Intresset för datajournalistik har ökat både på redaktionerna och inom forskningen det senaste decenniet i takt med att tillgången på data har ökat och därmed behovet av att kunna hitta nyheter och berätta med hjälp av data. De flesta tidigare studier om datajournalistik har utgjorts av intervjuer med verksamma datajournalister och bland annat undersökt olika ideal. Men det finns få kvantitativa studier av vad datajournalisterna faktiskt gör, och av svensk datajournalistik. Den här uppsatsen syftar till att med innehållsanalytiska metoder beskriva och analysera datajournalistik som publicerats i svenska medier de senaste fem åren, och som journalister själva lyfter fram som exempel på datajournalistik. Urvalet är 91 datajournalistiska projekt som lämnats in som bidrag till NODA (Nordic Data Journalism Awards) eller som publicerats i Facebookgruppen Datajournalistik mellan 2013 och 2017. Ur en genomgång av tidigare forskning om datajournalistik har fyra olika ideal identifierats: ett undersökande, ett vetenskapligt, ett entreprenöriellt och ett från hackerkulturen, vilka utgör grunden för en analysmodell. Dessutom undersöks vilka producenterna är, vilka ämnen som är vanligast, vilka metoder och datakällor som används och hur publiken inbjuds att ta del av data och att vara delaktiga utifrån teorier om interaktivitet. Resultatet visar att datajournalistiken i denna undersökning ofta bygger på unika data, det vill säga självständig research, och att det undersökande idealet är relativt starkt. Trots att datajournalistik sägs präglas av hackerkulturens ideal om samarbete och deltagande är det ofta få producenter och yrkesroller bakom varje publicering och publiken bjuds sällan in att delta i processen.

The aim of this thesis is to give a perspective on the development of the Swedish automobility between 1950 and 2007. New knowledge on automobility’s role for economic historical development will be achieved by studying the interaction between the diffusion of the private car on the national and the regional level, and the households’ preferences and the government’s regulations of car ownership. The first paper, Two Sides of the Same Coin?, compares car diffusion in Norway and Sweden to find explanations for the national and regional patterns. We ask whether the slower diffusion in Norway can be explained with national differences in income, institutions, infrastructure and population settlements; or if regional differences in income and population density have affected the outcome? Our conclusion is that car diffusion in Norway and Sweden displays two sides of the same coin; the national levels converged, but the process did not follow the same regional pattern. Regional differences in income and population density have in general been a significant explanation for car density in Sweden, but not in Norway.   The second paper, Driving from the Centre to the Periphery?, examines whether the diffusion of private cars followed the over-all socio-economic and geographical changes in Sweden from 1960 to 1975. In particular, it studies if ownership per capita followed changes in income or changes in population density (urbanisation). The analysis is based on unique Swedish parish-scale census material that includes all private car owners for the years 1960, 1970 and 1975. Our conclusion is that income levels were more important than other explanations for the diffusion of private cars in Sweden between 1960 and 1975. The third paper, ‘En ledande och samordnande funktion’, contributes with new knowledge on how the Swedish government has organised traffic safety in certain ways since the 1950s. The emphasis is on the establishment and closing down of the National Road Safety Office (TSV) and how the changing forms of organisations before, during and after TSV have been reflected in the road plans from 1958, 1970 and 1990. Our conclusion is that the motives for both establishment and closing down of the TSV were the same; to create a more efficient organisation regarding traffic safety. These changes have been reflected in the road plans where an increased control over the infrastructure can be recognised, especially during the last two decades. The fourth paper, A Dark Side of Car Ownership, examines whether improved technical performance with respect to fuel consumption have been counterbalanced through increasing engine power and weight, how such properties are valued by the consumers, and in what way political instruments have affected this development. The analysis is based on historical data covering all car models within the 50 percentiles of new registrations. Our conclusion is that a vehicle purchase rebound effect can be identified since the fuel consumption has decreased over time, while the engine effect has increased. Also, the Swedish car fleet has developed in a setting of political instruments and regulations working in favour of larger and more fuel consuming cars.

