Academic literature on the topic 'Leaf angle impacts'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Leaf angle impacts.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Leaf angle impacts"
1
Zhang, Libo, Jian Jin, Liangju Wang, Tanzeel U. Rehman, and Mark T. Gee. "Elimination of Leaf Angle Impacts on Plant Reflectance Spectra Using Fusion of Hyperspectral Images and 3D Point Clouds." Sensors 23, no. 1 (December 21, 2022): 44. http://dx.doi.org/10.3390/s23010044.
Full textAbstract:
During recent years, hyperspectral imaging technologies have been widely applied in agriculture to evaluate complex plant physiological traits such as leaf moisture content, nutrient level, and disease stress. A critical component of this technique is white referencing used to remove the effect of non-uniform lighting intensity in different wavelengths on raw hyperspectral images. However, a flat white tile cannot accurately reflect the lighting intensity variance on plant leaves, since the leaf geometry (e.g., tilt angles) and its interaction with the illumination severely impact plant reflectance spectra and vegetation indices such as the normalized difference vegetation index (NDVI). In this research, the impacts of leaf angles on plant reflectance spectra were summarized, and an improved image calibration model using the fusion of leaf hyperspectral images and 3D point clouds was built. Corn and soybean leaf samples were imaged at different tilt angles and orientations using an indoor desktop hyperspectral imaging system and analyzed for differences in the NDVI values. The results showed that the leaf’s NDVI largely changed with angles. The changing trends with angles differed between the two species. Using measurements of leaf tilt angle and orientation obtained from the 3D point cloud data taken simultaneously with the hyperspectral images, a support vector regression (SVR) model was successfully developed to calibrate the NDVI values of pixels at different angles on a leaf to a same standard as if the leaf was laid flat on a horizontal surface. The R-squared values between the measured and predicted leaf angle impacts were 0.76 and 0.94 for corn and soybean, respectively. This method has a potential to be used in any general plant imaging systems to improve the phenotyping quality.
2
Roth, Benjamin D., Adam A. Goodenough, Scott D. Brown, Jan A. van Aardt, M. Grady Saunders, and Keith Krause. "Simulations of Leaf BSDF Effects on Lidar Waveforms." Remote Sensing 12, no. 18 (September 8, 2020): 2909. http://dx.doi.org/10.3390/rs12182909.
Full textAbstract:
Establishing linkages between light detection and ranging (lidar) data, produced from interrogating forest canopies, to the highly complex forest structures, composition, and traits that such forests contain, remains an extremely difficult problem. Radiative transfer models have been developed to help solve this problem and test new sensor platforms in a virtual environment. Many forest canopy studies include the major assumption of isotropic (Lambertian) reflecting and transmitting leaves or non-transmitting leaves. Here, we study when these assumptions may be valid and evaluate their associated impacts/effects on the lidar waveform, as well as its dependence on wavelength, lidar footprint, view angle, and leaf angle distribution (LAD), by using the Digital Imaging and Remote Sensing Image Generation (DIRSIG) remote sensing radiative transfer simulation model. The largest effects of Lambertian assumptions on the waveform are observed at visible wavelengths, small footprints, and oblique interrogation angles relative to the mean leaf angle. For example, a 77% increase in return signal was observed with a configuration of a 550 nm wavelength, 10 cm footprint, and 45° interrogation angle to planophile leaves. These effects are attributed to (i) the bidirectional scattering distribution function (BSDF) becoming almost purely specular in the visible, (ii) small footprints having fewer leaf angles to integrate over, and (iii) oblique angles causing diminished backscatter due to forward scattering. Non-transmitting leaf assumptions have the greatest error for large footprints at near-infrared (NIR) wavelengths. Regardless of leaf angle distribution, all simulations with non-transmitting leaves with a 5 m footprint and 1064 nm wavelength saw around a 15% reduction in return signal. We attribute the signal reduction to the increased multiscatter contribution for larger fields of view, and increased transmission at NIR wavelengths. Armed with the knowledge from this study, researchers will be able to select appropriate sensor configurations to account for or limit BSDF effects in forest lidar data.
3
Zhang, Weikang, Zhi Zhang, Huan Meng, and Tong Zhang. "How Does Leaf Surface Micromorphology of Different Trees Impact Their Ability to Capture Particulate Matter?" Forests 9, no. 11 (October 30, 2018): 681. http://dx.doi.org/10.3390/f9110681.
Full textAbstract:
Particulate matter (PM), including PM10 and PM2.5, has a major impact on air quality and public health. It has been shown that trees can capture PM and improve air quality. In this study, we used two-way ANOVA to investigate the significance of micro-morphological leaf surface characteristics of green trees in capturing PM at different parks in Beijing. The results show that leaf structure significantly impacts the ability of plants to capture PM. Pinus tabuliformis Carr. and Pinus bungeana Zucc. were mainly impacted by the density of stomata, waxy cuticle, and epidermis, while the major contributor to PM retention in other test trees, including Acer truncatum Bunge, Salix matsudana Koid., Populus tomentosa Carr. and Ginkgo biloba Linn. was leaf roughness. There were significant variations in leaf-droplet contact angle (representative of leaf wettability) and the ability of trees to capture PM (p < 0.05): the bigger the contact angle, the less able the plant was to capture particulate matter.
4
Kern, Stephen O., Mark J. Hovenden, and Gregory J. Jordan. "The impacts of leaf shape and arrangement on light interception and potential photosynthesis in southern beech (Nothofagus cunninghamii)." Functional Plant Biology 31, no. 5 (2004): 471. http://dx.doi.org/10.1071/fp03211.
