Corona Treatment Research Articles

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Electrospun Nanofibers Containing Natural Deep Eutectic Solvents Exhibiting a 3D Rugose Morphology and Charge Retention Properties.

In the present study, electrospun nanofibers of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a biodegradable polyester, containing natural deep eutectic solvents (NADES) were obtained and reported for the first time, exhibiting an unreported 3D morphology and enhanced charge retention properties. Choline chloride (ChCl)/urea/water in a molar ratio of 1:2:1 was used as the NADES model system. Electrospun nanofibers were produced from a 10 wt % solution of PHBV containing 26 wt % NADES with respect to the polymer and were deposited on different substrates, that is, aluminum foil and non-woven spunbond polypropylene (PP). The morphology and charge retention ability were characterized under different conditions and on different substrates. The attained fiber morphology for the NADES-containing mats showed an average fiber diameter of around 300 nm, whereas the pure PHBV polymer under the same conditions produced electrospun fibers of around 880 nm. However, the deposition of PHBV/ChCl/urea/water fibers resulted in a surprising macroscopic rugose 3D surface morphology made of aligned nanofibers when processed at 50% relative humidity (RH). The nanofiber grammages above which this 3D morphology, associated with NADES-induced charge retention, formed was found to be dependent on the substrate used and RH. This morphology was not seen at 20% RH nor when pure PHBV was produced. Charge stability studies revealed that PHBV/ChCl/urea/water nanofibers exhibited lasting charge retention, especially when sandwiched between spunbond polypropylene textiles. Finally, such multilayer structures containing a very thin double layer of PHBV/ChCl/urea/water fibers after corona treatment exhibited improved paraffin aerosol penetration, which was ascribed to the combination of thinner fibers and their charge retention capacity. The here-developed electrospun PHBV fibers containing NADES demonstrated for the first time a new potential application as electret filter media.

P(VDF-TrFE)/BaTiO3 Nanofibrous Membrane with Enhanced Piezoelectricity for High PM0.3 Filtration and Reusable Face Masks

In the background of air pollution and regular COVID-19 prevention, personal protective masks are necessary for our daily life. However, protective masks with high PM0.3 filtration usually have poor air permeability and are mostly disposable, leading to a heavy burden on the environment. In this work, a reusable membrane based on piezoelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] nanofibers embedded with BaTiO3 nanoparticles (BTO NPs) was developed. The P(VDF-TrFE)/BTO composite nanofibers not only have enhanced piezoelectricity and surface polarity but also have reduced diameters that could be beneficial for electrostatic adhesion, pole-polar interactions, and mechanical sieving to increase the PM0.3 capture capacity. Moreover, the BTO NPs also improved the charge storage capacity of the composite membrane, which could further enhance the PM0.3 filtration efficiency after corona treatment. The piezoelectric mask based on P(VDF-TrFE)/BTO composite nanofibers has high filtration efficiencies of 96% for PM0.3 and 98% for bacteria, while the pressure drop was only 182 Pa, which is lower than the commercial N95 standard of 343.2 Pa. Furthermore, the piezoelectric mask has a long and stable filtration performance after 5 cycles of 75% alcohol disinfection, demonstrating that the P(VDF-TrFE)/BTO composite membrane has a potential application in personal protective masks with comfortable and reusable properties.

Level of Awareness & Attentiveness Associated to Novel Corona Virus (Covid-19) among People of Pakistan

Background: Corona viruses are huge family of viruses named for the crown-like spikes on their surface. There are seven CoV viruses which will infect humans, including the “2019 Novel Corona virus” (the infection right now making features), SARS and MERS.. Symptoms include fever, breathlessness, and coughing. The illness spreads through animals and shut contact with people that have already been infected currently the virus is spreading from person to person in China as many recent cases don't seem to be related to animal markets. Method: A cross sectional investigation about the attention of corona virus (CoV), its symptoms, diagnosis and treatment was directed in several groups of individuals i.e, literate and illiterate people of Pakistan. Data was collected by means of survey based questionnaire which was prepared by the pharmacy students of Jinnah University for Women. Result: According to demographic data obtained by the cross sectional investigation about the attention of corona virus in Pakistan which was conducted among literate and illiterate people (18-25 of age).Out of which 47.9% were medical students, among these people 92.6% knew about corona virus and 97.5% people knew about its person to person transmission, and 58.8% understand its symptoms in keeping with this survey only 23.5% people knew the treatment, 76.5% people didn’t even understand the diagnosis of corona virus. Conclusion: The motivation behind this study was to assemble the information about the extent of control of corona virus with improving knowledge awareness of CoV (COVID-19) to raised inform patients about this life threatening disease in health care systems.

