Vainshelboim A . *, Korotkov K . **, Shigalev V . ***, Beljakov V . *** , Korenugin D . G . ***

  Part 2. Effect of Differing TEMPERATURE AND Humidity Levels on GDV response in human hair

*Aveda Corporation, Blaine, Minnesota USA; ** State University SPITMO, St. Petersburg, Russia; *** State Politechnical University, St. Petersburg, Russia

However, the hair swatches showed no significant decline in activity, as opposed to that shown by the samples from live subjects.

Results and Discussion

Experiment Introduction

Experiment 2

In the first part of our paper [1] an experimental data were presented on Observing the Behavioral r esponse of h uman h air to a Specific External Stimulus p hysical s eparation Using Dynamic Gas Discharge Visualization observed with Gas Discharge Visualization (GDV) analysis. The aim of this study was to see the response of GDV parameters of hair to change of humidity and temperature. Within this study three different types of experiments were conducted. The first type of experiment involved measurement of dynamic GDV response to in vitro hair during the cycling of humidity from 0% to 98% humidity at st andard temperature and barometric pressure. The second type of experiment involved long-term conditioning of hair at various relative humidit ies y levels , and measuring the respective GDV response at these various humidities . As in the first case, temperature and barometric pressure were held constant. And in the third type of experiment the temperature changed from 20 C 0 to 80 C 0 at the constant humidity 25%. Temperature of hair swatch was changed by heating with in-focused intensive light beam for the particular time with control by hromel-copel thermocouple with electronic transducer. The methodical approach was the same as in the previous publications.

In both cases, collection of hair and sample preparation were the same. In both sets, the same models were used.

Experimental results

A swatch of hair was collected from a live model, and was immediately placed in the sealed chamber containing the GDV setup at the elect rode at ambient temperature and humidity (humidity ? = 35%) and sealed within the chamber. Initi . ally Initially , the humidity within this chamber was 35%. Humidity was then decreased to 0% over a period of 3 hours at room temperature. Hair was kept at 0% for two hours. A GDV measurement was taken at this point . Humidity was then increased to 35%. Hair was kept at 35% for two hours. After two hours at 35%, another GDV measurement was taken. Hair The hair sample was left overnight at ? = 35%. In the morning first thing the another measurement was repeated taken at 35%. Variation Variation between these two measurements at 35% was consistently was less than 8%. Then humidity was increased to 39% and the hair sample was kept for two hours. After this dynamical Another GDV measurement was recorded done. . T

This This procedure was repeated for ? = 43.5 % ; 49 % ; 57 % ; 66 % ; 75 % ; 83 % ; 89.5 % ; 94.5 % and 98 %. % RH. It is known that hair fibers have a moisture regain of approximately 31%, which varies depending on the relative humidity and duration of exposure to that environment . The time required for equilibrium is generally recognized as 18 – 24 hours [2] . [Robbins , p 332]. A titanium cylinder has been used as a reference point, as this material does not absorb water from the environment ( fig . 1) .

The level of variation between repeatable measurements of the same sample at the same conditions is less than 8%. With this consideration w hen comparing the GDV parameter of intensity of fig.1 , no significant difference is seen except in humidity levels higher than 66%. This reduction of corona discharge is most likely due to ionization caused by atmospheric water molecules [Protasevich, 199 9 ] REF. KK [2] . Especially noteworthy is the similarity between the readings at 0% and at normal ambient conditions (30-70%) ; a signal was still detectable in the absence of bound water.

Relative GDV Area & Intensity vs. Humidity: Titanium Cylinder Human Hair

Expressed as a proportion: reading at 0% is divisor

f F igure x 12 . Shows parameters of Area and Intensity expressed as a proportion – value of the parameter at 0% is the divisor.

Figure 1 . Intensity of gas discharge images of human hair and metal cylinder , expressed as a proportion – value of the parameter at 0% is defined as 1.

Relative GDV Area vs. Humidity: Titanium Cylinder

Expressed as a proportion: reading at 0% is divisor

Figure. Humidity-dependent behavior of titanium cylinder. Shows GDV parameter of Area. “Up” indicates a reading taken while the humidity level was increasing; “Down” indicates a reading taken while the humidity levels were decreasing.

The similarity between the readings for the titanium cylinder and the hair samples indicates that the effect of humidity on the tested material is largely independent of the substrate [ Protasevich, 1999]. . Same effect we had for the dried old hair. [Ref email]. In addition, the effect that humidity has on the tested material in the normal range of humidity (30-70%) is within the abovementioned range of variations.

