940 resultados para Rising Powers
Resumo:
Owing to the structural flexibility, uncomplicated processing and manufacturing capabilities, plasma polymers are the subject of active academic as well as industrial research. Polymer thin films prepared from non-synthetic monomers combine desirable optical and physical properties with biocompatibility and environmental sustainability. However, the ultimate expediency and implementation of such materials will dependent on the stability of these properties under varied environmental conditions. Polyterpenol thin films were manufactured at different deposition powers. Under ambient conditions, the bulk of ageing occurred within first 150h after deposition and was attributed to oxidation and volumetric relaxation. Films observed for further 12 months showed no significant changes in thickness or refractive index. Thermal degradation behaviour indicated thermal stability increased for the films manufactured at higher RF powers. Annealing the films to 405°C resulted in full degradation, with retention between 0.29 and 0.99%, indicating films' potential as sacrificial material.
Resumo:
After more than twenty years of basic and applied research, the use of nanotechnology in the design and manufacture of nanoscale materials is rapidly increasing, particularly in commercial applications that span from electronics across renewable energy areas, and biomedical devices. Novel polymers are attracting significant attention for they promise to provide a low−cost high−performance alternative to existing materials. Furthermore, these polymers have the potential to overcome limitations imposed by currently available materials thus enabling the development of new technologies and applications that are currently beyond our reach. This work focuses on the development of a range of new low−cost environmentally−friendly polymer materials for applications in areas of organic (flexible) electronics, optics, and biomaterials. The choice of the monomer reflects the environmentally−conscious focus of this project. Terpinen−4−ol is a major constituent of Australian grown Melaleuca alternifolia (tea tree) oil, attributed with the oil's antimicrobial and anti−inflammatory properties. Plasma polymerisation was chosen as a deposition technique for it requires minimal use of harmful chemicals and produces no hazardous by−products. Polymer thin films were fabricated under varied process conditions to attain materials with distinct physico−chemical, optoelectrical, biological and degradation characteristics. The resultant materials, named polyterpenol, were extensively characterised using a number of well−accepted and novel techniques, and their fundamental properties were defined. Polyterpenol films were demonstrated to be hydrocarbon rich, with variable content of oxygen moieties, primarily in the form of hydroxyl and carboxyl functionalities. The level of preservation of original monomer functionality was shown to be strongly dependent on the deposition energy, with higher applied power increasing the molecular fragmentation and substrate temperature. Polyterpenol water contact angle contact angle increased from 62.7° for the 10 W samples to 76.3° for the films deposited at 100 W. Polymers were determined to resist solubilisation by water, due to the extensive intermolecular and intramolecular hydrogen bonds present, and other solvents commonly employed in electronics and biomedical processing. Independent of deposition power, the surface topography of the polymers was shown to be smooth (Rq <0.5 nm), uniform and defect free. Hardness of polyterpenol coatings increased from 0.33 GPa for 10 W to 0.51 GPa for 100 W (at 500 μN load). Coatings deposited at higher input RF powers showed less mechanical deformation during nanoscratch testing, with no considerable damage, cracking or delamination observed. Independent of the substrate, the quality of film adhesion improved with RF power, suggesting these coatings are likely to be more stable and less susceptible to wear. Independent of fabrication conditions, polyterpenol thin films were optically transparent, with refractive index approximating that of glass. Refractive index increased slightly with deposition power, from 1.54 (10 W) to 1.56 (100 W) at 500 nm. The optical band gap values declined with increasing power, from 2.95 eV to 2.64 eV, placing the material within the range for semiconductors. Introduction of iodine impurity reduced the band gap of polyterpenol, from 2.8 eV to 1.64 eV, by extending the density of states more into the visible region of the electromagnetic spectrum. Doping decreased the transparency and increased the refractive index from 1.54 to 1.70 (at 500 nm). At optical frequencies, the real part of permittivity (k) was determined to be between 2.34 and 2.65, indicating