scholarly journals A Mars Environment Chamber Coupled with Multiple In Situ Spectral Sensors for Mars Exploration

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2519
Author(s):  
Zhongchen Wu ◽  
Zongcheng Ling ◽  
Jiang Zhang ◽  
Xiaohui Fu ◽  
Changqing Liu ◽  
...  
Keyword(s):  
Spectral Data ◽  
Environmental Conditions ◽  
Environmental Parameter ◽  
Laboratory Simulation ◽  
Glow Discharge Plasma ◽  
Spectral Features ◽  
Mars Exploration ◽  
Environment Chamber ◽  
Accuracy And Repeatability

Laboratory simulation is the only feasible way to achieve Martian environmental conditions on Earth, establishing a key link between the laboratory and Mars exploration. The mineral phases of some Martian surface materials (especially hydrated minerals), as well as their spectral features, are closely related to environmental conditions. Therefore, Martian environment simulation is necessary for Martian mineral detection and analysis. A Mars environment chamber (MEC) coupled with multiple in situ spectral sensors (VIS (visible)-NIR (near-infrared) reflectance spectroscopy, Raman spectroscopy, laser-induced breakdown spectroscopy (LIBS), and UV-VIS emission spectroscopy) was developed at Shandong University at Weihai, China. This MEC is a comprehensive research platform for Martian environmental parameter simulation, regulation, and spectral data collection. Here, the structure, function and performance of the MEC and the coupled spectral sensors were systematically investigated. The spectral characteristics of some geological samples were recorded and the effect of environmental parameter variations (such as gas pressure and temperature) on the spectral features were also acquired by using the in situ spectral sensors under various simulated Martian conditions. CO2 glow discharge plasma was generated and its emission spectra were assigned. The MEC and its tested functional units worked well with good accuracy and repeatability. China is implementing its first Mars mission (Tianwen-1), which was launched on 23 July 2020 and successfully entered into a Mars orbit on 10 February 2021. Many preparatory works such as spectral databases and prediction model building are currently underway using MECs, which will help us build a solid foundation for real Martian spectral data analysis and interpretation.

MixAR

2019 ◽  
Vol 12 (4) ◽  
pp. 1-33 ◽  
Author(s):  
Telmo Adão ◽  
Luís Pádua ◽  
David Narciso ◽  
Joaquim João Sousa ◽  
Luís Agrellos ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Mixed Reality ◽  
The Real ◽  
Points Of Interest ◽  
Real Scene ◽  
The Future

MixAR, a full-stack system capable of providing visualization of virtual reconstructions seamlessly integrated in the real scene (e.g. upon ruins), with the possibility of being freely explored by visitors, in situ, is presented in this article. In addition to its ability to operate with several tracking approaches to be able to deal with a wide variety of environmental conditions, MixAR system also implements an extended environment feature that provides visitors with an insight on surrounding points-of-interest for visitation during mixed reality experiences (positional rough tracking). A procedural modelling tool mainstreams augmentation models production. Tests carried out with participants to ascertain comfort, satisfaction and presence/immersion based on an in-field MR experience and respective results are also presented. Ease to adapt to the experience, desire to see the system in museums and a raised curiosity and motivation contributed as positive points for evaluation. In what regards to sickness and comfort, the lowest number of complaints seems to be satisfactory. Models' illumination/re-lightning must be addressed in the future to improve the user's engagement with the experiences provided by the MixAR system.

scholarly journals In-Situ Metatranscriptomic Analyses Reveal the Metabolic Flexibility of the Thermophilic Anoxygenic Photosynthetic Bacterium Chloroflexusaggregans in a Hot Spring Cyanobacteria-Dominated Microbial Mat

2021 ◽  
Vol 9 (3) ◽  
pp. 652
Author(s):  
Shigeru Kawai ◽  
Joval N. Martinez ◽  
Mads Lichtenberg ◽  
Erik Trampe ◽  
Michael Kühl ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Environmental Conditions ◽  
Microbial Mats ◽  
Carbon Fixation ◽  
Hot Springs ◽  
Hot Spring ◽  
Photosynthetic Bacterium ◽  
Early Morning ◽  
Metabolic Flexibility

Chloroflexus aggregans is a metabolically versatile, thermophilic, anoxygenic phototrophic member of the phylum Chloroflexota (formerly Chloroflexi), which can grow photoheterotrophically, photoautotrophically, chemoheterotrophically, and chemoautotrophically. In hot spring-associated microbial mats, C. aggregans co-exists with oxygenic cyanobacteria under dynamic micro-environmental conditions. To elucidate the predominant growth modes of C. aggregans, relative transcription levels of energy metabolism- and CO2 fixation-related genes were studied in Nakabusa Hot Springs microbial mats over a diel cycle and correlated with microscale in situ measurements of O2 and light. Metatranscriptomic analyses indicated two periods with different modes of energy metabolism of C. aggregans: (1) phototrophy around midday and (2) chemotrophy in the early morning hours. During midday, C. aggregans mainly employed photoheterotrophy when the microbial mats were hyperoxic (400–800 µmol L−1 O2). In the early morning hours, relative transcription peaks of genes encoding uptake hydrogenase, key enzymes for carbon fixation, respiratory complexes as well as enzymes for TCA cycle and acetate uptake suggest an aerobic chemomixotrophic lifestyle. This is the first in situ study of the versatile energy metabolism of C. aggregans based on gene transcription patterns. The results provide novel insights into the metabolic flexibility of these filamentous anoxygenic phototrophs that thrive under dynamic environmental conditions.

