Academic literature on the topic 'Fog layer'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Fog layer.'

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 "Fog layer"

1

Singh, Sonia, Ankita Bansal, Rajinder Sandhu, and Jagpreet Sidhu. "Fog computing and IoT based healthcare support service for dengue fever." International Journal of Pervasive Computing and Communications 14, no. 2 (June 4, 2018): 197–207. http://dx.doi.org/10.1108/ijpcc-d-18-00012.

Full text
Abstract:
Purpose This paper has proposed a Fog architecture-based framework, which classifies dengue patients into uninfected, infected and severely infected using a data set built in 2010. The aim of this proposed framework is to developed a latency-aware system for classifying users into different categories based on their respective symptoms using Internet of Things (IoT) sensors and audio and video files. Design/methodology/approach To achieve the aforesaid aim, a smart framework is proposed, which consist of three components, namely, IoT layer, Fog infrastructure and cloud computing. The latency of the system is reduced by using network devices located in the Fog infrastructure. Data generated by IoT layer will first be processed by Fog layer devices which are in closer proximity of the user. Raw data and data generated will later be stored on cloud infrastructure, from where it will be sent to different entities such as user, hospital, doctor and government healthcare agencies. Findings Experimental evaluation proved the hypothesis that using the Fog infrastructure can achieve better response time for latency sensitive applications with the least effect on accuracy of the system. Originality/value The proposed Fog-based architecture can be used with IoT to directly link it with the Fog layer.
APA, Harvard, Vancouver, ISO, and other styles
2

Han, Yu, De Liu, Huan Wang, and Fan Hua Min. "Cause Analysis of Rainy Fog and Radiation Fog in Chongqing." Advanced Materials Research 599 (November 2012): 261–67. http://dx.doi.org/10.4028/www.scientific.net/amr.599.261.

Full text
Abstract:
With the NCEP reanalysis data and L-band radar data to analyze the circulation situation and the vertical structure of temperature, humidity and wind speed of radiation fog and rainy fog in Chongqing by compositely analysis method. The result shows that: When radiation fog takes place, the 500hPa areas of Central Asia and Qinghai-Tibet plateau become high pressure ridge, and the cold front have reached the South China. When rainy fog takes place, the 500hPa area of Qinghai-Tibet plateau is controlled by the low pressure trough and the center of ground cold anticyclone will be in the northern area of China. Temperature inversion in the surface layer is obviously stronger when it’s radiation fog than rainy fog; And the moisture vertical structure are reflected as being dry in the upper layer, being moist in the lower layer when radiation fog occurs, and the moisture layer being deep and thick when rainy fog takes place. However in regard to wind speed, it’s slow in the surface layer during the formation of each fog.
APA, Harvard, Vancouver, ISO, and other styles
3

Wang, Zhao Yu, Bin Gui Wu, and He Huang. "Tower Atmosphere Characteristic of Advection Fog." Applied Mechanics and Materials 137 (October 2011): 369–73. http://dx.doi.org/10.4028/www.scientific.net/amm.137.369.

Full text
Abstract:
Using the profile data observed by the Tianjin 250m Meteorological Tower, vertical distribution characteristic of meteorological elements in the advection fog on Feb. 13, 2006 has been analyzed. The results show that the meteorological elements distribution of the fog is distinct from known fog structure. The lower atmosphere state gradually became moist unstable which the temperature decreased at wet-adiabatic lapse rate and humidity increased obviously in 250m companied with the process of the low level jet stream. During the fog continuance, there is a temperature inversion layer in the surface layer and double-deck strong inversion structure at upper layer of the tower. The inversion layers disappeared in the surface layer and weaken at upper layer of the tower and humidity decreases rapidly after the fog. In addition, the wind shear is not obvious in horizontal and is remarkable in vertical during the advection fog developing. The fog dissipates from the top down.
APA, Harvard, Vancouver, ISO, and other styles
4

Hu, Jianqiang, Keshou Wu, and Wei Liang. "An IPv6-based framework for fog-assisted healthcare monitoring." Advances in Mechanical Engineering 11, no. 1 (January 2019): 168781401881951. http://dx.doi.org/10.1177/1687814018819515.

Full text
Abstract:
The new generation healthcare monitoring system combines technologies of wireless body sensor network, cloud computing, and Bigdata, and there are still limitations in protocol security, response delay, and prediction of potential severity disease. In response to the above situation, an Internet Protocol Version 6 (IPv6)-based framework for fog-assisted healthcare monitoring is proposed. This framework is composite of body-sensing layer, fog layer, and cloud layer. The body-sensing layer generates physiological data, and fog computing node in fog layer collects and analyses time-sensitive data. Fog layer sends physiological data to cloud computing node in cloud layer for further processing. Mobile intelligent device connects fog computing node and helps individuals to predict the potential disease with its level of severity. The proposed framework uses advanced techniques such as IPv6-based network architecture, cloud–fog resource scheduling algorithm based on time threshold, and classification model of chronic diseases based on cascaded deep learning and so on. In order to determine the validity of the framework, health data were systematically generated from 45 patients for 30 days. Results depict that the proposed classification model of chronic diseases has high accuracy in determining the level of severity of potential disease. Moreover, response delay is much lower than Internet Protocol Version 4 (IPv4)-based cloud-assisted environment.
APA, Harvard, Vancouver, ISO, and other styles
5

Izett, Jonathan G., and Bas J. H. van de Wiel. "Why Does Fog Deepen? An Analytical Perspective." Atmosphere 11, no. 8 (August 14, 2020): 865. http://dx.doi.org/10.3390/atmos11080865.

Full text
Abstract:
The overall depth of a fog layer is one of the important factors in determining the hazard that a fog event presents. With discrete observations and often coarse numerical grids, however, fog depth cannot always be accurately determined. To address this, we derive a simple analytical relation that describes the change in depth of a fog interface with time, which depends on the tendencies and vertical gradients of moisture. We also present a lengthscale estimate for the maximum depth over which mixing can occur in order for the fog layer to be sustained, assuming a uniform mixing of the vertical profiles of temperature and moisture. Even over several hours, and when coarse observational resolution is used, the analytical description is shown to accurately diagnose the depth of a fog layer when compared against observational data and the results of large-eddy simulations. Such an analytical description not only enables the estimation of sub-grid or inter-observation fog depth, but also provides a simple framework for interpreting the evolution of a fog layer in time.
APA, Harvard, Vancouver, ISO, and other styles
6

Aleisa, Mohammed A., Abdullah Abuhussein, Faisal S. Alsubaei, and Frederick T. Sheldon. "Examining the Performance of Fog-Aided, Cloud-Centered IoT in a Real-World Environment." Sensors 21, no. 21 (October 20, 2021): 6950. http://dx.doi.org/10.3390/s21216950.