a potential low-k material. These permittivity values were confirmed at microwave frequencies, where permittivity increased with input RF energy – from 2.32 to 2.53 (at 10 GHz ) and from 2.65 to 2.83 (at 20 GHz). At low frequencies, the dielectric constant was determined from current−voltage characteristics of Al−polyterpenol−Al devices. At frequencies below 100 kHz, the dielectric constant varied with RF power, from 3.86 to 4.42 at 1 kHz. For all samples, the resistivity was in order of 10⁸−10⁹ _m (at 6 V), confirming the insulating nature of polyterpenol material. In situ iodine doping was demonstrated to increase the conductivity of polyterpenol, from 5.05 × 10⁻⁸ S/cm to 1.20 × 10⁻⁶ S/cm (at 20 V). Exposed to ambient conditions over extended period of time, polyterpenol thin films were demonstrated to be optically, physically and chemically stable. The bulk of ageing occurred within first 150 h after deposition and was attributed to oxidation and volumetric relaxation. Thermal ageing studies indicated thermal stability increased for the films manufactured at higher RF powers, with degradation onset temperature associated with weight loss shifting from 150 ºC to 205 ºC for 10 W and 100 W polyterpenol, respectively. Annealing the films to 405 °C resulted in full dissociation of the polymer, with minimal residue. Given the outcomes of the fundamental characterisation, a number of potential applications for polyterpenol have been identified. Flexibility, tunable permittivity and loss tangent properties of polyterpenol suggest the material can be used as an insulating layer in plastic electronics. Implementation of polyterpenol as a surface modification of the gate insulator in pentacene-based Field Effect Transistor resulted in significant improvements, shifting the threshold voltage from + 20 V to –3 V, enhancing the effective mobility from 0.012 to 0.021 cm²/Vs, and improving the switching property of the device from 10⁷ to 10⁴. Polyterpenol was demonstrated to have a hole transport electron blocking property, with potential applications in many organic devices, such as organic light emitting diodes. Encapsulation of biomedical devices is also proposed, given that under favourable conditions, the original chemical and biological functionality of terpinen−4−ol molecule can be preserved. Films deposited at low RF power were shown to successfully prevent adhesion and retention of several important human pathogens, including P. aeruginosa, S. aureus, and S. epidermidis, whereas films deposited at higher RF power promoted bacterial cell adhesion and biofilm formation. Preliminary investigations into in vitro biocompatibility of polyterpenol demonstrated the coating to be non−toxic for several types of eukaryotic cells, including Balb/c mice macrophage and human monocyte type (HTP−1 non-adherent) cells. Applied to magnesium substrates, polyterpenol encapsulating layer significantly slowed down in vitro biodegradation of the metal, thus increasing the viability and growth of HTP−1 cells. Recently, applied to varied nanostructured titanium surfaces, polyterpenol thin films successfully reduced attachment, growth, and viability of P. aeruginosa and S. aureus.
Resumo:
The rising demand for medical implants for ageing populations and ongoing advancements in medical technology continue to drive the use of implantable devices. Higher implant usage has a consequent increased incidence of implant-related infections, and associated prolonged patient care, pain and loss of limb and other organ function. Numerous antibacterial surfaces have been designed that prevent the onset of biofilm formation, thus reducing or preventing implant-associated infections through inhibiting bacterial adhesion or by killing the organisms that successfully attach to the surface of the implant. Other surfaces have been designed to stimulate a local immune response, promoting the natural clearing of the invading pathogen. The desired antibacterial effects are typically achieved by modulating the surface chemistry and morphology of the implant material, by means of the controlled release of pharmacological agents and bioactive compounds from the surface of the material, or by a combination of both processes. An important issue for any type of antibacterial surface modification lies in balancing the non-fouling, bacteriostatic or bactericidal effects against local and systemic biocompatibility. In this chapter, we will first describe the concept of biocompatibility and its evolution, from devices that do not evoke a negative host response to those that actively drive host regeneration. We will then review the challenges associated with merging the need for an implant material to withstand a bacterial load with those associated with supporting function restoration and tissue healing.
