Organizational work with enterprise systems: a double agency perspective

Enterprise Systems are used by most large, and also by some small-medium enterprises, as tools to streamline internal and external activities. Installation of an Enterprise System usually entails changes in the organization, in terms of updating or rewriting business processes to match the ones inscribed in the Enterprise System. Consequently, the work of managers and employees in the organization changes accordingly. The purpose of this paper is to investigate the nature of work that is afforded by an Enterprise System, according to the intentions of managers and users. In particular, the way that managers and employees interact with the Enterprise System and the issues that arise from this interaction are explored. The paper proposes a theoretical conceptualisation for the dynamic interaction between users, management, and the Enterprise System

Enterprise Systems as Embedding and Disembedding Technologies - Power Implications for Work Relationships

This paper examines Enterprise Systems as a form of disembedding (and conversely reembedding) technology that alters the work relationships in an organization, by altering the power and control bases in such an organization. Enterprise Systems are used to facilitate the seamless integration and data exchange between the various departments within an organization. Their purpose is to automate the exchange of information and streamline the business processes within the organization. Use of an Enterprise System accords to its users responsibilities different from before, and allows for various control mechanisms to take place. Enterprise Systems as (re)embedding and disembedding technologies, lead to different levels of employee empowerment and corresponding managerial control. The results presented here are preliminary and come from an investigation in a single company. These results tend to suggest that Enterprise Systems change the work patterns in a company by disembedding the power bases and reembedding the control mechanisms used. This is accomplished with the empowerment of individuals with increased responsibilities, but also with the better managerial control of employee actions

ERP use, control and drift: an agency perspective

Enterprise Resource Planning (ERP) systems are information systems that integrate organizational activities across geographical and functional divisions. Being enterprise-wide systems, they are used within an organization in order to standardise its data and streamline its business processes. However, the envisaged benefits of installing an ERP system, such as better control over the company’s operations and seamless integration and data exchange, often fail to materialize. Although the literature has looked into the factors affecting a successful ERP implementation and adoption, it has largely overlooked the actual use of the system. However, as ERP systems have become widespread in many organizations, it is important to examine the use of such systems and their organizational consequences in-situ. This research is particularly concerned with the impact of the use of ERP systems on organizational control and drift. The main argument is that there are contextual factors, in the form of existing organizational control and drift, which influence the use of the ERP system by its users. The actual use of the ERP system can then also lead to organizational control or drift itself. This depends on the way the system is used by its users, as well as the affordances of the system. The former is characterized as human agency in this thesis, while the latter is characterized as machine agency. An interpretive case study approach is adopted to examine those issues. A main case study is examined in depth, aided by four auxiliary case studies. The main contribution of this research is the provision of rich insights regarding the use of ERP systems and their organizational consequences.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

H-terminated polycrystalline boron doped diamond electrode for geochemical sensing into underground components of nuclear repositories