Full textAbstract:
The impact of differences in leaf shape, size and arrangement on the efficiency of light interception, and in particular the avoidance of photoinhibition, are poorly understood. We therefore estimated light exposure of branches in the cool temperate rainforest tree, Nothofagus cunninghamii (Hook.) Oerst., in which leaf shape, size and arrangement vary systematically with altitude and geographic origin. Measurements of incident photosynthetic photon flux density (PPFD) were made in the laboratory at solar angles corresponding to noon at summer solstice, winter solstice and equinox on branches collected from a common garden experiment. Tasmanian plants showed more self-shading than Victorian plants in summer and equinox. This was related to branch angle, leaf arrangement and leaf shape. Using a modelled light response-curve, we estimated the carbon assimilation rate and the flux density of excess photons at different incident PPFD. Victorian plants had higher predicted assimilation rates than Tasmanian plants in summer and equinox, but were exposed to substantially greater levels of excess photons. Because of the shape of the light-response curve, self-shading appears to reduce the plant's exposure to excess photons, thus providing photoprotection, without substantially reducing the carbon assimilation rate. This is dependent on both regional origin and season.
5
Lenz, Anne-Kristin, Ulrike Bauer, and Graeme D. Ruxton. "An ecological perspective on water shedding from leaves." Journal of Experimental Botany 73, no. 4 (November 2, 2021): 1176–89. http://dx.doi.org/10.1093/jxb/erab479.
Full textAbstract:
Abstract Water shedding from leaves is a complex process depending on multiple leaf traits interacting with rain, wind, and air humidity, and with the entire plant and surrounding vegetation. Here, we synthesize current knowledge of the physics of water shedding with implications for plant physiology and ecology. We argue that the drop retention angle is a more meaningful parameter to characterize the water-shedding capacity of leaves than the commonly measured static contact angle. The understanding of the mechanics of water shedding is largely derived from laboratory experiments on artificial rather than natural surfaces, often on individual aspects such as surface wettability or drop impacts. In contrast, field studies attempting to identify the adaptive value of leaf traits linked to water shedding are largely correlative in nature, with inconclusive results. We make a strong case for taking the hypothesis-driven experimental approach of biomechanical laboratory studies into a real-world field setting to gain a comprehensive understanding of leaf water shedding in a whole-plant ecological and evolutionary context.
6
Yang, Guotao, Rong Liu, Peng Ma, Hong Chen, Rongping Zhang, Xuechun Wang, Yongyan Li, and Yungao Hu. "Effects of Nitrogen and Phosphorus Regulation on Plant Type, Population Ecology and Sheath Blight of Hybrid Rice." Plants 11, no. 17 (September 2, 2022): 2306. http://dx.doi.org/10.3390/plants11172306.
Full textAbstract:
(1) Background: Sheath blight is one of the most economically significant rice diseases worldwide. A study was conducted in order to find the relationship and impact of the amount of nitrogen (N) and phosphorus (P) application on the hybrid rice population microclimate and the severity of sheath blight. (2) Methods: Four N and four P application levels were used to determine their impact on plant type, temperature, and humidity variation in different positions of population and the severity of sheath blight in the later stage. (3) Results: We found that N and P application levels could affect the plant type and change the population temperature and humidity by increasing the leaf length and leaf angle. (4) Conclusions: N application had a more significant (p < 0.05) impact on the plant type. High N application caused decreased temperature (hybrid rice population), while increased humidity (especially the population base layer at grain filling stage) resulted in severe sheath blight. High P application had similar impacts; however, P application increased material and nitrogen transport in plants and reduced the severity of sheath blight.
7
Chen, Xiuqin, Liangmiao Qiu, Qiquan Liu, and Yuxian He. "Preparation of an Environmentally Friendly Nano-Insecticide through Encapsulation in Polymeric Liposomes and Its Insecticidal Activities against the Fall Armyworm, Spodoptera frugiperda." Insects 13, no. 7 (July 13, 2022): 625. http://dx.doi.org/10.3390/insects13070625.
Full textAbstract:
The insecticide emamectin benzoate (EB) was formulated with nanoparticles composed of DSPE-PEG2000-NH2 by the co-solvent method to determine its adverse impacts on the environment and to reinforce its dispersion, adhesion, and biocompatibility. A good encapsulation efficiency (70.5 ± 1.5%) of EB loaded in DSPE-PEG2000-NH2 polymeric liposomes was confirmed. Dynamic light scattering (DLS), transmission electron microscopy (TEM), and contact angle meter measurements revealed that the DSPE-EB nanoparticles had a regular distribution, spherical shape, and good leaf wettability. The contact angle on corn leaves was 47.26°, and the maximum retention was higher than that of the reference product. DSPE-EB nanoparticles had strong adhesion on maize foliage and a good, sustained release property. The efficacy trial showed that the DSPE-EB nanoparticles had a strong control effect on S. frugiperda larvae, with the LC50 of 0.046 mg/L against the third-instar S. furgiperda larve after 48 h treatment. All these results indicate that DSPE-EB nanoparticles can serve as an insecticide carrier with lower environmental impact, sustained release property, and effective control of pests.
8
Li, Ping, Jinxin Wang, Jiale Huang, and Jianhua Xiang. "The Transitional Wettability on Bamboo-Leaf-like Hierarchical-Structured Si Surface Fabricated by Microgrinding." Nanomaterials 12, no. 16 (August 22, 2022): 2888. http://dx.doi.org/10.3390/nano12162888.
Full textAbstract:
Stabilizing the hydrophobic wetting state on a surface is essential in heat transfer and microfluidics. However, most hydrophobic surfaces of Si are primarily achieved through microtexturing with subsequent coating or modification of low surface energy materials. The coatings make the hydrophobic surface unstable and impractical in many industrial applications. In this work, the Si chips’ wettability transitions are yielded from the original hydrophilic state to a stable transitional hydrophobic state by texturing bamboo-leaf-like hierarchical structures (BLHSs) through a diamond grinding wheel with one-step forming. Experiments showed that the contact angles (CAs) on the BLHS surfaces increased to 97° and only reduced by 2% after droplet impacts. This is unmatched by the current texturing surface without modification. Moreover, the droplets can be split up and transferred by the BLHS surfaces with their 100% mass. When the BLHS surfaces are modified by the low surface energy materials’ coating, the hydrophobic BLHS surfaces are upgraded to be superhydrophobic (CA > 135°). More interestingly, the droplet can be completely self-sucked into a hollow micro-tube within 0.1 s without applying external forces. A new wetting model for BLHS surfaces based on the fractal theory is determined by comparing simulated values with the measured static contact angle of the droplets. The successful preparation of the bamboo-leaf-like Si confirmed that transitional wettability surfaces could be achieved by the micromachining of grinding on the hard and brittle materials. Additionally, this may expand the application potential of the key semiconductor material of Si.
