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In this study, we investigated the beneficial properties of ZnO nanowires grown via a MOCVD (Metal Organic Chemical Vapor Deposition) process for the photocatalytic treatment of a solution containing seven xenobiotics that are commonly found in waste or surface water. A physicochemical characterization of the ZnO nanowires was performed to highlight the advantages of the high-temperature gas-phase MOCVD process for the synthesis of photocatalytic ZnO materials. In addition, the photocatalytic degradation of carbamazepine, diclofenac, lidocaine, metoprolol, propranolol, sulfadimidine and atenolol was studied for the first time using a one-step experiment under a low power 365 nm UV light (2.28 mW cm −2 ). We determined the fast photodegradation kinetics of all of the xenobiotics present in the solution. These results support the use of photocatalytic methods for the removal and degradation of xenobiotics.

Human activity results in the production of a wide range of pollutants that can enter the water cycle through stormwater or wastewater. Among others, heavy metals are still detected in high concentrations around urban areas and their impact on aquatic organisms is of major concern. In this study, we propose to use a substance flow analysis as a tool for heavy metals management in urban areas. We illustrate the approach with the case of copper in Lausanne, Switzerland. The results show that around 1,500 kg of copper enter the aquatic compartment yearly. This amount contributes to sediment enrichment, which may pose a long-term risk for benthic organisms. The major sources of copper in receiving surface water are roofs and catenaries of trolleybuses. They represent 75% of the total input of copper into the urban water system. Actions to reduce copper pollution should therefore focus on these sources. Substance flow analysis also highlights that copper enters surface water mainly during rain events, i.e., without passing through any treatment procedure. A reduction in pollution could also be achieved by improving stormwater management. In conclusion, the study showed that substance flow analysis is a very effective tool for sustainable urban water management.

Misconceptions about disasters and their social and health consequences remain prevalent despite considerable research evidence to the contrary. Eight such myths and their factual counterparts were reviewed in a classic report on the public health impact of disasters by Claude de Ville de Goyet entitled, The Role of WHO in Disaster Management: Relief, Rehabilitation, and Reconstruction (Geneva, World Health Organization, 1991), and two additional myths and facts were added by Pan American Health Organization.In this article, we reconsider these myths and facts in relation to Hurricane Katrina, with particular emphasis on psychosocial needs and behaviors, based on data gleaned from scientific sources as well as printed and electronic media reports. The review suggests that preparedness plans for disasters involving forced mass evacuation and resettlement should place a high priority on keeping families together—and even entire neighborhoods, where possible—so as to preserve the familiar and thereby minimize the adverse effects of separation and major dislocation on mental and physical health.

Le Fascicule 70 du Cctg – Titre I, en application depuis un peu plus de deux annees, a permis par le biais de sa revision d’ameliorer le contenu technique du fascicule anterieur, mais surtout d’imprimer un elan nouveau a son application dans les domaines de la qualite et de la durabilite des reseaux.Cette demarche a consiste a integrer notamment les nombreux retours d’experiences des annees anterieures, d’y associer les concepts developpes dans le cadre des chartes de qualite et de se referer aux demarches qualite existantes dans l’execution des travaux par le biais des manuels d’assurance qualite et des plans d’assurance de la qualite, ainsi que le cadre des controles prealables a la reception en se referant aux demarches d’accreditations proposees par le Cofrac.Le groupe de travail « Fiabilite des reseaux » de l’Astee a tout naturellement participe a l’ensemble de ces actions, en etant present au sein de la commission de revision du Fascicule 70 d’une part, en assurant l’animation du sousgroupe de travail lie a la reception des reseaux, et d’autre part en elaborant les referentiels d’accreditation Cofrac ainsi que le guide pratique d’application du Fascicule 70.Nous developpons dans cette communication l’esprit et le contenu de deux documents essentiels destines a garantir la perennite des ouvrages d’assainissement, l’un permettant une comprehension plus pedagogique du CCTG Travaux (Guide d’application du Fascicule 70), l’autre destine a reactualiser les referentiels techniques en matiere de controle dans le domaine des reseaux permettant d’accompagner les organismes de controle dans une demarche d’accreditation, assuree par le Cofrac. La premiere partie du document illustrera la necessite et l’importance des guides d’accreditation, veritables pieces maitresses, dans le processus d’evaluation des organismes de controle et dans la reconnaissance de leurs competences.La seconde partie, precisera le contenu du guide d’application du Fascicule 70 qui se veut avant tout un outil pedagogique et pratique offrant un eclairage precis et detaille des differents chapitres du nouveau fascicule.

