bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of Information Systems (Mobile Phone App) for Enhancing Smallholder Farmers’ Productivity in Eastern Cape Province, South Africa: Implications on Food Security
Authors: Mdoda Lelethu , Christian Mzuyanda , Agbugba Ikechi 
Published: March 2023

AbstractThe rapid growth of information systems in the form of mobile phone applications in developing countries resulted in several benefits compared to other choices in relation to costs, environmental exposure, and simplicity of usage. However, smallholder farmers fail to meet the soaring demand for food and other agro commodities in time, and dodging market overflows is an extreme encounter among communal farmers due to a deficiency of information and unacquainted administration. Therefore, the study analyzes the factors influencing the use of information systems for enhancing smallholder production in the Eastern Cape Province of South Africa. The study applied a descriptive survey research design. A multi-stage simple random technique was used to collect data from 220 emerging growers using a semi-structured survey. Data collected were analyzed using descriptive statistics and a logistic regression model. The study indicated that most smallholder growers in the mentioned study area use information systems (IS) for their agricultural activities and agribusinesses and have further changed the farming landscape. Interestingly, agricultural productivity has been enhanced, as well as improved the food security status among rural households. Smallholder farmers have experienced problems in using information systems on their farms. Empirical results reveal that socio-economic factors influence the use of mass media for agricultural purposes by smallholder farmers. Therefore, the study recommends the government should embark on educational awareness and training of farmers in using information systems to enhance productivity.
Tribological behavior of shape memory cyanate ester materials and their tunable friction mechanism
Authors: Tang Zhangzhang , Guo Lihe , Xu Mingkun , Ruan Hongwei , Yang Jing , Wang Tingmei , Zhang Jianqiang , Wang Qihua , Zhang Yaoming 
Published: March 2023

AbstractHigh-performance polymer friction materials with tunable tribological behavior to fit varied work conditions remain a challenge of widespread interest for a variety of applications. Shape memory polymer exhibits morphing and modulus changing over temperature changing provides a promising material to adjust the friction process. Herein, we investigated the tribological properties of shape memory cyanate ester (SMCE) under different conditions. The SMCE exhibits the tribological behavior of good friction material with stable high coefficient of friction (COF) and a low wear rate. Besides, the COF increases and wear rate decreases with the temperature increasing show the tunable friction property of the SMCE. We propose a new model of wear-compensation through shape recovery to explain the adjustable friction behavior of thermal-responsive polymer from the aspect of shape recovery and energy conversion. This study provides a high-performance friction material and paves the route for the application of shape memory polymer (SMP) in tribology field with tunable property.
Crystallographic orientation dependence on nanoscale friction behavior of energetic β-HMX crystal
Authors: Yin Ying , Li Hongtao , Cao Zhihong , Li Binghong , Li Qingshan , He Hongtu , Yu Jiaxin 
Published: March 2023

AbstractTribology behaviors of energetic crystals play critical roles in the friction-induced hotspot in high-energy explosive, however, the binder and energetic crystals are not distinguished properly in previous investigations. In this study, for the first time, the nanoscale friction of β-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (β-HMX) crystal is studied with nanoscratch tests under the ramping load mode. The results show that the nanoscale friction and wear of β-HMX crystal, as a typical energetic material, is highly depended on the applied load. The friction coefficient of β-HMX crystal is initially high when no discernible wear is observed, and then it decreases to a stable value which varies from ∼0.2 to ∼0.7, depending on the applied load, scratch direction, and crystal planes. The β-HMX (011) surfaces show weakly friction and wear anisotropy behavior; in contrast, the β-HMX (110) surfaces show strongly friction and wear anisotropy behavior where the friction coefficient, critical load for the elastic—plastic deformation transition and plastic—cracking deformation transition, and deformation index at higher normal load are highly depended on the scratch directions. Further analyses indicate the slip system and direction of β-HMX surfaces play key roles in determining the nanoscale friction and wear of β-HMX surfaces. The obtained results can provide deeper insight into the friction and wear of energetic crystal materials.
Interpretable Dropout Prediction: Towards XAI-Based Personalized Intervention
Authors: Nagy Marcell , Molontay Roland 
Published: March 2023