Full text
Abstract:
The fog layer provides substantial benefits in cloud-based IoT applications because it can serve as an aggregation layer and it moves the computation resources nearer to the IoT devices; however, it is important to ensure adequate performance is achieved in such applications, as the devices usually communicate frequently and authenticate with the cloud. This can cause performance and availability issues, which can be dangerous in critical applications such as in the healthcare sector. In this paper, we analyze the efficacy of the fog layer in different architectures in a real-world environment by examining performance metrics for the cloud and fog layers using different numbers of IoT devices. We also implement the fog layer using two methods to determine whether different fog implementation frameworks can affect the performance. The results show that including a fog layer with semi-heavyweight computation capability results in higher capital costs, although the in the long run resources, time, and money are saved. This study can serve as a reference for fundamental fog computing concepts. It can also be used to walk practitioners through different implementation frameworks of fog-aided IoT and to show tradeoffs in order to inform when to use each implementation framework based on one’s objectives.
APA, Harvard, Vancouver, ISO, and other styles
7

Mangla, Cherry, Shalli Rani, and Henry Kwame Atiglah. "Secure Data Transmission Using Quantum Cryptography in Fog Computing." Wireless Communications and Mobile Computing 2022 (January 22, 2022): 1–8. http://dx.doi.org/10.1155/2022/3426811.

Full text
Abstract:
Fog computing’s idea is to bring virtual existence into objects used on a daily basis. The “objects” layer of fog architecture is also known as the smart object layer (SOL). SOL has provided the fog network with a strong platform to outperform. Although the fog architecture decentralizes data, uses more data centers, and collects and transmits it to adjacent servers for faster processing in fog networks, it faces several security challenges. The security problems of fog computing need to be alleviated for the exploitation of all benefits of fog computing in classical networks. This article has addressed the security challenges in fog computing, potential solutions via quantum cryptography, a use case portraying the importance of quantum cryptography in fog computing along future scope, and research directions.
APA, Harvard, Vancouver, ISO, and other styles
8

Gultepe, I. "Fog and Boundary Layer Clouds: Introduction." Pure and Applied Geophysics 164, no. 6-7 (June 2007): 1115–16. http://dx.doi.org/10.1007/s00024-007-0209-4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

G., Shruthi, Monica R. Mundada, S. Supreeth, and Bryan Gardiner. "Deep Learning-based Resource Prediction and Mutated Leader Algorithm Enabled Load Balancing in Fog Computing." International Journal of Computer Network and Information Security 15, no. 4 (August 8, 2023): 84–95. http://dx.doi.org/10.5815/ijcnis.2023.04.08.

Full text
Abstract:
Load balancing plays a major part in improving the performance of fog computing, which has become a requirement in fog layer for distributing all workload in equal manner amongst the current Virtual machines (VMs) in a segment. The distribution of load is a complicated process as it consists of numerous users in fog computing environment. Hence, an effectual technique called Mutated Leader Algorithm (MLA) is proposed for balancing load in fogging environment. Firstly, fog computing is initialized with fog layer, cloud layer and end user layer. Then, task is submitted from end user under fog layer with cluster of nodes. Afterwards, load balancing process is done in each cluster and the resources for each VM are predicted using Deep Residual Network (DRN). The load balancing is accomplished by allocating and reallocating the task from the users to the VMs in the cloud based on the resource constraints optimally using MLA. Here, the load balancing is needed for optimizing resources and objectives. Lastly, if VMs are overloaded and then the jobs are pulled from associated VM and allocated to under loaded VM. Thus the proposed MLA achieved minimum execution time is 1.472ns, cost is $69.448 and load is 0.0003% respectively.
APA, Harvard, Vancouver, ISO, and other styles
10

Bhatt, Chintan, and C. K. Bhensdadia. "Fog Computing." International Journal of Grid and High Performance Computing 9, no. 4 (October 2017): 105–13. http://dx.doi.org/10.4018/ijghpc.2017100107.

Full text
Abstract:
The Internet of Things could be a recent computing paradigm, defined by networks of extremely connected things – sensors, actuators and good objects – communication across networks of homes, buildings, vehicles, and even individuals whereas cloud computing could be ready to keep up with current processing and machine demands. Fog computing provides architectural resolution to deal with some of these issues by providing a layer of intermediate nodes what's referred to as an edge network [26]. These edge nodes provide interoperability, real-time interaction, and if necessary, computational to the Cloud. This paper tries to analyse different fog computing functionalities, tools and technologies and research issues.
APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic "Fog layer"

1

Bakhshi, Valojerdi Zeinab. "Persistent Fault-Tolerant Storage at the Fog Layer." Licentiate thesis, Mälardalens högskola, Inbyggda system, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-55680.

Full text
Abstract:
Clouds are powerful computer centers that provide computing and storage facilities that can be remotely accessed. The flexibility and cost-efficiency offered by clouds have made them very popular for business and web applications. The use of clouds is now being extended to safety-critical applications such as factories. However, cloud services do not provide time predictability which creates a hassle for such time-sensitive applications. Moreover, delays in the data communication between clouds and the devices the clouds control are unpredictable. Therefore, to increase predictability an intermediate layer between devices and the cloud is introduced. This layer, the Fog layer, aims to provide computational resources closer to the edge of the network. However, the fog computing paradigm relies on resource-constrained nodes, creating new potential challenges in resource management, scalability, and reliability. Solutions such as lightweight virtualization technologies can be leveraged for solving the dichotomy between performance and reliability in fog computing. In this context, container-based virtualization is a key technology providing lightweight virtualization for cloud computing that can be applied in fog computing as well. Such container-based technologies provide fault tolerance mechanisms that improve the reliability and availability of application execution.  By the study of a robotic use-case, we have realized that persistent data storage for stateful applications at the fog layer is particularly important. In addition, we identified the need to enhance the current container orchestration solution to fit fog applications executing in container-based architectures. In this thesis, we identify open challenges in achieving dependable fog platforms. Among these, we focus particularly on scalable, lightweight virtualization, auto-recovery, and re-integration solutions after failures in fog applications and nodes. We implement a testbed to deploy our use-case on a container-based fog platform and investigate the fulfillment of key dependability requirements. We enhance the architecture and identify the lack of persistent storage for stateful applications as an important impediment for the execution of control applications. We propose a solution for persistent fault-tolerant storage at the fog layer, which dissociates storage from applications to reduce application load and separates the concern of distributed storage. Our solution includes a replicated data structure supported by a consensus protocol that ensures distributed data consistency and fault tolerance in case of node failures. Finally, we use the UPPAAL verification tool to model and verify the fault tolerance and consistency of our solution.
APA, Harvard, Vancouver, ISO, and other styles
2

Harbaugh, Bradley J. "Freezing fog formation in a supercooled boundary layer solving the winter fog forecasting challenge for Elmendorf Air Force Base, Alaska /." Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion.exe/07Mar%5FHarbaugh.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Harbaugh, Bradley J. "Freezing fog formation in a supercooled boundary layer solving the winter fog forcasting challenge for Elmendorf Air Force Base, Alaska." Thesis, Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion.exe/07Mar%5FHarbaugh.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Crofoot, Robert F. "Investigations of scalar transfer coefficients in fog during the Coupled Boundary Layers and Air Sea Transfer Experiment : a case study." Thesis, Monterey, California. Naval Postgraduate School, 2004. http://hdl.handle.net/10945/1202.

