Procedure and layout for the development of a fatigue test on an agricultural implement by a four poster test bench

The increasing demand in agricultural vehicles’ power requirements, payloads and driving speeds increases issues related to tractors and farm implements exposure to solicitations. One of the main factors to be taken into account for fatigue test developing on agricultural machines is the heterogeneity of the environment and activity in which the tractor operates. In particular, for contractors the use in transport conditions both on terrain and road becomes important. As far as transport is concerned. factors mainly affecting solicitations on carried implement are soil profile roughness, tractor settings and forward speed. In this paper, CRA-ING laboratory of Treviglio, Italy, together with Frandent Group s.r.l. (Osasco, Italy), analyse the possibility of creating a solicitation profile by means of one four poster test bench for fatigue test on a carried implement simulating transport conditions. Accelerations at the hubs of the tractor were acquired during transport on terrain and reproduced with one electro-hydraulic four posters test bench on one dummy of a tractor developed for carrying the implement. Artificial bumps were mathematically created and introduced in the time history to simulate squares solicitations. Twelve hours of test were carried out. This experience confirmed the possibility of carrying out laboratory fatigue test on agricultural implements by reproducing specific field conditions solicitations with four poster test bench

Analysis of driving seat vibrations in different transfer conditions

The vibration transmitted through the seat of a four-wheel drive tractor, developing 179 kW, and equipped with front suspension axle and shock absorber for the implement, were measured and analysed according to the ISO standard. Several tests were carried out in different conditions considering: type of operation (transfer with and without mounted implement); type of track (conglomerate bituminous road, country lane); connected and disconnected suspension and/or shock absorber; and forward speeds. For the transfer on bituminous conglomerate road, it was observed that the suspension always reduces acceleration av, in both tests without and with implement, for all the considered forward speeds. For the tests conduced on country lane, the front axle suspension involved a reduction of the acceleration, but it was less evident than on the road Results showed that the forward speed and the mass distribution were the most important factors on tractor behaviour influencing the driver comfort. The daily exposure time which could compromise the driver's health increased from 2.5 to 8 h decreasing the speed from 3.06 to 2.22 m/s during transfer in country lane without implement. In the other condition the time exposure is approximately more than a working day

DOPAL derived alpha-synuclein oligomers impair synaptic vesicles physiological function

Parkinson's disease is a neurodegenerative disorder characterized by the death of dopaminergic neurons and by accumulation of alpha-synuclein (aS) aggregates in the surviving neurons. The dopamine catabolite 3,4-dihydroxyphenylacetaldehyde (DOPAL) is a highly reactive and toxic molecule that leads to aS oligomerization by covalent modifications to lysine residues. Here we show that DOPAL-induced aS oligomer formation in neurons is associated with damage of synaptic vesicles, and with alterations in the synaptic vesicles pools. To investigate the molecular mechanism that leads to synaptic impairment, we first aimed to characterize the biochemical and biophysical properties of the aS-DOPAL oligomers; heterogeneous ensembles of macromolecules able to permeabilise cholesterol-containing lipid membranes. aS-DOPAL oligomers can induce dopamine leak in an in vitro model of synaptic vesicles and in cellular models. The dopamine released, after conversion to DOPAL in the cytoplasm, could trigger a noxious cycle that further fuels the formation of aS-DOPAL oligomers, inducing neurodegeneration

Human SOD2 Modification by Dopamine Quinones Affects Enzymatic Activity by Promoting Its Aggregation: Possible Implications for Parkinson’s Disease