9
Yun, Jiang, Hou, An, Chen, Jiang, Li, and Xue. "Rubber Tree Crown Segmentation and Property Retrieval using Ground-Based Mobile LiDAR after Natural Disturbances." Remote Sensing 11, no. 8 (April 13, 2019): 903. http://dx.doi.org/10.3390/rs11080903.
Full textAbstract:
Rubber trees in southern China are often impacted by natural disturbances, and accurate rubber tree crown segmentation and property retrieval are of great significance for forest cultivation treatments and silvicultural risk management. Here, three plots of different rubber tree clones, PR107, CATAS 7-20-59, and CATAS 8-7-9, that were recently impacted by hurricanes and chilling injury, were taken as the study targets. Through data collection using ground-based mobile light detection and ranging (LiDAR) technology, a weighted Rayleigh entropy method based on the scanned branch data obtained from the region growing algorithm was proposed to calculate the trunk inclination angle and crown centre of each tree. A watershed algorithm based on the extracted crown centres was then adopted for tree crown segmentation, and a variety of tree properties were successfully extracted to evaluate the susceptibility of different rubber tree clones facing natural disturbances. The results show that the angles between the first-order branches and trunk ranged from 35.1–67.7° for rubber tree clone PR107, which is larger than the angles for clone CATAS 7-20-59, which ranged from 20.2–43.2°. Clone PR107 had the maximum number of scanned leaf points, lowest tree height, and a crown volume that was larger than that of CATAS 7-20-59, which generates more frontal leaf area to oppose wind flow and reduces the gaps among tree crowns, inducing strong wind loading on the tree body. These factors result in more severe hurricane damage, resulting in trunk inclination angles that are larger for PR107 than CATAS 7-20-59. In addition, the rubber tree clone CATAS 8-7-9 had the minimum number of scanned leaf points and the smallest tree crown volume, reflecting its vulnerability to both hurricanes and chilling injury. The results are verified by field measurements. The work quantitatively assesses the susceptibility of different rubber tree clones under the impacts of natural disturbances using ground-based mobile LiDAR.
10
Liu, Leizhen, Wenhui Zhao, Jianjun Wu, Shasha Liu, Yanguo Teng, Jianhua Yang, and Xinyi Han. "The Impacts of Growth and Environmental Parameters on Solar-Induced Chlorophyll Fluorescence at Seasonal and Diurnal Scales." Remote Sensing 11, no. 17 (August 24, 2019): 2002. http://dx.doi.org/10.3390/rs11172002.
Full textAbstract:
Solar-induced chlorophyll fluorescence (SIF) is considered to be a potential indicator of photosynthesis. However, the impact of growth and environmental parameters on SIF at different time-scales remains unclear, which has greatly restricted the application of SIF in detecting photosynthesis variations. Thus, in this study, the impact of growth and environmental parameters on SIF was thoroughly clarified. Here, continuous time series of canopy SIF (760 nm, F760) over wheat and maize was measured based on an automated spectroscopy system. Meanwhile, field measurements of growth and environmental parameters were also collected using commercial-grade devices. Relationships of these parameters with F760, apparent SIF (F760/solar radiance, AF760), and SIF yield (F760/canopy radiance of 685 nm, Fy760) were analyzed using principal component analysis (PCA) and Pearson correlation to reveal their impacts on SIF. Results showed that F760 at seasonal and diurnal scales were mainly driven by solar radiation (SWR), leaf area index (LAI), chlorophyll content (Chl), mean leaf inclination angle (MTA), and relative water content (RWC). Other environmental parameters, including air temperature (Ta), relative humidity (Rh), vapor pressure deficit (VPD), and soil moisture (SM), contribute less to the variation of seasonal or diurnal F760. AF760 and Fy760 are likely to be less dependent on Ta, Rh, and VPD due to the removal of the impact from SWR, but an enhanced relationship of AF760 (and Fy760) with SM was observed, particularly under water stress. Compared with F760, wheat AF760 was better correlated to LAI and RWC as expected, while maize AF760 did not show an enhanced relationship with all growth parameters, probably due to its complicated canopy structure. The relationship of wheat Fy760 with canopy structure parameters was further reduced, except for maize measurements. Furthermore, SM-induced water stress and phenological stages should be taken into consideration when we interpret the seasonal and diurnal patterns of SIF since they were closely related to photosynthesis and plant growth (e.g., LAI in our study). To our knowledge, this is the first exploration of the impacts of growth and environmental parameters on SIF based on continuous ground measurements, not only at a seasonal scale but also at a diurnal scale. Our results could provide deep insight into the variation of SIF signals and also promote the further application of SIF in the health assessments of terrestrial ecosystems.
Dissertations / Theses on the topic "Leaf angle impacts"
1
Twohy, Kyra Elizabeth. "Impact of an Ankle Foot Orthosis on Reactive Stepping in Healthy Young Adults Using a Lean-and-Release Paradigm." University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1597064801653152.
Full textBooks on the topic "Leaf angle impacts"
1
Anderson, Owen. Running Form. Human Kinetics, 2019. http://dx.doi.org/10.5040/9781718214590.
