High Load Research Articles

Smart Mesoporous Silica Nanoparticles Loading Curcumin Inhibit Liver Cancer.

Curcumin (CUR) as one of the natural edible pigments is approved by the World Health Organization due to its nontoxic and anticancer effect. However, the utility of CUR is restricted due to its low oral bioavailability. Nanoparticle drug delivery systems like mesoporous silica nanoparticles (MSNs) have been extensively used due to their high specific surface area, high loading rate, and ease of modification. This study developed lactobionic acid (LA)-modified carboxymethyl chitosan (CMCS)-coated MSNs to deliver CUR specifically targeting hepatocellular carcinoma. Among these nanoparticles, LA targets liver cancer cells. CMCS utilizes pH-responsive release of CUR. The LA-CMCS-MSN@CUR (MSN@CUR) were evaluated using several methods, including Fourier transform infrared spectroscopy, transmission electron microscopy, and zeta potential measurements. Liver cellular uptake of MSN@CUR depends on a specific LA receptor-mediated endocytosis mechanism. Additionally, MSN@CUR performed with a better antitumor effect than Cur in H22 orthotopic transplantation of liver cancer and H22 solid tumor mouse models. Treatment with MSN@CUR significantly reduced the protein of VEGF, p-PI3K, and AKT, increased the protein of caspases 3 and 8, ultimately inhibited tumor migration, and promoted apoptosis. This study provides a new path for delivery of natural active ingredients with excellent bioavailability in the antitumor field.

Enhanced biochemical treatment of pulping wastewater by Fenton process: Water quality optimization and detoxification efficiency

Pulping wastewater, characterized by enormous quantities, high pollution load and significant biotoxicity, making its effective treatment crucial for environmental protection. This study evaluated the performance of typical (anaerobic/aerobic) and advanced oxidation (Fenton) processes in pulping wastewater treatment, in relation to physicochemical parameters, acute toxicity and organic indexes. Raw wastewater contains numerous aromatic pollutants with benzene rings and unsaturated bonds, resulted in high pollution load and acute toxicity. Typical treatment process effectively reduced various pollution parameters, with toxicity was significantly decreased or completely removed (83.57–100.00 %). The residual toxicity unit (TU) of aerobic effluent for luminousbacteria and chlorella was only 2.76 and 1.23, respectively. Specifically, acute toxicity showed significantly positively correlated with total nitrogen (TN) and total organic carbon (TOC), positively associated with UV254, while negatively related to humification index (HIX). Although Fenton process optimized wastewater quality, it generated toxic intermediates that increased luminousbacteria toxicity to 5.12 TU, and Daphnia magna toxicity from 0.33 to 0.84 TU. Notably, newly organic pollutants such as Tricosane and Dibutyl phthalate may contributed to increased toxicity. In summary, these results concluded that advanced treatment processes may introduce unexpected toxicity and emphasized the importance of evaluate biotoxicity for environment protection.

Redox Mediator as Highly Efficient Charge Storage Electrode Additive for All‐Solid‐State Lithium Metal Batteries

AbstractAll‐solid‐state lithium metal batteries (ASSLBs) have the potential to provide a significant increase in energy density and safety. However, most ASSLBs are still suffering from low cathode loading, poor rate capability, and low attainable energy/power densities, which seriously limit their practical application. Besides developing solid electrolytes with high conductivity, constructing a highly loaded cathode with rapid reaction kinetics is also essential for achieving high‐performance ASSLBs. Herein, the methylamine hydroiodide (CH6NI) is investigated as a functional electrode additive to enable rapid Li+ transport and charge transfer in LiFePO4 (LFP) cathode, whereby the CH6NI serves as a charge storage carrier that facilitates the reaction kinetics during the delithiation and lithiation process of LFP. As a result, the ASSLB assembled with LFP@CH6NI cathode shows excellent cycling stability over 700 cycles at 2 C with a high capacity retention of 87.6%, while the cell with bare LFP cathode shows no capacity at high current rates (≥0.5 C). Moreover, the ASSLB pared with a high active loading cathode (5.6 mg cm−2) still exhibits a high specific capacity of 144.9 mAh g−1 at 0.5 C. This work provides a facile strategy that opens new possibilities for designing high‐loading electrodes for high‐performance ASSLBs.

