scholarly journals Physicochemical Assessment of the Biodegradability of Agricultural Nonwovens Made of PLA

2021 ◽  
Vol 29 (1(145)) ◽  
pp. 26-34
Author(s):  
Patrycja Miros-Kudra ◽  
Karolina Gzyra-Jagieła ◽  
Michał Kudra
Keyword(s):  
Mass Loss ◽  
Natural Environment ◽  
Environmental Conditions ◽  
Circular Economy ◽  
Polymer Materials ◽  
Gel Chromatography ◽  
Test Procedures ◽  
Biodegradation Process ◽  
Petroleum Derivatives ◽  
Loss Determination

Compostable biodegradable plastics are an ecological alternative to traditional products based on petroleum derivatives, whose post-use waste may pollute the natural environment. Modern polymer materials show the functional properties of plastics obtained by conventional methods, but they also may be degraded as a result of biochemical transformations in composting. This allows such materials to be included in the scheme of the currently implemented circular economy, which does not generate post-consumer waste. This paper presents methods for the assessment of the biodegradation process of selected agricultural nonwovens produced from commercial PLA 6252D polylactide, supplied by Nature Works® LLC, USA. The agricultural nonwovens tested, obtained by the spun-bond technique, were characterised by different degrees of crystallinity in the range from 11.1% to 31.4%. Biodegradation tests were carried out as simulated aerobic composting while maintaining constant environmental conditions in accordance with test procedures based on PN-EN/ISO standards using the method of sample mass loss determination. Gel chromatography (GPC/SEC) and FTIR spectroscopy were also applied to assess the degree of biodegradation. The aim of this study was to evaluate the effect of the crystallinity of nonwoven made of PLA 6252 D on its degradation in a compost environment.

Digestion in the tsetse fly Glossina morsitans Westw.: the effect of feeding field-caught flies on guineapigs in the laboratory

1967 ◽  
Vol 57 (3) ◽  
pp. 447-450 ◽  
Author(s):  
P. A. Langley
Keyword(s):  
Natural Environment ◽  
Environmental Conditions ◽  
Tsetse Fly ◽  
Rapid Loss ◽  
Glossina Morsitans ◽  
The Third ◽  
Laboratory Conditions ◽  
Effect Of Feeding ◽  
Blood Meals

It has been shown that adults of Glossina morsitans Westw. that have fed from a bait ox in their natural environment digest their blood meals more rapidly than others that have emerged and been fed in the laboratory, even when both are maintained under identical environmental conditions after feeding.In further experiments with G. morsitans in Rhodesia, flies caught in the field and fed in the laboratory were found to lose their ability to digest their meals rapidly. Measurements, made throughout three hunger cycles, of the rate of digestion, as reflected in the rate of excretion, of blood meals by field-caught flies fed on guineapigs in the laboratory showed that this was not significantly different from that of the normal, flied-fed flies during the first two hunger cycles but that during the third it fell to a level comparable to that of flise that emerged and were fed in the laboratory.It is concluded that whatever may be the events that condition the field flies to digest their meals rapidly in the natural environment, these are repeated with the ingestion of each meal, and that laboratory conditions cause a rapid loss of this greater digestive capability.

scholarly journals Damage of polyesters by the atmospheric free radical oxidant NO3 •: a product study involving model systems

2013 ◽  
Vol 9 ◽  
pp. 1907-1916 ◽  
Author(s):  
Catrin Goeschen ◽  
Uta Wille
Keyword(s):  
Free Radical ◽  
Environmental Conditions ◽  
Hot Spots ◽  
Polymer Materials ◽  
Model Systems ◽  
Night Time ◽  
High Performing ◽  
Work Model ◽  
Product Study ◽  
Insight Into

Manufactured polymer materials are used in increasingly demanding applications, but their lifetime is strongly influenced by environmental conditions. In particular, weathering and ageing leads to dramatic changes in the properties of the polymers, which results in decreased service life and limited usage. Despite the heavy reliance of our society on polymers, the mechanism of their degradation upon exposure to environmental oxidants is barely understood. In this work, model systems of important structural motifs in commercial high-performing polyesters were used to study the reaction with the night-time free radical oxidant NO3 • in the absence and presence of other radical and non-radical oxidants. Identification of the products revealed ‘hot spots’ in polyesters that are particularly vulnerable to attack by NO3 • and insight into the mechanism of oxidative damage by this environmentally important radical. It is suggested that both intermediates as well as products of these reactions are potentially capable of promoting further degradation processes in polyesters under environmental conditions.

