Measured light from an IEC

Micropropagation of Dev-ringal [ Thamnocalamus spathiflorus (Trin.) Munro] — a temperate bamboo, and comparison between in vitro propagated plants and seedlings

Light intensity is a critical variable of the dye-sensitized photooxidation reaction, and the rate of house fly, Musca domestica , mortality is observed to increase with increasing light intensity. Relative toxicities were described for 6 xanthene dyes (rose bengal, octabromofluorescein, erythrosin B, phloxin B, eosin Y, and tetrachlorofluorescein) as a function of the 3rd-order rate constant of photooxidation, k3, obtained for each dye and determined from the LT50, tissue dye levels, and light intensity measurements. The ranking of these 6 xanthenes by their respective k3 values is almost identical to the ranking of these same dyes by their k2, or second-order rate constant. The number of accumulated photons needed to produce 50% mortality was observed to decrease with an increase in light intensity.

Characterization of an ultra-compact neutron source based on an IEC fusion device and its prospective applications in radiography

Induction of high-frequency shoot regeneration using nodal segments containing axillary buds from a 1-yr-old mother plants of Cannabis sativa was achieved on Murashige and Skoog (MS) medium containing 0.05–5.0 μM thidiazuron. The quality and quantity of regenerants were better with thidiazuron (0.5 μM thidiazuron) than with benzyladenine or kinetin. Adding 7.0 μM of gibberellic acid into a medium containing 0.5 μM thidiazuron slightly increased shoot growth. Elongated shoots when transferred to half-strength MS medium supplemented with 500 mg l−1 activated charcoal and 2.5 μM indole-3-butyric acid resulted in 95% rooting. The rooted plants were successfully acclimatized in soil. Following acclimatization, growth performance of 4-mo-old in vitro propagated plants was compared with ex vitro vegetatively grown plants of the same age. The photosynthesis and transpiration characteristics were studied under different light levels (0, 500, 1,000, 1,500, or 2,000 μmol m−2 s−1). An increase in photosynthesis was observed with increase in the light intensity up to 1,500 μmol m−2 s−1 and then decreased subsequently at higher light levels in both types of plants. However, the increase was more pronounced at lower light intensities below 500 μmol m−2 s−1. Stomatal conductance and transpiration increased with light intensity up to highest level (2000 μmol m−2 s−1) tested. Intercellular CO2 concentration (C i) and the ratio of intercellular CO2 concentration to ambient CO2 (C i/C a) decreased with the increase in light intensity in both in vitro as well as ex vitro raised plants. The results show that in vitro propagated and hardened plants were functionally comparable to ex vitro plants of same age in terms of gas and water vapor exchange characteristics, within the limits of this study.

Eupatorium adenophorum is one of main invasive plants in China and has caused great economic losses. A study was conducted to determine the biomass allocation, leaf morphology and growth response of E. adenophorum seedlings that grew under five different intensities (relative irradiances RI 10%, 20%, 30%, 55%, 100%) for 14 months. Results reveal that the species shows typical leaf morphological adaptation to different light conditions. The total biomass of seedlings increased with the increase of light intensity from 10% to 55% RI but decreased at RI 100% (full sunlight). Height growth increased with the increase of light intensity from 10% to 30% RI but decreased when light intensity was over 30% RI. At low light levels, plants enhanced light availability by means of increasing biomass allocation to leaves and formation of larger, thinner leaves with high specific leaf area (SLA), leading to a high leaf area ratio (LAR) and high stem strips length (SSL). The mean relative growth rate (RGR) of the plant increased with the light intensity increase and attained the maximum at 55% RI. The growth of seedlings at 30%-55% RI was much better than that at full light condition. This might be an adaptive strategy that supports the vigorous invasiveness of this species, because a high-shaded canopy could prevent other plant species from surviving and growing. This study indicates that E. adenophorum could adapt to different light conditions, especially to low light habit. This can explain its greater invasiveness.

