scholarly journals Experimental investigation of a one-level eight-channel cyclone-separator incorporating quarter-rings

2021 ◽  
Vol 75 (4) ◽  
pp. 241-251
Author(s):  
Aleksandras Chlebnikovas
Keyword(s):  
Particulate Matter ◽  
Collection Efficiency ◽  
Cascade Impactor ◽  
Cyclone Separator ◽  
Cleaning Efficiency ◽  
Air Cleaning ◽  
Before And After ◽  
Cleaning Device ◽  
The One ◽  
Pm2.5 And Pm10

The main aim of this investigation was an experimental analysis of the air cleaning efficiency in a mock-up next-generation air cleaning device - one-level 8-channel industrial cyclone-separator with quarter-rings - while changing parameters of the inner structure and the assessment of the effects of dispersion of particulate matter. Therefore, the research was carried out in two stages: the first stage covered the analysis of the efficiency of the multi-channel cyclone with particulate matter of <20 and <50 ?m. During the second stage, a cascade impactor was used to measure the particle collection efficiency in the multi-channel cyclone by fractions: PM1, PM2.5 and PM10. Results of the tests with using the cascade impactor were compared to show changes in the PM composition before and after the multi-channel cyclone-separator. According to the obtained experimental data, the one-level 8-channel cyclone-separator collects 70 to 80 % of PM up to 10 ?m in size, 45 to 60 % of PM up to 2.5 ?m in size and 21 to 25 % of PM up to 1 ?m in size.

scholarly journals Experimental Investigation of Discoloration Generated by a CI ICE's Exhaust Gas on Various Stone Types

2018 ◽  
Vol 46 (3) ◽  
pp. 158-163 ◽  
Author(s):  
Orsolya Farkas ◽  
György Szabados ◽  
Ákos Antal ◽  
Ákos Török
Keyword(s):  
Particulate Matter ◽  
Construction Materials ◽  
Exhaust System ◽  
Mass Effect ◽  
Small Scale ◽  
Exhaust Gas ◽  
Colour Measurement ◽  
Compression Ignition Engine ◽  
Before And After ◽  
The One

The effect of particulate matter - as a component of an internal combustion engine's exhaust gas - on 8 different types of construction materials have been studied under laboratory conditions. Our aim was double. On the one hand it was to investigate the degree of discolouration, whether there is a difference between the 8 types of rock in the same exposure, after laboratory contamination. On the other hand to measure the mass effect of particulate on the rocks. For testing the adverse effects of diesel soot and particulate matter on stones a small scale laboratory exposure chamber was constructed and built in the exhaust system of the engine. A compression ignition engine was used to pollute directly the set of stones. Mass and colour measurement tests have been carried out on the stones before and after the exposure. The result is as expected small difference in the mass properties and a greater changes in terms of colour measurement.

scholarly journals EXPERIMENTAL REEARCH ON APPLYING LAVSAN IN THE AIR BIOFILTRATION PROCESS / LAVSANO TAIKYMO ORO BIOFILTRACIJOS PROCESE EKSPERIMENTINIAI TYRIMAI

2013 ◽  
Vol 5 (4) ◽  
pp. 376-381 ◽  
Author(s):  
Alvydas Zagorskis ◽  
Aleksandra Milaknytė
Keyword(s):  
Environmental Protection ◽  
Cleaning Efficiency ◽  
Initial Concentration ◽  
Air Cleaning ◽  
Air Volume ◽  
Air Stream ◽  
Cleaning Device ◽  
Rich Solution ◽  
Material Load ◽  
Air Biofiltration

