Статті в журналах: "Hydrogène vert"

1

Sebbahi, Seddiq, Nouhaila Nabil, Samir Rachidi, Mohammed El Ganaoui, and Abdelilah Benyoussef. "Hydrogène vert au Maroc : état des lieux et perspectives." Annales des Mines - Réalités industrielles Août 2024, no. 4 (November 2, 2022): 148–53. http://dx.doi.org/10.3917/rindu1.224.0148.

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2

Lepercq, Thierry. "Hydrogène : vers une renaissance industrielle de la France ?" Hors les murs N° 506, no. 5 (March 28, 2021): 24–26. http://dx.doi.org/10.3917/ehlm.506.0024.

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3

Zhao, Zeying, Min Liu, Guoping Xiao, Tiancheng Cui, Qingxin Ba, and Xuefang Li. "Numerical Study on Protective Measures for a Skid-Mounted Hydrogen Refueling Station." Energies 16, no. 2 (January 13, 2023): 910. http://dx.doi.org/10.3390/en16020910.

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Hydrogen refueling stations are one of the key infrastructure components for the hydrogen-fueled economy. Skid-mounted hydrogen refueling stations (SHRSs) can be more easily commercialized due to their smaller footprints and lower costs compared to stationary hydrogen refueling stations. The present work modeled hydrogen explosions in a skid-mounted hydrogen refueling station to predict the overpressures for hydrogen-air mixtures and investigate the protective effects for different explosion vent layouts and protective wall distances. The results show that the explosive vents with the same vent area have similar overpressure reduction effects. The layout of the explosion vent affects the flame shape. Explosion venting can effectively reduce the inside maximum overpressure by 61.8%. The protective walls can reduce the overpressures, but the protective walls should not be too close to the SHRS because high overpressures are generated inside the walls due to the confined shock waves. The protective wall with a distance of 6 m can effectively protect the surrounding people and avoid the secondary overpressure damage to the container.

4

Kim, Chae-Hyoung, and In-Seuck Jeung. "Forced Combustion Characteristics Related to Different Injection Locations in Unheated Supersonic Flow." Energies 12, no. 9 (May 8, 2019): 1746. http://dx.doi.org/10.3390/en12091746.

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This work focuses on forced combustion with regards to the relationship between vent mixer models and several injection locations in unheated supersonic flow. A plasma jet torch was used to ignite the hydrogen-air mixture in a laboratory-scaled combustor duct. The flow field of the combustion was visualized with pressure and gas-sampling measurements. The vent mixers indicate good dispersion characteristics of the mixture for both parallel and normal 1 injections. However, forced combustion is dominantly governed by the injection rate toward the plasma jet (hot source) because the combustible region is restricted under the cold main flow. For this reason, the parallel injection, which provides the hydrogen-air mixture directly toward the plasma jet, shows good combustion performance. The normal 1 injection interacted with the vent mixers and shows slightly good combustion performance. Lastly, the normal 2 injection is little affected by the vent mixers and has poor combustion performance.

5

Nam, Hyeonsu, Gun Woo Kim, Hyunyong Lee, Byung Chul Choi, Gilltae Roh, and Youngseung Na. "Numerical Study of the Action of Convection on the Volume and Length of the Flammable Zone Formed by Hydrogen Emissions from the Vent Masts Installed on an International Ship." Journal of Marine Science and Engineering 9, no. 12 (November 30, 2021): 1348. http://dx.doi.org/10.3390/jmse9121348.

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International ships carrying liquefied fuel are strongly recommended to install vent masts to control the pressure of cargo tanks in the event of an emergency. However, the gas emitted from a vent mast may be hazardous for the crew of the ship. In the present study, the volume and length of the flammable zone (FZ) created by the emitted gas above the ship was examined. Various scenarios comprising four parameters, namely, relative wind speed, arrangement of vent masts, combination of emissions among four vent masts, and direction of emission from the vent-mast outlet were considered. The results showed that the convection acts on the volume and length of an FZ. The volume of an FZ increases when there is a reduction in convection reaching the FZ and when strong convection brings hydrogen from a nearby FZ. The length of the FZ is also related to convection. An FZ is elongated if the center of a vortex is located inside the FZ, because this vortex traps hydrogen inside the FZ. The length of an FZ decreases if the center of the vortex is located outside the FZ, as such a vortex brings more fresh air into the FZ.

6

Tatsumoto, H., D. Lyngh, P. Arnold, M. Segerup, P. Tereszkowski, and Y. Beßler. "Design of a hydrogen vent line for ESS cryogenic moderator system." IOP Conference Series: Materials Science and Engineering 1240, no. 1 (May 1, 2022): 012116. http://dx.doi.org/10.1088/1757-899x/1240/1/012116.

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Abstract The ESS cryogenic moderator system (CMS) circulates subcooled liquid hydrogen at 17 K and 1 MPa to remove nuclear heating at two hydrogen moderators. All the hydrogen will be safely released to the atmosphere on the roof top of the Target building through a hydrogen vent line (HVL) with a total length of 36 m. Two-phase hydrogen would flow through the HVL because the hydrogen expands by isenthalpic process. The HVL has been designed to avoid decreasing the wall penetration temperature below 253 K and to be sized big enough to limit the backpressure below the design pressure. One-dimensional transient thermohydraulic analysis code that can treat two-phase flow heat transport behavior has been developed. A natural convection heat transfer from air to the cold surface is considered. In this work, the wall temperature reductions and the pressure drop along the HVL during release of cryogenic hydrogen are analyzed. The size and thickness of the HVL have been verified based on the analysis results.

7

Zhang, Xiaolu, Qiubo Wang, Xulei Hou, Yuejuan Li, Yang Miao, Kun Li, and Li Zhang. "Numerical Analysis of the Hydrogen Dispersion Behavior in Different Directions in a Naturally Ventilated Space." Applied Sciences 11, no. 2 (January 10, 2021): 615. http://dx.doi.org/10.3390/app11020615.

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Studies on hydrogen leakage have mainly focused on the influences of location and geometrical configuration on the distribution of the hydrogen in various spaces. The present study developed a simplified model for the leakage diffusion of hydrogen in an enclosed cuboid space with two vents, at the top and at the bottom, respectively. The effect of different leakage positions on the diffusion of the hydrogen was analyzed. The results showed that when hydrogen diffused vertically from the bottom to the top of the space, the farther the leakage position was from the vent on the side wall, the more hydrogen accumulated. When the hydrogen leaked in the vertical direction from the floor, the distance between the leakage position and the bottom vent had little effect on the horizontal diffusion speed of the hydrogen at the top of the space. The diffusion speed for the leakage in the horizontal direction was faster than that in the vertical direction. When the hydrogen leaked in the horizontal direction from the side wall, the height of the leakage had little effect on the horizontal diffusion speed of the hydrogen at the top of the space. Stratification occurred for models set up in the present study whenever the envelope of 1% mole fraction, or 4% mole fraction, of hydrogen extended to the whole ceiling.

8

Zhang, Xiaolu, Qiubo Wang, Xulei Hou, Yuejuan Li, Yang Miao, Kun Li, and Li Zhang. "Numerical Analysis of the Hydrogen Dispersion Behavior in Different Directions in a Naturally Ventilated Space." Applied Sciences 11, no. 2 (January 10, 2021): 615. http://dx.doi.org/10.3390/app11020615.

