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Glacier flow over rough hard beds is controlled by basal processes, such as friction, the opening of cavities behind obstacles and any interaction between the glacier bed and basal ice. In this PhD, we study a multitude of these processes.Current theories to describe drag of glaciers over hard beds are formulated on the basis that ice is free of debris and slides without friction over the glacier bed.However, debris at the basal layers and cold ice cause additional resistance to glacier flow.We provide an analytical model of glacier sliding that accounts for the effect of local shear stress at the ice-bed interface in the framework of Weertman (1957), and expand the solution to account for the opening of cavities.This additional drag slows glacier sliding but due to additional strain enhancement of the basal ice, the viscosity of the ice decreases and the basal speed is higher than expected.The inclusion of local shear stress makes the friction law implicit, complicating the identification of scaling parameters from the geometry alone.We further study this problem using a numerical finite element model of glacier sliding over a sinusoidal bed under steady-state conditions.We find that the law with non-zero local shear stress at the base retains the overall form of the friction law with zero local shear stress, such that an appropriate scaling can be obtained.The similarity between a friction law with zero and non-zero local shear stress is convenient for generalising empirical friction laws at the field scale, although it complicates the identification of the effect of local shear stress on glacier flow.Glacier internal deformation is controlled by the ice rheology which is described by the Glen’s law through two material parameters, the creep factor A and the flow law exponent n.There is great uncertainty in the values of these parameters as a result of scarce observations at the natural scale.One of the techniques that has been used to study ice deformation and constrain material properties is borehole inclinometry.We present here the results of an inclinometry study carried out at the ablation zone of Glacier d'Argentière, a temperate glacier in the French Alps.We monitored glacier deformation during 2020 with borehole-installed tiltmeters that record tilt change every 30 minutes. We are able to reconstruct the deformation rates profile with depth and the deformation velocity. Complementing our dataset with a dense network of GPS stations we are able to indirectly observe the basal velocity during the studied period. We infer the rheological parameters by comparing our observations with the deformation rates retrieved with a three-dimensional model solving the Stokes equation.We demonstrate that the yearly-averaged deformation rates profile has limited sensitivity to the flow law exponent n and instead mainly reflects an increase in the creep factor A with depth which could be explained with depth-increasing interstitial water content.The depth-averaged creep factor is found to be 1.5 times higher than the recommended one for temperate ice. We further show that internal ice deformation exhibits seasonal variability, such that surface velocity changes cannot be attributed solely to changes in basal conditions.At longer timescales, surface velocity variability is better explained with changes in the deformation rates, while shorter velocity variability (weeks or days) is better explained with changes in basal velocity.Further work remains to be conducted in order to confirm if the observed creep enhancement is due to depth-increasing water content, and to determine the causes behind the seasonal changes in internal deformation and basal velocity. Our results will help future assessment of the state and evolution of the cryosphere.; L'écoulement des glaciers sur des lits durs et rugueux est contrôlé par des processus basaux, tels que la friction, l'ouverture de cavités derrière des obstacles et toute interaction entre le lit du glacier et la glace basale. Dans cette thèse, nous étudions une multitude de ces processus.Les théories actuelles pour décrire la traînée des glaciers sur des lits durs sont formulées sur la base que la glace est exempte de débris et glisse sans friction sur le lit du glacier.Cependant, les débris dans les couches basales et la glace froide causent une résistance supplémentaire à l'écoulement.Nous fournissons un modèle analytique du glissement des glaciers qui tient compte de l'effet de la contrainte de cisaillement locale à l'interface glace-lit dans le cadre de Weertman (1957), et étendons la solution pour tenir compte de l'ouverture des cavités.Cette traînée