Optimal operation of water reclamation facilities (WRFs) is critical for an indirect potable reuse (IPR) system, especially when the reclaimed water constitutes a major portion of the reservoir's safe yield. It requires timely and informed decision-making in response to the fluctuating operational conditions, e.g., weather patterns, plant performance, water demand, etc. Advanced integrated modeling techniques can be used to develop reliable operational strategies to mitigate future risks associated with water quality without needing high levels of financial investment. The Upper Occoquan Service Authority (UOSA) WRF, located in northern Virginia, discharges nitrified reclaimed water directly into a tributary of the Occoquan Reservoir, one of the major water supply sources for Fairfax County. Among the many operational challenges at UOSA, one is to regulate the nitrate concentration in its reclaimed water based on the denitrifying capacity of the reservoir. This study presents an integrated model that is used to predict future reservoir conditions based on the weather and streamflow forecasts obtained from the Climate Forecast System and the National Water Model. The application captures the dynamic transformations of the pollutant loadings in the streams, withdrawals by the water treatment plant, WRF effluent flows, and plant operations to manage the WRF performance. It provides plant operators with useful feedback for correctly targeting the effluent nitrates using an intelligent process simulator called IViewOps. The platform is powered by URUNME, a new software that fully automates the operation of the reservoir and process models integrating forecasting products, and data sources. URUNME was developed in C#.NET to provide out-of-the-box functionality for model coupling, data storage, analysis, visualization, scenario management, and decision support systems. The software automatically runs the entire integrated model and outputs data on user-friendly dashboards, displaying historical and forecasting trends, on a periodic basis. This decision support system can provide stakeholders with a holistic view for the design, planning, risk assessments, and potential improvements in various components of the water supply chain, not just for the Occoquan but for any reservoir augmentation type IPR system. / Doctor of Philosophy / In an indirect potable reuse (IPR) system, reclaimed water from an advanced wastewater treatment facility is blended with a natural water source, such as a reservoir, to augment drinking water supply. Reliable operation of such a system is critical, especially when the reclaimed water constitutes a major portion of the withdrawals from the reservoir for treatment and distribution. One example of such an IPR system is the Upper Occoquan Service Authority (UOSA) water reclamation facility (WRF) which discharges its reclaimed water into the Occoquan Reservoir, a key water resource for Fairfax County. Integrated environmental modeling (IEM) provides a comprehensive approach towards the design and operation of water resource systems in which water supply, drainage, and sanitation are simulated as a single entity rather than independent units. In IEM, different standalone models, each representing a single subsystem, are linked together to analyze the complex interactions between various components of the system. This approach can be used for developing operational support tools for an IPR system to ensure timely and informed decision-making in response to the fluctuating conditions, e.g., weather patterns, plant performance, water demand, etc. The overarching goal of this research was to integrate different models and the data sources and develop a decision support system (DSS) to manage the UOSA-WRF performance. This resulting integrated model is used to predict future reservoir conditions based on the weather and streamflow forecasts obtained from the National Weather Service. The application runs various future scenarios to capture the possible variations of the pollutant loadings in the streams, withdrawals by the water treatment plant, WRF effluent flows, and plant operations and provide feedback to plant operators. The entire integrated model is operated periodically to output data on user-friendly dashboards, displaying historical and forecasting trends. The DSS provides stakeholders with a holistic view for the design, planning, risk assessments, and potential improvements in various components of the water supply chain, not just for the Occoquan but for any reservoir augmentation type IPR system.

