Can Galactic Cosmic Rays Account for Solar 6Li Without Overproducing Gamma Rays?

Cosmic-ray interactions with interstellar gas produces both 6Li, which accumulates in the interstellar medium (ISM), and $\pi^0$ mesons, which decay to gamma-rays which propagate throughout the cosmos. Local 6Li abundances and extragalactic gamma-rays thus have a common origin which tightly links them. We exploit this connection to use gamma-ray observations to infer the contribution to 6Li nucleosynthesis by standard Galactic cosmic-ray (GCR) interactions with the ISM. Our calculation uses a carefully propagated cosmic-ray spectrum and accounts for 6Li production from both fusion reactions ($\alpha \alpha \to ^6Li$) as well as from spallation channels ({p,\alpha+CNO \to ^6Li). We find that although extreme assumptions yield a consistent picture, more realistic ones indicate that solar 6Li cannot be produced by standard GCRs alone without overproducing the hadronic gamma rays. Implications for the primordial 6Li production by decaying dark matter and cosmic rays from cosmological structure formation are discussed. Upcoming gamma-ray observations by GLAST will be crucial for determining the resolution of this problem.Comment: 4 pages, 1 figure To be published in ApJ

Imobilizacija invertaze preko ugljenohidratnog dela na makroporozni glicidil metakrilat

Immobilization via carbohydrate moiety is suitable for immobilization of glycoenzymes because it has little effect on enzyme active site. Macroporous glycidyl methacrylate is better support for enzyme immobilization from the much more used polystyrene because of its lesser hydrophobicity. We found optimal conditions for invertase immobilization via its carbohydrate moiety on macroporous glycidyl methacryate by varying enzyme concentration. We obtained immobilized enzyme with specific activity of 5500 lU/g, which is the highest activity reported in the literature. Immobilized enzyme has Km=43 mmol/l, temperature optimum of 60ºC, and pH optimum between 3.5 and 5.5.Imobilizacija preko šećernog dela je pogodna za glikoenzime zato što ima malo uticaja na aktivno mesto enzima. Makroporozni glicidil metakrilat je bolji nosač za imobilizaciju enzima od više korišćenog polistirena zbog svoje hidrofilnosti. Utvrđeni su optimalni uslovi za imobilizaciju invertaze preko šećernog dela na makroporozni glicidil metalkrilat variranjem koncentracije enizima. Dobijen je imobilizovani enzim specifične aktivnosti 5000 IU/g, što je najveća aktivnost do sada opisana u literaturi. Imobilizovani enzim je imao Km 43 mmol/l, temperaturni optimum na 60ºC i pH optimum između 4 i 5

Biosorption of copper(II) and chromium(VI) by modified tea fungus

The tea fungus was found to have good adsorption capacities for heavy metal ions. In this work it was treated with HCl or NaOH at 20°C or 100°C, with the aim to improve its adsorption ability. The sorption of Cu(II) and Cr(VI) ions from aqueous solutions by raw and treated tea fungus was investigated in the batch mode. The largest quantity of adsorbed Cu(II), of about 55 mg/g, was achieved by tea fungus modified with NaOH at 100°C. For Cr(VI), the largest quantity of adsorbed anions, of about 58 mg/g, was achieved by the adsorbent modified with NaOH at 20°C. It was shown that acid modification of tea fungus biomass was not effective. [Projekat Ministarstva nauke Republike Srbije, br. III 43005 i br. TR 31002

The status of common sense in contemporary social theory: toward a pragmatic reconceptualization of the relationship between theory and practice

