First Stages Of Growth Research Articles

Exploring the interfacial structure and crystallinity for direct growth of Mn3Sn(0001) on sapphire (0001) by molecular beam epitaxy

The Kagome antiferromagnet Mn3Sn has garnered a lot of attention due to the presence of interesting properties such as anomalous Hall effects and Nernst effects. Until now, few papers have been reported to grow using molecular beam epitaxy with a buffer layer or on other substrates. In this paper, we discuss the synthesis of crystalline Mn3Sn layers, prepared on Al2O3 (0001) without a buffer layer using molecular beam epitaxy. The growth is monitored in-situ using reflection high energy electron diffraction and measured ex-situ using X-ray diffraction, Rutherford back-scattering, and cross-sectional scanning transmission electron microscopy. The samples were deposited at 524 ± 5 °C, with an Mn: Sn atomic flux ratio of 3.2:1 for 90 min. Orientation relationships between the Mn3Sn films and the sapphire substrates are determined from in-plane and out-of-plane measurements. Our analysis indicates that the resulting film is predominantly c−plane oriented. Lastly, the samples prepared in this way were found to be discontiguous, showing a 3-dimensional morphology. According to first-principles calculations, the Mn3Sn exhibits a displaced Kagome structure in the very first stages of growth, for 2 ML and 4 ML growth on Al2O3 (0001). This result is corroborated by calculating the surface formation energies and explains the observed RHEED patterns.

Germination and First Stages of Growth in Drought, Salinity, and Cold Stress Conditions of Plasma-Treated Barley Seeds.

Numerous works have demonstrated that cold plasma treatments constitute an effective procedure to accelerate seed germination under nonstress conditions. Evidence also exists about a positive effect of plasmas for germination under environmental stress conditions. For barley seeds, this work studies the influence of cold plasma treatments on the germination rate and initial stages of plant growth in common stress environments, such as drought, salinity, and low-temperature conditions. As a general result, it has been found that the germination rate was higher for plasma-treated than for untreated seeds. Plasma also induced favorable changes in plant and radicle dimensions, which depended on the environment. The obtained results demonstrate that plasma affects the biochemical metabolic chains of seeds and plants, resulting in changes in the concentration of biochemical growing factors, a faster germination, and an initially more robust plant growth, even under stress conditions. These changes in phenotype are accompanied by differences in the concentration of biomarkers such as photosynthetic pigments (chlorophylls a and b and carotenoids), reactive oxygen species, and, particularly, the amino acid proline in the leaves of young plants, with changes that depend on environmental conditions and the application of a plasma treatment. This supports the idea that, rather than an increase in seed water imbibition capacity, there are clear beneficial effects on seedling of plasma treatments.

Inhomogeneous HfO2 layer growth at atomic layer deposition

Abstract Thin HfO2 films atomic layer deposited from hafnium alkyl amide and oxygen plasma were analysed using spectroscopic ellipsometry and X-ray reflectivity. Low refractive index of the material for samples with less than 30 nm thickness marks the index inhomogeneity at the first stage of growth. The transition from rising density to a more stable growth takes place at about 10 to 25 nm film thickness. HfO2 films used for resistive switching experiments demonstrate either clockwise or counterclockwise behaviour depending on the film thickness. The reason for this may be the disruption of the conductive filament at different metal-insulator interfaces, which could be favoured by several mechanisms.

