KAYABA TECHNICAL REVIEW No. 66 APR. 2023

Editorial

Thoughts on the Degradation of Oil
DEGUCHI Mikio*

1.

Introduction
The author has been involved in a joint research project with KYB Corporation for several years. The projectis intended to develop a sensor that can detect changes in
the properties of oil caused by its degradation by using a
low-cost simple device. Oil is used in mechanical equipment for various purposes including lubrication, cooling,
electrical insulation, and rust prevention. It is also widelyused as a working fluid in hydraulic systems virtually everywhere in the world. However, oil gradually changes inproperty with time as the systems are operated as seen in
the familiar example where the engine oil used in automobiles gets black little by little as the mileage increases.
Such changes generally progress unfavorably. Therefore,
this is called "degradation".
Oil degradation is mainly caused by oxidation andcontamination. The degradation appears as changes invarious physical parameters.1)-6) The degree of oxidation
can be evaluated by total acid value but we are focusedon "permittivity", which is an electrical parameter that
may be relatively highly correlated with total oxidation.
The permittivity of a material can be determined as thecapacitance (a parameter indicating how easily the material can charge electricity) between two electrodes filledwith the material. Capacitance measurement itself is oneof the basic electrical measurement techniques and may
be carried out using various methods. In fact, there is sufficient space for exploring an appropriate method for detecting changes in oil properties from various angles.
This paper briefly introduces our related efforts and describes my various thoughts about the word "degradation" of oil.
2.

What is Permittivity?
The “permittivity” of a material can be plainly described as how easily the material can be electricallydrawn. Electricity borne by an object is called "electriccharge". Electric charge can be positive (+) or negative(-). It is well known that like charges (positive charges ornegative charges) repel each other and unlike charges*

Professor emeritus, National Institute of Technology KOSEN,
Niihama College(positive and negative charges) attract each other. All
matter consists of elements that are combinations of atoms as a basic unit. Each atom includes a positively
charged nucleus surrounded by negatively charged electrons. In other words, matter contains countless positive
and negative charges. Normally, matter has the sameamount of positive and negative charges. The center ofgravity of positive charges is aligned with that of negative charges. These two types of charges are evenly distributed in the matter as a whole.
When matter is filled between two electrodes and applied with a voltage, the positive charges in the matterare repelled by the positive electrode and attracted by thenegative electrode. The negative charges are applied witha force in the opposite direction. As a result, the center ofgravity of the positive charges in the matter is misalignedwith that of the negative charges. This is called "polarization". Thus, permittivity is a parameter indicating howeasily this polarization takes place.
There are several possible causes of polarization. One
is that the electron cloud surrounding the nucleus of each
atom is attracted by the positive side to cause displacement. This is called electron polarization, which is a phenomenon that always takes place in all matter as long as
matter consists of atoms. Some kinds of matter consist of
atoms that are divided into positive and negative ions andare bound together by attractive forces between the positive and negative ions. In this case, if a force is applied tothe positive and negative ions in opposite directions toeach other, the ions each move from a position of equilibrium in the opposite direction, resulting in a positional
difference in the center of gravity between the positive
and negative charges. This is called ionic or atomic polarization.
Some other kinds of matter originally consist of molecules in which the center of gravity of their positive
charges is dislocated from that of their negative charges.
Molecules that have originally been polarized are called"permanent dipoles". Matter consisting of permanent dipoles, when viewed as a whole, are not particularly biased in terms of polarity, because the dipoles are usuallyoriented at random. However, when the positive/negativepoles are applied with a force in the opposite direction,―3―

Thoughts on the Degradation of Oil

the dipoles are aligned in a direction parallel with theforce. As a result, the matter as a whole is polarized. Thisis called orientation polarization.
It can be said that the majority of molecules constituting matter consist of permanent dipoles. One typical andfamiliar example is water molecules. A water moleculeconsists of two hydrogen (H) atoms and one oxygen (O)atom. Hydrogen is assigned the atomic number 1, whichmeans that it has only one electron. This electron is used
to bond to the oxygen atom. This uncovers the positive
charge of the nucleus (proton) of the hydrogen atoms to
make them positive and the oxygen atom negative. The
two hydrogen atoms and the oxygen atom are not aligned
in a line but bonded together at an angle of 104.5°. Thismeans that the center of gravity of the positive charge isdislocated from that of the negative one. Therefore, watershows a notably high permittivity among liquids.
3.

