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This fact sheet describes how DOE's Data Center Energy Profiler (DC Pro) Software Tool Suite and other resources can help U.S. companies identify ways to improve the efficiency of their data centers.

The military is facing a significant issue of increasing fuel cost to deploy troops overseas and establish and maintain Forward Operating Bases (FOBs) or outposts. Liquid fuel is one of the primary energy source for these FOBs, which is a non-renewable source, flammable, and needs large convoys with specialized equipment to transport, therefore being both unsafe and expensive for the operation of FOBs. To help reduce energy consumption, transportation, and cost an Energy Resource Planning Tool (ERPT) is needed. This ERPT will help the military in making crucial decisions about the optimal shelter and equipment configuration for their Forward Operating Bases (FOBs) prior to deployment. To make this tool effective, load profile data of shelters needs to be simulated and uploaded into a database, so that it can be easily available when outposts need to be configured and optimized with respect to energy consumption for a given set of constraints. This research has developed a programmatic modeling framework to generate load profiles for shelters of interest for outposts for different weather profiles, equipment, occupancy, and other relevant parameters of interest, and upload data points into a database. The modeling framework is developed using the programming language Ruby and simulation platforms OpenStudio and EnergyPlus. In order to make sure the ERPT estimates reasonably accurate load profiles for a shelter through regression techniques, a large set of data points, on the order of around 500,000 data points, needs to be uploaded into the database. The database is named DEnCity and is established using Amazon Web Services (AWS). This research developed programmatic workflow to perform Sensitivity analyses along with Sampling and Uncertainty analyses to generate and upload the data points needed into the DEnCity database. It analyzes different Sensitivity and Uncertainty methods for creating and uploading data points. It compares these computational methods and discusses their pros and cons in context of the ...

Die Metropolregion Santiago (MRS) verzeichnete in den letzten Jahren ein großes Bevölkerungswachstum und einen Anstieg des Lebensstandards. Als Folge davon hat sich das Aufkommen von Siedlungsabfällen fast innerhalb von 10 Jahren verdoppelt. Die Daten für den aktuellen Zustand des Abfallmanagements wurden durch Feldforschungen, Fragebögen, Feldbesuche und durch eine systematische Auswertung von bereits vorliegender Literatur erhoben. Das integrative Nachhaltigkeitskonzept der Helmholtz-Gemeinschaft diente als konzeptioneller Rahmen für die Studie. Zur Bewertung des aktuellen Zustands des Abfallmanagements wurden Nachhaltigkeitsindikatoren identifiziert, deren aktuelle Werte bestimmt und Zielwerte festgelegt. Die Nachhaltigkeitsanalyse zeigt, dass die größten Defizite darin liegen, dass nahezu die gesamte Abfallmenge ohne jegliche Vorbehandlung deponiert wird. Damit verbunden sind lang andauernde Emissionen von Treibhausgasen. Um herauszufinden, wie der informelle Sektor im Abfallmanagement zur Nachhaltigkeit beiträgt, wurden veröffentlichten Erfahrungen mit informellen Müllsammlern in Lateinamerika analysiert. Dabei wurden die entsprechenden Akteure sowie etablierte Allianzen zwischen diesen Akteuren identifiziert. Schlüsselfaktoren für ein nachhaltiges Abfallmanagement unter Einbeziehung des informellen Sektors sind die Legalisierung der Schattenwirtschaft und feste Verträge mit Partnerunternehmen. Relevante Akteure für die Gestaltung der Arbeitsbedingungen des informellen Sektors sind Vertreter privater und öffentlicher Unternehmen, einzelne gesellschaftliche Gruppen sowie Vertreter von Nichtregierungsorganisationen. Schließlich wurden drei explorative Szenarien für das Bezugsjahr 2030 entwickelt: Business as Usual (BAU), Collective Responsibility (CR) und Market Individualism (MI). Das BAU-Szenario enthält eine getrennte Sammlung von Bioabfall und von Wertstoffen; hervorgerufen durch einen verstärkten Organisationsgrad der informellen Müllsammler und den Ausbau von Bring-Systemen. Die Errichtung mechanischer Sortierungsanlagen trägt zur Verwertung der Materialien und zum Recycling bei. Das entstehende Deponiegas und Biogas wird als erneuerbare Energiequelle genutzt. Das CR-Szenario enthält eine getrennte Sammlung von Bioabfall und Wertstoffen. Dies wird erreicht durch eine verstärkte Zusammenarbeit mit den jetzt organisierten Müllsammlern und durch den Ausbau von Bring-Systemen. Mechanische Sortierungsanlagen tragen zur Verwertung von Materialien und zum Recycling bei. Durch Abtrennung einer heizwertreichen Fraktion in mechanisch biologischen Anlagen werden Sekundärbrennstoffe produziert. Darüber hinaus werden, das entstehende Deponiegas sowie das in Vergärungsanlagen erzeugte Biogas energetisch genutzt. Im MI-Szenario sind Wiederverwertungsstrategien von untergeordneter Bedeutung. Es gibt kein Interesse an einer Zusammenarbeit mit den informellen Müllsammlern und keine Anreize für einen verstärkten Organisationsgrad in diesem Bereich. Deshalb bleibt die Branche weitgehend informell. Technologische Entwicklungen in diesem Szenario enthalten die mechanische Sortierung von gemischtem Abfall und die energetische Verwertung von Deponiegas. Die Ergebnisse zeigten, dass das Pro-Kopf-Aufkommen an Siedlungsabfällen im Jahr 2030 in allen Szenarien deutlich höher als im Jahr 2007 ist und der festgelegte Zielwert von 1,6 kg/Kopf/Tag nicht erreicht wurde. Den höchsten Wert (2,0 kg/Kopf/Tag) weist das MI-Szenario auf, der niedrigste Wert (1,8 kg/Kopf/Tag) wurde im CR-Szenario gefunden. Eine Vorbehandlung der gesammelten gemischten Siedlungsabfälle findet nur im CR-Szenario statt, der entsprechende Wert beträgt 18 %, der Zielwert wird damit nicht erreicht. Die höchsten Treibhausgasemissionen treten im MI-Szenario (295 kg CO2-eq/Kopf/Jahr) auf, den niedrigsten Wert (155 kg CO2-eq/Kopf/Jahr) findet man im CR-Szenario. All diese Werte sind, verglichen mit dem festgelegten Zielwert von 71 kg/Kopf/Jahr, deutlich zu hoch. Der Zielwert für die Wiederverwertungsquote wurde im CR-Szenario erreicht (43 %), den niedrigsten Wert zeigt das MI-Szenario (20 %). Die Zielwerte für das Einkommen der Müllsammler wurden im CR-Szenario erreicht (128 %). Im MI-Szenario beträgt dieser Wert lediglich 51 %. Die Kosten für das Abfallmanagement im Verhältnis zum Bruttoinlandsprodukt sinken in den drei Szenarien. Aus den Ergebnissen lässt sich ableiten, dass ein Einbeziehen von mehreren Faktoren erforderlich ist, um die Nachhaltigkeit des Abfallmanagementsystems in den drei Szenarien zu steigern und dass es von wesentlicher Bedeutung ist, schon vorhandene und gut funktionierende Subsysteme, wie das der informellen Müllsammler, zu nutzen und zu stärken. Ebenso ist die Umsetzung robuster Behandlungstechnologien, die einen Beitrag zur Reduktion negativer Umweltauswirkungen leisten, zu forcieren. Diese Technologien sollten preiswert sein, um ihren Einsatz auch unter wirtschaftlich vertretbaren Gesichtspunkten zu ermöglichen. The Metropolitan Region of Santiago (MRS) has experienced a large growth in population in recent years and a rise in the standard of living. Therefore, its municipal solid waste (MSW) has almost doubled in 10 years. Data about the current situation of MSW management in MRS were collected during field research, interviews, field visits and by a systematic evaluation of existing documentary literature. The Integrative Sustainability Concept of the Helmholtz Association provided a conceptual framework for the study. The sustainability analysis showed that the largest deficits are in the current amount of MSW deposited at sanitary landfills without any pre-treatment, and the emission values of greenhouse gases associated with waste treatment and final disposal. To find out if