Full text
Abstract:
The uncertainty in the determination of the momentum and scalar fluxes remains one of the main obstacles to accurate numerical forecasts in low to moderate wind conditions. For example, latent heat fluxes computed from data using direct covariance and bulk aerodynamic methods show that there is good agreement in unstable conditions when the latent heat flux values are generally positive. However, the agreement is relatively poor in stable conditions, particularly when the moisture flux is directed downward. If the direct covariance measurements are indeed accurate, then they clearly indicate that the bulk aerodynamic formula overestimate the downward moisture flux in stable conditions. As a result, comparisons of the Dalton number for unstable and stable conditions indicate a marked difference in value between the two stability regimes. Investigations done for this thesis used data taken primarily at the Air-Sea Interaction Tower (ASIT) during the Coupled Boundary Layers and Air-Sea Transfer (CBLAST) Experiment 2003 from the 20-27 August 2003. Other data from the shore based Martha's Vineyard Coastal Observatory (MVCO) and moored buoys in the vicinity of the ASIT were also incorporated. During this eight day period, the boundary layer was often characterized by light winds, a stably stratified surface layer and a swell dominated wave field. Additionally, the advection of warm moist air over cooler water resulted in fog formation and a downward flux of moisture on at least three occasions. Therefore, a primary objective of this thesis is to present a case study to investigate the cause of this shortcoming in the bulk formula under these conditions by examining the physical processes that are unique to these boundary layers. Particular attention will be paid to the behavior of the Dalton number in a stable marine atmospheric boundary layer under foggy conditions using insights derived from the study of fog formation and current flux parameterization methods.
APA, Harvard, Vancouver, ISO, and other styles
5

Li, F. "DEVELOPMENT OF NANO-MATERIAL FOR FOOD PACKAGING." Doctoral thesis, Università degli Studi di Milano, 2013. http://hdl.handle.net/2434/215685.

Full text
Abstract:
La cellulosa è il polimero naturale più abbondante sulla terra, una risorsa rinnovabile che ogni anno viene prodotta in miliardi di tonnellate da molti organismi vegetali. Per questa ragione, su di essa si sta concentrando una crescente attenzione nell’ipotesi di una sua sempre maggiore applicazione nei più diversi campi. Quello del food packaging, che è ancora fortemente dipendente da materiali di sintesi e provenienti da risorse non rinnovabili, è particolarmente interessato ad un suo più ampio impiego, anche con il fine di aumentare la sostenibilità dei suoi prodotti e di ridurne l’impatto ambientale. Con questa tesi di dottorato si è inteso mettere a fuoco le potenzialità di impiego della nano cellulosa (cellulose nanocrystals, CNs), sperimentare la produzione e valutare le proprietà di alcune lacche a base di CNs, destinate a ricoprire convenzionali materiali flessibili per il confezionamento alimentare. La tesi si compone di quattro parti distinte. Nella prima parte si è inteso rappresentare lo stato dell’arte delle conoscenze e delle applicazioni della nanocellulosa, attraverso un ampio lavoro di documentazione bibliografica. Dapprima si è voluto mettere a fuoco quanto noto sulla struttura e la classificazione delle varie forme di nanocellulosa che è oggi possibile produrre e, a proposito della cellulosa nanocristallina in particolare, si è fatto il punto sulle tecniche di preparazione, la morfologia e le principali applicazioni. Da questo lavoro di documentazione sono emerse le notevoli proprietà di barriera ai gas ed a potenziali migranti, le eccellenti proprietà meccaniche (resistenza alla rottura, massima elongazione tensile, modulo di Young) e le interessanti caratteristiche termiche (transizione vetrosa, punto di fusione e di decomposizione) della CNs da sola ed in combinazione con altri materiali. Nella seconda sezione della tesi, al fine di comprendere meglio la struttura e la morfologia dei nanocristalli di cellulosa ottenuti attraverso un processo di idrolisi acida di linter di cotone, sono state utilizzate diverse tecniche analitiche avanzate, sia per la caratterizzazione qualitativa che quantitativa. E’ stato così possibile ottenere informazioni precise sulle dimensioni dei nano cristalli, il rapporto di forma, la solubilità e numerose altre loro importanti proprietà. In particolare le tecniche di TEM, SEM, e AFM sono apparse come le più adatte per osservare la morfologia dei cristalli, studiare le caratteristiche e la rugosità delle superfici trattate con lacche a base di CNs. Si è inoltre indagato sulla distribuzione delle dimensioni dei cristalli ottenuti e, grazie all’uso di FTIR, XPS e NMR, sulla natura dei gruppi funzionali disponibili e sulle loro interazioni. La terza parte della tesi è dedicata ad uno studio delle proprietà di alcuni differenti film, largamente impiegati per il food packaging (PET, OPP, OPA e cellophane), rivestiti con uno strato sottile di CNs. In particolare, è statomesso a punto il processo di laccatura e sono state misurate le proprietà ottiche (la trasparenza, l’opacità e le proprietà anti-fog), il coefficiente di frizione statico e dinamico, le energie superficiali e gli angoli di contatto, le proprietà di barriera all’ossigeno ed al vapor d’acqua. Da questo lavoro è emerso come sia effettivamente possibile rivestire di uno strato sottile (intorno ad un micron di spessore), omogeneo e continuo, film plastici differenti e che attraverso questo processo di laccatura, si riduce significativamente il coefficiente di frizione, si incrementano le proprietà anti-fog, si aumenta decisamente la barriera all’ossigeno, senza pregiudicare la trasparenza dei film di supporto. La prospettiva molto concreta è quella di costituire, in un modestissimo spessore, un coating multifunzionale con spiccate caratteristiche di sostenibilità e di sicurezza alimentare. L’ultima sezione della tesi è dedicata al lavoro fatto per sperimentare la possibile applicazione di una tecnica di rivestimento molto moderna (layer-by-layer coating, LbL) che sfrutta la formazione di legami elettrostatici tra biopolimeri caricati diversamente. In particolare si è dimostrata la possibilità di costituire lacche di un composito ottenuto mediante la sovrapposizione alternata di sottilissimi strati (da 6 a circa 30 nm) di chitosano e cellulosa nanocristallina. Il diverso pH delle soluzioni in cui vengono dispersi i due biopolimeri determina un diverso grado di ionizzazione delle cariche, rispettivamente positive del chitosano e negative della cellulosa, e di conseguenza diversi spessori e proporzioni relative dei due biopolimeri nel coating composito che si realizza. Ciò, evidentemente, permette di modulare in un ampio intervallo di valori, la permeabilità del film ricoperto. Il coefficiente di permeabilità del composito giunge a valori pari 0.02 cm3 µm m-2 24h-1 kPa-1, molto simili a quelli espressi da copolimeri a base di EVOH, in condizioni anidre. I vantaggi di un simile rivestimento sono comunque fondamentalmente legati alla sicurezza e non tossicità dei biopolimeri impiegati, dalla loro sostenibilità e dall’ampio grado di libertà disponibile nel modulare le caratteristiche finali di barriera, secondo le esigenze del prodotto da confezionare. Lo strato di lacca LbL così costituita rappresenta, in definitiva, una barriera all’ossigeno particolarmente promettente negli impieghi reali più critici anche per la concreta possibilità di realizzarla convenientemente su oggetti tridimensionali come bottiglie, vassoi e altri imballaggi finiti. In conclusione, le ricerche condotte rappresentano una base di partenza molto promettente per un’innovazione di sostenibilità e di prestazioni nel campo dell’imballaggio flessibile e meritano ulteriori approfondimenti ed applicazioni.
Being cellulose the most abundant natural polymer in biosphere, more and more attention has been paid on its new functionalities, sustainability, and renewability. Meanwhile, food packaging materials is one of the largest products we are using in daily life, but most of conventional materials are still oil-based due to their low cost and good performances. Therefore, in order to improve the sustainability and renewability of food packaging materials, this PhD dissertation focuses on development new nano-material (cellulose nanocrystals, CNs) for food packaging and includes mainly four sections. In the first section of this PhD dissertation, we reviewed the progress in knowledge on nano-cellulose first and then, specifically, on CNs. In this section the structure and classifications of various nano-cellulose preparations are included, as well as the preparation, the morphologies, and applications of CNs. In CNs applications, we reviewed that it exhibits excellent barrier, mechanical, and thermal properties itself or combined with other polymers. Particularly, the barrier properties refer to oxygen, water vapor, and migration barrier; mechanical properties are related with tensile strength, Young’s modulus, and strain percentage; the thermal properties include glass transition and melting or decomposition temperature, heat flow, and thermal mechanical parameters. In the second section of this PhD dissertation, to better understand the structure and status of CNs itself or in other polymers, we have used different powerful analytical tools for qualification and quantification. Firstly, we have obtained the relatively precise dimensions of CNs and observe its redispersability in different solvents, mainly water solutions. In the following, we could gain the information of the CNs status in other polymers in order to interpret the final performance efficiently. Finally, we preliminarily concluded that TEM, SEM, and AFM are suitable tools for observing individual crystals, estimating the roughness, and learning the morphology in different scale, respectively. As for the size distribution, functional groups, and interactions between the atoms of CNs, the particle size distributor, FTIR, XPS, and NMR are used for determinations, respectively. In the third section of this PhD dissertation, we have systematically investigated the properties of conventional films coated with CNs. In particular, we have analyzed their optical properties (transparency and haze), mechanical properties (static and dynamic coefficient of friction), anti-fog (contact angle and surface energy) and barrier properties (oxygen and water vapor transmission rates). In doing this, we have demonstrated that CNs coatings mainly lead to a reduction of friction, a premium feature for industrial applications, and that their influence on the optical properties of the packaging is not significant. Excellent anti-fog property guarantees customers more conveniently to evaluate the product inside the packages easily. At last but not the least, CNs coatings dramatically improve not only the oxygen barrier properties of conventional flexible food packaging, but also lead to a certain reduction in the water vapor transmission rate. The perspective use of CNs as multi-functional coatings favors a reduction of the required thickness for plastic films, towards a more environmentally-friendly and sustainable approach to packaging. In the last section of this PhD dissertation, we demonstrated the use of chitosan (CS)/CNs nanocomposites realized by layer-by-layer (LbL) self-assembly as oxygen barrier under different pH combinations. The oxygen permeability coefficient of CS/CNs nanocomposites is as low as 0.02 cm3 µm m-2 24h-1 kPa-1, close to EVOH co-polymers, under dry conditions. Meanwhile, we consider that CNs has no potential risks for human beings and the renewable origin of the carbohydrate polymers as significant added values that justify a deeper investigation. Finally, it deserves to be underlined also the chance of finely tuning the oxygen permeability by means of the pH values and the sharp control of the thickness associated with this process. Therefore, based on the advantages outlined above, the LbL CS/CNs nanocomposite represents a promising oxygen barrier component in transparent flexible packaging materials and semi rigid tridimensional objects (bottles, trays, boxes and etc.). Based on our researches, we conclude that CNs leads to very promising applications in food packaging field and deserves to be further investigated in the future.
APA, Harvard, Vancouver, ISO, and other styles
6

