bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frictional relaxation in avalanches
Authors: Bartelt Perry , Buser Othmar 
Published: May 2010

AbstractWe use velocity profile measurements captured at the Vallée de la Sionne test site, Switzerland, to find experimental evidence for the value of extreme, Voellmy-type runout parameters for snow avalanche flow. We apply a constitutive relation that adjusts the internal shear stress as a function of the kinetic energy associated with random motion of the snow granules, R. We then show how the Voellmy dry-Coulomb and velocity-squared friction parameters change (relax) as a function of an increase in R. Since the avalanche head is characterized by high random energy levels, friction decreases significantly, leading to rapidly moving and far-reaching avalanches. The relaxed friction parameters are near to values recommended by the Swiss avalanche dynamics guidelines. As the random kinetic energy decreases towards the tail, friction increases, causing avalanches to deposit mass and stop even on steep slopes. Our results suggest that the Voellmy friction model can be effectively applied to predict maximum avalanche velocities and maximum runout distances. However, it cannot be applied to model the full range of avalanche behaviour, especially to find the distribution of mass in the runout zone. We answer a series of questions concerning the role of R in avalanche dynamics.
Impact energy of an avalanche on a structure
Authors: Thibert E. , Baroudi D. 
Published: May 2010

AbstractThe impact energy of an avalanche on the flat surface of an instrumented structure has been quantified by full-scale experiments performed at the Lautaret avalanche test site, France. The deformation and acceleration of the structure were measured during the avalanche. The impact energy of the avalanche was calculated from an energy balance via the mechanical energy theorem. First the elastic potential energy and kinetic energy of the structure were calculated from the measured deformations and an adequate mechanical model of the structure. Internal energy dissipation due to material damping and potential plastic deformation was calculated. Finally the mechanical work done on the structure by the avalanche forces was deduced from the energy balance. Results show that the elastic energy is the main component of the energy injected in the structure. The kinetic and viscous components are negligible because of the very low displacement rate of the structure during the impact. Another important result is that the maximum of the mechanical power (work rate) is done when the head of the avalanche impacts the structure. This occurs before the pressure reaches its nominal value, approximately when the product of the pressure by the pressure rate is maximum.
Snowpack tests for assessing snow-slope instability
Authors: Schweizer Jürg , Bruce Jamieson J. 
Published: May 2010

AbstractInformation on snowpack instability is crucial for assessing avalanche risk in backcountry operations as well as for operational forecasting of the regional avalanche danger. Since slab avalanche release requires both fracture initiation and fracture propagation in a weak snowpack layer, field observations should ideally provide reliable information on the probability or propensity of both fracture processes. Even simple field observations that do not require digging a snow pit can provide useful information. Traditional snowpack tests include the shovel shear test, the shear frame test, the compression test (CT) and the rutschblock test (RB). Interpretation of the test results for the CTand RB has been improved by considering the appearance or type of the fracture in addition to the score. More recently, two tests have been developed that focus on fracture propagation rather than initiation: the extended column test (ECT) and the propagation saw test (PST). We compare the sensitivity, specificity and unweighted average accuracy of various stability tests. Comparative studies indicate that the RB, ECT and PST have comparable accuracy. For most test methods the unweighted average accuracy of a single test was 70–90% depending on the dataset. Test methods such as the RB, ECT and PST, which fracture an area large enough to include fracture propagation, are generally more accurate than test methods that fracture smaller areas (e.g. the CT). The threshold-sum method was also less accurate. Even with very experienced observers for the RB, ECT and PST an error rate of at least about 5–10% has to be expected. Performing a second, adjacent test on the same slope improves test reliability.
Back analysis of drifting-snow measurements over an instrumented mountainous site
Authors: Naaim-Bouvet Florence , Bellot Hervé , Naaim Mohamed 
Published: May 2010

