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Zaštita materijala 4. 2017

 

Dragan Veselinović

Univerzitet u Beogradu, Fakultet za fizičku hemiju,
Beograd, Srbija

Aktuelni stavovi
ISSN 0351-9465, E-ISSN 2466-2585
UDC:504.064:800.6
doi: 10.5937/ZasMat1704421V

Zastita Materijala 58 (4)
421 – 423  (2017)

Zagađivanje jezika kao dela životne sredine

Izvod

Jezik i reči koje ga čine su deo životne sredine i deo našeg dnevnog života. Jezik je, takođe, jedan od ključnih karakteristika odgovarajuće nacije. Razvoj nauke i kulture dovodi do nastajanja novih reči. To je povećanje rečnika. Ali zamena reči svoga jezika sa reči iz drugog jezika je zagađenje jezika. Takođe, korišćenje konstrukcije rečenice iz drugog jezika u svom jeziku je, takođe, zagađivanje jezika. To je posledica niskog nivoa kulture i niskog nivoa znanja, nedovoljno kvalifikovanih.

Ključne reči: zagađenje jezika, jezik, nove reči.

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POLLUTION OF LANGUAGE AS A PART OF THE ENVIRONMENT

Abstract

Language, and words which make it, is a part of the environment and a part of our daily lives.  Language is also the essential characteristic of the corresponding nation. Development of the science and culture drive to the formation of new words. That is the increase of vocabulary. But the echange a word of one’s own language with a word of another language is pollution of language. Also the using of sentence construction from forein language in one’s own language is also language pollution. This is a consequence of the low culture level and the low knoweledge level of individues with a half qualification.

Keywords: language pollution, language, new words.

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Thomas Laminger1*, Gerd Mauschitz1,
Dunja Sokolovic2, Wilhelm Hoeflinger1

1Vienna University of Technology, Institute of Chemical Engineering, Vienna, Austria, 2
University of Novi Sad, Faculty of Technical Sciences, Novi Sad, Serbia

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
UDC:685.763.067.4
doi: 10.5937/ZasMat1704425L


Zastita Materijala 58 (4)
425 – 431  (2017)

Influence of the test emulsion on filtration efficiency and pressure drop of mist Separators for cooling lubricants

Abstract

This work deals with standardized filter tests of mist separators for cooling lubricants aerosols. The Austrian standard ÖNORM Z1263 describes a filter test rig and test procedure for standardized comparable filter tests and futher for a classificiation.

Following this guideline six industiral used filter elements with different designs and materials were tested to determine filtration specific parameters like the pressure drop, total liquid holdup, oil holdup and separation efficiency. Finally, filter elements will be classified by their separation efficiency into a filter-class from 1 to 10.

The ÖNORM Z1263 does not give any specific test substance, so there is an interest to study the influence of various coolant oils as used in industry.

Therefore for the filter test, three different coolant oils were used as test substance: mineral oil, semi-synthetic oil and full-synthetic oil. The six filter elements have been tested according to the guideline to reach a steady-state liquid equilibrium within 2-4 hours.

Comparing the results of the steady-state pressure drop, total holdup and oil holdup as well as the separation efficiency in four particle size ranges there was no significant influence of the test oil base found. The achieved filter-class numbers differ only by one number.

Keywords: Coolant oil, emulsion, filter elements, separation efficiency, pressure drop, filter testing.

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Uticaj test emulzije na efikasnost filtracije i pad pritiska kod filtera za uklanjanje aerosola formiranog od SHP sredstava

Izvod

Ovaj rad se bavi standardizacijom procedure za ispitivanje filtera za separaciju tečnog aerosola formiranog od SHP sredstava u radnoj sredini mašina alatki. Austrijski standard  ÖNORM Z1263 opisuje opremu za ispitivanje aerosol filtera, postupak njihovog ispitivanja,  kao i način njihove klasifikacije. Prateći ove smernice šest filtera različite konsutrukcije i materijala, koji se primenjuju u industriji testirani su u cilju određivanja filtracionih parametara, kao što su: pad pritiska, ukupno zadržavanje tečnosti u filteru, zadržavanje ulja u filteru i efikasnost separacije. Na osnovu efikasnosti separacije testirani filteri će se klasifikovati u određenu klasu filtera od 1 do 10.