and how the informal waste sector contributes to sustainability, experiences of organization of informal primary collectors in Latin America were analyzed. The key factors which have an influence on their working conditions were identified. These factors include the existence of a legal framework for the informal waste sector; the existence of alliances with production companies guaranteeing a reliable industrial market for secondary raw materials and expansion of activities beyond collection of recyclables. Key stakeholders included people from the public and the private sector, from the civil society and from NGOs. Three explorative scenarios were developed for the year 2030: Business as Usual (BAU), Collective Responsibility (CR), and Market Individualism (MI). Waste generation, waste composition and different practices of waste collection, recovery and treatment were taken into account for the scenarios formulation. The BAU scenario incorporated separate collection of biowaste, recyclable materials with some participation of organized primary collectors and an expansion of drop-off systems. The mechanical sorting of mixed waste was introduced. The utilization of landfill gas as an energy source was promoted and the production of biogas in anaerobic digestion plants was implemented. The CR scenario incorporated separate collection of biowaste, commitment to work together with the primary waste collectors and an expansion of drop-off systems. The mechanical and mechanical biological treatment of mixed waste was introduced. The utilization of landfill gas as an energy source is promoted and the production of biogas in anaerobic digestion plants was implemented. In the MI separate collection of biowaste and recyclable materials was irrelevant. An organization of the informal primary collectors did not take place. Mechanical sorting of mixed waste was introduced. Utilization of landfill gas as an energy source was promoted. The results showed that the generation flux of MSW is at least 50% larger in all scenarios in 2030 compared to the year 2007, exceeding the limit value proposed. The highest value (2.0 kg/(person•day) is obtained in the MI scenario, and the lowest (1.8 kg/(person•day)) in the CR scenario. Pre-treatment of mixed MSW collected is only achieved in the CR scenario with a value of 18%, however, the target value is not achieved. The highest greenhouse gas emission value is obtained in the MI scenario with 295 kg CO2eq/(person•year), the lowest value of 155 kg CO2-eq/(person•year) is obtained in the CR scenario; a value that is still very high in comparison with the suggested target. The largest recycling rate is obtained in the CR scenario (43%), which is better than the target value proposed, the lowest recycling rate is obtained in the MI scenario (20%). The income of primary collectors in comparison with the income of one individual household is improved significantly in the CR scenario (128%), in the MI scenario, earnings of primary collectors decreased to 51%. The share of GDP spent on MSW management is lower in 2030, compared to the year 2007, in all scenarios the largest value of 0.17% is obtained in the CR scenario, and the lowest value of 0.14% is obtained in the MI scenario. The results of the evaluation of the scenarios showed that the largest sustainability deficits are the amount of mixed MSW which undergoes pre-treatment, the greenhouse gas emissions associated to MSW treatment and disposal, as well as the share of GDP spent on MSW management. The results obtained suggested that an integration of several factors is required to increase sustainability. It is essential to strengthen and take advantage of the subsystems which are working within the waste management system, as in the case of the informal sector. In addition to the implementation of flexible treatment technologies which help to decrease negative environmental impacts. Moreover, the costs of these technologies should be affordable, allowing a better financial management.