AbstractStudent drop-out is one of the most burning issues in STEM higher education, which induces considerable social and economic costs. Using machine learning tools for the early identification of students at risk of dropping out has gained a lot of interest recently. However, there has been little discussion on dropout prediction using interpretable machine learning (IML) and explainable artificial intelligence (XAI) tools.In this work, using the data of a large public Hungarian university, we demonstrate how IML and XAI tools can support educational stakeholders in dropout prediction. We show that complex machine learning models – such as the CatBoost classifier – can efficiently identify at-risk students relying solely on pre-enrollment achievement measures, however, they lack interpretability. Applying IML tools, such as permutation importance (PI), partial dependence plot (PDP), LIME, and SHAP values, we demonstrate how the predictions can be explained both globally and locally. Explaining individual predictions opens up great opportunities for personalized intervention, for example by offering the right remedial courses or tutoring sessions. Finally, we present the results of a user study that evaluates whether higher education stakeholders find these tools interpretable and useful.
Customer satisfaction and sale performance in New York State brewery tasting rooms
Authors: Li Jie , Wagner Sara M. , Gómez Miguel I. , Mansfield Anna Katharine 
Published: March 2023

AbstractThe US craft brewery industry has grown steadily in recent years before the 2020 COVID-19 pandemic. The majority of small, independently owned craft breweries rely on tasting rooms for revenues and profits. Using data collected from a survey of tasting room visitors from 21 craft breweries in New York, this research investigates factors influencing visitors’ customer satisfaction (CS) and the link between brewery tasting room CS and sales performance. The results show that brewery interior ambience, beer tasting execution, and friendliness and knowledge of servers are the main factors influencing CS in tasting rooms. Furthermore, results suggest that higher CS levels increase visitors’ purchase likelihood and beer purchase amounts (by volume and value). These findings indicate that breweries should focus on such factors as strengthening staff training, enhancing tasting room ambience, and improving beer tasting execution that have the highest positive influence on CS to increase sales. This study has implications for the rapidly growing craft brewery industry in the USA.
Association Among Negative Life Events, Sense of Security, and Depressive Symptoms in Chinese Adolescents After the 2013 Ya’an Earthquake
Authors: Fung Hong Wang , Liu Caimeng , Yuan Guangzhe Frank , Liu Jiaxin , Zhao Jingjing , Chien Wai Tong , Lee Vincent Wan Ping , Shi Wei , Lam Stanley Kam Ki 
Published: March 2023

Abstract

Objective:
About a fourth of Chinese adolescents developed clinically significant depressive symptoms following a disaster. However, little is known about whether and how post-trauma negative life events and a sense of security are associated with depressive symptoms in this population. This study examined the psychological experiences of Chinese young people who had experienced the 2013 Ya’an earthquake in Sichuan, China.

Methods:
This cross-sectional study was conducted in 2019. A total of 693 Chinese middle school students completed a questionnaire that measured their level of depressive symptoms, trauma exposure, stressful life events, and sense of security.

Results:
Results of hierarchical multiple-regression analyses showed that the level of life stress from stressful life events was positively associated with the level of depressive symptoms (β = 0.416, P < 0.001) and the level of the sense of security was negatively associated with the level of depressive symptoms (β = −0.352, P < 0.001) when analysis controlled for age, gender, and trauma exposure.

Conclusions:
These findings highlight the importance of considering the influence of life stressors and the sense of security in devising measures and strategies for the prevention of the manifestation of depression among young people, particularly those who were exposed to disasters.
Increasing rate of 21st century volume loss of the Patagonian Icefields measured from proglacial river discharge
Authors: Van Wyk de Vries Maximillian , Romero Matias , Penprase Shanti B. , Ng G.-H. Crystal , Wickert Andrew D. 
Published: March 2023