AbstractThe NEMO numerical model of drifting snow, whose general outlines are presented in this paper, is based on a physical model for saltation and turbulent diffusion. The model needs a set of input parameters including fall velocity, threshold shear velocity, shear velocity, mass concentration and roughness, which are obtained from empirical formulae and wind speed measured at a given height. To better determine the required field data in an alpine context, our experimental site, Col du Lac Blanc (2700ma.s.l.), French Alps, was first equipped with one anemometer and blowing-snow acoustic sensors, which proved not to be accurate enough for research purposes in the current state of development even though a new calibration curve was used. We therefore set up a Snow Particle Counter and we returned to the traditional, robust mechanical traps and a 10 m mast with six anemometers, two temperature sensors and a depth sensor to better determine friction velocity and aerodynamic roughness. Based on the studied drifting-snow events we conclude: (1) the proportionality of the aerodynamic roughness to the square of the friction velocity was confirmed, but with a varying proportionality ratio depending on the snowdrift event; (2) values of σsUF were relatively well approximated by empirical formulae from data originating from Antarctica, and (3) snowdrift concentration profiles obtained by Pomeroy’s semi-empirical formulae for the saltation layer coupled with a theoretical approach for the diffusion layer overestimated the concentration profiles for the studied blowing-snow event.
Estimation of equivalent permeability of snowpack using a snowmelt lysimeter at Patsio, northwest Himalaya
Authors: Datt Prem , Srivastava P.K. , Sood G.K. , Satyawali P.K. 
Published: May 2010

AbstractThe meltwater percolation process through the snowpack greatly influences its physical and mechanical properties. The percolation process is important for understanding the spring avalanche phenomenon as well as the meltwater runoff for basin hydrology studies. The permeability of individual snow layers depends on parameters such as porosity, pore connectivity and the geometrical shape of the pores. Snowpack equivalent permeability plays an important role in governing the transmission of meltwater through the different layers of the snowpack. In this paper, we present the design, fabrication and installation of a snowmelt lysimeter at Patsio field research station, Himachal Pradesh, India, and determine the snowpack equivalent permeability using lysimeter discharge data. The snowmelt lysimeter, having a collector area of 6.25 m2 and a high-capacity snowmelt measuring tipping bucket, was installed on flat ground near the observatory with a data acquisition system. Snowmelt discharge measurements were made for two melt seasons, 2006/07 and 2007/08. Snow and meteorological data were collected at 15 min intervals using a semi-automatic weather station. The hourly surface snowmelt was estimated using an energy-balance approach. The maximum daily discharge was >2 mm w.e.h−1 for most of the observation period. The daily mean wave speed of the meltwater front varied from 109 to 285 mm h−1 for a daily mean discharge range of 0.6–1.8 mm w.e.h−1, while wave speeds for a particular melt flux of 2 mm w.e.h−1 varied between 113 and 486 mm h−1. The pore-size distribution index was estimated using the power-fit relation between wave speed and discharge. The equivalent permeability of the snowpack was found to vary between 3.4 × 10−8 and 9.9 × 10−12 m2.
Incident Diabetes in Women With Patterns of Gestational Diabetes Occurrences Across 2 Pregnancies
Authors: Mussa Joseph , Rahme Elham , Dahhou Mourad , Nakhla Meranda , Dasgupta Kaberi 
Published: May 2024

ImportanceGestational diabetes is a type 2 diabetes risk indicator, and recurrence further augments risk. In women with a single occurrence across 2 pregnancies, it is unclear whether first- vs second-pregnancy gestational diabetes differ in terms of risk.ObjectiveTo compare the hazards of incident diabetes among those with gestational diabetes in the first, in the second, and in both pregnancies with women without gestational diabetes in either.Design, Setting, and ParticipantsThis was a retrospective cohort study with cohort inception from April 1, 1990, to December 31, 2012. Follow-up was April 1, 1990, to April 1, 2019. Participants were mothers with 2 singleton deliveries between April 1, 1990, and December 31, 2012, without diabetes before or between pregnancies, who were listed in public health care insurance administrative databases and birth, stillbirth, and death registries in Quebec, Canada. Data were analyzed from July to December 2023.ExposureGestational diabetes occurrence(s) across 2 pregnancies.Main outcomes and measuresIncident diabetes from the second delivery until a third pregnancy, death, or the end of the follow-up period, whichever occurred first.ResultsThe 431 980 women with 2 singleton deliveries studied had a mean (SD) age of 30.1 (4.5) years at second delivery, with a mean (SD) of 2.8 (1.5) years elapsed between deliveries; 373 415 (86.4%) were of European background, and 78 770 (18.2%) were at the highest quintile of material deprivation. Overall, 10 920 women (2.5%) had gestational diabetes in their first pregnancy, 16 145 (3.7%) in their second, and 8255 (1.9%) in both (12 205 incident diabetes events; median [IQR] follow-up 11.5 [5.3-19.4] years). First pregnancy–only gestational diabetes increased hazards 4.35-fold (95% CI, 4.06-4.67), second pregnancy–only increased hazards 7.68-fold (95% CI, 7.31-8.07), and gestational diabetes in both pregnancies increased hazards 15.8-fold (95% CI, 15.0-16.6). Compared with first pregnancy–only gestational diabetes, second pregnancy–only gestational diabetes increased hazards by 76% (95% CI, 1.63-1.91), while gestational diabetes in both pregnancies increased it 3.63-fold (95% CI, 3.36-3.93).Conclusions and relevanceIn this retrospective cohort study of nearly half a million women with 2 singleton pregnancies, both the number and ordinal pregnancy of any gestational diabetes occurrence increased diabetes risk. These considerations offer greater nuance than an ever or never gestational diabetes dichotomy.
Metastatic Hormone-Sensitive Prostate Cancer and Combination Treatment Outcomes
Authors: Hussain Maha , Fizazi Karim , Shore Neal D. , Heidegger Isabel , Smith Matthew R. , Tombal Bertrand , Saad Fred 
Published: May 2024

