Cantab Research Articles

The State of Research and Weight of Evidence on the Epigenetic Effects of Bisphenol A.

Bisphenol A (BPA) is a high-production-volume chemical with numerous industrial and consumer applications. BPA is extensively used in the manufacture of polycarbonate plastics and epoxy resins. The widespread utilities of BPA include its use as internal coating for food and beverage cans, bottles, and food-packaging materials, and as a building block for countless goods of common use. BPA can be released into the environment and enter the human body at any stage during its production, or in the process of manufacture, use, or disposal of materials made from this chemical. While the general population is predominantly exposed to BPA through contaminated food and drinking water, non-dietary exposures through the respiratory system, integumentary system, and vertical transmission, as well as other routes of exposure, also exist. BPA is often classified as an endocrine-disrupting chemical as it can act as a xenoestrogen. Exposure to BPA has been associated with developmental, reproductive, cardiovascular, neurological, metabolic, or immune effects, as well as oncogenic effects. BPA can disrupt the synthesis or clearance of hormones by binding and interfering with biological receptors. BPA can also interact with key transcription factors to modulate regulation of gene expression. Over the past 17 years, an epigenetic mechanism of action for BPA has emerged. This article summarizes the current state of research on the epigenetic effects of BPA by analyzing the findings from various studies in model systems and human populations. It evaluates the weight of evidence on the ability of BPA to alter the epigenome, while also discussing the direction of future research.

Sustainable composites with ultrahigh energy absorption from beverage cans and polyurethane foam

The worldwide annual consumption of metal beverage cans is enormous. Reusing these discarded empty beverage cans (EBCs) as an energy absorber for kinetic energy absorption would be highly beneficial for promoting energy savings, reducing greenhouse gas emissions, and establishing a circular economy. However, EBCs are susceptible to deformation in an undesirable failure mode under axial crushing loads, which is unfavorable for energy absorption. This study demonstrates the effectiveness of combining empty cans with polyurethane (PU) foam to enhance the energy absorption performance of EBCs. The study develops low-cost and sustainable composite structures (SCSs) from waste beverage cans. Surprisingly, the specific energy absorption (energy absorption per unit mass) of the SCSs is 2.44 times that of the EBCs under axial quasi-static compression. The average axial crushing force of SCSs is approximately 23.4 times the weight of the empty can itself. Furthermore, the SCSs exhibit excellent crashworthiness performance in various dynamic impact scenarios and superior energy absorption characteristics compared to other typical tubular composites and metamaterials. This study demonstrates an extremely feasible approach for developing next-generation eco-friendly and high-performance energy-absorbing composite materials.

Pembentukan Komposit Zeolit X - Bayerit dari Perlakuan Abu Sekam Padi dan Aluminium Kemasan Produk Pangan dalam Larutan NaOH Teknis pada Suhu Ruangan

Various research efforts have been carried out to obtain efficient zeolite synthesis methods, including the use of waste as the main ingredient or carried out at room temperature. One type of zeolite that has been synthesized at room temperature is zeolite X (ZX) within a minimum of 28 days using synthetic chemicals. The purpose of this study is to explore how ZX can be formed from waste materials and NaOH technical grade solution (TGS) at room temperature for 40 days without stirring treatments. The waste materials are rice husk ash from the traditional red brick industry, aluminum beverage cans, and food packaging aluminum waste. The materials were homogeneously mixed with the NaOH TGS in such a way as to produce a mixture with a mole ratio of 7.23Na2O : 0.26Al2O3 : 1SiO2 : 280H2O, with mole ratios of Na2O/H2O and Al2O3/SiO2 that were 30% higher than the literature for ZX synthesis, respectively. The results of characterization showed that the treatment yield was ZX along with the presence of the bayerite phase, which had been formed since the 20-day observation period. The use of excess Na2O/H2O and Al2O3/SiO2 mole ratios in this study impacts the formation of bayerite first and the ability of dissolved silica to condense, thus slowing the crystallization of ZX. The result of this study led to the new finding that zeolite-bayerite composite can be synthesized directly in a simple, inexpensive, and environmentally friendly manner, where the composite materials have been reported as catalysts and adsorbents.