supplémentaire ralentit le glissement du glacier, mais en raison de l'augmentation de la déformation de la glace basale, la viscosité diminue et la vitesse basale est plus élevée que prévu.L'inclusion de la contrainte de cisaillement locale rend la loi de friction implicite, ce qui complique l'identification des paramètres d'échelle à partir de la géométrie seule.Nous constatons que la loi avec une contrainte de cisaillement locale non nulle à la base conserve la forme générale de la loi de friction avec une contrainte de cisaillement locale nulle, de sorte qu'une mise à l'échelle appropriée peut être obtenue. La similitude entre une loi de friction avec une contrainte de cisaillement locale nulle et non nulle est pratique pour généraliser les lois de friction empiriques à l'échelle du champ, bien qu'elle complique l'identification de l'effet de la contrainte de cisaillement locale sur l'écoulement des glaciers. La déformation interne des glaciers est contrôlée par la rhéologie de la glace qui est décrite par la loi de Glen à travers deux paramètres matériels, le facteur de fluage A et l'exposant n de la loi d'écoulement. Il existe une grande incertitude quant aux valeurs de ces paramètres en raison de la rareté des observations à l'échelle naturelle. Nous présentons ici les résultats d'une étude d'inclinométrie réalisée dans Glacier d'Argentière, un glacier tempéré des Alpes françaises.Nous avons suivi la déformation du glacier au cours du 2020 grâce à des inclinomètres installés dans des forages qui enregistrent les changements d'inclinaison toutes les 30 minutes.Nous pouvons reconstruire le profil des taux de déformation avec la profondeur et la vitesse de déformation. Nous complétons notre ensemble de données par un réseau de stations GPS qui permet d'observer la vitesse basale pendant la période étudiée.Nous déduisons les paramètres rhéologiques en comparant nos observations avec les taux de déformation obtenus à l'aide d'un modèle tridimensionnel résolvant l'équation de Stokes.Le profil des taux de déformation en moyenne annuelle a une sensibilité limitée à l'exposant n de la loi d'écoulement et reflète principalement une augmentation de A avec la profondeur qui pourrait être expliquée par une augmentation de la teneur en eau interstitielle en profondeur.Nous montrons également que la déformation interne de la glace présente une variabilité saisonnière, de sorte que les changements de vitesse de surface ne peuvent être attribués uniquement aux changements des conditions basales. Sur des échelles de temps plus longues, la variabilité de la vitesse de surface est mieux expliquée par les changements dans les taux de déformation, tandis que la variabilité de la vitesse plus courte est mieux expliquée par les changements à la base.D'autres travaux restent à mener pour confirmer si l'augmentation du fluage observée est due à l'augmentation de la teneur en eau, et déterminer les causes des changements saisonniers de la déformation et de la vitesse basale. Nos résultats contribueront à l'évaluation future de l'état et de l'évolution de la cryosphère.

Based on the customer's product recognition sustainability and environmental protection become key sales arguments within the automotive industry. Thereby the customer expects reduced resource consumptions, environmental friendly manufacturing and an optimised long customer usage phase. Especially product reliability saves resources in many ways. Manufacturer product reliability is associated with higher development and production costs, but, especially in industries with high innovation rates, customer usage is limited to the product actuality, which leads to two key questions: a. How much product reliability and, in addition, customer usage makes sense out of the view of manufacturers, customers and environmental protection? b. How to refurbish used components by integration of the recycling process into the manufacturing layout of the OEM (Original Equipment Manufacturer)? Furthermore, the main interest is the determination of the quantitative impact of reliable products regarding to the reduction of resources. At first, this paper discusses the requirements and impacts of the product recycling integration in OEM manufacturing plants. Afterwards the paper outlines the “Collaborative development, manufacturing and field verification for higher product reliability towards sustainability (CDMF-RELSUS) concept” focusing on influences and interdependences of the product development, the manufacturing planning and the field observation regarding to the integration of recycling and refurbishing principals into the original manufacturing processes of the successor product (new product generation).

