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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Návrh koncepce leteckého motoru na CNG / Concept of the aircraft CNG engine

Šmerda, Ondřej January 2019 (has links)
Master’s thesis deals with comparsion and rating the compressed natural gas as an aircraft piston engine fuel. An information search of conventional fuels and differences of the fuel systems for AVGAS and CNG is included. Next part describes the aircraft and its engine on which is the mathematic model based. After that perfomance and consumption data are calculated for both fuels and the results are then compared. At the end of the thesis, a design of the CNG fuel system with components selection is described.
12

Návrh softwarového modulu trenažéru přistání na padákovém kluzáku / Design of software module for paraglider landing simulator

Šulc, Dalibor January 2011 (has links)
The aim of this diploma thesis is software designed to simulate landing of the paragliding wing. It means the development of the mathematic model describing the final stage of flight and landing. The model comprises the effects of controls (brakes, speed bar, weight-shifting). One part of the thesis is the description of the implementation in C# language with complete source codes.
13

Modelling Drug Abuse and Drug-related Crime: A Systems Approach

Coetzee, Lezanie 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2015 / ENGLISH ABSTRACT : In this study we look at the syndemic of substance abuse and drug-related crime in the Western Cape province of South Africa. The intent of this study is to provoke critical thinking about the possibilities systems thinking and system dynamics posses for social and health challenges in a diverse and complex environment like that of South Africa, especially the Western Cape. This study ventures into cross-discipline work between Epidemiology, Biomathematics and System Dynamics, with the hope of encouraging researchers from different fields to collaborate in order to curb the scourge of substance abuse and drug-related crime in South Africa. Substance abuse and the associated health and social hazards such as drug-related crime is a major problem in the Western Cape. Drug-related crime cases reported by the South African Police Services (SAPS) for the Western Cape exhibited a 311.5% growth in the past decade. This highlights how the reduction of substance abuse and drug-related crime within theWestern Cape province, will be an elixir for the safety and development of the communities. The fight against substance abuse has been driven by a multi-sectorial approach involving several government departments, non-governmental organisations and communities. With systems thinking the assumption is that the world is systemic, which means that phenomena is understood to be an emergent property of the interrelated whole. Firstly, using non-linear ordinary differential equations, we formulate a deterministic mathematical model for the substance abuse and drug-related crime syndemic, evaluate the threshold number and use sensitivity analysis to analyze the model. Secondly, a dynamic system, called the Substance Abuse and Drug-related Crime in theWestern Cape (SADC-WC) system is constructed using the STELLA in order to explore and classify the underlying relationships and structures within the substance abuse and drug-related crime system. Both the sensitivity analysis, and the simulations of the SADC-WC system indicate that an increase of successful convictions will have a significant influence on the syndemic, and promise to reduce drug-related crime cases. / AFRIKAANSE OPSOMMING : In hierdie studie ondersoek on die syndemie (‘syndemic’) van dwelmmisbruik en dwelmverwante misdaad in die Wes-Kaap provinsie, in Suid-Afrika. Die moontlikhede wat sistemiese denke en dinamiese sisteme inhou vir sosiale en gesondheid kwale in ’n diverse en komplekse omgewing soos Suid-Afrika, word ondersoek. Hierdie studie waag interdisiplinêre werk tussen Epidemiologie, Biowiskunde en Dinamiese sisteme, met die hoop om navorsers van verskillende velde aan te moedig om saam te werk om die plaag van dwelmmisbruik en dwelm-verwante misdaad in Suid-Afrika te bekamp. Dwelmmisbruik en die gepaardgaande gesondheid en maatskaplike gevare soos dwelmverwante misdaad is ’n groot probleem in dieWes-Kaap. Die SAPD se vermelde dwelmverwante midaad het ’n groei van 311,5% ondergaan in die afgelope dekade, en is aanduidend vir hoe die beheer en beperking van dwelmmisbruik en dwelm-verwante misdaad in die Wes-Kaap provinsie bevordering van beide die veiligheid en ontwikkeling van die gemeenskap sal verseker. Dit beklemtoon hoe die vermindering van dwelmmisbruik en dwelm-verwante misdaad in dieWes-Kaapland, sal ’n elikser vir die veiligheid en ontwikkeling van die gemeenskappe. Die stryd teen dwelmmisbruik is gedryf deur ’n multi-sektorale benadering waarby verskeie regeringsdepartemente, nie-regerings organisasies en gemeenskappe. Stelsels denke en dinamiese sisteme is gebasseur op die aanname, dat die wÃłreld is sistemiese en dat verskynsels verstaan word ten opsigte van die ontluikende eienskap van die omvattende geheel. Eerstens stel ons ’n kompartementele model op wat deur nie-liniêre gewone differensiële vergelykings beskryf kan word vir die dwelmmisbruik en dwelm-verwante misdaad epidemies. Ons evalueer die drumpel getal en gebruik sensitiwiteitsanalise om die parameters van die model te analiseer. Tweedens, is ’n dinamiese sisteem genaamd die Middelmisbruik en dwelmverwante misdaad in dieWes-Kaap (SADC-WC) stelsel gebou met behulp van die STELLA platform om te verken en klassifiseer die onderliggende verhoudings en strukture binne die dwelmmisbruik en dwelm-verwante misdaad stelsel. Beide die sensitiwiteitsanalise, en die simulasies van die SADC-WC stelsel dui aan dat ’n toename in suksesvolle vonisse ’n beduidende invloed op die epidemies sal hê; en beloof om sake van dwelmverwante misdaad te verminder.
14

具可靠度考量之全球運籌管理完整模式之探討 / An Extended Reliability Model for Global Logistic Complete Systems under Uncertain Environment

