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| 2. |
- Dong, C. L., et al.
(författare)
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Electronic structure and surface structure of Cu2S nanorods from polarization dependent X-ray absorption spectroscopy
- 2006
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 151:1, s. 64-70
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Tidskriftsartikel (refereegranskat)abstract
- Highly aligned CuS nanorods have been studied by polarization dependent X-ray absorption spectroscopy. In contrast to bulk Cu2S, strong s, p, and d hybridization is found in the nanorods. The polarization dependence shows a predominant d(z2) character of Cu 3d states. Ab initio multiple-scattering calculations confirm the strong hybridization, and reveal that CuS nanorods are grown along the z-axis of chalcocite structure with Cu-7 and Cu-10 sites being the main building blocks. The hybridized absorption peak in the nanorods is shifted towards lower energies for smaller diameter of nanorods, which is attributed to surface reconstruction due to strong Cu-Cu interactions on the Cu-rich surface of the nanorods.
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| 3. |
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| 4. |
- Nyokabi, Simon, et al.
(författare)
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Milk quality and hygiene : Knowledge, attitudes and practices of smallholder dairy farmers in central Kenya
- 2021
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Ingår i: Food Control. - : Elsevier. - 0956-7135 .- 1873-7129. ; 130
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Tidskriftsartikel (refereegranskat)abstract
- Milk production is an important livelihood source for smallholder dairy farmers in low-to-middle-income countries (LMICs) such as Kenya. However, milk quality and safety are a challenge due to unhygienic handling and non-adherence to food safety standards. The objective of this study was to investigate the knowledge, attitudes and adoption of milk quality and food safety practices by smallholder farmers in Kenya. Ten Focus Group Discussions (FGDs), involving 71 smallholder farmers, were held to collect qualitative data on knowledge, attitudes and practices (KAPs) of smallholder dairy farmers in Laikipia, Nakuru, and Nyandarua counties. Additionally, data were collected through a cross-sectional administered to 652 smallholder farming households. The results of the study revealed low knowledge level and negative attitudes towards respecting antibiotics treatment withdrawal periods, milk quality standards and food safety regulations. Farmers stated they had received low levels of training on milk quality and safety standards. The majority of farmers adopted animal health measures and hygienic measures such as hand washing and udder cleaning. However, unhygienic milking environments, the use of plastic containers, the use of untreated water, and lack of teat dipping compromised milk quality and safety. Currently, milk production, handling and consumption could expose actors along the dairy value chain to health risks. The adoption of milk quality and food safety practices was influenced by farmers' knowledge, socioeconomic characteristics, and choice of marketing channel. There is a need to improve farmers' knowledge and attitudes and implement hygienic control, disease control and antibiotic residue control practices in the milk production process to meet required milk quality and food safety standards. Awareness campaigns and training programmes for smallholder dairy farmers could foster behavioural change and lead to an improvement in milk quality in Kenya.
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| 5. |
- Nyokabi, Simon N., et al.
(författare)
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Milk quality along dairy farming systems and associated value chains in Kenya : An analysis of composition, contamination and adulteration
- 2021
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Ingår i: Food Control. - : Elsevier. - 0956-7135 .- 1873-7129. ; 119
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Tidskriftsartikel (refereegranskat)abstract
- Poor milk safety constitutes a persistent public health risk in Kenya. Poor milk composition, microbial contamination and adulteration is a constraint to dairy sector development. We hypothesise that variation in milk quality and safety depends on variation between farming systems. We argue that this variation between farming systems is associated with spatial location which affects the agro-ecological conditions and the avail-ability of labour and land. We used a spatial framework based on the distance to urban markets to distinguish the following farming systems: relatively intensive dairy systems in urban locations (UL), semi-intensive dairy systems in mid-rural locations (MRL) and extensive dairy systems in extreme rural locations (ERL). We aimed to investigate the variation in the quality of raw milk in these dairy farming systems and associated value chains in central Kenya. For this reason, we combined several methods such as participatory rural appraisal, participant observation, and milk physicochemical and microbiological analyses to collect data. Milk samples were collected at the informal and informal value chain nodes farms, informal collection centres, informal retailing centres including milk vending machines, and formal bulking centres where milk changes hands between value chain actors. Milk quality was compared to standards recommended by the Kenya Bureau of Standards (KeBS). There were no differences in the quality of raw milk between locations or between nodes. The overall milk physicochemical composition means (standard error) of the milk were within KeBS standards: fat 3.61 (0.05), protein 3.46 (0.06), solid-not fats 9.18 (0.04), density 1.031 (0.0002) and freezing point-0.597 (0.019). The protein percentage was below KeBS standards at all value chain nodes, except at the formal bulking node. There was significant contamination of milk samples: 16.7% of samples had added water, 8.8% had somatic cell count SCC above 300,000, 42.4% had E. coli, 47.9% had Pseudomonas spp., 3.3% had Staphylococcus spp. and 2.9% tested positive for brucellosis antibodies. Unsanitary milk handling practices were observed at farms and all value chains nodes. Milk physicochemical composition except for protein content meets the KeBS Standard. High levels of microbial contamination of milk pose a public health risk to consumers and show that urgent action is needed to improve milk quality.