ImportanceMetastatic hormone-sensitive prostate cancer is currently an incurable disease. Despite a high response rate to androgen-deprivation therapy, most cases progress to castration-resistant disease, the terminal phase. This review provides a summary of the most recent evidence for current and emerging management strategies, including treatment intensification with combinations of therapies. It also provides recommendations on applying the evidence in clinical practice to encourage appropriate treatment to improve survival outcomes among patients with metastatic hormone-sensitive prostate cancer.ObservationsAndrogen-deprivation therapy is the backbone of treatment for metastatic hormone-sensitive prostate cancer; however, it is insufficient alone to provide sustained disease control and long-term survival. Addition of an androgen receptor pathway inhibitor and/or docetaxel significantly improves survival, as demonstrated by several international phase 3 randomized clinical trials. Triplet therapy composed of androgen-deprivation therapy plus an androgen receptor pathway inhibitor plus docetaxel has been shown to improve overall survival over androgen-deprivation therapy plus docetaxel. In the ARASENS trial (darolutamide), the hazard ratios (HRs) were 0.68 (95% CI, 0.57-0.80) in the overall population; 0.71 (95% CI, 0.59-0.85) and 0.61 (95% CI, 0.35-1.05) in patients with de novo and recurrent disease, respectively; 0.69 (95% CI, 0.57-0.82) and 0.72 (95% CI, 0.41-1.13) in patients with high-volume and low-volume disease, respectively; and 0.71 (95% CI, 0.58-0.86) and 0.62 (95% CI, 0.42-0.90) in patients with high-risk and low-risk disease, respectively. In the PEACE-1 trial (abiraterone acetate + prednisone), the HRs were 0.75 (95% CI, 0.59-0.95; all de novo) in the overall population and 0.72 (95% CI, 0.55-0.95) and immature in the high-volume and low-volume subgroups, respectively. In the ENZAMET trial (enzalutamide), the HRs were 0.82 (95% CI, 0.63-1.06) in the overall population; 0.73 (95% CI, 0.55-0.99) and 1.10 (95% CI, 0.65-1.86) in the de novo and recurrent subgroups, respectively; and 0.87 (95% CI, 0.66-1.17) and 0.61 (95% CI, 0.33-1.10) in the high-volume and low-volume subgroups. Combination regimens are generally well tolerated, with adverse effects dependent on the profiles of the component drugs.Conclusions and relevanceThe findings of this review show compelling evidence from phase 3 randomized clinical trials in favor of initiating triplet combination therapy for patients with metastatic hormone-sensitive prostate cancer for the best overall survival. Patients who are eligible for chemotherapy should be offered androgen-deprivation therapy plus an androgen receptor pathway inhibitor plus docetaxel, particularly patients with high-volume, high-risk, or de novo metastatic disease.
Steering Interfacial Renovation with Highly Electronegative Cl Modulated Trinity Effect for Exceptional Durable Zinc Anode
Authors: Zhao Qiwen , Liu Wen , Ni Xuyan , Yu Huaming , Zhang Chunxiao , Wang Bin , Jiang Liangliang , He Hanwei , Chen Yuejiao , Chen Libao 
Published: May 2024

