Instantaneous Production Research Articles

Effects of Glucose Concentration on Ethanol Fermentation of White-Rot Fungus Phanerochaete sordida YK-624 Under Aerobic Conditions.

White-rot fungi are microorganisms capable of ethanol fermentation; however, the specific conditions activating ethanol fermentation are unclear in contrast to fermentation by yeasts. In this study, we investigated the conditions favoring ethanol fermentation by the white-rot fungus Phanerochaete sordida YK-624, which is able to produce ethanol from woody material. In aerobic stationary cultivation with various concentrations of glucose (0.8-33g/l), the fungus produced ethanol in media containing an initial glucose concentration of 2.8g/l or higher. The amount of glucose consumption, mycelial weight, and ethanol production on the second day of culture increased in a concentration-dependent manner at low glucose concentrations; however, these were saturated at high concentrations. Biomass yields (growth/glucose consumption) were decreased until the initial glucose concentration increased to 6.0g/l, after which the biomass yields showed constant values at higher concentrations (12-33g/l). On the other hand, ethanol yields increased with decreasing biomass yields. In short shaking cultivation using mycelial suspension, trace amounts of instantaneous aerobic ethanol production were observed with 1.1 and 2.1g/l glucose, but the relative gene expression levels of key enzymes at the pyruvate branch point showed no significant differences between ethanol production and non-production conditions. From these experimental results, it appears that the white-rot fungus P. sordida YK-624 produces ethanol due to overflow in sugar metabolism under aerobic conditions, although P. sordida YK-624 prioritizes glucose utilization for respiratory growth.

Numerical investigation of the energy flexibility of different heating and cooling systems

The significant expansion of intermittent renewable energy sources can compromise the stability of energy grids due to the mismatch between instantaneous energy use and production. Buildings have a large potential for energy storage and demand-side management, which can offer energy flexibility to a Smart Grid system. Smart control of heating, ventilation and air conditioning systems is a great solution for improving flexible energy use, load shifting and power peak shaving. This numerical study compares the energy flexibility potential of three different heating and cooling systems implemented in a nearly zero-energy office building. The energy flexibility strategy consists in the modulation of heating / cooling indoor temperature set points according to an energy price signal. The energy flexibility assessment was performed based on the energy shifting ability, indoor thermal comfort level and economic benefits. This article establishes a better understanding of the flexibility potential of common and innovative heating / cooling technologies. Lindab Solus system has the highest load shifting ability with a flexibility index of 67.41%, followed by the radiator heating system, scoring a 59.92%, and the underfloor heating system with 56.65%. It is clear that the selection between different heating/ cooling systems can have a great impact on the energy flexibility of the grid system.

In-flame soot quantification of diesel sprays under sooting/non-sooting critical conditions in an optical engine

Because of the challenge of meeting stringent emissions regulations for internal combustion engines, some advanced low temperature combustion modes have been raised in recent decades to improve combustion efficiency. Therefore, detailed understanding and capability for accurate prediction of in-flame soot processes under such low sooting conditions are becoming necessary. Nowadays, a lot of investigations have been carried out to quantify in-flame soot in Diesel sprays under high sooting conditions by means of different optical techniques. However, no information of soot quantification can be found for sooting/non-sooting critical conditions. In current study, the instantaneous soot production in a two-stroke optical engine under low sooting conditions has been measured by means of a Diffused back-illumination extinction technique (DBI) and two-color method (2C) simultaneously. The fuels used were n-dodecane and n-heptane, which have been injected separately though two different injectors equipped with single-hole nozzles. A large cycle-to-cycle variation on soot production can be observed under such operating conditions, however the in-cylinder heat release traces were quite repeatable. It is the same with the well-known trends of soot amount to operating conditions that the probability of sooting cycles increases with higher ambient temperature, higher ambient density and lower injection pressure. Both techniques present a pretty good agreement on soot amount when the peak of KL value is close to 1. However, the KL value of two-color method becomes bigger than that of DBI and the difference increases with lower sooting conditions.

