Static Cores Research Articles

Arbuscular Mycorrhiza Support Plant Sulfur Supply through Organosulfur Mobilizing Bacteria in the Hypho- and Rhizosphere.

This study aimed to elucidate the role of bacteria colonising mycorrhizal hyphae in organically bound sulfur mobilisation, the dominant soil sulfur source that is not directly plant available. The effect of an intact mycorrhizal symbiosis with access to stable isotope organo-34S enriched soils encased in 35 µm mesh cores was tested in microcosms with Agrostis stolonifera and Plantago lanceolata. Hyphae and associated soil were sampled from static mesh cores with mycorrhizal ingrowth and rotating mesh cores that exclude mycorrhizal ingrowth as well as corresponding rhizosphere soil, while plant shoots were analysed for 34S uptake. Static cores increased uptake of 34S at early stages of plant growth when sulfur demand appeared to be high and harboured significantly larger populations of sulfonate mobilising bacteria. Bacterial and fungal communities were significantly different in the hyphospheres of static cores when compared to rotating cores, not associated with plant hosts. Shifts in bacterial and fungal communities occurred not only in rotated cores but also in the rhizosphere. Arylsulfatase activity was significantly higher in the rhizosphere when cores stayed static, while atsA and asfA gene diversity was distinct in the microcosms with static and rotating cores. This study demonstrated that AM symbioses can promote organo-S mobilization and plant uptake through interactions with hyphospheric bacteria, enabling AM fungal ingrowth into static cores creating a positive feedback-loop, detectable in the microbial rhizosphere communities.

Cold Quark–Gluon Plasma EOS Applied to a Magnetically Deformed Quark Star with an Anomalous Magnetic Moment

We consider a QCD cold-plasma-motivated Equation of State (EOS) to examine the impact of an Anomalous Magnetic Moment (AMM) coupling and small shape deformations on the static oblate and prolate core shapes of quark stars. Using the Fogaça QCD-motivated EOS, which shifts from the high-temperature, low-chemical-potential quark–gluon plasma environment to the low-temperature, high-chemical-potential quark stellar core environment, we consider the impact of an AMM coupling with a metric-induced shape deformation parameter in the Tolman–Oppenheimer–Volkov (TOV) equations. The AMM coupling includes a phenomenological scaling that accounts for the weak and strong field characteristics in dense matter. The EOS is developed using a hard gluon and soft gluon decomposition of the gluon field tensor and using a mean-field effective mass for the gluons. The AMM is considered using the Dirac spin tensor coupled to the EM field tensor with quark-flavor-based magnetic moments. The shape parameter is introduced in a metric ansatz that represents oblate and prolate static stellar cores for modified TOV equations. These equations are numerically solved for the final mass and radius states, representing the core collapse of a massive star with a phase transition leading to an unbound quark–gluon plasma. We find that the combined shape parameter and AMM effects can alter the coupled EOS–TOV equations, resulting in an increase in the final mass and a decrease in the final equatorial radius without collapsing the core into a black hole and without violating causality constraints; we find maximum mass values in the range 1.6 Mʘ < M < 2.5 Mʘ. These states are consistent with some astrophysical, high-mass magnetar/pulsar and gravity wave systems and may provide evidence for a core that has undergone a quark–gluon phase transition such as PSR 0943 + 10 and the secondary from the GW 190814 event.

