Micro plastic: an imperceptible threat on Agua Dulce Beach, Chorrillos District

The use of plastics in the world is increasing, but their proper final arrangement is limited. Peru made regulatory efforts to reduce its use;however, they are isolated activities that have not represented a significant change in their management. This study allows to identify the presence of microplastic on one of the busiest beaches of the city of Lima Metropolitana, during the emergency period caused by the SARS-COV-2 pandemic. To achieve the objectives of the research, it has been sampled in high tide and supra-coastal areas, applying the methodology proposed in the Ministry of the Environment's Soil Sampling Guide. This study shows the presence of microplastics, with an abundance of 43 pieces per m2, and found that the predominance of the type of microplastic found is of secondary origin (polystyrene and polypropylene);however, 20.9% correspond to primary microplastics (pellets) whose source could not be determined. Finally, it is indicated that despite restrictions on the state of emergency the number of microplastics per m2 in Agua Dulce Beach between 2019 (40 pieces) and 2020 (43 pieces) increased by 7.5%.

Life Cycle Assessment of Nanofibrous Air Filtering Materials and Respirators

The current spread of COVID-19 pandemics resulted in a surge of a need of respiratory protection devices, including medical facemasks and facepiece respirators. Large amounts of products based on nonwoven filtration material from non-renewable petroleum based plastics (polyethylene) has raised global concerns about excessive environmental impacts of these products. Unfortunately, the replacement of polypropylene nonwoven microfibre based single use masks by the multiple use products did not appear as an effective strategy due to a lower filtration performance, although potentially lower environmental impacts. Nanofibre based filtration devices introduce themselves as potentially more environmentally friendly ones due to a lower overall usage of raw polymer compared to microfibrous ones. We present the LCA modelling of environmental impacts of respiratory protective devices with nanofibrous filter materials and compare those against traditional micro fibrous materials (FFP1 and FFP2 respirator) and medical facemask. Generally, due to a lower mass of nanofibre, these products emerge as a better environmental option, providing similar protection level. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.

ZnO coated nonwoven polypropylene fabric with antibacterial and antiviral function for medical applications

The present pandemic has highlighted the necessity of infection protection gear as a crucial protective approach, particularly given the fact that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) readily infects individuals in poorly ventilated environments. Embedding antimicrobial function onto protection gear would have major implications in minimizing pathogen contamination and lowering healthcare associated illness. In this study, non woven polypropylene fabric (NWPP) which is widely used in personal hygiene products and hospital protective gears has been subjected to surface fictionalization with corona treatment. Surface polarity of the treated fabric was studied by use of dyne liquid which showed generation of surface polarization. Subsequently, the resultant surface polarized NWPP were spray coated with zinc oxide (ZnO) antiviral agent. The antiviral agents were rendered to adhere to NWPP by use of polyurethane solution coating on the fabric. The effect of antiviral coatings on NWPP fabric with the use of polyurethane solution as an adhesive were investigated in terms of antiviral activity and anti-bacterial activity against MS2 bacteriophage and Staphylococcus aureus and Klebsiella pneumonia bacteria respectively. Coating of surface polarized NWPP with polyurethene binder reduced the leaching of antiviral coating. More importantly, the fabrics exhibited promising antiviral and anti bacterial activity with 99.90 % reduction in microorganisms after 24 hours of exposure. © 2022 IEEE.

Trash to treasure: Sulfonation-assisted transformation of waste masks into high-performance carbon anode for sodium-ion batteries

The global pandemic of COVID-19 poses significant challenge to the recycling of disposable polypropylene (PP)-based waste masks. Herein, a simple but effective sulfonation route has been proposed to transform PP-based waste masks into value-added hard carbon (CM) anode materials for advanced sodium-ion batteries. The sulfonation treatment improves the thermal stability of the PP molecule, preventing their complete decomposition and the release of massive gas molecules during the carbonization process. Meanwhile, the oxygen functional groups introduced during sulfonation effectively facilitates the cross-linking between the PP chains, hindering the rearrangement of carbon microcrystalline structures and enhancing its structural disorder. As a result, the prepared hard carbon anode (CM-180) with a high disorder degree and minimal surface defects realizes a high sodium storage capacity of 327.4 mAh g−1 with excellent cycle and rate capability. In addition, when coupled with O3–NaNi1/3Fe1/3Mn1/3O2 cathode, the fabricated sodium-ion full cell delivers a high energy density of 238 Wh kg−1 and achieves an outstanding rate capability with a retained capacity of 75 mAh g−1 even at an ultrahigh current rate of 50 C. This work offers a novel insight into transforming the waste masks to value-added hard carbons with promising prospects for sodium-ion batteries. © 2023