After these experiments were completed, the duration of exposure required to fully “ condition ” the hair - for its water-bonding surfaces to reach equilibrium to at specific relative humidity values - was investigated. It would therefore be logical to prolong periods of hair exposure to different humidit y levels . To explore this question, a A hair swatch was exposed to various humidity levels , including 0%, 35%, 60%, and 80% humidity , over a period of 80-120 hours at each level . Readings were taken every 20 – 24 hours, over a period of five days. When sample were exposed to humidity levels over a period of 80-120 hours, the results were similar to those above.

Increasing the duration of exposure to a constant humidity level did does not provide appreciably different data from than the previous above experiment. The consistency of the area measurements over several days indicates that the procedure of conditioning under different humidity levels has little effect . We can then determine that w ater absorption has little to do with changes in the GDV signal.

GDV signals in human hair were observed even in samples conditioned long-term at 0% humidity. These samples could be assumed to retain no bound water. The results from the above graphs show a distinct drop in activity as the humidity increases above 75%. This corresponds with previous research showing that the dielectric constant of hair, while steady at levels from 20-70% relative humidity, increases by a large factor at higher levels. [ Ref Odagiri-Shimizu, 1999 ] This has an effect on the GDV activity of hair, decreasing it at high humidity levels.

Therefore, one possible mechanism describing the transmission of these signals , that it is by means of bound molecules of water found in the hair , can be eliminated.

Changing the relative humidity of the hair samples within 0% - 60% produced a range of effect s that w ere not statistically distinguishable from each other . This suggests that the transmission of the EMF signals through the hair are not directly due to bound water absorbed by the substrate, but instead relies on the intrinsic structure of the hair.

Additionally, the profile of GDV –registered signals in human hair across the full range of humidity closely matches the profile of the control titanium cylinder. This indicates that the differences in readings at various humidity levels are due to the conditions of the atmosphere , rather than a difference in the substrate. The corona discharge occurs in the atmosp here surrounding the sample , and changing its humidity influences the ionization behavior of the discharge.

Temperature dependence was different for hair and metal reference cylinder. For the GDV image of metal cylinder the Area increased by 6% with heating from 20 C o to 80 C o , while the Intensity stayed constant. For hair strong increase both of Area and Intensity was detected (Fig. 2). The level of increase depended on the subject: for woman's, man's and dried hair the level of increase was different. At the moment we do not have enough data for any correlation between temperature dependence of hair and its properties.

Conclusions

Human hair exhibits GDV-measured activity that is not present in hair that has been separated from the body for a period of time. Cutting the hair from the head immediately results in a decline in this activity, and the majority of this decline takes place in the first 24 hours after cutting.

In every test subject, an immediate reaction to cutting was observed, using the GDV parameter of intensity. While the in vitro swatches underwent the same protocol of cutting under identical environmental conditions, the swatches' activity remained at constant levels after cutting . While further investigation of this phenomenon is needed, disruption of the GDV signal in the in vivo samples was not dependent on gross physical characteristics; nor was it observed on the in vitro , single-sourced hair . The GDV activity appear s to be due to electron flow that is specific to hair still attached to the body.

Fig. 2. Temperature dependence of Intensity of gas discharge images of swatch of fresh human hair and metal cylinder expressed as a proportion – value of the parameter at 20 C o is the divisor.

Due to the similar results in GDV measurements between samples that have been dried at 0% RH and those at ambient RH, it can be concluded that water molecules bound to the hair are not responsible for the transmission of electrons through the hair.

These results support the hypothesis of the transmission of signals between human hair and body, possibly dependent on the polypeptide composition of hai r, containing specific amino acids, notably cysteine, serine, and glutamic acid . [Robbins, p. 68] .

•  Vainshelboim A., Momoh K.S., Korotkov K., Shigalev V., Beljakov V. Observing the Behavioral Response of Human Hair to a Specific External Stimulus Physical Separation Using Dynamic Gas Discharge Visualization observed with Corona Discharge An a lysis . This issue.

•  Protasevich ET. Cold non-equilibrum plasma. Cambridge : Cambridge International Scientific Publishing. 1999.

•  Robbins, Clarence. Chemical and physical behavior of human hair. 3rd edition. New York : Springer 1994.