| 114391. |
- Baker, Darren A., et al.
(författare)
-
Opportunities in lignin based carbon fibre
- 2015
-
Ingår i: NWBC 2015. - Espoo : VTT. - 9789513883539 ; , s. 244-251
-
Konferensbidrag (refereegranskat)abstract
- Innventia AB's LignoBoost process enables the extraction of high purity lignin efficiently from the black liquor in kraft mills. A stream of black liquor is taken from the evaporation plant and the lignin is precipitated by acidification and filtered. The filter cake is redispersed and acidified and the resulting slurry is filtered and washed. High purity lignin can be produced at several scales, namely 10g, 1kg, 10kg and over 1,000kg. Innventia has invested significantly to demonstrate the potential of lignin as a viable feedstock for carbon fibre manufacture. Initially, the fibre melt spinning performance of the lignin is assessed using single filament melt extrusion and then melt spinning is performed at the multifilament scale, where fine fibres can be produced for conversion to carbon fibre. Oxidative thermostabilisation of the lignin fibres is carried out so that carbonisation can proceed. The effects of thermal treatment programmes and tensioning have been studied by using either thermomechanical analysis or by using test equipment specially designed to monitor carbonisation profiles with either stress or strain control. In addition, continuous processes for the conversion of lignin fibre to carbon fibre are being developed.
|
|
| 114392. |
- Baker, Darren A, et al.
(författare)
-
Structural carbon fibre from kraft lignin
- 2017
-
Ingår i: The 7th Nordic Wood Biorefinery Conference held in Stockholm, Sweden, 28-30 Mar. 2017. - Stockholm : RISE Bioekonomi. - 9789186018207 ; , s. 65-67
-
Konferensbidrag (refereegranskat)abstract
- The GreenLight consortium is working to demonstrate a biobased, renewable and economically viable carbon fibre from lignin. The aim is to provide a basis for commercial production of lignin, lignin filaments, carbon fibre and carbon fibre composites. The most difficult boundary to success in the developing lignin as a precursor for continuous filament carbon fibre has been identified as melt extrusion of lignin. The consortium is working to develop a robust melt spinning platform for use up to the 1,000 filament scale. Methodical studies have been performed to examine lignin separation from differing black liquors derived from both softwood and hardwood and assess their viability in terms of thermal, compositional and structural properties. The move will then be made to pilot scale melt spinning at the 100 filament scale. The characteristics of some kraft lignin fractions obtained from the same Sodra Monsteras softwood kraft black liquor have been studied. The lignins were manufactured in quantities of approximately 10-20kg. Several variations of the LignoBoost process were used to provide lignins with improved melt spinning properties. The lignins were of high purity, each having low carbohydrate, extractives and inorganic contents. All four lignins could be melt spun and converted to carbon fibre.
|
|
| 114393. |
|
|
| 114394. |
|
|
| 114395. |
- Baker, DJ, et al.
(författare)
-
Glycogen phosphorylase inhibition in type 2 diabetes therapy: a systematic evaluation of metabolic and functional effects in rat skeletal muscle
- 2005
-
Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 54:8, s. 2453-2459
-
Tidskriftsartikel (refereegranskat)abstract
- Inhibition of hepatic glycogen phosphorylase is a promising treatment strategy for attenuating hyperglycemia in type 2 diabetes. Crystallographic studies indicate, however, that selectivity between glycogen phosphorylase in skeletal muscle and liver is unlikely to be achieved. Furthermore, glycogen phosphorylase activity is critical for normal skeletal muscle function, and thus fatigue may represent a major development hurdle for this therapeutic strategy. We have carried out the first systematic evaluation of this important issue. The rat gastrocnemius-plantaris-soleus (GPS) muscle was isolated and perfused with a red cell suspension, containing 3 μmol/l glycogen phosphorylase inhibitor (GPi) or vehicle (control). After 60 min, the GPS muscle was snap-frozen (rest, n = 11 per group) or underwent 20 s of maximal contraction (n = 8, control; n = 9, GPi) or 10 min of submaximal contraction (n = 10 per group). GPi pretreatment reduced the activation of the glycogen phosphorylase a form by 16% at rest, 25% after 20 s, and 44% after 10 min of contraction compared with the corresponding control. AMP-mediated glycogen phosphorylase activation was impaired only at 10 min (by 21%). GPi transiently reduced muscle lactate production during contraction, but other than this, muscle energy metabolism and function remained unaffected at both contraction intensities. These data indicate that glycogen phosphorylase inhibition aimed at attenuating hyperglycaemia is unlikely to negatively impact muscle metabolic and functional capacity.
|
|
| 114396. |
- Baker, Darren, et al.
(författare)
-
Lignin-based carbon fiber : effect of softwood kraft lignin separation method on multifilament melt-spinning performance and conversion
- 2019
-
Ingår i: 20th International symposium on wood, fiber, and pulping chemistry.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A reference lignin separated from an industrial softwood kraft black liquor via an improved LignoBoost process was compared to four other lignins derived from the same liquor. The four lignins were produced by using a) pH-fractionation within the LignoBoost process, b) ultrafiltration of black liquor prior to the LignoBoost process, and c) solvent leaching of the reference lignin using methanol and d) ethanol.Lignin compositional characteristics and thermal properties were compared, and monofilament extrusion used to assess their potential for successful melt spinning at the 24 filament scale. The lignin prepared by ethanol leaching of the reference lignin was found to be most appropriate for potential pilot scale fibre production. This was owing to a high purity, lower comparative glass transition temperature (Tg), and good spinning performance.Thermal pretreatments of the ethanol leached lignin gave a selection of enhanced lignins which were characterized for comparison, and melt spun on pilot multifilament equipment. The enhanced lignins could be continuously melt spun giving filaments with diameters as low as 10 μm and with minimal defects. Conversion of selected filaments provided carbon fibres with a tensile strength of 1259 ± 159 MPa, tensile modulus of 67 ± 3 GPa and diameter of 7.3 ± 0.5 μm.
|
|
| 114397. |
|
|
| 114398. |
- Baker, Dan, et al.
