scholarly journals Hydrolysis as a basis for processing vegetable waste into bioplastics

2020 ◽  
Vol 221 ◽  
pp. 03009
Author(s):  
Guzel Ilalova ◽  
Ruslan Safin ◽  
Shamil Mukhametzyanov ◽  
Albina Gazizullina

The greening of processing waste from logging and woodworking industries involves measures to prevent the negative impact of production processes on the natural environment and is enabled by the development of resource-saving techniques that minimize harmful emissions to the environment. These production operations are based on hydrolytic cleavage of glycoside bonds of vegetable biomass polysaccharides with the formation of monosaccharides as the main reaction products. Despite the wide range of available methods of processing wood into promising materials (heat treatment, pyrolysis, hydrolysis, etc.), one of the most effective methods is to produce sugars by weak acids hydrolysis. In this regard, the paper describes the technology of high-temperature hydrolysis of pine sawdust with sulfurous acid in order to detect reducing substances (RS) in the hydrolysis residue. The paper considers the effect of sulfurous acid, temperature, and treatment time on the yield of RS.

2021 ◽  
Vol 274 ◽  
pp. 04013
Author(s):  
Ruslan Safin ◽  
Nour Galyavetdinov ◽  
Regina Salimgaraeva ◽  
Guzel Ilalova ◽  
Ksenia Saerova

Polymers and associated composite materials play an increasingly prominent role among structural materials. The relevance of the use of bioplastics as an alternative to synthetic polymers increases year by year. In this regard, the paper describes the production of a ligno-filled polymer material based on polyhydroxyalkanoates to be used in the production of building materials. The studies allowed us to produce the material from wood hydrolyzates. The highest yield of reducing substances in course of pine sawdust hydrolysis with 4% sulfurous acid occurred at 170°C. To obtain a biopolymer in liquid wood hydrolyzate medium, the Cupriavidus necator strain was used, which after 50 hours of cultivation gave a biopolymer yield of up to 15 g/l. The studies of the strength characteristics of the composite based on the obtained bioplastic and dried solid wood hydrolysates allowed us to produce a balanced composition for subsequent use in construction.


2018 ◽  
Vol 69 (9) ◽  
pp. 2416-2419
Author(s):  
Mihai Branzei ◽  
Mihai Ovidiu Cojocaru ◽  
Leontin Nicolae Druga ◽  
Florica Tudose ◽  
Roxana Trusca

Experimental research aimed to find a solution for replacing components with high toxicity (or generating such components as a result of reactions occurring in the environment at processing temperatures) from the environments used for ferritic nitrocarburising process (FNCP) with non-hazardous components, but extremely active during the process. In the temperature range in which this type of processing is applied (lower than the eutectoid transformation temperature in the Fe-N phase diagram), the most commonly used media are liquid or gaseous; liquid ones contain toxic components (sodium or potassium cyanates/cyanides), and gaseous ones require complex equipments. Packing is extremely rarely used, but in this case pack-mix contain toxic components (15 � 20 wt.% sodium or potassium ferrocyanide). Urea also called carbamide (CO (NH2)2) is the active component in the pack-mixing proposed to be used for FNCP. Carbamide is used in low temperature cyanidation thermochemical heat treatment (liquid FNC), together with sodium or potassium carbonates, resulting in very toxic reaction products (sodium or potassium cyanates). Compared to cyanidation, in the version proposed in the paper, the carbamide does not react with carbonates because they are not found in the composition of the environment but decomposes in the presence or absence of oxygen (by a disproportionation reaction) with the formation of some gas molecules interesting for the process. It has been concluded that the use of carbamide together with two other components, activated charcoal (having a triple role - dispersing, storage, surface saturation) and respectively ammonium chloride as surface reaction activator, is an effective solution for achieving the desired goals by applying this type of thermochemical processing to a wide range of products made of quality steels up to alloy miscellaneous steels.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Verónica Gamón ◽  
Isabel Hurtado ◽  
José Salazar-Fraile ◽  
Gabriel Sanfélix-Gimeno

AbstractSchizophrenia is a chronic mental condition presenting a wide range of symptoms. Although it has a low prevalence compared to other mental conditions, it has a negative impact on social and occupational functions. This study aimed to assess the appropriateness of antipsychotic medications administered to schizophrenic patients and describe current treatment patterns for schizophrenia. A retrospective cohort study was conducted in all patients over the age of 15 with an active diagnosis of schizophrenia and treated with antipsychotics between 2008 and 2013 in the Valencia region. A total of 19,718 patients were eligible for inclusion. The main outcome assessed was inappropriateness of the pharmacotherapeutic management, including polypharmacy use. Altogether, 30.4% of patients received antipsychotic polypharmacy, and 6.8% were prescribed three or more antipsychotics. Overdosage affected 318 individuals (1.6%), and 21.5% used concomitant psychotropics without an associated psychiatric diagnosis. Women and people with a comorbid condition like anxiety or depression were less likely to receive antipsychotic polypharmacy. In contrast, increased polypharmacy was associated with concomitant treatment with other psychoactive drugs, and only in user on maintenance therapy, with more visits to the mental health hospital. Overall, we observed a high level of inappropriateness in antipsychotic prescriptions. Greater adherence to guidelines could maximize the benefits of antipsychotic medications while minimizing risk of adverse effects.