Detecting Minute Changes in Permittivity
The capacitance between two electrodes is proportional
to the permittivity of the insulation between the electrodes. Any change (increase) in permittivity due to oil
degradation is as small as several percent at most, although it depends on the extent of the degradation. Furthermore, the electrodes of the sensor only show a small
capacitance themselves because the sensor cannot be solarge. So, it is necessary to detect tiny changes in such asmall value. These minute changes in permittivity may
be detected in several ways.
In general, when you try to measure a physical quantity using an electronic technique, you always end up measuring the magnitude of the target quantity in units ofvoltage or time. A challenge you must eventually overcome is how you can practically convert the magnitude
of capacitance into a voltage or time.
For example, it is useful to remember that the voltage
between two electrodes can be determined by dividing
the amount of charges accumulated between the electrodes by the capacitance between the electrodes. Measuring the voltage between the electrodes when a certain
amount of charges is present there will give the capacitance. To accumulate a certain amount of charges between the electrodes, you can just supply a certain
amount of current for a certain time. If the current has aknown fixed value, you may either supply the current fora certain time to measure the voltage of the charged electrodes or measure the time you need to complete thecharging. Anyway, the rate of change in capacitance isvery small and is similar to the rate of change of the measurement indicator. When trying to detect any minutechange, the measurement performance directly depends
on how you can suppress unavoidable noise to ensure an
appropriate signal-to-noise (S/N) ratio.
To resolve this challenge, a device should be preparedthat can convert minute changes in capacitance into muchlarger changes in another physical quantity. One of themeans to implement this is to make use of “resonance”.
Resonance refers to a phenomenon in which a systemwith a natural frequency (a resonance frequency) is excited at a frequency close to its natural frequency to vibrate with a large amplitude even with weak excitation.
In an electric circuit, resonance may occur with a combination of capacitance and “inductance”, which constitutethe two major parameters of electromagnetism. Inductance is normally implemented by a coil. A coil is a spiralconductor wrapped around any core. Since capacitance isrepresented by the letter C and inductance by the letter L,
resonance with capacitance and inductance is generally
called "LC resonance".
When resonance occurs, the phase relationship between the signal exciting the resonance and the vibration
caused by the excitation substantially changes around theresonance frequency. The phase is a quantity indicating
the timing at which the vibration swings in whichever direction. Therefore, when phase differences are plottedwith the horizontal-axis showing frequency and the vertical-axis showing the phase difference between the exciting signal and the vibration caused by the signal, thecurves (representing the phase characteristics) show asteep slope around the resonance frequency. On the other
hand, the resonance frequency changes as the capacitancechanges. With the frequency of the exciting signal kept at
a fixed value close to the resonance frequency, any minute change in resonance frequency can be expanded andFig. 1	Principle that a capacitance change is expanded to achange in phase difference and how it is observed―4―KAYABA TECHNICAL REVIEW No. 66 APR. 2023