The aim of this thesis was to study determinants of a readiness for pro-environmental travel behavior in households. Four empirical studies were conducted examining reduction in car use (Study I), acceptability of transport policy measures (Study II and III), and behavioral adaptations in response to travel demand management (TDM) measures (Study IV). In Study I, the aim was to interrupt habitual car use by means of a deliberation intervention and to examine the importance of moral motivation (i.e., personal norm) for car use reduction. Results showed that, as a result of the intervention, car use was mainly reduced among car users with a strong car use habit and a strong moral motivation to reduce car use. The aim of Study II was to examine factors important for the acceptability of three TDM measures: raised tax on fossil fuel, improved public transport, and an information campaign. The results demonstrated the importance of general environmental beliefs (i.e., pro-environmental orientation, problem awareness, personal norm, and willingness to reduce car use) and policy specific beliefs (i.e., perceived impact on freedom to choose travel mode and own car use, perceived effectiveness, and perceived fairness) for the acceptability of the measures. Furthermore, personal norm was found to be particularly important for the acceptability of raised tax and the information campaign, whereas problem awareness was more important for the acceptability of improved public transport. Following up on Study II, the purpose of Study III was to examine the acceptability of single and combined transport policy measures, more specifically, raised tax on fossil fuel, improved public transport, subsidies of renewable fuel, a package of raised tax on fossil fuel and improved public transport, and a package of raised tax on fossil fuel and subsidies of renewable fuel. General environmental beliefs (i.e., pro-environmental orientation, problem awareness, personal norm, and willingness to act) and policy specific beliefs (i.e., perceived effectiveness and perceived fairness) were found to be important for the acceptability of the measures. Moreover, personal norm was particularly important for the acceptability of raised tax on fossil fuel and the packages, while problem awareness was more important for the acceptability of improved public transport and subsidies of renewable fuel. The aim of Study IV was to examine the behavioral adaptations, more specifically, the expected car use reduction, in response to three hypothetical TDM measures: raised tax on fossil fuel, improved public transport, and a package of raised tax on fossil fuel and improved public transport. Furthermore, factors important for the expected car use reduction were analyzed. Results showed that a combination of the measures was expected to lead to a larger car use reduction compared to the single measures, and the most commonly chosen reduction strategies were more efficient car use and changing travel mode. Moreover, internal motivational factors, such as personal norm, and the perceived personal impact of the measures were important for expected car use reduction in response to the measures.

No description available.

Denna eventstudie syftar till att undersöka hur ett byte av noteringslista påverkar kumulativ onormal avkastning (CAR) 1 till och med 12 månader efter genomfört byte. I studien undersöks därför utförda byten av noteringsplats på den svenska aktiemarknaden under tidsperioden 1995-2009. I studien beräknas onormal avkastning delvis med marknadsmodellen (MM) som grund, men också med Fama & French tre-faktormodell (FF) för att öka reliabiliteten. Vidare undersöks om skillnader i CAR föreligger under olika tidsintervall samt om olikheter förekommer efter att berörda företag delats in i undergrupper baserade på typ av byte, industri samt storlek. Slutligen testas utifall den eventuella kumulativa onormala avkastningen är signifikant skild från noll med student t-test samt om det föreligger skillnader i medelvärde i de olika undergrupperna. Resultatet visar att den genomsnittliga kumulativa onormala avkastningen (CAR) uppgår till – 4,57 % (MM), - 3,74 % (FF) en månad efter bytet, vilket är signifikant på 1 % - nivån. Denna negativa tendens håller i sig och efter 12 månader uppvisas CAR på – 20,20 % (MM), -16,99 % (FF) även dessa statistisk säkerställda på 1 % - nivån. Detta resultat är i linje med liknade studier på andra aktiemarknader. Vi kan alltså dra slutsatsen att detta fenomen även föreligger på den svenska aktiemarknaden samt konstatera att händelsen listbyte är något både företag och aktieägare bör beakta mer varsamt.