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Studies on hydrogen leakage have mainly focused on the influences of location and geometrical configuration on the distribution of the hydrogen in various spaces. The present study developed a simplified model for the leakage diffusion of hydrogen in an enclosed cuboid space with two vents, at the top and at the bottom, respectively. The effect of different leakage positions on the diffusion of the hydrogen was analyzed. The results showed that when hydrogen diffused vertically from the bottom to the top of the space, the farther the leakage position was from the vent on the side wall, the more hydrogen accumulated. When the hydrogen leaked in the vertical direction from the floor, the distance between the leakage position and the bottom vent had little effect on the horizontal diffusion speed of the hydrogen at the top of the space. The diffusion speed for the leakage in the horizontal direction was faster than that in the vertical direction. When the hydrogen leaked in the horizontal direction from the side wall, the height of the leakage had little effect on the horizontal diffusion speed of the hydrogen at the top of the space. Stratification occurred for models set up in the present study whenever the envelope of 1% mole fraction, or 4% mole fraction, of hydrogen extended to the whole ceiling.

9

Breusing, Corinna, Jessica Mitchell, Jennifer Delaney, Sean P. Sylva, Jeffrey S. Seewald, Peter R. Girguis, and Roxanne A. Beinart. "Physiological dynamics of chemosynthetic symbionts in hydrothermal vent snails." ISME Journal 14, no. 10 (July 2, 2020): 2568–79. http://dx.doi.org/10.1038/s41396-020-0707-2.

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Abstract Symbioses between invertebrate animals and chemosynthetic bacteria form the basis of hydrothermal vent ecosystems worldwide. In the Lau Basin, deep-sea vent snails of the genus Alviniconcha associate with either Gammaproteobacteria (A. kojimai, A. strummeri) or Campylobacteria (A. boucheti) that use sulfide and/or hydrogen as energy sources. While the A. boucheti host–symbiont combination (holobiont) dominates at vents with higher concentrations of sulfide and hydrogen, the A. kojimai and A. strummeri holobionts are more abundant at sites with lower concentrations of these reductants. We posit that adaptive differences in symbiont physiology and gene regulation might influence the observed niche partitioning between host taxa. To test this hypothesis, we used high-pressure respirometers to measure symbiont metabolic rates and examine changes in gene expression among holobionts exposed to in situ concentrations of hydrogen (H2: ~25 µM) or hydrogen sulfide (H2S: ~120 µM). The campylobacterial symbiont exhibited the lowest rate of H2S oxidation but the highest rate of H2 oxidation, with fewer transcriptional changes and less carbon fixation relative to the gammaproteobacterial symbionts under each experimental condition. These data reveal potential physiological adaptations among symbiont types, which may account for the observed net differences in metabolic activity and contribute to the observed niche segregation among holobionts.

10

Suh, Chang-Min, Seung-Hoon Nahm, Jun-Hyong Kim, and Young-Sik Pyun. "A Study on the VHCF Fatigue Behaviors of Hydrogen Attacked Inconel 718 Alloy." Transactions of the Korean Society of Mechanical Engineers A 40, no. 7 (July 1, 2016): 637–46. http://dx.doi.org/10.3795/ksme-a.2016.40.7.637.

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11

Pareek, Sonia, Anup Nagaraj, Prateek Sharma, Mansi Atri, Satinder Walia, Shravani Naidu, and Asif Yousuf. "Disinfection of Dental Unit Water Line Using Aloe Vera: In Vitro Study." International Journal of Dentistry 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/618962.

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Context. Dental unit waterlines may be heavily contaminated with microorganisms and are a potential source of infection for both practicing staff and immunocompromised patients particularly. Contamination of dental unit water lines could be inhibited with the use of disinfectants. The present study investigates the effect of aloe-vera-based disinfectant in reducing the microbial growth in dental unit water lines (DUWLs).Aims. To compare the efficacy of aloe vera, hydrogen peroxide (H2O2), and 5% sodium hypochlorite (NaOCl) in controlling microbial contamination of DUWLs.Materials and Methods. After obtaining baseline water samples, the dental unit waterlines were treated with aloe vera, 10% hydrogen peroxide, and 5% sodium hypochlorite. Each of the three disinfectants was used in increasing concentrations and their inhibiting effect was compared. Water samples were analyzed for microbiological quality by the total viable count (TVC) method.Statistical Analysis Used. SPSS 16.Results. There was significant reduction in mean CFU/ml when treated with disinfectants each for a period of one week. Aloe-vera solution was found to be the most effective in reducing the microbial colonies.Conclusions. Improving the water quality from dental unit water lines is of considerable importance; chemical-based disinfectants can be replaced with herbal disinfectants for treating microbial contamination in dental unit waterlines.

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Abdal, Tarik Abdulqadir, Aziza Raof Haji, and Melen Mansour Markus. "Effects of aloe vera extracted on liver and kidney function changes induced by hydrogen peroxide in rats." International Journal of Research in Medical Sciences 8, no. 1 (December 25, 2019): 102. http://dx.doi.org/10.18203/2320-6012.ijrms20195891.

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Background: Aloe vera (Aloes) is a member of the Liliaceae family that is used as herbal medicine in many cultures for several purposes. The present study was designed to investigate the role of Aloe vera leaf gel extracts on lipid profiles and liver and kidney functions in rats.Methods: In this experimental investigation, a total of 20 healthy rats were divided into four following groups. Group I fed with normal diet and water. Group II administrated by 1% hydrogen peroxide with drinking water in a dark bottle prepared daily. Group III administrated with 5 ml of aloe vera oil added to 25 grams of their ratio for each rat (25 ml oil/125 g) also prepared daily with normal drinking water. Group IV also administrated with 5 ml of aloe vera oil added to 25 grams of their ratio with drinking water that contains 1% hydrogen peroxide in a dark bottle. The rats in all four groups fed for 21 days.Results: The subjects who were included in H2O2 had significantly higher concentrations of TG (146.79 vs. 73.09 mg/dL; p<0.001), cholesterol (123.60 vs. 68.90 mg/dL; p=0.001), and lower concentration of HDL (5.79 vs. 7.53 mg/dL; p<0.001) compared to the control group. While, the subjects in Aloe Vera group had lower concentration of cholesterol (55.90 vs. 68.90 mg/dL; p=0.004), and higher level of HDL (9.22 vs. 7.53 mg/dL; p<0.001). The subjects in the H2O2 had significantly higher concentrations of AST (76.64 vs. 30.04; p<0.001), ALT (64.94 vs. 23.38; p<0.001), urea (59.68 vs. 37.10; p=0.003), uric acid (0.92 vs. 0.59; p<0.001). Whereas, the subjects in Aloe Vera had substantially lower levels of AST (18.76 vs. 30.04; p=0.008).Conclusions: The present study showed that aloe vera gel extract is effective to improve the lipid profile and liver and kidney function.

13

Haryani, Reny, Urip Harahap, Masfria Masfria, and Denny Satria. "CYTOPROTECTIVE ACTIVITY OF ETHANOL FRACTION OF COLEUS AMBOINICUS LOUR. LEAVES AGAINST VERO CELLS INDUCED BY H2O2." Asian Journal of Pharmaceutical and Clinical Research 11, no. 13 (April 26, 2018): 28. http://dx.doi.org/10.22159/ajpcr.2018.v11s1.26559.

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Objective: The objective of this study is to assess the cytoprotective activity of Coleus amboinicus Lour. leaves ethanol fraction (EtF) in Vero cells which induced by hydrogen peroxide (H2O2).Methods: Cytoprotective activity was determined using 3-(4,5-dimethylthiazol-2)-2,5-diphenyltetrazolium bromide (MTT) method, apoptosis activity was analyzed by flow cytometry, and expression of radical spesies oxygen (ROS) was observed by imunocytochemistry.Result: The EtF (100 μg/mL) was showed the highest percent viability 74.42±0.28% using MTT method. Furthermore, the EtF was increased viability of Vero cell after induced with 0.8 mM H2O2 and EtF was decreased the expression of ROS.Conclusion: Based on the description, EtF has cytoprotective activity towards Vero cells which induced by 0.8 mM H2O2 .