Predmet istraživanja ovog rada biće istorijski prikaz i kritička analiza teorijskih sličnosti i razlika između pragmatizma i sociologije. U središtu našeg interesovanja će biti teorijski uvidi u zdravorazumsko mišljenje koji su prisutni u savremenoj sociologiji i pragmatizmu. Pažnju ćemo pre svega posvetiti autorima interpretativne sociologije i savremenim teoretičarima prakse. U radu ćemo ispitati kakvu ulogu je pragmatičko shvatanje zdravog razuma igralo pri formulaciji teorijskih uvida o svakodnevnom iskustvu koji se nude u interpretativnoj sociologiji i novim teorijama prakse. Pored toga, razmotrićemo značaj ovih istorijskih preklapanja izmenu pragmatizma i sociologije za potencijalnu rekonceptualizaciju međusobnog odnosa teorijskog znanja i svakodnevne prakse. Metod koji ćemo koristiti će pre svega podrazumevati istraživačke postupke s kojima se srećemo u studijama koje se bave međusobnim uticajem teorijskih ideja kao što su: poređenje ideja, teza i teorijskih polazišta; ispitivanje evolucije teorijskih stanovišta; ispitivanje kontekstualnih uslova nastanka i razvoja teorijskih ideja. Ova poređenja ćemo vršiti sa namerom da pokažemo da je konceptualizacija zdravorazumskog mišljenja igrala važnu ulogu pri stvaranju novih pristupa i pravaca u savremenoj sociologiji. Metod će takođe biti analitički kada su u pitanju procene logičke koherentnosti teorijskih određenja zdravog razuma u delima autora koji će biti u fokusu istraživanja. Cilj rada je da pokaže da pragmatičko poimanje zdravog razuma može da posluži kao teorijski okvir za povezivanje društvene teorije i svakodnevne prakse. Nastojaćemo da dokažemo da kontinuitet između zdravorazumskog načina mišljenja i sociološke teorije koji ne podrazumeva podrivanje kritičkog potencijala same društvene teorije. U uvodnom delu rada u kome ćemo se ukratko osvrnuti na radove klasičnih pragmatista i sociologa, Džona Djuija i Emila Dirkema. Videćemo da je između dvojice autora postojalo teorijsko saglasje po pitanju razumevanja osnova fenomena društvenosti, te da su se razlike uglavnom bazirale na različitim epistemološkom uvidima. Naime, naturalizam koji je svojstven Djuievom pragmatizmu je u određenoj meri podrazumevao kontinuitet između zdravorazumskog i naučnog mišljenja, a ovakvo gledište je pak bilo u suprotnosti sa Direkemovom verzijom pozitivizma u kome 5 svakodnevno, zdravorazumsko znanje nikada ne može samerljivo sa naučnom istinom. Tvrdićemo da je ova razlika temeljno pratila dalji razvoj odnosa sociologije i pragmatizma. Međutim, značaj Dirkemovih epistemoloških gledišta se svakako najviše ogledao u činjenici da su upravo ovi uvidi odigrali jednu od ključnih uloga u formiranju funkcionalizma, kao jednog od najuticajnih teorijskih struja u savremenoj sociologiji. U prvom poglavlju ćemo tako nastojati da objasnimo na koji način su fenomenologija i pragmatizam stvorile osnovu za prevazilaženje ove paradigme. Naročito pažnju ćemo posvetiti radovima Alfreda Šica i Džordža Herberta Mida koji su značajno uticale na interpretativnu sociologiju. U drugom poglavlju ćemo kritički razmotriti teorijske uvide dvojice prominentnih interpretativnih sociologa, Harolda Garfinkela i Ervinga Gofmana. Usredsredićemo se na njihovo tvrdnju da nesvodivosti konkretnog zdravorazumskog znanja na opšte obrasce razumevanja društvene stvarnosti, kao i na ustaljeni prigovor da se u okvirima njihovih sociologija ne mogu osvetliti odnosi moći u društvu. U trećem poglavlju analiziraćemo radove Pjera Burdijea i Lika Boltanskog koji su u okviru pravca novih teorija prakse upravo pokušali da formulišu sintezu partikularnog zdravorazumskog znanja i univerzalnog jezika teorijske kritike. U četvrtom poglavlju promatraćemo u kojoj meri nam uvidi neopragmatista Ričarda Rortija i Donalda Dejvidsona omogućavaju da prevaziđemo određene manjkavati novih teorija prakse. U zaključnom delu rada tvrdićemo da nam naša analiza sugeriše nužnost uviđanja strukture zdravog razuma. Shodno tome, obrazložićemo distinkciju između svojstava konkretnog, svakodnevnog znanja zdravog razuma i zdravorazumskih kvazi teorija. Pokazaćemo da se prva vrsta znanja ne može univerzalizovati i sledi uvide koje su formulisali Garfinkel i Gofman, dok druga vrsta znanja često reprodukuje odnose moći i nejednakosti i zahteva teorijsku kritiku.The object of the research conducted in this thesis will be an historical review and critical analysis of theoretical similarities and differences between pragmatism and sociology. The focus of my interest will be on