bluuebunny/crossref_metadata_2025 huggingface dataset:
Paraffin@poly(methyl methacrylate) Phase Change Microcapsules for Thermal Energy Storage and Temperature Regulation
Authors: Li Yujiao , Xu Lei , Jiang Zhuoni , Li Yongsheng , He Fangfang , Zhang Kai , He Ren , Chen Zhengguo , Yang Wenbin
Published: May 2023

A series of paraffin@poly(methyl methacrylate) phase‐change microcapsules (Pn@PMMA) were synthesized by suspension polymerization. The prepared Pn@PMMA had excellent latent heat storage and release properties (ΔHm=183.2 J/g, ΔHc=181.9 J/g), excellent thermal stability and cycle durability of at least 100 cycles. The effects of emulsifier type, cross‐linking agent content and core/shell mass ratio on structure and properties of Pn@PMMA were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT‐IR) and differential scanning calorimetry (DSC). The morphology of Pn@PMMA exhibited spherical profile with styrene‐maleic anhydride (SMA) as emulsifier and the agglomeration was significantly reduced. The enthalpy of the microcapsules was significantly improved with the addition of crosslinker. The anti‐permeability of Pn@PMMA subsequently further improved with continued increasing amount of cross‐linker. Besides, the enthalpy and anti‐leaking property of the microcapsules progressively reduced with the core/shell mass ratio decreased, while the thermal conductivity gradually increased. Therefore, the results showed that the Pn@PMMA with the enthalpy of 183.2 J/g and the leakage rate of 4.72 %, which displayed a high thermal reliability potential for thermal energy storage and temperature regulation.
Enhanced Sensing Performance of an Ammonia Gas Sensor Based on Ag‐Decorated ZnO Nanorods / Polyaniline Nanocomposite
Authors: Karmakar Narayan , Jain Shilpa , Fernandes Rohan , Shah Akshara , Patil Uday , Shimpi Navinchandra , Kothari Dushyant
Published: May 2023

The development of low‐cost ammonia sensors with high sensitivity and selectivity has gained considerable interest. Though the response of these sensors at room temperature is low and needs enhancement. In the present study high sensitivity ammonia gas sensors based on nanocomposite films of polyaniline (PANI) and with varying ZnO concentrations were synthesized and investigated. With a loading of 10 at% ZnO, the gas sensing response of 59 % was obtained for 120 ppm NH3 gas. The gas response was further enhanced by decorating the ZnO nanorods with different concentrations of silver (Ag) nanoparticles. The Ag‐decorated ZnO nanorods were embedded in the PANi matrix using the in‐situ oxidative polymerization technique. It was shown that PANi ZnO, p‐n junction, and the introduction of porosity in nanocomposite act synergistically in increasing the resistance caused by the deprotonation of PANi by NH3. Among various compositions studied, 2 % loading of Ag in ZnO embedded in PANi matrix, thin films were found to be highly selective and sensitive towards NH3 gas at room temperature with a chemiresistive response of 70 % at 120 ppm and a recovery time of less than 120 s. The selectivity of the nanocomposite was also studied towards various reducing and oxidizing gasses.
Peroxidase Mimic Sulfur‐Rich CuO‐Carbon Nitride Core‐Shell Nanorods for the Colorimetric Detection of Aminophenol Isomers
Authors: Sreeramareddygari Muralikrishna , Phanthong Chatuporn , Krishnappa Manjunath , Somasundrum Mithran , Surareungchai Werasak
Published: May 2023

A solid‐state method was used to derive a sulfur rich CuO‐carbon nitride core‐shell nano‐composite from a Cu‐organic hybrid. The synthesized material was characterized by XRD, morphology by SEM and TEM. Elemental analysis was investigated using EDS. The novel sulfur rich CuO‐carbon nitride core‐shell composite demonstrated as peroxidase activity for the oxidation of aminophenol isomers in the presence of H2O2. The oxidized products of o‐aminophenol (o‐AP) and p‐aminophenol (p‐AP) in phosphate buffer (PB, pH 7) showed strong absorption peaks at 435 and 475 nm, respectively in the UV‐Visible spectra. Whereas no oxidation reaction was observed for m‐aminophenol. Kinetic analysis of sulfur rich CuO‐graphitic carbon nitride revealed that the catalyst functioned by a ping‐pong mechanism for the oxidation of both o‐AP & p‐AP by hydrogen peroxide (H2O2). Based on KM values, substrate affinities were in the order o‐AP>H2O2>p‐AP. We further used this material for selective colorimetric detection of o‐AP and p‐AP in PB pH 7. The linear ranges obtained for o‐AP and p‐AP were 1–200 μM (LOD=1.5 μM, r2=0.99) and 10–500 μM (LOD=2.27 μM, r2=0.99), respectively. The developed analytical platform was used to detect these isomers in river water and p‐AP in artificial urine.
BF3 ⋅ CH3CN Promotes a Formation of Aryl α‐O‐Glycosides from Pyranoses: A Facile Approach to Oligosaccharide EPS‐G7
Authors: Zhong Xiuwen , Ying Danzhi , Huang Youchun , Zhang Lei , Wang Haiyang , Zhu Qi , Chen En , Yu Yongping , Chen Wenteng
Published: May 2023

