Control Chamber Research Articles

Doses to LiF :Ti, Mg chips encapsulated in plastic extremity rings as a result of radon gas exposure

Previous studies measured the effects of 222Rn on various thermoluminescent dosemeters (TLDs). This study quantified the effects of 222Rn on LiF : Ti,Mg chips encapsulated in plastic extremity rings. For 28 d, one batch of TLDs was left in a chamber with high radon levels, and another batch in a control chamber with normal background radon levels. A few TLDs in each batch were removed from the rings for direct exposure to the ambient air in each chamber. Passive continuous radon monitors (CRMs) recorded the 222Rn levels. TLDs were processed using a third-party dosimetry company, CRM data were analysed, and the relationship between integrated 222Rn concentration and TLD response was determined. The batch of TLDs in the experimental chamber showed a weak response to 222Rn gas, which was in the order of 0.5 nSv Bq−1 m3 d−1.

Investigation of long term coupled effect of high temperature and constant high humidity on corrosion rehabilitated patches of reinforced concrete structures

This paper aims at finding the long term coupled effect of high temperature and constant high relative humidity on the corrosion rehabilitated patches of chloride contaminated steel reinforced concrete. This paper is an extension of previous research in which the authors experimentally corroborated re-corrosion in the repaired reinforced concrete (RC) patches in the form of macro-cells. In previous research, the coupled effect was investigated by laboratory controlled experimentation at varying temperature of 30, 40 and 50°C and a high ambient relative humidity of 85% in environmental control chambers for duration of one year. The specimens were prepared having total chloride concentration in mixing water 3% and 5 % by mass of binder. In this present research paper, the two year results of the same specimens are presented to get a deep insight of the long term phenomenon of macro-cell corrosion under the coupled effect of high temperature and humidity on repaired RC patches.

Experimental investigation and hydraulic simulation of dynamic effects on diesel injection characteristics in indirect acting piezo-driven injector with bypass-circuit system

In recent years, the performance and emissions of HSDI diesel engines have been improved significantly by big progresses in the development of fuel injection equipment. This development is ongoing to fulfill stricter regulations by reducing emissions to near zero-impact levels while minimizing CO2. In most electro-hydraulic injectors for the common rail diesel fuel injection system the injection nozzle is opened and closed by the movement of an injector’s needle which is balanced by pressure at the nozzle seat and at the needle control chamber at the opposite end of the needle. In this study, spray experiment and hydraulic simulation of piezo-driven diesel injector with bypass-circuit indirectly acting as a needle’s driver have been investigated to evaluate the effect of injection control capability on spray formation processes and to predict the dynamic characteristics of the hydraulic component inside the injector by using AMESim numerical code. Results were compared with a conventional solenoid-driven injector equipped with the same micro-sac multi-hole injection nozzle. Further, a hydraulic model has been verified by comparison with the experimental results. It was found that a bypass-circuit type piezo-driven injector causes a short injection closing delay with where a rapid rate of falling slope of injection and a fast injection response and it had better injection control flexibility due to the hydraulic bypass system. Of course, the predicted simulation results in AMESim environment showed favorable agreement with experimental results.

Hydraulic Impulse-Testing System with Pressure Difference Feedback from a Second-Stage Valve

AbstractTo guarantee the reliability of hydraulic systems, it is of vital importance to do impulse testing for hydraulic components. A hydraulic impulse-testing system with pressure difference feedback from a second-stage valve is studied. A mathematical model of the system is built, and it shows that the inner closed-loop damping ratio of the system is influenced by the pressure difference feedback of the control chambers of the second-stage valve. And by changing the pressure difference feedback gain, various damping ratios can be achieved, which is a key factor affecting the system overshoot. The results of both the simulation and experiment show that with the same square wave input the system overshoot can be freely controlled between 0 and 50% by adjusting the pressure difference feedback gain, which is a new method to obtain both peak wave impulse pressure cycle and square wave impulse pressure cycle utilizing the same system and the same input.

