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High-protein algae bioproduct system boundaries for environmental sustainability risk analysis.

Poly(thioacetal)s with narrow molecular weight distributions were synthesized via lactone ring-opening polymerization. They showed ROS-responsive degradability according to their electronic structures.

Microalgae are regarded as a promising feedstock for biofuels and value-added products but still suffer from an inefficient lipid extraction process. In the present study, a simple and energy-efficient extraction method is demonstrated to extract oil directly from the wet cake (260 g/L) of Nannochloropsis sp. with an assist from the high shear mixer (HSM). After the initial solvent screening, the composition of co-solvent and operating conditions were optimized according to lipid composition and extraction yield. The high shear-assisted extraction process was found to achieve 83% lipid extraction yield (94% for EPA) in 5 min and 95% yield (100% for EPA) in 30 min with minimal amounts of solvents (0.9 ml hexane, 0.39 ml ethanol, and 0.057 ml sulfuric acid for 1 g of wet cell) at 8000 rpm, 55 °C. In comparison with various two-step wet extraction methods, the HSM offers the most economical extraction in terms of specific energy consumption of 1.38 MJ/kg dry cell. Therefore, the HSM can be considered as an attractive alternative to conventional extraction methods, providing a new paradigm of wet extraction for microalgae.

We report the first example of controlled polymerization of poly(disulfide)s with narrow molecular weight distributions. 1,4,5-oxadithiepan-2-one (OTP), a disulfide-containing 7-membered ring lactone, was polymerized by using the diphenylphosphate (DPP) catalyzed lactone ring-opening polymerization method. The polymerization proceeded in a living manner, and the resulting polymers displayed very narrow polydispersity index (PDI) values below 1.1 and excellent backbone degradability responding to reducing conditions and UV irradiation., We report the first example of controlled polymerization of poly(disulfide)s with narrow molecular weight distributions.

An inflammatory myofibroblastic tumor (IMT) is a solid tumor of unknown etiology frequently affecting children and young adults and commonly affecting the lung or orbital region. We present a case involving a 41-year-old man who had an IMT combined with Mycobacterium tuberculosis infection in the retroperitoneum. He presented with only pain in the right lower abdomen without accompanying symptoms; a retroperitoneal mass was found on computed tomography. The tumor had invaded the end of the ileum and was attached to the omentum, so mass excision could not be performed. The tumor was completely excised surgically and had histological features diagnostic of an IMT. Histologic findings of the omentum were positive for Ziehl-Nielsen staining for acid-fast bacilli and for a positive polymerase chain reaction for M. tuberculosis. The patient had no apparent immune disorder. These findings made this case exceptional because IMTs, which are mostly due to atypical mycobacteria, have been found mainly in immunocompromised patients.

The feasibility of a carbon recycling system that transforms algal residue to volatile fatty acids (VFAs) for re-cultivating microalgae was evaluated based on a carbon balance analysis of major VFAs consisting of acetate (HAc), propionate (HPr), and butyrate (HBu). This system largely involves two processes: (i) bioconversion of algal residue to VFAs by anaerobic fermentation, and (ii) cultivation of microalgae using the produced VFAs. The carbon balance for each unit process was examined to assess how much carbon in algal residue can be converted to these major VFAs and then assimilated to microalgae biomass. First, the yield and the profile of VFAs from raw algae (RA) and lipid-extracted algae (LEA) at psychrophilic (15 °C), mesophilic (35 °C), and thermophilic conditions (55 °C) were compared. When digesting the LEA under the thermophilic condition, the highest conversion yield, 0.36 (g carbon in VFAs/g carbon in biomass), with a compositional ratio of 6:1:3 (HAc: HPr: HBu) was obtained. Consumption of VFAs for microalgal growth reached a maximum value of 0.66 (g VFAs assimilated to biomass/g VFAs provided) at the compositional ratio of 6:1:3. Consequently, the maximum total carbon recycling ratio was 23.8% when fermenting LEA at the thermophilic condition. Our findings comprehensively revealed that establishing conditions that convert LEA to higher content of acetate is a decisive factor. It was estimated that around 40% of the total carbon from the LEA can be recovered for the production of algal biomass, when increasing the VFA conversion yield beyond 60% by adopting pretreatment methods.