A BF3 ⋅ CH3CN‐promoted synthesis of aryl α‐O‐glycosides from readily available glycosyl donors was developed. This reaction could proceed well on a gram‐scale under mild condition with α/β ratio up to 95 : 5. Moreover, a variety of the glycosyl donors including acetylated/benzoylated pyranoses, di‐ and trisaccharide derivatives as well as glycosyl acceptors from substituted phenols, sterically hindered aliphatic alcohols and carboxylic acid, were well tolerant. Importantly, the potential of this strategy was highlighted with a successful gram‐scale synthesis of oligosaccharide EPS‐G7, which is a commercial detection reagent for quantitative determination of α‐amylase.
Separation of Lithium and Transition Metals in Leaching Solution of Used Lithium Ion Battery with Sec‐octylphenoxyacetic Acid
Authors: Mo Ditang , Yu Guisu , Zeng Zhiyuan , Ni Shuainan , Zhang Sijia , Sun Xiaoqi
Published: May 2023

The recovery of critical metals from spent lithium‐ion batteries (LIBs) is important to sustainable development and environment protection. In this paper, sec‐octylphenoxyacetic acid (CA‐12) was first used to recover valuable metals in LIBs. The effects of phase modifier, initial feed pH, extraction kinetics and thermodynamics, CA‐12 concentration and saponification degree were studied and optimized. Under the optimal conditions, 99 % of nickel, cobalt and manganese were co‐extracted to the organic phase, and the loss of lithium was 7 %. The extracted metal ions could be stripped with 0.04 mol/L HCl equivalently. In the spent LIBs powder leaching experiment, leaching efficiencies of all components were greater than 95 %. In the impurity removal stage, extractant N902 was used to remove copper, while iron and aluminum were eliminated by hydrolysis. After two‐stage extraction, the total extraction efficiencies of nickel, cobalt and manganese reached 99.7 %, 99.4 %, 98.45 %, respectively. Finally, lithium in the raffinate was precipitated by saturated Na2CO3, the purity of recovered Li2CO3 was up to 97.7 %. After 5 times cycles, CA‐12 still maintained excellent extraction capacity, showing its potential application prospects for recovering critical metals form spent LIBs.
A Stable Green Amino Acid Hydrogel
Authors: Ma Mingfang , Qiu Shi , Qiao Ye , Xu Zhiyang , Du Xiaoan , Ding Derui , Yuan Yi , Xing Pengyao , Shang Wenqing
Published: May 2023

Natural amino acids are the most important building blocks in supramolecular chemistry which possess the best biocompatibility in nature. To the best of our knowledge, although hydrogels based on amino acid derivatives have already been studied widely, there is still no report about natural amino acids hydrogels constructed by metal ions induction method. Herein, the self‐assembly behaviors of twelve natural amino acids with eight metal ions were studied systematically. It is surprising that only sodium L‐Phenylalanine can self‐assemble into hydrogel with ZnCl2. Various methods were used to investigate the formation mechanism of hydrogel. The formation of hydrogel is triggered mainly via π‐π stacking and metal‐ligand interactions. Moreover, this green L‐Phenylalanine hydrogel displays acid responsiveness and relatively stability under high temperature, which has great potential applications in many fields.
Single therapeutic dose of an antiviral UL29 siRNA swarm diminishes symptoms and viral load of mice infected intranasally with HSV‐1
Authors: Lasanen Tuomas , Frejborg Fanny , Lund Liisa M. , Nyman Marie C. , Orpana Julius , Habib Huda , Alaollitervo Salla , Levanova Alesia A. , Poranen Minna M. , Hukkanen Veijo , Kalke Kiira
Published: May 2023

Herpes simplex virus type 1 (HSV‐1) is a human pathogen that causes recurrent infections. Acyclovir‐resistant strains exist and can cause severe complications, which are potentially untreatable with current therapies. We have developed siRNA swarms that target a 653 base pair long region of the essential HSV gene UL29. As per our previous results, the anti‐UL29 siRNA swarm effectively inhibits the replication of circulating HSV strains and acyclovir‐resistant HSV strains in vitro, while displaying a good safety profile. We investigated a single intranasal therapeutic dose of a siRNA swarm in mice, which were first inoculated intranasally with HSV‐1 and given treatment 4 h later. We utilized a luciferase‐expressing HSV‐1 strain, which enabled daily follow‐up of infection with in vivo imaging. Our results show that a single dose of a UL29‐targeted siRNA swarm can inhibit the replication of HSV‐1 in orofacial tissue, which was reflected in ex vivo HSV titers and HSV DNA copy numbers as well as by a decrease in a luciferase‐derived signal. Furthermore, the treatment had a tendency to protect mice from severe clinical symptoms and delay the onset of the symptoms. These results support the development of antiviral siRNA swarms as a novel treatment for HSV‐1 infections.
Enhanced Photovoltaic Property and Panchromatic Photocatalytic by Forming D‐π‐A‐Bacteriochlorin Dyads: A Computational Investigation
Authors: Yang Canpu , Song Peng , Ma Fengcai , Li Yuanzuo
Published: May 2023

