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Ecoeficiência em iluminação pública / Eco-efficiency in street lightingOswaldo Sanchez Junior 15 March 2016 (has links)
Na busca por eficiência energética em serviços e produtos de iluminação pública, a maioria das iniciativas concentra-se em procedimentos voltados estritamente à substituição de tecnologias convencionais por outras mais energeticamente eficientes, considerando somente a fase de operação, onde há mais consumo de energia, e o investimento inicial. No entanto, verifica-se que há uma carência de estudos dedicados à análise da sustentabilidade urbana, em particular com o foco na ecoeficiência das iniciativas, em que pese o crescente interesse das empresas por produtos economicamente e ambientalmente sustentáveis. Portanto, a qualidade do serviço de iluminação pública quanto à sua ecoeficiência (componente importante da sustentabilidade urbana) pode ser desenvolvida utilizando-se o pensamento de ciclo de vida de forma simplificada para avaliar tanto economicamente quanto ambientalmente o empreendimento, de modo a viabilizar a comparação de tecnologias, desenvolvimento de projetos e a tomada de decisão para gestores. O objetivo do presente trabalho é propor um modelo analítico que permita, tanto os desenvolvedores de produtos e projetos como a gestores de serviços de Iluminação Pública IP, gerenciar seus recursos para garantir maior ecoeficiência na transição para tecnologias mais avançadas (como o uso de LEDs em produtos), que mitigam os impactos ambientais e o custo desta transição. Como método, utilizou-se uma abordagem qualitativa, se aplicou a técnica de Avaliação de Ciclo de Vida (ACV) para avaliação ambiental e econômica de produtos e instalações para IP baseados na tecnologia convencional e produtos com tecnologia LED. Com isso obteve-se uma medida da ecoeficiência associada a diferentes soluções. Na sequência, as informações foram analisadas, comparadas e um conjunto de parâmetros foi definido para constituir um modelo para tomada de decisão. Em particular, foi dada ênfase à qualidade da iluminação na definição da Unidade Funcional. Todas as fases do ciclo de vida foram analisadas (extração de matérias primas, fabricação de componentes, integração e fabricação de luminárias, manutenção e descarte). Como resultados, foram obtidos critérios mínimos de comparação para instalações de Iluminação Pública a LED; identificação dos impactos de novas tecnologias (como uso da tecnologia LED) em termos de emissões de gases de efeito estufa (CO2 equivalentes) do setor de IP; identificação dos impactos de novas tecnologias (como uso da tecnologia LED) no Custo do Ciclo de Vida de instalações para IP e foi desenvolvido um Modelo de Análise para integrar o desempenho econômico ao ambiental (ecoeficiência) de produtos e instalações de IP. / Introduction: in the search for energy efficiency services and street lighting products, most of the initiatives focuses on procedures aimed strictly to the replacement of conventional technologies by more energy efficient ones considering only their use phase. However, it turns out that there is a lack of studies dedicated to analyzing this field with a focus on eco-efficiency initiatives, despite the growing interest of companies by products economically and environmentally sustainable. Therefore, the quality of the street lighting service for their eco-efficiency can be developed using the Life Cycle Assessment (LCA) technique in a systematic and objective manner, in order to facilitate the comparison of technologies, project development and decision making for managers. Objective: To generate an analytical model that allows both product and project developers and managers of street lighting services to manage its resources to ensure greater eco-efficiency in the transition to more advanced technologies (such as the use of LEDs in products) that mitigate the environmental impacts and the cost of this transition. Method: it was applied the LCA for environmental and economic evaluation of products and street lighting facilities based on conventional technology and products with LED technology. Further, the information was analyzed, compared and a set of parameters has been set to provide a model for decision-making. In particular, it was given emphasis to the quality of lighting in the definition of a functional unit. Every stage of the life cycle was analyzed (extraction of raw materials, component manufacturing, integration and manufacturing lighting fixtures, maintenance and disposal). Results: we obtained minimum criteria of comparison for Street Lighting LED installations, identifying the impact of new technologies (such as use of LED technology) in the carbon footprint of the street lighting industry. Besides, we identified the impact of new technologies (such as use of LED technology) in the cost of life cycle of street lighting facilities. Lastly, it was developed an Analysis Model to integrate environmental economic performance (eco-efficiency) products and street lighting facilities.
