A protonação e complexação de Ni(II) por 4-(2-piridilazo) resorcinol (PAR) em força iônica 0,1 mol L KNO 3 a 25 °C, foram estudadas por análise global. Em titulações espectrofotométricas, a dependência linear ou quase linear da concentração e a existência de espécies em menores concentrações podem causar dificuldades na avaliação dos dados. Espectros de absorção e as correspondentes constantes ...

The task of forecasting a time series over a long horizon is commonly tackled b y iterating one-step-ahead predictors.Despite the popularity that this approach gained in the prediction communit y, its design is still plagued by a number of important unresolved issues, the most important being the accumulation of prediction errors. We introduce a local method to learn one-step-ahead predictors w...

In addition to the w-5 olefinic acids found in other Grevillea species, about 10% ?f the acyl groups of G. decOI'a seed oil contain a hydroxy group and an w-5 double bond. Th: chamlengths of these acids are from C22 to C30 , with the largest concentration at the C26 and C28 chamle.ngths. ~le hydroxy group is located on odd carbons from carbon-5 through carbon-l3. These a~lds prevIously .were ~n...

The sorption properties of rice husk towards Cu(II), Cd(II) and Pb(II) were studied. The sorption isotherms are described by the Langmuir equation, and Pb(II) shows a higher affinity for rice husk compared to Cu(II) and Cd(II) under the same conditions. The kinetics of sorption obeys to a pseudo second-order equation for all metals. The sorption profiles as a function of the pH were used to ...

The constants b and c entering in this expression can be calculated, and especially in the result for c enters crucially the assumption of coherence: neglecting the effect of angular ordering would increase it by a factor of √ 2. The data up to the highest energies keep to be in fair agreement with this prediction 1 (see Fig.1). An important point in this measurement is that the LEP data have b...

l-Canavanine inhibits the appearance of nitrate reductase (NADH-nitrate oxidoreductase, EC 1.6.6.1) in both root tips and mature root sections of corn (Zea mays L.). Ten-fold more canavanine was required to cause a 50% reduction in the level of nitrate reductase activity (NRA) in root tips than in mature root sections. For example with one particular batch of seeds 500 mum canavanine was effect...

E lin o r ’s note: Today's Q an d A fea tu res M itc h e ll L ifton , cha irm an o f the Notre D am e-Sa int M ary 's D epartm ent o f C om m un ica tio n an d Theatre. This departm ent has experienced d ra m a tic c u rr ic u lu m changes an d g ro w th in the three years since L ifto n was nam ed to c h a ir the departm ent ( fo rm e rly kno w n as the D epartm ent o f Speech an d D ram a.) T...

Accumulation of K(+) is insensitive to the anion supplied with it at a solution concentration below 1 mm. Rates of K(+) transport to the xylem from the same solutions are, however, dependent upon the anion present and decrease in the order NO(3) (-) >> Cl(-) > SO(4) (2-). Parallel effects on rates of exudation and anion transport result from kind and concentration of anion supplied and time of ...

Background & Aim: Because of seed germination ability of medicinal plants seed is low and, generally exposed to problem. Priming is one of the techniques that help seeds to be germinated faster and uniformly. Experimental: A laboratory experiment was carried out on germination and growth improvement in Heracleum persicum Desf.  by seed osmo-primming in Seed Technology Labora...

هدف این پژوهش، طراحی مدل بهینه‌سازی دوسطحی برای زنجیره تأمین است؛ به‌طوری‌که تصمیم‌گیری غیرمتمرکز کمّی و کیفی را در سطوح استراتژی تاکتیکی ادغام کند. کارخانه تولیدی نقش تصمیم‌گیرنده سطح بالا با ارائه تخفیف مقداری، به دنبال ترغیب مشتریان سفارش خرید بیشتر است. پایین، به‌عنوان پایین تمایل دارند مقادیر از طریق مشارکتی، مقیاس اقتصادی دست یابند. یکی نخستین پژوهش­هایی است که یافتن راه‌حل‌های بهینه مسئله...