Pneumatic Theory Research Articles

The theory behind vessel length determination using gas flow rates and comparison between two pneumatic methods based on seven woody species.

In plants, xylem vessel length is important for long-distance water transport; however, the currently used methods for vessel length measurement are inconvenient and time-consuming. The recently developed semi-automated Pneumatron is a device based on the pneumatic theory that is similar to the air-injection method, and can rapidly estimate vessel length. Mean vessel length was compared between the Pneumatron and the air-injection method in seven woody species with a wide range of vessel lengths (2.3-78.7 cm). The results were consistent between the two methods, regardless of whether the same or different samples were used. The theory underlying the gas flow in vessels was improved and expanded, and compared to that underlying the water flow in order to better understand the pneumatic processes within a stem sample. Moreover, a new and simple equation for gas flow in vessels was derived based on the molar gas flow (mol s-1) rather than volume flow, because the former remains constant with distance throughout the stem axis. We strongly recommend using the Pneumatron in future studies owing to its low cost, convenience, rapidity, and simple operation. However, a number of potential issues need to be considered to avoid artifacts during measurements.

A Pneumatic Proportional Constant Flow Valve With Mechanical Feedback

To make the flow rate of a gas valve insensitive to changes in inlet pressure and to achieve proportional constant flow characteristics, a proportional constant flow valve is proposed, which is mechanically fed back by the pressure of the flowing gas itself. Using air as the source, the motion equation of the spool is established according to pneumatic theory. By means of the steady state equation, it is proved that the valve is insensitive to the change of inlet pressure compared with an ordinary proportional valve, and the optimization direction of the valve is analyzed. Based on Amesim software, the entire model of the pneumatic proportional constant flow valve is established, and the flow characteristic parameters of feedback holes with different diameters are obtained by numerical calculation. Subsequently, through overall simulation, we obtain the specific values of the optimization parameters. Finally, relevant experimental tests are conducted. The results show that the optimized proportional constant flow valve with mechanical feedback has a good proportional constant flow effect compared with the ordinary proportional flow valve.

Being ‘in Christ’ in the Letters of Paul.

Being ‘in Christ’ in the Letters of Paul.

Morův Spirit of Nature a Newtonův éter

The paper presents the notion of “Spirit of Nature” in Henry More and describes its position within More’s philosophical system. Through a thorough analysis, it tries to show in what respects it can be considered a scientific object (especially taking into account the goals of More’s natural philosophy) and in what respects it cannot. In the second part of this paper, More’s “Spirit of Nature” is compared to Newton’s various attempts at presenting a metaphysical cause of the force of gravity, using the similarities between the two to see this notorious problem of Newton scholarship in a new light. One thus sees that if Newton drew from Stoic and Neo-Platonic theories of aether or soul of the world, we need to fully acknowledge the fact that these substances were traditionally of a non-dualistic, half-corporeal, half-spiritual nature. Both More’s “Spirit of Nature” and Newton’s aether can thus be understood as different attempts at incorporating such a pneumatic theory into the framework of modern physics, as it was then being formed.

Research for Application of Save Energy Piston Valve for Water Pump Balance Control

This paper introduces new type of save energy piston valve for water pump balance control, which is save energy efficiency expert. This piston valve is designed by pneumatic theory, and drive power is delivered by air compressor or pressure air source in waterworks. Pressure air is lead into cavity of piston valve by transfer action of “two positions and five channels ” electromagnetic valve, then piston drive valve to open or close water pump. This piston valve has followed functions such as balance control action, avoiding refluence, zero flow open and close, accidental power stop for water hammer and son on. Application of this piston valve had proved saving energy to 3%.

