SE214
Grammar Exercises
8/2/07, Lab 4.
Fix the text
Rewrite this text making any changes you feel will improve its clarity and structure. You may
correct errors in grammar, omit or add words or phrases, rephrase wordy structures, adjust
punctuation or make other changes as required. Do not summarise the text.
Lamb wave and surface acoustic wave (SAW) devices, are being used in many applications from
simple transversal filters to gas detectors. Traditional Lambe wave and SAW devices use
piezoelectricity to generate ultrasonic waves in the substrate on which they are built. Electrodes
arranged in interdigital configuration on piezoelectric substrates or with piezoelectric films i.e.
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lead zirconium titanate, lithium niobate, zinc oxide, etc. However, these materials are not
compatible with the existing integrated circuit fabrication processes this limits the integration of
Lamb wave or SAW devices with the electronics. Instead of piezoelectricity, using capacitative
micromachined ultrasonic transducers (CMUTs) for generation and detection of acoustic waves
in the substrate, has greater potential for electronic integration. This results in inexpensive and
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cheap integrated circuits for mass production and devices with increased noise performance because the cabling between the transducers and the electronics are eliminated.
The CMUT has only been used to generate and detect ultrasonic waves for liquid
immersion and airbourne applications so far. A C.M.U.T. consists of a metalised silicon nitride
membrane supported by posts and it’s built on a silicon wafer using standard techniques of
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micromachinery. The electrode on the membrane and the highly doped silicon substrate form a
parallel plate capacitor, which is really used to discover, detect and generate ultrasonic waves in
the immersion medium. When a voltage is applied between the membrane and the substrate
electrostatic forces attract the membrane toward the substrate. Stress within the membrane and
the bending stiffness of the membrane resist the attraction. Driving the membrane with a time
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harmonic signal, acoustic waves are generated in the immersion medium
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Find the errors in these sentences and correct them.
1. Its important, that your punctuation is correct: because incorrect punctuation and Capital
Letters Used Wrongly may confuse your readers’
2. Just like, incorrect spelling incorrect punctuation can be very annoying for your reader who
may pay more attention to the mistakes, than to the content of your report or letter.
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3. You probably know, that exclamation marks are not used much in scientific reports! But they
are used in Advertisements as well as in notes.
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4. Contracted forms like Ive and weve are a feature of informal writing. They are not found in
most reports or academic writing which tend to be formal. Its best to use full forms; I have,
we have, etc
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5. It is usually easier for a reader to understand short well structured sentences rather than long
unnecessarily complicated ones.
Punctuate this passage.
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Because there are a number of methods analytical numerical experimental of solving a given
problem we may wonder whether solving laplaces equation in different ways yields different
solutions this leads to the question whether a solution to laplaces equation which satisfies a given
set of boundary conditions is unique the answer is yes any solution of laplaces equation that
satisfies the same boundary conditions must be the same regardless of the method used this is
known as the uniqueness theorem two solutions of laplaces equation that satisfy the same
boundary condition differ at most by an additive constant
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