Moderate Temperature Regime Research Articles

Comprehensive analysis and implications of Veronica persica germination and growth traits in their invasion ecology

Invasive alien species implications in ecological threats are attributed to their unique characteristics that are linked to their invasion. Veronica persica (Plantaginaceae family) is an alien weed species in Egypt. Regardless of its widespread globally in various regions, the growth traits and behavior of V. persica remain poorly understood. The comprehensive analysis, reveals the optimal germination (Gmax) was detected at 10/20 °C, 15/20 °C, and 20/25 °C at the moderate temperature regimes. The rapid germination rate (G rate) peaked at 10/20 °C regime, with a rate of 0.376 per day. Furthermore, under stress conditions, V. persica has 50% germination inhibition (G50) and 50% of growth inhibition occurred at − 0.91 MPa and 0.75 MPa of osmotic pressure and 3225.81 ppm and 2677.1 ppm of salt stress (NaCl) respectively. The germination ranged from 6 to 9 pH, with the highest germination percentage occurring at a pH of 7 & 8, reaching 88.75% compared to the control group. There is a strong interaction effect between habitats and plant stages, the plant stages and habitats have significant effects (p ≤ 0.00) on V. persica growth. There was high and moderate plasticity in the response of morphological and growth features between stages. During the seedling-juvenile interval and the juvenile-flowering stages, respectively, there was a noticeable increase in both Relative Growth Rate and Net Assimilation Rate. Demographic surveys identified approximately 24 species across 11 families associated with V. persica in invaded areas. The Sorenson indices of qualitative index exhibited high similarity values in the invaded sites by (82.35%) compared to (72.72%) in non-invaded sites. However, interactions with native communities were reflected in lower richness, diversity, and evenness, displaying slightly higher Simpson index 1 (λ) values compared to invaded and non-invaded sites (0.043 and 0.0290) vs. (0.0207 and 0.268), in rangelands and F. carica orchards respectively. These results emphasize the substantially higher adaptability of V. persica to variable environmental conditions and abilities to invade a new community. This knowledge about invasive V. persica weeds germination and growth is itemized as the consistent predictive base for future invasion and informs strategic management priorities.

Spin-related negative magnetoresistance in germanium films

Herein, we report the transport properties of Ge films. The variable-range hopping transport at low temperatures (T≲50K) and thermal activation transport at high temperatures (T≳50K) are observed in our Ge films. In the different temperature regimes, the anomalous magnetotransport properties are observed. In the low-temperature regime (T≲15K), the negative magnetoresistance (MR) at low field and positive MR at high field can be seen. In the moderate-temperature regime (15K≲T≲100K), the positive MR curve gradually evolves from a linear curve to a parabolic curve with increasing temperature, and the MR magnitude appears to be insensitive to temperature. In the high-temperature regime (T≳100K), the positive MR value increases with increasing temperature. By considering the angular-dependent MR, we can determine that the negative MR comes from the spin-related mechanism, and the positive MR is caused by the orbital-related mechanism. However, further study is required to determine the exact mechanisms behind the anomalous magnetotransport properties.

ВЛИЯНИЕ ЭЛЕМЕНТОВ ТЕХНОЛОГИИ НА УРОЖАЙНОСТЬ И КАЧЕСТВО ЗЕРНА ЯРОВОЙ ПШЕНИЦЫ НА ЧЕРНОЗЕМНЫХ ПОЧВАХ ПРЕДВОЛЖЬЯ РЕСПУБЛИКИ ТАТАРСТАН