Pipeline Processing via the Combination of Heat and Corona Treatments for Improving the Poly(p-phenylene benzobisoxazole) Fiber Surface and Anti-Aging Performances.

Although many strategies have been reported for modified poly(p-phenylene benzobisoxazole) (PBO) fiber surfaces, the absence of approaches with the potential of applications in industries limits the further applications of the fibers in a wide field. Herein, PBO fibers are modified by heat treatment combined with corona discharge treatment, which is a continuous industrialized method. Then, the surface morphology, wettability, orientation, and crystallinity of the PBO fibers are characterized in detail. Systematic experiments demonstrate that the high thermal treatment can improve the orientation and crystallization degree of the fibers, as well as the degradation resistance. In addition, owing to the synergistic mechanism of ozone and high-frequency shock, the corona discharge treatment increases the contents of O and N elements on the surfaces, which improves the superficial properties of the fibers. Based on the modification of PBO fibers, the inter-laminar shear strength between the fiber and the resin for the composite increases to 94.8%, and the tensile strength of the composite increases to 29.2%, compared to those using untreated fibers. In general, the proposed modification strategy not only easily improves the surface properties and the mechanical properties of composites but also can be used with great potential in industrial production.

Influence of corona poling on ZnO properties as n-type layer for optoelectronic devices

Corona poling effects on optical and structural characteristics of zinc oxide (ZnO) thin films prepared by sol–gel spin coating technique were investigated. Atomic force microscope study showed the formation of pyramidal grains structure on the Corona-treated surface. The green–yellow photoluminescence peak centered at 2.36 eV and correlated to the antisite oxygen OZn defect, was found to decrease. X-ray diffraction patterns demonstrated that the Corona treatment enhanced the polycrystalline nature and increased the grain sizes of the ZnO thin films, which was also beneficial for electron transport. The role of the surface roughness of the ZnO thin film as electron transport layer in determining the photovoltaic effect of the inverted solar cells (ISCs) was examined by fabricating ISCs based on P3HT/PC61BM. The power conversion efficiency (PCE) obtained from these fabricated ISCs increased from 3.05 to 3.34%.

Bilayer biocomposites of PVOH/WPI/nano‐silica treated with corona discharge

AbstractIn order to evaluate the influence of a different assembly of biocomposites of polyvinyl alcohol (PVOH), whey protein isolates (WPI), and nano‐silica (NS), a bilayer film treated with corona discharge was produced through a two‐step lamination. The first layer of PVOH/NS, treated with up to 90 s of discharge, and the second layer of WPI/NS, the bilayer films had their morphology, tensile strength, and water barrier investigated and compared to a single layer PVOH/WPI/NS film. Corona discharge increased the wettability of the first layer, improving the ability to interact with the second layer, thus increasing the adherence between these layers. Films treated with higher times of discharge showed a homogeneous transition between phases, suggesting compatibility, and adherence between layers. At 90 s of corona discharge treatment, bilayer films showed a tensile strength 72% higher than the bilayer film not treated and also 23% more resistant and 7.4 times more ductile than the single‐layer film. The lamination process and corona treatment increase the affinity of water with film constituents, thus leading to a higher permeability. The use of corona discharge associated with the lamination of PVOH/WPI/NS biocomposites provides a bilayer film and produces a more resistant, flexible, and ductile biocomposite film for packaging.

Influence of Crosslinking Extent on Free Volumes of Silicone Rubber and Water Diffusion after Corona Discharge.

Silicone rubber is widely used as an insulating material. In this article, silicone rubber samples were prepared by varying the content of crosslinker (2,5-bis(tert-butyl-peroxy)-2,5-dimethylhexane, DBPMH), and the free volume holes in the samples were investigated by means of positron annihilation lifetime spectroscopy (PALS) measurement. The surface chemical structure, surface micromorphology and water diffusion of the samples after corona discharge treatment were studied by FTIR, SEM and EIS measurements, respectively. As the crosslinker weight ratio increased from 0.2 wt.% to 1.5 wt.%, the mean free volume hole size first decreased and then remained unchanged. However, the concentration of free volume holes did not vary as the crosslinker weight ratio increased. SEM morphologies show that surface cracks were produced on samples having high crosslinking levels after corona treatment. The water diffusion coefficient of samples after corona treatment increased from 3.13 × 10−10 cm2 s−1 to 17.68 × 10−10 cm2 s−1 in the initial immersion period, as the crosslinker weight ratio increased from 0.2 wt.% to 3.0 wt.%. The results indicated that deterioration of samples with high crosslinking levels were more serious and water repellency more easily lost. The corona resistance ability of low crosslinking level silicone rubber stems from internal low molecular weight molecules.

