Polystyrene Sheets Research Articles

Thermal performance of solar dryer using bio-composite insulation material based on date palm waste for drying of hot chili: experimental investigation in Algerian Sahara

This paper investigates the thermal efficiency of solar dryers using different insulation materials, focusing on a bio-composite derived from discarded date palm residues. The current study introduces this sustainable material, created from local palm waste, as insulation material in Solar Air Heaters (SAHs) for agricultural products drying purposes. Thus, two SAH models are designed, fabricated and compared for their thermal efficiencies: the first one used the bio-composite (Model A) as insulation material and the second one is equipped with a polystyrene sheet in the rear insulation (Model B). The thermal performance of these models are assessed, alongside the drying kinetics of Algerian chili at different maturity stages under the climate of Biskra, Algeria. A local product that we aim to promote (Arab chili), widely used in southern Algeria during the harvest period in summer and early spring. It is generally grown using traditional techniques despite its very delicious taste, while (Gazelle’s horn) chili is grown in greenhouses throughout the year. Although the polystyrene-insulated SAH shows slightly better thermal efficiency, the bio-composite model achieves satisfactory drying temperatures, drying chili in 5 hours and 30 minutes.

Temperature and salt concentration behavior of a compact rectangular salinity gradient solar pond

Design of economical and effective solar ponds which are useful thermal energy storage devices, remains a huge challenge. The present work aims at investigating the thermal performance of low cost mini salt gradient solar pond. The portable pond was fabricated as a rectangular configuration having a volume of 0.5m3. Polystyrene and high density polyethylene sheets were employed for insulating the walls. The top of the pond was covered with a slender glass so that the dust accumulation could be prevented without affecting the absorption of solar radiation. Sodium chloride salt was used as the medium and the three salt gradient regions namely lower convective, non-convective, and upper convective regions were established through injection filling technique. The temperature and salt gradient data were observed experimentally for a period of 20 days at Coimbatore, India. The pond could absorb significant amount of available radiation (around 65%) and the maximum temperature of the pond was observed to be 49oC. Frequent washing of the water surface is necessary to maintain stable salt gradient. Nevertheless, portable pond fabricated with low cost materials exhibited good potential of storing solar energy for solar thermal applications.

Plant-mediated synthesis of thermally stable metal-polystyrene nanocomposites for antioxidant and antibacterial food packaging

Annually, millions of individuals are hospitalized worldwide because of illnesses attributed to foodborne pathogens. With the surge in foodborne diseases, the importance of reliable and optimized food packaging has become more crucial than ever. Okra (Abelmoschus esculentus) seed extract was utilized as a mediator for synthesizing thermally stable nanoparticles (NPs) of Fe0, Zn0, Ag0, Fe2O3, ZnO, and Ag2O. These NPs were subsequently incorporated into polystyrene (PS) sheets to fabricate NPs-PS composites. Nanoparticle synthesis with a uniform morphology and size range of 20–60 nm was confirmed through various characterization techniques, including surface plasmon resonance, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray (EDX) techniques. The antioxidant potential, as determined by the 2,2-diphenylpicrylhydrazyl (DPPH) free radical scavenging and Phosphomolybdenum assay, followed the order of Silver > Iron > Zinc. Conversely, the antimicrobial potential, evaluated through the agar well diffusion method, was in the order of Silver ≈ Zinc > Iron. Zero-valent metal NPs and NPs-PS Composites exhibited superior results compared to metal oxide NPs and NPs-PS Composites. Lemon and Apple slices wrapped in NPs-PS composite sheets exhibited significantly improved shelf life compared to pure PS, demonstrating the high effectiveness of metal NPs modified composites for food packaging by protecting it from oxidative decay and microorganisms.

Exploring the potential of bacterial-augmented floating treatment wetlands for the remediation of detergent-contaminated water

Due to industrialization and urbanization, the use of detergents inadvertently led to contamination of aquatic environments, thus posing potential threat to aquatic organisms and human health. One of the main components of detergents is linear alkylbenzene sulfonate (LAS), which can cause toxic effects on living organisms, particularly aquatic life in the environment. In this study, floating treatment wetlands (FTWs) mesocosms were developed and augmented with LAS-degrading bacteria. The plant species, Brachiaria mutica (Para grass), was vegetated to establish FTWs and bacterial consortium (1:1:1:1) of Pseudomonas aeruginosa strain PJRS20, Bacillus sp. BRRH60, Acinetobacter sp. strain CYRH21, and Burkholderia phytofirmans Ps.JN was augmented (free or immobilized) in these mesocosms. Results revealed that the FTWs removed LAS from the contaminated water and their augmentation with bacteria slightly increased LAS removal during course of the experiment. Maximum reduction in LAS concentration (94%), chemical oxygen demand (91%), biochemical oxygen demand (93%), and total organic carbon (91%) was observed in the contaminated water having FTWs augmented with bacterial consortium immobilized on polystyrene sheet. This study highlights that the FTWs supported with immobilized bacteria on polystyrene sheets can provide an eco-friendly and sustainable solution for the remediation of LAS-bearing water, especially for developing countries like Pakistan.

