Determination of the zinc and cadmium contents in low-alloyed tin

The method of anodic linear sweep voltammetry (ALSV) has been used to determine the content of Zn and Cd (up to 4% w/w) in eutectic type binary alloys with Sn. The alloy samples were prepared by casting. The effect of the type and the pH of the electrolyte, as well as of the sweep-rate on the dissolution of Zn and Cd from the alloy during an anodic potentinal-sweep was investigated. It was shown that ALSV is sensitive to low concentrations of both Zn and Cd in the investigated alloys, as well-defined peaks of the dissolution of the two metals were recorded before the massive dissolution of Sn commenced. Well-defined linear dependencies between the quantities of electricity under the dissolution peaks of Zn (Qzn) or Cd (Qcd) and the respective contents of the metals in the alloys were found. Intercepts at the abscissa were found in both investigated systems indicating the formation of solid solutions from which neither Zn nor Cd could be eluted. In both alloys, the smallest amount of the alloying component which could be detected was 0.25% (w/w). The application of the ALSV method has several advantages over other analytical methods: it is non-destructive as the dissolution involves only a very thin layer of the alloy; it requires simple and cheap instrumentation; it is fast and relatively sensitive. These make it suitable for routine analysis

The Relationship Between Occlusion and Temporomadibular Disorders

Etiologija temporomandibularnih poremećaja i može bitini utjecaj nisu potpuno razjašnjeni. Svrha istraživanja bila je utvrditi utjecaj okluzijskih odnosa na funkciju stomatognatoga sustava. Ispitivana skupina sastojala se je od 96 ispitanika u dobi od 24-52 godine (x = 35,03 ± 6,92). Kliničkim pregledom utvrđen je broj zuba, broj zuba u okluziji, okluzijska koncepcija (okluzija vođena očnjakom, grupna funkcija i bilateralno uravnotežena okluzija). Izjereni su iznosi okomitog preklopa i vodoravnog pregriza. RKP položaj određen je chin-point tehnikom i fiksiran Luciajigom. Klizanje iz RKP u IKP položaj izmjereno je u anteroposteriornom, okomitom i postraničnome smjeru. Mjerenja maksimalnih kretnji izvršena su s pomoću precizne pomične mjerke. Registrirana je možebitna pojava zvuka i boli. Izvršena je palpacija temporomandibularnih zglobova, žvačnih i vratnih mišića. Izračunani su Helkimov okuzijski, anamnestiči i klinički disfunkcijski indeks (indeks mandibularne pokretljivosti, indeks funkcije temporomandibularnoga zgloba, indeks bolnosti mandibularnih kretnji te indeks mišićne i zglobne boli). 3,21% ispitanika bilo je bez okluzijskih poremećaja (Oi0), 52,32% imalo je umjerene okluzijske poremećaje (OiI), a 38,56% imalo je ozbiljne okluzijske poremećaje (OiII). U usporedbi s anamnestičkim i kliničkim disfunkcijskim indeksom Pearson ?2 test pokazuje da ozbiljni okluzijski poremećaji nisu povezani sa ozbiljnim disfunkcijskim poremećajima. Razlika među skupinama nije statistički znatna (p > 0,05). Rezultati ovoga istraživanja upućuju na zaključak da okluzija nema utjecaja na nastanak i tijek TMD-a.The etiology of temporomandibular disorders and the role of occlusion, has still not been entirely clarified. The objective of this investigation was to determine the effect of occlusal relationship on the function of the stomatognathic system. A group of subjects, aged from 24-52 years (x = 35.03 ± 6.92) was examined. The number of teeth, the number of teeth in occlusion, type of occlusion (canine guided occlusion, group function and balanced occlusion) was determined by clinical examination. Overbite and overjet were measured. RCP position was determined by chinpoint technique and fixing by Lucia-jig. The sliding from RCP to IKP position was determined in the anteroposterior, vertical and lateral direction. A precise calliper was used to measure maximal jaw movement. Pain and sounds were registred. Temporomandibular joints, masticatory and neck muscles were palpated. Helkimo Occlusal, Anamnestic and Clinical Dysfunction Indexes (Index of mandibular movement, index of TMJ function, Index of painful mandibular movements, index of muscular and TMJ pain) were calculated. 3.21% of the subjects were without occlusal disorders (Oi0), 58.32% had moderate occlusal problems (OiI) and 38.56% had severe occlusal problems (OiII). When compared to Anamnestic and Clinical Dysfunction Index the Pearson ?2 test analysis shows that severe occlusal problems are not correlated to severe dysfunction. The difference between the groups is not statistically significant (p > 0.05). The results of this study suggest that occlusion does not have an influence on the occurrence of TMD

A DECISION SUPPORT TOOL ON DERELICT BUILDINGS FOR URBAN REGENERATION

Abstract. We present a decision suppport tool for the comparison and selection of projects of integrated renovation of derelict buildings and areas for the purpose of urban regeneration. Each project is defined as a subset of derelict properties to renovate together with their respective designated use, and is scored by the decision support tool on two criteria: expected effort and estimated effectiveness in terms of improved urban capabilities in the urban area of interest. The expected effort is estimated as a global transformation cost, factoring in legal and management overhead costs as well as possible economies of scale. The effectiveness in evaluated in terms of extension of urban capabilities centred on walkable distances. We have implemented a bi-objective evolutionary search algorithm to address the computational complexity of the problem of search for efficient (non-dominated) projects over the two criteria. For the purpose of illustration, we present an example case-study application on the historical core of the city of Sassari, Italy.</p