Summary form only given. The PDS1 particle-in-cell Monte-Carlo-Collision (PIC-MCC) code has been modified for simulating the Inertial Electrostatic Confinement (IEC) device which has multiple collision processes and electrical grids in a spherical geometry. PDS1 can give a detailed account of the transient and steady-state plasma physics occurring in the IEC device. Two experimental single-grid devices and one triple-grid conceptual device were simulated.

Detection of explosives has been identified as a near term commercial opportunity for using a fusion plasma. Typical explosive compositions contain low Z material (C, N, O) which are not easily detected using conventional x-rays or metal detectors. However, 2.45 MeV neutrons produced in a D-D fusion reaction can be used for detection of explosives or other clandestine materials in suitcases, packages, or shipping containers.Steady-state D-D operation is possible using an Inertial Electrostatic Confinement (IEC) fusion device. The University of Wisconsin IEC device has produced D-D neutrons at 1.8 × 108 neutrons/second at a true cathode voltage of 166 kV and a meter current of 68 mA. These neutron production rates are approaching the levels required for the detection of explosives. In order to increase and optimize the neutron production rate in the IEC device, experiments were performed altering the cathode’s size (diameter), geometry, and material composition. Preliminary results indicate that significant differences in neutron production rates are not achieved by altering the geometry or material composition of the cathode. However, the neutron production rate was found to increase approximately 20% by doubling the cathode’s diameter from 10 cm to 20 cm. In addition, increasing the cathode voltage from 34 kV to 94 kV at a meter current of 30 mA increased the neutron production rate from 1.24 × 106 n/s to 2.83 × 107 n/s.

For the past 15 years, the Inertial Electrostatic Confinement (IEC) fusion group at the University of Wisconsin-Madison has been conducting experiments to demonstrate that there can be many near term applications of fusion research long before the production of electricity in commercial fusion power plants. This research has concentrated on three fuel cycles: DD, D3He, and 3He3He. Some of the major accomplishments are listed below:a. The production of > 108 DD neutrons per second on a steady state basisb. The production of pulsed DD neutrons to over 1010 per second in 10Hz, 100 μs bursts.c. The production of 14.7 MeV protons at > 108 per second (steady state) from the D3He reaction.d. Demonstrated the detection of the explosive C-4 with steady state DD neutrons.e. Demonstrated the detection of Highly Enriched U (HEU) with pulsed DD neutron fluxes.f. Production of the positron emission tomography (PET) isotopes, 94mTc and 13Nusing D3He protons.g. Production of the first measured 3He3He fusion reactions in an IEC device.h. Development of unique diagnostic techniques to measure the rate, spectrum, and location of fusion reactions in IEC devices.i. Use of an IEC device to study the behavior of materials at high temperature during charged particle bombardment.The accomplishments above were carried out in 3 devices HOMER, 3HeCTRE, and HELIOS that have operated up to 180 kV and meter currents of 65 mA. New applications are currently being explored and expanded roles for the IEC device will be described.

A two-dimensional numerical code has been developed for simulating dc discharges in inertial electrostatic confinement (IEC) fusion devices. Unlike the existing IEC codes, the developed code is not based on Monte Carlo scheme by the use of random number nor time-domain particle-in-cell (PIC) method, aiming at a drastic reduction of computational efforts. It is based on a time-independent scheme, i.e. iterative calculations of particle-tracking and induced self-field, leading to a much faster convergence than the time-domain PIC scheme on steady-state self-consistent solutions. Also, a new scheme for atomic process treatment is proposed, which is completely free from the inherent difficulty of Monte Carlo method, i.e. requiring many particles for simulating rare events. Preliminary numerical result from the this code showed agreement with experimental helium discharge characteristics in an IEC device.

