Photolysis of Some N‐Arylbenzamidoximes in Acetonitrile

The photolysis of five N‐arylbenzamidoxime derivatives I‐V in dry acetonitrile gives rise to anilides 8 and benzimidazoles 1 as the major products in addition to benzonitrile 4 , arylamines 5 , benzoic acid 6 , and 2‐phenyl benzoxazoles 7 . In the presence of naphthalene, I gave α‐ and β‐naphthols 2 and 3 beside the previous products. The isolated products have been interpreted in the terms of a free radical mechanism involving the homolysis of N‐O and/or C‐N bonds. This photodegradation process can be considered as an alternative method for the synthesis of anilide, benzimidazole and benzoxazole derivatives in addition to other organic compounds.     

Turn‐On Ratiometric Fluorescent Probe for Selective Discrimination of Cr3+ from Fe3+ in Aqueous Media for Living Cell Imaging

Pyrene‐based turn‐on ratiometric fluorescent probe 1 demonstrates high sensitivity and exceptional selectivity toward Cr³⁺ in the presence of other metals, including Fe³⁺ in aqueous media. Interaction of Cr³⁺ with probe 1 brings pyrene moieties close enough to have better aligned π–π stacking, thus enhancing the excimer peak many fold. On the other hand, the interaction of Fe³⁺ with probe 1 brings forth a negligible difference in stacking, resulting in an insignificant change in fluorescence intensity. Exceptional selectivity of probe 1 with Cr³⁺ over Fe³⁺ and other metals has been confirmed by theoretical studies in addition to experimental results. Imaging of HeLa cells observed by confocal fluorescence microscopy reveals that probe 1 can be used to monitor Cr³⁺ in live cells to map its subcellular distribution.     

Confidence Intervals Verification for Simulated Error Rate Performance of Wireless Communication System

In this paper, we derived an efficient simulation method to evaluate the error rate of wireless communication system. Coherent binary phase-shift keying system is considered with imperfect channel phase recovery. The results presented demonstrate the system performance under very realistic Nakagami-m fading and additive white Gaussian noise channel. On the other hand, the accuracy of the obtained results is verified through running the simulation under a good confidence interval reliability of 95 %. We see that as the number of simulation runs N increases, the simulated error rate becomes closer to the actual one and the confidence interval difference reduces. Hence our results are expected to be of significant practical use for such scenarios.     

The Effect of TiO2 and MgO on the Thermoluminescence Properties of a Lithium Potassium Borate Glass System

The influence of dopant TiO₂ and co-dopant MgO on the thermoluminescence (TL) properties of lithium potassium borate glass (LKB) is reported in this paper. The glow curve exhibits a prominent peak (T_m) at 230 °C. The TL intensity was enhanced by a factor of ~3 due to the incorporation of MgO, and this was attributed to the creation of extra electron traps mediated by radiative recombination energy transfer. We achieved good linearity of the TL yield with dose, low fading, excellent reproducibility and a promising effective atomic number (Z_eff=8.89), all of which are highly suitable for dosimetry. The effect of heating rate, sunlight and dose rate on the TL are also examined. These attractive features demonstrate that our dosimeter is useful in medical radiation therapy.     

Radiation damage in triglycine sulphate due to fast neutron irradiation

Abstract

The change in electrical properties of TGS crystals due to induced defects created by fast neutron irradiation of two different energies (2 and 14 MeV) and different integrated neutron fluxes have been studied in the vicinity of phase transition. It is observed that the electrical conductivity increases with increase of neutron fluence up to 1.7 × 10¹⁰ n · cm^?2 and the values of the relative change of electrical conductivity in case of 2 MeV are higher than that of 14 MeV neutrons at the same neutron fluence (φ)     

Ultrasound-assisted extraction of Na and K from swine feed and its application in a digestibility assay: A green analytical procedure

The study is aimed to evaluate the efficiency of ultrasound-assisted extraction (UAE) as a simple strategy focused on sample preparation for metal determination in biological samples. The extraction of sodium and potassium extraction was carried out from swine feed followed by determination of the concentration of these metals by flame atomic emission spectrometry (FAES). The experiment was performed to cover the study of the variables influencing the extraction process and its optimal conditions (sample mass, particle size, acid concentration, sonication time and ultrasound power); the determination of these analytical characteristics and method validation using certified reference material; and the analysis of pre-starter diets. The optimal conditions established conditions were as follows: mass: 100 mg, particle size:<60 μm, acid concentration: 0.10 mol L^?1 HCl, sonication time: 50 s and ultrasound power: 102 W. The proposed method (UAE) was applied in digestibility assays of those nutrients present in different piglet pre-starter feeds and their results proved to be compatible with those obtained from mineralized samples (P < 0.05). The ultrasound extraction method was demonstrated to be an excellent alternative for handless sampling and operational costs and the method also has the advantage of does not generating toxic residues that may negatively affect human health and contaminate the environment.     

支持空间迷你时槽重用的IEEE 802.16Mesh网络多播调度算法

In this paper, we propose a mechanism for multicast data transmission in IEEE 802.16 mesh networks aimed at increasing the throughput by incorporating mini-slot spatial reuse. The proposed mechanism includes two novel algorithms: a source-based multicast tree topology construction algorithm followed by an interference-aware multicast scheduling algorithm. The proposed multicast interfer-ence-aware scheduling algorithm can be ap-plied to both source-based and rendez-vous-based multicast tree topologies. Results of our simulation study show that in compari-son to the mechanism used for the IEEE 802.16’s standard, the proposed multicast tree generation algorithm reduces the number of consumed mini-slots by 64% on average. Moreover, using the proposed interfer-ence-aware scheduling algorithm decreases the number of required mini-slots by a further 22% on average. Therefore, the proposed multicast scheduling mechanism shows a higher throughput than the previous ap-proaches and it is more scalable with respect to increasing the number of multicast groups as well as increasing the number of members inside each multicast group.     

Analyticity and nonexistence of classical steady Hele‐Shaw fingers

This paper concerns analyticity of a classical steadily translating finger in a Hele‐Shaw cell and nonexistence of solutions when relative finger width λ is smaller than ½. It is proved that any classical solution to the finger problem, if it exists for sufficiently small but nonzero surface tension and is close to some Saffman‐Taylor zero‐surface‐tension solution and satisfies some algebraic decay conditions at ∞, must belong to the analytic function space A ₀, as defined in Section 1, and chosen in a previous study [34] of existence of finger solutions. Further, it is proved that for any fixed λ ∈ (0, ½), there can be no classical steady finger solution when surface tension is sufficiently small, in disagreement with a previous conclusion based on numerical simulation. © 2002 Wiley Periodicals, Inc.     

Elimination of photorefractive grating writing instabilities in iron-doped lithium niobate

Two types of instabilities, one slow (seconds) and one fast (nanoseconds), are observed while writing volume gratings in bulk crystals of iron-doped lithium niobate using contra-directional two-beam coupling along the c axis. A method to eliminate the fast instability was achieved by coating the z surfaces of the crystal with either dielectric (anti-reflection) or transparent conductive coatings. For the second case, electrically shorting the crystal eliminated the slow instability.