Make Once, Use A Hundred Times

Single-use consumer packaging is littering the world with waste. Earlier this year, the UK government proposed a deposit system on drinks cans and bottles from 2025. Research carried out by the packaging industry is charting a future course of action

Study Thermal Resistance of γ-Al<sub>2</sub>O<sub>3</sub> at Various Reaction Temperatures via TGA Analysis

The discarded empty aluminium beverage cans can pose a serious environmental contamination issue. Recently, studies are now focusing on reducing and utilising solid wastes which have grown to be a significant environmental concern. Thus, this study focuses on producing γ-Al2O3 from readily available aluminium garbage cans using a Sol-gel technique and analysing its thermal properties using TGA analysis. The effect of the reaction temperatures was further investigated to comprehend the synthesis of alumina at (room temperature, 50 °C, and 70 °C) at a fixed aging duration of 12 h. Experimental findings demonstrated the potential of producing γ-Al2O3 from used aluminium cans, which may then be used as sustainable catalysts and catalytic supports for a variety of applications. The results showed that all the synthesised alumina had a good result with a maximum weight loss less than 5%; this reflected its strong stability. The alumina that was created at 70 °C reaction temperature recorded the lowest weight loss and the highest residue at 2.78% and 97.22%, respectively.

From the “Lager Lovelies” to “The Feminist”: Tennent’s Lager Marketing, 1960–1997

This article traces the marketing of Scottish brewer Tennent Caledonian’s “Lager Lovelies” beer cans, which featured sexualized photographs of women, from the initial production of the cans in the 1960s to the rebranding of Tennent’s Lager in 1997. The article considers the development of the cans and situates the marketing in the social and historical context. Oral history interviews with former models, industry employees, and people who remember the cans provide insights into people’s attitudes toward the marketing. The images on the cans are examined using visual discourse analysis, which shows that the marketing was derivative of the pervasive sexual objectification of women’s bodies in media and pornography. The marketing of the cans to White heterosexual men is located within twentieth-century capitalism and patriarchal structures that enabled Tennent’s to commodify and objectify women and eroticize an everyday activity like drinking lager. The article considers the end of the Lager Lovelies cans in the early 1990s and the subsequent attempt to reposition Tennent’s Lager in 1997 as a desirable alcoholic drink for younger generations.

Hitting the mark: probing at the initiation site allows for accurate prediction of a thin shell's buckling load.

Geometric imperfections are understood to play an essential part in the buckling of a thin shell, but how multiple defects interact to control the onset of failure remains unclear. Here, we examine the failure of real cylindrical shells by experimentally poking soda cans with a large imparted dimple. By high-speed imaging of the can's surface, the initiation of buckling from axial loading is directly observed, revealing that larger dimples tend to set the initial buckling location. However, the influence of the shell's background geometric imperfections can still occasionally dominate, causing initiation to occur far from the dimple. In this situation, probing at the dimple leads to an over-prediction of the axial capacity. Using finite-element simulations, we understand our experimental results as a competition between the large dimple and the shell's inherent defect structure. In our simulations, we empirically observe a deformation-based criterion that connects the ideal poking location to the initiation site. This article is part of the theme issue 'Probing and dynamics of shock sensitive shells'.

Foreword to the special issue on new developments in structural stability.

Foreword to the special issue on new developments in structural stability.

Identification of BADGE derivatives in beverage cans

Identification of BADGE derivatives in beverage cans

Hydrogen Sulfide Formation in Canned Wines Under Long-Term and Accelerated Conditions