The Effects of Water Stress on Cotton Leaf Area and Leaf Morphology

The most important effect of water stress on plants is that it reduces leaf area and leads to changes in leaf morphology. Decreased leaf area results in reduces crop yield through the reduction in photosynthesis. This study investigates the effects of the decrease in leaf area on seed cotton yield, evapotranspiration (ET), water use efficiency (WUE), and leaf geometry in cotton plants under water stress in different growth periods. The cotton plant was divided into three different growth periods (vegetative period (VP), flowering and boll growth period (FB), and boll opening (BO) period), and irrigation water was applied at field capacity level during the periods of full irrigation (T), while non-irrigation was applied during the water stress periods (O). In the experiment, 6 different irrigation strategies were based on: OOO, TTT, OTO, TOO, OTT, and TOT. In each treatment, five leaves were taken from three plants in every replicate during three growth periods, and the leaf area and geometric lengths of each leaf were measured. Seed cotton yield, evapotranspiration, and WUE decreased significantly depending on the severity and duration of the water stress to which the cotton was exposed. Physiologically, cotton leaves under water stress in the first stage of growth tended to increase the leaf lobe numbers while reducing the leaf area. Therefore, there were more leaf lobes numbers measured in OOO than in other treatments. Irrigation in the vegetative growth period was more effective in increasing the leaf area than the other growth periods.

Nucleation and Growth of Dendritic Islands during Platinum Oxidation-Reduction Cycling

Platinum is the model catalyst in fuel cells because of its high activity toward oxygen reduction and hydrogen oxidation. However, its applicability is limited due to the degradation of the catalyst under operating conditions. This degradation process has been extensively studied by repeatedly oxidizing and reducing the electrode, which leads to the roughening of the surface due to the nucleation and growth of platinum nano-islands. Although the general picture of this surface roughening is well known, the atomic details concerning the nucleation and early growth of the islands are still under debate. In this work, we use Density Functional Theory (DFT) to calculate formation energies and diffusion barriers of an adatom, in both the unoxidized and the oxidized state, with the aim to provide further insight into the nucleation phenomena. Moreover, we analyze from STM images obtained experimentally the shape of the nano-islands during the first stages of growth. Our results show not only that the islands form during the reduction of the surface, but also that they grow with a dendritic island shape, similarly to the platinum islands formed in vacuum by Molecular Beam Epitaxy (MBE).

Maize Growth, Fodder Yield and Nutrient Uptake in relation to Phosphorus and Sulphur Nutrition

Phosphorus (P) and Sulphur (S) are the most important plant nutrients which play significant roles in enhancing the early growth and development and increasing the fodder yield of maize. This important field study was planned to evaluate the P-S interaction effects on maize growth, fodder yield and nutrient (P and S) uptake. The soil used for study was clay loam, medium-alkaline (pH: 7.9), non-saline (EC: 0.85 dS m-1), strongly calcareous (CaCO3: 24 %), adequate in organic matter (1.6 %), low in ABDTPA-P (3.5 mg kg-1), while medium in SO4-S (21.5 mg kg-1). Eight P and S treatments were involved in this study, i.e. single application of each 90 kg P2O5 (T1) and 20 kg S ha-1 (T2); integration of 90 kg P2O5 with S @ 20, 40 and 60 kg ha-1 (T3, T4 and T5, respectively), and integration of 120 kg P2O5 with S @ 20, 40 and 60 kg ha-1 (T6, T7 and T8, respectively). The experiment followed an RCBD arrangement that was replicated thrice. Recommended seed rate of maize (95 kg ha-1) was used for sowing. The results revealed that shoot biomass production was maximum when maize plants received higher doses of P and S in an integrated manner (120-60 kg P2O5-S ha-1). At 30 DAS, shoot fresh biomass was found maximum, and statistically alike, when 90 or 120 kg P2O5 was integrated with S @ 60 kg ha-1. Shoot fresh biomass was maximum, at 40 DAS when 120-60 kg P2O5-S ha-1 was applied to maize. Shoot dry biomass after 30 days of sowing was highest when 90 kg P2O5 was applied with S @ 60 kg ha-1 or when, 120 kg P2O5 was used with S @ 40 and 60 kg ha-1. Shoot length was maximum, both at 30 and 40 DAS, in case of using 120-60 kg P2O5-S ha-1. Chlorophyll content of maize was maximum, both at 30 and 40 DAS, when 90 kg P2O5 was applied with S @ 60 kg ha-1. Maximum fodder yield of maize was noted when 120 kg P2O5 was applied with 60 kg S ha-1. Highest P-uptake, both at 30 and 40 DAS was noted when 120 kg P2O5 was applied with S @ 60 kg ha-1. At the first stage of growth, S-uptake was highest when 60 kg S was integrated with 90 kg P2O5 ha-1. The study advocated integrated application of 120-60 kg P2O5-S ha-1 for obtaining economically maximum fodder yield of maize.