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Avaliação do ciclo de vida e custeio do ciclo de vida de evaporadores para usinas de açúcar. / Evaporators life cycle assessment and life cycle costing for sugar cane plants.Lino José Cardoso Santos 20 September 2007 (has links)
O setor de açúcar e álcool etílico no Brasil tem experimentado um grande crescimento. Contribuem para isto as demandas crescentes do álcool etílico, um biocombustível, e do açúcar. A área industrial produtora de açúcar, um alimento, ainda convive com uma prática industrial ultrapassada, que vem a ser o uso do aço carbono, um material barato, mas com pequena resistência à corrosão. Os aços inoxidáveis são os materiais mais indicados para a substituição do aço carbono, entretanto, eles são considerados caros. Os evaporadores das usinas de açúcar são equipamentos importantes para a sua operação. Quando são usados tubos de aço carbono para a troca térmica, eles começam a ser substituídos a partir do segundo ano de operação devido à corrosão. Enquanto isso, os tubos em aços inoxidáveis podem durar décadas. O presente trabalho objetivou a avaliação do desempenho ambiental e financeiro de tubos para evaporadores construídos com aço carbono e, comparativamente, com os aços inoxidáveis 304, 444 e 439. Para alcançar estes objetivos foram utilizadas as metodologias de Avaliação do Ciclo de Vida (ACV) e de Custeio do Ciclo de Vida (CCV), respectivamente. Neste estudo de ACV foi adotada como função dos sistemas em estudo a massa de água evaporada. Na definição destes sistemas de produtos foram adotados os subsistemas de fabricação das bobinas de lâminas dos aços e fabricação, instalação e limpeza dos tubos. O consumo de gás natural, eletricidade e o transporte foram usados como subsistemas secundários. O período de avaliação destes sistemas foi de trinta anos. A partir dos resultados desta ACV, concluiu-se que os tubos em aço carbono apresentaram maior impacto ambiental que os tubos em aço inoxidável 304, 444 e 439, pois emitiram mais que 4,2 vezes a quantidade de dióxido de carbono; 2,8 vezes a de óxidos de nitrogênio; 3,1 vezes a de materiais particulados, 13 vezes a de materiais suspensos e 4,5 vezes a de resíduos totais. Os tubos em aço carbono consumiram também mais que 11 vezes o total de recursos naturais utilizados (carvão; lignita; calcita; dolomita; óleo; gás natural e minérios de ferro, cromo, níquel, molibdênio e manganês); 1,8 vezes a de água e 5 vezes a de energia. Com relação à emissão de óxidos de enxofre, os tubos em aço carbono emitiram quantidades semelhantes às emitidas pelos tubos em aços 444 e 439 e a metade que os tubos em aço 304. Na elaboração do CCV foram utilizados os componentes de custo compra, transporte, instalação, substituição e limpeza dos tubos e a venda das sucatas. Na avaliação financeira, todos os custos que aconteceram no período de trinta anos foram trazidos ao valor presente. A partir dos resultados obtidos concluiu-se que os aços inoxidáveis 439 e 444 apresentaram-se como opções de investimento mais interessantes que os tubos fabricados em aço carbono, já que apresentaram custos trazidos ao valor presente menores, na proporção de 0,76 para os tubos em aço 439; 0,79 para os tubos em aço 444 com 1,20 mm de espessura e 0,93 para tubos em aço 444 com 1,50 mm de espessura. Os tubos em aço 304 com 1,20 mm de espessura apresentaram desempenho financeiro semelhante aos tubos em aço carbono; enquanto que os tubos em aço 304 com 1,50 mm apresentaram custos ao valor presente 1,19 vezes maior. Os resultados obtidos indicam também que as metodologias ACV e CCV devem ser usadas em conjunto, pois mostram que produtos mais seguros ambientalmente podem vir a ser opções de investimentos também mais interessantes. / The sugar and ethanol sectors in Brazil have tried a great growth. The increasing demands for ethanol, a biocombustible, and for the sugar contributes for this situation. The producing industrial area of sugar, a foodstuff, still adopts the use of carbon steel pipes, a cheap product, of low corrosion resistance. The stainless steels are the materials more indicated for the substitution of carbon steel, however they are considered expensive. In sugar cane plants, the evaporators, are important equipments to operation. Carbon steel pipes are the main product used for the thermal exchange, and these pipes start to be replaced after the second year of operation. Meanwhile, stainless steel pipes can last for decades. This work evaluates the enviromental and financial performance of