bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilización de lodos residuales en el compostaje de orujos y escobajo en la industria vitivinícola
Authors: Arqueros Eduardo , Morales-Vera Rodrigo , Roco Rosa Roa , Gonzalez Alvaro
Published: February 2023

Este estudio tiene por objetivo evaluar la factibilidad de integrar lodos provenientes de una planta de tratamiento de aguas vitivinícolas en el compostaje de orujos y escobajo. Los ensayos se llevaron a cabo en un viñedo de la zona central de Chile, se estudió la evolución del proceso de compostaje mediante el monitoreo de temperaturas, pH, humedad y densidad aparente. Se determinaron los efectos 3 distintas proporciones v/v de lodos (0, 10 y 20%), en las propiedades fisicoquímicas y el contenido de metales pesados durante la etapa mesófila inicial, termófila y mesófila tardía. Los resultados indican un incremento en el contenido de nutrientes y porcentaje de humedad al incorporar los lodos en las primeras etapas del proceso, además de mejorar la estructura física de las pilas. Sin embargo, existe un riesgo de fitotoxicidad asociado al contenido de metales pesados cuando el lodo es usado en mayores proporciones (20%). Con dosis menores (10%) se obtuvo un compost sin riesgos fitotóxicos y dentro de los parámetros establecidos por la normativa vigente en Chile. Por lo anterior, es factible integrar los lodos de la planta de tratamiento de aguas vitivinícolas, en una proporción de 10% de lodos y 90% de orujo y escobajo.
Current trends in ŒNO-NMR based metabolomics
Authors: Herbert-Pucheta José Enrique , Austin-Quiñones Paz , Rodríguez-González Francisco , Pino-Villar Cristina , Flores-Pérez Guadalupe , Arguello-Campos Santiago José , Arámbula Victor Villalobos
Published: February 2023

Present work discusses strengths and limitations of two Nuclear Magnetic Resonance outliers obtained with a water-to-ethanol solvent multi pre saturation acquisition method, recently included in the Compendium of International Methods of Analysis of Wines and Musts, published as OIV-MA-AS316-01, and their accuracy for metabolomics analysis. Furthermore, it is also presented an alternative to produce more discriminant and sensitive NMR data matrices for metabolomics studies, comprising the use of a novel NMR acquisition strategy in wines, the double pulsed-field gradient echo (DPFGE) NMR scheme, with a refocusing band-selective uniform-response pure-phase selective pulse, for a selective excitation of the 5-10 ppm chemical shift range of wine samples, that reveals novel broad aromatic 1H resonances, directly associated to complex polyphenols. Both aromatics and full binned OIV-MA-AS316-01,as well as the selective 5-10 ppm DPFGE NMR outliers were statistically analyzed with diverse non-supervised Principal Component Analysis (PCA) and supervised Partial Least Squares -Discriminant Analysis (PLS-DA), sparse (sPLS-DA) least squares- discriminant analysis, and orthogonal projections to latent structures discriminant analysis (OPLS-DA). Supervised multivariate statistical analysis of DPFGE and aromatics’ binned OIV-MA-AS316-01NMR data have shown their robustness to broadly discriminate geographical origins and narrowly differentiate between different fermentation schemes of wines from identical variety and region.
Strategies for the sensorial optimization of alcohol-free wines
Authors: Schmitt Matthias , Freund Maximilian , Schuessler Christoph , Rauhut Doris , Brezina Silvia
Published: February 2023

De-alcoholized wines are currently experiencing an increasing demand, but are also being discussed very controversially at this time. The de-alcoholization process is usually carried out by distillation processes under vacuum. The treatment is accompanied by a series of changes in terms of analytical and sensory parameters of the wines. Ethanol has a very complex and far ranging influence on the wine sensory character. Even more, the de-alcoholization process goes along with certain losses of aroma components. Several strategies were assessed to buffer and balance the effect of de-alcoholizing wines below 0.5% v/v. Compared to the addition of tannins and mannoproteins, sweetening showed clearer results on the panelist’s preference. The assessment of a commercial resin treatment to recover aroma from de-alcoholization process showed promising results.
What are the challenges to producing high quality red wines from interspecific grapes?
Authors: Watrelot Aude A. , Vavra Carmen , Gapinski Alexander , Cheng Yiliang
Published: February 2023

In the U.S. Midwest region, interspecific cold hardy grape cultivars have been developed to be resistant to the harsh cold winter, late spring frosts, and hot and humid summer. However, interspecific grape red wines tend to have higher acidity and lower tannins content than Vitis vinifera wines. This leads to unbalanced wines and an increase of the risk of oxidation and therefore impact the overall quality over time. The content and type of phenolic compounds differ in interspecific grapes and wines, depending on the cultivars, the viticultural practices, the environmental conditions and the wine making process. Because the chemical properties of red wines produced from interspecific grapes compared to Vitis vinifera is not well known, it is a challenge to determine the best wine making practices to produce a high quality wine that remains stable over time. This study focuses on evaluating phenolic compounds, oxidation-related compounds, and sulfur dioxide content in Marquette and Frontenac wines aged in bottles for up to 9 years. The goal is to help improve quality of red wines made from interspecific cold-hardy grape cultivars to increase consumer acceptance and develop optimal wine making practices.
The intra-laboratory study of EIM-IRMS® (Ethanol Isotope Measurement–Isotope Ratio Mass Spectrometry) method performance with CS-qNMR (Cumulative Screening–quantitative NMR)
Authors: Smajlović Ivan , Kolesnov Alexander , Smajlović Margarita , Tsimbalaev Sergey , Gennady Kalabin , Ivlev Vasily , Tereshenko Galina
Published: February 2023