Characterization of the Maximal Nutritional Value of Lactuca sativa (Lettuce) Based upon Elemental Analysis

Multielemental content of the Lactuca sativa (lettuce) was monitored during 7 weeks of growth in order to identify the optimal harvest period from the maximum nutritional point of view. Spring and tap water, having a slight difference in terms of element content, were used for plant growth. The most important accumulation of macrominerals, in leaves, is reached during the first stage of growth, which leads to a maximum nutritional contribution, corresponding to immature plants. From the third week, the maximum elemental accumulation was concentrated in roots. This study highlights the variation of the elemental content of Lactuca sativa among growing stages.

Calcium Requirement and Vitamin D Supplementation in Meat-Type Quail at First Stage of Growth

Currently, feed formulations for quail are based on foreign data or data from other species; this undermines productivity with the use of excessive or deficient levels of some nutrients. Therefore, this study aimed to determine the nutritional requirement levels of calcium (Ca) and supplementation vitamin D in meat-type quail from 1 to 14 d of age. The experiment was a 4 × 4 factorial arrangement of treatments (levels of Ca: 0.42, 0.58, 0.74 and 0.90% and levels of vitamin D: 1,000, 2,000, 3,000 and 4,000 IU) with 3 replicate pens and 43 quails per pen. Weight gain increased quadratically with increased levels of Ca and vitamin D; this variable yielded estimated levels of 0.73% Ca and 2,883 IU vitamin D. There was no Ca x vitamin D interaction effect on bone variables. Bone Ca, bone phosphorus, bone ash, femoral bone strength, tibial bone strength and the femoral Seedor index increased quadratically with an increase in Ca levels. These variables yielded estimated values of 0.78, 0.71, 0.78, 0.77, 0.83, and 0.71% Ca, respectively. It is concluded that the requirements of Ca and vitamin D for the maximum weight gain of meat-type quails, in the period from one to 14 days of age, were 0.73% Ca (p=0.001) and 2,883 IU vitamin D (p=0.02), respectively.

The Use of Electrostatic Field to Improve Soybean Seed Germination in Organic Production

Soybean production in the system of organic agriculture is not very demanding, and this has been well documented both through experimental results and commercial production. However, one of the biggest problems in organic production is the lack of adequate pre-sowing treatments. Therefore, the aim of this study was to examine the effect of the electrostatic field. This is a physical treatment that was first used for seed treatment in the 18th century but has mostly been neglected since then. Seeds of five soybean genotypes with differently colored seed coats (yellow, green, dark green, brown, and black) were included in this study. The seeds were exposed to different values of direct current (DC) with the following voltages: 0 V (control), 3 V, 6 V, and 9 V, to which the seeds were exposed for 0 min (control), 1 min, and 3 min. After exposing the seeds to the electric field, the physiological properties of seeds and seedlings at the first stage of growth were evaluated. The results show that the effect of the electrostatic field on seed quality depends on the genotype, voltage, and exposure time. The application of DC can be a suitable method for improving seed germination and the initial growth of soybean seedlings. In addition, the results indicate that it is necessary to adjust the DC treatment (voltage and duration of exposure of seeds) to particular genotypes since inadequate treatments may reduce the quality of seeds.

On the Disintegration of A1050/Ni201 Explosively Welded Clads Induced by Long-Term Annealing.