Soil aquifer treatment (SAT), the removal of contaminants during percolation through soil, is a strategy employed in managed aquifer recharge (MAR), one method of indirect potable water reuse. As part of Hampton Roads Sanitation District's (HRSD) MAR project, The Sustainable Water Initiative for Tomorrow (SWIFT), a soil column study was performed using four columns filled with sand taken from the Potomac Aquifer System (PAS) as well as water from various stages in SWIFT's 1MGD demonstration facility. Two pairs of two columns were operated in series, simulating 3 days and 1 month of travel time through aerobic to anaerobic conditions. During Phase 1 of testing, each pair of columns was fed from different stages in the SWIFT treatment process. During Phase 2 of testing, one set of columns was spiked with a conservative tracer bromide, and several contaminants of emerging concern (CECs). The contaminants monitored during both phases included total organic carbon (TOC), nitrogen species, and the disinfection byproducts bromate and NDMA. During Phase 2 of testing, CECs, iron, arsenic, bromide, and sulfate were monitored in addition to those monitored during Phase 1. About 50% of the TOC was removed within 3 days of travel time, with no additional removal observed in 1 month. Nitrate was conserved in the 3-day columns, but completely removed after 1 month, indicating denitrification. Bromate and NDMA were reduced significantly in the 3-day columns and mostly non-detect in the 1-month effluent. Many of the spiked CECs were reduced significantly in the 3-day column indicating degradation. Three compounds exhibited some retardation through both columns but were not degraded. A few compounds, notably perfluorooctanoic acid (PFOA), showed no retardation or degradation. / Master of Science / In order to continue to meet the water demands of the future, potable reuse is a necessary and effective solution. HRSD's SWIFT project aims to create a sustainable source of drinking water through advanced treatment of its wastewater effluent and subsequent recharge of the Potomac Aquifer in a process known as managed aquifer recharge (MAR). During MAR, chemical and biological contaminants are attenuated or removed through a process known as soil aquifer treatment (SAT). HRSD installed pilot-scale soil columns at their 1MGD SWIFT demonstration facility to evaluate the potential removal of contaminants. During the study, removal of contaminants, both regulated and unregulated, was observed. This study demonstrated that SAT provides an effective environmental barrier against many contaminants and helped to inform the level of treatment necessary to protect public health during MAR potable reuse projects.

Soil aquifer treatment (SAT) during managed aquifer recharge has been studied as a method of providing additional environmental barriers to pathogens and contaminants in indirect potable reuse (IPR) applications. A soil column study was conducted by Hampton Roads Sanitation District in order to evaluate the effectiveness of SAT, as a component of its IPR project involving the replenishment of the Potomac Aquifer System (PAS), in providing a sustainable source of drinking water. Four packed soil columns were constructed with sand from the PAS and were designed to simulate the travel time of 3 days and 30 days. The tests conducted aimed at evaluating pathogen removal (MS2, E. coli and Cryptosporidium oocysts); evaluating attenuation of regulated (nitrate, nitrite, bromate, trihalomethane (THM), haloacetic acids (HAA), organic carbon) and unregulated contaminants of concern that affect drinking water quality. Effective pathogen removal was observed with 6 to 7-log removals of MS2 and E. coli and 3 to 5-log removals of microbeads, used as a surrogate for Cryptosporidium. Removal across 3 day columns was comparable to 30-day columns but the potential to achieve higher removal with longer retention time was acknowledged. Nitrate, bromate, THMs and HAAs were completely reduced in 30-day columns. Total organic carbon was removed at 25 – 35% in all four columns. Seven out of the 106 contaminants of emerging concern (CEC) tested were consistently detected in the column feed and effluent at concentrations greater than 100 ng/L; some compounds showed potential for removal while no conclusive results were drawn for the remaining compounds. / MS / Potable reuse is a sustainable solution to the increasing water demands of the present and more so the future. Hampton Road Sanitation District (HRSD) aims to treat effluent from its wastewater treatment plants using advanced treatment process for direct recharge of the Potomac aquifer system. This is a method of indirect potable reuse termed as managed aquifer recharge (MAR). MAR can provide additional environmental barriers to contaminants present in water through a process of natural attenuation called soil aquifer treatment (SAT). A soil column study was conducted at HRSD’s pilot scale facility in order to asses SAT under controlled conditions at a meaningful scale. Attenuation of pathogens; regulated contaminants (nitrate, nitrite, bromate, etc.) and contaminants of emerging concern was evaluated through the soil columns. The results showed effective removal of most contaminants of interest which demonstrated that SAT potentially improves water quality and meets public health standards in potable reuse applications.

