Piezoelectrically Mediated Reversible Addition-Fragmentation Chain Transfer Polymerization

A well-controlled piezoelectrically mediated reversible addition-fragmentation chain transfer polymerization (piezo-RAFT) was carried out under ultrasound agitation with piezoelectric ZnO nanoparticles as the mechano-chemical trans-ducer. The resulting polymer had predictable molecular weight, high end-group fidelity, low dispersity, and capacity for chain extension. This chemistry was further adopted in curing composite resins to circumvent the light penetration limit of UV curing. This work opened a new avenue of piezoelectrically mediated chemistry and showed its good potential in curing applications.

Photo-Degradation of Orange G as an Environmental Pollutant with TiO2-ZnO Composite Material

The increasing water pollution is a great concern as millions of people don't have access to pure water in Bangladesh. A considerable number of people are dying of contaminated water each year not only in Bangladesh but all over the world. Many industries, tanneries, companies, etc. are emitting lots of environmentally hazardous materials into the surrounding water. Many of these pollutants are industrial dyes. The dyes loss from the industrial water during dyeing operation damage the esthetic merit of surface water. They minimize light penetration, hamper aquatic lives and hinder photosynthesis. Some dyes may also have toxic, mutagenic, and carcinogenic characteristics. The purpose of this research is to get rid of the pollutant dye Orange G before the water is contaminated. A method named photo-degradation using different light sources is used to mineralize Orange G dye with composite materials including TiO2-ZnO. This composite was prepared by the hydrothermal method. The photocatalytic behavior of the prepared composite TiO2-ZnO helps in minimizing the effect of this dye to save the water from contamination. The composite compoundwas studied by experimenting on photo-degradation with Orange G under different light sources such as visible light, UV light, and sunlight. The photo-degradation percentage was found to maximum of 79.60 in the presence of sunlight. The percentages of photo-degradation under UV light and visible light were 48.0 and 18.40 respectively.

The Photograph Registration of Petri Dishes in High Quality and Image Editing of Microbiological Testing

Science is based on evidence that can be measured or observed through methodical techniques which are expressed in several ways, either quantitatively or qualitatively. The technical photograph becomes one of the most important key tools to the result’s disclosure. In the microbiological research, several pieces of evidence can be indicated with variables that are deeply related to the means of culture; pH and color variation, halo formation, overlay of structures, culture shape, among others. The employment of technical photographs, as a strategy of the experimental observation and reliable representation, is indispensable. The protocol presented here suggests the production of the photographic support in microbiological tests runs on Petri dishes, taken by a smartphone to obtain high-quality images, besides showing tools to edit images through PowerPoint. The support is composed of a paper tube with a transparent border, whose reduced light penetration avoids problems, such as the luminous reflection over the Petri dishes or the environment itself. The edition consists of the photograph variation, and in clipping and pasting on uniform backgrounds to provide further detailing. The protocol allowed a standardized photograph collection in high quality, which is ideal for a comparative portrait of microbiological behaviors. The image editing enabled a framework and greater visibility of physical and biological structures in the exhibition of photographs inside the manuscript, such as the removal of noises, background alterations, deformities or irregularities. This protocol is a tool that helps the researcher on the knowledge-obtaining process, and it is applied to different experiments or adapted into the most variable research subjects.

Light Penetration Properties of Visible and NIR Radiation in Tomatoes Applied to Non-Destructive Quality Assessment

Tomato is an important food product for which the development of non-destructive quality assessment methods is of great interest. Using visible and near-infrared (NIR) spectroscopy, the sugar content, acidity and even taste can be estimated through the use of chemometric methods (e.g., partial least squares regression). In the case of reflection spectra, which are the common modality for imaging spectroscopy, the question arises regarding how much of the interior of the tomato contributes to the measured spectra. An experiment was performed with tomatoes of four different types: beef tomato, classic round tomato, cocktail tomato, and snack tomato. The tomatoes were sliced at different thicknesses and imaged on a 98% reflective white background and a 4% reflective black background. Spectral images were acquired with VNIR (400–1000 nm) and NIR (900–1700 nm) imaging spectrographs. The difference between the spectra with a white and black background was used to determine the relationship between the wavelength and the light penetration depth. The results show that at wavelengths between 600 and 1100 nm, light penetrates the tomatoes up to a distance of 20 mm. The relation more or less follows the law of Lambert–Beer. This relation was the same for all four types of tomatoes. These results help the interpretation of chemometric models based on reflection (imaging) spectroscopy.