<h3>Background and goals</h3> Wines in aluminum beverage cans (“canned wines”) are a rapidly growing packaging segment due to several factors, including convenience and sustainability advantages. However, canned wines have higher concentrations of hydrogen sulfide (H₂S; “rotten egg”) than wines in glass packaging. It was hypothesized that wine composition and liner selection affect H₂S formation in canned wines. <h3>Methods and key findings</h3> Commercial wines (n=10) were stored in either glass or aluminum beverage cans with one of three liners for up to 32 weeks. Wines stored in glass showed negligible H₂S production after 32 weeks. Wines stored in acrylic lined cans produced up to 1307 μg/L H₂S (median = 162 μg/L) within 8 weeks. Wines stored in BPA epoxy cans produced less H₂S (maximum = 51.8 μg/L median = 11.8 μg/L after 32 weeks), with comparable performance observed for BPA non-intent (BPA-NI) epoxy liners. H₂S formation was well-correlated with visible damage to the interior liners, but poorly correlated with dissolved aluminum. H₂S from accelerated aging of wines with lined aluminum coupons (50 ºC, up to 14 d, anoxic conditions) correlated with H₂S produced during long-term aging, but not with H₂S produced by unlined aluminum coupons. Molecular SO2 was best correlated with increased H₂S production in epoxy lined cans during long-term aging of commercial wines, and similar results were observed under accelerated conditions with coupons in a model-wine factorial experiment. <h3>Conclusions and significance</h3> Maintaining low molecular SO2 (less than ~0.4 mg/L) and using epoxy liners (BPA or BPA-NI) appear critical for ensuring low H₂S during long-term can storage up to 8 months. The accelerated aging approach described in this work may be applicable to other corrosive beverages.

Techno-economically feasible beverage can as superior anode in rechargeable Al-air batteries

Porous Fe nitrogen-doped carbon (Fe-NC) with a polyhedron structure, derived from zeolitic imidazolate framework 8 (ZIF8), was synthesized as an efficient electrocatalyst in Al-air batteries, complemented by a low-cost aluminium anode based on beverage cans. The highly-loaded porous Fe-NC demonstrated efficient catalytic activity towards the oxygen reduction reaction (ORR). This was linked to the good conductivity and the large surface area originating from the observed 3D porous architecture. The RDE test confirmed that the favourable 4-electron pathway for porous Fe-NC was higher than that of the 20 wt% Pt/carbon. Besides the high ORR activity, the Al-air battery demonstrated a maximum power density of 46 mW/cm2 at a current density of 80 mA/cm2. The galvanostatic discharge studies showed a stable voltage discharge plateau (>1.1 V) for current densities between 5 and 20 mA/cm2. The Al-air battery with porous Fe/NC catalyst exhibited a remarkably increased discharge capacity of 1920 mAh/g for the pure Al foil and 1173 mAh/g for the commercial Al can foil at a current density of 20 mA/cm2. The finding indicates that both anode and cathode in this work are techno-economically feasible materials. In addition, the Al-air battery showed large charge-discharge cycles (i.e., 180 cycles, 31 h) at 10 mA/cm2 with a low voltage gap using a beverage can.

Novel polypropylene-TiO2:Bi spherical floater for the efficient photocatalytic degradation of the recalcitrant 2,4,6-TCP herbicide

In this work, spherical photocatalytic floaters were fabricated by depositing TiO2:Bi (TBi) particles on polypropylene (PP) spheres (recycled from beer cans). These particles were deposited on the sphere (TBi-sphere) by the spray coating technique and evaluated their performance for the photocatalytic degradation of 2,4,6-trichlorophenol (2,4,6-TCP) herbicide. SEM images demonstrated that the BTi powders consisted in conglomerated grains with sizes of 20–80 nm and the analysis by X-ray diffraction confirmed the presence of rutile and anatase phases in the BTi. The photocatalytic experiments showed that the TBi and TBi-sphere produced maximum degradation of 90 and 97% for 2,4,6-TCP, respectively, after 4 h under UV–Vis light. The photocatalytic powders/composites were reused 3 times and the loss of degradation efficiency was 3 and 16% for the TBi powder and TBi-sphere, respectively. This means that the TBi-sphere is more stable for the continuous degradation of the 2,4,6-TCP contaminant. The TiO2:Bi powder was compared with the commercial TiO2 (P25) and found that the TiO2:Bi powder had higher light absorption (≈42%) and higher surface area (≈105%) than the P25. Therefore, the degradation percentage for the 2,4,6-TCP was 52% higher in the sample doped with Bi. Also, scavenger experiments were carried out and found that the main oxidizing agents produced for the degradation of 2,4,6-TCP were •OH− radicals and •O2− anions. Other species such as h+ were also produced at lower amount. Hence, our results demonstrated that spherical/floatable photocatalytic composites are a viable option to remove herbicide residuals from the water, which is of interest in water-treatment-plants.