The article presents the results of two-year experiments (2020-2021) conducted in the conditions of Volga region of the Republic of Tatarstan. The effect of mineral fertilizers on the content of the mass fraction of gluten and protein in wheat grain was studied. The productivity and grain quality of several wheat varieties included in the State Register for the 7th region were compared when using fertilizers at a dose of N10-14P24-26K16-37 and chemical plant protection products. It was found that from the application of fertilizers and the use of the plant protection unit, an increase in grain yield for the studied varieties was obtained from 0.32-0.92 t/ha compared with the control. The field experiment was conducted in LLC Avangard of Buinsky district of the Republic of Tatarstan. The soil is leached chernozem and has the following agrochemical characteristics: humus content – 7.0-8.5%, mobile forms of phosphorus – 182-255 mg/kg, potassium – 159-193 mg/ kg and salt pH – 5.5-5.8.
 Agrochemical analyses of soils were performed in Federal State Budgetary Institution “Tatarskiy” by generally accepted methods: GOST 26213-91 (humus content), GOST 26484-85 (pHsol.), GOST 26207-91 (mobile forms of phosphorus and potassium).
 Meteorological conditions in 2020 were characterized by sufficient soil moisture and a moderate temperature regime during the growing season of spring wheat (GTK-1.28) and had a positive impact on the value of the future harvest.
 Meteorological indicators for the growing season of the research object in 2021 were extremely unfavorable for the formation of the crop. May and June were acutely arid, GTC-0.27. The precipitation in July (57% of the norm) did not have a significant impact on the formation of the spring wheat crop. From the application of fertilizers and the use of plant protection products, an increase in grain yield for the studied varieties from 0.32 to 0.92 t/ha was obtained compared to the variant without fertilizers and plant protection products. Improving the nutritional conditions of plants by applying mineral fertilizers led to an increase in the protein content of spring wheat grains and the protein content was 0.6 ... 0.8 higher, depending on the varietal characteristics of spring wheat, than on an unfertilized background. Under the conditions of chernozem soils of the Pre-Volga zone of the Republic of Tatarstan, the best results over the years of research were obtained in variants where the application of mineral fertilizers was combined with the use of plant protection products of such spring wheat varieties as Yoldyz, Burlak and Ekada 109. In the same variants, the highest protein content was noted in grain. The use of chemical protection against the background of mineral fertilizers in the varieties Yoldyz, Burlak, Ekada109 contributed to a significant increase in the gross collection of protein per unit area.

RF Sputtered ZnO Nanoballs on Porous Substrate for Highly Sensitive NO2 Gas Sensing Applications

In this work, zinc oxide (ZnO) nanoballs were directly deposited on porous silicon (PS) substrates using RF magnetron sputtering method. The PS substrates were synthesised at room temperature via metal assisted chemical etching technique. The structural, surface morphological and cross-sectional properties of as prepared ZnO nanoballs were investigated by x-ray diffraction, Raman spectroscopy and field emission scanning electron microscopy techniques, respectively. The interaction of nitrogen dioxide (NO2 ) gas molecules with sensing layer and all sensing properties under lower detection limit (2 ppm–100 ppm) were studied in detail. The proposed ZnO nanoballs sensor chip exhibits high sensing response (29.2%) with fast response/recovery times (70 sec/96 sec) to 20 ppm NO2 in dry air at 250°C. Thus, the findings recommend the viability of ZnO nanoballs sensor as highly sensitive and selective NO2 gas sensor at moderate operating temperature regime.

Experimental study on sustainable stabilization of marine soil with ultrafine slag and activator for controlling its cracking characteristics

Desiccation cracking results in deterioration of soil properties, accelerates infiltration of water in soil, increases settlement and reduces the strength of soil. Soil stabilization has been utilized for mitigation of cracking in soils. However, the effect of soil stabilization on cracking behaviour of marine soils, has not received much attention. In this regard, the present study evaluates the cracking and shrinkage behaviour of marine soil. Efforts have also been made to understand the effect of ultrafine slag as sustainable admixture with/without activators (lime/cement) on crack mitigation and shrinkage reduction for marine soil. It has been observed that at lower proportion of ultrafine slag (upto 10%), the effect of stabilization is negligible, probably due to inadequate nucleation sites for cementation. However, at higher proportion of ultrafine slag (20–40%), the reduction in crack and shrinkage intensity factor (CSIF) and shrinkage intensity factor (SIF) for restrained and unrestrained specimen has been noted as 12–38% and 17–49%, respectively. From the study, it has been further observed that stabilization of marine soil with ultrafine slag and activator is more effective in reducing the crack/shrinkage intensity, as compared to only ultrafine slag; wherein soil M1 with 19.5% ultrafine slag and 0.5%C has been noted to be the optimum combination in the study, exhibiting crack mitigation during drying for moderate (27 °C) and high temperature (45 °C) regimes. The study also presents the mechanism for understanding the cracking and shrinkage behaviour of unstabilized and stabilized marine soils. The study findings would be quite useful for stabilization of marine soils for shore protection applications, and for stabilization of dredged material for their reutilization in infrastructure applications.

