Effectiveness of Work Zone Intelligent Transportation Systems, TPF-5(081), 2013

In the last decade, Intelligent Transportation Systems (ITS) have increasingly been deployed in work zones by state departments of transportation. Also known as smart work zone systems they improve traffic operations and safety by providing real-time information to travelers, monitoring traffic conditions, and managing incidents. Although there have been numerous ITS deployments in work zones, a framework for evaluating the effectiveness of these deployments does not exist. To justify the continued development and implementation of smart work zone systems, this study developed a framework to determine ITS effectiveness for specific work zone projects. The framework recommends using one or more of five performance measures: diversion rate, delay time, queue length, crash frequency, and speed. The monetary benefits and costs of ITS deployment in a work zone can then be computed using the performance measure values. Such ITS computations include additional considerations that are typically not present in standard benefit-cost computations. The proposed framework will allow for consistency in performance measures across different ITS studies thus allowing for comparisons across studies or for meta analysis. In addition, guidance on the circumstances under which ITS deployment is recommended for a work zone is provided. The framework was illustrated using two case studies: one urban work zone on I-70 and one rural work zone on I-44, in Missouri. The goals of the two ITS deployments were different – the I-70 ITS deployment was targeted at improving mobility whereas the I-44 deployment was targeted at improving safety. For the I-70 site, only permanent ITS equipment that was already in place was used for the project and no temporary ITS equipment was deployed. The permanent DMS equipment serves multiple purposes, and it is arguable whether that cost should be attributed to the work zone project. The data collection effort for the I-70 site was very significant as portable surveillance captured the actual diversion flows to alternative routes. The benefit-cost ratio for the I-70 site was 2.1 to 1 if adjusted equipment costs were included and 6.9 to 1 without equipment costs. The safety-focused I-44 ITS deployment had an estimated benefit-cost ratio of 3.2 to 1.

SDF 1-alpha (CXCL12) triggers glutamate exocytosis from astrocytes on a millisecond time scale: Imaging analysis at the single-vesicle level with TIRF microscopy

Chemokines are small chemotactic molecules widely expressed throughout the central nervous system. A number of papers, during the past few years, have suggested that they have physiological functions in addition to their roles in neuroinflammatory diseases. In this context, the best evidence concerns the CXC-chemokine stromal cell-derived factor (SDF-1alpha or CXCL12) and its receptor CXCR4, whose signalling cascade is also implicated in the glutamate release process from astrocytes. Recently, astrocytic synaptic like microvesicles (SLMVs) that express vesicular glutamate transporters (VGLUTs) and are able to release glutamate by Ca(2+)-dependent regulated exocytosis, have been described both in tissue and in cultured astrocytes. Here, in order to elucidate whether SDF-1alpha/CXCR4 system can participate to the brain fast communication systems, we investigated whether the activation of CXCR4 receptor triggers glutamate exocytosis in astrocytes. By using total internal reflection (TIRF) microscopy and the membrane-fluorescent styryl dye FM4-64, we adapted an imaging methodology recently developed to measure exocytosis and recycling in synaptic terminals, and monitored the CXCR4-mediated exocytosis of SLMVs in astrocytes. We analyzed the co-localization of VGLUT with the FM dye at single-vesicle level, and observed the kinetics of the FM dye release during single fusion events. We found that the activation of CXCR4 receptors triggered a burst of exocytosis on a millisecond time scale that involved the release of Ca(2+) from internal stores. These results support the idea that astrocytes can respond to external stimuli and communicate with the neighboring cells via fast release of glutamate.