李亞暉, Lee ,Ya Hui Unknown Date (has links)
當企業面對資源與競爭全球化之市場發展趨勢,如何有效地運用多樣化且散佈的全球資源,做最有效的佈局,來因應日益激烈的市場競爭與挑戰,全球運籌管理愈行重要。但隨著企業經營的全球化,面對的風險與不確定性也逐漸增加,所以企業在做全球運籌管理時不確定因素應納入考量。 許多文獻對全球運籌管理模式作了不同角度的問題探討,其中Vidal and Goetschalckx從過去的文獻中將全球運籌模式加以比較,得到三點過去模式不足的部分:(1)不確定因素都未考慮,(2)BOM的限制,(3)國際化的因素如匯率及稅都未考慮。遂即於其研究中對不確定因素如需求變化及供應商可靠度等因素的改變與最小總成本對全球運籌管理系統的影響進行分析。 吳釜蒼(2002)以Vidal的架構,增加對於貨物自原物料採購至成品完成間的正向物流過程中,所可能經過的成員如供應商、工廠、倉庫、運輸管道進均加入可靠度考量來進行分析探討。本研究延伸其做法,除正向物流外,並擴展到商品或物料退貨、維修及資源回收的逆向物流過程中,可能經過的成員均加入可靠度的考量;並且針對兩種操作情境加以分析(1)特定成本之下求最大可靠度,(2)特定可靠度之上求最小總成本。其次,利用Fault Tree Analysis方法,配合績效評核項目,對可靠度加以量化分析,使其更符合實際狀況。 最後以範例資料來分析驗證此數量模式,並提出一方法論提供決策者在進行全球佈局規劃時,能以本研究提供的決策程序,找出影響全球運籌可靠度的關鍵因子,並可對合作夥伴可靠度進行分析,改善彼此關係或對其之取捨上能有一較客觀的參考依據,使其對總成本之影響能降至最低。 / Since the late 80s, due to the tensive pressures from globalization, customer demands, uncertainties, IT innovation, as well as the shorter product life cycle, businesses were struggling in how to quick response customer desires, in an effort to retain their niches. As a consequence, Global Logistic (GL), in turn, becomes the sharp weapon in this regard. Literature studied GL from various perspectives. Among these studies, Vidal & Goetschalckx compared models in previous studies, and came up with three major challenges in this area:(1) uncertainty was not taken into account; .(2) restrictions of the BOM structure are not clearly dealt with; and (3) key financial factors of internationalization, such as the exchange rate and taxes, were not modeled. Hence, in order to deal with such problems, Vidal & Goetschalckx carried on the analysis on the effects toward key factors of GL and total cost minimization by modeling the factor of suppliers’ reliability in their study. However, in Vidal & Goetschalckx‘s study, there was no further concerns of uncertainties on other players in the logistic system. Fu-Cang Wu takes uncertainties into account on the players of forward logistic system. As a consequence, this research aims to extend Vidal & Goetschalckx’s modus. In the mathematic model, this study adds the settings of reliabilities on players either in the forward logistics or in the reverse logistics. Besides, two operation modes are provided in the model:(1) seeking minimum cost on a target of system reliability; and (2) seeking maximum system reliability on a target of cost. Then, this research makes use of the Fault Tree Analysis (FTA) for in depth analysis on reliability patterns. Finally, a methodology is established, which provides decision makers a reference basis, whenever he or she needs to place a global logistics system. Via the use of this prototype, it is believed to have a good mechanism for finding out the key influence factors of the reliability, enhancing buyer-seller relationships, and ensuring the goal of total cost minimization
15

"Disponibilidade e gerenciamento sustentável do aqüífero Serra Grande no município de Picos - Piauí" / Availability and sustainable management of the Serra Grande aquifer in the municipality of Picos, Piauí

Vidal, Claudio Luiz Rebello 16 October 2003 (has links)
Este trabalho objetivou determinar a disponibilidade do aqüífero Serra Grande e estabelecer as diretrizes para o seu gerenciamento sustentável no município de Picos, localizado no sudeste do Estado do Piauí. Principal sistema de água subterrânea da região, este aqüífero é o único com capacidade para atender as demandas futuras da população. Porém, a falta de regras básicas na exploração dos seus recursos poderá comprometer sua sustentabilidade. O desenvolvimento deste estudo teve início com a elaboração do modelo conceitual da área e a análise das condições de uso dos recursos hídricos. Nesta etapa, verificando-se que os conceitos hidrogeológicos vigentes consideravam apenas o limite físico do sistema para definir sua disponibilidade, foi estabelecido um novo princípio para determinação do volume de recursos que pode ser explorado de um aqüífero, denominado de princípio sustentável, tendo como base os fatores econômicos envolvidos na sua exploração. Para determinação da disponibilidade física e econômica do aqüífero Serra Grande, primeiramente, foi estimado o déficit hídrico acumulado desde o início da exploração do sistema, estabelecida sua relação com a posição do nível potenciométrico e calculado o custo atual de produção da água. Em seguida, foram traçados dois cenários futuros para a exploração dos recursos hídricos no município, representando os modelos de gestão da oferta e gestão da demanda, para o período de 15 e 50 anos. Posteriormente, foi construído um modelo matemático para representar o sistema de subsuperfície, no qual foi simulada a evolução futura do nível d’água. Com base nos valores obtidos, foi estimado o volume de água a ser produzido do armazenamento, a quantidade de recursos que deverão ser incorporados ao sistema e o custo futuro de produção. Os resultados mostraram que o aqüífero precisará incorporar um volume significativo de recursos, que talvez não esteja disponível na região estudada, e que a elevação real do custo da água poderá comprometer a capacidade de pagamento da população para dispor destes recursos. Verificada esta situação, foram definidas as medidas que precisam ser implementadas para o gerenciamento sustentável do aqüífero estudado, de modo a garantir o abastecimento futuro do município e da região. Com a elaboração deste trabalho, concluiu-se que o aqüífero Serra Grande não é “intensamente explorado" em Picos, porém é mal explorado atualmente, o que deverá provocar prejuízos na exploração futura dos seus recursos. / This work’s goals were to determinate the availability of the Serra Grande aquifer and to establish the governess for its sustainable management in the municipality of Picos, located on the southeast of Piauí State. This aquifer, the region’s most important groundwater system, has an unique capacity of fulfilling the population’s future demand. However, the absence of basic rules for the exploitation of its resources would compromise its sustainability. The study began with the development of the conceptual model of the area and the analyses of the water resources use. During this step, after verify that the hydrological actual concepts only observe the physical limit of the system to define its availability, it was established a new principle to determinate the volume of resources that can be exploited from an aquifer, named sustainable principle, based on the economical factors involved in its exploitation. In order to determine the physical and economical availability of the Serra Grande aquifer, first, it was estimated the water deficit accumulated since the begging exploitation of the system, established its relationship with the potenciometric level and was calculated the present cost of water production. Later on, two hypothetical scenarios concerning future exploration of water resources were drawn, representing the models of supply and demand management, for a period of 15 and 50 years. Furthermore, a mathematic model was built to represent the subsurface system, which was simulated the evolution of the water level. Based on the values found, it was estimated the amount of water that should be produced from storage, the quantity of resources that have to be incorporated to the system and the future production cost. Moreover, the results showed that the aquifer will need to incorporate a meaningful quantity of resources, that may be not available in the studied region, and that the real increase of the cost of the water would compromise the payment capacity of the population to dispose those resources. After verify this situation, it was defined the actions that must be taken for the sustainable management of the studied aquifer, to guarantee the future water supply of the municipality and the region. In conclusion, this work confirmed that the Serra Grande aquifer is not “overexploited" in Picos, instead, it is not being correctly exploited, which will negatively affect the future exploitation of its resources.
16

