A functional nanometer-scale hybrid coating layer with multi-walled carbon nanotubes (MWCNTs) and/or nanoclays, as mechanical enhancement to ‘heal’ surface microcracks and environmental barrier layer is applied to alkaliresistant glass (ARG) fibres. The nanostructured and functionalised traditional glass fibres show both significantly improved mechanical properties and environmental corrosion resistance. Early warning material damage can be achieved by carbon nanotubes concentrated interphases in the composites. / Eine funktionale nanometerskalige Hybridbeschichtung mit multi-walled carbon nanotubes (MWCNTs) und/oder Nanoclay wurde als mechanische Verbesserung des „Ausheilens“ von Oberflächen-Mikrorissen und Barriereschicht gegenüber Umwelteinflüssen auf alkaliresistente Glasfasern (ARG) appliziert. Die nanostrukturierten und funktionalisierten traditionellen Glasfasern zeigen signifikant verbesserte mechanische Eigenschaften und Korrosionsbeständigkeit. Die Frühwarnung des Materialversagens kann durch Carbon Nanotubes, konzentriert in der Grenzschicht der Composites, erreicht werden.

This work, conceived as a second step in the development of high-performance damping materials suitable for seismic application, describes the preparation and characterization of complex natural rubber-based composites containing hybrid nano- and conventional fillers. The cluster–cluster aggregation model was used to assess the apparent filler networking energy. The values obtained suggested that the presence of the hybrid nanofiller strengthens the filler networking. The same model was used to understand the mechanisms of energy dissipation. The damping coefficient was found to be in the sought range between 10% and 20% (at 0.5 Hz and high shear strain).

Der Bericht enthält Untersuchungsergebnisse zur Kohlenstoffspeicherung und –dynamik sowie Grundnährstoffverfügbarkeit in Ackerböden nach 20-jähriger konservierender Bodenbearbeitung bzw. Direktsaat. Die Untersuchungen wurden an zwei Dauerversuchsflächen im Mittelsächsischen Lößhügelland durchgeführt. Dabei wurde auch der praxisrelevanten Fragestellung nachgegangen, wie sich ein erneuter Pflugeinsatz auf die Kohlenstoffdynamik langjährig konservierend bzw. in Direktsaat bestellter Flächen auswirkt. Redaktionsschluss: 30.06.2017

Die Auswertung des Ist-Zustands von 546 Dauerbeobachtungsflächen gibt einen Überblick über die N- und Humusversorgung sächsischer Ackerböden. Auf dieser Basis wurden Handlungsempfehlungen zur Optimierung des Kohlenstoff- und Stickstoffkreislaufs erarbeitet. Die Methoden zur Anrechnung der N-Verfügbarkeit und der N-Mineralisation aus organischen Düngern und Humusumsatz bedürfen bei der N-Düngebedarfsermittlung in Abhängigkeit von den Standortbedingungen der weiteren Optimierung. Redaktionsschluss: 09.12.2019

Die Modifizierung von Carbon Black Partikeln und multi-walled Carbon Nanotubes mit Poly(vinylformamid-co-vinylamin) wurde in Abhängigkeit vom pH-Wert untersucht, um primäre Aminogruppen auf die Oberfläche der Kohlenstoffspezies einzuführen. Mit einer anschließenden Pfropfreaktion der Aminogruppen tragenden Nanotubes mit Maleinsäureanhydrid-Copolymeren sind eine Vereinzelung und ein Stabilisieren der der Carbon Nanotubes möglich. Durch eine Auswahl an Maleinsäureanhydrid-Copolymeren war nach einer Funktionalisierung der mit PVFA-co-PVAm beschichteten Carbon Nanotubes die Änderung der Oberflächeneigenschatften von hydrophil bis hin zu ultrahydrophob möglich. Die Charakterisierung der Partikel und Nanotubes erfolgte mit Hilfe der Elementaranalyse, BET-Untersuchungen, XPS, Kontaktwinkelmessungen, TGA-Untersuchungen, elektrokinetischer Messungen und REM-Aufnahmen.

Impacts of land use and climate change in tropical forests on the global carbon budget are of principal interest in the recent research, as these forests amount to about 48 % of the world’s forested area. Interest has been focused on lowland tropical forests mainly, but tropical montane forests occupy about 20 % of all tropical forests. Soils of tropical montane forests are frequently waterlogged and characterised by high soil organic carbon stocks. Furthermore, along altitudinal gradients, changes in stand structure and net primary production can be observed that have not been fully explained yet. As causes reduced microbial activity and nitrogen turnover in soils of tropical montane forests have been suggested. Against the background of climate change, carbon turnover mechanisms in soils of these forests are of special interest. The present study therefore aimed at determining and quantifying relevant carbon and nitrogen pools as well as nitrogen mineralisation potentials. Furthermore, size, activity, and structure of microbial biomass were characterised. The collected data was supposed to provide basic knowledge on carbon and nitrogen cycling in tropical montane forest soils. Thus, evaluation of the susceptibility of their carbon stocks for climate change as well as nitrogen and carbon limitation of microbial organic matter decomposition was possible. Field work of this study was conducted during 2003–2005 at an altitudinal transect that in- cluded five study sites between 1 050 and 3 060 m amsl. Total soil respiration was recorded biweekly over two years, the contribution of roots to total soil CO2 efflux over one year. Soils of the study sites were sampled twice and biochemical and microbial parameters were determined.

