Free Oxygen
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2021 ◽  
Author(s):  
Adriano Intiso ◽  
Federico Rossi ◽  
Antonio Proto ◽  
Raffaele Cucciniello

AbstractMayenite (12CaO·7Al2O3) is a mesoporous calcium aluminum oxide, with a characteristic crystalline structure. The framework of mayenite is composed of interconnected cages with a positive electric charge per unit cell that includes two molecules [Ca24Al28O64]4+, and the remaining two oxide ions O2−, often labelled “free oxygen”, are trapped in the cages defined by the framework. Starting from mayenite structure several derivatives have been prepared through advanced synthetic protocols by free oxygen substitution with various anions. Mayenite and its derivates have been intensively investigated in many applications which include catalysis (oxidation and reduction, ammonia synthesis, pinacol coupling), environmental sensors and CO2 sorbent materials. In this review, we summarize our recent results on the main applications of mayenite and its derivatives.


2021 ◽  
Vol 10 (2) ◽  
pp. 82-89
Author(s):  
Maya Sarah ◽  
Erni Misran ◽  
Seri Maulina ◽  
Ika Pertiwi ◽  
Nahlionny Ritman ◽  
...  

The world's energy supply is very dependent on non-renewable energy in the form of fossil fuels. This causes fossil fuels depletion and the need for alternative energy sources such as biogas. Biogas is produced from the fermentation process of organic matter with the help of anaerobic bacteria in free oxygen absence. This study aims to produce biogas from cabbage and tomato waste separately. Biogas production was carried out by varying feed concentrations of 100 g/L, 200 g/L, and 300 g/L for cabbage waste and 81.6 g/L; 215 g/L; and 237 g/L for tomato waste. This study consisted of 10 days seeding and acclimatization process, followed by a start-up stage using insulated anaerobic bioreactors. The largest methane from cabbage and tomato waste was 60% at a feed concentration of 200 g/L and 50% at a feed concentration of 237 g/L, respectively. The maximum growth rates (µm) for biogas from cabbage and tomato waste were 0.122 day-1 and 0.121 day-1, respectively.


2021 ◽  
Vol 9 (1) ◽  
pp. 27-41
Author(s):  
Juliana Maia ◽  
◽  
Abdul Qadir ◽  
Eny Widajati ◽  
Yohannes Aris Purwanto ◽  
...  

Sandalwood seed has two types of dormancy, namely physical dormancy and physiological dormancy which is a combination of the Two-part is called morphophysiological dormancy. There is for breaks dormancy in sandalwood for earlier embryo maturation and elongation also it has hard and impermeable skin. Its structure consists of layers of thick-walled palisade-like cells especially on the outermost surface and the inside has a waxy coating and curse material. The objective of this study was to break of seed dormancy with technology Ultrafine Bubbles (UFB) on the morphophysiological dormancy on sandalwood seeds. The experiments used a randomized complete block designed (RCBD) with 3 replications. The data were analyzed using ANOVA and will be continued using the DMRT test at the 5% level. The research was conducted from February - March 0f 2020. The results showed that immersion using UFB water with oxygen 20 ppm or either UFB free oxygen for 24 and 48 hours combined with physical scarification and chemical scarification could accelerate germination in 13 days after germination (appeared radicle), percentage of growth speed (GS) is 4.67%, maximum growth (MG) in 21 days after sowing is 66.67% with normal sprouts 2-4 leaves have grown.


2021 ◽  
Author(s):  
Yasir Furkan Cagin ◽  
Ihsan Kulaksiz ◽  
Nigar Vardi ◽  
Onural Ozhan ◽  
Azibe Yildiz ◽  
...  

Abstract Background and Aims. Sepsis causes release of free oxygen radicals that destroy membrane integrity.We evaluated the antioxidant effects of parsley, Petroselinum crispum(Pc), which has been used therapeutically for centuries in Anatolia, using a rat model of sepsis caused by cecal ligation and puncture (CLP).Methods.Wistar albino rats were separated into four groups of eight: a sham group with incised and sutured abdomen, a Pc extract(PcE) group was given 2 g/kg parsley extract for 14 days by gastric gavage, a CLP group with sepsis caused by CLP and a PcE + CLP group given parsley extract for 14 days, then made septic by CLP. PcE is given for 14 days and then sepsis is performed by the CLP procedure. Results. The groups were compared in terms of hemogram, biochemical and histological characteristics. It has been proven that the administration of PcE before CLP-induced sepsis increases neutrophil, PLT counts and TAS levels which decrease with sepsis and decreases biochemical changes (BUN, AST, ALT, LDH, TOS, OSI) which increase with sepsis, to have a protective effect on sepsis . In the PcE + CLP group, the severity of intestinal infiltration was decreased significantly compared to the CLP group; epithelial damage was similar to the CLP group. In the PcE + CLP group, the crypt and villus length was greater and the decrease in Paneth cell degranulation intensity was found to be more than for the CLP group ; also, the morphology of the cells was similar to the Sham group. Discussion. PcE exhibit potential for prophylaxis for sepsis.


Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 910
Author(s):  
Yongchun Guo ◽  
Fengman Shen ◽  
Haiyan Zheng ◽  
Shuo Wang ◽  
Xin Jiang ◽  
...  

With the consumption of high-quality iron ore resources, the grade of iron ore raw used in the iron making process has gradually decreased. The high aluminum raw materials has led to an increase in the Al2O3 content in the blast furnace slag, which has affected the normal operation of the blast furnace. The activity of the components involved in the desulfurization reaction is an important factor affecting the desulfurization process. In this paper, the effects of B(w(CaO)/w(SiO2)) and w(MgO)/w(Al2O3) on the desulfurization ability of a CaO-SiO2-MgO-Al2O3 quaternary blast furnace slag system were studied by using a double-layer graphite crucible to simulate the process of molten iron dropping through the slag at 1773 K. The desulfurization reaction mechanism of high alumina blast furnace slag is explained from the aspects of slag structure and component activity, which provides a theoretical basis for the reasonable selection of a slag making system under the condition of a high alumina content. The effects of different B and w(MgO)/w(Al2O3) on the slag structure 2343 analyzed by Fourier transform infrared spectroscopy (FT-IR). The results show that when w(MgO)/w(Al2O3) = 0.50 and w(Al2O3) = 20%, the desulfurization ability and MgO activity of slag increased with the increase of B; when w(Al2O3) = 20% and B = 1.30, the desulfurization ability and MgO activity of the slag increased with the increase of w(MgO)/w(Al2O3). The FT-IR analysis showed that with the increase of B or w(MgO)/w(Al2O3), the dissociated free oxygen ions (O2-) in the slag increased, and the dissociated free oxygen ions (O2-) interacted with the bridging oxygen (O0) of silicate, which made the complex Si-O structure in the slag gradually depolymerize and increase the desulfurization ability.


2021 ◽  
pp. 100538
Author(s):  
Xia Guo ◽  
Hongwei Liao ◽  
Jiaming Tian ◽  
Chuang Yang ◽  
Fan Xia ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yuhei Nishimura ◽  
Yasunari Kanda ◽  
Hideko Sone ◽  
Hiroaki Aoyama

The developing brain is extremely sensitive to many chemicals. Perinatal exposure to neurotoxicants has been implicated in several neurodevelopmental disorders, including autism spectrum disorder, attention-deficit hyperactive disorder, and schizophrenia. Studies of the molecular and cellular events related to developmental neurotoxicity have identified a number of “adverse outcome pathways,” many of which share oxidative stress as a key event. Oxidative stress occurs when the balance between the production of free oxygen radicals and the activity of the cellular antioxidant system is dysregulated. In this review, we describe some of the developmental neurotoxins that target the antioxidant system and the mechanisms by which they elicit stress, including oxidative phosphorylation in mitochondria and plasma membrane redox system in rodent models. We also discuss future directions for identifying adverse outcome pathways related to oxidative stress and developmental neurotoxicity, with the goal of improving our ability to quickly and accurately screen chemicals for their potential developmental neurotoxicity.


Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4685
Author(s):  
Jing Liu ◽  
Yan Chen ◽  
Hongyan Zhang

Formaldehyde (HCHO) gas sensors with high performance based on the ZnO/CuO heterostructure (ZC) were designed, and the sensing mechanism was explored. FTIR results show that more OH− and N–H groups appeared on the surface of ZC with an increase in Cu content. XPS results show that ZC has more free oxygen radicals (O*) on its surface compared with ZnO, which will react with more absorbed HCHO molecules to form CO2, H2O and, electrons, accelerating the oxidation-reduction reaction to enhance the sensitivity of the ZC sensor. Furthermore, electrons move from ZnO to CuO in the ZC heterostructure due to the higher Fermi level of ZnO, and holes move from CuO to ZnO until the Fermi level reaches an equilibrium, which means the ZC heterostructure facilitates more free electrons existing on the surface of ZC. Sensing tests show that ZC has a low detection limit (0.079 ppm), a fast response/recovery time (1.78/2.90 s), and excellent selectivity and sensitivity for HCHO detection at room temperature. In addition, ambient humidity has little effect on the ZC gas sensor. All results indicate that the performance of the ZnO sensor for HCHO detection can be improved effectively by ZC heterojunction.


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