The photovoltaic characteristics and panchromatic photocatalysis based on monomers and bithiophene‐chlorophyll dyads is investigated. The optical properties and the electron transport capacity of the titled dyes are explicated by investigating the geometry, electronic structure, electron injection, and recombination, intramolecular charge transfer, regeneration process, dye aggregation, and light‐harvesting. The results manifest that the original 3,3′‐dithioalkyl‐2,2′‐bithiophene (SBT)‐based molecule behaves better with photovoltaic performance and an enhanced JSC and VOC. For molecular design, the designed dyads not only show the enhanced absorption range and prolonged excited lifetimes but also noticeable electron transfer ability. Moreover, the strong interfacial interaction, fast electron transfer process, long recombination distance, inhibition in dye aggregate, enhanced regenerative interaction energy are elucidated, which is beneficial for a better photocurrent response. However, the slight shift of the conduction band edge in dyads significantly reduces the VOC, especially for SBT‐Chl. Among dyads, SBT‐BChl exhibits outstanding photovoltaic performance of 14%. Besides, photocatalysis analysis manifests that the dyad composites behave with red‐shifted spectra, enhanced dipole moments, better interfacial interaction to ensure electron transfer, which significantly improved the photocatalytic performance of TiO2. Our study is expected to offer theoretical guidelines for further screening the promising D‐π‐A‐bacteriochlorin dyads in photoelectric functional materials.
Improve Perovskite Solar Cell Stability and Efficiency via Multifunctional Multiple‐Ring Aromatic Dopant Passivation
Authors: Ren Mudan , Chen Chunyang , Tang Yizhe , Yang Husheng , Wang Hao , Huang Jin , Zhang Dan
Published: May 2023

Organic–inorganic perovskite solar cells, as a representative of the new generation of solar cells, have made satisfactory advancements in development over the past few years. However, the low carrier transport characteristics and energy loss brought on by defects severely restrict its development. This study develops a new liquid crystal material 1‐naphthalene acetic acid potassium salt (C12H9KO2, K‐NAA) as a dopant into the MA0.6FA0.4PbI3−xClx material. The presence of free K+ ions in K‐NAA modifies the perovskite lattice gap, and the CO structure can efficiently passivate the Pb2+ defect caused by the absence of coordination. Therefore, the grain boundaries, which serve as points of moisture penetration become blurred, hence suppressing charge trapping/recombination centers and enhancing the film quality and stability. The naphthalene in K‐NAA has a conjugated multiple‐ring aromatic structure. The abundant π‐electron delocalization present in the conjugated structure of the benzene ring may provide an electron‐rich environment outside the connected crystal structure, resulting in field‐effect passivation and effectively enhancing carrier transport performance. Hence, the devices deliver a champion power conversion efficiency (PCE) of 19.86%. After 700 h under the dark at 25 °C and 30% humidity, the optimized unencapsulated device PCE maintains at 92% of its initial efficiency.
Conformation Flipping of Asymmetric Nonfullerene Acceptors Enabling High‐Performance Organic Solar Cells with 77% Fill Factors
Authors: Zhu Jintao , Zhang Zhuohan , Lan Ai , Zhou Jialing , Lv Yifan , Lu Hong , Zhou Erjun , Do Hainam , Chen Zhi-Kuan , Chen Fei
Published: May 2023

Considerable progress on high‐performance organic solar cells (OSCs) has been achieved in the past due to the rapid development of nonfullerene acceptors (NFAs). Typically, two kinds of methods have been employed to manipulate energy levels and aggregation of NFAs, i.e., molecular engineering on alkyl side chains and modification of the heterocyclic rings in the backbone. Herein, a novel asymmetric thiophene[3,2‐b] pyrrole (TP)‐based NFA with flipped molecular conformation, named as PTBTT‐4F, is designed and synthesized. The introduction of the pyrrole ring in the novel NFA would not only afford extra reaction sites for side chain modification, but also induce substantial intramolecular charge transfer, thus leading to elevated energy levels of the NFA and thereby lower energy loss of the OSCs. When pairing with polymer donor PBDB‐TF to fabricate OSCs, concurrent improvement in open‐circuit voltage, short‐circuit current (JSC), and fill factor (FF) is realized, which delivers an outstanding power conversion efficiency (PCE) of 14.49%. Benefitting from effective molecular stacking and optimized phase separation induced by molecular conformation variation, asymmetric PTBTT‐4F fabricated OSCs exhibit much higher JSCs and FFs than the symmetrical PTBTP‐4F devices.
Plasmonics: A Versatile Toolbox for Heterogeneous Photocatalysis
Authors: Brissaud Charlène , Besteiro Lucas V. , Piquemal Jean-Yves , Comesaña-Hermo Miguel
Published: May 2023

Plasmonic photocatalysis is a dynamic field of research devoted to the activation of chemical transformations thanks to the unique optoelectronic features of plasmonic nanomaterials such as their high electromagnetic field enhancements or their ability to generate nonthermalized charge carriers and localized temperature gradients. Importantly, the use of these objects as photocatalysts can lead to new reactivities when compared with classical heterogeneous photocatalysts, including an unprecedented control over efficiency and chemical selectivity within a broader range of the solar spectrum. In the present study, the most important aspects that need to be taken into consideration when designing a plasmonic photocatalytic system are summarized. Representative examples from the literature toward the rational design of the plasmonic photocatalyst are provided, together with a comprehensive list of organic and inorganic transformations that have been successfully modulated by plasmons. The importance of single nanoparticle measurements as a new means to characterize these systems is also discussed, allowing a better insight into single object heterogeneities or structure–function relationships that are usually lost in ensemble characterization techniques. Finally, the major role played by reaction intermediates when performing photoredox processes in solution is highlighted, particularly important when driving photochemical reactions in biological environments.
Sputtered PbI2 with Post‐Processing for Perovskite Solar Cells
Authors: Hwang Jae-Keun , Lee Sang-Won , Lee Wonkyu , Bae Soohyun , Kang Dongkyun , Jeong Seok-Hyun , Lee Solhee , Pyun Dowon , Hwang Ji-Seong , Cho Sujin , Kim Donghwan , Kang Yoonmook , Lee Hae-Seok
Published: May 2023

