Plastic Media Research Articles

Impacts of Waste Rubber Products on the Structure and Properties of Modified Asphalt Binder: Part II-Rubber Reclaim.

The issue of forming a reliable and stable structure of a crumb-rubber-modified binder is an important scientific and technical task. The authors supplemented existing concepts of the mechanism of effective interaction with rubber crumb by introducing a preliminary first stage: controlled partial physical destruction of rubber crumb-producing rubber reclaim. Proposed physical methods of rubber crumb destruction include high shear force (roll mills), high temperature, and a plasticizing medium. The controllability and degree of devulcanization of rubber were determined by acetone-chloroform extraction in different time intervals. The degree of devulcanization of rubber in the rubber reclaim was found to be 22 ± 0.24%, with stability over 14 days. It was found that the size of the particles of the rubber reclaim in the bitumen is less than 2 µm. The properties of the structure of the binder modified with rubber reclaim, characterizing the stability and sustainability, have been studied and established. The developed modified binders are stable in storage. Rheological parameters of the structure characterizing intermolecular interaction, such as shear stability for original and RTFOT-aged, modified bitumen, meet requirements of the state standard at test temperature 64 °C. The elastic structural component of the crumb-rubber-modified binder, as indicated by the relative irreversible deformation parameter J3,2, does not exceed 2.6 kPa (<4.5 kPa) at 64 °C. Additionally, it was determined that the rheological structural parameter for fatigue resistance, which characterizes the durability of road pavement under intensive operational conditions, does not exceed 4699 kPa (<5000 kPa) at 16 °C. The use of 10% rubber reclaim combined with waste frying oil provided the opportunity to obtain a modified binder with a stable and sustainable structure without the introduction of additional stabilizers and agents. Test results showed that the overall performance characteristics of the modified binder meet the 64(S)-40 grade standards.

Abstract We042: Gelatin hydrogel elasticity influences TBX18-induced pacemaker cell behavior

Introduction: Extracellular matrix (ECM) stiffness plays a role in determining cell behavior during development and maintenance of organ function. Polystyrene dishes typically show an elastic modulus of 1 gigaPa, which is far from the elastic modulus of 10 to 15 kiloPa for myocardium. Gelatin, a derivative of collagen, is a major structural scaffolding in the myocardium including the sinoatrial node. Hypothesis: We hypothesized that gelatin hydrogel at varying stiffness serves as a platform to modulate the automaticity of cardiac pacemaker cells. Methods: Freshly isolated neonatal rat ventricular myocytes (NRVMs) were cultured as monolayers on regular, plastic cell culture plate or on 3%, 5%, and 10% gelatin hydrogel that represents a stiffness of 1.3 ± 0.3, 6.4 ± 1.5, and 13.6 ± 3.5 kPa, respectively. All cell culture surface was coated with fibronectin. NRVMs were transduced with Adv-TBX18 or Adv-GFP at day 0 (d0). Results: TBX18-NRVMs showed significantly more spontaneous synchronous contractions on the gelatin hydrogel (22 ± 12, 29 ± 1, 33 ± 9 on 3, 5, or 10% gelatin, respectively) than on plastic (10 ± 11) at d4. Control, GFP-NRVMs showed few spontaneous synchronous contractions regardless of the cell culture platform (3 ± 4, 2 ± 3, 0 ± 0 bpm at 3, 5, 10% gelatin, respectively; 3 ± 7 bpm on plastic, n = 5 to 6 wells/group) at d4. TBX18-NRVMs exhibited significantly more spontaneous synchronous Ca 2+ transients/min on 10% gelatin hydrogel (33 ± 2) than on 3% gelatin hydrogel (9 ± 2) or 5% gelatin hydrogel (19 ± 8) (n = 3, p&lt;0.05) at d8. Immunostaining revealed that Hcn4 protein expression in TBX18-NRVMs was higher on 10% gelatin than on plastic at d2. The percentage of vimentin+ nonmyocytes in TBX18-NRVMs was higher on 10% gelatin (39.5 ± 2.2 %) compared to either on 5% (26.6 ± 1.7%) or on 3% gelatin (27.5 ± 4.2) at d6. Conclusions: Our data indicate that spontaneous and synchronized contractions of TBX18-induced pacemaker cells were significantly higher on gelatin hydrogel with myocardium-like stiffness compared to those grown on plastic culture medium. The data suggest that modulating ECM stiffness may impact the automaticity of cardiac pacemaker tissues, and could serve as a platform to study sinus node dysfunction.

