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Integration of QTL and transcriptome approaches for the identification of genes involved in tomato response to nitrogen deficiency
Get PDFOptimizing plant nitrogen (N) usage and inhibiting N leaching loss in the soil–crop system is crucial to maintaining crop yield and reducing environmental pollution. This study aimed at identifying quantitative trait loci (QTLs) and differentially expressed genes (DEGs) between two N treatments in order to list candidate genes related to nitrogen-related contrasting traits in tomato varieties. We characterized a genetic diversity core-collection (CC) and a multi-parental advanced generation intercross (MAGIC) tomato population grown in a greenhouse under two nitrogen levels and assessed several N-related traits and mapped QTLs. Transcriptome response under the two N conditions was also investigated through RNA sequencing of fruit and leaves in four parents of the MAGIC population. Significant differences in response to N input reduction were observed at the phenotypic level for biomass and N-related traits. Twenty-seven QTLs were detected for three target traits (leaf N content, leaf nitrogen balance index, and petiole NO3− content), 10 and six in the low and high N condition, respectively, while 19 QTLs were identified for plasticity traits. At the transcriptome level, 4752 and 2405 DEGs were detected between the two N conditions in leaves and fruits, respectively, among which 3628 (50.6%) in leaves and 1717 (71.4%) in fruit were genotype specific. When considering all the genotypes, 1677 DEGs were shared between organs or tissues. Finally, we integrated DEG and QTL analyses to identify the most promising candidate genes. The results highlighted a complex genetic architecture of N homeostasis in tomato and novel putative genes useful for breeding tomato varieties requiring less N input
Thermal Analysis of Parabolic and Fresnel Linear Solar Collectors Using Compressed Gases as Heat Transfer Fluid in CSP Plants
Get PDFThis study introduces the use of compressed air as a heat transfer fluid in small-scale, concentrated linear solar collector technology, evaluating its possible advantages over traditional fluids. This work assumes the adoption of readily available components for both linear parabolic trough and Fresnel collectors and the coupling of the solar field with Brayton cycles for power generation. The aim is to provide a theoretical analysis of the applicability of this novel solar plant configuration for small-scale electricity generation. Firstly, a lumped thermal model was developed in a MatLab® (v. 2023a) environment to assess the thermal performance of a PT collector with an evacuated receiver tube. This model was then modified to describe the performance of a Fresnel collector. The resulting optical–thermal model was validated through literature data and appears to provide realistic estimates of temperature distribution along the entire collector length, including both the receiver tube surface and the Fresnel collector’s secondary concentrator. The analysis shows a high thermal efficiency for both Fresnel and parabolic collectors, with average values above 0.9 (in different wind conditions). Th5s study also shows that the glass covering of the Fresnel evacuated receiver, under the conditions considered (solar field outlet temperature: 550 °C), reaches significant temperatures (above 300 °C). Furthermore, due to the presence of the secondary reflector, the temperature difference between the upper and the lower part of the glass envelope can be very high, well above 100 °C in the final part of the collector string. Differently, in the case of PTs, this temperature difference is quite limited (below 30 °C)
Performance of Protection Devices Integrated into Lithium-Ion Cells during Overcharge Abuse Test
Get PDFLithium-ion batteries currently represent the most suitable technology for energy storage in various applications, such as hybrid and electric vehicles (HEVs and BEVs), portable electronics and energy storage systems. Their wide adoption in recent years is due to their characteristics of high energy density, high power density and long life cycle. On the other hand, they still face challenges from a safety point of view for the possible faults that could generate several problems, ranging from simple malfunctioning to a dangerous thermal runaway. Overcharge is one of the most critical types of faults, and, depending on the level of abuse, it may trigger a thermal runaway. To prevent high levels of overcharge abuse, some cells include integrated protection devices that cut off the circuit when a critical condition is met. In this paper, the performance of these protection devices is evaluated to assess their effectiveness. The cells were tested at different ambient temperatures and current levels. In the worst-case scenarios, the maximum cell temperature slightly exceeded 70 °C and the State of Charge (SOC) reached a peak of 127% when the Current Interruption Device (CID) was activated. These conditions were not critical, so serious events such as thermal runaway were not triggered. These outcomes confirm the effectiveness of the CID, which always intervenes in maintaining a safe state. However, since it never intervened in the overcharge abuse tests, a specific set up was also used to investigate the operation of the other protection device, the Positive Temperature Coefficient
Mechanical Tests on Reduced Scale Mock-Ups of ITER Pre-compression Rings