evaporators pipes constructed with carbon steel and with 304, 444 and 439 stainless steel. To reach these objectives the methodologies of Life Cycle Assessment (LCA) and the Life Cycle Costing (LCC) were applied, respectively. The water mass evaporated was adopted as function of the systems in LCA study. In the definition of these product systems were adopted the manufacturing of steel and the manufacturing, installation and cleanness of the pipes. Natural gas, electricity and transport had been considered. The evaluation time was thirty years. From the LCA results, there were concluded that the steel carbon pipes presented more enviromental impact performance than 304, 444 and 439 stainless steel pipes, because they emitted more than 4.2 times of carbon dioxide; 2.8 times nitrogen oxides; 3.1 times of particulated materials; 13 times of suspended materials and 4.5 times of total residues. The carbon steel pipes also consumed more than 11 times the sum of all natural resources used (coal, lignite, iron ground, chromium, nickel, molybdenum, manganese; calcite, dolomite; oil and natural gas); 1.8 times more of water and 5 times more of energy. Regards to sulphur oxides emission, the carbon steel pipes emitted the same amount of sulphur oxides as 444 and 439 stainless steel pipes and they emitted half than of 304 stainless steel pipe. In the life cycle costing (LCC) elaboration were applied the cost components: purchase, transportation, installation, substitution, cleanness and the scraps sale. In the financial evaluation, all the costs that have incurred in the period of thirty years have been brought to the present value. As results concluded that 439 and 444 stainless steels presented the best investment options, due to this they have presented less costs brought to the present value, in the ratio of 0.76 for the 439 steel pipe; 0.79 for 444 the steel pipe with 1.20 mm of thickness and 0.93 for 444 steel pipe with 1.50 mm of thickness. The 304 stainless steel pipes with 1.20 mm of thickness presented similar financial performance compared to carbon steel pipes; whereas the 304 steel pipes 1.50 mm of thickness presented costs to 1.19 times higher of the present value. The results also indicate that LCA and LCC methodologies must be used together; therefore, they show that safer enviromental products can become the more interesting investment options.
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Beiträge zur analytischen Berechnung und Reduktion der aus Netzspannungsunsymmetrien resultierenden Harmonischen in Systemen der Hochspannungs-Gleichstrom-ÜbertragungAchenbach, Sven 26 August 2009 (has links)
An AC system’s voltage unbalance by a fundamental frequency negative sequence system is usually the main cause for the emission of non-characteristic harmonics by current source converters as used in conventional HVDC systems. This emission takes place on both sides of each 12-pulse converter.
On the DC side mainly a 2nd harmonic voltage appears driving a 2nd harmonic current. The magnitude of this harmonic current can exceed the magnitudes of the characteristic harmonics even if no low order resonance exists. Further non-characteristic harmonics generated by the converter under such unbalanced supply voltage conditions have frequencies with a frequency distance to the characteristic harmonics of 2 times the fundamental frequency. The main technical drawbacks are the unintended coupling between both AC systems and the risk of thyristor over-stresses by DC current discontinuities at low power transfer levels.
On both AC sides the largest 2 non-characteristic current harmonics generated by a 12-pulse HVDC converter under unbalanced supply voltage conditions are a negative sequence system of the fundamental harmonic and a positive sequence system of the 3rd harmonic. Also on the AC sides further harmonics are emitted by the converter with a order number distance of 2 to the orders of the characteristic harmonics. However, in practical AC system operation special attention has to be paid to the 3rd harmonic distortion level, in particular when low order resonance appears between the system impedance and the impedance of the converter station AC filters.
In order to avoid the above mentioned problems, large smoothing reactors and sometimes large blocking filters are installed on the DC side and the voltage distortion on the AC sides is reduced by AC filters. However, these filters require an expensive high component rating if they are tuned to the 2nd or 3rd harmonic respectively.