Mitochondrial dysfunction and oxidative stress are considered central in dopaminergic neurodegeneration in Parkinson’s disease (PD). Oxidative stress occurs when the endogenous antioxidant systems are overcome by the generation of reactive oxygen species (ROS). A plausible source of oxidative stress, which could account for the selective degeneration of dopaminergic neurons, is the redox chemistry of dopamine (DA) and leads to the formation of ROS and reactive dopamine-quinones (DAQs). Superoxide dismutase 2 (SOD2) is a mitochondrial enzyme that converts superoxide radicals to molecular oxygen and hydrogen peroxide, providing a first line of defense against ROS. We investigated the possible interplay between DA and SOD2 in the pathogenesis of PD using enzymatic essays, site-specific mutagenesis, and optical and high-field-cw-EPR spectroscopies. Using radioactive DA, we demonstrated that SOD2 is a target of DAQs. Exposure to micromolar DAQ concentrations induces a loss of up to 50% of SOD2 enzymatic activity in a dose-dependent manner, which is correlated to the concomitant formation of protein aggregates, while the coordination geometry of the active site appears unaffected by DAQ modifications. Our findings support a model in which DAQ-mediated SOD2 inactivation increases mitochondrial ROS production, suggesting a link between oxidative stress and mitochondrial dysfunction

Feeding emitters for microirrigation with a digestate liquid fraction up to 25% dilution did not reduce their performance

Irrigation with wastewater can strongly contribute to the reduction of water abstraction in agriculture with an especial interest in arid and semiarid areas. However, its use can have drawbacks to both soil and micro-irrigation systems, especially when the total solids in the wastewater are high, such as in digestate liquid fractions (DLF) from plant material. The aim of this study was thus to evaluate the performances of a serpentine shaped micro-emitter injected with a hydrocyclone filtered DLF (HF-DLF) from corn + barley biomass and evaluate the traits of the liquid released within a 8-h irrigation cycle. HF-DLF was injected at 10%, 25%, and 50% dilution compared to tap water (at pH = 7.84) and the system performances were measured. No clogging was found, which likely depended on both the shape of the emitter and the high-pressure head (200 kPa). HF-DLF dilution at 10%, 25%, and 50% consisted in +1.9%, +3.5, and -4.9% amount of liquid released compared to the control. Fluid temperature during irrigation (from 9:00 to 17:00) did not explain the difference in the released amounts of liquid. In 10% HF-DLF % and 25% HF-DLF, a pH difference of + 0.321 ± 0.014 pH units compared to the control was found, and such difference was constant for both dilutions and at increasing the time. In contrast, 50% HF-DLF increased pH by around a half point and such difference increased with time. Similar differences among treatments were found for the total solids in the liquid. These results indicate that 50% HF-DLF was accumulating materials in the serpentine. These results suggest that a low diluted HF-DLF could directly be injected in irrigation systems with few drawbacks for the irrigation system and contribute to water conservation since such wastewater are available from the late spring to the early fall, when water requirements are high

Proposal to estimate the engine oil consumption in agricultural tractors

Lubrication plays a crucial role in a tractor engines' efficiency and durability. Without suitable lubrication, excessive friction will significantly reduce an engine's power, and high-intensity wear will damage the moving parts in a short period of time. A set of 178 agricultural tractor models from 20 different international manufacturers located in Europe, North America and Asia was used in this study. The tractor models were produced between 2000 and 2015 with rated engine power ranging from 30 to 428.8 kW. Rated engine power, crankcase oil capacity, and oil change intervals were derived from official test reports. Engine oil consumption was calculated using the method described in ASABE Standard D497.7, clause 3.4. A linear relationship between rated engine power and hourly oil consumption rate was confirmed, but the regression coefficients deviated from current values in the ASABE Standard. These results indicate that ASABE equation coefficients should be updated to more accurately estimate engine oil consumption for use in technical/economical evaluations and in the analysis of operating costs of new tractor models