Density, Growth, Production, and Feeding Dynamics of Juvenile Weakfish (Cynoscion regalis) in Delaware Bay and Salt Marsh Tributaries: Spatiotemporal Comparison of Nursery Habitat Quality

Biomass, growth, production, and feeding of young-of-the-year weakfish were examined in salt marsh tributary and nearshore habitats of Delaware Bay to describe the dynamic nursery habitat function for this species. Weakfish were collected from June through October 2005–2007 at seven sites in Delaware Bay, each with one nearshore bay station and three stations in an adjacent tributary. Weakfish biomass was consistently highest in the mid-bay, with a shifting peak down-bay in the late stages of the nursery period. Specific growth rates (SGR) ranged from − 2.98 to 9.57% mass day−1 and exhibited a seasonal bimodal pattern of the highest growth in early and late summer. This pattern coincided with that of biomass, suggesting an absence of density-dependent effects on growth. SGR declined in mid-summer and appeared to be associated with reduced stomach fullness. Growth was highest at sites in the mid- and lower bay, and lowest in the upper bay. Variation in instantaneous production primarily reflected trends in biomass, although low growth in August exacerbated a mid-summer production decline. Stomach fullness also declined in mid-summer, suggesting low resource availability. In most cases, fish at sites with high biomass, growth, and production had a higher proportion of mysids in the diet. Both tributary and nearshore areas adjacent to large expanses of salt marsh with abundant mysid resources served as the most important nurseries for juvenile weakfish, though importance of each habitat was temporally dynamic. This study presents a novel approach to quantifying dynamic nursery habitat quality for estuary-dependent fishes during their nursery period.

Explicit diagnosis of the local ozone production rate and the ozone-NOx-VOC sensitivities

In the troposphere, ozone is a harmful gas compound to both human health and vegetation. Ozone is produced from the reaction of NOx (NO + NO2) and VOCs (volatile organic compounds) with light. Due to the highly nonlinear relationships between ozone and its precursors, proper ozone mitigation relies on the knowledge of chemical mechanisms. In this study, an observation-based method is used to simulate ozone formation and elucidate its controlling factors for a rural site on the North China Plain. The instantaneous ozone production rate is calculated utilizing a box model using the dataset obtained from the Wangdu campaign. First, the model was operated in a time-dependent mode to calculate the ozone production rate at each time stamp. The calculated ozone formation rate showed a diurnal average maximum value of 17 ppbv/h (1-h diurnal averaged). The contribution of individual peroxy radicals to ozone production was analyzed. In addition, the functional dependence of calculated P(O3) reveals that ozone production was in a NOx-limited regime during the campaign. Furthermore, the missing peroxy radical source will further extend NOx-limited conditions to earlier in the day, making NOx limitation dominate more of a day than the current chemical model predicts. Finally, a multiple scenarios mode, also known as EKMA (empirical kinetic modeling approach), was used to simulate the response of P(O3) to the imaginary change in precursor concentrations. We found that ozone production was in the NOx-limited region. However, the use of NO2 measured by the molybdenum converter and/or the absence of a peroxy radical source in the current chemical model could over-emphasize the VOC-limited effect on ozone production.

Degradation of sulfonamide antibiotics and their intermediates toxicity in an aeration-assisted non-thermal plasma while treating strong wastewater

Aeration-assisted non-thermal plasma (NTP) process is known as promising due to simultaneous generation of oxygen- and nitrogen-based reactive chemicals for non-biodegradable pollutants removal in a wastewater. Despite its effective oxidizing capability, the decomposition mechanism of antibiotics is not yet clarified well. This study verifies the NTP's removal potential of non-biodegradable sulfonamide antibiotics in the treatment of strong wastewater. The instantaneous production of hydrogen peroxide (H2O2) was quantified to prove synergistic advanced oxidation, and degradation kinetic coefficients of N, N-Dimethyl-4-nitrosoaniline (RNO) reveals rapid oxidation rate of NTP. Also, the results of an acute-toxicity test using Daphnia magna demonstrate how the toxicity of antibiotics intermediates responds to the NTP. Results indicate that the NTP has better potential than conventional oxidation processes in terms of OH-radical generation due to the interplay of reactive species. This study provides useful information that aeration-assisted NTP application to wastewater treatment can be a viable option to enhance treatment efficiency via plasma-related reactive species and that how environmental ecotoxicity responds to the by-products of sulfonamide antibiotics.