Conformal deposition of perovskite films on textured silicon surfaces using a dry process is crucial for producing high‐performance perovskite/silicon tandem solar cells. Herein, a radio frequency magnetron sputtering process is used with a PbI2 target to deposit precursor films. Iodination, thermal annealing, and dimethyl sulfoxide treatment are employed as posttreatment processes to improve the stoichiometry, crystallinity, and surface morphology of the PbI2 precursor. The precursor films are converted into perovskite using direct contact conversion process, and the interfacial and bulk properties are enhanced by methylamine vapor annealing to fabricate perovskite solar cells with a power conversion efficiency of 12.2%. Also, 18.3% efficiency is confirmed at a wider voltage sweep range, which suggests that further efficiency improvement is possible by removing defects inside the perovskite. Finally, uniform perovskite films are conformally deposited on a 25 cm2 textured silicon surface. With such high‐efficiency potential and conformality, the method of sputtering PbI2 can open a new way to fabricate perovskite/silicon tandem solar cells.
Simultaneously Achieved Defect Passivation and Crystallization Modulation by a Multifunctional Pseudohalogen Salt for Efficient and Stable Perovskite Solar Cells
Authors: He Dongmei , Yang Yinrun , Yu Hua , Wei Tingting , Zhang Hong , Chen Jiangzhao
Published: May 2023

The accumulation of defects and ion migration at the surfaces and grain boundaries of perovskite impedes the improvement of performance and stability in perovskite solar cells. Therefore, developing strategies to reduce trap‐assisted nonradiative recombination and suppress ion migration in perovskite films is urgently needed. Herein, a multifunctional pseudohalogen salt additive, (benzotriazol‐1‐yloxy) dipyrrolidinocarbenium hexafluorophosphate (denoted as BDPF6), composed of a benzotriazole derivative cation and hexafluorophosphate anion, is incorporated into the perovskite precursor solution. The anion vacancies of perovskite films are filled by , whereas the cation and anion in BDPF6 form ionic and coordination bonds with the perovskites. The BDPF6 additive promotes the crystallization of perovskite films with large grain size, reducing defect densities, prolonging carrier lifetimes, and inhibiting ion migration. Thus, the power conversion efficiency (PCE) of the BDPF6‐modified device remarkably improves from 20.36% to 22.68%. The unencapsulated BDPF6‐modified device maintains 97% of its initial PCE after 1,400 h of exposure to an ambient environment with a relative humidity of 10–20%, whereas the control device maintains only 85% of its initial PCE. Similarly, the BDPF6‐modified device maintains 78% of its original PCE after aging at 60 °C for 1,400 h, whereas the control device only maintains 55%.
Self‐Assembled Monolayer Ti3C2TxMXene as Electron Selective Heterocontact for Crystalline Silicon Solar Cells
Authors: Ding Yang , Huang Zhiping , Di Chong , Wang Huipeng , Xin Yu , Sun Biao , Chen Jingwei , Xu Ying , Wei Deyuan , Fu Guangsheng
Published: May 2023

Carrier‐selective contact is an essential strategy to improve the power conversion efficiency (PCE) of crystalline silicon (c‐Si) solar cells by enhancing carrier transport and reducing recombination. Many two‐dimensional transition metal carbides/nitrides (MXene) possess excellent electrical conductivity and tunable work function, enabling them as potential carrier‐selective contact materials for c‐Si solar cells. Herein, low work function (3.71 eV) monolayer Ti3C2Txthin films are fabricated with an ordered arrangement of nanosheets by interfacial self‐assembly method, and the Ti3C2Tx/n‐type c‐Si heterostructure achieves extremely low contact resistivity (22.64 mΩ cm2). Dopant‐free heterojunction crystalline silicon solar cell with self‐assembled monolayer Ti3C2Txelectron‐selective contact is reported for the first time, showing the highest PCE of 16.46% among MXene monolayer‐based c‐Si solar cells, which is mainly attributed to the greatly increased fill factor and open circuit voltage by the accession of self‐assembled monolayer Ti3C2Txas electron transport layer. This work opens up the possibility of applying MXene as electron transport material for photovoltaic devices.
Spectroscopic and Chemical Properties of Ionic Liquids: Computational Study
Authors: Kim Hyung J.
Published: May 2023

A brief account is given of highlights of our computational efforts – often in collaboration with experimental groups – to understand spectroscopic and chemical properties of ionic liquids (ILs). Molecular dynamics, including their inhomogeneous character, responsible for key spectral features observed in dielectric absorption, infra‐red (IR) and fluorescence correlation spectroscopy (FCS) measurements are elucidated. Mechanisms of chemical processes involving imidazolium‐based ILs are illustrated for CO2 capture and related reactions, transesterification of cellulose, and Au nanocluster‐catalyzed Suzuki cross‐coupling reaction with attention paid to differing roles of IL ions. A comparison with experiments is also made.
Visualizable intracardiac flow pattern in fetuses with congenital heart defect: pilot study of blood speckle‐tracking echocardiography
Authors: Xu R. , Hou M. , Zhou D. , Liu Y. , Xie L. , Zeng S.
Published: May 2023

Objectives

Blood‐flow pattern is an essential factor in cardiovascular development. Recently, blood speckle‐tracking echocardiography (BST) based on high‐frame‐rate ultrasound has emerged as a promising technique for the assessment of blood‐flow patterns and properties. The objectives of this study were to determine the feasibility of BST in the fetus and to assess intracardiac blood‐flow patterns of fetuses with a congenital heart defect (CHD) using this technique.