계절에 따른 실험실 환경변화를 이용한 토크측정기의 온도 및 습도 감도계수 결정

This paper presents a new method to determine sensitivity coefficients of temperature and humidity of torque transducers by using a natural and seasonal variation of ambient conditions at the laboratory. We had measured the sensitivities of the torque transducers over almost one year using the KRISS 2 kN m torque standard machine. The sensitivity data acquired at various ambient conditions were processed using our measurement model to extract the sensitivity coefficients of temperature and humidity simultaneously with high precision. A comparison with a previous method using an environmental control chamber was carried out to test the feasibility of using our new method. Two results agreed within the uncertainty. We revealed that the torque measuring errors could be 8 times higher than the measurement and calibration capability of KRISS torque standard machine if the sensitivity changes due to the temperature and humidity are not properly corrected during a calibration.

CO2 enrichment and N addition increase nutrient loss from decomposing leaf litter in subtropical model forest ecosystems.

As atmospheric CO2 concentration increases, many experiments have been carried out to study effects of CO2 enrichment on litter decomposition and nutrient release. However, the result is still uncertain. Meanwhile, the impact of CO2 enrichment on nutrients other than N and P are far less studied. Using open-top chambers, we examined effects of elevated CO2 and N addition on leaf litter decomposition and nutrient release in subtropical model forest ecosystems. We found that both elevated CO2 and N addition increased nutrient (C, N, P, K, Ca, Mg and Zn) loss from the decomposing litter. The N, P, Ca and Zn loss was more than tripled in the chambers exposed to both elevated CO2 and N addition than those in the control chambers after 21 months of treatment. The stimulation of nutrient loss under elevated CO2 was associated with the increased soil moisture, the higher leaf litter quality and the greater soil acidity. Accelerated nutrient release under N addition was related to the higher leaf litter quality, the increased soil microbial biomass and the greater soil acidity. Our results imply that elevated CO2 and N addition will increase nutrient cycling in subtropical China under the future global change.

An Avoidable Tragedy at the Sea Cliff (Rincon) Oil Field

Three men were killed and four others were injured during a well drill operation on Hobson Well C-10A in the Sea Cliff Oil Field (also known as Rincon Oil Field), in Ventura County, California, United States, on August 10, 1994, as a result of errors made by the work supervisors at the site. The oil field was under management by Vintage Petroleum, Ltd., which was sued for negligence by the families of the deceased and injured. The coroner's autopsy examination concluded that the cause of the deaths was due to the inhalation of the toxic gas carbon monoxide (CO). This gas was assumed to have been released from the firing of high-energy guns (HEGs) using carbon-rich explosive pentaerythritol tetranitrate (PETN) in an oxygen-depleted environment, during a fracking operation by Schlumberger Corporation on Well C-10A. The author of this article was appointed as an expert witness by Schlumberger to evaluate if the coroner's conclusion was correct. A series of chemical analytical analyses were conducted on the vapor phase of samples, in addition to dissolved components in water from Well C-10A and two adjacent wells. Stable isotope analyses were also conducted on hydrogen (H2), methane (CH4), nitrogen (N2), CO, and water (H2O) 3 weeks after the accident, as well as on four additional occasions from September to December 1994. Control test analyses were performed on the products from HEG firings, using the same explosives as those used in the perforation of Well C-10A in control chambers at a Schlumberger facility in Houston, Texas. The conclusion reached was that the dominant products of PETN detonations are H2, CH4, CO, and N2. However, the isotope ratios (D/H and 13C/12C) of methane in the control experiments were different in Well C-10A, following the detonation on August 10, 1994, than those resulting from controlled PETN explosions. The conclusion reached in this study was that the fracking of the well at a depth of around 2,150 ft had increased the permeability of the sediment layers in the Padres Zone at that depth to allow the rapid release of a large quantity of natural gas, primarily CH4, which supersaturated the water in the well. This event caused the formation of a large bubble, which ballooned out of the well to the surface, displacing air in the location where the men were working, and thus causing asphyxiation, which resulted in the death of the three men. The judge accepted this interpretation.

Development Automated System Control Heat Chamber Based on Programmable Logic Controller Siemens S7-200

The aim of this work is to develop a computer-aided control and heat chamber on the basis of PLC Siemens S7-200, its installation, adjustment and subsequent commissioning.