2021 ◽  
Vol 11 (14) ◽  
pp. 6445
Author(s):  
David Ibarra ◽  
Raquel Martín-Sampedro ◽  
Bernd Wicklein ◽  
Úrsula Fillat ◽  
María E. Eugenio

Motivated by the negative impact of fossil fuel consumption on the environment, the need arises to produce materials and energy from renewable sources. Cellulose, the main biopolymer on Earth, plays a key role in this context, serving as a platform for the development of biofuels, chemicals and novel materials. Among the latter, micro- and nanocellulose have been receiving increasing attention in the last few years. Their many attractive properties, i.e., thermal stability, high mechanical resistance, barrier properties, lightweight, optical transparency and ease of chemical modification, allow their use in a wide range of applications, such as paper or polymer reinforcement, packaging, construction, membranes, bioplastics, bioengineering, optics and electronics. In view of the increasing demand for traditional wood pulp (e.g., obtained from eucalypt, birch, pine, spruce) for micro/nanocellulose production, dedicated crops and agricultural residues can be interesting as raw materials for this purpose. This work aims at achieving microfibrillated cellulose production from fast-growing poplar and olive tree pruning using physical pretreatment (PFI refining) before the microfibrillation stage. Both raw materials yielded microfibrillated cellulose with similar properties to that obtained from a commercial industrial eucalypt pulp, producing films with high mechanical properties and low wettability. According to these properties, different applications for cellulose microfibers suspensions and films are discussed.


Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 518
Author(s):  
Bronwyn Egan ◽  
Zwannda Nethavhani ◽  
Barbara van Asch

Macrotermes termites play important ecological roles and are consumed by many communities as a delicacy and dietary complement throughout Africa. However, lack of reliable morphological characters has hampered studies of Macrotermes diversity in a wide range of scientific fields including ecology, phylogenetics and food science. In order to place our preliminary assessment of the diversity of Macrotermes in South Africa in context, we analysed a comprehensive dataset of COI sequences for African species including new and publicly available data. Phylogenetic reconstruction and estimates of genetic divergence showed a high level of incongruity between species names and genetic groups, as well as several instances of cryptic diversity. We identified three main clades and 17 genetic groups in the dataset. We propose that this structure be used as a background for future surveys of Macrotermes diversity in Africa, thus mitigating the negative impact of the present taxonomic uncertainties in the genus. The new specimens collected in Limpopo fell into four distinct genetic groups, suggesting that the region harbours remarkable Macrotermes diversity relative to other African regions surveyed in previous studies. This work shows that African Macrotermes have been understudied across the continent, and that the genus contains cryptic diversity undetectable by classic taxonomy. Furthermore, these results may inform future taxonomic revisions in Macrotermes, thus contributing to advances in termitology.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1818
Author(s):  
Jennifer Routh ◽  
Sharmini Julita Paramasivam ◽  
Peter Cockcroft ◽  
Vishna Devi Nadarajah ◽  
Kamalan Jeevaratnam

The public health implications of the Covid-19 pandemic have caused unprecedented and unexpected challenges for veterinary schools worldwide. They are grappling with a wide range of issues to ensure that students can be trained and assessed appropriately, despite the international, national, and local restrictions placed on them. Moving the delivery of knowledge content largely online will have had a positive and/or negative impact on veterinary student learning gain which is yet to be clarified. Workplace learning is particularly problematic in the current climate, which is concerning for graduates who need to develop, and then demonstrate, practical core competences. Means to optimise the learning outcomes in a hybrid model of curriculum delivery are suggested. Specific approaches could include the use of video, group discussion, simulation and role play, peer to peer and interprofessional education.


2018 ◽  
Vol 26 (2) ◽  
pp. 237-267 ◽  
Author(s):  
Chao Qian ◽  
Yang Yu ◽  
Ke Tang ◽  
Yaochu Jin ◽  
Xin Yao ◽  
...  