In our earlier publications we proposed the possibility of using new EIM–IRMS® instrumental technique and analytical parameter δDn wine ethanol, which represents δ2H value of non-exchangeable hydrogen stable isotope ratio in ethanol, to improve detection of illegal wine production practices such as addition of sugar and/or water to grape must prior to alcoholic fermentation. This article shows a comparative performance study between EIM-IRMS® and CS-qNMR methods in order to evaluate potential and demonstrate the precision of two isotopic concepts and their degree of detection of illegal wine production practices. Three batches of laboratory wine samples were prepared from three different types of grapes (N=24 samples). Sample results obtained from both methods are compared and a statistical data processing was carried out. Based on the results obtained using the EIM-IRMS® method we detected 11 out of 21 of previously adulterated wine samples which represents a success rate of 52.4% detection of illegal practices (beet sugar, water or beet sugar syrup additions). In addition, wines from the Republic of Serbia (90 samples) were examined as well using the EIM-IRMS® method and appropriate equipment to confirm their authenticity.
Impacto de levaduras autóctonas no Saccharomyces en la reducción de etanol y perfil químico del vino chileno Sauvignon blanc
Authors: Urtubia Alejandra , Franco Wendy , De Lecco Consuelo Ceppi , Benavides Sergio , Durán Angélica
Published: February 2023

El estudio de levaduras No-Saccharomyces (NSY) en fermentaciones enológicas permite explorar nuevas alternativas para la reducción de etanol en vinos. El objetivo de este trabajo fue evaluar la capacidad fermentativa de dos levaduras autóctonas y poco exploradas del tipo NSY (NSYa, NSYb) en fermentaciones monocultivo y secuenciales (escala laboratorio y microvinificación) para producir vino Sauvignon Blanc chileno. Las fermentaciones se monitorearon mediante la determinación de etanol, glicerol, ácidos orgánicos y azúcares residuales. Los resultados indicaron que a escala de laboratorio tanto para las fermentaciones monocultivo y secuenciales fue posible reducir la concentración de etanol, a un 0,77% v/v (monocultivo) y 1,5% v/v (secuencial) para NSYa y 0,50% v/v (monocultivo) y 0,04% v/v (secuencial) para NSYb comparado con S. cerevisiae (12,87% v/v). Adicionalmente, mayores concentraciones de glicerol fueron obtenidas en fermentaciones monocultivo en comparación a las secuenciales (NSYa: 9,47 g/L y NSYb 10,97 g/L). A escala de microvinificación, las fermentaciones monocultivo y secuenciales con NSYb lograron reducir el contenido de etanol en 0,17% v/v y 0,54% v/v, respectivamente, comparado al control de S. cerevisiae (13,74% v/v). En el caso de NSYa, la reducción solo se observó en fermentaciones secuenciales con 0,62% v/v
Proteolytic activity under white wine fermentation by Hanseniaspora vineae yeast strains
Authors: Martin Valentina , Risso Cecilia , Listur Belén , Medina Karina , Valera María José , Schneider Rémi , Dellacassa Eduardo , Carrau Francisco
Published: February 2023

Apiculate yeasts from Hanseniaspora genus are predominant on the native flora of grapevines, while Hanseniaspora uvarum is well known for its abundant presence in grapes, it results generally, in detrimental quality effects on wine due to high production of acetic acid. By contrast, Hanseniaspora vineae is better adapted to fermentation, increasing flavor complexity in wines as it has been demonstrated in winemaking practices during the last decade. We obtained a collection of more than 22 different Hanseniaspora vineae strains from which we could detect, by a plating screening method, high and moderate protease activity. In this study, we tested these strains under real winemaking conditions on a Sauvignon blanc white wine must. Results obtained demonstrated that there is an interesting protease active diversity in all H. vineae strains when compared to conventional fermentations conducted by Saccharomyces cerevisiae. Four H. vineae strains showed a decrease in wine protein turbidity, up to three times lower than that observed in S. cerevisiae, which imply a significant decrease in the demand for bentonite before bottling. This attribute of some H. vineaestrains should be very attractive at the commercial level to reduce manipulations and flavor removal in the production of delicate white wines such as Sauvignon blanc.
Adaptación y desarrollo del velo de flor en vinos “sobretablas” de la D.O. Jerez-Xèrés-Sherry fortificados con alcoholes no vínicos
Authors: Cantoral Jesús Manuel , Florido-Barba Antonio , Lopez-Molina María Fernanda , Cordero-Bueso Gustavo
Published: February 2023

The EC 2019/187 shows the rules for the usage of ethyl alcohols to fortify wines. These must be obtained from products derived from agriculture and the use of alcohols of mineral or chemical origin is not authorized. The ethyl alcohols authorized for the fortification in the D.O. Sherry have wine origin. But, there are other alcohols that could be equally productive and at a lower economic cost, such as beet or sugar cane alcohol. The effect that different types of ethyl alcohols may have on the yeasts of flor remains unknown. Our goal was to analyze the effects of other alcohols (beet, sugar cane, etc.) on the development of the veil of flor. In this way, the yeasts that constitute the veil of flor of Fino wines were isolated and identified by microbiological techniques and characterized by molecular tools and by biochemical and microbiological tests such as cellular hydrophobicity, flocculation, acetic acid production, etc. Then, base wines were fortified with different distilled alcohols, such as malt brandy, tequila, among others. Biological aging under the veil of flor was monitored to later determine the volatile fractions. Alcohol from sugar cane could be a promising alternative to fortify Fino wines.
Validation of a routine HPLC method for added fumaric acid determination in wines
Authors: Karastergiou Anna , Gancel Anne-Laure , Payan Claire , Christmann Monika , Teissedre Pierre-Louis
Published: February 2023

