High Production Rate Research Articles

Restoration of Strength in Polyamide Woven Glass Fiber Organosheets by Hot Pressing: Case Study of Impact and Compression after Impact.

Thermoplastic composite organosheets (OSs) are increasingly recognized as a viable solution for automotive and aerospace structures, offering a range of benefits including cost-effectiveness through high-rate production, lightweight design, impact resistance, formability, and recyclability. This study examines the impact response, post-impact strength evaluation, and hot-pressing repair effectiveness of woven glass fiber nylon composite OSs across varying impact energy levels. Experimental investigations involved subjecting composite specimens to impact at varying energy levels using a drop-tower test rig, followed by compression-after-impact (CAI) tests. The results underscore the exceptional damage tolerance and improved residual compressive strength of the OSs compared to traditional thermoset composites. This enhancement was primarily attributed to the matrix's ductility, which mitigated transverse crack propagation and significantly increased the amount of absorbed energy. To mitigate impact-induced damage, a localized hot-pressing repair approach was developed. This allowed to restore the post-impact strength of the OSs to pristine levels for impact energies below 40 J and by 83.6% for higher impact energies, when OS perforation was observed. The measured levels of post-repair strength demonstrate a successful restoration of OS strength over a wide range of impact energies, and despite limitations in achieving complete strength recovery above 40 J, hot-pressing repair emerges as a promising strategy for ensuring the longevity of thermoplastic composites through repairability.

Size-Controllable and Monodispersed Lipid Nanoparticle Production with High mRNA Delivery Efficiency Using 3D-Printed Ring Micromixers.

Lipid nanoparticles (LNPs) are gaining recognition as potentially effective carriers for delivery of therapeutic agents, including nucleic acids (DNA and RNA), for the prevention and treatment of various diseases. Much effort has been devoted to the implementation of microfluidic techniques for the production of monodisperse and stable LNPs and the improvement of encapsulation efficiency. Here, we developed three-dimensional (3D)-printed ring micromixers for the production of size-controllable and monodispersed LNPs with a high mRNA delivery efficiency. The effects of flow rate and ring shape asymmetry on the mixing performance were initially examined. Furthermore, the physicochemical properties (such as hydrodynamic diameter, polydispersity, and encapsulation efficiency) of the generated LNPs were quantified as a function of these physical parameters via biochemical analysis and cryo-electron microscopy imaging. With a high production rate of 68 mL/min, our 3D-printed ring micromixers can be used to manufacture LNPs with diameters less than 90 nm, low polydispersity (<0.2), and high mRNA encapsulation efficiency (>91%). Despite the simplicity of the ring-shaped mixer structure, we can produce mRNA-loaded LNPs with exceptional quality and high throughput, outperforming costly commercial micromixers.

Metabolic adaptations underpin high productivity rates in relict subsurface water

Groundwater aquifers are ecological hotspots with diverse microbes essential for biogeochemical cycles. Their ecophysiology has seldom been studied on a basin scale. In particular, our knowledge of chemosynthesis in the deep aquifers where temperatures reach 60 °C, is limited. Here, we investigated the diversity, activity, and metabolic potential of microbial communities from nine wells reaching ancient groundwater beneath Israel’s Negev Desert, spanning two significant, deep (up to 1.5 km) aquifers, the Judea Group carbonate and Kurnub Group Nubian sandstone that contain fresh to brackish, hypoxic to anoxic water. We estimated chemosynthetic productivity rates ranging from 0.55 ± 0.06 to 0.82 ± 0.07 µg C L−1 d−1 (mean ± SD), suggesting that aquifer productivity may be underestimated. We showed that 60% of MAGs harbored genes for autotrophic pathways, mainly the Calvin–Benson–Bassham cycle and the Wood–Ljungdahl pathway, indicating a substantial chemosynthetic capacity within these microbial communities. We emphasize the potential metabolic versatility in the deep subsurface, enabling efficient carbon and energy use. This study set a precedent for global aquifer exploration, like the Nubian Sandstone Aquifer System in the Arabian and Western Deserts, and reconsiders their role as carbon sinks.