Long-term and long range migration of radioisotopes in terrestrial systems : mechanisms of radioisotopes (Cs, Sr, Pu, Am) mobilization in soils

Summary Artificial radionuclides were released in the environment during the atmospheric nuclear weapon tests and after accidental events involving nuclear industries. As a primary receptor of the deposition, the soil is a very sensitive compartment and understanding the interaction and migration of radionuclides within soils allows the development of scenario for the contamination risk of the population and of the environment. Most available field studies on radionuclides in soils only concern one or two isotopes, mostly 137Cs, and few physico-chemical soil parameters. The purpose of this study was a broader understanding of the radioecology of an Alpine valley. In a first part, we aimed to describe the depth distribution of 137Cs, 90Sr, 239+240Pu, and 241Am within different alpine soils and to identify some stable elements as indicators for accumulating layers. In the central part of the study, the goal was to investigate the repartition of ^Sr and 239Pu between the truly dissolved fraction and the colloidal fraction of the soil solutions and to identify the nature of colloids involved in the adsorption of ^Sr and 239Pu. These results were integrated in an "advection- sorption" transport model seeking to explain the migration of 239Pu and 90Sr within the soils and to assess the importance of colloidal transport for these two isotopes. A further aspect studied was the role of the competition between the radioisotopes (137Cs and 90Sr) and their stable chemical analogues (K and Ca) with respect to plant uptake by different plant species. The results on the depth distribution within the soils showed that 137Cs was mostly retained in the topsoil, to the exception of an organic-rich soil (Histosol 2) receiving important surface runoff, where migration down to a depth of 30 cm was observed. 137Cs depth distribution within the soils was similar to unsupported 210Pb depth distribution. The plant uptake of 137Cs clearly depended on the concentration of exchangeable potassium in the soils. Moreover, we showed that the 137Cs uptake by certain species of the taxonomic orders Poales and Rosales was more sensitive to the increase in exchangeable Κ compared to other orders. Strontium-90 was much more mobile in the soils than 137Cs and depth migration and accumulation in specific AI- and Fe-rich layers were found down to 30 cm. Copper and Ni showed accumulations in these same layers, indicating their potential to be used as indicators for the migration of ^Sr within the soils. In addition, we observed a 90Sr activity peak in the topsoil that can be attributable to recycling of 90Sr by plant uptake. We demonstrated for the first time that a part of 90Sr (at least 40%) was associated with the colloids in organic-rich soil solutions. Therefore, we predict a significant effect of the colloidal migration of ^Sr in organic-rich soil solutions. The plant uptake results for 90Sr indicated a phylogenetic effect between Non-Eudicot and Eudicots: the order Poales concentrating much less 90Sr than Eudicots do. Moreover, we were able to demonstrate that the sensitivity of the 90Sr uptake by 5 different Alpine plant species to the amount of exchangeable Ca was species-independent. Plutonium and 241Am accumulated in the second layer of all soils and only a slight migration deeper than 20 cm was observed. Plutonium and 241Am showed a similar depth distribution in the soils. The model results suggested that the present day migration of 239Pu was very slow and that the uptake by plants was negligible. 239Pu activities between 0.01 to 0.08 mBq/L were measured in the bulk soil solutions. Migration of 239Pu with the soil solution is dominated by colloidal transport. We reported strong evidences that humic substances were responsible of the sorption of 239Pu to the colloidal fraction of the soil solutions. This was reflected by the strong correlation between 239Pu concentrations and the content of (colloidal) organic matter in the soil solution. Résumé Certains radioéléments artificiels ont été disséminés dans l'environnement suite aux essais atmosphériques de bombes nucléaires et suite à des accidents impliquant les industries nucléaires. En tant que récepteur primaire de la déposition, le sol est un compartiment sensible et des connaissances sur les interactions et la migration des radioéléments dans le sol permettent de développer des modèles pour estimer la contamination de la population et de l'environnement. Actuellement, la plupart des études de terrain sur ce sujet concernent uniquement un ou deux radioéléments, surtout le 137Cs et peu d'études intègrent les paramètres du sol pour expliquer la migration des radioéléments. Le but général de cette étude était une compréhension étendue de la radio-écologie d'une vallée alpine. Notre premier objectif était de décrire la distribution en profondeur de 137Cs, ^Sr, 239+240pu et 241Am dans différents sols alpins en relation avec des éléments stables du sol, dans le but d'identifier des éléments stables qui pourraient servir d'indicateurs pour des horizons accumulateurs. L'objectif de la deuxième partie, qui était la partie centrale de l'étude, était d'estimer le pourcentage d'activité sous forme colloïdale du 239Pu et du 90Sr dans les solutions des sols. De plus nous avons déterminé la nature des colloïdes impliqués dans la fixation du ^Sr et 239Pu. Nous avons ensuite intégré ces résultats dans un modèle de transport développé dans le but de décrire la migration du 239Pu et 90Sr dans le sol. Finalement, nous avons étudié l'absorption de 137Cs et 90Sr par les plantes en fonction de l'espèce et de la compétition avec leur élément analogue stable (K et Ca). Les résultats sur la migration en profondeur du 137Cs ont montré que ce radioélément était généralement retenu en surface, à l'exception d'un sol