Nowadays, grape berries mature earlier due to climate change. Higher sugar contents are observed, whereas lower ones in organic acids, leading to increased pH values. Those biochemical changes have direct consequences on the balance and quality of wines made from such grapes. Chemical acidification, commonly used to compensate for the lack of acidity in musts or wines, includes tartaric, malic, lactic, and citric acids. Fumaric acid (FA), naturally present in the grape berries at low concentrations and already authorized in the member states of the OIV to inhibit malolactic fermentation in wines, seems to be a promising alternative to those acids to lower the pH. However, the evolution of FA levels added at bottling and its impact on wine quality during its conservation have not yet been studied. Therefore, the aim of the present study was to develop and validate a simple method using liquid chromatography coupled with a diode array detector, which can be used routinely for the determination of the added fumaric acid in wines. The proposed and validated method uses a ProntoSIL C-18 analytical column and an isocratic elution with water acidified at 0.1% formic acid. The run time, including column cleaning with acetonitrile and re-equilibration, was 40 minutes.
UV-C treatment: A non-thermal inactivation method for microbiological stabilisation of must and wine
Authors: Cvetkova Svetlana , Hirt Benedikt , Stahl Mario , Scharfenberger-Schmeer Maren , Durner Dominik
Published: February 2023

UV-C treatment is discussed as an effective and efficient method to inactivate harmful microorganisms in wine and other viticultural products. In comparison to other stabilisation techniques, the application of UV-C is thought to be beneficial to reduce energy costs and to minimize SO2 addition. The object of this work was to determine the lethal UV-C dose for harmful microorganisms such as Brettanomyces bruxellensis and Acetobacter aceti. The concept of 5-log inactivation was applied and the Weibull model was used to compare different microbial and wine parameters. Microbial relevant UV-C doses and 2-fold overdose treatments and how they affected chemical and sensory changes of wine were investigated. Riesling and Pinot noir wine, which have different absorbance at 254 nm, were individually inoculated with microorganisms at different inoculation numbers. The results showed that the Weibull model is appropriate to predict the lethal UV-C dose. Already at microbially relevant doses, UV-C treatment can lead to significant changes in the colour and concentration of aroma compounds in white wine. Higher concentrations of 2-aminoacetophenone were found with increasing UV-C doses. Hence, UV-C overdosing can cause the “atypical ageing” off-flavour in wine. However, microbially relevant UV-C doses change the sensory properties of wine more towards a typical ageing character.
Retos de la Industria Vitivinícola de Baja California, México
Authors: Aulcy Lizzette Velasco , Rivera Sheila Delhumeau , Del Rocío Castro López Liliana , De Lira Garcia Cynthia
Published: February 2023

La industria vitivinícola de Baja California se ha desarrollado de manera significativa en las últimas décadas, a partir del incremento del consumo del vino en México y del impulso del gobierno estatal para el desarrollo de las vocaciones regionales. Sin embargo, su crecimiento no ha sido acompañado de una integración del sector entre los productores y con las comunidades donde se asienta. Este trabajo presenta un análisis de la situación actual de la vitivinicultura en el estado a partir de su cadena de valor, para identificar los retos previos y posteriores ante la pandemia COVID-19, considerando las acciones llevadas a cabo desde la producción de la uva, transformación del vino, distribución, mercadotecnia y comercialización, destacando la problemática social que afecta el desarrollo del sector y la identidad cultural. En esta investigación se utilizó la metodología para la sistematización, que articula las experiencias de actores clave relacionados con la industria con un enfoque territorial. Para obtener la información se realizaron grupos de enfoque organizados por actividades vinculadas con el sector vitivinícola en el Valle de Guadalupe.
Facing post crisis challenges through leadership and inclusion: The case of Napa Valley
Authors: Pesme Jacques-Olivier , Reiff Linda
Published: February 2023

The years 2010 through 2020 brought difficult challenges for the Napa Valley, a wine region in the heart of California, representing 4% of its vineyard land and 30% in economic value. Napa experienced an earthquake in 2014, wildfires in 2017 and 2020 and then, like everywhere, was hit by the pandemic. Consequently, both the production and the sale of wines were impacted with a form of relentlessness which terribly affected the entire local sector. In addition to the devastating effects of fires and smoke on some vineyards, the health crisis came to question a well-installed business model in Napa where wines are sold directly to consumers. Here, 68% of the wineries produce less than 50,000 bottles/year and it is not uncommon to see a winery sell 2/3 of its production directly from the estate. Two other observations complete the table with a paradigm shift: an aging of Napa wine consumers, mainly American, and the social evolution of a valley which attracts the wealthy classes of people and challenges the housing needs of not just vineyard workers, but also intermediate professionals. In 2020, Napa Valley Vintners (NVV) initiated a vast strategic reflection in order to question the conditions of its development and its competitiveness to the face of these developments. The 550 wineries from the valley were invited to participate in thinking about the values ​​of Napa, its leadership and the priorities to reconsider for the years to come. Collective commitment, leadership programs for high potentials, action local communities, diversity, integration of minorities … The list is long and it is enlightening to see how a wine region has been able to take advantage of a crisis situation to adjust its modus operandi with current issues, strengthen its leadership and create an inspiring new chapter for this world-class wine region.
Make sustainable the Prosecco DOC wine chain: The case of Prosecco Sustainability Project
Authors: Pomarici Eugenio , Di Chiara Valentina , Liggieri Silvia
Published: February 2023

