Production Rate Research Articles

Mechanisation applied to entomological production cannot ignore insect reactivity: a case study on Bombyx mori in the context of the 'Serinnovation' project.

In December 2017 the Venetian Region (local Authority), financed the creation of the Operational Group (OG) 'Serinnovation', within the framework of the Rural Development Plan supported by the European Community. The OG aims at coordinating and spreading innovation in sericulture through mechanisation of processes and centralisation of some rearing steps, the use of waste as by-products and traceability to promote local productions. The project acts on perceived quality by increasing the added value, through production cost efficiency, and on the recovery of the waste material for further applications (circular economy). The final target was to develop a niche-process to obtain traceable 'Made-in-Italy' silk for the luxury market and non-textile applications. A first strategy to increase the efficiency of the process was to build an automatic leaf cutting machine to prepare the feed for the first three instars of the silkworm (Bombyx mori Linnaeus). This new machine - based on a patent - was validated through several tests and compared with the cutting system previously used. The study was completed by a bioassay of production and survival rate associated with the introduction of this innovation. The results showed that labour saving is in the order of 10% compared to a semi-manual process, the leaf quality is not affected, survival of larvae and silk production are not significantly different from the control. This methodology is proposed as a study case for other similar mechanisation processes in entomological production, as the impact of innovations on insect physiology should be carefully considered.

Impact of MHD mixed convection on heat and mass transfer in a typical DCLL breeder blanket

Abstract A typical dual-coolant lead lithium (DCLL) liquid blanket employs eutectic liquid lithium lead alloy (PbLi) as coolant and tritium breeder for Tokamak nuclear fusion reactor, and is responsible for transporting heat and tritium. The blanket is subjected to both strong magnetic field and strong radially non-uniform neutron volume heating. The flow of liquid metal is influenced by the combined effects of magnetohydrodynamics (MHD), buoyancy, and inertial effects, resulting in a complex MHD mixed convection phenomenon. This study employs direct numerical simulation (DNS) based on finite volume method to analyze the flow, heat transfer, and mass transfer within blanket unit. The results demonstrate that mixed convection has a significant impact on the MHD pressure drop and flow characteristics. The complex MHD mixed convection gives rise to a considerable number of vortices, particularly in regions of the turn and the downward poloidal duct. The formation of low-speed zones and jets within the blanket has the potential to significantly impact heat and mass transfer, leading to the accumulation of heat and tritium. On the other hand, the markedly elevated tritium production rate is a significant contributing factor to the obviously elevated tritium concentration in the vicinity of the first wall.

Census-based estimates of Mediterranean Oligocene–Miocene reef carbonate production

Census-based approaches to reefal carbonate budgets are increasingly being used to project the near-future fate of tropical coral reefs. Some of the census parameters are difficult to achieve in fossil reef systems, which may be the reason why no census-based estimates of fossil reef carbonate production have been published until now. Here, we apply a census-based estimate of gross carbonate production in two reef systems from southeastern Italy to (1) test if reasonable estimates are possible and (2) assess the variability of carbonate production rates over time and reef environment. We confirm that estimates of late Oligocene and late Miocene reef gross carbonate production are within the range of modern coral reefs with the late Oligocene reef front showing the greatest carbonate production (6.1 ± 1.3 kg CaCO3 m−2 year−1) and the late Miocene reef front exhibiting the lowest production (1.7 ± 0.5 kg CaCO3 m−2 year−1). The decline of reef carbonate production from the Oligocene to the Miocene is accompanied by a decline of reef builder biodiversity but driven by the lower coral cover and coral growth rates in the Miocene. The decline of reefal carbonate production may be related to late Cenozoic cooling.

Optimum pricing decision for the retailer with warranty and price-dependent variable demand

Buying inventory on a credit basis is an effective pricing plan, and trade credit is a popular component of market transactions that increase demand. In a dynamic situation, most businesses offer different rewards and services to their consumers under certain terms and conditions during commodity sales. The accompanying companies provide a warranty period facility to increase consumer demand for products. The holding cost often increases over time. This study determines a production model wherein the production rate is proportionate to the price-warranty period based on the demand rate with time-dependent holding cost and trade credit policy. This work leads to three vital conventions: (I) the rate of product demand is considered to be price-warranty period dependent; (II) the non-linear function is considered for the rate of replacement failure, wherein the capital of the manufacturer depends on the warranty period; and (III) the rate of inflation is constant; moreover, the present time value of money also measured. This study aims to find the selling price, cycle time, and warranty period by using an algorithm to optimize the total profit function of the manufacturer. The results are validated by solving three numerical examples with their graphical representation based on different situations and the major parameters, and sensitivity analysis is analyzed with important decision-making implications.

