scholarly journals Biodegradation of low-density polyethylene (LDPE) sheet by microalga, Uronema africanum Borge

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elumalai Sanniyasi ◽  
Rajesh Kanna Gopal ◽  
Dinesh Kumar Gunasekar ◽  
Preethy P. Raj
Keyword(s):  
Solid Waste Management ◽  
Complete Solution ◽  
Natural Habitat ◽  
Chemical Oxidation ◽  
Dark Field ◽  
Healthy Environment ◽  
Global Issue ◽  
Plastic Bag ◽  
Average Size ◽  
Water Canals

AbstractPlastic (polyethylene) pollution is a severe cause of deterioration of a healthy environment. For example, ingestion of plastics in the animal gut, clogging of water canals and retarded solid waste management. Many conventional methods of polyethylene degradation include UV photooxidation, thermal oxidation, incineration, chemical oxidation and landfill are being practiced. However, these methods are not feasible, costlier and not a complete solution for this global issue. Therefore, plausible, alternative solution for this issue is biodegradation. Microbes such as bacteria, fungi and algae are involved in polyethylene degradation in its natural habitat. Among them, algae were given very less importance. In our present study, a potential microalga, morphologically identified as Uronema africanum Borge, isolated from a waste plastic bag collected from a domestic waste dumping site in a freshwater lake. This microalga was further treated with the LDPE sheet in BBM culture medium. Based on the results obtained from light microscopy, dark field microscopy, GC–MS, FT-IR, SEM and AFM, it was concluded that the microalga has initiated degradation of LDPE sheet within 30 days of incubation. Concurrently, the configuration of corrosions, abrasions, grooves and ridges were found similar with the morphological features of the microalga. For example, the configuration of the radial disc-like attachment structure of the microalga was found corresponding to the abrasions on the surface of LDPE sheet at an average size of 20–30 µm in diameter. Whereas, the configuration of ridges and grooves were found similar with the filamentous nature of the microalga (10–15 µm width). This is a hitherto report on the biodegradation of LDPE sheet by the microalga Uronema africanum Borge.

scholarly journals Continuous-Flow Photocatalytic Microfluidic-Reactor for the Treatment of Aqueous Contaminants, Simplicity, and Complexity: A Mini-Review

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1325
Author(s):  
Zhongwei Gao ◽  
Changqing Pan ◽  
Chang-Ho Choi ◽  
Chih-Hung Chang
Keyword(s):  
Continuous Flow ◽  
Lower Energy ◽  
High Efficiency ◽  
Diffusion Length ◽  
Physical Adsorption ◽  
Chemical Oxidation ◽  
Microfluidic Reactor ◽  
Global Issue ◽  
The Individual ◽  
Aqueous Contaminants

Water pollution is a growing global issue; there are many approaches to treating wastewater, including chemical coagulation, physical adsorption, and chemical oxidation. The photocatalysis process has provided a solution for removing pollutants from wastewater, where the pair of the photoelectron and hole works through an asymmetric way to degrade the contaminants under UV irradiation. This method offers an alternative route for treating the pollutant with a lower energy cost, high efficiency, and fewer byproducts. A continuous-flow microfluidic reactor has a channel size from tens to thousands of micrometers, providing uniform irradiation and short diffusion length. It can enhance the conversion efficiency of photocatalysis due to the simple spatial symmetry inside the microreactor channel and among the individual channels. In addition, the bandgap of TiO2, ZnO, or other photocatalyst nanoparticles with symmetric crystal structure can be modified through doping or embedding. In this mini-review, a review of the reported continuous-flow photocatalytic microfluidic reactor is discussed from the perspective of both microreactor design and material engineering.

Solid waste management- sustainability towards a better future, role of CSR – a review

2019 ◽  
Vol 15 (6) ◽  
pp. 762-771
Author(s):  
Preethi Rajesh
Keyword(s):  
Waste Management ◽  
Solid Waste ◽  
Solid Waste Management ◽  
Content Type ◽  
Air Contamination ◽  
Healthy Environment ◽  
Multi Level ◽  
Corporate Social ◽  
Practical Implications