THE USED SURGICAL MASKS: FROM WASTE TO RESOURCE

The general focus of research is the development of recycling protocols for disposable surgical masks into new raw materials for different possible applications. Separation of various constituent materials was performed by manual procedure or by water floating. The potentially targeted end applications are thin film and glass fibre composites. Polypropylene thin-films with a thickness of 100 micron were produced by compounding the face mask polymer with different content of a virgin PP, in the range 20-80 wt%. Face mask polypropylene (FM-PP) composites containing glass fibre of 15 wt% and 30 wt% were also prepared, evidencing an improvement of stiffness and strength, furtherly increased in presence of coupling agent. © 2022 Fambri et al.

Structure, Morphology, and Surface Chemistry of Surgical Masks and Their Evolution up to 10 Washing Cycles

The Covid-19 crisis has led to a massive surge in the use of surgical masks worldwide, causing risks of shortages and high pollution. Various decontamination techniques are currently being studied to reduce these risks by allowing the reuse of masks. In this study, surgical masks were washed up to 10 times, each cycle under the same conditions. The consequences of the washing cycles on the structure, fiber morphology, and surface chemistry have been studied through several characterization techniques: scanning electron microscopy, wetting angle measurements, infrared spectroscopy, X-ray diffraction, and X-ray photoelectrons spectroscopy. The washing process did not induce large changes in the hydrophobicity of the surface, the contact angle remaining constant throughout the cycles. The composition observed in the IR spectrum also remained unchanged for washed masks up to 10 cycles. Some slight variations were observed during X-ray analysis: the crystallinity of the fibers as well as the size of the crystals increases with the number of wash cycles. The XPS analysis shows that after 10 cycles, the surface of the masks underwent a slight oxidation. In the SEM images, changes were observed in the arrangement of the fibers, which are more visible the more times the mask has been washed: they align themselves in bundles, form areas with holes in the mask layer, and are crushed in some areas. © 2023 American Chemical Society

Eco-Friendly Hierarchical Nanoporous Microfiber Respirator Filters Fabricated Using Rotary Jet Spinning Technology (RJS)

The current global health crisis caused by the SARS-CoV-2 virus (COVID-19) has increased the use of personal protective equipment, especially face masks, leading to the disposal of a large amount of plastic waste causing an environmental crisis due to the use of non-biodegradable and non-recyclable polymers, such as polypropylene and polyester. In this work, an eco-friendly biopolymer, polylactic acid (PLA), was used to manufacture hierarchical nanoporous microfiber biofilters via a single-step rotary jet spinning (RJS) technique. The process parameters that aid the formation of nanoporosity within the microfibers were discussed. The microstructure of the fibers was analyzed by scanning electron microscopy (SEM) and a noninvasive X-ray microtomography (XRM) technique was employed to study the three-dimensional (3D) morphology and the porous architecture. Particulate matter (PM) and aerosol filtration efficiency were tested by OSHA standards with a broad range (10-1000 nm) of aerosolized saline droplets. The viral penetration efficiency was tested using the ΦX174 bacteriophage (∼25 nm) with an envelope, mimicking the spike protein structure of SARS-CoV-2. Although these fibers have a similar size used in N95 filters, the developed biofilters present superior filtration efficiency (∼99%) while retaining better breathability (<4% pressure drop) than N95 respirator filters. © 2023 American Chemical Society

Property assessment of an eco-friendly mortar reinforced with recycled mask fiber derived from COVID-19 single-use face masks

