CFD-Based Method of Determining Form Factor k for Different Ship Types and Different Drafts

The value of form factor k at different drafts is important in predicting full-scale total resistance and speed for different types of ships. In the ITTC community, most organizations predict form factor k using a low-speed model test. However, this method is problematic for ships with bulbous bows and transom. In this article, a Computational Fluid Dynamics(CFD)-based method is introduced to obtain k for different type of ships at different drafts, and a comparison is made between the CFD method and the model test. The results show that the CFD method produces reasonable k values. A grid generating method and turbulence model are briefly discussed in the context of obtaining a consistent k using CFD.

Electrochemical CO2 reduction over nitrogen-doped SnO2 crystal surfaces

Crystal planes of a catalyst play crucial role in determining the electrocatalytic performance for CO2 reduction.The catalyst SnO2 can convert CO2 molecules into valuable formic acid(HCOOH).Incorporating heteroatom N into SnO2 further improves its catalytic activity.To understand the mechanism and realize a highly efficient CO2-to-HCOOH conversion,we used density functional theory(DFT)to calculate the free energy of CO2 reduction reactions(CO2RR)on different crystal planes of N-doped SnO2(N-SnO2).The results indicate that N-SnO2 lowered the activation energy of intermediates leading to a better catalytic performance than pure SnO2.We also discovered that the N-Sn O2 (211)plane possesses the most suitable free energy during the reduction process,exhibiting the best catalytic ability for the CO2-to-HCOOH conversion.The intermediate of CO2RR on N-SnO2 is HCOO*or COOH* instead of OCHO*.These results may provide useful insights into the mechanism of CO2RR,and promote the development of heteroatomdoped catalyst for efficient CO2RR.

Dynamic active sites on plasma engraved Ni hydroxide for enhanced electro-catalytic urea oxidation

The urea oxidization reaction(UOR)is an important anodic reaction in electro-catalytic energy conversion.However,the sluggish reaction kinetics and complex catalyst transformation in electrocatalysis require activity improvement and better mechanistic understanding of the state-of-the-art Ni(OH)_(2) catalyst.Herein,by utilizing low-temperature argon(Ar)plasma processing,tooth-wheel Ni(OH)_(2) nanosheets self-supported on Ni foam(Ni(OH)_(2)-Ar)are demonstrated to have improved UOR activity compared to conventional Ni(OH)_(2).The theoretical assessment confirms that the edge has a smaller cation vacancy formation energy than the basal plane,consequently explaining the structural formation.Operando and quasi-operando methods are employed to investigate the dynamic evolution of the Ni(OH)_(2) film in UOR.The crucial dehydrogenation products of Ni(OH)_(5)O^(-)intermediates are identified to be stable on the etched edge and explain the enhanced UOR in the low potential region.In addition,the dynamic active sites are monitored to elucidate the reaction mechanism in different potential ranges.

Promoted CO2 electroreduction over indium-doped SnP3: A computational study

It is generally considered that the hydrogenation of CO2 is the critical bottleneck of the CO2 electroreduction.In this work,with the aid of density functional theory(DFT)calculations,the catalytic hydrogenation of CO2 molecules over Indium-doped SnP3 catalyst were systematically studied.Through doping with indium(In)atom,the energy barrier of CO2 protonation is reduced and OCHO*species could easily be generated.This is mainly due to the p orbital of In exhibits strong hybridization with the p orbital of O,indicating that there is a strong interaction between OCHO*and In-doped SnP3 catalyst.As a result,In-doped SnP3 possesses high-efficiency and high-selectivity for converting CO2 into HCOOH with a low limiting potential of-0.17 V.Our findings will offer theoretical guidance to CO2 electroreduction.

Establishment of a Rat Model of Liver Venous Deprivation:Simultaneous Portal and Hepatic Vein Ligation

Background and Aims:The aim was to establish a liver venous deprivation(LVD)model in rats,compare hepatic hypertrophy between LVD and associated liver partition and portal vein ligation for staged hepatectomy(ALPPS),and explore the underlying mechanisms.Methods:The LVD or extended-LVD(e-LVD)group received portal vein ligation(PVL)combined with hepatic vein ligation(HVL).The ALPPS or eALPPS group received PVL plus parenchyma ligation.Liver regeneration was assessed by measuring the liver weight and performing pathological analysis.Liver functions and the sphingosine kinase 1(SPHK1)/sphingosine-1-phosphate(S1P)/sphingosine-1-phosphate receptor 1(S1PR1)pathway were also investigated.Results:All future liver remnants(FLRs)in the ALPPS,e-ALPPS,LVD,and e-LVD groups exhibited significant hypertrophy compared with the control group.The LVD and e-LVD procedures induced similar liver hypertrophy than that in the corresponding ALPPS groups.Furthermore,the LVD and e-LVD methods led to obvious cytolysis in the venous-deprived lobes as well as a noticeable increase in serum transaminase levels,while no necrosis was observed in the ALPPS and e-ALPPS groups.SPHK1/S1P/S1PR1 pathway were distinctly activated after operation,especially in congestive/ischemic livers.Conclusions:We describe the first rat model of LVD and e-LVD with simultaneously associated HVL and PVL.Compared with the ALPPS technique,the LVD or e-LVD procedure had a comparable overall effect on the hypertrophy response and a stronger effect on liver function.The SPHK1/S1P/S1PR1 pathway was involved in the LVD-or ALPPS-induced liver remodeling.

