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An HPLC method was developed to determine the various carotenoids in Taiwanese mango ( Mangifera indica L.). Initially, the peel and seed of mangoes were removed, the pulps were cut into pieces, freeze-dried, ground into powder, extracted and subjected to HPLC analysis. A mobile phase of methanol–isopropanol (99:1, v/v) (A) and methylene chloride (100%) (B) with the following gradient elution was developed: 100% A and 0% B in the beginning, maintained for 15 min, decreased to 70% A in 45 min, maintained for 15 min and returned to 100% A in 65 min. A total of 25 carotenoids were resolved within 53 min by using a C-30 column with flow rate at 1 mL/min and detection at 450 nm. α-Carotene was used as an internal standard to quantify all the carotenoids. All- trans -β-carotene was present in largest amount (29.34 μg/g), followed by cis isomers of β-carotene (9.86 μg/g), violaxanthin and its cis isomers (6.40 μg/g), neochrome (5.03 μg/g), luteoxanthin (3.6 μg/g), neoxanthin and its cis isomers (1.88 μg/g), zeaxanthin (1.16 μg/g) and 9- or 9′- cis -lutein (0.78 μg/g).

A high-resolution and low-damage method for patterning relief structures in thin Ta2O5 films by chemically assisted UV laser selective etching is presented. The method is based on the initial exposure of the Ta2O5 films to pulsed UV radiation (quadrupled Nd:YAG laser at 266 nm) at fluences below the ablation threshold, for the creation of volume damage in the exposed areas. Subsequent immersion of the exposed sample in a KOH solution results in selective etching of the UV-exposed areas, developing relief structures of high quality. Interferometric exposure was used for the patterning of such gratings with periods of the order of 500 nm in films with a thickness of 100 and 500 nm. The behaviour of the patterning process is studied using diffraction efficiency measurements and AFM scans. Diffraction efficiency increases by a factor of ~63, compared to the undeveloped structure, were obtained for gratings exposed with 1000 pulses of 30 mJ/cm2 energy density, which were developed in a KOH solution. The etching method presented is being applied to the fabrication of gratings in optical waveguides.

An experimental apparatus was designed to investigate the crystal morphology and growth rate of naphthalene crystals grown in various processes using supercritical carbon dioxide, including SCG (single crystal growth), SESS (slow expansion of supercritical solution), and RESS (rapid expansion of supercritical solution). Photographs were taken to identify crystal habits. The growth rates of naphthalene in the SCG and SESS processes were measured and compared with those in a RESS process.

We have studied the double perovskite [1] structure Sr2Y(Ru1-xCux)O6 system. The parent compound is an antiferromagnetic insulator with Neel temperature ∼ 26 K. Partially substituted the Ru ion by Cu the compounds increase their conductivity drastically and eventually become superconducting. More intriguingly is the observation of the coexistence of superconductivity and magnetic ordering. The superconducting transition temperature Tc and the magnetic ordering temperature Tm are of the same order. The observed magnetic structure and superconductivity of these compounds can be understood in terms of a plausible theoretical model based on the double exchange idea.

Taguchi quality control method is a cost-effective experimental design technique for characterizing the optimal operating parameters for a manufacturing process. Most previous applications of the Taguchi method have been concerned with the optimization of a single-response process and a large amount of satisfactory implementation results have been published. However, for multi-response cases, an effective and user-friendly technique is still lacking. The multi-response technique presented in this paper modifies the traditional Taguchi method by adopting an empirical loss function to sum up the impact of each process variable. Compared with previous methods, this technique is distinguished in two aspects: (1) it theoretically optimizes the single-response case in a more accurate way; (2) it can optimize multi-response processes involving discrete and continuous data types. Considering a surface mount technology (SMT) process for a VGA card (a typical multi-response process involving six variables and nine responses), experiments applying the proposed technique were conducted and showed satisfactory results. The yield rate for the SMT process improved from 88% to 98%.