The Potomac River Basin is significant for both public and ecological health as it flows directly into the ecologically-sensitive Chesapeake Bay. It is a drinking water source for about 5 million people living in Maryland, Virginia, and Washington D.C. The discovery of intersex fish, an indicator of poor ecological health, in the Chesapeake Bay occurred in the 2000s, and has led to a series of studies in the watershed to determine the sources and magnitude of endocrine disruption. Endocrine disrupting compounds (EDCs) are exogenous chemicals that interfere with the endocrine system and can cause detrimental health effects at low concentrations. This study aims to understand a best management practice referred to as planned indirect potable reuse (IPR) and its impacts on EDCs. The Occoquan Watershed is a planned IPR subwatershed of the Potomac River Basin. Water samples were collected at the water reclamation plant discharge (Upper Occoquan Service Authority), up- and downstream of that location along Bull Run, and at the water treatment plant intake (Frederick P. Griffith WTP) in the Occoquan Watershed to assess planned IPR. Samples were also collected at a water treatment plant (James J. Corbalis WTP) along the Potomac River for comparison as an unplanned IPR location. These two groups of samples were analyzed for EDCs (categorized into two groups: estrogen hormones and other synthetic organic compounds (SOCs)), nutrients, and other water quality parameters. The infrequency of estrogen hormones and SOC patterns indicate planned and unplanned IPR are both viable approaches to provide safe drinking water / Master of Science / Our river systems are important to maintain both for human and environmental health. The Potomac River Basin is the area of land drained by the Potomac River and its tributaries. The Potomac River Basin is significant for both public and ecological health as it flows directly into the ecologically-sensitive Chesapeake Bay. It is a drinking water source for about 5 million people living in Maryland, Virginia, and Washington D.C. The discovery of intersex fish, or when a single fish has both male and female characteristics, occurred in the Chesapeake Bay in the 2000s. Fish health is often an indicator of poor environmental health, and in this case endocrine disruption. This discovery led to a series of studies in the watershed to determine the sources and magnitude of endocrine disruption. Endocrine disrupting compounds (EDCs) are external chemicals that interfere with the endocrine system once they enter the body of a human or another organism, and can cause detrimental health effects even at low concentrations. This study aims to understand a best management practice, or a type of water pollution control, referred to as planned indirect potable reuse (IPR) and its impacts on EDCs. IPR occurs when wastewater from a community is discharged into to a river or a reservoir, and then downstream it is withdrawn from that same source for drinking water purposes. This can be either planned or unplanned. Planned IPR is becoming more common as population, especially in urban areas, increases. The Occoquan Watershed is a planned IPR subwatershed of the Potomac River Basin. Water samples were collected at the water reclamation plant discharge (Upper Occoquan Service Authority), up- and downstream of that location along Bull Run, and at the water treatment plant intake (Frederick P. Griffith WTP) in the Occoquan Watershed to assess planned IPR. Samples were also collected at a water treatment plant (James J. Corbalis WTP) along the Potomac River for comparison as an unplanned IPR location. These two groups of samples were analyzed for EDCs (categorized into two groups: estrogen hormones and other synthetic organic compounds (SOCs)), nutrients, and other water quality parameters. The infrequency of estrogen hormones and SOC patterns indicate planned and unplanned IPR are both viable approaches to provide safe drinking water.