Quorum sensing (QS) inhibitor-based therapy is an attractive strategy to inhibit bacterial biofilm formation without excessive induction of antibiotic resistance. Thus, we designed Ca2+-binding poly(lactide- co-glycolide) (PLGA) microparticles that can maintain a sufficient concentration of QS inhibitors around hydroxyapatite (HA) surfaces in order to prevent biofilm formation on HA-based dental or bone tissues or implants and, therefore, subsequent pathogenesis. Poly(butyl methacrylate- co-methacryloyloxyethyl phosphate) (PBMP) contains both Ca2+-binding phosphomonoester groups and PLGA-interacting butyl groups. The PBMP-coated PLGA (PLGA/PBMP) microparticles exhibited superior adhesion to HA surfaces without altering the sustained release properties of uncoated PLGA microparticles. PLGA/PBMP microparticle-encapsulating furanone C-30, a representative QS inhibitor, effectively inhibited the growth of Streptococcus mutans and its ability to form biofilms on HA surface for prolonged periods of up to 100 h, which was much longer than either furanone C-30 in its free form or when encapsulated in noncoated PLGA microparticles.

Recently, the issue of how to involve actual service users in the service designs for Smart cities has grown in importance, as this is a key factor in determining the serviceability and sustainability of developed services. Reckless participation of users can make the service design process inefficient and cause a cost increase. So, in this study, we propose the needs map which can be applied to various stages of service development and help service designers to make efficient and reasonable decisions without being too time-consuming. The proposed needs map is a schematization of theoretical concepts for Smart city planning in accordance with the framework of service-technology-infrastructure-management (STIM). Through the needs map, various urban problems, statistical data, and users' needs in a smart city are classified and analyzed concept by concept, and these focused analysis results suggest a proper direction to researchers in the service development plan. To demonstrate experimentally the feasibility of the needs map, we applied it in practice to a service design for the Smart city experience zone located in Daejeon, South Korea.

Polymers having α,β-unsaturated anhydrides as repeating units were synthesized by ring opening metathesis polymerization (ROMP). The anhydride moieties were ready-to-be-grafted with amines to form acid-labile cis-α,β-unsaturated acid amide linkages. The pH-responsive reversible de-grafting can be controlled by changing the intramolecular accessibility between acid and amide groups. The alendronate-grafted ROMP polymers showed distinct pH-dependent cytotoxicity according to the anhydride structures.

A physical barrier is one of the most effective strategies to alleviate excessive postoperative adhesion (POA) between tissues at an injury site. To overcome the limitations of current polymeric film-type physical barriers, we suggest a film of poly(lactic-co-glycolic acid) (PLGA) that is non-covalently coated with poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)) (PMB). While maintaining the degradability and mechanical properties of PLGA, the PMB coating introduces strong anti-adhesive properties to the film by forming a zwitterionic MPC-based surface through the hydrophobic interactions between BMA moieties and PLGA. Compared to SurgiWrap®, the commercially available poly(lactic acid)-based anti-adhesive film against POA, the PMB-coated PLGA film is much more inhibitory against protein adsorption and fibroblast adhesion, processes that are crucial to the POA process. PMB coating also inhibits the expression of fibronectin containing extra domain A (FN-EDA), α-smooth muscle actin (α-SMA), and collagen type IV alpha 2 (COL4A2), which are marker genes and proteins involved in fibroblast activation and excessive fibrosis during POA. Such inhibitory activities are clearly observed in a 3-dimensional culture of fibroblasts within a collagen matrix, which mimics the in vivo environment of an injury site, as well as in a 2-dimensional culture. The kinetics and the stability of the PMB coating suggest potential future clinical use to coat PLGA films to create a film-type anti-adhesion barrier that overcomes the limitations of current products.

In support of successful biomass production of green microalga Ettlia sp. through attached cultivation, estimation of footprint biomass productivity and optimization of the system was evaluated through comprehensive simulation of solar irradiation. Both temporal and spatial variation of solar irradiation and biomass productivity on the surface of the microalgae-attached panel (MAP) with every combination of design factors (tilt angle, facing direction, height, and distance of the MAP) were closely studied. While an increase in the height to the distance ratio (HDR) increased footprint biomass productivity, fixing the distances at their minimum made steeper tilt angle more favorable for footprint biomass productivity by having a smaller minimum distance. Footprint biomass productivity over the height revealed another important design index, a critical height, where footprint biomass productivity becomes maximum and saturated. Ultimately, three optimum conditions were identified based on economic circumstances: (1) double-side vertically standing MAP facing east/west, (2) 1 m high single-side MAP facing south with seasonal optimum angles, and (3) over 2.5 m high single-side MAP facing west with seasonal optimum angles. Corresponding estimated yearly average footprint biomass productivities were 22, 11, and 11.5 g/m2/day at the height of 3 m, 1 m, and 3 m, respectively.