No full textThe ITER Pre-Compression Ring (PCR) system consists of two sets of 3 rings each, located on the top and the bottom inner region of the Toroidal Field (TF) coils providing a centripetal load and a radial constraint with beneficial effects on the force distribution in the TF magnet system. PCRs are large and thick rings with a diameter of 5 m manufactured by winding and bonding a flat pultruded tape made of fiberglass in epoxy matrix. Due to the particular composite material and to the innovative process an overall qualification phase has been planned including a dedicated testing campaign on reduced scale ring mock-ups with the aim to characterize their mechanical properties and to verify the compliance to requirements. The mock-ups were procured by F4E with a diameter of 1 m (1/5 of the full scale) and the tests were performed at ENEA Frascati by using a dedicated hydraulic testing facility consisting of 18 radial pulling actuators aiming at reproducing the loads and displacements occurring to the rings. The testing campaign consisted in a detailed sequence of Stress Relaxation (SR) tests performed at different stress levels/durations and followed by final ultimate tensile strength (UTS) tests at room temperature. Acoustic emission (AE) monitoring was also performed during testing of one ring mock-up. This paper describes the testing programme, the ring mock-ups, the test equipment and reports the main results of the testing campaign
Recent Advancements in Pd-Based Membranes for Hydrogen Separation
Get PDFThe use of hydrogen is pivotal for the energy and industrial transition in order to mitigate the effects of climate change. As technologies like fuel cells, e-fuels, and the semiconductor industry increasingly demand pure hydrogen, the development of efficient separation methods is crucial. While traditional methods such as pressure-swing adsorption are common, palladium (Pd)-based membranes are a promising alternative due to their energetic efficiency. This review summarizes the recent advances in Pd-based membranes for hydrogen separation over the last six years. It provides a theoretical overview of hydrogen permeation through membranes and examine the characteristics of various Pd alloys adopted in membrane fabrication, discussing the advantages and disadvantages of binary and ternary alloys, for different membrane types, including self-supported and supported membranes, as well as the role of intermediate layers. Additionally, the membrane characteristics used in some recent works on self-supported and supported Pd membranes are analyzed, focusing on operational parameters like permeability, selectivity, and durability. Finally, this review emphasizes the significant progress made in enhancing membrane performance and discusses future directions for industrial applications
Optical investigation of degradation of graphene oxide in alkaline environment: Evidence of two distinct photon-emitting phases in visible region
Get PDFIn this work we show a procedure of treating of the graphene oxide in alkaline environment as a function of the treatment time in order to obtain novel structures with strong luminescence properties, water-stable, useful as potential replacement for critical raw materials employed as example in optical and optoelectronic devices or for diagnostic and therapeutic technology. These structures have distinct blue and green-luminescence properties which derived most likely from different structural conformations, one associable with that of carbon quantum dots (or as an alternative to that of the Oxidative Debris), the other, lighter and more similar to organic compounds, reported in literature as fulvic-like molecules, but whose nature has to be further investigated. We show that the lighter fraction has a dual mechanism of photoemission: the excitation-independent PL for excitation wavelength within 350 nm and the excitation-dependent component for excitation wavelength ranging in the visible spectrum. The PL dual behaviour could depend on fluorescent nanoclusters composed by specific organic fluorophores with a carbonaceous core. FTIR analysis shows reasonably the same functional groups unless of some difference discussed in the text, meanwhile UV–Vis and PL analysis clearly highlight two distinct emissions (450 nm and 530 nm) in the visible region of the electromagnetic spectrum. Excitation-dependent photoluminescence, water stability and organic fluorescent nanostructures are issues particularly required for application in the biological field but also in materials science
Search for Strange Quark Matter and Nuclearites on Board the International Space Station (SQM-ISS): A Future Detector to Search for Massive, Non-Relativistic Objects in Space
Get PDFSQM-ISS is a detector that will search from the International Space Station for massive particles possibly present among the cosmic rays. Among them, we mention strange quark matter, Q-Balls, lumps of fermionic exotic compact stars, Primordial Black Holes, mirror matter, Fermi balls, etc. These compact, dense objects would be much heavier than normal nuclei, have velocities of galaxy-bound systems, and would be deeply penetrating. The detector is based on a stack of scintillator and piezoelectric elements which can provide information on both the charge state and mass, with the additional timing information allowing to determine the speed of the particle, searching for particles with velocities of the order of galactic rotation speed (v ≲ 250 km/s). In this work, we describe the apparatus and its observational capabilities
Effects of surface tension on the collapse time of an empty bubble