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Hirayama, Hisako, Michinari Sunamura, Ken Takai, Takuro Nunoura, Takuro Noguchi, Hanako Oida, Yasuo Furushima, Hiroyuki Yamamoto, Tamotsu Oomori, and Koki Horikoshi. "Culture-Dependent and -Independent Characterization of Microbial Communities Associated with a Shallow Submarine Hydrothermal System Occurring within a Coral Reef off Taketomi Island, Japan." Applied and Environmental Microbiology 73, no. 23 (October 5, 2007): 7642–56. http://dx.doi.org/10.1128/aem.01258-07.

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ABSTRACT Microbial communities in a shallow submarine hydrothermal system near Taketomi Island, Japan, were investigated using cultivation-based and molecular techniques. The main hydrothermal activity occurred in a craterlike basin (depth, ∼23 m) on the coral reef seafloor. The vent fluid (maximum temperature, >52°C) contained 175 μM H2S and gas bubbles mainly composed of CH4 (69%) and N2 (29%). A liquid serial dilution cultivation technique targeting a variety of metabolism types quantified each population in the vent fluid and in a white microbial mat located near the vent. The most abundant microorganisms cultivated from both the fluid and the mat were autotrophic sulfur oxidizers, including mesophilic Thiomicrospira spp. and thermophilic Sulfurivirga caldicuralii. Methane oxidizers were the second most abundant organisms in the fluid; one novel type I methanotroph exhibited optimum growth at 37°C, and another novel type I methanotroph exhibited optimum growth at 45°C. The number of hydrogen oxidizers cultivated only from the mat was less than the number of sulfur and methane oxidizers, although a novel mesophilic hydrogen-oxidizing member of the Epsilonproteobacteria was isolated. Various mesophilic to hyperthermophilic heterotrophs, including sulfate-reducing Desulfovibrio spp., iron-reducing Deferribacter sp., and sulfur-reducing Thermococcus spp., were also cultivated. Culture-independent 16S rRNA gene clone analysis of the vent fluid and mat revealed highly diverse archaeal communities. In the bacterial community, S. caldicuralii was identified as the predominant phylotype in the fluid (clonal frequency, 25%). Both bacterial clone libraries indicated that there were bacterial communities involved in sulfur, hydrogen, and methane oxidation and sulfate reduction. Our results indicate that there are unique microbial communities that are sustained by active chemosynthetic primary production rather than by photosynthetic production in a shallow hydrothermal system where sunlight is abundant.

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Karaçaylı, Naim Göksel, and Nikhil Padmanabhan. "Anatomy of cosmic tidal reconstruction." Monthly Notices of the Royal Astronomical Society 486, no. 3 (April 5, 2019): 3864–73. http://dx.doi.org/10.1093/mnras/stz964.

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Abstract 21-cm intensity surveys aim to map neutral hydrogen atoms in the universe through hyper-fine emission. Unfortunately, long-wavelength (low-wavenumber) radial modes are highly contaminated by smooth astrophysical foregrounds that are six orders of magnitude brighter than the cosmological signal. This contamination also leaks into higher radial and angular wavenumber modes and forms a foreground wedge. Cosmic tidal reconstruction aims to extract the large-scale signal from anisotropic features in the local small-scale power spectrum through non-linear tidal interactions; losing small-scale modes to foreground wedge will impair its performance. In this paper, we review tidal interaction theory and estimator construction, and derive the theoretical expressions for the reconstructed spectra. We show the reconstruction is robust against peculiar velocities. Removing low line-of-sight k modes, we demonstrate cross-correlation coefficient r is greater than 0.7 on large scales (k ≲ 0.1 h Mpc−1) even with a cut-off value $k^c_{\Vert }=0.1$h Mpc−1. Discarding wedge modes yields 0.3 ≲ r ≲ 0.5 and completely removes the dependency on $k^c_{\Vert }$. Our theoretical predictions agree with these numerical simulations.

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Chhatri, Amita, Smarika Lawrance, and Anjali Dsouza. "Aloe vera Loaded (Polyvinyl Alcohol) Cryogel: Potential Wound Healer." Asian Journal of Chemistry 34, no. 10 (2022): 2567–72. http://dx.doi.org/10.14233/ajchem.2022.23793.

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The present work describes the preparation methodology of polyvinyl alcohol and Aloe vera hydrogels and their potential role in wound healing. Aloe vera is frequently used in treating many diseases due to its spectacular properties (anti-inflammatory, antiviral, antitumor and antibacterial) which assist in wound healing and help in treating many diseases a range of ailments. The designing of Aloe vera loaded polyvinyl alcohol (PVA) blend hydrogels (coined as cryogels) was done following repeated freeze-thaw cycles method. Characterization of the cryogels was done using some analytical techniques to study its properties and possible applications. The FTIR spectra shows that Aloe vera loaded PVA cryogels are interconnected by hydrogen bonding. Scanning electron microscope analysis established the porous nature of crogels. These hydrogels show water imbibing capacity, which depends on the experimental conditions and the chemical composition of the gel. The factors affecting the swelling ratio of crogels are amount of PVA, Aloe vera, number of Freez-Thaw cycles, pH and medium. The pore size of the cryogels also decreases with increasing number of freeze-thaw cycles. The Aloe vera-PVA cryogel is healing compatible with blood as there is less than 2% hemolysis.

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Safriana, Safriana, Rosidah Rosidah, Poppy Anjelisa Zaitun Hasibuan, and Denny Satria. "CYTOPROTECTIVE EFFECT OF ETHANOL FRACTION OF VERNONIA AMYGDALINA DEL. LEAVES AGAINST THE VERO CELLS." Asian Journal of Pharmaceutical and Clinical Research 11, no. 13 (April 26, 2018): 146. http://dx.doi.org/10.22159/ajpcr.2018.v11s1.26592.

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Objectives: The objective of this study is to assess the cytoprotective effect of ethanol fraction (EtF) of Vernonia amygdalina Del. leaves EtF against Vero cells which induced by hydrogen peroxide (H2O2).Methods: Cytoprotective effects of EtF were analyzed by 3-(4,5-dimethylthiazolyl-2)2,5-dipheniltetrazolium bromide to Vero cells which induced by 0.8 mM H2O2, apoptosis was determined by flow cytometry, and reactive oxygen species (ROS) expression was analyzed by immunocytochemistry.Results: EtF was showed the largest percentage viable cell (78.75±2.51%) at 50 μg/mL. In the analysis of apoptosis by flow cytometry was showed the percentage of viable cell count of 59.56% and EtF was decreased the expression of ROS.Conclusion: EtF has cytoprotective activity toward Vero cells induced by 0.8 mM H2O2.

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Safriana, Safriana, Rosidah Rosidah, Poppy Anjelisa Zaitun Hasibuan, and Denny Satria. "CYTOPROTECTIVE EFFECT OF ETHANOL FRACTION OF VERNONIA AMYGDALINA DEL. LEAVES AGAINST THE VERO CELLS." Asian Journal of Pharmaceutical and Clinical Research 11, no. 13 (April 26, 2018): 214. http://dx.doi.org/10.22159/ajpcr.2018.v11s1.26610.