Aims Our objective was to investigate the effects of different light intensities on leaf morphology, photosynthetic capacity, heat dissipation and antioxidant enzyme activities in seedlings of Alnus formosana and A. cremastogyne from a hilly region near Lingyan Mountain in northwestern Sichuan Province in China. We also discuss photosynthetic acclimation and photoprotection strategies in seedlings of the two species Methods Three light regimes of 100%, 56.2% and 12.5% of natural light were simulated to match forest openings, forest gaps and forest canopies, respectively. After more than three months, we measured the parameters of gas exchange, including maximum net photosynthetic rate (Pmax), light saturation point (LSP), light compensation point (LCP), net photosynthetic rate (P n ), stomatal conductance (G s ), transpiration rate (T r ), intercellular CO 2 concentration (C i ), fluorescent non-photochemical quenching (NPQ), maximum efficiency of PSII photochemistry (F v /F m ) and light use efficiency (LUE), using a LI-6400 in seedling leaves. We also determined pigment contents per unit leaf area, lamina mass per unit area (LMA) and activity of antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase). Important findings LMA, carotenoid content (Cars), ratio of carotenoid to total chlorophyll (Car/Chl) and activities of superoxide dismutase, catalase and ascorbate peroxidase in leaves increased with the increase of light intensities. P max , LSP, LCP and NPQ tended to increase, while the chlorophyll content (Chl) and LUE decreased. However, the C i decreased with the increase of P n , G s and stomatal limitation value (L s ). We speculated that non-stomatal limitation was the main factor that inhibited P n . Seedlings of the two alder species could acclimate to different light regimes in this study through changing of physiological and morphological traits. Under all lightregimes, diurnal photoinhibition of photosynthesis, as judged by F v /F m , was significantly more severe in A. cremastogyne than in A. formosana. The acclimation capacity to high light regime was stronger in A. formosana than in A. cremastogyne. With the increase of light intensities, P max and antioxidant enzyme activities increased significantly, but not NPQ in A. formosana. The opposite trends occurred in A. cremastogyne. At the same light intensity, thermal dissipation was much lower, but P max was much higher in A. formosana than in A. cremastogyne. These results indicated that A. formosana seedlings might adapt resistance to photoinhibition through improving the use of solar energy by higher P max and antioxidant enzyme system, while A. cremastogyne seedling avoided photoinhibition mainly through converting excess light energy to heat energy in the form of non-radiative dissipation through the antenna system.

An external helicon ion source is used on HELIOS, an inertial electrostatic confinement (IEC) fusion device in which ions are accelerated radially to fusion-relevant energies by the electrostatic field between the spherical chamber wall and a concentric cathode grid. The external ion source has allowed for the demonstration of 3He-3He fusion in an IEC device for the first time, as part of the advanced fuels program at the University of Wisconsin.1

We examined the relationship between light intensity, migratory behavior of sockeye salmon Oncorhynchus nerka fry, and predation by cottids Cottus spp. We tested the hypothesis that above-natural intensities of nighttime light would increase cottid predation of sockeye salmon fry. In circular tank experiments under controlled laboratory conditions, we tested the ability of cottids to prey on sockeye salmon fry under six different light intensities using minimal water circulation to separate the effect of the migratory behavior of fry from the ability of cottids to capture them. We found that cottids preyed most effectively in complete darkness, whereas the lowest predation occurred at the brightest light intensity. We next tested the predation ability of cottids at four light intensities in a pair of artificial streams to simulate more natural conditions. In experiments without cottids, the majority of fry passed quickly through the artificial streams under complete darkness, but as light intensity was increased, fewer fry emigrated and did so at a slower rate. With cottids present and increased light intensity, even fewer fry emigrated but they did so at a faster rate than did those in the stream without cottids. We determined that cottids probably consumed about 5% of the sockeye salmon fry under complete darkness and ate about 45% of the fry at the brightest light intensity tested. In experimental field trials, the shoreline abundance of fry and predation by cottids increased as light intensities increased. Using two small lights within an 8-m shoreline section on the Cedar River, Washington, we delayed as many as 550 sockeye salmon fry and observed predation of as many as 7.6 fry/cottid. At the end of the experiment, we turned the lights off and noted that the shoreline abundance of fry declined dramatically. At two locations on the Cedar River lit by city lights, the abundance of sockeye salmon fry and predation by cottids was substantially greater than at nearby sites with low light. Also, we demonstrated at one site that reducing light intensity substantially reduced predation on sockeye salmon fry. Overall, we conclude that increased light intensity appears to slow or stop out-migration of fry, making them more vulnerable to capture by predators such as cottids.