Because of the magnitude of the existing corn harvest shortfall coupled with the large ethanol mandates, policymakers face extreme uncertainties looking into the future with potentially large economic ramifications. Precisely, because neither the economic modelers nor the decision makers can foretell all of the factors affecting corn harvests and ethanol use in 2013, a waiver is a wise course of action. To be sure, a waiver may have no effect and turn out to be irrelevant. Even so, we argue that it has no downside. But if an anemic harvest rebound occurs in 2013, a waiver could avoid substantial economic dislocations in 2013 and beyond. Regulators should opt for flexibility. ; Bush School of Government and Public Service

The importance of emission control has increased sharply due to increased need of energy from combustion. However, biomass utilization in energy production is not free from problems because of physical and chemical characteristics which are substantially different from conventional energy sources. In this situation, the quantity and quality of emissions as well as used renewable source as wood or corn grain are often unknown. To assess this problem the paper addresses the objectives to quantify the amount of greenhouse gases during the combustion of corn as compared to the emissions in fossil combustion (natural gas, LPG and diesel boiler). The test was carried out in Friuli Venezia Giulia in 2006-2008 to determine the air pollution (CO, NO, NO2, NOx, SO2 and CO2) from fuel combustion in the family boilers with power between 20-30 kWt. The flue gas emission was measured with a professional semi-continuous multi-gas analyzer, (Vario plus industrial, MRU air Neckarsulm-Obereisesheim). Data showed a lower emission of fossil fuel compared to corn in family boilers in reference to pollutants in the flue gas (NOx, SO2 and CO). In particular way the biomass combustion make a higher concentration of carbon monoxide (for a incomplete combustion because there aren’t a good mixing between fuel and air) and nitrogen oxides (in relation at higher content of nitrogen in herbaceous biomass in comparison of another fuel). Proceedings of the 19th European Biomass Conference and Exhibition, 6-10 June 2011, Berlin, Germany, pp. 1296-1304

Item 856-E ; S/N 041-011-00054-8 ; "January 1981." ; Includes bibliographical references. ; Mode of access: Internet.

Мировые цены на энергоносители с начала текущего года стремительно увеличивались, достигнув настолько высокого уровня, что целые отрасли промышленности, предприятия малого и среднего бизнеса активно переходят в категорию неконкурентоспособных, а рядовые потребители электроэнергии становятся неплатежеспособными. Энергетическая политика ЕС с упором на развитие альтернативных источников энергии способствовала тому, что использование угля и природного газа в качестве источников для производства электроэнергии стало низкорентабельным. Цель исследования - выявление ключевых причин газового энергокризиса в Европе и возможностей его преодоления. Для анализа причин энергокризиса поставлены задачи: оценить возможности существующих и альтернативных поставок газа на европейский рынок, проанализировать привязку действующих контрактов на поставку газа к спотовым ценам. Проведенный анализ показал, что в среднесрочной перспективе (2022-2030 гг.) основным ограничением для расширения альтернативных поставок газа в страны Европы является отсутствие в мировом масштабе ввода новых мощностей сжиженного природного газа, инвестиции в которые на фоне снижения цен на энергоносители и коронавирусной инфекции не были осуществлены в предшествующих периодах. В работе сделан вывод, что резкий энергетический переход промышленности и домохозяйств к использованию возобновляемых источников энергии стал одной из причин, по которым падение объемов электроэнергии из возобновляемых источников не могло быть своевременно замещено традиционными источниками - электроэнергией, вырабатываемой угольными, газовыми и атомными электростанциями. Дальнейшим направлением развития представленного исследования является оценка вероятности возврата от рынка продавца к рынку покупателя с доминированием на нем стороны спроса. Since the beginning of 2021, world energy prices have been rapidly increasing, reaching such a high level that entire industries, small and medium-sized enterprises became uncompetitive, while retail electricity consumers became insolvent. The European Union energy policy, now focused on the development of alternative energy sources, contributed to a decline in profitability of fossil fuel used for electricity generation. The present paper examines the roots of the current economic crisis in the European market and opportunities to overcome it. To this end, the following objectives were set: to assess existing and alternative gas supply to the European market, to consider the link between existing gas contracts and spot prices. According to the conducted analysis, the lack of new liquefied natural gas (LNG) facilities due to a decrease in investment in the context of energy price reduction and the COVID-19 spread is the main constraint to the expansion of alternative gas supply to Europe in the medium term (2022-2030). The study revealed that a sharp transition of industries and households to the use of renewable energy sources has become one of the reasons for current crisis. Electricity generation from renewables nowadays cannot catch up with the demand for energy that can be produced by coal, gas and nuclear power plants. Further research directions include assessment of the probability of a transition from the seller’s market to the buyer’s market. The authors would like to express gratitude to the reviewers for their valuable comments. Авторы выражают благодарность рецензентам за содержательные комментарии.