captured as a phase difference because of the steep slopeof the curves (Fig. 1).
To enable sensitive detection of changes in capacitanceusing this method, it is desirable that the phase characteristics curve has a slope as steep as possible at the resonance frequency. When inductance is usually implemented by a coil, however, the coil does not necessarily havecomponents only for inductance, but also those for winding resistance or capacitance between the windings,
which can reduce the sharpness of the resonance. Another challenge is that the magnetic field generated by a current flowing through the coil is always expanded to thesurroundings because of its inherent nature, leading to an
unavoidable problem of interference with the surroundings.
To resolve these problems, we use an electronic circuit
to implement the characteristics equivalent to those of
the inductance usually implemented by the coil.7) This
does not mean using special electronic devices but only a
combination of generally available devices. This circuit
is called a General Impedance Converter (GIC) and canvirtually convert capacitance into inductance. In the sensor we are developing, we can cause LC resonance totake place between the capacitance of the sensor electrodes and the equivalent inductance with GIC, thereby
enabling sensitive detection of very minute changes inpermittivity caused by changes in oil property. The GIC
thus features the excellent benefit that the whole device
can be set up only with general materials at low costwithout using special components.
4.

Consideration of Oil Degradation
Then, why does the permittivity of oil change (increase) when the oil degrades? One major factor of oil
degradation or change in material properties is the oxidation of oil molecules. In other words, the question is why
the permittivity of oil changes when the oil molecules areoxidized.
An oil basically consists of a number of combinationsof carbon (C) atoms and hydrogen (H) atoms. Unlike water molecules, oil molecules are not permanent dipoles
themselves and do not have polarity. This is one of thereasons why water and oil cannot be mixed.
When oil molecules are bonded with oxygen atoms
due to oxidation, however, the parts of the oil moleculesthat are bonded with oxygen atoms will be charged negative. This is because oxygen is located around the top
right corner of the periodic table, which means that its atoms have relatively high electronegativity. As a result,the oil molecules will be polarized. With this acting as anadditional factor of orientation polarization, the oil molecules will increase in permittivity as a whole.
There are literally many kinds of oil. I find it somewhat strange that countless types of oil are basicallymade from only two elements: C and H. Incidentally, acomputer program is similar to oil in that it also consistsof numerous combinations of two types of elements: zero(0) and one (1). Moreover, it is well known that the DNA
information of living organisms consists of a sequence offour kinds of bases: adenine (A), guanine (G), thymine(T), and cytosine (C). In fact, these bases can only generate two types of pairs: A-T and G-C. So, the DNA information also consists of only these two patterns of basesequence. In short, all things existing in the world consistof a few or limited number of types of elements. Theircharacteristics or differences are implemented by numerous combinations of these elements.
In a computer program, 0 and 1 when alone only givethe information that they are present there. Then, combining 0s and 1s in a series can represent a meaning as anumber or a command. The relationship between the
combination and the meaning is not fixed or certain. In
language for instance, Japanese is expressed by a combination of 50 notes and English by combinations from a
26-letter alphabet. Even the sound of an identical combination of "a" and "i" may indicate "love" in Japanese or"I" in English.
As human genome analysis has progressed and genediagnosis technology has advanced, it has become possible to learn which specific diseases you are likely to suffer from in future by examining your DNA. This meansthat you are now able to understand the meaning of abase sequence of A-T and G-C just by reading it. But I
wonder what links the base sequence with its meaning tobegin with.
The mechanism by which oil permittivity increases
with oxidation is as described above. However, whatgave oxygen atoms the property of being likely to be
negatively charged in the first place? Of course, this isbecause oxygen is located around the top right corner ofthe periodic table, but why do elements located in the top
right corner of the periodic table have higher electronegativity? This can be explained through calculation of theelectron orbit of atoms based on quantum mechanics as
you know, but why are electrons negatively charged to
begin with? When you pursue the answer to these questions in this way, you may finally reach a point where nobody can explain what it is all about.
A discipline that pursues the source of matter is particle physics. According to theory, an atom can be divided
into quarks, leptons and other elemental particles thathave different characteristics. However, nobody can explain why those elemental particles have such characteristics. Different combinations of these elemental particles
can constitute various types of atoms or matter, but nobody can explain why a specific combination of the elemental particles forms a specific material or generates theunique property of the material. A familiar example may
be metallic elements. The metal with the atomic number
26 is iron and that with the atomic number 29 copper.
Iron and copper have obviously different properties. How
can you explain the difference in property between the―5―Thoughts on the Degradation of Oil

