The phrase "at the upper sections" is correct and usable in written English.
It can be used to refer to the higher parts or areas of something, such as a building, document, or any other structure.
Example: "The view from the upper sections of the observation deck is breathtaking."
Alternatives: "in the higher areas" or "at the top sections".
In this paper, the characteristic of the radiation fields at the upper section of the reactor of an ADS was analyzed.
Reichelt was not clean at the upper section of the 2.1-kilometer (1.3-mile) course, which was set with an unusual amount of short, sharp turns, almost making it look like a giant-slalom course.
In this study, an empirical correlation was developed to predict the solids holdup at the upper section of the riser in circulating and interconnected fluidized beds with an improved level of accuracy for a broad range of operating conditions and riser dimensions.
The location of the first successful implementations was the Gulf of Mexico, where thick Pleistocene Miocene sediments are represented by clastic rock, which are poorly consolidated at the upper section and are often overpressured from the very top.
By increasing cutting density, they tend to precipitate more, and the fluid will no longer be a mixture of mud cutting, i.e., there will be a low-viscosity fluid at the upper section of the drill string, which reduces the stress applied on this section.
For the AHPMW waveguide with triangle metal nanowire, the electric field component E y distributes asymmetrically along the Y-axis of the waveguide, and the major E y is confined at the upper section of the triangle metal, which results in the decline of the propagation length.
The state that gained independence from the United Kingdom in 1957 took the name the "Federation of Malaya", chosen in preference to other potential names such as "Langkasuka", after the historic kingdom located at the upper section of the Malay Peninsula in the first millennium CE.
In each experimental series, two replicate blots were horizontally cut at the ~60 kD size position; the upper sections were used to probe for phosphorylated and total STAT3 and the lower sections for phosphorylated ERK and total ERK.
Thus, the investigation of a customized manipulator, having a bi-directional stroke in order to approach the upper sections, is a most worthwhile subject in the automation of the shipbuilding process since such a system should be capable of carrying out continuous blast cleaning from the upper to the lower sections at one time, without the need for any additional operations.