Methods

This was a prospective study consisting of 35 normal fetuses, 35 fetuses with left‐sided obstructive lesion (LSOL) and 35 fetuses with right‐sided obstructive lesion (RSOL). BST images of fetal intracardiac regions of interest (ROIs), including the left ventricle (LV), right ventricle (RV), ascending aorta (AAo), aortic arch (AA), descending aorta (DAo) and pulmonary artery (PA), were obtained and analyzed. The feasibility of BST was assessed, and blood‐flow pattern and number of vortices in the ROIs were recorded.

Results

The median gestational age of the fetuses was 24.7 weeks (range, 19.6–34.3 weeks). BST was feasible in 81.6% of cases, and the cut‐off value of depth for an adequate BST image was ≤ 7.9 cm. There were no differences in the presence of vortex/turbulent blood flow in the LV or RV among the three groups. Vortex/turbulent blood flow in the AAo was detected in 0% (0/35), 14.3% (5/35) and 57.1% (20/35) of cases in the control, LSOL and RSOL groups, respectively. The respective values were 5.7% (2/35), 14.3% (5/35) and 51.4% (18/35) for the AA; 0% (0/35), 48.6% (17/35) and 0% (0/35) for the DAo; and 0% (0/35), 40.0% (14/35) and 51.4% (18/35) for the PA. With the exception of the DAo in the RSOL group, vortex/turbulent flow in the great artery ROIs was significantly more common in the LSOL and RSOL groups than in controls (P < 0.01). In the LSOL group, the number of vortices in the AAo, AA, DAo and PA was significantly greater compared with that in controls (P < 0.01). In the RSOL group, the number of vortices in the LV, AAo, AA and PA was significantly greater compared with that in controls (P < 0.01).

Conclusions

Fetuses with CHD were more likely to exhibit vortex/turbulent blood flow and increased number of vortices in the great arteries compared with healthy controls. Further research is needed to determine the biomechanical effect of blood‐flow patterns, especially vortex flow, on fetal cardiovascular structure and function. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.
On calibrated inverse probability weighting and generalized boosting propensity score models for mean estimation with incomplete survey data
Authors: Kang Joseph , Morris Darcy Steeg , Joyce Patrick , Dompreh Isaac
Published: May 2023

Incomplete data, whether realized from nonresponse in survey data or counterfactual outcomes in observational studies, may lead to biased estimation of study variables. Nonresponse and selection bias may be mitigated with techniques that weight the incomplete data to match characteristics of the partially unobserved complete data. Inverse probability weighting is a widely used method in causal inference that relies on a propensity model to construct adjusted weights; whereas calibration is a common method used by survey statisticians to use constrained optimization to construct adjusted weights. This article reviews inverse probability weighting and entropy balancing calibration by distinguishing them in the statistical sense of variable balancing, extending propensity score construction to include generalized boosting models, and demonstrating the use of inverse probability weighting and calibration separately and together through a widely cited simulation study evaluation.

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Sampling

Data: Types and Structure > Categorical Data

Statistical Learning and Exploratory Methods of the Data Sciences > Modeling Methods
A comparative meta‐analysis of gains in efficiency in Pb‐ and Sn‐based perovskite solar cells over the last decade
Authors: Huang Chengou , Gajewiak Emil , Wright Aidan , Rodriguez‐Kazeem William , Heift Dominikus , Bear Joseph C.
Published: May 2023

Perovskite solar cells have seen rapid development over the last decade due to their potential to surpass current market‐leading solar cell technologies. Power conversion efficiency values of perovskite solar cells have reached more than 25 %, making them comparable to their market‐leading silicon‐based counterparts with comparatively few years of development. Whilst large‐scale trials are ongoing, the long‐term stability of perovskite materials remains a significant challenge in their deployment. The first successful perovskite‐based solar cells were lead‐based (Pb‐based). Environmental concerns surrounding Pb‐based perovskites are a significant impediment to their application in industry leading to a substantial increase in research into alternatives that are more environmentally sound.

The meta‐analysis study presented in this paper intends to harvest efficiency and synthetic method data from the literature to chart the progress of efficiency over the last decade of BOTH Pb‐ and Sn‐based perovskite solar cells. We then use these data to test the hypothesis: “Did the advancements in the development of earlier Pb‐based perovskite solar cells mean the efficiency of Sn‐based alternatives developed at a faster rate?”

The meta‐analysis found that materials engineering, i. e., identifying the suitable materials for perovskite, electron and transport layers and the solution and fabrication process contributed significantly to the rapid annual efficiency growth rates in Pb‐based perovskite solar cells (more than 25 %) from 2011 to 2014. More steady annual efficiency growth rates (2 to 7 %) from 2014 to 2021 are attributed to more advanced compositional engineering, such as optimizing bandgap and addressing stability problems, solution and additive engineering with regard thermal annealing, ageing, doping, improving crystallinity and passivating defects. Ultimately, this report states the challenges Sn‐based perovskite materials face and improvements that will have to be made to become successful on a commercial scale. One of our key findings is the increase in efficiency from 5 % in 2014 to 13 % in 2020 of Sn‐based perovskites making them one of the main contenders to replace Pb‐based perovskites. However, significant challenges remain, including reducing their instability and increasing their efficiencies beyond 20 % to make them competitive against their Pb‐based counterparts.
Nutrients and Eutrophication
Authors: Devlin Michelle , Brodie Jon
Published: May 2023