Attached cultivation systems have been receiving extensive attention as a breakthrough in microalgae cultivation technology. However, there is a lack of studies that emphasize precise optimization of important parameters in attached cultivation of microalgae. In this study, the effects of two major environmental parameters in photoautotrophic cultivation, light intensity and CO2 concentration, on the biomass and lipid surface productivity of Ettlia sp. YC001 were optimized by employing Response Surface Methodology (RSM) and validated experimentally. The optimum initial conditions for attached cultivation were use of seed from the late exponential phase (LE) and an inoculum surface density of 2.5 g/m2. By optimization, maximum biomass surface productivity of 28.0 ± 1.5 g/m2/day was achieved at 730 μE/m2/s with 8% CO2. The maximum lipid surface productivity was 4.2 ± 0.3 g/m2/day at 500 μE/m2/s with 7% CO2. Change of the fatty acid composition with respect to changes in environment parameters led to improvement of biodiesel quality at higher light intensity and higher CO2 concentration. Attached cultivation of Ettlia sp. YC001 has successfully produced biomass and lipids at a high production rate with relatively low light energy demand and high CO2 utilization.

Dual-energy CT can be represented as the dual-energy equations by decomposing the linear attenuation coefficient of the X-ray scanned object into two material basis functions of photoelectric absorption and Compton scatter. To solve the dual-energy equations, in this paper, we apply the mean-value theorem for integrals and propose a new projection-based iterative algorithm. We discuss the convergence of the proposed algorithm and carry out various numerical simulations for demonstrating its feasibility.

Changes in algal and bacterial communities during thiocyanate (SCN − ) decomposition in a microalga-mediated process were studied. Pyrosequencing indicated that Thiobacillus bacteria and Micractinium algae predominated during SCN − hydrolysis, even after its complete degradation. Principal components analysis and evenness profiles (based on the Pareto–Lorenz curve) suggested that the changes in the bacterial communities were driven by nitrogen and sulfur oxidation, pH changes, and photoautotrophic conditions. The populations of predominant microalgae remained relatively stable during SCN − hydrolysis, but the proportion of bacteria – especially nitrifying bacteria – fluctuated. Thus, the initial microalgal population may be crucial in determining which microorganisms dominate when the preferred nitrogen source becomes limited. The results also demonstrated that microalgae and SCN − -hydrolyzing bacteria can coexist, that microalgae can be effectively used with these bacteria to completely treat SCN − , and that the structure of the algal-bacterial community is more stable than the community of nitrifying bacteria alone during SCN − degradation.

We consider the problem of identifying a complex valued coefficient γ ( x , ω ) \gamma (x,\omega ) in the conductivity equation ∇ ⋅ γ ( ⋅ , ω ) ∇ u ( ⋅ , ω ) = 0 \nabla \cdot \gamma (\cdot ,\omega )\nabla u(\cdot ,\omega )=0 from knowledge of the frequency differentials of the Dirichlet-to-Neumann map. For a frequency analytic γ ( ⋅ , ω ) = ∑ k = 0 ∞ ( σ k + i ϵ k ) ω k \gamma (\cdot ,\omega )=\sum _{k=0}^\infty (\sigma _k+i\epsilon _k)\omega ^k , in three dimensions and higher, we show that d j d ω j Λ γ ( ⋅ , ω ) | ω = 0 \left .\frac {d^j}{d\omega ^j}\Lambda _{\gamma (\cdot ,\omega )}\right |_{\omega =0} for j = 0 , 1 , … , N j=0,1,\dots ,N recovers σ 0 , … , σ N \sigma _0,\dots , \sigma _N and ϵ 1 , … , ϵ N \epsilon _1,\dots ,\epsilon _N . This problem arises in frequency differential electrical impedance tomography of dispersive media.