Depletion and fractionation of nitrogen in collapsing cores

Measurements of the nitrogen isotopic ratio in Solar System comets show a constant value, ≈140, which is three times lower than the protosolar ratio, a highly significant difference that remains unexplained. Observations of static starless cores at early stages of collapse confirm the theoretical expectation that nitrogen fractionation in interstellar conditions is marginal for most species. Yet, observed isotopic ratios in N2H+ are at variance with model predictions. These gaps in our understanding of how the isotopic reservoirs of nitrogen evolve, from interstellar clouds to comets, and, more generally, to protosolar nebulae, may have their origin in missing processes or misconceptions in the chemistry of interstellar nitrogen. So far, theoretical studies of nitrogen fractionation in starless cores have addressed the quasi-static phase of their evolution such that the effect of dynamical collapse on the isotopic ratio is not known. In this paper, we investigate the fractionation of 14N and 15N during the gravitational collapse of a pre-stellar core through gas-phase and grain adsorption and desorption reactions. The initial chemical conditions, which are obtained in steady state after typically a few Myr, show low degrees of fractionation in the gas phase, in agreement with earlier studies. However, during collapse, the differential rate of adsorption of 14N- and 15N-containing species onto grains results in enhanced 15N:14N ratios, in better agreement with the observations. Furthermore, we find differences in the behavior, with increasing density, of the isotopic ratio in different species. We find that the collapse must take place on approximately one free-fall timescale, based on the CO abundance profile in L183. Various chemical effects that bring models into better agreement with observations are considered. Thus, the observed values of 14N2H+:N15NH+ and 14N2H+:15NNH+ could be explained by different temperature dependences of the rates of dissociative recombination of these species. We also study the impact of the isotopic sensitivity of the charge-exchange reaction of N2 with He+ on the fractionation of ammonia and its singly deuterated analog and find significant depletion in the 15N variants. However, these chemical processes require further experimental and theoretical investigations, especially at low temperature. These new findings, such as the depletion-driven fractionation, may also be relevant to the dense, UV-shielded regions of protoplanetary disks.

Distribution Characteristics and Fluxes of Nitrogen and Phosphorus at the Sediment-water Interface of Yuqiao Reservoir

Yuqiao Reservoir is an important source of drinking water in Tianjin. In recent years, the eutrophication status is becoming more and more serious, but its internal loading and distribution characteristics of nitrogen and phosphorus is not clear. The profiles of nitrogen and phosphorus at the sediment-water interface were analyzed using the Peeper (pore water equilibrium) technique and the spatial distribution was investigated. The existing forms of the released nitrogen and phosphorus were investigated by the static intact sediment cores, and the fluxes of nitrogen and phosphorus at the sediment-water interface were estimated by static incubations with intact sediment cores. The results demonstrated the following. ① The contents of PO43--P, NH4+-N, NO3--N, and NO2--N in sediments were 0.5-6.5, 0.5-10.9, 2.2-16.2, and 0.05-0.6 mg ·kg-1, respectively. The contents of nutrient were lower as depth increased, and horizontal distribution characteristics indicated significant differences. ② The contents of PO43--P and NH4+-N in the interstitial water were much higher than in the overlying water, suggesting that the interstitial water had the potential to diffuse nutrients to the overlying water. The concentrations of PO43--P and NH4+-N in the interstitial water increased rapidly at 0-5 cm and then decreased gradually. ③ PO43--P and NH4+-N diffused from the sediment to the overlying water, and the fluxes of them were 1.1-13.3 mg ·(m2 ·d)-1 and 20.6-250.5 mg ·(m2 ·d)-1, respectively. The exchange fluxes of NO3--N and NO2--N ranged from -20.4 to 33.4 mg ·(m2 ·d)-1 and from -7.4 to 0.4 mg ·(m2 ·d)-1, respectively. PO43--P and NH4+-N were the main nutrients in the sediment released to the overlying water. The fluxes were high in the south and low in the north, and also high in the mouth of the Linhe River and downstream of the reservoir. Compared with similar studies, the fluxes at the sediment-water interface of Yuqiao Reservoir were relatively high, indicating that the sediment was an important source of nutrients for the overlying water in Yuqiao Reservoir.

CLOUD COMPUTING ENERGY DISSIPATION REDUCTION USING SHADOW REPLICATION

As the interest for cloud computing keeps on expanding, cloud specialist organizations confront the overwhelming test to meet the arranged SLA agreements, as far as dependability and convenient .execution, while accomplishing cost and energy efficiency. This paper proposes Shadow Replication, a novel fault-tolerance mechanism for cloud computing, which flawlessly addresses fault at scale, while limiting energy utilization and lessening its effect on cost. Energy conservation is achieved by creating dynamic cores rather than static cores. Cores are created by the application of cloudlets. In other words proportionate cores are created. Core failure metrics are considered to be memory capacity, energy and power consumption. In case any of the parameter exceeded threshold value, core is supposed to be faulted and progress is maintained within shadow which is maintained 1 per host. Progress of deteriorated Core is shifted to next core within other VM. In case all the core within VM deteriorated, VM migration is performed. Results obtained through purposed system appears to better in terms of listed energy consumption, latency, cost and fault rate.

