HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY DETERMINATION OF ANILINES WITH FLUORESCENT DETECTION AND PRE-COLUMN DERIVATIZATION

A simple, sensitive, and rapid reverse-phase high-performance liquid chromatography (RP-HPLC) method for the determination of anilines in water is proposed. The use of 2,7-diethylamino-2-oxo-2H-chromen-3-yl-benzothiazole-6-sulfonylchloride (coumarin 6-SO₂Cl) as a fluorigenic-labeling reagent was investigated. The label reacted with aniline within 30 min under mild conditions (ambient temperature, pH 9.0) to give sulfonamides that were separated by RP-HPLC employing fluorescence detection with an excitation wavelength of 470 nm and an emission wavelength of 520 nm. The optimum conditions for fluorescence, derivatization, and chromatographic separation were established. The calibration curves were linear for the range 0–800 ppb. The proposed method was applied for the determination of anilines in spiked drinking water samples and irrigation water samples with recoveries of 90.0–103.9% and relative standard deviations of 1.2–4.7%, respectively. This method showed good accuracy and repeatability that can be used for the quantification of aniline in real samples.     

Identification of caprolactam oligomers and related compounds in aqueous extracts of nylon‐6

Cyclic oligomers of caprolactam were isolated from a multilayered polyolefin plastic film containing a nylon‐6 layer and subsequently characterized. Nylon‐6 was extracted with aqueous solutions and the levels of the oligomers were measured in the resulting extracts. Oligomers up to n = 5 were present at high and comparable levels in all the nylon‐6 extracts. The levels of the oligomers dropped off rapidly with increased compound size after n = 5, with the heptamer being barely observable in the extract chromatograms. The effect of extracting solution pH on the compound's concentration in the extract was small, except for the monomer, whose accumulation was significantly decreased at low pH. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1262–1274, 2005     

有助于无线探头测量感应式电源的低功耗电压-频率转换器

为执行长期监视任务的便携式遥测系统供电．向人们提出了有趣的设计挑战。电池不适合于某些关键性应用，且在这些环境中，设计人员一般用无线感应链路来传输功率与数据。感应链路由一个驱动固定初级线圈的射频发射器与一个为便携式装置提供电源的松耦合次级线圈组成。对设计工程师来说．测量发射功率相当重要．因为它会限制设计人员可包含至便携式装置中的电路数量。但不幸的是，传统测试设备不适合执行该任务．     

Biological Performance of Calcium Pyrophosphate‐coated Porous Alumina Scaffolds

The present work aims at synthesis and study the bioactivity of porous alumina scaffolds coated with calcium pyrophosphate. Characterization of the formed calcium pyrophosphate and the coated scaffolds was assessed by X‐ray diffraction analysis and scanning electron microscope examinations. The in vivo studies revealed the ability of the porous scaffolds to regenerate bone tissue in femur defects of albino rats. Histological analysis showed that the defect is almost entirely filled with new bone. The formed bone is characterized as a mature bone. The produced bone grafts are intended to be used as bone substitute or bone filler.     

Tailoring the structural,magnetic and dielectric properties of Ni-Zn-CdFe2O4 spinel ferrites by the substitution of lanthanum ions

In this paper, we have tailored the structural, magnetic and dielectric properties of Ni_0.5Zn_0.3Cd_0.2Fe_2-yLa_yO₄ (y?=?0.0–0.21) nano-structured spinel ferrites by the substitution of La³⁺ ions. The investigated samples were synthesized by Sol-gel auto-combustion method and were characterized using XRD, SEM, VSM, FTIR and dielectric measurements. Single phase nanostructure formation of synthesized material was confirmed by XRD analysis. The effect of La³⁺ ions on crystallite size, grain size, lattice constant and bulk densities was calculated and it was found that lattice constant first increased upto concentration y?=?0.105 then decreased with further substitution of dopant ions. FTIR results for all synthesized samples demonstrated two absorption bands at υ₁ =?540.8?cm^?1 and υ₂ =?490.8?cm^?1 corresponds to tetrahedral and octahedral sites of spinel structure respectively. With the increase in La³⁺ ions concentration, saturation magnetization and remanence both found to be decreased down to lowest M_s value of 34.1?emu/g which is not yet reported in the literature according to best of our knowledge. Dielectric results showed that by decreasing frequency, both dielectric loss and dielectric constant decreases. AC conductivity has two regions, at low frequency region ac conductivity increases while at high frequency region, it decreases with increasing frequency. The measured results for all synthesized nano-ferrites suggested that synthesized nanoferrites are recommended for high frequency and microwave absorbing applications.     

