The nonlinear absorption (NLA) properties of free base and metalated porphyrins with a unique 5,10-A(2)B(2) substitution pattern were studied with open Z-scan technique at 532 nm in the nanosecond regime over a broad range of input fluence. The NLA responses were found to be dependent on structural features and the solvent used. In most cases, the character of the response differed from that ty...

We explore phenomenologies of the topflavour model for the LEP experiment at m Z scale and the atomic parity violation (APV) experiment in the Cs atoms at low energies. Implications of the model on the Z peak data are studied in terms of the precision variables ǫ i 's. We find that the LEP data give more stringent constraints on the model parameters than the APV data.

Few metabolic balance studies of manganese have been reported and the results from these are bewildering. Except for the study of Kent & McCance (1941) on two women, each study has indicated a daily accumulation of M n in both normal men and normal women which approaches in a matter of weeks the estimated total body pool of 12-20 mg M n (Cotzias, 195s). Schroeder, Balassa & Tipton (1966) confir...

The quantitative analysis of molecular density matrices in terms of oriented quasi-atomic orbitals (QUAOs) is shown to yield detailed conceptual insight into the dissociation of dioxetane on the basis of ab initio wave functions. The QUAOs persist and can be followed throughout the reaction path. The kinetic bond orders and the orbital populations of the QUAOs quantitatively reveal the changes ...

カ ド ミウム(Cd)作 業者 のCd曝 露 指 標 として,血 液 お よび 尿 中Cdの 測 定 が有 効 であ り1),こ れ ら生体 試 料 中 のCd測 定方 法 と しては黒 鉛 炉原 子 吸 光法2~6)が 広 く 用 い られ て い る.こ の方 法 に よるCd定 量 では, Cdお よび そ の化合 物 の融点 が低 いた め,原 子 化 段階 以 前 での 揮 散 が問 題 で あ り,対 策 と して適 当な 干渉 抑制 剤 を添 加 す る ことに よ り,揮 散 を 抑制 す る方 法 が と られ て い る. Cd定 量 に 対 して は, HNO32-4), NH4H2PO43,4), NH4NO33-5), NH4F4,6)お よびPd(NO3)25)な どが 干渉 抑制 剤 と して提 唱 され て い る.血 中Cd(Cd-B)の 定量 に従...

An evaluation of the performance of a continuous flow hydride generator-nebulizer for flame atomic absorption spectrometry was carried out. Optimization of nebulizer gas flow rate, sample acid concentration, sample and tetrahydroborate uptake rates and reductant concentration, on the As and Se absorbance signals was carried out. A hydrogen-argon flame was used. An improvement of the analytical ...

A method has been described for the estimation of calcium and magnesium in serum and urine using atomic absorption spectrophotometry. The precision and accuracy of the techniques have been determined and were found to be acceptable. THE RANGE OF VALUES FOR CALCIUM AND MAGNESIUM IN THE SERA OF NORMAL ADULTS WAS FOUND TO BE: serum calcium (corrected to a specific gravity of 1.026) 8.38-10.08 mg. ...

Two flow methods, based, respectively, on flow-injection analysis (FIA) and on multicommutated flow analysis (MCFA), were compared with regard to their use for the determination of total selenium in infant formulas by hydride-generation atomic absorption spectrometry. The method based on multicommutation provided lower detection and quantification limits (0.08 and 0.27 μg L(-1) compared to 0.59...

The changes in the oxidation state of vanadium in artificial and natural seawater samples were studied by electrothermal atomic absorption spectrometry (ETAAS) with a direct injection of a resin suspension. V(IV) and V(V) were extracted as the complex with Chromazurol B and with N-cinnamoyl-N-2,3-xylylhydroxylamine, respectively, using a suspension of an anion-exchange resin and determined by E...

The concentration of Cadmium (Cd) and lead (Pb) in different cigarette brands sold and/or produced in Saudi Arabia were determined by atomic absorption spectrometry (AAS). Average levels of Cd and Pb in different cigarette brands in Saudi Arabia were 1.81 and 2.46 μg g1 (dry weight), respectively. The results obtained in this study estimate the average quantity of Cd inhaled from smoking one pa...