Probing the friction mechanism of diamond-like carbon films in aqueous environments based on molecular dynamics simulations

Abstract The frictional behavior of diamond-like carbon (DLC) films in an aqueous environment is of tremendous interest. To compare the impacts of the quantity of water molecules, sliding velocity, and loading on the friction behavior of DLC films, a molecular model of DLC films in an aqueous environment was built. The results show that the DLC film under high load and high sliding velocity leads to severe friction behavior, but the water molecules can prevent the occurrence of this severe friction behavior. Also increasing the number of water molecules can effectively reduce the increase in friction during the running-in stage and keep it at a low value. The primary explanation is that if there are enough water molecules, they will create a stable water film at the friction interface and prevent large-scale contact and distortion between the upper and lower DLC films, significantly reducing friction.

Occurrence, transformation, and transport of PFAS entering, leaving, and flowing past wastewater treatment plants with diverse land uses

Per- and polyfluoroalkyl substances (PFAS) have been detected ubiquitously throughout the environment. Wastewater treatment plants (WWTPs) have been identified as potential hotspots for the introduction of PFAS into the environment. Therefore, the occurrence, transformation, and transport of 18 PFAS in two WWTPs with varying treatment processes, prevailing land uses, and during two distinct time periods were investigated. Polar Organic Chemical Integrative Samplers (POCIS) were installed at two WWTPs in Central Kentucky during April and July of 2022. PFAS concentrations typically increased from influent to effluent at both WWTPs, regardless of wastewater treatment processes, but changes in surface water concentrations from upstream to downstream of the effluent mixing zones varied. Both WWTPs discharged the 18 PFAS at higher loads than received, indicating prevalent transformation of PFAS precursors and non-measured PFAS analytes into measurable PFAS. Nearly all measured PFAS persisted in aqueous (86–98%) compartments rather than sediment or biosolids (2–14%). All biosolids had low content of PFAS with the dominant compound being PFOS (1.59–2.60 ng/g). Based on recent US EPA proposed maximum contaminant levels, hazard indexes for drinking water were exceeded in effluent and downstream surface waters at both WWTPs. The WWTP located in a heavily developed area and downstream from a firefighting training facility, had significantly higher concentrations of most PFAS species at most monitoring sites and was less impacted by sampling period compared to the WWTP located in a moderately developed, pastured area. Findings support the importance of WWTPs and land use practices as contributing to PFAS impact to downstream ecosystems along with potentially increasing strains on downstream drinking water source waters in regions that are surface water dependent.

Scalable Atomic‐Layer Tailoring of Abundant Oxide Supports Unlocks Superior Interfaces for Low‐Metal‐Loading Dehydrogenation

Liquid organic hydrogen carriers (LOHCs) offer a promising solution for global hydrogen infrastructure, but their practical application faces two key challenges: sluggish dehydrogenation processes and the reliance on catalysts with high noble metal loadings. This study presents a scalable approach to reduce noble metal usage while maintaining high catalytic activity. We synthesized an ultralow Pt content (0.1 wt%) catalyst using γ‐Al2O3‐based pellet support with atomic layer deposition (ALD) of TiO2. Advanced characterization techniques reveal that the thin ALD‐TiO2 shell provides a heterogeneous interface, confining electronically rich Pt‐nanoparticle ensembles. The catalyst outperforms both equivalent Pt‐content catalysts and a commercial 0.5 wt% Pt/γ‐Al2O3 catalyst in homocyclic LOHC dehydrogenation. This study provides insights into the beneficial role of ALD‐engineered interfaces for catalytic supports and offers an efficient approach for scalable production of low‐noble‐metal‐content catalysts, with implications for various catalytic processes.