Recent progress of thin-film photovoltaics for indoor application

Indoor photovoltaics have attracted increasing attentions owing to their great potential in supplying energy for low power devices under indoor light in our daily life.The third generation thin-film solar cells,including dye-sensitized solar cells,perovskite solar cells and organic solar cells,have made rapid progress from the aspect of materials design to photovoltaic performance.This review provides an overview on the recent advances in the development of indoor photovoltaic technologies based on the third generation solar cells.The design principles of advanced thin-film indoor photovoltaics were also summarized according to the characteristics of indoor light and the advantages of the third generation solar cells.Finally,after summarizing the current research progress,the perspective on this topic is provided.

An Organic–Inorganic Hybrid Material Based on Benzo[ghi]perylenetri-imide and Cyclic Titanium-Oxo Cluster for Efficient Perovskite and Organic Solar Cells

Perovskite and organic solar cells usually require electron-transport interlayers to efficiently transport electrons from the photoactive layer to the metal electrode.In general,pure organic or inorganic materials are applied into the interlayers,but organic–inorganic hybrid materials have been rarely reported for this application.In this work,we report using the first titanium-oxo cluster-based organic–inorganic hybrid as the interlayer material by introducing largeπ-conjugated benzo[ghi]perylenetriimides as an organic part via a simple ligand-exchange reaction.This new hybrid material showed excellent solubility,well-aligned energy levels,and excellent electron mobilities,enabling its great potential application as an interlayer in solar cells such as perovskite and organic solar cells,providing high power conversion efficiencies of>20%and 16%,respectively.Therefore,we claim that our present work introduces a new class of cluster-based organic–inorganic hybrid interlayer materials that exhibit promising application in organic electronics.

Comparisons of minimally invasive esophagectomy and open esophagectomy in lymph node metastasis/dissection for thoracic esophageal cancer

Background:The study aimed to clarify the characteristics of lymph node metastasis(LNM)and to compare the oncologic outcomes of minimally invasive esophagectomy(MIE)with open esophagectomy(OE)in terms of lymph node dissection(LND)in thoracic esophageal cancer patients.Methods:The data from esophageal cancer patients who underwent MIE or OE from January 2016 to January 2019 were retrospectively reviewed.The characteristics of LNM in thoracic esophageal cancer were discussed,and the differences in numbers of LND,LND rate,and LNM rate/degree of upper mediastinum between MIE and OE were compared.Results:For overall characteristics of LNM in 249 included patients,the highest rate of LNM was found in upper mediastinum,while LNM rate in middle and lower mediastinum,and abdomen increased with the tumor site moving down.The patients were divided into MIE(n=204)and OE groups(n=45).In terms of number of LND,there were significant differences in upper mediastinum between MIE and OE groups(8[5,11]vs.5[3,8],P<0.001).The comparative analysis of regional lymph node showed there was no significant difference except the subgroup of upper mediastinal 2L and 4L group(3[1,5]vs.0[0,2],P<0.001 and 0[0,2]vs.0,P=0.012,respectively).Meanwhile,there was no significant difference in terms of LND rate except 2L(89.7%[183/204]vs.71.1%[32/45],P=0.001)and 4L(41.2%[84/204]vs.22.2%[10/45],P=0.018)groups.For LNM rate of T3 stage,there was no significant difference between MIE and OE groups,and the comparative analysis of regional lymph node showed that there was no significant difference except 2L group(11.1%[5/45]vs.38.1%[8/21],P=0.025).The LNM degree of OE group was significantly higher than that of MIE group(27.2%[47/173]vs.7.6%[32/419],P<0.001),and the comparative analysis of regional LNM degree showed that there was no significant difference except 2L(34.7%[17/49]vs.7.7%[13/169],P<0.001)and 4L(23.8%[5/21]vs.3.9%[2/51],P=0.031)subgroups.Conclusion:MIE may have an advantage in LND of upper mediastinum 2L and 4L groups,while it was similar to OE in other stations of LND.