Hydrogen Production via Pd-TiO2 Photocatalytic Water Splitting under Near-UV and Visible Light: Analysis of the Reaction Mechanism

Photocatalytic hydrogen production via water splitting using a noble metal on a TiO2 is a technology that has developed rapidly over the past few years. Specifically, palladium doped TiO2 irradiated with near-UV or alternatively with visible light has shown promising results. With this end in mind, strategically designed experiments were developed in the Photo-CREC Water-II (PCW-II) Reactor using a 0.25 wt% Pd-TiO2 under near-UV and visible light, and ethanol as an organic scavenger. Acetaldehyde, carbon monoxide, carbon dioxide, methane, ethane, ethylene, and hydrogen peroxide together with hydrogen were the main chemical species observed. A Langmuir adsorption isotherm was also established for hydrogen peroxide. On this basis, it is shown that pH variations, hydrogen peroxide formation/adsorption, and the production of various redox chemical species provide an excellent carbon element balance, as well as OH• and H• radicals balances. Under near-UV irradiation, 108 cm3 STP of H2 is produced after 6 h, reaching an 99.8% elemental carbon balance and 98.2% OH• and H• and radical balance. It is also proven that a similar reaction network can be considered adequate for the photoreduced Pd-TiO2 photocatalyst yielding 29 cm3 STP of H2 with 97.5% carbon and the 99.2% OH•–H• radical balance closures. It is shown on this basis that a proposed “series-parallel” reaction network describes the water splitting reaction using the mesoporous Pd-TiO2 and ethanol as organic scavenger.

The main plant mineral nutrition balance on using ecological fertilizers

The experiments were performed in stationary cylindrical lysimeters, which were filled with soil typical of the Eastern Lithuanian region: sandy loam and loamy sand soil (Haplic Luvisol). In the experiment, the main aim was to investigate the balance of nitrogen (N), phosphorus (P) and potassium (K) in the sandy loam and loamy sand Haplic Luvisol and to evaluate their effectiveness and suitability for the light texture soil and agricultural crop harvest in organic agriculture. It was found that, in general, during the three years of the experiment, the balance of N in the sandy loam and loamy sand soil was negative, but fertilization with organic sapropel showed the positive results: less N leaching losses content, compared to other organic-organic fertilizers. Fertilization with cattle manure did not ensure the P positive element balance, in both types of soils, due to a small amount of P in the fertilizer and a high accumulation in the yield. The amount of potassium added each year with NPK fertilizer ensured a positive element balance only in the sandy loam soil.

Can the scaling of plant nitrogen to phosphorus be altered by global change? An empirical test

Aims Global change may cause unparalleled supplies of soil nutrients and further lead to stoichiometric imbalance of nitrogen (N) and phosphorus (P) in terrestrial plants. While previous studies had reported the effects of global change factors on plant N, P contents and their ratios, few had examined whether or how these factors may influence the scaling of these two elements. Methods Taking advantage of a manipulative experiment with altered precipitation, warming and N addition, and using the general scaling function N = βPα, we examined how the scaling of plant N to P may respond to global change factors in a Loess grassland in northwestern China. Important Findings We found that precipitation reduction (PR) and warming decreased plant P concentrations, while N addition increased plant N concentrations, resulting in increased N:P ratios. The slopes of the linear regressions between plant N and P (i.e. log-transformed N versus P) did not change significantly, whereas the intercepts increased significantly under PR, warming and N addition. These results indicate that global change factors may not affect the synergistic variation of plant N and P, showing a closely coupled relationship between them. Our findings may help to better understand plant nutrient dynamics and element balance in a changing world.

Dynamic Analysis of Bevel Gear System in Main Retarder

The main retarder of vehicle is gear rotor system, its vibration property is complex. The whole transfer matrix method is a new algorithm to study, relationship of the displacements and forces are established considering gyroscopic moment and coupling vibration. The meshing point between rotors is treated as coupling element, balance equations are estalished on deformation compatibility condition. The globe status vectors including forces and displacements of all shafts were integrated into a whole transfer matrix. So it can be programming and has high numerical stability and accuracy. The influence of the meshing effect on vibration of the system can be systematically studied. The status vectors such as displacements, deflection angles, torsion angles, shearing forces, bending moments and torques are no longer independent. The vibration property of the geared rotor system was calculated and analyzed. The numerical results revealed that many coupling critical rational speeds of the system are derived. vibration of main retarder can be improved.

Dynamic Analysis of Bevel Gear System in Main Retarder

The main retarder of vehicle is gear rotor system, its vibration property is complex. The whole transfer matrix method is a new algorithm to study, relationship of the displacements and forces are established considering gyroscopic moment and coupling vibration. The meshing point between rotors is treated as coupling element, balance equations are estalished on deformation compatibility condition. The globe status vectors including forces and displacements of all shafts were integrated into a whole transfer matrix. So it can be programming and has high numerical stability and accuracy. The influence of the meshing effect on vibration of the system can be systematically studied. The status vectors such as displacements, deflection angles, torsion angles, shearing forces, bending moments and torques are no longer independent. The vibration property of the geared rotor system was calculated and analyzed. The numerical results revealed that many coupling critical rational speeds of the system are derived. vibration of main retarder can be improved.

Melatonin attenuates caspase-dependent apoptosis in the thoracic aorta by regulating element balance and oxidative stress in pinealectomised rats

The aim of this study was to explain the possible mechanisms by which melatonin deficiency results in cardiovascular injury and to investigate the effects of melatonin administration on important signalling pathways and element equilibrium in the thoracic aorta (TA). For this purpose, we analysed the cellular and molecular effects of melatonin deficiency or administration on oxidative stress, DNA damage, molecular chaperone response, and apoptosis induction in TA tissues of pinealectomised rats using ELISA, RAPD, qRT-PCR, and Western blot assays. The results showed that melatonin deficiency led to an imbalance in essential element levels, unfolded or misfolded proteins, increased lipid peroxidation, and selectively induced caspase-dependent apoptosis in TA tissues without significantly affecting the Bcl-2/BAX ratio (2.28 in pinealectomised rats, 2.73 in pinealectomised rats treated with melatonin). In pinealectomised rats, the genomic template stability (80.22%) was disrupted by the significantly increased oxidative stress, and heat shock protein 70 (20.96-fold), TNF-α (1.73-fold), caspase-8 (2.03-fold), and caspase-3 (2.87-fold) were markedly overexpressed compared with the sham group. Melatonin treatment was protective against apoptosis and inhibited oxidative damage. In addition, melatonin increased the survivin level and improved the regulation of element equilibrium in TA tissues. The results of the study indicate that melatonin deficiency induces TNF-α-related extrinsic apoptosis signals and that the administration of pharmacological doses of melatonin attenuates cardiovascular toxicity by regulating the increase in the rate of apoptosis caused by melatonin deficiency in TA tissue of Sprague–Dawley rats.