Computer simulation of block polymerization of 1,6-Hexanediol Diacrylate

In this paper, a computer model of the block three-dimensional free-radical polymerization of 1,6-Hexanediol Diacrylate (HDDA) is proposed. The model of the reaction system is based on an ideal mixing reactor. The reaction process is modeled by the Monte Carlo method. Accounting for the diffusion inhibition of the reaction is described using the free volume model. An adequate description of the experimental data of the calculated conversion rate curve is obtained. The nature of the change in the rate constant of the growth reaction with increasing conversion is shown.

Methionine controlled impediment of secondary nucleation leading to nonclassical growth within self-assembled de novo gold nanoparticles

The conventional key steps for seed mediated growth of noble metal nanostructures involve classical and nonclassical nucleation. Furthermore, the surface of the seed catalytically enhances the secondary nucleation involving Au+ to Au0reduction, thus providing in-plane growth of seed. In contrast to this well-established growth mechanism, herein we report the unique case of methionine (Met) controlled seed mediated growth reaction, which rather proceeds via impeding secondary nucleation in presence of citrate stabilized gold nanoparticle (AuNP). The interaction between the freshly generated Au+ and thioether group of Met in the medium restricts the secondary nucleation process of further seed catalyzed Au+ reduction to Au0. This incomplete conversion of Au+, as confirmed by X-ray photoelectron spectroscopy (XPS), results in a significant enhancement of the zeta (z) potential even at low Met concentration. Nucleation of in situgenerated small-sized particles (nAuNPs) takes place on the parent seed surface followed by their segregation from the seed. Self-assembly process of these nAuNPs arises from the aurophilic interaction among the Au+. Furthermore, the time dependent growth of smaller particles to larger sized particles through assembly and merging within the same self-assembly validates the non-classical growth. This strategy has been successfully extended towards the seed mediated growth reaction of AuNP in presence of three bio-inspired decameric peptides having varying number of Met residues. The study confirms the nucleation strategy even in presence of single Met residue in the peptide and also the self-assembly of nucleated particles with increasing Met residues within the peptide.

Changes of Tree and Stand Growth: Review and Implications

In this chapter, we review the current long-term growth trends and short-term growth reaction to single or repeated stress events on tree and stand level in Europe. Based on growth trend analyses, the chapter reveals the strong human footprint on forest ecosystems.First, we use long-term experiments and increment cores to show change in growth trends within the last centuries. Growth reactions are caused by deposition and climate change rather than by silvicultural measures. Second, we look closer on regional-specific deviations from the general trend. Climate change, drought events, acid rain and O3 are causing regional-specific growth reaction patterns. Third, we assess stress events and the resilience and resistance of monospecific and mixed stands against biotic and abiotic stress in view of the ongoing growth trends.The revealed tree and stand growth behaviours are highly relevant, as any changes of forest growth and structure have strong impacts on the provision of goods and ecosystem services. The results underline the importance of biomonitoring and suggest counteracting measures by forest planning, adaptation of silvicultural guidelines for existing forest and innovative design of future forests stands.

Methionine-stabilized nonclassical growth within self-assembled de novo gold nanoparticles in conjunction with secondary nucleation inhibition

The key steps for seed mediated growth of noble metal nanoparticles involve primary and secondary nucleation, which depends upon the energy barrier and ligand supersaturation standards of the medium. Herein we report the unique case of methionine (Met) controlled growth reaction, which rather proceeds via impeding secondary nucleation in presence of citrate stabilized gold nanoparticle (AuNP). The interaction between freshly generated Au+ and thioether group of Met in the medium restricts the secondary nucleation process involving further Au+ reduction. This incomplete conversion of Au+ results in a significant enhancement of the zeta (ζ) potential even at low concentration of Met. Furthermore, the aurophilic interaction of Au+ controls the self-assembly process of the in situ generated emissive nucleated particles. Nucleation of primary particles on seed surface, their segregation and time dependent conversion to larger particles within self-assembly confirm the nonclassical growth, which has further been explored with Met containing bio-inspired peptides.

Delay of growth release after a windthrow event and climate response in a light-demanding species (European larch Larix decidua Mill.)

Key message Larch trees respond to stand opening with an approximately 4-year delay of growth, and low precipitation in July limits radial growth after a windthrow event. Abstract Precise cross-dating of disturbance events is crucial to understanding the functioning of forest stands, and may help explain ongoing ecological processes in a forest. Tree rings are very often used to reconstruct the history of disturbances and to study the response of trees to climatic factors. This study analyzed how quickly European larch can benefit from an abrupt change after catastrophic windthrow events and the extent of trees’ sensitivity to climate. The study is based on cores from 83 larch trees collected in a post-disturbance 100 ha plot established after a catastrophic windstorm in 2004 in the Slovakian High Tatras. Growth release was calculated from the percentage of growth change (PGC) measured in tree rings. The time lag between the disturbance event and release was related to tree diameter at breast height, tree age, and tree’s previous growth. The time lag between the year of the event and the year of growth reaction was 4.6 years on average (median 4 years) in a multi-aged group of trees. The climate analyses employed residual chronology. The new environmental conditions in the post-disturbance area have altered the trees’ growth reaction to climate; in particular, they show sensitivity to water deficit in July.