Breaking Mass Transport Limit for Hydrogen Evolution-Inhibited and Dendrite-Free Aqueous Zn Batteries.

It is commonly accepted that batteries perform better at low current densities below the mass-transport limit, which restricts their current rate and capacity. Here, it is demonstrated that the performance of Zn metal electrodes can be dramatically enhanced at current densities and cut-off capacities exceeding the mass-transport limit by using pulsed-current protocols. These protocols achieve cumulative plating/stripping capacities of 11.0 Ah cm-2 and 3.8 Ah cm-2 at record-high current densities of 80 and 160 mA cm-2, respectively. The study identifies and understands the promoted (002)-textured Zn growth and suppressed hydrogen evolution based on the thermodynamics and kinetics of competing reactions. Furthermore, the over-limiting pulsed-current protocol enables long-life Zn batteries with high mass loading (29 mgcathode cm-2) and high areal capacity (7.9 mAh cm-2), outperforming cells using constant-current protocols at equivalent energy and time costs. The work provides a comprehensive understanding of the current-capacity-performance relationship in Zn plating/stripping and offers an effective strategy for dendrite-free metal batteries that meet practical requirements for high capacity and high current rates.

Evaluation of a time-varying cut-off frequency low-pass filter for assessing knee joint moments and ACL injury risk

ABSTRACT Conventional low-pass filtering of 3D motion capture signals prior to estimating knee joint moments and ACL injury risk has known limitations. This study aimed to evaluate the fractional Fourier filter (FrFF), which employs a time-varying cut-off frequency, for assessing peak knee moments during common ACL injury risk screening tasks. Ground reaction force and motion data were collected from 23 team sport athletes performing 45° unanticipated sidesteps and drop jumps. Peak knee abduction, internal rotation and non-sagittal moments were estimated using inverse dynamics after five different low-pass filter approaches were applied (FrFF vs. four variations of a fourth-order Butterworth filter). The FrFF produced peak knee moments larger than “matched” (i.e. force and motion cut-off frequencies were equivalent) and closer to “unmatched” (i.e. force and motion cut-offs were different) Butterworth filter approaches and removed problems with representing foot-to-ground impact peaks. Participants with larger peak moments were identified as “at risk” of injury irrespective of filter approach, but the FrFF identified “at risk” classifications conventional approaches did not. Preliminary evidence suggests that the FrFF displays enhanced sensitivity to movement strategies that induce high knee loads. This was most evident for sidestepping, with more research warranted to optimise the FrFF for drop jumps.

Synergistic Regulation of Anode and Cathode Interphases via an Alum Electrolyte Additive for High‐Performance Aqueous Zinc‐Vanadium Batteries

AbstractA zinc (Zn) metal anode paired with a vanadium oxide (VOx) cathode is a promising system for aqueous Zn–ion batteries (AZIBs); however, side reactions proliferating on the Zn anode surface and the infinite dissolution of the VOx cathode destabilise the battery system. Here, we introduce a multi‐functional additive into the ZnSO4 (ZS) electrolyte, KAl(SO4)2 (KASO), to synchronise the in situ construction of the protective layer on the surface of the Zn anode and the VOx cathode. Theoretical calculations and synchrotron radiation have verified that the high‐valence Al3+ plays dual roles of competing with Zn2+ for solvation and forming a Zn−Al alloy layer with a homogeneous electric field on the anode surface to mitigate the side reactions and dendrite generation. The Al‐containing cathode–electrolyte interface (CEI) considerably alleviates the irreversible dissolution of the VOx cathode and the accumulation of byproducts. Consequently, the Zn||Zn cell with KASO exhibits an ultra‐long cycle of 6000 h at 2 mA cm−2. Importantly, the VOx cathodes (VO2, V2O5 and NH4V4O10) in the ZS−KASO electrolyte showed excellent cycling stability, including Zn powder||VO2 cells and Zn||VO2 pouch cells. Even better, the full cell exhibits excellent cycling stability at low negative/positive (N/P) ratio of 2.83 and high mass loading (~16 mg cm−2). This study offers a straightforward and practical reference for concurrently addressing challenges at the anode and cathode of AZIBs.