Air cleaning efficiency tests on placing material load into the lavsan biofilter were carried out. Testing included butanol vapour-contaminated air stream pulled during the boot. The studies were conducted by the Department of Environmental Protection at VGTU that developed a biofilter – an experimental biological air cleaning device. Measurements were done using 60 l/min and 90 l/min air volume aspirators under the initial pollutant concentration making 180, 305, 350, 440 and 545 mg/m3. Before measuring the concentrations of butanol lavsan cartridge, loading was periodically irrigated with nutrient-rich solution. In order to evaluate the influence of microorganisms on genus Pseudomonas, cleaning efficiency tests were repeated – Boot was moistened with water only, which allowed measuring butanol vapour concentrations after the cartridge. At the concentration of 180±9 mg/m3, efficiency reached 41% at a speed of 0,07 m/s and 46 % at a speed of 0,10 m/s. Measuring the performance of the initial concentration of 545±67 mg/m3, efficiency was 54% at 0,07 m/s and 53 % at 0,10 m/s respectively. Article in Lithuanian. Santrauka Atlikti oro valymo efektyvumo tyrimai į lašelinį biofiltrą įkrovus lavsano medžiagos įkrovą. Bandymų metu pro įkrovą buvo traukiamas butanolio garais užterštas oro srautas. Tyrimai atliekami naudojant VGTU Aplinkos apsaugos katedroje sukurtą eksperimentinį biologinį oro valymo įrenginį – biofiltrą. Matavimai atlikti leidžiant 60 l/min. ir 90 l/min. oro kiekį aspiratoriumi. Pradinės teršalo koncentracijos – 180, 305, 350, 440, 545 mg/m3. Prieš matuojant butanolio koncentracijas panaudojant lavsano medžiagos kasetę, įkrova buvo periodiškai drėkinama maistinių medžiagų prisotintu tirpalu. Pseudomonas genties mikroorganizmų įtakai valymo efektyvumui įvertinti tyrimai buvo pakartoti – įkrovos sudrėkinamos tik vandeniu, leidžiami butanolio garai, ir matuojamos koncentracijos panaudojus lavsano medžiagos kasetę. Esant 180±89 mg/m3 koncentracijai biofiltro oro valymo efektyvumas siekė 41 %, kai per įkrovą leidžiamo dujų srauto greitis buvo 0,07 m/s, ir 46 %, kai greitis 0,10 m/s. Nustatyta valymo efektyvumas. Esant 545±55 mg/m3 pradinei koncentracijai jis siekė 54 % (0,07 m/s) ir 53 % (0,10 m/s).

scholarly journals PLASMA COATING FORMED TIO2 CATALYSTS USAGE IN CLEANING THE AIR FROM NITROGEN OXIDES AND CARBON MONOXIDE / PLAZMINIU PURŠKIMU SUFORMUOTŲ TIO2 KATALIZATORIŲ TAIKYMAS VALANT IŠ ORO AZOTO OKSIDUS IR ANGLIES MONOKSIDĄ

2015 ◽  
Vol 7 (4) ◽  
pp. 365-371
Author(s):  
Vitalij Kolodynskij ◽  
Pranas Baltrėnas
Keyword(s):  
Carbon Monoxide ◽  
Nitrogen Oxides ◽  
Plasma Coating ◽  
Air Purification ◽  
Average Flow Rate ◽  
Cleaning Efficiency ◽  
Average Flow ◽  
Air Cleaning ◽  
Air Stream ◽  
Cleaning Device

The present catalytic air purification device–air cleaning device is capable to reduce nitrogen oxide sand carbon monoxide concentrations in polluted air stream and to achieve high cleaning efficiency. The principle of operation of catalytic air cleaning device is based on plasma coating formed catalysts usage. At high temperatures and oxygen concentrations in the experimental device channel, catalysts become active and reactions of conversion of pollutants start. In this research, the efficiency of cleaning the air from nitrogen oxides and carbon monoxide, by using plasma coating formed titanium oxide and copper-chromium catalysts, is carried out. 50% propane – 50% butane gas mix was used to generate polluted air flow. The maximum cleaning efficiency, cleaning the air of nitrogen oxides and carbon monoxide, reached 86% and 77%, when the average flow rate of polluted air was 0.10 m/s, oxygen concentration in II section of device was 0.5–0.6% and in I section – 0.1–0.2%. Nagrinėjamas įrenginys – katalitinis oro valymo įrenginys, mažinantis azoto oksidų ir anglies monoksido koncentracijas užterštame oro sraute. Katalitinis oro valymo įrenginys veikia naudodamas plazminiu purškimu suformuotus katalizatorius. Esant aukštai temperatūrai ir optimaliai deguonies koncentracijai įrenginio eksperimentiniame kanale, katalizatorių paviršius tampa aktyvus, ir vyksta sudėtingos teršalų konversijos reakcijos. Atliktuose tyrimuose nagrinėtas suminis titano oksido ir vario-chromo oksido katalizatorių, kurie buvo pagaminti plazminio purškimo metodu, srauto, užteršto azoto oksidais ir anglies monoksidu, valymo efektyvumas. Užterštam oro srautui sugeneruoti buvo naudojamas 50 % propano – 50 % butano dujų mišinys. Didžiausias valymo efektyvumas, valant orą nuo azoto oksidų ir anglies monoksido, atitinkamai siekė 86 % ir 77 %, esant 0,10 m/s vidutiniam užteršto srauto greičiui, 0,5–0,6 % deguonies koncentracijai II-ojoje įrenginio sekcijoje ir 0,1–0,2 % deguonies koncentracijai I-ojoje įrenginio sekcijoje.

scholarly journals Lost in Migration – Mirandese at a Crossroads

2019 ◽  
Vol 5 (1) ◽  
pp. 488-495
Author(s):  
Cláudia Martins ◽  
Sérgio Ferreira
Keyword(s):  
Minority Language ◽  
Three Dimensions ◽  
Highly Qualified ◽  
Linguistic Rights ◽  
The Bible ◽  
Literary Forms ◽  
Before And After ◽  
The 1960S ◽  
The One ◽  
The 19Th Century