Evaluation Of The Effectiveness Of Oil-Dispersing Chemicals

1969 ◽  
Vol 1969 (1) ◽  
pp. 199-207 ◽  
Author(s):  
T.A. Murphy ◽  
L.T. McCarthy
Keyword(s):  
Environmental Conditions ◽  
Salt Water ◽  
Water Solution ◽  
Field Tests ◽  
Field Performance ◽  
Standard Test ◽  
Oil Composition ◽  
Test Procedures ◽  
Test Conditions ◽  
Limited Precision

Abstract A procedure for evaluating the effectiveness of oil-dispersing chemicals has been developed. Using the apparatus originally designed for the Navy specification for solvent-emulsifiers, test conditions were adapted to correspond more closely to typical environmental conditions. Test conditions having the greatest effect on dispersant performance included: type of oil, composition of salt water solution, degree of agitation of chemical/oil mixture, and the degree of contact between chemical and oil prior to agitation. Results from this modified procedure, the Simulated Environmental Tank (SET) Test, correspond well with results from simple field tests. Field tests have limited precision and reproducibility. This lack of a reliable index of field performance with which to compare laboratory results hinders refinement of standard test procedures. The SET Test, which produces results corresponding favorably with field performance, to the extent field performance can be determined, and which simulates typical environmental conditions, is proposed as a meaningful interim solution to this problem of dispersant evaluation.

Effects of N Deposition Induced by Environmental Pollution on Litter Decomposition Rate of Cortex phellodendri chinensis in Shenyang City

2012 ◽  
Vol 518-523 ◽  
pp. 1913-1917
Author(s):  
Fang Qin Guo ◽  
Wei Chen
Keyword(s):  
Environmental Pollution ◽  
Mass Loss ◽  
Litter Decomposition ◽  
Environmental Conditions ◽  
Decomposition Rate ◽  
Litter Quality ◽  
N Deposition ◽  
Shenyang City ◽  
Litter Decomposition Rate ◽  
Cortex Phellodendri

The effects of N deposition induced by environmental pollution on litter decomposition rate in Shenyang city are analyzed by the reciprocal transplant experiment. By contrasting environments and intraspecific variations in Cortex Phellodendri Chinensis leaf litter quality on mass loss rates to investigate the effects of N deposition on mass loss rates in urban and suburb. The results showed that N deposition in urban significantly affected litter decomposition rate by affecting litter quality and environmental conditions. There was a faster decomposition rate when the environmental conditions or litter quality was affected by N deposition.

scholarly journals RIGHT TO CHILD HEALTH IN CONTEXT OF NATURAL ENVIRONMENTAL SECURITY

2019 ◽  
Vol 72 (3) ◽  
pp. 418-424 ◽  
Author(s):  
Vitalii M. Pashkov ◽  
Maryna V. Trotska ◽  
Oleksii S. Soloviov
Keyword(s):  
Child Health ◽  
Natural Resources ◽  
Transition To Adulthood ◽  
Natural Environment ◽  
Environmental Conditions ◽  
Well Being ◽  
Causal Link ◽  
Environmental Security ◽  
Potential Child ◽  
And Child Health