No full textThe collapse of an empty spherical bubble in an ideal liquid, in the absence of viscosity and surface tension, was studied by Lord Rayleigh. Using energy conservation, he derived an exact expression for the total collapse time as a function of the initial radius of the bubble, the density of the liquid, and the far-field pressure. In the present work, we extend Rayleigh's expression to include surface tension effects. Results are found to depend on a dimensionless parameter ε that measures the ratio between the work done by surface tension and that done by pressure during the collapse. This parameter is small for large bubbles but can be of order unity or larger for bubbles of small radius and, eventually, small pressure. We show that the ratio between the collapse time in the presence of surface tension and Rayleigh's collapse time is proportional to a definite integral that is a smooth, monotonically decreasing function of ε. This function can be easily bounded analytically for any value of ε, yielding a simple and accurate approximation for the collapse time that, for all practical purposes, provides a complete analytical solution to the problem at hand. We finally extend results to the case of a hyperspherical collapsing empty bubble
Dosimetry for repetitive transcranial magnetic stimulation: a translational study from Alzheimer’s disease patients to controlled in vitro investigations
Get PDFObjective. Recent studies have indicated that repetitive transcranial magnetic stimulation (rTMS) could enhance cognition in Alzheimer’s Disease (AD) patients, but to now the molecular-level interaction mechanisms driving this effect remain poorly understood. While cognitive scores have been the primary measure of rTMS effectiveness, employing molecular-based approaches could offer more precise treatment predictions and prognoses. To reach this goal, it is fundamental to assess the electric field (E-field) and the induced current densities (J) within the stimulated brain areas and to translate these values to in vitro systems specifically devoted in investigating molecular-based interactions of this stimulation. Approach. This paper offers a methodological procedure to guide dosimetric assessment to translate the E-field induced in humans (in a specific pilot study) into in vitro settings. Electromagnetic simulations on patients’ head models and cellular holders were conducted to characterize exposure conditions and determine necessary adjustments for in vitro replication of the same dose delivered in humans using the same stimulating coil. Main results. Our study highlighted the levels of E-field and J induced in the target brain region and showed that the computed E-field and J were different among patients that underwent the treatment, so to replicate the exposure to the in vitro system, we have to consider a range of electric quantities as reference. To match the E-field to the levels calculated in patients’ brains, an increase of at least the 25% in the coil feeding current is necessary when in vitro stimulations are performed. Conversely, to equalize current densities, modifications in the cells culture medium conductivity have to be implemented reducing it to one fifth of its value. Significance. This dosimetric assessment and subsequent experimental adjustments are essential to achieve controlled in vitro experiments to better understand rTMS effects on AD cognition. Dosimetry is a fundamental step for comparing the cognitive effects with those obtained by stimulating a cellular model at an equal dose rigorously evaluated
Treasures of Italian Microbial Culture Collections: An Overview of Preserved Biological Resources, Offered Services and Know-How, and Management
Get PDFMicroorganisms, microbiomes, and their products (e.g., enzymes, metabolites, antibiotics, etc.) are key players in the functioning of both natural and anthropized Earth ecosystems; they can be exploited for both research purposes and biotechnological applications, including fighting the big challenges of our era, such as climate change. Culture collections (CCs) and microbial Biological Resource Centres (mBRCs) are repositories of microorganisms that investigate and safeguard biodiversity and facilitate the scientific and industrial communities’ access to microbial strains and related know-how by providing external users with skills and services. Considering this, CCs and mBRCs are pivotal institutions for the valorisation of microorganisms, the safeguarding of life, and the fostering of excellent bioscience. The aim of this review is to present the state-of-the-art of Italian CCs and mBRCs, highlighting strengths, weaknesses, threats, and opportunities. Italy is, indeed, a hotspot of microbial biodiversity with a high rate of endemism and incredible potential, not only for the food and beverage sector (i.e., “Made in Italy” products), where microorganisms can have a beneficial or a spoiling function, but also to guarantee environmental sustainability and foster the bioeconomy through the design of new bioprocesses and products. However, weaknesses, such as the lack of management rules in accordance with international quality standards, are also analysed and ways of overcoming them are discussed. In this context, an overview is given of the Joint Research Unit MIRRI-IT and the European-funded SUS-MIRRI.IT project, which aims to improve the management and sustainability of Italian microbial collections, and serves as a starting point for an innovative revolution in the context of CCs and mBRCs worldwide