The influence of initial conditions during dissipative collapse

Starting off with two distinct initially static stellar cores (i) Florides interior (constant density, vanishing radial pressure) and (ii) Wyman interior (constant density, nonvanishing radial pressure), we explore the dynamics of these two models once hydrostatic equilibrium is lost. We show that although the time of formation of horizon, evolution of the mass and proper radius are independent of the chosen initially static configurations, there is a significant difference in the temperature profiles of the radiating bodies as the collapse proceeds.

Thermal mass limit of neutron cores

Static thermal equilibrium of a quantum self-gravitating ideal gas in general relativity is studied at any temperature, taking into account the Tolman-Ehrenfest effect. Thermal contribution to the gravitational stability of static neutron cores is quantified. The curve of maximum mass with respect to temperature is reported. At low temperatures the Oppenheimer-Volkoff calculation is recovered, while at high temperatures the recently reported classical gas calculation is recovered. An ultimate upper mass limit $M = 2.43M_\odot$ of all maximum values is found to occur at Tolman temperature $ T = 1.27mc^2$ with radius $R = 15.2km$.

The sharing architecture

Businesses and Academics are increasingly turning to Infrastructure as a Service (IaaS) Clouds such as Amazon's Elastic Compute Cloud (EC2) to fulfill their computing needs. Unfortunately, current IaaS systems provide a severely restricted pallet of rentable computing options which do not optimally fit the workloads that they are executing. We address this challenge by proposing and evaluating a manycore architecture, called the Sharing Architecture, specifically optimized for IaaS systems by being reconfigurable on a sub-core basis. The Sharing Architecture enables better matching of workload to micro-architecture resources by replacing static cores with Virtual Cores which can be dynamically reconfigured to have different numbers of ALUs and amount of Cache. This reconfigurability enables many of the same benefits of heterogeneous multicores, but in a homogeneous fabric, and enables the reuse and resale of resources on a per ALU or per KB of cache basis. The Sharing Architecture leverages Distributed ILP techniques, but is designed in a way to be independent of recompilation. In addition, we introduce an economic model which is enabled by the Sharing Architecture and show how different users who have varying needs can be better served by such a flexible architecture. We evaluate the Sharing Architecture across a benchmark suite of Apache, SPECint, and parts of PARSEC, and find that it can achieve up to a 5x more economically efficient market when compared to static architecture multicores. We implemented the Sharing Architecture in Verilog and present area overhead results.

The sharing architecture

Businesses and Academics are increasingly turning to Infrastructure as a Service (IaaS) Clouds such as Amazon's Elastic Compute Cloud (EC2) to fulfill their computing needs. Unfortunately, current IaaS systems provide a severely restricted pallet of rentable computing options which do not optimally fit the workloads that they are executing. We address this challenge by proposing and evaluating a manycore architecture, called the Sharing Architecture, specifically optimized for IaaS systems by being reconfigurable on a sub-core basis. The Sharing Architecture enables better matching of workload to micro-architecture resources by replacing static cores with Virtual Cores which can be dynamically reconfigured to have different numbers of ALUs and amount of Cache. This reconfigurability enables many of the same benefits of heterogeneous multicores, but in a homogeneous fabric, and enables the reuse and resale of resources on a per ALU or per KB of cache basis. The Sharing Architecture leverages Distributed ILP techniques, but is designed in a way to be independent of recompilation. In addition, we introduce an economic model which is enabled by the Sharing Architecture and show how different users who have varying needs can be better served by such a flexible architecture. We evaluate the Sharing Architecture across a benchmark suite of Apache, SPECint, and parts of PARSEC, and find that it can achieve up to a 5x more economically efficient market when compared to static architecture multicores. We implemented the Sharing Architecture in Verilog and present area overhead results.

RF authenticated reconfiguration-based access control protection scheme for SRAM-based FPGA IP cores

The constantly growing demand for ready to use design components, also known as intellectual property IP cores, has created a very lucrative and flourishing market which is very likely to continue its current path not only into the near future. With increase in use of field programmable gate arrays FPGAs in production designs, and with growth of system on FPGA SOF applications, the security of FPGA IP cores cannot be taken for granted anymore. In this paper, we have proposed a novel wireless-based IP core infringement preventive approach for intellectual property protection IPP of static random access memory SRAM-based FPGA IP cores. The proposed scheme exploits reconfiguration aspect of SRAM-based FPGA and incorporates special tag bypass features for increase suitability of proposed scheme as an IPP technique for reconfigurable IP cores. A hardware prototype is developed for evaluation of proposed scheme and the testing results are quite encouraging.