Excess nutrientsfrom fertiliser application, pollution discharge and water regulations outflow through rivers from lands to oceans, seriously impact coastal ecosystems. Terrestrial runoff of waters polluted with nutrients (primarilynitrogen[N] andphosphorus[P] compounds) from point source/s, such as sewage treatment plant (STP) discharges, and diffuse sourcesvia river discharges, such as fertiliser losses, are having devastating adverse effects in coastal and marine ecosystems globally (Carpenter et al., Ecol Appl 8:559–568, 1998; Halpern et al., Science 319:948–952, 2008; Crain et al., Ecol Lett 11:1304–1315, 2008; Smith and Schindler, Trends Ecol Evol 24:201–207, 2009). The nutrients can be dissolved such as dissolved nitrate and Phosphate typically discharged from STPs or agricultural runoff or in a particulate form, often associated with soil erosion.
Metals and Metalloids
Authors: Reichelt-Brushett Amanda , Batley Graeme
Published: May 2023

This chapter introduces you tometalsandmetalloidsthat are a concern to the health of marine ecosystems. It provides a general chemical understanding of important metals and metalloids, their sources, behaviour, impacts and management. Metals, metalloids and non-metals all make up the periodic table (Appendix II) and are classified into these categories according to their properties. Metals are good conductors of heat and electricity and are malleable and ductile, making them very useful to humans and therefore economically valuable. Metalloids sit on the periodic table in a jagged line at the division between metals and non-metals and have intermediate properties.
Overview of Concrete Deterioration Due to Sulphate Attack and Comparison of Its Requirements in International Codes
Authors: Al-Haddad Diala Basim , Jokhio Gul Ahmed , Tair Abid Abu
Published: May 2023

Any material or geometric property change that has an impact on structural performance is known as structural deterioration. Although this phenomenon is gradual, if it is not evaluated and fixed in a timely manner, it will have a severe impact on the structure and, in some historical occasions, may result in collapse. Deterioration has a variety of causes and mechanisms. Some are regarded as external, such as the environment, which is critical in areas with tough climate conditions, as the Arab Gulf, where temperatures and humidity are high, another factor is the low quality of the materials and poor craftsmanship. Depending on the type of materials used in the structure and the environment in which it is created, several precaution approaches for structural degradation may be adapted.

Sulphate attack is one of the most widespread deteriorating mechanisms; this type of chemical damage can result in cracks, spalling, and disintegration of the structure, diminishing its strength. This paper presents a thorough investigation of this degrading agent, including its causes, effects, international code provisions, as well as recent studies on the subject with a focus on the Arab Gulf Countries.

The outcomes of this study demonstrated that this phenomenon, with its various mechanisms, has a negative impact on structures. Despite the distribution of sulphates in the Gulf, the existence of chloride and the precautionary measures taken successfully limited their impact on structures.
Scale setting and the light baryon spectrum in Nf = 2 + 1 QCD with Wilson fermions
Authors:   The RQCD collaboration, Bali Gunnar S. , Collins Sara , Georg Peter , Jenkins Daniel , Korcyl Piotr , Schäfer Andreas , Scholz Enno E. , Simeth Jakob , Söldner Wolfgang , Weishäupl Simon
Published: May 2023

Abstract

We determine the light baryon spectrum on ensembles generated by the Coordinated Lattice Simulations (CLS) effort, employingNf= 2 + 1 flavours of non-perturbatively improved Wilson fermions. The hadron masses are interpolated and extrapolated within the quark mass plane, utilizing three distinct trajectories, two of which intersect close to the physical quark mass point and the third one approaching the SU(3) chiral limit. The results are extrapolated to the continuum limit, utilizing six different lattice spacings ranging froma≈ 0.10 fm down to below 0.04 fm. The light pion mass varies fromMπ≈ 429 MeV down to 127 MeV. In general, the spatial extent is kept larger than four times the inverse pion mass and larger than 2.3 fm, with additional small and large volume ensembles to investigate finite size effects. We determine the Wilson flow scales$$ \sqrt{t_{0,\textrm{ph}}}={0.1449}_{(9)}^{(7)}\textrm{fm} $$t0,ph=0.144997fm[1] and$$ {t}_0^{\ast}\approx {t}_{0,\textrm{ph}} $$t0∗≈t0,ph[2] from the octet cascade (Ξ baryon). Determining the light baryon spectrum in the continuum limit, we find the nucleon mass$$ {m}_N={941.7}_{(7.6)}^{(6.5)} $$mN=941.77.66.5MeV and the other stable baryon masses to agree with their experimental values within sub-percent level uncertainties. Moreover, we determine SU(3) and SU(2) chiral perturbation theory low energy constants, including the octet and the Ω baryon sigma termsσπN= 43.9(4.7) MeV,$$ {\sigma}_{\pi \Lambda}={28.2}_{(5.4)}^{(4.3)} $$σπΛ=28.25.44.3MeV,$$ {\sigma}_{\pi \Sigma}={25.9}_{(6.1)}^{(3.8)} $$σπΣ=25.96.13.8MeV,$$ {\sigma}_{\pi \Xi}={11.2}_{(6.4)}^{(4.5)} $$σπΞ=11.26.44.5and$$ {\sigma}_{\pi \Omega}={6.9}_{(4.3)}^{(5.3)} $$σπΩ=6.94.35.3MeV, as well as various parameters, renormalization factors and improvement coefficients that are relevant for simulations with our lattice action.
The Scale of Supersymmetry Breaking and the Dark Dimension
Authors: Anchordoqui Luis A. , Antoniadis Ignatios , Cribiori Niccolò , Lüst Dieter , Scalisi Marco
Published: May 2023