Estimation of porosity distribution from formation image logs and comparing the results with NMR log analysis: Implications for the heterogeneity analysis of carbonate reservoirs with an example from the Asmari reservoir, southwest Iran

Estimating heterogeneity in carbonate rocks is the most important parameter in identifying reservoir and non-reservoir areas. Diagenetic and sedimentary processes directly control reservoir heterogeneity. In this regard, the high hydrocarbon production rate and the reduction of the complexity of the carbonate reservoirs require the evaluation of a new architecture of the reservoir, in which the simultaneous impact of the diagenetic-sedimentary processes on the petrophysical logs is investigated. The current study studies the Oligocene-Miocene Asmari Formation Iran's giant carbonate reservoir. Based on petrographic studies, sedimentary facies, depositional environment and diagenetic processes were characterized. Formation evaluation was conducted to determine lithology, water saturation, fluid volume, and effective porosity. The estimated porosity from the evaluation of the conventional logs (full suite) was compared with the results of estimating the porosity from the NMR T2 distribution curve and the porosity histogram of the image logs. Lorenz's coefficient of heterogeneity was used to understand the heterogeneity of the reservoir. Diagenetic-sedimentary processes and petrophysical logs were used to investigate the pore type and their distribution. The results of petrographic studies, NMR T2 distribution curve, and porosity histogram show that the diagenetic-sedimentary process is the most important factor enhancing the reservoir heterogeneity. Diagenetic and sedimentary processes were traced by evaluating NMR and Image logs. Based on the results, the porosity distribution using the T2 curve and Image show a good agreement. Diagenetic processes mainly dissolution and dolomitization increased the heterogeneity of the main production zones (zones 3 and 4) of the Asmari reservoir that was confirmed using NMR and Image logs.

Nitrate Uptake and Primary Production Along the Amazon River Plume Continuum

AbstractThe Amazon River plume (ARP) has been shown to support high rates of nitrogen fixation and primary production. However, nitrogen fixation alone cannot account for total primary production determined in the region, hinting that other nitrogen uptake processes might play a role. For the first time, we measured nitrate uptake rates in the ARP during three cruises in May 2018, June 2019 and April/May 2021, along with primary production rates and an analysis of phytoplankton community composition via high performance liquid chromatography. Based on a classification according to the salt content the region was divided into estuarine (ES), mesohaline (MH) and oceanic (OC) stations. Primary production was light limited near the river mouth at ES stations and was maximal off the coasts of French Guiana and Suriname, where also nitrate uptake was highest with rates of 11.4 mmol m−2 d−1. The role of eddies pinching off a deflecting plume are discussed as possible reason for higher nutrient concentrations at the MH stations. Surprisingly, at most MH stations north of 5°N, nitrate uptake rates were low despite the presence of sufficient substrate concentration (up to 1.44 μM nitrate). Diatoms, dinoflagellates or Synechococcus sp. dominated phytoplankton communities. OC stations showed lowest productivity rates in accordance with oligotrophic conditions. However, rates seem to be sufficient to completely deplete the remaining riverine nitrate, preventing its export to the open ocean.

Giant sediment-wave field and supercritical flows in a distally steepened ramp, Fort Payne Formation (Lower Mississippian), Kentucky–Tennessee, U.S.A.

ABSTRACT Sediment waves are common in confined to unconfined settings on modern marine slopes and basin floors worldwide. Their morphology and stratal patterns show that many of them migrate upslope and upflow, a characteristic thought to record Froude-supercritical flow conditions associated with sediment gravity flows and density cascades. Few sediment waves of this type have been observed in the ancient rock record. This study reports the discovery of a giant (&amp;gt; 20,000 km2) sediment-wave field in Lower Mississippian carbonates and shales of the Fort Payne Formation in Tennessee and Kentucky, U.S.A. Sediment waves are present in the clinothem slopes and basin floor of a distally steepened ramp as seismic-scale bedforms ranging from 100 to 700 m long and 15 to 50 m high. Dominant facies include crinoidal shales, packstones, and rudstones. Many of the beds are sharp-based and graded, indicating sediment-gravity-flow deposition. Upslope-inclined rudstones (backsets) and wavy beds with upflow and downflow laminae are common and indicate supercritical flow conditions. These observations and interpretations are in stark contrast to previous interpretations of crinoidal bioherms and Waulsortian-type mounds. Basin physiography, a cool-water heterozoan carbonate factory and coastal upwelling were key factors in establishing a rapidly prograding ramp characterized by high rates of sediment production and basinward shedding. Sediment gravity flows and density cascades transported crinoidal grains downslope and entrained crinoids that inhabited the slope. Flows frequently reached Fr-supercritical flow conditions that led to the formation of sediment waves similar to those on modern marine slopes. This sediment-wave field is one of the first to be documented in the ancient rock record, and its extent is enormous. The near absence of other reported ancient examples must be due to misinterpretation (mounds, slumps) and the problem of observational scale and resolution. Sediment waves are often larger than outcrops. Lack of recognition of sediment waves in subsurface seismic sections is probably due to misinterpretation and insufficient resolution. Perhaps this study demonstrates the need for revisiting and updating existing facies models of carbonate-sediment transport and depositional processes across slopes and basin floors.