Resumo:
Rapid change in climate is challenge for the adaptation of forest trees in the future. In wind pollinated tree species pollen mediated long distance gene flow may provide alleles that are (pre)adapted to a future climate. In order to examine the long distance pollen flow in Scots pine (Pinus sylvestris L.), we measured the amount and viability of airborne pollen and flowering phenology in central, northern, and northernmost Finland during four years. Viable airborne pollen grains were detected during female flowering and before local pollen shedding in all study sites. The situation when there was nonlocal pollen in the air lasted from one to four days depending on the year and study site. The amount of nonlocal airborne pollen varied also between years and study sites, the total amount of nonlocal viable pollen in the air was 2.3% from all detected viable pollen grains. The effect of pollen origin on seeds siring ability was studied with artificial pollination experiments. Pollen genotypes originating from southern Finland sired 76% and 48 % of the analysed seeds in competition studies where both pollen origin were introduced simultaneously into the female strobili. We examined the importance of arrival order of pollen grains in to the strobili in a study where pollen genotypes of different origin were introduced in two hours interval. Northern genotypes sired 76% of the analysed seeds when it was injected first, but in the "southern first" experiment both pollen types sired equal amount of seeds. The first pollen grain in the pollen chamber do not always fertilizes the ovum, instead there likely is more complex way of competition between pollen grains. To examine chemically mediated pollen-pollen interactions we conducted in vitro germination experiment where different pollen genotypes had chemical but not physical contact. Both positive and negative effects of interactions were found. We found highly negative effects in germinability of northern pollen grains when they were germinating with southern pollen, and increase in the germinability of southern pollen. There were no variation in the size of the dry pollen grains between pollen origins, and minor variation between different genotypes. After hydration and germination northern pollen grains were larger than southern pollen. Pollen genotypes having high hydration rates had low germinability and tube growth rate, however, germinated pollen grains were larger in size than nongerminated. This supports the suggestion that the early germination and growth of pollen tube is dependent on pollen storage materialsand less dependent on water intake and hydration. Long distance pollen movements and good competition ability of southern pollen makes gene flow possible, although rising temperature and timing of pollen movements may affect pollen competition and the amount of gene flow.
Resumo:
The study focused on the different ways that forest-related rights can be devolved to the local level according to the current legal frameworks in Laos, Nepal, Vietnam, Kenya, Mozambique and Tanzania. The eleven case studies represented the main ways in which forest-related rights can be devolved to communities or households in these countries. The objectives of this study were to 1) analyse the contents and extent of forest-related rights that can be devolved to the local level, 2) develop an empirical typology that represents the main types of devolution, and 3) compare the cases against a theoretical ideal type to assess in what way and to what extent the cases are similar to or differ from the theoretical construct. Fuzzy set theory, Qualitative Comparative Analysis and ideal type analysis were used in analysing the case studies and in developing an empirical typology. The theoretical framework, which guided data collection and analyses, was based on institutional economics and theories on property rights, common pool resources and collective action. On the basis of the theoretical and empirical knowledge, the most important attributes of rights were defined as use rights, management rights, exclusion rights, transfer rights and the duration and security of the rights. The ideal type was defined as one where local actors have been devolved comprehensive use rights, extensive management rights, rights to exclude others from the resource and rights to transfer these rights. In addition, the rights are to be secure and held perpetually. The ideal type was used to structure the analysis and as a tool against which the cases were analysed. The contents, extent and duration of the devolved rights varied greatly. In general, the results show that devolution has mainly meant the transfer of use rights to the local level, and has not really changed the overall state control over forest resources. In most cases the right holders participate, or have a limited role in the decision making regarding the harvesting and management of the resource. There was a clear tendency to devolve the rights to enforce rules and to monitor resource use and condition more extensively than the powers to decide on the management and development of the resource. The empirical typology of the cases differentiated between five different types of devolution. The types can be characterised by the devolution of 1) restricted use and control rights, 2) extensive use rights but restricted control rights, 3) extensive rights, 4) insecure, short term use and restricted control rights, and 5) insecure extensive rights. Overall, the case studies conformity to the ideal type was very low: only two cases were similar to the ideal type, all other cases differed considerably from the ideal type. The restricted management rights were the most common reason for the low conformity to the ideal type (eight cases). In three cases, the short term of the rights, restricted transfer rights, restricted use rights or restricted exclusion rights were the reason or one of the reasons for the low conformity to the ideal type. In two cases the rights were not secure.