scholarly journals Transplantation of the Mediterranean seagrass Posidonia oceanica through naturalistic engineering techniques: value, weakness and further improvements

2015 ◽  
Author(s):  
Stefano Acunto ◽  
Luigi Piazzi ◽  
Francesco L. Cinelli ◽  
Anna Maria De Biasi ◽  
Lorenzo Pacciardi ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Large Scale ◽  
Focal Point ◽  
Posidonia Oceanica ◽  
Hydrodynamic Conditions ◽  
Coastal System ◽  
Pros And Cons ◽  
The Mediterranean ◽  
Selection Of

Transplantation of seagrasses is considered a useful method to favour the recovery of degraded meadows. Hence, many projects have been carried out worldwide and a manifold of techniques have been applied. However, the choice of transplantation procedures remains a main problem to be assessed. In order to optimize efforts and to minimize risks of plants loss, the applied methodologies should take into account typology of hosting substratum, hydrodynamic conditions, depth and seagrass species. Due to their fundamental ecological role in the Mediterranean coastal system, many restoration projects aiming to preserve Posidonia oceanica meadows took place in the last decades. Several transplantation techniques have produced different results. In fact the same transplanting methodology may originate diverse results under different environmental conditions. Recently, naturalistic engineering techniques developed on land, have been used for transplantations of P. oceanica. Pilot projects concerning small surfaces were carried out between 2006 and 2010. More recently, a large-scale program (0.1 km2) was realized in 2012 at Civitavecchia (Roma, Thyrrenian Sea). The applied technique consists basically of mattresses filled with sand coupled with a net covering able to hold steady in situ the plant rhizomes. These structures have been variously modified in time to be adapted to the different type of substratum and various hydrodynamic conditions of the transplanting sites. Following the results of these transplantation experiences, we analyzed pros and cons of the techniques in order to improve the methodology. Firstly, these techniques may be considered suitable to large-scale projects allowing to minimize transplantation times. Secondly, the rhizomes may be successfully fixed to the structures; the majority of the transplanted shoots was not damaged showing a very good vegetative vitality with the production of new rhizomes, leaves and roots few months after transplanting. Finally, this procedure is flexible, as the basic technique can be modified and tailored to the various environmental conditions of the different receiving site. However, the results obtained in different areas are highly heterogeneous suggesting that a careful selection of the hosting site is a focal point. To this aim, a pilot study before the beginning of large-scale project seems mandatory, providing a fundamental support to guarantee successful results.

scholarly journals Feasibility study of in-situ bioremediation for nitrobenzene-contaminated groundwater

2017 ◽  
Vol 17 (4) ◽  
pp. 1160-1167 ◽  
Author(s):  
Na Liu ◽  
Yue Wang ◽  
Yonglei An ◽  
Feng Ding ◽  
Xiaolong Yu ◽  
...  
Keyword(s):  
Simulation Experiment ◽  
Laboratory Simulation ◽  
Contaminated Groundwater ◽  
Site Conditions ◽  
In Situ Bioremediation ◽  
Degrading Bacterium ◽  
Bacterium Strain ◽  
Negative Factors ◽  
Sufficient Oxygen

Although many studies have simulated in-situ bioremediation of contaminated groundwater, most of them have not considered hydrochemical conditions and indigenous microorganisms, thus potentially rendering results inapplicable to actual in-situ groundwater bioremediation projects. This study focused on a nitrobenzene-contaminated groundwater site located in Jilin City, China. The actual nitrobenzene-contaminated groundwater was taken from Jilin City to simulate in-situ groundwater bioremediation in the laboratory. The feasibility of in-situ bioremediation for nitrobenzene-contaminated groundwater was studied according to actual site conditions and characteristics of nitrobenzene-degrading microorganisms in groundwater. The results showed that nitrobenzene-degrading bacterium strain NB1 was the dominant species that could effectively and rapidly degrade nitrobenzene by a partial reductive pathway. No negative factors on the growth or degrading function of this strain in groundwater could be detected. During a laboratory simulation experiment, combined in-situ bioremediation technologies, namely air sparging and bioaugmentation, could readily remove approximately 89.56% of nitrobenzene from groundwater without adding nutrients; oxygen was found to be the important growth factor for strain NB1. As the substrate of nitroreductase, encoded by the nitrobenzene nitroreductase (nbzA) gene, nitrobenzene was likely to significantly affect the expression of this gene. In conclusion, in-situ bioremediation is a feasible way to solve the problem of nitrobenzene-contaminated groundwater in Jilin City as long as sufficient oxygen and biomass of strain NB1 is ensured.

