Spatial Dominance and Inorganic Carbon Assimilation by Conspicuous Autotrophic Biofilms in a Physical and Chemical Gradient of a Cold Sulfurous Spring: The Role of Differential Ecological Strategies

The study covers the investigation of pesticides in terms of consumption, toxicological classification and various intrinsic physical and chemical properties like DT50, KOC, GUS, solubility that describe the important mechanisms prevailing in soil, namely persistence and mobility. These mechanisms help to estimate the transportation pathways of pesticides on soil till they reach the receiving water after being applied on land. Classification is done in three groups, those likely to appear in surface flow, those that appear in groundwater and those that present transient conditions. Such an approach that also takes into account toxicological levels and annual consumption values of pesticides will act as a tool to prepare the priority list of pesticides that need special care during their transportation. The fate of pesticides is a difficult task to solve, however, such a methodology, puts forth a rough estimate on their behavior in spite of uncertainties in many of the parameters describing mechanisms like persistence and mobility. The agricultural areas of two watersheds of Istanbul are selected as target areas to describe the approach, which is also checked with another approach estimating pesticide pollution potential that considers various other properties of pesticides. Almost similar findings are depicted with 85% proximity. The methodology presented in the paper illustrates and emphasizes the significant role of pesticide properties in determining their fate in soil after being applied.

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Di-imide: Some Physical and Chemical Properties, and the Kinetics and Stoichiometry of the Gas-phase Decomposition

Canadian Journal of Chemistry ◽

10.1139/v73-536 ◽

1973 ◽

Vol 51 (21) ◽

pp. 3605-3619 ◽

Cited By ~ 35

Author(s):

C. Willis ◽

R. A. Back

Keyword(s):

Gas Phase ◽

Room Temperature ◽

Chemical Properties ◽

Phase Decomposition ◽

Important Intermediate ◽

Long Lifetime ◽

Physical And Chemical ◽

Text Formation ◽

Kinetics Of

Preparation of di-imide by passing hydrazine vapor through a microwave discharge yields mixtures with NH3 containing typically about 15% N2H2, estimated from the gases evolved on decomposition. The behavior of the mixture (which melts at −65 °C) on warming from −196 to −30 °C suggests a strong interaction between the components. Measurements of magnetic susceptibility and e.p.r. experiments showed that N2H2 is not strongly paramagnetic, which with other observations points to a singlet rather than a triplet ground-state.Di-imide can be vaporized efficiently, together with NH3, by rapid warming, and the vapor is surprisingly long-lived, with a typical half-life of several minutes at room temperature. The near-u.v. (3200–4400 Å) absorption spectrum of the vapor was photographed; it shows well-defined but diffuse bands, with εmax = 6(± 3) at 3450 Å.Di-imide decomposes at room temperature in two ways:[Formula: see text][Formula: see text]Formation of NH3 was not observed but cannot be ruled out. The decomposition of the vapor is complicated by a sizeable and variable decomposition that occurs rapidly during the vaporization. The stoichiometry of this and the vapor-phase decomposition depends on total pressure and di-imide concentration. The kinetics of the decomposition of the vapor were studied from 22 to 200 °C by following the disappearance of N2H2 by absorption of light at 3450 Å, or the formation of N2H4 by absorption at 2400 Å, and by mass spectrometry. The kinetics are complex and can be either first- or second-order, or mixed, depending on surface conditions. The effect of olefin additives on the decomposition was studied, and is also complex.Mechanisms for the decomposition are discussed, including the possible role of trans-cis isomerization. The relatively long lifetime found for di-imide in the gas phase suggests that it may be an important intermediate in many reactions of hydronitrogen systems.