Magistro baigiamajame darbe išanalizuota Lietuvos lengvųjų automobilių parko atnaujinimo politika ekologiniu požiūriu. Iškeltos Lietuvos lengvųjų automobilių parko atnaujinimo problemos bei pateikti pasiūlymai kaip šias problemas spręsti. Teorinėje dalyje teoriniu aspektu tiriamas lengvųjų automobilių parko atnaujinimo reikalingumas, apžvelgiant mokslinę literatūrą, nagrinėjami Europos Sąjungos ir Lietuvos teisės aktai, reglamentuojantys aplinkosauginių programų transporto srityje įgyvendinimą. Išanalizuoti svarbiausi su šiuo transporto sektoriumi susiję duomenys bei įvertinta lengvųjų automobilių parko atnaujinimo ekologiniu požiūriu situacija Lietuvoje, lyginant ją su ES šalimis. Trečioje dalyje atliekama statistinė duomenų ir lyginamoji situacijos analizė, nagrinėjamas ekspertų požiūris apie Lietuvos ir ES šalių lengvųjų automobilių parko atnaujinimo politiką. / In the Master’s Thesis, there is analyzed the renewal policy for Lithuanian car fleet under ecological approach. There are set renewal issues of Lithuanian car fleet and delivered proposals for the solution of the following issues. In the theoretical part under theoretical aspect there is researched the renewal necessity for the car fleet through the review of scientific literature and legal acts of the European Union and Lithuania, which regulate the implementation of environmental protection programmes in the field of transport. There are analyzed the most significant data related to the following transport sector and assessed the renewal situation of the car fleet in Lithuania under ecological approach and its comparison with the EU countries. In the third part there is carried out statistical analysis of data and comparative analysis of the situation, and analyzed experts’ approach towards the renewal policy of the car fleet in Lithuania and the EU countries.

In der vorliegenden Arbeit wird eine prädiktive Fahrstrategie vorgestellt, die auf Basis von Ampel-Fahrzeug-Kommunikationsdaten generiert wird. Dazu wird ein aktueller Ansatz für eine prädiktive Fahrstrategie zur Annäherung an eine Lichtsignalanlage (LSA) untersucht. Es werden verschiedene Optimierungsansätze deutlich, von denen ein großer Teil bei der Systemerweiterung berücksichtigt wird. Bei der Analyse konnte gezeigt werden, dass die bisherige Strategieempfehlung durch den Einfluss vorausfahrender Verkehrsteilnehmer eingeschränkt wird. Es ergaben sich potentielle Problemsituationen, welche sich im realen Straßenverkehr negativ auf die Funktionalität des Fahrerassistenzsystems (FAS) auswirken. Für Anfragen des Öffentlichen Personen Nachverkehrs (ÖPNV) wurde ermittelt, dass keine allgemeingültigen Aussagen über die Eignung der Assistenzfunktion gegeben werden können. Die wesentliche Neuerung zu bisheriger Strategieansätze für die Annäherung an Knotenpunkte mit LSA ist die Berücksichtigung anderer Verkehrsteilnehmer. Dazu werden die neuen Größen effektive Freigabezeit und virtuelle Position der Haltelinie eingeführt, auf Basis derer die Strategieempfehlung des FAS an die Anzahl wartender Fahrzeug angepasst wird. Zur Untersuchung des möglichen Energieeinsparpotentials durch den Einsatz eines FAS wurde ein Simulationsmodell in MATLAB/SIMULINK entwickelt. Mit dessen Hilfe konnten verschiedene Situationen dargestellt werden, an denen der Einfluss der Funkreichweite sowie die Auswirkungen der Warteschlange auf das FAS verdeutlicht werden. Ferner kann der positive Effekt auf den Kraftstoffverbrauch und die Haltezeit an der LSA bestätigt werden. Das Simulationsmodell stellt eine gute Grundlage für weiterführende Untersuchung dar und kann an unterschiedliche Situationen angepasst werden. Um den Nutzen auch praktisch zu verifizieren wird eine Reihe von Fahrversuchen durchgeführt. Dem Fahrer wird dabei die Strategie in einem Display visualisiert. Für Situationen, in denen der Fahrzeugstillstand vermeidbar ist erhält dieser eine Geschwindigkeitsempfehlung. Ist ein Stillstand nicht vermeidbar, so erfolgt unmittelbar vor der Haltelinie, die Ausgabe der Restlaufzeit der Rotphase. Bei der Versuchsauswertung wird das Einsparpotential deutlich. Durch eine entwickelte GUI wird dem Fahrer eine Strategie auf dem Display visualisiert. Innerhalb mehrerer Versuchsfahrten konnten das FAS erprobt und in der anschließenden Versuchsauswertung klar die Verbesserungen aufgezeigt werden. / In this paper a predictive driving strategy is presented, which is generated based on car to infrastructure communication data. An actual approach for a driver assistance system has been analyzed to identify room for improvements. The additional benefit of the presented work is the consideration of other road users driving ahead of the ego-vehicle in the process of finding the optimal speed for approaching the traffic-light. A MATLAB/SIMULINK model has been developed, which allows the simulation of different traffic situations to investigate the fuel consumption benefit of a vehicle equipped with the considered system. It illustrates the influence of the radio range and the length of the queue in front of the stop line. Furthermore the positive effect to the fuel consumption of the developed system could be evaluated. The simulation model is a good basis for further tests and could be easily adapted to various situations and vehicles. In addition to the simulation, a human machine interface was developed for evaluating the advanced driver assistance system in test runs. The driver assistance system was tested in several situations to show the benefit of the system. It has been tested via multiple test runs. In the following test evaluation the improvement could clearly be shown.