Wearing a face mask is strongly advised to prevent the spread of the virus causing the COVID-19 pandemic, though masks have produced a tremendous amount of waste. As masks contain polypropylene and other plastics products, total degradation is not achievable, and masks may remain in the form of microplastics for several years in the environment. Therefore, this urgent issue ought to be addressed by properly handling waste face masks to limit their environmental impact. In relation to this goal, a novel application of recycled mask fiber (MF) derived from COVID-19 single-use surgical face masks (i.e., shredded mask fiber-SMF and cut mask fiber-CMF) has been undertaken. Eighteen mortar mixes (9 for water and 9 for 10% CO2 concentration curing) were fabricated at 0%, 0.5%, 1.0%, 1.5%, and 2.0% of both SMF and CMF by volume of ordinary Portland cement-based mortar. The compressive strength, flexural strength, ultrasonic pulse velocity, shrinkage, carbonation degree, permeable voids, and water absorption capabilities were assessed. The outcomes reveal that the compressive strength decreased with an increased percentage of MFs due to increased voids of the mixes with MFs as compared to a control mix. In contrast, significantly higher flexural strength was noted for the mortar with MFs, which is augmented with an increased percentage of MFs. Furthermore, the inclusion of MFs decreased the shrinkage of the mortar compared to the control mix. It was also found that MFs dramatically diminished the water absorption rate compared to the control mix, which reveals that MFs can enhance the durability of the mortar. © 2023 Elsevier Ltd

CO2-mediated thermal treatment of disposable plastic food containers

In accordance with global economic prosperity, the frequencies of food delivery and takeout orders have been increasing. The pandemic life, specifically arising from COVID-19, rapidly expanded the food delivery service. Thus, the massive generation of disposable plastic food containers has become significant environmental problems. Establishing a sustainable disposal platform for plastic packaging waste (PPW) of food delivery containers has intrigued particular interest. To comprise this grand challenge, a reliable thermal disposable platform has been suggested in this study. From the pyrolysis process, a heterogeneous plastic mixture of PPW was converted into syngas and value-added hydrocarbons (HCs). PPW collected from five different restaurants consisted of polypropylene (36.9 wt%), polyethylene (10.5 wt%), polyethylene terephthalate (18.1 wt%), polystyrene (13.5 wt%), polyvinyl chloride (4.2 wt%), and other composites (16.8 wt%). Due to these compositional complexities, pyrolysis of PPW led to formations of a variety of benzene derivatives and aliphatic HCs. Adapting multi-stage pyrolysis, the different chemicals were converted into industrial chemicals (benzene, toluene, styrene, etc.). To selectively convert HCs into syngas (H2 and CO), catalytic pyrolysis was adapted using supported Ni catalyst (5 wt% Ni/SiO2). Over Ni catalyst, H2 was produced as a main product due to C[sbnd]H bond scission of HCs. When CO2 was used as a co-reactant, HCs were further transformed to H2 and CO through the chemical reactions of CO2 with gas phase HCs. CO2-assisted catalytic pyrolysis also retarded catalyst deactivation inhibiting coke deposition on Ni catalyst. © 2022 Elsevier B.V.

High efficacy of activated carbon fabric filters and masks developed to prevent the inhalation of microorganisms and particles associated with respiratory tract infections

As a major international public health emergency, COVID-19 has posed many challenges for healthcare professionals who have been heavily exposed to contamination. This article describes the development of a high-filtration capacity mask consisting of filter-element layers interspersed with super-activated carbon fiber fabric, non-woven polypropylene for dental–medical–hospital use and antiviral polyamide with nanostructured SiO2 thin film coating. The study found 98.18% particle filtration efficiency and determined 2.11 mmH2O/cm2 differential pressure, while fluid repellency complied with Brazilian standard NBR ABNT 15052:2004. © The Author(s) 2022.

Optimization of gasification process parameters for COVID-19 medical masks using response surface methodology