Análise de atitudes de alunos na educação de jovens e adultos em situação de resolução de problemas

Barros, Cláudio Pousa Moraes 09 December 2008 (has links)
Made available in DSpace on 2016-04-27T16:58:50Z (GMT). No. of bitstreams: 1 CLAUDIO POUSA MORAES BARROS.pdf: 2561452 bytes, checksum: a376460767645f9ab4bfe18e84f30888 (MD5) Previous issue date: 2008-12-09 / Secretaria da Educação do Estado de São Paulo / The term Problems Resolution has been on focus at Mathematic Education and the students of Education for Young and Adult Students have been facing difficulties on problematic situations. The objective of this work was to evaluate the student s ability on solving problems with First degree function, analyzing their attitudes and methods and aiming to answer the following questions: are the first year high school students, of Education for Young and Adults, able to answer a sequence of ordinary problems evolving First degree function? Which are the methods adopted by these students to solve them? The chosen ordinary problems are found in a preparatory book to National Exam of Certification of Young and Adults Competencies. This research is based on the Notes of Semiotic Representation. It s also based on the Mathematic educational proposal for Education for Young and Adult Students, first and second level of fundamental school, and on the Mathematic matrix of national exam of Competency Certification of young and adults in high school. After this research it s possible to notice the student s difficulties on solving the problems and the lack of basic knowledge which should be acquired during the fundamental school / O objetivo deste trabalho é o de pesquisar o desempenho de alunos na Resolução de Problemas envolvendo Função do 1º Grau, estudando suas atitudes e procedimentos e visando a responder às seguintes questões: os alunos do primeiro ano do Ensino Médio da Educação de Jovens e Adultos resolvem uma seqüência de problemas referenciados na vida cotidiana que envolve Função Polinomial do 1º Grau? Quais são os procedimentos adotados por esses alunos na resolução de problemas? Os problemas do cotidiano que foram escolhidos são citados em um livro preparatório ao Exame Nacional de Certificação de Competências de Jovens e Adultos (ENCCEJA). A pesquisa apoiou-se na noção de Registros de Representação Semiótica e, também, baseou-se na Proposta Curricular de Matemática para a Educação de Jovens e Adultos para os primeiro e segundo segmentos do Ensino Fundamental e na Matriz de Matemática para o Exame Nacional para Certificação de Competências de Jovens e Adultos do Ensino Médio. Nesta pesquisa, pôde-se evidenciar a dificuldade dos alunos na Resolução dos Problemas e a falta de conhecimentos básicos que deveriam ser adquiridos no Ensino Fundamental
17

Περιβαλλοντική - υδρογεωλογική έρευνα στη λεκάνη του Γλαύκου / Environmental - hydrogeological research of Glafkos river basin