At present there are different reliability standards that are being used for carrying out reliability prediction. They take into consideration different factors, environments and data sources to give reliability data for a wide range of electronic components. However, the users are not aware of the differences between the different reliability standards due to the absence of benchmarks of the reliability standards that would help classify and compare between them. This lack of benchmark denies the users the opportunity to have a top-down view of these different standards and choose the appropriate standard based on qualitative judgement in performing reliability prediction for a specific system. To addres this issue, the benchmark of a set of reliability standards are developed in this dissertation. The benchmark helps the users of the selected reliability standards understand the similarities and differences between them and based on the evaluation criterion defined can easily choose the appropriate standard for reliability prediction in different scenarios. Theoretical reliability prediction of two electronic products in Bombardier is performed using the standards that have been benchmarked. One of the products is matured with available incident report from the field while the other is a new product that is under development and yet to enter in service. The field failure data analysis of the matured product is then compared and correlated to the theoretical prediction. Adjustment factors are then derived to help bridge the gap between the theoretical reliability prediction and the reliability of the product in field conditions. Since the theoretical prediction of the product under development could not be used to compare and correlate any data due to unavailability, instead, the accelerated life test is used to find out the product reliability during its lifetime and find out any failure modes intrinsic to the board. A crucial objective is realized as an appropriate algorithm/model is found in order to correlate accelerated test temperature-cycles to real product temperature-cycles. The PUT has lead-free solder joints, hence, to see if any failures occurring due to solder joint fatigue has also been of interest. Additionally, reliability testing simulation is a performed in order to verify and validate the performance of the product under development during ALT. Finally, the goal of the thesis is achieved as separate models are proposed to predict product reliability for both matured products and products under development. This will assist the organization in realizing the goal of predicting their product reliability with better accuracy and confidence. För närvarande finns det olika tillförlitlighetsstandarder som används för att utföra tillförlitlighet förutsägelse. De tar hänsyn till olika faktorer, miljöer och datakällor för att ge tillförlitlighetsdata för ett brett spektrum av elektronikkomponenter. Men användarna inte är medvetna om skillnaderna mellan de olika tillförlitlighetsstandarder på grund av avsaknaden av riktmärken för tillförlitlighetsstandarder som skulle hjälpa klassificera och jämföra mellan dem. Denna brist på jämförelse förnekar användarna möjlighet att få en top-down bakgrund av dessa olika standarder och välja lämplig standard baserad på kvalitativ bedömning att utföra tillförlitlighet prognos för ett specifikt system. För att lösa detta problem, är riktmärket en uppsättning av tillförlitlighetsstandarder som utvecklats i denna avhandling. Riktmärket hjälper användarna av de utvalda tillförlitlighetsstandarder förstå likheter och skillnader mellan dem och på grundval av bedömningskriteriet definieras kan enkelt välja lämplig standard för pålitlighet förutsägelse i olika scenarier. Teoretisk tillförlitlighet förutsäga två elektroniska produkter i Bombardier utförs med hjälp av standarder som har benchmarking. En av produkterna är mognat med tillgängliga incidentrapport från fältet, medan den andra är en ny produkt som är under utveckling och ännu inte gå in i tjänsten. Analysen av den mognade produkten fält feldata jämförs sedan och korreleras till den teoretiska förutsägelsen. Justeringsfaktorer sedan härledas för att överbrygga klyftan mellan den teoretiska tillförlitlighet förutsägelse och tillförlitligheten av produkten i fältmässiga förhållanden. Eftersom den teoretiska förutsägelsen av produkt under utveckling inte kan användas för att jämföra och korrelera alla data på grund av otillgängligheten, i stället är det accelererade livslängdstest som används för att ta reda på produktens tillförlitlighet under dess livstid och reda ut eventuella felmoder inneboende till styrelsen . Ett viktigt mål realiseras som en lämplig algoritm /modell finns i syfte att korrelera accelererade provningen temperaturcykler på verkliga produkttemperatur cykler. PUT har blyfria lödfogar därmed att se om några fel inträffar på grund av löda gemensam trötthet har också varit av intresse. Dessutom är tillförlitlighet testning simulering en utförs för att verifiera och validera produktens prestanda under utveckling under ALT. Slutligen är målet med avhandlingen uppnås som separata modeller föreslås att förutsäga produktens tillförlitlighet för både förfallna och produkter under utveckling. Detta kommer att hjälpa organisationen att förverkliga målet att förutsäga deras tillförlitlighet med bättre noggrannhet och förtroende.