Tesis por compendio / [EN] For many years energy needs of ruminants have tried to be known to formulate rations adjusted, but it has been found that there are a variety of factors that affect them. Therefore, lots of studies are needed for evaluating the effect of these factors. Consequently, the main objective of this Thesis was to design and validate a respirometry system based on indirect calorimetry, which would allow assessing energy needs of small ruminants accurately. It was intended from the beginning it was a mobile system and of relatively low cost. Furthermore, a methane gas analyzer was incorporated to this system, which allowed the measurement of emissions of this greenhouse gas and quantification of energy losses in the form of methane. Initially the system had connected a mask, which was placed on the animal's face. A sample of exhaled gas was stored in a gas collection bag which was connected to the analyzer, and it measured the concentration of O2, CO2 and CH4 from the air. The proper functioning of the system was checked by a pilot experiment with dry Murciano-Granadina breed goats fed at maintenance level. Later this system was improved. Some of the most important changes were the replacement of the mask by a head hood in which the animal introduced the whole head, and the development of software that recorded and kept automatically concentrations of O2, CO2 and CH4 in exhaled air. This improvement allowed gas measurements during longer periods of time and recording more data. These changes were also validated through a pilot test with dry Manchega breed sheep. Subsequently, three experiments were performed. One of them with dry Guirra ewes and the other two with Murciano-Granadina goats during mid lactation. Diets were mixed rations that differed in the inclusion of cereal or fibrous by-products. In these experiments the effect of diet was studied on digestibility, energy balance and carbon-nitrogen, oxidation of nutrients, rumen parameters and methane production; in the case of lactating goats, also on milk performance. The determination of the calibration factor for O2 (1.005 ± 0.0101) confirmed the proper functioning of equipment. Moreover, small differences between the heat production obtained by indirect calorimetry and the carbon-nitrogen balance (2% in sheep and 1% in goats) demonstrated that this system allows determining the heat production of the animals reliably and accurately. In the experiments of this Thesis have been estimated maintenance energy needs of two Spanish native sheep breeds, such as the sheep from the Guirra and Manchega breeds; net maintenance requirements were 270 kJ/kg BW0.75, on average. In the case of Murciano-Granadina breed goats, in the middle of lactation, the average utilization efficiency of metabolizable energy for lactation was 0.61. / [ES] Desde hace años se ha tratado de conocer las necesidades energéticas de los rumiantes con el fin de formular raciones ajustadas, pero se ha comprobado que hay una gran variedad de factores que les afectan; por ello son necesarios estudios que evalúen el efecto de estos factores. Como consecuencia, el principal objetivo de esta tesis fue diseñar y validar un equipo de respirometría, basado en calorimetría indirecta, que permitiese evaluar las necesidades en energía de pequeños rumiantes de forma precisa. Se pretendió desde el inicio que fuese un sistema móvil y de relativo bajo coste. Además, a este sistema también se le incorporó un analizador de gas metano, que permitía la medición de las emisiones de este gas de efecto invernadero y la cuantificación de las pérdidas energéticas en forma de metano. Inicialmente el equipo tenía conectada una máscara que se colocaba en la cara del animal. Una muestra del gas espirado era almacenada en una bolsa de recogida de gases que era conectada al analizador, el cual medía la concentración de O2, CO2 y CH4 del aire. Se comprobó el correcto funcionamiento del sistema mediante una prueba piloto con cabras de raza Murciano-Granadina secas, alimentadas a nivel de mantenimiento. Posteriormente este sistema fue mejorado. Algunos de los cambios más importantes fueron la sustitución de la máscara por una urna en la que el animal introducía la cabeza entera, y el desarrollo de un software que registraba y guardaba de forma automática las concentraciones de O2, CO2 y CH4 del aire espirado. Esta mejora permitía medidas de gases durante periodos de tiempo más largos y el registro de muchos más datos. Estas modificaciones también fueron validadas mediante una prueba piloto con ovejas de raza Manchega secas. Posteriormente se realizaron tres experimentos. Uno de ellos con ovejas de raza Guirra secas y los otros dos con cabras Murciano-Granadinas en mitad de lactación. Las dietas fueron raciones mixtas que diferían en la inclusión de