Energy efficiency of solar illuminated vertical farms with different illumination strategies

Energy efficiency of a solar illuminated vertical farm is investigated considering different illumination scenarios. The analysis considers the energy consumed by a typical vertical farming facility for heating, cooling and lighting with and without ventilation. Different illumination scenarios consider utilizing fluorescent reflectors converting green light, which is reflected by green leaved produce, to red to increase photosynthetic production, IR filters preventing solar wavelengths, which do not contribute to photosynthetic growth, to enter the facility to reduce cooling load, and light emitting diodes used as a means of complementary/main lighting. Through analyzing 5 different scenarios where these technologies are used in different combinations, the contribution of each technology is identified for 22o, 41o and 60o latitudes in the Northern Hemisphere. It was found that using IR filters is the most effective means of increasing energy efficiency, whereas the impact of using fluorescent coating to energy efficiency is limited in presence of supplementary light emitting diodes illumination. Relying solely on light emitting diodes yield a significant increase in energy consumed to grow per kg of crop. High production rate can be achieved using solar illumination with IR filters, fluorescent coatings and supplementary LED lighting with ventilation that can lead to energy savings of 22 %, 28 %, 29 % with respect to solely relying on LED illumination for 22°N, 41°N, 60°N, respectively. Whereas the corresponding savings, when no ventilation is used are 19 %, 18 %, 13.6 %, for 22°N, 41°N, 60°N, respectively.

A Straightforward Approach of Wet‐Spinning Poly(3,4‐ethylenedioxythiophene):Polystyrene Sulfate Fibers for Use in All Conducting Polymer‐Based Textile Actuators

Poly(3,4‐ethylenedioxythiophene) (PEDOT), an inherently electrically conductive or conjugated polymer (CP), exhibits the potential to play a significant role in the development of innovative fiber materials for use in smart textiles, such as wearables. Furthermore, these fibers can function as artificial muscles in the emerging field of interactive fiber rubber composites. This study introduces a straightforward and efficient method for creating PEDOT‐based, biomimetic, fiber‐shaped, linearly contracting ionic electroactive polymer actuators. To achieve this, a wet‐spinning technique is presented, which enables a continuous production of PEDOT:polystyrene sulfate (PSS) fibers at high production rates of 34 m h−1, an additional fiber washing step and a sulfuric acid posttreatment step to increase the fibers conductivity. The fibers provide a high conductivity of 1028 S cm−1, maximum tensile strength reaching 182 MPa, and a maximum elongation of 24%. When utilized as CP actuators in an aqueous sodium dodecylbenzenesulfonate electrolyte medium, the fibers demonstrate a repeatable maximum isometric contractile force of 1.64 mN and repeatable linear contractile strain up to 0.56%. Furthermore, a high level of cyclic long‐term actuation stability can be demonstrated. Notably, these contractile strains are, to the best of knowledge, the highest reported values for pristine PEDOT:PSS fibers.