If there are metals located in the X-ray scanned object, a point outside the metals gas its range of projection angle at which projections passing through the point are disturbed by the metals. Roughly speaking, this implies that attenuation information at the point is missing in the blocked projection range. So conventional projection completion MAR algorithms to use the undisturbed projection data on the boundary of the metaltrace is less efficient in reconstructing the attenuation coefficient in detailed parts, in particular, near the metal region. In order to overcome this problem, we propose the algebraic correction technique (ACT) to utilize a prereconstructed interim image of the attenuation coefficient outside the metal region which is obtained by solving a linear system designed to reduce computational costs. The reconstructed interim image of the attenuation coefficient is used as prior information for MAR. Numerical simulations support that the proposed correction technique shows better performance than conventional inpainting techniques such as the total variation and the harmonic inpainting.

An acidogenic reactor with a 0.5-L working volume and a methanogenic digester with a 5-L of working volume were operated for 150 days on a continuous mode to investigate the structure of a microbial community during food wastewater treatment. During the steady state of anaerobic digestion, volatile solids (VS) removal efficiency in the pilot plant was approximately 65%. The bacterial population was higher than any other methanogens detected during the entire anaerobic process and treatment of raw food wastewater. Methanomicrobiales (MMB), Methanosarcinales (MSL), and Methanobacteriales (MBT) were detected during digestion. The methanogenic population present in the acidogenic reactor was directly affected by the archaeal community in raw food wastewater. However, the shift of microbial community in the methanogenic digester was relatively gradual. The performance of methanogenic digester might be more related to the change of microbial metabolism affected by the physicochemical properties of the input substrate.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

The Ln3+ (Ln3+ = Eu3+, Dy3+, Tb3+ or Sm3+)-doped Gd2GeO5 phosphors are produced by using the solid-state reaction. The Gd2GeO5 has a high effective Z-number (Z eff = 46) and density (7.12 g/cm3) and is sensitive to X-rays. The emission wavelengths of Ln3+-doped phosphors are expected adequate for the CCDs. We fabricated Ln3+-doped Gd2GeO5 phosphors and studied their structural and luminescence properties. The Ln3+-doped Gd2GeO5 phosphors were excited by ultraviolet (UV) light, X-rays, and protons. The emission wavelengths were measured to be from 450 nm to 750 nm. The 45-MeV proton beam at the MC-50 cyclotron in the Korea Institute of Radiological and Medical Sciences was used for this purpose. These emission wavelengths matched well with those for a typical CCD. Therefore, Ln3+-doped Gd2GeO5 phosphors are good candidates for use of radiation-imaging phosphors.

This paper presents a projective reconstruction method of electrical impedance distribution using two boundary measurements of current-voltage data. The proposed method has a major advantage over existing electrical impedance tomography systems: relatively high resolution impedance image in a near-surface region underneath the voltage-sensing probe that is placed on a skin surface. We attach two pairs of electrodes on the border of the probe in such a way that each pair of electrodes generates electrical current flowing underneath the voltage-sensing probe and two currents flow across each other. A careful analysis of the measured data with respect to local perturbation of admittivity leads to the projective reconstruction method and its rationale. Numerical simulations show that the proposed method successfully reconstructs high resolution image of local perturbation of admittivity, due to object position changes or admittivity value changes or the both, in a near-surface region underneath the probe.

Recent research in electrical impedance tomography produced images of biological tissue from frequency differential boundary voltages and corresponding currents. Physically one is to recover the electrical conductivity $\sigma$ and permittivity $\epsilon$ from the frequency differential boundary data. Let $\gamma=\sigma+i\omega\epsilon$ denote the complex admittivity, $\Lambda_{\gamma}$ be the corresponding Dirichlet-to-Neumann map, and $\frac{d\Lambda_{\gamma}}{d\omega}|_{\omega=0}$ be its frequency differential at $\omega=0$. If $\sigma\in C^{1,1}(\overline\Omega)$ is constant near the boundary and $\epsilon\in C^{1,1}_0(\Omega)$, we show that $\frac{d\Lambda_{\gamma}}{d\omega}|_{\omega=0}$ uniquely determines $\nabla\cdot(\nabla\epsilon-\epsilon\nabla\ln\sigma)/\sigma$ inside $\Omega$. In addition, if $\Lambda_{\gamma}|_{\omega=0}$ is also known, then $\epsilon$ and $\sigma$ can be reconstructed inside. The method of proof uses the complex geometrical optics solutions.