The magnetic and crystallographic properties of LaNi/sub (5-x)/Fe/sub x/ samples (1/spl les/x/spl les/1.4) have been studied by X-ray diffraction, neutron diffraction, SQUID and Mossbauer spectroscopy. Samples with x/spl ges/1.2 display typical ferromagnetic behavior. The substitution of iron for nickel in LaNi/sub 5/ increases the unit cell volume and Curie temperature. The majority (>90%) of the Fe atoms appear to occupy the 3g site. Induced Ni magnetic moments at 30 K have been calculated using the bulk magnetization data and iron magnetic moments.

Short duration cadmium diffusion in sealed ampoules was studied at a temperature of 550/spl deg/C and a Cd/P molar ratio of 0.28. The starting sources were physical mixtures of either elemental Cd metal and red P or Cd/sub 3/P/sub 2/ and red P. The Cd profiles were determined by SIMS. In relatively short diffusion anneals up to two hours, the surface concentration, or solubility of Cd with either diffusion source is the same. However, Cd penetration was shallower in samples diffused with elemental (Cd,P) mixture than in samples diffused with (Cd/sub 3/P/sub 2/,P) mixture as the starting source. The slower diffusion of Cd with elemental starting source (Cd,P) appears to be related to the kinetics involved in reaching the thermal equilibrium between CdP/sub 2/ and CdP/sub 4/. The formation of Cd/sub 3/P/sub 2/ en route to the eventual formation of CdP/sub 2/ and CdP/sub 4/ or surface related kinetics are proposed as plausible mechanisms. The results appear to be consistent with the establishment of thermal equilibrium between CdP/sub 2/ and CdP/sub 4/ at a Cd/P ratio of 0.28 per the available phase equilibria data. The diffusion kinetics and defect structure are discussed on the basis of quasi-equilibrium among the three condensed phases InP, CdP/sub 2/ and CdP/sub 4/.

Oseltamivir carboxylate is a potent and specific inhibitor of influenza A and B neuraminidase (NA). Oseltamivir phosphate, the ethyl ester prodrug of oseltamivir carboxylate, is the first orally active NA inhibitor available for the prophylaxis and treatment of influenza A and B. It offers an improvement over amantadine and rimantadine which are active only against influenza A and rapidly generate resistant virus. The emergence of virus resistant to oseltamivir carboxylate in the treatment of naturally acquired influenza infection is low (about 1%). The types of NA mutation to arise are sub-type specific and largely predicted from in vitro drug selection studies. A substitution of the conserved histidine at position 274 for tyrosine in the NA active site has been selected via site directed mutagenesis, serial passage in culture under drug pressure in H1N1 and during the treatment of experimental H1N1 infection in man. Virus carrying H274Y NA enzyme selected in vivo has reduced sensitivity to oseltamivir carboxylate. The replicative ability in cell culture was reduced up to 3 logs, as was infectivity in animal models of influenza virus infection. Additionally, pathogenicity of the mutant virus is significantly compromised in ferret, compared to the corresponding wild type virus. Virus carrying a H274Y mutation is unlikely to be of clinical consequence in man.

We present a method to achieve lithographic control of the lateral oxidation of AlAs layers. The technique uses impurity induced layer disordering (IILD) in buried, heavily Si-doped layers to introduce Ga atoms into the AlAs layers to be oxidized. By selectively patterning the wafer surface and combining point defect generation mechanisms from the uncapped surface and in the highly Si-doped layers, this intermixing may be localized. Because lateral oxidation rates are heavily dependent on Al mole-fraction, lateral oxidation stop layers can thus be formed. Results are discussed for several types of capping conditions, and SUPREM simulations of the two-dimensional disordering process are presented.

The lateral oxidation of AlAs is becoming an important processing tool, but has proven difficult to control. A method is presented to achieve lithographic control of the lateral oxidation process. The technique uses impurity induced layer disordering in buried, heavily Si-doped layers to locally change the oxidation rate of an AlAs layer. Several types of capping conditions during the anneal are discussed.