A qualitative analysis of rural fishermen: Potential for blockchain-enabled framework for livelihood sustainability.

Rural fishing communities face numerous challenges related to livelihood security, as they are engaged in a risky and labour-intensive occupation. They often receive only a small portion of the profits, due to the influence of self-serving local intermediaries, lack of transparency in the business processes, trust issues, and power differentials among stakeholders. Although still in its infancy, blockchain technology has been adopted in various urban settings to mitigate similar challenges and to build trust through its security attributes, data ledger transparency, and smart contract automation. Yet, few have explored the efficacy of blockchain technology in addressing the unique challenges faced by rural fishermen in marketing their catch and connecting them to a broader range of customers for improved livelihood resilience. This study aims to examine how the livelihood resilience of fishermen can be increased through the potential of a blockchain, in a fishing community in the coastal village of Alappad in Kerala, India. Thematic analysis of data acquired from 43 semi-structured qualitative interviews and participatory rural appraisal tools revealed five categories of challenges: business cost and profitability, government regulations, low education and digital illiteracy, socio-cultural limitations, and over-dependence on middlemen as inhibitors to fishermen's livelihoods. The study proposes a blockchain-based e-commerce framework to mitigate selected challenges that emerged due to a lack of trust and transparency in the local fish market. It contributes to rural development by exploring an innovative, solution aligned with five UN Sustainable Development Goals, in contrast to the Business-as-usual approach in offering technological solutions.

Sustainable PET Waste Recycling: Labels from PET Water Bottles Used as a Catalyst for the Chemical Recycling of the Same Bottles.

We report using a waste material, poly(ethylene terephthalate) (PET) water bottle labels, for the chemical recycling of the same PET water bottles. The solid fillers used for the manufacturing of the packaging labels were recovered by thermolysis in an electrical furnace at 600, 800, and 1000 °C with 13.5, 12.0, and 10.4 wt % recovery. Characterization of the solid residue showed the presence of calcium carbonate, calcium oxide, and titanium dioxide, which are typical fillers used for packaging film manufacturing, such as water bottle labels. These solid residues were then used as a catalyst for PET depolymerization by glycolysis, in which the catalyst recovered from bottle labels and shredded PET reacted in the presence of excess ethylene glycol at 200 °C. The reaction mixtures were analyzed for PET conversion and the yield of the bis(2-hydroxyethyl)terephthalate (BHET) monomer as the final product of the glycolysis reaction to determine the efficiency of the catalyst. Our results show that the catalyst prepared at 800 °C (Cat-800) has the best performance and provides a 100% PET conversion with a 95.8% BHET yield with a 1.0 wt % loading in 1.5 h. The catalyst from the PET water bottle labels is nontoxic, readily available, cost-effective, environmentally friendly, and can be used as a model for the self-sufficient chemical recycling of PET via glycolysis.

Magnetic ionic liquid catalyst functionalized with antimony (III) bromide for effective glycolysis of polyethylene terephthalate.

In a previous study, we demonstrated the efficient depolymerization of polyethylene terephthalate (PET) through glycolysis using antimony (III) oxide, a commonly used catalyst in PET synthesis. In the present research, we introduce a novel approach involving the synthesis of a magnetic bifunctional ionic liquid, Fe3O4@PMIM.SbBr4, containing only 2.2 wt% of antimony. The aim is to reduce the required antimony dosage for the reaction and enable its facile recovery and reuse. By employing this catalyst in PET chemical recycling through glycolysis to generate bis (2-hydroxyethyl) terephthalate (BHET) monomer, we achieved 100% PET conversion with a 96.4% yield and selectivity for BHET. This outcome was obtained using a catalyst loading of 6.0 wt% at 200 °C and 0.6 bar in a high-pressure reactor. We explored the impact of catalyst loading on BHET yield and conducted a comparative assessment of the Fe3O4@PMIM.SbBr4 catalyst against antimony (III) bromide, and another synthesized unsupported antimony-containing ionic liquid. Our results revealed the superior catalytic activity of the magnetic ionic liquid catalyst in PET glycolysis. The utilization of this catalyst offers promising potential for PET glycolysis due to its effortless separation using an external magnet, ability to produce highly pure BHET, and recyclability for repetitive use.

Controlled Glycolysis of Poly(ethylene terephthalate) to Oligomers under Microwave Irradiation Using Antimony(III) Oxide.