AbstractThe linguistic rights of Mirandese were enshrined in Portugal in 1999, though its “discovery” dates back to the very end of the 19th century at the hands of Leite de Vasconcellos. For centuries, it was the first or only language spoken by people living in the northeast of Portugal, particularly the district of Miranda do Douro. As a minority language, it has always moved among three dimensions. On the one hand, the need to assert and defend this language and have it acknowledged by the country, which proudly believe(d) in their monolingual history. Unavoidably, this has ensued the action of translation, especially active from the mid of the 20th century onwards, with an emphasis on the translation of the Bible and Portuguese canonical literature, as well as other renowned literary forms (e.g. The Adventures of Asterix). Finally, the third axis lies in migration, either within Portugal or abroad. Between the 1950s and the 1960s, Mirandese people were forced to leave Miranda do Douro and villages in the outskirts in the thousands. They fled not only due to the deeply entrenched poverty, but also the almost complete absence of future prospects, enhanced by the fact that they were regarded as not speaking “good” Portuguese, but rather a “charra” language, and as ignorant backward people. This period coincided with the building of dams on the river Douro and the cultural and linguistic shock that stemmed from this forceful contact, which exacerbated their sense of not belonging and of social shame. Bearing all this in mind, we seek to approach the role that migration played not only in the assertion of Mirandese as a language in its own right, but also in the empowerment of new generations of Mirandese people, highly qualified and politically engaged in the defence of this minority language, some of whom were former migrants. Thus, we aim to depict Mirandese’s political situation before and after the endorsement of the Portuguese Law no. 7/99.

scholarly journals Real-World Experience of the One-Year Efficacy of Rifaximin Add-On to Lactulose Is Superior to Lactulose Alone in Patients with Cirrhosis Complicated with Recurrent Hepatic Encephalopathy in Taiwan

2021 ◽  
Vol 11 (6) ◽  
pp. 478
Author(s):  
Ching Chang ◽  
Chien-Hao Huang ◽  
Hsiao-Jung Tseng ◽  
Fang-Chen Yang ◽  
Rong-Nan Chien
Keyword(s):  
Hepatic Encephalopathy ◽  
Real World ◽  
Ammonia Level ◽  
Decompensated Cirrhosis ◽  
Control Group ◽  
Multivariable Logistic Regression Model ◽  
Before And After ◽  
One Year ◽  
The One ◽  
Serum Ammonia

Background: Hepatic encephalopathy (HE), a neuropsychiatric complication of decompensated cirrhosis, is associated with high mortality and high risk of recurrence. Rifaximin add-on to lactulose for 3 to 6 months is recommended for the prevention of recurrent episodes of HE after the second episode. However, whether the combination for more than 6 months is superior to lactulose alone in the maintenance of HE remission is less evident. Therefore, the aim of this study is to evaluate the one-year efficacy of rifaximin add-on to lactulose for the maintenance of HE remission in Taiwan. Methods: We conducted a real-world single-center retrospective cohort study to compare the long-term efficacy of rifaximin add-on to lactulose (group R + L) versus lactulose alone (group L, control group). Furthermore, the treatment efficacy before and after rifaximin add-on to lactulose was also analyzed. The primary endpoint of our study was time to first HE recurrence (Conn score ≥ 2). All patients were followed up every three months until death, and censored at one year if still alive. Results and Conclusions: 12 patients were enrolled in group R + L. Another 31 patients were stratified into group L. Sex, comorbidity, ammonia level, and ascites grade were matched while age, HE grade, and model for end-stage liver disease (MELD) score were adjusted in the multivariable logistic regression model. Compared with group L, significant improvement in the maintenance of HE remission and decreased episodes and days of HE-related hospitalizations were demonstrated in group R + L. The serum ammonia levels were significantly lower at the 3rd and 6th month in group 1. Concerning changes before and after rifaximin add-on in group R + L, mini-mental status examination (MMSE), episodes of hospitalization, and variceal bleeding also improved at 6 and 12 months. Days of hospitalization, serum ammonia levels also improved at 6th month. Except for concern over price, no patients discontinued rifaximin due to adverse events or complications. The above results provide evidence for the one-year use of rifaximin add-on to lactulose in reducing HE recurrence and HE-related hospitalization for patients with decompensated cirrhosis.

scholarly journals Analysis of the Particulate Matter Pollution in the Urban Areas of Croatia, EU

2020 ◽  
Vol 4 (1) ◽  
pp. 9
Author(s):  
Martina Habulan ◽  
Bojan Đurin ◽  
Anita Ptiček Siročić ◽  
Nikola Sakač
Keyword(s):  
Particulate Matter ◽  
Urban Areas ◽  
Fossil Fuels ◽  
Negative Impact ◽  
Electric Energy ◽  
Two Cities ◽  
Adriatic Coast ◽  
Pm2.5 And Pm10 ◽  
Autumn And Winter ◽  
Particulate Matter Pollution