Full textAbstract:
For many runners, running technique is an afterthought—one they don't think about until an injury or plateau keeps them from achieving their goals. Running Form underscores the importance of proper form and shows you how to elevate your performance to the greatest possible extent with the smallest risk of injury. Owen Anderson, PhD, is a coach to elite runners from around the globe. In Running Form, he describes the common problem of runners moving on “square wheels” by braking with each step, adopting inefficient stances, or risking injury with excessive ground impact. He pinpoints the components of good form—foot-strike, shin and shank angle, stance time, cadence, body lean, and posture—to help you understand where you can make small changes that offer significant improvements. Then, using a basic video camera or smartphone, you can analyze your own form and apply specific drills and exercises to correct any deficiencies. Numerous photos incorporate lines and arrows to help you clearly identify the appropriate angles and movements of sound technique. No expensive software or biomechanics degree is required to learn how to run faster and with more efficiency and to significantly reduce your risk of injury. Get rid of those running patterns that hurt performance and destroy running economy. Running Form gives you the knowledge to perfect your running form so you can train consistently and improve with each stride. AUDIENCE A guide for serious runners, coaches, and triathletes. Runners who have experienced chronic injuries due to form flaws will appreciate this book.
2
Davage, William. The Congress Movement. Edited by Stewart J. Brown, Peter Nockles, and James Pereiro. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199580187.013.41.
Full textAbstract:
In this chapter the author explores the origin of the Anglo-Catholic Congress Movement, the Congresses held in the 1920s and 1930s and their impact on the Catholic Revival, and the amalgamation of the Congress Movement and the English Church Union. The chapter argues that the Congresses marked the high-water mark of the Catholic Revival and formed the most substantial articulation of the Catholic Revival. However, within that conspectus there could also be discerned the shaping of different understandings of the Movement, which would lead to divisions within the Catholic Movement and its loss of influence in the late twentieth century.
3
Erickson, Christina L. Spanked. Oxford University PressNew York, 2022. http://dx.doi.org/10.1093/oso/9780197518236.001.0001.
Full textAbstract:
Abstract Tracing the history of spanking from our earliest records, the trail of spankings’ influence on society and individuals is explored. The book covers the slow transition from the whip and rod to the hand, the first questioning of spankings’ utility, and the inception of spanking stigma. Stories of religion, school paddling, and the development of child protection in the United States highlight historical factors on the edges of spanking and show their connections to our modern conundrum—why do we hit people smaller than us who we love so much? To understand the real meaning of spanking, the book explores the private lives of family and the public sphere of our social lives. Spanking has been a common and accepted discipline for hundreds of years. Filled with stories of families, researchers, and community organizers, the book helps us see varied angles of family spanking we have avoided for far too long. The research outcomes on spanking are causal and clear, and the data have been repeated in many studies. Brain research, parent child synchrony, touch, trauma, and communication all lead us to new understandings of spanking’s impact on adults and children alike. Maybe most important of all is the question never asked before: Is spanking a child good for the parent? Book group questions and prompts for organizations and professionals provide a framework for conversation and dialogue. A rich appendix includes laws on physical discipline from each state, laws on school paddling, and corporal punishment laws around the world.
Book chapters on the topic "Leaf angle impacts"
1
Kim, Cheol Woong, and Dong Joon Oh. "Characteristic of the Residual Strength Rate by Variation of Impact Velocities for the Leaf Spring in Ankle Foot Orthosis." In Materials Science Forum, 350–53. Stafa: Trans Tech Publications Ltd., 2005. http://dx.doi.org/10.4028/0-87849-966-0.350.
Full text
2
Kırbaş, İsmail, Musa Peker, Gültekin Basmacı, and Mustafa Ay. "Predictive Modeling and Optimization of Cutting Forces Through RSM and Taguchi Techniques in the Turning of ASTM B574 (Hastelloy C-22)." In Advances in Computational Intelligence and Robotics, 398–417. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-4766-2.ch018.
Full textAbstract:
In this chapter, the impact of cutting parameters (depth of cut, cutting speed, feed, flow, rake angle, lead angle) on cutting forces in the turning process with regard to ASTM B574 (Hastelloy C-22) material has been investigated. Variance analysis has been applied in order to determine the factors affecting the cutting forces. The optimization of the parameters affecting the surface roughness has been obtained using response surface methodology (RSM) based on the Taguchi orthogonal experimental design. The accuracy of the developed models required for the estimation of the force values (Fx, Fy, Fz) is quite successful. In this study, where the R2 value has been used as the criterion/measure, accuracy values of 93.35%, 95.03%, and 95.09% have been achieved for Fx, Fy, and Fz, respectively. As a result of the ANOVA analysis, the most effective parameters for Fx at a 95% confidence interval are depth of cut, feed rate, flow, and rake angle. The most effective parameter for Fy is depth of cut, while the most effective parameters for Fz are depth of cut, feed rate, and flow, respectively.
3
Stacey, Richard. "Shakespeare, King James and the Northern Yorkists." In Shakespeare in the North, 79–102. Edinburgh University Press, 2021. http://dx.doi.org/10.3366/edinburgh/9781474435925.003.0004.
Full textAbstract:
Richard Stacey develops a focus on cross-border matters to explore the Yorkist iconography and ideology underpinning James VI and I’s complex claim to the throne of England, particularly in plays debating political authority such as Macbeth and King Lear. Stacey’s innovative study of a crucial regional powerbase offers an ambitious and original reading of Shakespeare’s Scottish play as Yorkist. In doing so he extends the reach of the North as examined in this collection in extremely productive ways. This fresh interpretation of a great tragedy situates it firmly within the preoccupations of the medieval history plays of the 1590s and vitally reminds readers of the richness and complexity of the Yorkist impact on Anglo-Scottish politics in the period. This is a new lead on Macbeth as a border-crossing drama in terms of genre and geography that others will want to follow.
4
Laallam, Abdelkader, Salina Kassim, Engku Rabiah Adawiah, and Buerhan Saiti. "Towards Knowledge-Based Waqf Organizations." In Challenges and Impacts of Religious Endowments on Global Economics and Finance, 100–120. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-1245-6.ch006.
Full textAbstract:
The world is changing at a great pace and acceleration. The role of science, knowledge, and learning has emerged, in developing and adopting appropriate methods to manage and transfer knowledge and experience within an organization and making it available for everyone to share and exchange easily, through knowledge fountains and databases. This chapter introduces the concept of knowledge management to waqf institutions and the potential contribution that can be provided by this in solving many problems and challenges confronting them, in the hope of achieving a qualitative leap in performance and restoring their leading role in societies. There is some evidence that researchers have addressed the issue of knowledge management in the context of waqf institutions. Consequently, this chapter draws attention to the importance of knowledge management for waqf institutions, with the intent of providing a comprehensive understanding of this topic and its association with the organizational performance enhancements, from different angles.