Experimental Study on Gas Production Capacity of Composite Reservoir Depletion in Deep Carbonate Gas Reservoirs

Deep carbonate gas reservoirs exhibit diverse reservoir types and complex seepage patterns. To study the gas production capabilities of different composite reservoir types, we classified the reservoirs of the fourth member of the Dengying Formation in the Anyue Gas Field into high-quality reservoirs (HRs) and poor-quality reservoirs (PRs) based on high-pressure mercury injection (HPMI) experiment results. By varying the differential pressure of the depletion experiment and the connection method, as well as the permeability and water saturation of the composite core, the effects of well location deployment, permeability ratio of the high-quality reservoir and poor-quality reservoir (PRHPR), gas well production pressure difference (GWPPD), and water saturation on the depletion gas production characteristics of the composite reservoir were studied. The research results show that (1) deploying wells on HR enables high gas production rates and ultimate recovery rates; (2) only when the PRHPR falls within a reasonable range (21.88–43.19) can the “dynamic recharge” capability of PR and the high permeability of HR be coordinated to achieve high gas recovery rates; (3) a GWPPD of 3 MPa is optimal, resulting in fast gas production rates and high ultimate recovery rates for PR; (4) high water saturation (≥50%) leads to premature water breakthrough at the well bottom, decreased gas production rate, and sealing of HR and PR reserves by formation water. Combining experimental results with field production data is our next research focus. Our future research focus will be on integrating experimental results with field production data to provide solid theoretical support for the efficient development of this type of gas reservoir.

Isolation and Molecular Characterization of Pigment Producing Bacteria from Soil of Different Locality of Assam

Pigment is the most attractive attribute and integral part of human life. The source of the pigment used for different applications is chemically synthesised. However, pigment produced from natural sources (such as plants and microorganisms) can also be applied as a coloring agent. In addition to being colorants, many natural pigments are also fascinating bioactive substances with possible health benefits. Agrochemicals, food, medicine, pharmacology, cosmetics, and numerous other industries use these compounds. In this study, a total of 7 pigmented colonies were isolated from the soil samples of different areas of Assam. Out of 7 pigmented colonies, 3 colonies showed orange color and 4 colonies showed yellow color. Based on the similarity of growth pattern and high intensity of pigmentation one colony from each pigment was picked for further studies. The isolated orange and yellow pigments were denoted as S1 and S2, respectively. With the help of Bergey’s Manual of Determinative Bacteriology the isolated pigmented strains were preliminary identified based on their morphological, microscopic, and biochemical characteristics and after that 16S rRNA gene sequencing helped to identify the bacteria at the species level and the strains were identified as (S1) Micrococcus aloeverae ON377368 and (S2) Exiguobacterium aestuarii ON377409. The identified strains Micrococcus aloeverae and Exiguobacterium aestuarii showed a high pigment production rate at specific optimized conditions such as at temperature 37°C, pH 6, and NaCl concentrations at 1.5-2% and strains also showed a good characteristic growth pattern at a specific time interval. Therefore, the present study may be a helpful step towards the large-scale manufacture of pigments and the extraction, purification, and characterization of the pigment extracted from these strains will lead to provide a potent eco-friendly natural dye in the industrial sector.

Constructing GO films/CdS nanoparticles/MoS2 nanosheets ternary nanojunction with enhanced photocatalytic hydrogen evolution activity

CdS, as a visible-light responsible photocatalyst, has gained considerable attentions for its relatively narrow bandgap and negative conduction band edge. However, its photocatalytic activity is hindered by challenges such as severe charge recombination, insufficient active sites and poor stability. In this work, a robust strategy is proposed to optimize the transfer channel for charge carriers and enhance the active sites by heterojunction and cocatalyst engineering. The well-designed GO/CdS/MoS2 shows remarkable durability (20 h without significant loss of H2 production rate) with a high photocatalytic H2 production rate of 1.45 mmol h−1g−1 (about 6.6-fold enhancement compared with CdS) at GO content of 0.1 wt% and MoS2 loading amount of 5.0 wt%. The bolstered H2 production rate is attributed to the augmented transfer channels of mass owing to the holey structure of GO, the enhanced active sites since the introduction of MoS2, and the unidirectional transfer of electrons from CdS to MoS2, which is ascribed to the built-in electric field in the CdS/MoS2 interface. Thanks to the directional transfer of holes from CdS to GO in the GO/CdS interface, the assemblage of holes in CdS is prevented, thus contributing to the amplified stability GO/CdS/MoS2. Our findings offer insights for the enhanced photocatalytic activity of CdS based photocatalysts, which may inspire the development of the heterostructure photocatalysts for solar-to-fuel conversion.

