Ultrazvučna karakterizacija cementnih kompozita tijekom hidratacije

Ultrasonic measurements used to monitor the hydration of cement based materials are becoming an important tool in the quality assurance in production. Also, using these methods can be cost benefit for the construction companies because they can provide information about evolution of material properties in real time. In this paper ultrasonic testing is used to characterize a hydration process of cement paste. A technique is based on the system for measuring the ultrasonic pulse velocity (UPV). To obtain more information about wave propagation characteristics the technique of acoustic emission (AE) is also used. Entire waveform of the signal is recorded. AE parameters are extracted from the signal and used to characterize different processes in cement paste during hydration. An analysis is performed on cement pastes made with different water-cement ratios. Ultrasonic wave parameters are compared to the initial and final setting time using the Vicat needle test and compressive strength development.Korištenje ultrazvučnih mjerenja za praćenje hidratacije materijala na bazi cementa postaje važan alat osiguranja kvalitete u proizvodnji. Također, korištenje tih metoda može biti ekonomski isplativo za izvođačke tvrtke jer omogućavaju trenutno dobivanje informacija o razvoju svojstava materijala. U ovom radu ispitivanje ultrazvukom je primijenjeno za karakterizaciju procesa hidratacije cementne paste. Metoda mjerenja temeljena je na sustavu za mjerenje brzine ultrazvučnog impulsa (UPV). Kako bi se dobilo više informacija o svojstvima širenja valova korištena je i metoda akustične emisije (AE). Cijeli valni zapis je sniman te su iz signala izračunati parametri akustične emisije koji su korišteni za karakterizaciju različitih procesa u cementnoj pasti tijekom hidratacije. Analiza je provedena na cementnim pastama izrađenim s različitim vodo-cementnim omjerima. Parametri ultrazvučnih valova uspoređeni su s početkom i krajem vezanja dobivenim Vicatovom iglom i razvojem tlačne čvrstoće

Development and assessment of development strategy alternatives in strategic environmental assessment

Development and evaluation of alternatives is a key process in the strategic environmental assessment (SEA), which enables improvement of the environment, informed decision-making, greater transparency and better opportunities for public participation. It is also the most challenging part of the assessment, because the alternatives are often avoided or considered to the extent to meet the legal requirements. The absence of alternatives in the assessment process significantly diminishes the contribution of SEA to the environmental protection system. The paper will outline the generally applicable methodology for the development and assessment of alternatives in the SEA process, on the example of the Development Strategy of the City of Solin, which is based on the development of the environmental alternative, which significantly contributes to the development of sustainable strategic solutions

SURVEY ON SUSTAINABLE CONSTRUCTION SYSTEMS: LEED, BREEAM, DGNB

S obzirom da je graditeljstvo veliki potrošač prirodnih i energetskih resursa, od velike je važnosti smanjiti negativne utjecaje gradnje na okoliš kao i zadovoljiti ostale kriterije održivosti. U svijetu su razvijeni razni sustavi ocjenjivanja za mjerenje razine održivosti gradnje i osiguranja najbolje kvalitete u svojoj najvišoj razini certifikacije. Ovaj rad daje pregled relevantne znanstvene literature vezane uz održivu gradnju. Osim koncepta održive gradnje u radu su opisani globalno prepoznati sustavi certificiranja održive gradnje LEED (engl. Leadership in Energy and Environmental Design), BREEAM (engl. Building Research Establishment Environmental Assessment Methodology) i DGNB (njem. Deutsche Gesellschaft für Nachhaltiges Bauen), te su uz usporedbu njihovih kriterija za ocjenjivanje, predložene mjere za daljnje unaprjeđenje. Također, stavljen je naglasak i na dobrobit samog ocjenjivanja i certificiranja održivosti gradnje, kao i na važnost poticanja održive gradnje.Since construction is a major consumer of natural and energy resources, it is essential to reduce the negative impacts of construction on the environment and satisfy other sustainability criteria. Therefore, various assessment systems have been developed to measure the level of building sustainability and to assure the best quality at its highest level of certification. This paper presents an overview of relevant scientific literature related to sustainable construction. In addition to the concept of sustainable construction, the paper individually describes several globally recognized sustainable building certification systems LEED (Leadership in Energy and Environmental Design), BREEAM (Building Research Establishment Environmental Assessment Methodology) and DGNB (germ. Deutsche Gesellschaft für Nachhaltiges Bauen) and by comparing their criteria for evaluation, actions for further improvement have been proposed. Also, emphasis was set on the benefits of the evaluation and certification of construction sustainability, as well as the importance of encouraging sustainable construction

Assessment of water quality status in the impact area of the “Piškornica” landfill