Abstract

We argue for a relation between the supersymmetry breaking scale and the measured value of the dark energy density Λ. We derive it by combining two quantum gravity consistency swampland constraints, which tie the dark energy density Λ and the gravitino mass M3/2, respectively, to the mass scale of a light Kaluza-Klein tower and, therefore, to the UV cut-off of the effective theory. Whereas the constraint on Λ has recently led to the Dark Dimension scenario, with a prediction of a single mesoscopic extra dimension of the micron size, we use the constraint on M3/2 to infer the implications of such a scenario for the scale of supersymmetry breaking. We find that a natural scale for supersymmetry signatures is$$ M=\mathcal{O}\left({\Lambda}^{\frac{1}{8}}\right)=\mathcal{O}\left(\textrm{TeV}\right). $$
M
=
O

Λ

1
8

=
O

TeV

.

This mass scale is within reach of LHC and of the next generation of hadron colliders. Finally, we discuss possible string theory and effective supergravity realizations of the Dark Dimension scenario with broken supersymmetry.
Freedom near lightcone and ANEC saturation
Authors: Huang Kuo-Wei , Karlsson Robin , Parnachev Andrei , Valach Samuel
Published: May 2023

Abstract

Averaged Null Energy Conditions (ANECs) hold in unitary quantum field theories. In conformal field theories, ANECs in states created by the application of the stress tensor to the vacuum lead to three constraints on the stress-tensor three-point couplings, depending on the choice of polarization. The same constraints follow from considering two-point functions of the stress tensor in a thermal state and focusing on the contribution of the stress tensor in the operator product expansion (OPE). One can observe this in holographic Gauss-Bonnet gravity, where ANEC saturation coincides with the appearance of superluminal signal propagation in thermal states. We show that, when this happens, the corresponding generalizations of ANECs for higher-spin multi-stress tensor operators with minimal twist are saturated as well and all contributions from such operators to the thermal two-point functions vanish in the lightcone limit. This leads to a special near-lightcone behavior of the thermal stress-tensor correlators — they take the vacuum form, independent of temperature.
Cyclic products of Szegö kernels and spin structure sums. Part I. Hyper-elliptic formulation
Authors: D’Hoker Eric , Hidding Martijn , Schlotterer Oliver
Published: May 2023

Abstract

The summation over spin structures, which is required to implement the GSO projection in the RNS formulation of superstring theories, often presents a significant impediment to the explicit evaluation of superstring amplitudes. In this paper we discover that, for Riemann surfaces of genus two and even spin structures, a collection of novel identities leads to a dramatic simplification of the spin structure sum. Explicit formulas for an arbitrary number of vertex points are obtained in two steps. First, we show that the spin structure dependence of a cyclic product of Szegö kernels (i.e. Dirac propagators for worldsheet fermions) may be reduced to the spin structure dependence of the four-point function. Of particular importance are certain trilinear relations that we shall define and prove. In a second step, the known expressions for the genus-two even spin structure measure are used to perform the remaining spin structure sums. The dependence of the spin summand on the vertex points is reduced to simple building blocks that can already be identified from the two-point function. The hyper-elliptic formulation of genus-two Riemann surfaces is used to derive these results, and its SL(2, ℂ) covariance is employed to organize the calculations and the structure of the final formulas. The translation of these results into the language of Riemann ϑ-functions, and applications to the evaluation of higher-point string amplitudes, are relegated to subsequent companion papers.
SYK Model with global symmetries in the double scaling limit
Authors: Narayan Prithvi , Swathi T S
Published: May 2023

Abstract

We discuss the double scaling limit of the SYK model with global symmetries. We develop the chord diagram techniques to compute the moments of the Hamiltonian and the two point function in the presence of arbitrary chemical potential. We also derive a transfer matrix acting on an auxiliary hilbert space which can capture the chord diagram contributions. We present explicit results for the case of classical group symmetries namely orthogonal, unitary and symplectic groups. We also find the partition functions at fixed charges.
Factors determining the distribution of Erica patches on the Sanetti Plateau, Bale Mountains, Ethiopia
Authors: Mekonnen Betelhem , Glaser Bruno , Zech Michael , Bromm Tobias , Nemmomisa Sileshi , Bekele Tamrat , Zech Wolfgang
Published: May 2023

In the Bale Mountains, the ericaceous belt ranges between 3200 and 3800 m asl. Studies indicate an expansion on the Sanetti Plateau at the end of the Late Glacial and during the early Holocene. Currently, only patches of Erica growing between boulders are found on the Plateau, while most of the landscape above 3800 m asl is covered by afro-alpine plants. Driving factors for Erica patches above the upper ericaceous ecotone is a matter of debate. This study evaluates site variables and biogeochemical properties of soils under Erica patches and nearby Erica-free control to understand the environmental conditions responsible for the patchy occurrence of Erica on the Sanetti Plateau. Except for the boulder richness, Erica and control plots have comparable topography, soil texture, and electrical conductivity. However, soils below Erica patches have higher total organic carbon, nitrogen, carbon-to-nitrogen ratios, and black carbon contents than the control plots indicating fresh organic matter input and availability of combustible fuel. This implies that Erica did not fully cover the control plots in former times. Carbon and nitrogen stocks were slightly higher in control plots due to the lower stone contents of the profiles. In addition, soils of the Erica plots showed more positive δ13C values than the control soils, possibly attributed to water stress. In general, the relief and soil conditions of control plots may support the growth of Erica. However, Erica growing between boulders seems to benefit from the favorable microclimate and physical protection against grazing and fire.
Holistic plug-n-play autonomous solar system integration: a real-life small-scale demonstration—a practical approach
Authors: Dimara Asimina , Sougles Christos , Athanasiou Sotirios , Grigoropoulos Konstantinos , Sfakianou Panagiota , Papaioannou Alexios , Krinidis Stelios , Triantafyllidis Dimitrios , Tzitzios Ioannis , Anagnostopoulos Christos-Nikolaos , Karamanidis Aristoklis , Saltagianni Vaia , Ioannidis Dimosthenis , Tzovaras Dimitrios
Published: May 2023