the theoretical insights into common sense that can be found in contemporary sociology and pragmatism. I will mainly dedicate my attention to the authors of interpretive sociology and new theories of practice. In the thesis I will investigate the role that the pragmatic view on common sense had on the formulation of theoretical insights into everyday experience offered by the interpretive sociology and new theories of practice. Aside from this, I will also reflect on the importance that the theoretical overlapping between pragmatism and sociology had for the potential reconceptualization of the relation between theoretical knowledge and everyday practice. The method that I am going to rely on generally entails research procedures that can be found in studies that deal with mutual influence of theoretical ideas such as: comparison of ideas and theoretical standpoints; investigation of evolution of theoretical insights; investigation of contextual factors that influence the emergence and development of theoretical ideas. The goal of these comparisons that I will be making is to prove that conceptualization of common sense played an important role in creation of new approaches and paradigms in contemporary sociology. The method will also be analytical in the sense that I will systematically question logical coherence of theoretical designations of common sense in the works of authors that will be in the focus of this work. The goal of this thesis is to show that pragmatic understating of common sense could serve as a theoretical frame in which social theory and everyday practice might become closer. I will try to prove that there is continuity between common sense and sociological theory which does not imply that the critical potential of the social theory becomes undermined by this fact. In the introductory part of the thesis, we will shorty review the works of two classical pragmatists and sociologist, John Dewey and Emile Durkheim. We will see that there was a theoretical accordance between the two authors regarding the basis of the phenomena of sociability, and that the differences were mainly grounded on epistemological insights. Namely, Dewey’s naturalism largely entailed a certain amount 7 of continuity between commonsense and scientific ways of thinking and this view was in opposition with Durkheim’s positivism, which implied that everyday knowledge of common sense can ever be commensurable with scientific truth. I will maintain that this difference thoroughly followed further development of both sociology and pragmatism. However, the importance of Durkheim’s epistemological insights can primarily be found in the fact that they played a crucial role in the appearance of functionalism, as one of the most influential theoretical currents in modern sociology. Therefore, in the first chapter I will try to explain how phenomenology and pragmatism laid the foundation for the overcoming of this paradigm. I will especially focus my attention to the works of Alfred Schutz and George Herbert Mead that profoundly influenced interpretative sociology. In the second chapter, I will critically reflect on the theoretical insights of two prominent interpretative sociologists, Harold Garfinkel and Erving Goffman. We will center our analysis on their claim that the concrete everyday knowledge can never be reduced to general forms of understanding social reality, as well as on the typical objection to their work according to which this kind of sociology cannot shed light on power relations present in the society. In the third chapter we will analyze the works of Pierre Bourdieu and Luc Boltanski in which they tried to formulate a synthesis of particular common sense knowledge and universal language of social critique. In the fourth chapter we will consider to which extent the views of the neopragmatists, Richard Rorty and Donald Davidson can help us to overcome some of the shortcomings of the new theories of practice. In the concluding part of the thesis I will claim that our examination suggests that we must take into account the structure of common sense. Therefore, we I will explain the distinction between the properties of concrete everyday knowledge of common sense and commonsensical quasi theories. I will show that the first kind of knowledge cannot be universalized and that it follows the insights Garfinkel and Goffman, while the second kind of knowledge often reproduces the power relations and inequality and demands a theoretical critique