AbstractThe Northern and Southern Patagonian Icefields are rapidly losing volume, with current volume loss rates greater than 20 km3 a−1. However, details of the spatial and temporal distribution of their volume loss remain uncertain. We evaluate the rate of 21st-century glacier volume loss using the hydrological balance of four glacierised Patagonian river basins. We isolate the streamflow contribution from changes in ice volume and evaluate whether the rate of volume loss has decreased, increased, or remained constant. Out of 11 glacierised sub-basins, seven exhibit significant increases in the rate of ice volume loss, with a 2006–2019 time integrated anomaly in the rate of glacier volume loss of 135 ± 50 km3. This anomaly in the rate of glacier-volume-loss is spatially heterogeneous, varying from a 7.06 ± 1.69 m a−1 increase in ice loss to a 3.18 ± 1.48 m a−1 decrease in ice loss. Greatest increases in the rate of ice loss are found in the early spring and late summer, suggesting a prolonging of the melt season. Our results highlight increasing, and in some cases accelerating, rates of volume loss of Patagonia's lake-terminating glaciers, with a 2006–2019 anomaly in the rate of glacier volume loss contributing an additional 0.027 ± 0.01 mm a−1 of global mean sea-level rise.
Early voting experiences and habit formation
Authors: Dinas Elias , Valentim Vicente , Broberg Nikolaj , Franklin Mark N. 
Published: March 2023

AbstractResearch has shown that first-time voting experiences affect subsequent voting behavior, with salient elections boosting subsequent turnout and non-salient ones suppressing it. We challenge this view. Following research on the context-dependent nature of habit formation, we argue that all elections should affect subsequent turnout in elections of the same type. Comparing individuals that differ only in how salient their first eligible election was (Presidential or Midterm), we find support for this expectation. Individuals are more likely to vote for, and be interested in, elections of the same type as their first voting experience. Leveraging voting age laws in the US, we also show that such laws affect subsequent participation by changing the type of election individuals are first eligible for.
On short-scale inviscid instabilities in flow past surface-mounted obstacles and other non-parallel motions
Authors: Smith F.T. , Bodonyi R. J. 
Published: March 2023

SummaryA theoretical investigation of short-scale inviscid instability in boundary-layer flow past an obstacle on a surface is described, with the application to trip-wire transition and wall roughness effects in mind. An analytical model and computational results show that the occurrence of an inflexion point in a local velocity profile is necessary but not sufficient for the instability to arise.
The ‘Minituft’ surface flow visualisation method; experience of use in the RAE 5m pressurised low-speed wind tunnel
Authors: Dobney D. G. , Hanson P. , Fiddes S. P. 
Published: March 2023

SummaryThe development and use of a ‘minituft’ surface flow visualisation technique in the RAE 5m Pressurised Low-Speed Wind Tunnel is described.The method, due to Crowder, uses very fine nylon monofilaments to show surface flow direction. These tufts are made visible by coating them in a fluorescent dye and then illuminating them with a powerful ultra-violet light source.Because of their small size, a large number of tufts may be used without interfering with the flow to a great extent. However, it is shown that if accurate force measurements are required, then it is advisable to test the model in the absence of tufts.
Experimental investigation of the turbulent boundary layer at high Reynolds numbers and a Mach number of 0·8
Authors: Gaudet L. 
Published: March 2023

SummaryMeasurements of the turbulent boundary layer on a sidewall of the RAE 8 ft × 8 ft wind tunnel are described. Velocity profiles and wall shear-stress measurements were obtained for a Mach number of 0·8 over a Reynolds number range of over a decade up to a value of nearly 400 million.A skin-friction relationship is deduced together with a description of the velocity profile and boundary-layer growth based upon the velocity-defect law using kinematic parameters for constant-pressure flows without heat transfer.Previous data for Mach numbers up to 2·8 obtained in the same tunnel are shown to be well matched with the present analysis and the use of simple scaling factors for compressible flows is confirmed.
Software position and velocity limiting for a synergistic six degree-of-freedom motion system
Authors: Campbell D. R. 
Published: March 2023