Resolving Strain Localization in Frictional and Time‐Dependent Plasticity: Two‐ and Three‐Dimensional Numerical Modeling Study Using Graphical Processing Units (GPUs)

AbstractShear strain localization refers to the phenomenon of accumulation of material deformation in narrow slip zones. Many materials exhibit strain localization under different spatial and temporal scales, particularly rocks, metals, soils, and concrete. In the Earth's crust, irreversible deformation can occur in brittle as well as in ductile regimes. Modeling of shear zones is essential in the geodynamic framework. Numerical modeling of strain localization remains challenging due to the non‐linearity and multi‐scale nature of the problem. We develop a numerical approach based on graphical processing units (GPU) to resolve the strain localization in two and three dimensions of a (visco)‐hypoelastic‐perfectly plastic medium. Our approach allows modeling both the compressible and incompressible visco‐elasto‐plastic flows. In contrast to symmetric shear bands frequently observed in the literature, we demonstrate that using sufficiently small strain or strain rate increments, a non‐symmetric strain localization pattern is resolved in two‐ and three‐dimensions, highlighting the importance of high spatial and temporal resolution. We show that elasto‐plastic and visco‐plastic models yield similar strain localization patterns for material properties relevant to applications in geodynamics. We achieve fast computations using three‐dimensional high‐resolution models involving more than 1.3 billion degrees of freedom. We propose a new physics‐based approach explaining spontaneous stress drops in a deforming medium.

Representation of Racial Diversity on US Plastic Surgery Websites: A Cross-sectional Study: Racial Diversity on Plastic Surgery Websites.

The racial diversity portrayed in plastic and reconstructive surgery (PRS) media is an important indicator of an inclusive environment for potential patients. To evaluate the degree to which PRS websites demonstrate inclusivity, we assessed the racial composition of both patients and plastic surgeons depicted on the most visited academic and private PRS websites to determine the extent to which racial diversity is represented. A cross-sectional study was conducted in September 2023. The 10 most visited websites in each state were identified. Sociodemographic characteristics including race and sex of patients and plastic surgeons, as well as the type of practice, were collected. Race was classified according to individuals' Fitzpatrick Phototypes into White and non-White. Differences in patient and surgeon representation were compared to the 2020 US Census and the 2020 ASPS demographics using χ2 tests. Subgroup analyses were conducted to identify differences by type of practice and region. We analyzed a total of 2,752 patients from 462 websites belonging to 930 plastic surgeons. PRS websites were predominantly from private practices (93%). Regarding patient representation, 92.6% were female, 7.4% were male, 87.6% were White, and 12.4% were non-White. The surgeon population on the studied webpages was 75.1% male, 92.1% White, and 7.8% non-White. Statistically significant differences were found in the patient population when compared to the 2020 national (P < 0.001) and regional (P < 0.001) US Census demographics and the 2020 ASPS Statistics Report (P < 0.001). Although minority representation was significantly higher on academic websites compared to private practice (22.9% vs. 12.1%; P = 0.007), both were significantly lower than the percentage of minority patients undergoing PRS. This study illuminates racial disparities in the representation of racial groups among patients and plastic surgeons in the most frequented plastic surgery websites. Moreover, it underscores the imperative to bolster racial diversity within the digital content of both private and academic PRS websites. Greater racial representation can foster a more inclusive perception of the plastic surgery field, which may potentially broaden access to care and enrich the professional landscape.

Optimal product quantity linear programming model for profit maximization in plastic small medium manufacturing firms

Planning production and maximizing profits can be difficult tasks for small and medium-sized manufacturing businesses (SMEs). Owing to their difficulties implementing the newest and most advanced Industry 4.0 technologies, small and medium-sized enterprises (SMEs) generally depend more on expert guidance. Thus this study focuses on the development of a Linear programming model for determining the optimum quantities of product in order to maximize profit profits in manufacturing Small medium enterprises. Data spanning over a period of forty five months was obtained from a manufacturing small and medium-sized enterprise. An optimization was developed in the study to determine the optimal product quantity for profit maximization. Based on the developed model and its optimization, it was determined that the optimal production quantity for the plastic factory to be 12000cups resulting in a maximum profit of N456000. This optimization approach provides valuable insights for the plastic factory’s production planning.