The work shows that a modification of the valve firing can reduce the levels of the 2nd and 3rd harmonic without investment into additional primary equipment. Furthermore, this offers the chance to reduce the minimum power transfer level since also the risk of an intermittent DC current can be reduced. A corresponding algorithm and a control strategy are proposed.
However, the calculation of an appropriate firing pattern requires a detailed modelling of the processes within the converters, especially the formation of the harmonics and the harmonic transfer between AC and DC sides. The work proposes a component vector model for the calculation of the harmonics.
This model assumes that each harmonic consists of a first component representing the ideal conversion process, a 2nd component representing the impact of different commutation angles and in the case of the modified firing a 3rd component considering the impact of the intended non-equidistant firing.
The work shows, that the harmonic component vectors resulting from voltage unbalance and from firing modulation can be treated separately and superimposed linearly.
The calculation of the harmonic component vectors is performed applying the method of switching functions. For the consideration of the commutation and firing angle differences the modelling of switching functions based on differential impulses is proposed. However, especially an accurate representation of the above mentioned 2nd component vector requires a correct calculation of the commutation angles and their valve-specific differences.
The investigations of this work have revealed that the conventional method of calculating the commutation angles – assuming an ideal smoothed DC current - may not produce results of sufficient accuracy. This is especially true in the case of a high ripple of the DC current, e.g. smoothed with a small smoothing reactor. A small smoothing reactor is typical for HVDC back-to-back applications.
Therefore a new analytical method for the calculation of the commutation angles has been developed which in particular considers the typical pulse form of the DC current and additionally the impacts of the voltage unbalance and of the proposed modification of the firing on the ripple shape of the DC current.
Moreover, as this analytical method requires the instantaneous values of the DC current at the instants of valve firing, a further analytical method for the calculation of these discrete current values has been developed. The equations are valid under the same conditions as the new ones for calculation of the commutation angles, i.e. resistive-inductive AC system fundamental frequency impedances, any degree of DC current smoothing between ideal smoothing and a ripple at the limit for current discontinuities. Symmetrical conditions, supply voltage unbalances and non-equidistant firing as proposed are applied. It is shown that, using this method, also the discrete values of the DC current at the end of the commutation intervals can be determined. In practice one of these discrete current values indicates the minimum value during one period of the fundamental frequency. This offers the chance for a more exact analytical determination of the limit for the appearance of DC current discontinuities.
For typical parameters of a back-to-back installation the new methods and the new analytical equations have been compared with simulation results showing excellent correlation for typical voltage unbalances of not more than 1...2% and firing angle differences of not more than 2.5°. This verification is performed for the harmonics, the commutation angles and the discrete values of the DC current at the firing instants as well.:1 Einleitung und Ziel der Arbeit
1.1 Einführung in die Problematik
1.2 HGÜ-Systeme als Quelle von Strom- und Spannungsharmonischen
1.3 Netzspannungsunsymmetrien
1.4 Abgrenzung der betrachteten technischen Systeme
1.5 Beweggründe für die Betrachtung
1.6 Zielstellungen
2 Erkenntnisstand und Analyse der Aufgabenstellung
2.1 Harmonische
2.2 Aktive Kompensation von Harmonischen
2.3 Diskrete Werte des Zwischenkreisstromes am Beginn und Ende der Kommutierungsintervalle
2.4 Kommutierungswinkel
3 Grundlagen
3.1 Methodischer Ansatz
3.2 Allgemeine Voraussetzungen, Annahmen und Festlegungen
3.3 Maßgebliche Impedanzen für die Stromaufteilung
3.4 Maßgebliche Impedanz für die gleichstromseitigen Stromharmonischen
3.5 Leerlauf-Klemmenspannung des Stromrichters
3.6 Kommutierungsspannung
3.7 Nummerierungssystem der Ventile