An iatrochemist in Lower Canada: François Blanchet and his Research on medicine, or application of chemistry in medicine

Francois Blanchet holds a central place in the history of medicine in Lower Canada (now Quebec): a prime mover in the professionalization of French-Canadian physicians, Blanchet was also one of the first Canadians to have studied outside of Canada. While he was in New York, where he studied medicine at Columbia College, he published a book entitled Recherches sur la medecine ou application de la chimie a la medicine. The historiography of Canadian medicine frequently cites this book and presents it as one of the first Canadian medical publications but has not always explored its scientific content. This article therefore examines the medico-chemical aspects of Blanchet's work. Influenced by the Lavoisian revolution in chemistry, Blanchet elaborated a system where etiology and therapy rested on two new elements of nomenclature put forward by French chemists--oxygen and caloric. After examining Blanchet's iatrochemical system, this article compared Recherches sur la medecine with contemporaneous American and European publications in medicine which were themselves inspired by the pneumatic theory of French chemists.

CT-scanning of ancient Greenlandic Inuit temporal bones.

Additional morphological evidence of former infectious middle ear disease (IMED) was found by CT-scanning in 5 of 6 Greenlandic Inuit crania strongly suspected for former IMED due to earlier examination revealing either bilateral hypocellularity or asymmetry of the pneumatized area of the temporal bones. The CT-scans showed sclerosing and obliteration of the air cells and even destruction of the cellular septae, and a high degree of irregularity of the cells. Sclerosing of the surrounding bone tissue was also found. The findings in one cranium were dubious and could both be regarded as a congenital malformation or an infection in infanthood. CT-scan confirms and even adds to the results of conventional X-ray of temporal bones making hypotheses of paleopathology more reliable. The findings also support the environmental theory of pneumatization of the air cell system in the temporal bones.

Effect of Middle Ear Infection on Pneumatization and Growth of the Mastoid Process

The intention of this experiment was to investigate whether anatomical variations of the temporal bone such as low middle fossa dura, anterior position of the sigmoid sinus or small mastoid process, which are often seen at surgery in cholesteatoma patients, are caused by inflammation in early childhood. In 7 pigs, 1.5 ml paraffin liquid were instilled into the left tympanic cavity 2 or 7 days after birth in order to produce inflammation of the middle ear and tubal dysfunction. After six and a half months the length and area of the mastoid process were significantly smaller on the left instilled side than on the right, normal side. In all cases there was remarkable hypocellularity and increased thickness of the cortical bone strongly supporting the environmental theory of pneumatization that inflammation suppresses the pneumatization process and growth of the mastoid process.

The pneumatic theory of female Warao herbalists

Among the Warao Indians of eastern Venezuela herbalism is a nonritualized occupation practiced by women. As a medical practice herbalism complements the ritual occupation of shamanism practiced by men. But whereas Warao herbalism is governed by a theory of supernatural causation of illness mystically brought about by contagion, Warao shamanism is a theory of supernatural causation of illness attributed to spirit aggression and object intrusion. According to herbalist theory, pathogenesis results from odoriferous agents that invade the body regions (head, thorax, abdomen) of the victim. Here they expand in the form of fetid gas, producing clinical symptoms by affecting the organs and the soul of a particular region. Treatment of disease by herbal medicines is allopathic. Upon administration the remedy transforms into an aromatic gas which is denser, hence more powerful, than the noxius gas. This enables the therapeutic air to displace the pathogenic air. A cure is achieved after both gases have left the body, returning the patient to an inodorous state. This study presents physical, cultural and ideational data as they relate to health, disease and herbal medicine among the Warao. The status and role of the female herbalist are described. Warao herbal curers make use of more than 100 plant species from which they prepare 259 remedies. The collecting and processing of materia medica conform to a meticulous protocol which is transmitted from mother to daughter through informal methods of training. Treatment of ‘symptom-oriented’ diseases is effected through the administration of ablutants, ingestants and/or inhalants. While practicing medicine in a nonritual way Warao herbalists are nevertheless directly aligned with the Mother of the Forest. As a personage of the Warao pantheon she is the mistress of the trees and ultimate owner of herbal medicines. Tree people are anthropomorph and the body/tree, people/forest metaphors connote the compatibility of the Warao as potential patients and the ‘forest people’ as providers of medicinal herbs.