AbstractThe poor anode/electrolyte interface triggered by abysmal dendritic growth and hydrogen evolution reactions (HER) hinders the development of aqueous zinc‐ion batteries (AZIBs). Here, a highly efficient electrolyte is formulated with sucralose (Sucral) additive to refresh solvated structure and steer interfacial renovation, for building highly electronegative Cl‐modulated trinity effect in the bulk‐interface between electrolyte and electrode. Experiment results and theoretical studies jointly reveal that Sucral with highly zincophilic and hydrophilic hydroxyl groups can remodel primary Zn2+ solvation shell and interrupt strong H‐bond network from H2O molecules, thus boosting fast de‐solvation and restricting undesirable HER. Simultaneously, three highly electronegative chlorides in the adsorbed Sucral possessing hydrophobic features can enable a H2O‐poor electric double‐layer (EDL), thus remodeling the Zn surface against corrosion. Additionally, it realizes preferential exposure of the Zn (002) plane for helping uniform interfacial deposition. The synergy of the above factors achieves a prolonged lifespan of 3000 h (1.0 mA cm−2, 1.0 mAh cm−2), much better than that with Sucrose (Suc) electrolyte. The Zn//V2O5 full cell at 5 A g−1 also maintains enhanced stability of 1500 cycles with 160 mAh g−1.
Bio‐Inspired Crystalline Core‐Shell Guanine Spherulites
Authors: Alus Lotem , Houben Lothar , Shaked Noy , Niazov‐Elkan Angelica , Pinkas Iddo , Oron Dan , Addadi Lia 
Published: May 2024

AbstractSpherical particles with diameters within the wavelength of visible light, known as spherulites, manipulate light uniquely due to their spatial organization and their structural birefringence. Most of the known crystalline spherulites are branched, and composed of metals, alloys, and semi‐crystalline polymers. Recently, a different spherulite architecture is discovered in the vision systems of decapod crustaceans ‐ core‐shell spherulites composed of highly birefringent () organic single‐crystal platelets, with exceptional optical properties. These metastructures, which efficiently scatter light even in dense aqueous environments, have no synthetic equivalence and serve as a natural proof‐of‐concept as well as synthetic inspiration for thin scattering media. Here, the synthesis of core‐shell spherulites composed of guanine crystal platelets (() is presented in a two‐step emulsification process in which a water/oil/water emulsion and induced pH changes are used to promote interfacial crystallization. Carboxylic acids neutralize the dissolved guanine salts to form spherulites composed of single, radially stacked, β‐guanine platelets, which are oriented tangentially to the spherulite surface. Using Mie theory calculations and forward scattering measurements from single spherulites, it is found that due to the single‐crystal properties and orientation, the synthetic spherulites possess a high tangential refractive index, similarly to biogenic particles.
Bi‐Interlayer Strategy for Modulating NiCoP‐Based Heterostructure toward High‐Performance Aqueous Energy Storage Devices
Authors: Xu Jian , Gong Xiliang , Meng Zeshuo , Chen Peiyuan , Nan Haoshan , Li Yaxin , Deng Ting , Wang Dong , Zeng Yi , Hu Xiaoying , Tian Hongwei , Niu Zhiqiang , Zheng Weitao 
Published: May 2024

AbstractNickel‐cobalt (NiCo) phosphides (NCPs) possess high electrochemical activity, which makes them promising candidates for electrode materials in aqueous energy storage devices, such as supercapacitors and zinc (Zn) batteries. However, the actual specific capacitance and rate capability of NCPs require further improvement, which can be achieved through reasonable heterostructural design and loading conditions of active materials on substrates. Herein, novel hierarchical Bi‐NCP heterogeneous structures with built‐in electric fields consisting of bismuth (Bi) interlayers (electrodeposited on carbon cloth (CC)) are designed and fabricated to ensure the formation of uniform high‐load layered active materials for efficient charge and ion transport. The resulting CC/Bi‐NCP electrodes show a uniform, continuous, and high mass loading (>3.5 mg) with a superior capacitance reaching 1200 F g−1 at 1 A g−1 and 4129 mF cm−2 at 1 mA cm−2 combined with high‐rate capability and durable cyclic stability. Moreover, assembled hybrid supercapacitors (HSCs), supercapatteries, and alkaline Zn‐ion (AZBs) batteries constructed using these electrodes deliver high energy densities of 64.4, 81.8, and 319.1 Wh kg−1, respectively. Overall, the constructed NCPs with excellent aqueous energy storage performance have the potential for the development of novel transition metal‐based heterostructure electrodes for advanced energy devices.
Synthesis of n‐Propanol from CO2 Electroreduction on Bicontinuous Cu2O/Cu Nanodomains
Authors: Zhang Renjie , Zhang Jianling , Wang Sha , Tan Zhonghao , Yang Yisen , Song Yi , Li Meiling , Zhao Yingzhe , Wang Hao , Han Buxing , Duan Ran 
Published: May 2024