The acylation of veratrole (1,2-dimethoxybenzene) by acetic anhydride in the presence of HY and Hβ zeolites was carried out at 90 °C in a batch reactor. The reaction led to acetoveratrole (3,4-dimethoxyacetophenone) selectively. HY was more active than Hβ by a factor of about 1.5. Soxhlet extraction with methylene chloride of the catalyst recovered after reaction made it possible to eliminate approximately 80% of the organic material remaining on the catalyst. After soxhlet extraction the catalyst samples were dissolved with HF. In addition to veratrole and acetoveratrole the organic residue obtained by this procedure contained di- and triketones as well as cyclization products. These compounds were suspected to contribute to the irreversible deactivation of the catalysts. The IR analysis of the zeolite samples after adsorption of the diketone in the presence of veratrole as well as the acylation of the latter in the presence of the diketone confirmed that this compound took part in the deactivation of the catalysts. This conclusion was also supported by the analysis of the composition of the material remaining strongly adsorbed or entrapped in the zeolites after experiments of various durations. However, the IR spectra of the catalysts after soxhlet extraction showed that another compound at least was also responsible for the deactivation of the zeolites, specially of Hβ. However this compound, presumably a triketone resulting from the C-acylation of the diketone, was only stable when entrapped in the zeolitic material. It could not be synthesised and isolated by conventional means.

Violence-related behavior in schools has declined in recent years, but the perception of risk remains high. Disturbingly high percentages of students and teachers report staying home out of fear, and many students bring weapons to school for protection. Current proposals for preventing school violence include punishing the violence-prone, expulsion for weapon carriers, and creating a culture of nonviolence through various behavioral methods like conflict resolution. None of these proposals address the issue of lethal violence and hence personal safety. The risk of lethal violence in schools(related mainly to firearms) could be substantially reduced by creating an effective barrier between firearms and people. This could be achieved by using entry-based weapons detection systems similar to those now used in airports and courts. Decreasing the risk and fear of violence by converting schools into weapons-free zones would also be expected to increase attendance and improve scholastic performance. Randomized, controlled studies should be undertaken to evaluate the efficacy and cost-effectiveness of entry-based weapons detection systems for achieving these outcomes.

International audience

International audience; In future high-speed optical time-division-multiplexed (OTDM) systems, an important factor that needs to be considered for optical pulse generation schemes is the impact of pulse pedestals on the overall system performance. The results presented in this letter are two-fold; first, the impact due to the height of pulse pedestals in an 80-Gb/s OTDM system are established. Second, a solution is provided to overcome these high pedestal levels through the use of a vertical microcavity saturable absorber, which can significantly reduce the pulse pedestal level and give enhanced system performance.

In this paper, we study the behavior of a current-mode-controlled boost converter and exhibit its chaotic behavior. We then introduce a practical method (sliding mode control) aiming at eliminating this chaotic behavior. We establish a mathematical modeling of the whole circuit (closed-loop) and study its performance. Finally, simulation results clearly show the disappearance of the instability. This control method does not only provide stability, it also increases the input voltage variation domain for which the system remains stable.

As part of a wider seakeeping program conducted by the David Taylor Naval Ship Research and Development Center, two mission-critical workstations were evaluated for the United States Coast Guard (USCG). These workstations (the communications support center and the communications center) have been specifically identified by the USCG as having exceptional seasickness problems. Five potentially applicable human factors engineering (HFE) approaches to enhance seakeeping through prevention and mitigation of adverse ship motion effects, especially seasickness, were recognized and are discussed in this report in the light of observations made aboard the ship. These are: (1) locate critical stations near ship's effective center of rotation; (2) minimize head movements; (3) align operator stations with a principal axis of the ship's hull; (4) avoid combining provocative sources; and (5) provide an external visual frame of reference at stations where seasickness may seriously impair mission effectiveness. This report relates how the application of relatively simple HFE principles (ideally at the early ship design and arrangement stage) may reduce seasickness and other adverse ship motion effects and so enhance seakeeping.