Due to the COVID-19 pandemic, large amounts of medical wastes have been produced and their disposal has resulted in environmental and human health problems. This medical waste may include face masks, gloves, face shields, goggles, coverall suits, and other related wastes, such as hand sanitizer and disinfectant containers. To address this issue, the effect was investigated of gasification process parameters (type of COVID-19 medical mask based on the polypropylene ratio, pressure, steam ratio, and temperature) on hydrogen syngas and cold gas efficiency. The gasification model was developed using process modeling based on the Aspen Plus software. Response surface methodology with a 3k statistical factorial design was used to optimize the process aiming for the highest hydrogen yield and cold gas efficiency. Analysis of variance showed that both the steam ratio and temperature were significant parameters regarding the hydrogen yield and cold gas efficiency. Proposed models were constructed with very high accuracy based on their coefficient of determination (R2) values being greater than 0.97. The optimum conditions were: 65 % polypropylene in the mixture, a pressure of 1 bar, a steam ratio of 0.38, and a temperature of 900 °C, producing a maximum hydrogen yield of 40.61 % and cold gas efficiency of 81.43 %. These results supported the efficacy of the primary design for steam gasification using a mixture of plastic wastes as feedstock. The hydrogen could be utilized in chemical applications, whereas the efficiency could be used as a basis for further development of the process. © 2022 THE AUTHORS

Amino-terminated hyperbranched polymer functionalized graphene oxide with in situ trapped silver nanoparticles for high-performance antibacterial nonwoven fabric

Antibacterial fabric with high thermal stability and mechanical strength is important for personalized protection, especially under the background of coronavirus pandemic (COVID-19). This paper presents a facile approach toward high-efficient antibacterial polypropylene spunbonded nonwoven fabrics (SNFs), which are decorated by a composite of graphene oxide embedded with silver nanoparticles (AgNPs/GO) through dip-coating and in situ reduction effect of pre-introduced amino-terminated hyperbranched polymer (HBP-NH2). Typically, HBP-NH2 was grafted onto the GO nanosheets, then silver ions were trapped and self-reduced by the HBP-NH2 to generate silver nanoparticles decorated GO. The produced AgNPs are uniformly dispersed on the GO with a size of 13 nm. As an antibacterial coating, the Ag/GO composite could tightly wrap the SNFs fibers through the dip-padding method, capable of enhancing the thermal stability and mechanical property of SNFs. The treated SNFs exhibited excellent antibacterial activities (~99.9%) against both Echerisia coli and Staphylococcus aureus, promising important potential for biomedical and personal protection applications. © 2022 Wiley Periodicals LLC.

Virus removal from aqueous environments with polyelectrolyte coatings on a polypropylene fleece

The adsorption of viruses from aqueous solution is frequently performed to detect viruses. Charged filtration materials capture viruses via electrostatic interactions, but lack the specificity of biological virus-binding substances like heparin. Herein, we present three methods to immobilize heparin-mimicking, virus-binding polymers to a filter material. Two mussel-inspired approaches are used, based on dopamine or mussel-inspired dendritic polyglycerol, and post-functionalized with a block-copolymer consisting of linear polyglycerol sulfate and amino groups as anchor (lPGS-b-NH2). As third method, a polymer coating based on lPGS with benzophenone anchor groups is tested (lPGS-b-BPh). All three methods yield dense and stable coatings. A positively charged dye serves as a tool to quantitatively analyze the sulfate content on coated fleece. Especially lPGS-b-BPh is shown to be a dense polymer brush coating with about 0.1 polymer chains per nm2. Proteins adsorb to the lPGS coated materials depending on their charge, as shown for lysozyme and human serum albumin. Finally, herpes simplex virus type 1 (HSV-1) and severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) can be removed from solution upon incubation with coated fleece materials by about 90% and 45%, respectively. In summary, the presented techniques may be a useful tool to collect viruses from aqueous environments. © 2022 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals LLC.

A Short and Highly Efficient Method for Producing Meltblown Nano Yarn with a Helical Structure and High Conductivity

The COVID-19 outbreak has led to the overproduction of meltblown fabrics commonly used in personal protective equipment such as face mask. Moreover, the yield ofconventional fabrication methods for meltblown fabrics have poor mechanical properties and lack accessional value and functional applicability. In this study, a short and highly efficient process was employed to produce polypropylene/polypyrrole (PPy) meltblown nanoyarn (PPMNY). The mechanical properties were improved by utilizing a helical structure, and the conductivity was enabled using a combination of PPy nanoparticles. The breaking force of the proposed PPMNY was as high as 10.1cN/tex at 9T/10 cm, nearly 3.3 times more than PPMNY without the helical structure. The breaking force of the proposed PPMNY was unaffected by the washing process, and the frictional properties and snarling information were similarly maintained by the helical structure. Additionally, the optimal conductivity of the proposed PPMNY reached 0.044S·m-1. Therefore, the novel methods investigated in this study can improve the properties of meltblown fabrics to yield a highly efficient and low-cost technique to produce conductive PPMNY. This concept can be extended for solving the problems of the single two-dimensional structure with poor mechanical properties and application on Smart Wearable with preferable conductivity. © Textile Bioengineering and Informatics Symposium Proceedings 2022 - 15th Textile Bioengineering and Informatics Symposium, TBIS 2022.