Particulate matter (PM) comprises a mixture of chemical compounds and water particles found in the air. The size of suspended particles is directly related to the negative impact on human health and the environment. In this paper, we present an analysis of the PM pollution in urban areas of Croatia. Data on PM10 and PM2.5 concentrations were measured with nine instruments at seven stationary measuring units located in three continental cities, namely Zagreb (the capital), Slavonski Brod, and Osijek, and two cities on the Adriatic coast, namely Rijeka and Dubrovnik. We analyzed an hourly course of PM2.5 and PM10 concentrations and average seasonal PM2.5 and PM10 concentrations from 2017 to 2019. At most measuring stations, maximum concentrations were recorded during autumn and winter, which can be explained by the intensive use of fossil fuels and traffic. Increases in PM concentrations during the summer months at measuring stations in Rijeka and Dubrovnik may be associated with the intensive arrival of tourists by air during the tourist season, and lower PM concentrations during the winter periods may be caused by a milder climate consequently resulting in lower consumption of fossil fuels and use of electric energy for heating.

scholarly journals On the measurement of the ratio of the specific heats using small volumes of gas.—The ratios of the specific heat of air and of hydrogen at atmospheric pressure and a temperatures between 20°C. and —183°C

1925 ◽  
Vol 107 (743) ◽  
pp. 510-543 ◽  
Keyword(s):  
Systematic Error ◽  
Low Temperatures ◽  
Room Temperature ◽  
Expansion Chamber ◽  
Small Vessels ◽  
Specific Heats ◽  
Large Expansion ◽  
Before And After ◽  
The One ◽  
Chamber Capacity

Introduction .—In nearly all the previous determinations of the ratio of the specific heats of gases, from measurements of the pressures and temperature before and after an adiabatic expansion, large expansion chambers of fror 50 to 130 litres capacity have been used. Professor Callendar first suggests the use of smaller vessels, and in 1914, Mercer (‘Proc. Phys. Soc.,’ vol. 26 p. 155) made some measurements with several gases, but at room temperature only, using volumes of about 300 and 2000 c. c. respectively. He obtained values which indicated that small vessels could be used, and that, with proper corrections, a considerable degree of accuracy might be obtained. The one other experimenter who has used a small expansion chamber, capacity about 1 litre, is M. C. Shields (‘Phys. Rev.,’ 1917), who measured this ratio for air and for hydrogen at room temperature, about 18° C., and its value for hydroger at — 190° C. The chief advantage gained by the use of large expansion chambers is that no correction, or at the most, a very small one, has to be made for any systematic error due to the size of the containing vessels, but it is clear that, in the determinations of the ratio of the specific heats of gases at low temperatures, the use of small vessels becomes a practical necessity in order that uniform and steady temperature conditions may be obtained. Owing, however, to the presence of a systematic error depending upon the dimensions of the expansion chamber, the magnitude of which had not been definitely settled by experiment, the following work was undertaken with the object of investigating the method more fully, especially with regard to it? applicability to the determination of this ratio at low temperatures.

Doing politics by other means: Abdelmalek Sayad and the political sociology of a collective intellectual

2020 ◽  
Vol 68 (5) ◽  
pp. 999-1014
Author(s):  
Amín Pérez
Keyword(s):  
International Organizations ◽  
Political Action ◽  
The Political ◽  
Host Society ◽  
Intellectual Work ◽  
Academic Fields ◽  
The Social ◽  
Social Fields ◽  
Before And After ◽  
The One

This article proposes a new understanding of the constraints and opportunities that lead intellectuals engaged in different political and social fields to create alternative modes of resistance to domination. The study of the Algerian sociologist Abdelmalek Sayad offers insights into the social conditions of this mode of committed scholarship. On the one hand, this article applies Sayad’s theory of immigration to his transnational intellectual engagements. It establishes how immigrants’ intellectual work are conditioned by their trajectories, both before and after leaving their country, and by the stages of emigration (from playing a role in the society of origin to becoming caught up in the reality of the host society). On the other hand, the article illuminates the constraints and the spaces of possible action intellectuals face while moving across national universes and disparate political and academic fields. Sayad’s marginal position within the academy constrained him to work for the French and Algerian governments and international organizations while he was simultaneously engaged with political dissidents, unionists, writers, and social movements. In tracking Sayad’s roles as an academic, expert and public sociologist, the article uncovers the conditions that grounded improbable alliances between those fields and produced new forms of critique and political action. The article concludes by drawing out some reflections that ‘collective intellectual’ engagements elicit to the sociology of intellectuals.

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