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Objectives: The objective of this study is to assess the cytoprotective effect of ethanol fraction (EtF) of Vernonia amygdalina Del. leaves EtF against Vero cells which induced by hydrogen peroxide (H2O2).Methods: Cytoprotective effects of EtF were analyzed by 3-(4,5-dimethylthiazolyl-2)2,5-dipheniltetrazolium bromide to Vero cells which induced by 0.8 mM H2O2, apoptosis was determined by flow cytometry, and reactive oxygen species (ROS) expression was analyzed by immunocytochemistry.Results: EtF was showed the largest percentage viable cell (78.75±2.51%) at 50 μg/mL. In the analysis of apoptosis by flow cytometry was showed the percentage of viable cell count of 59.56% and EtF was decreased the expression of ROS.Conclusion: EtF has cytoprotective activity toward Vero cells induced by 0.8 mM H2O2.

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Nahm, Seung-Hoon, Un-Bong Baek, Chang-Min Suh, and Young-Sik Pyun. "Study on VHCF Fatigue Behaviors and UNSM Effects of Hydrogen Attacked STS 316L." Transactions of the Korean Society of Mechanical Engineers - A 41, no. 11 (November 30, 2017): 1011–20. http://dx.doi.org/10.3795/ksme-a.2017.41.11.1011.

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Portail, M., K. Olu, E. Escobar-Briones, J. C. Caprais, L. Menot, M. Waeles, P. Cruaud, P. M. Sarradin, A. Godfroy, and J. Sarrazin. "Comparative study of vent and seep macrofaunal communities in the Guaymas Basin." Biogeosciences 12, no. 18 (September 21, 2015): 5455–79. http://dx.doi.org/10.5194/bg-12-5455-2015.

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Abstract. Understanding the ecological processes and connectivity of chemosynthetic deep-sea ecosystems requires comparative studies. In the Guaymas Basin (Gulf of California, Mexico), the presence of seeps and vents in the absence of a biogeographic barrier, and comparable sedimentary settings and depths offers a unique opportunity to assess the role of ecosystem-specific environmental conditions on macrofaunal communities. Six seep and four vent assemblages were studied, three of which were characterised by common major foundation taxa: vesicomyid bivalves, siboglinid tubeworms and microbial mats. Macrofaunal community structure at the family level showed that density, diversity and composition patterns were primarily shaped by seep- and vent-common abiotic factors including methane and hydrogen sulfide concentrations, whereas vent environmental specificities (higher temperature, higher metal concentrations and lower pH) were not significant. The type of substratum and the heterogeneity provided by foundation species were identified as additional structuring factors and their roles were found to vary according to fluid regimes. At the family level, seep and vent similarity reached at least 58 %. All vent families were found at seeps and each seep-specific family displayed low relative abundances (< 5 %). Moreover, 85 % of the identified species among dominant families were shared between seep and vent ecosystems. This study provides further support to the hypothesis of continuity among deep-sea seep and vent ecosystems.

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Tatsumoto, Hideki, Tomokazu Aso, Takashi Kato, Kiichi Ohtsu, Shoichi Hasegawa, Fujio Maekawa, and Masatoshi Futakawa. "Design of hydrogen vent line for the cryogenic hydrogen system in J-PARC." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 600, no. 1 (February 2009): 269–71. http://dx.doi.org/10.1016/j.nima.2008.11.042.

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Petersen, Jillian M., Frank U. Zielinski, Thomas Pape, Richard Seifert, Cristina Moraru, Rudolf Amann, Stephane Hourdez, et al. "Hydrogen is an energy source for hydrothermal vent symbioses." Nature 476, no. 7359 (August 2011): 176–80. http://dx.doi.org/10.1038/nature10325.

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23

Zhang, Sihong, and Qi Zhang. "Effect of vent size on vented hydrogen-air explosion." International Journal of Hydrogen Energy 43, no. 37 (September 2018): 17788–99. http://dx.doi.org/10.1016/j.ijhydene.2018.07.194.

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Portail, M., K. Olu, E. Escobar-Briones, J. C. Caprais, L. Menot, M. Waeles, P. Cruaud, P. M. Sarradin, A. Godfroy, and J. Sarrazin. "Comparative study of vent and seep macrofaunal communities in the Guaymas Basin." Biogeosciences Discussions 12, no. 11 (June 10, 2015): 8497–571. http://dx.doi.org/10.5194/bgd-12-8497-2015.

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Abstract. Understanding the ecological processes and connectivity of chemosynthetic deep-sea ecosystems requires comparative studies. In the Guaymas Basin (Gulf of California, Mexico), the presence of seeps and vents in the absence of biogeographic barrier, comparable sedimentary settings and depths offers a unique opportunity to assess the role of ecosystem specific environmental conditions on macrofaunal communities. Six seep and four vent assemblages were studied, three of which were characterised by common major foundation taxa: vesicomyid bivalves, siboglinid tubeworms and microbial mats. Macrofaunal community structure at the family level showed that density, diversity and composition patterns were primarily shaped by seep and vent common abiotic factors including methane and hydrogen sulphide concentrations. The type of substratum and the heterogeneity provided by foundation species were identified as additional structuring factors and their roles were found to vary according to fluid regimes. Surprisingly, the presence of vent environmental specificities, with higher temperature, higher metal concentrations and lower pH was not significant in explaining community patterns. Moreover, Guaymas seep and vent shared an important number of common species suggesting frequent connections between the two ecosystems. Finally, this study provides further support for the hypothesis of continuity among deep-sea seep and vent ecosystems.

25

Nahm, Seung-Hoon, Un-Bong Baek, Chang-Min Suh, and Young-Sik Pyun. "A Study on the VHCF Fatigue Behaviors and UNSM Effects of Hydrogen Attacked STS 304." Transactions of the Korean Society of Mechanical Engineers - A 42, no. 6 (June 30, 2018): 541–50. http://dx.doi.org/10.3795/ksme-a.2018.42.6.541.

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Ng, Wei-Ling, Cheng-Ann Chen, Stephenie Demie Kawi, Baba Musta, and Tin-Yam Chan. "Effects of hydrogen peroxide treatment on the particle size distribution of hydrothermal vent sediments: A case study in Guishan Island, Taiwan." Borneo Journal of Marine Science and Aquaculture (BJoMSA) 3, no. 2 (December 10, 2019): 52–56. http://dx.doi.org/10.51200/bjomsa.v3i2.1995.

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Particle size analysis is able to reveal essential information about processes like production, transportation, sorting, and deposition of a study area. Pre-treatment of sediment by using hydrogen peroxide is recommended for more accuracy of particle size distribution as it removes organic matter which is adsorbed on the grain particle. A shallow water where hydrothermal vents site are located in Guishan Island is selected as the study site in this research. Sediment samples were collected at the depth of 3 â€“ 5 cm from the seabed surface by SCUBA diving. Particle size analysis was conducted by dry sieving before and after hydrogen peroxide treatment. Results showed significant differences in very coarse sand (p < 0.05) as it decreases significantly in weight after treatment (10.62% of change). The other particle size level of sediment increases slightly in weight and the changes ranged from 1.20% to 2.60%, showing no significant difference (500Î¼m=0.59; p value 250Î¼m=0.67; p value 125Î¼m=0.48; p value 63Î¼m=0.47; p value >63Î¼m=0.38). Therefore, in order to accurately determine the particle size distribution at hydrothermal vent site, pre-treatment using hydrogen peroxide is recommended to remove organic material because hydrothermal vent is proved to have high organic matter content.