Data-driven analysis of process, structure, and properties of additively manufactured Inconel 718 thin walls

In additive manufacturing of metal parts, the ability to accurately predict the extremely variable temperature field in detail, and relate it quantitatively to structure and properties, is a key step in predicting part performance and optimizing process design. In this work, a finite element simulation of the directed energy deposition (DED) process is used to predict the space- and time-dependent temperature field during the multi-layer build process for Inconel 718 walls. The thermal model results show good agreement with dynamic infrared images captured in situ during the DED builds. The relationship between predicted cooling rate, microstructural features, and mechanical properties is examined, and cooling rate alone is found to be insufficient in giving quantitative property predictions. Because machine learning offers an efficient way to identify important features from series data, we apply a 1D convolutional neural network data-driven framework to automatically extract the dominant predictive features from simulated temperature history. Very good predictions of material properties, especially ultimate tensile strength, are obtained using simulated thermal history data. To further interpret the convolutional neural network predictions, we visualize the extracted features produced on each convolutional layer and compare the convolutional neural network detected features of thermal histories for high and low ultimate tensile strength cases. A key result is the determination that thermal histories in both high and moderate temperature regimes affect material properties.

Inter-provenance variation in seed germination response of a cash crop halophyte Suaeda fruticosa to different abiotic factors

Information about provenance-based differences in seed attributes of potential cash crop halophytes is limited but important to define sources for the highest quality seeds. This study examined inter- provenance variations in seed morphology, germination, and tolerance responses of Suaeda fruticosa to common abiotic factors. Seed size varied significantly among provenances, and the largest sized seeds were developed in the highly moist moderately-saline coastal area of Manora. Seed germination responses also varied among provenances and seeds from highly moist provenance of Manora showed the highest germination in 400 mM NaCl in light under low to moderate temperature regimes. The light requirement for germination was lowest in the seeds from highly saline provenance of Gaddani. The highest germination recovery of un-germinated seeds from the high salinity (600 mM NaCl) was for seeds from dry provenance of Bahawalpur irrespective of temperature regime. Recovery for seeds from the (moderately) moist (highly) saline provenances of Gaddani and Hawke's Bay was highly temperature-dependent. However, recovery of dark-incubated un-germinated seeds after transfer to light was salinity-dependent, but not dependent on provenance. Thus, these data indicate that provenance can affect the size, germinability, and stress tolerance of S. fruticosa seeds. Generally, seeds from less stressful provenance of Manora had better quality, i.e., larger size, higher germination, and qualify for mass-scale cultivation / restoration programs under most environmental conditions.

Interactive Effects of Moderate Hypoxia and Temperature Regimes on Blue Crab (Callinectes Sapidus) Physiological Responses

Interactive Effects of Moderate Hypoxia and Temperature Regimes on Blue Crab (Callinectes Sapidus) Physiological Responses

Environmental legacy effects and acclimatization of a crustose coralline alga to ocean acidification