High‐Entropy Electrolyte Driven by Multi‐Solvation Structures for Long‐Lifespan Aqueous Zinc Metal Pouch Cells

Aqueous zinc metal batteries (AZMBs) are promising for grid‐scale energy storage due to their low cost and high safety. However, poor stability and an unfavorable freezing point hinder their actual application. Herein, a ternary salts‐based high‐entropy electrolyte (HEE) composed of Zn0.2Na0.4Li0.4(ClO4)1.2·7H2O is proposed to address the above issues. The addition of perchlorate salts with different cations reduces the size of ion clusters, significantly increases the solvation structure species, and promotes the anion‐rich Zn2+ solvation structures, resulting in an enlarged electrochemical stability window, favorable viscosity and ionic conductivity, and low freezing point. Furthermore, characterization and calculations confirm that multiple types of solvation structures effectively increase the electrolyte entropy. As a consequence, the Zn/Zn symmetric cells in HEE can sustainably cycle for at least 1000 hours and 1500 hours under room and subzero temperatures, respectively. The Na0.33V2O5/Zn and polyaniline/Zn full cells can even last for 30000 and 20000 cycles without capacity decay at −20 °C, respectively. The pouch cells employing HEE deliver promising capacity and stability, even at high mass loading of active materials. This strategy of introducing multiple salts with different cations to construct a high‐entropy environment provides a facile approach for high‐performance and long‐lifespan AZMBs across a wide temperature range.

Psychometric Testing of the Cross-Culturally Adapted Thai Version of the Caregiver Self-Efficacy in Contributing to Patient Self-Care Scale in Caregivers of Patients With Chronic Illnesses.

To evaluate the psychometric properties of the Caregiver Self-Efficacy in Contributing to Patient Self-Care Scale (CSE-CSC). The CSE-CSC scale was developed congruently with the Caregiver Contribution to Self-Care of Patient with Chronic Illness Inventory (CC-SC-CII) to assess caregiver self-efficacy (CSE), the motivation factor of caregiving. Its applicability in Asian populations, including Thailand, was limited. Psychometric tests were guided by COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) principles. This included translating the English version into Thai, following the principles of good practice for the translation and cultural adaptation process for patient-reported outcome (PRO) measures. Nine nursing experts evaluated the content validity. The analysis included caregivers of patients with chronic conditions from 16 primary care centres in Thailand. We tested the structural validity using exploratory factor analysis (EFA), confirmatory factor analysis (CFA) and concurrent validity for CC-SC-CII-v2. We tested the scale's reliability with methods for multidimensional and unidimensional constructs, the intraclass correlation coefficients (ICCs) and measurement error variance. Kappa coefficient (k = 1.00) indicated the scale's excellent content validity. The final analysis included a total of 407 samples. The EFA with the first split-half subsample (n = 194) extracted a two-dimensional structure. One reflected CSE in Maintenance and Monitoring behaviour and another captured CSE in Management behaviour. CFA with the second split-half subsample (n = 213) and the overall sample (n = 407) supported the scale's bidimensional model with high factor loadings. Each dimension and the overall CSE-CSC scale positively correlated with each scale and the overall CC-SC-CII-v2. McDonald's ω and Cronbach's α (both ranged from 0.91-0.94) indicated excellent internal reliability. Test-retest reliability showed ICCs between 0.95 and 0.96. Measurement error yielded satisfactory results. Testing of the Thai CSE-CSC scale supported validity and reliability, indicating that the scale can apply to Thai caregivers. This scale can be used in clinical practice and research to evaluate CSE in contribution to patient self-care.