5
Werneke, Ursula, and Ingvar A. Bergdahl. "Diet, environment, and mental health." In Oxford Textbook of Public Mental Health, edited by Dinesh Bhugra, Kamaldeep Bhui, Samuel Y. S. Wong, and Stephen E. Gilman, 441–58. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198792994.003.0047.
Full textAbstract:
This chapter reviews dietary and environmental factors that may affect mental health. It takes a public health angle but examines the individual patient perspective where relevant. In the first part, the chapter looks at the impact of various nutritional constituents on mental health, including omega-3 fatty acids, vitamins, and minerals. Then, it reviews the evidence for diets and ‘superfoods’, which people might try to improve their mental health. Here, the focus is on neurodevelopmental disorders, depression, and psychosis. Potential interactions between foodstuffs and psychotropic medicines are also explored. The final part concerns environmental toxins that populations may be exposed to that may affect mental health, including lead, methylmercury, and various organic compounds.
6
Davis, Ralph. "War and the Shipping Industry." In The Rise of the English Shipping Industry in the Seventeenth and Eighteenth Centuries, 303–25. Liverpool University Press, 2012. http://dx.doi.org/10.5949/liverpool/9780986497384.003.0015.
Full textAbstract:
This chapter considers the financial impact of war on British shipping during the seventeenth and eighteenth centuries. It attempts to discern the number of merchant ship losses during the Anglo-Spanish War, Anglo-French War, Seven Years’ War, and the Dutch Wars by scrutinising Admiralty records of loss estimates. It examines privateering activity; wartime insurance rates; the rise in seafaring wages; naval impressment; the disruption to trade cycles; the hiring of ships by the government; and a contrast of tonnage rates between periods of peace and war to determine the financial cost of war to the shipping industry. It concludes that though war made many demands of the merchant shipping industry, merchants and shipowners knew that successful campaigns would lead to the expansion of a British shipping monopoly, and so deemed war financially worthwhile in the long run.
7
Chapman, Graham, and Philip Helliwell. "Pathomechanics and gait analysis." In The Foot and Ankle in Rheumatology, 227–48. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780198734451.003.0013.
Full textAbstract:
Gait analysis is the systematic study of human walking. This chapter summarizes currently available gait analysis techniques that are available to the clinician and researcher. Gait analysis can be used alongside clinical history and examination and other special investigations to gain a better understanding of the relationship between joint disease, impairment, and compensatory gait mechanisms. Abnormal pathology leads to abnormal biomechanics, and tools that demonstrate these changes can lead to insights into the effects of the disease on function, in disease progression, and the impact of physical treatments. Plantar pressure measurement techniques yield valuable information on structure and function and are probably the most likely tool to be used in clinical practice. Three-dimensional joint kinematic and kinetic analyses are more difficult to perform and interpret and are likely to remain largely research tools. Gait analysis techniques will drive experimental work to further advance core knowledge and inform future development of customized approaches to conservative therapies such as footwear and orthosis manufacture, as well as foot surgery.
8
Yuce, Baris, and Ernesto Mastrocinque. "Supply Chain Network Design Using an Enhanced Hybrid Swarm-Based Optimization Algorithm." In Handbook of Research on Modern Optimization Algorithms and Applications in Engineering and Economics, 95–112. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-4666-9644-0.ch003.
Full textAbstract:
Supply chain network design is one of the most important strategic issues in operations management. The main objective in designing a supply chain is to keep the cost as low as possible. However, the modelling of a supply chain requires more than single-objective such as lead-time minimization, service level maximization, and environmental impact maximization among others. Usually these objectives may cause conflicts such as increasing the service level usually causes a growth in costs. Therefore, the aim should be to find trade-off solutions to satisfy the conflicting objectives. The aim of this chapter is to propose a new method based on a hybrid version of the Bees Algorithm with Slope Angle Computation and Hill Climbing Algorithm to solve a multi-objective supply chain network design problem. A real case from the literature has been selected and solved in order to show the potentiality of the proposed method in solving a large scale combinatorial problem.
9
Yuce, Baris, and Ernesto Mastrocinque. "Supply Chain Network Design Using an Enhanced Hybrid Swarm-Based Optimization Algorithm." In Supply Chain and Logistics Management, 266–83. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-0945-6.ch013.
Full textAbstract:
Supply chain network design is one of the most important strategic issues in operations management. The main objective in designing a supply chain is to keep the cost as low as possible. However, the modelling of a supply chain requires more than single-objective such as lead-time minimization, service level maximization, and environmental impact maximization among others. Usually these objectives may cause conflicts such as increasing the service level usually causes a growth in costs. Therefore, the aim should be to find trade-off solutions to satisfy the conflicting objectives. The aim of this chapter is to propose a new method based on a hybrid version of the Bees Algorithm with Slope Angle Computation and Hill Climbing Algorithm to solve a multi-objective supply chain network design problem. A real case from the literature has been selected and solved in order to show the potentiality of the proposed method in solving a large scale combinatorial problem.
10
"The Angler in the Environment: Social, Economic, Biological, and Ethical Dimensions." In The Angler in the Environment: Social, Economic, Biological, and Ethical Dimensions, edited by Andy J. Danylchuk, Steven J. Cooke, Cory D. Suski, Tony L. Goldberg, David Petersen, and Sascha E. Danylchuk. American Fisheries Society, 2011. http://dx.doi.org/10.47886/9781934874240.ch6.