Standard ÖNORM Z1263 ne definiše test supstancu, tako da postoji interes za proučavanje uticaja različitih test supstanci. Kao test supstance ispitivana su tri ulja koja se koriste u  industriji: mineralno ulje, polusintetičko i sintetičko ulje. Ova ulja se primenjuju kao emulzije, i spadaju u grupu SHP sredstava. Šest filtera je testirano po ÖNORM Z1263 standardu. Upoređivanjem dobijenih rezultata primenom različitih test ulja, odnosno njihovih emulzija uočava se se da ne postoji značajan uticaj ulja na klasifikaciju filtera. Postignuta klasa filtera se samo u pojedinim slučajevima razlikovala za jednu klasu, što je zanemarljivo sa obzirom na usku granicu među klasama.

Ključne reči: sredstva za hlađenje i podmazivanje (SHP), emulzija, aerosol filteri, efikasnost separacije, pad pritiska, testiranje filtera.

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Tamara Erceg1*, Ivan Ristić1, Suzana Cakić2, Jaroslava Budinski-Simendić1

1University of Novi Sad, Faculty of Technology Novi Sad,
Novi Sad, Serbia, 2University of Niš,  Faculty of Technology Leskovac, Leskovac, Serbia

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
UDC:620.192.53:661.717
doi: 10.5937/ZasMat1704433E


Zastita Materijala 58 (4)
421 – 423 (2017)

The influence of synthesis parameters on swelling behaviour of pH-sensitive acrylate based hydrogels

Abstract

In this work poly(acrylamide-co-acrylic acid) based hydrogels were prepared using the two types of initiators – potassium persulfate (KPS) and ammonium persulfate (APS) and accelerator N,N,N’,N’-tetramethylethylenediamine (TEMED). N,N’-methylenebis(acrylamide) (MBAM) was used as crosslinking agent (1 and 3% per total weight of monomers). For the synthesis of hydrogels, acrylic acid (Aac) and acrylamide (Aam) were used in the following mass ratios: 30:70, 50:50, 70:30 and 0:100% Aac/Aam. The swelling behaviour of cross-linked copolymers was characterized in acidic (pH=4.5) and alkaline (pH=10) medium at constant temperature of 37 °C. Lower amount of crosslinking agent has given the hydrogels with greater water absorption capacity. The forming of polymer network has been confirmed by FT-IR method. Thermal properties of obtained hydrogels were analyzed by differential scanning calorimetry (DSC). Obtained results have showed the strong correlation between hydrogels composition and their swelling and thermal properties.

Keywords: hydrogel, swelling ratio, acrylic acid, acrylamide, monomer ratio.

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UTICAJ PARAMETARA SINTEZE NA BUBRENJE pH OSETLJIVIH AKRILATNIH HIDROGELOVA

U ovom radu su sintetisani hidrogelovi na osnovu poli(akrilamid-ko-akrilne kiseline) primenom dva tipa inicijatora – kalijum persulfata (KPS) i amonijum persulfata (APS) i akceleratora N,N,N’,N’-tetrametil etilen diamina (TEMED). Umrežavanje je vršeno posredstvom N,N’-metilen bisakrilamida (MBAM) koji je korišćen u udelima 1 i 3% u odnosu na ukupnu masu monomera. Pripremljeni su hidrogelovi sa sledećim masenim odnosima monomera akrilne kiseline i akrilamida: 70:30, 50:50, 30:70 i 0:100%. Svojstva bubrenja sintetisanih gelova ispitana su u kiseloj (pH=4.5) i alkalnoj sredini (pH=10) na konstantnoj temperaturi od 37 °C. Niži udeo umreživača dao je hidrogelove sa većom sposobnošću bubrenja. Struktura hidrogelova potvrđena je FT-IR metodom. Toplotna svojstva su ispitana diferencijalnom skenirajućom kalorimetrijom (DSC). Dobijeni rezultati pokazali su postojanje izražene korelacije između sastava hidrogela i njegovih toplotnih svojstava i svojstava bubrenja.

Ključne reči: hidrogel, stepen bubrenja, akrilna kiselina, akrilamid, odnos monomera.

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