Experimental Investigation of Solid Attitude Control System Using Proportional Pintle Thrusters

In order to investigate the characteristics of solid attitude control system (SACS) using proportional pintle thrusters, an ACS comprised of dual collaborative thrusters was designed and studied by theory and cold-flow test. Experiments were conducted to ascertain thrust variation at different pintle locations. With the purpose of studying thrust control principle, the thrust, chamber pressure and pintle displacement of two thrusters were measured, which worked differentially in the process. Results show that a nearly linear relationship is found between the thrust and valve pintle position and the two thrusters can work synchronous to produce a resultant force, whose direction and value can vary continuously. Besides, collaborative work mode of dual thrusters is conducive to the stabilization of chamber pressure which is beneficial to the choice of propellant.

温度与降水协同作用对短花针茅(Stipa breviflora)生物量及其分配的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 温度与降水协同作用对短花针茅生物量及其分配的影响 DOI: 10.5846/stxb201304150710 作者: 作者单位: 中国科学院植物研究所植被与环境变化国家重点实验室,中国科学院植物研究所植被与环境变化国家重点实验室,中国气象科学研究院; 中国科学院植物研究所植被与环境变化国家重点实验室,中国科学院植物研究所植被与环境变化国家重点实验室,中国科学院植物研究所植被与环境变化国家重点实验室,中国科学院植物研究所植被与环境变化国家重点实验室,中国科学院植物研究所植被与环境变化国家重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点基础研究发展计划(973计划) (2010CB951300); 中国科学院战略性先导科技专项-应对气候变化的碳收支认证及相关问题(XDA05050400) Interactive effects of changing precipitation and elevated temperatures on plant biomass and its allocation of Stipa breviflora Author: Affiliation: State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Chinese Academy of Meteorological Sciences; State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:采用人工气候箱法模拟研究温度变化(对照、增温1.5、2.0、4.0、6.0 ℃)、降水变化(W-30%、W-15%、对照W0、W+15%、W+30%) (以1978-2007年6-8月的月均温和月均降水量为对照)及其协同作用对内蒙古荒漠草原优势种短花针茅生物量及其分配的影响表明:温度和降水协同作用显著影响短花针茅生物量及其分配。增温使短花针茅总生物量、叶和根生物量增加,茎生物量和根冠比分别在在增温1.5 ℃、4 ℃后随增温而减小。干旱高温使总生物量减小,增温和降水增加使总生物量、根和叶生物量增加,茎生物量在增温小于2 ℃时随降水增加而增加,则适当的增温和增加降水可促进短花针茅生物量的积累。短花针茅的各器官生物量分配对温度和降水协同作用的敏感性为茎生物量比>叶生物量比>根生物量比,最敏感性器官为茎。这表明,短花针茅可根据不同器官生物量对水热变化的敏感性,调节干物质累积分配来适应气候变化。 Abstract:Although many studies have studied the effects of single environmental factor (temperature, precipitation, CO2 etc.) on plants, the interactive effects of changing precipitation and temperature on plants, especially of multiple precipitation and temperature regimes have drawn few attention to date. Stipa breviflora, which is one of the dominant species of desert steppe in the arid region, would be highly sensitive to changes of temperature and precipitation. Our objectives of this study are to determine the interactive effects of changing precipitation and elevated temperatures on biomass and its allocation of S. breviflora, and to discover its sensitive organs, in order to provide a reference for the biomass change of S. breviflora in the future climate scenarios and the adaptability of desert steppe to future climate change. In this paper, five artificial control chambers were used to simulate the elevated temperatures (control, T1.5, T2.0, T4.0, T6.0) and changing precipitation (W-30%, W-15%, control W0, W+15% and W+30%) (based on the average monthly temperature and precipitation of 6-8 months during 1978-2007 in Siziwangqi county, Inner Mongolia). There are six replicates for every temperature and precipitation treatment. The seeds were sowed and well watered before control experiment in greenhouse. Then, 150 pots of plants (four plants per pot) with consistent growing vigor were randomly selected and placed into five artificial control chambers as different treatments. Temperature treatments were controlled by artificial control chambers with different daytime and nighttime temperatures, each precipitation treatment was converted to irrigation amounts of every month and then divided into 10 times to water. The biomasses of S. breviflora were measured based on leaves, stems and roots after 3 months. The results showed that the interactive effects of elevated temperature and changing precipitation on biomass and its allocation of S. breviflora were significant. Total biomass, leaf biomass and root biomass increased due to warming, stem biomass and root shoot ratio (R/S) decreased with the increase of temperature when warming was more than 1.5 ℃ and 4 ℃. With the warming of 6 ℃ and decreased precipitation of 30%, total, leaf and root biomasses decreased significantly, but stem biomass and R/S were not affected significantly. With warming and increasing precipitation, total, root and leaf biomasses of S. breviflora increased, stem biomass increased only when warming was less than 2 ℃, so warming and increased precipitation within an appropriate range might promote biomass accumulation. Under interactive effects of warming and changing precipitation, the sensitivity of organ biomass allocation of S. breviflora was ranged as shoot mass ratio (SMR)> leaf mass ratio (LMR)> root mass ratio (RMR), the stem was the most sensitive organ. S. breviflora would adapt to the future climate change by adjusting the biomass allocation into different organs based on its sensitivity. There was difference between the interactive effects of temperature and precipitation and its single effect, therefore we should consider the scene of interactive effects of temperature and precipitation in predicting the adaption of desert grassland plants. 参考文献 相似文献 引证文献