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Sojo, Victor, Aya Ohno, Shawn McGlynn, Yoichi Yamada, and Ryuhei Nakamura. "Microfluidic Reactors for Carbon Fixation under Ambient-Pressure Alkaline-Hydrothermal-Vent Conditions." Life 9, no. 1 (February 1, 2019): 16. http://dx.doi.org/10.3390/life9010016.

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The alkaline-hydrothermal-vent theory for the origin of life predicts the spontaneous reduction of CO2, dissolved in acidic ocean waters, with H2 from the alkaline vent effluent. This reaction would be catalyzed by Fe(Ni)S clusters precipitated at the interface, which effectively separate the two fluids into an electrochemical cell. Using microfluidic reactors, we set out to test this concept. We produced thin, long Fe(Ni)S precipitates of less than 10 µm thickness. Mixing simplified analogs of the acidic-ocean and alkaline-vent fluids, we then tested for the reduction of CO2. We were unable to detect reduced carbon products under a number of conditions. As all of our reactions were performed at atmospheric pressure, the lack of reduced carbon products may simply be attributable to the low concentration of hydrogen in our system, suggesting that high-pressure reactors may be a necessity.

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Wang, Benjin, Yahao Shen, Hong Lv, and Pengfei He. "A Numerical Simulation on the Leakage Event of a High-Pressure Hydrogen Dispenser." World Electric Vehicle Journal 12, no. 4 (December 10, 2021): 259. http://dx.doi.org/10.3390/wevj12040259.

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For the sake of the increasing demand of hydrogen fuel cell vehicles, there are more concerns on the safety of hydrogen refueling stations. As one of the key pieces of equipment, the hydrogen dispenser has drawn attention on this aspect since it involves massive manual operations and may be bothered by a high probability of failure. In this paper, a numerical study is conducted to simulate the possible leakage events of the hydrogen dispenser based on a prototype in China whose working pressure is 70 MPa. The leakage accident is analyzed with respect to leakage sizes, leak directions, and the time to stop the leakage. It is found that, due to the large mass flow rate under such high pressure, the leak direction and the layout of the components inside the dispenser become insignificant, and the ignitable clouds will form inside the dispenser in less than 1 s if there is a leakage of 1% size of the main tube. The ignitable clouds will form near the vent holes outside the dispenser, which may dissipate quickly if the leakage is stopped. On the other hand, the gas inside the dispenser will remain ignitable for a long time, which asks for a design with no possible ignition source inside. The results can be useful in optimizing the design of the dispenser, regarding the reaction time and sensitivity requirements of the leakage detector, the size and amount of vent holes, etc.

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Li, Yuejuan, Xulei Hou, Wei Qi, Zehui Hong, Cheng Wang, Bo zhang, Qiubo Wang, and Xiaolu Zhang. "Dispersion analysis of hydrogen released from a fuel cell electric vehicles with ventilations." Journal of Physics: Conference Series 2198, no. 1 (May 1, 2022): 012017. http://dx.doi.org/10.1088/1742-6596/2198/1/012017.

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Abstract Hydrogen is one of most attractive clean energy and has been broadly used as fuel for vehicles. However, the accidental leakage of the hydrogen may cause fire and casualties. So, it is extremely important to have a good knowledge of the leaking hydrogen dispersion. This study focuses on the effect of vent amount, location and wind pattern on the distribution of leaked hydrogen using CFD models. The dispersion of high-pressure hydrogen horizontally released from a hydrogen fuel cell transit bus in an enclosure with multiple vents is simulated using CFD models. The results figure out an improvement in ventilation with two vents or forced wind imposed at the vents and the results also illustrate keeping distance between two vents makes the improvement much apparently. The hydrogen mass fraction at monitors closed to the vents that is imposed with the wind keeps low level. As a result, all these kinds of positions are not suggested to be the locations for installing the sensors.

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Cesar, Vera, Iva Jozić, Lidija Begović, Tea Vuković, Selma Mlinarić, Hrvoje Lepeduš, Suzana Borović Šunjić, and Neven Žarković. "Cell-Type-Specific Modulation of Hydrogen Peroxide Cytotoxicity and 4-Hydroxynonenal Binding to Human Cellular Proteins In Vitro by Antioxidant Aloe vera Extract." Antioxidants 7, no. 10 (September 21, 2018): 125. http://dx.doi.org/10.3390/antiox7100125.

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Although Aloe vera contains numerous bioactive components, the activity principles of widely used A. vera extracts are uncertain. Therefore, we analyzed the effects of genuine A. vera aqueous extract (AV) on human cells with respect to the effects of hydrogen peroxide (H2O2) and 4-hydroxynonenal (HNE). Fully developed A. vera leaves were harvested and analyzed for vitamin C, carotenoids, total soluble phenolic content, and antioxidant capacity. Furthermore, human cervical cancer (HeLa), human microvascular endothelial cells (HMEC), human keratinocytes (HaCat), and human osteosarcoma (HOS) cell cultures were treated with AV extract for one hour after treatment with H2O2 or HNE. The cell number and viability were determined using Trypan Blue, and endogenous reactive oxygen species (ROS) production was determined by fluorescence, while intracellular HNE–protein adducts were measured for the first time ever by genuine cell-based HNE–His ELISA. The AV extract expressed strong antioxidant capacities (1.1 mmol of Trolox eq/g fresh weight) and cell-type-specific influence on the cytotoxicity of H2O2, as well as on endogenous production of ROS and HNE–protein adducts induced by HNE treatment, while AV itself did not induce production of ROS or HNE–protein adducts at all. This study, for the first time, revealed the importance of HNE for the activity principles of AV. Since HMEC cells were the most sensitive to AV, the effects of AV on microvascular endothelia could be of particular importance for the activity principles of Aloe vera extracts.

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Jiao, Mingyu, Haoran Zhu, Jinglong Huang, and Xin Zhang. "Numerical Simulation of Hydrogen Leakage and Diffusion Process of Fuel Cell Vehicle." World Electric Vehicle Journal 12, no. 4 (October 15, 2021): 193. http://dx.doi.org/10.3390/wevj12040193.

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Regarding the problem of hydrogen diffusion of the fuel cell vehicle (HFCV) when its hydrogen supply system leaks, this research uses the FLUENT software to simulate numerical values in the process of hydrogen leakage diffusion in both open space and closed space. This paper analyzed the distribution range and concentration distribution characteristics of hydrogen in these two different spaces. Besides, this paper also took a survey about the effects of leakage rate, wind speed, wind direction in open space and the role the air vents play on hydrogen safety in closed space, which provides a reference for the hydrogen safety of HFCV. In conclusion, the experiment result showed that: In open space, hydrogen leakage rate has a great influence on its diffusion. When the leakage rate doubles, the hydrogen leakage range will expand about 1.5 times simultaneously. The hydrogen diffusion range is the smallest when the wind blows at 90 degrees, which is more conducive to hydrogen diffusion. However, when the wind direction is against the direction of the leakage of hydrogen, the range of hydrogen distribution is maximal. Under this condition, the risk of hydrogen leakage is highest. In an enclosed space, when the vent is set closest to the leakage position, the volume fraction of hydrogen at each time is smaller than that at other positions, so it is more beneficial to safety.

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Rimmer, Paul, and Oliver Shorttle. "Origin of Life’s Building Blocks in Carbon- and Nitrogen-Rich Surface Hydrothermal Vents." Life 9, no. 1 (January 24, 2019): 12. http://dx.doi.org/10.3390/life9010012.