Prior exposure to variable environmental conditions is predicted to influence the resilience of marine organisms to global change. We conducted complementary 4-month field and laboratory experiments to understand how a dynamic, and sometimes extreme, environment influences growth rates of a tropical reef-building crustose coralline alga and its responses to ocean acidification (OA). Using a reciprocal transplant design, we quantified calcification rates of the Caribbean coralline Lithophyllum sp. at sites with a history of either extreme or moderate oxygen, temperature, and pH regimes. Calcification rates of in situ corallines at the extreme site were 90% lower than those at the moderate site, regardless of origin. Negative effects of corallines originating from the extreme site persisted even after transplanting to more optimal conditions for 20 weeks. In the laboratory, we tested the separate and combined effects of stress and variability by exposing corallines from the same sites to either ambient (Amb: pH 8.04) or acidified (OA: pH 7.70) stable conditions or variable (Var: pH 7.80-8.10) or acidified variable (OA-Var: pH 7.45–7.75) conditions. There was a negative effect of all pH treatments on Lithophyllum sp. calcification rates relative to the control, with lower calcification rates in corallines from the extreme site than from the moderate site in each treatment, indicative of a legacy effect of site origin on subsequent response to laboratory treatment. Our study provides ecologically relevant context to understanding the nuanced effects of OA on crustose coralline algae, and illustrates how local environmental regimes may influence the effects of global change.

Isotopic separation of helium through graphyne membranes: a ring polymer molecular dynamics study.

Microscopic-level understanding of the separation mechanism for two-dimensional (2D) membranes is an active area of research due to potential implications of this class of membranes for various technological processes. Helium (He) purification from the natural resources is of particular interest due to the shortfall in its production. In this work, we applied the ring polymer molecular dynamics (RPMD) method to graphdiyne (Gr2) and graphtriyne (Gr3) 2D membranes having variable pore sizes for the separation of He isotopes, and compare for the first time with rigorous quantum calculations. We found that the transmission rate through Gr3 is many orders of magnitude greater than Gr2. The selectivity of either isotope at low temperatures is a consequence of a delicate balance between the zero-point energy effect and tunneling of 4He and 3He. In particular, a remarkable tunneling effect is reported on the Gr2 membrane at 10 K, leading to a much larger permeation of the lighter species as compared to the heavier isotope. RPMD provides an efficient approach for studying the separation of He isotopes, taking into account quantum effects of light nuclei motions at low temperatures, which classical methods fail to capture.

Conditions and terms of storage of confectionery products

The article discusses the conditions and terms of storage of confectionery products. The purpose of this article is to compare the temperature and humidity storage conditions of different types of confectionery products regulated in various legal documents, as well as to identify criteria for the end of the shelf life of certain classification subgroups. It is established that the majority of sugar and flour-based confectionery products, except for cakes and pastries, as well as roll cakes, belong to the group with a moderate temperature and humidity regime (temperature-18±3°C with relative humidity — no more than 75%). Only cakes and pastries with creams and fruit trimmings belong to the group of refrigerated goods. The result of this work is also determining the criteria for limiting shelf life or storage for different subgroups, types and varieties of confectionery products.

ФОРМИРОВАНИЕ СТРУКТУРЫ ПОСЕВА И ПРОДУКТИВНОСТИ РАСТЕНИЙ СОИ СЕВЕРНОГО ЭКОТИПА ПРИ РАЗНЫХ СПОСОБАХ ПОСЕВА В УСЛОВИЯХ ЛЕСОСТЕПИ СРЕДНЕГО ПОВОЛЖЬЯ