Energy performance of school roofing materials in hot and humid climates

Effective roof insulation plays a pivotal role in reducing the energy used for air-conditioning, particularly in Taiwan’s extreme summer climate. In the present study, 1108 cases of rooftop insulation renovations in Taiwanese schools between 2018 and 2022 were investigated, and the thermal insulation performance and air-conditioning-related electricity savings associated with these renovations were analyzed through a cost–benefit assessment of the investment in insulation. The EnergyPlus software was used to model typical classroom roofs in seven climate zones in Taiwan. All the adopted thermal insulation methods considerably reduce air-conditioning-related electricity use; however, diminishing returns occur faster for thicker thermal insulation. The four main roof insulation materials used in the analyzed cases are galvanized corrugated steel, foam concrete, polystyrene sheets, and insulating bricks, which are associated with average maximum electricity-saving ratios of 17%, 15.3%, 10.2%, and 9.7%, respectively, and payback periods of 6.1, 6.4, 4.5, and 9.3 years, respectively. Electricity savings are greater and the payback period is shorter for the hotter southern zones of Taiwan than for the cooler northern zones. Galvanized corrugated steel has average energy efficiency of 21% and 13% in the southern and northern zones, respectively. The selection of roof construction materials strongly influences the consumption of energy for air-conditioning. Moreover, different construction costs result in distinct payback periods. The results of this study serve as a reference for school administrators and governments in the selection of insulation methods and design of building energy conservation and management, respectively.

SIP construction with EPS and galvanised electro-welded mesh

SIP stands for structure insulated panels which is usually constructed of oriented strand boards (OSB) on the interior and exterior sides with foam like Expanded polystyrene (EPS), extruded polystyrene (XPS) or rigid poly-urethane foam, sandwiched in between the OSB sheets. Around the polystyrene; plywood, pressure treated plywood, aluminium, thin mesh of steel, stainless steel etc can also be used in replacement to OSB panels. This article focus on a new idea which is using polystyrene sheets 170mm thick, 2.4m long and 1.2m wide with 3mm electro-welded mesh on both faces with both main and distribution bars. Depending on the loading the spacing can be reduced and some extra bars at length L/3 can be welded to the mesh. The SIP with galvanized electro-welded mesh acts like RC structure and if installed by trained persons it is suitable for all design loads as all the factory tests have been conducted on them. The advantages of using SIP panels with electro-welded mesh are easy to install, economical (at least half a price of traditional build), speedy construction (takes about half of the time as compared to traditional build), light weight, fire resistant, flexibility, thermal properties, easy transportation etc.

Experimental Research on Seismic Performance of Masonry-Infilled RC Frames Retrofitted by Using Fabric-Reinforced Cementitious Matrix Under In-Plane Cyclic Loading

Fabric-reinforced cementitious matrix (FRCM) composites, also known as textile-reinforced mortars (TRMs), represent a new advancement in structural repair and reinforcement technology. Aiming to improve the energy efficiency and seismic performance of existing buildings, this research focused on the development of an FRCM system in combination with phase change materials (PCMs) and extruded polystyrene sheets (XPS) to achieve adequate mechanical and thermal properties for reinforced concrete (RC) and masonry structures. Accordingly, the in-plane behaviour of five FRCM-strengthened RC frames with hollow-brick wall infill was tested under cyclic loading to investigate the improvement in earthquake resistance. The system was comprehensively evaluated by calculating hysteresis curves; comparing the lateral stiffness, ductility, and energy dissipation capacity; measuring the deformations of the specimens; and analysing the failure modes mechanically. Finally, it was proved that this novel integrated approach could significantly enhance the mechanical and seismic performance of masonry-infilled RC frames.