Twenty young Naval enlisted male volunteers were first rehearsed and then tested before, during, and after vertical (z-axis) whole-body vibration. Fourteen were tested only at 8 Hz, and six were tested at 8 Hz/0.21 gz rms, 16 Hz/0.43 gz rms and 32 Hz/0.85 gz rms, using three paper-and-pencil tasks involving visual, motor, and cognitive skills. The tasks were ‘Spoke’, a speed of tapping test; “Aiming”, a test of fine motor coordination; and “Coding”, involving mental computation. Results showed an approximately equal decrement across conditions in the Spoke and Coding (but not Aiming) tests that conforms with the frequency function embodied in the current international standard (ISO 2631–1978) on human exposure to vibration. In addition, it was found that a modicum of vibration experience may be necessary before reliable data are obtained in this kind of testing. Implications for methodology and for the application of the current standard are briefly discussed.

A Landolt C visual acuity test was evaluated for inclusion in a battery of Performance Evaluation Tests for Environmental Research (PETER) for use in repeated measures experiments. Eight subjects were tested for 12 days to determine stability of means, standard deviations and cross-day correlations. Mixed results for these cross-day correlation analyses made questionable the stability of speed and error measures. Fine-structure analyses indicated that the task was more a measure of response accuracy than acuity. Fine-structure analyses in future performance test evaluation and exploration of alternative visual acuity tests are recommended. It is concluded that the Landolt C test in the form used is not stable and cannot be recommended as a test of visual acuity for inclusion in PETER.

An auditory-input/keypad-output system was evaluated for use as a performance test system that would be independent of artifactual vibrational decrement. Six young Navy volunteers were administered a non-cognitive Auditory Response Task Before, During, and After whole-body sinusoidal vibration. Two were tested at each of three vibration conditions (8 Hz/0.21 gzrms, 16 Hz/0.43 gzrms, and 32 Hz/0.85 gzrms). Results showed no direct decrement due to vibration, but a moderately significant subjects-within-conditions by frequency interaction. This interaction, paired with subjective measures taken during experimentation, pointed to a deficit in the keypad output system. It was concluded that the system was not satisfactory for future experimentation and recommended that a modified input system be developed. It is noted that purely cognitive effects of vibration have not been identified in the body of previous research.

Independent groups of male college student volunteers were exposed in a standard seated posture to one of 5 conditions of vertical (Z-axis) harmonic oscillation for two hours or until vomiting. A control condition, sinusoidal motion at 0.17 Hz with a root mean square acceleration of 0.13 g, served as the basis of comparison with the remaining four conditions, which were generated by the sum of two sinusoids, namely, the fundamental at 0.17 Hz plus the second (0.33 Hz) or third (0.50 Hz) harmonic. The experimental conditions differed either in the phase relationship or the relative acceleration level of the added harmonic. The predicted motion sickness incidence (MSI) was calculated for each sinusoid alone from a previously derived mathematical model and compared with the obtained MSIs. While the overall differences may have been due to chance, certain motion combinations provoked unexpectedly high MSI. No simple relationship between predicted MSI for single-frequency motion and the obtained complex-motion MSIs emerged from this study. Until further data are forthcoming, guidelines for motion sickness prevention based on the presumption of independence of action of component frequencies in a complex motion must be interpreted with caution.

The frequency-dependent effects of mechanical vibration on human comfort and working efficiency are now clearly recognized, as are the effects of airborne noise on hearing. But vibration and intense noise at very low frequencies can also provoke disturbing non-auditory symptoms which are as yet ill understood. Moreover, the establishment of frequency-and time-dependence of these effects calls for further research. The author reviews current problems in this field and mentions the work of the International Organization for Standardization aimed at defining limits of acceptable human exposure to vibration and intense noise.