Optical study on characteristics of non-reacting and reacting diesel spray with different strategies of split injection

Even though studies on split-injection strategies have been published in recent years, there are still many remaining questions about how the first injection affects the mixing and combustion processes of the second one by changing the dwell time between both injection events or by the first injection quantity. In this article, split-injection diesel sprays with different injection strategies are investigated. Visualization of n-dodecane sprays was carried out under both non-reacting and reacting operating conditions in an optically accessible two-stroke engine equipped with a single-hole diesel injector. High-speed Schlieren imaging was applied to visualize the spray geometry development, while diffused background-illumination extinction imaging was applied to quantify the instantaneous soot production (net result of soot formation and oxidation). For non-reacting conditions, it was found that the vapor phase of second injection penetrates faster with a shorter dwell time and independently of the duration of the first injection. This could be explained in terms of one-dimensional spray model results, which provided information on the local mixing and momentum state within the flow. Under reacting conditions, interaction between the second injection and combustion recession of the first injection is observed, resulting in shorter ignition delay and lift-off compared to the first injection. However, soot production behaves differently with different injection strategies. The maximum instantaneous soot mass produced by the second injection increases with a shorter dwell time and with longer first injection duration.

Phase-space analysis of the Schwinger effect in inhomogeneous electromagnetic fields

Schwinger pair production in spatially and temporally inhomogeneous electric and magnetic fields is studied. The focus is on the particle phase-space distribution within a high-intensity few-cycle pulse. Accurate numerical solutions of a quantum kinetic theory (DHW formalism) are presented in momentum space and, with the aid of coarse-graining techniques, in a mixed spatial-momentum representation. Additionally, signatures of the carrier-envelope phase as well as spin-field interactions are discussed on the basis of a trajectory-based model taking into account instantaneous pair production and relativistic single-particle dynamics. Although our simple semi-classical single-particle model cannot describe every aspect of the particle production process (quantum interferences), essential features such as spin-field interactions are captured.

In Vivo and In-stantaneous Production of Chimeric Antigen Receptor T Cells: Overcoming Treatment Delays

In Vivo and In-stantaneous Production of Chimeric Antigen Receptor T Cells: Overcoming Treatment Delays

On the design of a jet-aerated microfluidic flow-through reactor for wastewater treatment by electro-Fenton

Abstract The design of cost-effective reactors for wastewater treatment by electrochemical advanced oxidation processes is still a challenge. In this work, a novel electro-Fenton reactor concept is presented. The combination of a jet aerator and a microfluidic flow-through cell configures a reactor with low ohmic drop, improved mass transfer which is, in addition, aerated by a compressor-free system. The production of H2O2 was assessed, obtaining an instantaneous production rate of 12.4 mg H2O2 cm−3 electrode h−1 at an instantaneous current efficiency of 98.6% with a low electrical energy consumption of 7.8 kWh kg H2O2−1 in 0.05 M Na2SO4 using a RVC with a deposition of CB/PTFE as the cathode. The performance of two mesh anodes (covered with mixed mineral oxides and boron doped diamond) and two cathodes (Duocel® RVC and Aluminium foams) was evaluated for the degradation of 0.75 dm3 with 100 mg dm−3 of clopyralid as model bio-refractory organic pollutant. The combination of BDD + CB/PTFE – Al was found to be synergistic due to the production of oxidizing radicals from water oxidation and electro-generated Fenton reagent. It was selected as the optimum configuration allowing a fast and efficient degradation of clopyralid after the application of approximately 0.44 Ah dm−3 (less than 1 h) resulting in an energy consumption of 0.02 kWh g−1 clopyralid at 20 mA cm−3 in a medium with only 7 mM Na2SO4 of supporting electrolyte.