Protein Tyrosine Phosphatases: Mechanisms in Cancer

Protein tyrosine kinases, especially receptor tyrosine kinases, have dominated the cancer therapeutics sphere as proteins that can be inhibited to selectively target cancer. However, protein tyrosine phosphatases (PTPs) are also an emerging target. Though historically known as negative regulators of the oncogenic tyrosine kinases, PTPs are now known to be both tumor-suppressive and oncogenic. This review will highlight key protein tyrosine phosphatases that have been thoroughly investigated in various cancers. Furthermore, the different mechanisms underlying pro-cancerous and anti-cancerous PTPs will also be explored.     

Honeycomb-like polyaniline for flexible and folding all-solid-state supercapacitors

Porous polyaniline (PANI) was prepared through an efficient and costeffective method by polymerization of aniline in the NaCl solution at room temperature. The resulting PANI provided large surface area due to its highly porous structure and the intercrossed nanorod, resulting in good electrochemical performance. The porous PANI electrodes showed a high specific capacitance of 480 F·g^-1, 3 times greater than that of PANI without using the NaCl solution. We also make chemically crosslinked hydrogel film for hydrogel polymer electrolyte as well as the flexible supercapacitors (SCs) with PANI. The specific capacitance of the device was 234 F·g^-1 at the current density of 1 A·g^-1. The energy density of the device could reach as high as 75 W·h·kg^-1 while the power density was 0.5 kW·kg^-1, indicating that PANI be a promising material in flexible SCs.     

Radio interference challenges in a multiprotocol compact RF hardware platform for home and building automation applications

In the field of smart home and smart building, there is a wide range of products using various proprietary and open standards for their interconnection. However, the coexistence of those standards imposes serious constraints because of the inherent nature of the radio frequency propagation. A way to investigate this issue is to study the interferences in a compact hardware platform/box in which several radio transceivers work side by side, potentially causing interference and radio link degradation due to antennas coupling. To achieve this analysis and predict the radio issues, a simulation tool was developed, and several experimental tests were conducted indoors and outdoors to validate the simulation model. The compact platform investigated consists of multiprofile KNX‐RF modules for home automation and smart grid control, and a radio alarm module for security needs. Simulations were conducted using MATLAB/Simulink, which are based on a calculation of bit error rate according to the signal to noise ratio in order to deduce the radio coverage range in different interference scenarios. The simulation tool developed was optimized to match the behavior of a specific transceiver commonly used for KNX‐RF devices. Yet the tool can be adapted to simulate other kinds of transceivers. Furthermore, the methodology applied to evaluate the cross‐technology interference can be extended to other technologies like Wi‐Fi, ZigBee, and EnOcean.     

Biological activity during co-composting of sludge issued from the OMW evaporation ponds with poultry manure-Physico-chemical characterization of the processed organic matter

Olive mill sludge (OMS), a by-product resulting from natural evaporation of olive oil processing effluent, poses a major environmental threat. A current cost-effective practice of OMS management is composting. A mixture of OMS (60%) with poultry manure (PM) was successfully composted for 210 days. During the process, effluents of olive oil mill and confectionary were used to keep moisture at optimal level (40-60%). Biological indicators reflecting stability of the compost (microbial biota respiration and enumeration, and germination index) were analysed for the assessment of the product quality. The composted mixture showed a high microbial activity with a succession of microbial populations depending on the temperature reached during the biodegradation. The pathogen content from PM decreased with composting as did phytotoxic compounds. Phenols and lipids were reduced, respectively, by 40% and 84% while germination index increased with composting progress. Fourier transform infrared (FTIR) spectroscopic analysis revealed that the final compost improved the aromatic content compared to the starting materials, with a decrease in aliphatic groups and a reduction in the easily assimilated components by the microflora acting during the biological process. The final compost was characterized by relatively high organic matter content (26.21%), a low C/N ratio (16.21), an alkaline pH (8.32), a relatively high electrical conductivity (9.21mS/cm) and a high level of nutrients. The germination index for Lepidium sativum L. was 87.71% after 210 days of composting, showing that the final compost was not phytotoxic.