In this thesis, bulk and local scale spectroscopic and microscopic tools have been applied to investigate the purified raw material of SWCNT and synthesized MWBNNT, BN-nanocapsules, B-doped SWCNT and SiC nanostructures. Using bulk scale sensitive techniques, including optical absorption spectroscopy, Raman spectroscopy, high-resolution electron energy-loss spectroscopy, the average response of the whole sample is obtained. On the other hand, on a local scale transmission and scanning electron microscopy as well as TEM-electron energy-loss spectroscopy provide information on single tubes or other nanostructures. First, diverse chemical and oxidation methods for the purification of as-produced SWCNT were presented. Purified samples were investigated using TEM and OAS. The analysis of the optical absorption spectra in the UV-Vis energy range revealed that some of the chemical treatments are harmful to nanotubes. In contrast to the chemical treatments an oxygen burning procedure was used on the raw material in high vacuum and a temperature range 450?650oC. The purification processes of SWCNT by HNO3 and oxygen burning procedures resulted in SWCNT comprised of selected diameters and a reduced diameter distribution. Both HNO3 and oxygen burning treatments can be used to selectively remove SWCNT with smaller diameters from the samples. In addition, an adapted substitution reaction was used for the synthesis of multiwall boron nitride nanotubes. It was shown that the IR-response of MWBNNT can be used as a fingerprint to analyse MWBNNT. As in h-BN for the analysis one has to be aware of the sample texture and the LO-TO splitting of the IR-active modes. TEM images and B1s and N 1s excitation edges of the grown material reveal the presence of multiwall BN nanotubes with an inner diameter of 3.1 nm and with a larger interplanar distance than in h-BN. The electronic properties of the multiwall BN nanotubes as derived from the q-dependent dielectric function e(w,q) are dominated by the band structure of the hexagonal-like BN sheets, as revealed by the large degree of momentum dispersion observed for the p and s+p plasmons, in agreement with that previously reported for different graphitic allotropic forms. Moreover, a fast and highly efficient synthesis route to produce BN nanocapsules with a narrow size distribution was developed. This was achieved by an adapted substitution process using SWCNT as templates followed by a rapid cooling treatment. The IR responses reveal the strong dipole active fingerprint lines of h-BN with distinct differences, which are due to texturing effects and which highlight the BN nanocapsules potential application as a reference source when deriving the sp2 to sp3 ratio in BN species due to their random orientation Furthermore, the idea of substitution was used for the systematic studies of B-doped SWCNT. The experiments carried out have resulted in 1, 5, 10, and 15 % boron incorporated into the single wall carbon nanotubes. Core level excitation spectroscopy of the B1s and C1s edges revealed that the boron atoms substitute carbon atoms in the tube lattice keeping an sp2-like bond with their nearest C neighbour atoms. Our results show that a simple rigid band model as has been applied previously to intercalated SWCNT is not sufficient to explain the changes in the electronic properties of highly doped B-SWCNT and a new type of a highly defective BC3 SWNT with new electronic properties is obtained. Finally, different silicon carbide nanostructures were produced. The spectroscopic and microscopic data led to a good understanding of the formation process. NH3 acts as a source of hydrogen that plays a key role in the formation of the structures through its ability to decompose SiC at high temperature such that along with the stacking faults that arise from the many polytypes of SiC the produced SiC nanorods become porous then hollow and eventually are completely decomposed.