In vitro studies on the induction of sporogenous tissue on leaves of cinnamon fern. I. Environmental factors

1972 ◽  
Vol 50 (12) ◽  
pp. 2673-2682 ◽  
Author(s):  
William H. Harvey ◽  
James D. Caponetti
Keyword(s):  
Environmental Factors ◽  
Light Intensity ◽  
Environmental Conditions ◽  
Light Exposure ◽  
Progressive Increase ◽  
Light Phase ◽  
Sporogenous Tissue ◽  
Light Darkness

Intact, set III, cinnamon fern cataphyll and frond primordia, which were shown to have no predisposition to fertility in situ, produced sporangia when excised and cultured under sterile conditions in Knudson's medium supplemented with various levels of sucrose and maintained on 11 different regimens of light, darkness, and temperature for 10 weeks. Increasing levels of sucrose resulted in increased fertility under all environmental conditions, but the highest percentage of fertility was obtained under conditions of continuous dark at 26 °C. As the length of the light phase of the photoperiods decreased, a progressive increase in induction of fertile leaves was observed, suggesting that periods of long light exposure are inhibitory to the initiation of sporangia. Conversely, as the light intensity was increased, an inhibition of sporophyll differentiation occurred. Sporangia excised from dark-induced sporophylls and cultured in the light produced viable spores which germinated yielding haploid gametophytes that ultimately produced sporophytes.

Optimizing Preloading Pressure of Precharged Gas for Isobaric Gas-Tight Hydrothermal Samplers

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Haocai Huang ◽  
Liang Huang ◽  
Wei Ye ◽  
Shijun Wu ◽  
Canjun Yang ◽  
...  
Keyword(s):  
Volume Change ◽  
Theoretical Models ◽  
Sample Volume ◽  
Field Application ◽  
Laboratory Simulation ◽  
Application Process ◽  
Sampling Depth ◽  
Ambient Temperatures ◽  
Gas Tight

Isobaric gas-tight hydrothermal samplers, with the ability to maintain pressure, can be used to keep in situ chemical and biological sample properties stable. The preloading pressure of the precharged gas is a major concern for isobaric gas-tight hydrothermal samplers, especially when the samplers are used at different sampling depths, where the in situ pressures and ambient temperatures vary greatly. The most commonly adopted solution is to set the preloading pressure for gas-tight samplers as 10% of the hydrostatic pressure at the sampling depth, which might emphasize too much on pressure retention; thereby, the sample volume may be unnecessarily reduced. The pressure transition of the precharged gas was analyzed theoretically and modeled at each sampling stage of the entire field application process. Additionally, theoretical models were built to represent the pressure and volume of hydrothermal fluid samples as a function of the preloading pressure of the precharged gas. Further, laboratory simulation and examination approaches were also adopted and compared, in order to obtain the volume change of the sample and accumulator chambers. By using theoretical models and the volume change of the two chambers, the optimized preloading pressure for the precharged gas was obtained. Under the optimized preloading pressure, the in situ pressure of the fluid samples could be maintained, and their volume was maximized. The optimized preloading pressure obtained in this study should also be applicable to other isobaric gas-tight hydrothermal samplers, by adopting a similar approach to pressure maintenance.

The Urey Instrument: An Advanced In Situ Organic and Oxidant Detector for Mars Exploration

Astrobiology ◽  
2008 ◽  
Vol 8 (3) ◽  
pp. 583-595 ◽  
Author(s):  
Andrew D. Aubrey ◽  
John H. Chalmers ◽  
Jeffrey L. Bada ◽  
Frank J. Grunthaner ◽  
Xenia Amashukeli ◽  
...  
Keyword(s):  
Mars Exploration

Measuring Radon and Thoron Levels in Sri Lanka

2013 ◽  
Vol 718-720 ◽  
pp. 721-724
Author(s):  
Deepal Subasinghe Nalaka ◽  
Mahakumara Prasad ◽  
Thusitha B. Nimalsiri ◽  
Nuwan B. Suriyaarchchi ◽  
Takeshi Iimoto ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Environmental Conditions ◽  
In Situ Measurements ◽  
Physical Factors ◽  
Preliminary Results ◽  
Radon Measurements ◽  
First Time

For the first time in Sri Lanka, an attempt was made to measure the outdoor radon levels using CR 39 type passive radon detectors. Preliminary results indicate that in Sri Lanka, 220Rn isotope is more abundance than 222Rn isotope. These results were also confirmed by in-situ measurements. Sri Lanka has one of the highest 220Rn values in the region. It was also noted that environmental conditions and other physical factors have a significant effect on the outdoor radon measurements using passive discriminative detectors.

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