We report here the production of higher-order oligomers from the glycolysis of poly(ethylene terephthalate) (PET) by using microwave irradiation in a controlled fashion, instead of its fully glycolyzed product, bis(2-hydroxyethyl)terephthalate (BHET). We show that different catalysts can generate either BHET as the ultimate glycolysis product or higher oligomers of PET under microwave irradiation. Depolymerization of waste PET with an average degree of polymerization (DP) of 417 from water bottles was performed in the presence of 0.25 wt % antimony(III) oxide (Sb2O3) as the catalyst at 240 °C and 400 W microwave power, resulting in an oligomer yield of 96.7% with an average DP of 37. Under these conditions, the conversion of PET to oligomers reached 100% in only 5 min at 240 °C (with a 10 min ramping time) and with a ethylene glycol to PET weight ratio of 2.5. In comparison, under the same reaction conditions, 0.04 wt % of zinc acetate (Zn(OAc)2), a well-known catalyst for PET glycolysis, produces only the BHET monomer in 96.3% yield. Our results demonstrated that by using Sb2O3, the same catalyst that is used extensively for PET synthesis from BHET, under microwave irradiation, the PET glycolysis can be controlled to produce higher PET oligomers as an alternative for a complete chemical depolymerization to the BHET monomer. These oligomers are more suitable for being used as additives for many applications and to produce high-quality second-generation products, including regenerated PET.

Screening the Degradation of Polymer Microparticles on a Chip.

Enzymatic degradation of polymers has advantages over standard degradation methods, such as soil burial and weathering, which are time-consuming and cannot provide time-resolved observations. We have developed a microfluidic device to study the degradation of single microparticles. The enzymatic degradation of poly (1,4-butylene adipate-co-terephthalate) (PBAT) microparticles was studied using Novozym 51032 cutinase. PBAT microparticles were prepared via an oil-in-water emulsion solvent removal method, and their morphology and chemical composition were characterized. Then, microparticles with varying diameters of 30-60 µm were loaded into the microfluidic chip. Enzyme solutions at different concentrations were introduced to the device, and changes in the size and transparency of PBAT microparticles were observed over time. The physicochemical properties of degraded products were analyzed by FT-IR, NMR, mass spectrometry, and differential scanning calorimetry. The degradation process was also performed in bulk, and the results were compared to those of the microfluidic method. Our analysis confirms that the degradation process in both bulk and microfluidic methods was similar. In both cases, degradation takes place on aliphatic and soft segments of PBAT. Our findings serve as a proof of concept for a microfluidic method for easy and time-resolved degradation analysis, with degradation results comparable to those of conventional bulk methods.

Starch Janus Particles: Bulk Synthesis, Self-Assembly, Rheology, and Potential Food Applications.

Although incredible progress in the field of Janus particles over the last three decades has delivered many promising smart-material prototypes, from cancer-targeting drug delivery vehicles to self-motile nanobots, their real-world applications have been somewhat tempered by concerns over scalability and sustainability. In this study, we adapt a simple, scalable 3D mask method to synthesize Janus particles in bulk using starch as the base material: a natural biopolymer that is safe, biocompatible, biodegradable, cheap, widely available, and versatile. Using this method, starch granules are first embedded on a wax droplet such that half of the starch is covered; then, the uncovered half is treated with octenyl succinic anhydride, after which the wax coating is removed. Janus particles with 49% Janus balance can be produced in this way and were observed to self-assemble into wormlike strings in water due to their hydrophobic/hydrophilic nature. Our Janus starch granules outperform the non-Janus controls as thickening and gelling agents: they exhibit a fourfold increase in water-holding capacity, a 30% lower critical caking concentration, and a viscosity greater by orders of magnitude. They also form gels that are much firmer and more stable. Starch Janus particles with these functional properties can be used as novel, lower-calorie, highly efficient, plant-based super-thickeners in the food industry, potentially reducing starch use in food by 55%.

Solid phase wax coating of N-acetylcysteine (NAC) to decrease its solubility profile as a ready to mix supplement.