Resumo:
The incidence of obesity is rising worldwide at an alarming rate and is becoming a major public health concern with incalculable social and economic costs. Studies have exposed the relationship between the adiposity, inflammation and the development of other metabolic disorders, so dietary factors that influence some or all of these are of interest. Dietary phytochemicals appear to be able to target different stages of the adipocyte (fat cell) lifecycle. For example, several classes of polyphenols have been implicated in suppressing the growth of adipose tissue through modifying the adipocyte lifecycle. Many dietary phytochemicals also have strong anti-inflammatory activity, but the amount present in plants varies and may be affected by processing. In this review we summarise the likely mechanisms of action of plant phytochemicals. We highlight the major vegetable sources of polyphenols, including those with possible synergistic attributes, discuss the variation in polyphenol levels and their distribution in cultivars and outline the effects of food processing. The identification and characterisation of the anti-obesogenic properties of phytochemicals in vegetables, as well as an appreciation of the effect of cooking on phytochemical content provide significant new information supporting dietary guidelines that encourage vegetable consumption for the prevention and management of lifestyle related disease.
Resumo:
There is an increasing need to understand what makes vegetation at some locations more sensitive to climate change than others. For savanna rangelands, this requires building knowledge of how forage production in different land types will respond to climate change, and identifying how location-specific land type characteristics, climate and land management control the magnitude and direction of its responses to change. Here, a simulation analysis is used to explore how forage production in 14 land types of the north-eastern Australian rangelands responds to three climate change scenarios of +3A degrees C, +17% rainfall; +2A degrees C, -7% rainfall; and +3A degrees C, -46% rainfall. Our results demonstrate that the controls on forage production responses are complex, with functional characteristics of land types interacting to determine the magnitude and direction of change. Forage production may increase by up to 60% or decrease by up to 90% in response to the extreme scenarios of change. The magnitude of these responses is dependent on whether forage production is water or nitrogen (N) limited, and how climate changes influence these limiting conditions. Forage production responds most to changes in temperature and moisture availability in land types that are water-limited, and shows the least amount of change when growth is restricted by N availability. The fertilisation effects of doubled atmospheric CO2 were found to offset declines in forage production under 2A degrees C warming and a 7% reduction in rainfall. However, rising tree densities and declining land condition are shown to reduce potential opportunities from increases in forage production and raise the sensitivity of pastures to climate-induced water stress. Knowledge of these interactions can be applied in engaging with stakeholders to identify adaptation options.
Resumo:
The Road Safety Remuneration Act 2012 (Cth) (the Act) explicitly enables the Road Safety Remuneration Tribunal to make orders that can impose binding requirements on all the participants in the road transport supply chain, including consignors and consignees at the apex the chain, for the pay and safety of both employee and independent contractor drivers. The tribunal is also specifically empowered to make enforceable orders to reduce or remove remuneration related incentives and pressures that contribute to unsafe work practices in the road transport industry. Recently the tribunal handed down its first order. The article considers whether, and the degree to which, the tribunal has been willing to exercise its explicit power to impose enforceable obligations on consignors and consignees — such as large supermarket chains — at the apex of road transport supply chains. It examines the substance and extent of the obligations imposed by the tribunal, including whether the tribunal has exercised the full range of powers vested in it by the Act. We contend that the tribunal’s first order primarily imposes obligations on direct work providers and drivers without making large, powerful consignors and consignees substantively responsible for driver pay and safety. We argue that the tribunal’s first order could have more comprehensively fulfilled the objectives of the Act by more directly addressing the root causes of low pay and poor safety in the road transport industry.