Nuclear waste repositories are being installed in deep excavated rock formations in some places in Europe to isolate and store radioactive waste. In France, Callovo-Oxfordian formation (COx) is potential candidate for nuclear waste repository. It is thus necessary to measure in situ the state of a structure's health during its entire life. The monitoring of the near-field rock and the knowledge of the geochemical transformations can be carried out by a set of sensors for a sustainable management of long-term safety, reversibility and retrievability. Among the chemical parameters, the most significant are pH, conductivity and redox potential. Wide band gap semiconductors are favored materials for chemical sensing because of their high stability to many chemical agents. Among the wide band gap materials, Chemical Vapor Deposition (CVD) boron doped diamond (BDD) benefits from a large band gap (5.45 eV), which gives rise to a wide electrochemical potential window (~3 V/Saturated Calomel Electrode(SCE)) (Angus et al. 1999). It is moreover described as a radiation, corrosion and bio-corrosion resistant. These remarkable properties, in addition to a low double layer capacity and a low residual current, make BDD a promising material for geochemical sensor elaboration. This work aimed to investigate BDD- based electrodes coated with p-type polycrystalline BDD- hydrogen-terminated surfaces (1 cm2) for pH and/or redox measurements into the underground components of nuclear repositories. The boron-doped p-type channel was grown in a microwave plasma reactor (BJS 150) (Silva et al. 2009). The boron-doped channel was hydrogen terminated by a hydrogen plasma treatment in the CVD reactor, resulting in full saturation of the surface carbon bonds with hydrogen atoms. Figure 1 shows the Scanning Electron Microscopy (SEM) of the polycrystalline BDD coating with a Bore/Carbon ratio of 500 ppm and its Raman spectrum. SEM micrograph illustrates the typical columnar growth of the polycrystalline CVD diamond. A homogeneous surface was observed concerning the crystallite size which average was 1.5 microns. On the Raman spectrum of a single crystal diamond intrinsic film (undoped), the diamond peak is usually observed at 1332 cm-1. In Figure 1, the intense peak at 1327 cm-1 corresponding to diamond is shifted due to the "Fano" effect according to doping, which is observed through a broad peak at 910 cm-1. Its intensity shows that the investigated sample was highly doped. Gheeraert et al. (1993) suggested that the peaks at 500 and 1230 cm-1 appears when the boron concentration reaches the critical value of 3×1020 at.cm-3 corresponding to a metallic conductivity. The lack of peak around 1350 cm-1 and 1570 cm-1, which corresponds respectively to D and G graphite peak of impurity phases of non-diamond carbon (sp2), attests to the crystalline quality of the deposit. The slight width at half maximum of the characteristic peak of diamond compared to that of natural diamond reflects the degree of organization and structural perfection of this phase indicating that the coating was of high quality. Electrodes made in this way have been used for 8 month without any surface treatments or conditioning. The electrochemical behavior of Hydrogen-terminated BDD was studied by cyclic voltammetry. Electrodes showed a wide potential range of about 2 V/SCE. They also showed and a rapid reversible charge transfer in the presence of redox probes such FeCN63-/4- and Ru(NH)63+/2+. Performances, reliability and robustness for pH or redox monitoring were examined by potentiometric measurements at 25°C under anaerobic conditions (oxygen-free atmosphere, 100 % nitrogen) in a glove box. Investigation has been limited in pH, ranging from 5.5 to 13.5, close to those encountered in the environment of the nuclear repositories. The feasibility of measuring pH with BDD electrodes was first tested in NH4Cl/NH3-NaCl (0.1mol L-1) buffer solutions, leading to electrode calibration over the widest range of pH, from around neutral to basic pH. Experiments were also conducted in NaHCO3/Na2CO3 buffer samples, similar to conditions prevailing in the COx formation. For redox measurements, [Fe3+]/[Fe2+] ratios were analysed at different pH and/or ionic strengths (supporting electrolytes concentration ranged from 0.05 to 1 mol.L-1). The same measurements were also done using a 10-mm disk platinum electrode with a surface of 78.54 mm². No pH sensitivity was observed, thus the energy level of the state was not moved. However, for redox measurements the potential acquired by Hydrogen-terminated BDD and Platinum electrode converged to a value of the same order of magnitude, independently of the sample. This fact demonstrates that, under the same experimental conditions, the redox couples fixe identically the potential of the electrodes. Investigations with reference to ionic strength in thermodynamically equilibrated Fe(III)/Fe(II) samples were highly interesting. Independently of the electrode, the voltage measurement was not or little affected, whereas both the solution conductivity as well as the speciation were affected, due to the increase in salinity. This means that the term [Fe3+]/[Fe2+] is practically unaffected. This implies that assuming the ratio of the activity coefficients, γFe3+/ γFe2+ as equal to 1 has a minor effect on the measured redox potential. H-terminated BDD electrode appears well suited for redox monitoring. Work is in progress to demonstrate the robustness of the H-terminated BDD electrode for redox monitoring into COx over a long period

Aquifer Biothermoremediation using Heat Pumps : sound theoretical basis and results on thermal, geochemical and biological impacts on aquifers