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ROLE OF NANOTECHNOLOGY IN DENTAL SCIENCES: A REVIEW

International Journal of Medical and Biomedical Studies ◽

10.32553/ijmbs.v4i3.1055 ◽

2020 ◽

Vol 4 (3) ◽

Author(s):

Ramakoteswara Rao N ◽

Kranthi kiran Reddy E ◽

Leena Gahane ◽

SV Ranganayakulu

Keyword(s):

Materials Science ◽

Biological Properties ◽

Synthesis Methods ◽

Nano Technology ◽

New Science ◽

Physical Chemical ◽

Health Related ◽

Nano Science ◽

Physical And Chemical

Nano technology is the multi disciplinary science and technology, which has emerged as new science exploiting specific phenomena and direct manipulation of materials on nanoscale. Nanotechnology deals with the physical, chemical, and biological properties of structures and their parts at nanoscale dimensions. It's established on the concept by creating functional structures by controlling corpuscles and molecules on a one-by-one basis by different physical and chemical synthesis methods. Developments in materials science and, nano biotechnology is especially forestalled to provide elevates in dental sciences and initiations in oral health-related diagnostic and therapeutical methods. Keywords: Nano Science, dentistry, Nanocomposite, Nanorobots, Nanomaterials.

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Oxycline oscillations induced by internal waves in deep Lake Iseo

10.5194/hess-2018-542 ◽

2018 ◽

Author(s):

Giulia Valerio ◽

Marco Pilotti ◽

Maximilian Peter Lau ◽

Michael Hupfer

Keyword(s):

Internal Waves ◽

Water Layer ◽

Sediment Surface ◽

Chemical Gradient ◽

Deep Lakes ◽

Deep Lake ◽

Deep Waters ◽

Basin Scale ◽

First Time

Abstract. Lake Iseo is undergoing a dramatic de-oxygenation of the hypolimnion, representing an emblematic example among the deep lakes of the prealpine area that are, to a different extent, suffering from reduced deep water mixing. In the anoxic deep waters, the release and accumulation of reduced substances and phosphorus from the sediments is a major concern. Since the hydrodynamics of this lake was shown to be dominated by internal waves, in this study we investigate for the first time the role of these oscillatory motions on the vertical fluctuations of the oxycline, currently situated at a depth of around 95 m, where a permanent chemocline inhibits deep mixing by convection. Temperature and dissolved oxygen data measured at moored stations show large and periodic oscillations of the oxycline, with amplitude up to 20 m and periods ranging from 1 to 4 days. A deep dynamics characterized by larger amplitudes at lower frequencies is shown to be favoured by the excitation of second vertical modes in strongly thermally stratified periods and of first vertical modes in weakly thermally stratified periods, when the deep chemical gradient can support baroclinicity anyhow. These basin-scale internal waves cause in the water layer between 85 and 105 m depth a fluctuation of the oxygen concentration between 0 and 3 mg L−1 that, due to the bathymetry of the lake, changes the redox condition at the sediment surface. This forcing, involving about 3 % of the lake's sediment area, can have major implications for the biogeochemical processes at the sediment water interface and for the internal matter cycle.

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Phenolic Compounds in Honey and Their Relationship with Antioxidant Activity, Botanical Origin, and Color

Antioxidants ◽

10.3390/antiox10111700 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1700

Author(s):

Ana L. Becerril-Sánchez ◽

Baciliza Quintero-Salazar ◽

Octavio Dublán-García ◽

Héctor B. Escalona-Buendía

Keyword(s):

Antioxidant Activity ◽

Phenolic Compounds ◽

Geographical Origin ◽

Sensory Characteristics ◽

Intrinsic Properties ◽

The Status ◽

Great Relevance ◽

Therapeutic Properties ◽

Physical And Chemical

Honey has been employed since antiquity due to its sensory, nutritional, and therapeutic properties. These characteristics are related to its physical and chemical composition. For example, phenolic compounds are substances that can determine antioxidant activity, as well as sensory characteristics, and can be employed as biomarkers of floral and geographical origin. This has generated a growing interest in the study of phenolic compounds and their influence in the intrinsic properties of this beekeeping product. This review aims to summarize, analyze, and update the status of the research that demonstrates the role of phenolic compounds in antioxidant activity, botanical-geographical origin, and the sensory characteristics of honey. These phenolic compounds, according to various results reported, have great relevance in honey’s biological and functional activity. This leads to research that will link phenolic compounds to their floral, geographical, productive, and territorial origin, as well as some sensory and functional characteristics.

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