Antibacterial and antibiofilm performance of low-frequency ultrasound against Escherichia coli O157:H7 and its application in fresh produce

Ultrasound technology has been focused on due to its unique advantages in biofilm removal compared with traditional antibacterial methods. Herein, the anti-biofilm properties of low-frequency ultrasound (LFUS) were studied against Enterohemorrhagic Escherichia coli O157: H7 (E. coli O157:H7). After ultrasonication (20 kHz, 300 W) for 5 min, the removal rate of biofilm from polystyrene sheets reached up to 99.999 %. However, the bacterial cells could not be inactivated completely even extending the duration of ultrasonic irradiation to 30 min. Fortunately, this study indicated that LFUS could efficiently weaken the metabolic capacity and biofilm-forming ability of bacterial cells separated from biofilm. It could be associated with the removal of cell surface appendages and damage to cell membrane induced by mechanical vibration and acoustic cavitation. Besides, the genetic analysis proved that the transcription level of genes involved in curli formation was significantly down-regulated during ultrasonic irradiation, thus impeding the process of irreversible adhesion and cells aggregation. Finally, the actual application effect of LFUS was also evaluated in different fresh produces model. The results of this study would provide a theoretical basis for the further application of ultrasound in the food preservation.

Biodegradation of Oil-Based Plastic Wastes by Bacteria Isolated from Fish Breeding Tanks

Several studies have shown that certain microbes, mainly bacteria may have the ability to digest plastic wastes. The goal of this study was to see how well Bacillus subtilis, Staphylococcus lentus, Aeromonas hydrophila, Sphingomonas paucimobilis and Kocuria paedia degrade three kinds of oil-based plastics: low-density polyethylene (LDPE), polystyrene (PS) and polyvinylchloride (PVC) polymer sheets. The experiment was conducted for 30 days under laboratory conditions with occasional shaking at 180 rpm and 32°C. Biodegradation was measured in terms of weight loss.. Accordingto IR Spectroscopy, the C-H stretch band at 2920cm-1 improved as a result of bacterial degradation of polyethylene. The most affected polymers were LDPE and PVC films. While PS films were the least affected polymers. B. subtilis was shown to be the most successful of the five bacterial species, whereas K. paedia was determined to be the least effective.

Performance augmentation of a solar thermal desalination system using different floating absorber plates

Interfacial evaporation is known to boost the evaporation rate compared to conventional bulk evaporation, as energy conversion and vapor generation simultaneously occur at the air–liquid interface. This work presents the investigation details on the design, fabrication, and testing to determine the performance of a floating absorber structure with the sole interest of maximizing the evaporation rate. Polyvinyl alcohol cloth is the wicking cum absorber material, while extruded polystyrene sheet is the floating structure cum thermal insulator. Phase I of the study involves the comparative study between bulk and interfacial heating and the effect of different types of patterns with the same area on interfacial heating with a single absorber. Phase II involves the effect of multiple absorbers on interfacial evaporation. To identify a better design, different absorber configurations (single, patterned, multiple, and multiple blocks with full coating and patterns) were compared to bulk heating. The study highlighted the improvement in evaporation rate achieved using floating absorbers by 43% and 56% for single and multiple absorbers under one sun illumination compared to bulk heating. Also, a multiple absorber design yields a 10% higher evaporation rate than a single absorber. An extended analysis with and without black coating on multiple absorbers design indicates an improvement of 17% evaporation efficiency compared to bare multiple absorbers. In selecting a suitable pattern embedded on the single absorber, the stripe-type pattern resulted in a 21% improvement in evaporation rate than the bare absorber among the four patterns tested. The multiple absorbers with stripe patterns obtained an evaporation rate of 1.17 kg m−2 h−1 under one sun (1 kWm−2) irradiation. Further, the multiple absorbers with stripe-type patterns obtained an evaporation rate of 1.69 kg m−2 h−1 under 1.5 sun irradiation (1.5 kWm−2).

A simple polystyrene microfluidic device for sensitive and accurate SERS-based detection of infection by malaria parasites.

Early and accurate detection of infection by pathogenic microorganisms, such as Plasmodium, the causative agent of malaria, is critical for clinical diagnosis and ultimately determines the patient's outcome. We have combined a polystyrene-based microfluidic device with an immunoassay which utilises Surface-Enhanced Raman Spectroscopy (SERS) to detect malaria. The method can be easily translated to a point-of-care testing format and shows excellent sensitivity and specificity, when compared to the gold standard for laboratorial detection of Plasmodium infections. The device can be fabricated in less than 30 min by direct patterning on shrinkable polystyrene sheets of adaptable three-dimensional microfluidic chips. To validate the microfluidic system, samples of P. falciparum-infected red blood cell cultures were used. The SERS-based immunoassay enabled the detection of 0.0012 ± 0.0001% parasitaemia in a P. falciparum-infected red blood cell culture supernatant, an ∼7-fold higher sensitivity than that attained by most rapid diagnostic tests. Our approach successfully overcomes the main challenges of the current Plasmodium detection methods, including increased reproducibility, sensitivity, and specificity. Furthermore, our system can be easily adapted for detection of other pathogens and has excellent properties for early diagnosis of infectious diseases, a decisive step towards lowering their high burden on healthcare systems worldwide.