Seawater desalination constitutes an important water supply to the population bordering the Arabian Gulf, the Mediterranean Sea and the Red Sea. The three regions represent about 11.8% of the world land area and the countries hosted approximately 9% of the world population in 1950 and 2008 and are also projected to do so in 2050. The results obtained for desalination capacity in the study area were 62%, 58% and 60% of the world capacity for 1996, 2008, and 2050, respectively. The increase in the recovery ratio is considered an important factor in this study. In 1996 this ratio was about 30 to 35%, and in 2008 it was 40 to 45%, although in some plants it reached up to 50%. The gulf desalination capacities were obtained as 50, 40 and 45% of total world capacity at the end of 1996, 2008 and 2050 (prognosis) respectively. All Middle Eastern countries suffer from a shortage of water along with increasing demand due to high population growth. Desalination can be a cost-effective way to produce fresh water and possibly electricity. A suggested solution for Sinai and the Gaza Strip involves the building of a joint power and desalination plant, located in Egypt close to the border with Gaza. This joint Egypt-Palestine project would increase the water supply by 500,000 m3/d and the power supply by 500MW. The result emerged from field work and the two experiments can also be applied to the design of this project. Water and salt mass balances for the Dead Sea were modelled by including and excluding the water from the proposed Red Sea Dead Sea Canal project, RSDSC. Precipitation, evaporation, river discharges, ground water flows, input/output from potash companies and salt production in addition to brine discharge were included in the models. The mixing time in the Dead Sea was modelled using a single-layer (well-mixed) and a two-layer (stratified) system. An efficient method for increasing the dilution rate of brine water discharged into the sea is an inclined negatively buoyant jet of a single port or multi-diffuser. Two small-scale experimental studies were conducted to investigate the behaviour of a dense jet discharged into lighter ambient water. The first lab-scale experiment concerned the benefit of the initial angle of inclined dense jets, where the slope increased for the maximum levels as a function of this angle. An angle of 60 deg. led to a better result than 30 or 45 deg. An empirical prediction was found based on five geometric quantities to be considered in the future plan. Field work measurements have been conducted in Cyprus, where the brine from a desalination plant and the Mediterranean Sea coastline have been investigated at the Eastern Mediterranean University. The result from the measured data demonstrates the need for more than one outfall (a series of outfalls) to the sea to avoid or minimize environmental impact on the coastline. The result also agreed well with simple, two dimensional mathematical models assuming Gaussian distribution. The calculated bottom slope is about 7.4%, which can explain the pollution that appears at the coast close to the discharge point. Thus small slope could be one reason. The second lab-scale experiment studied the near and intermediate fields of negatively buoyant jets. The dilution along the flow was increased by about 10% and 40% with bottom slope and bottom slope together with a 30 degree jet inclination, respectively. This method can be applied in brine discharge outlets to recipients to minimize concentration and facilitate faster and greater dilution. Over 16% bottom slope and more field work is needed for comparison with this result. It was found that an inclination of 30 degrees with 16 % bottom slope was more sustainable in designing brine discharge outfall. A Matlab code can be used to describe the lateral spreading and centerline dilution of buoyant jets and plumes in near and intermediate fields. Avsaltning av havsvatten utgör en viktig källa för vattenförsörjning till befolkningen som bor vid Persiska viken, Medelhavet och Röda havet. De tre regionerna utgör ca 11,8 % av världens landyta och hade omkring 9 % av världens befolkning under 1950 och 2008, samt lika mycket enligt prognos för år 2050. Dessa områden är hemvist för 62 %, 58% och 60% av världens avsaltningskapacitet för år 1996, 2008 respektive 2050. Utbytet av dricksvatten ur havsvatten har identifierats som en viktig faktor i denna studie. Under 1996 uppgick utbytet till cirka 30-35 % och år 2008 var det cirka 40-45 %, medan vissa avsaltningsanläggningar nådde upp till hela 50 %. Runt Persiska viken fanns och finns 50 %, 40 % och 45 % av världens totala avsaltningskapacitet i slutet av 1996, 2008 respektive 2050 (prognos). Alla länder i Mellanöstern lider av brist på vattenresurser samtidigt med en ökad efterfrågan av vatten på grund av den höga befolkningstillväxten. Avsaltning kan vara ett kostnadseffektivt sätt att producera färskvatten och möjligtvis också el. En lösning för Sinai och