The paper presents the microstructure and phase composition of the interface zone formed in the explosive welding process between technically pure aluminum and nickel. Low and high detonation velocities of 2000 and 2800 m/s were applied to expose the differences of the welded zone directly after the joining as well as subsequent long-term annealing. The large amount of the melted areas was observed composed of a variety of Al-Ni type intermetallics; however, the morphology varied from nearly flat to wavy with increasing detonation velocity. The applied heat treatment at 500 °C has resulted in the formation of Al3Ni and Al3Ni2 layers, which in the first stages of growth preserved the initial interface morphology. Due to the large differences in Al and Ni diffusivities, the porosity formation occurred for both types of clads. Faster consumption of Al3Ni phase at the expense of the growing Al3Ni2 phase, characterized by strong crystallographic texture, has been observed only for the weld obtained at low detonation velocity. As a result of the extended annealing time, the disintegration of the bond occurred due to crack propagation located at the A1050/Al3Ni2 interface.

Plant neighbours shape fungal assemblages associated with plant roots: A new understanding of niche‐partitioning in plant communities

Abstract Understanding the assembly rules of mycorrhizal fungi is crucial, given their tremendous importance in plant nutrition and health. Differentiation in plant‐associated arbuscular mycorrhizal fungi (AMF) is likely driven by a host‐preference effect. Coexisting plant species may then affect a focal plant microbiota through fungal dispersal among plants, and plant preferential recruitment of AMF. Both mechanisms are likely shaped by the plant's phylogenetic and functional strategies. We expected that (a) the structure of AMF assemblages associated with a focal plant depends on the identity of the neighbouring plant species; (b) this effect would be predicted by the phylogenetic and functional similarity between the focal and neighbouring plant species. These predictions were tested during the first stages of growth, by simulating the early development of plants within a community Using an experimental matrix‐focal plant species design testing 15 neighbouring plants from five taxonomic families, we demonstrated that the neighbouring plants provided different species pools for the focal plant, Medicago truncatula, and influenced AMF communities associated with focal plant, especially in terms of richness but not relative evenness. Medicago truncatula grown with Brassicaceae or other Poaceae species displayed respectively no or low AMF richness compared to those grown with Rosaceae and Asteraceae species. These effects were weakly dependent on the phylogenetic distance from the neighbouring plant but were predicted by the functional proximity. AMF assemblages were enriched and bore more resemblance to the neighbouring plants when the neighbouring plants were functionally dissimilar from the focal one. Functional dissimilarity was only a significant predictor when based on traits characterizing the nutrient use and uptake strategy rather than on a more integrated growing strategy of the plant. Microbiota composition was shown to be dependent on the identity of the neighbouring plant, particularly on its functional below‐ground niche. At the colonization stage, when the plant arrives in a community, plant mycobiota might be influenced by the spatial distribution of plants already present in the community. This work suggests a new view of the concept of niche partitioning in space for plants based on microorganism–plant interactions. A free Plain Language Summary can be found within the Supporting Information of this article.

Analysis and Growth Modeling of CuInSe2 Films by Electrodeposition for Photocell Applications

CuInSe2 (CIS) thin films were deposited onto FTO/glass substrates by continuous current potentiostatic electrodeposition method. The aqueous deposition bath was prepared from a pH = 3.0 NaBF4 supporting electrolyte, containing CuSO4, In2(SO4)3, and SeO2 precursors. The characterization of these samples was done by scanning electron microscopy, energy-dispersive X-ray spectrometry, X-ray diffractometry, Raman spectroscopy, and optical spectroscopy. The experimental techniques have allowed the understanding of the atomic concentration dynamics of samples, and its relationship with the concentration of precursors. It was obtained p-type polycrystalline semiconductor samples, with 0.95 eV gap energy; the crystalline quality of these samples was also verified. Besides this, the nucleation and growth of CIS were studied during its electrochemical deposition on top of FTO, and vitreous carbon electrodes. Chronoamperometry I-t plots permitted the study of current transients, through classic nucleation models, which were used to understand the nucleation mechanism which occurred during the electrodeposition process, besides predicting some of its characteristic properties, as its diffusion coefficient, density of active sites, and nucleation rate constant per active site. Atomic force microscopy measurements were used to investigate the first stages of growth of these CIS films, deposited at different overpotentials. Preliminary devices CIS/In2Se3/FTO were mounted, with In2Se3 (IS) film also deposited by continuous current electrodeposition. Its electrical properties were analyzed, revealing a Schottky diode like behavior; there were observed light dependent open circuit voltage generation and resistance drop, disclosing promising characteristics for photovoltaic production.