The studies were carried out in order to study the effect of the row spacing on the formation of the structure and productivity of plants of the early maturing soybean of Milyausha variety. In a field experiment on gray forest soils with a weakly acidic reaction and a humus content of 3.21 ... 3.83%, two sowing methods were compared: continuous sowing with a distance between rows of 15 cm and a series of rows - 30 cm. In the conditions of Kama region of the Republic of Tatarstan in dry years (2016, 2018), the duration of the growing season of the variety did not depend on the sowing methods and was 89 ... 91 days. With a moderate temperature regime and abundant precipitation (2017), with row sowing with a row spacing of 15 cm, it increased up to 105 days, in the variant with a row spacing of 30 cm - up to 109 days. An increase in the duration of the period from sowing to emergence of seedlings with a lack of heat led to a decrease in field germination according to the variants of the experiment to 70.0 ... 72.5%, plant survival - to 57.5 ... 66.0%. The maximum field germination in the experiment (95.0 and 85.0%), safety (98.2 and 94.1%) and plant survival (93.3 and 80.0%) were noted in 2018 with a high sum of air temperatures above 10 ° C and moderate moisture (total precipitation 102 mm) during the growing season. In the variant with a row spacing of 30 cm, the mass of seeds per plant in arid conditions was higher than with continuous sowing, by 2.2 ... 2.7, and in conditions of excessive moisture - by 1.7 times. An increase in the mass of seeds provided an increase in branching, the number of beans and seeds per plant. In terms of productivity and yield per unit area, there were no significant differences between the options for sowing methods. The maximum realization of the potential of productivity (289.1 and 314.7 g / m2) and yield (2.78 and 2.81 t / ha) in the experiment was achieved with the duration of the growing season 105 and 109 days (2017)

Influence of seed color on germination performance and storage organ color in the high-Andean crop Lepidium meyenii (Maca)

ABSTRACT Maca (Lepidium meyenii) is a high-Andean crop whose subterranean storage organs (hypocotyls) show distinctive colors that are related to pharmacological properties. Little is known about seed color variation and its influence on germination performance, hypocotyl pigmentation and plant survival. Germination rate is critical for maca plants to survive frost events during early development. We evaluated the effect of germination promoters (gibberellic acid and sodium hypochlorite) and temperature regimes (constant and cold: 4°C; variable and moderate: 5–10°C; constant and warm: 16°C) on germination of seeds with different embryo color (yellow, reddish-purple and blue). We also assessed the association between seed color, hypocotyl color and plant survival under field conditions. Seeds with blue and yellow embryos had the lowest and highest germination rates, respectively, across cold and moderate temperature regimes. At warm temperature, germination was not affected by seed color. Germination promoters only enhanced seed germination at cold and moderate temperatures. In the field, black seeds (with blue embryos) showed the greatest survival. Seeds with reddish-purple embryos produced a higher proportion of pigmented hypocotyls – mainly purple – than other seed colors. Seed color should be taken into account in maca breeding programs, particularly in the context of climate change.

Effects of chloride and sulfate salts on seed germination of halophytes from dry alpine climate

A soil’s ionic profile along with other climatic factors influences seed germination in natural habitats. This study evaluates the role of different chloride and sulfate salts during germination of three halophytes (Halogeton glomeratus, Lepidium latifolium, and Peganum harmala) distributed in temperate salt playa habitats of Pakistan. Seeds were germinated in six salts concentrations (0 to 500 mM) under five temperature regimes (5/15 to 25/35 °C) and two photoperiods (12 h photoperiod and 24 h-dark). Germination percentage and germination velocity decreased with an increase in salt concentration and corresponding osmotic potentials. Germination of H. glomeratus and L. latifolium in iso-osmotic solutions of various salts was faster in K+ salts compared to Na+ and Mg2+ while in P. harmala germination was higher in Mg2+ and Na+ salts. H. glomeratus and L. latifolium were more tolerant to SO42− than Cl− salts, however, P. harmala was unaffected by anion. Optimal temperature was 20/30 °C for germination of all species irrespective of salt type. Sulfate seems to be less inhibitory only during germination of H. glomeratus in complete dark. The climatic condition of dry alpine habitat allows selected species to germinate at moderate temperature regimes (April–May) in the presence of light. High ionic concentration in soil may inhibit germination of all species but P. harmala appears to be more adapted in comparison to others. High sulfate soil content may favor seedling recruitment of H. glomeratus (annual plant) under mountain cracks.

