Narrow Results

In this paper, the softening behavior of higher Nb content X80 pipeline steel was investigated by means of the stress relaxation curve. Deformed above 1050°C, the softening of the steel is fast and controlled by static recrystallization. Although the softening at 1000°C is slower obviously, it was also controlled by static recrystallization, no more than the grain growth rate was declined because of the drag effect of solute Nb. Moreover, the pinning effect of precipitation is more effective to retarding the softening at relatively lower temperature and that can be revealed by the softening curve too.

Imidazoline surfactants belong to the category of cationic surfactants. Cationic surfactants are often quaternary nitrogen salts and are widely used both in nonaqueous systems and in applications such as textile softeners, dispersants, and emulsifiers. This study describes the surface-active properties of cationic imidazolinium surfactants synthesized from different fatty acids. Their laundry performance in combination with nonionic surfactants like detergency, foaming property, softening property, rewettability etc., is also emphasized.

An approach for predicting the response of non-ductile reinforced concrete (RC) frames subjected to seismic loading is proposed. A beam-column element is developed based on component tests. The main characteristic of the developed element is its ability to represent the drop in the strength of non-ductile RC members after reaching the ultimate strength level. The term softening is used to define the reduction in the component strength capacity under cyclic loading after reaching the ultimate strength limit. Moment and deformation capacities of the frame members are estimated. The analytical predictions are compared with experimental measurements of the response of members of non-ductile frames. The approach is applied to study the seismic response of a three-storey non-ductile frame. The response calculated using the softening model is compared with the prediction using traditional models that do not represent the strength softening of the frame members. It is concluded that ignoring the strength softening underestimates the deformation as members of the frames pass their ultimate strength.

The present study aimed at identifying and developing the most appropriate water treatment scheme for ground water to be used for air conditioning/cooling, in large quantity for commercial utility in Delhi (India). High values of TDS, hardness and alkalinity up to 600, 400 and 400 mg/L, respectively, are reported in the source water. Dealkalization using weak acid cation exchanger and degasification coupled with multi-media and activated carbon filtration emerged as the optimal treatment scheme, efficiently reducing hardness and alkalinity. The maximum hardness and alkalinity reduction was 99.42 and 100%, respectively. The scheme has an added credential of eliminating handling of large quantity of brine solution for regeneration.

We study the structure of the σ meson, the lowest-lying resonance of the ππ scattering in the scalar-isoscalar channel, through the softening phenomena associated with the partial restoration of chiral symmetry. We build dynamical chiral models to describe the ππ scattering amplitude, in which the σ meson is described either as the chiral partner of the pion or as the dynamically generated resonance through the ππ attraction. It is shown that the internal structure is reflected in the softening phenomena; the softening pattern of the dynamically generated σ meson is qualitatively different from the behavior of the chiral partner of the pion. On the other hand, in the symmetry restoration limit, the dynamically generated σ meson behaves similarly to the chiral partner.