Особенности разработки термостабилизированных германиевых фотодиодов

Рассмотрены подходы к конструированию лавинных и нелавинных германиевых фотодиодов с применением эпитаксиальных структур и термоэлектрического охлаждения

Quantifying synergies and trade-offs in the global water-land-food-climate nexus using a multi-model scenario approach

The human-earth system is confronted with the challenge of providing a range of resources for a growing and more prosperous world population while simultaneously reducing environmental degradation. The sustainable development goals and the planetary boundaries define targets to manage this challenge. Many of these are linked to the land system, such as biodiversity, water, food, nutrients and climate, and are strongly interconnected. A key question is how measures can be designed in the context of multi-dimensional sustainability targets to exploit synergies. To address this, a nexus approach is adopted that acknowledges the interconnectedness between the important sub-systems water, land, food, and climate. This study quantifies synergies and trade-offs from ambitious interventions in different components of this water-land-fod-climate nexus at the global scale. For this purpose, a set of six harmonized scenarios is simulated with the model of agricultural production and its impact on the environment and Integrated model to assess the global environment models. The multi-model approach improves robustness of the results while shedding light on variations coming from different modelling approaches. Our results show that measures in the food component towards healthy diets with low meat consumption have synergies with all other nexus dimensions: Increased natural land improving terrestrial biodiversity (+4% to +8%), lower greenhouse gas emissions from land (−45% to −58%), reduced irrigation water withdrawals to protect or restore hydrological environmental flows (−3% to −24%), and reductions in nitrogen surpluses (−23% to −35%). Climate mitigation measures in line with the Paris Agreement have trade-offs with the water and food components of the nexus, as they adversely affect irrigation water withdrawals (+5% to +30% in 2050 compared to reference scenario) and food prices (+1% to +20%). The analysis of a scenario combining all measures reveals how certain measures are in conflict while others reinforce each other. This study provides an example of a nexus approach to scenario analysis providing input to the next generation of pathways aiming to achieve multiple dimensions of sustainable development.SHAPEHorizon 2020 Framework Programmehttp://dx.doi.org/10.13039/100010661Deutsche Bundesstiftung Umwelthttp://dx.doi.org/10.13039/100007636Peer Reviewe

Projecting terrestrial biodiversity intactness with GLOBIO 4

Scenario-based biodiversity modelling is a powerful approach to evaluate how possible future socio-economic developments may affect biodiversity. Here, we evaluated the changes in terrestrial biodiversity intactness, expressed by the mean species abundance (MSA) metric, resulting from three of the shared socio-economic pathways (SSPs) combined with different levels of climate change (according to representative concentration pathways [RCPs]): a future oriented towards sustainability (SSP1xRCP2.6), a future determined by a politically divided world (SSP3xRCP6.0) and a future with continued global dependency on fossil fuels (SSP5xRCP8.5). To this end, we first updated the GLOBIO model, which now runs at a spatial resolution of 10 arc-seconds (~300 m), contains new modules for downscaling land use and for quantifying impacts of hunting in the tropics, and updated modules to quantify impacts of climate change, land use, habitat fragmentation and nitrogen pollution. We then used the updated model to project terrestrial biodiversity intactness from 2015 to 2050 as a function of land use and climate changes corresponding with the selected scenarios. We estimated a global area-weighted mean MSA of 0.56 for 2015. Biodiversity intactness declined in all three scenarios, yet the decline was smaller in the sustainability scenario (-0.02) than the regional rivalry and fossil-fuelled development scenarios (-0.06 and -0.05 respectively). We further found considerable variation in projected biodiversity change among different world regions, with large future losses particularly for sub-Saharan Africa. In some scenario-region combinations, we projected future biodiversity recovery due to reduced demands for agricultural land, yet this recovery was counteracted by increased impacts of other pressures (notably climate change and road disturbance). Effective measures to halt or reverse the decline of terrestrial biodiversity should not only reduce land demand (e.g. by increasing agricultural productivity and dietary changes) but also focus on reducing or mitigating the impacts of other pressures.Peer reviewe

Reducing sectoral hard to abate emissions to limit reliance of Carbon Dioxide Removal in 1.5°C scenarios

Achieving net-zero greenhouse gas targets is often achieved by compensating residual greenhouse gas emissions in the hard to abate (HtA) sectors, with carbon dioxide removal (CDR) options. However, large-scale application of CDR may lead to environmental, technical and social concerns. The extent to which residual emissions can be reduced in the industry, agriculture, buildings and transport sector is analysed based on integrated assessment of scenarios with ambitious measures in the HtA sectors. Two scenarios that explore demand and technology-focused approaches show that by reducing residual emissions, the CDR ceiling can be significantly lowered (23-30%) compared to reference in the net-zero year. The agriculture sector plays a critical role in this given the large share of residual emissions. The additional measures allow to create a 1.5°C scenario in which crop-based bioenergy use is limited to 40 EJ/yr, therefore within sustainable limits, and afforestation can be limited to abandoned cropland and grassland

Impact of Tenancy on Land Management

Leasing of agricultural land is gaining in importance in North America. The impact of leasing on soil management practices is examined in an area in the Canadan province of Ontario. Prevailing land contracts are insecure and the rental land market appears to be imperfect in the area. Under these conditions leasing leads to undesirable soil management practices and consequently to a lower state of conservation and to lower crop productivity over time. A difference in soil management and crop productivity has been observed between owner-operated and rented land

Ideologie en metode : 'n struktuuranalitiese ondersoek na die metodologies benaderde ideologiekritiek van Karl Marx in die 'Grundrisse der Kritik der Politischen Okonomie'

Proefskrif (D.Phil.) -- Universiteit van Stellenbosch, 1979.Full text to be digitised and attached to bibliographic record

Taxation of the Digital Economy : the impact of South Africa’s Value-added Tax provisions on Tax compliance

No abstractMini Dissertation (MCom)--University of Pretoria, 2019.TaxationMCom TaxationUnrestricte

Ideologie en tyd : 'n ondersoek na die aard van ideologie deur middel van struktuuranalises van tydkonsepsies onderliggend aan sekere politieke teoriee

Skripsie (M.A.) -- Universiteit van Stellenbosch, 1969.Full text to be digitised and attached to bibliographic record