 5G networks. Caching contents at the network edge is considered as a promising approach to reduce the delivery time. In this paper, we propose a marketplace for providing a number of caching options for a broad range of applications. In addition, we propose a security scheme to secure the caching contents with a simultaneous potential of reducing the duplicate contents from the caching server by dividing a file into smaller chunks. We model different caching scenarios in NS-3 and present the performance evaluation of our proposal in terms of latency and throughput gains for various chunk sizes

    City tumour board Karachi: an innovative step in multidisciplinary consensus meeting and its two years audit.

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    Management of cancer patients is a team work which usually comprises of surgeons, oncologists, radiologists, pathologists, psychiatrist, nutritionist and a nurse. Any patient who is suffering from any tumour needs a multimodality meeting as cancer treatment is not a single persons job. Most of the time, it is difficult to get the whole team together for a plan discussion due to their busy schedule. This problem was overcome by starting a tumour board meeting early morning of Sunday in Karachi which was named City Tumour Board (CTB) Karachi . Its first meeting was held on Sunday March 28, 2010 and since then it takes place regularly fortnightly. Till March 2012, 44 sessions were conducted and total 264 cases were discussed. Here we present an audit of these two years. On average, in 60% of cases, tumour was up (36%) or down staged (12%) while in 52% of cases the stage remained unchanged. In 70% of cases (inclusive of above 60%), initial treatment plan was changed after discussion in the tumour board. This data signifies the importance of tumour board especially in a Pakistani setup where patient and even referring persons are not well aware of this disease and its outcome. It is advisable that every case should be discussed in tumour board before embarking on any treatment so that the best treatment plan can be given. It is also important that all relevant specialists should be present in the tumour board when planning for any treatment

    PRIMARY MALIGNANT MELANOMA UTERINE CERVIX

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    A 40-year-old premenopausal female presented with foul-smelling per vaginal discharge for 3 months. Diagnostic work revealed a locally advanced primary malignant melanoma of uterine cervix. The patient declined pelvic surgery and was treated with Dacarbazine. Malignant melanoma is a rare tumour of skin and has been ranked in the top ve cancers of Australia and Sweden. It is a tumour of melanocytes which forms melanin pigment in the skin. In men, the most common site is trunk while in females common site is limbs. However, melanoma can arise from mucosal surfaces where the melanocytes are present. Most common mucosal sites are head and neck followed by female genital tract. Key words: Cervix, dacarbazine, malignant melanoma

    Conformal Ricci collineations of static spherically symmetric spacetimes

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    Conformal Ricci collineations of static spherically symmetric spacetimes are studied. The general form of the vector fields generating conformal Ricci collineations is found when the Ricci tensor is non-degenerate, in which case the number of independent conformal Ricci collineations is \emph{fifteen}; the maximum number for 4-dimensional manifolds. In the degenerate case it is found that the static spherically symmetric spacetimes always have an infinite number of conformal Ricci collineations. Some examples are provided which admit non-trivial conformal Ricci collineations, and perfect fluid source of the matter

    Thermal instability in ionized plasma

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    We study magnetothermal instability in the ionized plasmas including the effects of Ohmic, ambipolar and Hall diffusion. Magnetic field in the single fluid approximation does not allow transverse thermal condensations, however, non-ideal effects highly diminish the stabilizing role of the magnetic field in thermally unstable plasmas. Therefore, enhanced growth rate of thermal condensation modes in the presence of the diffusion mechanisms speed up the rate of structure formation.Comment: Accepted for publication in Astrophysics & Space Scienc

    Influence of NaCl salinity on growth analysis of strawberry cv. Camarosa

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    In order to study of salinity effect on growth analysis of strawberry, a greenhouse experiment was conducted in Vali-e-Asr University of Rafsanjan in 2010. This study was carried out RCBD design with 4 replications to determine the influence of salinity (30, 60, 90 Mmol and control with distilled water) on strawberry growth analysis. Results indicated that relative growth rate (RGR), crop growth rate (CGR), leaf area ratio (LAR) and dry matter accumulation were decreased with increasing salinity. The lowest RGR, CGR and LAR were observed in 90 Mmol NaCl salinity. Results also indicated that maximum dry matter accumulations were observed in 1050, 1200 and 1400 degree days in 30, 60 and 90 Mmol NaCl salinity, respectively. Water salinity more than 30 Mmol NaCl L-1 will decreased fresh fruit yield more than 50 percent in hydroponics strawberry production. Dry mass partitioning in NaCl-stressed plants was in favor of crown and petioles and at expense of root, stem and leaf whereas leaf, stem and root DM progressively declined with an increase in salinity

    Weyl collineations that are not curvature collineations

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    Though the Weyl tensor is a linear combination of the curvature tensor, Ricci tensor and Ricci scalar, it does not have all and only the Lie symmetries of these tensors since it is possible, in principle, that "asymmetries cancel". Here we investigate if, when and how the symmetries can be different. It is found that we can obtain a metric with a finite dimensional Lie algebra of Weyl symmetries that properly contains the Lie algebra of curvature symmetries. There is no example found for the converse requirement. It is speculated that there may be a fundamental reason for this lack of "duality".Comment: 9 page
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