Kilogram Flash Joule Heating Synthesis with an Arc Welder.

Flash Joule heating has been used as a versatile solid-state synthesis method in the production of a wide range of products, including organic, inorganic, and ceramic products. Conventional flash Joule heating systems are large and customized, presenting significant barriers in the cost of assembly, the expertise needed to operate, and uniformity of results between different systems. Even laboratory-scale flash Joule heating systems struggle to operate above 10 g capacity, and they suffer from poor temperature controllability. We present here the use of commercial off-the-shelf arc welders as a superior alternative to standard flash Joule heating systems due to their low cost ($120), ease of use, compact size, high temperature controllability, and tunability. We demonstrate the gram-scale synthesis of a variety of organic and ceramic species using these systems. With the addition of another reactor configuration for only $260, we scale up the synthesis of these products to record rates for the laboratory scale, achieving a production rate of 3 kg/h for graphene and kilogram-per-day production rates for SiC, carbon nanotubes, SnSe2, and SnS2.

Bioenergy Production from Sorghum Distillers Grains via Dark Fermentation

Sorghum distillers grains (SDGs) produced from a sorghum liquor company were used for generating biohydrogen via dark fermentation at pH 4.5–6.5 and 55 °C with a batch test, and the biohydrogen electricity generation potential was evaluated. The experimental results show that pH markedly affects hydrogen concentration, hydrogen production rate (HPR) and hydrogen yield (HY), in that high acidic pH values result in high values. The HPR and HY ranged from 0.76 to 3.2 L/L-d and 21.4 to 62.3 mL/g chemical oxygen demand, respectively. These hydrogen production values were used to evaluate bioelectricity generation using a newly developed gas/liquid-fuel engine. The results show a new and prospective biomass source for biohydrogen production, bioelectricity generation and simultaneously solving the problem of treating SDGs when producing kaoliang liquor. Applications of the experimental results are also discussed.

Integrated Experimental and Mathematical Modeling to Guide Microbial Biocatalysis: Pseudomonas putida Conversion of L-Phenylalanine to trans-Cinnamic Acid.

trans-Cinnamic acid (tCA) can be produced by the deamination of L-phenylalanine using phenylalanine ammonia-lyase (PAL). In bioprocesses, optimizing production processes to improve key performance metrics such as titer, rate, and yield has proved challenging. This study investigates tCA production in Pseudomonas putida KT2440 using a whole-cell biocatalyst expressing four different PAL genes. Among these, RmXAL showed the highest titer and rate. Biocatalysis at pH 8.5 and 37°C were identified as the best conditions, giving a tCA concentration of 2.65 g L-1 and a production rate of 0.44 g L-1 h-1. To improve the metrics further, a decoupled bioprocess with various biocatalyst concentrations in the second stage was examined. With a whole-cell biocatalyst concentration of 30 gDCW L-1, optimal process parameters were achieved, giving a titer of 29.88 g L-1, rate of 5.99 g L-1 h-1, yield on glucose of 0.27 g tCA g glucose-1, and yield on L-phe of 0.75 g tCA g L-phe-1. This study is the first report of a model that enables performance metrics to evaluate a suitable process for tCA production and provides valuable insights into tCA production using a decoupled bioprocess. This would appear applicable to larger-scale production, paving the way for an efficient and sustainable industrial process.