Characterization and utilization of the permeate and retentate obtained after “dead-end” ultrafiltration

In the recent years, with the increase in bioethanol production, the increasing amounts of distillery wastewater are generated. Such wastewater (stillage) is one of the most polluted waste product of the food and beverage industries. The present study evaluates the treatment of distillery wastewater by ultrafiltration (UF), in order to reduce its pollution and evaluate the composition of the permeate and retentate. Polyethersulfone ultrafiltration membrane with molecular weight cut-off (MWCO) 30000 Da, was used for the experiments. The UF was carried out in dead-end mode. The results of the analyses of the permeate and retentate obtained after ultrafiltration were considered as well as different ways for their further utilization. The pollutant level in the permeate was decreased significantly in comparison to the raw stillage, and suspended solids were completely removed from the stillage. [Projekat Ministarstva nauke Republike Srbije, br. TR 31002

Imobilizacija glukoamilaze na makroporoznim sferama

Glucoamylase was covalently immobilized through the spacer-arm of the poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) spheres by using a glutaraldehyde as a coupling agent. The influence of the enzyme load applied to the support on immobilization, yield and specific activity, has been determined. Obtained specific activity was 700 U/g with immobilization yield of 35 %. The Km value for immobilized glucoamylase was 1.28 % (w/v), pH and temperature optimum were 4.5 and 70°C, respectively. The conversion of 20 % (w/w) starch hydrolysate achieved with the immobilized glucoamylase was 97 % after 5 hours.Glukoamilaza je imobilizovana preko spejsera na sfere kopolimera glicidil metakrilata i etilen glikol dimetakrilata uz pomoć glutaraldehida. Određen je uticaj količine dodatog enzima na prinos imobilizacije kao i na specifičnu aktivnost dobijenog imobilizata. Dobijena je specifična aktivnost od 700 U/g sa prinosom imobilizacije od 35%. Km vrednost imobilizovane glukoamilaze je 1,28 % (w/v), pH i temperaturni optimumi su 4,5 i 70°S. Imobilizovani enzim je pri hidrolizi 20 % (w/w) hidrolizata skroba postigao konverziju od 97 % nakon 5 sati

Opasnost za zdravlje u proizvodnji i primjeni pesticida

The results of a long-term survey of working conditions and health status of workers in a pesticide industry in Serbia are presented. The survey has been completed with ophthalmological findings as well as with a description of ten cases of intoxication in pesticide applicators. The difficulties in assessing health hazards in the course of simultaneous exposure to products known for different toxicodynamic properties are pointed out. In conclusion the authors suggest further improvement of preventive measures as well as a more systematic investigation of the combined effects of pesticides in which ophthalmological examinations should be included.Prikazani su rezultati višegodišnjeg praćenja radnih uvjeta i zdravstvenog stanja radnika jedne industrije pesticida u Srbiji. Izvještaj obuhvaća i podatke oftalmoloških pretraga jednog dijela izloženih radnika kao i deset slučajeva otrovanja u toku primjene pesticida. Istaknute su teškoće pri ocjeni opasnosti kada se radi o istodobnoj izloženosti komercijalnim pripravcima različita mehanizma djelovanja. U zaključcima su dani prijedlozi za djelotvorniju preventivu profesionalnih otrovanja kao i za temeljitiji studij mogućih kombiniranih učinaka pesticida pri kojem se, po mišljenju autora, valja koristiti i oftalmološkim nalazima

Microfiltration of distillery stillage: Influence of membrane pore size

Stillage is one of the most polluted waste products of the food industry. Beside large volume, the stillage contains high amount of suspended solids, high values of chemical oxygen demand and biological oxygen demand, so it should not be discharged in the nature before previous purification. In this work, three ceramic membranes for microfiltration with different pore sizes were tested for stillage purification in order to find the most suitable membrane for the filtration process. Ceramic membranes with a nominal pore size of 200 nm, 450 nm and 800 nm were used for filtration. The influence of pore size on permeate flux and removal efficiency was investigated. A membrane with the pore size of 200 nm showed the best filtration performance so it was chosen for the microfiltration process