Attention to sustainability is growing in the wine sector, but the rate of association to wine sustainability programs or schemes still appears to be limited. To encourage participation in sustainability programs, a collaborative approach adoption to share in wine communities the skills and knowledges necessary to manage the transition from a conventional organisation of production to a sustainable one, seems to be a functional strategy. This paper, present as case study, the Prosecco Sustainability Project, to investigate how a participatory/collaborative approach coordinated by an interbranch organization to facilitate the adoption of sustainable best practices by companies, can actually be developed. Results show that is necessary a strong integration and collaboration between different actors and that guidance from a coordinating figure who is able to foster dialogue and cooperation among the various stakeholders involved is needed.
Identifying defects on solar cells using magnetic field measurements and artificial intelligence trained by a finite-element-model
Authors: Buehler Kjell , Kaufmann Kai , Patzold Markus , Sprenger Mawe , Schoenfelder Stephan
Published: February 2023

Renewable energies have an increasing share in the energy supply. In order to ensure the security of this supply, the reliability of the systems is therefore increasingly important. In photovoltaic modules or in manufacturing, defective solar cells due to broken busbars, cross-connectors or faulty solder joints must be detected and repaired quickly and reliably. This paper shows how the magnetic field imaging method can be used to detect defects in solar cells and modules without contact during operation. For the evaluation of the measurement data several neural networks were used, which were trained with the help of results from finite element simulations. Different training data sets were set up in the simulation model by varying the electrical conductivities of the different parts of the solar cell. The influence of the neural network type and the variation of the training data sets as well as an advantage of a combination of simulated and experimental training data are presented and discussed.
Führungsstile in der Wirbelsäulenchirurgie: Kollegiale Führung – flache Struktur
Authors: Kothe Ralph
Published: February 2023

Die kollegiale Teamführung hat in der deutschprachigen „Kliniktradition“ nicht den
Stellenwert wie in dem angelsächsischen Sprachraum. Transformationale Führung ist hingegen in
der Wirtschaft ein Begriff: der Konsens über vereinbarte Werte und gemeinsame übergeordnete
Ziele bilden die Grundlage der Teamleistung. Vorteile der kollegialen Teamführung sind:
intensiver Wissenstransfer auf Augenhöhe, der zu kreativen Lösungen von medizinischen
Problemen führen kann, Aufteilung der administrativen Aufgaben unter den Teammitgliedern,
Abwesenheiten im Führungsteam können leichter kompensiert werden und eine stärkere Position
des Führungsteams gegenüber der Geschäftsführung. Als Alternative zu der traditionellen
hierarchischen Führungsstruktur ist die kollegiale Variante „risikoreicher“, weil sie
Kontrolle, zumindest teilweise, durch Vertrauen ersetzt und „anstrengender“, weil sie
hierarchische Anweisung durch Überzeugungsarbeit ausgleicht. Auch sind die Voraussetzungen für
kollegiale Führung nicht trivial: Integration unterschiedlicher fachlicher Schwerpunkte
(Orthopädie, Neurochirurgie, Traumatologie), überdurchschnittliche Kommunikations- und
Delegationsfähigkeit sowie Konfliktfairness und Festlegung einer klaren Arbeitsteilung. Was
kollegiale Führung sicher nicht ist: jeder kann machen was er will!
Ethische Herausforderungen einer palliativen PEG-Anlage in der
Endoskopie
Authors: Maltsev Elina
Published: February 2023

Die perkutane endoskopische Gastrostomie (PEG) zählt
als endoskopischer Routineeingriff, zu den lebenserhaltenden Methoden. Die PEG
wird bei Patienten mit Schluckstörungen unterschiedlicher Genese
eingesetzt, um eine physiologische Nahrungsaufnahme zu ermöglichen. Die
PEG wird auch bei palliativen Patienten durchgeführt, um eine
ausreichende Versorgung mit Nahrung und Flüssigkeit zu
gewährleisten. Im Wohlwollen zu helfen, wird nicht oft hinterfragt, ob
eine solche Maßnahme in Palliation wirklich profitabel oder gar ethisch
vertretbar ist. Ein Fallbeispiel soll für moralische Grenzsituationen
sensibilisieren, sowie Grundlagen und Entscheidungsfindung ermitteln.
Seltene Ursache von Wadenschmerzen bei einer 56-jährigen Patientin: die zystische Adventitiadegeneration
Authors: Stammler Frank , Wenzler Marion
Published: February 2023

Einführung Die zystische Adventitiadegeneration (CAD) ist eine seltene Gefäßerkrankung; sie betrifft meist Männer im mittleren Alter und stellt als nicht atherosklerotische Erkrankung eine ungewöhnliche Differenzialdiagnose der Claudicatio intermittens dar.