Pump Hydro Energy Storage systems (PHES) in groundwater flooded quarries

Pump storage hydroelectricity is an efficient way to temporarily store energy. This technique requires to store temporarily a large volume of water in an upper reservoir, and to release it through turbines to the lower reservoir, to produce electricity. Recently, the idea of using old flooded quarries as a lower reservoir has been evoked. However, these flooded quarries are generally connected to unconfined aquifers. Consequently, pumping or injecting large volumes of water, within short time intervals, will have an impact on the adjacent aquifers. Conversely, water exchanges between the quarry and the aquifer may also influence the water level fluctuations in the lower reservoir. Using numerical modelling, this study investigates the interactions between generic flooded open pit quarries and adjacent unconfined aquifers, during various pump-storage cyclic stresses. The propagation of sinusoidal stresses in the adjacent porous media and the amplitude of water level fluctuations in the quarry are studied. Homogeneous rock media and the presence of fractures in the vicinity of the quarry are considered. Results show that hydrological quarry – rock interactions must be considered with caution, when implementing pump – storage systems. For rock media characterized by high hydraulic conductivity and porosity values, water volumes exchanges during cycles may affect significantly the amplitude of the water level fluctuations in the quarry, and as a consequence, the instantaneous electricity production. Regarding the impact of the pump – storage cyclic stresses on the surrounding environment, the distance of influence is potentially high under specific conditions, and is enhanced with the occurrence of rock heterogeneities, such as fractures. The impact around the quarry used as a lower reservoir thus appears as an important constraining factor regarding the feasibility of pump – storage systems, to be assessed carefully if groundwater level fluctuations around the quarry are expected to bring up adverse effects. Results highlight opportunities and challenges to be faced, to implement pump – storage hydroelectricity systems in old flooded open pit quarries.

Measuring the respiratory gas exchange by grazing cattle using an automated, open-circuit gas quantification system.

Ruminants are a source of enteric CH4, which has been identified as an anthropogenic greenhouse gas that contributes to climate change. With interest in developing technologies to decrease enteric CH4 emissions, systems are currently being developed to measure CH4 emissions by cattle. An issue with grazing cattle is the ability to measure CH4 emissions in open-air environments. A scientific instrument for this task is an automated, open-circuit gas quantification system (GQS; C-Lock, Inc., Rapid City, SD). The GQS is a head chamber that grazing cattle occasionally visit (3 to 8 min/visit; 3 to 6 visits/d), and while the animal consumes a small portion of bait (0.5 to 1.0 kg/visit), the GQS captures the animal's breath cloud by exhausting air through the GQS. The breath cloud is then analyzed for CH4, CO2, and O2 concentrations. Data are hourly uploaded to a server where it is processed using algorithms to determine total daily fluxes. Several factors affect emission estimates generated by the GQS including the animal's visitation rate, length of sampling period, and airflow through the system. The location of the GQS is an important factor in determining the cattle's willingness to visit. Further, cattle need to be trained to use the GQS, which normally requires 4 to 8 wk. Several researchers have shown that 30 or more visits are required to obtain high-quality estimates of gas fluxes. Once cattle are trained to use the GQS, the bait delivery rate has little effect on the animal's willingness to use the system. Airflow through the GQS is an important factor, but as long as airflow is maintained above 26 L/s the breath-cloud capture seems nearly complete. There is great concern regarding circadian variation in the instantaneous production rates of CH4 because the GQS normally only spot-samples 2 to 4 times/d. Preliminary analysis has shown that variation in the instantaneous production rates of CH4 do not vary as greatly with grazing cattle compared with meal-fed cattle. It seems that increasing the visitation length decreases variation in estimated emissions, but there is a diminishing return to increasing visitation length. The GQS is a useful tool for researching the nutrition and emissions of grazing cattle, but great care must be taken to obtain the best quality data possible for use in this high-impact research.

Development and validation of a comprehensive dynamic mathematical model for hybrid PV/T solar collectors

In this paper, a model for the simulation of a hybrid photovoltaic-thermal collector under transient regime is developed and validated. The model is built using a control volume approach, the collector is divided into small elemental volumes where energy equation is solved using a bi-dimensional finite difference method. The model is validated against experimental data obtained from a two weeks testing in real environmental weather conditions on two hybrid PV/T solar tiles connected in series. An agreement between the experimental and numerical values of the instantaneous power production and the water outlet temperature within ±4 W and within ±0.5 K respectively is found. On a daily basis, the calculated electrical and thermal energies agree within −2.64% to +1.73% and within −4.90% to +7.37% with experimental data, allowing to state that the developed model is quite a reliable tool both for short-term and long-term yield analysis at component or system level.