In real-world optimization tasks, the objective (i.e., fitness) function evaluation is often disturbed by noise due to a wide range of uncertainties. Evolutionary algorithms are often employed in noisy optimization, where reducing the negative effect of noise is a crucial issue. Sampling is a popular strategy for dealing with noise: to estimate the fitness of a solution, it evaluates the fitness multiple ([Formula: see text]) times independently and then uses the sample average to approximate the true fitness. Obviously, sampling can make the fitness estimation closer to the true value, but also increases the estimation cost. Previous studies mainly focused on empirical analysis and design of efficient sampling strategies, while the impact of sampling is unclear from a theoretical viewpoint. In this article, we show that sampling can speed up noisy evolutionary optimization exponentially via rigorous running time analysis. For the (1[Formula: see text]1)-EA solving the OneMax and the LeadingOnes problems under prior (e.g., one-bit) or posterior (e.g., additive Gaussian) noise, we prove that, under a high noise level, the running time can be reduced from exponential to polynomial by sampling. The analysis also shows that a gap of one on the value of [Formula: see text] for sampling can lead to an exponential difference on the expected running time, cautioning for a careful selection of [Formula: see text]. We further prove by using two illustrative examples that sampling can be more effective for noise handling than parent populations and threshold selection, two strategies that have shown to be robust to noise. Finally, we also show that sampling can be ineffective when noise does not bring a negative impact.


Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 269
Author(s):  
Megawati Zunita

Mercury (Hg) is one of heavy metals with the highest toxicity and negative impact on the biological functions of living organisms. Therefore, many studies are devoted to solving the problem of Hg separation from wastewater. Membrane-based separation techniques have become more preferable in wastewater treatment area due to their ease of operation, mild conditions and also more resistant to toxic pollutants. This technique is also flexible and has a wide range of possibilities to be integrated with other techniques. Graphene oxide (GO) and derivatives are materials which have a nanostructure can be used as a thin and flexible membrane sheet with high chemical stability and high mechanical strength. In addition, GO-based membrane was used as a barrier for Hg vapor due to its nano-channels and nanopores. The nano-channels of GO membranes were also used to provide ion mobility and molecule filtration properties. Nowadays, this technology especially nanofiltration for Hg removal is massively explored. The aim of the review paper is to investigate Hg removal using functionalized graphene oxide nanofiltration. The main focus is the effectiveness of the Hg separation process.


Author(s):  
L.L. Zakharova ◽  
◽  
G.A. Zhorov ◽  
V.I. Dorozhkin ◽  
◽  
...  

Negative impact on the environment as a result of economic activity of man increasingly becomes the character of combined pollution of ecotoxicants, including xenobiotics of radiation and chemical nature. In animal husbandry in ecologically unfavorable regions, sorbtion-detoxication technologies based on the complex application of bioprotective substances of different origin are used to reduce the intake and accumulation of xenobiotics, to normalize the physiological state of animals and to obtain safe products. It is necessary to observe certain principles ensuring compatibility of components, a wide range of bioprotective action, efficiency and safety at their use in developing the compositions of such sorption-detoxifying complexes. The article substantiates the criteria that should be followed in creating sorption-detoxifying complexes and presents groups of drugs with different mechanisms of action (sorbents, antioxidants, immunomodulators, adaptogens and other biologically active substances) for inclusion in the formulations of combined compositions.


2021 ◽  
Author(s):  
Elena Evstafeva ◽  
Svetlana Tymchenko ◽  
Anna Bogdanova ◽  
Olga Zalata ◽  
Yuliia Boyarinceva ◽  
...  

<p>The implementation of basic principles of medical and ecological monitoring programs in Crimea previously reported in EGU proceedings consists of determining the content of a wide range of toxic, essential and rare earth elements in various biological substrates: soil, plants, water, human body. Biosubstrates are sampled in different locations with contrast natural and anthropogenic conditions: urbanized-rural, industrial-agricultural, natural resources. Lichens and poplar leaves are used as indicators of environmental contamination, particularly atmospheric pollution; liquid precipitation is used as an indicator showing the negative impact of air pollution on ecosystems; hair is used as an indicator of the total body intake of chemical elements. The update of databases, on some of the territories (Simferopol, Sevastopol, geographical regions with different soil characteristics, etc.) with regard to some of the elements (mercury, lead, cadmium, selenium, etc.) at this stage allowed to determine their biogeochemical status in conditions of intensive growth of anthropogenic load in recent years, and to compare it with the elemental status of the humans living in this territory. The databases for other types of territories continue to be extended, the relationship between morbidity to estimate of the environmental burden of disease for environmentally determined diseases (neurodegenerative, endocrine, respiratory, etc.) and chemical load on the territories, based on USEtox model; the functional state of target systems (nervous, immune, cardiovascular) and level of chemical elements in the human body and the overall elemental imbalance, is established. This has provided us with a degree of understanding on how the degree of population and individual health risk could be determined.</p><p>Mercury analysis was funded by RFBR according to the research project № 18-29-24212\19 entitled “Development of neutralization of mercury-containing waste without heating and the formation of wastewater”, 2018–2021 years; elemental composition was possible to determine due to RFBR project № 18-45-920042\20 entitled “Bioecological monitoring of heavy metals at board of Black Sea of Crimea”, 2018–2020 years. Physiological part of research was possible to accomplish due to funds by the V.I. Vernadsky Crimean Federal University (Project No VG2019/15, АААА-А20-120012090158-7).</p>


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