riche en matière organique dans lequel nous avons observé une nette migration en profondeur. Dans tous les sols, la distribution en profondeur du 137Cs était corrélée avec la distribution du 210Pb. L'absorption du 137Cs par les plantes, était dépendante de la concentration en Κ échangeable dans le sol, le potassium étant un compétiteur. De plus, nous avons observé que les espèces ne réagissaient pas de la même manière aux variations de la concentration de Κ échangeable. En effet, les espèces appartenant aux ordres des Poales et des Rosales étaient plus sensibles aux variations de potassium échangeable dans le sol. Dans tous les sols Le 90Sr était beaucoup plus mobile que le 137Cs. En effet, nous avons observé des accumulations de 90Sr dans des horizons riches en Fe et Al jusqu'à 30 cm de profondeur. De plus, le Cu et le Ni montraient des accumulations dans les mêmes horizons que le 90Sr, indiquant qu'il pourrait être possible d'utiliser ces deux éléments comme analogues pour la migration du 90Sr. D'après le modèle développé, le pic de 90Sr dans les premiers centimètres du sol peut être attribué à du recyclage par les plantes. Le 90Sr en solution était principalement sous forme dissoute dans des solutions de sols peu organique (entre 60 et 100% de 90Sr dissous). Par contre, dans des solutions organiques, un important pourcentage de 90Sr (plus de 40%) était associé aux colloïdes. La migration colloïdale du 90Sr peut donc être significative dans des solutions organiques. Comme pour le 137Cs, l'absorption du 90Sr par les plantes dépendait de la concentration de son analogue chimique dans la fraction échangeable du sol. Par contre, les espèces de plantes étudiées avaient la même sensibilité aux variations de la concentration du calcium échangeable. Le plutonium et l'américium étaient accumulés dans le deuxième horizon du sol et nous avons observé seulement une faible migration plus profondément que 20 cm. Selon le modèle, la migration actuelle du plutonium est très lente et l'absorption par les plantes semble négligeable. Nous avons mesuré entre 0.01 et 0.08 mBq/L de 239Pu dans les solutions de sol brutes. La migration du plutonium par la solution du sol est due principalement aux colloïdes, probablement de nature humique. Résumé grand public Dans les années 1950 à 1960, l'environnement a été contaminé par des éléments radioactifs (radioéléments) artificiels provenant des essais des armes atomiques et de l'industrie nucléaire. En effet, durant ces années, les premiers essais de bombes atomiques se faisaient dans l'atmosphère, libérant de grandes quantités d'éléments radioactifs. De plus certains accidents impliquant l'industrie nucléaire civile ont contribué à la dissémination d'éléments radioactifs dans l'environnement. Ce fut par exemple le cas de l'accident de la centrale atomique de Tchernobyl en 1986 qui a causé une importante contamination d'une grande partie de l'Europe par le 137Cs. Lorsqu'ils sont libérés dans l'atmosphère, les radioéléments sont dispersés et transportés par les courants atmosphériques, puis peuvent être déposés dans l'environnement, principalement par les précipitations. Une fois déposés sur le sol, les radioéléments vont interagir avec les composants du sol et migrer plus ou moins vite. La connaissance des interactions des éléments radioactifs avec le sol est donc importante pour prédire les risques de contamination de l'environnement et de l'homme. Le but général de ce travail était d'évaluer la migration de différents éléments radioactifs (césium-137, strontium-90, plutonium et américium-241) à travers le sol. Nous avons choisi un site d'étude en milieu alpin (Val Piora, Tessin, Suisse), contaminé en radioéléments principalement par les retombées de l'accident de Tchernobyl et des essais atmosphériques de bombes atomiques. Dans un premier temps, nous avons caractérisé la distribution en profondeur des éléments radioactifs dans le sol et l'avons comparée à divers éléments stables. Cette comparaison nous a permit de remarquer que le cuivre et le nickel s'accumulaient dans les mêmes horizons du sol que le strontium-90 et pourraient donc être utilisés comme analogue pour la migration du strontium-90 dans les sols. Dans la plupart des sols étudiés, la migration du césium-137, du plutonium et de l'américium-241 était lente et ces radioéléments étaient donc accumulés dans les premiers centimètres du sol. Par contre, le strontium-90 a migré beaucoup plus rapidement que les autres radioéléments si bien qu'on observe des accumulations de strontium-90 à plus de 30 cm de profondeur. Les radioéléments migrent dans la solution du sol soit sous forme dissoute, soit sous forme colloïdale, c'est-à-dire associés à des particules de diamètre < Ιμηι. Cette association avec des colloïdes permet à des radioéléments peu solubles, comme le plutonium, de migrer plus rapidement qu'attendu. Nous avons voulu savoir quelle était la part de strontium-90 et plutonium associés à des colloïdes dans la solution du sol. Les résultats ont montré que le plutonium en solution était principalement associé à des colloïdes de type organique. Quant au strontium-90, ce dernier était en partie associé à des colloïdes dans des solutions de sol riches en matière organique, par contre, il était principalement sous forme dissoute dans les solutions de sol peu organiques. L'absorption de radioéléments par les plantes représente une voie importante pour le transfert vers la chaîne alimentaire, par conséquent pour la contamination de l'homme. Nous avons donc étudié le transfert du césium-137 et du strontium-90 de plusieurs sols vers différentes espèces de plantes. Les résultats ont montré que l'absorption des radioéléments par les plantes était liée à la concentration de leur analogue chimique (calcium pour le strontium-90 et potassium pour le césium- 137) dans la fraction échangeable du sol. De plus certaines espèces de plantes accumulent significativement moins de strontium-90.