Tracking the critical roles of Cu+ and Cu0 sites and the optimal Cu+/Cu0 ratio for CH3OH steam reforming (MTSR) to manufacture H2

Understanding the nature of surface-active sites is of critical importance for catalyst design, yet remains great challenges because of the complexity of solid surfaces. To tracking the valence states and roles of various Cu sites played in CH3OH steam reforming (MTSR) on Cu-based catalysts and the factors to determine the reactivity, appropriate Cu/Ce1-xZrxO2 solid solution catalysts have been purposely designed. On a catalyst having a Ce/Zr ratio of 0.7/0.3 (Cu/Ce0.7Zr0.3O2), the optimal Cu+/Cu0 ratio around 1.00 can be obtained to accomplish the best performance, with a high H2 production rate but very low CO selectivity. With the combination of experiments and DFT calculation, it has been discovered that CH3OH molecules mainly be adsorbed/activated on the Cu+ sites, but H2O molecules could mainly be adsorbed/activated on the Cu0 sites. We have substantiated that to fabricate Cu/Ce1-xZrxO2 catalysts with high efficiency, nearly equal amount of surface Cu+ and Cu0 sites should be engineered.

The Shelf Life of Yellow Passion Fruit with an Edible Biocomposite Coating Based on Chitosan, Graphene Oxide Nanoparticles, and Beeswax

Yellow or sour passion fruit is a climacteric fruit with a high rate of respiration and ethylene production, and postharvest technology is needed to extend its shelf life. This study investigated the properties of a biocomposite film with chitosan (CH) incorporated with beeswax (BW) and graphene oxide (GO) nanoparticles for use as an edible coating to extend the shelf life of yellow passion fruit at 22 °C and 70% RH for eight days. CH films associated with BW showed lower water vapor permeability (WVP) than films with CH alone. However, adding GO to the CH + BW biopolymer matrix improved the WVP, decreased the solubility (12.8%), and increased the opacity of the film by 9% compared to those of the CH film. Fruits coated with CH + BW or CH + BW + GO exhibited a reduction in respiration rate, a slower ripening process by approximately 3 days, and a significant decrease in weight loss. This also resulted in a higher soluble solids content and increased antioxidative capacity of the pulp. The incorporation of GO into the CH + BW matrix resulted in a more pronounced delay of fruit ripening, as evidenced by the lower depigmentation of the peel at eight days, with a lightness approximately 10.7% lower at 54.92, a chroma value 16.5% lower at 49.33, a hue angle 7.2% higher at 92.56, a soluble solid (SS) content 16.7% higher at 11.32°Brix, and an acidity 31.9% higher at 4.18% compared to the control. Furthermore, the biopolymer packaging led to a higher consumer acceptance score for the fruit.

Stable production of hydrogen peroxide over zinc oxide @ zeolitic imidazolate Framework-8 composite catalysts

A promising method of producing hydrogen peroxide (H2O2) is the electrochemical two-electron water oxidation reaction (2e− WOR). In this process, it is important to design electrocatalysts that are both earth abundant and environmentally friendly, as well as offering high stability and production rates. The research of WOR catalysts, such as the extensively used transition metal oxides, is mainly focused on the modification of transition metal elements. Few studies pay attention to the protective heterostructure of metal oxides. Here, we demonstrate for the first time an organometallic skeleton protection strategy to develop highly stable WOR catalysts for H2O2 generation. Unlike the pure ZnO and zeolite imidazole framework-8 (ZIF-8) catalysts, ZnO@ZIF-8 enabled the production of hydrogen peroxide at high voltages. The experimental results demonstrate that the ZnO@ZIF-8 catalyst stably generates H2O2 even under a high voltage of 3.0 V vs. RHE, with a yield reaching 2845.819 μmolmin−1 g−1. ZnO@ZIF-8 shows a relatively low overpotential, with a current density of 10 mA cm−2 and an overpotential of 110 mV. The ZnO@ZIF-8 catalyst’s maximal FE value was 4.72 %. Moreover, the ZnO@ZIF-8 catalyst exhibits remarkable durability even after an extended 60-hour stability test. Operando Raman and theoretic calculation analyses reveal that the metal–organic skeleton being encapsulated on the metal oxide surface synergizes with each other, not only expanding the electrochemical surface area, but also adjusting the catalyst metal sites’ adsorption capacity. A novel approach to the modification of 2e− WOR metal oxide catalyst is presented in this work.