Purpose Human activities in household and industries generate an enormous amount of waste material, both organic and non-biodegradable matter, which substantially contribute to land, water and air contamination. The study aims to highlight the possible methods in solid waste management (SWM) and its influence on economy and environment. The paper is an attempt to bring out the necessity of corporate social responsibility (CSR) in the management of solid waste. Design/methodology/approach The paper is prepared after an elaborate review of literature connected with SWM. Findings The paper emphasizes the need of SWM and the role of corporate bodies in building a robust system in the management of solid waste, creating a healthy environment to all. Research limitations/implications The paper is entirely based on literature review and reports and not on individual's research. Practical implications The paper has a multi-level faceted approach where real-time practices in different countries have been explored. Social implications This study can enable the collaboration of corporates, scientific community and the municipal local bodies in the area of SWM. Originality/value This paper deliberates on how CSR can be a driving force for a sustainable model for SWM.

scholarly journals A Novel Approach of Targeted Immunotherapy against Adenocarcinoma Cells with Nanoparticles Modified by CD16 and MUC1 Aptamers

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Lianyuan Yu ◽  
Yan Hu ◽  
Jinhong Duan ◽  
Xian-Da Yang
Keyword(s):  
Nk Cells ◽  
Cancer Cells ◽  
Dark Field ◽  
Negative Control ◽  
Mucin 1 ◽  
Novel Approach ◽  
Adenocarcinoma Cells ◽  
Dark Field Microscopy ◽  
Average Size ◽  
Nk Cytotoxicity

Mucin 1 (MUC1) is a potentially important target of cancer therapy, being a glycoprotein that is overexpressed on cell surface of many types of adenocarcinomas, including breast, ovarian, colon, lung, and prostatic cancers. Several MUC1-targeted drug delivery systems have been developed and reported, but mobilizing natural killer cells (NK) to fight against MUC1-positive tumor has not been attempted. In this study, we introduced a novel amphipathic nanoparticle (NP) for enhancing the NK cytotoxicity to MUC1-positive cancer cells. The amphipathic NP had CD16 and MUC1 aptamers on its surface and was designed to bind with both the CD16-positive NK cells and the MUC1-positive tumor cells and pull the two types of cells close to each other. The fabricated amphipathic NP had an average size of 574 nm. The aptamers’ conjugation with the NP was confirmed by DNA hybridization experiments. Dark-field microscopy revealed that the amphipathic NP could recruit more NK cells to the vicinity of MUC1-positive cancer cells. Additionally, the amphipathic NP significantly enhanced the NK cytotoxicity to MUC1-positive cancer cellsp<0.01, but not that to the MUC1-negative control cells. The results suggest that NK cells may potentially be mobilized to selectively fight against MUC1-positive cancer cells.

Microstructure and interdiffusion behaviour of β-FeSi2 flat islands grown on Si(111) surfaces

2013 ◽  
Vol 46 (4) ◽  
pp. 1076-1080
Author(s):  
Sung-Pyo Cho ◽  
Yoshiaki Nakamura ◽  
Jun Yamasaki ◽  
Eiji Okunishi ◽  
Masakazu Ichikawa ◽  
...  
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
Single Phase ◽  
Spherical Aberration ◽  
Dark Field ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Annular Dark Field ◽  
Abrupt Interface ◽  
Average Size ◽  
20 Nm

β-FeSi2 flat islands have been fabricated on ultra-thin oxidized Si(111) surfaces by Fe deposition on Si nanodots. The microstructure and interdiffusion behaviour of the β-FeSi2/Si(111) system at the atomic level were studied by using spherical aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. The formed β-FeSi2 flat islands had a disc shape with an average size of 30–150 nm width and 10–20 nm height, and were epitaxically grown on high-quality single-phase Si with a crystallographic relationship (110)β-FeSi2/(111)Si and [001]β-FeSi2/[1\bar 10]Si. Moreover, the heterojunction between the β-FeSi2(110) flat islands and the Si(111) substrate was an atomically and chemically abrupt interface without any irregularities. It is believed that these results are caused by the use of ultra-thin SiO2 films in our fabrication method, which is likely to be beneficial particularly for fabricating practical nanoscaled devices.

scholarly journals A Long-Standing Problem: A Review on the Solid Waste Management in the Philippines

2021 ◽  
Vol 2 (3) ◽  
pp. 213-220
Author(s):  
Ericson E. Coracero ◽  
RB J. Gallego ◽  
Kristine Joy M. Frago ◽  
Ruel Joseph R. Gonzales
Keyword(s):  
Waste Management ◽  
Solid Waste ◽  
Solid Waste Management ◽  
Good Governance ◽  
The Philippines ◽  
The People ◽  
Sanitary Landfills ◽  
Global Issue ◽  
The Government ◽  
Waste Diversion