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There are two dominant and contrasting classes of origin of life scenarios: those predicting that life emerged in submarine hydrothermal systems, where chemical disequilibrium can provide an energy source for nascent life; and those predicting that life emerged within subaerial environments, where UV catalysis of reactions may occur to form the building blocks of life. Here, we describe a prebiotically plausible environment that draws on the strengths of both scenarios: surface hydrothermal vents. We show how key feedstock molecules for prebiotic chemistry can be produced in abundance in shallow and surficial hydrothermal systems. We calculate the chemistry of volcanic gases feeding these vents over a range of pressures and basalt C/N/O contents. If ultra-reducing carbon-rich nitrogen-rich gases interact with subsurface water at a volcanic vent they result in 10 − 3 – 1 M concentrations of diacetylene (C4H2), acetylene (C2H2), cyanoacetylene (HC3N), hydrogen cyanide (HCN), bisulfite (likely in the form of salts containing HSO3−), hydrogen sulfide (HS−) and soluble iron in vent water. One key feedstock molecule, cyanamide (CH2N2), is not formed in significant quantities within this scenario, suggesting that it may need to be delivered exogenously, or formed from hydrogen cyanide either via organometallic compounds, or by some as yet-unknown chemical synthesis. Given the likely ubiquity of surface hydrothermal vents on young, hot, terrestrial planets, these results identify a prebiotically plausible local geochemical environment, which is also amenable to future lab-based simulation.

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Molkov, Vladimir, Ritsu Dobashi, Masataro Suzuki, and Toshisuke Hirano. "Modeling of vented hydrogen-air deflagrations and correlations for vent sizing." Journal of Loss Prevention in the Process Industries 12, no. 2 (March 1999): 147–56. http://dx.doi.org/10.1016/s0950-4230(98)00049-7.

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Chen, Ye, Yi Li, Ziting Li, Chao Ji, and Xuanya Liu. "Effect of vent area, vent location and number of vents on vented hydrogen deflagrations in a 27 m3 chamber." International Journal of Hydrogen Energy 45, no. 55 (November 2020): 31268–77. http://dx.doi.org/10.1016/j.ijhydene.2020.08.032.

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Campbell, Barbara J., Christian Jeanthon, Joel E. Kostka, George W. Luther, and S. Craig Cary. "Growth and Phylogenetic Properties of Novel Bacteria Belonging to the Epsilon Subdivision of the Proteobacteria Enriched fromAlvinella pompejana and Deep-Sea Hydrothermal Vents." Applied and Environmental Microbiology 67, no. 10 (October 1, 2001): 4566–72. http://dx.doi.org/10.1128/aem.67.10.4566-4572.2001.

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ABSTRACT Recent molecular characterizations of microbial communities from deep-sea hydrothermal sites indicate the predominance of bacteria belonging to the epsilon subdivision of Proteobacteria(epsilon Proteobacteria). Here, we report the first enrichments and characterizations of four epsilonProteobacteria that are directly associated withAlvinella pompejana, a deep sea hydrothermal vent polychete, or with hydrothermal vent chimney samples. These novel bacteria were moderately thermophilic sulfur-reducing heterotrophs growing on formate as the energy and carbon source. In addition, two of them (Am-H and Ex-18.2) could grow on sulfur lithoautrotrophically using hydrogen as the electron donor. Optimal growth temperatures of the bacteria ranged from 41 to 45°C. Phylogenetic analysis of the small-subunit ribosomal gene of the two heterotrophic bacteria demonstrated 95% similarity to Sulfurospirillum arcachonense, an epsilon Proteobacteria isolated from an oxidized marine surface sediment. The autotrophic bacteria grouped within a deeply branching clade of the epsilonProteobacteria, to date composed only of uncultured bacteria detected in a sample from a hydrothermal vent along the mid-Atlantic ridge. A molecular survey of various hydrothermal vent environments demonstrated the presence of two of these bacteria (Am-N and Am-H) in more than one geographic location and habitat. These results suggest that certain epsilonProteobacteria likely fill important niches in the environmental habitats of deep-sea hydrothermal vents, where they contribute to overall carbon and sulfur cycling at moderate thermophilic temperatures.

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MISONO, Hitoshi, Junji SAKAMOTO, Jo NAKAYAMA, Naoya KASAI, Tadahiro SHIBUTANI, and Atsumi MIYAKE. "Safety design of hydrogen vent system for emergency response in hydrogen fueling station using physical modeling." Proceedings of Mechanical Engineering Congress, Japan 2016 (2016): G1700303. http://dx.doi.org/10.1299/jsmemecj.2016.g1700303.

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Arndt, C., F. Gaill, and H. Felbeck. "Anaerobic sulfur metabolism in thiotrophic symbioses." Journal of Experimental Biology 204, no. 4 (February 15, 2001): 741–50. http://dx.doi.org/10.1242/jeb.204.4.741.

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Hydrogen sulfide is generally accepted to be the energy source for the establishment of sulfur-oxidizing symbiotic communities. Here, we show that sulfur-storing symbioses not only consume but also produce large amounts of hydrogen sulfide. The prerequisite for this process appears to be the absence of oxygen. Anaerobic sulfide production is widespread among different thiotrophic symbioses from vent and non-vent sites (Riftia pachyptila, Calyptogena magnifica, Bathymodiolus thermophilus, Lucinoma aequizonata and Calyptogena elongata). The extent of H2S generation correlates positively with the amount of elemental sulfur stored in the symbiont-bearing tissues of the hosts. Sulfide production starts a few hours after anoxia sets in, with H2S initially accumulating in the circulatory system before it is excreted into the surrounding environment. We propose that not sulfate but the elemental sulfur deposited in the symbionts serves as a terminal electron acceptor during anoxia and is reduced to sulfide. In anoxia-tolerant symbioses such as L. aequizonata, anaerobic sulfur respiration may be important for producing maintenance energy to help the species survive several months without oxygen. The increased levels of cysteine in the gills of L. aequizonata may be caused by a lack of reoxidation due to the absence of oxygen.

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Василяк, Л. М., Н. Н. Кудрявцев, and А. Д. Смирнов. "Efficiency of gas discharge methods for odor control in municipal wastewater transportation and treatment systems." Vodosnabzhenie i sanitarnaia tehnika, no. 12 (December 16, 2021): 15–19. http://dx.doi.org/10.35776/vst.2021.12.02.

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В процессе транспортировки и очистки сточных вод в воздух выделяются дурнопахнущие вещества, среди которых одним из наиболее трудноудаляемых является сероводород. Для очистки воздуха от дурнопахнущих веществ используются различные методы, в том числе газоразрядные (плазменные, ионизационные), которые хорошо зарекомендовали себя в других областях промышленности. Вентиляционные выбросы, образующиеся при обработке и очистке сточных вод, имеют ряд особенностей: высокая влажность, высокая концентрация сероводорода, потенциальная взрывоопасность. Эти свойства ограничивают возможность использования газоразрядных методов для очистки данного типа вентиляционных выбросов. Описывается специфика применения газоразрядных методов при очистке воздуха на очистных сооружениях канализации и канализационных насосных станциях. Приведены возникающие при этом технические сложности. In the process of wastewater transportation and treatment malodorous substances are released into the air; among them hydrogen sulfide being one of the most difficult to remove. Various methods are used to remove malodorous substances from the air, including gas-discharge (plasma, ionization) methods that have proven remarkably effective in other industries. Vent emissions generated during wastewater treatment are specified by high humidity, high concentration of hydrogen sulfide, potential explosion hazard. These properties limit the possible use of gas discharge methods for the purification of this type of vent emissions. The specificity of applying gas discharge methods for air purification at the wastewater treatment facilities and wastewater pumping stations is described. The arising technical difficulties are presented.