Μανδηλαράς, Δημήτρης 22 June 2007 (has links)
Η λεκάνη του ποταμού Γλαύκου εκτείνεται επί των δυτικών κλιτύων του Παναχαϊκού, στο ΒΔ/κό τμήμα του νομού Αχαΐας, NA/κά της πόλης των Πατρών καταλαμβάνοντας συνολική έκταση 101,67 Km2 και αποτελεί την κύρια πηγή κάλυψης των υδατικών αναγκών της. Χαρακτηρίζεται από μέτρια ανάπτυξη υδρογραφικού δικτύου δενδριτικού τύπου αποστράγγισης και κατά συνέπεια υψηλή διαπερατότητα των πετρωμάτων και σημαντική κατείσδυση, σε βάρος της επιφανειακής απορροής. Οι σπουδαιότεροι από τους χείμαρρους που διαρρέουν την περιοχή έρευνας είναι ο Ξηροπόταμος, ο Φίλιουρας, η Σούτα, του Βερβενίου και το Ελεκιστριάνικο, οι οποίοι συμβάλουν εντός του Γλαύκου. Το αλπικά πτυχωμένο υπόβαθρο της λεκάνης περιλαμβάνει μια ακολουθία προορογενετικών ιζημάτων (πελαγικοί ασβεστόλιθοι, ραδιολαρίτες, κ.α.) της ζώνης Πίνδου, και μια συνορογενετική κλαστική ακολουθία (φλύσχης), που αποτελείται από εναλλαγές ιλυολίθων, ψαμμιτών και σπανιότερα κροκαλοπαγών. Τα στρώματα της ζώνης Πίνδου αναδύθηκαν με την τελική φάση των πτυχώσεων στο Κάτω Ολιγόκαινο, όπου έλαβε χώρα η επώθηση της Πίνδου, υπό μορφή καλύμματος, πάνω στη ζώνη Γαβρόβου – Τριπόλεως. Τα μέτωπα των επωθήσεων μεταξύ των λεπιών και οι άξονες των πτυχώσεων έχουν διεύθυνση ΒΔ – ΝΑ με κατεύθυνση της κίνησης από τα ανατολικά προς τα δυτικά και άμεση σχέση με την πλειονότητα των καρστικών πηγών. Στην περιοχή του Πατραϊκού κόλπου επικρατεί ένα ρομβοειδές σύστημα ρηγμάτωσης με μεγάλης κλίσης και ΑΒΑ/κής και ΔΒΔ/κής διεύθυνσης κανονικά ρήγματα που δημιουργεί ένα μωσαϊκό κατατεμαχισμένων τεκτονικών μπλοκ και μια γενική ανύψωση της περιοχής που συνεχίζεται μέχρι σήμερα. Τη διάνοιξη των κοιλάδων της ευρύτερης περιοχής έρευνας, η οποία συχνά συνοδεύεται από κατολισθήσεις, την καθορίζουν 4 δέσμες νεοτεκτονικών ρηγμάτων, ΒΔ/κής, ΒΑ/κής, ΔΒΔ/κής, και ΒΒΑ/κής διεύθυνσης. Το Πλειοτεταρτογενές επικάλυμμα που εμφανίζεται στην παράκτια και λοφώδη περιοχή αποτελείται από δύο λιθοστρωματογραφικές ενότητες. Η κατώτερη συνίσταται από αργίλους και άμμους, που αποτέθηκαν σε ένα λιμναίο έως υφάλμυρο περιβάλλον ιζηματογένεσης κατά τη διάρκεια του Πλειόκαινου έως το Κατώτερο Πλειστόκαινο και η ανώτερη από Καλάβριας ηλικίας δελταϊκά και χερσαία κροκαλοπαγή. Γενικά οι προσχώσεις χαρακτηρίζονται από λιθολογική ανομοιομορφία τόσο κατά την κατακόρυφη όσο και κατά την οριζόντια διεύθυνση και το πάχος τους παρουσιάζει βαθμιαία αύξηση από τα βορειότερα και νοτιότερα όρια προς το κεντρικό τμήμα της λεκάνης, όπου και υπερβαίνει τα 200 μ. Το ετήσιο ύψος βροχόπτωσης (1071 mm) στην περιοχή έρευνας είναι αρκετά υψηλό για τα δεδομένα της χώρας μας και κυμαίνεται από 640 – 900 mm στις πεδινές περιοχές, ενώ στις ορεινές περιοχές φθάνει τα 1560 mm. Τα τελευταία χρόνια παρουσιάζεται μια εποχιακή μετακίνηση των βροχοπτώσεων από τον χειμώνα προς την άνοιξη και το φθινόπωρο, η οποία συνεπάγεται απώλεια του διαθέσιμου νερού της ενεργής κατείσδυσης, λόγω αυξημένης εξατμισοδιαπνοής. Από υδρολογικής άποψης η λεκάνη του Γλαύκου δέχεται ετησίως κατά μέσο όρο 108,89 106 m3 νερού από βροχόπτωση, εκ’ των οποίων ποσοστό 48,9 % επανέρχεται στην ατμόσφαιρα με τις διαδικασίες της εξάτμισης και διαπνοής, 28,6 % απορρέει επιφανειακά και 22,5 % κατεισδύει, κυρίως σε σημαντικούς από υδρογεωλογική άποψη σχηματισμούς (ασβεστόλιθους και τεταρτογενείς αποθέσεις). Χαρακτηριστικό υδρογεωλογικό γνώρισμα της περιοχής έρευνας αποτελούν οι ημιαυτόνομες υδρογεωλογικά καρστικές ενότητες, που αναπτύσσονται λόγω της λεπιοειδούς και ρηξιγενούς τεκτονικής στην περιοχή και διαφοροποιούν την κίνηση του υπόγειου νερού. Σχετικά με τις προσχωματικές αποθέσεις του Τεταρτογενούς ο ελεύθερος υδροφόρος ορίζοντας της ανώτερης ζώνης κάμπτεται προοδευτικά και μεταπίπτει σε επάλληλους υπό πίεση υδροφόρους ορίζοντες στην παράκτια ζώνη. Στις αρχές της δεκαετίας του ’90 στην παράκτια περιοχή, λόγω της υπεράντλησης, διαπιστώθηκαν αρνητικές τιμές της πιεζομετρικής επιφάνειας σε απόσταση έως 3 Κm από την ακτή, με συνέπεια την αλμύρινση του προσχωματικού υδροφόρου από τη διείσδυση της θάλασσας. Η μείωση των αντλήσεων στα μέσα της δεκαετίας του ’90 οδήγησαν στην άνοδο των πιεζομετρικών στάθμεων και στην επανεμφάνιση φαινομένων αρτεσιανισμού των γεωτρήσεων της παράκτιας ζώνης. Από την επεξεργασία των αντλητικών δεδομένων διαπιστώθηκε η εμφάνιση υψηλών τιμών του συντελεστή της υδραυλικής αγωγιμότητας τόσο στους προσχωματικούς υδροφόρους της παράκτιας ζώνης, όσο και στους καρστικούς σχηματισμούς. Μικρότερες ταχύτητες κίνησης του υπόγειου νερού εμφανίζουν οι υδροφόροι των αποθέσεων του Νεογενούς, αλλά και των προσχώσεων της νότιας όχθης του ποταμού Γλαύκου σε σχέση με αυτούς της βόρειας όχθης, λόγω της επικράτησης των λεπτομερών έναντι των αδρομερών υλικών. Ο σημαντικότερος παράγοντας τροφοδοσίας του προσχωσιγενή υδροφόρου της λεκάνης του Γλαύκου είναι η πλευρική τροφοδοσία κατά μήκος της κοίτης του ποταμού και εν’ συνεχεία αυτός της πλευρικής τροφοδοσίας από τους ασβεστόλιθους, ενώ λιγότερο σημαντικοί εμφανίζονται οι παράγοντες του απευθείας κατεισδύοντος νερού από τις βροχοπτώσεις και από το περίσσευμα του προς αρδευτική χρήση νερού. Με βάση το ισοζύγιο εισροών – εκροών των προσχωματικών υδροφόρων της λεκάνης του Γλαύκου, για τα υδρολογικά έτη 1999 – 2002 προέκυψε μέσο ετήσιο πλεόνασμα 6,5*106 m3 νερού. Γενικά, αν εξαιρεθεί η παράκτια ζώνη της λεκάνης του Γλαύκου, η ποιότητα του νερού των προσχωσιγενών υδροφόρων, καθώς και των νεογενών αποθέσεων, αλλά και των καρστικών σχηματισμών της λεκάνης, κρίνεται καλή. Στην πλειονότητά τους τα υπόγεια νερά, όπως και τα επιφανειακά και τα πηγαία, εμφάνιζαν τον τύπο Ca-HCO3, που περιλαμβάνει γενικά νερά με καλή τροφοδοσία και ανανέωση κυρίως κατά μήκος των αξόνων αποστράγγισης. Η χωροχρονική μετακίνηση της ζώνης υφαλμύρινσης στην παράκτια ζώνη, την περίοδο 1999 – 2002, διαπιστώθηκε εκτός από την αυξημένη κατανομή διάφορων ιόντων και με την χρησιμοποίηση των συντελεστών S.A.R., Revelle και Schoeller, αλλά και των λόγων rBr-/rCl- και rBr-/rI-. Στη διάρκεια της περιόδου 1999 – 2002, προέκυψε μια αισθητή μείωση της ρύπανσης από τη διείσδυση θαλασσινού νερού στην παράκτια περιοχή. Σημαντικό ρόλο στην επιτάχυνση του ρυθμού της αποκατάστασης των παράκτιων υδροφόρων της λεκάνης του Γλαύκου διαδραμάτισε η πληθώρα γεωτρήσεων αυτόματης ροής στην παράκτια ζώνη, οι οποίες παροχετεύουν περί τα 3,5*106 m3 ρυπασμένου νερού, σε ετήσια βάση, προς τη θάλασσα. Η θέση και η χωροχρονική μετακίνηση της ζώνης υφαλμύρινσης στην παράκτια ζώνη διαπιστώθηκε επίσης από γεωηλεκτρικές έρευνες που πραγματοποιήθηκαν με τις διατάξεις Schlumberger, Wenner – Schlumberger και Pole – Pole. Από τη γεωηλεκτρική έρευνα διαπιστώθηκε ότι η διείσδυση του υφάλμυρου νερού σπανίως εμφανίζεται με τη μορφή μετώπου, αλλά ακολουθεί επιλεκτικές οδούς μέσω των αδρομερέστερων σχηματισμών, ενώ οι λεπτομερείς αργιλικοί σχηματισμοί παίζουν τον ρόλο υδραυλικού φραγμού. Τέλος, με τη μέθοδο της σεισμικής ανάκλασης προσδιορίστηκαν η γεωμετρία και το βάθος συνάντησης του υποβάθρου στην παράκτια ζώνη. Επισημαίνεται η ανάγκη τεχνητού εμπλουτισμού του προσχωσιγενή υδροφόρου ορίζοντα με τις χειμερινές απορροές του Γλαύκου για την ταχύτερη αποκατάσταση της ποιότητας του νερού και την αύξηση του υδατικού δυναμικού της λεκάνης. Εφαρμόστηκε η μέθοδος DRASTIC για την εκτίμηση της τρωτότητας των υπόγειων νερών απέναντι σε εξωτερική ρύπανση, όπου με βάση τις τιμές του δείκτη DRASTIC κατασκευάστηκε χάρτης τρωτότητας της περιοχής. Περιοχές υψηλής τρωτότητας εντοπίζονται στο παράκτιο τμήμα του υδροφορέα, ενώ αντίθετα περιοχές μέσης τρωτότητας στο Α/κό τμήμα του υδροφορέα. Τέλος, κατασκευάστηκε μαθηματικό ομοίωμα των υδροφορέων της προσχωματικής λεκάνης του Γλαύκου με την εφαρμογή του κώδικα MODFLOW παρέχοντας έτσι ένα όσο το δυνατόν πιο αξιόπιστο πρότυπο διαχείρισης του υπόγειου υδατικού δυναμικού της περιοχή έρευνας. / The Glafkos’ river basin is extended on the west side of the Panaxaikon