EFFECT OF PHYTASE ENZYME AND CITRIC ACID ON PRODUCTIVE PERFORMANCE, NUTRIENT RETENTION AND TIBIA BONE OF BROILER CHICKS FED LOW AVAILABLE PHOSPHORUS DIET

The study investigate the effect of feeding low available phosphorus (AP) diet supplemented with three levels of microbial phytase (MP) and /or three levels of citric acid (CA) on broiler performance, tibia bone and nutrient retention. Four hundred day- old Ross broiler chicks were randomly allocated into ten treated groups, with four replicates of 10 birds each. The chicks were fed ten different diets as normal phosphorus 0.45% AP (positive control, PC) and nine groups with phosphorus deficient diets 0.25% AP (negative control, NC) supplemented with three CA levels as 0%, 1% or 2% and / or MP levels 0, 500 and 1000 FTU/Kg. The results indicated that supplementation of MP and /or CA into NC diet significantly improved body gain of chicks. Feed intake significantly increased due to adding 1% CA and MP levels into NC diet. Feed conversion ratio improved due to supplementing MP or CA into NC diet. There is no significant effect on tibia width and breaking strength by adding MP and/or CA into NC diet. Adding MP into NC diet significantly improved tibia length, weight, and ash content while, citric acid affected significantly at the first stage of growth only. Blood phosphorus increased significantly by supplementing MP into NC diet at the 5th week of age, while blood calcium was not affected significantly by MP and/or CA. Tibia calcium of chicks fed NC diet was higher than those fed PC diet or NC diet enriched with MP and/or CA. Tibia phosphorus did not response clearly for adding MP or CA into NC diet. Nitrogen and calcium retention of chicks fed NC were significantly lower than those fed PC or NC diet supplemented with 1000 FTU/kg MP and CA. Phosphorus retention of chicks fed NC diet was significantly similar for those fed PC or NC diets supplemented with MP and/or CA. It can be concluded that adding MP at 500 FTU/kg level with 1% CA into NC diet was effectiveness to improve body weight gain and tibia bone characteristics as like as those fed PC or NC diet enriched with 1000 FTU/kg MP.

The necessary of constructing preventive health intervention policy under the trend of deep aging in China

China has developed into an aging population since 2000, following the global pattern of population aging. China has been ideally placed because of its excellent aging characteristics, which involve an ample proportion of the older population, speedy growth, and rapid expansion of the most past and unequal aging distribution. The aging demographic rises against the increasing burden of disease, high disability rate, and a low level of social involvement. The issue has been resolved by introducing the Low Fertility Economic State Aging Model (LFESAM) to shape unequal aging distribution based on health care perspectives. In the conventional health care model, the sustainable provision of treatment has primarily been loaded, which results in an unequal distribution of aging. LFESAM has multiple advantages when compared with traditional health care systems as a result of rapid advances and helps to distribute the aging population in a distributed manner. In its first stage of growth, the Chinese Government is responsible for introducing the intelligent health care service and the necessity of constructing preventive health intervention policies under the trend of deep aging in china.

