Carbon fibers have been produced for the first time from a commercially available kraft lignin, without any chemical modification, by thermal spinning followed by carbonization. A fusible lignin with ...excellent spinnability to form a fine filament was produced with a thermal pretreatment under vacuum. Blending the lignin with poly(ethylene oxide) (PEO) further facilitated fiber spinning, but at PEO levels greater than 5%, the blends could not be stabilized without the individual fibers fusing together. Carbon fibers produced had an over-all yield of 45%. The tensile strength and modulus increased with decreasing fiber diameter, and are comparable to those of much smaller diameter carbon fibers produced from phenolated exploded lignins. In view of the mechanical properties, tensile 400–550 MPa and modulus 30–60 GPa, kraft lignin should be further investigated as a precursor for general grade carbon fibers.
The economics of producing cellulosic ethanol using loblolly pine, natural mixed hardwood, Eucalyptus, corn stover, and switchgrass as feedstocks was simulated in Aspen Plus using the thermochemical ...process via indirect gasification and mixed alcohol synthesis developed by NREL. Outputs from the simulation were linked to an economic analysis spreadsheet to estimate NPV, IRR, payback and to run further sensitivity analysis of the different combinations of feedstocks. Results indicate that forest-based feedstocks including loblolly pine, natural hardwood and eucalyptus may present more attractive financial returns when compared to switchgrass and corn stover, mainly due to their composition (%C, %H, %ash) and alcohol yield. Simulated alcohol yields from forest-based feedstock were significantly higher than from switchgrass and corn stover. Simulations run with switchgrass and corn stover, also demonstrated greater sensitivity to changes in ethanol price, alcohol yield, capital investment and biomass costs. Furthermore, moisture content of receiving feedstocks greatly affected the economics of the biorefinery. A difference of −
10% in the moisture content of the receiving feedstock affected the NPV of the simulated project by +
25% (with respect to central NPV of ~$192
million).
► Economics of producing cellulosic ethanol using the thermochemical process via indirect gasification and mixed alcohol synthesis developed by NREL. ► Feedstock considerably affect the economics of the biorefinery facility. ► Lower moisture content improves financial performance of the biorefinery. ► Agricultural biomass is more sensitive to changes in CAPEX, yield, price and biomass cost.
Two survey instruments measuring undergraduate students’ beliefs about bioproducts/bioenergy and related careers were developed and validated in this research study. The Beliefs about ...Bioproducts/Bioenergy (BABB) and Career Interest in Bioproducts/Bioenergy (CIBB) surveys were administered to undergraduate students enrolled in courses in a natural resources college. BABB (N = 168) and CIBB (N = 203) survey results were analyzed using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Validity and reliability were demonstrated. The BABB has two related scales, Personal (P) and Societal (S), which can be used together or separately. ANOVA and t-test analyses determined that students with majors closely related to bioproducts/bioenergy held significantly more positive personal and societal beliefs about bioproducts/bioenergy, as well as related career interests. Differences were identified based on gender, but not by race/ethnicity. Measuring student beliefs about bioproducts/bioenergy and interest in related careers may help to gauge trends and changes in beliefs that influence environmentally-related choices and support efforts to prepare a diverse workforce for the bioeconomy. The authors recommend the use of these surveys to measure the impacts of academic and professional development experiences.
In 2019 during the second long shutdown (LS2) of the CERN Large Hadron Collider, the injector chain will be upgraded, allowing the instantaneous luminosity of the colliding beams to reach 2⋅1034 ...cm−2s−1 during the next run (Run 3). The physics program of the LHC experiments will benefit from the augmented luminosity; the sensitivity CMS experiment to the new physics and to Standard Model will be fully exploited, providing that a suitable upgrade will enable the CMS detector to cope the Run 3 data-taking conditions. Among the upgrades, the installation of a new station based on GEM technology (GE1/1), in the endcap of the Muon System will start in early 2019. The CMS GEM Collaboration is working on the production of the 144 GEM detectors to be installed, sharing the assembly and testing of the detectors among several production sites spread all over the world. A detailed common assembly protocol and quality control procedure (QC) has been deployed, with the ambitious goal to ensure standardization of the performance of the detectors produced by the different sites. In this contribution the results of the QC tests performed on the GEM chambers, assembled by the production sites following the common specification parameters, will be presented.
•In 2019 the LHC instantaneous luminosity will reach twice the design value.•To fully exploit it, CMS detector will be equipped with a new GEM based muon station.•The CMS GEM Collaboration is working on the production of the 144 GEM detectors.•A detailed common assembly protocol and quality control procedure has been deployed.•Characterization of the GEM chambers, assembled following this procedure, is presented.
► Economics of producing cellulosic ethanol and bio-power in the same facility using an autohydrolysis process. ► Feedstock considerably affect the economics of the biorefinery facility. ► Lower ...moisture content improves financial performance of the bio-power business.
