Search results for "SSP"
showing 10 items of 221 documents
Meliorācijas ietekme uz Vesetnieku ekoloģiskā stacionāra kūdras augsnes ķīmisko sastāvu
2015
Darbā pētīti nosusinātā un nenosusinātā pārejas tipa purva augsnes paraugi, sadarbībā ar Latvijas Valsts mežzinātnes institūta „Silava” pētniekiem. Darba ietvaros ķīmiskajām analīzēm kūdras paraugi ņemti no 6 parauglaukumiem, no noteiktiem augsnes dziļumiem (O horizonts, 0-10 cm, 10-20 cm, 20-40 cm, 40-80 cm, kopā 26 paraugi). Augsnes paraugiem noteikta oglekļa un slāpekļa stabilo izotopu attiecība, 1 M HNO3 ekstrahējamo Fe, Zn, Cu, Mn, K, Pb, Cr, Cd un Ni saturs, augsnes pH un homogenitāte. Noteikta elementu analizatora izotopu attiecības masspektrometra mērījumu linearitāte un stabilitāte ar laboratorijas references materiāla.
Elementu identifikācijas metožu salīdzinājums farmaceitiskajos paraugos
2019
Elementu identifikācijas metožu salīdzinājums farmaceitiskajos paraugos. Sleže V., zinātniskais vadītājs Mg. Chem. Bērtiņš M. Bakalaura darbs, 43 lappuses, 15 attēli, 12 tabulas, 31 literatūras avoti. Latviešu valodā. Organisko vielu sintēzēs tai starpā farmaceitisko preparātu ražošanā nereti tiek izmantoti katalizatori, lai ražošanas process notiktu ātrāk. Katalizatoru atliekas galaproduktā nav vēlamas, it īpaši farmaceitiskajos preparātos, kuri tiek lietoti cilvēku uzturā. Ir noteiktas direktīvas, kuras ierobežo katalizatoru maksimālās devas farmaceitiskajos preparātos. Tāpēc ir sastādītas ķīmiski analītiskās metodes, kuras spēj noteikt, cik daudz ir palikuši katalizatoru atlikumi.
Daudzfaktoru analīzes pielietojums dažādu ārstniecisko zāļaugu pētījumos
2021
Daudzfaktoru analīzes pielietojums dažādu ārstniecisko zāļaugu pētījumos. I.Kumačeva, zinātniskais vadītājs pētnieks Mg. chem. Māris Bērtiņš. Bakalaura darbs, 38 lappuses, 26 attēli, 7 tabulas, 36 literatūras avoti, 6 pielikumi. Latviešu valodā. Darbā ir apskatītas trīs paraugu sagatavošanas metodes un vairākas analīzes metodes, to teorētiskais pamatojums, kā arī priekšrocības un trūkumi. Veikta parauga sagatavošana mikroviļņu sistēmā, ICP-MS analīze un spektroradiometriskie mērījumi . Dati tika apstrādāti pielietojot PCA metodi.
Makro- un mikroelementu plūsmas pētījumi tauriņziežu – gumiņbaktēriju simbiotiskajā sistēmā
2020
Darbā tiek veikta sojas un pupu paraugu sagatavošana un analīze. Makro un mikroelementu koncentrācijas noteikšana tika veikta, izmantojot induktīvi saistītas plazmas masspektrometru. Paraugu sagatavošanai izmantoja slapjo mikroviļņu mineralizāciju.
Hemostatic, inflammatory, and oxidative markers in pesticide user farmers
2016
Research Article; International audience; The aim of this work was to investigate inflammatory, oxidative, and thrombotic parameters as biomarkers in farmers exposed to pesticides. Fifty farmers using chemical pesticides and 60 unexposed control men participated in this study. The Mediterranean diet compliance, the duration of pesticide use, and personal protection for pesticides handling were recorded using self-administered questionnaires. Serum biochemical parameters, oxidant/antioxidant, inflammatory, and thrombosis markers were determined. Our findings showed oxidative stress reflected by an increase in malondialdehyde, carbonyl proteins and superoxide anion levels and a decrease in vi…
Antispasmodic Effects and Structure−Activity Relationships of Labdane Diterpenoids from Marrubium globosum ssp. libanoticum
2009
Marrubium globosum ssp. libanoticum is a medicinal plant used in Lebanon to reduce pain and smooth muscle spasms. A chloroform extract obtained from M. globosum aerial parts reduced acetylcholine-induced contractions in the isolated mouse ileum. The purification of this extract identified, among 12 isolated labdane diterpenoids, four new compounds, named 13-epicyllenin A (4), 13,15-diepicyllenin A (5), marrulibacetal (9), and marrulactone (11). Their structures were determined by spectroscopic methods. Compound 9, which exerted antispasmodic activity, is likely the active ingredient of the extract. Preliminary structure-activity relationships for this class of compounds are suggested.
A Large Scale Test of the Effect of Social Class on Prosocial Behavior
2015
Does being from a higher social class lead a person to engage in more or less prosocial behavior? Psychological research has recently provided support for a negative effect of social class on prosocial behavior. However, research outside the field of psychology has mainly found evidence for positive or u-shaped relations. In the present research, we therefore thoroughly examined the effect of social class on prosocial behavior. Moreover, we analyzed whether this effect was moderated by the kind of observed prosocial behavior, the observed country, and the measure of social class. Across eight studies with large and representative international samples, we predominantly found positive effect…
Intellectual engagements of accounting academics: The ‘forecasted losses' intervention
2022
This paper explores the social and political potential of accounting scholarship, presenting and discussing an intellectual intervention challenging a legislative reform that significantly affected Spanish industrial relations. In this reform, an accounting artifact (forecasted losses) played an unexpected role and was misrepresented, prompting a sizeable number of scholars to sign two manifestos in 2010 and 2012 against the use of forecasted losses made by the new legislation. As promoters of this manifesto, we perform in this paper a collaborative autoethnography to reflect on the context, events, reactions, and significance of this intervention for both the academic and the industrial re…
How does an In-containing underlayer prevent the propagation of defects in InGaN QW LEDs?: identification of SRH centers and modeling of trap profile
2021
Recent reports indicated that the use of an InAlN underlayer (UL) can significantly improve the efficiency of InGaN/GaN quantum well (QW) LEDs. Currently, this result is explained by considering that the UL reduces the density of nonradiative recombination centers in the QWs. However, an experimental proof of the reduction of defects in the QWs is not straightforward. In this paper, we use combined electrical (I-V), optical (L-I), capacitance (C-V), steady-state photocapacitance (SSPC) and light-assisted capacitance-voltage (LCV) measurements to explain why devices with UL have a much higher efficiency than identical LEDs without UL. Specifically, we demonstrated an improvement in both elec…
The role of forest fire severity on vegetation recovery after 18 years. Implications for forest management of Quercus suber L. in Iberian Peninsula
2016
Wildfires are a widespread phenomenon in Mediterranean environments. Wildfires result in different fire severities, and then in contrasting plant cover and floristic composition. This paper analyses the recovery of the vegetation eighteen years after a wildfire in Catalonia. The Pinus pinaster ssp. forest was affected by three different severities in July 1994, and studied the spring of 1995 and again in 2008. After eighteen years (2012), our research found that burnt sites constitute a dense forest with a broad variety of species, including many young pines, shrubs and herbaceous plants, but that the risk of fire remains very high, due to the large quantity of fuel and the flammability of …