Macroscopic thermal diode with stable rectification ratio by thermal null medium

Thermal diode can achieve a unidirectional and irreversible thermal transport, which can be used for direction-selective thermal management. Here we demonstrate a macroscopic thermal diode by asymmetrically embedding staggered structure of copper and expanded polystyrene sheets in stainless steel background, which can achieve a stable high thermal rectification ratio at room temperature. For the fabricated samples measured here, we observe a nearly constant thermal rectification ratio ∼1.6 at room temperature, when the temperature bias applied on both sides changes from 25 K to 50 K or the input heat power changes from 10 W to 15 W. In contrast to the conventional methods, this approach provides a new way to design macroscopic thermal diode with a stable thermal rectification effect at room temperature, which opens up new possibilities for macroscopic heat preservation, energy-saving buildings, and direction-selective thermal camouflages.

Hierarchical Slice Patterns Inhibit Crack Propagation in Brittle Sheets

By introducing hierarchical patterns of load-parallel cuts into axially loaded brittle sheets, the resistance to propagation of mode-I cracks is very significantly enhanced. We demonstrate this effect by simulation of two-dimensional beam network models and experimentally by testing paper and polystyrene (PS) sheets that are sliced with a laser cutter to induce load-perpendicular hierarchical cut patterns. Samples endowed with nonhierarchical reference patterns of the same cut density and nonsliced sheets are considered for comparison. We demonstrate that hierarchical slicing can increase failure load, apparent fracture toughness, and work of fracture of notched paper and PS sheets by factors between 2 and 10.

Printed 3D Gesture Recognition Thermoformed Half Sphere Compatible with In‐Mold Electronic Applications

The development of conformable electronic systems’ focuses on the multifunctional smart materials transform areas from the automotive industry to biomedicine, based on improved integration and advanced functionalities. In‐mold electronics (IME) combines thermoforming, injection molding, and printed electronics, resulting in sensing structural parts integrated into smart surfaces, communicating with computer systems, and enabling advanced experiences in terms of human‐machine interaction. Contrary to flexible electronics, designed as bend conductors around a single axis, thermoformed electronics allow deformations in the three‐axial directions for different geometries. Herein, a 2D screen‐printed pattern using conductive silver ink thermoformed into a spherical surface suitable for 3D gesture recognition is reported. The mechanical deformation of the high‐impact polystyrene sheet (HIPS) and polyethylene terephthalate‐glycol (PETG) substrates during the thermoforming process of the electrical circuit is characterized experimentally. The electrical resistance changes through the circuit in the stages of the fabrication process due the thickness decrease and the propagation of the small cracks. Both evaluations contribute to a better understanding of the performance of the materials when subject to the IME process. Validation of the 3D gesture recognition operation is carried out, demonstrating their full operability, as well as the possibilities that the combination of technologies allows.

Modified polymer nanopillars array for enhanced light trapping on large area

ABSTRACT Electroless plating is used to enhance the strength of anodised aluminium oxide (AAO) which can be further utilised as a mould to fabricate the structures on large area of polymer for anti-reflection properties. Nanopillars of high aspect ratio are fabricated on polymer (polystyrene) sheet by hot embossing process which has ensured repeatability with precision and high throughput. The height of nanopillars matches the depth of the mould cavity. The enhanced light trapping performance is attributed to the high aspect ratio nanopillars with cup-shaped top surface.

Reducing the cost of energy used for adaptation by using different exterior wall covering materials in Iraq

<p><span>This paper aimed to study how to reduce the amounts of heat transfer from or to the internal space of the building by covering its external walls with many locally available materials, thus reducing the rate of consumption of electrical energy used in adaptation, which leads to reducing energy consumption costs. The researcher built a model room with dimensions (1 x 1 x 2) m on the third floor of a building in Baghdad (L = 33.2 N), the dimensions of its walls (1 x 2 m) east for the installation of the sample, and the other surfaces are insulated with 200 mm polystyrene sheets. Use a 0.5 ton air conditioner to provide the room thermal comfort. The researcher found that the metal sheet with a thickness of 10 mm and covered with an insulating layer of thermoplastics is considered the best among the materials used in construction, as it saves 57% of the electrical energy consumed in air conditioning. While the use of marble, porcelain, Helen stone, and fiberglass slabs with a thickness of 10 mm, comes last because it saves less than 30% of electrical energy.</span></p>