Evaluation of deproteinized bone mineral (DBM) as an onlay bone-graft in the rabbit mandible

Abstract Objective To evaluate bone regeneration in a heterogenous, deproteinized bone mineral (DBM) when used as an onlay graft. Materials and methods In this study, eight rabbits received two titanium bone graft holders (TBGHs), one on the left and one on the right lateral surface of the mandible. Each TBGH possessed two cylindrical chambers, which were perforated with numerous sub-millimeter pores. On the experimental side of the jaw, the chambers were filled with DBM particles (Bio-Oss®, Geistlich Pharmaceutical AG, Walhusen, Switzerland). Chambers on the opposite (control) side of the jaw were empty (no DBM). Following TBGH placement both the control and experimental TBGHs were covered with a barrier layer of collagen membrane (Bio-Gide®, Geistlich Pharmaceutical AG, Walhusen, Switzerland). After twelve weeks, sections of the mandible were harvested for radiographic and histomorphometric evaluation. Results New bone formation was seen in both test and control chambers. However, the newly generated bone was greater in the experimental (DBM) group (18.41%) than in the control group (5.31%). The difference was statistically significant ( p 2 ± 1.48) than the control group (8.59 mm 2 ± 3.54) ( p p Conclusion DBM can enhance greater new bone formation when used as an onlay graft, underneath a rigid barrier.

Effect of elevated CO2 and temperature on oxidative stress and antioxidant enzymes activity in coconut (Cocosnucifera L.) seedlings

Increasing atmospheric CO2 concentration is one of the factors driving climate change. We have investigated the individual effect of elevated CO2 and temperature on oxidative stress and antioxidant enzymes activity in coconut (Cocosnucifera L.) seedlings. Three cultivars (WCT, LCT and COD) and two hybrids (WCT × COD and COD × WCT) were grown in six open top chambers (OTCs) and responses were analyzed after three years. In two OTCs the CO2 was set at 550 and 700 µmol mol−1 and control chamber had ambient level of 393 µmol mol1. In two separate OTCs, air temperature was elevated by 2 °C above the ambient control chamber. Remaining two chambers served as chamber control. Elevated CO2 and temperature increased the activities of superoxide dismutase and catalase , whereas it reduced polyphenol oxidase activity. On the other hand, peroxidase (POX) activity was decreased in elevated temperature, while it increased under elevated CO2 conditions. The POX activity and membrane stability index (MSI) were positively correlated. By virtue of greater MSI and lower MDA content, WCT and hybrid COD × WCT were observed to be tolerant to oxidative stress among the five cultivars under elevated CO2 and temperature conditions. These cultivars may adapt better to changing climates.