Autonomous PV systems offer a substitute for or a safety net against the transmission and distribution companies’ rising and expanding electricity delivery fees. Across the world, delivery fees have climbed by about 3% annually while the cost of energy supply has only gone up by 5% over the past 15 years. In this paper, the drawbacks of PV system integration are highlighted while introducing a unique autonomous PV system. The system is also constructed in a reproducible way so that it can be duplicated. Replicability is showcased by the presentation of two separate PV systems that were created and evaluated using the same methodology. One system uses Si-based conventional photovoltaics, while the other uses dye-sensitized solar cells. The systems that are being offered also support remote connections, allowing all of the data from the PV system to be transmitted to a single endpoint (e.g., a visualization platform). Moreover, the system’s batteries were modified to accommodate the two PV systems. Finally, experimental results showcase the operability of the proposed architecture.
Dual sourcing inventory management with nonconsecutive lead times from a supply chain perspective: a numerical study
Authors: Hamdouch Younes , Boulaksil Youssef , Ghoudi Kilani
Published: May 2023

We study a stochastic multi-period two-echelon dual sourcing inventory system where the buyer can source a product from two different suppliers: a regular and an expedited supplier. The regular supplier is a low-cost offshore supplier, whereas the expedited supplier is a responsive nearshore supplier. Such dual sourcing inventory systems have been well studied in the literature, mostly being solely evaluated from the buyer’s perspective. Since the buyer’s decisions have an impact on the supply chain profit, we adopt the perspective of the entire supply chain, i.e., by taking the suppliers explicitly into consideration. In addition, we study this system for general (nonconsecutive) lead times for which the optimal policy is unknown or very complex. We numerically compare the performance of two different policies in a two-echelon setting: the Dual-Index Policy (DIP) and the Tailored Base-Surge Policy (TBS). From earlier studies we know that when the lead time difference is one period, DIP is optimal from the buyer’s perspective, but not necessarily from the supply chain perspective. On the other hand, when the lead time difference grows to infinity, TBS becomes optimal for the buyer. In this paper, we evaluate the policies numerically (under various conditions) and we show that from a supply chain perspective, TBS typically outperforms DIP at a limited lead time difference of a few time periods. Based on data collected from 51 manufacturing firms, the results of our paper imply for many supply chains with a dual sourcing setting that TBS quickly becomes a beneficial policy alternative, especially given its simple and appealing structure.
Ruth Beutler: the woman behind Karl von Frisch
Authors: Zupanc Günther K. H.
Published: May 2023

The Journal of Comparative Physiology A was founded in 1924 as the Zeitschrift für vergleichende Physiologie by Karl von Frisch and Alfred Kühn. Given the marginalization of women in science at that time, it is remarkable that the first article in the Journal was authored by a female scientist, Ruth Beutler. Throughout her scientific career, she was affiliated with the Zoological Institute of the University of Munich, which, under the leadership of von Frisch, evolved into a world-class academic institution. Despite chronic health problems, Beutler was one of the first women who succeeded in obtaining the Habilitation as qualification for appointment to a professorial position. She was also one of the first scientists who applied methods from physiological chemistry to the study of zoological phenomena. Yet, for many years she was employed as a technician only, and she was never appointed to an Ordinarius (tenured full professorship) position. Her most important contributions to comparative physiology outside her own area of research were her support for, and protection of, Karl von Frisch, particularly during the Nazi era when he, as a ‘quarter-Jew,’ faced imminent threat of forced retirement; and after World War II, when her efforts as interim Ordinarius were instrumental in re-building the bombed-out Zoological Institute to persuade Karl von Frisch to return to Munich. It was also one of her observations that prompted him to revisit, and revise, his earlier (incorrect) model of how honeybees communicate, through their dances, the direction and distances of food sources from the hive.
Lagrangian particle-based simulation of waves: a comparison of SPH and PFEM approaches
Authors: Salis Nicolò , Franci Alessandro , Idelsohn Sergio , Reali Alessandro , Manenti Sauro
Published: May 2023

Lagrangian numerical methods are particularly suitable to reproduce flows involving large and rapid deformation of the domain, fluid splitting and coalescence, jets and sprays. The absence of the convective terms in the governing equations avoids numerical diffusion. This paper provides a comparative study between two Lagrangian particle models based on the Smoothed Particle Hydrodynamics (SPH) and the Particle Finite Element Method (PFEM). The description of the methods is provided; features and drawbacks of each method are compared and discussed. The introduced models, which represent widely used advanced analysis tools, are compared and validated in the simulation of five test cases: Two solitary waves, two regular wave trains and a non-linear wave-structure impact. Results from each model are similar and quite close to reference data. Therefore, both models have been validated against new test cases never simulated before, showing that these models can be effectively used for the analysis of regular and non-linear wave with structure impact.