N-Acetylcysteine (NAC) has health benefits attributed to its antioxidant properties and disulfide bond cleavage ability. Unfortunately, solutions of NAC are acidic with an undesirable taste and an unpleasant aftertaste. A method for slowing NAC release in water was developed using a solid phase wax coating. A coating of natural waxes, using food grade corn oil as the solvent and surfactants to facilitate the wax coating on the particles was used to decrease the solubility of NAC powder, crystals, and granules in water. A high NAC loading, between 55 and 91% for NAC granules and NAC crystals, was achieved as measured using LC-MS. The NAC wax-coated particles were fully characterized, and microscopy and SEM images revealed the shape, morphology, and size of the particles. Conductometry was used to study NAC release profile in water from wax-coated particles and the results indicate that solid phase wax coatings slowed the release of NAC into water.

A Review of the Methods of Modeling Multi-Phase Flows within Different Microchannels Shapes and Their Applications.

In industrial processes, the microtechnology concept refers to the operation of small devices that integrate the elements of operational and reaction units to save energy and space. The advancement of knowledge in the field of microfluidics has resulted in fabricating devices with different applications in micro and nanoscales. Micro- and nano-devices can provide energy-efficient systems due to their high thermal performance. Fluid flow in microchannels and microstructures has been widely considered by researchers in the last two decades. In this paper, a review study on fluid flow within microstructures is performed. The present study aims to present the results obtained in previous studies on this type of system. First, different types of flows in microchannels are examined. The present article will then review previous articles and present a general summary in each section. Then, the multi-phase flows inside the microchannels are discussed, and the flows inside the micropumps, microturbines, and micromixers are evaluated. According to the literature review, it is found that the use of microstructures enhances energy efficiency. The results of previous investigations revealed that the use of nanofluids as a working fluid in microstructures improves energy efficiency. Previous studies have demonstrated special attention to the design aspects of microchannels and micro-devices compared to other design strategies to improve their performance. Finally, general concluding remarks are presented, and the existing challenges in the use of these devices and suggestions for future investigations are presented.

Electrolytic transesterification of waste frying oil using Na+/zeolite-chitosan biocomposite for biodiesel production.

Given the economic and environmental advantages of using Waste Fried Oil (WFO) as a starting material, this investigation explores the conversion of WFO to Fatty Acid Methyl Ester (FAME) via electrolysis for use in waste. In electrolysis, hydroxyl ions are generated from water in close proximity to the cathode. When hydroxyl ions react with methanol, they produce a species of nucleophilic methoxide which is the main actor in converting WFO into FAME. This study specifically investigates the effects of voltage, catalyst concentration, co solvent amount, rotation speed, and molar ratio of methanol to WFO in electrolytic transesterification converting WFO into FAME using graphite electrodes in the presence of a heterogeneous, catalytic zeolite-chitosan composite. With an alcohol to WFO molar ratio of 8:1, 1 wt% zeolite-chitosan composite concentration at 40 V in the presence of 2 wt% H2O of the whole solution at room temperature and stirrer rate of 400 rpm and reaction time of 30 min, a 96.5% yield of FAME was achieved. Characterization of physical and biodiesel fuel properties was performed using American Society for Testing and Materials (ASTM) methods. The biocomposite was characterized using Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD), Transmission Electron Microscopy(TEM), Brunauer Emmett Teller(BET), Thermogravimetric analysis (TG), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectrometry (EDX). Finally, the physical properties of FAME produced under optimal conditions were studied using Gas Chromatography-Mass Spectrometry (GC-MS), FTIR, surface tension, and viscosity.

Synthesis, Stability, and Bioavailability of Nicotinamide Riboside Trioleate Chloride.

Nicotinamide riboside chloride (NRCl) is an effective form of vitamin B3. However, it cannot be used in ready-to-drink (RTD) beverages or high-water activity foods because of its intrinsic instability in water. To address this issue, we synthesized nicotinamide riboside trioleate chloride (NRTOCl) as a new hydrophobic nicotinamide riboside (NR) derivative. Contrary to NRCl, NRTOCl is soluble in an oil phase. The results of stability studies showed that NRTOCl was much more stable than NRCl both in water and in oil-in-water emulsions at 25 °C and 35 °C. Finally, we evaluated the bioavailability of NRTOCl by studying its digestibility in simulated intestinal fluid. The results demonstrated that NRTOCl was partially digestible and released NR in the presence of porcine pancreatin in a simulated intestinal fluid. This study showed that NRTOCl has the potential to be used as an NR derivative in ready-to-drink (RTD) beverages and other foods and supplement applications.