cereal o subproductos fibrosos. En estos experimentos se estudió el efecto de la dieta sobre la digestibilidad, balances de energía y carbono-nitrógeno, oxidación de los nutrientes, parámetros del rumen y producción de metano; en el caso de las cabras en lactación, también sobre los rendimientos productivos. La determinación del factor de calibrado para el O2 (1,005 ± 0,0101) confirmó el buen funcionamiento del equipo. Por otro lado, las pequeñas diferencias entre la producción de calor obtenida mediante calorimetría indirecta y el balance de carbono-nitrógeno (2% en ovejas y 1% en cabras) demostraron que este sistema permite determinar la producción de calor de los animales de forma fiable y precisa. En los trabajos de esta Tesis se han estimado las necesidades energéticas de mantenimiento en dos razas de ovejas autóctonas españolas, como son las razas Guirra y Manchega; las necesidades netas de mantenimiento fueron 270 kJ/kg PV0,75, de media. En el caso del ganado caprino de raza Murciano-Granadina, en mitad de lactación, la eficacia media de utilización de la energía metabolizable para la lactación fue de 0,61. / [CA] Des de fa anys s'ha tractat de conèixer les necessitats energètiques dels remugants a fi de formular racions ajustades, però s'ha comprovat que hi ha una gran varietat de factors que els afecten; per això són necessaris estudis que avaluen l'efecte d'estos factors. Com a conseqüència, el principal objectiu d'aquesta Tesi va ser dissenyar i validar un equip de respirometría, basat en calorimetria indirecta, que permetera avaluar les necessitats en energia de menuts remugants de forma precisa. Es va pretendre des de l'inici que fóra un sistema mòbil i de relatiu baix cost. A més, a este sistema també se li va incorporar un analitzador de gas metà, que permetia el mesurament de les emissions d'este gas d'efecte hivernacle i la quantificació de les pèrdues energètiques en forma de metà. Inicialment l'equip tenia connectada una màscara que es col·locava en la cara de l'animal. Una mostra del gas expirat era emmagatzemada en una bossa d'arreplega de gasos que era connectada a l'analitzador, el qual mesurava la concentració d'O2, CO2 i CH4 de l'aire. Es va comprovar el funcionament correcte del sistema per mitjà d'una prova pilot amb cabres de raça Murciano-Granadina seques, alimentades a nivell de manteniment. Posteriorment este sistema va ser millorat. Alguns dels canvis més importants van ser la substitució de la màscara per una urna en què l'animal introduïa el cap sencera, i el desenrotllament d'un programari que registrava i guardava de forma automàtica les concentracions d'O2, CO2 i CH4 de l'aire expirat. Esta millora permetia mesures de gasos durant períodes de temps més llargs i el registre de moltes més dades. Estes modificacions també van ser validades per mitjà d'una prova pilot amb ovelles de raça Manxega seques. Després es van realitzar tres experiments. Un d'ells amb ovelles de raça Guirra seques i els altres dos amb cabres Murciano-Granadinas en mitat de lactació. Les dietes van ser racions mixtes que diferien en la inclusió de cereal o subproductes fibrosos. En estos experiments es va estudiar l'efecte de la dieta sobre la digestibilitat, balanços d'energia i carboni-nitrogen, oxidació dels nutrients, paràmetres del rumen i producció de metà; en el cas de les cabres en lactació, també sobre els rendiments productius. La determinació del factor de calibrat per a l'O2 (1,005 ± 0,0101) va confirmar el bon funcionament de l'equip. D'altra banda, les xicotetes diferències entre la producció de calor obtinguda per mitjà de calorimetria indirecta i el balanç de carboni-nitrogen (2% en ovelles i 1% en cabres) van demostrar que este sistema permet determinar la producció de calor dels animals de forma fiable i precisa. En els treballs d'esta Tesi s'han estimat les necessitats energètiques de manteniment en dos races d'ovelles autòctones espanyoles, com són les races Guirra i Manxega; les necessitats netes de manteniment van ser 270 kJ/kg PV0,75, de mitja. En el cas del bestiar caprí de raça Murciano-Granadina, en mitat de lactació, l'eficàcia mitjana d'utilització de l'energia metabolitzable per a la lactació va ser de 0,61. / López Luján, MDC. (2015). Development of a mobile open-circuit system based on indirect calorimetry for energetic metabolism studies in small ruminants [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/50430 / Compendio