RF authenticated protection scheme for SRAM-based FPGA IP cores

Field programmable gate arrays (FPGAs) have become increasingly popular due to their rapid development times and low costs. Many FPGA-based systems utilise third-party intellectual property (IP) in their development. With their increased use, the need to protect the IP against unauthorised use has become important. In this paper, we have proposed a novel wireless intellectual property protection (IPP) technique that overcomes the secure secret decryption key storage problem associated with traditional encryption-based IPP techniques that are widely used for IPP of static random access memory-based FPGA IP cores. The proposed scheme also provides an extra authentication protection for IP cores to make it more security efficient. The results derived from the testing of hardware prototype used for the evaluation of the proposed scheme are quite encouraging.

Multicore reconfiguration platform an alternative to RAMPSoC

The current state of the art in processor performance improvement is multicore-processor systems. These systems offer a number of homogeneous and static processor cores for the parallel distribution of computational tasks. A novel idea in this research field is introduced by the Runtime Adaptive Multi-Processor System-on- Chip (RAMPSoC) approach. It uses a dynamic and partial reconfigurable system to offer a heterogeneous multicore-processor system. It is runtime adaptable to applications needs and provides a high degree of freedom for system design and task distribution. The continuation of this idea is the Multicore Reconfiguration Platform (MRP) presented in this paper. Its fine grained reconfiguration framework offers a higher degree of freedom and achieves a better FPGA space exploitation, reduced power consumption and a more precise adaption to application requirements.

INTERNAL MOTIONS IN STARLESS DENSE CORES

This paper discusses the statistics of internal motions in starless dense cores and the relation of these motions to core density and evolution. Four spectral lines from three molecular species are analyzed from single-pointing and mapped observations of several tens of starless cores. Blue asymmetric profiles are dominant, indicating that inward motions are prevalent in sufficiently dense starless cores. These blue profiles are found to be more abundant, and their asymmetry is bluer, at core positions with stronger $\rm N_2H^+$ line emission or higher column density. Thirty three starless cores are classified into four types according to the blue and red shifts of the lines in their molecular line maps. Among these cores, contracting motions dominate: 19 are classified as contracting, 3 as oscillating, 3 as expanding, and 8 as static. Contracting cores have inward motions all over the core with predominance of those motions near the region of peak density. Cores with the bluest asymmetry tend to have greater column density than other cores and all five cores with peak column density $> \rm 6\times 10^{21} cm^{-2}$ are found to be contracting. This suggests that starless cores are likely to have contracting motions if they are sufficiently condensed. Our classification of the starless cores may indicate a sequence of core evolution in the sense that column density increases from static to contracting cores: the static cores in the earliest stage, the expanding and/or the oscillating cores in the next, and the contracting cores in the latest stage.

Automatic fracture density update using smart well data and artificial neural networks

This paper presents a new methodology to continuously update and improve fracture network models. We begin with a hypothetical model whose fracture network parameters and geological information are known. After generating the “exact” fracture network with known characteristics, the data were exported to a reservoir simulator and simulations were run over a period of time. Intelligent wells equipped with downhole multiple pressure and flow sensors were placed throughout the reservoir and put into production. These producers were completed in different fracture zones to create a representative pressure and production response. We then considered a number of wells of which static (cores and well logs) and dynamic (production) data were used to model well fracture density. As new wells were opened, historical static and dynamic data from previous wells and static data from the new wells were used to update the fracture density using Artificial Neural Networks (ANN). The accuracy of the prediction model depends significantly on the representation of the available data of the existing fracture network. The importance of conventional data (surface production data) and smart well data prediction capability was also investigated. Highly sensitive input data were selected through a forward selection scheme to train the ANN. Well geometric locations were included as a new link in the ANN regression process. Once the relationship between fracture network parameters and well performance data was established, the ANN model was used to predict fracture density at newly drilled locations. Finally, an error analysis through a correlation coefficient and percentage absolute relative error performance was performed to examine the accuracy of the proposed inverse modeling methodology. It was shown that fracture dominated production performance data collected from both conventional and smart wells allow for automatically updating the fracture network model. The proposed technique helps in generating another – readily available at no cost – data source for fracture characterization as a supplement to limited 1D data obtained from well logs and cores.

