Teflon is a trade name strongly associated with polytetrafluoroethylene, whose repeat unit is $-\mathrm{C}{\mathrm{F}}_2-\mathrm{C}{\mathrm{F}}_2-$. The fluorinated chain gives the polymer a low-energy surface and high chemical resistance in many conditions.

Its familiar low-friction and nonwetting behavior belongs to a material surface, not to a free fluorine atom. Product formulations and other fluoropolymers sold under the same brand context should be specified separately when material identity matters.

The sympathetic nervous system is an autonomic division with pathways connecting central activity to peripheral organs. Preganglionic and postganglionic stages have different locations and transmitter relationships. Its effects depend on target tissue and receptor, rather than one uniform increase in every organ’s activity.

An adrenal gland is an endocrine organ near a kidney, containing distinct cortical and medullary regions. These regions have different developmental origins and secretory products. The adrenal medulla is closely connected to sympathetic neural signaling, rather than being equivalent to the whole gland.

Online text: s3.us-east-2.amazonaws.com/asc-mag-media/ArborLabs/PDF_Files/ASLab_43.pdf

Two-page teaching worksheet and teacher notes issued by Arbor Scientific. No personal byline or publication date is stated; the Amazon S3 host is distinct from the issuer. The student readings are blank.

Cited passages: PDF p. 1, Teacher’s Notes, Required Equipment, Concept Overview and Lab Tips; PDF p. 2, Materials and Procedure 1–11.

By Thomas J. Fellers and Michael W. Davidson.

Online text: www.microscopyu.com/microscopy-basics/linear-measurements-micrometry

MicroscopyU educational article published by Nikon Instruments Inc.. The Contributing Authors byline names both authors; no article publication date is established.

Cited passages: Stage Micrometers; Eyepiece Reticle Calibration, Figure 4 and procedure; Conclusions, line-edge errors and digital calibration at identical pixel resolution.

Online text: www.microscopyu.com/microscopy-basics/infinity-optical-systems

MicroscopyU educational article issued by Nikon Instruments Inc.. The displayed Contributing Authors heading is empty; no personal author or publication date is established. Footer copyright is distinct from article publication.

Cited passages: finite-system introduction; Figure 2(a–b); parallel bundles, tube lens and magnification discussion before Figure 3.

Institutional laboratory guide issued by Physics Undergraduate Labs, University of Colorado Boulder, in the PHYS 4430 course route. No individual instructor authorship is assigned.

Online text: physicslabs.colorado.edu/courses/phys-4430/lab-guides/michelson-interferometer/week-1/

Page revision: 15 August 2026, explicitly labeled Last Updated; this is an online revision date.

Cited passages: §4.1 and Figure 1: source, splitter, mirrors and detector; §§5.1–5.3: hardware, manual micrometer, near/far alignment, fringe patterns and live voltage or oscilloscope readout; §§6.1–6.4: angular mismatch, splitter ratio, polarization controls and noise estimates. The guide gives a protocol, rather than a published measured dataset.

By Charles H. Holbrow, Enrique Galvez, Beth Parks; the paper prints C. H. Holbrow, E. Galvez and M. E. Parks.

Published in American Journal of Physics 70(3), pp. 260–265, March 2002. DOI: 10.1119/1.1432972. Colgate University hosts this copy.

Online text: www.colgate.edu/media/5506/download

Cited passages: §IV and §IV.A, printed p. 262, Figure 4 and equations (1)–(5): field transformations and unitary beam-splitter model; §IV.D, printed p. 264, Figure 5: polarization routing into separate detected paths. The source uses its own port and phase conventions.

By Randall M. Schoonover, Mei-Sywe Hwang, James Taylor, Cheryl Smith.

NISTIR 5375, issued by National Institute of Standards and Technology in February 1994, reprinting ISA paper 93-091, printed pp. 299–320. The reprinted paper bears an ISA 1993 copyright; this is distinct from the NIST report publication.^[ref]

Online text: nvlpubs.nist.gov/nistpubs/Legacy/IR/nistir5375.pdf

Cited passages: printed pp. 313–316, Pycnometer Calibration, Figure 5 and Pycnometer Application: calibration and correction for bath-versus-weighing temperature; printed p. 315: tin-oxide charge precaution, no detected charge, and pycnometer data not yet analyzed.

Online text: www.thorlabs.com/catalogpages/Obsolete/2021/HFB001.pdf

Institutional issuer: Thorlabs. The catalogue PDF contains the teaching insight “Is the max acceptance angle constant across the core of a multimode fiber?”; no personal author is identified.

The inspected indexed teaching section labels 2 January 2019 as its last-edit date. No catalogue publication date is established.

Cited passages: Search-index extracted PDF p. 4/9, Is the max acceptance angle constant across the core of a multimode fiber?; Figs. 3–5 and Step-Index Multimode Fiber / Graded-Index Multimode Fibers paragraphs; Date of Last Edit: Jan. 2, 2019.