Badokhon, Alaa. "An Adaptable, Fog-Computing Machine-to-Machine Internet of Things Communication Framework." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1492450137643915.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Crofoot, Robert Farrington. "Investigations of scalar transfer coefficients in fog during the Coupled Boundary Layers and Air Sea Transfer experiment : a case study." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/39165.

Full text
Abstract:
Thesis (S.M.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Ocean Engineering; and the Woods Hole Oceanographic Institution), 2005.
Includes bibliographical references (leaves 70-72).
The uncertainty in the determination of the momentum and scalar fluxes remains one of the main obstacles to accurate numerical forecasts in low to moderate wind conditions. For example, latent heat fluxes computed from data using direct covariance and bulk aerodynamic methods show that there is good agreement in unstable conditions when the latent heat flux values are generally positive. However, the agreement is relatively poor in stable conditions, particularly when the moisture flux is directed downward. If the direct covariance measurements are indeed accurate, then they clearly indicate that the bulk aerodynamic formula overestimate the downward moisture flux in stable conditions. As a result, comparisons of the Dalton number for unstable and stable conditions indicate a marked difference in value between the two stability regimes. Investigations done for this thesis used data taken primarily at the Air-Sea Interaction Tower (ASIT) during the Coupled Boundary Layers and Air-Sea Transfer (CBLAST) Experiment 2003 from the 20-27 August 2003. Other data from the shore based Martha's Vineyard Coastal Observatory (MVCO) and moored buoys in the vicinity of the ASIT were also incorporated.
(cont.) During this eight day period, the boundary layer was often characterized by light winds, a stably stratified surface layer and a swell dominated wave field. Additionally, the advection of warm moist air over cooler water resulted in fog formation and a downward flux of moisture on at least three occasions. Therefore, a primary objective of this thesis is to present a case study to investigate the cause of this shortcoming in the bulk formula under these conditions by examining the physical processes that are unique to these boundary layers. Particular attention will be paid to the behavior of the Dalton number in a stable marine atmospheric boundary layer under foggy conditions using insights derived from the study of fog formation and current flux parameterization methods.
by Robert Farrington Crofoot.
S.M.
APA, Harvard, Vancouver, ISO, and other styles
8

Bari, Driss. "Etude du brouillard en zone côtière par modélisation des processus physiques de la couche limite atmosphérique : cas du Grand Casablanca (Maroc)." Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30316/document.