Copper Nanoparticle Synthesis on Plasma Treated Poly(lactic) Acid Nonwoven Fabrics

The demand for antibacterial fabric surfaces is increasing day by day. With the covid-19 pandemic situation, there is attention to antibacterial and antiviral nonwoven fabrics which can be used towards the development of personal protective wear. To reduce the environmental pollution caused by disposable and non-biodegradable polymer-made personal protective wear can be replaced by biodegradable polymers like poly(lactic) acid (PLA), which is quite similar to polypropylene, but biodegradable. In this study, the non-thermal plasma treatment method is used to increase the surface reactivity of the PLA nonwoven polymer surface. On the activated nonwoven surface copper nanoparticles are in-situ synthesized by chemical treatments. After 30 minutes of plasma treatment, better copper nanoparticle distribution and higher yield were achieved. Fourier transformed infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were used to characterize the treated PLA nonwoven fabric surfaces. © 2022 IEEE.

MOBILE SOLAR POWERED INSTRUCTIONAL TECHNOLOGY EQUIPMENT FOR ONLINE TEACHING AND LEARNING DURING COVID-19 PANDEMIC FOR REMOTE COMMUNITY

As the COVID-19 pandemic continues globally, the disruption of the traditional face-to-face classes in educational institutions is evident. In the Philippines, these educational institutions have shifted to Flexible Learning System (FLS). However, in the implementation of FLS, the teachers and the learners in the remote communities experience internet connectivity problems. This problem is minimized using mobile solar-powered instructional technology equipment for online teaching and learning activities. This equipment is designed to carry all the necessary accessories in the online delivery of FLS like television, solar panel, WiFi routers, inverters, and other power accessories. It is made of Polypropylene Random Copolymer (PPR) pipe material and is mounted on a four-wheel bicycle. Several tests were conducted to evaluate the performance of the equipment. These were the following: stress analysis, solar energy utilization test, portability assessment, connectivity speed test, and quality assessment. Results suggest that the developed equipment is ready for actual deployment in a remote community in the Philippines. With such deployment, internet connectivity problems can be minimized. As a result, the less fortunate learners can have free and reliable internet access. Moreover, a possible related future work is designing bigger mounting equipment that can carry more accessories due to its portability and mobility aspects. Copyright © 2021 by ASME

Influence of COVID-19 on Microplastics Pollution in Coastal Water and Sediment of Chennai, India

Event of microplastics (plastic garbage < 5 mm) along the coast is a developing concern around the world, because of the expanded contribution of disposed of squanders from different sources. Around 400 million tons of plastic are produced per year worldwide, out of which only 18% is recycled that has led to its poor disposal practices. The significance of my work is to analyze mainly the positive impacts due to lockdown during COVID-19. The discharged plastics remain in the environment for several 100 years either in their original or fragmented form. The fragmentation of particles is caused by several factors like wind currents, wave currents, abrasions, exposure to sunlight, etc. The study of the distribution of microplastics in time and space, as well as their distribution on parameters, such as polymer type, size, shape, in different coastal environmental all over the world, is the need of the hour. This study describes a framework to assess the presence and distribution of microplastics in marine water and sediments of Adyar and Cooum Estuary along the Chennai coast. Ten sampling sites from each estuary were selected from which surface water and sediments were collected. The samples were carried over to the laboratory for analyzing the presence of microplastic content, and also basic seawater quality parameters were analyzed in the Environmental Engineering Department laboratory. The study investigated the presence and distribution of microplastics before and during COVID-19. The presence and distribution study of microplastics in coastal waters and sediments were carried out by means of FTIR and XRD spectroscopy methods. From this analysis, microplastics occur in both estuaries and there is a significant reduction in Microplastic content in both estuaries because of continuous lockdown due to COVID-19. From FTIR analysis, it was found that the concentration of Polyethylene(PE) and Polypropylene (PP) was higher than the other types of polymer in both the locations and both the times (August 2019 and 2020). And from XRD analysis, black residues were found on most of the microplastics surfaces. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Effect of the Graphene Nanoplatelets (GnPs) on the Mechanical Properties in Recycled PP-Based Hybrid Composites