Measurements of the Prompt Fission Neutron Spectrum at LANSCE: The Chi-Nu Experiment

The goal of the Chi-Nu experiment at the Los Alamos Neutron Science Center is to measure the prompt fission neutron spectra from major actinides using a double time-of-flight method with a pulsed, white incoming neutron source. Fission events are detected with a parallel-plate avalanche counter and outgoing neutrons are detected with either a 6Li-glass or liquid scintillator detector array for low- or high-energy neutrons, respectively. A detector response matrix for the interaction of neutrons with the experimental environment for neutrons measured with the Chi-Nu 6Li-glass detector array has been calculated to obtain a full understanding of the measured Chi-Nu data and also to allow for nearly instantaneous production of simulated Chi-Nu data spectra. Prompt fission neutron spectra corresponding to 19 incoming neutron energy ranges from 0.7-20 MeV have been extracted using the ratio-of-ratios method with Chi-Nu 6Li-glass data on the neutron-induced fission of 235U.

Coupling irrigation scheduling with solar energy production in a smart irrigation management system

In recent years, pressurized pipe networks have improved the efficiency of irrigation systems while substantially increasing their energy demand. The progressive rise in energy costs makes it difficult to maintain the profitability of agricultural holdings. Moreover, global warming is a serious problem that threatens the environment worldwide and low CO2 emission processes should be promoted. To address these issues, it is necessary to look for sustainable and more profitable alternatives for the agricultural sector. One of these new alternatives is the use of renewable energies for pumping irrigation water at farm level, particularly photovoltaic energy. Nevertheless, the instability of irradiation hinders its management for stand-alone photovoltaic installations. In this work, a real-time model called the Smart Photovoltaic Irrigation Manager (SPIM) is developed to synchronize the photovoltaic power availability with the energy required to pump the irrigation requirements of different sectors of irrigation networks. SPIM consists of different modules to calculate the key management variables of the photovoltaic irrigation system: the daily irrigation requirements, the hydraulic behavior of the irrigation network, the instantaneous photovoltaic power production and the daily soil water balance. The lack of photovoltaic energy during daylight hours on any day of the irrigation season to supply the daily required amount of water is balanced with either the water stored in the soil or by extending the duration of the irrigation events in the following days when necessary. SPIM has been applied to simulate the management of photovoltaic irrigation in a real olive orchard in Southern Spain during the 2013 irrigation season. The results showed that the proper management of the photovoltaic irrigation system provided enough water to satisfy crop irrigation requirements throughout the irrigation season and avoided the emission of 1.2 tn CO2 eq using only the energy generated by solar panels.

Termination, Propagation, and Transfer Kinetics of Midchain Radicals in Methyl Acrylate and Dodecyl Acrylate Homopolymerization

Methyl acrylate (MA) and dodecyl acrylate (DA) homopolymerizations (1.5 M in toluene) were investigated via single pulse–pulsed laser polymerization in conjunction with detection of the type and of the concentration of radicals by electron paramagnetic resonance spectroscopy (SP–PLP–EPR). The evolution of secondary propagating (SPR) and midchain (MCR) radicals, after instantaneous laser-induced production of an intense burst of primary radicals, was measured with a time resolution of microseconds from 0 to 60 °C. With the kinetics of chain-length-dependent termination and of propagation for SPRs being already known from experiments at subzero temperature, the rate coefficients for the formation of MCRs from SPRs by backbiting, kbb, of propagation from MCRs, kpt, and of cross-termination between an SPR and an MCR, ktst, were deduced. The present paper aims at elucidating the impact of the size of the ester side chain on kbb, kpt, and ktst. In passing from MA to DA (in 1.5 M solution of toluene), the rate c...

