Life cycle assessment of chemically treated and copper coated sustainable biocomposites.

The current demand for composites reinforced with renewable fibers is greater than it has ever been. In comparison to glass fibers, natural fibers yield the advantages of lesser density and cost. Although comparable specific properties exist between glass and natural fibers, the latter shows lower strength. However, with the copper coating and chemical treatment of natural fibers, the strength of the composites can be increased nowadays. The current research investigation focuses on the life cycle assessment of the raw, chemically treated, and copper coated fiber reinforced bagasse and banana composites to compare the emissions on the environment of these samples to prove their applicability. The study includes all the processes, from the extraction of fibers to the formation of composites, i.e., from cradle to gate, and detailed inventory. The ReCiPe H midpoint method has been utilized in SimaPro software to quantify the emissions. The results indicate that the maximum global warming emission is due to the energy consumption used during the manufacturing of these composites. Electricity contribution for chemically treated and copper coated composites in global warming contribution is slightly greater than that of raw composites i.e., 73.275 % in C- BG/P, 73.06 % in Cu- BG/P, 73.65 % in C- BN/P and 74.28 % in Cu- BN/P which is comparatively higher than 63.8 % in R- BG/P and 64.97 % in R- BN/P. The next major contributions come from polylactic acid for all the three samples of bagasse fiber reinforced PLA composite and banana fiber reinforced PLA composite. The raw samples also show improved fiber strength compared to chemical and copper coated samples.

Effect of Different Surface Treatments as Methods of Improving the Mechanical Properties after Repairs of PMMA for Dentures.

Denture fractures are a common problem in dental practice, and their repair is considered a first option to restore their functional properties. However, the inter-material resistance may become compromised. Typically, the bond between these materials weakens. Therefore, various surface treatment methods may be considered to enhance their mechanical properties. Poly(methyl methacrylate) (PMMA) heat-polymerized resin (HPR) was used as the repaired material, cold-polymerized material (CPR) for the repairs, and different variants of alumina abrasive blasting (AB), methyl methacrylate (M), ethyl acetate (EA), methylene chloride (CH), and isopropyl alcohol (IA) treatments were applied. Finally, combined surface treatments were chosen and analyzed. Surface morphologies after treatments were observed by scanning electron microscopy and the flexural, shear, and impact strengths were tested. AB and chemical treatment with CH, M, and EA was used to improve all mechanical properties, and further improvement of the properties could be achieved by combining both types of treatments. Varied changes in surface morphologies were observed. Treatment with IA yielded less favorable results due to the low impact strength. The best results were achieved for the combination of AB and CH, but during the application of CH it was necessary to strictly control the exposure time.

Effect of Chemical Treatment of Cotton Stalk Fibers on the Mechanical and Thermal Properties of PLA/PP Blended Composites.

Different chemical treatment methods were employed to modify the surface of cotton stalk fibers, which were then utilized as fillers in composite materials. These treated fibers were incorporated into polylactic acid/polypropylene melt blends using the melt blending technique. Results indicated that increasing the surface roughness of cotton stalk fibers could enhance the overall mechanical properties of the composite materials, albeit potentially leading to poor fiber-matrix compatibility. Conversely, a smooth fiber surface was found to improve compatibility with polylactic acid, while Si-O-C silane coating increased fiber regularity and interfacial interaction with the matrix, thereby enhancing heat resistance. The mechanical properties and thermal stability of the composite materials made from alkali/silane-treated fibers exhibited the most significant improvement. Furthermore, better dispersion of fibers in the matrix and more regular fiber orientation were conducive to increasing the overall crystallinity of the composite materials. However, such fiber distribution was not favorable for enhancing impact resistance, although this drawback could be mitigated by increasing the surface roughness of the reinforcing fibers.

Chemical Treatments on Invasive Bivalve, Corbicula fluminea.