Performance, digestion, nitrogen balance, and emission of manure ammonia, enteric methane, and carbon dioxide in lactating cows fed diets with varying alfalfa silage-to-corn silage ratios

Two trials were conducted simultaneously to study the effects of varying alfalfa silage (AS) to corn silage (CS) ratio in diets formulated to avoid excess protein or starch on lactating dairy cow performance, digestibility, ruminal parameters, N balance, manure production and composition, and gaseous emissions [carbon dioxide (CO2), methane (CH4), and ammonia-N (NH3-N)]. In trial 1 all measurements, except gas emissions, were conducted on 8 rumen-cannulated cows in replicated 4×4 Latin squares. In trial 2, performance and emissions were measured on 16 cows randomly assigned to 1 of 4 air-flow controlled chambers in a 4×4 Latin square. Dietary treatments were fed as total mixed rations with forage-to-concentrate ratio of 55:45 [dietary dry matter (DM) basis] and AS:CS ratios of 20:80, 40:60, 60:40, and 80:20 (forage DM basis). Measurements were conducted the last 3d of each 21-d period. Treatments did not affect DM intake, DM digestibility, and milk/DM intake. However, responses were quadratic for fat-and-protein-corrected milk, fat, and protein production, which reached predicted maxima for AS:CS ratio of 50:50, 49:51, and 34:66, respectively. Nitrogen use efficiency (milk N/N intake) decreased from 31 to 24g/100g as AS:CS ratio increased from 20:80 to 80:20. Treatments did not alter NH3-N/milk-N but tended to have a quadratic effect on daily NH3-N emission. Treatments had a quadratic effect on daily CH4 emission, which was high compared with current literature; they influenced CH4 emission per unit of neutral detergent fiber (NDF) intake and tended to influence CO2/NDF intake. Ruminal acetate-to-propionate ratio and total-tract NDF digestibility increased linearly with increasing AS:CS ratio. In addition, as AS:CS ratio increased from 20:80 to 80:20, NDF digested increased linearly from 2.16 to 3.24kg/d, but CH4/digested NDF decreased linearly from 270 to 190g/kg. These 2 counterbalancing effects likely contributed to the observed quadratic response in daily CH4 emission, which may have been influenced also by increasing starch with increasing CS in the diet as reflected by the increased ruminal propionate molar proportion. Overall, production performances were greatest for the intermediate AS:CS ratios (40:60 and 60:40), but daily excretion of urine, manure, fecal N, urinary urea N, and urinary N decreased with increasing proportion of CS in the diet, whereas daily CH4 emission was reduced for the 2 extreme AS:CS ratios (20:80 and 80:20). However, the proportion of AS and CS in the diet did not affect CH4/fat-and-protein corrected milk.

Subchronic effects of inhaled ambient particulate matter on glucose homeostasis and target organ damage in a type 1 diabetic rat model

Epidemiological studies have reported associations between particulate matter (PM) and cardiovascular effects, and diabetes mellitus (DM) patients might be susceptible to these effects. The chief chronic injuries resulting from DM are small vascular injuries (micro-vascular complications) or large blood vessel injuries (macro-vascular complications). However, toxicological data regarding the effects of PM on DM-related cardiovascular complications is limited. Our objective was to investigate whether subchronic PM exposure alters glucose homeostasis and causes cardiovascular complications in a type 1 DM rat model. We constructed a real world PM2.5 exposure system, the Taipei Air Pollution Exposure System for Health Effects (TAPES), to continuously deliver non-concentrated PM for subchronic exposure. A type 1 DM rat model was induced using streptozotocin. Between December 22, 2009 and April 9, 2010, DM rats were exposed to PM or to filtered air (FA) using TAPES in Taipei, Taiwan, 24h/day, 7days/week, for a total of 16weeks. The average concentrations (mean [SD]) of PM2.5 in the exposure and control chambers of the TAPES were 13.30 [8.65] and 0.13 [0.05]μg/m3, respectively. Glycated hemoglobin A1c (HbA1c) was significantly elevated after exposure to PM compared with exposure to FA (mean [SD], 7.7% [3.1%] vs. 4.7% [1.0%], P<0.05). Interleukin 6 and fibrinogen levels were significantly increased after PM exposure. PM caused focal myocarditis, aortic medial thickness, advanced glomerulosclerosis, and accentuation of tubular damage of the kidney (tubular damage index: 1.76 [0.77] vs. 1.15 [0.36], P<0.001). PM exposure might induce the macro- and micro-vascular complications in DM through chronic hyperglycemia and systemic inflammation.

