水力空化改质对重质原油沥青质及性质的影响

利用水力空化过程产生局部的高温、高压、高射流以及强大的剪切力等极端化学物理条件改质处理沙特重质原油，试验结果表明：沙特重质原油经过水力空化改质后粘度由13.61降低至7.22mm2/s，残碳由7.16%降低至6.48%，实沸点蒸馏后减压渣油降低1个百分点。进一步采用APPI FT-IR MS、XRD、FT-IR、SEM和粒度分布等技术研究了水力空化改质对沙重原油分子组成，沥青质团聚体微晶结构、沥青质胶束粒径分布、沥青质官能团、沥青质形貌等方面的影响，从分子角度阐述空化改质重油的机理。研究结果表明：水力空化改质后沙重原油分子量分布、芳烃类化合物缔合作用变小；沥青质对低DBE化合物吸附性能降低；沥青质团聚体微晶结构更加松散；沥青质胶束粒度分布降低；沥青质分子相互团聚作用力减弱。进一步考察了水力空化改质前后减压渣油延迟焦化性能，改质处理后焦炭产率降低1.85个百分点，液体收率和气体产率分别增加1.52和0.33个百分点，水力空化改质对沥青质性质、结构特点的改善能够有效的提高其加工性能。     

Italian translation,validation, and repeatability of Standard Patient Evaluation of Eye Dryness (SPEED) Questionnaire

PurposeThe assessment of symptoms of dry eye disease using a questionnaire is an effective and simple method of quantifying symptoms. The aim of this study was to translate the SPEED questionnaire and adapt it for the Italian language and verify the main psychometric performance of the translated version, including repeatability and agreement.MethodsThe SPEED questionnaire was translated into Italian following a standard methodology. The resulting questionnaire was administered to 206 adult participants in order to perform a validation analysis. A subgroup of 82 participants was retested after one week to give a repeatability and agreement assessment.ResultsInternal consistency showed an alpha of 0.852 (95% CI 0.818–0.881) and no unnecessary items. The factor analysis showed a saturation for three main factors related to (i) Dryness and Soreness, (ii) Fatigue, and (iii) Burning. Repeatability was high, with a CCC of 0.896 (95% CI 0.844–0.931). Agreement analysis showed no significant bias between sessions and an interval of agreement of 5 points for SPEED score.ConclusionThe translation and adaptation of the SPEED questionnaire for the Italian language have demonstrated good psychometric properties for the translated questionnaire, confirming and expanding the original psychometric characteristics. Consequently, the SPEED questionnaire could be used to measure the presence of symptoms of dry eye quantitatively.     

Diet composition and overlap for adult walleye,lake whitefish,and yellow perch in Green Bay,Lake Michigan

Interspecific interactions among walleye Sander vitreus, lake whitefish Coregonus clupeaformis, and yellow perch Perca flavescens in Green Bay could influence the population status of each species, but potential trophic interactions are poorly understood. Our objectives were to determine if diet assemblages for each species and diet overlap among species varied spatially and temporally within Green Bay. Adult walleye (≥381 mm total length (TL); N = 981), lake whitefish (≥432 mm TL; N = 1507), and yellow perch (≥150 mm TL; N = 1174) were collected during May-October of 2018 and 2019 from multiple locations in southern and northern Green Bay. Diet assemblages of each species varied between northern and southern Green Bay, but walleye diets were more temporally variable (among months within zones and between years) than diets of lake whitefish or yellow perch. Lake whitefish represented a seasonally important prey item for walleye in southern Green Bay, composing 10 % and 41 % of walleye diets by weight in May and June, respectively. Yellow perch generally composed <15 % of walleye diets by weight but were consumed at a broader spatiotemporal scale than lake whitefish. Diet overlap between walleye and both lake whitefish and yellow perch was generally weak or moderate, whereas diet overlap between whitefish and perch was generally strong. Our assessment of adult trophic interactions suggests that changes in the population status of one species could influence fisheries for all three, and we identify additional research questions to address potential population-level effects of these trophic interactions.     