Dense Y-doped ion conducting perovskite films of BaZrO3, BaSnO3, and BaCeO3 for SOFC applications produced by powder aerosol deposition at room temperature

State-of-the-art solid oxide fuel cells (SOFC) are based on oxide ion conducting zirconia electrolytes, typically doped by yttria or scandia. Major drawback of these systems are their high operation temperatures of 800 °C and above. These are necessary for a sufficient ionic conductivity. Instead of oxide ions, also protonic charge carriers could be used in SOFC. The material classes of barium zirconates (BaZrO3), barium stannates (BaSnO3), and barium cerates (BaCeO3) are described as good proton conductors, especially when the B-site of the ABO3 perovskite structure is aliovalently doped by yttria. Their protonic conductivity values in the moderate temperature regime up to 600 °C are comparable to YSZ at 800 °C, making these compounds ideal candidates for a usage in future SOFC. Unfortunately, very high sintering temperatures up to 1800 °C are required to process dense and therefore gas-tight solid electrolyte membranes. However, a novel spray coating method called powder aerosol deposition (PAD, also known as AD) enables to form fully dense ceramic films directly at room temperature without any necessary sintering processes. Films are deposited from ceramic powders that are accelerated by a dry carrier gas flow under vacuum conditions.In this work, we investigated the film formation of three different barium based perovskite ceramics, namely yttria doped barium zirconate, barium stannate, and barium cerate by powder aerosol deposition. The optical and mechanical quality of films was evaluated using scanning electron microscopy and microhardness indentation and their crystallographic properties were characterized by X-ray diffraction. The electrical behavior was analyzed by electrochemical impedance spectroscopy and DC polarization methods up to temperatures of 1000 °C and 800 °C, respectively. Furthermore, a preliminary study about the film formation on porous electrodes was conducted.

Influence of temperature regime and epizootic shell disease on ecdysterone concentrations in American lobster from the Gulf of Maine

The American lobster, Homarus americanus H. Milne-Edwards, 1837, supports the most economically important shellfish fishery worldwide, with the state of Maine contributing the majority of US landings. Incidence of epizootic shell disease (ESD) is increasing along the Maine coast, highlighting the need to increase our understanding of factors affecting its etiology. Molting lessens the severity or eliminates the disease, and lobsters in the wild with shell disease have been shown to have increased concentrations of hemolymph ecdysteroids, key steroid hormone regulators of molting. Here, we examine the effects of cold, moderate, and warm temperature regimes mimicking annual temperature cycles from regions along the New England coast on hemolymph ecdysterone (20E) concentrations. At baseline sampling from lobsters collected in the field, it was determined that 20E was significantly elevated in lobsters with severe shell disease, but not in those with low to moderate levels of the disease. Hemolymph 20E concentrations correlated with relative molt stage, and were significantly higher in summer than winter for all temperature regime treatments. Lobsters with shell disease were more likely to molt, and more likely to die, than lobsters with no signs of the disease, regardless of temperature treatment. In the winter sampling period, 20E was highest in lobsters from the warm temperature regime, but not in summer. Therefore, these data suggest that temperature regime does impact hemolymph 20E concentrations in both diseased and non–shell diseased lobsters, and is consistent with the hypothesis that elevated 20E may be a mechanism to mitigate the effects of shell disease.

Aqueous Solution Processing of Combustible Precursor Compounds into Amorphous Indium Gallium Zinc Oxide (IGZO) Semiconductors for Thin Film Transistor Applications.

Combustion synthesis of semiconducting amorphous indium gallium zinc oxide IGZO (In:Ga:Zn, 7:1:1.5) thin films was carried out using urea nitrate precursor compounds of indium(III), gallium(III) and zinc(II). This approach provides further understanding towards the oxide formation process under a moderate temperature regime by employment of well-defined coordination compounds. All precursor compounds were fully characterized by spectroscopic techniques as well as by single crystal structure analysis. Their intrinsic thermal decomposition was studied by a combination of differential scanning calorimetry (DSC) and thermogravimetry coupled with mass spectrometry and infrared spectroscopy (TG-MS/IR). For all precursors a multistep decomposition involving a complex redox-reaction pathway under in situ formation of nitrogen containing molecular species was observed. Controlled thermal conversion of a mixture of the indium, gallium and zinc urea nitrate complexes into ternary amorphous IGZO films could thus be achieved. Thin film transistors (TFTs) were fabricated from a defined compositional mixture of the molecular precursors. The TFT devices exhibited decent charge carrier mobilities of 0.4 and 3.1 cm2 /(Vs) after annealing of the deposited films at temperatures as low as 250 and 350 °C, respectively. This approach represents a significant step further towards a low temperature solution processing of semiconducting thin films.