Secretory otitis and pneumatization of the mastoid process: Sexual differences in the size of mastoid cell system

Seventy-nine children (41 girls and 38 boys) were subjected to tympanometry nine times from the age of 2 years to the age of 7 years. In addition, otoscopy was performed, and the children's otologic history was recorded. At the age of 7 years, roentgenograms were taken of the mastoid process, and the area of the air cell system was measured by planimetry. The smallest cell systems were found in ears with a history of secretory otitis or chronic tubal dysfunction--a finding which supports the environmental theory of pneumatization. Boys had significantly smaller cell systems (mean, 7.5 cm2; range, 2.75-16.75) than girls (mean, 9.0 cm2; range, 2.5-15.7). The degree of middle ear pathology was significantly higher in boys, as expressed by the total tympanometric score. The more pronounced middle ear pathology in boys was caused by more frequent and severe episodes of upper respiratory tract infections. The analysis of the sex differences provides substantial support of the environmental theory of pneumatization, since upper respiratory tract infections in childhood often cause tubal dysfunction and secretory otitis, conditions that disturb the normal process of pneumatization and result in hypocellularity.

Mastoid pneumatization. Evidence of the environmental theory.

Forty-one randomized, otherwise healthy children with tympanometry were observed from birth until the age of 6 years. At a total of 13 trials, tympanometry and otoscopy were performed. The tympanometric profile was correlated to the size of the mastoid air cell system, as determined by planimetric measurement of roentgenograms taken at age 6 years. There was a notable correlation between the size of the cell system and the tympanometric profile. Thus, the least affected ears with mostly normal or slightly abnormal tympanometry had considerably larger cell systems than the most affected ears with secretory otitis and tubal dysfunction. The findings support the environmental theory of pneumatization.

Mastoid pneumatization in secretory otitis. Further support for the environmental theory.

A cohort of 222 randomized healthy children was followed with 7 repetitive tympanometries from the age of 4 to the age of 7 years. At the age of 8, the size of the mastoid air cell system in 17 children with normal tympanometric profiles and in 27 children with pathological tympanometric profiles, indicating secretory otitis, was examined by planimetry. The air cell system was significantly larger in the normal group than in the abnormal group, strongly indicating the validity of the environmental theory of pneumatization.

Mastoid Pneumatization

The hereditary theory of pneumatization is based on the fact that the size of mastoid air cells in normal adults almost follows a Gaussian distribution. In this work it was shown that middle ear mucosa in children, when the pneumatization process takes place, is exposed to pathological stimuli of varying degrees of severity and duration. This may have a considerable effect on the process of pneumatization, the end result of which may be a large variation in the size of the cellular system.

Voluntary Control of ‘Involuntary’ Functions: The Approach of the Stoics

ABSTRACTThe Stoics expressed great concern about emotion related psychophysiological phenomena as pathological states of body and spirit. They outlined procedures through which all bodily functions could be brought under voluntary control. The Pneumatist School of Medicine of the first century A.D. adopted these philosophical convictions and instituted them in their diagnostic and treatment techniques for psychosomatic disorders. Pneumatic theory, and its application in this context, is described. How easy it is to repel and to wipe away every impression which is troublesome or unsuitable, and immediately to be in all tranquility…. Nature has not so mingled the intelligence with the composition of the body, as not to have allowed thee the power of circumscribing thyself and of bringing under submission to thyself all that is thy own.Marcus Aurelius