Lakes in Hanoi play an important role in local human life. However, along with the economic and social development, some urban lakes have been polluted, especially organic pollution. This paper presents the monthly survey results for organic pollution assessment of ten selected lakes in Ha Noi city: the Ho Tay, Truc Bach, Thien Quang, Ba Mau, Bay Mau, Hoan Kiem, Ngoc Khanh, Giang Vo, Thanh Cong and Thu Le lakes during the period from March 2014 to February 2015. The survey results showed that the Ba Mau lake was organic polluted at level IV whereas other lakes were contaminated by organic matters at level III. Organic pollution may come from both autochthonous and allochthonous sources. Compared with the results of previous studies, the water quality of 10 lakes in the period from March 2014 to February 2015 has been improved thank for the recent application of some positive solutions for lake environmental protection. / Hệ thống hồ ở Hà Nội đóng vai trò quan trọng trong đời sống của người dân. Tuy nhiên, cùng với sự phát triển kinh tế xã hội, nhiều hồ trong nội đô đã và đang bị ô nhiễm, đặc biệt là ô nhiễm hữu cơ. Bài báo này trình bày kết quả khảo sát ô nhiễm hữu cơ tại 10 hồ trong thành phố Hà Nội: hồ Tây, Trúc Bạch, Thiền Quang, Ba Mẫu, Bảy Mẫu, Hoàn Kiếm, Ngọc Khánh, Giảng Võ, Thành Công và Thủ Lệ trong thời gian từ tháng 3 năm 2014 đến tháng 2 năm 2015. Kết quả khảo sát cho thấy hồ Ba Mẫu bị ô nhiễm hữu cơ ở mức IV, các hồ còn lại bị ô nhiễm hữu cơ ở mức III. Ô nhiễm hữu cơ tại các hồ có thể do cả hai nguồn cung cấp chất hữu cơ, ngoại lai và nội sinh. So với kết quả quan trắc trước đây, chất lượng nước 10 hồ Hà Nội đã được cải thiện do gần đây đã áp dụng một số biện pháp bảo vệ môi trường cho các hồ.

Biomass and carbon stock of the natural forests in Vietnam are still not clear due to limitation of knowledge and financial. In this paper, the results of estimating biomass and carbon stocks of the natural forests at Me Linh Biodiversity Station are shown. There are two forest types in this study: the forest vegetation restored after shifting cultivation (vegetation type I) and the forest vegetation restored after clear cutting exploitation (vegetation type II). As the results, the estimated biomass of the forest vegetation restored after shifting cultivation is 86.80 ton.ha-1 and the estimated biomass of the forest vegetation restored after clear cutting exploitation is higher, about 131.59 ton.ha-1. The carbon stock in plants was about 43.40 ton.ha-1 of vegetation type I and 65.79 ton.ha-1 of vegetation type II. The carbon storage in soil of vegetation type I is 79.01 ton.ha-1 and vegetation type II is 99.65 ton.ha-1. Hence, the total of carbon stock in forest vegetation I and II are accounted by 122.41ton.ha-1 and 165.44 ton.ha-1, respectively. In general, it can be pointed out that the naturally recovering secondary forest at Me Linh Station is the secondary young forest with the low economic value due to shortly restored process (about 10-20 years), the flora is not rich and abundant, and there are only commonly pioneer and light demanding tree species. / Sinh khối và trữ lượng các bon của rừng tự nhiên ở Việt Nam vẫn ít được quan tâm của do hạn chế về kiến thức và tài chính. Trong bài báo này, chúng tôi đưa ra kết quả của việc ước lượng sinh khối và tổng hợp các bon của các thảm thực vật rừng thứ sinh phục hồi tự nhiên tại Trạm Đa dạng Sinh học Mê Linh, tỉnh Vĩnh Phúc- Việt Nam, nơi có loại hình thảm thực vật chính, đó là thảm thực vật phục hồi sau nương rẫy (kiểu thảm thục vật I) và thảm thực vật phục hồi sau khai thác kiệt (kiểu thảm thực vật II) nhằm mục đích đánh giá tiềm năng của rừng thứ sinh tại khu vực nghiên cứu. Sinh khối của thảm thực vật phục hồi sau nương rẫy là 86,80 tấn/ha. Sinh khối của thảm thực vật phục hồi sau khai thác cao hơn, đạt 131.59 tấn/ha. Lượng các bon hấp thu trong đất của thảm thực vật I là 79,01 tấn/ha và thảm thực vật II là 99,65 tấn/ha. Như vậy, tổng lượng các bon được hấp thu trong mỗi loại hình thảm thực vật trên là: 122,41 tấn/ha (thảm thực vật I) và 165,14 tấn/ha. Nhìn chung, rừng thứ sinh phục hồi tự nhiên tại Trạm Đa dạng Mê Linh chủ yếu là rừng non thứ sinh, ít có giá trị kinh tế do quá trình phục hồi diễn ra ngắn (khoảng 10-20 năm) nên thành phần thực vật nghèo nàn, không phong phú, thành phần chính chủ yếu là các cây gỗ tiên phong, ưa sáng.

Eine polymorphe Orbitalskulptur, die aus einer 3D-Kohlenstoff -Betonstruktur besteht, die von einem Polypeptidnetzwerk inspiriert ist, das ein geringeres Gewicht und eine geringere Zähigkeit bewirkt und auf einer überfluteten Stadtstraße steht, die von der anthropozentrischen Wärmeakkzeleration herrührt. - Meine künstlerische Praxis besteht aus partizipativen Performances, Malerei und Skulptur im Zusammenspiel von Tanz, Musik, wacher Zeitgenossenschaft und farbintensiven Werken, denn alles Sichtbare ist nur durch die Farbe begehrenswert.