Search results for "RPT"
showing 10 items of 5119 documents
Analysis of a GC/MS Thermal Desorption System with Simultaneous Sniffing for Determination of Off-Odor Compounds and VOCs in Fumes Formed during Extr…
2001
A thermal desorption equipment introducing volatile organic compounds (VOCs) into the gas chromatographic/ mass spectrometric system (GC/MS) with simultaneous sniffing (SNIFF) is a suitable method for identifying the volatile organic off-odor compounds formed during the extrusion coating process of low-density polyethylene. Fumes emitted during the extrusion coating process of three different plastic materials were collected at two different temperatures (285 and 315 degrees C) from an outgoing pipe and near an extruder. The VOCs of fumes were analyzed by drawing a known volume of air through the adsorbent tube filled with a solid adsorbent (Tenax GR). The air samples were analyzed by using…
Preparation of tungstophosphoric acid/cerium-doped NH2-UiO-66 Z-scheme photocatalyst: a new candidate for green photo-oxidation of dibenzothiophene a…
2021
International audience; The goal of this study was to introduce an effective visible-light induced photocatalytic system with a good ability for photocatalytic oxidative desulfurization (PODS) and denitrogenation (PODN) using molecular oxygen (O2) as an oxidant. In this regard, tungestophosphoric acid (PW12) was supported onto cerium-doped NH2-UiO-66 (PW12/Ce-NUiO-66) and employed for the photo-oxidation of dibenzothiophene (DBT) and quinoline (Qu). Herein, using cerium (Ce) as a “mediator” facilitated the separation of charge carriers, while NH2-UiO-66 remarkably enhanced the surface area with plentiful adsorption sites and shifted the adsorption edge of PW12to the visible region. The sum …
Effects of pyrolysis temperature on the hydrologically relevant porosity of willow biochar
2018
Biochar pore space consists of porosity of multiple length scales. In direct water holding applications like water storage for plant water uptake, the main interest is in micrometre-range porosity since these pores are able to store water that is easily available for plants. Gas adsorption measurements which are commonly used to characterize the physical pore structure of biochars are not able to quantify this pore-size range. While pyrogenetic porosity (i.e. pores formed during pyrolysis process) tends to increase with elevated process temperature, it is uncertain whether this change affects the pore space capable to store plant available water. In this study, we characterized biochar poro…
Selective Laser Sintering of Metal-Organic Frameworks: Production of Highly Porous Filters by 3D Printing onto a Polymeric Matrix.
2019
Metal‐organic frameworks (MOFs) have raised a lot of interest, especially as adsorbing materials, because of their unique and well‐defined pore structures. One of the main challenges in the utilization of MOFs is their crystalline and powdery nature, which makes their use inconvenient in practice. Three‐dimensional printing has been suggested as a potential solution to overcome this problem. We used selective laser sintering (SLS) to print highly porous flow‐through filters containing the MOF copper(II) benzene‐1,3,5‐tricarboxylate (HKUST‐1). These filters were printed simply by mixing HKUST‐1 with an easily printable nylon‐12 polymer matrix. By using the SLS, powdery particles were fused t…
Inside Cover: Hydrogen-Bonded Open-Framework with Pyridyl-Decorated Channels: Straightforward Preparation and Insight into Its Affinity for Acidic Mo…
2017
International audience; A hydrogen-bonded open framework with pores decorated by pyridyl groups was constructed by off-charge-stoichiometry assembly of protonated tetrakis(4-pyridyloxymethyl)methane and [Al(oxalate)(3)](3-), which are the H-bond donor and acceptor of ionic H-bond interactions, respectively. This supramolecular porous architecture (SPA-2) has 1nm-large pores interconnected in 3D with large solvent-accessible void (53%). It demonstrated remarkable affinity for acidic organic molecules in solution, which was investigated by means of various carboxylic acids including larger drug molecules. Competing sorption between acetic acid and its halogenated homologues evidenced good sel…
