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2022 ◽  
Vol 924 (1) ◽  
pp. 5
Author(s):  
Merel L. R. van ’t Hoff ◽  
Daniel Harsono ◽  
Martijn L. van Gelder ◽  
Tien-Hao Hsieh ◽  
John J. Tobin ◽  
...  

Abstract The water snowline location in protostellar envelopes provides crucial information about the thermal structure and the mass accretion process as it can inform about the occurrence of recent (≲1000 yr) accretion bursts. In addition, the ability to image water emission makes these sources excellent laboratories to test indirect snowline tracers such as H13CO+. We study the water snowline in five protostellar envelopes in Perseus using a suite of molecular-line observations taken with the Atacama Large Millimeter/submillimeter Array (ALMA) at ∼0.″2−0.″7 (60–210 au) resolution. B1-c provides a textbook example of compact H 2 18 O (31,3−22,0) and HDO (31,2−22,1) emission surrounded by a ring of H13CO+ (J = 2−1) and HC18O+ (J = 3−2). Compact HDO surrounded by H13CO+ is also detected toward B1-bS. The optically thick main isotopologue HCO+ is not suited to trace the snowline, and HC18O+ is a better tracer than H13CO+ due to a lower contribution from the outer envelope. However, because a detailed analysis is needed to derive a snowline location from H13CO+ or HC18O+ emission, their true value as a snowline tracer will lie in the application in sources where water cannot be readily detected. For protostellar envelopes, the most straightforward way to locate the water snowline is through observations of H 2 18 O or HDO. Including all subarcsecond-resolution water observations from the literature, we derive an average burst interval of ∼10,000 yr, but high-resolution water observations of a larger number of protostars are required to better constrain the burst frequency.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Lingzhi Wang ◽  
Kang Tian

The practice has proven that relying solely on large-scale transportation facilities cannot fundamentally alleviate urban transportation problems. Since the motor vehicle drivers are the main participants of transportation, they should improve their knowledge of transportation. Moreover, the drivers should equally cope with transportation problems. This paper establishes an evaluation index system for traffic literacy of urban drivers. In addition, it proposes a method of information contribution sensitivity to optimise the index system. The main results and achievement of this paper include the following: (1) A traffic literacy evaluation index system including 13 evaluation indexes such as traffic rules and general knowledge of machinery has been constructed. (2) Based on the calculation results of the sensitivity of the information contribution, the first 10 indexes that satisfy the cumulative information contribution rate’s value of greater than 90% are retained and 3 indexes with lower contribution rates are eliminated. This study provides a theoretical framework and basic methods to evaluate the traffic literacy of urban drivers.


Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3226
Author(s):  
Manas Khan ◽  
Vaskar Dahal ◽  
Hanseok Jeong ◽  
Momcilo Markus ◽  
Rabin Bhattarai

Rainfed agricultural systems have become more vulnerable to climate change due to their significant dependence on natural precipitation. Drastic changes in precipitation, superimposed with anthropogenic activities, including land use land cover change, can modify the hydrologic response, especially in agricultural watersheds. In this study, Fisher Information and cumulative sum charts (CUMSUM) methods were applied to detect the hydrologic regime shifts in six watersheds in Illinois, USA. The regime shift analysis identified shifts in streamflow regime in three agricultural watersheds, mainly around the 1970s; whereas, no significant change in streamflow was observed for forest-dominated watersheds. Furthermore, the Budyko framework was used to determine the relative contribution in streamflow alterations (i.e., regime shifts in streamflow) for the agricultural watersheds, which evidenced significant shifts in streamflow. The Budyko analysis inferred that alterations in streamflow could be primarily attributed to anthropogenic activities with a comparatively lower contribution from climate in agricultural watersheds. The relative contribution from anthropogenic activities were 71.66%, 81.46%, and 74.04%; whereas, the relative contribution from climate were 28.34%, 18.54%, and 25.96% for the Sangamon, Vermillion, and Skillet agricultural watersheds, respectively. The techniques used and the results obtained from the study would be helpful for future research in assessing the vulnerability and impact of management practices in a highly managed agricultural watershed.