Anamnese Eine 56-jährige Patientin stellte sich wegen unklarer, nicht konstant belastungabhängiger, rechtsseitiger Wadenschmerzen in unserer Praxis vor. Die Beschwerden fluktuierten erheblich mit längeren beschwerdefreien Intervallen.

Untersuchung und Befunde Klinisch präsentierte die Patientin regelrechte Pulse, welche auch bei Provokationsmanövern wie Plantarflexion und Kniebeugung erhalten blieben. Duplexsonografisch waren zystische Raumforderungen um die A. poplitea nachweisbar. Bei der MRT-Untersuchung schien zusätzlich eine tubuläre geschlängelte Verbindung zu der Kniegelenkkapsel darstellbar. Die Diagnose einer zystischen Adventitiadegeneration wurde gestellt.

Therapie und Verlauf Bei nicht konstanter Beeinträchtigung der Gehleistung mit beschwerdefreien Intervallen sowie fehlenden Zeichen einer Stenosierung wurde eine interventionelle oder chirurgische Therapie seitens der Patientin nicht gewünscht. Bei kurzfristigen Verlaufskontrollen konnte über eine Beobachtungsdauer von bislang 6 Monaten klinisch und sonomorphologisch ein stabiler Befund erhoben werden.

Diskussion Auch bei weiblichen Patienten mit atypischen Beinbeschwerden sollte eine CAD erwogen werden. Einheitliche Therapieempfehlungen für die CAD liegen nicht vor, weshalb es eine Herausforderung darstellt, das optimale, in der Regel interventionelle Prozedere auszuwählen. Bei beschwerdearmer Klinik ohne kritische Ischämie kann jedoch auch ein konservatives Vorgehen mit engmaschigen Verlaufskontrollen gerechtfertigt sein.
Zentrale Beschaffungsstruktur: Sichere und stabile Versorgung
Authors: Gadanac Janis
Published: February 2023

Mit der Inbetriebnahme des Logistikzentrums in Bad Oldesloe geht der Klinikbetreiber Asklepios den nächsten Schritt in der zentralen Versorgungs- und Beschaffungsstruktur des Konzerns. Die Zentralisierung im strategischen und operativen Einkauf sowie der Logistik ist deutschlandweit einzigartig.
Serie: Digitalisierung in Beschaffung und Logistik (Teil 1/6): Transport: Neue Robotiklösungen für das Krankenhaus
Authors: Rauch Christian , Wibbeling Sebastian
Published: February 2023

Auch in der Krankenhauslogistik sollen in Zukunft vermehrt Roboter zum Einsatz kommen. Dabei ist die Bandbreite der eingesetzten Systeme groß. Besonders die Interaktion mit Menschen stellt die Entwickler noch vor zahlreiche Herausforderungen.
Logistik – Neu Ausgerichtet: Eine zentrale Materialwirtschaft für Deutschlands größten kommunalen Klinikkonzern
Authors: Vetter Kathy
Published: February 2023

Wie viele andere Krankenhäuser stand auch der Vivantes Konzern vor dem Hintergrund der Entwicklungen im Gesundheitswesen vor der Herausforderung, die strukturellen und baulichen Gegebenheiten an seinen Standorten zu überdenken und neu auszurichten. Infolgedessen rückten auch die Reorganisation und Optimierung der Krankenhauslogistik in den Fokus.
Autonome Reinigungslsungen: Einsatz von Reinigungsrobotern in Kliniken und Pflegeeinrichtungen
Authors: Tegeler Sven
Published: February 2023

Personalmangel, steigende Lohn- und Sachkosten sowie erhöhte Hygieneanforderungen setzen Reinigungsdienstleister im Gesundheitswesen zunehmend unter Druck. Um den Reinigungskräften die Arbeit zu erleichtern und Abläufe effizienter zu gestalten, setzen einige Anbieter für infrastrukturelle Dienstleistungen inzwischen vermehrt auf Reinigungsroboter. Doch wie gestaltet sich deren Einsatz in der Praxis?
Tunable transport properties of dual-gated InAs/GaSb core/shell nanowires
Authors: Pan Zhencun , Pan Dong , Zhou Yifeng , Zhao Jianhua , Xu H. Q. , Huang Shaoyun
Published: February 2023

Dual-gate structures were fabricated on a single high-quality InAs/GaSb core/shell nanowire, enabling control of the band structure and Fermi level in the crossed bandgap heterostructure. The nanowire was grown using the molecular-beam-epitaxy method in a pure crystal phase for both the core and the shell. We demonstrated clear ambipolar transport characteristics derived separately from n-type InAs and p-type GaSb. A relatively high resistance region was found between n- and p-type conduction regions; the entrance to an energy gap was thus indicated. The gap's size varied with the electric fields of dual gates and could even be closed; after closure, a weak and non-vanishing energy gap appeared. The reopened energy gap was considerably suppressed in an in-plane magnetic field only when the field was perpendicular to the axis of the nanowire (i.e., the current direction) and was identified as an electron–hole interaction induced hybridization gap.
Using machine learning to anticipate tipping points and extrapolate to post-tipping dynamics of non-stationary dynamical systems
Authors: Patel Dhruvit , Ott Edward
Published: February 2023