Disposal of household and industrial waste at the Piškornica site began in 1982 on what was then an unmanaged landfill cell, which allowed contamination to pass into underground layers. Landfill rehabilitation was conducted between 2005 and 2013 and conformed to the environmental protection conditions and measures that were prescribed by an EIA procedure, but rehabilitation still has not been fully completed. An environmental permit was issued for rehabilitation of the landfill. The decision and environmental permit prescribed groundwater quality monitoring. Prior to these documents, five piezometers were placed into operation in 1991. The objective of this paper is to determine the potential differences in ground and surface water quality that may have resulted from landfill operations, effectiveness of the rehabilitation efforts, and the potential risk of contamination of the Ivanščak water well. The results of the research were subjected to statistical analyses (e.g., T-test and ANOVA). Based on the regional flow model, a numerical groundwater flow model and contamination transport model were created, which provided scenarios for the potential spread of pollution from the Piškornica landfill while considering different water well operation regimes. It was concluded that a) even though rehabilitation has not been completed, the groundwater quality status improved and b) none of the analysed real flow scenarios generated redirection of streamline patterns towards the Ivanščak water well. Considering future development and likely increase of the Ivanščak well capacity, the expansion of monitoring was proposed for additional measuring locations

Ultrazvučna karakterizacija cementnih kompozita tijekom hidratacije

Ultrasonic measurements used to monitor the hydration of cement based materials are becoming an important tool in the quality assurance in production. Also, using these methods can be cost benefit for the construction companies because they can provide information about evolution of material properties in real time. In this paper ultrasonic testing is used to characterize a hydration process of cement paste. A technique is based on the system for measuring the ultrasonic pulse velocity (UPV). To obtain more information about wave propagation characteristics the technique of acoustic emission (AE) is also used. Entire waveform of the signal is recorded. AE parameters are extracted from the signal and used to characterize different processes in cement paste during hydration. An analysis is performed on cement pastes made with different water-cement ratios. Ultrasonic wave parameters are compared to the initial and final setting time using the Vicat needle test and compressive strength development.Korištenje ultrazvučnih mjerenja za praćenje hidratacije materijala na bazi cementa postaje važan alat osiguranja kvalitete u proizvodnji. Također, korištenje tih metoda može biti ekonomski isplativo za izvođačke tvrtke jer omogućavaju trenutno dobivanje informacija o razvoju svojstava materijala. U ovom radu ispitivanje ultrazvukom je primijenjeno za karakterizaciju procesa hidratacije cementne paste. Metoda mjerenja temeljena je na sustavu za mjerenje brzine ultrazvučnog impulsa (UPV). Kako bi se dobilo više informacija o svojstvima širenja valova korištena je i metoda akustične emisije (AE). Cijeli valni zapis je sniman te su iz signala izračunati parametri akustične emisije koji su korišteni za karakterizaciju različitih procesa u cementnoj pasti tijekom hidratacije. Analiza je provedena na cementnim pastama izrađenim s različitim vodo-cementnim omjerima. Parametri ultrazvučnih valova uspoređeni su s početkom i krajem vezanja dobivenim Vicatovom iglom i razvojem tlačne čvrstoće

Inertizacija galvanskog mulja s pomoću kalcijeva oksida, aktivnog ugljena i fosforne kiseline

In this study we compared three methods for the treatment of electroplating sludge highly loaded with zinc and iron: (1) calcium oxide-based solidifi cation/stabilisation; (2) conversion into inert material by adsorption of organic and inorganic pollutants onto activated carbon; and (3) conversion of mobile waste components into insoluble phosphates. All three methods proved highly efficient in the conversion of hazardous waste into inert material. Under optimum treatment conditions zinc concentration in the leachate of solidified waste was reduced by 99.7 % compared to untreated sludge. Zinc retention effi ciency in the waste treated with activated carbon and phosphoric acid was 99.9 % and 98.7 %, respectively. The advantages of electroplating sludge treatment with activated carbon over the other two methods are high sorption capacity, insignificant pH and volume changes of the sludge, and simple use.U radu su prikazani i uspoređeni rezultati triju metoda obrade galvanskog mulja visoko opterećenog cinkom i željezom: (1) solidifi kacija/stabilizacija otpada primjenom kalcijeva oksida; (2) inertizacija otpada adsorpcijom organskog i anorganskog opterećenja na aktivni ugljen; (3) prevođenje mobilnih komponenata otpada u teško topljive fosfate. Sve tri metode pokazale su se efikasnima u prevođenju opasnog otpada u inertno stanje. Kod optimalnih uvjeta koncentracija cinka u eluatu solidificiranog otpada snizila se za 99,7 % u odnosu prema neobrađenom otpadu. Efikasnost retencije cinka u otpadu inertiziranom aktivnim ugljenom iznosila je 99,9 %, a fosfornom kiselinom 98,7 %. Prednost inertizacije aktivnim ugljenom u odnosu prema ostalim dvjema metodama očituje se visokim sorpcijskim kapacitetom, neznatnim promjenama pH-vrijednosti i volumena tretiranog otpada, kao i jednostavnošću primjene