Cīņa par varu Krievijas postimpērijas Rietumu perifērijā, 1917-1920
2015
"Cīņa par varu Krievijas postimpērijas Rietumu perifērijā (1917–1920): teorētiskās un historiogrāfiskās problēmas” ir pētīts, kā mūsdienu vēstures literatūrā ir problematizēta cīņa par varu reģionā starp Baltijas jūru un Melno jūru (Somijas, Igaunijas, Latvijas, Lietuvas, Polijas, Baltkrievijas, Ukrainas teritorijās) periodā no carisma krišanas 1917. gada pavasarī līdz Polijas un Padomju Krievijas pamiera noslēgšanai 1920. gada rudenī. Darbs ir veikts, salīdzinoši analizējot priekšvēsturi cīņai par varu Krievijas postimpērijas Rietumu perifērijā, historiogrāfijā ietvertās cīņu definējošās koncepcijas, kā arī cīņas sekas un nozīmi jeb pēcvēsturi. Apzinoties pētnieku teorētisko ideju un empīr…
Sponge‐Like Behaviour in Isoreticular Cu(Gly‐His‐X) Peptide‐Based Porous Materials
2015
We report two isoreticular 3D peptide-based porous frameworks formed by coordination of the tripeptides Gly-L-His-Gly and Gly-L-His-L-Lys to Cu(II) which display sponge-like behaviour. These porous materials undergo structural collapse upon evacuation that can be reversed by exposure to water vapour, which permits recovery of the original open channel structure. This is further confirmed by sorption studies that reveal that both solids exhibit selective sorption of H2 O while CO2 adsorption does not result in recovery of the original structures. We also show how the pendant aliphatic amine chains, present in the framework from the introduction of the lysine amino acid in the peptidic backbo…
Protein recovery as a resource from waste specifically via membrane technology : from waste to wonder
2021
Economic growth and the rapid increase in the world population has led to a greater need for natural resources, which in turn, has put pressure on said resources along with the environment. Water, food, and energy, among other resources, pose a huge challenge. Numerous essential resources, including organic substances and valuable nutrients, can be found in wastewater, and these could be recovered with efficient technologies. Protein recovery from waste streams can provide an alternative resource that could be utilized as animal feed. Membrane separation, adsorption, and microbe-assisted protein recovery have been proposed as technologies that could be used for the aforementioned protein re…
Piesardzības principa statuss starptautiskajās vides tiesībās
2017
Piesardzības princips ir koncepts starptautiskajās vides tiesībās, kas ietver ideju, ka zinātniskā neskaidrība nav attaisnojums, lai veiktu darbības, kas kaitīgi ietekmē vidi. Tā statuss kā paražai starptautiskajās tiesībās joprojām tiek uztverts skeptiski, tāpēc darba mērķis ir noskaidrot, vai piesardzības princips ir šādu stausu ieguvis. Šī darba ietvaros tiks aplūkots normatīvais regulējums, tiesu prakse un valstu prakse, lai izpildītu darba uzdevumus- noteikt piesardzības principa definīciju, kā arī noteikt kāds ir opinio juris un valstu prakse attiecībā uz to. Autore uzskata, ka darba rezultātā ir noteicams, ka ir radusies paražu tiesībā attiecībā uz piesardzības principu.
Darba efektivitātes, drošības un arodveselības problēmas un risinājumi kokapstrādes uzņēmuma SIA “ĪVE AG” procesu vadībā
2015
Darba efektivitātes, drošības un arodveselības problēmas un risinājumi kokapstrādes uzņēmuma SIA “ĪVE AG” procesu vadībā. Maģistra darbs ir uzrakstīts uz 77 lappusēm, tas satur 27 attēlus, 18 tabulas, 33 literatūras avotus, 7 pielikumus. Darbs ir uzrakstīts latviešu valodā. Maģistra darbā tika apskatīti kokapstrādes uzņēmuma SIA „Īve AG” ražošanas procesi, problēmrisinājumi procesu vadībā, vides aizsardzībā un darba aizsardzībā, analizēta ISO starptautisko standartu loma nelielās kokzāģētavās, ar aptaujas palīdzību novērtēta darbinieku izpratne par šiem standartiem 5 kokzāģētavās, novērtēti pastāvošie darba vides riski SIA „Īve AG” ar risku analīzes metodēm. Tika noskaidrots, ka sakārtota o…