Dottorato di ricerca in Scienze e tecnologie per la gestione forestale e ambientale ; European beech represents one of the most important European forest tree species, hence possible adverse factors affecting productivity and management of this species can have strong ecological and economic impacts in Europe. Rising atmospheric CO2 concentration, higher temperatures and changes in precipitation are likely to have significant effects on the vegetation period, growth, health and distribution of trees as well as on forest ecosystems, and thus on the goods and services provided by forests. In the 21st century, the Mediterranean Basin could be most sensitive to climate change due to global warming among the European regions and most of the current climate projections for Central Europe predict increased temperatures that are expected to cause an increase in the frequency and duration of intense summer droughts. Owing to its sensitivity towards low water availability and longer drought periods, physiological performance, growth and competitive ability of European beech may be adversely affected by such changing environmental conditions. Most European Beech forests have been historically managed trough different silvicultural systems, which acting directly on structure affect many ecophysiological processes. Tree rings are uniquely widespread relative to all comparable natural archives of climate signals and beech has been concerned extensively in tree ring studies, taking advantage of its widespread distribution, sensitivity to climate and longevity. Air (CO2) and water absorbed by a tree are subtly modified by physiological processes and in response to the varying environment in which the tree lives, and these small changes affect isotopic ratios of elements into the uptaken molecules (CO2, H2O, nutrients). In this context the objectives were to: (1) assess the relationship of climatic parameters, growth and carbon isotope discrimination (Δ13C), (2) evaluate the effect of different types of forest management on tree physiology and growth, (3) assess the response to recent atmopsheric CO2 concentration increment of trees growing in different sites. Hence, we selected four beech forests along a latitudinal gradient: central and southern Apennines (Pian di Limina, CAL1 and Collelongo ABR1, Italy), pre-Alps (Pian del Cansiglio VEN1, Italy), and middle European lowlands (Zoolithenhöhle ZOO, Germany). At each site, co-dominant trees were sampled to build tree ring site chronology and five trees were selected to develop the site Δ13C chronology. At all sites, our results suggested a negative effect of the temperature of the previous summer on the growth of the current year. This demonstrates that reserves are mobilized at bud break to sustain spring growth and that a severe drought period affecting reserve accumulation and partitioning may also influence phenology and spring growth rate in the subsequent year. The effect of summer temperatures was significant in the Apennine sites, but in recent times a similar effect appeared also in the North sites of our transect. In the cold sites we observed a positive relation between spring temperature and Δ13C, suggesting an "earliness effect". The increasing temperature causing the early onset of photosynthetic activities allowed trees to make a substantial part of their growth during the favorable spring conditions (i.e. soil water availability). At the same time increasing temperature affected the summer growth. In all our sites we observed an active response of trees to the increase of atmospheric CO2 concentration, that is reflected in increasing water use efficiency (iWUE). The increase of iWUE from 1950 to 2013 was different among the sites, showing decreasing sensitivity from north to south, suggesting that trees adaptability involved both genetic and physiological mechanism. Despite higher iWUE, the expected increase in growth rates in response to rising atmospheric CO2 was observed only in the Zoolithenhöhle and Collelongo, where important silvicultural treatments occurred immediately before the study period. Probably, the increase of iWUE after silvicultural treatments is related to the increase