A decision framework model for hospital selection in COVID-19 pandemic: A FIS approach

ABSTRACT Covid-19 has affected many countries resulting in the loss of many human lives. During the first and second waves of the pandemic, hospitals played a crucial role in saving human lives and hence became the last hope of survival for corona patients. Hence the hospital selection is a crucial decision to be made by corona patients keeping the third wave of the pandemic in view. This work proposes a decision framework for hospital selection considering the essential criteria in the context of providing corona treatment to patients. The proposed framework is based on the Fuzzy Inference System (FIS) and utilizes rules framed by decision-makers for determining the Performance Index (PI) of hospitals. Based on the values of PI patients can select the hospital to which they can get admitted with assurance to get the best possible treatment. Further, the sensitivity analysis has been done to demonstrate the robustness of the framework. The results of the work also provide hospitals a deep insight into their performance and customers’ perception of their performance, helping them to initiate appropriate enhancement measures. Six hospitals from central India have been considered as case hospitals to demonstrate the applicability of the proposed framework.

Effects of Corona Treatment on Cellular Attachment and Morphology on Polydimethylsiloxane Micropillar Substrates

Effects of Corona Treatment on Cellular Attachment and Morphology on Polydimethylsiloxane Micropillar Substrates

An Application of Corona-Treated and Chemically Modified Poly(D-Lactic Acid) Films as Benzydamine Hydrochloride Carriers

In the present article, chitosan and casein polyelectrolyte multilayers (PEMs) deposited on poly(D-lactic acid) (PDLA) substrates are investigated. PDLA substrates are modified both physically under negative corona discharge and chemically with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> -ethyl- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N ^\prime $ </tex-math></inline-formula> -(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC). The substrates modified by a combination of corona discharge and chemical modification are also studied. The topology of the multilayers is studied with AFM. The electret properties of the substrates obtained are investigated. The dependencies of the normalized surface potential on the storage time are studied. A layer-by-layer (LbL) deposition technique is used for multilayer deposition on the substrates. PEMs with eight layers are obtained. Benzydamine hydrochloride (Benz) is immobilized in the resulting PEMs. Drug loading efficiency and drug release from PDLA multilayers are studied. The results of PDLA multilayers demonstrate that the chemical modification of the PDLA substrates increases the amount of Benz loaded in the multilayers. The combination of corona treatment and chemical modification results in lower amounts of loaded drugs in both combination cases, when compared with only chemically modified samples.

Atmospheric Pressure Plasma in Industrial Applications: Surface treatment of thermally sensitive polymers

AbstractFor several years now, atmospheric pressure plasma has been discussed as a future technology. It is a key technology with a long and successful past. For many decades, corona treatment has been an atmospheric pressure plasma application, well established within the extrusion and converting industry. Corona technology has been applied in industrial use since the 1950s, mostly within converting polymer films and to some degree paper, board, and metal foil. Corona treatment is used to improve the adhesion of printing inks, lacquers, adhesives, and coatings. From this strong base, atmospheric pressure plasma is growing into new applications. This paper introduces atmospheric pressure plasma basics and compares modern atmospheric pressure plasma technologies for grafting chemical functional groups on polymer surfaces.

EMERGENCE OF NEW STRAINS OF SARS-COV-2: AFRICA'S FATE AND ITS PREPAREDNESS AGAINST COVID-19 INFECTION WAVES.

Background:Severe acute respiratory syndrome coronavirus-2(SARS-CoV-2) has infected over 100million individuals worldwide with diverse impacts on nations. The rising cases of new strains and resultant infection waves create an urgent need to assess the readiness of countries especially in Africa to mitigate the impact on community transmission. This paper delivers a brief synopsis of the novel SARS-CoV-2, emerging cases of new variants reported worldwide, and implications for genetic surveillance of disease transmission in low- and middle-income countries (LMICs) especially Africa.Materials and Methods:Literature search used keywords like SARS-CoV-2; COVID-19 epidemiology; pandemic waves; corona outbreak, clinical syndromes, treatments, prevention and control. Cross-sectional and observational studies published on COVID-19 from 2019 till date of study provided main information sources. Databases such as Web of Science, Embase, PubMed and Google Scholar were utilised.Main findings:Over 220 countries have documented COVID-19 cases with varied severity till date. Before the spikes in resurgence, a highly virulent mutated (>90% fatality rate) novel strain of COVID-19 had been documented. There is very little data to ascertain the impact of the COVID-19 infection waves in LMICs.Discussion:LMICs especially African countries still grapple with significant challenges like inefficient surveillance mechanisms, inadequate vaccination coverage, inadequate enforcement of environmental health strategies, poor health systems etc. Hence, Africa’s fate remains dicey in the face of the dynamic evolution of the SARS-CoV-2 and other identified challenges.Conclusion:The adoption of a multidisciplinary approach to mitigate the impact of emergence of mutant SARS-CoV-2 variants and resurgence of infection spike is recommended.