Full textAbstract:
<i>Abstract</i> .—Recreational fishing is popular worldwide. However, the potential negative impacts of this leisure activity can influence the sustainability of targeted fish stocks. Although management strategies are frequently used to control the actions of anglers, participants themselves must ultimately be confident that changes in their behavior will lead to the conservation of recreational fish stocks before regulations are followed and best practices adopted. Directly involving recreational anglers in research used to quantify the value of best practices, such as in the case of catch and release, can help reinforce the notion among anglers that best practice behaviors facilitate conservation and sustainable exploitation. Using the framework of citizen science and the principles of experiential education (immersion, involvement, ownership, and legacy), we present a case study whereby recreational anglers were directly involved in research that tested how attributes of catch-and-release fishing for bonefish <i>Albula </i> spp. can influence the postrelease survival. By accompanying anglers to the shallow flats and actively involving them in hands-on research aimed at addressing relevant behaviors in the context of catch and release, such programs can promote an increased awareness and sense of personal ownership over the research question and the conservation benefits that it intends to facilitate. With data generated through direct involvement, the participation of recreational anglers in our research culminated in the development of a best practices brochure about catch and release for bonefish. It is our experience that research programs involving recreational anglers need to be well conceived and structured so as to adequately balance the quality of the experience for the participants with the need for generating quality data. Welldesigned “research angler” programs as a form of tourism or even ecotourism could help scientists not only to enhance their ability to conduct fisheries research, but also to broaden the impacts of their research program and the speed at which best practices are adopted.
Conference papers on the topic "Leaf angle impacts"
1
Zhang, Bin, Qian Lv, Penghua Guo, and Jingyin Li. "Experimental Study of Impact Force of a Low-Speed Droplet Colliding on the Solid Surface at Different Impact Angles." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-70882.
Full textAbstract:
Erosion problems due to droplet impacts are widely encountered in many fields. This may result in deterioration or even failure of the elements, and should be taken into consideration in the design of machines. The impact force is thought of as an essential factor in material erosion. In this paper, a highly sensitive piezoelectric force transducer was employed to record the impact force of the low-speed droplet colliding on an aluminum plate at different impact angles, in combination with a high-speed camera used to capture the impact process of the droplet. The results showed that the experimental setup can measure the impact force evolution precisely and reliably. The peak of the normal impact force increases with the normal velocity quadratically, while the impulse increases with the normal velocity linearly. In addition, a smaller impact angle would lead to longer time duration of the impact force. The high-speed images show that the initial impact patterns of the droplet have similar behavior in the initial impact process, with regardless of vertical or oblique impacts.
2
Zheng, Siyu, Jinfang Teng, Yu Wu, Fushui Guo, Shaopeng Lu, and Xiaoqing Qiang. "Impact of Nonuniform Stagger Angle Distribution on High-Pressure Compressor Rotor Performance." In ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/gt2018-76067.
Full textAbstract:
The focus of the present study is to find a solution to the manufacturing tolerances of rotor stagger angle in the high pressure compressor. The manufacturing processes of compressor blades may lead the stagger angle to be out of tolerance, which would reduce the performance of the high-pressure compressor. Meanwhile, the assembly may cause the nonuniform distribution of the variable blades. To investigate the influence of stagger angle variability and its nonuniform distribution in multiple passages, amount of 3D numerical simulations of a high pressure compressor rear-stage rotor were conducted in the present paper. The Gaussian Probabilistic Density Function was used to obtain the sampled blades with variable stagger angles, and then the blades were randomly allocated in a single passage to a half period, respectively. Numerical results show that with the increase of passage number, the total performance varies more stably. In order to get an appropriate tolerance range of the stagger angle to control the deterioration of the total performance, different ranges were tried, and [−1.5°, +1.5°] was determined as the final range to do further analyses. The different stagger angle distribution along the circumferential direction of a specific group of several sampled blades led to the different performance variations. When the stagger angle distribution approximately satisfied the sinusoidal function during assembly, the rotor performance was better than other distributions. Hence, the sinusoidal function during assembly is an effective solution to the manufacturing tolerances of rotor stagger angle.
3
MUTHULINGAM, JEEVA, NAND KISHORE SINGH, RATNESHWAR JHA, and BEHRAD KOOHBOR. "MODELING COLD SPRAY DEPOSITION OF THERMOPLASTIC POLYMERS: EFFECTS OF IMPACT ANGLE AND TEMPERATURE." In Proceedings for the American Society for Composites-Thirty Seventh Technical Conference. Destech Publications, Inc., 2022. http://dx.doi.org/10.12783/asc37/36387.
Full textAbstract:
Cold spray additive manufacturing is gaining popularity for polymers due to its low operating temperature and reduced manufacturing time. In the present study, the likeon- like impact of single thermoplastic polymer (polyether ether ketone, PEEK) particles on PEEK substrates is modeled to explore the effects of impact angle, initial particle temperature, and impact velocity on cohesion. The particle impact angle varies from 30o to 90o with 15o intervals for impact velocities ranging from 200 to 1000 m/s. Particle temperature in each case is varied from room temperature to the glass transition temperature of PEEK. Results obtained herein provide an insight into the energy balance and the temperature-velocity conditions likely to lead to bond formation. Modeling results demonstrate that the likelihood of bond formation increases with an increase in impact angle, particle temperature, and velocity, at the cost of bond strength.
4
Wu, Jie, and Jiejin Cai. "Initial Wire-Wrapped Angle Optimization Analysis of a Liquid Lead-Bismuth Cooled Fuel Assembly Based on OpenFOAM." In 2022 29th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/icone29-92097.
Full textAbstract:
Abstract The helical wire spacer of liquid lead-bismuth cooled fast reactor (LFR) fuel assembly plays a significant role in the strengthening of the flow and heat transfer. However, most LFRs have a fixed initial angle of wire-wrapped direction in rod bundles, and the optimization analysis of their angle in the subchannel is absent. More analysis of the impacts that the wire spacer has on the liquid lead-bismuth eutectic (LBE) coolant should be obtained. In this paper, three different turbulence viscosity models and two constant turbulent Prandtl numbers were applied in the open source Computational Fluid Dynamics (CFD) platform OpenFOAM. The numerical results, which were considered with an extensive mesh sensitivity study, were validated against a series of experiment data. The simulations about key thermal hydraulic parameters such as temperature, velocity distribution, pressure drop, local and average Nusselt number were carried out based on 7-pin wire-wrapped rod bundles whose wires winding from internal, edge and corner channel. The results show that the k-ε model with Prt = 2.0 can be used to predict the flow and heat transfer characteristics of LBE. The influence of wire-wrapped starting position indicates that an optimum point exists in the internal channel. This work is useful in future safety design of fuel assemblies in the LFR.