Solid waste management is considered a pressing global issue calling for an immediate response from the government and its people. The Philippines has a continuously rising amount of waste and is expected to further increase in the succeeding years. As reviewed, associated problems with solid waste management in the country include an increasing amount of solid waste, weak law implementation, scarcity of sanitary landfills, and improper disposal. The ultimate solution existing in the country is the RA 9003 or the Ecological Solid Waste Management Act of 2000 which highlights the practices of segregation, proper disposal, and waste diversion. The importance of envisioning a trash-free Philippines and encouraging people’s participation and awareness is also emphasized. Another possible solution to solid waste management is valorization which can also address other environmental problems such as the depletion of natural resources. These solutions enumerated will only be possible with the presence of good governance, active participation of the people of the country, and the cooperation of all constituents and agencies in the Philippines.

scholarly journals PRIVATIZATION OF SOLID WASTE MANAGEMENT: OPPORTUNITIES AND CHALLENGES

2021 ◽  
Vol 4 (2) ◽  
pp. 142
Author(s):  
Yahya Muhammed Bah ◽  
Myrtati Dyah Artaria
Keyword(s):  
Waste Management ◽  
Solid Waste ◽  
New Technologies ◽  
Solid Waste Management ◽  
Healthy Environment ◽  
Negative Impacts ◽  
Resources Conservation ◽  
Prompt Action ◽  
Google Search ◽  
Innovative Techniques

<p><strong>Aim:</strong> The fundamental rationale for a systematic literature review is to examine opportunities and challenges in the privatization of solid waste management, and share knowledge to spark and inspire a process that will usher in public private partnership to ensure cities are kept clean for habitability. <strong>Methodology and Results:</strong> A systematic review of the literature using information obtained from different sources was performed. The Google Search Engine was used to search for these articles. During the search numerous combinations of words and phrases were used to ensure articles reflect the most recent knowledge and scholarly works. Only peer-reviewed articles published after 2000 were selected, except extracts perceived to be of fundamental mileage to the study. However, articles published by staunch international organizations working in privatization of solid waste management for years which had produced indefatigable knowledge in the field were stealthily appraised. The privatization of solid waste management has resulted in some successes which include, but not restricted to: effectiveness, cost saving, timely service delivery, access to funding and expansion, quality services, partnership and community participation, cleanliness and healthy environment, jobs creation and better income, elimination of public monopoly and promotion of competition, new technologies and innovative techniques, public sector concentration on supervision, resources conservation and protection from risks; less bureaucracy and prompt action regarding concerns and complaints. <strong>Conclusion, significance and impact of study:</strong> With a well-thought model and proper public supervision, the privatization of solid of waste management can deliver habitable cities, though not without negative impacts and obstacles.</p>

scholarly journals Solid Waste Generation, Composition and Management in Paro Hotel Industry

2017 ◽  
pp. 15-27
Author(s):  
Choni Zangmo ◽  
Alice Sharp
Keyword(s):  
Waste Management ◽  
Solid Waste ◽  
Solid Waste Management ◽  
Hotel Industry ◽  
Current Status ◽  
Management Problem ◽  
Waste Generation ◽  
Global Issue ◽  
Solid Waste Generation ◽  
Environmentally Sound

Management of solid waste has become an increasingly important global issue as a result of population growth, as well as increasing individual needs, changes in lifestyle and growth in tourism. This waste management problem has become severe in the Paro region of Bhutan, driven by growth in tourism, changes in consumption patterns and growth in GDP. This research aimed to study the amount of waste sent to landfill, and the current status of solid waste management systems and waste composition in Paro District hotels. The current composition of solid waste from hotels comprises organic waste (53 %), glass (14 %), paper (9 %), metal (7 %), LDPE (7 %), textiles (5 %), HDPE (3 %), rubber (1 %), and others (1 %). To improve solid waste management (SWM) in the hotel industry and to reduce total amount of waste generated, environmentally sound practices in various nations are recommended such as implementation of guidelines, monitoring systems, education and special training programs for hoteliers and customers.