Full text
Abstract:
Le brouillard est un phénomène météorologique très difficile à prévoir, même à très courte échéance, en raison de sa grande variabilité spatiale et temporelle qui est due à des interactions complexes entre divers processus physiques. Dans cette thèse, les caractéristiques météorologiques locales et les processus synoptiques favorables aux brouillards sur la région du Grand Casablanca (Maroc) sont examinés à l'aide des observations horaires aux deux stations météorologiques permanentes de cette région côtière. Un algorithme de classification objectif est développé et utilisé pour classer les événements en des types de brouillard les plus rencontrés. Cette étude climatologique a mis en évidence que le brouillard a le plus souvent un caractère localisé et que le type d'advection-rayonnement est le plus fréquent sur la région, suivi des types d'affaissement de stratus et de rayonnement. Quand le brouillard intéresse simultanément les deux stations, la probabilité d'observer deux types différents est assez élevée. Les processus advectifs liés à la circulation de brise de mer au cours de l'après-midi, suivis de ceux radiatifs en début de nuit jouent un rôle important dans la formation du brouillard sur la région. Des simulations numériques à l'aide du modèle Méso-NH sont réalisées. Ces simulations ont confirmé que les processus physiques impliqués dans le cycle de vie du brouillard peuvent être différents selon la nature géographique de la surface. Elles ont aussi mis en évidence que la prévision numérique du brouillard en zone côtière est sensible à la température de la surface de la mer, à la topographie locale, et à l'occupation du sol. De plus, la prévision du brouillard côtier dépend fortement de la capacité du modèle à reproduire correctement la circulation de brise au cours de l'après-midi et les processus radiatifs en début de nuit. Les simulations systématiques des cas de brouillard de l'hiver 2013-2014 a montré la capacité du modèle Méso- NH à reproduire l'occurrence du brouillard avec néanmoins un taux relativement élevé de fausses alarmes, en particulier à la station côtière
The prediction of fog remains a challenge due to its time and space variability and to the complex interaction between the numerous physical processes influencing its life cycle. During the first stage of this thesis, the local meteorological and synoptic characteristics of fog occurrence over the Grand Casablanca region (Morocco) are investigated. To achieve this, hourly surface meteorological observations, at two synoptic stations of this coastal region, are used. An objective fog-type classification has been developed in this work and used to discriminate the fog events into the well known types. This fog climatology points out that the fog is often localized and that it is predominantly of advection-radiation type, followed by fog resulting from cloud base lowering and radiation fog. Besides, two different fog types can occur when fog simultaneously concerns the two stations. The advective processes associated with sea breeze circulation during the daylight, followed by the radiative processes often leads to fog formation over this coastal region. Numerical simulations are performed later using the meso-scale non-hydrostatic model Meso-NH. These simulations confirm that the physical processes, governing the life cycle of fog, can be different according to the physiographic features of the area. Moreover, the numerical prediction of coastal fog over heterogeneous area is very sensitive to sea surface temperature, land local topography and land cover. It also depends on the model's ability to reproduce the sea breeze circulation during the daylight followed by the radiative processes early in the night. The systematic numerical simulations of the fog events that occurred during the winter 2013-2014 indicate the Meso-NH's ability to well capture the fog occurrence with a relatively high false alarm rate, particularly over the coastal station
APA, Harvard, Vancouver, ISO, and other styles
9

Vehil, Raoul. "Etude de l'effet radiatif de l'aerosol dans la couche limite atmospherique." Toulouse 3, 1987. http://www.theses.fr/1987TOU30259.

Full text
Abstract:
Le travail presente est centre sur la situation ou l'effet radiatif des aerosols modifie la structure de la couche limite atmospherique. Trois situations sont etudiees: le cas des brumes seches, le cas des aerosols urbains et la cas du brouillard. La simulation numerique et l'approche experimentale conduisent au developpement ou la mise au point de programmes de calcul du transfert radiatif
APA, Harvard, Vancouver, ISO, and other styles
10

Liu, Hao [Verfasser]. "Atomic layer deposition for high power laser applications: Al2O3 and HfO2 / Hao Liu." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2018. http://d-nb.info/1174302542/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Fog layer"

1

Ismail, Gultepe, ed. Fog and boundary layer clouds: Fog visibility and forecasting. Basel: Birkhäuser, 2007.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Gultepe, Ismail, ed. Fog and Boundary Layer Clouds: Fog Visibility and Forecasting. Basel: Birkhäuser Basel, 2007. http://dx.doi.org/10.1007/978-3-7643-8419-7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

SOFOS: A new satellite-based operational fog observation scheme. Marburg, Lahn: Selbstverlag der Marburger Geographischen Gesellschaft, 2007.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Kenneth, King, and Munasinghe Mohan 1945-, eds. Ozone layer protection: Country incremental costs. Washington, D.C: Global Environment Facility, 1995.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Jane, Parry, Great Britain. Department for Work and Pensions., and Policy Studies Institute, eds. Independent living in later life. Leeds: Corporate Document Services, 2004.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

United Nations Environment Programme. Ozone Secretariat. Synthesis of the reports of the Scientific, Environmental Effects, and Technology and Economic Assessment Panels of the Montreal Protocol: A decade of assessments for decision makers regarding the protection of the ozone layer : 1988-1999. Edited by Albritton Daniel L. 1936- and Kuijpers Lambert. Nairobi: UNEP, 1999.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Workshop for the Implementation of the Montreal Protocol in Pacific Island Countries (2001 Apia, Samoa). Report on the Workshop for the Implementation of the Montreal Protocol in Pacific Island Countries : Apia, Samoa 24-26 April 2001. Apia, Samoa: SPREP, 2001.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

British Association for Adoption & Fostering, ed. Writing a later life letter. London: British Association for Adoption & Fostering, 2012.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Schmall, Vicki L. Living arrangements in later life. [Corvallis, Or?]: Oregon State University Extension Service, Washington State University Cooperative Extension, University of Idaho Cooperative Extension Service, and U.S. Dept. of Agriculture, 1987.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

Programme, United Nations Environment, and United Nations Environment Programme. Technology and Economics Assessment Panel., eds. Handbook on essential use nominations. [Nairobi?]: UNEP, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Fog layer"

1

Roquelaure, Stevie, and Thierry Bergot. "Seasonal Sensitivity on COBEL-ISBA Local Forecast System for Fog and Low Clouds." In Fog and Boundary Layer Clouds: Fog Visibility and Forecasting, 1283–301. Basel: Birkhäuser Basel, 2007. http://dx.doi.org/10.1007/978-3-7643-8419-7_11.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