Utilization of Fish Scales for Microbe-mediated Gelatin Extraction: A New Biotechnology and Microbiology Avenue

Waste materials are of major concern around the globe. This study aimed to utilize the scales of fish (Labeo rohita) in microbe-mediated gelatin extraction. Three bacterial isolates were isolated from the fish scales and one bacterial isolate FSW3 showing maximum gelatin yield (61.4 %) was subjected to further analysis. The bacterial culture FSW3 (identified as Staphylococcus spp.) with enhanced production of extracted gelatin was set for physiochemical testing, FTIR analysis, UV-Vis spectroscopy, and stereomicroscopic analysis. The extracted gelatin was successfully utilized in various applications including plant growth promotion under salt stress, anti-adhesion films, firmness of yogurt, biodegradable plastic, and anti-microbial food coatings. Results showed that 0.01 mM gelatin promoted plant growth promotion under salt stress. FSW3 extracted gelatin decreased the 2-fold biofilm-forming ability of E. coli, when exposed to the gelatin-based anti-adhesion films coated on a glass slide and polystyrene sheet. The gelatin showed promising findings as anti-microbial food coatings for tomatoes preservation after 21 days and helpful in the firmness of yogurt. Another advantage of gelatin was casting it into biodegradable plastic. The current study provides a promising approach for fish scales microbe-mediated gelatin extraction and uses it to explore new avenues in biotechnology and microbiology.

CARS spectra of polystyrene sheet at excitation of fs pulses and chirped pulses

Two-beam coherent anti-Stokes Raman scattering (CARS) spectroscopy setup is built. Measurements of CARS spectra generated from polystyrene (PS) sheet under excitation of femtosecond (fs) pulses and chirped pulses are demonstrated. The pump-Stokes time delay is adjusted at fixed step of 6 fs and transient CARS spectra is measured at every pump-Stokes time delay. Two-dimensional plots depicting intensity of fs CARS, chirped Stokes CARS, chirped pump/probe CARS and spectral focusing CARS as a function of the wavenumber and the pump-Stokes time delay are realized. Excitation situation of Raman resonances in fingerprint region of polystyrene molecule is discussed in conditions of un-chirped and chirped CARS spectra. Capacity of chirped Stokes CARS, chirped pump/probe CARS and spectral focusing CARS in improving spectral resolution over fs CARS is systematically analyzed.

Shrinky‐Dink millifluidics‐based continuously reconfigurable dielectric liquid‐assisted microstrip patch antenna

AbstractReconfigurable dielectric liquid‐assisted antennas provide a solution to the need for multifunctional antennas that can service the multiple frequency bands required for modern wireless communications. However, fabricating these reconfigurable antennas requires complex processes that lack the potential for more compact designs. In this study, a novel continuously reconfigurable dielectric liquid‐assisted microstrip patch antenna fabricated with a Shrinky‐Dink millifluidics‐based substrate is designed, fabricated, and characterized. Shrinky‐Dinks are prestretched polystyrene sheets that can have patterns cut into them before shrinking under heat to form a millifluidic channel. By filling the millifluidic channel with differing amounts of water, a microstrip patch antenna fabricated on top of the rigid polystyrene substrate can be continuously reconfigured from 4.70 to 5.16 GHz with a bandwidth of 660 MHz. The fabrication process demonstrated in this study provides a path forward to produce reconfigurable dielectric liquid‐assisted antennas with smaller footprints, as well as other reconfigurable radiofrequency and electronic devices and components.

Experimental investigation of high impact polystyrene/metal self‐piercing riveted joint

AbstractSelf‐piercing riveting was adopted to join high impact polystyrene (HIPS) and metal sheets which had huge difference in material properties. Three kinds of metal sheet (AA1060, AA5052, and HC340LA) were joined to HIPS sheet. The effect of polymer sheet thickness on mechanical properties of joints was investigated. The static loads of joints were measured in tensile and shearing tests. The failure modes of joints were analyzed. The cross sections of joints were observed by metallographic microscope. Results showed that self‐piercing riveting could effectively join HIPS and metal sheets when polymer sheet was placed as top sheet. All joints failed in the manner of polymer fracture in both tensile and shearing tests. For joints with different sheet material combinations, though the cross sections and geometrical parameters of joints had great difference, the static loads and absorbed energy values of joints were nearly the same. When AA5052 sheets were joined to HIPS sheets with different thickness values, with the increase of polymer sheet thickness, the flaring degree of rivet decreased, while static loads and absorbed energy values of joints increased. This was because the strength of interlock structure was higher than that of polymer sheet and the strength of joint was determined by the strength of polymer sheet.