two metals with different atomic numbers? How could
you describe the reason why the element with the atomic
number 26 has the property of "iron", not that of "copper"?
I teach my students computer programming. I insistently tell them to always put comments on programs
they are writing. The term comment here means words tobe added to the relevant parts of a program to explain
what is processed in the parts. Comments are made withwords describing, for example, what a specific variable
here expresses or the meaning of a specific calculation
written there. By putting comments on your program,you can re-organize ideas in your mind, being moreaware of errors. During writing, you may certainly feelOK with your program while you are thinking in various
ways for the program. With no comments, however, you
may often forget what made you write this part of the
program in this way after a while. In some cases, you
might even forget the fact that you wrote the program
yourself.
In a computer program in which each line comes withadequate comments, you can ideally read the comments
like a series of text describing what the program is processing. In other words, making a program is comparable
to writing a paper, as I always tell my students. A program written with alphanumeric characters and mathematical expressions is practically the same as language.
Processes of programs can be expressed in words. Machine-level instructions of computer programs consist of
combinations of 0s and 1s. Various patterns of a series of
0s and 1s are connected to meaning indicated by theircorresponding words.
A specific sequence of 0s and 1s could be reproducedby randomly putting 0s and 1s together. However, such asequence is made by chance and does not have any specific meaning. For computers, programmers intentionallycreate a pattern of 0s and 1s to represent the meaning of
the program. By using the means of different combinations of elements, programmers can express their intention.
As mentioned above, is it known that base sequencesof DNA have their own meaning and the combination including 26 protons, and 26 electrons indicates an element
having the properties of a metal called "iron". These are
the facts in the real world. Any combinations made bychance should not have any meaning. If such a combination has a meaning, this is contradictory to the assumption that the combination was made by chance. Given
that the words "by chance" or "randomly" denote that athing takes place with no reason or no cause-and-effectrelation, evolutionism is an incoherent theory in thissense.
Anything with meaning should involve an entity who
has given the meaning as in computer programs that always involve their programmer. The entity who has given
the meaning must be a being with intelligence as in the

programmer who exercised their wits to create the program. The "meaning" of things is usually expressed by"words". Let me here collectively call "meaning" that can
not necessarily be expressed by voice or text (so-calledlanguage) "words". Without these "words", all matter inthis world is just random assemblies of atoms and molecules.
The Bible says, "In the beginning was the Word". The
beginning of the Bible also includes the phrase: "In the
beginning God created the heavens and the earth". In Japan where Bible-based philosophy has seldom been proliferated in the local culture, the term "God" (Kami inJapanese) may remind people of somewhat "cheap"
words such as Kamiwaza (literally meaning acts of God)or Kamitaiou (super-excellent response). God in the Bible in turn refers to the Creator. The famous phrase "In
the beginning was the Word" is followed by "and theWord was with God, and the Word was God". Namely,
what created heaven and earth (the Creator) is the Word
itself. The Bible declares that the meaning of everythingcan be sourced to the Word, that is, God.
Even if the base sequence of DNA accidentally represents the DNA pattern of human beings, no living humanbeing could have been created without the “Word” of"life". I heard that 23 types of amino acids were found inasteroid samples brought back by the Japanese spaceprobe Hayabusa. Amino acids are just a small part of thecomponents of the human body. Without activation of aprogram (i.e., words) to select and combine the necessary
parts (levorotatory amino acids), no human body can becreated. Even if a human body could be created by thismethod, it would just be a physical object called a humanbody without "life" breathed in.
People, particularly Japanese who have grown up witheducation heavily centered in Evolutionism, usually haveno idea about the Creator. This is noted as "original sin"by the Bible. However, the Bible says, "God saw everything that he had made, and behold, it was very good".
What was very good when God created heaven and earthchanged, which means that everything tended to getworse. When oil changes in property due to oxidation,
the phrase of the Bible is elicited as the "degradation" ofoil.
The Bible also says, God created man in “his own image". In other words, man was created to concretely express how wonderful the wisdom of God is and how glorious the nature of God is. This can explain the decisivedifferences between human beings and other animals thatcan obviously be recognized in the real world. Some species of plant have beautiful flowers. They may come into
flower for the purpose of attracting insects for easier pollination. But, if that is the only purpose, do they have tobe decorated with those petals that all differ in color, pattern and shape? We feel a sense of beauty when we see
flowers. This is because we are what God created in his
own image. Is there any other reason?