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| 6. |
- von Korff Schmising, C., et al.
(författare)
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Imaging Non-Local Magnetization Dynamics
- 2016
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Ingår i: Synchrotron Radiation News. - : Informa UK Limited. - 0894-0886 .- 1931-7344. ; 29:3, s. 26-31
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Tidskriftsartikel (refereegranskat)abstract
- Many fundamental processes in magnetism take place on a nanometer length and sub-picosecond time scale. An important example of such phenomena in magnetism is ultrafast, spin-polarized transport of laser-excited hot electrons, which is now being recognized as playing a crucial role for novel spintronic devices and for optically induced magnetic switching. Recent experimental examples include the demonstration of all-optical helicity dependent control of spin-polarized currents at interfaces [1], the design of novel and efficient terahertz emitters [2], and nanoscale spin reversal in chemically heterogeneous GdFeCo driven by non-local transfer of angular momentum [3]. In particular, for advanced information technologies with bit densities already exceeding 1 terabit per square inch with bit cell dimensions of (15 × 38 nm2) [4], it is of fundamental importance to understand and eventually control the mechanisms responsible for optically induced spin dynamics on the nanoscale.
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| 7. |
- Broitman, E., et al.
(författare)
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Structural and mechanical properties of diamond-like carbon films deposited by direct current magnetron sputtering
- 2003
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 21:4, s. 851-859
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Tidskriftsartikel (refereegranskat)abstract
- A systematic study of physical properties of sputter-deposited DLC films was performed as a function of flux ratio and ion energy. The energy and flux ions and neutral atoms impinging on the surface of the growing films were deduced from Langmuir probe measurements and theoretical calculations. The bombardment of growing films by the energetic particles led to changes in microstructure and mechanical properties. Results suggest that the presence of defective graphite formed by subplanted C and Ar atoms is the dominant influence on the mechanical properties of the DLC films.
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| 8. |
- Ekholm, V., et al.
(författare)
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Core-hole localization and ultra-fast dissociation in SF6
- 2020
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 53:18
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Tidskriftsartikel (refereegranskat)abstract
- Resonant inelastic x-ray scattering spectra excited at the fluorine K resonances of SF(6)have been recorded. While a small but significant propensity for electronically parity-allowed transitions is found, the observation of parity-forbidden electronic transitions is attributed to vibronic coupling that breaks the global inversion symmetry of the electronic wavefunction and localizes the core hole. The dependence of the scattering cross section on the polarization of the incident radiation and the scattering angle is interpreted in terms of local pi/sigma symmetry around the S-F bond. This symmetry selectivity prevails during the dissociation that occurs during the scattering process.
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| 9. |
- Fisher, Eleanor, et al.
(författare)
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Gold Matters : Visualizing Mining Worlds
- 2023
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Bok (populärvet., debatt m.m.)abstract
- A book of photographs that centre on visualizing mining worlds, notably the worlds of artisanal and small-scale gold miners working in the Brazilian and Surinamese Amazon, and in parts of West and East Africa. Often this gold mining is portrayed in negative, stereotyped, and homogenizing ways. Since miners typically operate in the shadows of the law, their lifeways are remote from the public eye. Visualization by means of photgraphy helps bring to light the diversity of mining terrains and the close connections between miners and these terrains. Images presented in the book are the result of collaboration with gold miners for a project "Sustainability Transformations in Artisanal and Small-scale Gold Mining: Trans-Regional and Multi-Actor Perspectives" (2018-2022).
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| 10. |
- Fisher, Eleanor, et al.
(författare)
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The lifeways of small-scale gold miners : Addressing sustainability transformations
- 2023
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Ingår i: Global Environmental Change. - 0959-3780 .- 1872-9495. ; 82
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Tidskriftsartikel (refereegranskat)abstract
- Small-scale gold mining sustains millions of people’s lives and yet it stimulates environmental harms and social conflicts. Global environmental crises drive calls for fundamental change to how people live on the planet. For small-scale gold mining, this raises questions about whether current dynamics can provide a basis for sustainability transformations. Proposing the notion of gold lifeways to focus on the lived experience of mining and gold resources as relational phenomena, we ask what sustainability looks like from different miners’ perspectives and probe the practice dynamics of current transformation. Our methodology is social science-led and transdisciplinary. From multi-sited and trans-regional research between South America and Africa, we draw cases from Suriname, Guinea Conakry, and Uganda. Our study finds that gold lifeways give expression to different strands of sustainability: sustaining everyday life in mining; discourses framing mining practices; and government repression of mining. Hence, as our empirical data demonstrates, miner perspectives on sustainability gain content not in isolation, but as part of gold lifeways embedded within different contexts and shaped by societal dynamics. Ultimately, the transformative potency of small-scale gold mining is located in personal lives and precarious dynamics rather than glittering promises of a sustainable future.
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