The Asian clam Corbicula fluminea is a native aquatic species in Eastern Asia and Africa but has become one of the ecologically and economically harmful invasive species in aquatic ecosystems in Europe, North America, and South America. Due to their natural characteristics as a hermaphroditic species with a high fecundity and dispersal capacity, Asian clams are extremely difficult to eradicate once they have infiltrated a waterbody. This is an emerging issue for states in the Northeastern United States, as Asian clams expand their range farther North due to climate change. There has been extensive research conducted to develop chemical treatments for reactively controlling invasive mollusc populations and proactively preventing their further spread. However, treatments are mostly targeted toward biofouling bivalves in industrial settings. A comprehensive review of Asian clam chemical treatments used in natural open-water systems was performed to evaluate molluscicides and identify the toxicity ranges of emerging treatments that maximize Asian clam mortality and minimize the negative impact on water quality and non-target species. The potential chemical applications in Asian clam control and management are summarized in this report to assist resource managers and practitioners in invasive Asian clam management.

Revealing spatial distribution and accessibility of cell wall polymers in bamboo through chemical imaging and mild chemical treatments.

Understanding the distribution and accessibility of polymers within plant cell walls is crucial for addressing biomass recalcitrance in lignocellulosic materials. In this work, Imaging Fourier Transform Infrared (FTIR) and Raman spectroscopy, coupled with targeted chemical treatments, were employed to investigate cell wall polymer distribution in two bamboo species at both tissue and cell wall levels. Tissue-level Imaging FTIR revealed significant disparities in the distribution and chemical activity of cell wall polymers between the fibrous sheath and fibrous strand. At the cell wall level, Imaging Raman spectroscopy delineated a distinct difference between the secondary wall and intercellular layer, with the latter containing higher levels of lignin, hydroxycinnamic acid (HCA), and xylan, and lower cellulose. Mild acidified sodium chlorite treatment led to partial removal of lignin, HCA, and xylan from the intercellular layer, albeit to a lesser extent than alkaline treatment, indicating susceptibility of these polymers to chemical treatment. In contrast, lignin in the secondary wall exhibited limited reactivity to acidified sodium chlorite but was slightly removed by alkaline treatment, suggesting stable chemical properties with slight alkaline intolerance. These findings provide valuable insights into the inherent design mechanism of plant cells and their efficient utilization.

Synthesis of multi-layer graphene oxide from HCl-treated coke and Brazilian coals by sulfuric acid thermal exfoliation and ozone oxidation.

This study involved the synthesis and characterization of graphene oxide (GO) from mineral coke and bituminous coal. HCl treated and non-HCl treated ultrafine powder obtained from both precursors were treated with H2SO4, followed by thermal treatment, and oxidation with ozone and ultra-sonication for GO production. The synthesized materials were characterized using Fourier transform infrared spectroscopy (FTIR), zeta potential (ZP), particle size distribution (PSD), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. The results confirmed the exfoliation of the material primarily at the edges of its structure and the formation of multilayer graphene oxide (GO) from mineral coke and bituminous coal. Furthermore, it was found that carbonaceous materials with graphitic morphology are easier to exfoliate and oxidize, leading to the production of higher quality graphene oxide. Therefore, the GO synthesized from mineral coke exhibited the best quality in this study. The methodology used proposes an innovative approach, offering a faster, more economical, and environmentally friendly synthesis compared to the traditional Hummers' method, thereby adding value to other raw materials that can be utilized in this process, such as Brazilian coke and coal.

Sequestration of cyanide ions from aqueous medium by physio-chemically fabricated biochar of peels of banana and grape fruit in ecofriendly way.