A Feasibility Study on Embedded Micro-Electromechanical Sensors and Systems (MEMS) for Monitoring Highway Structures, TR-575, 2011

Micro-electromechanical systems (MEMS) provide vast improvements over existing sensing methods in the context of structural health monitoring (SHM) of highway infrastructure systems, including improved system reliability, improved longevity and enhanced system performance, improved safety against natural hazards and vibrations, and a reduction in life cycle cost in both operating and maintaining the infrastructure. Advancements in MEMS technology and wireless sensor networks provide opportunities for long-term continuous, real-time structural health monitoring of pavements and bridges at low cost within the context of sustainable infrastructure systems. The primary objective of this research was to investigate the use of MEMS in highway structures for health monitoring purposes. This study focused on investigating the use of MEMS and their potential applications in concrete through a comprehensive literature review, a vendor survey, and a laboratory study, as well as a small-scale field study. Based on the comprehensive literature review and vendor survey, the latest information available on off-the-shelf MEMS devices, as well as research prototypes, for bridge, pavement, and traffic applications were synthesized. A commercially-available wireless concrete monitoring system based on radio-frequency identification (RFID) technology and off-the-shelf temperature and humidity sensors were tested under controlled laboratory and field conditions. The test results validated the ability of the RFID wireless concrete monitoring system in accurately measuring the temperature both inside the laboratory and in the field under severe weather conditions. In consultation with the project technical advisory committee (TAC), the most relevant MEMS-based transportation infrastructure research applications to explore in the future were also highlighted and summarized.

