12 research outputs found

    Analysis and Measurement of Foundation Vibrations at Two Compressor Stations in Yugoslavia

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    The design procedure and the measurements of foundation vibrations at two compressor stations are presented. Simple methods and models were used to predict machine foundation behavior-and it is shown that they were effective in estimating the expected range of amplitudes through simple parameter variation. In attempt to lower vibrations amplitudes, spreading of gravel layer under machine foundation was suggested, the effect of which is discussed in the paper

    Estimation of bored pile capacity and settlement in soft soils

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    Iako se tehnologije izvedbe pilota sve viÅ”e usavrÅ”avaju, problemi procjene nosivosti i slijeganja su i dalje prisutni, pri čemu metode procjene u znatnoj mjeri predstavljaju kombinaciju teorije i empirije. U radu se analizira nosivost i slijeganje buÅ”enih pilota, kao najčeŔće koriÅ”tenog tipa pilota u domaćoj praksi. Empirijske metode procjene nosivosti iz geotehničkih parametara tla uvode niz određenih pojednostavljenja, čime se izostavljaju pojedini elementi složene interakcije pilot-tlo. S druge strane, rezultati terenskih ispitivanja pilota su izravna zbirna posljedica složenih sveukupnih uvjeta na kontaktu tla i pilota.Although the technologies of pile construction are improving, the problems of load capacity and settlements determination are still present, where estimation methods are mostly a combination of theory and empiricism. This paper analyzes the bearing capacity and settlement of bored piles, as the most frequently used type of piles in local practice. Empirical methods based on geotechnical soil parameters for capacity estimation, introduce some simplifications which lead to neglecting certain elements of a complex pile-soil interaction. On the other hand, the results of pile field testing methods are a direct summary consequence of the overall complex conditions on pile-soil contact

    Overview of parameters for stability analysis on waste disposal sites

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    U radu su navedeni bitni parametri za analize globalne stabilnosti odlagaliÅ”ta komunalnog otpada. Predočen je iscrpan prikaz parametara otpada te njihove varijabilnosti. Ističe se da sadaÅ”nji podaci imaju ograničenu vrijednost pa su potrebni neposredni podaci i mjerenja. Upozorava se na probleme određivanja parametara čvrstoće na dodirnim plohama u brtvenim slojevima i predlaže jednostavan postupak statističke obrade rezultata pokusa za određivanje nelinearne anvelope sloma.An overview of parameters significant in the analysis of global stability of communal waste disposal sites is presented. A detailed account is given of waste parameters and their variability. It is emphasized that present data have limited value and that direct data and measurements are required. The attention is drawn to problems of determining strength parameters on contact surfaces of liners, and a simple procedure of statistical treatment of test results is recommended as a way of determining the nonlinear failure envelope

    Numerical investigations of interaction between geogrid/wire fabric reinforcement and cohesionless fill in pull-out test

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    Interakcija geomreža/mrežastih armatura i zasipa u zidovima od armiranog tla, kao i njeno kvantificiranje predstavljaju složen problem koji ovisi o brojnim faktorima. U ovom radu su prikazana i komentirana dosadaÅ”nja saznanja o numeričkim modelima pokusa izvlačenja kojim se ispituje interakcija armatura i nekoherentnog zasipa. Također su prikazani i rezultati posebno osmiÅ”ljene skupine numeričkih simulacija, te su uspoređeni s preporukama američkih i europskih normi za provođenje ovakvih pokusa.The interaction between geogrid/wire fabric reinforcement and fill material in reinforced earth walls, as well as its quantification, is a complex problem that depends on a number of factors. This paper presents and discusses state of the art related to numerical simulations of pull-out tests used for investigation of interaction between cohesionless fill and reinforcement. In addition, the results of a specially designed group of numerical simulations are presented and compared with recommendations of American and European standards related to such experiments

    Geotechnics as an unavoidable segment of earthquake engineering

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    Ovaj rad daje Å”iri pregled uloge geotehnike u potresnom inženjerstvu te obuhvaća niz praktičnih primjera kvantifikacije geotehničkih seizmičkih pokazatelja za potrebe izgradnje pojedinih objekata, kao i osvrt na nadolazeće promjene u sadaÅ”njim projektnim normama koje evaluiraju utjecaj tla na građevine u potresnim uvjetima. S obzirom na seizmičku aktivnost područja Hrvatske, istaknuta je nužnost sveobuhvatnog pristupa seizmičkom mikrozoniranju koji uzima u obzir čitav niz pokazatelja, od litoloÅ”kih, inženjerskogeoloÅ”kih i hidrogeoloÅ”kih karakteristika te položaja aktivnih rasjeda, do identifikacije nestabilnih padina i zona izraženog likvefakcijskog potencija, za Å”to je potrebna provedba opsežnih geofizičkih i geotehničkih istraživanja.A broader overview of the role of geotechnics in earthquake engineering is given, and a set of practical examples of the quantification of geotechnical seismic indicators for construction of individual buildings is provided. An overview of oncoming changes to the current design standards for evaluating the effect the soil has on buildings in earthquake conditions is also given. Considering the level of seismic activity in Croatia, the need for adopting a comprehensive approach to seismic microzoning is emphasized, which involves a whole array of indicators, from lithological, engineering geological, and hydrogeological properties, and position of active faults, to identification of unstable slopes and zones of pronounced liquefaction potential, for which extensive geophysical and geotechnical investigations are required