Development of PES-based hydrophilic membranes via corona air plasma for highly effective water purification

An ecological and practical approach based on the corona-induced graft copolymerization technique was applied to modify the surface properties of the polyethersulfone (PES) membrane using SBMA zwitterionic monomers to improve the anti-fouling ability during the process of separating oil-water emulsions. As a result, the effects of corona treatment conditions on the physicochemical properties of the membrane were characterized using different analytical instruments. The surface hydrophilicity of the PES membrane was considerably improved, characterized by a decrease in CA from 72 to ∼17◦. In addition, the highest pure water and emulsion fluxes of the PES-g-SBMA membrane were improved by 1247% and 325% compared to the unmodified membrane, reaching 840 Lm−2.h−1 and 364 Lm−2.h−1, respectively. The modified membranes exhibited not only high flux but also high oil rejection (> 99%), showing promising potential for use in industrial applications due to the production of high-quality water with a concentration of oil less than six ppm. Overall, this study provides an easy one-step preparation method for PES graft membranes with high anti-fouling property whose thickness and morphology can only be fully controlled by changing the corona parameters (power and time) without the need for a chemical initiator or the use of more monomer.

Very Early Corona Treatment-Mediated Artificial Incubation of Silkworm Eggs and Germline Transformation of Diapause Silkworm Strains

Diapause is an important biological characteristic for many insect species to adapt to adverse environmental conditions and maintain the continuity of the race. Compared with the traditional hydrochloric acid or/and cold storage treatment methods, the artificial corona incubation technology of silkworm (Bombyx mori) eggs has many advantages including, the absence of pollution, easy operation and safety. However, this technology has not yet been applied in sericulture. In this study, we developed a novel artificial corona instrument to successfully disrupt the diapause of newly laid and refrigerated eggs from various Chinese and Japanese lineage silkworm strains. Subsequently, we invented a very early corona treatment (VECT) strategy to prevent the diapause of newly laid silkworm eggs within 4 h of oviposition. The hatching rates of the larvae were more than 95% in all diapause silkworm strains, which was comparable to the effect of the traditional HCl treatment strategy. In addition, we developed a combination strategy of VECT and pre-blastoderm microinjection and successfully created transgenic silkworms in various diapause strains. The results of the current study can aid in improving the corona artificial incubation technology and promote its application in sericulture.

Detection of primary aromatic amines content in food packaging ink and migration from printed plastic bags

The extraction experiment of PAAs is carried out by using different solvents to seek out the best extraction one among methylene chloride, n-hexane, ethyl acetate and methanol. Migration test of PAAs from different polymer flexible packaging composite materials under both conditions of 40 ℃/10d and 70 ℃/2 h in neutral and oil simulants are conducted. An effective HPLC method in ESI+ mode is proposed to separate and screen 25 kinds of PAAs listed in SN/T 2893–2011. The extraction test clearly confirms the existence of PAAs in both polyurethane ink and UV-ink which are supposed to be yielded from dye intermediate and azo auxiliary. The comparison study of migration under 70 ℃/2 h for the corona and non-corona surfaces of the above-mentioned two kinds of films reveals that corona treatment improves the printing capacity and thus motivates the migration of PAAs, but has no effect on the final migration quantity.

Vol4 num3-7 Study of the influence of surface treatments in kraft paper for the compatibilization with thermoplastic polymers

The transports industry has been presenting a set of solutions that integrates natural fibers and their compatibility with structural materials, like polymers. However, it is fundamental to ensure the fulfillment of mechanical requirements. One of the main reasons that is driving the use of this type of fibers, instead of synthetic fibers, is related with the some actual trends, such as weight reduction, which is linked with its lower density. Moreover, weight reduction also contributes, indirectly, to the sustainability and decrease of greenhouse gases emissions, since it makes possible to reduce the fuel consumption of transports.However, due to the different polarities verified between apolar thermoplastic polymers, such as polypropylene (PP), and natural fiber reinforcements, such as kraft paper, a study of the effect of physical and chemical surface treatments was carried out in order to verify their influence on the fiber-matrix interface properties. The physical process, corona treatment, was applied in the kraft paper with different discharge dosages, while the chemical treatment was performed through the use of several alkali solutions with different concentrations of NaOH. The obtained results from the performed tests shows that the alkali solution treatments improved, up to 57%, the mechanical properties of tensile strength and Young Modulus of the composite material, comparatively with the effect of corona treatment on its surface. These results induce an increase of interface compatibility between the matrix and kraft paper.