Purpose: To examine how IR-related press releases affect share price for stock companies, and to explore how said companies practice Investor Relations. Methods: The study was conducted using an event study as well as e-interviews. The event study has a quantitative deductive research approach where the market model is used for calculating the abnormal return based on press releases. The e-interviews have a qualitative research approach and follow a semi structured interview guide. The study includes all listed stock companies within the Swedish construction industry and includes press releases from the last decade. Theory: The study is based on the efficient market hypothesis and its semi strong form, theories within Investor Relations and previous research. Results: The event study shows a significant negative abnormal return during a four day period starting the day after the press release event. The negative abnormal return could derive from investor relations being used by companies as damage control, or that the investors’ expectations are too high as a result of IR. No significant differences in how companies practice IR was found in e-interviews. To the contrary, companies show similar tendencies in IR practice. It can be concluded that stock companies, through investor relations, are able to affect their share price. / Syfte: Att undersöka hur IR-relaterade pressmeddelanden påverkar aktiekursen hos börsnoterade företag samt att undersöka hur företagen arbetar med Investor Relations. Metod: Studien är utförd med hjälp av en eventstudie tillsammans med e-intervjuer. Eventstudien har en kvantitativ deduktiv ansats där marknadsmodellen används för beräkning av avvikande avkastning baserat på pressmeddelanden. E-intervjuerna har en kvalitativ ansats och följer en semistrukturerad intervjuguide. Studien innefattar alla börsnoterade företag i den svenska byggindustrin och pressmeddelanden från det senaste decenniet. Teori: Den effektiva marknadshypotesen och dess halvstarka form, teorier inom investor relations tillsammans med tidigare genomförda forskning har legat till grund för studien. Resultat: Resultatet från eventstudien visar på en signifikant negativ avvikande avkastning med start dagen efter händelsedagen till och med fyra dagar efter händelsedagen. Den negativa avvikande avkastningen kan bero på att arbetet med IR försöker dämpa befintlig negativitet hos investerare, alternativt kan det bero på att investerares förväntningar är för höga på grund av positiv IR. Utmärkande strategier för hur IR-arbetet går till i praktiken bland de observerade företagen har inte funnits i e-intervjuerna, istället liknar företagens IR-arbete varandra i stort. Slutsatsen dras att börsnoterade företag kan påverka sin aktiekurs med hjälp av investor relations.

