6,091 research outputs found
Silica‐immobilized cumyl dithiobenzoate as mediating agent in reversible addition fragmentation chain transfer (RAFT) polymerization
No full textReversible addition fragmentation chain transfer (RAFT) polymerizations of styrene and methyl methacrylate were performed in bulk at 60 degrees C, using cumyl dithiobenzoate as the mediating RAFT agent that has been immobilized via the stabilizing Z-group to nanometer-sized fumed silica particles. Increasing molecular weights with monomer conversion and absence of conventional polymerization activity in the interstitial solution phase were observed when the overall concentration of silica particles was carefully balanced with their respective cumyl dithiobenzoate loading. After completion of the polymerization, potentially sulfur-free polymers with controlled molecular weights were obtained, initially via collecting the terminated polymeric material from the interstitial solution phase and, secondly, via cleavage of the surface-confined polymer by a single addition fragmentation chain transfer step, which provides a pathway for recovery of the solid-supported RAFT agent. Copyright (c) 2006 John Wiley & Sons, Ltd
Beth Nguyen: 47th Annual ODU Literary Festival
No full textBeth Nguyen is the author of the recent memoir Owner of a Lonely Heart, which was a New York Times Editors’ Choice Pick, as well as the memoir Stealing Buddha’s Dinner, and two novels. She has received an American Book Award and a PEN/Jerard Award and her work has appeared in publications including The New Yorker, The Paris Review, Time, and Best American Essays. She teaches at the University of Wisconsin–Madison, where she also directs the MFA Program in Creative Writing
On the mechanism of radical polymerization of methyl methacrylate with dithiobenzoic acid as mediator
No full textDithiobenzoic acid (DTBA) induces controlled polymerization behaviour in methyl methacrylate polymerization at 60 degrees C, accompanied by a pronounced induction period of several hours. DTBA is partially transformed during this induction period into a dithioester with a tertiary ester group moiety, which constitutes an efficient reversible addition-fragmentation chain transfer (RAFT) agent. The transformation reaction is proposed to proceed via a hydrogen abstraction from DTBA by radicals and subsequent termination of the formed phenylcarbonothioylsulfanyl radical with propagating radicals. The proposed reaction scheme was implemented into a computer model, by which the rate coefficient of the hydrogen abstraction from DTBA and of the reinitiation of the intermediate phenylcarbonothioylsulfanyl radical was estimated. The model is in agreement with all of the species observable by electrospray ionization mass spectrometry, with the extent of the experimental induction periods, and with the absolute concentrations of dithioesters that act as efficient RAFT agents during the polymerization. A protocol that uses a cocktail of initiators is introduced, by which the induction period in DTBA-mediated polymerization is effectively eliminated
Suggestions for improvement in Vietnam employment laws in the context of gender equality
No full text5 p.Improving gender equality in the workplace is an urgent task for Vietnam Communist Party and the Government. Despite the ratification of international conventions on labour, women rights, as well as amendment to relevant domestic laws, it appears that the provisions have not satisfied the requirements set forth to combat discrimination at work against women. Through this article, the author intends to propose some ideas to improve the laws on the protection of the current female workers’ rights based on the 2012 Labour Code (amended and supplemented in 2019), related laws and sub–law documents
Citizen's Satisfaction With Public Administrative Services At The One-Stop Shop Of Districts In Thai Nguyen Province, Viet Nam
No full textThe research was conducted to determine the factors affecting Citizens's satisfaction with public administrative services in the one-stop department of districts in Thai Nguyen Province. The study is based on the survey data of 324 citizens. Data analysis method through SPSS software with descriptive statistical tools, test scale with Cronbach alpha coefficients, discovery factor analysis (EFA) and Regression analysis was performed to clarify the problems related to the research hypothesis. The Regression model consisting of six variables: Capacity of civil servants, Service attitude of civil servants, Facilities, Work assignment process, Time and Cost is used to identify the factors that affect Citizens's satisfaction. The research results show that the variables in the model have a positive relationship with Citizens's satisfaction. In particular, the Capacity of civil servant factor has the highest Beta coefficient of 0.303. From the research results, the author also proposed a number of solutions to improve the satisfaction of citizens at the One-stop shop of districts in Thai Nguyen Provinc
Unifying Access and Resource Usage Control over Standard Client-Server Interactions
No full textWe propose a novel framework for integrated access and resource usage control over standard clientserver interactions. Historically, access control has been developed without considering resource usage. Resource control has thus developed as an ad hoc server-centric set of mechanisms (e.g., file system quota, network bandwidth quote, etc.). We believe that resource usage control is strongly related to access control and so should be implemented using a unified, global enforcement framework. We introduce such a framework, where services have resource usage constraints and principals have resource usage histories. To access and use a service, a principal must have the appropriate access and sufficient resource usage rights when considering its usage history. Our framework is able to enforce global stateful policies, yet do not require changes to existing message-passing applications. We have built a prototype and used it to specify and enforce an example policy that includes role-based control and delegation. We applied our system to control access and resource usage for three different services, network, DNS, and SMB file systems, to demonstrate its effectiveness and wide applicability.Technical report DCS-TR-67
Litinium quangi Tchesunov, Nguyen Dinh Tu & Nguyen Vu Thanh, sp. n.