Multi-dimensional modeling of mixture preparation in a direct injection engine fueled with gaseous hydrogen

With the recent advances of direct injection (DI) technology, introducing hydrogen into the combustion chamber through DI is being considered as a viable approach to circumvent backfire and pre-ignition encountered in early generations of hydrogen engines. As part of a broader vision to develop a robust numerical model to study hydrogen spark ignition (SI) combustion in internal combustion (IC) engines, the present numerical investigation focuses on mixture preparation in a hydrogen DI SI engine. This study is carried out with a single hole injector with gaseous hydrogen injected at 100 bar injection pressure. Simulations are carried out for high and low tumble configurations and validated against optical data acquired from planar laser induced fluorescence (PLIF) measurements. Varying mesh configurations are investigated for the impact on in-cylinder mixture distribution. A particular emphasis is placed on the effect of nozzle geometry and mesh orientation near the wall. Overall, the computational model is found to predict the mixture distribution in the combustion cylinder reasonably well. The results showed that the alignment of mesh with the flow direction is important to achieve good agreement between numerical analysis and optical measurement data.     

Investigation the effect of FeNiCoCrMo HEA addition on properties of B4C ceramic prepared by spark plasma sintering

In this study, monolithic B₄C and B₄C-based ceramics incorporating FeNiCoCrMo dual-phase (FCC and BCC) high entropy alloys (HEAs) were produced by spark plasma sintering (SPS). The effect of additives on the densification behavior, mechanical properties, microstructures, and phase evaluation of the samples were investigated. X-ray analysis confirmed the existence of FCC structured HEA and depletion of BCC structured HEA, after high-temperature reaction between B₄C-HEAs. The addition of HEAs enhanced the densification behavior by liquid phase sintering. Furthermore, hardness and fracture toughness values of the samples increased with increasing HEAs content. Fracture toughness and hardness values for all composites were higher than the monolithic B₄C. A combination of the highest density (∼99.22 %) and the best mechanical properties (32.3 GPa hardness and 4.53 MPa m^1/2 fracture toughness) was achieved with 2.00 vol.% HEA addition.     

Engineering Silver-Enriched Copper Core-Shell Electrocatalysts to Enhance the Production of Ethylene and C2+ Chemicals from Carbon Dioxide at Low Cell Potentials

Copper catalysts are widely studied for the electroreduction of carbon dioxide (CO₂) to value-added hydrocarbon products. Controlling the surface composition of copper nanomaterials may provide the electronic and structural properties necessary for carbon-carbon coupling, thus increasing the Faradaic efficiency (FE) towards ethylene and other multi-carbon (C₂₊) products. Synthesis and catalytic study of silver-coated copper nanoparticles (Cu@Ag NPs) for the reduction of CO₂ are presented. Bimetallic CuAg NPs are typically difficult to produce due to the bulk immiscibility between these two metals. Slow injection of the silver precursor, concentrations of organic capping agents, and gas environment proved critical to control the size and metal distribution of the Cu@Ag NPs. The optimized Cu@Ag electrocatalyst exhibited a very low onset cell potential of −2.25 V for ethylene formation, reaching a FE towards C₂₊ products (FE_C2+) of 43% at −2.50 V, which is 1.0 V lower than a reference Cu catalyst to reach a similar FE_C2+. The high ethylene formation at low potentials is attributed to enhanced C C coupling on the Ag enriched shell of the Cu@Ag electrocatalysts. This study offers a new catalyst design towards increasing the efficiency for the electroreduction of CO₂ to value-added chemicals.     