Enhanced hydrogen peroxide production under visible light via pyrimidine and glucose polymer modified graphitic carbon nitride in pure water

Photocatalytic H2O2 production by g-C3N4 (CN) has drawn intense research attention in the past decade. However, it suffers from drawbacks of weak light absorption capacity and rapid recombination of photogenerated electron-hole pairs. Here, we report a 4, 6-diamino-2-mercaptomidine (DAMP) and glucose (GLU) polymer modified CN (CN-DAMP-GLU) to enhance the photocatalytic performance of CN. The reported modified CN shows a high H2O2 production rate of 284.0 μmol g−1h−1 in pure water, surpassing most of the reported modified g-C3N4 catalysts. The mechanistic study confirms that the rapid conversion of •O2− is the key step in the visible-light-driven 2e− oxygen reduction reaction. This step favors efficient H2O2 generation and ensures the stable photocatalytic performance of the system. Experimental and DFT results further reveal that the donor-mediator-acceptor structure (polyfuran-DAMP-CN) with DAMP as the electron transfer mediator can inhibit the electron-hole recombination. We also demonstrate that this photocatalytic H2O2 production system can effectively degrade ciprofloxacin (CIP) through Fenton reaction. This work will promote the development of g-C3N4 for efficient photocatalytic production of H2O2 and possible applications in organic pollutant removal.

Synergistic effect of interstitial phosphorus doping and MoS2 modification over Zn0.3Cd0.7S for efficient photocatalytic H2 production

ZnxCd1-xS photocatalysts have been widely investigated due to their diverse morphologies, suitable band gaps/band edge positions, and high electronic mobility. However, the sluggish charge separation and severe charge recombination impede the application of ZnxCd1-xS for hydrogen evolution reaction (HER). Herein, doping of phosphorus (P) atoms into Zn0.3Cd0.7S has been implemented to elevate S vacancies concentration as well as tune its Fermi level to be located near the impurity level of S vacancies, prolonging the lifetime of photogenerated electrons. Moreover, P doping induces a hybridized state in the bandgap, leading to an imbalanced charge distribution and a localized built-in electric field for effective separation of photogenerated charge carriers. Further construction of intimate heterojunctions between P-Zn0.3Cd0.7S and MoS2 accelerates surface redox reaction. Benefiting from the above merits, 1 % MoS2/P-Zn0.3Cd0.7S exhibits a high hydrogen production rate of 30.65 mmol·g−1·h−1 with AQE of 22.22 % under monochromatic light at 370 nm, exceeding most ZnxCd1-xS based photocatalysts reported so far. This work opens avenues to fabricate examplary photocatalysts for solar energy conversion and beyond.

Boosting the activity of BiVOx via vanadium-promotion for highly selective oxidation of biomass-derived xylose toward formic acid

Formic acid is a versatile and promising value-added chemical derived from the chemoselective transformation of renewable biomass resources. However, achieving a high production rate of formic acid remains a pivotal and enormous challenge. Herein, we synthesized a sequence of BiVOx catalysts based on vanadium-promotion by a facile and cost-effective strategy for selective oxidation of biomass-derived xylose in water under O2 atmosphere. Particularly, the resultant Bi1V2Ox exhibited a remarkably enhanced catalytic activity, higher selectivity toward formic acid, and excellent recyclability, giving a yield of 75.8 % and a production rate of formic acid (9.22 mol FA molV−1h−1) at 170 °C within only 20 min. Such pronounced improved performance was largely attributed to the synergistic effect between V and Bi species, with higher surface area, abundant surface acidity, as well as stronger adsorption energy, meanwhile efficiently suppressing the formation of undesired by-products. This study demonstrates that the promotion of V in BiVOx leads to more efficient catalytic oxidation of xylose to formic acid, and with further driven research that proved great potential for generating formic acid from renewable biomass resources for future industrial application.