Abstractn‐propanol is an important pharmaceutical and pesticide intermediate. To produce n‐propanol by electrochemical reduction of CO2 is a promising way, but is largely restricted by the very low selectivity and activity. How to promote the coupling of *C1 and *C2 intermediates to form the *C3 intermediate for n‐propanol formation is challenging. Here, we propose the construction of bicontinuous structure of Cu2O/Cu electrocatalyst, which consists of ultra‐small Cu2O nanodomains, Cu nanodomains and large amounts of grain boundaries between Cu2O and Cu nanodomains. The n‐propanol current density is as high as 101.6 mA cm−2 at the applied potential of −1.1 V vs. reversible hydrogen electrode in flow cell, with the Faradaic efficiency up to 12.1 %. Moreover, the catalyst keeps relatively stable during electrochemical CO2 reduction process. Experimental studies and theoretical calculations reveal that the bicontinuous structure of Cu2O/Cu can facilitate the *CO formation, *CO‐*CO coupling and *CO‐*OCCO coupling for the final generation of n‐propanol.
Advancing Pore‐Space‐Partitioned Metal–Organic Frameworks with Isoreticular Cluster Concept
Authors: Xiao Yuchen , Chen Yichong , Wang Wei , Bu Xianhui , Feng Pingyun 
Published: May 2024

AbstractTrigonal planar M3(O/OH) trimers are among the most important clusters in inorganic chemistry and are the foundational features of multiple high‐impact MOF platforms. Here we introduce a concept called isoreticular cluster series and demonstrate that M3(O/OH), as the first member of a supertrimer series, can be combined with a higher hierarchical member (double‐deck trimer here) to advance isoreticular chemistry. We report here an isoreticular series of pore‐space‐partitioned MOFs called M3M6 pacs made from co‐assembly between M3 single‐deck trimer and M3x2 double‐deck trimer. Important factors were identified on this multi‐modular MOF platform to guide optimization of each module, which enables the phase selection of M3M6 pacs by overcoming the formation of previously‐always‐observed same‐cluster phases. The new pacs materials exhibit high surface area and high uptake capacity for CO2 and small hydrocarbons, as well as selective adsorption properties relevant to separation of industrially important mixtures such as C2H2/CO2 and C2H2/C2H4. Furthermore, new M3M6 pacs materials show electrocatalytic properties with high activity.
Synthesis of Stable 2D Conductive Lanthanide Organic Frameworks (Lu‐HHTP) for High‐Performance Humidity Sensors
Authors: Jiang Shan , Mo Xichao , Zhao Xuefei , Yan Xiaohui , Zhang Zhaorui , Liu Jiahao , Hu Huashuai , Wang Nan , Yang Minghui 
Published: May 2024

AbstractTwo‐dimensional conductive metal‐organic frameworks (MOFs) featuring structural diversity and high porosity represent promising platforms for chemiresistive humidity sensing. The precise control of the structure of lanthanide‐based MOFs and an exploration of its impact on charge transport and sensing applications have consistently been focal points for researchers. In this study, we present the synthesis and characterization of Lu‐HHTP (HHTP=2,3,6,7,10,11‐hexahydroxytriphenylene) as highly crystalline and conductive porous materials. The polymeric framework of Lu‐HHTP encompasses 1D hexagonal channels and exhibits interlayer π–π stacking, resulting in a material with a high surface area and uniform rod‐like microstructure. Benefiting from its elevated electrical conductivity, the Lu‐HHTP‐based humidity sensor exhibited commendable sensing properties within the relative humidity range of 33 % to 95 % at room temperature (25 °C), achieving a response value as high as 19 at 95 % relative humidity. Furthermore, the sensor displayed superior repeatability, characterized by rapid response and recovery speeds in the presence of moisture. These findings indicate that Lu‐HHTP holds substantial promise as a material for humidity sensors.