SummaryHardware and software limiting of the velocity and displacement of motion platform hydraulic jacks is an important source of spurious cue generation in the important frequency range below 2 Hz. Until recently the cross-coupling effect of such limiting has been ignored in motion-drive-software. By setting software limits and scaling jack demands with respect to this limit and the maximum jack demand, a limiting strategy which maintains the directional fidelity of the acceleration cue is achieved. This simple scheme includes a soft limiting approach to reduce motion jerks. In addition the scheme requires negligible extra computing time or storage over the traditional schemes.
The prediction of the drag of aerofoils and wings at high subsonic speeds
Authors: Lock R. C. 
Published: March 2023

SummaryAfter a brief discussion of alternative ways in which the drag of an aircraft wing can be derived theoretically, attention is focused on a technique whereby the separate ‘far-field’ components of drag — viscous, trailing-vortex (induced) and wave — are calculated separately. In particular, a new approximate method is described for estimating the wave drag. Based on an exact two-dimensional analysis involving the flow conditions just upstream of the shock wave, a simple formula is derived which, to first order, involves only a knowledge of the Mach number distribution on the surface of the aerofoil ahead of the shock and of the surface geometry at its foot. The accuracy of this formula is assessed for aerofoils by comparison with more exact theoretical results and with experiment. A ‘strip theory’ extension to swept wings is proposed and illustrated by applying it to a particular transport-type wing body combination. Using experimental pressure measurements as input, all three components of drag are estimated theoretically, and by adding their sum to separate balance measurements of the body drag comparisons between ‘theory’ and experiment for the overall drag can be made. These show a satisfactory standard of accuracy, the error varying between —5% and — 1% of the total drag over a wide range of Mach number and lift coefficient.
Large deflections of a cantilever beam subjected to a tip concentrated rotational load
Authors: Nageswara Rao B. , Shastry B. P. , Venkateswara Rao G. 
Published: March 2023

SummaryLarge deflection analysis of a cantilever beam under a tip concentrated rotational load governed by a second order non-linear differential equation is solved using a fourth-order Runge-Kutta integration scheme. Initially the two point boundary value problem is converted to an initial value problem by estimating one of the two required initial conditions in an iterative process, so as to satisfy the other boundary condition. The details of load deflection curves are presented.
Damage thresholds for low velocity impact on aircraft structural composites
Authors: O’Kane B. A. A. , Benham P. P. 
Published: March 2023

SummarySeven composite laminates, three carbon, one Kevlar and three hybrid as supplied by an aircraft manufacturer were assessed for damage tolerance. Rectangular coupons were subjected to low velocity impact in the range 0-4 Joules by a swinging pendulum. The coupons were ultrasonically C-scanned to measure delamination area and visually inspected for damage. Residual strength tests in tension, compression, flexure and shear were then carried out on the damaged coupons. Visual damage, delamination damage and strength reduction thresholds were determined from the data and compared. Of the three thresholds, delamination damage and strength reduction tended to coincide. For the various lay-ups these were in the range of 1·5 to 2·0 J for the longer (tensile) specimens or in the case of the smaller (shear) specimens between 0·2-0·3 J. In all cases onset of visible damage occurred at slightly higher values of impact energy. The significance of specimen stiffness was noted.
Photographic surveying of flow speed and direction adjacent to a surface
Authors: Barrett R.V. 
Published: March 2023

SummaryA flow surveying technique is described which provides a direct and quick output of either flow speed or direction. The computer based system enables ‘contour plots’ of these quantities to be obtained for fixed offset distances from a surface, using a series of surface contacting cylindrical probes. Pre-set values of the signal from the flow sensing system are used to switch a tri-coloured light source which traverses in unison with the probe, while a time exposure photograph is taken. For flow direction measurement, the signal activating the lights is computed from the pressure difference between yaw meter tappings on the cylinder in conjunction with the cylinder base pressure. Flow velocity is obtained from the base pressure alone, or alternatively from a hot wire probe.Results are presented to show that the method can provide useful and detailed data. It is seen mainly as a complement to other methods available for visualising complex flows.
The equations of motion for a parachute system descending through a real fluid
Authors: Yavuz T. 
Published: March 2023