From July through September 1975, a series of ship motion simulation experiments was conducted using the ONR Motion Generator at Human Factors Research, Inc., Goleta, California. The motions were based on the mathematical model for the 2000 ton surface effect ship (2000T-SES). Nineteen volunteer human research subjects, selected at different times from 600 naval enlisted recruits, briefed on NAMRL Detachment research, were exposed to several motion profiles. These subjects were extensively evaluated before acceptance. Those with any medical defects which would place them at extra risk of injury while undergoing biodynamic experiments were excluded. Those with anomalous vestibular response were also excluded. The motions to be experienced were those predicted for a 2000T-SES running in a bow quartering sea in 3 separate conditions: (1) sea state three at 80 knots; (2) sea state four at 60 knots; and (3) sea state five at 40 knots. The subjects were to be run in pairs for 48 hours in each of the three conditions. Performance tasks representative of shipboard activities were administered on a prescheduled basis. The 48-hour motion condition periods were alternated with 48-hour static control periods and 24-hour rest periods. The experimental design called for 12 subjects assuming no voluntary withdrawals. A total of 19 subjects was used, primarily because of volunteer withdrawals following continued emesis. Substantial alternations of the design also occurred due to operational problems with the simulator. For a variety of reasons many runs were undertaken with attenuation of the motion either by a percentage amount or to a selected rms acceleration level.

1 The sensitivity to flickering light at various light frequencies (DeLange curve) was determined in 20 controls and 45 patients receiving maintenance doses of digoxin. 2 Flicker thresholds (mean percentage of maximal light modulation +/- s.d.; F 30 Hz) were 7.6 +/- 1.7 in controls and 9.4 +/- 1.7 in patients with optimal plasma digoxin levels (0.5-1.9 ng/ml), but they rose to 15.5 +/- 1.9 at subtoxic levels (2.0-3.0 ng/ml), and to 21.8 +/- 2.6 at toxic levels (above 3.0 ng/ml). 3 Flicker sensitivity was inversely correlated with plasma digoxin levels and returned to baseline values when the administration of digoxin was interrupted. 4 The DeLange curve seems to be a valuable tool to measure the toxic effects of digitalis on the visual system.

Le lecteur en spirale exige le déplacement simultané de trois films comportant les clichés stéréoscopiques dans deux formats pour les chambres de 0,80 m et 2 m. Il comprend donc trois systèmes indépendants de transport de film commandé par le calculateur.

Cet appareil est caractérisé par un dispositif original de corrélation des impulsions résultant de l'analyse d'une photographie par un balayage télévision qui permet de détecter les éléments linéaires et par une stratégie d'association de ces éléments en traces par approximations successives.

Large surface effect ship (SES) motion simulations and supporting studies using low‐frequency (0.17–0.5 Hz) harmonic “heave” (vertical) motion indicated an urgent need to continue research to elucidate mechanisms of motion sickness and to develop predictive models of motion sickness incidence suitable for incorporation into human vibration exposure standards. Nineteen young male naval volunteers underwent severe SES motion simulations and a larger cohort of civilian volunteers underwent compound harmonic motion in a large‐amplitude motion generator. Occurrence of and time to emesis were recorded, as well as head inertial and related biomedical responses, during the SES simulations. [The harmonic motion experiments have been reported previously by J. C. Guignard and M. E. McCauley, Aviat. Space Environ. Med. 53, 554–563 (1982)]. Severe kinetosis, usually leading to abandonment of tasks, was observed in 16 of 19 subjects exposed to the simulated operational environment; and marked postrun illness and postural instability were frequent. Habituation to severe motion was not observed. Some correlation emerged between inertial head motion and susceptibility to sickness. Time to emesis varied idiosyncratically and is of uncertain value as a criterion of exposure severity. Further systematic research is recommended to establish the significant parameters of the physical stimulus to seasickness. [Work performed while the authors were at the NAMRL Detachment, now the Naval Biodynamics Laboratory, New Orleans, LA.]

Magnitude estimation of the subjective distress of seasickness has not been used for scaling in operational environments, although it has previously been utilized in laboratory studies [e.g., O. L. Bock and C. M. Oman, Aviat. Space Environ. Med. 53, 773–777 (1982)]. During sea trials, the method was used by one of us (ACB) to scale the provocativeness of five shipboard areas: Communications Center (CC), Communications Support Center (CSC), mess, bunk, and other areas. In addition, prediction weights for incremental changes in a “general motion illness” factor were independently derived by regression analysis on the responses of 16 crewmen during the same trials [A. C. Bittner, Jr. and J. C. Guignard, “Motion Sickness Evaluations in an At‐Sea Environment: Seakeeping Trials of a USCG Cutter (WMEC 901), Naval Biodynamics Laboratory Rep. NBDL‐86R002 (manuscript under review)]. These were: 0.12 (CC); 0.04 (CSC); − 0.09 (mess); − 0.35 (bunk); and 0.00 (other). Using a mess location as a comparison stimulus (assigned modulus 4), the comparable geometric means of (3–5) magnitude estimates for the same areas were: 10 (CC); 6 (CSC); 4 (mess); 2 (bunk); and 5 (other). The correlation between the direct (magnitude) and indirect (factor) scales was substantial and significant (RHO = 1.00; p < 0.017). These results demonstrate the utility of magnitude estimation of motion sickness for operational comparisons. [Work supported by DTNSRDC MIPR Z70099‐4‐00758 under an agreement with the U. S. Coast Guard. Views not necessarily those of USCG or Department of the Navy.]