Dihydronicotinamide riboside: synthesis from nicotinamide riboside chloride, purification and stability studies.

In the present work, we describe an efficient method for scalable synthesis and purification of 1,4-dihydronicotinamide riboside (NRH) from commercially available nicotinamide riboside chloride (NRCl) and in the presence of sodium dithionate as a reducing agent. NRH is industrially relevant as the most effective, synthetic NAD+ precursor. We demonstrated that solid phase synthesis cannot be used for the reduction of NRCl to NRH in high yield, whereas a reduction reaction in water at room temperature under anaerobic conditions is shown to be very effective, reaching a 55% isolation yield. For the first time, by using common column chromatography, we were able to highly purify this sensitive bio-compound with good yield. A series of identifications and analyses including HPLC, NMR, LC-MS, FTIR, and UV-vis spectroscopy were performed on the purified sample, confirming the structure of NRH as well as its purity to be 96%. Thermal analysis of NRH showed higher thermal stability compared to NRCl, and with two major weight losses, one at 218 °C and another at 805 °C. We also investigated the long term stability effects of temperature, pH, light, and oxygen (as air) on the NRH in aqueous solutions. Our results show that NRH can be oxidized in the presence of oxygen, and it hydrolyzed quickly in acidic conditions. It was also found that the degradation rate is lower under a N2 atmosphere, at lower temperatures, and under basic pH conditions.

Protein content of amaranth and quinoa starch plays a key role in their ability as Pickering emulsifiers.

Growing concerns about the safety of using synthetic surfactants to stabilize food emulsions have inspired a trend towards the use of natural ingredients like starch as alternative food stabilizers in what are called Pickering emulsions. The hydrophilicity of commercially available starches, however, necessitates further chemical treatment to increase their hydrophobicity and emulsifying ability. Here we demonstrate an alkaline isolation method to extract amaranth and quinoa starch from flour while retaining a high protein content, which gives these materials an emulsifying ability comparable to octenyl succinylated starches in the literature. We highlight the key role played by protein by showing that a serial reduction of the protein content leads to a parallel reduction in emulsifying ability, and that pH affects this ability. Our method of retaining proteins naturally present in amaranth and quinoa not only bolsters their nutritional profile but also takes advantage of these proteins' native hydrophobicity for improved emulsification.

A digital imaging method for evaluating the kinetics of vapochromic response.

This work describes the novel use of a cell phone camera and the L*a*b method (color space defined by the International Commission on Illumination) to characterize the color change in different vapochromic platinum(II) complexes in order to get quantitative and more reliable data. In this study, we have developed a semi-automatic CCA software that digitally analyzes images (e.g., video frames) collected while a vapochromic material is absorbing vapor and changing its color. The advantages of using this method, compared to reflectance or transmission spectroscopy through a thin film, include its low cost, convenience, portability, ease of sample preparation, the lack of need for specialized equipment, and the possibility of simultaneously collecting data on different samples under identical conditions. The results show that this strategy is effective in producing quantitative information about the kinetics of processes.

Synthesis of Cross-Linked Spherical Polycationic Adsorbents for Enhanced Heparin Recovery.

Heparin, as an anticoagulant drug, is almost entirely produced via isolation from mucosal tissues of different animals; therefore, it is it is crucial to maximize its recovery. Adsorption of heparin from this complex biological mixture needs a specialized and highly effective adsorbent that almost separates only heparin from the mixture. In this work, a series of spherical cross-linked polymer bead adsorbents were synthesized via inverse suspension polymerization of water soluble monomers in corn oil, a benign solvent, and their performance for heparin adsorption from a biological sample of porcine mucosa was evaluated. To tune the performance and swelling of the resins, we varied the molar ratio of the monomer(s) to the cross-linker as well as the molar ratio of the monomers. The results of heparin recovery from biological porcine mucosa show that our optimized resin can outperform the commercially available resin in terms of adsorption efficiency of up to 18%. The adsorbed heparin was eluted, isolated, and its anticoagulant potency measured using the standard sheep plasma clotting assay. The isolated heparin samples were also analyzed by 1H NMR spectroscopy to check the possible impurities, and the results show the presence of chondroitin sulfate and dermatan sulfate, as is the case for the heparin eluted from the commercial resin. Furthermore, the effects of some experimental variables including the adsorbent dosage, pH, time, and recycling on heparin adsorption were studied, and the results show that these resins can be used for efficient recovery of heparin.