Made available in DSpace on 2014-12-17T14:07:23Z (GMT). No. of bitstreams: 1 MauricioRB.pdf: 2052566 bytes, checksum: ecabe62a65c1b9db9e09054f3321c5b1 (MD5) Previous issue date: 2007-03-12 / Sugar esters are substances which possess surfactant, antifungical and bactericidal actions and can be obtained through two renewable sources of raw materials: sugars and vegetable oils. Their excellent biodegradability, allied to lhe fact that they are non toxic, insipid, inodorous, biocompatible, no-ionic, digestible and because they can resist to adverse conditions of temperature, pH and salinity, explain lhe crescent use of these substances in several sections of lhe industry. The objective of this thesis was to synthesize and characterize surfactants and polymers containing sugar branched in their structures, through enzymatic transesterification of vinyl esters and sugars, using alkaline protease from Bacillus subtilis as catalyst, in organic medium (DMF).Three types of sugars were used: L-arabinose, D-glucose and sucrose and two types of vinyl esters: vinyl laurate and vinyl adipate. Aiming to reach high conversions from substrates to products for a possible future large scale industrial production, a serie of variables was optimized, through Design of Experiments (DOE), using Response Surface Methodology (RSM).The investigated variables were: (1) enzyme concentration; (2) molar reason of substrates; (3) water/solvent rale; (4) temperature and (5) time. We obtained six distinct sugar esters: 5-0-lauroyl L-arabinose, 6-0-lauroyl D-glucose, 1'-O-lauroyl sucrose, 5-0-vinyladipoyl L-arabinose, 6-0-vinyladipoyl D-glucose and 1 '-O-vinyladipoyl sucrose, being lhe last three polymerizable. The progress of lhe reaction was monitored by HPLC analysis, through lhe decrease of sugar concentration in comparison to lhe blank. Qualitative analysis by TLC confirmed lhe formation of lhe products. In lhe purification step, two methodologies were adopted: (1) chromatographic column and (2) extraction with hot acetone. The acylation position and lhe chemical structure were determined by 13C-RMN. The polymerization of lhe three vinyl sugar esters was possible, through chemical catalysis, using H2O2 and K2S2O8 as initiators, at 60?C, for 24 hours. IR spectra of lhe monomers and respective polymers were compared revealing lhe disappearance of lhe vinyl group in lhe polymer spectra. The molar weights of lhe polymers were determined by GPC and presented lhe following results: poly (5-0-vinyladipoyl L-arabinose): Mw = 7.2 X 104; PD = 2.48; poly (6-0-vinyladipoyl D-glucose): Mw = 2.7 X 103; PD = 1.75 and poly (1'-O-vinyladipoyl sucrose): Mw = 4.2 X 104; PD = 6.57. The six sugar esters were submitted to superficial tension tests for determination of the critical micelle concentrations (CMC), which varied from 122 to 167 ppm. Finally, a study of applicability of these sugar esters, as lubricants for completion fluids of petroleum wells was' accomplished through comparative analysis of lhe efficiency of these sugar esters, in relation to three commercial lubricants. The products synthesized in this thesis presented equivalent or superior action to lhe tested commercial products / ?steres de a??car s?o compostos que possuem a??o surfactante, antif?ngica e bactericida e podem ser obtidos a partir de duas fontes renov?veis de mat?ria-prima: a??cares e ?leos vegetais. Sua capacidade de se biodegradar, aliada ao fato de serem at?xicos, ins?pidos, inodoros, biocompat?veis, n?o-i?nicos, digest?veis e resistirem a condi??es severas de temperatura, pH e salinidade, explicam o crescente emprego destas subst?ncias em diversos setores da ind?stria. O objetivo desta tese foi sintetizar e caracterizar surfactantes e pol?meros, contendo a??cares ramificados em suas estruturas, atrav?s de transesterifica??o enzim?tica de ?steres vin?licos com a??cares, empregando-se protease alcalina de Bac?llus subtilis como catalisador, em meio org?nico (DMF). Foram empregados tr?s tipos de a??cares: L-arabinose, D-glicose e sacarose e dois tipos de ?steres vin?licos: laurato de vinila e adipato de vinila. Para a obten??o de altas convers?es de substratos em produtos, visando uma futura produ??o em larga escala, uma s?rie de vari?veis foram otimizadas, atrav?s de an?lise estat?stica experimental (DOE), por metodologia de resposta de superf?cie (RSM). As vari?veis investigadas foram: (1) a concentra??o de enzima; (2) a raz?o molar entre substratos; (3) a raz?o ?gua/solvente org?nico; (4) a temperatura e (5) o tempo. Foram obtidos seis ?steres de a??car: 5-0-lauroil L-arabinose, 6-0lauroil D-glicose, 1 '-O-Iauroil sacarose, 