The ability of machine learning (ML) models to “extrapolate” to situations outside of the range spanned by their training data is crucial for predicting the long-term behavior of non-stationary dynamical systems (e.g., prediction of terrestrial climate change), since the future trajectories of such systems may (perhaps after crossing a tipping point) explore regions of state space which were not explored in past time-series measurements used as training data. We investigate the extent to which ML methods can yield useful results by extrapolation of such training data in the task of forecasting non-stationary dynamics, as well as conditions under which such methods fail. In general, we find that ML can be surprisingly effective even in situations that might appear to be extremely challenging, but do (as one would expect) fail when “too much” extrapolation is required. For the latter case, we show that good results can potentially be obtained by combining the ML approach with an available inaccurate conventional model based on scientific knowledge.
Design of high efficiency cylindrical dielectric resonator antenna based on topological photonic crystals
Authors: Zhou Yifan , Li Ruoyu , Jiang Pengpeng , Guo Xiaowei , Li Shaorong
Published: February 2023

Over the last 30 years, various dielectric resonator antennas (DRAs) have been developed for application in portable wireless communications and millimeter wave systems. However, current methods to feed the antennas suffer from radiation leakage and high losses. In this paper, we propose using a topological photonic crystal (TPC) as an effective feeding method, which can effectively suppress the reflecting loss at the feeder/DRA interface. As a demonstration, we numerically design a DRA with a TPC feeder, operating in a high-order resonant mode at 1.5 THz. Simulation results show that the antenna has a return loss as low as 44 dB, an impedance bandwidth of 3.9%, a maximum gain of 7.4 dBi, and 3dB angular widths of 58 degrees. Over 99% radiation efficiency can be achieved at the operating THz band. The proposed all-dielectric antenna can be suitably used for integrated photonic chips, biomedical applications, and 6G.
Tunable Fano resonance in coupled topological one-dimensional photonic crystal heterostructure and defective photonic crystal
Authors: Sharifi Maryam , Rezaei Behrooz , Pashaei Adl Hamid , Zakerhamidi Mohammad Sadegh
Published: February 2023

In this paper, we theoretically investigate the transmission properties of a structure composed of a topological one-dimensional photonic crystal (1D PhC) heterostructure and a conventional 1D PhC containing indium-antimonide (InSb) as a defect layer using the transfer matrix method. The phenomenon of Fano resonance can be achieved by coupling the defect mode with the topological edge state mode, which is supported by the topological PhC. The numerical results show that a narrow Fano resonance is observed in the transmission spectrum of the structure in the presence of the external magnetic field applied to the InSb defect layer. The optical properties of the InSb defect layer, and, therefore, the Fano resonance, can be dynamically controlled by changing the applied external magnetic field. The results obtained with the proposed structure reveal that the magnetic field has the greatest influence on controlling the optical properties of the Fano resonance. These findings could be beneficial for optical devices such as optical filters, sensors, and optical switches.
Hydrated electrons as nodes in porous clathrate hydrates
Authors: Huang Haibei , Xue Lijuan , Lu Gang , Cheng Shibo , Bu Yuxiang
Published: February 2023

We investigate the structures of hydrated electrons (e−aq) in one of water’s solid phases, namely, clathrate hydrates (CHs). Using density functional theory (DFT) calculations, DFT-based ab initio molecular dynamics (AIMD), and path-integral AIMD simulations with periodic boundary conditions, we find that the structure of the e−aq@node model is in good agreement with the experiment, suggesting that an e−aq could form a node in CHs. The node is a H2O defect in CHs that is supposed to be composed of four unsaturated hydrogen bonds. Since CHs are porous crystals that possess cavities that can accommodate small guest molecules, we expect that these guest molecules can be used to tailor the electronic structure of the e−aq@node, and it leads to experimentally observed optical absorption spectra of CHs. Our findings have a general interest and extend the knowledge of e−aq into porous aqueous systems.
Magnetic properties of Ni-coated fibers in a polymer matrix for electro-magnetic interference shielding applications
Authors: Couture P. , Goldman S. , Camley R. E. , Livesey K. L. , Robinson T. , Meyers D. , Maat S. , Celinski Z.
Published: February 2023

Electromagnetic interference shielding composite materials can be designed with properties that are tailored for specific applications. We have explored the magnetic properties of Ni-coated carbon fibers embedded in a polymer matrix through an extrusion process. This method can produce large, pliable flat sheets, which can be easily bent and shaped. Microscopy imaging shows that the extrusion process preferentially orders most of the fibers with their long axis along the extrusion direction. The measured samples reached 90% of the saturation magnetization value at a field of approximately 800 Oe along the extrusion direction, much lower than needed for other directions (in-plane perpendicular to the extrusion or perpendicular to the foil surface). A field on the order of 6 kOe must be applied to obtain the full saturation of the magnetization in all three directions. The absorption characteristics were measured, with zero external applied field to determine the shielding effectiveness of the composite materials for multiple orientations with respect to the TE10 mode of an S-band waveguide. The nickel-coated carbon fiber composite materials exhibit dramatic orientation-dependent shielding effectiveness. The most effective orientation has shielding effectiveness of up to 45 dB at 4.5 GHz, which is comparable to multi-walled carbon nanotube composites with similar volumetric filling fractions.
Parabolic mirrors collimating and focusing fluxes of thermal phonons
Authors: Singh Dhanishtha , Anufriev Roman , Nomura Masahiro
Published: February 2023