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Lee, Hyo-Geun, Hyun-Soo Kim, Jae-Young Oh, Dae-Sung Lee, Hye-Won Yang, Min-Cheol Kang, Eun-A. Kim, et al. "Potential Antioxidant Properties of Enzymatic Hydrolysates from Stichopus japonicus against Hydrogen Peroxide-Induced Oxidative Stress." Antioxidants 10, no. 1 (January 14, 2021): 110. http://dx.doi.org/10.3390/antiox10010110.

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A comprehensive antioxidant evaluation was performed on enzymatic hydrolysates of Stichopusjaponicus (S. japonicus) using Vero cells and zebrafish models for in vitro and in vivo studies, respectively. S. japonicus was hydrolyzed with food-grade enzymes (alcalase, α-chymotrypsin, flavourzyme, kojizyme, neutrase, papain, pepsin, protamex, and trypsin), and the free radical scavenging activities were screened via electron spin resonance (ESR) spectroscopy. According to the results, the enzymatic hydrolysates contained high protein and relatively low polysaccharide and sulfate contents. Among these hydrolysates, the α-chymotrypsin assisted hydrolysate from S. japonicus (α-chy) showed high yield and protein content, and strong hydroxyl radical scavenging activity. Therefore, α-chy was chosen for further purification. The α-chy was fractionated by ultrafiltration into three ultrafiltration (UF) fractions based on their molecular weight: >10 kDa (α-chy-I), 5–10 kDa (α-chy-II), and <5 kDa (α-chy-III), and we evaluated their antioxidant properties in H2O2 exposed Vero cells. The α-chy and its UF fractions significantly decreased the intracellular reactive oxygen species (ROS) generation and increased cell viability in H2O2 exposed Vero cells. Among them, α-chy-III effectively declined the intracellular ROS levels and increased cell viability and exhibited protection against H2O2 induced apoptotic damage. Furthermore, α-chy-III remarkably attenuated the cell death, intracellular ROS and lipid peroxidation in H2O2 exposed zebrafish embryos. Altogether, our findings demonstrated that α-chy and its α-chy-III from S. japonicus possess strong antioxidant activities that could be utilized as a bioactive ingredient for functional food industries.

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Saha, Priyanka, Prakash Roy Choudhury, Subrata Das, Anupam Das Talukdar, and Manabendra Dutta Choudhury. "IN VITRO ANTIOXIDANT ACTIVITY OF BARK EXTRACTS OF OROXYLUM INDICUM (L) VENT." Asian Journal of Pharmaceutical and Clinical Research 10, no. 8 (August 1, 2017): 263. http://dx.doi.org/10.22159/ajpcr.2017.v10i8.18977.

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Objectives: The aim of the present work is to screen the antioxidant potentiality of the bark extract of Oroxylum indicum (L) Vent, ethnomedicinally prescribed plant as hepatoprotective.Methods: Bark extracts were prepared using soxhlet apparatus. Total phenol, flavonoid, and total alkaloid were analyzed using Folin–Ciocalteu assay, aluminum chloride colorimetric assay, atropine standard, respectively. Antioxidant capacity and free radical scavenging potentialities were done by several in vitro methods, viz.; 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide scavenging activity, reducing power assay, metal chelating activity, ferric reducing ability of plasma (FRAP) assay, and thiobarbituric acid (TBA) method.Result: Total phenol, flavonoid, and alkaloid were found to be highest in methanolic extract of O. indicum (L) Vent. Methanolic extract of the bark showed very low inhibitory concentration (IC50) and effective concentration values for DPPH assay and reducing power assay compared to another extract. In hydrogen peroxide scavenging activity assay, the lowest IC50 value was recorded in methanolic extract with 153.45±0.06 μg/ml. The FRAP assay for O. indicum methanolic extract showed the highest activity at 940.09±0.07 μg/mL of ascorbic acid equivalent. The ferric reducing capacity and TBA values of the plant extracts confirmed the presence antioxidant principles in the bark of the said plant.Conclusion: These underused plants may be used for mitigating the detrimental effect of oxidative stress and reactive oxygen species-mediated disease and thus justifies its use in folklore medicines.

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Louise, Isana Supiah Yosephine, Endang Widjajanti Laksono, and Dewi Yuanita Lestari. "COMPARISON STUDY OF STAINLESS STEEL CYCLIC VOLTAMMOGRAMS IN VARIOUS NATURAL MEDIA ADDITION: PRODUCT AND VOLTAGE EFFICIENCY." IIUM Engineering Journal 20, no. 2 (December 2, 2019): 1–11. http://dx.doi.org/10.31436/iiumej.v20i2.1030.

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The cyclic voltammogram is widely used to analyse the electrolysis process. The use of various media, namely rambutan seed flour (Nephelium lappaceum), mango seed flour (Mangifera indica), breadfruit leaf powder (Artocarpus altilis), peria extract (Momordi charantia) and aloe vera extract (Aloe vera), in this study is to deliberately mimic the occurrence of those media in wastewater produced by several industries. The electrolysis analysis on the presence of several media would minimize the preparation steps on wastewater utilization for generating hydrogen as renewable energy. The research looks at the potential of wastewater as the raw material for the electrolysis process. In this research, stainless steel cyclic voltammograms were studied on water electrolysis. The electrolysis was done in base solution and adding various media, such as rambutan seed flour (Nephelium lappaceum), mango seed flour (Mangifera indica), breadfruit leaf powder (Artocarpus altilis), peria extract (Momordi charantia) and aloe vera extract (Aloe vera) in various concentrations, 0 - 10 g per litter of water. By reviewing the activity of a stainless steel electrode to decompose water molecules, the media generally caused the occurrence of covering by relatively large molecules around the electrode surface, resulting in decreased activity of the stainless steel electrodes. The optimum condition occurred with the addition of breadfruit leaf powder in all treatments with similar electrode activity as much as 1.68. The result could be implemented in a wastewater electrolysis processes containing the media to generate hydrogen gas. ABSTRAK: Voltammogram berkitar banyak digunakan bagi menganalisis proses elektrolisis. Dalam kajian ini pelbagai jenis media telah sengaja digunakan seperti tepung biji rambutan (Nephelium lappaceum), tepung biji mangga (Mangifera indica), serbuk daun sukun (Artocarpus altilis), ekstrak peria (Momordi charantia) dan ekstrak lidah buaya (Aloe vera), bagi memimik terjadinya media-media tersebut dalam sisa air buangan yang terhasil daripada beberapa industri. Analisis elektrolisis pada pelbagai media dapat mengurangkan langkah-langkah persiapan pada penggunaan sisa air bagi menghasilkan hidrogen sebagai tenaga boleh baharu. Penilitian kajian ini bertumpu pada potensi sisa air sebagai bahan kasar bagi proses elektrolisis. Kajian ini adalah tentang elektrolisis air voltammogram berkitar pada keluli tahan karat. Proses elektrolisis telah dilakukan pada larutan dasar dan dengan menambah pelbagai media, seperti tepung biji rambutan (Nephelium lappaceum), tepung biji mangga (Mangifera indica), serbuk daun sukun (Artocarpus altilis), ekstrak petola (Momordi charantia) dan ekstrak lidah buaya (Aloe vera) dalam pelbagai kepekatan, 0 - 10 gram pada setiap liter air. Penurunan aktiviti elektrod keluli tahan karat telah disebabkan oleh aktiviti elektrod keluli tahan karat yang mengurai molekul air dan diliputi molekul-molekul besar pada permukaan elektrod. Keadaan optimum telah berlaku dengan penambahan serbuk daun sukun pada semua rawatan dengan aktiviti elektrod serupa sebanyak 1.68. Dapatan kajian dapat digunakan dalam proses elektrolisis sisa air yang mengandungi media bagi menghasilkan gas hidrogen.