(författare)
-
Structure-borne Road Noise Target Allocation to Tire-Wheel Subsystem in Autonomous Vehicles
- 2023
-
Ingår i: Aachen Acoustics Colloquium.
-
Konferensbidrag (refereegranskat)abstract
- Personal transportation as we know it is being reimagined thanks to the introduction of autonomous electric vehicles. With autonomous vehicles (AV) on the rise, especially for Transportation Network Companies (TNC), it is expected that the experience inside of the vehicle cabin will be tailored engineered for riders, not drivers. As a result, customer-facing attributes such as noise, vibration, and harshness (NVH) will need to be considered with a new perspective. Of the many challenges in developing NVH performance of an AV, road noise and component noise have, and continue, to require the most amount of development and refinement effort. It is well known that a critical component in the chain from the tire-road interface to the occupant’s ears is the tire-wheel assembly and, therefore, allocating targets for this subsystem is essential. When in motion, the tire-wheel system possesses complex structural-acoustic properties like centrifugal, gyroscopic, fluid-structure coupling, pre-load effects, and excitation that may be described by random enforced motion at the tire contact patch and road interface. Component targets are derived by experimental and virtual methods, enabling simulation-driven product development. For tire testing and development, experimental methods are often limited by the availability of complex and expensive test infrastructure. An alternative approach is explored in order to develop tire-wheel subsystem targets using experimental tests and virtual methods applying transmissibility theory with multiple degrees of freedom based on frequency response functions derived at free-free boundary conditions.
|
|
| 114399. |
- Baker, DJ, et al.
(författare)
-
The experimental type 2 diabetes therapy glycogen phosphorylase inhibition can impair aerobic muscle function during prolonged contraction
- 2006
-
Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 55:6, s. 1855-1861
-
Tidskriftsartikel (refereegranskat)abstract
- Glycogen phosphorylase inhibition represents a promising strategy to suppress inappropriate hepatic glucose output, while muscle glycogen is a major source of fuel during contraction. Glycogen phosphorylase inhibitors (GPi) currently being investigated for the treatment of type 2 diabetes do not demonstrate hepatic versus muscle glycogen phosphorylase isoform selectivity and may therefore impair patient aerobic exercise capabilities. Skeletal muscle energy metabolism and function are not impaired by GPi during high-intensity contraction in rat skeletal muscle; however, it is unknown whether glycogen phosphorylase inhibitors would impair function during prolonged lower-intensity contraction. Utilizing a novel red cell–perfused rodent gastrocnemius-plantaris-soleus system, muscle was pretreated for 60 min with either 3 μmol/l free drug GPi (n = 8) or vehicle control (n = 7). During 60 min of aerobic contraction, GPi treatment resulted in ∼35% greater fatigue. Muscle glycogen phosphorylase a form (P < 0.01) and maximal activity (P < 0.01) were reduced in the GPi group, and postcontraction glycogen (121.8 ± 16.1 vs. 168.3 ± 8.5 mmol/kg dry muscle, P < 0.05) was greater. Furthermore, lower muscle lactate efflux and glucose uptake (P < 0.01), yet higher muscle Vo2, support the conclusion that carbohydrate utilization was impaired during contraction. Our data provide new confirmation that muscle glycogen plays an essential role during submaximal contraction. Given the critical role of exercise prescription in the treatment of type 2 diabetes, it will be important to monitor endurance capacity during the clinical evaluation of nonselective GPi. Alternatively, greater effort should be devoted toward the discovery of hepatic-selective GPi, hepatic-specific drug delivery strategies, and/or alternative strategies for controlling excess hepatic glucose production in type 2 diabetes.
|
|
| 114400. |
- Baker, Ethan A. G., et al.
(författare)
-
In silico tissue generation and power analysis for spatial omics
- 2023
-
Ingår i: Nature Methods. - : Springer Nature. - 1548-7091 .- 1548-7105. ; 20:3, s. 424-
-
Tidskriftsartikel (refereegranskat)abstract
- As spatially resolved multiplex profiling of RNA and proteins becomes more prominent, it is increasingly important to understand the statistical power available to test specific hypotheses when designing and interpreting such experiments. Ideally, it would be possible to create an oracle that predicts sampling requirements for generalized spatial experiments. However, the unknown number of relevant spatial features and the complexity of spatial data analysis make this challenging. Here, we enumerate multiple parameters of interest that should be considered in the design of a properly powered spatial omics study. We introduce a method for tunable in silico tissue (IST) generation and use it with spatial profiling data sets to construct an exploratory computational framework for spatial power analysis. Finally, we demonstrate that our framework can be applied across diverse spatial data modalities and tissues of interest. While we demonstrate ISTs in the context of spatial power analysis, these simulated tissues have other potential use cases, including spatial method benchmarking and optimization. This paper presents a statistical framework for power analysis of spatial omics studies, facilitated by an in silico tissue-generation method.
|
|