Chemical Structure of Lean and Stoichiometric Laminar Flames of Methylcyclohexane at Atmospheric Pressure

Methylcyclohexane (MCH, C7H14) is a typical component in hydrocarbon fuels and is frequently utilized in surrogate fuel mixtures as a typical representative of alkylated cycloalkanes. However, comprehensive experimental studies on speciation during its combustion remain limited. This research investigates for the first time the chemical structure of laminar premixed flames of lean and stoichiometric mixtures (φ = 0.8 and 1.0) of MCH/O2/Ar under atmospheric pressure. Using probe-sampling molecular-beam mass spectrometry (MBMS), the spatial distribution of 18 compounds, including reactants, products, and intermediates, in the flame front was measured. The obtained results were compared with numerical simulations based on three established chemical–kinetic models of MCH combustion. The comparative analysis demonstrated that while the models effectively describe the profiles of reactants, primary products and key intermediates, significant discrepancies were observed for various C2–C6 compounds. To indicate the roots of the discrepancies, a rate of production (ROP) analysis was performed in each simulation. ROP analyses revealed that the primary cause for the discrepancies could be attributed to the overprediction of the rates of initial stages during MCH decomposition. Particularly, the role of non-elementary reactions was emphasized, indicating the need for refinement of the mechanisms based on new experimental data.

Impacts of automated single barrel bourbon processing on overall product quality and production rate

The global market is experiencing a significant increase in demand for premium single barrel bourbon products. The need for separate manipulation of each barrel’s contents exerts a significant technical strain on all processing operations from barrel emptying to the filling of the bottle. Each of the two blending steps where water is added to the spirit were particularly error prone, occupied large physical footprints, withdrew labor from other critical tasks, and were limiting to the overall single barrel production volume. In this study, we measured the impacts of converting the manual blending operations to an automated process at the Four Roses Warehouse and Bottling Facility from before the changeover in 2019 until the end of 2022. During this time, the use of automated blending enabled a 62% increase in overall production of single barrel cases while the total number of quality holds was reduced by 46%. The daily single barrel processing rate increased by 15% immediately after automation, and the daily production rate was more consistent after automation. This automated approach enabled a significant increase in throughput without additional process footprint.

Isolation and characterization of novel bacterial strain from sewage sludge and exploring its potential for hydrogen production.

Hydrogen (H2) energy has garnered significant attention due to its numerous advantages. Nonetheless, for future commercialization, it is imperative to screen and identify strains with enhanced H2-producing capacities. In order to attain a high and consistent production performance, the conversion of biomass sources into H2 requires careful selection of the most appropriate H2-producing bacteria. This study aimed to isolate and identify a highly effective H2 producing bacteria from local sewage sludge and assess its fermentability for H2 production. The isolate was first identified by means of morphological, phenotypic, biological, and 16S rRNA investigations. A facultative anaerobe that produces H2 and is gram-negative was identified as Alcaligenes ammonioxydans strain SRAM. For the purpose of determining whether the isolate could produce H2 using glucose as the substrate, its fermentability was evaluated in 500 mL serum bottles. This strain demonstrated the ability to produce H2 from glucose under anaerobic environment, achieving a maximum H2 yield of 2.9mol H₂/mol of glucose. The highest rate of H2 production, 9.261 mmol H₂/ g dry cell weight per hr, was attained at 37°C and an initial pH of 6.8. This work effectively illustrated the use of a novel locally isolated strain in the biotechnological conversion of glucose to H2. This strategy offers an effective remedy for the world's energy instability in addition to addressing environmental issues related to industrial operations.

Does the TruBlue Laser Set Microlaryngoscopy Equipment on Fire? A Systematic Evaluation.

The risk of fire during laser microlaryngoscopy is well known. However, limited information is available about fire risk with the novel TruBlue laser. This study systematically evaluates its interactions with common surgical supplies, offering valuable insights into safety considerations for surgeons. We used experimental conditions to test the extent to which TruBlue laser energy produces smoke, perforation, or fire in Rüsch®, Medtronic™ and microlaryngeal endotracheal tubes and in surgical pledgets. Only the Microlaryngeal Tube (MLT) caught fire. Notably, it happened only when the laser fiber shifted on the tube's surface. Smoke emerged solely from the laser fiber applied to the Medtronic™ shaft and only during continuous contact mode. Cuff perforation and smoke emanating from the shaft occurred in three-quarters of the Rüsch® trials. The pledgets' radiopaque segment exhibited a greater combustibility than other segments (p < 0.01). In many of the pledget trials, faster smoke emission occurred with shorter laser-to-target distances (p < 0.05). Water-soaked pledgets displayed a reduced rate of smoke production (p < 0.01) and string division. The Medtronic™ tube assures remarkable safety with a nonignitable shaft and low cuff ignition. The MLT poses the highest ignition risk. Cuff perforation risk is mitigated by maintaining a 0.3-cm distance from the laser fiber tip. Pledget fire risk is mitigated by positioning the radiopaque part away from the laser beam and by soaking the pledget with water. Laser division of the pledgets' string was common. NA Laryngoscope, 2024.