International audienceGeothermal heat pumps have been operated on aquifer over the past thirty years. Currently, these systems constitute a major sector of renewable energy development. However, this development is accompanied by several difficulties at scientific, technical and administrative levels, to describe short and long term interactions with aquifers, at both the local and regional scale, especially close to urbanized or industrialized areas. As a typical example, the long-term use of groundwater heat pumps for air conditioning of homes or buildings can induce significant increases in temperature of the aquifer, if, for given groundwater flow direction and rate, there is an imbalance between the demands for cooling and heating. Therefore, the aquifer (groundwater and sediments) can be affected. In fact, it is expected that a wide variety of geochemical reactions and microbiological changes with variable intensity should occur which depends on the sediment characteristics and hydrogeological background. The presence of organic pollutants in the aquifer can amplify these phenomena. The predictable results may progressively be: (i) precipitation, which reduces the porosity of the aquifer and/or the well productivity, (ii) an inappropriate temperature for the use of groundwater heat pumps for air conditioning, but also and especially (iii) pollutant bioremediation, which has a beneficial impact on the aquifer. Under certain conditions, this bio-thermo-remediation can be considered as an attractive option for some contaminated aquifers, taking into account the fact that, administratively in European countries, any action is subject to authorization. Notably in the framework of the collaborative project BIOTHERMEX (French Region Centre, convention n° 200800034163), exploratory studies were focused on three objectives: i) Improving the understanding of the concept of bio-thermo-remediation of aquifers by using effects induced by geothermal heat pumps. ii) examining realistic configurations, on a laboratory scale, pilot-scale and in-situ, in order to identify the most determining factors for possible (undesirable or helpful) aquifer impacts, e.g. temperature increase, bacterial development, organic pollutants degradation iii) evaluating if those configurations can present interests for bio-thermo-remediation of polluted aquifers by using heat pumps. A literature survey led to the consolidation of the basic principles of bio-thermo-remediation of most organic pollutants: increase in volatilization, solubility, degradation kinetics and mobility of the residual pure phases by reduction of their viscosity. The different heat pump systems and processes are discussed in the article, to identify what is suitable for bio-thermo-remediation. To reproduce the underground thermal conditions encountered in groundwater heat pumps systems (temperature range of water production from 10 to 25 °C, temperature range of water injection between 20 and 35 °C), batch-experiments, at laboratory and pilot scale have been carried out to investigate the impacts of the different parameters on the geochemical equilibrium (solubility, mobility, precipitation, dissolution, volatilization,) on the aquifer inorganic content and organic pollutants as well as on microbial populations activities. Two different sediments were used. Depending on the nature of the sediments and the water composition, the impacts are more significant: (i) thermally, with a low water flow rate, (ii) geochemically, with the high bicarbonate and Ca/Mg contents in water and (iii) biologically, with a organic contaminants contents in water. Some results from in-situ measurements (especially with an aquifer polluted by chlorinated solvents) are used to corroborate the conclusions. Even if the most part of the work is still in progress, the obtained results are validated by biogeochemical modelling. The combination of a low-enthalpy geothermal system using aquifer heat pumps (water pumping and re-injection) and remediation approaches appears to be an appropriate method to treat aquifers polluted by organic contaminants without use of any other way than the thermal energy

Investigations on structural iron electrochemical properties in layered silicates using massive mica electrodes