Tests diagnostiques rapides (TDR): la panacée pour le praticien [Rapid diagnostic tests (RDT): the cure-all for the practitioner?].

Many rapid diagnostic tests (RDT) for the diagnosis of infectious diseases have been developed over the last 20 years. These allow (1) administering a treatment immediately in case of a potentially fatal disease, (2) prescribing a specific rather than presumptive treatment, (3) quickly introducing measures aimed at interrupting the transmission of the disease, (4) avoiding useless antibiotic treatments and (5) implementing a sequential diagnostic strategy to avoid extensive investigations. Using the example of malaria, a new strategy that includes a RDT as first-line emergency diagnostic tool and, when negative, delayed microscopy at the laboratory opening time is implemented in Lausanne since 1999. This strategy has been shown to be safe. Each TDR has its own characteristics that imperatively need to be known by the practitioner if he/she wants to use it in a rational way.

Non-viral gene therapy for GDNF production in RCS rat: the crucial role of the plasmid dose.

Glial cell line-derived neurotrophic factor (GDNF) is one of the candidate molecules among neurotrophic factors proposed for a potential treatment of retinitis pigmentosa (RP). It must be administered repeatedly or through sustained releasing systems to exert prolonged neuroprotective effects. In the dystrophic Royal College of Surgeon's (RCS) rat model of RP, we found that endogenous GDNF levels dropped during retinal degeneration time course, opening a therapeutic window for GDNF supplementation. We showed that after a single electrotransfer of 30 μg of GDNF-encoding plasmid in the rat ciliary muscle, GDNF was produced for at least 7 months. Morphometric, electroretinographic and optokinetic analyses highlighted that this continuous release of GDNF delayed photoreceptors (PRs) as well as retinal functions loss until at least 70 days of age in RCS rats. Unexpectedly, increasing the GDNF secretion level accelerated PR degeneration and the loss of electrophysiological responses. This is the first report: (i) demonstrating the efficacy of GDNF delivery through non-viral gene therapy in RP; (ii) establishing the efficacy of intravitreal administration of GDNF in RP associated with a mutation in the retinal pigment epithelium; and (iii) warning against potential toxic effects of GDNF within the eye/retina.

Dispositifs de délivrance de principes actifs pour des applications ophtalmologiques [Drug delivery systems for intraocular applications].

Numerous drug delivery systems (DDSs) can be used as intraocular tools to provide a sustained and calibrated release for a specific drug. Great progress has been made on the design, biocompatibility, bioavailability, and efficacy of DDSs. Although several of them are undergoing clinical trials, a few are already on the market and could be of a routine use in clinical practice. Moreover, miniaturization of the implants makes them less and less traumatic for the eye tissues and some DDSs are now able to target certain cells or tissues specifically. An overview of ocular implants with therapeutic application potentials is provided.

Détection des lésions focales hépatiques malignes. Comparaison de l'échographie, de la porto-tomodensitométrie, de la tomodensitométrie tardive et de l'imagerie par résonance magnétique [Detection of malignant focal hepatic lesions. Comparison of ultrasonography, computerized tomography during arterial portography, delayed computerized tomography and magnetic resonance imaging]

AIMS: This study was performed to compare the sensitivity of ultrasonography, computerized tomography during arterial portography, delayed computerized tomography, and magnetic resonance imaging to detect focal liver lesions. Forty three patients with primary or secondary malignant liver lesions were studied prior to surgical intervention. METHODS: The results of the imaging studies were compared with intraoperative examination of the liver, intraoperative ultrasonography and pathology results (29 patients). In the non-operated (14 patients) group, we compared the number of lesions detected by each technique. RESULTS: One hundred and forty six lesions were detected. There was 84% sensitivity with computerized tomography during arterial portography, 61.3% with delayed scan, 63.3% with magnetic resonance imaging and 51% with ultrasonography in operated patients. In patients who did not undergo surgery, magnetic resonance imaging was more sensitive in detecting lesions. CONCLUSIONS: In operated and non-operated patients series, CT during arterial portography had the highest sensitivity, but magnetic resonance imaging had the most consistent overall results.