No / The purpose of this paper is to utilize the existing theories and knowledge surrounding information systems (IS) evaluation and Green information technology (IT)/IS investments to develop a conceptual model for helping decision makers to overcome and reduce the impacts from Green IT/IS investment related to cost overruns or under-optimized budgets. The paper is discursive, based on the analysis and synthesis of literature pertaining to IS evaluation, Green IT/IS adoption and Sustainable/Green/CSR within an aviation context. Gaps in the preceding research have been identified, and a conceptual model is proposed. Additionally, further research and a methodology are suggested. The paper proposes a conceptual model that can identify factors including external factors derived from institutional theory, internal organizational factors, and a list of indirect costs associated with Green IT/IS investments for an aviation organization. As a conceptual paper, the study is limited to literature, identifying gaps, and proposing a model. The paper recommends further empirical validation of the proposed conceptual model. The conceptual model is helpful for decision makers within the aviation industry to enhance their understanding of the identification and management of indirect costs within the aviation context, which results in effective management of Green IT/IS indirect costs. The paper fills gaps in the knowledge of IS evaluation, Green IT/IS adoption/evaluation within aviation context through helping decision makers to understand, identify, and manage the associated indirect costs.

<p dir="ltr">The increased interest in deep space missions is creating an increased interest in cislunar space. The need for fast and efficient methods of traversing the lunar vicinity in creases as more spacecraft enter the region. This investigation discusses methods of low thrust transfer design in order to create low cost and low time of flight transfers. Indirect optimization is employed to compute minimum energy and minimum fuel transfers in the circular restricted three body problem. Sigmoid smoothing techniques are leveraged to ap proximate the optimal bang-coast-bang solution with continuous functions. The minimum fuel solution is employed as an initial guess to target an inertially fixed thrust direction transfer. This process is applied to a variety of cislunar orbital transfer problems. Transfers are constructed between orbits in the L1 halo, L2 halo, distant retrograde, and L4 short period orbit families. The resulting trajectories are compared to impulsive and free transfers from the literature based on the required propellant mass and time of flight.</p>

Kiekvienai gamybinę veiklą vykdančiai ar paslaugas teikiančiai įmonei tikslus gaminamos produkcijos ar paslaugų savikainos įvertinimas pinigine reikšme yra itin svarbus klausimas. Savikainos skaičiavimų metodų ir būdų yra labai daug, jų parinkimą įmonei lemia taikomos gamybos pobūdis ir jos organizavimas, įmonės vykdoma veikla, aplinka ir kiti veiksniai. Norint teisingai apskaičiuoti produktų savikainą, visas įmonės patiriamas išlaidas pirmiausia reikia tinkamai identifikuoti, tiesiogines priskirti konkretiems gaminimas, o netiesiogines išlaidas racionaliai paskirstyti tarp numatytų objektų, kurių savikainą reikia apskaičiuoti. Tačiau pagal gamybos pobūdį parinktas savikainos kalkuliavimo metodas dažniausiai nėra pats tinkamiausias netiesioginėms išlaidoms apskaityti ir paskirstyti. Tuo tarpu autoriai tyrę ABC sistemą, savo straipsniuose pažymi, kad šiuo metu su netiesioginių išlaidų paskirstymo užduotimi geriausiai susidoroja būtent ABC metodas. Norint pasinaudoti pagal gamybos pobūdį parinkto metodo (šiuo atveju procesinio fazinio metodo) ir ABC sistemos privalumais susiduriama su problema: mokslinėje literatūroje procesinis ir ABC produkcijos kalkuliavimo metodai pateikiami atskirai, neanalizuojama galimybė šiuos metodus sujungti į vieną savikainos kalkuliavimo modelį. Darbo objektas – procesinio fazinio ir ABC savikainos kalkuliavimo metodų ypatybės bei privalumai. Darbo tikslas – sukurti savikainos skaičiavimo modelį, kuris leistų tiksliai ir efektyviai apskaičiuoti... [toliau žr. visą tekstą] / Exact value of production or service costs is important issue for all manufacturing or service companies. There are many methods and approaches of costing. The mode of production, the organization of production, company activities, environment and other factors influence method to use for production costing. In order to get correct calculation of production costs, all costs incurred by company firstly must be properly indentified, direct costs should be assigned, overhead allocated to objects which cost must be calculated. However, method of calculation chosen by nature of the production is not most appropriate for accounting and allocating indirect costs. Meanwhile the authors, who analyzed the ABC system, points out that ABC method the indirect cost allocation task handle most notably. In order to use benefits of ABC method and method chosen by nature of production (in this case process phase costing method) encountered a problem: process costing and ABC methods are presented separately into science or professional literature, no one does not examine the possibility to use these two methods in single production costs calculation model. The object – features and benefits of process phase costing and ABC methods. The aim – to design a costing model which can accurately and effectively calculate the direct cost of products, rationally allocate cost of company activities to production. The objectives: • To analyze the nuances of choice cost calculation method by company... [to full text]