A process economic analysis of co-producing bioethanol and electricity (value prior to combustion) from mixed southern hardwood and southern yellow pine is presented. Bioethanol is produced by extracting carbohydrates from wood via autohydrolysis, membrane separation of byproducts, enzymatic hydrolysis of extracted oligomers and fermentation to ethanol. The residual solids after autohydrolysis are pressed and burned in a power boiler to generate steam and electricity. A base case scenario of biomass combustion to produce electricity is presented as a reference to understand the basics of bio-power generation economics. For the base case, minimum electricity revenue of $70–$96/MWh must be realized to achieve a 6–12% internal rate of return. In the alternative co-production cases, the ethanol facility is treated as a separate business entity that purchases power and steam from the biomass power plant. Minimum ethanol revenue required to achieve a 12% internal rate of return was estimated to be $0.84–$1.05/l for hardwood and $0.74–$0.85/l for softwood. Based on current market conditions and an assumed future ethanol selling price of $0.65/l, the co-production of cellulosic bioethanol and power does not produce financeable returns. A risk analysis indicates that there is a probability of 26.6% to achieve an internal rate of return equal or higher than 12%. It is suggested that focus be placed on improving yield and reducing CAPEX before this technology can be applied commercially. This modeling approach is a robust method to evaluate economic feasibility of integrated production of bio-power and other products based on extracted hemicellulose.
Diamond-Like Carbon for the Fast Timing MPGD Colaleo, A.; De Robertis, G.; Licciulli, F. ...
Journal of physics. Conference series,
04/2020, Letnik:
1498, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The present generation of Micro-Pattern Gaseous Detectors (MPGDs) are radiation hard detectors, capable of detecting effciently particle rates of several MHz/cm2, while exhibiting good spatial ...resolution (≤ 50 µm) and modest time resolution of 5-10 ns, which satisfies the current generation of experiments (High Luminosity LHC upgrades of CMS and ATLAS) but it is not sufficient for bunch crossing identification of fast timing systems at FCC-hh. Thanks to the application of thin resistive films such as Diamond-Like Carbon (DLC) a new detector concept was conceived: Fast Timing MPGD (FTM). In the FTM the drift volume of the detector has been divided in several layers each with their own amplification structure. The use of resistive electrodes makes the entire structure transparent for electrical signals. After some first initial encouraging results, progress has been slowed down due to problems with the wet-etching of DLC-coated polyimide foils. To solve these problems a more in-depth knowledge of the internal stress of the DLC together with the DLC-polyimide adhesion is required. We will report on the production of DLC films produced in Italy with Ion Beam Sputtering and Pulsed Laser Deposition, where we are searching to improve the adhesion of the thin DLC films, combined with a very high uniformity of the resistivity values.
High strength/weight ratio and effective corrosion resistance are primary reasons to use titanium alloys replacing steel and aluminum in some aeronautical components. However, titanium alloys have ...poor tribological properties, which reduce devices performance under friction; making surface treatments a requirement to improve wear. Thermal spray coatings have attractive characteristics as high hardness and strong coating/substrate adhesion. Compared with thermal spray processes, the High Velocity Oxygen Fuel (HVOF) presents less porosity and oxide contents due to the lower flame temperature used in the process operation.
Electroplated coatings used to improved abrasive wear and corrosion properties, affects negatively the fatigue strength, providing lower results than those for uncoated parts. To increase fatigue strength of coated materials, techniques as compressive residual stresses induced by shot peening are used.
In this study the influence of WC–10%Co–4%Cr coating deposited by HVOF on the fatigue strength of Ti–6Al–4V alloy was evaluated. Comparison of fatigue strength of coated specimens and base material shows also a decrease when parts are coated. It was observed that the influence is more significant in high cycle fatigue tests. The shot peening prior to the thermal spray coating is an efficient surface treatment to improve fatigue resistance of coated Ti–6Al–4V. Scanning electron microscopy technique (SEM) was used to observe crack origin sites and thickness in all the coatings.
Methods to improve the physical properties of recycled paper can greatly enhance its potential applications, especially for packaging. This study aimed to understand the effect of refining, cationic ...starch addition, and cellulosic nanofibers (CNF) generated from old corrugated containers (OCC) addition with recycled OCC on tensile index (TI) and ring crush index (RCI). Linerboard from OCC made on an industrial paper machine was compared with the lab prepared handsheets, and the results indicated that the lab procedure including the refining step produced board reflective of the industrially made linerboard. CNF addition was observed to decrease the drainage rate of the unrefined OCC pulp stock but not significantly when the OCC pulp stock was refined to a freeness of 300 mL CSF. The results of a statistically designed experiment showed that cationic starch, refining, and the interaction between cationic starch and CNF were significant parameters that improve TI. Through experiments that measured the retention of the pulp stock, it was determined that CNF retention was only 44.8% without cationic starch and increased to 90.0% with cationic starch present, thus explaining their interaction. This study indicates that CNF from OCC can be combined with cationic starch at appropriate levels to improve properties of the resulting board without critically decreasing the drainage rate.
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