Development of a new photocatalytic oxidation air filter for aircraft cabin.

UNLABELLED: A new photocatalytic oxidation air filter (PCO unit) has been designed for aircraft cabin applications. The PCO unit is designed as a regenerable VOC removal system in order to improve the quality of the recirculated air entering the aircraft cabin. The PCO was designed to be a modular unit, with four UV lamps sandwiched between two interchangeable titanium dioxide coated panels. Performances of the PCO unit has been measured in a single pass mode test rig in order to show the ability of the unit to decrease the amount of VOCs (toluene, ethanol, and acetone) entering it (VOCs are fed separately), and in a multipass mode test rig in order to measure the ability of the unit to clean the air of an experimental room polluted with the same VOCs (fed separately). Triangular cell panels have been chosen instead of the wire mesh panels because they have higher efficiency. The efficiency of the PCO unit depends on the type of VOCs that challenges it, toluene being the most difficult one to oxidise. The efficiency of the PCO unit decreases when the air flow rate increases. The multipass mode test results show that the VOCs are oxidized but additional testing time would be necessary in order to show if they can be fully oxidized. The intermediate reaction products are mainly acetaldehyde and formaldehyde whose amount depends on the challenge VOC. The intermediate reaction products are also oxidized and additional testing time would be necessary in order to show if they can be fully oxidized. The development of this new photocatalytic air filter is still going on. PRACTICAL IMPLICATIONS: The VOC/odor removing adsorbers are available for only a small proportion of aircraft currently in service. The photocatalytic oxidation (PCO) technique has appeared to be a promising solution to odors problems met in aircraft. This article reports the test results of a new photocatalytic oxidation air filter (PCO unit) designed for aircraft cabin applications. The overall efficiency of the PCO unit is function of the compound (toluene, ethanol, and acetone) that challenges the unit and toluene appears to be the most difficult compound to oxidize. Test results have shown the influence of the design of the PCO unit, the air flow rate and the type of UV on the efficiency of the PCO unit. The results obtained in this study represent a first attempt on the way to design a filter for VOC removal in cabin aircraft applications. The PCO technique used by the tested prototype unit is able to partially oxidized the challenge VOCs but one has to be aware that some harmful intermediate reaction products (mainly formaldehyde and acetaldehyde) are produced during the oxidation process before being partially oxidized too.

[Coronary arteriography in recent myocardial infarct]. / L'artériographie coronaire au cours de l'infarctus du myocarde récent.

Sixty patients with a recent transmural acute myocardial infarction had seletive coronary arteriography carried out between the 7th and the 29th day (mean 17 +/- 2 days) after the onset of the condition. The anterior infarction (n = 25 cases) had a total obliteration in 36% of cases, and most often (64%) a stenosis of the anterior descending artery with an excellent distal bed (80%). The collateral circulation is often zero (76% of cases); 80% have adjacent lesions on the right coronary or circumflex artery, but 7 patients out of 25 would have been able to have a preventive bypass operation. The posterior infae lesions are often sited electively at the level of the artery of the S/A node or in the middle of the second vertical segment in the region of the right ventricular branch. Thus the infarct is the result of a complex lesion of the right coronary and circumflex arteries, because the latter is affected in three cases out of four. 63% of patients with a postero-inferior infarction have diffuse lesions, and 13 out of 35 could have had a preventive bypass procedure. This study shows: 1. That this investigation is well-tolerated after a recent infarction; 2. The high incidence (43%) of stenoses at the edge of the area of necrosed myocardium; 3. The importance of this investigation in finding the nearby lesions which are very frequently associated: in 33% of cases, preventive bypass would have possible.

[Relationships between pheochromocytoma and obstructive myocardiopathy. Apropos of a case]. / Relations entre phéochromocytome et myocardiopathie obstructive. A propos d'une observation

The authors report the case of a 45 year old man who presented with a combination of a phaechromocytoma and obstructive cardiomyopathy. They discuss the possible inter-relationships between hypertension, catecholamines, phaeochromocytoma, and outflow stenosis.

[Hemodynamic effects and effects on plasma renin activity of injectable acebutolol in arterial hypertension]. / Effets hémodynamiques et effets sur l'activité rénine plasmatique de l'acébutolol injectable dans l'hypertension artérielle

The purpose of the study was to determine the early haemodynamic effects of injectable acebutolol and to study in parallel the changes in plasma renin activity (P.R.A.) in 11 patients, most of whom were affected with labile arterial hypertension. The haemodynamic measurements and P.R.A. determinations were carried out before and 5 and 15 mn after very slow intravenous injection of 10 mg acebutolol. The results obtained under these conditions were as follows: 1) Decrease in cardiac index (I.C.). It was particularly significant after 5 mn, since the I.C. decreased from 4.43 to 3.75 1/mm (p less than .01). It was essentially due to a decrease in heart rate, that fell from 90.45 to 77 beats/mn (p less than .001), while stroke volume changed virtually not. 2) Decrease in blood pressure, more marked on systolic blood pressure (110 mm Hg after 15 mn as against 154 mm Hg before injection; p less than .001), associated with a decrease in left ventricular work (4.7 kgm/mn/m2 after 5 mn as against 6.2 kgm/mn/m2 before injection; p less than .001), without significant changes in total systemic arterial resistances. 3) Increase in diastolic pulmonary arterial pressure (10.4 mm Hg after 5 mn against 8.09 mm Hg before injection; p less than .001), testifying to a slight left ventricular myocardial depression. 4) Decrease in supine P.R.A. level (0.72 nanogram/1/mn after 5 mn as against 1.15 nanogram/1/min before injection; p less than .01). A significant correlation was found between this decrease in P.R.A. and that in I.C., testifying to a close parallelism between the inhibition of cardiac beta-1 receptors and that of the receptors involved in renine secretion. 5) The tolerance of injectable acebutolol appeared to us to be excellent.

[Aneurysms of the membranous septum. Apropos of 4 cases]. / Les anévrysmes du septum membraneux. A propos de quatre observations

Three cases of aneurysm of the membranous septum were diagnosed in vivo. The fourth case was discovered at post-mortem examination in a patient who had a conductive disorder. These four cases give us reason to review the anatomical, clinical, radiological and haemodynamic features of this condition.

[Modifications of contractility after left ventriculography. A new test in evaluation of myocardial function]. / Modifications de la contractilité après ventriculographie gauche. Un nouveau test d'évaluation de la fonction myocardique

The action of the contrast material over the various contractility indices was assessed five minutes after left ventriculography. There was an increase of the contractility index in normal subjects. On the contrary, in coronary patients, the contractility function remained unchanged or was depressed, related to the presence or not, of signs of cardiac failure. Depression of the various indices was noted in subjects with primary cardiomyopathy. After recalling the mechanism of action of the contrast products on the cardiovascular haemodynamic parameters, the following practical conclusions were drawn in relation with a series of 65 cases of coronary heart disease: the late diastolic left ventricular pressure remained lower than 20 mmHg after ventriculography in the subjects with a normal ejection fraction; it incraeased between 20 and 30 mmHg in most of the subjects with an ejection fraction ranging from 0.4 and 0.6, finally it was constantly found above 35 mmHg in the subjects with severely disturbed ventricular contraction with an ejection fraction lower than 0.4. These results underline the interest of this simple test, easy to perform, consisting in measuring the left ventricular late diastolic pressure before and 5 minutes after left ventriculography.