High-Entropy Electrolyte Driven by Multi-Solvation Structures for Long-Lifespan Aqueous Zinc Metal Pouch Cells.

Aqueous zinc metal batteries (AZMBs) are promising for grid-scale energy storage due to their low cost and high safety. However, poor stability and an unfavorable freezing point hinder their actual application. Herein, a ternary salts-based high-entropy electrolyte (HEE) composed of Zn0.2Na0.4Li0.4(ClO4)1.2·7H2O is proposed to address the above issues. The addition of perchlorate salts with different cations reduces the size of ion clusters, significantly increases the solvation structure species, and promotes the anion-rich Zn2+ solvation structures, resulting in an enlarged electrochemical stability window, favorable viscosity and ionic conductivity, and low freezing point. Furthermore, characterization and calculations confirm that multiple types of solvation structures effectively increase the electrolyte entropy. As a consequence, the Zn/Zn symmetric cells in HEE can sustainably cycle for at least 1000 hours and 1500 hours under room and subzero temperatures, respectively. The Na0.33V2O5/Zn and polyaniline/Zn full cells can even last for 30000 and 20000 cycles without capacity decay at -20 °C, respectively. The pouch cells employing HEE deliver promising capacity and stability, even at high mass loading of active materials. This strategy of introducing multiple salts with different cations to construct a high-entropy environment provides a facile approach for high-performance and long-lifespan AZMBs across a wide temperature range.

Academic stress in dental students: suggestions for care in university institutions

Stress is a challenging situation that is generated by the arrival of an unexpected or novel situation that is difficult to solve. Dental students are subjected to high stress loads. The purpose of this paper is to briefly review the most recent literature on this topic and to make suggestions on how to approach it according to this and the authors' experience.

Scalable Atomic-Layer Tailoring of Abundant Oxide Supports Unlocks Superior Interfaces for Low-Metal-Loading Dehydrogenation.

Liquid organic hydrogen carriers (LOHCs) offer a promising solution for global hydrogen infrastructure, but their practical application faces two key challenges: sluggish dehydrogenation processes and the reliance on catalysts with high noble metal loadings. This study presents a scalable approach to reduce noble metal usage while maintaining high catalytic activity. We synthesized an ultralow Pt content (0.1 wt%) catalyst using γ-Al2O3-based pellet support with atomic layer deposition (ALD) of TiO2. Advanced characterization techniques reveal that the thin ALD-TiO2 shell provides a heterogeneous interface, confining electronically rich Pt-nanoparticle ensembles. The catalyst outperforms both equivalent Pt-content catalysts and a commercial 0.5 wt% Pt/γ-Al2O3 catalyst in homocyclic LOHC dehydrogenation. This study provides insights into the beneficial role of ALD-engineered interfaces for catalytic supports and offers an efficient approach for scalable production of low-noble-metal-content catalysts, with implications for various catalytic processes.

A hybrid system based on the combination of adsorption, electrocoagulation, and wetland treatment for the effective remediation of industrial wastewater from underground coal gasification (UCG)

