scholarly journals The Role of Groundwater Oxidation Potential and Radiolysis on Waste Glass Performance in Crystalline Repository Environments

1985 ◽  
Vol 50 ◽  
Author(s):  
Carol M. Jantzen ◽  
Ned E. Bibler

AbstractLaboratory experiments have shown that groundwater conditions in a granite repository will be as reducing as those in a basalt repository. Chemical analysis of the reduced groundwaters confirmed that the Fe2+/Fe3+ couple controls the oxidation potential (Eh). The reducing groundwater conditions were found to decrease the time-dependent release of soluble elements (Li and B) from the waste glass. However, due to the lower solubility of multivalent elements released from the glass when the groundwaters are reducing, these elements have significantly lower concentrations in the leachates.Gamma radiolysis reduced the oxidation potential of both granitic and basaltic groundwater in the absence of both waste glass and oxygen. This occurred in tests at atmospheric pressure where H2 could have escaped from the solution. The mechanism for this decrease in Eh is under investigation but appears related to the reactive amorphous precipitate in both groundwaters. The results of these tests suggest that radiolysis may not cause the groundwaters to become oxidizing in a crystalline repository when abundant Fe2+ species are present.

1946 ◽  
Vol 24d (2) ◽  
pp. 51-70 ◽  
Author(s):  
W. G. Wellington

This paper constitutes a review and an analysis of the available literature on the effects of pressure changes upon insects. The variations of atmospheric pressure that occur are classified briefly, but the effects of pressure changes upon insects are considered from the standpoint of the reactions of insects to extremely low pressure, extremely high pressure, and slight variations in pressure. It is concluded that extreme changes of pressure exert no direct influence upon insects. On the other hand, there is evidence that slightly reduced pressure increases the rates of the development and of the various activities of insects, while slightly increased pressure does not appear to have any positive influence on these processes. A discussion of the possible role of chordotonal organs in the observed responses of some insects to fluctuating pressure is included, and some laboratory experiments are suggested that might aid in quantitative determinations of the effects of varying atmospheric pressure upon insects.


Author(s):  
L.D. Schmidt ◽  
K. R. Krause ◽  
J. M. Schwartz ◽  
X. Chu

The evolution of microstructures of 10- to 100-Å diameter particles of Rh and Pt on SiO2 and Al2O3 following treatment in reducing, oxidizing, and reacting conditions have been characterized by TEM. We are able to transfer particles repeatedly between microscope and a reactor furnace so that the structural evolution of single particles can be examined following treatments in gases at atmospheric pressure. We are especially interested in the role of Ce additives on noble metals such as Pt and Rh. These systems are crucial in the automotive catalytic converter, and rare earths can significantly modify catalytic properties in many reactions. In particular, we are concerned with the oxidation state of Ce and its role in formation of mixed oxides with metals or with the support. For this we employ EELS in TEM, a technique uniquely suited to detect chemical shifts with ∼30Å resolution.


Author(s):  
Massimiliano Di Ventra

This chapter expands on the previous one on the role of experiments in Science. It explains the difference between observations of phenomena and controlled laboratory experiments.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Azizul Moqsud

AbstractIn this research, bioremediation of tsunami-affected polluted soil has been conducted by using collective microorganisms and recycled waste glass. The Tohoku earthquake, which was a mega earthquake in Japan triggered a huge tsunami on March 11th, 2011 that caused immeasurable damage to the geo-environmental conditions by polluting the soil with heavy metals and excessive salt content. Traditional methods to clean this polluted soil was not possible due to the excess cost and efforts. Laboratory experiments were conducted to examine the capability of bioremediation of saline soil by using recycled waste glass. Different collective microorganisms which were incubated inside the laboratory were used. The electrical conductivity (EC) was measured at different specified depths. It was noticed that the electrical conductivity decreased with the assist of the microbial metabolisms significantly. Collective microorganisms (CM2) were the highly capable to reduce salinity (up to 75%) while using recycled waste glass as their habitat.


2017 ◽  
Vol 313 (5) ◽  
pp. L899-L915 ◽  
Author(s):  
Fumiaki Kato ◽  
Seiichiro Sakao ◽  
Takao Takeuchi ◽  
Toshio Suzuki ◽  
Rintaro Nishimura ◽  
...  