Racial Diversity of Patient Population Represented on United States Plastic Surgeons' Webpages.

Current literature demonstrates a lack of racial diversity in plastic surgery media. However, to our knowledge, no study has yet examined the racial diversity of Webpage content as if from a patient-search perspective. The objective of this study is to determine if there is a racial discrepancy between the US Census, American Society of Plastic Surgeons (ASPS) statistics, and the media featuring implied patients on US plastic surgeons' Webpages from a patient-focused approach. A Google search was completed using the term "(state) plastic surgeon." The first 10 relevant Web sites were collected for each state, and homepages were analyzed. In line with previous studies, the implied patients in media were classified into 1 of 6 skin tone categories: I, ivory; II, beige; III, light brown; IV, olive; V, brown; and VI, dark brown. These correlate to Fitzpatrick phototypes; however, the Fitzpatrick scale measures skin's response to UV exposure. Skin tone was used as a guide to measure racial representation in the media, with the caveat that skin tone does not absolutely correlate to racial identity. Categories I-III were further classified as "white" and IV-VI as "nonwhite." These data were compared with the 2020 ASPS demographics report and US Census. Four thousand eighty individuals were analyzed from 504 Webpages, the majority of which were those of private practice physicians. A total of 91.62% of individuals were classified as "white" and 8.38% "nonwhite." The distribution by category was as follows: I = 265, II = 847, III = 2626, IV = 266, V = 71, and VI = 5. Using χ2 analyses, a statistically significant difference was found between the racial representation within this sample and that of the 2020 US Census nationally (P < 0.001), regionally (P < 0.001), and subregionally (P < 0.001); the 2020 ASPS Cosmetic Summary Data (P < 0.001); and the 2020 ASPS Reconstructive Summary Data (P < 0.001). This study highlights the significant difference between racial representation on plastic surgeons' Webpages and the demographics of patients they serve. Further analyses should identify the impact of these representational disparities on patient care and clinical outcomes, as well as examine how best to measure racial diversity and disparities in patient-oriented media.

Plastic vs. glass: the effect of the synthetic material in contact with DMEK tissue during staining on endothelial cell loss.

Endothelial cell loss (ECL) during Descemet membrane endothelial keratoplasty (DMEK) graft preparation has been shown to affect graft survival and the need for re-grafting. The purpose of this study was to quantitatively assess the impact of the plastic and glass mediums in contact with DMEK donor tissue during intra-operative graft staining on ECL. Retrospective study that included patients who underwent DMEK surgery between January 2019 and June 2021 at Hôpital Maisonneuve-Rosemont and the Jewish General Hospital in Montreal, Canada. DMEK grafts were stained with 0.06% Trypan blue ophthalmic solution (VisionBlue®, Dutch Ophthalmic, USA, Exeter, NH) for 120s in either a plastic or glass medium prior to delivery into the recipient's eye. The ECL was compared between the two groups 12-30months post-operatively. ECL at 12-30months was significantly less in the eyes that had received grafts stained in a plastic medium compared to those stained in a glass medium. Graft survival and re-bubbling was higher in the glass group however this difference was not statistically significant. Staining of the DMEK graft in a plastic medium caused less ECL compared to the glass medium.

Determining the patterns of asymmetric interaction of plastic medium with counter-directional metal flow

The plane problem of rolling theory is analytically solved using the method argument of functions of a complex variable. The solution to the plane problem has been strengthened from the point of view of the asymmetry of the process, which made it possible to consider the applied problem as the interaction of differently directed zones in the deformation zone. The interaction of lagging and advancing zones is represented as a combination of multidirectional processes in a single deformation zone. With a change in kinematic, power characteristics in local zones, the process parameters change in the entire deformation zone. Stressed states of intermediate loading schemes between stable and unstable rolling are considered. A feature of the interaction of zones with the opposite flow of metal is the analogy with the action of back tension on the deformation zone in literally all parameters - this is the presence of tensile stresses in the lagging zone, a decrease in local specific pressures, a shift in maximum normal stresses towards the exit from the rolls, a change in the length of the advance zone, reduction in rolling force. The studies confirm and repeat the generally accepted provisions of the theory of rolling but reveal the effects of changes in the stress state under different loading models. The results of the work make it possible to determine the modes of rolling processes visually and computationally under conditions of strong and weak interaction of zones with an oppositely directed metal flow. The effects of plastic deformation with a decrease in the total effort in the processes that are within the reach of the limiting focus of crimping under conditions of increasing kinematic load when the gripping angles vary between 0,077…0,168 are given