mountain in the northwest area of the prefecture of Achaia, southeast of the city of Patras, occupying a total extent of 101,67 Km2 and constituting the main source of Patras’ water needs. It is characterized by the mediocre growth of the hydrographical network (a dendrite type of draining) and consequently the high permeability of rocks and the important infiltration at the expense of the runoff. The most important torrents that flow through the region of research are Xiropotamos, Filiouras, Souta, Verveniou and Elekistrianiko, which contribute inside the Glafkos River. The Alpine folded basin’s basement includes a sequence of pre-orogenetic sediments (marine limestone, radiolarites, etc) of the Pindos zone, and a clastic orogenetic sequence (flysch), which is constituted by alternations of silt rocks, sandstones and rarely conglomerates. The layers of the Pindos zone emerged at the final phase of the folding tectonics in the Lower Oligocene, where the Pindos’ thrust occurred in the form of a nappe, above the Gavrovo – Tripolitsa zone. The foreheads of the thrusts between the slices as well as the axes of folds have a NW – SE direction, with the direction of movement from east to west, and have a direct relation to the majority of the karstic springs. In the region of Patraikos Gulf, what prevails is a rhomboid faulting system with high slope and ENE, WNW directed normal faults that create a mosaic of fragmentized tectonic blocks and a general rising of region that continues until today. The opening up of the valleys in the wider region of research, which is often accompanied by landslides, is determined from 4 bunches of neotectonic faults directed NW, NE, WNW and NNE. The Plio-quaternary cover that appears in the coastal and hilly region is constituted by two stratigraphical units. The lower one consists of clays and sands, which were deposited in a lacustrine to brackish environment of sedimentation during the Pliocene to the Lower Pleistocene and the upper one consists of Calabria dating from the deltaic and land conglomerates. Generally the alluvium deposits are characterized by lithological heterogeneity both at the vertical and the horizontal direction and their thickness presents a gradual increase from the northerner and southerner limits to the central department of the basin, which exceeds 200 m. The annual height of rainfall (1071 mms) in the region of research is quite high for our country’s data and fluctuates from 640 to 900 mms in flat regions, whereas in the mountainous regions it reaches 1560 mms. During the last years, what takes place is a seasonal displacement of rainfall from winter to spring and autumn, which leads to the loss of the available water of the active infiltration because of increased evaporotranspiration. From a hydrologic aspect, the Glafkos basin receives annually, on average, 108,89 106 m3 of the water from rainfall, from which 48,9 % comes back to atmosphere with the processes of evaporation and transpiration, 28,6 % rises on the surface and 22,5 % infiltrates, mainly in important, from a hydrogeological aspect, formations (limestones and quaternary depositions). The semi-independent hydrogeologically karstic units, which are developed because of the laminated and faulty tectonics in the region and differentiate the movement of groundwater, constitute a characteristic hydrogeological feature of the region of research. In relation to the alluvium deposits, the unconfined aquifer of the superior area is progressively bent and falls into successive under pressure (confined) aquifers in the coastal area. At the beginning of the ‘90s in the coastal region, because of the overpumping, negative values of the piezometric surface in a distance up to 3 Km from the coastline were realised, having as a consequence the salinity of coastal alluvium aquifer from the seawater intrusion. The reduction of pumping in the middle of the ‘90s led to the rise of piezometric levels and to the reappearance of the phenomena of artesian wells in the coastal area. Due to the elaboration of the pumping data, what was realised is the appearance of high values of the hydraulic conductivity’s factor in the alluvium aquifers of the coastal zone as well as in the karstic aquifers. The aquifers of the Neogene formations as well as the alluvium aquifers of the southern bank of the river Glafkos present a smaller speed of movement of groundwater as compared to those of the northern bank, because of the predominance of the fine-grained clastics. The most important factor of the recharge of the Glafkos’ basin alluvium aquifer is basically the costal recharge from the river bank and then follows the inductive recharge from the limestones, whereas the direct infiltrated water from the rainfall and from the surplus of the irrigation water seem to be the least important factors. Based on the balance of the inflows – outflows of the Glafkos’ basin alluvium aquifer, an average annual surplus of 6,5*106 m3 of water has resulted, during the hydrologic years 1999 –2002. Generally, the quality of water in the alluvium aquifers as well as in the aquifers of Neogene formations, but also that in the karstic aquifers is considered to be good, if the coastal area of the Glafkos’ basin is excluded. Most of the groundwater, as well as the surface and spring water, presented the geochemical type Ca-HCO3, which generally includes water of good recharge and renewal, mainly along the drainage axes. The time-space movement of the brackish zone in the coastal area, in the period 1999 –2002, was realised not only by the increased distribution of various ions but also by the utilisation of factors S. A. R., Revelle and Schoeller, as well as the ratios rBr-/rCl- and rBr-/rI-. During the period 1999 – 2002, a perceptible reduction of the pollution from the saline intrusion in the coastal region took place. The abundance of wells of automatic flow into coastal area, which drain 3,5*106 m3 of brackish water, annually, to the sea played an important role in the acceleration of the restoration of the coastal basin aquifers of the river Glafkos. The position and the time-space movement of the brackish zone in the coastal area was realised also by geoelectrical researches that took place with the dispositions Schlumberger, Wenner – Schlumberger and Pole – Pole. Geoelectrical research revealed that seawater intrusion rarely appears in the form of a forehead, but follows selective paths via the coarse-grained clastics, while the fine-grained clastic formations play the role of a hydraulic barrier. Finally, the geometry and the depth of the basement in the coastal area were determined with the application of the seismic reflection method. The need of artificial enrichment of the alluvium aquifer from the wintry flows of the Glafkos River is pointed out, for a more rapid restoration of the water quality and the increase of the Glafkos’ basin water potential. The DRASTIC method was applied for the estimation of the vulnerability of the groundwater towards exterior pollution, where based on the DRASTIC indicator’s values, a map of the vulnerability of the region of research was constructed. Areas of high vulnerability are located in the coastal part of the aquifer, while areas of medium vulnerability are located in the eastern part of the basin. Finally, a mathematic model of the Glafkos’ basin alluvium aquifers was constructed with the application of code MODFLOW, thus providing an as much as possible reliable model of the management of the Glafkos’ basin groundwater potential.
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"Disponibilidade e gerenciamento sustentável do aqüífero Serra Grande no município de Picos - Piauí" / Availability and sustainable management of the Serra Grande aquifer in the municipality of Picos, Piauí