In the day we fight against Covid-19, the use of disposable masks and isolation clothing is multiplied by 12 compared to the time before the Covid-19 pandemic. Considering that these disposable masks are made of polypropylene (PP), an average of 480 kilotons of PP waste is produced each year, exclusively from masks. After the use of these masks, it is important to collect and re-evaluate them in a controlled manner so as not to pose a risk of contamination and not to threaten the environment. Because of its advantageous properties, PP is used in the production of many parts in the automotive industry. With this study, it is aimed to develop composite materials to be used in car bumper manufacturing by using recycled PP obtained from melt blown PP fabrics (surgical mask fabric). Due to accidents or road conditions, impact damage can occur on the bumpers. Therefore, the impact resistance of the bumpers must be improved. In addition, in case of microscale damage resulting from the impacts received, microcracks may develop and cause material failure below the maximum tensile stress. In summary, effective reinforcements should be used to improve impact strength in composites for use in car bumpers. Accordingly, novel recycled PP (rPP) based composites are manufactured by using elastomer-styrene-ethylene-butylene-styrene (SEBS) and graphene nanoplatelets (GnPs) as compatible reinforcements with rPP. As experimental characterization, three-point bending tests and Charpy impact tests were carried out. Incorporation of GnPs increased the flexural strength and blending with SEBS improved the impact resistance of the developed composites. Certain clusters of the graphene nanoplatelets were observed by means of microscopy. © 2022, The Society for Experimental Mechanics.

Correlation of antibacterial performance to electrostatic field in melt-blown polypropylene electret fabrics

Respirators have become popular personal protective equipment since the COVID-19 pandemic. The key material in respirators is the melt-blown polypropylene electret fabric (MBPPEF). In this article, the filtering and inactivating effects of electrostatic fields in the respirator materials on Staphylococcus aureus (S. aureus) are studied. As a typical airborne microorganism, S. aureus is often employed to evaluate the antibacterial performance of air filtration equipment. The results prove that the electrostatic field in MBPPEF plays the key role in filtrating S. aureus. All MBPPEF from different charging method can have a filtering efficiency of more than 99% against S. aureus. The inactivation rate of positive corona charged sample is the highest. The charging method will affect the formation of electrostatic fields in the MBPPEF, thereby affecting their antibacterial performance. © 2022

Augmenting google sheets to improvise community COVID-19 Mask Distribution

During the COVID-19 pandemic, face mask scarcity in the US hindered infection control efforts. Because areas with a history of racial segregation and poverty experienced differential COVID-19 morbidity and mortality rates, supplying masks to these communities equitably and rapidly became an urgent public health priority. To address this need, a partnership was formed in April 2020 between a local manufacturer with available polypropylene fabric and the Medical College of Wisconsin, with the capability to assemble and distribute masks. An improvised logistics framework allowed for rapid distribution more than 250,000 masks, and later facilitated hand-off to other organizations to distribute over 3 million masks. Using a multi-actor, action research framework three phases of the effort are considered, 1) initial deliveries to community clinics, 2) equitable distribution to community agencies while under emergency shelter in place orders, and 3) depot deliveries and transfer of logistics management as larger agencies recovered. Through the multi-actor lens, we interrogated the information needs of faculty and staff remotely directing distribution, medical student volunteers delivering masks, and the manufacturer monitoring overall inventory. Logistics information was managed using Google Sheets augmented with a small SQLite component. A phenomenological view, toggling back and forth from the "socio" to the "technical" provides detailed insight into the strengths and limitations of digital solutions for humanitarian logistics, highlighting where paper-based processes remain more efficient. This case study suggests that rather than building bespoke logistics software, supporting relief efforts with non-traditional responders may benefit from extensible software components that augment widely used digital tools. © 2021 Information Systems for Crisis Response and Management, ISCRAM. All rights reserved.