In this paper, we introduce a new elliptic PDE:(∇ · |γ ω (r)| 2 σ ∇v ω (r) = 0, r∈ Ω,v ω (r) = f(r), r∈ ∂Ω,where γ ω = σ + iωǫ is the admittivity distribution of the conductingmaterial Ω and it is shown that the introduced elliptic PDE can replacethe standard elliptic PDE with conductivity coefficient in EIT imaging.Indeed, letting v 0 be the solution to the standard elliptic PDE with con-ductivity coefficient, the solution v ω is quite close to the solution v 0 andcan show spectroscopic properties of the conducting object Ω unlike v 0 . Inparticular, the potential v ω can be used in detecting a thin low-conductinganomaly located in Ω since the spectroscopic change of the Neumann dataof v ω is inversely proportional to thickness of the thin anomaly. 1. IntroductionLet Ω be a two- or three-dimensional conducting bounded object with Lip-schitz boundary ∂Ω and let D be an anomaly located inside Ω. Since theadmittivity distribution γ ω of the conducting object Ω changes abruptly acrossthe anomaly, we suppose that the admittivity distribution γ

This article deals with an inverse problem of electrical capacitance tomography (ECT) for visualizing cross-sectional images of the mixture of high/low conducting flow components in pipelines from boundary measurements using capacitive electrode sensors. The capacitive technique relies on changes in capacitances between electrodes due to the changes in permittivities and conductivities of flow components. In Woo et al. [A direct tracking method for a grounded conductor inside a pipeline from capacitance measurements, Inverse Prob. 22 (2006), pp. 481–494], the single-drive interleaved ECT system has been proposed for estimating the inclusion of high-contrast conductivity flow, and the corresponding inverse problem is based on a special 2D forward model which appears to be quite different from the simple 2D projection of the actual 3D forward model. In this system, we employ a single set of measured capacitance with a fixed applied voltage. In this article, we justify the validity of the 2D forward model pr...

This paper proposes a new nondestructive evaluation method for detecting cracks, voids, and other hidden defects inside concrete structures, called “frequency differential electrical impedance scanning (fdEIS).” The primary benefit of fdEIS over the conventional nondestructive methods is that it is possible to determine the thickness of the voids. In fdEIS, we inject a sequence of electrical currents with various frequencies through the tested concrete wall by applying a sinusoidal voltage difference between a surface electrode and a scan probe, which are placed on opposite surfaces of the wall. Through the probe, we measure the derivative $\frac{d}{d\omega}g_{\omega}$ of exit currents (Neumann data) with respect to the angular frequency variable $\omega$. We find the fundamental concept in fdEIS relating the thickness of the voids to $\frac{d}{d\omega}g_{\omega}$ and derive an approximation formula for estimating the thickness of the voids. We demonstrate the performance of our method in numerical simula...

A trans-admittance scanner (TAS) is a device for breast cancer diagnosis based on numerous experimental findings that complex conductivities of breast tumors significantly differ from those of surrounding normal tissues. In TAS, we apply a sinusoidal voltage between a hand- held electrode and a scanning probe placed on the breast skin to make current travel through the breast. The scanning probe has an array of electrodes at zero voltage. We measure exit currents (Neumann data) through the electrodes that provide a map of trans-admittance data over the breast surface. The inverse problem of TAS is to detect a suspicious abnormality underneath the breast skin from the measured Neumann data. Previous anomaly detection methods used the difference between the measured Neumann data and a reference Neumann data obtained beforehand in the absence of anomaly. However, in practice, the reference data is not available and its computation is not possible since the inhomogeneous complex conductivity of the normal breast is unknown. To deal with this problem, we propose a frequency-difference TAS (fdTAS), in which a weighted frequency difference of the trans-admittance data measured at a certain moment is used for anomaly detection. This paper provides a mathematical framework and the feasibility of fdTAS by showing the relationship between the anomaly information and the weighted frequency difference of the Neumann data.

In this paper, we provide a mathematical approach to reconstruct the Compton scatter and photo-electronic coefficients using the dual-energy CT system. The proposed imaging method is based on the mean value theorem to handle the non-linear integration coming from the polychromatic energy based CT scan system. We show a numerical simulation result for the validation of the proposed algorithm

We present a new non-iterative method for tracking conductive water in a pipeline using a single excitation pattern from an interleaved ECT system. The problem arises, for example, in the oil industry where brine is often mixed with oil in a pipeline. If the size of the body of brine is very large compared with the size of electrodes attached to the pipeline, the corresponding electric potential in the region of brine is close to zero. This model leads to the inverse problem of identifying the dynamic change of the cross section of a grounded conducting region in a pipeline. Unfortunately, standard iterative reconstruction algorithms in ECT associated with the sensitivity matrix do not work in this case. Furthermore, due to the unavailability of Neumann data at the drive electrodes, the previously published layer potential methods for capturing the inhomogeneity are not applicable to this system. In this work, we derive a formula providing a concrete relation between the capacitance change in each receive electrode and the dynamical change in a grounded conducting region inside the pipeline. The proposed method successfully reconstructs feature information such as location and rough shape of the cross section of the water region. We demonstrate the performance of our method in numerical simulations and actual experiments.