Introduction : Après un traitement orthodontique, la rétention (ou contention) est essentielle pour éviter les récidives vers la malocclusion initiale. Le fil de rétention lingual est un appareil fixe, relativement facile à installer et bien accepté par les patients pour maintenir la position finale des dents antérieures inférieures. Étant de plus en plus utilisé, il devient important de s’assurer de sa fiabilité pour la stabilité de l’alignement dentaire. Objectif : Le but de cette étude clinique randomisée prospective est de déterminer le taux de survie d’un fil lingual mandibulaire de rétention en comparant les méthodes de collage direct et de collage indirect à court et moyen termes. Méthodologie : L’échantillon est constitué de 117 patients consécutifs aléatoirement distribués dans 2 groupes : collage direct (n=58) et collage indirect (n=59). Les fils torsadés de diamètre 0,0175’’ sont préformés par un technicien de laboratoire soit selon la méthode de collage direct, soit selon la méthode de collage indirect. Une matrice de transfert en silicone assure le positionnement précis du fil lingual en bouche. Assure® et Filtek™ Flow ont été utilisés pour le collage direct. Filtek™ Flow, Assure®, and Sondhi™ ont été utilisés pour le collage indirect. Les fils de rétention ont été évalués pour le décollement, l’infiltration, la distorsion et le bris à 2 mois (T1) et 6 mois (T2). Résultats : À T1, le taux de survie du fil de rétention est de 90,2% pour le groupe de collage direct, comparativement à 79,5% pour le groupe de collage indirect (p=0,232). À T2, le fil est resté intact pour 74,1% des participants dans le groupe de collage direct et pour 70,0% des participants dans le groupe de collage indirect (p=0,481). Les différences ne sont pas statistiquement significatives entre les 2 groupes. La fréquence du décollement est plus haute que les autres problèmes enregistrés à T1 (p<0,022), représentant 85,7% des échecs. À T2, le décollement est plus fréquent que la distorsion ou le bris (p<0,04), mais pas statistiquement plus fréquent que l’infiltration (p=0,109). Il représente alors 86,4% des échecs. Conclusion : Le décollement est la principale cause d’échec d’un fil de rétention lingual. Il n’y a pas de différence statistiquement significative du taux de survie d’un fil lingual mandibulaire de rétention entre les techniques de collage direct et de collage indirect à court et moyen termes. / Background: The lingual wire has been shown to be an effective way to ensure the retention of the lower anterior segment after orthodontic treatment. As it is increasingly used, it is important to achieve proper bonding of the wire to ensure stability. Objective: The aim of this prospective randomized clinical study is to assess the short and medium term survival rate of the mandibular lingual retention wire using 2 different bonding techniques (direct and indirect). Materials and Methods: The sample of 117 consecutive patients was randomly distributed into 2 groups: direct bonding (n=58) and indirect bonding (n=59). The multi-strand twist wires (0,0175”) used were all preformed by a technician and prepared for either direct or indirect bonding technique with a transfer matrix. Assure® and Filtek™ Flow were used for direct bonding. Filtek™ Flow, Assure®, and Sondhi™ were used for indirect bonding. The lingual wires were evaluated for bonding failure, infiltration, breakage, and distortion at 2 months (T1) and 6 months (T2). Results: At T1, survival rate for the lingual wire was 90,2% for direct bonding and 79,5% for indirect bonding (p=0,232). At T2, the lingual wire was intact for 74,1% of the participants in the direct bonding group and 70,0% for the indirect bonding group (p=0,481). The differences between the 2 groups were not statistically significant. Debonding was more frequent than all other problems at T1 (p<0,022), accounting for 85,7% of the failures. At T2, debonding was more frequent than distortion and breakage (p<0,04), but not statistically more frequent than infiltration (p=0,109). It then accounted for 86,4% of the failures. Conclusion: Debonding is the main cause of failure for a lingual retention wire. There is no statistically significant difference in the survival rate of a lingual retention wire using direct and indirect bonding techniques in the short and medium term.

