scholarly journals An Empirical Model for Predicting Biodegradation Profiles of Glycopolymers

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1819
Author(s):  
Toma-Leonida Dragomir ◽  
Ana-Maria Pană ◽  
Valentin Ordodi ◽  
Vasile Gherman ◽  
Gabriela-Alina Dumitrel ◽  
...  
Keyword(s):  
Empirical Model ◽  
Correlation Coefficients ◽  
Point Of View ◽  
State Equations ◽  
Plastic Materials ◽  
Complex Process ◽  
Biodegradation Process ◽  
Mathematical Operations ◽  
Statistical Indicators ◽  
Insight Into

Pollution caused by plastic materials has a great impact on the environment. The biodegradation process is a good treatment solution for common polymers and biodegradation susceptible ones. The present work introduces new insight into the biodegradation process from a mathematical point of view, as it envisions a new empirical model for this complex process. The model is an exponential function with two different time constants and a time delay, which follows the weight loss profile of the polymer during the biodegradation process. Moreover, this function can be generated as the output variable of a dynamic exogenous system described through state equations. The newly developed models displayed a good fit against the experimental data, as shown by statistical indicators. In addition, the new empirical model was compared to kinetics models available in the literature and the correlation coefficients were closest to 1 for the new empirical model in all discussed cases. The mathematical operations were performed in the MATLAB Simulink environment.

scholarly journals The Influence of New and Artificial Aged Microplastic and Leachates on the Germination of Lepidium sativum L.

Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 339 ◽  
Author(s):  
Stephan Pflugmacher ◽  
Amalia Sulek ◽  
Hannah Mader ◽  
Jeongin Heo ◽  
Ji Hyeon Noh ◽  
...  
Keyword(s):  
Plastic Material ◽  
Germination Rate ◽  
Point Of View ◽  
Lepidium Sativum ◽  
Plastic Materials ◽  
Root And Shoot Length ◽  
Germination Speed ◽  
Germinating Seeds ◽  
Insight Into ◽  
Lepidium Sativum L

With the increase in environmental monitoring and assessing, we are gaining insight into the extent of microplastic pollution in our environment. The threat posed by microplastics to biota could come, e.g., from leached substances. As some plastic materials have been decaying in nature for extended periods already, the toxic effects of leaching compounds need to be investigated. It is furthermore essential to understand the adverse effects of new plastic and how these effects differ from the effects elicited by old plastic material. Therefore, in the present study, the effects of exposure to leachates from new and artificial aged polycarbonate as well as new and aged polycarbonate granules on various germination parameters of Lepidium sativum were studied. Germination, root, and shoot length, as well as the calculated germination rate index as a measure for germination speed, was negatively influenced in substrate-free and substrate containing exposures. From an ecological and agricultural point of view, this implies possible yield losses with less germinating seeds, slower plant germination speed, and smaller seedlings in general.

Methods of Network Planning and Management when Implementing Territory Planning Projects

2019 ◽  
pp. 49-54
Keyword(s):  
Large Scale ◽  
Housing Stock ◽  
Network Planning ◽  
Network Models ◽  
Point Of View ◽  
Residential Areas ◽  
Basic Principles ◽  
Planning And Management ◽  
Planning Project ◽  
Complex Process

The success of the Program of housing stock renovation in Moscow depends on the efficiency of resource management. One of the main urban planning documents that determine the nature of the reorganization of residential areas included in the Program of renovation is the territory planning project. The implementation of the planning project is a complex process that has a time point of its beginning and end, and also includes a set of interdependent parallel-sequential activities. From an organizational point of view, it is convenient to use network planning and management methods for project implementation. These methods are based on the construction of network models, including its varieties – a Gantt chart. A special application has been developed to simulate the implementation of planning projects. The article describes the basic principles and elements of modeling. The list of the main implementation parameters of the Program of renovation obtained with the help of the developed software for modeling is presented. The variants of using the results obtained for a comprehensive analysis of the implementation of large-scale urban projects are proposed.

scholarly journals Systemic Lupus Erythematosus before and after COVID-19 Lockdown: How the Perception of Disease Changes through the Lenses of Narrative Medicine

Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 726
Author(s):  
Fulvia Ceccarelli ◽  
Venusia Covelli ◽  
Giulio Olivieri ◽  
Francesco Natalucci ◽  
Fabrizio Conti
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Lupus Erythematosus ◽  
Narrative Medicine ◽  
Good Control ◽  
Final Analysis ◽  
Point Of View ◽  
Systemic Lupus ◽  
Before And After ◽  
Text Content ◽  
Insight Into

