Optical analysis of adsorption sensitivity of titanium, Ti-6Al-4V, and Ti-35Nb-6Ta

Here we report the optical analysis of protein adsorption sensitivity of titanium (Ti), Ti(6)Al(4)V, and Ti(35)Nb(6)Ta. The optical sensor used was a diffractive optical element based sensor, which analyzes magnitude and coherence of probe beam reflected from the measured surfaces. Also, the roughness and other necessary parameters were taken into account on the final verdict. The material Ti(35)Nb(6)Ta showed positive initial reaction to the human plasma fibrinogen, which was the protein used. The Ti(35)Nb(6)Ta was observed to be more active than the grade 2 titanium.     

Synthesis,crystal structure,optical and third order nonlinear optical properties of phosphoric acid pyridine-1-ium-2-carboxylate

A semi-organic nonlinear optical material phosphoric acid pyridine-1-ium-2-carboxylate (PAPC) crystal has been synthesized and grown. Vibrational spectral analysis and NMR spectral analysis has been carried out. Mechanical studies on the grown crystal has been performed which disclose the material belongs to soft materials category. The thermal behaviour of the grown crystal has been investigated by thermogravimetric and differential thermal analysis. UV–Visible spectral analysis has been carried out which reveals that the grown crystal is transparent in the entire visible region with the lower cut-off wavelength of 298 nm and the derived optical constant attests the suitability of this material for non-linear optical applications. The third order nonlinearity has been studied by z-scan method and the enhanced third-order nonlinearity shows PAPC is a potential material for device applications. Second harmonic generation efficiency has been studied by Kurtz and Perry powder test and is found as 0.14 times greater than the KDP.     

Cave-ins in the Päijänne Tunnel and their repair

Two cave-ins occurred in the Päijänne Tunnel, the repair of both being completed in the spring of 1999. One cave-in occurred near Hämeenkoski and the other near Pulkkila. The Hämeenkoski cave-in was probably caused by the accelerated weathering of a weakness zone, which led to a rather complex cave-in process. The construction of the tunnel in the 1970s changed the groundwater conditions, thus increasing the rate of weathering. The Hämeenkoski cave-in was repaired by a bypass tunnel. The Pulkkila cave-in was caused by a water flow, which flushed out joint fillings, leading to the fall of key-blocks. The Pulkkila cave-in was repaired by penetrating the cave-in.     

Flavonol glycosides in wild and cultivated berries of three major subspecies of Hippophaërhamnoides and changes during harvesting period

Flavonol glycosides are an important group of bioactive components of sea buckthorn (Hippophaë rhamnoides). The content and profile of flavonol glycosides of some major subspecies and most cultivars as well as the variation amongst the harvesting years and dates are largely unknown. This study investigated flavonol glycosides in wild berries of two major subspecies H. rhamnoides ssp. rhamnoides and ssp. sinensis and berries of eight cultivars of ssp. rhamnoides and mongolica by reverse phase high performance liquid chromatography combined with diode array detection. The major flavonol glycosides were isorhamnetin-3-O-glucoside-7-O-rhamnoside, isorhamnetin-3-O-rutinoside, isorhamnetin-3-O-glucoside, isorhamnetin-3-O-sophoroside-7-O-rhamnoside, quercetin-3-O-rutinoside, quercetin-3-O-glucoside and quecertin-3-O-sophoroside-7-O-rhamnoside. The total content of flavonol glycosides fell in the range of 27–130 mg per 100 g fresh berries with considerable variation amongst the origins and the harvesting years. Compared with the berries of ssp. sinensis and ssp. mongolica, the berries of ssp. rhamnoides contained high levels of isorhamnetin-3-O-glucoside-7-O-rhamnoside and isorhamnetin-3-O-glucoside and lower levels of quercetin-3-O-rutinoside and quercetin-3-O-glucoside. In the wild berries of ssp. sinensis, the contents of flavonol glycosides reached maxima around late September to early October and decreased thereafter, whereas a general decreasing trend was seen in the cultivated berries of ssp. rhamnoides from the end of August to the end of October.