Claudio Luiz Rebello Vidal 16 October 2003 (has links)
Este trabalho objetivou determinar a disponibilidade do aqüífero Serra Grande e estabelecer as diretrizes para o seu gerenciamento sustentável no município de Picos, localizado no sudeste do Estado do Piauí. Principal sistema de água subterrânea da região, este aqüífero é o único com capacidade para atender as demandas futuras da população. Porém, a falta de regras básicas na exploração dos seus recursos poderá comprometer sua sustentabilidade. O desenvolvimento deste estudo teve início com a elaboração do modelo conceitual da área e a análise das condições de uso dos recursos hídricos. Nesta etapa, verificando-se que os conceitos hidrogeológicos vigentes consideravam apenas o limite físico do sistema para definir sua disponibilidade, foi estabelecido um novo princípio para determinação do volume de recursos que pode ser explorado de um aqüífero, denominado de princípio sustentável, tendo como base os fatores econômicos envolvidos na sua exploração. Para determinação da disponibilidade física e econômica do aqüífero Serra Grande, primeiramente, foi estimado o déficit hídrico acumulado desde o início da exploração do sistema, estabelecida sua relação com a posição do nível potenciométrico e calculado o custo atual de produção da água. Em seguida, foram traçados dois cenários futuros para a exploração dos recursos hídricos no município, representando os modelos de gestão da oferta e gestão da demanda, para o período de 15 e 50 anos. Posteriormente, foi construído um modelo matemático para representar o sistema de subsuperfície, no qual foi simulada a evolução futura do nível d’água. Com base nos valores obtidos, foi estimado o volume de água a ser produzido do armazenamento, a quantidade de recursos que deverão ser incorporados ao sistema e o custo futuro de produção. Os resultados mostraram que o aqüífero precisará incorporar um volume significativo de recursos, que talvez não esteja disponível na região estudada, e que a elevação real do custo da água poderá comprometer a capacidade de pagamento da população para dispor destes recursos. Verificada esta situação, foram definidas as medidas que precisam ser implementadas para o gerenciamento sustentável do aqüífero estudado, de modo a garantir o abastecimento futuro do município e da região. Com a elaboração deste trabalho, concluiu-se que o aqüífero Serra Grande não é “intensamente explorado” em Picos, porém é mal explorado atualmente, o que deverá provocar prejuízos na exploração futura dos seus recursos. / This work’s goals were to determinate the availability of the Serra Grande aquifer and to establish the governess for its sustainable management in the municipality of Picos, located on the southeast of Piauí State. This aquifer, the region’s most important groundwater system, has an unique capacity of fulfilling the population’s future demand. However, the absence of basic rules for the exploitation of its resources would compromise its sustainability. The study began with the development of the conceptual model of the area and the analyses of the water resources use. During this step, after verify that the hydrological actual concepts only observe the physical limit of the system to define its availability, it was established a new principle to determinate the volume of resources that can be exploited from an aquifer, named sustainable principle, based on the economical factors involved in its exploitation. In order to determine the physical and economical availability of the Serra Grande aquifer, first, it was estimated the water deficit accumulated since the begging exploitation of the system, established its relationship with the potenciometric level and was calculated the present cost of water production. Later on, two hypothetical scenarios concerning future exploration of water resources were drawn, representing the models of supply and demand management, for a period of 15 and 50 years. Furthermore, a mathematic model was built to represent the subsurface system, which was simulated the evolution of the water level. Based on the values found, it was estimated the amount of water that should be produced from storage, the quantity of resources that have to be incorporated to the system and the future production cost. Moreover, the results showed that the aquifer will need to incorporate a meaningful quantity of resources, that may be not available in the studied region, and that the real increase of the cost of the water would compromise the payment capacity of the population to dispose those resources. After verify this situation, it was defined the actions that must be taken for the sustainable management of the studied aquifer, to guarantee the future water supply of the municipality and the region. In conclusion, this work confirmed that the Serra Grande aquifer is not “overexploited” in Picos, instead, it is not being correctly exploited, which will negatively affect the future exploitation of its resources.
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Élaboration et mise en oeuvre d'un modèle organisationnel favorisant l'open innovation : contribution à l'innovation collaborative / Design and implementation of an organizational model for Open Innovation : Contribution to collaborative innovation