Denitrification in shallow, sublittoral Gulf of Mexico permeable sediments

We examined nitrogen cycling over a 1‐yr period in shallow, sandy sediments at two contrasting sites near a barrier island in the northeastern Gulf of Mexico, and we provide here the direct determination of dinitrogen gas (N2) production at ambient nitrate concentrations in permeable marine sediments. Nitrogen‐stable isotope tracer techniques were used to quantify N2‐production rates and pathways in sediment cores and slurries. To simulate pore‐water advection, the dominant transport process in the upper layer of the permeable sand beds, intact sediment cores were perfused with aerated seawater. This perfusion increased denitrification rates up to 2‐fold in Apalachicola Bay sands and up to 17‐fold in Gulf of Mexico sublittoral sands, respectively, relative to static cores. Seasonal N2‐production rates were highest in spring and fall. Denitrified nitrate originated almost entirely from benthic nitrification at the exposed Gulf site, whereas water‐column nitrate dominated sedimentary denitrification at the sheltered Bay site. Sediment incubations in stirred chambers were used to determine net fluxes of oxygen (O2), N2, nitrate, and ammonium across the sediment‐water interface during varied degrees of continuous pore‐water exchange. Rates of N2 efflux correlated with rates of pore‐water flow increasing from 0.12 mmol N m‐2 d‐1 under diffusion‐limited transport conditions up to 0.87 mmol N m‐2 d‐1 with pore‐water advection. Mineralized nitrogen was completely converted to N2 gas in Gulf of Mexico sediments. Our results demonstrate that advective pore‐water circulation will accelerate benthic N2 production by coupled nitrification‐ denitrification and that substantial nitrogen loss occurs from coastal permeable sediments.

Molecular line profiles as diagnostics of protostellar collapse: modelling the ‘blue asymmetry’ in inside-out infall

The evolution of star-forming core analogues undergoing inside-out collapse is studied with a multipoint chemodynamical model which self-consistently computes the abundance distribution of chemical species in the core. For several collapse periods the output chemistry of infalling tracer species such as HCO+, CS and N2H+ is then coupled to an accelerated Λ-iteration radiative transfer code, which predicts the emerging molecular line profiles using two different input gas/dust temperature distributions. We investigate the sensitivity of the predicted spectral line profiles and line asymmetry ratios to the core temperature distribution, the time-dependent model chemistry, as well as to ad hoc abundance distributions. The line asymmetry is found to be strongly dependent on the adopted chemical abundance distribution. In general, models with a warm central region show higher values of blue asymmetry in optically thick HCO+ and CS lines than models with a starless core temperature profile. We find that in the formal context of Shu-type inside-out infall, and in the absence of rotation or outflows, the relative blue asymmetry of certain HCO+ and CS transitions is a function of time and, subject to the foregoing caveats, can act as a collapse chronometer. The sensitivity of simulated HCO+ line profiles to linear radial variations, subsonic or supersonic, of the internal turbulence field is investigated in the separate case of static cores.

EFFECTS OF RESTORATION AND REFLOODING ON SOIL DENITRIFICATION IN A LEVEED MIDWESTERN FLOODPLAIN

River floodplains have the potential to remove nitrate from water through denitrification, the anaerobic microbial conversion of nitrate to nitrogen gas. An important factor in this process is the interaction of river water with floodplain soil; however, many rivers have been disconnected from their historic floodplains by levees. To test the effect of reflooding a degraded floodplain on nitrate removal, we studied changes in soil denitrification rates on the Baraboo River floodplain in Wisconsin, USA, as it underwent restoration. Prior to this study, the site had been leveed, drained, and farmed for more than 50 years. In late fall 2002, the field drainage system was removed, and a gate structure was installed to allow controlled flooding of this site with river water. Soil moisture was extremely variable among zones and months and reflected local weather. Soil organic matter was stable over the study period with differences occurring along the elevation gradient. High soil nitrate concentrations occurred in dry, relatively organic-poor soil samples and, conversely, all samples with high moisture soils characterized by low nitrate. We measured denitrification in static cores and potential denitrification in bulk samples amended with carbon and nitrogen, one year before and two years following the manipulation. Denitrification rates showed high temporal and spatial variability. Static core rates of individual sites ranged widely (from 0.00 to 16.7 microg N2O-N x [kg soil](-1) x h(-1), mean +/- SD = 1.10 +/- 3.02), and denitrification enzyme activity (DEA) rates were similar with a slightly higher mean (from 0.00 to 15.0 microg N2O-N x [kg soil](-1) x h(-1), 1.41 +/- 1.98). Denitrification was not well-correlated with soil nitrate, organic matter content, or moisture levels, the three parameters typically thought to control denitrification. Static core denitrification rates were not significantly different across years, and DEA rates decreased slightly the second year after restoration. These results demonstrate that restored agricultural soil has the potential for denitrification, but that floodplain restoration did not immediately improve this potential. Future floodplain restorations should be designed to test alternative methods of increasing denitrification.