The study verified the effectiveness of treating post-process underground coal gasification (UCG) wastewater, containing high loads of inorganic and organic pollutants, using constructed wetlands (CW) enhanced by hybrid adsorption and electrocoagulation (EC) techniques. Four different system configurations were tested: wetland, EC/wetland, adsorbent/wetland, and EC/adsorbent/wetland. Each experiment lasted 60 days. The feed and effluents from each treatment step were analysed for their basic physicochemical parameters such as metals and trace elements, phenols, sulphides, cyanides, total organic carbon (TOC), chemical oxygen demand (COD), biological oxygen demand (BOD), benzene, toluene, ethylene, xylene (BTEX), and polyaromatic hydrocarbons (PAHs).Systems with electrocoagulation proved to be effective in the case of metal removal. The best results were obtained for Fe, Ni, Sb and As (up to 96%, 98%, 94% and 82% respectively). The systems were ineffective in removing Mn. All tested systems showed the greatest effectiveness in the treatment of wastewater from phenols, BTEX and CN (almost 100% removal). CWs without preliminary electrocoagulation showed practically 100% effectiveness in removing BTEX after 14 days of treatment. Electrocoagulation was particularly effective in reduction of large quantity of PAH compounds (from 1228 μg/l to below 0.050 μg/l). Effective toxicity reduction from V class to II class after 60 days in comparison with meeting the requirements contained in the Best Available Techniques (BAT) document, showed that all tested systems were favorable in terms of UCG wastewater treatment. A significant decrease in toxicity was observed in just 14 days (around 90% reduction of toxicity measured in TU values for systems without adsorbent and around 75% for systems with adsorbent). The wastewater were still toxic due to the formation of degradation intermediates of organic compounds (BTEX, PAHs, phenol compounds), despite a significant decrease in the concentration of contaminants, therefore toxicity assessment should be one of the evaluation criteria for industrial wastewater treatment.

Soil arthropod diversity, richness, and abundance in agroecological and conventional cotton production systems in Chaco, Argentina

In Argentina, agroecology has grown in last years as a scientific paradigm that seeks to design and evaluate agroecosystems considering sustainability, complexity, and uncertainty. Diversity is a key factor in the design and management of production systems and a necessary component for conservation biological control and the reduction of agrochemicals use. Cotton (Gossypium hirsutum) crop in northern Argentina is usually managed with high load of agrochemicals: agroecological production arises as an alternative. This study evaluated the diversity, richness, and abundance of soil arthropods using pitfall traps in two experimental cotton plots under conventional (CONV) and agroecological management (AE) in Chaco, Argentina. AE system presented higher diversity and richness of predators compared with CONV, even when natural preparations were used for pest control. The phytophagous arthropods showed higher diversity and richness in CONV, even when pyrethroid insecticides were applied for pest control and preventively. The abundance in AE was lower for predators and higher for phytophagous arthropods. Agroecological production of cotton can be a tool that favors conservative biological control and an alternative for areas where protecting the health of farmers and the ecosystem is a priority.

Encapsulation of Rifampicin in Solid Lipid Nanoparticles by Microwave‐Assisted Microemulsion Method

AbstractRifampicin (RF) is a potent antibiotic, but its clinical effectiveness is limited by poor water solubility and stability. To overcome these limitations, RF is encapsulated in solid‐lipid nanoparticles (SLNs) using a one‐pot microwave microemulsion method. This study aimed to synthesize and characterize RF‐loaded SLNs, evaluating their physicochemical characteristics and antimicrobial efficacy. The synthesized SLNs exhibit particle sizes ranging from 150 to 200 nm, with a high encapsulation efficiency of ≈55% and high loading capacity. The particles are imaged by cryogenic‐transmission electron microscopy and found to be circular and elongated, with RF homogenously distributed throughout the particles. The RF‐loaded SLNs demonstrate potent antimicrobial activity, as evidenced by disc diffusion assays. The SLNs exhibits a sustained drug release profile, highlighting their potential as an effective drug delivery system for antimicrobial treatment. These findings suggest that SLNs can enhance the stability, bioavailability, and therapeutic efficacy of hydrophobic drugs like RF.

Challenges of Congenital HHV6 Infection Diagnosis and Treatment: Two Case Reports and Literature Review