of photosynthesis rate. In these sites we observed a negative correlation between Basal Area Increment (BAI) and Δ13C. In general the canopy is “organized” to maximize carbon fixation and thinning modified the ratio between shade and light leaves, increasing the amount of light leaves that have a higher photosynthetic rates. This produced a reduction of internal CO2 concentration (Ci) in the canopy and a decrease of Ci/Ca producing an enrichment in 13C (less negative δ13C and lower Δ13C). After that canopy closed the gaps, the ratio between shade and light leaves changed again but this time with an increasing fraction of shade leaves, with an overall lower photosynthesis rate, that caused an increment of Ci, so our results suggested a reduction of growth related to an overall lower photosynthesis rate. In conclusion, we observed that climate is changing (i.e. increase of temperature, increase of atmospheric CO2, changes in precipitation regimes) causing consequent effects on forest growth and tree physiology. Hence, a sustainable and adaptive forest management can have a central role in climate change mitigation and adaptation through preserving and enhancing forest carbon uptake. ; Il faggio (Fagus sylvatica L.) rappresenta una delle più importanti specie arboree forestali europee, quindi possibile avversità che influenzano la sua produttività e la sua fisiologia possono avere forti impatti ecologici ed economici. L'aumento della concentrazione di CO2 atmosferica, temperature più elevate e variazioni delle precipitazioni possono avere effetti significativi sulla lunghezza del periodo vegetativo,sulla crescita,sulla salute dei singoli alberi e sulla distribuzione della specie, così come sugli ecosistemi forestali, quindi sui beni e servizi forniti dalle foreste. Nel XXI secolo, a causa del riscaldamento globale, il bacino del Mediterraneo potrebbe essere tra le più sensibili regioni Europee e la maggior parte delle proiezioni climatiche per l'Europa Centrale -prevedrebbe un aumento delle temperature con un conseguente aumento della frequenza e la durata di intense siccità estive. Vista la sensibilità alla bassa disponibilità idrica e ai lunghi periodi di siccità, le prestazioni fisiologiche, la crescita e la capacità competitiva del faggio possono essere influenzate negativamente da tali condizioni ambientali mutevoli. La maggior parte delle faggete europee sono storicamente gestite seguendo diversi sistemi selvicolturali, che agendo sulla direttamente sulla struttura forestale influenzano molti processi ecofisiologici. Gli anelli degli alberi rappresentano gli archivi naturali più efficienti nel registrare i segnali climatici ed il faggio è stato ampiamente utilizzato in studi dendrocronologici per la sua ampia distribuzione geografica, la sensibilità al clima e la longevità. La CO2 e l'acqua assorbita da un albero sono modificate da processi fisiologici e in risposta alle variazioni dell'ambiente in cui l'albero vive, questi cambiamenti influenzano il rapporto isotopico degli elementi assorbiti (C, H and O) e sono alla base della teoria isotopica applicata agli anelli legnosi. In questo contesto, gli obiettivi erano: (1) valutare l'effetto dei parametri climatici sulla crescita e la fisiologia del faggio, (2) valutare l'effetto di diversi tipi di gestione forestale sulla fisiologia e la crescita, (3) valutare la risposta al recente incremento della concentrazione di CO2 atmosferica di alberi che cresciuti in luoghi diversi. Quindi, abbiamo selezionato quattro faggete lungo un gradiente latitudinale: Appennino centrale e meridionale (Pian di Limina, CAL1 e Collelongo ABR1, Italia), pre-Alpi (Pian del Cansiglio VEN1, Italia), e pianure dell'Europa centrale (Zoolithenhöhle ZOO, Germania ). In ogni sito,sono stati campionati alberi co-dominanti per costruire cronologie di crescita e cinque alberi per sviluppare cronologie degli isotopi stabili del carbonio. In tutti i siti, i nostri risultati suggeriscono un effetto negativo della temperatura dell'estate precedente sulla crescita dell'anno in corso. Questo ha dimostrato che le riserve sono mobilitate all'inizio della stagione vegetativa per sostenere la crescita iniziale e che un periodo