Author(s):  
Helena Schmidt ◽  
Gerdien de Vries ◽  
Reint Jan Renes ◽  
Roland Schmehl

Airborne wind energy (AWE) systems use tethered flying devices to harvest higher-altitude winds to produce electricity. For a successful deployment of these systems, it is crucial to understand how the public perceives them. If public concerns about the technology are not taken seriously, implementation could be delayed or, in some cases, prevented, resulting in increased costs for project developers and a lower contribution of the sector to renewable energy targets. This literature review assessed the current state of knowledge on public responses to AWE. An exhaustive literature search led to the identification of 40 relevant publications that were reviewed. The literature assumed that the safety, visibility, acoustic emissions, ecological impacts, and the siting of AWE systems shape public responses to the technology. The reviewed literature views people’s responses to AWE very optimistically but lacks scientific evidence to back up its claims. It seems to overlook that the influence of AWE’s characteristics (e.g., visibility) on public responses will also depend on a range of situational and psychological factors (e.g., people’s general attitude towards AWE, the public’s trust in project developers). Therefore, empirical social scientific research is needed to increase the field’s understanding of public responses to AWE and thereby facilitate deployment.


Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2008
Author(s):  
Lucía González-Mulero ◽  
Marta Mesías ◽  
Francisco J. Morales ◽  
Cristina Delgado-Andrade

In 2019, the European Commission recommended monitoring the presence of acrylamide in certain foods not included in Regulation 2158/2017, to consider other sources of exposure to the contaminant. In the present study, eleven groups of processed foods commonly consumed in Spain were classified, according to their food matrix, into potato-based food, cereal-based food and food based on cereal mixed with meat, fish or vegetables. Samples were collected from three different settings: household, catering services and industrial origin, to evaluate the influence of the food preparation site on acrylamide formation. The highest concentrations of acrylamide were observed in chips (French fries), especially those prepared at home. Although at lower levels, all the other foods also contained significant concentrations of acrylamide, confirming the need to control its content in foods not included in the EU regulation. Industrially processed foods made a lower contribution to acrylamide exposure, probably due to the more stringent controls exercised on culinary processes in this context. The higher levels recorded for households and catering services highlight the need for greater awareness of culinary processes and for measures to be adopted in these settings to limit the formation of acrylamide in food preparation.


2021 ◽  
pp. 105678952110130
Author(s):  
Daniel Castillo ◽  
Tuan HA Nguyen ◽  
Jarkko Niiranen

This paper explores the computational modeling of nonlocal strain, damage, and fracture in concrete, considering the isolated contribution of two random, spatially variable properties related to the fracture process: Young’s modulus (E) and tensile strength (ft). Applying a continuum damage model, heterogeneous specimens of concrete with random and spatially varying E or ft were found to produce substantial differences when contrasted with traditional homogeneous (non-random) specimens. These differences include variable and uncertain strain and damage, wandering of the failure paths, and differing (sometimes lower) peak forces, i.e. increased probabilities of failure in the heterogeneous specimens. It is found that ft variability contributes more (from 1.7 to up to 4 times more, depending on the parameter) to the overall performance variability of the concrete than E variability, which has a comparatively lower contribution. Performance is evaluated using (1) force-displacement response, (2) individual, average, and standard deviation maps of non-local strain and damage, (3) fracture paths and strain and damage values along the fractures. The modeling methodology is illustrated for two specimen geometries: a square plate with a circular hole, and an L-shaped plate. The computational results correlate well with reported experimental data of fracture in concrete specimens.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2091
Author(s):  
Valentina Zubkova ◽  
Andrzej Strojwas ◽  
Marcin Bielecki

A research study was conducted on the thermal behaviour of leaves of urban greenery (birch, maple, and rowan) and the products of their pyrolysis and extraction as assisted by microwaves. The obtained products of pyrolysis and extraction were investigated with the use of FT-IR and UV spectroscopies and XRD techniques. A contractive analysis of samples of chars, condensates, after-extraction residue, and extracts showed that the changes in structural-chemical parameters of leaves of different types of trees during pyrolysis and extraction take place in distinct ways. About 22% of material was removed from birch leaves during extraction, and more than 17% of material was extracted from maple and rowan leaves. It was determined that, during pyrolysis of after-extraction residue of leaves, many fewer PAH compounds with carbonyl groups along with alcohols and phenols are emitted than during pyrolysis of non-extracted leaves. Taking into account that pyrolysis is the first stage of combustion, a decrease in the amount of dangerous compounds in the volatile products of pyrolysis leads to a lower contribution of such compounds in combustion products. This indicates that leaves of urban greenery can be subjected to combustion after extraction, and the obtained extracts can be used as a source of phytochemicals and chemical reagents.