축소 모형실험을 이용한 동결-융해 반복작용이 옹벽 구조물의 거동에 미치는 영향

본 논문에서는 계절적 환경변화로 인한 동결-융해 반복과정에 노출되는 옹벽구조물의 거동에 관한 축소 모형실험 연구 내용을 다루었다. 이를 위해 먼저 동결-융해 과정을 모사할 수 있는 모형 옹벽 실험 장치를 구현하고 실제 계절별 온도 변화 과정을 모사하였으며 다양한 흙의 함수비 및 뒤채움흙의 종류 등을 따른 영향 변화를 고찰을 위한 모형실험을 수행하였다. 실험 결과 계절별 온도변화에 따른 동결-융해 반복 과정은 옹벽의 변위를 증가시키고 토압을 증가시키는 것으로 검토되었다. 아울러 동결-융해 반복 사이클의 영향은 흙의 초기 함수비가 클수록 그리고 세립분을 많이 포함할수록 증가되는 것으로 검토되었다. 본 논문에서는 도출된 연구결과가 실무적 차원에서 지니는 의미에 대한 내용을 기술하였다. This paper presents the results of a reduced-scale physical model investigation into the behavior of retaining walls subject to cycles of freezing and thawing due to seasonal temperature change. Reduced-scale model walls equipped with a temperature control chamber that can simulate freezing and thawing conditions were first constructed and a series of tests were conducted with due consideration of different initial water contents of backfill soil and soil types. The results indicate that cycles of freezing and thawing process increase wall deformation as well as earth pressure acting on the wall. Also revealed was that the effect of the freezing and thawing cycles becomes more pronounced for cases with a larger initial water content and for soils with a larger fine content. Practical implications of the findings from this study are discussed in great detail.

Use of a free ocean CO₂ enrichment (FOCE) system to evaluate the effects of ocean acidification on the foraging behavior of a deep-sea urchin.

The influence of ocean acidification in deep-sea ecosystems is poorly understood but is expected to be large because of the presumed low tolerance of deep-sea taxa to environmental change. We used a newly developed deep-sea free ocean CO2 enrichment (dp-FOCE) system to evaluate the potential consequences of future ocean acidification on the feeding behavior of a deep-sea echinoid, the sea urchin, Strongylocentrotus fragilis. The dp-FOCE system simulated future ocean acidification inside an experimental enclosure where observations of feeding behavior were performed. We measured the average movement (speed) of urchins as well as the time required (foraging time) for S. fragilis to approach its preferred food (giant kelp) in the dp-FOCE chamber (-0.46 pH units) and a control chamber (ambient pH). Measurements were performed during each of 4 trials (days -2, 2, 24, 27 after CO2 injection) during the month-long period when groups of urchins were continuously exposed to low pH or control conditions. Although urchin speed did not vary significantly in relation to pH or time exposed, foraging time was significantly longer for urchins in the low-pH treatment. This first deep-sea FOCE experiment demonstrated the utility of the FOCE system approach and suggests that the chemosensory behavior of a deep-sea urchin may be impaired by ocean acidification.

Plastic responses to elevated temperature in low and high elevation populations of three grassland species.

Local persistence of plant species in the face of climate change is largely mediated by genetic adaptation and phenotypic plasticity. In species with a wide altitudinal range, population responses to global warming are likely to differ at contrasting elevations. In controlled climate chambers, we investigated the responses of low and high elevation populations (1200 and 1800 m a.s.l.) of three nutrient-poor grassland species, Trifolium montanum, Ranunculus bulbosus, and Briza media, to ambient and elevated temperature. We measured growth-related, reproductive and phenological traits, evaluated differences in trait plasticity and examined whether trait values or plasticities were positively related to approximate fitness and thus under selection. Elevated temperature induced plastic responses in several growth-related traits of all three species. Although flowering phenology was advanced in T. montanum and R. bulbosus, number of flowers and reproductive allocation were not increased under elevated temperature. Plasticity differed between low and high elevation populations only in leaf traits of T. montanum and B. media. Some growth-related and phenological traits were under selection. Moreover, plasticities were not correlated with approximate fitness indicating selectively neutral plastic responses to elevated temperature. The observed plasticity in growth-related and phenological traits, albeit variable among species, suggests that plasticity is an important mechanism in mediating plant responses to elevated temperature. However, the capacity of species to respond to climate change through phenotypic plasticity is limited suggesting that the species additionally need evolutionary adaptation to adjust to climate change. The observed selection on several growth-related and phenological traits indicates that the study species have the potential for future evolution in the context of a warming climate.

