| 1 | Isolation of Thermally Stable Cellulose Nanocrystals from Spent Coffee Grounds via Phosphoric Acid Hydrolysis显示文摘As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This rapid growth in food production results in an ever increasing amount of agricultural wastes,of which already occupies nearly 50%of the total landfill area.For example,is the billions of dry tons of cellulose-containing spent coffee grounds disposed in landfills annually.This paper seeks to provide a method for isolating cellulose nanocrystals(CNCs)from spent coffee grounds,in order to recycle and utilize the cellulosic waste material which would otherwise have no applications.CNCs have already been shown to have vast applications in the polymer engineering field,mainly utilized for their high strength to weight ratio for reinforcement of polymer-based nanocomposites.A successful method of purifying and hydrolyzing the spent coffee grounds in order to isolate usable CNCs was established.The CNCs were then characterized using current techniques to determine important chemical and physical properties.A few crucial properties determined were aspect ratio of 12±3,crystallinity of 74.2%,surface charge density of(48.4±6.2)mM/kg cellulose,and the ability to successfully reinforce a polymer based nanocomposite.These characteristics compare well to other literature data and common commercial sources of CNCs. | Brody A.Frost E.Johan Foster | 2020 | Journal of Renewable Materials2020，8，2： | 1 |
| 3 | Robust Adaptive Model Tracking for Distributed Parameter Control of Linear Infinite-dimensional Systems in Hilbert Space显示文摘This paper is focused on adaptively controlling a linear infinite-dimensional system to track a finite-dimensional reference model.Given a linear continuous-time infinite-dimensional plant on a Hilbert space with disturbances of known waveform but unknown amplitude and phase,we show that there exists a stabilizing direct model reference adaptive control law with the properties of certain disturbance rejection and robustness.The plant is described by a closed,densely defined linear operator that generates a continuous semigroup of bounded operators on the Hilbert space of states.The central result will show that all errors will converge to a prescribed neighborhood of zero in an infinitedimensional Hilbert space.The result will not require the use of the standard Barbalat’s lemma which requires certain signals to be uniformly continuous.This result is used to determine conditions under which a linear infinite-dimensional system can be directly adaptively controlled to follow a reference model.In particular,we examine conditions for a set of ideal trajectories to exist for the tracking problem.Our results are applied to adaptive control of general linear diffusion systems described by self-adjoint operators with compact resolvent. | Mark J.Balas Susan A.Frost | 2014 | IEEE/CAA Journal of Automatica Sinica2014，1，3： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员