De La Fuente, Lorenzo, Yves Delage, Serge Desjardins, Allan MacAfee, Garry Pearson, and Harold Ritchie. "Can Sea Fog be Inferred from Operational GEM Forecast Fields?" In Fog and Boundary Layer Clouds: Fog Visibility and Forecasting, 1303–25. Basel: Birkhäuser Basel, 2007. http://dx.doi.org/10.1007/978-3-7643-8419-7_12.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Hyvärinen, Otto, Jukka Julkunen, and Vesa Nietosvaara. "Climatological Tools for Low Visibility Forecasting." In Fog and Boundary Layer Clouds: Fog Visibility and Forecasting, 1383–96. Basel: Birkhäuser Basel, 2007. http://dx.doi.org/10.1007/978-3-7643-8419-7_16.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Gultepe, I., R. Tardif, S. C. Michaelides, J. Cermak, A. Bott, J. Bendix, M. D. Müller, et al. "Fog Research: A Review of Past Achievements and Future Perspectives." In Fog and Boundary Layer Clouds: Fog Visibility and Forecasting, 1121–59. Basel: Birkhäuser Basel, 2007. http://dx.doi.org/10.1007/978-3-7643-8419-7_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Müller, M. D., C. Schmutz, and E. Parlow. "A One-dimensional Ensemble Forecast and Assimilation System for Fog Prediction." In Fog and Boundary Layer Clouds: Fog Visibility and Forecasting, 1241–64. Basel: Birkhäuser Basel, 2007. http://dx.doi.org/10.1007/978-3-7643-8419-7_9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Ordóñez-Morales, Esteban F., Martín López-Nores, Yolanda Blanco-Fernández, Efrén P. Reinoso-Mendoza, Jack F. Bravo-Torres, and José J. Pazos-Arias. "Vehicular Fog Computing on Top of a Virtualization Layer." In Lecture Notes in Computer Science, 77–91. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-05081-8_6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Brighente, Alessandro, Mauro Conti, and Foroogh Mohammadnia. "Physical Layer Security Challenges and Solutions for Beyond 5G Fog Computing Networks." In Internet of Things, 59–77. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-08254-2_4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Bessem, J. M., C. Nieuwvelt, J. C. Stouthart, and J. C. H. Zeegers. "A Turbulent Wall Layer Visualization System Using a Dense Fog and a Scanning Laser Beam." In Advances in Turbulence 2, 244–50. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-83822-4_37.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Negash, Behailu, Tomi Westerlund, Pasi Liljeberg, and Hannu Tenhunen. "Rethinking ‘Things’ - Fog Layer Interplay in IoT: A Mobile Code Approach." In Lecture Notes in Business Information Processing, 159–67. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-94845-4_14.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Vyas, Mayank, Garv Anand, Ram Narayan Yadav, and Sanjeet Kumar Nayak. "DASA: An Efficient Data Aggregation Algorithm for LoRa Enabled Fog Layer in Smart Agriculture." In Advanced Information Networking and Applications, 40–52. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-28451-9_4.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Fog layer"

1

Legakis, Justin. "Fast multi-layer fog." In ACM SIGGRAPH 98 Conference abstracts and applications. New York, New York, USA: ACM Press, 1998. http://dx.doi.org/10.1145/280953.282233.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Cheng, Yanrong, and Hongyan Qian. "Minimize Fog Nodes in Double-layer Distributed Fog Radio Access Networks." In 2022 IEEE 6th Advanced Information Technology, Electronic and Automation Control Conference (IAEAC ). IEEE, 2022. http://dx.doi.org/10.1109/iaeac54830.2022.9929717.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Bellavista, Paolo, Carlo Giannelli, and Dmitrij David Padalino Montenero. "Multi Layer Routing in SDN-enabled Fog Environments." In ICC 2020 - 2020 IEEE International Conference on Communications (ICC). IEEE, 2020. http://dx.doi.org/10.1109/icc40277.2020.9149289.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Dave, Shrinal, Sheshang Degadwala, and Dhairya Vyas. "DDoS Detection at Fog Layer in Internet of Things." In 2022 International Conference on Edge Computing and Applications (ICECAA). IEEE, 2022. http://dx.doi.org/10.1109/icecaa55415.2022.9936524.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Samara, Ghassan, Mohammed Rasmi, Nael A. Sweerky, Essam Al Daoud, and Amer Abu Salem. "Improving VANET's Performance by Incorporated Fog-Cloud Layer (FCL)." In 2021 22nd International Arab Conference on Information Technology (ACIT). IEEE, 2021. http://dx.doi.org/10.1109/acit53391.2021.9677345.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Riedl, Anton, and Nazli Siasi. "Optimal Service Provisioning Schemes for Multi-Layer Fog Networks." In 2021 IEEE Globecom Workshops (GC Wkshps). IEEE, 2021. http://dx.doi.org/10.1109/gcwkshps52748.2021.9681995.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Faticanti, Francescomaria, Marco Savi, Francesco De Pellegrini, Petar Kochovski, Vlado Stankovski, and Domenico Siracusa. "Deployment of Application Microservices in Multi-Domain Federated Fog Environments." In 2020 International Conference on Omni-layer Intelligent Systems (COINS). IEEE, 2020. http://dx.doi.org/10.1109/coins49042.2020.9191379.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

MacDonald, Michael, Marcin J. Kurowski, and Joao Teixeira. "Direct numerical simulation of fog formation within the surface layer." In 22nd Australasian Fluid Mechanics Conference AFMC2020. Brisbane, Australia: The University of Queensland, 2020. http://dx.doi.org/10.14264/278baa7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Li, Zhongtao, Kai Wang, Xiangyu Kong, and Bo Zhang. "Zone-code based optimal connecting layer scheme in fog MMVE." In 2016 3rd International Conference on Informative and Cybernetics for Computational Social Systems (ICCSS). IEEE, 2016. http://dx.doi.org/10.1109/iccss.2016.7586430.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Iyeswariya, K., and R. Muthubharathi. "Investigation of Edge-Fog Layer for Accuracy and Power Consumption." In 2020 6th International Conference on Advanced Computing and Communication Systems (ICACCS). IEEE, 2020. http://dx.doi.org/10.1109/icaccs48705.2020.9074194.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Fog layer"

1

Rigotti, Christophe, and Mohand-Saïd Hacid. Representing and Reasoning on Conceptual Queries Over Image Databases. Aachen University of Technology, 1999. http://dx.doi.org/10.25368/2022.89.

Full text
Abstract:
The problem of content management of multimedia data types (e.g., image, video, graphics) is becoming increasingly important with the development of advanced multimedia applications. Traditional database management systems are inadequate for the handling of such data types. They require new techniques for query formulation, retrieval, evaluation, and navigation. In this paper we develop a knowledge-based framework for modeling and retrieving image data by content. To represent the various aspects of an image object's characteristics, we propose a model which consists of three layers: (1) Feature and Content Layer, intended to contain image visual features such as contours, shapes,etc.; (2) Object Layer, which provides the (conceptual) content dimension of images; and (3) Schema Layer, which contains the structured abstractions of images, i.e., a general schema about the classes of objects represented in the object layer. We propose two abstract languages on the basis of description logics: one for describing knowledge of the object and schema layers, and the other, more expressive, for making queries. Queries can refer to the form dimension (i.e., information of the Feature and Content Layer) or to the content dimension (i.e., information of the Object Layer). These languages employ a variable free notation, and they are well suited for the design, verification and complexity analysis of algorithms. As the amount of information contained in the previous layers may be huge and operations performed at the Feature and Content Layer are time-consuming, resorting to the use of materialized views to process and optimize queries may be extremely useful. For that, we propose a formal framework for testing containment of a query in a view expressed in our query language. The algorithm we propose is sound and complete and relatively efficient.
APA, Harvard, Vancouver, ISO, and other styles
2

Rigotti, Christophe, and Mohand-Saïd Hacid. Representing and Reasoning on Conceptual Queries Over Image Databases. Aachen University of Technology, 1999. http://dx.doi.org/10.25368/2022.89.