Fast Lagrangian analysis of the short-term bearing capacity of shallow foundations in clays on the basis of the cone penetration test

Based on a numerical modelling of the cone penetration test CPT as well as the vertical response of shallow foundation in saturated clays, derivation of the cone factor Nk led to propose a CPT-based method of computation of the bearing capacity. This study was carried out by launching a detailed parametric study using the software FLAC-2D (Fast Lagrangian Analyses of Continua) based on the finite difference method. The soil material was modeled as a homogeneous elastic-perfectly plastic medium obeying the Mohr-Coulomb criterion, and the effects of the soil rigidity index Ir, the cone-soil interface, and the initial depth of the penetration on the cone factor Nk were investigated leading to an analytical formulation of Nk. After a comparative study with those proposed in the literature, the cone factor Nk was used to derive the bearing capacity factor Kc of a shallow foundation. Compared to current CPT-based methods proposed in the literature, this method reasonably predicts the short-term bearing capacity of shallow foundations in saturated clayey soil.

Performing Plasticity: On Recycling, Prosthetic Memories, and the Precarious Working-Class Renaissance

This paper examines the representation of post-industrial malaise in post-socialist China through a case study of the plastic characters of the 2019 hit song Disco Alaskan Wolves (野狼disco). Gem Dong, the singer/composer from Northeastern China, inflects Cantonese with accented Mandarin, utilizing a "disco" motif to express his generation's traumatic transition to the market economy in a laid-off worker's family. Taking a threefold connotation of “plasticity” as references to the materiality of media affordance, the kitschy aesthetic form, and a mode reflective of neoliberalist flexible corporeal politics, I claim that lyrics, singing, and derivative amateur dancing videos of the song all demonstrate “plasticity” as a performing tactic that undermines the glorification of post-socialist economic reform through a paradoxical self-exploitation of underclass bodies. I argue that the song’s parody of Cantonese and stunt performances manifests prosthetic memories formed with spectatorial experiences of "plastic media waste" — cut-out disco CDs and pirate Hong Kong films. They simultaneously unsettle the neoliberalist aesthetic of flexibility through plastic clumsiness. Controversies around the copyright of choreography, however, reveal an uneven distribution of cultural capital in the global capitalist structure that may continuously mutate and ironize the social undertone. Plasticity thus embodies and delivers sensory knowledge of desire, trauma, and precariousness for the post-socialist working class and asks for an ecological understanding of the working-class cultural renaissance.

Microbial Formation on Different Biomedia Surface for Wastewater Treatment

Even though commercial plastic media such as Cosmoball successfully treated municipal wastewater without clogging, its inadequate surface area prevents its use for high biofilm growth rates. This study compares microbial formation on the activated carbon (AC)-coated and non-coated Cosmoball media by submerging four activated carbon AC-coated Cosmo balls and non-coated Cosmo balls in five-liter beakers containing municipal wastewater. The researchers then analyzed the surface morphology of the biofilms on the coated and non-coated surfaces and applied the next-generation sequencing (NGS) technology to the ecology of microbial-mediated processes. By Day 11, the AC-coated media showed a biofilm coverage of 95%, whereas the non-coated media had a biofilm coverage of about 70%. The research has demonstrated that the coated media has a four times higher surface area, thus saving as much as 50% of the aeration tank volume.