In this paper, we consider the inverse problem of determining the shape and location of inhomogeneity D in an elliptic equation with a Neumann boundary condition on ?? where and ?D is the characteristic function of a subdomain D. We discuss the global uniqueness in determining D by a single measurement of Dirichlet data u on ?? and prove uniqueness results with extra information on domains D.

In a bounded domain , we consider div((l(x) + m(x)χD(x))∇u(x)) + k(x)u(x) = 0, where satisfy l, l + m > 0 on , the subdomain D is the union of a finite number of polygons, χD denotes the characteristic function of D and k L∞(Ω), k ≥ 0 on . We discuss an inverse problem of determining D by the boundary data of u. Our main results are stated as follows. (i) Case k ≡ 0: a suitably given single Dirichlet datum of u on ∂Ω yields the uniqueness of the convex hull of D. (ii) Case 0 < k(x) < λ0, where λ0 is the product of the minimum of l and the first eigenvalue of −Δ with the zero Dirichlet boundary condition. By changing Dirichlet inputs to u on ∂Ω twice and suitably, the resulting two Neumann data guarantee the uniqueness of the convex hull.

We consider an inverse problem of identifying the support D of a source term in an elliptic equation $$ -\Delta u(x) + q(x)\chi_D(x)u(x) = 0, \quad x\in \Omega, \qquad \text{and} \qquad u(x) = f(x)...

We consider the inverse problem of determining the shape and location of inhomogeneity in an elliptic equation with a Neumann boundary condition where ⊂ Ω and χD is the characteristic function of a subdomain D. For the determination of D, we measure Dirichlet data u on ∂Ω. We prove the uniqueness in this inverse problem within some classes of subdomains of Ω .

The conformational property of phthalan has been investigated using ab initio calculation and natural bond orbital (NBO) analysis methods. Geometry optimizations for the planar (C2v) and puckered (Cs) conformers have been carried out using the HF, B3LYP, and MP methods, and the results indicate that this molecule has a tiny ring-puckering barrier. This barrier appears to be in good agreement with the previous experimental result. NBO analysis shows that the tiny ring-puckering barrier is closely related to the molecular orbital interactions around the C–O bonds of the five-membered ring. The gas-phase infrared and liquid-phase Raman spectra of phthalan and 1,3-benzodioxole have been recorded and analyzed in terms of C2v symmetry. Vibrational frequency calculations using the B3LYP method have also been performed to compare with the spectroscopic data. The B3LYP frequency calculations do a reasonable job of estimating the frequencies.

This paper considers the fundamental questions, such as existence and uniqueness, of a mathematical model arising in the MREIT system, which is an electrical impedance tomography technique integrated with magnetic resonance imaging. The mathematical model for MREIT is the Neumann problem of a nonlinear elliptic partial differential equation $\nabla\cdot(\frac{a(x)}{|\nabla u(x)|}\nabla u(x))=0$. We show that this Neumann problem belongs to one of two cases: either infinitely many solutions exist or no solution exists. This explains rigorously the reason why we have used the modified model in [O. Kwon, E. J. Woo, J. R. Yoon, and J. K. Seo, IEEE Trans. Biomed. Engrg., 49 (2002), pp. 160--167], which is a system of the Neumann problem associated with two different Neumann data. For this modified system, we prove a uniqueness result on the edge detection of a piecewise continuous conductivity distribution.

This paper deals with the inverse problem of inferring the position of an electrically grounded conductor D from a single measurement of electric field (Cauchy data) on the boundary of a smooth domain \mbox{$\Omega \subset R^n,$ $n=2,3$,} that contains $\overline D$. We present new simple and real time algorithms for locating D with a rigorous mathematical verification. These location search techniques use a special property of the surface charge density of the electrically grounded conductor. The computations in these location search methods are very simple, so that the location of a moving grounded conductor can be detected in a instant even in three dimensions.