The Behaviors of Interfacial Nanobubbles on Flat or Rough Electrode Surfaces in Electrochemistry.

The existence of interfacial nanobubbles on electrode surfaces is thought to block the active area, leading to a considerable decrease in the energy conversion efficiency. Gaining insight into how bubbles form on electrodes will be beneficial for designing effective electrochemical cells and enhancing the electrolytic efficiency. In this article, molecular dynamics (MD) simulations are employed to make a systematic comparison of behaviors of interfacial nanobubbles on both flat and rough electrode surfaces in electrochemistry. On a flat electrode surface, bubble nucleation can be categorized into single-site and multisite nucleation, influenced by the electrode sizes and electrolytic rates. The various rates of gas production result in three different scenarios for single-site nucleation: "growth-growth," "growth-shrinking," and "growth-stabilization" behaviors. On a rough one, bubbles are pinned at an early stage. Either through cooperative release or self-release, the bubbles continue to grow until the influx and outflux gas of the bubble reach an equilibrium. In addition, the evolutionary mechanism of interface nanobubbles was discussed on a rough nanoelectrode surface. Based on the dynamic equilibrium mechanism, a theoretical relationship between contact angle and base diameter of equilibrium interfacial nanobubbles was developed. The theoretical model can qualitatively describe the simulation observation of how bubble's shape depends on the electrode surface morphology.

Cascading Water Activation and Interfacial Lattice Oxygen over Nanocluster CuOx‐modified MnO2 for Electrocatalytic Propylene Oxidation

Direct electrooxidation of propylene using water‐oxidation intermediates represents a promising route for propylene glycol production. Unfortunately, this economic and environmentally friendly process suffers from low yield and poor Faradaic efficiency resulting from the mismatched oxidative capacity of reactive oxygen species and pronounced side reactions. Herein, we developed an earth‐abundant metal‐based nanocluster CuOx‐modified MnO2 catalyst for the efficient electrooxidation of propylene into propylene glycol, achieving a remarkable production rate of 63.0 g/m2/h and 95% Faradaic efficiency at 1.3 V vs. Ag/AgCl. Mechanistic studies revealed that the oxygen vacancy‐mediated water activation on CuOx‐MnO2 in synergy with the activated interfacial lattice oxygen drove the propylene oxidation to a novel *OOH pathway rather than the traditional *OH route. Additionally, the interfacial interactions intensified the propylene adsorption and polarization for its activation. This work offers new insights into the mechanism of electrocatalytic propylene oxidation and presents great opportunities for the synthesis of commercial chemicals based on earth‐abundant metal catalysts and renewable electricity‐driven route.

Balancing Activity and Selectivity in Two-electron Oxygen Reduction through First Coordination Shell Engineering in Cobalt Single Atom Catalysts.

The electrochemical two-electron oxygen reduction reaction (2e- ORR) offers a potentially cost-effective and eco-friendly route for the production of hydrogen peroxide (H2O2). However, the competing 4e- ORR that converts oxygen to water limits the selectivity towards hydrogen peroxide. Accordingly, achieving highly selective H2O2 production under low voltage conditions remains challenging. Herein, guided by first-principles density functional theory (DFT) calculations, we show that modulation the first coordination sphere in Co single atom catalysts (Co-N-C catalysts with Co-NxO4-x sites), specifically the replacement of Co-N bonds with Co-O bonds, can weaken the *OOH adsorption strength to boost the selectivity towards H2O2 (albeit with a slight decrease in ORR activity). Further, by synthesizing a series of N-doped carbon-supported catalysts with Co-NxO4-x active sites, we were able to validate the DFT findings and explore the trade-off between catalytic activity and selectivity for 2e- ORR. A catalyst with trans-Co-N2O2 sites exhibited excellent catalytic activity and H2O2 selectivity, affording a H2O2 production rate of 12.86 [[EQUATION]]and an half-cell energy-efficiency of 0.07 [[EQUATION]] during a 100-h H2O2 production test in a flow-cell.