Steiner, Alexis 26 September 2014 (has links)
L’avènement du concept d’Open Innovation a été perçu par les industriels comme une formidable opportunité pour améliorer leur processus d’innovation et augmenter leur marge. En effet, ce concept prônant la large distribution des connaissances, suggère que les entreprises doivent solliciter leur environnement pour acquérir de nouvelles technologies par le biais de collaborations et que la valorisation des technologies internes à l’entreprise peut se faire de divers manières, comme le licensing. Alors les frontières de l’entreprise deviennent poreuses pour permettre une forte interaction avec des partenaires externes. Malgré toutes les promesses de ce concept, celui-ci a apporté un certain nombre de problématiques allant de la propriété intellectuelle à la culture d’entreprise en passant par les freins cognitifs. En accord avec le partenaire industriel de cette thèse, notre observation terrain et les constats bibliographiques, nous nous sommes concentrés sur les aspects organisationnels à mettre en œuvre pour mener une politique d’Open Innovation. Ainsi, cette thèse propose un premier modèle conceptuel pour ancrer une organisation dans son environnement et prendre pleinement en compte le paradigme d’Open Innovation. Ce modèle se base sur l’hypothèse que l’environnement est composé de facteurs d’influence qui ont un impact sur les projets de l’entreprise et que ceux-ci doivent posséder un capital compétence adéquate pour maitriser ces facteurs et atteindre les objectifs. Fort de ce cadre conceptuel, nous avons modélisé mathématiquement une organisation avec une approche coût/bénéfice pour comprendre le fonctionnement d’une organisation en mode « open ». Cela nous a permis de mettre en évidence le rôle de la structure organisationnelle et de la stratégie pour une politique d’Open Innovation. Enfin, en accord avec notre posture épistémologique d’action-recherche, nous avons développé un outil d’aide à l’orientation de l’action, RO²I (Relevant Organization for Open Innovation). L’objectif de cet outil est de proposé aux porteurs de projets, à t=0 du projet, une aide pour prendre en compte les aspects collaboratifs afin de mener leurs projets à bien et de choisir le bon modèle organisationnel pour inclure les compétences des partenaires. Nous avons pu tester la pertinence de notre proposition sur plusieurs projets passés d’une équipe d’innovation de rupture. Une fois validé, nous avons souhaité vérifier que notre outil était utilisable par les porteurs de projet, eux-mêmes, donc nous avons effectué une expérimentation sur deux projets en phase de démarrage dans les services supports de Solvay. Ce travail conclue sur la nécessité de posséder une organisation adaptée aux activités de collaboration et sur la nécessité d’un outil permettant de prendre en compte l’Open Innovation. Nous proposons, en perspective, d’utiliser cet outil pour mesurer la capacité à Open Innover d’une entreprise / Companies showed the arising of the Open Innovation concept as an amazing opportunity to improve their innovation process and increase profitability. Indeed, Open Innovation proposes to solicit external environment to acquire new technologies thanks to collaborations and, also, to add value to internal technologies by different path, like licensing-out, for instance. Then, firm boundaries become porous to allow strong interactions with external stakeholders. Despite to promises of this concept, it brings a lot of specific issues as intellectual property, firm culture or cognitive brakes. According to our industrial partner, our field observation and our state of art, we focused this work on organizational issues to perform an Open Innovation policy. To solve these issues, first, this these proposes a conceptual model to anchor an organization into it environment and to fully encompass the Open Innovation paradigm. We base our model on the next assumption: environment is composed by influence factors which impact projects of organization and these projects have to own an appropriate capital competence to master the factors and reach the purposes. Thanks to this conceptual framework, we modeled an organization with a mathematic cost/benefits approach to understand the functioning of an organization with « open » policy. Then, we highlighted the role of organizational structure and strategy to perform Open Innovation. Finally, we developed a decision-making tool, RO²I (Relevant Organization for Open Innovation). The objective of this tool is to help project manager to take into account the collaborations to lead his project at t=0 and to choose a suitable organization to anchor his project and acquire external competences. We tested our proposal on past project in an innovation team. After the validation, we verified the usability of our tool in industrial context. We experiment our tool on two projects into shared services of Solvay. We conclude this work on the necessity to anchor a project into a suitable organization for collaboration and on the necessity of a decision-making tool to take into account Open Innovation. For further researches based of our work, we propose to use RO²I to measure the capacity to Open Innovate of a firm
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Adsorció d'or i zinc amb resines impregnades XAD-2. Superfície d'Equilibri, un nou concepte per a l'adsorció