Pakistan is an agricultural country producing plenty of fruits, like: mango, banana, apple, peaches, grapes, plums, variety of citrus fruits including lemon, grapefruit, and oranges. So far the peels of most of the fruits are usually wasted and not properly utilized anywhere. In this work, the peels of banana and grapefruit are converted into biochar by slow pyrolysis under controlled supply of air and used for sequestering cyanide ions from aqueous medium after chemical modification with ZnCl2 and sodium dodecyl sulfate (SDS). The modified biochar was characterized by various instrumental techniques, like: SEM, FTIR, TGA, and CHNS. Different parameters, like: time, temperature, pH, and dose of adsorbent affecting the adsorption of cyanide ions, onto prepared biochar were optimized and to understand the adsorption phenomenon, kinetic and thermodynamic studies were performed. Concentration of cyanide ions was estimated by employing standard ion selective electrode system and it is found that Sodium Dodecyl Sulfate treated biochar of banana peels shown more adsorption capacity, i.e.,: 17.080 mg/g as compared to all samples. Present work revealed that the biochar produced from the fruit waste has sufficient potential to eliminate trace quantities of cyanide from water, especially after treatment with sodium dodecyl sulfate.

An industrial area in Asian and African countries where mining is done using traditional techniques is the major cause of cyanide toxicity in wastewater streams. So, here chemically fabricated biochar made by peels of banana and grape fruit is employed for removal of cyanide ion for controlling aquatic pollution using local resources in green way. Favorable results indicated the feasibility of this process, which is cost effective, convenient, ecofriendly, and sustainable.

Predicted roles of long non-coding RNAs in abiotic stress tolerance responses of plants.

The plant genome exhibits a significant amount of transcriptional activity, with most of the resulting transcripts lacking protein-coding potential. Non-coding RNAs play a pivotal role in the development and regulatory processes in plants. Long non-coding RNAs (lncRNAs), which exceed 200 nucleotides, may play a significant role in enhancing plant resilience to various abiotic stresses, such as excessive heat, drought, cold, and salinity. In addition, the exogenous application of chemicals, such as abscisic acid and salicylic acid, can augment plant defense responses against abiotic stress. While how lncRNAs play a role in abiotic stress tolerance is relatively well-studied in model plants, this review provides a comprehensive overview of the current understanding of this function in horticultural crop plants. It also delves into the potential role of lncRNAs in chemical priming of plants in order to acquire abiotic stress tolerance, although many limitations exist in proving lncRNA functionality under such conditions.

Synthesis and characterization of hydroxyapatite nanoparticles from calcium hydroxide fouled with gases evolved from smokestack of glass industry.

In glass industry, the evolved gases and fumes from burning the gas fuel absorbed in calcium hydroxide to minimize the pollution of environment. After a period of time, the calcium hydroxide fouled with sulphate and carbonate as action of the absorbed SO3 and CO2 gases. Based on our interest to treatment the solid waste materials, this study intended to convert the obtained waste of calcium hydroxide fouled with gases to valuable products. Firstly, this waste was treated with water, caustic soda and acids. The results confirmed the conversion of waste to pure calcium sulfate by treatment with 6 v/v% sulfuric acid. Secondly, the obtained calcium sulfate was reacted with ammonium dihydrogen phosphate solution for preparation of calcium hydroxyapatite (HAp) nanoparticles. The produced HAp sample was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and N2 adsorption measurements. The obtained findings confirmed that the HAp can be produced after calcination at 700 °C, nanorods-like of sizes ranged from 11 to 15 nm and with main surface functional groups of hydroxyapatite. TGA and DTA data indicated that HAp is thermally stable up to 700 °C. Also, the obtained HAp has Ca/P molar ratio of 1.60 and exhibited high total surface area of 146 m2/g with mesoporous structure which make this material can be used in medical and water purification applications.

Chemically treated Posidonia oceanica fibers as a potential sorbent for oil spill clean up.