L’article 1844 C. civ. suggère que seuls les associés sont titulaires du droit de vote. Une telle affirmation suscite cependant des interrogations. Elle laisse insatisfait, de prime abord, au vu de l’imprécision des contours de la notion d’associé. Elle invite, en outre, à s’interroger sur sa justification. Une analyse attentive des textes montre que pour déterminer le titulaire du droit de vote, ceux-ci se réfèrent indifféremment, à la qualité d’associé ou à la qualité de propriétaire de parts sociales ou d’actions – les deux étant censées se confondre. Et cela s’explique par le fait que les associés sont supposés supporter l’aléa social, aléa inhérent à la propriété de parts sociales ou d’actions. Mais seule la propriété dotée de l’absolutisme que les rédacteurs du Code civil voulaient lui conférer permet de présumer l’aléa social. Or le développement de propriétés temporaires ou pour autrui a conduit à attribuer le droit de vote à des associés ne le supportant pas, ébranlant ainsi la construction sociétaire. A cela, s’ajoutent des pratiques permettant à un non-associé de voter, sans garantie qu’il agisse pour le compte d’un associé. La recherche d’une solution cohérente et complète invite à redéfinir la notion d’associé en la fondant sur l’aléa social. Le droit de vote bénéficierait ainsi aux seuls acteurs courant un tel aléa. Cette solution peut être aisément mise en oeuvre moyennant quelques aménagements des modalités de reconnaissance de la qualité d’associé et des prérogatives sociales. Un encadrement spécifique des mécanismes d’accès au vote par un non-associé reste cependant nécessaire. / Article 1844 of the Civil Code suggests that only shareholders hold voting rights. Such an assertion gives rise to several questions. It leaves dissatisfied, prima facie, considering the vagueness of the concept of shareholder. In addition, it leads to a question about the justification of the allocation of voting rights to shareholders. A careful analysis of the texts shows that, in view of defining the holders of voting rights, they indifferently refer to the capacity of shareholder or to the capacity of owner of shares – as both are supposed to coincide. And this can be explained by the idea that shareholders are meant to bear the corporate hazard. However, this hazard can only be inferred from an ownership corresponding to the absolutist conception of the Civil Code’s authors. Yet, the development of temporary ownerships or ownerships for others has lead to assign voting rights to shareholders who do not bear this hazard, and has undermined the corporate construction. In addition to this, practices allowing a non-shareholder to vote, without assurance that the vote will be cast on behalf of a shareholder, have a similar effect. The pursuit of a coherent and complete solution prompts to redefine the notion of shareholder, basing it on the concept of corporate hazard. Voting rights would thus only benefit to persons who bear such a hazard. This solution can easily be implemented by slightly adapting the current methods for recognizing shareholder’s capacity and corporate rights. Nevertheless, a specific legal framework for devices allowing non-shareholder to vote remains necessary.