High-Performance Silicone Sponge Evaporators with Low Thermal Conductivity for Long-Term Solar Interfacial Evaporation and Freshwater Harvesting.

Solar interfacial evaporation (SIE) has emerged as a highly promising approach for sustainable freshwater harvesting. However, maintaining a stable evaporation rate and achieving a high freshwater yield in high-salinity brines remain a significant challenge. In this study, we present the development of silicone sponge-based evaporators with a "free-salt" structure, designed to enhance the efficiency of SIE and freshwater collection. These evaporators, designated as PSS@Fe3O4/CNTs, were fabricated by grafting durable silicone onto a silicone sponge framework, followed by the incorporation of Fe3O4 nanoparticles and carbon nanotubes. The unique combination of exceptional photothermal properties and a controlled yolk-shell structure with low thermal conductivity enabled the PSS@Fe3O4/CNT evaporators to sustain a stable evaporation rate of 1.87 kg m-2 h-1 in real seawater over 200 h of continuous operation under 1 sun illumination. Importantly, no salt accumulation was observed on the evaporator surfaces, even when exposed to highly concentrated brines. In a closed system equipped with a condenser, these evaporators achieved freshwater production rates of 14.5 and 11.8 kg m-2 over 10 h from 10 and 20 wt % NaCl solutions, respectively, under 1 sun illumination. These values correspond to normalized production rates of 1.45 and 1.18 kg m-2 h-1, showcasing the consistent and efficient performance of the evaporators across varying salinity levels. Beyond salt rejection, the PSS@Fe3O4/CNT evaporators also demonstrated the ability to effectively remove various heavy metal ions (e.g., Cu2+ and Zn2+) and organic pollutants from contaminated water. This work provides valuable insights into innovative evaporator designs for efficient freshwater production from seawater and wastewater.

Balancing Activity and Selectivity in Two‐electron Oxygen Reduction through First Coordination Shell Engineering in Cobalt Single Atom Catalysts

The electrochemical two‐electron oxygen reduction reaction (2e‐ ORR) offers a potentially cost‐effective and eco‐friendly route for the production of hydrogen peroxide (H2O2). However, the competing 4e‐ ORR that converts oxygen to water limits the selectivity towards hydrogen peroxide. Accordingly, achieving highly selective H2O2 production under low voltage conditions remains challenging. Herein, guided by first‐principles density functional theory (DFT) calculations, we show that modulation the first coordination sphere in Co single atom catalysts (Co‐N‐C catalysts with Co‐NxO4‐x sites), specifically the replacement of Co‐N bonds with Co‐O bonds, can weaken the *OOH adsorption strength to boost the selectivity towards H2O2 (albeit with a slight decrease in ORR activity). Further, by synthesizing a series of N‐doped carbon‐supported catalysts with Co‐NxO4‐x active sites, we were able to validate the DFT findings and explore the trade‐off between catalytic activity and selectivity for 2e‐ ORR. A catalyst with trans‐Co‐N2O2 sites exhibited excellent catalytic activity and H2O2 selectivity, affording a H2O2 production rate of 12.86 [[EQUATION]]and an half‐cell energy‐efficiency of 0.07 [[EQUATION]] during a 100‐h H2O2 production test in a flow‐cell.

Accelerated interfacial hole transfer over Au/TiO2 photocatalysts for highly efficient oxidative coupling of methane.

Accelerated interfacial hole transfer over Au/TiO2 photocatalysts facilitates a highly efficient oxidative coupling of methane, achieving a C2 hydrocarbon production rate of 3.3 mmol g-1 h-1 and selectivity of up to 97%.