Climate ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 106
Author(s):  
Demamu Mesfin ◽  
Belay Simane ◽  
Abrham Belay ◽  
John W. Recha ◽  
Ute Schmiedel

This paper explores the different components of the adaptive capacity of households in the Central Rift Valley (CRV) of Ethiopia and quantifies their relative contributions. The data were derived from a survey of 413 households randomly selected from four Kebeles (the smallest government administrative units) in the CRV. The adaptive capacity of the households was assessed using the Local Adaptive Capacity (LAC) framework and measured in terms of both aggregate and composite indices, with sixty indicators distributed across five major components and subcomponents. The index score for major components shows that intangible variables such as institutions and entitlements, knowledge and information, and innovation contributed to adaptive capacity better than decision–making and governance and asset–base. The composite indices for sub–components showed that the contribution of woodlands to adaptive capacity was positive and superior to other natural assets. Grazing land was the next best contributor, while farmland and water resources made a much lower contribution. The findings of this study are useful to better understand the nature of adaptive capacity and its components at the household level. This study suggests the need for an integrated assessment and enhancement of adaptive capacity with all its components rather than focusing only on asset possession as an indicator of adaptive capacity.


2020 ◽  
Vol 128 (3) ◽  
pp. 688-697
Author(s):  
Simon Avrillon ◽  
François Hug ◽  
Gaël Guilhem

Hamstring strain injuries (HSIs) involve tissue disruption and pain, which can trigger long-term adaptations of muscle coordination. However, little is known about the effect of previous HSIs on muscle coordination and in particular, after the completion of rehabilitation and in the absence of symptoms. This study aimed to determine if elite athletes with a prior unilateral HSI have bilateral differences in coordination between the hamstring muscle heads after returning to sport. Seventeen athletes with a unilateral history of biceps femoris (BF) injury participated in the experiment. Surface electromyography was recorded from three hamstring muscles [BF, semimembranosus (SM), and semitendinosus] during submaximal isometric torque-matched tasks at 20% and 50% of maximal voluntary contraction. The product of normalized electromyographic amplitude with functional physiological cross-sectional area (PCSA) and moment arm was considered as an index of individual muscle torque. The contribution of the injured muscle to total knee flexion torque was lower in the injured than the uninjured limb (−5.6 ± 10.2%, P = 0.038). This reduced contribution of BF was compensated by a higher contribution of the SM muscle in the injured limb (+5.6 ± 7.5%, P = 0.007). These changes resulted from a lower contribution of PCSA from the injured muscle (BF) and a larger contribution of activation from an uninjured synergist muscle (SM). In conclusion, bilateral differences in coordination were observed in previously injured athletes despite the completion of rehabilitation. Whether these bilateral differences in hamstring coordination could constitute an intrinsic risk factor that contributes to the high rate of hamstring injury recurrence remains to be investigated. NEW & NOTEWORTHY We used an experimental approach, combining the assessment of muscle activation, physiological cross-sectional area, and moment arm to estimate force-sharing strategies among hamstring muscles during isometric knee flexions. We tested athletes with a history of hamstring injury. We observed a lower contribution of the injured biceps femoris to the total knee flexor torque in the injured limb than in the contralateral limb. This decreased contribution was mainly due to selective atrophy of the injured biceps femoris muscle and was compensated by an increased activation of the semimembranosus muscle.


2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Sandrine Péneau ◽  
Kelly Virecoulon-Giudici ◽  
Julia Baudry ◽  
Caroline Méjean ◽  
Denis Lairon ◽  
...  

AbstractOrganic food consumption has risen in many countries during the past decades, but individual behaviors leading to these choices remain unclear.. The aim of this study was to evaluate the associations between cognitive restraint, weight loss diet history and organic food intake, in French adults. This cross-sectional analysis included 21,516 participants from the NutriNet-Santé cohort (26.4% male, mean age 55.3 years; SD = 13.8). Cognitive restraint was evaluated by the Three-Factor Eating Questionnaire and practice of weight-loss diet in the past years was assessed by an ad hoc questionnaire. Organic food intake of 17 food groups was assessed by the Organic-Food Frequency Questionnaire. Adjusted means of proportions of organic food intakes out of total food intakes were compared across quartiles of the cognitive restraint score and weight loss diet history. Analyses were adjusted for sociodemographic and lifestyle factors. Women with higher levels of cognitive restraint had in average a lower contribution of organic foods in their diet (26.5% in Q4 vs. 30.9% in Q1; p < 0.0001). In addition, women with a history of weight loss diet had in average a lower contribution of organic foods in their diet (27.1% in current/past vs. 28.5% in never dieters; p = 0.0012). Associations were observed in men for specific food groups. Overall, individuals, and in particular women, with higher cognitive restraint scores or with a history of weight loss diet consumed less organic food. Results suggest that it can be too complex to follow both weight control and organic food choice strategies at the same time.


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