Pulmonary arterial hypertension (PAH) is characterized by progressive obstructive remodeling of pulmonary arteries. However, no reports have described the causative role of the autophagic pathway in pulmonary vascular endothelial cell (EC) alterations associated with PAH. This study investigated the time-dependent role of the autophagic pathway in pulmonary vascular ECs and pulmonary vascular EC kinesis in a severe PAH rat model (Sugen/hypoxia rat) and evaluated whether timely induction of the autophagic pathway by rapamycin improves PAH. Hemodynamic and histological examinations as well as flow cytometry of pulmonary vascular EC-related autophagic pathways and pulmonary vascular EC kinetics in lung cell suspensions were performed. The time-dependent and therapeutic effects of rapamycin on the autophagic pathway were also assessed. Sugen/hypoxia rats treated with the vascular endothelial growth factor receptor blocker SU5416 showed increased right ventricular systolic pressure (RVSP) and numbers of obstructive vessels due to increased pulmonary vascular remodeling. The expression of the autophagic marker LC3 in ECs also changed in a time-dependent manner, in parallel with proliferation and apoptotic markers as assessed by flow cytometry. These results suggest the presence of cross talk between pulmonary vascular remodeling and the autophagic pathway, especially in small vascular lesions. Moreover, treatment of Sugen/hypoxia rats with rapamycin after SU5416 injection activated the autophagic pathway and improved the balance between cell proliferation and apoptosis in pulmonary vascular ECs to reduce RVSP and pulmonary vascular remodeling. These results suggested that the autophagic pathway can suppress PAH progression and that rapamycin-dependent activation of the autophagic pathway could ameliorate PAH.


2012 ◽  
Vol 51 (3) ◽  
pp. 389-417 ◽  
Author(s):  
Francisco J León ◽  
José A Noguera ◽  
Jordi Tena-Sánchez

Prosocial motivations and reciprocity are becoming increasingly important in social-science research. While laboratory experiments have challenged the assumption of universal selfishness, the external validity of these results has not been sufficiently tested in natural settings. In this article we examine the role of prosocial motivations and reciprocity in a Pay What You Want (PWYW) sales strategy, in which consumers voluntarily decide how much to pay for a product or service. This article empirically analyses the only PWYW example in Spain to date: the El trato (‘The deal’) campaign launched by the travel company Atrápalo, which offered different holiday packages under PWYW conditions in July 2009. Our analysis shows that, although the majority of the customers did not behave in a purely self-interested manner, they nonetheless did so in a much higher proportion than observed in similar studies. We present different hypotheses about the mechanisms that may explain these findings. Specifically, we highlight the role of two plausible explanations: the framing of the campaign and the attribution of ‘hidden’ preferences to Atrápalo by its customers, which undermined the interpretation of El trato as a trust game.


2014 ◽  
Vol 42 (6) ◽  
pp. 1007-1014 ◽  
Author(s):  
Yun-Qing Chen ◽  
Hong Zhu ◽  
Meng Le ◽  
Yi-Zhen Wu

We conducted 3 laboratory experiments to determine how face consciousness influences consumption of counterfeit luxury goods, along with the moderating roles of usage occasion and brand prominence. The participants in the first study were 138 Chinese undergraduates who were allocated to a 2 × 2 design to evaluate their intention to purchase a counterfeit luxury item that would be used either in public or in private. In Studies 2 and 3, using two 2 × 2 designs we evaluated the purchase intention of the participants (132 and 136, respectively) in order to investigate the moderating role of brand prominence. The results showed that participants' face consciousness had a significant positive influence on intention to purchase counterfeit luxury goods. In addition, the products' usage occasion and brand prominence positively moderated the influence that face consciousness had on counterfeit luxury item purchase intention of our participant groups.


2011 ◽  
Vol 10 (4) ◽  
pp. 335-340 ◽  
Author(s):  
J.R. Marshall ◽  
R.L. Mancinelli

AbstractLaboratory experiments were conducted to determine the effect of descent-engine plumes on the scouring of surface (microbial) contaminants from a spacecraft. A simulated touchdown of a half-scale lander engine and deck configuration was conducted at Mars atmospheric pressure in the NASA Ames Planetary Aeolian Laboratory. Low-density particles were used for the soil simulant to emulate the lower Martian gravity. The underside of the model had small witness plates with controlled microbial surface populations and particle impact detectors. For both steady-state engine thrust (Viking) and pulsed engine thrust (Phoenix), the exhaust plumes from the engines violently excavated the soil and produced particle-laden eddies beneath the lander that sandblasted the lander underside. The result was nearly complete erosion of microbial contaminants from the spacecraft model with their subsequent deposition in the surrounding area. It is concluded that different planetary protection cleanliness levels for different parts of a spacecraft do not necessarily prevent soil contamination because these cleaning strategies evolved without consideration of the effects of the descent engine plumes.


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