Manipulating heat fluxes at the nanoscale has become increasingly important in modern microelectronics. However, many methods of heat manipulations rely on complex nanofabrication. Here, we propose simple designs for collimation and focusing of thermal phonons based on parabolic mirrors that require no nanofabrication. We perform Monte Carlo simulations of a ballistic phonon transport in silicon membranes with parabolic boundaries. Our simulations demonstrate that parabolic surfaces can act as parabolic mirrors for phonons, thus collimating or focusing phonon fluxes in semiconductors. Such parabolic mirrors can create a directional flux of thermal phonons emitted from a nanoscale hot spot or focus a collimated phonon flux into a hot spot. These devices open new possibilities in the thermal management of low-temperature systems, such as quantum circuits or cryogenic particle detectors.
Order controllable enhanced stimulated Brillouin scattering utilizing cascaded diamond Raman conversion
Authors: Chen Hui , Bai Zhenxu , Cai Yunpeng , Yang Xuezong , Ding Jie , Qi Yaoyao , Yan Bingzheng , Li Yunfei , Wang Yulei , Lu Zhiwei , Mildren Richard P.
Published: February 2023

We report on the design and operation of a laser, which outputs wavelengths in the 1.2 and 1.5 μm ranges by leveraging two non-linear processes of stimulated Raman scattering and stimulated Brillouin scattering in diamond. By precisely controlling characteristics of the laser resonator formed around the diamond crystal, we are able to selectively control the onset of each non-linear process so as to tailor laser output characteristics both in way of wavelength and output power. This work demonstrates the high degree of flexibility and power-handling capacity of diamond for wavelength conversion of common laser wavelengths (such as 1064 nm as used in this work) and the generation of a span of discrete wavelengths (with up to eight cascaded orders being demonstrated in this work).
Onset of unsteadiness in the flow past a blade cascade
Authors: Fang Yibo , Du Lin , He Chen , Sun Dakun , Sun Xiaofeng
Published: February 2023

There has been little research on the system stability of the flow past a blade when the domain is finite in the transverse direction. In this study, we first explore the influence of the domain size and periodic boundary conditions in the transverse direction on the stability of the flow past a single blade in a finite domain. As the transverse width decreases, the base flow and instability characteristics change. Furthermore, the stability of the flow past a cascade including n blades is analyzed. There exist n perturbation modes corresponding to different temporal growth rates and frequencies with various staggered spatial distributions of the dominant region, embodied as the inter-blade phase angle in the frequency domain. The critical value and leading mode are related to the blade number. Therefore, when analyzing the stability of the flow past a cascade, it is important to extend the domain to the real blade number. The influence of the geometric cascade parameters on system stability is also studied. Finally, when the circumferential periodic flow is broken in a cascade including n blades, there exists only one eigenvalue near the stability boundary. The system stability deteriorates, and the critical Reynolds value drops sharply, even when several blades are restaggered to have a smaller angle of attack. From the distribution of the leading mode, the initial location of unsteadiness is associated with the region of maximum deficit in the velocity profile of the wake flow.
Splitter trees of superconducting nanowire cryotrons for large fan-out
Authors: Huang Yang-Hui , Zhao Qing-Yuan , Chen Shi , Hao Hao , Wang Hui , Guo Jia-Wei , Tu Xue-Cou , Zhang La-Bao , Jia Xiao-Qing , Chen Jian , Kang Lin , Wu Pei-Heng
Published: February 2023

A fan-out circuit is a basic block for scaling up digital circuits for overcoming the limited driving capability of a single logic gate. It is particularly important for superconducting digital circuits as the driving power is typically weak for having high energy efficiency. Here, we design and fabricate a fan-out circuit for a superconducting nanowire cryotron (nTron) digital circuit. A classic splitter tree architecture is adopted. To transmit switching signal and avoid crosstalk among nTrons, we introduced an “R–L–R” interface circuit. Experimentally, a two-stage splitter tree of a fan-out number of four was demonstrated. Correct operation was observed with a minimum bit error rate (BER) of 10−6. The bias margin was 10% at BER of 10−4. The average time jitter was 82 ps. Moreover, crosstalk was not observed. Based on these results, we envision that the fan-out circuit can be used in future development of superconducting-nanowire-based circuits.
Robust half-metallicity and tunable ferromagnetism in two-dimensional VClI2
Authors: Mukherjee T. , Kumari P. , Kar S. , Datta C. , Ray S. J.
Published: February 2023

Recent theoretical and experimental discoveries of two-dimensional (2D) ferromagnetic (FM) materials have sparked intense interest for their potential applications in spintronics. 2D FM materials with high spin polarization are extremely desirable for future low-dimensional spintronics. Half-metallicity plays a key role in the development of such devices. Here, we reported a new 2D nanomagnet VClI2 using the first-principles based density functional theory calculations. VClI2 shows an exciting half-metallic character with a wide half-metallic gap of 0.4 eV. The ground state favors ferromagnetic coupling with a Curie temperature Tc of 21 K. The half-metallicity with a FM ground state is further achieved by the application of an external strain and by the combined effects of the strain and the electric field. A phase transition from a half-metallic → semiconductor → metal was further observed under different stimuli with an antiferromagnetic ground state. At Ez=7.5 V/nm and in the presence of η=5% strain, the calculated Tc is estimated at 35 K, which shows a 67% increment than the Tc observed in the unstrained condition. The fascinating and unique properties suggest that VClI2 is a promising two-dimensional ferromagnetic half-metal, which can be useful for applications in future memory devices to enrich the 2D magnetic materials library.
Doped rare gas clusters up to completion of first solvation shell, CO2–(Rg)n, n = 3–17, Rg = Ar, Kr, Xe
Authors: Barclay A. J. , McKellar A. R. W. , Moazzen-Ahmadi N.
Published: February 2023