Background: The COVID-19 pandemic contributes to the burden of living with different diseases, including Systemic Lupus Erythematosus (SLE). We described, from a narrative point of view, the experiences and perspectives of Italian SLE adults during the COVID-19 emergency, by distinguishing the illness experience before and after the lockdown. Methods: Fifteen patients were invited to participate. Illness narratives were collected between 22 and 29 March 2020 using a written modality to capture patients’ perspectives before and after the COVID-19 lockdown. We performed a two-fold analysis of collected data by distinguishing three narrative types and a qualitative analysis of content to identify the relevant themes and sub-themes reported. Results: Eight narratives included in the final analysis (mean length 436.9 words) have been written by eight females (mean age 43.3 ± 9.9 years, mean disease duration 13.1 ± 7.4 years). Six patients provided a quest narrative, one a chaos and the remaining one a restitution narrative. By text content analysis, we identified specific themes, temporally distinct before and after the lockdown. Before COVID-19, all the patients referred to a good control of disease, however the unexpected arrival of the COVID-19 emergency broke a balance, and patients perceived the loss of health status control, with anxiety and stress. Conclusions: We provided unique insight into the experiences of people with SLE at the time of COVID-19, underlining the perspective of patients in relation to the pandemic.

scholarly journals Array Gain of a Linear Array in an Ocean Waveguide

2021 ◽  
Vol 11 (11) ◽  
pp. 5046
Author(s):  
Zong-Wei Liu ◽  
Chun-Mei Yang ◽  
Ying Jiang ◽  
Lei Xie ◽  
Jin-Yan Du ◽  
...  
Keyword(s):  
Transmission Loss ◽  
Spatial Coherence ◽  
Correlation Coefficients ◽  
Channel Correlation ◽  
Acoustic Channel ◽  
Physical Mechanisms ◽  
Channel Characteristics ◽  
Special Case ◽  
Array Gain ◽  
Insight Into

Array gain is investigated based on the acoustic channel characteristics manifested by the fluctuant transmission loss and decrease in the acoustic channel spatial coherence. An analytical expression is derived as the summation of the products of the acoustic channel correlation coefficients and root-mean-square pressures. The formula provides insight into the physical mechanisms of the gain degradation in the ocean waveguide. Furthermore, this formula provides a new method to study array gain in the ocean waveguide from underwater acoustic field. The obtained expression is a more general formula that is applicable to shallow water, deep sea, and continental slope, with the traditional methods as a special case. Numerical results show that the array gain calculated by previous formulas are generally overestimated, caused by ignoring the effect of transmission loss fluctuation.

scholarly journals Sex Work in Slovenia: Assessing the Needs of Sex Workers

2021 ◽  
pp. 136078042110184
Author(s):  
Leja Markelj ◽  
Alisa Selan ◽  
Tjaša Dolinar ◽  
Matej Sande
Keyword(s):  
Needs Assessment ◽  
Sex Work ◽  
Sex Workers ◽  
Point Of View ◽  
Social Distress ◽  
Legal Advice ◽  
The Law ◽  
Client Relations ◽  
Insight Into

The research comprehensively identifies the needs and problems of sex workers in Slovenia from the point of view of three groups of actors in a decriminalized setting. The objective of the rapid needs assessment was to identify the needs of sex workers as perceived by themselves. In order to gain a deeper insight into this topic, we analyzed the functioning of the organizations working with the population, and examined the perspective of the clients. The results of the study show that no aid programmes have been developed for sex workers, even though organizations from various fields often come in contact with this population. Sex workers express the need to be informed about various topics (health, the law, legal advice) and emphasize client relations as the primary issue. The findings indicate the need for the development of a specialized aid programmes to address the fields of advocacy, reducing social distress and providing psychosocial assistance.

scholarly journals Natural Variation in Plant Pluripotency and Regeneration

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1261
Author(s):  
Robin Lardon ◽  
Danny Geelen
Keyword(s):  
De Novo ◽  
Shoot Organogenesis ◽  
In Vitro Regeneration ◽  
Relative Role ◽  
Root Explants ◽  
Experimental Systems ◽  
Complex Process ◽  
Insight Into ◽  
Molecular Framework

Plant regeneration is essential for survival upon wounding and is, hence, considered to be a strong natural selective trait. The capacity of plant tissues to regenerate in vitro, however, varies substantially between and within species and depends on the applied incubation conditions. Insight into the genetic factors underlying this variation may help to improve numerous biotechnological applications that exploit in vitro regeneration. Here, we review the state of the art on the molecular framework of de novo shoot organogenesis from root explants in Arabidopsis, which is a complex process controlled by multiple quantitative trait loci of various effect sizes. Two types of factors are distinguished that contribute to natural regenerative variation: master regulators that are conserved in all experimental systems (e.g., WUSCHEL and related homeobox genes) and conditional regulators whose relative role depends on the explant and the incubation settings. We further elaborate on epigenetic variation and protocol variables that likely contribute to differential explant responsivity within species and conclude that in vitro shoot organogenesis occurs at the intersection between (epi) genetics, endogenous hormone levels, and environmental influences.