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KAYABA TECHNICAL REVIEW No. 66 APR. 2023

There is one thing that I have long doubted. Music, especially Western music, may be played in a major scale
or in a minor scale. Music played in a major scale generally sounds bright and cheerful while that played in a minor key sounds depressing or sorrowful. The only difference in main chords between the major and minor scales
is the third note, i.e., half-tone higher or not. I wonder
why these notes sound cheerful or sorrowful just byslightly changing the note pattern. We, as human beings,
have been connected to a program (words) that can makeus have such specific feelings in response to particularpatterns of notes. I cannot understand this in any otherway. We can be moved by or feel beauty from a piece ofmusic because we were created by God in his own image. Is there any other reason?
We, who used to be "very good" in the beginning, became unaware of the Creator because of our own "sin".
However, the Creator had known very well from the beginning that we would become so. We do not have thecapability of making amends for our own "sin". The Bible says, "the wages of sin is death". We were separated
from the Creator because of “sin”. As a result, our body"deteriorates" with time and eventually dies. We cannot
do anything about this fate ourselves. Then, the Creator
prepared an astonishing plan to resolve our fate. That is,behold, he planned to come to the earth as a human being, and to die as a scapegoat for us. This was implemented by Jesus Christ about two thousand years ago.
Furthermore, he died by Crucifixion on a cross, which
was probably one of the most barbaric ways of dying.
Still, the death was beyond his death as he was the Creator. He still exists with the phrase, "I am who I am".
Apostle John, who directly saw Jesus Christ and lived
together with him for a while, wrote in the gospel-book,"For God so loved the world that he gave his
one and only Son, that whoever believes in him
shall not perish but have eternal life".
Of course, the only Son here means Jesus Christ himself.
John also wrote in the letter: "Whoever does notlove does not know God, because God is love.
This is how God showed his love among us:
He sent his one and only Son into the world that
we might live through him.
This is love: not that we loved God, but that heloved us and sent his Son as an atoning sacrifice for our sins".
In other words, man was created by God "in his own image" to concretely express "God is love" as a visible form
to all.
If you believe in Evolutionism assuming that God is
nowhere, the oil should change in property with time asyou use it, and amino acids should be generated at somepoint in time, leading in the end to the birth of life. You
may believe that oil "evolves", not "deteriorates". All
materials necessary to make up amino acids are avail-able: C and H contained in oil and O and N available in
the air. Then, assuming that life was created by chancefrom these materials, does that life-form have “love” onearth?

References
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2) FURUMOTO Keizi: "The Oxidation Properties of Non-Additive Lubricating Oils", Journal of the Marine Engineering Society in Japan, Vol.19 (1984)，pp. 590-596.
3) HONDA Tomomi: "Deterioration Diagnosis and Inspection
Technology for the Lubricating Oil", Journal of the Japan Society for Precision Engineering, Vol.75 (2009), pp. 359-362.
4) C.T. DERVOS, et al.: "A Complex Permittivity Based Sensor
for the Electrical Characterization of High-Voltage Transformer
Oils", Sensors Vol. 5 (2005)，pp. 302-316.
5) A.T. PEREZ and M. HANDFIELD: "Low-Cost Oil Quality
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7) M . DEGUCHI: "A simple method for detecting very smallchanges in capacitance or inductance", Microelectronics Journal―7―

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