Prevalence of Self-Reported Symptoms of TMD in a Population of Rijeka, Croatia

Svrha ovog istraživanja bila je ispitati prevalenciju simptoma TMD u stanovništvu Rijeke. Istraživanje je provedeno na uzorku 408 odraslih osoba starih od 18-84 godine, podijeljenih po dobi i spolu. Postojanje TMD simptoma dobili smo upotrebom kliničko- anamnestičkih upitnika koji se sastojao od 11 pitanja tipičnih za TMD simptomatologiju. Okluzalne parametre dobili smo raščlambom RCP, ICP prednjega vođenja i lateralnih kretnji. Kliničke znakove TMD dobili smo palpacijom mišića žvakača i TMJ. Anamnezom smo došli do podatka da je 16 % ispitanika izjavilo kako ima noćni bruksizam, a 33 % dnevni. 26 % ispitanika osjetilo je škljocanje u zglobu. 37 % pacijenata ima uz bruksizam i glavobolju, 35 % ima bolan vrat i ramena, a 33 % ima škljocanje u TMZ. U skupini pacijenata bez bruksizma 41 % ima glavobolju, 29 % bolni vrat i 24 % ima škljocanje. Možemo zaključiti da postoji veza između pojave noćnog bruksizma i bolnosti mišića vrata i ramena te škljocanje TMZ.The aim of this study was to evaluate the prevalence of temporomandibular disorder (TMD) symptoms in a population of Rijeka, Croatia. The study was performed on a sample of 408 adult subjects, aged 18-84 years divided into three groups by age and gender. The presence and severity of TMD was determined by using a self reported anamnestic questionnaire comprised of 11 questions regarding common TMD symptoms. Occlusal evaluation included analyses of RCP, ICP, anterolateral guidance, and nonworking side contacts during mandibular movements. Palpation of the muscles and TMJ was performed to detect clinical signs of TMD. A total of 16 % of the examinees had self-reported nocturnal bruxism and 33 % had daily bruxism. 26 % of the examinees experienced TMJ clicking. 28 % of the examinees experienced tension type headache, more than once a month. 37 % of the patients with bruxism had headaches, 35 % had painful necks and shoulders, and 33 % experienced TMJ clicking. Of those who did not suffer from bruxism, 41 % had headaches, 29 % had painful neck and sholders and 24% had TMJ clicking. It appears that sleep bruxism is related with the presence of painful neck and sholders and TMJ clicking

Shift of the western boundary of the distribution area of Micromeria cristata (Hampe) Griseb. and Steptorhamphus tuberosus (Jacq.) Grossh.

During field investigations of Mt Rumija, two new taxa for the flora of Montenegro were recorded: Micromeria cristata (Hampe) Griseb. and Steptorhamphus tuberosus (Jacq.) Grossh. From the phytogeographic point of view these data indicate a change in the distribution area of both taxa, which have shifted to the west. Ashort overview of the taxonomic treatment of both genera is given

Ultramafic vegetation and soils in the circumboreal region of the Northern Hemisphere

The paper summarizes literature on climate, soil chemistry, vegetation and metal accumulation by plants found on ultramafic substrata in the circumboreal zone (sensu Takhtajan, Floristic regions of the world, 1986) of the Northern Hemisphere. We present a list of 50 endemic species and 18 ecotypes obligate to ultramafic soils from the circumboreal region of Holarctic, as well as 30 and 2 species of Ni and Zn hyperaccumulators, respectively. The number of both endemics and hyperaccumulators are markedly lower compared to that of the Mediterranean and tropical regions. The diversity of plant communities on ultramafics soils of the circumboral region is also described. The underlying causes for the differences of ultramafic flora between arctic, cold, cool temperate and Mediterranean and tropical regions are also discussed. © 2018, The Ecological Society of Japan

FACTORY FOR THE PRODUCTION OF WELD-

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Immobilization of zinc from metallurgical waste and water solutions using geopolymerization technology

Geopolymeraization technology is recognized as a promising method for immobilization of heavy metals by the stabilization or solidification process. This process involves the chemical reaction of alumino-silicate oxides with highly alkaline activator yielding the new material with amorphous or semi-amorphous structure, called geopolymer. Fly ash and blast furnace slag were mainly used as a raw material for geopolymerization process. In this paper we have investigated the possibility of immobilization of Zn from electric arc furnace dust (EAFD) through geopolymerization of fly ash and possibility of Zn2+ adsorption from waste waters using fly ash based geopolymers. Efficacy of Zn immobilization from electric arc furnace dust was evaluated by TCLP test while the immobilization of Zn2+ ions from the water solution was evaluated through the removal efficiency. The results have shown that geopolymerization process may successfully be used for immobilization of Zn by stabilization of EAFD and for production of low cost adsorbent for waste water treatment