3.8 Überlappungsformen der Kommutierungsintervalle
3.9 Komplexer Spannungsunsymmetriefaktor
3.10 Anwendung und Modifikation von Schaltfunktionen
3.11 Verifikation der Ergebnisse
4 Harmonische auf der Gleichstromseite
4.1 Bildungsgesetz
4.2 Charakteristische Harmonische
4.3 Nichtcharakteristische Harmonische infolge unsymmetrischer Netzspannungen
4.4 Nichtcharakteristische Harmonische infolge Ansteuermodifikation
5 Diskreter Wert des Zwischenkreisstromes im Zündzeitpunkt
5.1 Vorgehensweise
5.2 Lösungsansatz
5.3 Konstante Gegenspannung
5.4 Reale Gegenspannung des HGÜ-Stromrichters
5.5 Berücksichtigung von Resistanzen
5.6 Unsymmetrische Netzspannungen
5.7 Ansteuermodifikation
5.8 Unsymmetrische Netzspannungen und gleichzeitige Ansteuermodifikation
5.9 Ergebnisse
6 Kommutierungswinkel
6.1 Vorgehensweise
6.2 Konstante Gegenspannung
6.3 Reale Gegenspannung des HGÜ-Stromrichters
6.4 Berücksichtigung von Resistanzen
6.5 Unsymmetrische Netzspannungen
6.6 Ansteuermodifikation
6.7 Unsymmetrische Netzspannungen und gleichzeitige Ansteuermodifikation
6.8 Ergebnisse
7 Vertiefende Betrachtung der nichtcharakteristischen Harmonischen auf der Gleichstromseite
7.1 Vorbemerkungen
7.2 Unsymmetrische Netzspannungen
7.3 Ansteuermodifikation
7.4 Spannungsunsymmetrie und gleichzeitige Ansteuermodifikation
7.5 Ergebnisse
8 Harmonische auf der Netzseite
8.1 Bildungsgesetz
8.2 Charakteristische Harmonische
8.3 Nichtcharakteristische Harmonische
9 Betrachtungen zur aktiven Kompensation
9.1 Vorbemerkungen
9.2 Betrachtungsumfang
9.3 Grundlagen
9.4 Konzeptioneller Vorschlag für die Kompensation der 2. Stromharmonischen
9.5 Betrachtung der Drehstromseite
9.6 Vorschlag zur Weiterentwicklung des Konzeptes
9.7 Berechnungsbeispiel zur Kompensation der 2. Harmonischen im Zwischenkreis
9.8 Ergebnisse und Schlussfolgerungen
10 Zusammenfassung
11 Literatur
12 Formelzeichen und Abkürzungen
13 Anlagenverzeichnis
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Evaluation of DC Fault Current in Grid Connected Converters in HVDC StationsSinhaRoy, Soham January 2022 (has links)
The main circuit equipment in an HVDC station must be rated for continuous operation as well as for stresses during ground faults and other short circuits. The component impedances are thus selected for proper operation during both continuous operation and short circuit events. Normally, Electromagnetic Transient (EMT) simulations are performed for the short circuit current ratings, which can leadto time consuming iterations for the optimization of impedance values. Hence, sufficiently correct and handy formulas are useful. For that reason, in this research work, firstly, a thorough literature study is done to gain a deep understanding of the modular multilevel converter (MMC) and its behaviour after aDC pole-to-pole short circuit fault. Two associated simulation models are designed in PSCAD/EMTDC simulation software. The focus of this thesis is on DC pole-topoleshort circuit in Symmetric Monopole HVDC VSC Modular Multilevel Converter (MMC). The desired analytical expression for the steady state fault current is determined byusing mesh analysis and also by applying KCL and it is verified by doing a set of simulations in PSCAD. A detailed sensitivity study has been done in the PSCAD simulation software to understand the influence of the AC converter reactor inductance and the DC smoothing reactor inductance on the steady state as well as peak fault current respectively. From the sensitivity study, the simulated values of peak factor have been obtained. By means of the ratio in between DC side inductance (L_DC) and AC side inductance (L_AC), and by performing a number of calculations, the desired expression for the peak factor is derived. As a result, the peak fault current can be calculated. The calculated value of the peak fault current from the derived formula is compared to the simulated value and validated. An over-estimation is considered for the rating of the equipment. Along with that, the analysis of the effect of impedances of equipment and systems are done and also verified, to better judge the accuracy of the result. In the result, it is found that, the error margin obtained from the derived analytical expression for the steady state value is within 2% of the PSCAD simulated value, which means the error can be safely ignored. Similarly, the value obtained from the derived formula for the peak fault current is within 4% over-estimation margin of the PSCAD simulated value, which is quite good in terms of cost estimation for the rating of the components.