Serarols i Font, Joan Lluís 23 February 2001 (has links)
Dins dels processos de recuperació de metalls de dissolucions diluïdes s'ha realitzat un estudi del procés d'extracció d'or i de zinc mitjançant resines amberlite XAD-2 impregnades amb sulfur de triisobutil fosfina (TIBPS) i àcid di-(2-etilhexil) fosfòric (DEHPA) respectivament.S'ha realitzat un estudi de l'equilibri de l'adsorció d'espècies metàl·liques d'aquests metalls amb les resines indicades anteriorment. Amb la metodologia emprada per a la determinació dels punts d'equilibri dels experiments en batch i en columna, s'ha vist que una única isoterma no podia descriure el fenomen global d'equilibri i que en funció de la metodologia emprada s'obtenien isotermes diferents.Es va introduir una nova variable per poder explicar el fenomen observat, i per tant, amb aquesta nova variable l'equació de la isoterma es converteix amb l'equació d'una supèrfície que s'ha definit com a Superfície d'Equilibri.S'han determinat les equacions de les Suprfícies d'Equilibri dels sistemes d'adsorció estudiats (Au(III) TIBPS/XAD-2 i Zn(II) DEHPA/XAD-2) observan una bona coincidència de tots els punts d'equilibri obtinguts sobre la superfície, així com, un bon ajust de totes les isotermes obtingudes en funció de les diferents metodologies emprades sobre les respectives superfícies d'equilibri. Aquest nou concepte generalitza el concepte d'isoterma d'un procés d'adsorció.Fimalment, s'ha plantejat un model matemàtic d'adsorció per a determinar el coeficient efectiu de difusió (De) i el coeficient de transferància de matèria (kf) per ambdós sistemes d'adsorció estudiats mitjançant l'aplicació del model de difusió de sòlid homogeni (HSDM), utilitzant com a condició de contorn en el model la isoterma de Langmuir obtinguda mitjançant els experiments en columna de llit fix i emprant també l'equació obtinguda mitjançant el nou concepte de Superfície d'Equilibri.Els resultats obtinguts són molt satisfactoris, per tant, es pot concloure que la Superfície d'Equilibri és una bona eina per a descriure l'equilibri en els processos d'adsorció d'or i zinc amb les resines amberlite XAD-2 impregnades amb TIBPS i DEHPA respectivament. / The study of the extraction process of gold and zinc with Amberlite XAD-2 resins impregnated with tri-isobutylphosphine sulfide(TIBPS) and di-(2-ethylhexyl) phosphoric acid (DEHPA), respectively, has been studied.The equilibria governing the metallic ions adsorption by the studied systems have been established. Taking into account the methodology used to get the equilibria points corresponding to batch and column experiments performed, it was noticed that a unique isotherm could not describe the global equilibrium and that different isotherms were obtained in function of the experimental methodology carried out.It was introduced a new variable for explaining the phenomenon observed. By doing this, the isotherm became a surface that it was called equilibrium isotherm.The equations corresponding the Equilibrium Surfaces of the adsorption systems studied (Au(III) / TIBPS-XAD-2 and Zn(II) / DEHPA-XAD-2) were determined. The equilibria points obtained by batch and column experiments as well as obtained isotherms were very well placed on the surface. Thus, this new concept generalises the concept of isotherm in an adsorption process. Finally, the homogeneous solid diffusion model (HSDM) was applied for performing an adsorption mathematical model for determining the effective diffusion coefficient (De) and the mass transfer coefficient (kf) of both studied systems. The obtained results were very successful, so, it can be concluded that the Equilibrium Surface is a very good tool for describing the equilibria of the studied adsorption processes.

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