SummaryFor the computer simulation of bodies moving through real fluids input data about the aerodynamic and inertial forces and moments developed on them are required. It has long been known that under appropriate conditions the apparent masses of the body can play an important role in the determination of dynamic characteristics and this is certainly the case with parachute systems. In the past, because of inadequate experimental investigations, not all of the implications of apparent mass for this system have been fully appreciated. The current objective is therefore, in the light of experiments conducted on the measurement of apparent masses for some parachute canopies, to derive the relevant equations of motion for the parachute and store system and thus to determine the effects of various parameters on the dynamic characteristics of fully-deployed parachutes. In this system the store has been assumed to be rigidly connected to the canopy.
Investigations into the effects of scale and compressibility on lift and drag in the RAE 5m pressurised low-speed wind tunnel
Authors: Fiddes S. P. , Kirby D. A. , Woodward D. S. , Peckham D. H. 
Published: March 2023

Summary
A survey is presented of results obtained from experiments in the RAE 5m low-speed pressurised wind tunnel. The tunnel is capable of operation over a range of pressures (from one to three atmospheres) so that the effects of Mach and Reynolds number may be separated. This decoupling of scale and compressibility effects has made possible reliable extrapolation of test results to full-scale conditions (where this is necessary) as well as giving greater insight into the underlying flow mechanisms. The large size of the tunnel, combined with pressurisation to three atmospheres, has enabled some tests, on small combat/trainer aircraft and on bomb-like stores, to be carried out at full scale.Three facets of the work of the 5m tunnel are described — work aimed at predicting or improving the high-lift performance of specific aircraft, work of a more fundamental nature concerned particularly with the optimisation of high-lift devices on generalised research models, and work on the drag of stores carried externally on combat aircraft.
Online Reputation and Debt Capacity
Authors: Derrien François , Garel Alexandre , Romec Arthur , Weisskopf Jean-Philippe 
Published: March 2023

AbstractWe explore the effects of online customer ratings on financial policy. Using a large sample of Parisian restaurants, we find a positive and economically significant relationship between customer ratings and restaurant debt. We use the locally exogenous variations in customer ratings resulting from the rounding of scores in regression discontinuity tests to establish causality. Favorable online ratings reduce cash flow risk and increase resilience to demand shocks. Consistent with the view that good online ratings increase the debt capacity of restaurants and their growth opportunities, restaurants with good ratings use their extra debt to invest in tangible assets.
Future Atmospheric Rivers and Impacts on Precipitation: Overview of the ARTMIP Tier 2 High‐Resolution Global Warming Experiment
Authors: Shields Christine A. , Payne Ashley E. , Shearer Eric Jay , Wehner Michael F. , O’Brien Travis Allen , Rutz Jonathan J. , Leung L. Ruby , Ralph F. Martin , Marquardt Collow Allison B. , Ullrich Paul A. , Dong Qizhen , Gershunov Alexander , Griffith Helen , Guan Bin , Lora Juan Manuel , Lu Mengqian , McClenny Elizabeth , Nardi Kyle M. , Pan Mengxin , Qian Yun , Ramos Alexandre M. , Shulgina Tamara , Viale Maximiliano , Sarangi Chandan , Tomé Ricardo , Zarzycki Colin 
Published: March 2023

AbstractAtmospheric rivers (ARs) are long, narrow synoptic scale weather features important for Earth’s hydrological cycle typically transporting water vapor poleward, delivering precipitation important for local climates. Understanding ARs in a warming climate is problematic because the AR response to climate change is tied to how the feature is defined. The Atmospheric River Tracking Method Intercomparison Project (ARTMIP) provides insights into this problem by comparing 16 atmospheric river detection tools (ARDTs) to a common data set consisting of high resolution climate change simulations from a global atmospheric general circulation model. ARDTs mostly show increases in frequency and intensity, but the scale of the response is largely dependent on algorithmic criteria. Across ARDTs, bulk characteristics suggest intensity and spatial footprint are inversely correlated, and most focus regions experience increases in precipitation volume coming from extreme ARs. The spread of the AR precipitation response under climate change is large and dependent on ARDT selection.