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Life Cycle Cost Analysis and Optimization of Wastewater Pumping SystemChen, Chao, Bhamare, Yogesh Vishwas January 2019 (has links)
Different attempts have been made to facilitate successful operation of Wastewater Pumping (WWP) system. The WWP units which are already existed in different parts of the world have been studied to identify its success, failure and different parameters associated with its suboptimal performance. The performance of WWP depends on three parameters namely pump, hydraulics, control system and pump station. These parameters are interdependent and must be carefully matched to achieve efficient WWP system. Nowadays the scenario has changed where organizations has started looking increasingly at the total cost of ownership, another way of saying Life Cycle Cost Analysis (LCCA) and recognizing the need to get most out of their equipment purchase. The master thesis includes theory part which describes the different parameters associated with WWP unit especially focusing on Xylems WWP system. This thesis is an attempt to help companies to know how LCCA could be productive management tool in order to minimize maintenance cost and maximize energy efficiency The study reported in this thesis work has been conducted to shed light over the use of Life Cycle Cost Analysis in WWP system. The current study tries to suggest and assess an adopted approach to ensure successful and efficient operation of WWP system with lowering energy demand and decrease in maintenance cost. Initial cost, Maintenance cost and Energy costs are important issues in the operation of WWP system since they are responsible for total cost over time. Therefore, description of each cost, formulas necessary for LCC calculations, data and survey structure, material and energy flow has been described. This work also aims to provide an extensive literature review, different survey and data collection techniques, analysis of collected data, statistical modelling, customer interaction by questionnaires and an interview with experts were used. LCC calculations were used to support the design and selection of most cost-efficient WWP system. Therefore, the given thesis work is an attempt to achieve better functional performance, improve existing design principles associated with WWP System, contribution to asses economic viability, support decision making to enhance operational quality to achieve efficient and successful WWP system.
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Моделирование колебательных свойств пленок наноструктурного углерода на металлической подложке : магистерская диссертация / Modeling of vibrational properties of nanostructural carbon films on metal supportБокизода, Д. А., Boqizoda, D. A. January 2017 (has links)
Объект исследования – наноразмерные пленки двумерно упорядоченного линейно - цепочечного углерода на металлической подложке без примесей и с примесями.
Цель работы – теоретическое исследование структурных, механических и колебательных свойств наноразмерных пленок двумерно упорядоченного линейно - цепочечного углерода на металлической подложке.
Методы исследования: метода функционала плотности (DFT), сделан обзор экспериментальных и теоретических работ по применению DFT для вычисления структурных, упругих и колебательных свойств; использование пакетов ABINIT и Quantum-Espresso в приближении DFT; графическое представление результатов с помощью программного обеспечения MS Office Excel и Origin Pro.
Результаты работы: рассчитан спектр комбинационного рассеяние ЛЦУ пленок; совмещение экспериментального и расчетного спектров комбинационного рассеяния для линейной структурной модели кристалла карбина; анализ возможности аттестации линейно-цепочечных структур методом КРС. / The object of investigation is nanosized films of two-dimensionally ordered linear-chained carbon on a metal substrate without impurities and with impurities.
The aim of the work is a theoretical study of structural, mechanical and vibrational properties of nanosized films of two - dimensional ordered linear - chain carbon on a metallic substrate.
Research methods: density functional method (DFT), an overview of experimental and theoretical works on DFT application for calculation of structural, elastic and vibrational properties; the use of Abinit and Quantum-Espresso packages in the DFT approximation; graphical representation of results.
The results of the work: the spectrum of Raman scattering of LCC films was calculated; combining the experimental and calculated Raman spectra for the linear structural model of a carbyne crystal, analysis of the possibility of characterization of linear-chained structures by the Raman spectroscopy method was performed.