On mesure la surface occultée de l'élément d'analyse en asservissant le signal en l'absence de trace à une valeur constante. On utilise pour cela un amplificateur à gain variable inclus dans une boucle de rétroaction. Cette boucle est rompue au passage d'une trace grâce à une commutation à effet de champ.

To insure efficient utilization of the system, space station design and operations will require special habitability considerations for the occupants and crew because of the relatively long duration missions. Of particular concern is the environment in which the personnel will live and work, and how it affects both the performance and comfort of the occupants. The vibroacoustic aspect of that environment is the subject of this forum session. Although noise and vibration exposure criteria have been developed for earth-based work and living situations, several factors make the application of these criteria questionable in the context of space station design and operation. The interior noise and vibration environment of a space station is different in level and frequency than a comparable earth-based system. Complicating factors associated with reduced gravity, long duration and confinement are not included in existing criteria. In applying the criteria to space system designs, these factors either have been neglected or considered unimportant. The need for improved habitability is evidenced by physical and subjective assessments of previous missions. Astronauts have reported sleep interference, communication interference, distraction, and general annoyance as noise related complaints. The goal of the discussion is to establish, as Human Factors Specialists, where we are; what we should consider; and what the problems are as well as possible approaches and solutions. In other words, the aim is to stimulate thinking about space station vibroacoustic habitability that could ultimately lead to new research and technology in this area. Effects of the vibroacoustic environment on performance, hearing, communication, sleep, health, and annoyance will be discussed, as well as the results of interactions between the vibroacoustic environment and duration, weightlessness, and confinement.

Continuing interest in the immediate and long‐term effects of human exposure to low‐frequency mechanical vibration is reviewed, with particular reference to naval operational and occupational health applications of human whole‐body vibration research. The availability of data suitable for incorporation into cognate standards will be touched upon, as will aspects of research methods in human motion and vibration studies. Reference will be made to a recent workshop on the latter topic (to be convened in New Orleans in September 1981).

This review attempts to develop a simple theory of decrements in task performance associated with whole‐body vibration and low‐frequency motion. Postulated mechanisms are twofold: (1) direct mechanical interference acting at the man/task interface, and (2) centrally acting perceptual and cognitive effects that are mediated physiologically. Mechanical interference (for example, with locomotion, manual, and visual tasks) is usually heavily dependent on the vibration spectrum and largely independent of time; whereas the central, physiologically mediated effects are less clearly related to the vibration spectrum, are apt to exhibit a latent period before any impairment is measurable, and tend to worsen as a complex function of vibrational acceleration and the passage of time. The importance of this distinction to research methodology and to biodynamic standards development is addressed.

Vibration and noise are treated separately in Parts One and Two of this volume; while Part Three deals with the special aeromedical problem of auditory perception in aircrew and ground support personnel and its conservation. Part Four is a glossary of relevant terms. This division of the subject matter recognises that in practice vibration and noise are conveniently studied, measured and controlled as separate entities. It should, however, be borne in mind that these conditions rarely affect man singly. They are commonly present at the same time; and vibration and noise may often be associated with different kinds of environmental agent, such as heat, to make up a combined environmental stress. The human response to such combinations of stressful agents is still a largely neglected field of research.