Spectra of rare gas atom clusters containing a single carbon dioxide molecule are observed using a tunable mid-infrared (4.3 µm) source to probe a pulsed slit jet supersonic expansion. There are relatively few previous detailed experimental results on such clusters. The assigned clusters include CO2–Arn with n = 3, 4, 6, 9, 10, 11, 12, 15, and 17, and CO2–Krn and CO2–Xen with n = 3, 4, and 5. Each spectrum has (at least) a partially resolved rotational structure, and each yields precise values for the shift of the CO2 vibrational frequency (ν3) induced by the nearby rare gas atoms, together with one or more rotational constants. These results are compared with theoretical predictions. The more readily assigned CO2–Arn species tend to be those with symmetric structures, and CO2–Ar17 represents completion of a highly symmetric (D5h) solvation shell. Those not assigned (e.g., n = 7 and 13) are probably also present in the observed spectra but with band structures that are not well-resolved and, thus, are not recognizable. The spectra of CO2–Ar9, CO2–Ar15, and CO2–Ar17 suggest the presence of sequences involving very low frequency (≈2 cm−1) cluster vibrational modes, an interpretation which should be amenable to theoretical confirmation (or rejection).
Factors influencing ember accumulation near a building
Authors: Quarles Stephen L. , Standohar-Alfano Christine , Hedayati Faraz , Gorham Daniel J.
Published: February 2023

Background Embers, also known as firebrands, are the leading cause of building ignition during wildland–urban fires. This is attributed both to direct ignition of material on, in, or attached to the building, and indirect ignition where they ignite vegetation or other combustible material near the building, which results in a radiant heat and/or direct flame contact exposure that ignites the building. Indirect ignition of a building can occur when embers accumulate on and ignite nearby combustible fuel, resulting in radiant heat or flame constant exposure. Aims/implications Factors that influence ember accumulation near a building include building geometry, such as flat wall and re-entrant corners, building wind angle, wind speed and the surface roughness characteristics of the horizontal landscape close to the building. Methods Experiments conducted at the Insurance Institute for Business & Home Safety (IBHS) Research Center using full-scale buildings with the above-mentioned factors provided a means to quantify ember accumulation on a mass per unit area basis. Key results Ember accumulation was greatest at locations immediately adjacent to the building and higher wind speeds allowed more embers to reach the building. Conclusions The work presented in this paper provides data and insight on wind-blown ember accumulation near a full-scale building.
Microglia phagocytosis mediates the volume and function of the rat sexually dimorphic nucleus of the preoptic area
Authors: Pickett Lindsay A. , VanRyzin Jonathan W. , Marquardt Ashley E. , McCarthy Margaret M.
Published: February 2023

The sexually dimorphic nucleus of the preoptic area (SDN-POA) is the oldest and most robust sex difference reported in mammalian brain and is singular for its presence across a wide range of species from rodents to ungulates to man. This small collection of Nissl-dense neurons is reliably larger in volume in males. Despite its notoriety and intense interrogation, both the mechanism establishing the sex difference and the functional role of the SDN have remained elusive. Convergent evidence from rodent studies led to the conclusion that testicular androgens aromatized to estrogens are neuroprotective in males and that higher apoptosis (naturally occurring cell death) in females determines their smaller SDN. In several species, including humans, a smaller SDN correlates with a preference for mating with males. We report here that this volume difference is dependent upon a participatory role of phagocytic microglia which engulf more neurons in the female SDN and assure their destruction. Selectively blocking microglia phagocytosis temporarily spared neurons from apoptotic death and increased SDN volume in females without hormone treatment. Increasing the number of neurons in the SDN in neonatal females resulted in loss of preference for male odors in adulthood, an effect paralleled by dampened excitation of SDN neurons as evidenced by reduced immediate early gene (IEG) expression when exposed to male urine. Thus, the mechanism establishing a sex difference in SDN volume includes an essential role for microglia, and SDN function as a regulator of sexual partner preference is confirmed.
The evolution of the human DNA replication timing program
Authors: Bracci Alexa N. , Dallmann Anissa , Ding Qiliang , Hubisz Melissa J. , Caballero Madison , Koren Amnon
Published: February 2023

DNA is replicated according to a defined spatiotemporal program that is linked to both gene regulation and genome stability. The evolutionary forces that have shaped replication timing programs in eukaryotic species are largely unknown. Here, we studied the molecular causes and consequences of replication timing evolution across 94 humans, 95 chimpanzees, and 23 rhesus macaques. Replication timing differences recapitulated the species’ phylogenetic tree, suggesting continuous evolution of the DNA replication timing program in primates. Hundreds of genomic regions had significant replication timing variation between humans and chimpanzees, of which 66 showed advances in replication origin firing in humans, while 57 were delayed. Genes overlapping these regions displayed correlated changes in expression levels and chromatin structure. Many human–chimpanzee variants also exhibited interindividual replication timing variation, pointing to ongoing evolution of replication timing at these loci. Association of replication timing variation with genetic variation revealed that DNA sequence evolution can explain replication timing variation between species. Taken together, DNA replication timing shows substantial and ongoing evolution in the human lineage that is driven by sequence alterations and could impact regulatory evolution at specific genomic sites.