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LCC MSE WallsSmith, Joel 08 December 2023 (has links) (PDF)
Lightweight cellular concrete (LCC) is mainly a mixture of water, cement, and foam bubbles. LCC generally has a cast density between 20-60 pcf and an air content between 49-84%. LCC is often used as a fill material because it has a low unit weight which reduces settlement. LCC is increasingly being considered as a backfill behind Mechanically Stabilized Earth (MSE) walls and embankments. Although engineers are using LCC in MSE walls or free face walls (MSE wall without the concrete panels or reinforcements), there is presently a lack of information regarding the performance and behavior of LCC to guide them. This research attempts to answer questions on the design of MSE walls backfilled with LCC and free face LCC walls by providing a well-documented case history and evaluating if LCC can be modeled as a c-ϕ material. A steel frame test box (10 ft wide x 12 ft long x 10 ft high) with a MSE wall on one side was constructed for the research. The box was filled with four lifts of LCC with steel ribbed-strip reinforcements extending into the LCC behind the MSE wall panels at the center of each lift. After the LCC was cured, two static load tests were performed by applying a surcharge load to the surface of the LCC. In one test, surcharge pressure was applied adjacent to the MSE wall to produce failure of the wall system. In a second test, the surcharge pressure was placed adjacent to a free face of the LCC to produce failure. String potentiometers (string pots), load cells, pressure plates, and strain gages were used to measure the behavior of the MSE wall and free face wall during testing. These two tests provided a comparison between LCC behavior with a MSE wall relative to a LCC free face. Failure of the free face wall with unreinforced LCC backfill in this test can be predicted using Rankine’s lateral force equation using a c-ϕ model. Failure angle at the base of the free face wall was between 51-63° which corresponds with an average friction angle (ϕ) of 24° and cohesion (c) of 1575 psf with an upper bound ϕ = 34° and a c = 1285 psf. The presence of reinforcements in the LCC backfill behind the MSE wall increased the capacity of the wall to hold a surcharge load. The presence of reinforcements in the LCC behind MSE walls also led to a much more ductile surcharge pressure vs. lateral deflection curve for the MSE wall compared to the free face wall.
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A Spatial-Temporal Contextual Kernel Method for Generating High-Quality Land-Cover Time SeriesWehmann, Adam 25 September 2014 (has links)
No description available.
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UTVÄRDERING AV LCA, LCC & MERVÄRDEN FÖR NYPRODUKTION I OFFENTLIG SEKTOR : En jämförelse mellan valet av trä och betong som stomsystem i konceptförskolorNikzad, Emal, Hassan, Guleed January 2022 (has links)
Purpose: In this project work, the purpose is to perform an LCA as well as an LCC on two concept preschools, one with a wooden frame and one with a concrete frame. The result from the LCA is going to highlight, which of the building frames have the lowest environmental impact. In addition to the environmental impact, the project work is going to include indoor climate together with energy use to get a broader view of the building’s overall performance. Method: This project work is in collaboration with Futurum Fastigheter i Örebro AB, where the authors have been instructed to perform an LCA on two concept preschools. One preschool has a wooden frame and the other has a concrete frame. The objective is to find out which of the buildings has the largest environmental footprint. In addition to this, the authors have evaluated an LCC together with an additional value tool. There are many tools to analyze the consequences from an environmental as well as an economic perspective. The report includes an LCA, LCC and an additional value tool. Result: The results show that the impact on CO2e/m2 for Bettorp was lower than Silva. Furthermore, the comparison between both preschools illustrated that Bettorp had lower emissions in all greenhouse categories except for carbon storage. The additional value tool portrays positive values for each preschool, although they differ. Conclusion: With the help of the software "One Click LCA" and "Visualisering och kvantifiering av mervärden vid energieffektivisering i offentlig sektor", the questionnaire has been answered and they all point to the wooden frame having a less environmental impacts along with a lower social cost of coal. The additional value tool was answered with the help of three employees at Futurum Fastigheter i Örebro AB. One of the participants concluded that there was no difference with regard to additional value between the preschools. The other two participants agreed that the preschool with a wooden frame provided a higher additional value compared to the other preschool.