    Razine kortikosterona i biokemijskih pokazatelja u krvi Ŕtakora kao modela za streptozotocinski dijabetes: utjecaj omjera n3/n6 u hrani

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    The study was carried out to investigate the influence of dietary n6/n3 ratio in streptozotocin (STZ) induced diabetes on serum biochemistry and corticosterone values in blood in 15 Wistar male rats assigned into three experimental groups, two diabetic and a control group (STZ-N3, STZ-N6, CON) fed with different diets (n6/n3 ratio: ā‰ˆ 1, n6/n3 ratio: ā‰ˆ60, CON n6/n3 ratio: ā‰ˆ7). Significantly higher values of alkaline phosphatase (AP) and beta-hydroxybutyrate (BHB) and lower levels for triglyceride and albumin were noticed in both STZ treated groups compared to the control. The values for blood urea nitrogen (BUN) were increased in only the STZ-N3 group compared to the control (P<0.05). The values for the total bilirubin (P<0.05) and alanine aminotransferase (ALT) (P<0.05) were higher in only the STZ-N6 group compared to the control. In addition,the STZ-N3 group had lower albumin values compared to the STZ-N6 group (P < 0.001). Corticosterone values did not significantly differ among all three experimental groups indicating similar levels of stress. In conclusion, the n6/n3 ratio significantly influences blood biochemical parameters in STZ-treated rats. Nevertheless, neither the n6/n3 ratio nor blood sampling and handling influences corticosterone values, which proved the validity of the STZ-induced rodent model of diabetes mellitus in the experimental conditions described.Pokus je proveden kako bi se istražio utjecaj udjela n6/n3 u hrani na biokemijske pokazatelje i vrijednost kortikosterona u serumu Å”takora kojima je primjenom streptozotocina uzrokovan dijabetes. Istraživanjem je obuhvaćeno 15 mužjaka Å”takora Wistar podijeljenih u tri skupine: dvije skupine dijabetičara i kontrolnu skupinu (STZ-N3, STZ-N6, CON). Svaka je skupina hranjena različitim udjelom n3/n6: STZ-N3 udjelom n6/n3 ā‰ˆ 1, STZ-N6 udjelom n6/n3 ā‰ˆ 60, CON udjelom n6/n3 ā‰ˆ 7. U objema pokusnim skupinima utvrđene su znakovito viÅ”e vrijednosti alkalne fosfataze (AP) i betahidroksimaslačne kiseline (BHB) te niže vrijednosti triglicerida i albumina u odnosu na kontrolnu skupinu. Vrijednosti glukoze (BUN) bile su poviÅ”ene samo u skupini STZ-N3 u odnosu na kontrolnu (P < 0,05). Vrijednosti ukupnog bilirubina (P < 0,05) i alanine-transferaze (ALT) (P<0,05) bile su viÅ”e samo u skupini STZ-N6 u odnosu na kontrolnu skupinu. Skupina STZ-N3 imala je nižu vrijednost albumina u odnosu na skupinu STZ-N6 (P < 0,001). Vrijednost kortikosterona nije se znakovito razlikovala među skupinama posredno dokazujući da među njima postoji slična razina stresa. Zaključno, omjer n3/n6 u hrani utjecao je na određene biokemijske pokazatelje u krvi Å”takora tretiranih streptozotocinom. No omjer n3/ n6, postupak uzorkovanja krvi i baratanje Å”takorima nisu utjecali na vrijednosti kortikosterona čime je dokazana valjanost animalnog modela sa streptozotocinom uzrokovanom Å”ećernom boleŔću u opisanim uvjetima pokusa

    Electrical impedance meter for impedance cardiography based on AD5933 impedance converter

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    Impedancijska kardiografija je metoda mjerenja i proučavanja signala promjene impedancije u području prsnog koŔa. U ovom diplomskom radu opisano je razvijeno mjerilo impedancije zasnovano na integriranom krugu AD5933 za mjerenje signala impedancijske kardiografije. Opisana je struktura i funkcionalni dijelovi samog integriranog kruga AD5933 te evaluacijska pločica sa Stellaris LM3S6965 mikrokontrolerom koji upravlja tim mjerilom. ObjaŔnjen je razvijeni program za mjerenje promjene impedancije u vremenu te pojaŔnjen postupak mjerenja. Prezentirano je nekoliko ispitnih mjerenja signala impedancijske kardiografije te su prodiskutirani dobiveni rezultati.Impedance cardiography is a technique for measuring and studying impedance change signal in thorax region. In this thesis, electrical impedance meter for impedance cardiography based on integrated circuit AD5933 is described. Structure and functional parts of integrated circuit AD5933 plus evaluation board with Stellaris LM3S6965 microcontroller for impedance meter control are depicted. Developed firmware for time sweep impedance measurement is explained as well as measuring process. Several test impedance cardiography measurements are presented and obtained results are discussed
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