Explore BrainMass
Share

# Crystal Engineering

Crystal engineering studies molecular solid-state structures to understand the intermolecular interactions. There are two main concepts studied in crystal engineering which are hydrogen bonding and coordination complexation. These are understood with key concepts such as the supramolecular synthon and the secondary building unit.

Polymorphism is where the same chemical compound exists in different crystal forms. In the intial stages of crystal engineering, polymorphism was not understood and was incompletely studied. Today, it is one of the most exciting branches of the subject partly because polymorphic forms of drugs may be entitled to independent patent protection if they show new and improved properties over the known crystal forms.

© BrainMass Inc. brainmass.com December 10, 2019, 9:51 am ad1c9bdddf

### Laplace transform is used to mathematically model a piezoelectric crystal as a transfer function between vL and ip.

This problem is related to the modeling of a piezoelectric crystal by using a norton current generator and a capacitor. The transfer function is found to be equal to vL/ip. where vL is the load resistance and ip is the current from norton current generator.

### Plotting the Spectrum of a Sampled Signal

Plot the spectrum of the sampled signal. See attached file for full problem description. The signal x(t) = 3 + 4cos(10πt) + 5cos(14πt) + 2cos(20πt) is sampled at a rate of 30 samples per second. Plot the spectrum of the sampled signal showing all components for │f │< 80. Could you please explain how x(t) can be reco

### Mechanics of material: amorphous materials and polymers

(See attachment for full description) 4. True-False, You must justify your answer for full credit. a) Dislocations can appear in amorphous materials. b) A Voight model fully describes the mechanical behavior of most real polymers. c) The compliance of a testing frame is only important when one is testing a really compliant

### Mechanics of materials: strain hardening

Explain strain hardening, on a microstructural level. Testing: Dislocation motion, interaction and multiplication