Wireless chemiluminescence-based sensor for soil deformation detection

A novel sensing application based on chemiluminescence was designed and tested in the laboratory for deformation monitoring in soil. The device, containing the reactants stored in separate chambers, on activation when deformed under load, result in an almost instantaneous production of light which could be readily detected using low-cost optoelectronics. The attractiveness of this concept for deformation monitoring is that the chemiluminescence sensor is completely passive, requiring no power for it to function. In this paper, the effort was focused on demonstrating the sensing capability of the chemiluminescence-based device for detecting soil deformation or movement in the event of a landslide. Laboratory experiments were conducted to demonstrate the proof-of-concept through a prototype of the device fabricated specifically for this study. Wireless transmission capability was also incorporated into the prototype design in view of the potential deployment in the field.

Excess Entropy Production in Quantum System: Quantum Master Equation Approach

For open systems described by the quantum master equation (QME), we investigate the excess entropy production under quasistatic operations between nonequilibrium steady states. The average entropy production is composed of the time integral of the instantaneous steady entropy production rate and the excess entropy production. We propose to define average entropy production rate using the average energy and particle currents, which are calculated by using the full counting statistics with QME. The excess entropy production is given by a line integral in the control parameter space and its integrand is called the Berry-Sinitsyn-Nemenman (BSN) vector. In the weakly nonequilibrium regime, we show that BSN vector is described by $\ln \breve{\rho}_0$ and $\rho_0$ where $\rho_0$ is the instantaneous steady state of the QME and $\breve{\rho}_0$ is that of the QME which is given by reversing the sign of the Lamb shift term. If the system Hamiltonian is non-degenerate or the Lamb shift term is negligible, the excess entropy production approximately reduces to the difference between the von Neumann entropies of the system. Additionally, we point out that the expression of the entropy production obtained in the classical Markov jump process is different from our result and show that these are approximately equivalent only in the weakly nonequilibrium regime.

Impact of nuclear transmutations on the primary damage production: The example of Ni based steels

The recent nuclear evaluations describe more accurately the elastic and inelastic neutron-atoms interactions and allow calculating more realistically primary damage induced by nuclear reactions. Even if these calculations do not take into account relaxation processes occurring at the end of the displacement cascade (calculations are performed within the Binary Collision Approximation), they can accurately describe primary and recoil spectra in different reactors opening the door for simulating aging of nuclear materials with Ion Beam facilities. Since neutrons are only sensitive to isotopes, these spectra must be calculated weighting isotope spectra by the isotopic composition of materials under investigation. To highlight such a point, primary damage are calculated in pure Ni exhibiting a meta-stable isotope produced under neutron flux by inelastic neutron-isotope processes. These calculations clearly point out that the instantaneous primary damage production, the displacement per atom rate (dpa/s), responsible for the micro-structure evolution, strongly depends on the N59i isotopic fractions closely related to the inelastic neutron isotope processes. Since the isotopic composition of the meta-stable isotope vanishes for large fluences, the long term impact of this isotope does not largely modify drastically the total dpa number in Ni based steels materials irradiate in nuclear plants.

Fine root dynamics after soil disturbance evaluated with a root scanner method

Fine root production in ecosystems has been estimated mainly by excavation methods that cause soil disturbance. In this study, patterns of fine root dynamics following soil disturbance were monitored for multiple years and were analyzed quantitatively by applying a root scanner method that allows continuous observations. Eleven scanners were inserted into the soil of cypress and oak forests with soil disturbance, and weekly soil profiles were scanned for several years. Then fine root dynamics were estimated quantitatively by image analyses. Fine roots emerged intensively in the immediate year of the scanner installation. Seasonal patterns of cumulative root area production followed the logistic curve, but its parameters varied depending on stands and elapsed years after the scanner installation. Estimates of the annual production and instantaneous production rate from the logistic equation differed between the immediate and the following years after disturbance in the cypress and oak stands. The root scanner method is a viable technique to quantitatively describe fine root dynamics of forests, including the possible effects of soil disturbance. The results suggested that fine root production can be described by a logistic equation providing both an asymptotic upper boundary and a growth coefficient.