Full text
Abstract:
The problem of content management of multimedia data types (e.g., image, video, graphics) is becoming increasingly important with the development of advanced multimedia applications. Traditional database management systems are inadequate for the handling of such data types. They require new techniques for query formulation, retrieval, evaluation, and navigation. In this paper we develop a knowledge-based framework for modeling and retrieving image data by content. To represent the various aspects of an image object's characteristics, we propose a model which consists of three layers: (1) Feature and Content Layer, intended to contain image visual features such as contours, shapes,etc.; (2) Object Layer, which provides the (conceptual) content dimension of images; and (3) Schema Layer, which contains the structured abstractions of images, i.e., a general schema about the classes of objects represented in the object layer. We propose two abstract languages on the basis of description logics: one for describing knowledge of the object and schema layers, and the other, more expressive, for making queries. Queries can refer to the form dimension (i.e., information of the Feature and Content Layer) or to the content dimension (i.e., information of the Object Layer). These languages employ a variable free notation, and they are well suited for the design, verification and complexity analysis of algorithms. As the amount of information contained in the previous layers may be huge and operations performed at the Feature and Content Layer are time-consuming, resorting to the use of materialized views to process and optimize queries may be extremely useful. For that, we propose a formal framework for testing containment of a query in a view expressed in our query language. The algorithm we propose is sound and complete and relatively efficient.
APA, Harvard, Vancouver, ISO, and other styles
3

Nantung, Tommy E., Jusang Lee, John E. Haddock, M. Reza Pouranian, Dario Batioja Alvarez, Jongmyung Jeon, Boonam Shin, and Peter J. Becker. Structural Evaluation of Full-Depth Flexible Pavement Using APT. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317319.

Full text
Abstract:
The fundamentals of rutting behavior for thin full-depth flexible pavements (i.e., asphalt thickness less than 12 inches) are investigated in this study. The scope incorporates an experimental study using full-scale Accelerated Pavement Tests (APTs) to monitor the evolution of each pavement structural layer's transverse profiles. The findings were then employed to verify the local rutting model coefficients used in the current pavement design method, the Mechanistic-Empirical Pavement Design Guide (MEPDG). Four APT sections were constructed using two thin typical pavement structures (seven-and ten-inches thick) and two types of surface course material (dense-graded and SMA). A mid-depth rut monitoring and automated laser profile systems were designed to reconstruct the transverse profiles at each pavement layer interface throughout the process of accelerated pavement deterioration that is produced during the APT. The contributions of each pavement structural layer to rutting and the evolution of layer deformation were derived. This study found that the permanent deformation within full-depth asphalt concrete significantly depends upon the pavement thickness. However, once the pavement reaches sufficient thickness (more than 12.5 inches), increasing the thickness does not significantly affect the permanent deformation. Additionally, for thin full-depth asphalt pavements with a dense-graded Hot Mix Asphalt (HMA) surface course, most pavement rutting is caused by the deformation of the asphalt concrete, with about half the rutting amount observed within the top four inches of the pavement layers. However, for thin full-depth asphalt pavements with an SMA surface course, most pavement rutting comes from the closet sublayer to the surface, i.e., the intermediate layer. The accuracy of the MEPDG’s prediction models for thin full-depth asphalt pavement was evaluated using some statistical parameters, including bias, the sum of squared error, and the standard error of estimates between the predicted and actual measurements. Based on the statistical analysis (at the 95% confidence level), no significant difference was found between the version 2.3-predicted and measured rutting of total asphalt concrete layer and subgrade for thick and thin pavements.
APA, Harvard, Vancouver, ISO, and other styles
4

DeSantis, John, and Jeffery Roesler. Performance Evaluation of Stabilized Support Layers for Concrete Pavements. Illinois Center for Transportation, February 2022. http://dx.doi.org/10.36501/0197-9191/22-003.

Full text
Abstract:
A research investigation was conducted on the erosion potential of stabilized subbases under concrete pavements and asphalt layers supporting concrete overlays. Through field surveys and testing in Illinois, this project evaluated if existing concrete pavements with stabilized subbases and concrete overlays were exhibiting potential erosion of the underlying support layer. The field evaluation testing included falling weight deflectometer testing, distress surveys, coring, and ultrasonic tomography scanning. A laboratory performance test was also established using the Hamburg wheel-tracking device to assess the erodibility of the various stabilized subbase layers for new construction and existing asphalt layers available for a concrete overlay. The analyzed field test results were coupled together with the laboratory performance testing to provide recommendations for updating the Illinois Department of Transportation’s “Bureau of Design and Environment Manual” guidance. No changes were recommended for hot-mix asphalt stabilized subbases, but testing using the Hamburg wheel-tracking device should be considered for Portland cement concrete stabilized support layers (e.g., CAM II) under concrete pavements. For testing of asphalt support layers for concrete pavement overlays, the Hamburg wheel-tracking device is recommended with performance criteria similar to flexible pavements for appropriate functional classes.
APA, Harvard, Vancouver, ISO, and other styles
5

Bunn, M. I., T. R. Carter, H. A. J. Russell, and C. E. Logan. A semiquantitative representation of uncertainty for the 3D Paleozoic bedrock model of Southern Ontario. Natural Resources Canada/CMSS/Information Management, 2023. http://dx.doi.org/10.4095/331658.

Full text
Abstract:
The southern Ontario bedrock model is a valuable resource for researchers and practitioners, but its application is subject to uncertainty. To address this issue a semi-quantitative approach to visualize the relative effects of data sparsity for each layer, identify regions where a lack of data support reduces model confidence, and quantify potential errors in data collection and model construction is presented. This analysis summarizes several sources of error, including cartesian position error, error in the vertical position of the formation contact, error between the modelled topographic surface and recorded collar elevations, and error between the modelled formation top surface and formation top picks. Where data is present, these errors are added to provide an approximation of total uncertainty. Where data are not present, uncertainty is approximated as 50% of the range in formation top variation, with an average value of 27.5 m across all layers. The results show that data availability strongly influences the average total error for each layer, with deeper layers exhibiting higher total error due to lower data density. However, this analysis also suggests that the modelled surfaces likely carry errors of less than 5 to 10 m in most regions.
APA, Harvard, Vancouver, ISO, and other styles
6

Qamhia, Issam, Erol Tutumluer, and Han Wang. Aggregate Subgrade Improvements Using Quarry By-products: A Field Investigation. Illinois Center for Transportation, June 2021. http://dx.doi.org/10.36501/0197-9191/21-017.