The influence of selective light on the growth reaction and antioxidant system of seedlings Pisum sativum L.

Aim. Study of the effect of red (660 nm), green (530 nm) and blue (450 nm) light on the growth processes and the state of the antioxidant system in the axial organs of seedlings of pea plants. Methods. Etiolated seedlings of pea Maecenat variety were irradiated with selective light with different spectrum of RL (660 nm), GL (530 nm), BL (450 nm) to activate photoreceptor systems of plants. In 10-day-old seedlings, growth response was determined – linear growth and biomass accumulation, as well as indicators of antioxidant system – hydrogen peroxide content and activity of oxidases – catalase and nonspecific peroxidase in axial organs of seedlings: in the aboveground part and roots. Results. Irradiation of the RL and the GL stimulates the accumulation of seedling biomass in the aboveground part and roots. BL inhibits the growth response of seedlings. The maximum stimulating effect is shown by the GL. The state of the antioxidant system in etiolated seedlings is characterized by organ specificity. Under the action of selective light, the content of the main form of ROS – hydrogen peroxide and shoots and in the roots, significantly stimulates the activity of catalase and peroxidase enzymes in the aboveground part of the seedling and is inhibited in the roots. The maximum effect in the aboveground part is shown by the GL, in the roots of the RL and the BL. Conclusions. The established effects of selective light irradiation are manifested differently in the aboveground and underground parts of seedlings. Possible mechanisms of connection of a condition of antioxidant system with separate aspects of signaling in photomorphogenesis of plants are discussed. Keywords: Pisum sativum L., selective light, RL (660 nm), GL (530 nm), BL (450 nm), growth reaction, axial organs, H2O2, catalase, peroxidase.

The Effect of Sukuk Issuance on Price Reaction and Growth of Sharia Capital Market

This study aims to analyze the effect of the value of Sukuk, Sukuk rating, and risk of Sukuk on the growth of the Islamic capital market mediated by Sukuk price during the period of 2014-2019 using value at risk. This study uses secondary data obtained from the Indonesia Stock Exchange and The Indonesian Capital Market Institute. Data were analyzed using the SPSS statistical program with path analysis techniques. The results of this study indicate that the variable value of Sukuk and the rating of Sukuk have a positive and significant effect on the price reaction of Sukuk, while the risk variable of Sukuk shown a negative and significant score. The variable value of Sukuk has a positive and significant effect on the reaction to the growth of the Islamic capital market, while negative and significant results are indicated by the variable rating of Sukuk and the risk variable of Sukuk. The Sukuk price reaction variables have a positive and significant effect on the reaction to the growth of the Islamic capital market. Interestingly, the study found that the Sukuk price reaction variable is unable to mediate the relationship between the value of Sukuk and the growth reaction of the Islamic capital market. This mediation result is also the same for the Sukuk rating and Sukuk risk.

Biological control methods in Piper nigrum Linn. leaves infected with galls caused by Liothrips karneyi

Piper nigrum Linn. (Black pepper) belongs to the family Piperaceae and an economically and medicinally important spice and is a native of Southern India. Leaf marginal gall is transmitted by Liothrips karnyi belonging to family Phlaeothripidae of order Thysanoptera (Thrips). Insect induced galls arise due to growth reaction of plants due to the attack of cecidozoa, also known as zoocecidia. The growth and development of the host plant alter due to the infestation of the insect, which involves certain complex phenomena. The different groups of cecidozoa influence the plants in such a way as to produce galls at different stages in their life history. Most of the cecidozoa cause galls only in their developmental stages, but some of them are capable of inducing galls both in larval as well as adult stages. The crop production in India has been adversely affected due to the infestation of pests. And it is necessary to use different approaches of disease management to curb the infestation, and significant researchers have shown progress to protect the crops in an eco-friendly manner. Piperine exhibits diverse pharmacological activities like antihypertensive, antiplatelets, antioxidant, antitumor, antipyretic, analgesic, anti-inflammatory, anti-diarrheal, antibacterial, antifungal, anti-reproductive, insecticidal activities. In the present investigation, the biological method of disease management of marginal leaf gall transmitted by Liothrips karnyi has been undertaken. The biological control of leaf diseases has been significant on the increased reflection of environmental problems over pesticide uses.