The single‐frequency model of motion sickness incidence (MSI) developed by H. F. O'Hanlon and M. E. McCauley [Aerospace Med. 45, 366–369 (1974)] does not reliably predict MSI in complex oscillation typical of ship motion, as was shown by systematic measurements of MSI during combined heave motions [J. C. Guignard and M. E. McCauley, Aviat. Space Environ. Mede. 53, 554–563 (1982)]. Clinical and physiological observations (complemented by inertial measurements of head motion) during dynamically simulated 48‐h rough‐sea deployments of a projected 2000‐ton surface effect ship provided further insight into the phenomenon of seasickness. Sixteen of 19 fit young naval volunteers discontinued testing, because of severe motion sickness; and all experienced symptoms. Severe motion sickness caused abandonment of psychomotor task performance; but two subjects consistently resistant to sickness performed their tasks throughout the experiment (although experiencing some nausea and exhibiting post‐run postural instability). Ataxia, and symptomatic motion sickness in some cases, persisted for several hours after motion. Habituation to motion severe enough to provoke continuing vomiting did not occur in these simulations, although there was indirect evidence of some transfer of habituation from prior single‐frequency motion exposure. We recommend that motion effects be studied systematically in relation to the physical parameters of provocative motion. [Work of Naval Aerospace Medical Research Laboratory Detachment ♯ 1 (now Naval Biodynamics Laboratory), New Orleans; supported by Office of Naval Research. Views not necessarily those of the Department of the Navy. Archival data in letter report to ONR (1980) and Paper ♯9 to NATO/DRG Seminar, Toronto (1983).]

Oscillatory ship motion and vibration effects on crews in modern naval air and sea systems can be the limiting factor in mission performance. The mechanisms of these effects, however, have not yet been clearly delineated; nor have a practical taxonomy and standard methodology for distinguishing and evaluating the deleterious action of whole-body vibratory motion on human performance been established. Some effects of vibration on performance appear to be directly attributable to immediate mechanical disruption of input and /or output (i.e., interference at the points of contact—displays or controls—between operator and task). Far more meager is clear evidence for time-dependent disruptive or degrading effects of vibration on central cognitive processes: these of course may also be affected indirectly by changes in the physiological state (including motion sickness and fatigue) induced by the motion or vibration. The distinction between direct and indirect mechanisms of performance decrement in the motion environment has important implications for both protective measures and the focus of future research. This report considers published work on the performance effects of vibration in relation to the etiology of performance change and those implications. A critical review of the methodology of performance studies in motion and vibration environments is under way at the Naval Biodynamics Laboratory; and a series of experiments (some previously published) on whole-body vibration effects on performance is also in progress. While the duality of the mechanisms of action of oscillatory motion on performance remains an open question, the evidence so far adduced for other than direct mechanical effects is sparse, at least in the frequency range of major body resonance phenomena. Further experimentation, including long-duration studies, is needed to resolve this question. Implications both for future research directions and for current national and international standardization efforts in this area are discussed.

Sea‐keeping trials of a United States Coast Guard cutter included a human factors engineering evaluation having particular regard to problems of seasickness in certain work stations. Some motion sickness incidence and related data, and the derivation of human factors engineering principles therefrom, were reported in 1985 [A. C. Bittner, Jr. and J. C. Guignard, Nav. Eng. J. 97 (4), 207–213; 97 (5), 107–111]. Further analysis [A. C. Bittner, Jr. and J. C. Guignard, in Trends in Ergonomics/Human Factors V, edited by F. Aghazadeh (Elsevier, New York, 1988), pp. 529–539] showed that, contrary to traditional assumptions, seasickness is characterized by at least two functionally independent factors, identified as F1 (symptomatic general motion illness) and F2 (retching‐vomiting). It was shown that the validity of future sea trials requires: (a) multiple‐score scaling of motion sickness (e.g., using F1 and F2); (b) control of subject crew activity and movements about the ship during periods of observation; and (c) avoidance of steaming patterns that induce extraneous carryover effects. The present paper draws attention to an incidental finding concerning the influence of brief sleep and rest (lying down in the bunk) upon motion sickness susceptibility and recovery in the shipboard environment. Analyses of questionnaire data including amount and subjective quality of sleep showed that these were affected by the passage of time in an adverse (nauseogenic) motion environment, as has been observed generally in naval operations. An apparent ameliorative effect of unscheduled rest periods and naps upon susceptibility to adverse motion effects was incidentally detected and is commented upon in this report. [Observations made while the authors were at the Naval Biodynamics Laboratory, New Orleans.]