5-0-viniladipoil L-arabinose, 6-0viniladipoil D-glicose e 1 '-O-viniladipoil sacarose, sendo os tr?s ?ltimos polimeriz?veis. O progresso da rea??o foi monitorado por an?lise em HPLC, atrav?s do decr?scimo da concentra??o de a??car em rela??o ao branco. An?lises qualitativas, por TLC, confirmaram a forma??o dos produtos. Foram obtidas convers?es superiores a 98% na s?ntese do laurato de sacarose. Na purifica??o, foram adotadas duas metodologias: (1) coluna cromatogr?fica e (2) extra??o com acetona a quente. A posi??o de acila??o e a estrutura qu?mica foram determinadas por 13C-RMN. A polimeriza??o dos tr?s ?steres de a??car foi poss?vel, atrav?s de cat?lise qu?mica, empregando-se H2O2 e K2S2O8 como iniciadores, a 60?C, por 24 horas. Espectros de IR dos pol?meros foram comparados com os seus mon?meros, revelando o desaparecimento do grupo vinil. As massas molares dos pol?meros foram determinadas por GPC. Os pol?meros de a??car obtidos apresentaram as seguintes massas molares: poli (5-0-viniladipoil L-arabinose): Mw = 7,2 X 104; PD = 2,48; poli (6-0-viniladipoil D-glicose): Mw = 2,7 x 103; PD = 1,75 e poli (1 '-O-viniladipoil sacarose): Mw = 4,2 X 104; PD = 6,57. Os seis ?steres de a??car foram submetidos a ensaios de tens?o superficial para a determina??o das concentra??es micelares cr?ticas (CMC), que variaram de 122 a 167 ppm. Por fim, um estudo de aplicabilidade dos ?steres n?o polimeriz?veis, como lubrificantes para fluidos de completa??o de po?os de petr?leo foi realizado, atrav?s de an?lise comparativa da efici?ncia destes, em rela??o a tr?s lubrificantes comerciais. Os produtos sintetizados nesta tese apresentaram desempenho equivalente ou superior aos produtos comerciais testados

Made available in DSpace on 2014-12-17T14:48:14Z (GMT). No. of bitstreams: 1 ZodinioLMS_DISSERT.pdf: 3444132 bytes, checksum: eaa759b8b44f68beba82f44f669bcbf5 (MD5) Previous issue date: 2013-03-01 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Concrete is the second most consumed product in the world and the incorporation of the Sugar Bagasse Ash (SBA) into this material can provide solutions for the utilization of by-products from other industries, thus reducing the environmental impact. The general aim of this dissertation focuses on analyzing the mechanical behavior of concrete with addition of SBA from three different species of sugar cane, through tests of consistency, compressive strength, porosity, absorption, voids and Scanning Electron Microscopy (SEM). Were prepared 13 specimens for each specific pattern and level of incorporation of SBA (10%, 20% and 30%) of the three varieties collected, totaling 130 samples of concrete. The trait was employed 1:2:3 (cement: sand: aggregates) in relation to the cement mass with a water / cement ratio of 0.532 and 1% additive Tec 400 Mult also based on the weight of cement. According to the results obtained in this study, it was concluded that the variety of cane sugar, used in the production of the CBC, influenced the mechanical behavior of the resulting concrete. All concrete with addition of SBA, reported a reduction of at least 10% in the properties related to permeability and an increase in the compressive strength of at least 16% compared to standard concrete at 28 days / O concreto ? o segundo produto mais consumido do mundo e a incorpora??o da Cinza do Baga?o da Cana-de-a??car (CBC) a este material pode apresentar solu??es para o aproveitamento de subprodutos de outros setores, reduzindo assim o impacto ambiental. O objetivo geral dessa disserta??o concentra-se em analisar o comportamento mec?nico dos concretos que sofreram a adi??o de CBC de tr?s diferentes esp?cies de cana-de-a??car, mediante ensaios de consist?ncia, resist?ncia ? compress?o, porosidade total, absor??o, ?ndice de vazios e Microscopia Eletr?nica de Varredura (MEV). Foram confeccionados 13 corpos de prova para o concreto padr?o e para cada teor de incorpora??o de CBC (10%, 20% e 30%) das tr?s variedades coletadas, totalizando 130 amostras de concreto. Foi empregado o tra?o 1:2:3 (cimento:areia:brita) em rela??o a massa do cimento com um fator ?gua/cimento de 0,532 e 1% de aditivo Tec Mult 400 tamb?m baseado na massa do cimento. De acordo com os resultados obtidos na presente pesquisa, concluiu-se, que a variedade da cana-de-a??car, utilizada na produ??o das CBC, influenciou no comportamento mec?nico dos concretos resultantes. Todos os concretos com adi??o de CBC apresentaram uma redu??o de no m?nimo 10% nas propriedades relacionadas a permeabilidade e um incremento na resist?ncia ? compress?o de no m?nimo 16% em rela??o ao concreto padr?o aos 28 dias