Synthesis of UV-curable tung oil and UV-curable tung oil based alkyd

Two UV-curable tung oil-based resins were synthesized via a Diels–Alder cycloaddition. An UV-curable tung oil (UVTO) was prepared from bodied tung oil and trimethylolpropane trimethacrylate (TMPTMA). An inhibitor, phenothiazine, was added to avoid homopolymerization of TMPTMA. The UV-curable tung oil alkyd (UVTA) was prepared from the monoglyceride process and then reacted with TMPTMA via the Diels–Alder reaction similar to the UVTO. The UVTO and UVTA were characterized by ¹H NMR, ¹³C NMR, and MALDI-TOF mass spectroscopy. The UVTO and UVTA were formulated with a free radical reactive diluent, tripropylene glycol diacrylate (TPGDA) and photoinitiator Irgacure 2100. Photo differential scanning calorimeter (Photo-DSC) was used to investigate curing kinetics of the UVTO and the UVTA. Both the UVTO and UVTA were photocurable with the UVTA formula exhibiting a faster curing speed than the UVTO.     

Application of nanoporous silicon for a metal-semiconductor-metal visible light photodetector

In this paper we present a study on the application of nanoporous silicon to an optoelectronic device called a nanoporous silicon metal-semiconductor-metal (MSM) visible light photodetector. This device was fabricated on a nanoporous silicon layer which was formed by electrochemical etching of a silicon wafer in a hydrofluoric acid solution under various anodization conditions such as the resistivity of the silicon wafer, current density, concentration of the hydrofluoric acid solution and anodization time. The structure of this device has two square Al/nanoporous silicon Schottky-barrier junctions on the silicon substrate and the electrode spacing is 500 microm. The experiment will study photoresponse and the response time of a nanoporous silicon MSM photodetector which was fabricated on the various porosity of a nanoporous silicon layer. It is found that when devices are fabricated on a higher porosity nanoporous silicon layer, the photoresponse of the device will expand toward the short-wavelength and the bandwidth of the spectrum response will cover visible light. In addition, it is found that the response time of the device decreases.     

Phase formation and transitions in the lead nickel niobate–lead zirconate titanate system

Despite the many previous studies of the synthesis and characterization of several perovskite ferroelectric materials which have potential applications in electronic and medical diagnostic devices, the synthesis and phase formation of the whole series in the solid solution of (1 ? x)Pb(Ni_1/3Nb_2/3)O₃–xPb(Zr_1/2Ti_1/2)O₃ (PNN–PZT) system has rarely been studied. In this work, the phase formation, morphology, particle size and chemical composition of perovskite powders in the (1 ? x)PNN–xPZT system were investigated. Powders were prepared by a modified mixed-oxide synthesis route for various chemical compositions under different calcination temperatures. It is found that the perovskite phase undergoes a pseudo-cubic to tetragonal transition as composition changes. The degree of spherical shape and agglomeration were observed to increase with increasing PZT content.     

Characterization and Dehydration Behavior of a Natural,Ammonium Hydroxide,and Thermally Treated Zeolitic Tuff

Aqueous NH₄OH-treated and subsequently calcined forms of local natural zeolitic tuff were characterized by different techniques including scanning electron microscopy (SEM), X-ray powder diffraction, inductively coupled plasma–atomic emission spectroscopy (ICP-AES), volumetric N₂ adsorption at ?196°C, thermogravimetry (TG), differential scanning calorimetry (DSC), and transmittance infrared spectroscopy. The dehydration behavior of the samples was investigated using an in situ temperature-programmed diffuse reflectance Fourier transform infrared spectroscopy (TP-DRIFTS) method under vacuum. The DRIFTS spectra recorded yielded information about the effect of the NH₄OH treatment and subsequent calcination on the dehydration behavior of the natural zeolite. Changes in the infrared bands corresponding to vibrations of the O–H and N–H bonds upon in situ heating under vacuum were analyzed.     