Impact of corona and radio-frequency plasma treatment on the degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)

Impact of corona and radio-frequency plasma treatment on the degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)

Iranian nongovernmental organizations' initiatives in COVID-19 pandemic.

BACKGROUND:With the outbreak of the COVID-19 virus crisis worldwide, including Iran, the need for corona prevention and treatment has become a national priority. With many businesses closed in the wake of COVID-19 and job losses and declining incomes, vulnerable individuals' and families' access to the minimum wage and healthcare facilities is falling, and their health is exposed to a great risk. In Iran, a significant number of vulnerable groups are supported by nongovernmental organizations (NGOs). This study is designed to understand the performance of NGOs after the onset of the COVID-19 crisis.MATERIALS AND METHODS:This study was carried out based on qualitative research between June and September 2020 in Tehran. This study was conducted using individual interviews with 33 managers and experts of 24 active NGOs providing services to vulnerable groups and a member of an NGO network. Data were analyzed using content analysis.RESULTS:Two main themes of service initiatives were extracted: (a) service initiatives to protect the target population against COVID-19 infection and its aftermath and (b) management initiatives to retain staff, finance, and adapt the organization to crisis situations. Service initiatives included five categories of health service initiatives, livelihood, employment, education, and leisure initiatives, while organizational management initiatives include human resource management, financial management, and communication with organizations.CONCLUSION:The COVID-19 breadth and its special features have set it apart from other crises and have led NGOs to work hard on several fronts to care for the most vulnerable people against the epidemic and its consequences and maintain the performance of their organizations. The unique role of cyberspace has made it one of the definitive pillars of the activities of NGOs, not only during the epidemic but also after its end.

Development of Roll-to-Roll Manufacture Process for Stretchable Device Substrate

As the next generation of smart devices, many stretchable devices with have been developed. In this process, it is necessary to fabricate stretchable substrates and electrodes. However, in many studies, stretchable devices are currently manufactured by hand. Considering future social implementation, it is important to realize a mass production process for substrates and wiring. In this study, we conducted a PoC of a mass production process for stretchable devices by combining a substrate fabrication process by Roll-to-Roll (R2R) and a liquid metal wiring fabrication process by dispensing. To realize this process, we assembled a new R2R system by incorporating a slot die coater and applicator, which is the R2R coating process, and a corona treatment system to improve the wettability of polymeric materials into the R2R process equipment. Using this equipment, we evaluated the device at 50% elongation and fabricated a large scale stretch device.

Predicting vulnerability to stress based on psychological capitals and personality traits in the treatment staff of Corona

Background and purpose: Considering the importance of maintaining the medical force and keeping this group healthy as people who protect the health and well-being of other members of society, it is necessary to investigate the level of their anxiety and psychological pressure as well as the relative factors so that based on the results, steps can be taken to maintain and improve their mental health. Therefore, the present study aimed to predict vulnerability to stress based on psychological capital and personality traits in the treatment staff of Corona. Methodology: The research method was a correlation-descriptive type. The statistical population of the present study included all the treatment staff of the hospitals dealing with Corona in Tehran in 2020, and 228 people were selected as a statistical sample using the convenience sampling method. The data collection tool included the short-form Neo McCree and Costa (1985) personality questionnaire, the Luthans et al. (2007) psychological capital questionnaire, and the Seyed Khorasani and Sediqani (2008) stress syndrome measurement scale. Results: Pearson's correlation coefficient and regression analysis showed that personality traits and psychological capital have a correlation coefficient of 0.62 with the vulnerability to the stress of corona treatment staff. This means that 39% of the total variance of the stress vulnerability of the Corona treatment staff is explained by personality traits and psychological capital (P&lt;0.05). Conclusion: The results showed that among the personality traits, neuroticism, openness to experience, agreeableness, and conscientiousness, and among the psychological capitals, self-efficacy and optimism could predict the vulnerability to stress of the corona treatment staff.