Solid state recycling of used aluminum alloy beverage cans by thermomechanical consolidation

ABSTRACT Solid-state recycling of used aluminum alloy beverage cans was accomplished by thermomechanical consolidation of the sheet fragments produced by shredding the cans. Different samples were obtained using two thermomechanical consolidation routes, one involving direct hot extrusion of a sheet fragment compact and the other involving upset hot-forging of a sheet fragment compact followed by hot extrusion of the forged ingot. The microstructures and mechanical properties of the samples were investigated. It was found that the samples contained less pores and exhibited better mechanical properties with a higher extrusion temperature and involving upset forging than with only hot extrusion, the highest tensile strength is 209.5 MPa and the largest elongation to fracture is 29.1%. The surface layers of the samples exhibited a clearly higher strength and tensile ductility than the interior. They also showed significantly different fracture behaviors, with the former being like fully ductile fracture and the latter involving delamination of the sheet fragments, suggesting that the bonding between the fragments is significantly stronger in the surface layer, possibly due to a higher amount of plastic deformation in it. Overall, the best quality solid state recycled material has tensile properties comparable with those of wrought aluminum alloy with the same composition.

Extraction and characterization of highly pure alumina (α, γ, and θ) polymorphs from waste beverage cans: A viable waste management approach

The recycling and recovery of important materials from inexpensive feedstock has now become an intriguing area and vital from commercial and environmental viewpoints. In the present work, extraction of different single phases of alumina (α, γ, θ-Al2O3) having high purity (>99.5 %) from locally available waste beverage cans (∼95 % Al) through facile precipitation route calcined at distinct temperatures has been reported. The optimization of process technology was done by a variety of different synthesis parameters, and the production cost was estimated between 84.47-87.45 USD per kg of alumina powder. The as prepared alumina fine particles have been characterized using different sophisticated techniques viz. TG-DTA, WD-XRF, XRD, FT-IR, SEM, DLS-based particle size analysis (PSA) with zeta (ζ) potential measurement and UV–Visible Spectroscopy. X-ray diffractogram confirms the formation of γ-, θ-, and α-alumina at 500–700 °C, 900–1000 °C, and 1200 °C respectively and crystallite size, crystallinity, strain, dislocation density, and specific surface area were measured using major X-ray diffraction peaks which varies with temperature. The SEM studies showed that the as prepared alumina particles were agglomerated, irregular-shaped with particle size (0.23–0.38 µm), pore size, and porosity were calculated from SEM image. ζ-potentials at different pH values as well as isoelectric point (IEP) of α, γ, and θ alumina were calculated in an aqueous medium which changes with temperature. The direct band gap (Eg) energies were found between 4.09 and 5.19 eV of alumina obtained from different calcination temperatures. The synthesized materials can be used in sensors, ceramics, catalysis, and insulation applications.

Multielement analysis in beer cans using X-ray fluorescence

In this study the elemental concentrations of twenty-three beer cans of different brands and nationalities were determined using X-ray fluorescence technique. Beer cans from Brazil (20 beer cans), Germany, the United Kingdom and Colombia were analyzed, totalizing 15 different breweries. It was possible to calculate the concentration of 15 elements in the beer cans samples: Mg, Al, Si, S, Cl, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Zr and Pb. The results showed that aluminum concentrations ranged from 94 % to 96 %. Other's elements can be considered trace elements, being the highest concentrations of them for Mg (approximately 2%) and Mn (approximately 1%). Some elements showed differences between cans from different nationalities, with Zn being much higher in samples from Brazil. The Zr element showed similarities between German and UK beer cans. In addition, the beer can sample from Colombian had lower concentrations of Cl and Ga. This study shows that the values found are comparable to those found in the literature and that the concentrations of some trace elements in beer cans may represent signs of impurities brought during the recycling process.