Characterization of Dog Glutathione Transferase P1-1, an Enzyme Relevant to Veterinary Medicine

Glutathione transferases (GSTs) form a family of detoxication enzymes instrumental in the inactivation and elimination of electrophilic mutagenic and carcinogenic compounds. The Pi class GST P1-1 is present in most tissues and is commonly overexpressed in neoplastic cells. GST P1-1 in the dog, Canis lupus familiaris, has merits as a marker for tumors and as a target for enzyme-activated prodrugs. We produced the canine enzyme CluGST P1-1 by heterologous bacterial expression and verified its cross-reactivity with antihuman-GST P1-1 antibodies. The catalytic activity with alternative substrates of biological significance was determined, and the most active substrate found was benzyl isothiocyanate. Among established GST inhibitors, Cibacron Blue showed positive cooperativity with an IC₅₀ value of 43 nM. Dog GST P1-1 catalyzes activation of the prodrug Telcyta, but the activity is significantly lower than that of the human homolog.     

Influence of precursor materials on the fresh state and thermo-chemo-mechanical properties of sodium-based geopolymers

Aluminosilicates are the base precursors that combined with alkali solutions manufacture geopolymers. A wide variability of aluminosilicate precursors can be found in the market worldwide, which may be an issue when proposing single designs. The goal of this study is to compare the use of different precursors in the hardening mechanisms of geopolymers. For this, two types of metakaolin (a low (MK_LR) and a high-reactive (MK_HR) one), and partial replacements made with fly-ash (FA) and blast furnace slag (BFS) are used in SiO₂/Al₂O₃ = 4.00, Na₂O/SiO₂ = 0.25, and H₂O/Na₂O = 11.00 fixed design ratios. Fresh state (viscosity and squeeze flow), transient state (Vicat needle and sonic strength), and hardening measurements (compression tests under room and high temperature conditions), were used, supported by chemical analysis (calorimetry and SAM/HCl extraction) and materials characterization (particle analysis, density, BET and XRD). In general, the reactivity, chemical composition, and morphology of each precursor, as well as solid/liquid portions of each mix were major factors influencing the hardening process. The use of MK_LR achieved shorter setting times and enhanced viscosities due to its particles larger surface area, solid/liquid ratios, and unreactive portions, reaching the highest values of strength and diminished thermomechanical performance. Partial substitutions made with FA and BFS increased the amorphous part of the binder, increasing also its flowability, setting time, and its stability to thermal exposure. The geopolymer made with MK_HR presented the lowest viscosity and longer setting time due to its almost constant dissolution rate, attributed to its enhanced reactivity from highly amorphous parts and diminished solid-to-liquid ratio mixture. Therefore, the use of varied aluminosilicates significantly modifies the materials properties, leading to different potential applications that should be considered when designing geopolymers.     

Community involvement critical for revitalization: Grass-roots initiative key to environmental remediation and restoration in the Great River (St. Lawrence River)

This paper describes the creation of an environmentally conscious community group, the Great River Network, and the role that it has played in the remediation and restoration process as part of one of the Great Lakes environmental programs. Community engagement was initiated in the region as part of the Remedial Action Plan for the Area of Concern at Cornwall/Akwesasne/Massena within the Upper St. Lawrence River. The community group formalised as a network representing 50+ organisations in response to perceived inadequacies in the agency of the community to respond to new environmental concerns outside of the scope of the existing programs. As a grass-roots initiative, the Great River Network has successfully completed remediation and restoration actions of significant value to the environment. These include a series of river clean ups (>42 tonnes of garbage removed), fish habitat restoration, and addressing shoreline erosion issues. Success has been achieved through partnering with a range of organisations, including Indigenous, non-profit, governmental, Conservation Authorities, businesses and industry partners. The action-oriented approach showcases how remediation and restoration led by, and embedded in, the community can result in true revitalization. A simplified framework for adaptive management practices for remediation and restoration efforts that lead to revitalization, including knowledge translation, is proposed. This case study highlights the transformational opportunities that remediation and restoration initiatives can bring. In this instance, the process is intensely local and cooperative and lays the foundation for moving towards a collective impact approach for the region.