No full textLitinium quangi Tchesunov, Nguyen Dinh Tu & Nguyen Vu Thanh sp. n. Figs 1, 2, Table 1 Material. Holotype male, three paratype males, allotype female and paratype female. All the specimens are deposited in the Vietnam National Museum of Nature (18 Hoang Quoc Viet, Caugiay, Hanoi, Vietnam) with slide numbers VNMN.0011 (holotype male, paratype male 3 and allotype female), VNMN.0012 (paratype male 1 and paratype female 1) and VNMN.0013 (paratype male 2). Locality. South Vietnam coast, Dong Nai River Delta, Can Gio National Reserve, 10 ° 32 ' 176 ''N and 106 ° 45 ' 919 ''E, 0.5 m deep. Sediment consisted of silt and clay (80.5 %) and sand (19.5 %). NaCl content 13.5 ‰. Description. Body very long and slender, filiform. Cuticle thick, smooth over entire body. Head slightly separated off by a very slight narrowing at the level of the cephalic setae. Cuticle anterior to the amphideal fovea 1–1.3 µ m thick, posterior to the amphideal fovea 1.6–2 µ m, posterior to the cardia 2–3.4 µ m, tail terminal cuticle 3.9–4.2 µ m. Six inner labial and six outer labial sensilla equal in length and shape. Both circles united in a joint crown of twelve short setae where outer labial setae situated just posterior to inner labial setae. Four equally short cephalic setae situated separately just posterior to the amphideal foveas in area of postcephalic narrowing. Amphideal fovea large, longitudinally ovoid, with distinct cuticularised horseshoe-shaped fringe; aperture round, with very fine rim, located at anterior end of fovea. A few short ventral, subventral and lateral papillae and tiny setae situated posterior to the amphideal fovea, anterior to the excretory pore, at 62–67 µ m from anterior end. A very minute midventral seta about 1 Μ m long present 10–12 Μ m anterior to the ventral pore. No metanemes found. Mouth opening tiny. Buccal cavity not developed as such and its walls not differentiated from the cuticular lining of the pharynx. Pharynx evenly muscular and slender throughout its length but widening gradually to the posterior end. Cardia widely conical and surrounded by intestinal tissue. Midgut lumen is partially filled with mass of fine granular material. Ventral pore at about half distance from anterior end to the nerve ring, and posterior to the midventral seta. Only anterior portion of ventral gland duct discernible. Vulva situated at ~ one fifth of body length from anterior end. Single posterior antidromously reflected ovary disposed ventrally and slightly to the left of the intestine. Uterus elongate and voluminous; uterus empty in both females examined. A short spermatheca just posterior to the uterus filled densely with minute round spermatozoa. Only anterior male gonad present, situated ventrally to the intestine. Spicules short, flat, arcuate, with internal cuticular linear longitudinal stripes, with posterior ends pointed and anterior ends slightly narrowed. One short (0.8–2, µ m long) midventral precloacal seta present, just anterior to the anterior ends of the spicules, 32–35 µ m from the cloacal opening. Tail very short, rounded. Terminal pore and canal well developed, slightly subterminal. A pair of short subventral seta mid-tail length in both males and females; one ventral papilloid sensilla situated at mid-tail length discernible in some specimens. Diagnosis. Litinium. Body length 2523–2918 µ m; a 81–118; c 72.1–97.2; c' 1.12–1.63. Inner labial, outer labial, cephalic setae very short, 1.4–2.6 µ m. Amphideal fovea