Gazaremsan föreslås som innebär att en gemensam kraft- och avsaltningsanläggning uppförs i Egypten nära gränsen till Gazaremsan. Detta gemensamma Egypten-Palestina projekt skulle öka vattenförsörjningen med 500 000 m3/d och kraftförsörjningen med 500 MW i regionen. Resultatet från fältarbete och två experiment i laboratorieskala redovisas. De kan även tillämpas för att utforma detta projekt. Massbalanser för vatten och salt för Döda havet modellerades genom att inkludera och exkludera vatten från ett föreslaget projekt att överföra vatten från Röda havet till Döda havet i en kanal (RSDSC). Nederbörd, avdunstning, ytvattenflöde, grundvattenflöden, samt uppgifter för tillflöde och avlopp från mineralutvinningsföretag runt Döda havet användes i modellen. Blandningstiden i Döda havet modellerades genom att använda två olika ekvationssystem, för väl omblandade respektive skiktade förhållanden. En effektiv metod för att påskynda utspädningen av det salta rejektvattnet från avsaltningengsverket i recipienten är att använda en vinklad utgångsstråle eller spridning med multipla utlopp. Två experimentella studier i laboratorieskala utfördes för att undersöka hur en tung/tät stråle fördelades i omgivande vatten. Den första studien gjordes med vinklade tunga/täta strålar för att studera betydelsen av utloppsstrålens vinkel, där lutningen ökade för de maximala nivåerna som funktion av denna vinkel. En utloppsvinkel på 60 grader ger snabbare inblandning än 30 eller 45 grader. En empirisk relation för effektiv inblandning togs fram som funktion av fem geometriska parametrar, vilken kan användas för framtida planering. Fältundersökningar har gjorts på Cypern av hur rejektplymer från Eastem Mediterranean Universitys avsaltningsanläggning fördelas lokalt i Medelhavet. Mätningarna visar att det behövs mer än ett utlopp (multipla utlopp) ut till havet för att undvika eller minimera miljöpåverkan längs kusten. Resultatet överensstämde väl med en enkel två-dimensionell matematiska modell för spridning om plymen antas vara normalfördelad. Den beräknade bottenlutningen i fält var låg, omkring 7,4 %, vilket delvis kan förklara varför smuts från avsaltningen syntes på stranden i närheten av utsläppspunkten. Ett andra laboratorieexperiment gjordes för att undersöka hur flödesfältet från tunga saltvattenplymer såg ut nära utloppet och i mellanzonen innan plymen fördelats ut i recipienten. Utspädningen längs plymen ökade med cirka 10 % och 40 % om botten lutade respektive om botten lutade och strålen riktades 30 grader upp från horisontalplanet. Resultat av denna studie kan användas för konstruktion av utlopp från avsaltningsverk för att minimera saltkoncentrationsskillnader och för att få plymen att spädas ut snabbare och mera i recipient. Mer än 16 % bottenlutning rekommenderas, liksom flera fältmätningar. En utloppsvinkel på 30 grader med 16 % bottenlutning ger mindre miljöpåverkan. De geometriska effekterna kan modelleras framgångsrikt i Matlab.

This study applies NASS/CDS, GES and FARS data to examine occupant exposure plus injury and fatality rates for belted occupants in frontal crashes by seating position, age and gender. The NASS data was used to examine the distributions by crash severity. The GES data showed that when two elderly occupants (age 65+) were present, the female occupied the right front passenger position 73% of the time. A paired comparison analysis using FARS data showed that, for elderly occupants (age 65+), the fatality risk for elderly right front passengers is 42% higher than for elderly drivers. The NASS/CDS analysis found 74% of the seriously injured vulnerable passengers with MAIS 3+ injuries were in crashes less severe than 26 mph. This group of injured occupants was made up of 43% aged 50 and older and 42% younger females. The injury rates for the older (age 50+) right front passengers were 1.8 times the rates for the elderly drivers. These results suggest the need for more benign safety systems for the right front passenger that are appropriate for the lower injury tolerance of the predominant occupants of that seating position.

A weighted logistic regression with careful selection of crash, vehicle, occupant and injury data and sequentially adjusting the covariants, was used to investigate the predictors of the odds of head/face and neck (HFN) injuries during rollovers. The results show that unbelted occupants have statistically significant higher HFN injury risks than belted occupants. Age, number of quarter-turns, rollover initiation type, maximum lateral deformation adjacent to the occupant, A-pillar and B-pillar deformation are significant predictors of HFN injury odds for belted occupants. Age, rollover leading side and windshield header deformation are significant predictors of HFN injury odds for unbelted occupants. The results also show that the significant predictors are different between head/face (HF) and neck injury odds, indicating the injury mechanisms of HF and neck injuries are different.