RF22 | PMON03 Sex-specific Effects of Bisphenol-A and its Analogs on Monoamine Levels in the Paraventricular Nucleus

Abstract Bisphenol A (BPA) is known to produce adverse effects on fertility, cardiovascular, and metabolic health. The constraints placed on BPA production led companies to switch to BPA's structural analogs, Bisphenol S (BPS) and Bisphenol F (BPF). These chemicals are used in various equipment, food and drink cans, and paper, permitting widespread exposure. We recently found that prenatal exposure to low levels of these chemicals can increase blood pressure in the offspring. However, the underlying neurobiological mechanism is unclear. We hypothesized that these chemicals could alter the levels of monoamines, specifically in brain regions that regulate cardiovascular function such as the paraventricular nucleus (PVN) of the hypothalamus. Pregnant Sprague Dawley rats were exposed to saline, 5 µg/kg BW of BPA or BPS, or 1 µg/kg BW of BPF from gestation day 6 to 21. Their adult Male and Female offspring were implanted with a radiotelemetry device to measure blood pressure and heart rate levels. Following telemetry, animals were sacrificed, and the brains were collected, frozen and sectioned. The PVN was microdissected, and analyzed for monoamine levels using HPLC-EC. Males exposed to BPA had significant increases in the levels of serotonin (5HT) in the PVN compared to the control group, while a marked increase in 5HT levels were only observed in females exposed to BPF and not BPA (p = 0.0002). No significant changes were observed in Dopamine (DA) or norepinephrine (NE) levels. There were significant sex differences (p&amp;lt;0.0001) and treatment effects (p=0.0003) in the DOPAC/DA turnover ratio with males exposed to BPA, BPS, and BPF having markedly less turnover rates compared to control. No changes in DOPAC/DA turnover was apparent in females. There were significant sex (p&amp;lt;0.0001) and treatment effects (p&amp;lt;0.0001) in the 5HIAA/5HT turnover ratio, with males in the BPA and BPS groups having significantly less turnover compared to controls. In contrast, Females exposed to BPS and BPF had significantly lower 5HIAA/5HT turnover ratios but higher turnover ratios in the groups exposed to BPA. These results indicate that 5-HT production increases markedly in males exposed to BPA and in females exposed to BPF. This is associated with reduced metabolism of 5-HT. This suggests that the significant increases in 5-HT activity in the PVN could possibly contribute to the development of hypertension in these animals. Presentation: Sunday, June 12, 2022 12:30 p.m. - 12:35 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Bisphenol A (BPA) induces apoptosis of mouse Leydig cells via oxidative stress.

As one of the most frequently produced synthetic compounds worldwide, bisphenol A (BPA) has been widely used in many kinds of products such as appliances, housewares, and beverage cans. BPA has been shown to cause damage to male reproductive system; however, the potential mechanism remains to be investigated. In the present study, BPA exposure decreased the testis and epididymis coefficient, caused a disintegration of germinal epithelium, decreased the density and motility of sperm in the epididymis tissue, and increased the number of abnormal sperm morphology, which indicated that BPA exposure could cause damage to testis. BPA was also shown to induce apoptosis and oxidative stress in the testis tissue. The serum testosterone concentration was decreased in the BPA-treated group, suggesting that BPA could lead to Leydig cell damage. Subsequently, mouse TM3 cell, a kind of mouse Leydig cell line, was utilized to investigate the potential mechanism. Herein, we showed that BPA exposure could inhibit cell viability and induce apoptosis of TM3 cells. Furthermore, oxidative stress in the cells could also be induced by BPA, while the inhibition of oxidative stress by N-acetyl-L-cysteine (NAC), an oxidative stress scavenger, could reverse the inhibition of cell viability and induction of apoptosis by BPA exposure, indicating that oxidative stress was involved in BPA-induced apoptosis of TM3 cells. Finally, RNA-sequencing and real-time PCR were utilized to screen and validate the potential oxidative stress-related genes involving in BPA-induced apoptosis. We found that BPA exposure increased the mRNA levels of oxidative stress-related genes such as Lonp1, Klf4, Rack1, Egln1, Txn2, Msrb1, Atox1, Mtr, and Atp2a2, as well as decreased the mRNA level of Dhfr gene; while NAC could rescue the expression of these genes. Taken together, oxidative stress was involved in BPA-induced apoptosis of mouse Leydig cells.