On the Theory of Shock Waves in Isotropically Hardening Plastic Media

On the Theory of Shock Waves in Isotropically Hardening Plastic Media

Performance Optimization of Piled Raft Foundations in Layered Soil under Uniform Vertical Loading Using Plaxis 3D

Piled raft foundations are composite foundations that combine piles and raft to support civil engineering structure and to reduce the settlement. The data were obtained from Addis Ababa, Ethiopia. In this study, the effects of raft thickness, number of piles, pile length, spacing of piles, and pile diameter on the response of piled-raft foundations were investigated using the finite element-based program Plaxis 3D for layered soils (medium to very stiff high plastic silty clay and medium to very dense silty sand soil) subjected to uniform vertical loading. The results showed that increasing the thickness of the raft from 0.7 m to 1.7 m reduced the differential settlement by 78.21% when there were 16 piles. However, the maximum settlement also increased by 2.81%. Increasing the number of piles from 4 to 16 reduced the maximum settlement by 22.09% for a pile spacing of 4D. Moreover, increasing the pile length from 9 m to 15 m contributed to a 19.49% reduction in the total settlement for a pile spacing of 5D. Therefore, the current study provides a useful framework for analyzing and designing large piled-raft foundations.

Mathematical modelling and comparative analysis of treatment technologies for upgrading wastewater treatment plants: A case study of biofilm reactors in El-Gouna, Egypt

In recent years, Moving Bed Biofilm Reactors (MBBRs) have been preferred to conventional processes with suspended biomass. The main reason for this preference is that it can achieve better removal efficiencies than conventional systems with smaller footprints. However, unlocking the full potential of MBBRs in large-scale WWTPs remains challenging in real life. In this study, the performance of three different treatment technologies, Extended Aeration Activated Sludge (EAAS), Hybrid Fixed Bed Biofilm Reactor (HFBBR), and Hybrid Moving Bed Biofilm Reactor (HMBBR), was investigated over a year in a WWTP located in El-Gouna, Egypt. The COD removal efficiencies of the three systems were comparable, with the EAAS achieving 93.5%, HFBBR 94%, and HMBRR 95%. Nevertheless, the NH4 removal efficiency of the EAAS was slightly lower (97.5%) than that of the HFBBR and the HMBBR, that achieved a removal efficiency of 98%. BioWin Software was able to mimic the real case of the WWTP of El-Gouna and critically defined all plant limitations and operational data. Different simulations were modeled to test the hydraulic and organic loading capacities of the three systems under different scenarios and operating conditions. The HMBBR system failed to withstand the increase in organic load because of the biomass sloughing effect and subsequently high TSS loads in the settlers. Biomass sloughing overloaded the settlers and lead to biomass loss in the effluent. As the settleability of the HMBBR sludge was significantly lower than for the HFBBR the TSS loss in the effluent happened that much earlier that the moving carrier application had an adverse effect contradicting with the primary purpose of adding media carriers. Model simulations and data analysis findings were used to recommend the most suitable configuration for upgrading an existing system using the attached growth technique with all kinetic parameters and operational conditions. The recommended configuration focuses mainly on the separation of plastic media in a compartment with a very low hydraulic retention time to absorb the incoming shock load.

Primary Cardiac Fibroblast Cell Culture: Methodological Considerations for Physiologically Relevant Conditions.

Primary cardiac fibroblast (CF) tissue culture is a necessary tool for interrogating specific signaling mechanisms that dictate the phenotypic heterogeneity observed in vivo in different disease states. Traditional approaches that utilize tissue culture plastic and nutrient rich medium have been shown to induce CF activation and therefore alter CF subpopulation composition. This shift away from in vivo phenotypes complicate interpretation of results through the lens of the animal model. As the field works to identify CF diversity, these methodological flaws have begun to be addressed and more studies are focused on the dynamic interaction of CFs with their environment. This review focuses on the aspects of tissue culture that impact CF activation and therefore require consideration when designing in vitro experiments. The complexity of CF biology overlaid onto diverse model systems highlight the need for study-specific optimization and validation.

Efektivitas Stencil Print dalam Mengembangkan Kemampuan Motorik Halus Anak Usia 5-6 Tahun di Taman Kanak-kanak Mekar Bunga Padang

This research was conducted with the aim of finding out how effective the use of stencil print media is in developing children's fine motor skills at Mekar Bunga Kindergarten, Padang. This type of research is a quantitative research with quasi-experimental methods. Data collection techniques in the form of tests, observations, and documentation. The population in this study were all students of Mekar Bunga Kindergarten, Padang, totaling 43 children. While the sample consisted of 20 children, 10 children in class B1 and 10 children in class B2. Data analysis used is hypothesis testing, T test, and effect size test. The results of the study showed that there was an effectiveness of using stencil print media on the development of children's fine motor skills with an initial score (pre-test) of 21.80 and a final score (post-test) of 26.80. Then from the calculation of the hypothesis test shows a significant level of 0.001. The results of the study using the effect size test obtained a value of 1.60 which is included in the strong category. Thus stencil print media with plastic cup media is effective in developing children's fine motor skills at Mekar Bunga Padang Kindergarten.

