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1.
Int J Biol Macromol ; 180: 392-402, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-33737185

ABSTRACT

The present work focuses on the development of cellulose nanofibrils (CNF) film that derived from sustainable biomass resources, which potentially to work as bio-based conductive membranes that assembled into supercapacitors. The chemically purified cellulose was isolated from different parts of coconut (coconut shell and its husk) and further subjected to 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation for CNF preparation. Physicochemical properties of prepared CNFs were studied in terms of chemical characteristics & crystallinity, surface functionalities, surface morphology, and thermal properties. Both coconut shell-derived CNF and coconut husk-derived CNF fulfilled with nanocellulose's characteristics with fibres width ranged of 70-120 nm and 150-330 nm, respectively. CNF films were further prepared by solvent casting method to measure the modulus elasticity, piezoelectric and dielectric properties of the films. Mechanical study indicated that coconut shell-derived CNF film showed a higher value of elastic modulus than the coconut husk-derived CNF film, which was 8.39 GPa and 5.36 GPa, respectively. The effectiveness of electrical aspects for CNF films are well correlated with the crystallinity and thermal properties, associated with it's composition of different coconut's part.


Subject(s)
Cellulose/chemistry , Cocos/chemistry , Cyclic N-Oxides/chemistry , Nanofibers/chemistry , Biomass , Crystallization , Elastic Modulus , Electric Capacitance , Electric Conductivity , Oxidation-Reduction , Temperature , Tensile Strength
2.
RSC Adv ; 10(9): 4996-5009, 2020 Jan 29.
Article in English | MEDLINE | ID: mdl-35498286

ABSTRACT

Untreated waste cooking oil (WCO) with significant levels of water and fatty acids (FFAs) was deoxygenated over Co3O4-La2O3/ACnano catalysts under an inert flow of N2 in a micro-batch closed system for the production of green diesel. The primary reaction mechanism was found to be the decarbonylation/decarboxylation (deCOx) pathway in the Co3O4-La2O3/ACnano-catalyzed reaction. The effect of cobalt doping, catalyst loading, different deoxygenation (DO) systems, temperature and time were investigated. The results indicated that among the various cobalt doping levels (between 5 and 25 wt%), the maximum catalytic activity was exhibited with the Co : La ratio of 20 : 20 wt/wt% DO under N2 flow, which yielded 58% hydrocarbons with majority diesel-range (n-(C15 + C17)) selectivity (∼63%), using 3 wt% catalyst loading at a temperature of 350 °C within 180 min. Interestingly, 1 wt% of catalyst in the micro-batch closed system yielded 96% hydrocarbons with 93% n-(C15 + C17) selectivity within 60 min at 330 °C, 38.4 wt% FFA and 5% water content. An examination of the WCO under a series of FFA (0-20%) and water contents (0.5-20 wt%) indicated an enhanced yield of green diesel, and increased involvement of the deCOx mechanism. A high water content was found to increase the decomposition of triglycerides into FFAs and promote the DO reaction. The present work demonstrates that WCO with significant levels of water and FFAs generated by the food industry can provide an economical and naturally replenished raw material for the production of diesel.

3.
ScientificWorldJournal ; 2014: 631013, 2014.
Article in English | MEDLINE | ID: mdl-25247208

ABSTRACT

Lignocellulosic biomass is a complex biopolymer that is primary composed of cellulose, hemicellulose, and lignin. The presence of cellulose in biomass is able to depolymerise into nanodimension biomaterial, with exceptional mechanical properties for biocomposites, pharmaceutical carriers, and electronic substrate's application. However, the entangled biomass ultrastructure consists of inherent properties, such as strong lignin layers, low cellulose accessibility to chemicals, and high cellulose crystallinity, which inhibit the digestibility of the biomass for cellulose extraction. This situation offers both challenges and promises for the biomass biorefinery development to utilize the cellulose from lignocellulosic biomass. Thus, multistep biorefinery processes are necessary to ensure the deconstruction of noncellulosic content in lignocellulosic biomass, while maintaining cellulose product for further hydrolysis into nanocellulose material. In this review, we discuss the molecular structure basis for biomass recalcitrance, reengineering process of lignocellulosic biomass into nanocellulose via chemical, and novel catalytic approaches. Furthermore, review on catalyst design to overcome key barriers regarding the natural resistance of biomass will be presented herein.