Effect of Ascochyta blight disease on antioxidant enzymes activities, amount of proline and carbohydrate in some chickpea genotypes

Germplasm evaluation of crop plants as a repository of useful genes to cope with biological and abiotic stresses has always been the focus of plant breeders. The fungus causing Ascochyta blight is one of the most important biological factors limiting chickpea cultivation and production in most parts of the world, including Iran.The present study was conducted to identify the genetic sources of resistance of 20 chickpea genotypes in seedling, flowering, and podding stages in greenhouse conditions. Damages caused by the disease was recorded using a 9-degree scale after observing complete death in the sensitive control genotypes. Analysis of variance of the studied traits of chickpea genotypes was conducted via factorial experiment in a completely randomized design at two levels for factor A (disease-free and disease-contaminated conditions) and 18 levels (genotypes) for factor B (genotypes 13 and 15 were lost due to high susceptibility to the disease in the first stage of growth, samples were taken from 18 genotypes).The results showed that the resistant and susceptible genotypes were more accurately distinguished from each other in the podding stage. At this stage, 9 genotypes with a degree of damage 1, 2, and 3 (less than five) showed high resistance to the causative agent of Ascochyta blight. Physiological and biochemical traits involved in disease resistance were measured. The results showed that all traits except chlorophyll a, chlorophyll b and polyphenol oxidase had significant differences at 1% probability level in terms of disease stress. Chlorophyll a, chlorophyll b contents and polyphenol oxidase activity were significantly different at 5% probability level. In interaction of disease×genotype, only catalase was significantly different among all studied traits. The amount of peroxidase and polyphenol oxidase were affected by the disease and their rates increased. A positive relationship was observed between the level of polyphenol oxidase enzyme and pathogen resistance. Generally speaking, crops’ reactions to harsh environmental conditions seems impossible to predict without the analysis of the relevant mechanisms.

Inoculation with arbuscular mycorrhizal fungi improves melon (Cucumis melo) fruit quality under field conditions and plant performance in both field and greenhouse

Previous works have suggested that arbuscular mycorrhizal (AM) fungi can enhance the quality of plant products and fruits. Therefore, the aim of the present study was to investigate the effects of AM fungi on Cucumis melo plant growth, yield, fitness and fruit quality. Inoculated and uninoculated plants of two melon cultivars (Baggio and Expò) were grown in field under common agronomic practices. In addition, a greenhouse test was run on cv. Expò in order to assess the effects of AM inoculation on shoot, leaf and flower development in semi-controlled conditions. In comparison to controls, AM plants flowered earlier, produced more flowers and their pulp contained more sugars and carotenoids. The symbiosis also improved seed size and weight, as well as their germination and root elongation in the first stages of growth in field. Concluding, AM inoculation significantly improved fruit quality in field, under commercial production conditions, also leading to the development of seeds with higher germination rate and increasing plant fitness.

Decoupled ontogeny of in vivo bite force and mandible morphology reveals effects of weaning and sexual maturation in mice

Abstract The link between performance, morphology and their sources of variation is a major target of evolutionary functional biology. In vertebrates, many studies have linked in vivo bite force to skull morphology, mostly at the interspecific level. Within species, however, the ontogeny of bite force, in relation to the development of the mandible, remains poorly known, despite its relevance for life history and for the co-evolution of form and function. Here, ontogenetic trajectories of bite force, correlated with mandible size and shape, are reported for the first time in a wild-derived colony of laboratory mice. Bite forces were measured in vivo and mandible morphology was assessed using geometric morphometrics. Most coordinated changes in morphology and in vivo bite force occur during the first stages of growth, prior to weaning. Mandible shape stabilizes after day 23. The increases in mandible size and body mass slow down around day 40, but still increase during adulthood. Despite slowing down after weaning, bite force increases through a second phase during sexual maturation (days 30–40). This may be linked to the progressive tempering of weaning stress, continued growth and synchronization of the muscular and osteological systems, together with hormonal changes, as we observed a concomitant appearance of sexual dimorphism.

Heavy metal accumulation and distribution in Phragmites australis seedlings tissues originating from natural and urban catchment.