Synthesis of lactose lauryl ester in organic solvents using aluminosilicate zeolite as a catalyst.

Sugar-based biosurfactants are safer and healthier alternatives to synthetic surfactants especially for use in the food industry. In this work, biosurfactants were synthesized via the esterification of lactose with lauric acid in different organic solvents without using lipase or other enzymes. Commercial aluminosilicate zeolite was used as a catalyst. Conversions of up to 92% were obtained for pure lactose and 38% for raw lactose from whey. Surface-active properties including surface tension, interfacial tension, and contact angle were measured. All samples showed surface tensions lower than sodium dodecyl sulfate, SDS (19.59-36.57 mN/m compared to 38.8 mN/m for SDS) and interfacial tensions comparable with it (9.47-12.18 mN/m compared to 4.77 mN/m for SDS). Results showed that aluminosilicate zeolites can be used for the synthesis of lactose esters, which have potential applications as biosurfactants for the food industry featuring low surface and interfacial tensions.

Selective Electrochemical Capture and Release of Heparin Based on Amine-Functionalized Carbon/Titanium Dioxide Nanotube Arrays.

Heparin (HEP) is a sulfated glycosaminoglycan that is a clinical anticoagulant agent. Commercially derived from porcine intestinal mucosa, HEP is challenging to separate from this complex biological mixture for additional purification. This study aimed to raise the purity of isolated HEP using electrochemical potential to increase its selective capture and release. We demonstrate an electrochemical platform featuring an anode composed of amine-functionalized carbon/titanium dioxide nanotube arrays on titanium foil (Ti/C-TNTAs-NH2) and a cathode made of expanded graphite. Our results show that Ti and Ti/C-TNTAs control plates do not adsorb HEP, even while applying an external potential to the cell. However, when the Ti/C-TNTAs electrode is modified by 3 aminopropyltriethoxysilane, the terminal NH2 groups provide a high density of positive charges that serve as binding sites, enabling the adsorption of HEP. This attraction is further strengthened by applying an external potential to the anode. Subsequent release of the HEP molecules and regeneration of the Ti/C-TNTAs-NH2 electrode are easily accomplished by applying an anodic potential to the plate, as well as by increasing the concentration of NaCl in solution. This electrochemical system demonstrates the good selectivity of HEP, even within a mixture of other probable interfering species (e.g., bovine serum albumin and chondroitin sulfate). Additionally, it maintains 90.11% of its initial electrosorption efficiency after ten repeated HEP adsorption/desorption cycles, indicating this system's promising stability and reusability for HEP purification.

Synthesis and characterization of lactose fatty acid ester biosurfactants using free and immobilized lipases in organic solvents.

In this work, lactose fatty acid esters were enzymatically synthesized from fatty acids and lactose using Candida antarctica B lipase (CALB) in organic solvents. Products were purified using a solvent extraction method and analyzed using ATR-FTIR and surface-active properties measurements. Results showed that hexanes and acetonitrile provide the highest conversions for both free and immobilized lipases, up to 77% and 93% respectively. The conversion rate of esterification is solvent-dependent for free lipase; the conversion rate of immobilized lipase still shows solvent dependency, but to a lesser degree. Surface tension, interfacial tension, critical micelle concentration (CMC), and contact angles were also measured for all of the samples, showing the potentials of these sugar esters as naturally derived surfactants for the food industry.

Ultrafast SET-LRP with Peptoid Cytostatic Drugs as Monofunctional and Bifunctional Initiators.

To continue expanding the use of Single Electron Transfer-Living Radical Polymerization (SET-LRP) in applications at the interface between macromolecular science, biomacromolecules, biology and medicine, it is essential to develop novel initiators that do not compromise the structural stability of synthesized polymers in biological environments. Here, we report that stable 2-bromopropionyl peptoid-type initiators such as 1,4-bis(2-bromopropionyl)piperazine and 4-(2-bromopropionyl)morpholine are an alternative that meets the standards reached by the well-known secondary and tertiary α-haloester-type initiators in terms of excellent control over molecular weight evolution and distribution as well as polymer chain ends. SET-LRP methodologies in organic, aqueous, and biphasic organic-aqueous media were evaluated for this purpose.