Developments and expansions of a suite of trickling filters models

AbstractIn the United Kingdom, trickling filters remain the most widespread secondary biological treatment process for municipal sewage treatment in terms of number of installations. Ongoing improvement in environmental quality of surface waters requires many of these sites to meet stringent effluent standards. Since publication of the original model for nitrification on mineral media trickling filters by Pearce and Williams in 1999 and the model for nitrification on plastic media filters by Pearce and Edwards in 2010, they have attracted widespread use. Since publication, the models have undergone some refinement and benefitted from an increased application range. Furthermore, recent publications by Pearce and Yang have delivered widely based models for predicting average and seasonal humus tank effluent suspended solids and variability at a resolution of daily 95th percentile performance. This paper presents recent developments of the nitrification models and consolidates the suite of models now available for trickling filter design, evaluation and operation.

Elastic-plastic torsion of a two-layer rod

We study the elastic-plastic torsion of a two-layer rod under the action of torque in this article. It is assumed that the rod consists of two layers. Each layer has its own elastic properties, but the plastic properties of both layers are the same. The contact boundary of the layers is located along the oh axis. The lateral boundary of the rod is stress-free, displacements and stresses are continuous at the interface. The components of the stress tensor at a point are calculated using contour integrals derived from conservation laws calculated along the lateral boundary. Next, the second invariant of the stress tensor is compared with the yield strength. At those points where the yield point is reached, the plastic state is realized, in the rest -elastic. This allows you to build a boundary between the plastic and elastic regions. This technique provides a way to calculate elastic-plastic boundaries for the main rolling profiles of rods. This is supposed to be done in subsequent works. We remind you that earlier, with the help of conservation laws, the main boundary value problems for a plastic two-dimensional medium, elastic-plastic torsion of isotropic rods and elastic media for bodies of finite dimensions were solved.solutions.

Socio-economic factors affecting the distribution of marine litter: The Portuguese case study

Marine litter is a growing global problem with serious environmental, economic, social, and health threats. Understanding the socio-economic factors that influence the types and amounts of litter is of utmost importance. In this study, an integrative analysis of the socio-economic factors that characterize the beach litter distribution in continental Portugal and the Azores archipelago was conducted via a cluster analysis, implementing a novel technique to support the difficult task of marine litter characterization. The results highlighted that the most abundant beach litter material is plastic (92.9 %), followed by paper (2.2 %), wood (1.5 %), and metal (1.3 %). The majority of the items could not be attributed to a specific source (46.5 %). The remaining were attributed to public litter (34.5 % of total aggregated items), fishing (9.8 %), sewage-related debris (6.4 %) and shipping (2.2 %). The top-three beach litter categories were small plastic pieces (0–2.5 cm, 43.5 %), cigarette butts (30.1 %), and medium plastic pieces (2.5–50 cm, 26.4 %). A positive relation between both municipality environment expenditures and population density and the quantity and typology of litter was found. Beach litter quantity and categories were also associated with specific economic sectors, as well as with geographical/hydrodynamic conditions, demonstrating the utility of the technique and its applicability to other regions.

Efforts To Improve Learning Outcomes of Forearm Pass Volleyball by Plastic Ball Media

This study aims to improve the learning outcomes of forearm passing using plastic balls in class VIII students of MTS PAB 4 Patumbak for the 2022/2023 Academic Year. The sample used was 25 students. Data analysis was carried out by data reduction and data exposure. The results of the study concluded: (l) from the first cycle learning outcomes test, it was obtained that 15 students had reached the level of mastery learning while 10 students (40) had not yet reached the level of mastery learning. (2) from the cycle II learning outcomes test, data were obtained as many as 20 students with a conversion value of (80) who had achieved mastery in learning and 5 students (10) were still incomplete. The increase in the average value of student learning outcomes from the previous test was 10.82 and the increase in classical completeness was 20%. Based on the results of data analysis it can be said that using modified plastic ball media can improve learning outcomes of forearm passing in volleyball games for class VIII MTS PAB 4 Patumbak Academic Year 2022/2023.