Utilization of recyclable aluminum cans as fins in a vertical solar air heating system: An experimental and numerical study

Heating loads cover a large portion of the total energy consumption of buildings. Solar air heating is a sustainable and low-cost alternative for heating applications instead of employing fossil energy sources. In this work, vertical solar air collectors (VSACs) have been developed to be utilized in buildings. Moreover, aluminum beverage cans have been utilized as fins to improve the effectiveness of the collector system. In the initial stage of the study, various aluminum can configurations have been analyzed numerically. Numerical findings showed that symmetric placement of aluminum cans gave better results in comparison to the hollow VSAC and VSAC with asymmetric can placement. In this regard, symmetric can configuration has been applied to the VSACs with two plenum thicknesses including 100 mm and 150 mm for experimental investigation. Experiments have been performed at two flow rates and thermal efficiencies of the tested VSACs were found between the range of 55.16–76.22%. Also, average exergy efficiency values for VSACs with higher and lower plenum thicknesses were obtained between the ranges of 8.34–8.85% and 9.84–10.36%, respectively. The overall findings of the present research exhibited successful utilization of recyclable aluminum beverage can-integrated VSACs for air heating.

Separation of oil-water emulsions by a novel packed bed electrocoagulation (EC) process using anode from recycled aluminum beverage cans

Electrocoagulation (EC) is an emerging technology for the elimination of oil and COD content from oily wastewaters. However, higher operating costs and electrode passivation are pressing challenges for its wide speared application. To overcome this setback, the present work has attempted to develop a new and inexpensive electrode using recycled aluminum (Al) beverage cans for the treatment of oily wastewater by electrocoagulation (EC) technology. It could be an alternative to conventional plate or tube electrodes in the EC process, it is the first contribution into the literature. In current work, recycled Al beverage cans filled with steel wool was used as anode, and commercial stainless-steel mesh (304) with cylindrical shape was used as cathode. The main EC performance measure was COD removal efficiency, impacts of significant process parameters in the EC process (such as operating voltage, electrocoagulation time, stirring rate, and NaCl concentration) on the effectiveness of EC process were investigated by using response surface methodology (RSM) based Box-Behnken Design (BBD) model. The RSM analysis results demonstrated that the highest COD removal rate of 93.53% was achieved under optimal conditions of operating voltage (15 V), electrocoagulation time (10 min), stirring rate (250 rpm), and NaCl concentration (1 g/L). In addition, energy consumption analysis was performed, an electrical energy efficiency of 0.160 kWh/kg COD was achieved. Afterward, ATR-FTIR spectroscopy, scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), and XRD analysis were performed under optimal conditions to characterize anode, and generated sludge during the EC process. Collectively, the findings in this study paves the way toward the development of sustainable EC technology for separation of emulsified oil-water mixtures, which gives the importance of the circular economy and sustainable management of industrial wastewaters.

Evaluation of scrap metallic waste electrode materials for the application in electrocoagulation treatment of wastewater

The constant need for sacrificial electrodes is one of the limitations of applying the EC in wastewater treatment. Accordingly, this study proposes a sustainable alternative in reusing scrap metallic wastes as electrode materials. Four different types of metallic wastes (beverage cans, used aluminum (Al) foil, scrap iron, and scrap mild steel) are proposed as sacrificial electrodes for grey water (GW) treatment using the EC technique. At electrical current densities (CD) ranging between 5 and 20 mA/cm2, the treatment performance was evaluated for a reaction time of 10 min in terms of the removal efficiency of some key parameters such as color, turbidity, chemical oxygen demand (COD), and electrical conductivity, energy and material consumption, and metal contamination of GW from electrodes. The results demonstrated that using metallic wastes as sacrificial electrodes can achieve a considerable reduction in color, turbidity, COD, and electric conductivity of about 97.2%, 99%, 88%, and 89%, respectively. However, their reuse as electrodes revealed some important concerns. Al foil undergoes quick and substantial perforation and loss of surface area during electrolysis. The scrap iron and scrap mild steel were found to cause metal contamination by increasing Fe ions in the treated GW. Generally, metal scrap wastes can serve effectively as alternative sustainable electrodes. However, further research is recommended regarding the operating costs, which are considered crucial aspects of the EC process in terms of energy consumption and the most efficient method of fabricating the metallic wastes into a form suitable for reuse in the EC technique.