Behaviour of pre-parturient sows housed in intensive outdoor or indoor systems

This work compared the behaviour of pre-parturient sows housed in intensive confined and outdoor systems, during the morning and afternoon prior to delivery. Eight sows were kept individually in farrowing crates or in paddocks with access to fresh pasture from 8 to 10 days before expected parturition. All outdoor sows built a nest within 24 hours before farrowing. On the morning and afternoon before farrowing they spent 6.5% of the time collecting grass and 7.5% of the time organizing the nest. Outdoor sows were observed more often than confined sows rooting (4.60% vs. 0.25%), feeding (10.2% vs. 3.0%), standing (51% vs. 13%) and walking (8% vs. 0%). Indoor sows redirected the nesting behaviour to other behaviours like attempts to dig the ground, nosing, biting and rooting parts of the crate, feeder or drinker, during 4.7% of the time. They also spent more time than outdoor sows inactive (85% vs. 60%), lying (72% vs. 41%), drinking (2.1% vs. 0.5%) and vacuum chewing (3.7% vs. 0.1%). The pre-parturient behaviour of sows was considerably affected by the husbandry system. The outdoor system appears to be more appropriate for the sows' welfare than the conventional confinement.

Systèmes de délivrance des médicaments pour le segment antérieur: bases fondamentales et applications cliniques [Drug delivery systems to target the anterior segment of the eye: fundamental bases and clinical applications].

The development of new drug delivery systems to target the anterior segment of the eye may offer many advantages: to increase the biodisponibility of the drug, to allow the penetration of drug that cannot be formulated as solutions, to obtain constant and sustained drug release, to achieve higher local concentrations without systemic effects, to target more specifically one tissue or cell type, to reduce the frequency of instillation and therefore increase the observance and comfort of the patient while reducing side effects of frequent instillation. Several approaches are developed, aiming to increase the corneal contact time by modified formulation or reservoir systems, or by increasing the tissue permeability using iontophoresis. To date, no ocular drug delivery system is ideal for all purposes. To maximize treatment efficacy, careful evaluation of the specific pathological condition, the targeted Intraocular tissue and the location of the most severe pathology must be made before selecting the method of delivery most suitable for each individual patient.

Use of solaria to predict weed density and floristic composition in no-till cropping systems

The objective of this work was to evaluate the efficiency of a new method, developed for predicting density and floristic composition of weed communities in field crops. Based on the use of solaria (100 mm transparent plastic tarps lying on the soil) to stimulate weed seedlings emergence, the method was tested in Tandil, Argentina, from 1998 to 2001. The system involved corn and sunflower in commercial no-till system. Major weeds in the experiments included Digitaria sanguinalis, Setaria verticillata and S. viridis, which accounted for 98% of the weed community in the three years of experiments since 1998. Large numbers of Tagetes minuta, Chenopodium album and Ammi majus were present in 2001. Comparison of weed communities under solaria with communities in field crops indicated that the method is useful for predicting the presence and density of some major weed species, at both high and low densities, of individuals in areas of 10 ha using only five solaria. Low density of weed species makes the method particularly useful to help deciding the time for herbicide applications to avoid soil contamination.

Field Testing of Abrasive Delivery Systems in Winter Maintenance, TR-458, 2009

The key goals in winter maintenance operations are preserving the safety and mobility of the traveling public. To do this, it is in general necessary to try to increase the friction of the road surface above the typical friction levels found on a snow or ice covered roadway. Because of prior work on the performance of abrasives (discussed in greater detail in chapter 2) a key concern when using abrasives has become how to ensure the greatest increase in pavement friction when using abrasives for the longest period of time. There are a number of ways in which the usage of abrasives can be optimized, and these methods are discussed and compared in this report. In addition, results of an Iowa DOT test of zero-velocity spreaders are presented. Additionally in this study the results of field studies conducted in Johnson County Iowa on the road surface friction of pavements treated with abrasive applications using different modes of delivery are presented. The experiments were not able to determine any significant difference in material placement performance between a standard delivery system and a chute based delivery system. The report makes a number of recommendations based upon the reviews and the experiments.