Experimental investigation on accelerated generation of HHO gas using titanium electrodes with platinum and mixed metal oxide coating - A comparative study

HHO gas is an alternate source of fuel that can be used in automobiles as a clean fuel with reduced carbon emissions, replacing the conventional hydrocarbon fuels being used today. Many different methods are involved in the production of this gas. Among these methods, alkaline water electrolysis is one of the easiest and most reliable methods for production. Though there are many limitations in the storage of Hydrogen, the HHO gas has been produced on-site using alkaline water electrolysis. This article mainly focuses on the production of HHO gas for different operating parameters and conditions, such as change of electrolyte, electrode material coating, effect of temperature and the surface area of the electrode. The electrolytes used in the electrolyser are sodium hydroxide (NaOH) and potassium hydroxide (KOH). The electrode material is titanium coated with two different materials namely Mixed Metal Oxide (MMO) and Platinum (Pt) respectively. A maximum yield of 0.9 LPM of HHO gas has been generated when supplying 40 amps of current to the electrolyser unit coated with MMO and KOH as electrolyte. Use of KOH electrolyte results in higher production rate when compared to NaOH. MMO coated titanium electrode produces more HHO gas when compared to platinum coated electrode.

High Ammonia Yield Rate from Dilute Nitrate Solutions Using a Cu(100)-Rich Foil: A Step Closer to Large-Scale Production.

The electrochemical reduction of nitrate (NO3-) ions to ammonia (NH3) provides an alternative method to eliminate harmful NO3- pollutants in water as well as to produce highly valuable NH3 chemicals. The NH3 yield rate however is still limited to the μmol h-1 cm-2 range when dealing with dilute NO3- concentrations found in waste streams. Copper (Cu) has attracted much attention because of its unique ability to effectively convert NO3- to NH3. We have reported a simple and scalable electrochemical method to produce a Cu foil having its surface covered with a porous Cu nanostructure enriched with (100) facets, which efficiently catalyzes NO3- to NH3. The Cu(100)-rich electrocatalyst showed a very high NH3 production rate of 1.1 mmol h-1 cm-2 in NO3- concentration as low as 14 mM NO3-, which is 4-5 times higher than the best-reported values. Increasing the NO3- concentration (140 mM) resulted in an NH3 production yield rate of 3.34 mmol h-1 cm-2. The durability test conducted for this catalyst foil in a flow cell system showed greater than 100 h stability with a Faradaic efficiency greater than 98%, demonstrating its potential to be used on an industrially relevant scale. Further, density functional theory (DFT) calculations have been performed to understand the better catalytic activity of Cu(100) compared to Cu(111) facets toward NO3-RR.

Comprehensive strategies for effective fecal sludge management in Humanitarian Settings: A case study of Cox’s Bazar Rohingya Response

The influx of Forcibly Displaced Myanmar Nationals (FDMN) into Bangladesh has necessitated the development of robust Fecal Sludge Management (FSM) strategies in Cox’s Bazar to ensure safe and sustainable sanitation solutions. Effective fecal sludge management (FSM) is crucial in humanitarian settings for public health, environmental protection, and dignity. This study investigates comprehensive FSM strategies in Cox’s Bazar Rohingya refugee camps, one of the largest and most complex humanitarian crises. Using a mixed-methods approach, it combines quantitative data from surveys and field observations with qualitative insights from interviews and document analysis to examine the FSM value chain, including sludge production, containment, collection/emptying, transport, treatment, and disposal/reuse. Findings show high sludge production rates require frequent desludging, with challenges in containment due to structural weaknesses and privacy concerns. Collection and emptying face logistical and health issues, while transport is hindered by difficult terrain and limited vehicle availability. Treatment facilities are often inadequate, leading to operational challenges and environmental risks. Despite these issues, disposal and reuse practices in agriculture show promise but need safety and community acceptance improvements. The study recommends increasing desludging capacity, enhancing containment designs, improving transport infrastructure, expanding treatment facilities, and promoting safe disposal and reuse practices. Emphasizing community engagement, technological innovations, and coordinated efforts among stakeholders is crucial for sustainable FSM systems. Future research should focus on innovative technologies, long-term sustainability, and scalability of FSM strategies across contexts. This research provides valuable insights and practical recommendations for improving sanitation in similar emergency contexts worldwide.