Search results for "40"
showing 10 items of 17345 documents
Ortho -Functionalized Aryltetrazines by Direct Palladium-Catalyzed C−H Halogenation: Application to Fast Electrophilic Fluorination Reactions
2016
International audience; A general catalyzed direct C-H functionalization of s-tetrazines is reported. Under mild reaction conditions, N-directed ortho-C-H activation of tetrazines allows the introduction of various functional groups, thus forming carbon-heteroatom bonds: C-X (X=I, Br, Cl) and C-O. Based on this methodology, we developed electrophilic mono- and poly-ortho-fluorination of tetrazines. Microwave irradiation was optimized to afford fluorinated s-aryltetrazines, with satisfactory selectivity, within only ten minutes. This work provides an efficient and practical entry for further accessing highly substituted tetrazine derivatives (iodo, bromo, chloro, fluoro, and acetate precurso…
The Effect of Electrolytic Solution Composition on the Structure, Corrosion, and Wear Resistance of PEO Coatings on AZ31 Magnesium Alloy
2020
Plasma electrolytic oxidation coatings were prepared in aluminate, phosphate, and silicate-based electrolytic solutions using a soft-sparking regime in a multi-frequency stepped process to compare the structure, corrosion, and wear characteristics of the obtained coatings on AZ31 magnesium alloy. The XRD results indicated that all coatings consist of MgO and MgF2, while specific products such as Mg2SiO4, MgSiO3, Mg2P2O7, and MgAl2O4 were also present in specimens based on the selected solution. Surface morphology of the obtained coatings was strongly affected by the electrolyte composition. Aluminate-containing coating showed volcano-like, nodular particles and craters distributed over the …
Ginger and Turmeric Essential Oils for Weed Control and Food Crop Protection
2019
Ginger and turmeric are two food ingredients that are in high demand due to their flavor and positive effects on health. The biological properties of these spices are closely related to the aromatic compounds they contain. The chemical compositions of their essential oils and their in vitro phytotoxic activity against weeds (Portulaca oleracea, Lolium multiflorum, Echinochloa crus-galli, Cortaderia selloana, and Nicotiana glauca) and food crops (tomato, cucumber, and rice) were studied. Forty-one compounds, accounting for a relative peak area of 87.7% and 94.6% of turmeric and ginger essential oils, respectively, were identified by Gas Chromatography&ndash
Longitudinal Patterns of Ethical Organisational Culture as a Context for Leaders’ Well-Being: Cumulative Effects Over 6 Years
2021
AbstractThe aim of this longitudinal study was to investigate the temporal dynamics of ethical organisational culture and how it associates with well-being at work when potential changes in ethical culture are measured over an extended period of 6 years. We used a person-centred study design, which allowed us to detect both typical and atypical patterns of ethical culture stability as well as change among a sample of leaders. Based on latent profile analysis and hierarchical linear modelling we found longitudinal, concurrent relations and cumulative gain and loss cycles between different ethical culture patterns and leaders’ well-being. Leaders in the strongest ethical culture pattern exper…
La organización del trabajo por proyectos: La fábrica de la precariedad laboral
2019
The project-based organization, considered as a radical reorganization of work around one or more simultaneous projects, is nowadays widespread in large companies and public administrations. According to the managerial way of thinking, this system would be virtuous: by giving more autonomy to the employees in the act of production and by developing their skills through mobility and interdisciplinarity of work teams, it would be able to arouse their full commitment. This study confirms in some way how this opinion has been imposed, but at the expense of precarious working conditions, increasing the dedication of employees and silencing any form of criticism. The research is based on a review…
Analysis of the Potential of an Increase in Yeast Output Resulting from the Application of Additional Process Wastewater in the Evaporator Station
2019
This paper reports the results of an analysis of process wastewater streams in the context of an increase in yeast production. This research is based on the analysis of data from the biggest yeast factory in Europe. The research presented in this paper involves the analysis of the influence of direction of additional wastewater into the evaporator station on yeast production. In the process wastewater, nitrogen is mainly present in organic forms. The analysis reported in this paper involves the concentration of total nitrogen in wastewater streams, as it is the main parameter applied to determine the amount of wastewater that can be applied in agricultural fields. Directing additional waste…
Tila, kuuluminen ja kuva
2016
Kulttuuriympäristöt ovat alueita, jotka rakentuvat ajassa ja tilassa ihmisen ja ympäristön välisen toiminnan tuloksena. Kulttuuriympäristöt ovat jatkuvassa kehityksen ja muutoksen tilassa olevia tapahtumaketjuja, joissa maisemat avautuvat ja sulkeutuvat ja joissa uusia rakennuksia pystytetään ja vanhoja joko hylätään, puretaan tai suojellaan. Muuttuvaisuudestaan huolimatta kulttuuriympäristöillä mielletään olevan keskeinen merkitys ihmisen identiteetille ja viihtyvyydelle.[1] Miten ihmiset pystyvät luovimaan tässä muutoksen virrassa ja kiinnittymään ja tuntemaan kuuluvansa omaan elinympäristöönsä? Yhden lähestymistavan edellä esitettyihin kysymyksiin tarjoaa ympäristön kuvalliseen esittämis…
Humanismi nyky-yhteiskunnan haasteissa
2017
Puhe Suomalaisen Tiedeakatemian humanistipalkinnon jakotilaisuudessa Säätytalolla Helsingissä 10.9.2017.
“Quam mirabilis per omnen orbem terrae cultura!” Ihminen, ympäristö ja rakennettu maisema antiikin ja 1400-luvun ajattelussa
2016
2000-luvun ympäristöhistorian tutkimuksissa on painotettu ihmisen muovanneen maapallon ulkoasua radikaalisti viimeisimmän 500 vuoden aikana. Kehityksen taustalla on usein nähty teknisen ja tieteellisen kehityksen aiheuttama omanarvontunnon nousu ja ympäristöön kohdistuneet utilitaristiset asenteet. Tässä artikkelissa tarkastellaan uuden ajan alun asenneilmapiirin taustoja. Pääkohteina ovat 1400-luvun italialaiset humanistioppineet, joiden on katsottu esittäneen filosofisesti perusteltuja ihmiskeskeisiä näkemyksiä ja vaikuttaneen merkittävällä tavalla myöhempien luontoon utilitaristisesti suhtautuneiden käsitysten kehitykseen. Artikkelissa tarkastellaan teemoja, joita 1400-luvun kirjoittajie…
Fuga de cerebros y biografías low cost: nueva etapa en la precarización de la juventud
2015
0 false 21 18 pt 18 pt 0 0 false false false /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-fareast-language:EN-US;} La normalización de la precariedad entre las personas jóvenes está entrando en lo que parece una…