di grave siccità che colpisce l'accumulo di riserve e il partizionamento può anche influenzare la fenologia e il tasso di crescita per l'anno successivo. L'effetto negativo delle temperature estive era significativo nei siti appenninici, ma in tempi recenti (1975-2013) un effetto simile è apparso anche nei siti più nord del nostro transetti. Nei siti freddi abbiamo osservato una relazione positiva tra la temperatura primaverile e Δ13C, suggerendo un "effetto precocità". L'aumento di temperatura causa un anticipo dell'inizio dell' attività fotosintetica permettendo agli alberi di fare una parte sostanziale della loro crescita durante le condizioni favorevoli della primavera (ad esempio più disponibilità idrica nel suolo). Allo stesso tempo l'aumento di temperatura influisce sulla crescita estiva. In tutti i nostri siti abbiamo osservato una risposta attiva degli alberi all'aumento della concentrazione di CO2 atmosferica, che si riflette nella crescente efficienza d'uso idrico (iWUE). L'incremento di iWUE è stato diverso tra i siti, mostrando una diminuzione della sensitività da nord a sud, il che suggerisce che nell' adattabilità delle piante ai cambiamenti climatici sono coinvolti sia meccanismi fisiologici che genetici. Nonostante l'incremento di iWUE, il previsto aumento dei tassi di crescita in risposta ad aumento di CO2 atmosferica è stata osservata solo nel Zoolithenhöhle e Collelongo, dove importanti trattamenti selvicolturali si sono effettuati immediatamente prima del periodo di studio. Probabilmente, l'aumento di iWUE dopo trattamenti selvicolturali è legato all'aumento del tasso di fotosintesi. In questi siti abbiamo osservato una correlazione negativa tra l'Incremento di Area Basimetrica (BAI) e Δ13C. In generale, le chiome sono "organizzate" per massimizzare la fissazione del carbonio ed un diradamento modifica il rapporto tra foglie di ombra e di luce, aumentando la quantità delle ultime che hanno un tasso fotosintetico più elevato. Questo ha prodotto una riduzione della concentrazione interna CO2 (Ci) nella canopy e una diminuzione di Ci / Ca produce un arricchimento di 13C (δ13C meno negativo ed Δ13C più basso). Dopo che chiome chiudono i gap, il rapporto tra foglie di luce e di ombra cambia nuovamente, ma questa volta con una componente crescente di foglie d'ombra, che un tasso di fotosintesi complessivo inferiore, che causa un incremento di Ci, così i nostri risultati indicano una riduzione della crescita correlati ad un tasso di fotosintesi complessivo inferiore. In conclusione, abbiamo osservato che il clima sta cambiando (cioè aumento della temperatura, aumento di CO2 atmosferica, cambiamenti nei regimi delle precipitazioni) e di conseguenza anche i suoi effetti sulla crescita delle foreste e la fisiologia delle piante. Quindi una gestione sostenibile e adattativa delle foreste può avere un ruolo centrale nella mitigazione e nell'adattamento ai cambiamenti climatici attraverso il mantenimento e il miglioramento della capacità di assorbimento di carbonio delle foreste.

Over the next seven years, at least 5,000 new schools will be designed and constructed to meet the needs of American students in kindergarten through grade 12. National efforts are underway to encourage the use of daylighting, energy efficiency, and renewable energy technologies in school designs, which can significantly enhance the learning environment. Recent rigorous statistical studies, involving 21,000 students in three states, reveal that students perform better in daylit classrooms and indicate the health benefits of daylighting. This paper discusses the evidence regarding daylighting and student performance and development, and presents four case studies of schools that have cost effectively implemented daylighting into their buildings.

The purpose of the Small Wind Electric Systems Consumer's Guide produced for the AGCF is to provide members of the foundation with enough information to help them determine if a small wind electric system will work for them based on their wind resource, the type and size of their sites, and their economics. The cover of this guide contains the results of the 2003 National Corn Producer Survey Wind Energy Issues.