On Pathogenesis of Bronchiectasis and Emphysema

Based on the theory of pneumatization, which originated in the study on the structure and reaction of the mastoid cells, a following new theory on the pathogenesis of bronchiectasis and emphysema is experimentally and theoretically proposed.Both bronchiectasis and emphysema can be recognized as a repneumatization process following apneumatosis. Bronchiectasis is a manifestation of repneumatization of the pulmonary alveolar system under the condition of severe apneumatosis with organization, and emphysema is that of repneumatization under the condition of mild apneumatosis, in which alveolar epithelial cells are still remaining. In the former, reactive proliferation of the lung tissue occurs in the peripheral portion of the bronchioles, and in the latter, reactive proliferation takes a form of alveolar enlargement. Both are manifestations of active repneumatization in the lung, and the morphologic difference comes only from the difference of the apneumatic condition in the lung. Senile emphysema, however, is different from these secondary changes and it is due to physiological alveolar proliferation in the lung of the aged.Currently, bronchiectasis and emphysema are considered as having two different pathogeneses, and the morphologic alteration is understood only by passive mechanism of the lung tissue. Challenging to these contemporary theories, we would like to introduce a new idea of active pneumatization as the pathogenesis of both bronchiectasis and emphysema.

Mastoid Pneumatization and Normal Curve Distribution

The normal variant theory of pneumatization is based on my (1940) findings in groups representative of the population showing a size variation of the mastoid air cell system in adults ranging in an unbroken sequence of sizes from 0 cm2 to about 30 cm2 and a distribution of the various sizes in fair conformity to a normal curve.These findings alone, however, although confirmed by several subsequent authors, cannot definitely “prove” that all sizes of the mastoid air cell system are normal variants, i.e. are anatomically caused. The theory could, however, be substantiated by further (1945) investigations showing that hereditary factors play the main part for the growth into final sizes of the mastoid air cell system. If these findings, too, were confirmed by other authors by investigating the importance of heredity for instance in chickens where the pneumatization shows a corresponding variation of size, it would serve as a “close to a final proof” for the normal variant theory.It is analyzed why the sheer existence in the recordings of: (1) 0 cm2 values representing the lowest size value in the range of variation, (2) a slight over-representation of 0 cm2 values together with (3) statistically computed negative values in the distribution curve cannot be claimed to be a base for arguments against the normal variant theory and its claim that all sizes recorded, even those in ears with a simultaneously existing otitis media of any type, are in principle anatomically caused.

Societies and Academies

PARIS Academy of Sciences, September 6.—M. Émile Blanchard in the chair.—On presenting to the Academy a copy of a volume issued on the occasion of M. Chevreul's centenary, August 31, 1886, M. Berthelot remarked that this seemed a suitable occasion for reviving the old custom of celebrating Academic solemnities by the publication of special scientific and literary essays. The present work, in the preparation of which MM. Ch. Richet, G. Pouchet, E. Grimaux, E. Gautier, Dujardin-Beaumetz, E. Demarçay, and Berthelot had co-operated, has been executed with rare taste and care by the editor, M. Alcan, and by him dedicated to M. Chevreul on behalf of himself and his fellow-contributors.—Fluorescence of the compounds of manganese subjected to electric effluvium in vacuum, by M. Lecoq de Boisbaudran. In the experiments here described the author has aimed especially at determining the effects due to the presence of manganese. The fluorescence of some of its compounds is an extremely sensitive reaction, by means of which imponderable traces of this metal may be detected in natural or artificial substances that might otherwise be supposed free from its presence.—Paralytic ataxy of the heart, by M. Mariano Semmola. In this communication the author resumes the results of his further observations on cardiac disorders, already reported in the Transactions of the International Medical Congress, seventh session, London, August 1881.—Remarks in connection with three Italian essays submitted to the Academy, by M. Govi. The first of these papers deals with an episode in the life of Galileo, showing that the hostility of the Jesuits to the Florentine philosopher was not due to the letter addressed by him to his brother in 1606, announcing the expulsion of the Order from Venice. The second describes a curious plano-convex lens executed by Torricelli some time between 1644 and 1647, and recently discovered in the Cabinet of Physics attached to the University of Naples. The third refers to an unpublished letter written by Volta in 1785 on Lavoisier's pneumatic theory, which, although not accepted without reservations, is defended against the assumptions of an Englishman named Lubbock, who had essayed to transform oxygen into a new principle called by him the “sorbile principle.”—On certain differential equations of the first order, by M. Roger Liouville. It is shown that the differential equation—