Psychometric properties and factor structure of the Temperament and Character Inventory-Revised (TCI-R) in a Croatian psychiatric outpatient sample

OBJECTIVE: The goal of this study was to investigate psychometric properties and factorial structure of the Croatian adaptation of the Temperament and Character Inventory-Revised (TCI-R) in a sample of psychiatric outpatients (n=328). ----- METHOD: The participants filled out the TCI-R, as well as self-report measures of the Big-Five personality traits (IPIP-50), trait impulsivity (BIS-11), depression (BDI-II), suicidality (SBQ-R), and life satisfaction (SWLS). We explored the internal consistency of 7 domains and 29 subscales and compared it with the Croatian version of the original TCI used in prior studies. Principal component analysis with promax rotation was conducted on temperament and character subscales separately, while concurrent validity was examined through the TCI-R's relations with the abovementioned psychological measures. ----- RESULTS: The TCI-R scales showed adequate internal consistencies, with Cronbach's alpha values ranging from 0.77 to 0.93. The internal consistency showed to be higher in comparison with the Croatian version of the original TCI. The postulated four-factor structure of temperament and the three-factor structure of character were confirmed. The meaningful associations with other measures supported the concurrent validity of the TCI-R. ----- CONCLUSION: The Croatian adaptation of the TCI-R exhibited satisfactory reliability and validity in a sample of psychiatric outpatients. These findings support the use of the TCI-R in Croatian clinical settings over its predecessor (TCI)

ANHEDONIA IN SCHIZOPHRENIA: MINI-REVIEW

The perception of reward exerts a powerful influence on human behavior. While anhedonia might occur in healthy individuals, its prevalence and severity are much higher in psychiatric patients, particularly those with depression and schizophrenia. Anhedonia is a negative symptom, and presumably a trait marker in schizophrenia. Recent research confirmed that anhedonia is a complex construct, consisting of anticipatory, consummatory, and reward learning components. In general, schizophrenia patients show anticipation deficits, and a substantial portion of them have physical (PA) and social anhedonia (SA). The relationship between anhedonia and psychopathology appears bidirectional. While gene-environment interactions affect reward circuity, anhedonia modulates clinical features, such as suicidality and nicotine consumption. Future clinical research employing longitudinal designs may shed more light on the dynamics and treatment of anhedonia in schizophreni

ANHEDONIA IN SCHIZOPHRENIA: MINI-REVIEW

The perception of reward exerts a powerful influence on human behavior. While anhedonia might occur in healthy individuals, its prevalence and severity are much higher in psychiatric patients, particularly those with depression and schizophrenia. Anhedonia is a negative symptom, and presumably a trait marker in schizophrenia. Recent research confirmed that anhedonia is a complex construct, consisting of anticipatory, consummatory, and reward learning components. In general, schizophrenia patients show anticipation deficits, and a substantial portion of them have physical (PA) and social anhedonia (SA). The relationship between anhedonia and psychopathology appears bidirectional. While gene-environment interactions affect reward circuity, anhedonia modulates clinical features, such as suicidality and nicotine consumption. Future clinical research employing longitudinal designs may shed more light on the dynamics and treatment of anhedonia in schizophreni

Hepatitis E in patients with hepatic disorders and HIV-infected patients in Croatia: is one diagnostic method enough for hepatitis E diagnosis?

We assessed hepatitis E virus (HEV) seroprevalence in patients with hepatic disorders as well as in human immunodeficiency virus (HIV)-infected patients and emphasised the issue of possible non-specific anti-HEV seroresponse and need for combining diagnostic methods for hepatitis E diagnosis. Over a two-year period, from March 2011 to February 2013, we determined anti-HEV immunoglobulin M (IgM) and IgG by enzyme immunoassays (EIA; Mikrogen, Germany) in 504 hepatitis patients negative for acute viral hepatitis A-C. Furthermore, 88 samples from randomly selected consecutive HIV-infected patients were also analysed. All EIA reactive samples were additionally tested by line immunoblot assays (LIA; Mikrogen, Germany). HEV nested reverse transcription polymerase chain reaction (RT-PCR) was carried out in 14 anti-HEV IgM LIA-positive patients. Anti-HEV IgM or IgG were detected in 16.9 % of patients by EIA and confirmed by LIA in 10.7 % [95 % confidence interval (CI) 8.3-13.7 %] of hepatitis patients. HEV RNA was detected in five patients. The agreement between EIA and LIA assessed by Cohen's kappa was 0.47 (95 % CI 0.55-0.75) for IgM and 0.83 (95 % CI 0.78-0.93) for IgG. Anti-HEV IgM and IgG seroprevalence in HIV-infected patients was 1.1 %, respectively. Our findings show a rather high HEV seroprevalence in patients with elevated liver enzymes in comparison to HIV-infected patients. Discordant findings by different methods stress the need to combine complementary methods and use a two-tier approach with prudent interpretation of reactive serological results for hepatitis E diagnosis