Resumo:
The memoir contains poems, eulogies and family photos and was written in 1995 in Connecticut. Recollections of the author's childhood in an orthodox Jewish family in the Leopoldstadt, the second district in Vienna. He was the third of four children. His father was a businessman who was dealing with clothing and textile. Kurt was enrolled in the same class as his older brother Hans at Gymnasium. Memories of his Bar Mitzvah celebration. Cello lessons and concerts with his brother Hans. After graduation Kurt started to study medicine at the Anatomic Institute of Julius Tandler at the Vienna University. Member of the liberal medical students' union "Wiener Mediziner". Acquaintance with his future-wife Greta. Skiing trip in the mountains. Antisemitic attacks at University, particularly within the faculties of law and medicine. Arrest under the false accusation of distributing illegal literature. In January 1938 Greta and Kurt Tauber were married. Worsening of political situation and rising of the illegal Nazi movement in Austria. Recollections of the "Anschluss" (Nazi take-over) in March 1938. Affidavit for Greta and Kurt from her brother in the United States. In June 1938 they went to London, where they waited for their visas to the US. Fervent attempts to arrange exit permits for their families in Vienna. Greta and Kurt Tauber arrived in New York in October of 1938. Difficult start at the beginning. Kurt started to work in a bakery. Greta and Kurt moved to a small apartment in the Lower East Side. Move to Queens with Greta's parents. Kurt's parents arrived in 1940 and moved to Washington Heights. Kurt and Greta started a baking business in Kew Gardens, Queens. Birth of their daughters Judy in 1941 and Ellen in 1944. Recollections of Passover family celebrations and vacations in the mountains and at Fleischmann's in the Catskills. Description of business encounters and family events, such as the birth of their grandchildren. Journey to Israel. Retirement and
Resumo:
The memoirs were written in 1999. Childhood memories in a small town in Lower Austria. Passion for playing football (soccer). Recollections of daily life with rituals of coffeehouse visits and family dinners in the countryside. First experiences of antisemitism in the mid 1930s. Rising Nazi movement and illegal meetings in the local community. Annexation of Austria in 1938. First encounters with anti-Jewish regulations and discrimination by neighbors and acquaintances. Walter experienced severe difficulties at school and was frequently insulted and beaten up. Decision to leave school. The family was forced to leave Eggenburg soon thereafter, and the town declared itself "Judenfrei" (free of Jews). Move to Vienna, where they stayed with relatives. Walter, who had been brought up as a Catholic, suddenly saw himself confronted with orthodox Jewish people of different customs. Increasing restrictions for Jews. Walter was enrolled in a program at the Vienna Jewish community to learn carpentry. Recollections of the terror of Kristallnacht. Walter and his brother Ludwig were signed up for a children transport to England by the Quaker organization and left Vienna in December 1938. Difficult feeling to depart from their parents. Arrival in Harwige. They were taken to a camp in Lowestoft. Cultural differences. Walter and his brother were sent to a training farm in Parbold. Simple living conditions and difficult circumstances. Farm work and school lessons. Outbreak of the war. Scarce news of their parents, who tried to leave for Argentina. Walter's older brother Ludwig was sent to an internment camp in Adelaide, Australia. After two years he volunteered in the Pioneer Corps and returned to England. In 1941 their parents finally managed to emigrate to Argentina. Walter decided to join them, and in 1943 he left for Buenos Aires. During the passage on the Atlantic the ship was sunk by a German submarine. Rescue by the US Army. Continuation of his trip via New York.
Resumo:
The memoirs were written in 2000 in California and contains some of the author's diary entries during the years of the family's emigration and reminiscences of the author's father. Detailed description of family history going back to the early 19th century. The author's grandfather Moses Stern had a rawproduct business in Gelsenkirchen, Westphalia. His father Max Stern took his graduate exam (Abitur) at the Jacobsohn boarding school in 1904 and was sent to a business school in Brussles, Belgium. Work in the family business M. Stern AG. World War One and rise of the family business with branches throughout Germany and offices in New York, London, Milan and Stockholm. Due to political unrest at the end of the war the business administration moved to Essen. Description of the family background of Beate Herzberg, the author's mother. Courtship of his parents and marriage in 1922. Birth of his sister Annelore in 1923. Martin Stern was born in 1924. Description of the family household and domestic life in a well-to-do family the 1920s. Friday visits to the synagogue and celebration of Jewish holidays. Vacations at the North sea and skiinig in the Alps. Martin attended a Jewish elementary school. Rising National Socialism. After Hitler came to power in 1933 the author's father immediately started preparations for the family's emigration, but was persuaded to stay by his family. Life under National Socialism. Martin attended Gymnasium and was one of only two Jewish students in his class. Antisemitic incidents. Private lessons in piano and Hebrew. Bar Mitzvah in 1937. Recollections of performances of the Kulturbund.
Resumo:
Description of the author’s family background. His paternal family owned a tobacco and cigarres business in Ulm, which was transferred to Munich in 1888. The maternal family in Frankfurt am Main had a textile export business. Recollections of his schooldays at the Catholic St. Anna Schule. Antisemitic encounters at the local Gymnasium. Description of life in the 19th century. Reverence for the local royalties. The family was involved in the Zionist movement, as were most of the members of their local synagoge.