5
Lee, Samuel P., Simon M. Barrans, Martyn L. Jupp, and Ambrose K. Nickson. "Investigation Into the Impact of Span-Wise Flow Distribution on the Performance of a Mixed Flow Turbine." In ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/gt2018-76992.
Full textAbstract:
Current trends in the automotive industry towards engine downsizing means turbocharging now plays a vital role in engine performance. A turbocharger increases charge air density using a turbine to extract waste energy from the exhaust gas to drive a compressor. Most turbocharger applications employ a radial inflow turbine. However, to ensure radial stacking of the blade fibers and avoid excessive blade stresses, the inlet blade angle must remain at zero degrees. Alternately, mixed flow turbines can offer non-zero blade angles while maintaining radial stacking of the blade fibers. The additional freedom to manipulate the blade leading edge and varying tip speed allow for varying leading edge incidence in the span-wise direction. Furthermore, the flow development in the volute does not necessarily lead to uniform inlet conditions. The current paper investigates the performance of a mixed flow rotor passage under a range of span-wise flow distributions including that produced by a turbine volute. Initial unsteady pulsating simulations were conducted and the volute exit flows extracted. These distributions were then applied as boundary conditions to a single passage model. All simulations were carried out at a constant MFP and average leading edge relative flow angle. It was observed that the different inlet flow distributions resulted in marked difference in passage flow characteristics. A 2.17% variation was observed between cases in the radial passage. A tilted passage was also included providing an increased axial flow component at the inlet. This passage was found to result in greater swallowing capacity when compared to that of the radial passage.
6
Funazaki, K., C. F. F. Favaretto, and T. Tanuma. "Effects of Flow Injection From Outer Casing Upon Turbine Nozzle Vane Flow Field." In ASME Turbo Expo 2002: Power for Land, Sea, and Air. ASMEDC, 2002. http://dx.doi.org/10.1115/gt2002-30598.
Full textAbstract:
In the present paper steady three-dimensional numerical calculations were performed in order to investigate the effects of flow injection from the outer casing upon turbine nozzle vane flow field. Several test cases were analyzed by applying different nozzle vane configurations such as the blade lean, injection slot width and distance from the leading edge. Numerical simulations were conducted considering the no injection case, 5% and 10% main stream flow injection from the outer casing. The impact of the flow injection design variables and the blade lean angle on the aerodynamic loss in terms of the energy loss coefficient and the outlet flow angle were analyzed through a parametric study.
7
Vijay, S., B. Roy, N. Markocsan, and C. Lyphout. "Wetting Properties of Ceramic Reinforced Metal Matrix Composites on Varied Roughness Profiles." In ITSC2017, edited by A. Agarwal, G. Bolelli, A. Concustell, Y. C. Lau, A. McDonald, F. L. Toma, E. Turunen, and C. A. Widener. DVS Media GmbH, 2017. http://dx.doi.org/10.31399/asm.cp.itsc2017p0537.
Full textAbstract:
Abstract Superhydrophobic surfaces are of great importance in many industrial applications, especially where components are exposed to wet environments and low temperatures. Texturing of surfaces to reach superhydrophobicity can be achieved by thermal spraying technology, which is an attractive coating method as it is cheap, flexible and can employ a large range of feedstock materials. In this study, ceramic reinforced metal matrix composite (WC-CoCr) powders were sprayed using High Velocity Air Fuel method. They were varied based on their powder parameters such as carbide grain size, binder grain size and powder strength. The purpose was to investigate their hydrophobic characteristics and how these are influenced by different roughness profiles. The wetting properties such as contact angle and contact angle hysteresis were first investigated for the as-sprayed coatings. The roughness properties and Hausdorff Dimension were then related to the wetting properties. Aside from as-sprayed coatings, the effect of roughness and inherent wetting characteristics were studied by investigating the coating surface after grit blasting and polishing. Results show that powder parameters can lead to designing surfaces with higher surface roughnesses and thus having higher contact angles. It was also shown that surface composition of cermets has an impact on wettability, with the binder accounting for wetting characteristics and carbides accounting for roughness.
8
LI, JIN-MING, WEI WEI, WEN-MIN YAN, and SHU WANG. "ANALYSIS ON THE CORRELATION BETWEEN BULLETS DEFORMATION AND INCIDENT PARAMETERS OF PISTOL BULLET IMPACT TO CONCRETE." In 32ND INTERNATIONAL SYMPOSIUM ON BALLISTICS. Destech Publications, Inc., 2022. http://dx.doi.org/10.12783/ballistics22/36191.
Full textAbstract:
To study the correlation between the bullets deformation characteristics and incident parameters of a 7.62mm lead pistol bullet during impacting to concrete, and to find the sensitivity relationship between each characteristic eigenvalue and quantity parameters, the finite element model of a 7.62mm lead pistol bullet hitting the concrete target was established. The accuracy and effectiveness of the numerical simulation were verified by experiments, and the numerical method can truly reproduce the motion behavior of the bullets in the process of hitting concrete. The results showed that under normal penetration, the angle between the impact surface and the projectile axis can be judged as a normal penetration, the height of the bullet decreases with the increase of incident velocity and is more sensitive to incident velocity, and the deformation of the bullet showed more characteristics under oblique penetration, and the changing trend of each eigenvalue at a different incident angle is similar. In addition, the grey correlation analysis of each eigenvalue of bullets deformation was carried out, and the sensitivity relationship of each eigenvalue to incident parameters was obtained, which provides technical support for the ballistic reconstruction of gun-related cases.
9
Le Rouzic, Julian, and Mihai Arghir. "Experimental Analysis of Angled Injection Aerostatic Hybrid Bearings." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-63558.