Bibliometric profiles for British academic institutions: An experiment to develop research output indicators

In this paper, we report the results of an exploratory study commissioned by the Advisory Board for the Research Councils to produce bibliometric research profiles for academic and related institutions within the UK. The approach adopted is based on the methodology developed by CHI Research whereby publications from a given institution are weighted according to the influence of the journal in which they appear. Although certain technical limitations were encountered with the approach, the study nonetheless yielded potentially useful information on the comparative research output of British universities and polytechnics.The findings and conclusions presented are those of the authors alone and do not necessarily represent the views of their institutions or the Advisory Board for the Research Councils. Correspondence concerning the paper should be addressed toMartin at SPRU.     

Is technology becoming science?

Citation and referencing data from recent biotechnology patents and bioscience papers is used to show that the bibliometric properties in these two realms are quite similar. Specifically, it is shown that the time distribution of references from both patents and papers are similar, with peak citing at two to four years prior to publication or issue. This is shown to hold for patents citing patents, for papers citing papers, and for patents citing papers. Furthermore, it is shown that there is a very skewed distribution of cited material in both patents and papers, with a relatively small number of highly cited patents and papers, and a relatively large number of documents which are cited only once or twice, or not at all. Finally, it is shown that there is a substantial amount of citation from biotechnology patents to the central scientific literature. We conclude from this that science and technology are far more closely linked today than is normally perceived, and that, in fact, the division between leading edge biotechnology and modern bioscience has alsmot completely disappeared.     

Patent bibliometrics

In our 1975 monograph Evaluative Bibliometrics we discussed the many uses of publication and citation analysis in the evaluation of scientific activities, and some of the basic statistical properties of the scientific literature, particularly the skewness of the distributions of publications and citations, reference time distributions, and various anomalies in the citation patterns from one country to another. Over the last ten years we have devoted much of our energy to the development of an analogous research base and infrastructure for patent bibliometrics, that is for the use of patents, and patent citations in the evaluation of technological activities. There are remarkable similarities between literature bibliometrics and patent bibliometrics, and they are both applicable to the same wide ranges of problems. This paper will show that there are striking similarities between literature and patent distributions of national productivity, inventor productivity, referencing cycles, citation impact and within country citation preferences.Paper presented at the Fourth International Conference on Bibliometrics, Informetrics and Scientometrics in Berlin (Germany), September 11–15, 1993.     

A novel solid phase extraction procedure on Amberlite XAD-1180 for speciation of Cr(III), Cr(VI) and total chromium in environmental and pharmaceutical samples

Due to the toxicity of chromium, species depend on their chemical properties and bioavailabilities, speciation of chromium is very important in environmental samples. A speciation procedure for chromium(III), chromium(VI) and total chromium in environmental samples is presented in this work, prior to flame atomic absorption spectrometric determination of chromium. The procedure is based on the adsorption of Cr(III)-diphenylcarbazone complex on Amberlite XAD-1180 resin. After oxidation of Cr(III), the developed solid phase extraction system was applied to determinate the total chromium. Cr(III) was calculated as the difference between the total Cr content and the Cr(VI) content. The analytical conditions for the quantitative recoveries of Cr(VI) on Amberlite XAD-1180 resin were investigated. The effects of some alkaline, earth alkaline, metal ions and also some anions were also examined. Preconcentration factor was found to be 75. The detection limits (LOD) based on three times sigma of the blank (N: 21) for Cr(VI) and total chromium were 7.7 and 8.6 microg/L, respectively. Satisfactory results for the analysis of total chromium in the stream sediment (GBW7310) certified reference material for the validation of the presented method was obtained. The procedure was applied to food, water and pharmaceutical samples successfully.     

Synthesis and characterization of water‐soluble oligosalicylaldehyde‐sulfanilic acid and its Cu(II), Co(II), Pb(II) complexes

This work presents the synthesis and characterization of a new water‐soluble oligophenol derivative, 4‐(2‐hydroxybenzylideneamino)benzenesulfanilic acid (OSAL‐SA) and its metal complexes. The chemical structure of the water‐soluble polymer was characterized by nuclear magnetic resonance (¹H NMR) and Fourier transform infrared (FTIR) spectroscopies and thermogravimetric analyses (TGAs). Pb(II), Cu(II), Co(II) complexes of the polymer were also synthesized in methanol. Characterizations of water insoluble polymer‐metal complexes were performed by FTIR, flame atomic absorption spectroscopy, and TGA. The conductivity measurements of OSAL‐SA and polymer–metal complexes were carried out by the four‐probe technique. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008