Introduction: From different points of view, health in general and child health, in particular, constitute the highest value which preserves a significant amount of resource potential. Child health is understood as his/her state consisting of a certain system of elements (physical, psychological, etc.) each of which, on the one hand, is characterized by its specificity, and on the other hand, is in a complementary relationship with each other. A process of child health formation is influenced by a large number of various elements (social, economic, etc.) and the natural environment is one of them. Its compliance with certain rules and standards that form its qualitative status affects life and health both directly and indirectly, therefore, determination of interdependence between the natural environmental conditions and child health is important for understanding a causal link between the specified categories. The aim: To study provisions of international acts and other sources in order to clarify the concept of child health and a role of the natural environment of a proper quality in the process of its formation. Materials and methods: the paper examines provisions of international acts, some scientists’ conclusions and other sources. Different authors’ scientific viewpoints are studied with scientific methods in the context of medical and legal components. Within the framework of the system approach, as well as analysis and synthesis, the concepts of safe natural environment, health in general and child health, in particular, as well as importance of a safe natural environment for child health are researched. Review: The concept of health is complex and depends on various factors including proper natural environmental conditions. Presence of dangerous environmental factors affects occurrence of various children diseases. In the context of the natural environmental security, it is possible to indicate both general and individual natural resources. Their deterioration may affect its condition at large. Conclusions: Ensuring child health, his/her proper physical, psychological and other development is impossible without guaranteeing natural environmental security. Consumption of high-quality natural resources, observance of norms and standards for the environmental security allows the human body to develop fully accumulating relevant resources and attracting them at the right time. Ensuring the natural environment of a proper quality guarantees a greater range of opportunities for a child in the process of forming, coming into being and maintaining his/her physical and psychological well-being, which is a prerequisite for exercising his/her other rights and proper fulfillment of his/her duties in the process of his/her transformation and transition to adulthood.

scholarly journals Linear Economy Versus Circular Economy: A Comparative and Analyzer Study for Optimization of Economy for Sustainability

2017 ◽  
Vol 6 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Furkan Sariatli
Keyword(s):  
Conceptual Framework ◽  
Natural Environment ◽  
Circular Economy ◽  
Social Economic ◽  
Social Challenges ◽  
The Core ◽  
The Social ◽  
Essential Services ◽  
The Subject

Abstract Upon visiting the existing literature on the subject of linear vs. circular economy, this paper finds that, the blueprint of the current economy is hardly sustainable by using the comparative benchmarking method that drained from literature. The intrinsic mechanics of the linear economy, by relying on the wasteful take - make - dispose flow, is detrimental to the environment, cannot supply the growing populace of our planet with essential services and it naturally leads to strained profitability. Elements of a plausible solution to the challenges have been around for decades, although they have only recently been compiled in to the conceptual framework of circular economy. The core ideas of Circular Economy are elimination of waste by design, respect for the social, economic and natural environment and resource-conscious business conduct. Built on the backbone of these principles, the circular economy has demonstrated to deliver tangible benefits and viability to address the economic, environmental and social challenges of our days.

Experimental Procedures Used in the Development of Oil Retention Boom Designs

1972 ◽  
Vol 9 (03) ◽  
pp. 317-332
Author(s):  
E. R. Miller ◽  
W. T. Lindenmuth ◽  
W. E. Lehr ◽  
R. N. Abrahams
Keyword(s):  
Environmental Conditions ◽  
Weber Number ◽  
Full Scale ◽  
Design Criteria ◽  
Mooring System ◽  
Test Procedures ◽  
Towing Tank ◽  
Oil Retention ◽  
Scaling Parameters ◽  
Scale Data

The experimental procedures used in the development of oil retention boom design criteria are presented in detail. Emphasis is placed on the procedures used to determine the oil containment ability and structural loads on the boom as a function of environmental conditions. The critical scaling parameters for oil containment tests are presented and the test procedures which have been developed are described. It is concluded that it is critical to scale both Froude and Weber number. Tests to determine structural loads can be conducted using standard ship towing tank procedures. However, it is necessary to scale the elastic properties of the boom and its mooring system. There are uncertainties with respect to some parameters which cannot be properly scaled in oil containment tests. Thus, carefully conducted full-scale trial results are required. Available procedures and current plans to obtain full-scale data are presented.

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