A retrofit variable-rate control system for pressurized slurry tankers

n the last several decades, livestock effluent management practices and field slurry spreading operations have received increasing attention due to their economic and environmental implications. In this study, a variable-rate control system for pressurized slurry tankers was developed according a retrofit approach (i.e., as a self-standing module that can be adapted and mounted on existing slurry tanker equipment). The system provides farmers with a useful tool for achieving compliance with environmental protection regulations and for developing good practices for livestock and nitrogen management. This system is suitable for new and used pressurized tanker equipment. For field-testing purposes, this system was mounted on a double-axis 10 m3 slurry tanker equipped with a crawling nozzle distribution unit. Field experiments were conducted at two typical forward speeds (2 and 3 km h-1) and three different nitrogen application rates (170, 250, and 340 kg ha-1). Based on the experimental results, the system was generally capable of limiting the differences between the nominal and measured application rates to less than 9%. In addition, the data analysis indicated that the slurry spreading was not significantly affected by the forward speed of the tanker. The uniformity of nitrogen spreading was evaluated according to the UNI EN 13406:2002 standard. The results showed that the transverse field distribution was uniform throughout the working width of the machine and at all tested operating conditions, with maximum deviations that were limited to less than 15%

Problematiche di produzione di stampati e forgiati in acciaio inossidabile ASTM A182 F55

Nella presente memoria viene descritta la messa a punto del ciclo produttivo di due componenti in acciaiosuper duplex ASTM A182 F55, da realizzare uno mediante stampaggio ed uno mediante fucinatura. Verràdescritto il procedimento di deformazione plastica a caldo di entrambi i pezzi e il successivo trattamentotermico al fine di ottenere le caratteristiche meccaniche e la microstruttura desiderata. I risultati ottenuti daqueste prove dovranno fornire le basi per l’effettiva messa in produzione dei due componenti

Superoxide dismutating molecules rescue the toxic effects of PINK1 and parkin loss.

Reactive oxygen species exert important functions in regulating several cellular signalling pathways. However, an excessive accumulation of reactive oxygen species can perturb the redox homeostasis leading to oxidative stress, a condition which has been associated to many neurodegenerative disorders. Accordingly, alterations in the redox state of cells and mitochondrial homeostasis are established hallmarks in both familial and sporadic Parkinson's disease cases. PINK1 and Parkin are two genes which account for a large fraction of autosomal recessive early-onset forms of Parkinson's disease and are now firmly associated to both mitochondria and redox homeostasis. In this study we explored the hypothesis that superoxide anions participate in the generation of the Parkin and PINK1 associated phenotypic effect by testing the capacity of endogenous and exogenous superoxide dismutating molecules to rescue the toxic effects induced by loss of PINK1 or Parkin, in both cellular and fly models. Our results demonstrate the positive effect of an increased level of superoxide dismutase proteins on the pathological phenotypes, both in vitro and in vivo. A more pronounced effectiveness for mitochondrial SOD2 activity points to the superoxide radicals generated in the mitochondrial matrix as the prime suspect in the definition of the observed phenotypes. Moreover, we also demonstrate the efficacy of a SOD-mimetic compound, M40403, to partially ameliorate PINK1/Parkin phenotypes in vitro and in vivo. These results support the further exploration of SOD-mimetic compounds as a therapeutic strategy against Parkinson's disease

The N-Terminal residues 43 to 60 form the interface for dopamine mediated α-synuclein dimerisation

α-synuclein (α-syn) is a major component of the intracellular inclusions called Lewy bodies, which are a key pathological feature in the brains of Parkinson's disease patients. The neurotransmitter dopamine (DA) inhibits the fibrillisation of α-syn into amyloid, and promotes α-syn aggregation into SDS-stable soluble oligomers. While this inhibition of amyloid formation requires the oxidation of both DA and the methionines in α-syn, the molecular basis for these processes is still unclear. This study sought to define the protein sequences required for the generation of oligomers. We tested N- (α-syn residues 43-140) and C-terminally (1-95) truncated α-syn, and found that similar to full-length protein both truncated species formed soluble DA: α-syn oligomers, albeit 1-95 had a different profile. Using nuclear magnetic resonance (NMR), and the N-terminally truncated α-syn 43-140 protein, we analysed the structural characteristics of the DA:α-syn 43-140 dimer and α-syn 43-140 monomer and found the dimerisation interface encompassed residues 43 to 60. Narrowing the interface to this small region will help define the mechanism by which DA mediates the formation of SDS-stable soluble DA:α-syn oligomers