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The Value-chain of Biochar : Case developement and value validation for providers and customers from an environmental, economic and social perspectiveEriksson, Markus, Engel, Samuel January 2024 (has links)
The growing need for climate mitigation solutions has contributed so thatbiochar has gained significant interest. Primary for its ability as a carbon sinkbut there is also a growing interest due to several other aspects within industriese.g. substitution effects, increased resource efficiency, an enabler forindustrial symbiosis, and its beneficial properties when put in soil that can increasegrowth. Previous studies of biochar have been dominant within the environmentalperspective of biochar, analyzing detailed characteristics of its propertiesand carbon sink potential. Some studies have a holistic perspective reflectingon countries specific energy mix and the different benefits of producingbiochar. However, previous studies are far too few to determine the value-chainof biochar. Hence previous studies have knowledge gaps within the holistic lifecycle approach from a provider or customer perspective of biochar, not reflectingon demand for quality requirements in different utilization areas and markets.The need for validation of the environmental and the economic performanceof biochar has to be established, and the economic perspective of biochar hasmajor knowledge gaps since previous studies are scarce. The study aims to establish the value-chain of biochar by evaluating theenvironmental, economic, and social perspectives through life cycle thinking.The core of the study is to distinguish value, which first has to reflect thebiochar quality requirements from providers and customers, captured throughinterviews and literature research. The quality requirements enable a goal forproducing biochar and determine what processes and biomass are needed fordifferent markets. This is evaluated through a case development which considersthe different quality requirements. Life cycle assessment (LCA) with acradle-to-grave perspective and life cycle costing (LCC) with a cradle-to-gatewere then used to distinguish biochar´s environmental and economic performance. The interviews and researched literature resulted in three cases being developed,biochar application in electric arc furnaces in steel production, agriculturalapplication, and commercial application through biochar-macadam. Thesteel industry has higher quality requirements due to the need to have a similarcomposition as fossil coal, resulting in biochar produced from wood being theonly option. The limitations for agricultural application are more related tothe allowed amount of phosphorus per ha and thus all the researched biocharapplies to different degrees. Biochar application in biochar-macadam is similarto agricultural application, however limited due to the EBC certification notallowing the production of biochar from sludge. The generated results from the LCA show that the climate performance isvastly different depending on what biomass was utilized and the different markets.Biochar produced from park and garden, and wood results in a higher climateperformance due to the higher carbon sequestration compared to biocharproduced from straw and sludge, however depending on how the biocharis utilized, the performance varies. During biochar application in electric arcfurnaces, the majority of the produced carbon sink is destroyed which resultsin worse climate performance, instead the majority of the reduced emissionscomes from the substituted fossil coal. Compared to biochar application inagricultural and biochar-macadam where the carbon sink stays intact, steel applicationstill has worse climate performance even when including substitution.Biochar-macadam production results in more emissions compared to agriculturalapplication due to the need to mix biochar with stones and compost,thus biochar in agriculture is the best option from a climate perspective. The economic aspects are generated through the conducted LCC which resulted inbiochar produced from park and garden, and sludge being more beneficial dueto the absence of acquisition costs. Production of biochar from wood provesto be difficult when considering a larger time frame, with the market for steelproduction not returning the investment. Biochar produced from straw hasa positive return on investment when considering the agriculture market, butnot for the production of biochar-macadam. The results show that the marketof biochar is very uncertain due to being considered immature and a futuremarket. The major uncertainty is connected with the immaturity of the market.The quality requirements are not reflected in the market pricing which isone of the major reasons for biochar utilization in the steel industry not beingeconomically beneficial. The value chain of biochar is a combination of many different economic,environmental, and social values. The conducted LCA shows that there areclimate benefits due to carbon sequestration, and a possibility to replace fossilreferences. Other than biochar there are also by-products such as heat and oilwhich can be utilized, improving the climate performance further. The multipleproducts also have economic benefits due to the potential of creating multipleproducts. The carbon sink can be sold as carbon credits, and the heat can beutilized in district heating. For providers, the creation of biochar is an enablerto reduce environmental impact, utilize products already within the system,and create value from waste. The structure of biochar generates a lot of valuefor customers. The porosity enables water storing capabilities which increasesthe efficiency of watering. This reduced the amount needed for soil applications,while also securing the harvest from drought and flooding. Even though thevalue chain of biochar shows that there is a lot of potential, it is still uncertainhow it will be integrated into society, and how the market will be shaped in theyears to come.
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