Posidonia oceanica (PO) fibers were used as biodegradable solid waste material in the removal of oil spills from seawater. In the present study, PO fibers were chemically treated using H3PO4, KOH, ZnCl2 and H2O2. The Fourier Transform Infrared spectroscopy and scanning electron microscopy were used to compare and to determine the structure of the raw and the chemically-treated PO fibers. The main parameters studied in the two systems, a mixture system of oil and water and a system with only oil or only water, were the chemical solutions concentrations, initial oil concentration and time contact. The results revealed that PO fibers treated with phosphoric acid (H3PO4) showed an enhancement of oil sorption of 12% in oil/water layer, compared to raw PO fibers. An increase of hydrophobicity was also observed with treated fibers as revealed by the 50% decrease in water sorption capacity. The isotherm and kinetic models were determined to reveal the nature and the mechanism of the sorption. Langmuir isotherm appeared to be the best fitting model showing a one-layer oil sorption onto PO fibers. In addition, the results fitted well with the pseudo-second order kinetic model compared to pseudo-first order representing the chemical sorption of oil. The results indicated that the treated biosorbent could be used as biodegradable material to clean-up oil spills in aqueous solution.

Postharvest Physiology and Handling of Guava Fruit.

Guavas are typical tropical fruit with high nutritional and commercial value. Because of their thin skin and high metabolic rate, guavas are highly susceptible to water loss, physical damage, and spoilage, severely limiting their shelf-life. Guavas can typically only be stored for approximately one week at room temperature, making transportation, storage, and handling difficult, resulting in low profit margins in the industry. This review focuses on the physiological and biochemical changes and their molecular mechanisms which occur in postharvest guavas, and summarizes the various management strategies for extending the shelf-life of these sensitive fruits by means of physical and chemical preservation and their combinations. This review also suggests future directions and reference ideas for the development of safe and efficient shelf-life extension techniques.

Eco-friendly synthesis of clay-chitosan composite for efficient removal of alizarin red S dye from wastewater: A comprehensive experimental and theoretical investigation.

Alizarin Red S (ARS) is commonly utilized for dyeing in textile industry. The dye represents a refractory pollutant in the aquatic environment unless properly treated. To tackle this pollutant, the applicability of chitosan-clay composite (3C) for the ARS removal from textile wastewater was studied. Characterization studies were conducted on the synthesized adsorbent using Fourier transformation infrared (FT-IR), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) techniques. Optimized parameters such as adsorbent's dosage, pH, reaction time, and initial concentrations were tested in a batch system. Additionally, density functional theory (DFT) was calculated to understand the adsorption mechanism and the role of benzene rings and oxygen atoms in the ARS as electron donors. At the same initial concentration of 30 mg/L and optimized conditions of 50 mg of dose, pH 2, and 10 min of reaction time, about 86% of ARS removal was achieved using the composite. The pseudo-second-order kinetic was applicable to model a reasonable fitness of the adsorption reaction, while the Temkin model was representative to simulate the reaction with a maximum adsorption capacity of 44.39 mg/g. This result was higher than magnetic chitosan (40.12 mg/g), or pure chitosan (42.48 mg/g). With ΔH = 27.22 kJ/mol and ΔG<0, the data implied the endothermic and spontaneous nature of the adsorption process. Overall, this implies that the clay-chitosan composite is promising to remove target dye from contaminated wastewater.

Development of a Recycling Process and Characterization of EVA, PVDF, and PET Polymers from End-of-Life PV Modules.

Photovoltaic (PV) modules are highly efficient power generators associated with solar energy. The rapid growth of the PV industry will lead to a sharp increase in the waste generated from PV panels. However, electro-waste can be successfully used as a source of secondary materials. In this study, a unique procedure for recycling PV modules was developed. In the first stage, the aluminum frame and junction box, 18wt%. and 1wt%. of the module, respectively, were removed. The following stage was crucial, involving a mechanical-thermal method to remove the glass, which accounts for 70wt%. As a result, only 11wt%. of the initial mass of the PV was subjected to the next stage of chemical delamination, which reduced the amount of solvent used. Toluene was used to swell the ethylene vinyl acetate, EVA, and allow for the separation of the PV module. The effects of temperature and ultrasound on separation time were investigated. After the separation of silicon cells, metal ribbons, EVA, and the backsheet were obtained. The purity of the polymers was determined by FTIR and elemental analysis. Thermal properties were measured using DSC calorimetry to determine the basic parameters of the material.

Bridging the gap between surface physics and photonics.

