The conjunction “or” can be used not only to indicate two or more alternatives but also to indicate synonymous or equivalent expressions. When used for the latter purpose, “or” can be translated as “also referred to as,” “defined as,” or “in other words,” and sentences containing such an appositional “or” are punctuated differently than sentences in which “or” separates alternatives. Let’s look at some examples.
Infrared spectroscopy or electron paramagnetic resonance spectroscopy can be used to follow the kinetics of radical decay.
Here “or” is used to indicate two alternative techniques—infrared spectroscopy and electron paramagnetic resonance spectroscopy—either of which can be used to follow the decay kinetics. In this type of sentence, “or” separates the two parts of a compound subject, and no additional punctuation is required. What about the following, apparently similar sentence? Continue reading Appositional “or”
A series of weekly posts discussing revisions to a sentence from the scientific literature, highlighting various common grammar, syntax, and usage issues—and ways to address them.
This week’s sentence is…
The sequence can readily be programmed; that is, it is possible to start from a common set of reagents and steer all levels of selectivity by varying only the order of reagents and/or the catalyst used.
Here’s one possible revision:
The sequence can
readily be programmed; that is, it is possible to start from a common set of reagents and steer all levels of selectivity by varying only the order of reagents and/or the catalyst used.
- The adverb”readily” is now in its natural location between the auxiliary verb (“can be”) and the main verb (“programmed”). For more on adverb placement, see Garner’s Modern American Usage, 3rd ed. (Oxford University Press, 2009), pp. 23-24.
- Changing “it is possible to” to “one can” prevents readers from momentarily misreading the expletive “it” as a pronoun referring back to “the sequence.”
- “Control…selectivity” is more idiomatic than “steer…selectivity.”
- It’s the addition of the reagents, not the reagents themselves, that has an order. With the extra words required to convey that information precisely, the sentence is easier to read when the two variations (catalyst and order of reagent addition) are mentioned in the opposite order.
- “And/or” is generally frowned upon as being imprecise. For example, see The ACS Style Guide, 3rd ed. (American Chemical Society, 2006), p. 56.
Compound adjectives constructed from a noun plus the past participle of a verb are used frequently in English. Consider, for example, the sentence
The skiers raced down the snow-covered slopes.
Here, “snow-covered” is a compound adjective constructed from the noun “snow” and the past participle of the verb “to cover.” The compound describes the slopes; the slopes were covered. Covered with what? Covered with snow.
The bishop placed the jewel-encrusted crown on the queen’s head.
“Jewel-encrusted” is a compound adjective modifying “crown”; the crown was encrusted with jewels.
Now let’s look a couple of analogous sentence from the scientific literature.
The surface-adsorbed nitrogen was quantified by means of a transient-response experiment.
Here, “surface-adsorbed” is a compound adjective constructed from the noun “surface” and the past participle of the verb “to adsorb.” The compound modifies “nitrogen; the nitrogen was adsorbed. Where was it adsorbed? On the surface. Continue reading Compound adjectives formed with “adsorbed” and “immobilized”
In science writing—as opposed to, say, literary criticism or cultural studies—a premium is placed on precise, clear language. Unambiguous communication of information is in fact the fundamental goal of science writing. One way to achieve this goal is to consistently use the most precise language possible: choose a precise word or phrase and use it consistently. Consider the following (simplified) sentences taken from the abstract, introduction, discussion, and conclusion of a chemistry paper:
We investigated the antiatherogenic properties of the compound.
We investigated the antiatherosclerotic properties of the compound.
We investigated the antiatherosclerosis activity of the compound.
We investigated the atherosclerosis-preventing activity of the compound.
Continue reading Judicious consistency
Sentences with two subjects separated by “and” can be ambiguous when the first subject contains a prepositional phrase. Here’s an example I ran across recently in a chemistry paper I was editing: Continue reading Miscues involving prepositional phrases