Covalent Organic Frameworks for Boosting H2O2 Photosynthesis via the Synergy of Multiple Charge Transfer Channels and Polarized Field

AbstractCovalent organic frameworks (COFs) serve as one of the most promising candidates for hydrogen peroxide (H2O2) photosynthesis, while attaining high‐performance COFs remains a formidable challenge due to the insufficient separation of photogenerated charges. Here, through the rational design of bicarbazole‐based COFs (Cz‐COFs), we showcase the first achievement in piezo‐photocatalytic synthesis of H2O2 using COFs. Noteworthily, the ethenyl group‐modified Cz‐COFs (COF‐DH‐Eth) demonstrates a record‐high yield of H2O2 (9212 μmol g−1 h−1) from air and pure water through piezo‐photocatalysis, which is ca. 2.5 times higher than that of pristine Cz‐COFs without ethenyl groups (COF‐DH‐H) under identical condition and COF‐DH‐Eth without ultrasonic treatment. The H2O2 production rate originates from the synergistic effect between an ultrasonication‐induced polarized electric field and the spatially separated multiple charge transfer channels, which significantly promote the utilization of photogenerated electrons by directional transfer from bicarbazole groups to the ethenyl group‐modified benzene rings. Several Cz‐COFs and bifluorenylidene‐based COFs (COF‐BFTB‐H) with similar twisted monomers exhibit obvious piezoelectric performance for promoting H2O2 generation, signifying that organic ligands with a twistable structure play a crucial role in creating broken symmetry structures, thereby establishing piezoelectric properties in COFs.

Time series of phytoplankton net primary production reveals intense interannual variability and size‐dependent chlorophyll‐specific productivity on a continental shelf

AbstractPhytoplankton community size structure influences the production and fate of organic carbon in marine food webs and can undergo strong seasonal shifts in temperate regions. As part of the Northeast US Shelf (NES) Long‐Term Ecological Research program, we measured net primary production (NPP) rates and chlorophyll a (Chl a) concentrations in three phytoplankton size classes (&lt; 5, 5–20, and &gt; 20 μm) during winter and summer for 3 yr along a coastal‐to‐offshore transect. Mean depth‐integrated NPP was 37% higher in summer than winter, with limited cross‐shelf differences because of significant interannual variability. When averaged across the shelf, depth‐integrated NPP was dominated by the &gt; 20 μm size class in winter and generated equally by the three size fractions in summer because of substantial contributions from cells &gt; 20 μm at the Chl a maximum depth. Furthermore, the relationship between Chl a and NPP, in terms of relative contributions, varied by size class. Variations in this relationship have implications for models of primary productivity on the NES and beyond. In comparison to historical NPP data, we identified equivalent levels of winter NPP but observed a 25% decrease in summer NPP, suggesting a potential reduction in the seasonality of NPP on the NES. Together, our results highlight seasonal shifts in NPP rates of different phytoplankton size classes, with implications for food web structure and export production. These data emphasize the importance of quantifying size‐fractionated NPP over time to constrain its variability and better predict the fate of organic carbon in coastal systems under environmental change.

Bias‐Free Photoelectrochemical Water Oxidation Coupled with Electrochemical Oxygen Reduction Reaction via Fe‐Based Electrodes with Long‐Term Operation

AbstractPhotoelectrochemistry (PEC) is a green and sustainable approach in the synthesis of H2O2, depending on the semiconductor to initiate two‐electron water oxidation into hydrogen peroxide (H2O2). However, the photoanodes generally have sluggish charge transfer and a limited number of active sites, which limit the yield and faradaic efficiency (FE) for the production of H2O2. Herein, Ti‐doped Fe2O3 photoanode with the modification of ZnO passivation layer (ZnO/Ti‐Fe2O3) for PEC H2O2 production is developed. The optimized photoanode has shown a high FE and selectivity for two‐electron water oxidation, achieving a yield approaching 0.56 µmol min−1 cm−2 at 1.23 VRHE and an average FE over 80% in the potential range from 1.0 to 1.6 VRHE. Impressively, an unassisted PEC system is designed to generate H2O2 at the ZnO/Ti‐Fe2O3 photoanode while performing an oxygen reduction reaction (ORR) at the Fe(Co)‐NC cathode. The integrated system enables the average PEC H2O2 production rate of 0.275 µmol min−1 cm−2 without applying any additional bias. Moreover, an unassisted PEC cell obtains a long‐term stability of 100 h. This work demonstrates new possibilities in designing efficient and stable PEC assemblies using low‐cost earth‐abundant materials for light‐driven catalysis.