Introduction: Congenital human herpesvirus 6 (HHV6) infection occurs in 1% of the general population and may result from the transmission of an inherited chromosomally integrated HHV6 (iciHHV6) or transplacental infection. It is mostly asymptomatic. Case reports: Case 1: a 29th-week-old female preterm newborn, admitted to the neonatal intensive care unit, became clinically unstable and irritable on the 20th day of hospitalization. Cranial ultrasound, revealed a significant posthemorrhagic tetraventricular dilation, with signs of ventriculitis. Investigations revealed HHV6 positivity on cerebrospinal fluid polymerase chain reaction multiplex panel testing and HHV6-DNA high viral loads in plasma samples. Case 2: a female late preterm newborn was admitted to the neonatal intensive care unit due to early-onset sepsis. Investigations revealed group B streptococcus positive blood cultures and cerebrospinal fluid HHV6 positivity on polymerase chain reaction multiplex panel testing, with negative bacterial culture. After 3 days of adequate antibiotic treatment, she maintained persistent moaning, which motivated a cranial ultrasound, revealing mild brain edema. Clinical improvement was observed only after beginning antiviral treatment in both newborns. Due to the persistency of high viral loads in both cases, despite antiviral treatment and clinical improvement, an iciHHV6 was suspected and posteriorly confirmed. Discussion/conclusion: Congenital iciHHV6 infection diagnosis is challenging because the presence of an iciHHV6 results in persistently high viral loads, even in the absence of active infection. Only a few diagnostic techniques can confirm active replication; unfortunately, these are not available in most countries. The decision to initiate antiviral treatment should be based on clinical judgment. Better ways for the diagnosis of active infection are needed.

Near-Surface Reconfiguration of Biopolymer Blends by Mechanical Embossment: Creation of Friction-Reduced Foils

Biopolymer blends of polylactic acid (PLA) and polybutylene adipate-co-terephthalate (PBAT) are extruded into flexible monolayer films. These blends are excellent candidates for the realization of environmentally friendly packaging applications. A necessary pre-requisite for that are appropriate tribological properties under mechanical contact. Reasonable wear resistance allows good protection of packed goods, and low friction forces reduce difficulties in stacking. In this research, mechanical embossment under high loads at room temperature was used for the modification of polymer surfaces to exhibit a significant friction reduction under dry conditions. The results particularly show a systematic decrease in the coefficient of friction for biopolymer blends containing 30 wt% and 40 wt% PBAT. FTIR was used to analyze the change in surface composition after mechanical embossing. A sophisticated FTIR calibration method revealed that the blend with 30 wt% PBAT shows a modified distribution of PBAT and PLA at the surface due to mechanical embossment. This leads to a controlled and long-lasting modification of the surface properties without a substantial change in the chemical composition of the polymer in bulk. Without the use of additional coatings, biodegradable packaging foils with improved characteristics are accessible.

A detailed comparison of ethanol–diesel direct fuel blending to conventional ethanol–diesel dual-fuel combustion

Dual-fuel combustion is a well-known measure to enable the combustion of low-reactivity fuels (LRF) in compression-ignited engines with high thermal efficiency through a pilot injection of a high-reactivity fuel (HRF). In most cases, the LRF is introduced into the intake manifold and therefore premixed with the air before entering the combustion chamber during the intake stroke (premixed charge operation, PCO). In this work, this approach is investigated for bioethanol-diesel dual-fuel combustion using external and internal exhaust gas recirculation (EGR) to improve emissions and engine efficiency. In addition, PCO is compared to an alternative concept in which bioethanol and diesel are blended shortly upstream of the high-pressure pump (premixed fuel operation, PFO) at variable mixing ratios. The results show that higher ethanol shares of up to 70% can be achieved at low engine load when using PCO, while at medium and high load, the maximum energy share of ethanol is higher with PFO. While PCO is limited by engine knock, PFO rather suffers from the reduction in cetane number. In PCO, external and internal EGR allow for a reduction of unburned hydrocarbons (up to − 82%) and carbon monoxide (up to -60%), while nitrous oxide emissions are simultaneously lowered by up to − 65%. Both with and without EGR, PFO shows low emissions of unburned hydrocarbons and carbon monoxide (similar to conventional diesel combustion) and a significant reduction in nitrous oxide and soot formation. Brake thermal efficiency (BTE) drops in both modes compared to conventional diesel combustion, in PCO operation due to unburned and partially unburned fuel and in PFO due to increased friction in the high-pressure fuel pump caused by an increased fuel flow.