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Molkov, V., and M. Bragin. "Hydrogen–air deflagrations: Vent sizing correlation for low-strength equipment and buildings." International Journal of Hydrogen Energy 40, no. 2 (January 2015): 1256–66. http://dx.doi.org/10.1016/j.ijhydene.2014.11.067.

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Stoop, P. M., J. P. A. van den Bogaard, and H. Koning. "Dynamic loads on an RPV vent line piping system during hydrogen relief." International Journal of Pressure Vessels and Piping 18, no. 3 (January 1985): 183–208. http://dx.doi.org/10.1016/0308-0161(85)90011-0.

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Pang, Lei, Qianran Hu, Junjuan Zhao, Pengfei Lv, Siheng Sun, and Kai Yang. "Numerical study of the effects of vent opening time on hydrogen explosions." International Journal of Hydrogen Energy 44, no. 29 (June 2019): 15689–701. http://dx.doi.org/10.1016/j.ijhydene.2019.04.175.

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Haberbusch, Mark S., Chinh T. Nguyen, Robert J. Stochl, and Terry Y. Hui. "Development of No-Vent™ liquid hydrogen storage system for space applications." Cryogenics 50, no. 9 (September 2010): 541–48. http://dx.doi.org/10.1016/j.cryogenics.2010.02.025.

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Ogunmola, Julius Femi, Lidija Begovic, Tea Vukovic, Selma Mlinaric, Vera Cesar, and Neven Zarkovic. "Modulation of the cell growth by Aloe Vera extract and hydrogen peroxide." Free Radical Biology and Medicine 124 (August 2018): 572. http://dx.doi.org/10.1016/j.freeradbiomed.2018.05.048.

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Aicha, Lattab, Belkacem Imane, Djibaoui Rachid, Rebai Oifa, Chibani Abdelwaheb, and Arabi Abed. "Eradication of Pseudomonas biofilm by disinfectants and some plants extracts." South Asian Journal of Experimental Biology 5, no. 1 (July 4, 2015): 06–16. http://dx.doi.org/10.38150/sajeb.5(1).p06-16.

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In the present study three isolates belonging to Pseudomonas sp and one reference strain of P. aeruginosa ATCC 27853 were tested for biofilm formation on two types of support (glass and polystyrene), using two cultures medium Tryptone Soy Broth (TSB) and Modified Biofilm Broth (MBB). The results showed that the quantity of biofilm formed depends on the nature of culture medium, where the rate of the adherent bacteria was more significant in TSB medium. Polystyrene was more favorable to bacteria for adherence compared to glass. We examined the effectiveness of three types of disinfectants, sodium hypochlorite, hydrogen peroxide and temperature on a biofim formed by the studied bacteria. Sodium hypochlorite reached good levels of biofilm eradication using all isolates adhered on the two types of support. Hydrogen peroxide exerted less significant effect compared to sodium hypochlorite, eliminating approximately 56% from the biofilm adhered on polystyrene at concentration of 3%. The elimination of biofilm temperature (80°C) was rather weak compared with the two chemical disinfectants. Our study included the testing of extracts of three plants: Allium sativum, Aloe vera and Lawsonia inermis on biofilm eradication formed by P. aeruginosa ATCC 27853. The effect of these plant extracts on planktonic cells was also studied. The results showed that Allium sativum and Lawsonia inermis inhibit both bacterial growth and biofilm formation and no activity was detected for Aloe vera extract.

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Brinkman, T. J., and A. M. Smith. "Effect of climate change on crustose coralline algae at a temperate vent site, White Island, New Zealand." Marine and Freshwater Research 66, no. 4 (2015): 360. http://dx.doi.org/10.1071/mf14077.

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Natural CO2 vents allow study of the effects of climate change on marine organisms on a different scale from laboratory-based studies. This study outlines a preliminary investigation into the suitability of natural CO2 vents near White Island, Bay of Plenty, New Zealand (37°31.19′S, 117°10.85′E) for climate change research by characterising water chemistry from two vent and three control locations on a seasonal basis, as well as examining their effects on skeletons of the local calcifying crustose coralline algae. pH measurements at vent sites, calculated from dissolved inorganic carbon and alkalinity, showed reduced mean pH levels (7.49 and 7.85) relative to background levels of 8.06, whereas mean temperatures were between 0.0 and 0.4°C above control. Increases in sulfur and mercury at sites near White Island were probably a result of volcanic unrest. Crustose coralline algae did not show significant variability in skeletal Mg-calcite geochemistry, but qualitative comparisons of calcite skeletons under scanning electron microscopy saw greater deformation and dissolution in coralline algae calcite crystals from vent sites compared to controls. Although additional monitoring of pH fluctuations and hydrogen sulphides is still needed, the low pH and increased temperatures indicate potential for studying multistressor effects of projected climate changes in a natural environment.

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Brown, A. E. P., P. L. Metropolo, and Marcio A. Carvalho. "Explosion Study of an Iron Powder Reduction Furnace." Materials Science Forum 498-499 (November 2005): 28–33. http://dx.doi.org/10.4028/www.scientific.net/msf.498-499.28.

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Explosion study in an iron powder reduction furnace was performed. Pressurized gaseous hydrogen was used as reductive atmosphere to convert iron powder in the interior of the furnace. Hydrogen was fed to the pre-chamber of the iron powder reduction furnace. The furnace was located inside a brick building. Explosion potential causes were determined by the fault tree technique. The impact effects to people, environment and materials were also analyzed by using Chem-Plus software. The consequences and vulnerability analyzes were performed considering a confined explosion inside the furnace pre-chamber, resulting from formation of a hydrogen cloud within the H2 explosion limits. The vent area criteria recommended by NFPA 68 to confined spaces were employed to the reduction furnace and to the vulnerability calculations; probit equations of the Eisenberg model were used. As results, safety measures to enhance safety on the reduction of iron powder operation inside the furnace installation were recommended.

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Kang, Daehoon, Sungho Yun, Bo-kyong Kim, Jaewon Kim, Gildong Kim, Hyunbae Lee, and Sangyeol Choi. "Numerical Investigation of the Initial Charging Process of the Liquid Hydrogen Tank for Vehicles." Energies 16, no. 1 (December 21, 2022): 38. http://dx.doi.org/10.3390/en16010038.

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Liquid hydrogen has been studied for use in vehicles. However, during the charging process, liquid hydrogen is lost as gas. Therefore, it is necessary to estimate and reduce this loss and simulate the charging process. In this study, the initial charging process of a vehicle liquid hydrogen tank under room temperature and atmospheric pressure conditions was numerically investigated. A transient thermal-fluid simulation with a phase-change model was performed to analyze variations in the volume, pressure, mass flow rate, and temperature. The results showed that the process could be divided into three stages. In the first stage, liquid hydrogen was actively vaporized at the inner wall surface of the storage tank. The pressure increased rapidly, and liquid droplets were discharged into the vent pipe during the second stage. In the third stage, the mass flow rates of liquid and hydrogen gas at the outlet showed significant fluctuations, owing to complex momentum generated by the evaporation and charging flow. The temperatures of the inner and outer walls, and insulation layer, decreased significantly slower than that of the gas region because of its high heat capacity and insulation effect. The optimal structure should be further studied because the vortex, stagnation, and non-uniform cooling of the wall occurred near the inlet and outlet pipes.

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