Stimuli-responsive materials

Natural peptide-based material Stimulus Response Function... 

A practical method of predicting the molecular behavior within the flow system involves the RTD. A common experiment to test nonuniformities is the stimulus response experiment. A typical stimulus is a step-change in the concentration of some tracer material. The step-response is an instantaneous jump of a concentration to some new value, which is then maintained for an indefinite period. The tracer should be detectable and must not change or decompose as it passes through the mixer. Studies have shown that the flow characteristics of static mixers approach those of an ideal plug flow system. Figures 8-41 and 8-42, respectively, indicate the exit residence time distributions of the Kenics static mixer in comparison with other flow systems. 

In the previous sections it was demonstrated that the stimulus-responsive behavior of ELP was transferred to ELP fusion proteins and even to non-covalently bound moieties, such as proteins, plasmids, and heavy metals, mostly for biomedical and biotechnological applications. The ability of ELPs to reversibly switch their polarity is also of great interest for the development of stimulus-responsive materials. Many approaches have therefore recently been undertaken to integrate ELPs with, for example, polymers, particles, and surfaces. 

In a more general way, the two major driving forces for the design of novel micellar systems are the control over morphology (spheres, vesicles, rods, tubules etc. with controlled size) and function (stimulus-responsive materials, biological functions). Both of these aspects are intimately related since a given morphology can induce a specific function. 

The experimental technique used for finding this desired distribution of residence times of fluid in the vessel is a stimulus-response technique using tracer material in the flowing fluid. The stimulus or input signal is simply tracer introduced in a known manner into the fluid stream enter-... 

Thus we see that the stimulus-response technique using a step or pulse input function provides a convenient experimental technique for finding the age distribution of the contents and the residence-time distribution of material passing through a closed vessel. 

The regulation of calcitonin synthesis and release from the parafollicular C cells of the thyroid gland is calcium dependent. Rising serum calcium is the principal stimulus responsible for calcitonin synthesis and release. Other hormones, such as glucagon, gastrin, and serotonin, also stimulate calcitonin release. Calcitonin has been isolated in tissues other than the parafollicular C cells (parathyroid, pancreas, thymus, adrenal), but it is not known whether this material is biologically active. 

I am not so sure. There still remains the problem of our consciousness and its relationship to our material form - the Mind / Brain problem. Behavioural psychologists such as Skinner tried to reduce this to one level - the material brain - by viewing the mental or consciousness events from the outside as being merely stimulus-response loops. 

The physical process of material dispersion is due to the hydrodynamic processes taking place in the flowthrough system and is therefore conveniently investigated by the stimulus response technique, which is based on introduction of a tracer into a flowing stream and on measurement of the dispersion of the tracer as caused by the transport process throughout the system. If the tracer is injected as a zone (stimulus), then the observed... 

Mathematical models may be classified into deterministic and stochastic models. For deterministic models, knowledge of the relationship between dependent and independent variables is necessary. Consequently, the complex nature of polymer-based heterogeneous materials is rather incompatible with such requirements. Hence, stochastic models become necessary either when the existing knowledge about the stimulus-response behavior of a system is not enough as to ascertain its behavior or when it is not possible to build an efficient deterministic model able to score the system response. 

Chen JK, Chang CJ. Fabrications and applications of stimulus-responsive polymer films and patterns on surfaces a review. Materials 2014 7(2) 805—75. 

Colloidal nanosystems based on biodegradable polymeric materials that combine the capabilities of stimulus response and molecular recognition promise significant improvements in the ocular delivery of therapeutic agents. 

Lowik DWPM, Leunissen EHP, van den Heuvel M, Hansen MB, van Hest JCM (2010) Stimulus responsive peptide based materials. Chem Soc Rev 39 3394-3412... 

To understand the behavior of the fluidized bed, one can determine the average residence time or the residence time distribution (RTD) from the tracer technique. For instance, RTD in fluidized bed dryer is usually carried out by means of the stimulus-response technique, in which an impulse of solids marked with some appropriate tracer is fed to the dryer and its time of elution and concentration measured at the exit of the dryer. The material of the tracer has to be such that it can be detected and does not react with the substrate material, and its form of application and response are well known (Levenspiel, 1972). 

Sun L, et al. Stimulus-responsive shape memory materials a review. Mater Des 2012 33 577-640. 

Sun, L., Huang, W.M., Ding, Z., Zhao, Y., Wang, C.C., PumawaU, H., Tang, C., 2011. Stimulus-responsive shape memory materials a review. Materials and Design 33, 577-640. 

Environmental stimulus responsive material Responsive material... 

Figure 9.1 illustrates this classification. Importantly, all polymeric materials formed through these reactions have inherent stimulus response arising... 

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