Full textAbstract:
Counter-rotation angled injection employed for aerostatic hybrid bearings reduces the cross coupling stiffness that may lead to whirl-whip instabilities at high rotation speeds. The benefits of counter-rotation injection have been known for years. Theoretical investigations were performed for water or air fed hybrid bearings but experiments were conducted only for water fed bearings. The present work is the first effort dedicated to angled injection in air fed hybrid bearings. The tests were performed for a simple rotor supported by two identical hybrid bearings. The hybrid bearings are provided with small size, shallow pockets and are fed with air via counter-rotation oriented orifice type restrictors. An impulse turbine fed with air entrains the rotor. An impact gun applies dynamic excitations and the rotordynamic coefficients are identified from the equations of motion of the rotor. Different air feeding pressures are tested as well as high rotational speeds. Compared to the dynamic characteristics of radial injection hybrid bearings, the direct stiffness of counter-rotation injection bearings has slightly lower values and the direct damping is higher but the main impact is the drastic reduction of the cross-coupling stiffness that may have even negative values.
10
Yipeng, Cao, Ma Zequn, and Liu Chen. "Sensitivity Analysis of Impeller Blade Parameters to Compressor Performance and Aerodynamic Noise." In ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-81705.
Full textAbstract:
Abstract The effects of a series of impeller blade parameters on compressor performance and aerodynamic noise are numerical analyzed in this paper. The inversed impeller blade model of a turbocharger compressor was first constructed by the reverse engineering method. Then, the performance and aerodynamic noise of the inversed impeller blade model was validated using a numerical approach, which combines computational fluid dynamics (CFD) and computational aerodynamic acoustics (CAA). A parameterization of blade starts from the inversed impeller and then morphs it with a number of design parameters, which including tip clearance, the curvature of cut-off trailing edge, exit lean angle, inlet blade angle on shroud and inlet blade angle on hub. The influence of different structural parameters on compressor performance and noise was studied, and the sensitivity analysis of different structural parameters was carried out based on the Morris’s method. The results indicate that the tip clearance, the outlet lean angle of blade and the inlet blade angle at shroud have a significant effect on compressor aerodynamic performance, while the curvature of cut-off trailing edge and the inlet blade angle on hub have less impact. The overall sound pressure level (OASPL) of the aerodynamic noise radiated at compressor inlet shows that the inlet blade angle on shroud and the inlet blade angle on hub have a significant effect on compressor aerodynamic noise. The results of sensitivity analysis further indicate that the tip clearance and the inlet blade angle on shroud are the main parameters that affect compressor aerodynamic performance and noise.
Reports on the topic "Leaf angle impacts"
1
Nafakh, Abdullah Jalal, Franklin Vargas Davila, Yunchang Zhang, Jon D. Fricker, and Dulcy M. Abraham. Workzone Lighting and Glare on Nighttime Construction and Maintenance Activities. Purdue University, 2022. http://dx.doi.org/10.5703/1288284317379.
Full textAbstract:
Over the last two decades, an increasing number of highway construction and maintenance projects in the United States have been completed at night to avoid or alleviate traffic congestion delays. Working at night entails several advantages, including lower traffic volumes, less impact on local businesses, cooler temperatures for equipment and material, and fewer overall crashes. Although nighttime roadway operations may minimize traffic disruptions, there are several safety concerns about passing motorists and workers in the nighttime work zone. For instance, improper lighting arrangements or excessive lighting levels at the job site could cause harmful levels of glare for the traveling public and workers, which can lead to an increased level of hazards and crashes in the vicinity of the work zone. To address the issue of glare, the current report focuses on determining and evaluating disability glare on nighttime work zones in order to develop appropriate strategies for improving the safety of workers and motorists during nighttime highway construction and maintenance projects. Disability glare is the glare that impairs our vision of objects without necessarily causing discomfort, and it can be evaluated using the veiling luminance ratio (VL ratio). In this study, disability glare values were determined by using lighting data (vertical illuminance and pavement luminance measurements) from the testing of 49 lighting arrangements. Two LED balloon lights, a metal-halide light tower, and an LED light tower were utilized for the field lighting experiments. The glare assessment analyzed the effects of the lighting system setup’s parameters, such as the mounting height, power output, rotation angle, and aiming angle of luminaires on the veiling luminance ratio values (which is a criterion for limiting disability glare). The study revealed the following key findings: (1) an increase in mounting heights of both balloon lights and light towers resulted in lower disability glare levels; (2) compared to the "perpendicular" and "away" orientations, orienting the light towers "towards" the traffic (45 degrees) significantly increases the disability glare levels of the lighting arrangement; and (3) increasing the tilt angles of portable light tower luminaries resulted in an increase in disability glare levels.
2
Wilson, D., Michael Shaw, Vladimir Ostashev, Michael Muhlestein, Ross Alter, Michelle Swearingen, and Sarah McComas. Numerical modeling of mesoscale infrasound propagation in the Arctic. Engineer Research and Development Center (U.S.), October 2022. http://dx.doi.org/10.21079/11681/45788.
Full textAbstract:
The impacts of characteristic weather events and seasonal patterns on infrasound propagation in the Arctic region are simulated numerically. The methodology utilizes wide-angle parabolic equation methods for a windy atmosphere with inputs provided by radiosonde observations and a high-resolution reanalysis of Arctic weather. The calculations involve horizontal distances up to 200 km for which interactions with the troposphere and lower stratosphere dominate. Among the events examined are two sudden stratospheric warmings, which are found to weaken upward refraction by temperature gradients while creating strongly asymmetric refraction from disturbances to the circumpolar winds. Also examined are polar low events, which are found to enhance negative temperature gradients in the troposphere and thus lead to strong upward refraction. Smaller-scale and topographically driven phenomena, such as low-level jets, katabatic winds, and surface-based temperature inversions, are found to create frequent surface-based ducting out to 100 km. The simulations suggest that horizontal variations in the atmospheric profiles, in response to changing topography and surface property transitions, such as ice boundaries, play an important role in the propagation.