Use and performance criteria of photonic devices increase in various application areas such as information and communication, lighting, and photovoltaics. In many current and future photonic devices, surfaces of a semiconductor crystal are a weak part causing significant photo-electric losses and malfunctions in applications. These surface challenges, many of which arise from material defects at semiconductor surfaces, include signal attenuation in waveguides, light absorption in light emitting diodes, non-radiative recombination of carriers in solar cells, leakage (dark) current of photodiodes, and light reflection at solar cell interfaces for instance. To reduce harmful surface effects, the optical and electrical passivation of devices has been developed for several decades, especially with the methods of semiconductor technology. Because atomic scale control and knowledge of surface-related phenomena have become relevant to increase the performance of different devices, it might be useful to enhance the bridging of surface physics to photonics. Toward that target, we review some evolving research subjects with open questions and possible solutions, which hopefully provide example connecting points between photonic device passivation and surface physics. One question is related to the properties of the wet chemically cleaned semiconductor surfaces which are typically utilized in device manufacturing processes, but which appear to be different from crystalline surfaces studied in ultrahigh vacuum by physicists. In devices, a defective semiconductor surface often lies at an embedded interface formed by a thin metal or insulator film grown on the semiconductor crystal, which makes the measurements of its atomic and electronic structures difficult. To understand these interface properties, it is essential to combine quantum mechanical simulation methods. This review also covers metal-semiconductor interfaces which are included in most photonic devices to transmit electric carriers to the semiconductor structure. Low-resistive and passivated contacts with an ultrathin tunneling barrier are an emergent solution to control electrical losses in photonic devices.

Advances in identifying and managing emerging contaminants in aquatic ecosystems: Analytical approaches, toxicity assessment, transformation pathways, environmental fate, and remediation strategies.

Emerging contaminants (ECs) are increasingly recognized as threats to human health and ecosystems. This review evaluates advanced analytical methods, particularly mass spectrometry, for detecting ECs and understanding their toxicity, transformation pathways, and environmental distribution. Our findings underscore the reliability of current techniques and the potential of upcoming methods. The adverse effects of ECs on aquatic life necessitate both in vitro and in vivo toxicity assessments. Evaluating the distribution and degradation of ECs reveals that they undergo physical, chemical, and biological transformations. Remediation strategies such as advanced oxidation, adsorption, and membrane bioreactors effectively treat EC-contaminated waters, with combinations of these techniques showing the highest efficacy. To minimize the impact of ECs, a proactive approach involving monitoring, regulations, and public education is vital. Future research should prioritize the refining of detection methods and formulation of robust policies for EC management.

Chemical and Thermal Treatment for Drying Cassava Tubers: Optimization, Microstructure, and Dehydration Kinetics.

Perishable commodities like cassava necessitate effective postharvest preservation for various industrial applications. Hence, optimizing pretreatment processes and modeling drying kinetics hold paramount importance. This study aimed to optimize cassava pretreatment using the central composite design of a response surface methodology while also assessing microstructure and dehydration kinetics. Diverse chemical and thermal pretreatments were explored, encompassing sodium metabisulfite concentrations (0-4% w/w), citric acid concentrations (0-4% w/w), and blanching time (0-4 min). The four investigated responses were moisture content, whiteness index, activation energy (Ea), and effective moisture diffusivity (Deff). Employing five established drying models, suitability was appraised after optimal pretreatment conditions were determined. The findings revealed that moisture content ranged from 5.82 to 9.42% db, whereas the whiteness index ranged from 87.16 to 94.23. Deff and Ea ranged from 5.06 × 10-9 to 6.71 × 10-9 m2/s and 29.65-33.28 kJ/mol, respectively. The optimal pretreatment conditions for dried cassava were identified by optimizing the use of 1.31% citric acid, 1.03% sodium metabisulfite, and blanching time for 1.01 min. The microstructure indicated that particular chemical and thermal pretreatment configurations yielded particles in the shape of circular and elliptical granules. The logarithmic model provided the most accurate description of the dehydration kinetics, with the highest R2 value (0.9859) and the lowest χ2, RSME, and SSE values of 0.0351, 0.0015, and 0.0123, respectively.