Effect of plant bio-regulators on photosynthesis, growth and yield efficiency of pear trained on Y-trellis system

‘Patharnakh’ and ‘Punjab Beauty’ are major pear cultivars grown under the subtropical conditions of northwestern India. These pear cultivars tend to put up profuse vegetative growth under the high density planting that leads to excessive shading of bearing zone of canopy. To facilitate light penetration into inner plant canopy, there is a need to contrive an efficient approach for vegetative growth management. The foliar applications of varying concentrations of plant bio-regulators viz. Prohexadione calcium (Pro-Ca) (100, 200, 400 mg L-1) and Paclobutrazol (PBZ) (100, 250, 500 mg L-1) were done at 10 days after full bloom (DAFB) ‘Patharnakh’ and ‘Punjab Beauty’ pear plants trained on the Y-trellis training system. Shoot length, leaf area index and trunk cross-sectional areas (TCSA) were greatly reduced by Pro-Ca200 and 400 mg L-1 concentrations. Treatments enhanced light penetration and photosynthesis. Fruit weight improved with plant bio-regulator treatments resulting in increased yield efficiency of pear plants. This study exhibited a strong positive correlation between light availability and yield efficiency of pear plants.

Chlorophyll a concentration of Phytoplankton in Estuary Mangrove Kurau, Bangka Tengah, Indonesia

Chlorophyll a is bound within microalgae and other phytoplankton found in surface seawater. Chlorophyll is an important biochemical component in the molecular apparatus of microalgae that is responsible for photosynthesis. Photosynthesis is the process whereby phytoplankton use sunlight energy and dissolved nutrients to convert inorganic carbon to organic compounds and releasing oxygen. The objective of this research was to analyze chlorophyll a concentration of phytoplankton in estuary mangrove area in Kurau, Bangka Tengah, Indonesia. The research was carried out in estuary area that is mangrove Kurau, Bangka Tengah, Indonesia. Chlorophyll a concentration was determine using spectrophotometer methode. The chlorophyll a concentration and sea water parameters were recorded for all stations. The area was devided into four research sites. Based on the data, chlorophyll a concentrations were between 0.00587 mg/L – 0.00117 mg/L. It was considered low rate chlorophyll a concentration since lack of light penetration in the research area.

Smaller species experience mild adversity under shading in an old-field plant community

Plant competition experiments commonly suggest that larger species have an advantage, especially in light acquisition. However, within crowded natural vegetation, where competition evidently impacts fitness, most resident species are relatively small. It remains unclear, therefore, whether the size-advantage observed in controlled experiments is realized in habitats under intensive competition. We tested for evidence of a size-advantage in competition for light in an old-field plant community composed of herbaceous perennial species. We investigated whether larger species contributed to reduced light penetration (i.e., greater shading), and examined the impact of shade on smaller species by testing whether their abundance and richness were lower in plots with less light penetration. Light penetration in plots ranged from 0.3-72.4%. Plots with greater mean species height had significantly lower light penetration. Plots with lower light penetration had significantly lower small species abundance and richness. However, the impact of shade on small species abundance and richness was relatively small (R values between 8% and 15%) and depended on how we defined “small species”. Significant effects were more common when analyses focused on individuals that reached reproduction; focusing on only flowering plants can clarify patterns. Our results confirm that light penetration in herbaceous vegetation can be comparable to levels seen in forests, that plots with taller species cast more shade, and that smaller species are less abundant and diverse in plots where light penetration is low. However, variation in mean plot height explained less than 10% of variation in light penetration, and light penetration explained 5-15% of variation in small species abundance and richness. Coupled with the fact that reproductive small species were present even within the most heavily shaded plots, our results suggest that any advantage in light competition by large species is limited. One explanation is that some small species in these communities are shade tolerant.