scholarly journals Exhaled droplets due to talking and coughing

2009 ◽  
Vol 6 (suppl_6) ◽  
Author(s):  
Xiaojian Xie ◽  
Yuguo Li ◽  
Hequan Sun ◽  
Li Liu
Keyword(s):  
Respiratory Infections ◽  
Clinical Procedures ◽  
Food Dye ◽  
Glass Slides ◽  
Plastic Bag ◽  
Droplet Sizes ◽  
Series Of Experiments ◽  
The Times ◽  
Average Size ◽  
Respiratory Droplets

Respiratory infections can be spread via ‘contact’ with droplets from expiratory activities such as talking, coughing and sneezing, and also from aerosol-generating clinical procedures. Droplet sizes predominately determine the times they can remain airborne, the possibility of spread of infectious diseases and thus the strategies for controlling the infections. While significant inconsistencies exist between the existing measured data on respiratory droplets generated during expiratory activities, a food dye was used in the mouth during measurements of large droplets, which made the expiratory activities ‘unnatural’. We carried out a series of experiments using glass slides and a microscope as well as an aerosol spectrometer to measure the number and size of respiratory droplets produced from the mouth of healthy individuals during talking and coughing with and without a food dye. The total mass of respiratory droplets was measured using a mask, plastic bag with tissue and an electronic balance with a high precision. Considerable subject variability was observed and the average size of droplets captured using glass slides and microscope was about 50–100 µm. Smaller droplets were also detected by the aerosol spectrometer. More droplets seemed to be generated when a food dye was used.

Synthesis and Photocatalytic Activity of Yb Doped TiO2 Nanoparticles under Visible Light

2009 ◽  
Vol 5 ◽  
pp. 193-200 ◽  
Author(s):  
Mou Pal ◽  
Umapada Pal ◽  
R. Silva Gonzalez ◽  
E. Sanchez Mora ◽  
P. Santiago
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Diffuse Reflectance Spectroscopy ◽  
Dark Field ◽  
Energy Dispersion Spectroscopy ◽  
Transmission Electron ◽  
Degradation Rates ◽  
Annular Dark Field ◽  
Average Size

Developing new semiconductor materials with improved photocatalytic activity is a promising technology for the remedy of environmental pollution. Here we report on the synthesis of Yb containing TiO2 nanoparticles and their catalytic activity under visible light. Highly monodispersed, spherical TiO2 and TiO2 :Yb nanoparticles of 27- 40 nm size range were prepared through controlled hydrolysis of titanium tetrabutoxide (TTB) and characterized by X-ray diffraction (XRD), energy dispersion spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), high angle annular dark field (HAADF), and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) techniques. Average size of the nanoparticles was found to decrease with the increase of Yb doping concentration. The photocatalytic activity of Yb doped TiO2 was evaluated by measuring the degradation rates of methylene blue (MB) under UV and visible lights. Doping with ytterbium ions enhanced significantly the photocatalytic activity of TiO2 nanoparticles for MB oxidation under visible light.

scholarly journals Electron Microscopy Studies of Undoped and Phosphorus Doped Si:H and Si,C:H Films

1993 ◽  
Vol 297 ◽  
Author(s):  
Y.L. Chen ◽  
J. Bentley ◽  
C. Wang ◽  
G. Lucovsky ◽  
D.M. Maher
Keyword(s):  
Volume Fraction ◽  
Chemical Vapor ◽  
Dark Field ◽  
Degree Of Crystallinity ◽  
Phosphorus Doping ◽  
Two Phase ◽  
Dark Field Imaging ◽  
Electron Microscopes ◽  
Average Size ◽  
Phosphorus Doped

The microstructure of undoped and phosphorus doped Si:H and Si,C:H films was analyzed by selected-area diffraction, conical dark-field imaging, energy-dispersive x-ray spectroscopy and electron energy-loss spectroscopy in transmission electron microscopes. Thin films were synthesized by remote plasma-enhanced chemical vapor deposition and characterized in terms of degree of crystallinity. The distribution of phosphorus in the Si:H and Si,C:H films, and carbon in the Si,C:H films was evaluated. The results indicate that i) the microstructure of a film may be two phase, consisting of silicon microcrystallites in an amorphous matrix, ii) phosphorus doping as well as the presence of carbon influences the degree of crystallinity by reducing the average size and volume fraction of microcrystallites, iii) the presence of carbon and phosphorus doping completely suppresses the crystalline phase, iv) phosphorus is distributed at approximately the same concentration in both the crystalline and amorphous phases of diphasic films, and v) carbon is detected in the amorphous phase of the Si,C:H films.

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