There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

Non-conventional low-cost adsorbents for dye removal: A review

Detection of chemical and biological agents plays a fundamental role in biomedical, forensic and environmental sciences1–4 as well as in anti bioterrorism applications.5–7 The development of highly sensitive, cost effective, miniature sensors is therefore in high demand which requires advanced technology coupled with fundamental knowledge in chemistry, biology and material sciences.8–13

In general, sensors feature two functional components: a recognition element to provide selective/specific binding with the target analytes and a transducer component for signaling the binding event. An efficient sensor relies heavily on these two essential components for the recognition process in terms of response time, signal to noise (S/N) ratio, selectivity and limits of detection (LOD).14,15 Therefore, designing sensors with higher efficacy depends on the development of novel materials to improve both the recognition and transduction processes. Nanomaterials feature unique physicochemical properties that can be of great utility in creating new recognition and transduction processes for chemical and biological sensors15–27 as well as improving the S/N ratio by miniaturization of the sensor elements.28

Gold nanoparticles (AuNPs) possess distinct physical and chemical attributes that make them excellent scaffolds for the fabrication of novel chemical and biological sensors (Figure 1).29–36 First, AuNPs can be synthesized in a straightforward manner and can be made highly stable. Second, they possess unique optoelectronic properties. Third, they provide high surface-to-volume ratio with excellent biocompatibility using appropriate ligands.30 Fourth, these properties of AuNPs can be readily tuned varying their size, shape and the surrounding chemical environment. For example, the binding event between recognition element and the analyte can alter physicochemical properties of transducer AuNPs, such as plasmon resonance absorption, conductivity, redox behavior, etc. that in turn can generate a detectable response signal. Finally, AuNPs offer a suitable platform for multi-functionalization with a wide range of organic or biological ligands for the selective binding and detection of small molecules and biological targets.30–32,36 Each of these attributes of AuNPs has allowed researchers to develop novel sensing strategies with improved sensitivity, stability and selectivity. In the last decade of research, the advent of AuNP as a sensory element provided us a broad spectrum of innovative approaches for the detection of metal ions, small molecules, proteins, nucleic acids, malignant cells, etc. in a rapid and efficient manner.37



Figure 1

Physical properties of AuNPs and schematic illustration of an AuNP-based detection system.



In this current review, we have highlighted the several synthetic routes and properties of AuNPs that make them excellent probes for different sensing strategies. Furthermore, we will discuss various sensing strategies and major advances in the last two decades of research utilizing AuNPs in the detection of variety of target analytes including metal ions, organic molecules, proteins, nucleic acids, and microorganisms.

/pdf/gold-nanoparticles-in-chemical-and-biological-sensing-5e2qojkdzn.pdf

Gold nanoparticles in chemical and biological sensing.

Bagasse fly ash, a waste generated in sugar industries in India, has been converted into a low cost adsorbent and has been used for the removal of lead from aqueous solutions in the 4.80 A 10â4 to 4.83 A 10â3 M concentration range. Maximum removal takes place at pH 3.0 using lOgâ1 of the adsorbent of particle size 150–200 mesh. The effect of the presence of other metal ions, temperature, and contact time has also been studied. Sorption data have been correlated with both Langmuir and Freundlich adsorption models. The adsorbent has been satisfactorily.-used for the removal of Pb2+ from the effluent of a metal-finishing plant.

>Removal of Lead from Wastewater Using Bagasse Fly Ash—A Sugar Industry Waste Material

Voltammetric determination of adenosine and guanosine using fullerene-C60-modified glassy carbon electrode

Porphyrins as carrier in PVC based membrane potentiometric sensors for nickel(II)

Uranyl ion selective electrodes have been constructed from poly(vinyl chloride) matrix membranes containing neutral carrier, 2,3,11,12-dicyclohexano-1,4,7,10,13,16-hexaoxacyclooctadecane and organic resin, 2,4-dihydroxypropiophenoneoxime–formaldehyde using dibutyl phthalate and dioctyl phthalate as plasticizing solvent mediators These electrodes demonstrate linear response to UO2+2 ions in the concentration range 10–5–10–1 mol l–1 with a Nernstian or near Nernstian slope at pH 3 The electrodes are inert towards acids, salt solutions and non-aqueous media for a period of 3 months and exhibit a response time as fast as 30 s The electrodes with plasticizers have been found to be better compared with electrodes without plasticizers The electrodes are sufficiently selective over a large number of bivalent and trivalent cations including calcium, iron(III) and copper(II), with selectivity coefficient values of the order of 001 for bivalent and 0001 for trivalent cations Monovalent ions cause interference at higher concentrations with selectivity coefficient values of the order of 01 The electrodes work satisfactorily in a partially non-aqueous medium

Vinod Kumar Gupta

Papers

>Removal of Lead from Wastewater Using Bagasse Fly Ash—A Sugar Industry Waste Material

Voltammetric determination of adenosine and guanosine using fullerene-C60-modified glassy carbon electrode

Porphyrins as carrier in PVC based membrane potentiometric sensors for nickel(II)

Neutral carrier and organic resin based membranes as sensors for uranyl ions

Adsorptional photocatalytic degradation of methylene blue onto pectin-CuS nanocomposite under solar light.