Owens-Wendt Method for Comparing the UV Stability of Spontaneous Liquid-Repellency with Wet Chemical Treatment of Laser-Textured Stainless Steel.

The liquid-repellent properties of AISI 304 stainless steel surfaces textured with a femtosecond laser were studied, both after spontaneous hydrophobization and when treated with stearic acid and octyltrimethoxysilane. Surface topography has been shown to play a critical role in determining these properties. Although textures containing only LIPSS exhibited poor liquid-repellency, the performance was significantly improved after engraving the microtexture. The most effective topography consisted of 45 µm-wide grooves with a pitch of 60 µm and protrusions covered with a rough microcrystalline structure. Liquid-repellency, chemical treatment efficiency, and UV resistance were compared using derived Owens-Wendt parameters. The surface of femtosecond-laser-textured steel after spontaneous hydrophobization was found to be significantly less stable under UV irradiation than surfaces treated with stearic acid or octyltrimethoxysilane modifiers.

Health effects of herbicides and its current removal strategies.

The continually expanding global population has necessitated increased food supply production. Thus, agricultural intensification has been required to keep up with food supply demand, resulting in a sharp rise in pesticide use. The pesticide aids in the prevention of potential losses caused by pests, plant pathogens, and weeds, but excessive use over time has accumulated its occurrence in the environment and subsequently rendered it one of the emerging contaminants of concern. This review highlights the sources and classification of herbicides and their fate in the environment, with a special focus on the effects on human health and methods to remove herbicides. The human health impacts discussion was in relation to toxic effects, cell disruption, carcinogenic impacts, negative fertility effects, and neurological impacts. The removal treatments described herein include physicochemical, biological, and chemical treatment approaches, and advanced oxidation processes (AOPs). Also, alternative, green, and sustainable treatment options were discussed to shed insight into effective treatment technologies for herbicides. To conclude, this review serves as a stepping stone to a better environment with herbicides.

Chemical solutions for restoring scaling-induced injectivity impairment in offshore produced water re-injection.

Produced water re-injection (PWRI) is a promising and sustainable strategy to manage substantial quantities of produced water for subsurface energy production systems. This approach offers an alternative to the environmentally harmful practice of marine disposal. Nonetheless, produced water re-injection may lead to considerable reductions in the injectivity. The injectivity loss can be attributed to several factors, including inorganic scaling, which can obstruct the flow pathway through porous media near the wellbore as well as subsurface facilities (e.g., tubing). Scaling can also contribute to the formation of mixed organic-inorganic schmoo-like complexes. Iron-containing (FexSy, FexOy-FexOyHz), carbonate-, and sulfate-based scales (e.g., BaSO4, SrSO4, and CaCO3) are the primary precipitates that have disruptive effects during PWRI scheme, especially in reservoirs suffering from microbial souring activities. In this work, we first screened the mineral scales that may form under the relevant re-injection conditions using the composition of produced water and seawater samples from the Danish North Sea. Subsequently, we assessed the efficiency of a commercial scale inhibitor against the scaling of targeted mineral phases through a series of batch experiments, followed by the development of a model to simulate its inhibitory performance. To reduce the precipitation or deposition of different minerals in water injection applications, we evaluated the combined effect of adding other chemicals (i.e., an acid, an oxidizer, and a chelating agent) to the injection water along with the scale inhibitor. To do this, we described the relevant mineral-aqueous interactions (dissolution, precipitation, and solution complexation) in PHREEQC. This predictive model represents an alternative to time- and resource-intensive experiments and may aid in achieving optimized chemical recipes required to mitigate mineral scaling in water injection systems under various physiochemical conditions. This work can contribute to the development of more sustainable and efficient strategies for managing produced water, ultimately helping to reduce the environmental impacts of hydrocarbon production.