The Crash Injury Research and Engineering Network (CIREN) provides significant details on injuries, and data on patient outcomes that is unavailable in the National Automotive Sampling System (NASS). However, CIREN cases are selected from specific Level I trauma centers with different inclusion criteria than those used for NASS, and the assertion that a given case is similar to the population of NASS cases is often made qualitatively. A robust, quantitative method is needed to compare CIREN to weighted NASS populations. This would greatly improve the usefulness and applicability of research conducted with data from the CIREN database. Our objective is to outline and demonstrate the utility of such a system to compare CIREN and NASS cases. This study applies the Mahalanobis distance metric methodology to determine similarity between CIREN and NASS/CDS cases. The Mahalanobis distance method is a multivariate technique for population comparison. Independent variables considered were total delta V, age, weight, height, maximum AIS, ISS, model year, gender, maximum intrusion, number of lower and upper extremity injuries, and number of head and chest injuries. The technique provides a unit-independent quantitative score which can be used to identify similarity of CIREN and NASS cases. Weighted NASS data and CIREN data were obtained for the years 2001-2005. NASS cases with Maximum AIS 3 resulted in a subset of 1,869 NASS cases, and 2,819 CIREN cases.

Side impact pole/tree crashes can have devastating consequences. A series of 53 CIREN cases of narrow-object side impacts were analyzed. Twenty-seven of 53 had serious chest injury and 27 had serious head injury. Unilateral chest trauma led to the examination of residual crush pattern that often demonstrated oblique door intrusion into the occupant thorax space. It was hypothesized that unilateral chest trauma was caused by antero-lateral chest loading. This hypothesis was evaluated by conducting two (PMHS and ES2) vehicle side impact tests into a rigid pole. The PMHS test produced an oblique chest deformation pattern with injuries very similar to the real world trauma: unilateral rib fractures, spleen laceration, pelvic fracture, and a basilar skull fracture. Narrow-object side impacts are severe crash environments that can induce oblique chest loading and unique head trauma. Because the human may be more vulnerable in this type of crash scenario, dummy response and measurements, as well as a re-examination of side injury criteria may be necessary to design appropriate injury-mitigating safety devices.

The objective of this study was to characterize the risk of mild traumatic brain injury (MTBI) in living humans based on a large set of head impact data taken from American football players at the collegiate level. Real-time head accelerations were recorded from helmet-mounted accelerometers designed to stay in contact with the player’s head. Over 27,000 head impacts were recorded, including four impacts resulting in MTBI. Parametric risk curves were developed by normalizing MTBI incidence data by head impact exposure data. An important finding of this research is that living humans, at least in the setting of collegiate football, sustain much more significant head impacts without apparent injury than previously thought. The following preliminary nominal injury assessment reference values associated with a 10% risk of MTBI are proposed: a peak linear head acceleration of 165 g, a HIC of 400, and a peak angular head acceleration of 9000 rad/s2.

The ability of hydropower to adapt the electricity generation to the demand is necessary to integrate wind and solar energy into the electrical grid. Nowadays, hydropower turbines are required to work under harsher operating conditions and an advanced condition monitoring to detect damage is crucial. In this paper the methodology to improve the condition monitoring of Pelton turbines is presented. First, the field data obtained from the vibration monitoring of 28 different Pelton turbines over 25 years has been studied. The main types of damage found were due to fatigue, cavitation and silt erosion. By analyzing the vibration signatures before and after maintenance tasks, the symptoms of damage detected from the measuring locations were determined for each case. Second, a theoretical model using numerical methods (FEM) was created in order to simulate the dynamic behavior of the turbine. The model was validated with the results obtained from on-site tests that were carried out in an existing turbine. The deformations and the stresses of the runner under different operating conditions could then be computed. The calibrated model was used to analyze in detail the effect of misalignment between nozzle and runner. In historic cases, this abnormal operating condition lead to severe damage in the turbine, due to the effect of fatigue in some locations of the buckets. The model reproduced well the symptoms detected in the field measurements. The stresses could be calculated, which eventually can be used to estimate the remaining useful life of the turbine.