Subject(s)
Biomass , Cellulose/chemistry , Lignin/chemistry , Nanoparticles/chemistry , Cell Wall/chemistry , Cell Wall/metabolism , Cellulose/metabolism , Chemical Phenomena , Lignin/metabolism , Nanoparticles/metabolism , Polysaccharides/chemistry , Polysaccharides/metabolism
4.
J Exp Psychol Learn Mem Cogn ; 40(5): 1244-56, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24933702

ABSTRACT

Verbal overshadowing reflects the impairment in memory performance following verbalization of nonverbal stimuli. However, it is not clear whether the same mechanisms are responsible for verbal overshadowing effects observed with different stimuli and task demands. In the present article, we propose a multiprocess view that reconciles the main theoretical explanations of verbal overshadowing deriving from the use of different paradigms. Within a single paradigm, we manipulated both the nature of verbalization at encoding (nameability of the stimuli) and postencoding (verbal descriptions), as well as the nature (image transformation or recognition) and, by implication, the demands of the final memory task (global or featural). Results from 3 experiments replicated the negative effects of encoding and postencoding verbalization in imagery and recognition tasks, respectively. However, they also showed that the demands of the final memory task can modulate or even reverse verbal overshadowing effects due to both postencoding verbalization and naming during encoding.


Subject(s)
Pattern Recognition, Visual/physiology , Recognition, Psychology/physiology , Verbal Behavior/physiology , Emotions/physiology , Female , Humans , Imagination/physiology , Male , Neuropsychological Tests , Young Adult
5.
Psychon Bull Rev ; 12(6): 1032-7, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16615324

ABSTRACT

In this study, participants rated previously unseen faces on six dimensions: familiarity, distinctiveness, attractiveness, memorability, typicality, and resemblance to a familiar person. The faces were then presented again in a recognition test in which participants assigned their positive recognition decisions to either remember (R), know (K), or guess categories. On all dimensions except typicality, faces that were categorized as R responses were associated with significantly higher ratings than were faces categorized as K responses. Study ratings for R and K responses were then subjected to a principal components analysis. The factor loadings suggested that R responses were influenced primarily by the distinctiveness of faces, but K responses were influenced by moderate ratings on all six dimensions. These findings indicate that the structural features of a face influence the subjective experience of recognition.


Subject(s)
Face , Facial Expression , Mental Recall , Pattern Recognition, Visual , Humans
6.
Int J Artif Organs ; 22(11): 769-77, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10612305

ABSTRACT

There is a need to develop human hepatocyte cell lines which retain both replicating capacity and highly differentiated functions to facilitate the development of an efficient bioartificial liver. The present study was undertaken to differentiate, using sodium butyrate, the actively replicating immortalized human liver cell line. The effects of butyrate on cell growth and cell cycle were analyzed, and the albumin synthesis, cytochrome P450 and ammonia-detoxifying activity of the butyrate-treated cells were measured. Butyrate treatment resulted in G2/M arrest of the cell cycle and polygonal changes in the cell morphology. Neither the control nor the butyrate-treated cells showed transformed characteristics. Butyrate treatment increased the amount of albumin secretion, cytochrome P450 activity, and the urea production rate of the cells. The present study provides non-transformed human hepatocytes, which can replicate unlimitedly and then restore differentiated hepatocyte-specific functions by butyrate, and therefore, have applications for the development of an efficient bioartificial liver.


Subject(s)
Butyrates/pharmacology , Liver, Artificial , Liver/cytology , Urea/metabolism , Albumins/metabolism , Animals , Cell Cycle/drug effects , Cell Differentiation , Cell Division/drug effects , Cell Line , Cytochrome P-450 Enzyme System/metabolism , Flow Cytometry , Humans , Mice , Mice, Nude , alpha-Fetoproteins/biosynthesis
7.
Life Sci ; 53(10): 811-9, 1993.
Article in English | MEDLINE | ID: mdl-8355567

ABSTRACT

16 beta-[18F]Fluoromoxestrol (beta FMOX, 1) is a highly selective, metabolically stable estrogen with potential as a receptor imaging agent. It demonstrates receptor-mediated uptake in the immature rat in the estrogen receptor-rich primary target tissues, uterus and ovaries, as well as, in receptor-poor secondary target tissues, muscle, thymus and kidneys; uptake in the uterus is nearly four times that of the clinically useful 16 alpha-[18F]fluoroestradiol (FES), most likely due to the extended lifetime of the labeled beta FMOX in the blood afforded by its relatively slow metabolism. In vivo and in vitro studies demonstrate a nearly four-fold decrease in metabolism rate between beta FMOX and FES. Dosimetry studies indicate radiation absorbed doses comparable to FES. beta FMOX possesses desirable imaging characteristics and may prove to be a clinically useful imaging agent.


Subject(s)
Breast Neoplasms/diagnostic imaging , Breast Neoplasms/ultrastructure , Ethinyl Estradiol/analogs & derivatives , Receptors, Estrogen/analysis , Animals , Female , Fluorine Radioisotopes , Humans , Liver/cytology , Liver/metabolism , Rats , Rats, Sprague-Dawley , Tomography, Emission-Computed
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