BackgroundLight is a critical environmental factor in plants, encompassing two vital aspects: intensity and quality. To assess the influence of different light intensities on Origanum majorana L., pots containing the herb were subjected to four levels of light intensity: 20, 50, 70, and 100% natural light. After a 60-day treatment period, the plants were evaluated for metabolite production, including total sugar content, protein, dry weight, antioxidant indices, expression of monoterpenes biosynthesis genes, and essential oil compounds. The experimental design followed a randomized complete blocks format, and statistical analysis of variance was conducted.ResultsThe results indicated a correlation between increased light intensity and elevated total sugar and protein content, which contributed to improved plant dry weight. The highest levels of hydrogen peroxide and malondialdehyde (MDA) were observed under 100% light intensity. Catalase and superoxide dismutase enzymes exhibited increased activity, with a 4.23-fold and 2.14-fold increase, respectively, under full light. In contrast, peroxidase and polyphenol oxidase enzyme activities decreased by 3.29-fold and 3.24-fold, respectively. As light intensity increases, the expression level of the 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) gene increases. However, beyond a light intensity of 70%, the DXR gene expression level decreased. Furthermore, the expression levels of the cytochrome P450 genes CYP71D178 and CYP71D179 exhibited an increasing trend in response to elevated light intensity. Essential oil content increased from 0.02 to 0.5% until reaching 70% light intensity. However, with further increases in light intensity, the essential oil content decreased by 54 to 0.23%.ConclusionsThese findings emphasize the importance of balancing plant growth promotion and stress management under different light conditions. The research suggests that sweet marjoram plants thrive best in unshaded open spaces, resulting in maximum biomass. However, essential oil production decreases under the same conditions. For farmers in areas with an average light intensity of approximately 1700 µmol m−2s−1, it is recommended to cultivate sweet marjoram in shade-free fields to optimize biomass and essential oil production. Towards the end of the growth cycle, it is advisable to use shades that allow 70% of light to pass through. The specific duration of shade implementation can be further explored in future research.

The effect of high temperature (700-1200°C) implantation of deuterium and helium in candidate fusion first wall materials was studied in the University of Wisconsin Inertial Electrostatic Confinement (IEC) device. Tungsten coated TaC and HfC ’’foam’’, single crystal tungsten, and high-emissivity tungsten coated ’’foam’’ were compared to previous tungsten powder metallurgy samples studied in the IEC device for the High Average Power Laser (HAPL) program. Scanning electron microscopy was performed to evaluate changes in surface morphology for various ion fluences at temperatures comparable to first wall temperatures. Single crystal tungsten was shown to exhibit less damage than polycrystalline samples at a fluence of 4×1016 He+/cm2. It was found that no significant deformations occur with deuterium implantation up to ~1018 D+/cm2 at 800°C on W-coated TaC and HfC foam samples. However, helium fluences in excess of 6×1017 He+/cm2 show extensive pore formation at 800°C and higher. These changes may have an impact on the lifetime of tungsten coatings on the first walls of inertial and magnetic confinement fusion reactors.

New diagnostics are required to understand the physics operation of an inertial electrostatic confinement (IEC) device. In an attempt to understand the fusion source regimes within the IEC device, a new diagnostic called the eclipse disk has been introduced. This diagnostic was used to exploit the byproduct protons’ energy difference between the deuterium-deuterium (D–D) and deuterium—an isotope of helium with two protons and one neutron (D–He3) reactions to study the contributions of the protons generated from various source regimes. These source regimes are divided into five categories namely: converged core, embedded, beam background, volume, and wall-surface sources. The eclipse disk diagnostic has provided the first confirmed evidence that D–He3 reactions are predominantly embedded reactions. It has been observed that at the present operating power levels (6–10kW) most of the D–D reactions occur in the volume of the chamber caused by the charge exchanged neutrals, and the converged core contribution is significant only for D–D reactions. Since the branching ratio for the proton and neutron generation in a D–D fusion reaction is ∼50%, it is inferred that the proton to neutron count ratio is a better parameter to monitor than either proton or neutron counts measured alone while studying the source regimes. This parameter may also be used for studying the potential wells within the cathode grid.