Estimating traveltimes and groundwater flow patterns using 3D time-lapse crosshole ERT imaging of electrical resistivity fluctuations induced by infiltrating river water

The infiltration of river water into aquifers is of high relevance to drinking-water production and is a key driver of biogeochemical processes in the hyporheic and riparian zone, but the distribution and quantification of the infiltrating water are difficult to determine using conventional hydrological methods (e.g., borehole logging and tracer tests). By time-lapse inverting crosshole ERT (electrical resistivity tomography) monitoring data, we imaged groundwater flow patterns driven by river water infiltrating a perialpine gravel aquifer in northeastern Switzerland. This was possible because the electrical resistivity of the infiltrating water changed during rainfall-runoff events. Our time-lapse resistivity models indicated rather complex flow patterns as a result of spatially heterogeneous bank filtration and aquifer heterogeneity. The upper part of the aquifer was most affected by the river infiltrate, and the highest groundwater velocities and possible preferential flow occurred at shallow to intermediate depths. Time series of the reconstructed resistivity models matched groundwater electrical resistivity data recorded on borehole loggers in the upper and middle parts of the aquifer, whereas the resistivity models displayed smaller variations and delayed responses with respect to the logging data. in the lower part. This study demonstrated that crosshole ERT monitoring of natural electrical resistivity variations of river infiltrate could be used to image and quantify 3D bank filtration and aquifer dynamics at a high spatial resolution.

Report on Rest Area Water Systems for Interstate Highways, 1967

Introduction: As part of the roadside development along the Interstate Highway System, the Iowa State Highway Commission has constructed eight pair of rest area facilities. Furthermore, two pair are presently under construction with an additional two pair proposed for letting in 1967. An additional nine and one-half pairs of rest areas are in the planning phase, a grand total of 45 rest Brea buildings. The facilities existing were planned and designed in a relatively short period of time. The rest area facilities are unusual in terms of water use, water demand rates, and the fact that there are no applicable guidelines from previous installations. Such facilities are a pioneering effort to furnish a service -which the travelling public desires and will use. The acceptance and current use of the existing facilities shows that the rest areas do provide a service the public will use and appreciate. The Iowa State Highway Commission is to be congratulated for this· pioneering effort. However there are problems, as should be expected when design of a new type of facility has no past operating experience to use as a guide. Another factor which enters is that a rest area facility is quite different and rather unrelated to engineering in the highway field of practice. Basically, the problems encountered can be resolved into several areas, namely 1) maintenance problems in equipment due to 2) insufficient capacity of several other elements of the water systems, and 3) no provisions for water quality control. This study and report is supposed to essentially cover the review of the rest areas, either existing and under construction or letting. However, the approach used has been somewhat different. Several basic economically feasible water system schemes have been developed which are· adaptable to the different well capacities and different water qualities encountered. These basic designs are used as a guide in recommending modifications to the existing rest area water systems, anticipating that the basic designs will be used for future facilities. The magnitude of the problems involved is shown by the fact that the projected water use and demand variations of each rest area building is equivalent to the water supply for a community of about 100 people. The problems of proper operation and maintenance of an eventual thirty to forty-five such facilities are gigantic. For successful operation the rest area water systems must have a high degree of standardization and interchangeability of all elements of the water systems, even if it means a limited degree of over-design in some rest area facilities.

El just-in-time i la fallida dels sistemes productius al Japó al març de 2011

El document descriu com el just-in-time va afavorir la fallida dels sistemes productius de les empreses d'automoció al Japó durant el gran terratrèmol de l'any 2011.