Nuclear waste repositories are being installed in deep excavated rock formations in some places in Europe to isolate and store radioactive waste. In France, the Callovo-Oxfordian formation (COx) is a potential candidate for a nuclear waste repository. The redox reactivity (kinetics and thermodynamic redox potential) of COx clay rock samples are already under study using microscopic, spectrometric and wet analysis techniques. In order to cross and overcome certain limits by improvement in the knowledge, specific electrodes should be constructed and devoted to the deepening of the electrochemical behaviour of the COx system in different situations. Iron is one of the most common redox species in soils and sedimentary rocks. Iron-bearing phyllosilicates play key roles in various biogeochemical processes. The complexity of the physical and chemical (along with structural) changes involving their structural iron makes the studies of its redox properties challenging. Most of the recent reported efforts were focused on probing Fe redox on finely powdered clay (and often micas) particles, and have been hampered by inadequate interactions between particles and electrodes. Moreover, such experiments usually involve redox probe ions, thus adding supplementary difficulties in the determination of structural iron redox parameters such as redox potential (Eh) and kinetics. The present study aims at qualitatively investigating the above mentioned phenomena on minerals like iron-bearing micas. In the current work, we present initial insights regarding efforts to build a direct electrical interface between solid electrodes and conveniently shaped macroscopic mica crystals in order to investigate the redox properties of structural iron in dry and aqueous environments, in the presence of representative perturbations. A classical three electrode system has been used for voltammetric measurements. Platinum plate (1cm²) was the counter electrode. Potentials have been measured against either silver-silver chloride electrode (Ag-AgCl/3M KCl) or Saturated Calomel Electrode (SCE/KClsat) as reference electrodes. Open Circuit Potential (OCP) measurements and Cyclic Voltammetry (CV) were realised as well as Long term OCP measurements, along with pH and other parameters, are also measured. Most of the experiments discussed here have been conducted in unbuffered NaCl or KCl 0.1 M solutions, at 25°C. Anoxic conditions were maintained by first bubbling N2 and then maintaining a gas layer in the head space of the reactor. Long term measurements showed that in these conditions, pH stays at a value around 8.9 and is stable for several weeks. Experiments realised in buffered solution, at pH 7.5, using 1 mM Piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES) and 2 mM NaOH did not show any observable change. In some experiments, 5 mM ferricyanide (Fe(CN)63-) have also been used as a redox probe. High resistivities previously have been reported for this type of material, ranging from 1010 to 1015 Ω.cm at room temperature. Given the current flows detection limit of the apparatus used for measuring (~nA), the mm-thick pieces used in first experiments should normally behave like insulating screens on Ag (or maybe Cu-Ag) electrodes, e.g. no current could be measured across the sample with low iron content. OCP measurement consists in measuring the electrode rest potential against a reference electrode, in absence of observable current. It provides a first indication on the type of material present on the support electrode; normally no potential should be measured in absence of an electrically conductive path. Unfortunately, first records showed that OCP can be measured immediately after the immersion of all the first electrodes prepared (Figure 1, left) even on muscovite and lepidolite, clearly indicating the presence of water in the different samples. However, signals obtained for lepidolite and muscovite are less stable and can only be conveniently recorded in absence of external perturbation around the electrode such as vibration or even air movement, whereas signals obtained for the different biotite samples are very stable. Changing parameters in the electrolyte such as pH (figure 1, right) removal of O2, or change in Cl- does not seems to affect the measured OCP of this type of electrode as it stay stable for days. Several week-longs monitoring on ten biotite electrodes, dipped in unbuffered NaCl 0.1 M, showed that the OCP slowly decreases and stays stable, at values between 0.1 and 0.14 mV/NHE (data not shown), despite occasional pH oscillation between 4 and 9. Results of these experiments show that several aspects of the designs of such electrodes have to be improved for further experiments. From these observations, we can't preclude that water might participate in the electrical contact between the support electrode and the solution, but we can still hypothesize that it could be due to interlayer traces of water, offering a poorly electrically conductive path in lepidolite and muscovite, whereas another mechanism might participate in the biotite sample. First, lowering of the water content in the mineral must be realised, using smaller crystals, longer drying and vacuuming time, and using more penetrating and impregnating resins. Platinum plates and evaporated platinum or carbon are envisioned for the inert support electrode. Using thinned slices should reduce electrical resistivity of the whole bulk structure, allowing a more convenient observation of the coupled electrons transfers that might occur between separated crystal surfaces. Hence, more suitable cutting techniques, such as wire sawing, should be planned to obtain thinner slices. More mica samples must also be selected, with higher and lower iron contents than the one used in the present experiments. This first set of experiments in interfacing solid electrodes and conveniently shaped mica crystals offers hope that this will be a valuable technique for probing structural iron.

Intercomparison of Ta and Ti solid-electrodes for pH measurements under oxic and anoxic conditions in reconstituted waters of a future nuclear waste disposal

International audienceIn France, the deep geological disposal has been chosen to manage long-lived high and middle activity nuclear waste. This project is supervised by " the Agence National pour la Gestion des Déchets Radioactif" (ANDRA-French national radioactive waste management agency). An underground research laboratory (URL), dedicated to host-rock properties characterization was built at approximately-490m depth in the Callovo-Oxfordian geological formation (COx), which is a potential candidate for nuclear waste disposal. Based on this overall strategy, Andra has analysed the technical requirements that must be met by adapted monitoring equipment. First, these must be able to provide information on key THMCR (Thermal-Hydraulic-Mechanical-Chemical and Radiological) processes, to provide a three-dimensional image of its behaviour and thus to understand the underground installation functioning, in particular the cell interactions with the near-field. This study aims to develop innovative all-solid-state electrodes made of iridium (Ir), ruthenium (Ru), tantalum (Ta), titanium (Ti), tungsten (W), niobium (Nb) and a tin-lead alloy (Sn/Pb), for pH measurement. Moreover, the potentiometric response of these electrodes is mainly based on Metal Oxide (M x O y)/Metal (M) equilibriums, which make them react to changes of oxygen partial pressures. For now, the antimony electrode (Sb) showed excellent results regarding the measure of pH under oxic and anoxic conditions. Nevertheless, it is necessary to multiply the electrode materials considered for pH measurements, for preventing a dysfunction of electrodes which could occur over time. By multiplying the electrode materials for pH measurement, we indirectly increase, firstly, the measurement reliability by giving the possibility to inter-compare the potentiometric responses of the set of the electrodes dedicated to pH, and secondly, the monitoring duration, in the case of electrode surface alterations, which could be caused by variations of the physical and chemical parameters within the nuclear waste repository. In other words, this would provide alternatives electrode materials for pH measurements, in prevention to possible electrode surface alterations. Thus, the influence of pH from 5 to 13, on the potentiometric responses of the several electrodes was investigated by means of pH buffers solutions or by continuous and regulated addition of H 2 SO 4 or NaOH, under both oxic (exposed at air) and anoxic conditions (in glove box: 99% N 2 , 1% CO 2 and [O 2 ] < 2 ppm, 25°C). Titanium (Ti) and tantalum (Ta) electrodes showed a potentiometric linear response to pH variations, as shown on figures 1 and 2. In absence of oxygen, the Ti electrode showed a linear response to pH (from 5.8 to 11), close to the theory. After pH 11, a drop of potential is observed. In presence of oxygen, the response to pH is linear but further to the theory. In the same way, the potentiometric behaviour of the Ta electrode to pH variations is linear, but much more sensitive under anoxic conditions