Resumo:
The memoirs contain photocopies of documents and photos as well as extracts from letters and were written in October 1989 in the United States. Description of life in Baden, a famous health resort near Vienna. The family lived in Vienna in the second district (Leopoldstadt). Recollections of schoolteachers and childhood friends. Occasional Friday night services in the Leopoldstadt temple. Theater and opera visits and cultural life in Vienna. Private piano and music lessons. Description of the family apartment and Jewish life in the Leopoldstadt. The family celebrated Christmas and observed the high Jewish holidays. Recollections of the author's bar mitzvah celebration. His mother Charlotte, nee Schwadron, was an artistic woman, who studied painting at the Frauenakademie with Tina Blau. Walter's father Leo Schaffir was born in Byalistock, Russia and studied in Berlin. He was a travelling businessmen. His family lived in Lemberg, Galicia. Leo and Charlotte Schaffir got married in 1919 in Vienna by rabbi Dr. Grunwald. Recollections of a family trip to Poland and to the World Fair in Posen in 1930. Suicide of the author's father due to business failure in 1930. Schaffir and Schwadron family history. Both families originated in Galicia, Poland. Family and social life. Summer vacation at the Semmering. Austrian politics in the 1930's and rising National Socialism. Life in Vienna after the "Anschluss" in 1938. Walter had to leave school and took lessons in graphic arts with the artist Heinrich Koerner. Preparations to emigrate. Walter was picked up in the streets in the days after Kristallnacht and released due to his mother's intervention. He was sent with his brother Kurt on a "Kindertransport" to Holland. They were sent to a quarantine camp at Heyplaat. Reunition with their mother in the United States in December 1939. Reflections on life as an emigre.
Resumo:
VHF nighttime scintillations, recorded during a high solar activity period at a meridian chain of stations covering a magnetic latitude belt of 3°–21°N (420 km subionospheric points) are analyzed to investigate the influence of equatorial spread F irregularities on the occurrence of scintillation at latitudes away from the equator. Observations show that saturated amplitude scintillations start abruptly about one and a half hours after ground sunset and their onset is almost simultaneous at stations whose subionospheric points are within 12°N latitude of the magnetic equator, but is delayed at a station whose subionospheric point is at 21°N magnetic latitude by 15 min to 4 hours. In addition, the occurrence of postsunset scintillations at all the stations is found to be conditional on their prior occurrence at the equatorial station. If no postsunset scintillation activity is seen at the equatorial station, no scintillations are seen at other stations also. The occurrence of scintillations is explained as caused by rising plasma bubbles and associated irregularities over the magnetic equator and the subsequent mapping of these irregularities down the magnetic field lines to the F region of higher latitudes through some instantaneous mechanism; and hence an equatorial control is established on the generation of postsunset scintillation-producing irregularities in the entire low-latitude belt.
Resumo:
The memoirs were written in 1982 in Sydney, Australia and include excerpts of letters from various relatives during the years 1938-1941. Early childhood recollections of World War One. The family was living in the 6th district of Vienna. Description of domestic life with maids, laundresses and a French governess. Death of her mother in 1918. Trip with her stepmother Ida Plohn to Prague. Recollections of a stay in the countryside at their maid's family, where Selma and her older sister Martha awaited the birth of their younger sister Trude. Memories of Christmas celebrations. Summer vacations in the mountains. Description of the extended family. Inflation and economic depression in the 1920s. Strict upbringing by her stepmother. Children recreation trip to Grado, Italy in 1925. Selma was accepted at the "Bundeserziehungsanstalt" for gifted students. Only few fellow Jewish students. Religious education with beloved rabbi Diamant. Recovery from tonsilitis in a senatorium in Aflenz, Austria. Celebration of Jewish holidays and visits at the Synagogue on Yom Kippur. Transfer to Realschule. Due to a sudden onset of various illnesses Selma was unable to continue school and had put an end to her father's dream of an university education for her. Difficult to find a position in the depression times of the early 1930s. Only few working options for a Jewish woman. Position as a secretary in a Jewish firm. Outings in the Vienna Woods. Membership in the Zionist group Betar.