Improvement of the Thermoelectric Properties of the Perovskite SrTiO3 by Cr-Doping

In recent years, among different thermoelectric materials, SrTiO3 have been receiving great attention due to their greater capacity and conversion between electrical energy and heat energy. The thermoelectric properties of the SrTiO3 can be improved by substitutional doping on different sites (A-site and B-site) in the lattice. In this study, the improvement of the thermoelectric performance of the perovskite SrTiO3 by Cr-doping has been investigated. The doped SrTiO3 with Cr was synthesized by the conventional solid-state reaction method. The electronic transport properties including Seebeck coefficient, electrical conductivity, and thermal transport properties in a moderate temperature regime from 300 to 900 K have been investigated. The large absolute value of the Seebeck coefficient with low thermal conductivity was achieved by Cr-doping. The electrical conductivity was quite low but increased with increasing doping level up to x = 0.002 mol, and; hence, the power factor increased with increasing doping level up to x = 0.002 mol. The maximum ZT value was observed for SrTi0.998Cr0.002O3 at 773 K by the combination of a high value of the Seebeck coefficient and low thermal conductivity.

Seed germination ecology of a medicinal halophyte Zygophyllum propinquum: responses to abiotic factors

Information about the seed biology of the medicinally important halophyte Zygophyllum propinquum is limited. We therefore studied seed germination and recovery responses to different abiotic factors. Seed germination and recovery responses to different thermoperiods (10/20, 15/25, 20/30 and 25/35°C), photoperiods (12h light/12h dark and 24h dark), salts (chloride and sulphate salts of Na, K, Ca and Mg), and mannitol were studied. Seeds were non-dormant and germinated maximally (≈95%) in distilled water. Relatively high seed germination was observed under moderate (15/25 and 20/30°C) temperature regimes and in 12h photoperiod. Seed germination decreased with increases in salinity and only few seeds (<30%) germinated at 200mM NaCl. However, most un-germinated seeds from high salinity showed recovery of germination when transferred to water. Among chloride (Cl−) salts inhibitory effects at −1.2MPa under light were in following order of magnitude: KCl>CaCl2> NaCl=MgCl2, while for sulphate (SO4−−) salts inhibitory effects were in following order: K2SO4>MgSO4>Na2SO4. Germination inhibition under various osmotic treatments of mannitol was generally lesser than the iso-osmotic NaCl treatments. These results indicate that seeds Z. propinquum were moderately salt tolerant and preferred to germinate under moderate temperatures and in the presence of light. Recovery data following different salt treatments hints at greater role of osmotic constraint than the specific ion effects.

Platinum surface complexes as precursors for H2–O2 recombination catalysts

In this work, the adsorption of platinum (II, IV) chloride complexes from acidic solutions on silica gel modified with quaternary ammonium salts (QAS) was studied. The uptake of the platinum chloride complexes is caused by the formation of ionic (QAS+)2[PtCl x]2− ( x = 4, 6) associates on the surface of silica gel. The isotherms of adsorption are fitted by the Langmuir model. The maximum capacity for [PtCl4]2− and [PtCl6]2− is 0.99 and 1.13 mmol/g, correspondingly. The respective adsorption constants KL = 6.8 and 10 × 105 l/mol prove the high affinity of the adsorbates to the QAS-modified surface. Platinum metal nanoparticles supported on the surface of the silica gel were prepared by reducing the adsorbed platinum (II, IV) complexes. Such nanoparticles functioning at the moderate temperature regime have demonstrated a reasonable catalytic activity for the hydrogen and oxygen recombination, and an excellent stability over 35 cycles of the reaction.