Modeling the dioctahedral smectites layer charge variation versus structural Iron reduction level

Iron is one of the most common redox species in soils and sedimentary rocks. Amongst iron-bearing phases, phyllosilicates might play key roles in various bio-geochemical processes involving redox reactions, where structural Fe (Festr) can act as a renewable source/trap of electron. A large set of data from kinetics, spectroscopic or electrochemical studies on dioctahedral smectites demonstrates that reduction of Festr impacts many clay properties such as colour, layer charge, swelling pressure, colloidal properties that are linked to layer structural changes. Experiments also suggest that this mechanism is partly reversible, depending on type and properties of the primary oxidized clay, on how the reduction is induced (chemically and/or biologically) and on extent of iron reduction level. The complexity of the involved mechanisms makes the prediction of Festr redox properties challenging. For instance, only empirical models are currently available to quantify structural changes as a function of reduction level. However, a predictive and mechanistic model of these changes is a prerequisite to develop a thermodynamic model for Festr redox properties. In this contribution, we propose a mechanistic statistical model to explain 2:1 layer excess negative charge changes induced by structural Fe(III) to Fe(II) chemical reduction (by dithionite). This model completes this published by Drits and Manceau (2000) and was calibrated on data from our own and from the literature. Actually, a large number of studies on Festr redox properties (Eh and kinetics) neglects the major structural changes that occur during redox reactions of this material and that are partially reversible, and are focused in measuring a single Eh value. Actually, the complex relationship that exist between the different structural iron sites should lead to consider that not only one but several Fe(II)/Fe(III) poles (classes) must exist in the structure, thus exhibiting gradually decreasing Eh values. Hence, further developments of our model will include Crystal Field Theory (CFT) calculation to identify the variety of Festr redox potential, which arises from the varying Festr neighbouring inside the same structure and along the redox processes

Investigation of dental amalgam electrode behaviour for the long term monitoring of nuclear waste disposals

International audienc

Monitoring of the biodegradation of toluene-contaminated sand in columns by SIP measurements, CO2 content and its 13C/12C isotopic signature.

Hydrocarbon contaminated soils represent an environmental issue as it impacts on ecosystems and aquifers. Bioremediation uses the ability of bacteria naturally present in the ground to degrade hydrocarbons. It represents an effective solution to fight the pollution but in situ monitoring before and during soil treatment is difficult and challenging. Indeed, where significant subsurface heterogeneity exists, conventional intrusive groundwater sampling can be insufficient to obtain a robust monitoring as the information they provide is restricted to vertical profiles at discrete locations, with no information between sampling points. In order to obtain wider information, complementary methods can be used like geo-electrical techniques. Induced polarization (IP) seems to be the more promising to study the effects of biodegradation processes. Indeed, laboratory and field experiments have shown an enhancement of real and imaginary parts of electrical conductivity while bacterial treatment is progressing (Abdel Aal et al., 2006 ; Atekwana et Atekwana, 2010). Moreover, microbial activity induced CO2 production and isotopic deviation of carbon (Aggarwal and Hinchee, 1991). The ratio δ13C(CO2) will come closer to δ13C(hydrocarbon). From these findings, the French project BIOPHY, supported by the French National Research Agency (ANR), proposes to use electrical methods and gas analyses to develop a non-destructive method for monitoring in situ biodegradation of hydrocarbons in order to optimize soil treatment. Laboratory experiments in columns are carried out to demonstrate its feasibility. Our objectives were to monitor aerobic microbial activity in toluene-contaminated sand columns using complex electrical resistivity measurements (SIP, Spectral Induced polarization and GEIS, Galvanostatic Electrochemical Impedance Spectroscopy) and measuring concentration and δ13C isotopic ratio of produced CO2