ovoid in outline, with horseshoe-shaped cuticular rim. Cephalic setae at level of posterior end of the amphideal fovea. One precloacal midventral supplementary seta at level of anterior endof the spicules. Character Specimens Differential diagnosis. Litinium quangi sp. n. shares the ovoid shape of the amphideal fovea having a small round aperture with L. aequale, L. curticauda, L. parmatum, L. subterraneum and Litinium sp. 1 of Quang et al. (2008) but other known species have a fovea shaped as a half moon. Litinium quangi differs from all species by having only one midventral preanal seta instead of two or more setae. The female of L. quangi differs from L. parmatum with unknown males by having smaller anterior sensilla (1.1–2.5 vs 18 µ m) and a shorter rounded tail (c' 1.12 vs 4.2, conical tail). Litinium quangi differs from the most similar and sympatric species L. sp. 1 of Quang et al. (2008) by having shorter outer labial and cephalic setae (respectively, 2.1–2.6 µ m and 1.4–2.2 µ m vs 5.2 µ m and 4.4 µ m) and one vs two midventral precloacal setae. Litinium guangi differs from L. curticauda in the number of precloacal supplementary setae and by the greater distance from the head apex to the ventral pore (68–75 µ m vs 39.5–48 µ m), shorter spicules (30–33 µ m vs 43–49 µ m), slightly longer tail (c 72.1–94.1 and c ' 1.36–1.63 vs 110–119 and 0.83–0.94, respectively). Etymology. Species name is given in honour of Dr. Quang Ngo Xuan, the first author of the paper describing several Oxystominidae species from the Can Gio mangrove forest where two unnamed Litinium species were collected.Published as part of Tchesunov, Alexei V., Thanh, Nguyen Vu & Tu, Nguyen Dinh, 2014, A review of the genus Litinium Cobb, 1920 (Nematoda: Enoplida: Oxystominidae) with descriptions of four new species from two contrasting habitats, pp. 57-74 in Zootaxa 3872 (1) on pages 60-64, DOI: 10.11646/zootaxa.3872.1.5, http://zenodo.org/record/28722
Nouvelle méthode syntagmatique de vectorisation appliquée au self-organizing map des textes vietnamiens
No full text@inproceedings{CN-NGUYEN-2004, author = {Nguyen D.T.}, title = {Nouvelle méthode syntagmatique de vectorisation appliquée au self-organizing map des textes vietnamiens}, booktitle = {RECIRAL'04}, year = {2004}, address = {Fès, Maroc}, month = {avril} }National audienc
NGUYEN BINH KHIEM'S THOUGHT AND THE BUILDING OF ECOLOGICAL ETHICS IN THE CURRENT PERIOD
No full textEcological disasters have affected all countries and regions around the world. It hinders the process of social modernization, and threatens the survival of all mankind. In that context, the building of ecological ethics becomes one of the urgent and practical needs to contribute to environmental protection, ensuring sustainable development. Researching the history of Vietnamese thoughts in the 15th - 16th centuries reveal that Nguyen Binh Khiem is one of the typical thinkers whose moral philosophy is not only valuable for that historical period, but there are still many values for all areas of today's social life, including the area of ecological ethics. In this article, the author focuses on analyzing his three typical thoughts, including: thought on loving peace; thought on nature, thought on the relationship between man and nature; the philosophy of living in harmony with nature, thereby drawing the value of these thoughts for the issue of ecological ethics building in the current period.
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