The effects of temperature on the water weakening of chalk by seawater

Seawater is injected into the high temperature North Sea chalk reservoirs to improve oil recovery with great success. Increased compaction of the rock, which also is a significant contribution to the oil displacement, is observed in the water-flooded area. Very recent laboratory studies at high temperature documented that enhanced compaction took place when chalk cores were flooded by seawater under stress. The special composition of seawater, regarding reactive ions towards the chalk surface, appeared to be the reason. In this paper, two different water-weakening mechanisms are discussed: (1) Substitution of Ca 2+ at the inter-granular contacts by Mg 2+ and (2) Chemical dissolution. The effect of temperature is opposite for the two mechanisms. The impact of temperature on chalk compaction is studied both in a static (cores aged in water) and dynamic (cores flooded with water) way by performing hydrostatic tests by use of standard triaxial cells. Distilled water was used as a reference fluid in the static tests at 80–130 °C. The mechanical strength of chalk containing seawater was opposite to chalk containing distilled water. With seawater, the chalk became weaker as the temperature increased, while using distilled water, the chalk became stronger as the temperature increased. In the dynamic creep tests, at 50–130 °C, the cores flooded with seawater were significantly weaker than cores flooded with seawater without sulfate, but the difference in mechanical strength decreased as the temperature decreased. The mechanism for enhanced chemical induced weakening of chalk by seawater is discussed.

Centrally Condensed Collapse of Starless Cores

Models of self-gravitating gas in the early stages of pressure-free collapse are compared for initial states that are equilibrium layers, cylinders, and spheres. For each geometrical case the density profile has an inner region of shallow slope surrounded by an outer region of steep slope, and the profile shape during early collapse remains similar to the profile shape of the initial equilibrium. The two-slope density structure divides the spherical collapse history into a starless phase and a protostellar accretion phase. The similarity of density profiles implies that Bonnor-Ebert fits to observed column density maps may not distinguish spherical cores from oblate or prolate cores and may not distinguish static cores from collapsing cores. The velocity profiles discriminate better than the density profiles between initial geometries and between collapse ages. The velocity generally has a subsonic maximum value, which is approximately equal to the initial velocity dispersion times the ratio of collapse age to central free-fall time. Observations of starless-core line profiles constrain collapse models. Collapse from initial states that are strongly condensed and slightly prolate is consistent with infall asymmetry observed around starless cores and is more consistent than collapse from initial states that are weakly condensed and/or oblate. Spherical models match observed inward speeds of 0.05-0.09 km s-1 over 0.1-0.2 pc if the collapse has a typical age of 0.3-0.5 free-fall times and if it began from a centrally condensed state that was not in stable equilibrium. In a collapsing core, optically thin line profiles should broaden and develop a two-peak structure, as seen in L1544, once the typical velocity approaches the molecular velocity dispersion or when the collapse age exceeds ~0.4 free-fall times, for typical parameters, independent of depletion.

Chemiluminescence analysis of nitric oxide in small-volume samples by a modified injection method

To detect NO in samples of the headspace of static cores, a sample-mixing unit was developed which made it possible to detect NO in small-volume samples (50μl to 10 ml) by a continuous flow chemiluminescence NO analyzer. The sample-mixing unit enables the detector of the NO analyzer to reach a steady-state response. The detection limit was 3.5 pmol NO in a sample, which is equivalent to 8.5 ppbv NO in a 10-ml sample or 85 ppbv No in a 1-ml sample at room temperature. The coefficient of variation between replicates varied between 6.4% at low NO levels and 0.6% at high NO levels. The linear response was good, theR2 value was above 0.99 even in the lowest detection range. The sample-mixing unit in combination with an NO analyzer provides a sensitive, reliable, easy to use method for the detection of NO in incubation systems with small headspace volumes such as static cores.