Characteristic emission enhancement in the atmosphere with Rn trace using metal assisted LIBS

Several characteristic emission lines from the metal targets (Cu, Zn and Pb) were investigated in trace presence of radon gas in the atmospheric air, using Q-SW Nd:YAG laser induced plasma inside a control chamber. The emission lines of metal species are noticeably enhanced in (Rn+air), relative to those in the synthetic air alone. Similar spectra were also taken in various sub-atmospheric environments in order to determine the optimum pressure for enhancement. Solid-state nuclear track detectors were also employed to count the tracks due to alpha particles for the activity assessment.

The effects of henna (hair dye) on the embryonic development of zebrafish (Danio rerio)

The powder of henna is extensively used as decorative skin paint for nail coloring and as a popular hair dye in Asian countries. Its human health risk is extensive, and it is frequently released as waste into the aquatic environment raising the concerns. Zebrafish (Danio rerio) embryos were employed to study the developmental effects of henna. Normal fertilized zebrafish embryos under standard water were selected for the control and test chambers. Three predetermined sublethal concentrations (100, 200, and 275 μM) of henna in 24-well cell culture plates were tested on 1-h postfertilized embryo (pfe) for 96 h. Observation for rates of survival and mortality was recorded; digital camera was used to image morphological anomalies of embryos with a stereomicroscope; and functional abnormalities at 24, 48, 72, and 96 h were performed. The hatching rates of embryos were reduced significantly when treated with 200 and 275 μM or higher concentrations of henna. Slow blood circulation in the whole body was observed with a median effect on hatching exposed to 200 and 275 μM of henna at 48-h pfe. At 72- and 96-h pfe, blood circulation was ceased in the whole body but still had a heartbeat. At 96-h pfe, pericardial sac edema, yolk sac edema, head deformation, spine crooked malformation, and tail malformation (bent tails or hook-like tails) were observed in the surviving larvae at 100 μM. In summary, exposure to henna at 100, 200, and 275 μM causes some altered morphological and physiological abnormalities including increased mortality, hatching delay, slow blood circulation, pericardial sac edema, yolk sac edema, abnormal body axes, twisted notochord, tail deformation, weak heartbeat, and growth retardation and was also detected in some treated embryos and groups having adverse effects on embryonic development of zebrafish provoking potential human developmental risk studies.

UV-Light-Induced Water Condensation in Air and the Role of Hydrogen Peroxide

Abstract We report the UV-light-induced formation of water aerosol/droplets in air based on laser-light scattering measurements, differential mobility analyses and cavity ring-down laser spectroscopy (CRDS), and propose a mechanism. It was shown that UV-light (185 nm) irradiation of air within a soap bubble rapidly produced water droplets under supersaturated conditions. Multiple UV irradiation cycles were demonstrated to increase particle sizes in a controlled reaction chamber. We propose that the reaction mechanism is initiated by oxygen (O2) photodissociation and ozone (O3) formation and further photodissociation of O3 leads to sequential dark reactions, generating hydrogen peroxide (H2O2) as a hygroscopic stable product. Exciting excess O3 in wet air with mid-UV radiations (254 nm) was also demonstrated to produce water particles, indicating that this series of reactions can be started at an intermediate stage using a longer wavelength of UV light. For the first time, it was demonstrated that H2O2 in air is a precursor of the initial nucleation of water with two different aerosol formation schemes at 263 K: a) from a mixture of H2O2 and water vapor in dark and b) from a mixture of O3 and water vapor by mid-UV (266 nm) light irradiation. These results indicate that H2O2 can capture water molecules and form water particles.