Search results for "Zen"
showing 10 items of 3479 documents
On the nature of organic electron density transfer complexes within molecular electron density theory.
2019
The structural features of a series of organic molecular complexes formed between the strong electrophilic tetracyanoethylene and twelve benzene derivatives with increased nucleophilic character, herein called Electron Density Transfer Complexes (EDTCs), have been studied using Molecular Electron Density Theory. The favourable nucleophilic/electrophilic interactions, which favour the global electron density transfer (GEDT) towards the electrophile, are responsible for the formation of these species. Molecular complexes presenting a GEDT above 0.05e are classified as EDTCs. Analysis of the Parr functions of the separated reagents and the topological analysis of the electron density of the ED…
A molecular electron density theory study of the enhanced reactivity of aza aromatic compounds participating in Diels–Alder reactions
2019
The enhanced reactivity of a series of four aza aromatic compounds (AACs) participating in the Diels–Alder (DA) reactions with ethylene has been studied using Molecular Electron Density Theory (MEDT). The analysis of the electronic structure of these AACs allows establishing that the substitution of the C–H unity by the isoelectronic N: unity linearly decreases the ring electron density (RED) of these compounds and concomitantly decreases their aromatic character and increases their electrophilic character. These behaviours not only decrease drastically the activation energies of these DA reactions, but also increase the reaction energies when they are compared with the very unfavourable DA…
A 5-year multicentre randomized controlled trial comparing personalized, frozen and fresh blastocyst transfer in IVF.
2020
Abstract Research question Does clinical performance of personalized embryo transfer (PET) guided by endometrial receptivity analysis (ERA) differ from frozen embryo transfer (FET) or fresh embryo transfer in infertile patients undergoing IVF? Design Multicentre, open-label randomized controlled trial; 458 patients aged 37 years or younger undergoing IVF with blastocyst transfer at first appointment were randomized to PET guided by ERA, FET or fresh embryo transfer in 16 reproductive clinics. Results Clinical outcomes by intention-to-treat analysis were comparable, but cumulative pregnancy rate was significantly higher in the PET (93.6%) compared with FET (79.7%) (P = 0.0005) and fresh embr…
Sizing analysis of interior lighting using tubular daylighting devices
2017
Abstract Daylight access and indoor thermal comfort are key issues for high design level of sustainable buildings. In fact, daylight provides energy savings and visual comfort condition that can foster higher productivity and performance. This paper proposes a case study of sizing of daylight devices for zenith light. It enables the decision-making process of the designer to reach high levels of daylight factor. The proposed method is shown with an example of application. For the case study, a room in south of Italy, 24 different solar tunnels configurations and 12 cases with different number of skylights have been evaluated.
The impact of Kaizen Events on improving the performance of automotive components' first-tier suppliers
2009
Purpose - The aim of this paper is to explore the possibility of improving production indicators by implementing Kaizen Events. The teams are composed of both managers and operators with the aim of developing and/or implementing improvements in three to five days. Methodology - The empirical research will consists of the description of the results obtained in 11 industrial companies from the automotive components industry. In each company, we have followed up different interventions over a 9-12-month period. Findings - We shall present the initial situation, the activities carried out by the companies and the evolution of manufacturing performance approximately three months after the activi…
An interpretive framework for assessing and monitoring the sustainability of school gardens
2016
School gardens are, increasingly, an integral part of projects aiming to promote nutritional education and environmental sustainability in many countries throughout the world. In the late 1950s, FAO (Food and Agriculture Organization) and UNICEF (United Nations Children's Fund) had already developed projects to improve the dietary intake and behavior through school and community gardens. However, notwithstanding decades of experience, real proof of how these programs contribute to improving sustainability has not been well-documented, and reported findings have mostly been anecdotal. Therefore, it is important to begin a process of collecting and monitoring data to quantify the results and …
Latvijos ginkluotųjų pajėgų partizanų daliniai 1919 metais | From Guerrillas to Soldiers: The Activities of Guerrilla Units of the Latvian Army in 19…
2014
On the basis of documents in the Latvian State Archives, this paper discusses the armed struggleagainst the Soviet authorities in Vidzeme, in northern Latgala, and Sela, which took placeduring the Latvian Wars of Independence, and was joined voluntarily by the local populationin an organised way. The discussion tells about the armed guerrilla groups that operated inVidzeme and northern Latgala in 1919, and formed a serious obstacle to the establishmentof Soviet power, the participation of ethnic minorities in guerrilla groups, and the features ofthe guerrilla fighting. The collaboration between Latvian guerrillas and Lithuanian troops, andtheir role in the expulsion of Soviet Latvian troops…
Assessment of air passive sampling uptakes for volatile organic compounds using VERAM devices
2017
Abstract A calibration chamber has been designed and employed for the simple and easy determination of uptake sampling rate (RS) of volatile organic compounds (VOCs) from air using passive samplers. A flow of clean air was continuously spiked, at a constant VOC concentration, by the microinjection of a standard solution by means of a T-type tube. The developed system allowed the complete evaporation at room temperature of the standard solution in acetone and the air concentration of VOCs was easily controlled by the regulation of the clean air flow, the standard solution concentration and its flow. Active sampling was employed for monitoring the true concentration of the evaluated compounds…
Polychlorinated organic compounds in the Arctic cod liver: trends and profiles
2000
Polychlorinated organic compounds (POCs) have been measured in Arctic cod liver from Vestertana Fjord for a period of 1987-1998. Significant decrease was observed for DDD (p = 0.043), alpha-HCH (p = 0.001), and gamma-HCH (lindane; p = 0.001). Contents of DDE, 2,3,7,8-tetrachlorodibenzofuran, PCBs, chlordanes, chloronaphthalenes, hexachlorobenzene and polychlorodiphenyl ethers had no significant trend. Contents of three hexa- and two heptachlorodibenzofurans and octachlorodibenzofuran increased slightly from 1987 to 1994, but then at very high rate from 1994 to 1998. Trends of HCHs, profiles of PCBs and levels of chlordanes are in accordance with atmospheric long range transport. The hexa-, …
The miniaturised emission chamber system and home-made passive flux sampler studies of monoaromatic hydrocarbons emissions from selected commercially…
2017
Abstract The estimation of the emission rate of organic compounds released from various types of indoor materials can be performed using stationary environmental test chambers (ETC) classified as ex-situ methods or small-scale portable analytical devices based on the use of passive technique at the stage of analytes sampling from the gaseous phase (in-situ methods). The paper presents results of emissions of selected organic compounds from the monoaromatic hydrocarbons group (benzene, toluene, ethylbenzene, p,m-xylene and styrene) emitted from the surfaces of various types of commercially-available floor coverings and the underlay made of polyurethane foam which might be installed indoors u…