Online text: www.thorlabs.us/newgrouppage9.cfm?objectgroup_id=1362&pn=P1-630A-FC-10

Institutional issuer: Thorlabs. This teaching insight appears in the Insights into Optical Fiber section of a product page; no personal author is identified.

The inspected indexed section labels 20 January 2020 as its last-edit date. That date belongs to the insight, not to the product's introduction.

Cited passages: Search-index full extracted section When does NA provide a good estimate of the fiber's acceptance angle?; Geometry Defines the Relationship; Single Mode Fibers are Different; Date of Last Edit: Jan. 20, 2020.

Online text: www.cisco.com/c/en/us/support/docs/optical/synchronous-digital-hierarchy-sdh/29000-db-29000.html

Institutional issuer: Cisco. No personal author is identified in the inspected technical note.

The revision history identifies version 1.0 as the initial release on 20 April 2005; the page header also labels that date as its update date.

Cited passages: What is a Decibel?; Base 10 Logarithm Rules; Power/Voltage Gains; Optical Fiber Structure, Fig. 1; Understand Insertion Loss; Calculate a Power Budget; Revision History: 1.0, 20-Apr-2005, Initial Release.

Online text: ocw.mit.edu/courses/6-161-modern-optics-project-laboratory-fall-2005/862b690eb7d638cd6dd5a063942902af_lab7.pdf

Institutional issuer: Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science. MIT OpenCourseWare hosts the handout; no personal author is printed on the inspected title page.

The title page identifies Laboratory Exercise No. 7 and the Fall 2005 course term. This is a course date, not an independently established publication date.

Cited passages: MIT 6.161 Modern Optics Project Laboratory, Fall 2005, PDF title page p. 1; p. 3, Basic Procedures for Cleaning Fiber and Basic Procedure for Cleaving Fiber; pp. 6–7, §7.3 and Fig. 1: overfill, microscope objective, micropositioner, reference detector, angular calibration, 2-degree readout, underfilled launch control, optional mode stripping and bend leakage; p. 8, §7.4(a): single-mode designation depends on operating wavelength.

Online text: www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1

Resolution 1 adopted by the 26th CGPM in 2018, with the revised definitions effective on 20 May 2019. The CGPM is the issuer and BIPM the host. Adoption, implementation and brochure publication are different dates.

Cited passages: Resolution 1 of the 26th CGPM (2018), effective date; Appendix 2, third bullet; Appendix 3, kelvin definition.

By George T. Furukawa, Billy W. Mangum, Gregory F. Strouse.

Online text: tsapps.nist.gov/publication/get_pdf.cfm?pub_id=100290

Experimental journal article published in 1997 and credited in print to G. T. Furukawa, B. W. Mangum and G. F. Strouse. The full names correspond to George T. Furukawa, Billy W. Mangum and Gregory F. Strouse. NIST hosts the article and its publication record.

Cited passages: Furukawa, Mangum and Strouse, Effects of different methods of preparation of ice mantles of triple point of water cells on the temporal behaviour of the triple-point temperatures (1997), Abstract, §1 and §§3.2–3.5: aged reference, inner melt, bridge readout, zero-power and hydrostatic corrections.

Online text: www.nist.gov/video/triple-point-cell

NIST demonstration description uploaded on 21 December 2016. The preparation description was inspected; video playback is not claimed.

Cited passages: Triple-Point Cell, preparation description, uploaded 21 December 2016.

Online text: web.mit.edu/10.213/oldpages/f99/diagrams/phase/gibbs/index.html

Institution-hosted discussion of the Gibbs phase rule in MIT 10.213 materials. No named author or publication date is inferred from the hosting path.

Cited passages: Gibbs Phase Rule, displayed nonreacting rule and pure-substance table; Gibbs Phase Rule, single-, two- and three-phase counts and final pressure–temperature diagram paragraphs; Gibbs Phase Rule, three-phase count and pressure–temperature diagram discussion.

Online text: www.vernier.com/manuals/dfs-bta/

Manufacturer instrument documentation issued by Vernier. No personal author or publication date is established.

Cited passages: Vernier, Dual-Range Force Sensor User Manual, Using the Product; Calibration; Specifications; How the Sensor Works; Compatibility Notes, note 1.

Online text: www2.oberlin.edu/physics/catalog/demonstrations/mech/thirdlaw.html

Oberlin College physics demonstration instructions for collision carts and force sensors. No named author or date is established. The source does not supply measured traces or prescribe a sampling rate.

Cited passages: Oberlin College, Collision Carts and Force Sensors, Apparatus, Description, and Notes: ranges, mounting, zeroing, attachments, and unequal-mass control.

By Isaac Newton.