scholarly journals Correlation of a Temperate UV-Weathering Cycle to Outdoor Exposure for the Determination of the Environmental Instability of Polyethylene Films Using HT-GPC Analysis

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 591
Author(s):  
Gavin Hill ◽  
Celine Moreira ◽  
Florence Huynh ◽  
Ana Trufasila ◽  
Faith Ly ◽  
...  
Keyword(s):  
Physical Property ◽  
Gel Permeation Chromatography ◽  
Outdoor Exposure ◽  
Accelerated Weathering ◽  
Micro Particles ◽  
Exposure Site ◽  
Plastic Materials ◽  
Physico Chemical ◽  
Environmental Instability ◽  
Insight Into

Accelerated UV-weathering cycles are predominately used for evaluating the durability of plastic materials, particularly polyethylene (PE) films. The point of failure for this testing is usually the loss of a physical property, such as the loss of tensile strength over time. For plastics designed to be instable under environmental conditions, the accelerated weathering cycles are yet to be defined and their correlation to outdoor exposure has yet to be made. This study demonstrates the utility of a newly defined temperate accelerated UV-weathering cycle, recently codified in the British Standard PAS 9017:2020. In addition, the effectiveness of the laboratory weathering cycle has been correlated to real-world outdoor exposure through simultaneous testing of the same samples at a specialist outdoor exposure site in Florida. The utility of the testing methodology and the performance of the polyethylene samples was demonstrated through the use of High Temperature Gel Permeation Chromatography (HT-GPC) analysis. The data led to a detailed insight into the physico-chemical changes occurring in the PE films upon exposure to environmental stimuli. By comparison, and surprisingly, the techniques employed appear to provide an insight into the processes in which secondary micro-particles of PE are formed from macro-polyethylene samples. The temperate accelerated UV-weathering cycle over 14 days demonstrated an approximate correlation to 90 days of outdoor exposure in Florida for the PE film studied.

Testing of Automated Systems from the Safety Point of View

1981 ◽  
Vol 18 (03) ◽  
pp. 234-244
Author(s):  
John D. Vitkauskas ◽  
John R. Peters
Keyword(s):  
Test Procedure ◽  
Coast Guard ◽  
Point Of View ◽  
Automated Systems ◽  
Testing Procedures ◽  
Procedure Guidelines ◽  
Safety Systems ◽  
Insight Into

The Coast Guard NVIC 1–69 has provided guidelines for the design of automated systems so that human surveillance can be reduced without jeopardizing the vessel. An integral part of these guidelines is the preparation of a Test Procedure which periodically tests the vital safety systems to increase the probability that they will function properly when called on. However, the Test Procedure guidelines are general and subject to wide interpretation. This paper attempts to provide some insight into what needs to be periodically tested, why the testing is required, and what techniques are acceptable, at the same time stressing the need for efficient testing. Some examples are also provided of testing procedures that have been found to be efficient and sufficiently comprehensive.

Reconsidering Kant’s Rejection of Indirect Arguments in Transcendental Philosophy

2021 ◽  
pp. 1-19
Author(s):  
Marcel Buß
Keyword(s):  
Immanuel Kant ◽  
Explanatory Power ◽  
Transcendental Philosophy ◽  
Point Of View ◽  
Transcendental Arguments ◽  
Mathematical Proofs ◽  
Law Of Excluded Middle ◽  
The Law ◽  
Excluded Middle ◽  
Insight Into

Abstract Immanuel Kant states that indirect arguments are not suitable for the purposes of transcendental philosophy. If he is correct, this affects contemporary versions of transcendental arguments which are often used as an indirect refutation of scepticism. I discuss two reasons for Kant’s rejection of indirect arguments. Firstly, Kant argues that we are prone to misapply the law of excluded middle in philosophical contexts. Secondly, Kant points out that indirect arguments lack some explanatory power. They can show that something is true but they do not provide insight into why something is true. Using mathematical proofs as examples, I show that this is because indirect arguments are non-constructive. From a Kantian point of view, transcendental arguments need to be constructive in some way. In the last part of the paper, I briefly examine a comment made by P. F. Strawson. In my view, this comment also points toward a connection between transcendental and constructive reasoning.

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