The retention of heavy metal (HM) was studied in root and rhizomes (BLG), stems (ST), and leaves (LF) of Phragmites australis (common reed) seedlings collected from different locations, differing in the scale of anthropogenic interference. The analysis includes the reference samples of sediments in uncontaminated lake Garczonki and contaminated roadside ditch in Cieplewo. The concentrations of Zn, Cu, Pb, Cd, Ni, and Cr were analyzed in plant tissues and sediments using the atomic absorption spectrometry and inductively coupled plasma mass spectrometry. The general assessment of sediments collected in the Garczonki lake showed a good environmental status; while in the roadside ditch in Cieplewo, the sediments were considerably polluted with HM. In the first stage of plant growth, all of the analyzed HMs are mainly inhibited by BLG system. The decreasing trend of elements was as follows: BLG > ST > LF. The organs followed different decreasing trends of HM concentration; the trend Zn > Cu > Ni > Cr > Pb > Cd was found in ST and LF for the Garczonki lake seedlings and for BLG and LF for the roadside ditch in Cieplewo seedlings. Zn showed the highest concentration, while Cd the lowest concentration in each of the examined organs. The bioaccumulation factor indicated the higher mobility of HM in seedlings in the Garczonki lake than in the roadside ditch in Cieplewo. The morphological studies suggest the good state and health of seedling from both sites; however, the reduction of root hair surface was observed for the roadside ditch seedlings. The anatomical studies present changes in the size of the nucleus and count of chloroplasts in LF. No reaction on HM contamination sediments in the seedlings from the roadside ditch in Cieplewo in the aerenchyma was noted. Potentially, both types of seedlings can be used to decontaminate environments rich in HM. However, the level of HM absorbed by seedlings (in the first stage of growth) should be considered due to the behavior in the target phytoremediation site.

Size variability in embryonic axes, cotyledons, acorns and seedlings in fifteen species of the genus Quercus

Embryonic axes of acorns have greater variability of mass than cotyledons or pericarp. Above/below ground seedling mass depends on oak species. Species of the genus oak are of great importance for forest ecosystems in almost all of the Holarctic. Knowledge of the diversity of the size of acorns and their parts would allow better use of the opportunity of genetic resources storage, both for the protection of endangered oak species and for forestry practices. The initial development of seedlings in reference to the size of the acorn, its parts and acorn maturation time was also investigated. The fresh and dry mass of individual acorns, embryonic axes and cotyledons of 15 species (Quercus agrifolia, Q. gambelli, Q. kelloggii, Q. alba, Q. bicolor, Q. coccinea, Q. falcata, Q. lyrata, Q. nigra, Q. prinus, Q. rubra, Q. cerris, Q. ilex, Q. petraea, and Q. robur) were determined. In the second part of the study, the mass of the ca. 3-month-old seedlings that had completed the first stage of growth, with a division on the leaves, the shoot and the root, was measured. The greatest variation in mass both between and within the species was demonstrated for the embryonic axis. The mass of seedlings depends on the size of the acorn and the cotyledons contained therein; whereas, the mass of the embryonic axis has no significant influence on the mass of seedlings.

Deposition of diamond films on single crystalline silicon carbide substrates

Silicon carbide (SiC) is a wide band gap material that is slowly but steadily asserting itself as a reliable alternative to silicon (Si) for high temperature electronics applications, in particular for the electrical vehicles industry. The passivation of SiC devices with diamond films is expected to decrease leakage currents and avoid premature breakdown of the devices, leading to more efficient devices. However, for an efficient passivation the interface between both materials needs to be virtually void free and high quality diamond films are required from the first stages of growth. In order to evaluate the impact of the deposition and seeding parameters in the properties of the deposits, diamond films were deposited on SiC substrates by hot filament chemical vapor deposition (HFCVD). Before the seeding step the substrates were exposed to diamond growth conditions (pre-treatment PT) and seeding was performed with a solution of detonation nanodiamond (DND) particles and with 6–12 and 40–60 μm grit. Diamond films were then grown at different temperatures and with different methane concentrations and the deposits were observed in a scanning electron microscope (SEM); their quality was assessed with Raman spectroscopy.