Full text
Abstract:
This report presents a case study for constructing aggregate subgrade improvement (ASI) layers using quarry by-product aggregates (QBA), a quarry mix of large primary crushed rocks (PCR) and sand-sized quarry fines. The construction took place at Larry Power Road in Bourbonnais Township in Kankakee County, Illinois, where the Illinois Department of Transportation placed two QBA mixes. The first mix (QBA_M1) consisted of 45% quarry by-products and 55% railroad ballast–sized 3×1 PCR. The second mix (QBA_M2) consisted of 31% and 69% quarry by-products and PCR, respectively. Two conventional ASI sections were also constructed conforming to Illinois Department of Transportation’s CS02 gradation. All sections consisted of a 9 in. (229 mm) QBA/PCR layer topped with a 3 in. (76 mm) dense-graded capping layer. Laboratory studies preceded the construction to recommend optimum quarry by-product content in the QBA materials and construction practice. The Illinois Center for Transportation research team monitored the quality and uniformity of the construction using nondestructive testing techniques such as dynamic cone penetrometer, lightweight deflectometer, and falling weight deflectometer. The segregation potential was monitored by visual inspection and imaging-based techniques. Short-term field evaluation of the constructed QBA layers, particularly QBA_M2 with a 31% quarry by-product content, showed no evidence of abnormal segregation and did not jeopardize the structural integrity of the QBA ASI layers, which had slightly lower but comparable strength and stiffness profiles to the conventional ASI sections. The use of QBA materials in ASI was field validated as a sustainable construction practice to provide stable pavement foundation layers.
APA, Harvard, Vancouver, ISO, and other styles
7

Laxmi Prasanna, Porandla, B. Anil kumar, and Macha Sahithi. A STUDY TO EVALUATE THE TEAR FILM CHANGES IN PATIENTS WITH PTERYGIUM. World Wide Journals, February 2023. http://dx.doi.org/10.36106/ijar/3408221.

Full text
Abstract:
Introduction: Pterygium is a degenerative condition of the subconjunctival tissues which proliferate as vascularized granulation tissue to invade the cornea, destroying the supercial layers of the stroma and bowmans membrane, the whole being covered by conjunctival epithelium.The tear lm consists of three layers, the most supercial layer of tear lm is lipid layer produced by meibomian glands. The middle layer is the aqueous layer produced by the main lacrimal gland as well as accessory lacrimal glands of Krause and Wolfring. Aqueous layer constitutes over 90% of the tear lm. The layer closest to the cornea is the mucin layer produced by conjunctival goblet cells. Tear function abnormalities have been proposed as an etiologic factor for pterygium due to observation that a pterygium is exacerbated by dryness and dellen formation. Whether tear dysfunction is a precursor to pterygium growth or pterygium causes tear dysfunction is still not clear. The present study was taken up to study the tear lm changes in patients presenting with pterygium. Materials and methods: The present prospective study was conducted at the Department of Ophthalmology, Chalmeda Anand Rao Institute of Medical Sciences from Jan 2021- July 2022. 75 patients satisfying inclusion and exclusion criteria were included in the study. The eye with pterygium was considered as case and the normal eye of the same patient was considered as controls. The data was recorded for 150 eyes. All patients underwent visual acuity assessment, a detailed slit-lamp examination and ophthalmoscopy to rule out adnexal, anterior segment and posterior segment diseases. Patients were evaluated for tear lm changes using Schirmer's test(with anesthesia),Tear lm breakup time and Tear lm meniscus height. The mean age of the study population was 34.7±4.98 years, with 56% of ma Results: les and 44% of females. Pterygium was present in right eye in 73.33% (n=55) cases and 26.66% (n=20) had it in the left eye. All were on the nasal conjunctiva. Schirmer's test was signicantly lower in eyes with pterygium with P value of <0.001. Tear Film Break Up time and Tear Film meniscus height was signicantly lesser in the eyes with pterygium with P=<0.001. From the present study, we ca Conclusion: n suggest that unstable tear lm is found to a greater extent in eyes with pterygium than in eyes without pterygium. Pterygium is one of the most common ocular surface disorders which results in instability of tear lm indices and thus lead to dysfunctional tear lm and development of dry eye.
APA, Harvard, Vancouver, ISO, and other styles
8

Koch, J., E. Dewald, N. Izumi, B. Kozioziemski, O. Landen, and C. Siders. Pulsed Laser-Based X-Ray Sources for Rapid-Cool DT Layer Characterization. Office of Scientific and Technical Information (OSTI), August 2007. http://dx.doi.org/10.2172/917894.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Grossir, Guillaume. On the design of quiet hypersonic wind tunnels. Von Karman Institute for Fluid Dynamics, December 2020. http://dx.doi.org/10.35294/tm57.

Full text
Abstract:
This document presents a thorough literature review on the development of hypersonic quiet tunnels. The concept of boundary layer transition in high-speed flows is presented first. Its consequences on the free-stream turbulence levels in ground facilities are reviewed next, demonstrating that running boundary layers along the nozzle walls must remain laminar for quiet operation. The design key points that enable laminar boundary layers and hypersonic operation with low free-stream noise levels are then identified and discussed. The few quiet facilities currently operating through the world are also presented, along with their design characteristics and performances. The expected characteristics and performances of a European quiet tunnel are also discussed, along with flow characterization methodologies and different measurement techniques. It is finally shown that the required expertise to establish the first European quiet hypersonic wind tunnel is mostly at hand.
APA, Harvard, Vancouver, ISO, and other styles
10

Carter, T. R., C. E. Logan, J K Clark, H. A. J. Russell, E. H. Priebe, and S. Sun. A three-dimensional bedrock hydrostratigraphic model of southern Ontario. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/331098.

Full text
Abstract:
A hydrostratigraphic framework has been developed for southern Ontario consisting of 15 hydrostratigraphic units and 3 regional hydrochemical regimes. Using this framework, the 54 layer 3-D lithostratigraphic model has been converted into a 15 layer 3-D hydrostratigraphic model. Layers are expressed as either aquifer or aquitard based principally on hydrogeologic characteristics, in particular the permeability and the occurrence/absence of groundwater when intersected by a water well or petroleum well. Hydrostratigraphic aquifer units are sub-divided into up to three distinct hydrochemical regimes: brines (deep), brackish-saline sulphur water (intermediate), and fresh (shallow). The hydrostratigraphic unit assignment provides a standard nomenclature and definition for regional flow modelling of potable water and deeper fluids. Included in the model are: 1) 3-D hydrostratigraphic units, 2) 3-D hydrochemical fluid zones within aquifers, 3) 3-D representations of oil and natural gas reservoirs which form an integral part of the intermediate to deep groundwater regimes, 4) 3-D fluid level surfaces for deep Cambrian brines, for brines and fresh to sulphurous groundwater in the Guelph Aquifer, and the fresh to sulphurous groundwater of the Bass Islands Aquifer and Lucas-Dundee Aquifer, 5) inferred shallow karst, 6) base of fresh water, 7) Lockport Group TDS, and 8) the 3-D lithostratigraphy. The 3-D hydrostratigraphic model is derived from the lithostratigraphic layers of the published 3-D geological model. It is constructed using Leapfrog Works at 400 m grid scale and is distributed in a proprietary format with free viewer software as well as industry standard formats.
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography