1,261 research outputs found
Trajectory-based interpretation of laser light diffraction by a sharp edge
In the diffraction pattern produced by a half-plane sharp edge when it
obstructs the passage of a laser beam, two characteristic regions are
noticeable. There is a central region, where it can be noticed the diffraction
of laser light in the region of geometric shadow, while intensity oscillations
are observed in the non-obstructed area. On both sides of the edge, there are
also very long light traces along the normal to the edge of the obstacle. The
theoretical explanation to this phenomenon is based on the Fresnel-Kirchhoff
diffraction theory applied to the Gaussian beam propagation behind the
obstacle. Here we have supplemented this explanation by considering
electromagnetic flow lines, which provide a more complete interpretation of the
phenomenon in terms of electric and magnetic fields and flux lines, and that
can be related, at the same time, with average photon paths.Comment: 13 pages, 5 figure
Radiographic and Prosthetic Assessment Prior to Implantoprosthetic Therapy
Jedan od osnovnih uvjeta uspješnosti terapije oseointegrirajućim usadcima jest dobro predkirurško planiranje. Svrha je ovoga rada prikazati na slučaju djelomične bezubosti u distalnom dijelu mandibule mogućnosti radiološke i protetske ocjene prije kirurškoga tretmana. Na modelu čeljusti učinjeno je dijagnostičko navoštavanje. Nakon toga izrađena je šablona iz vakuum termoplastične folije. Metalne kuglice poznatoga promjera stavljene su u pozicije navoštanih zuba kako bi se radiološkom tehnikom ocijenila mogućnost implantacije u predviđenim pozicijama. Učinjen je klasični ortopantomogram te na temelju njega i slojeviti tomogram s točnim presjecima mandibule na položajima budućih usadaka. Na temelju rendgenskih nalaza određen je položaj i duljina usadaka. Prikazan je klasičan dvofazni kirurški protokol te operacijska tehnika s intraoralnim pretprotetskim šablonama. Uporabljeni su usadci Astratech microthread koničnoga profila kako bi se promjerom usatka što više približili promjeru budućega zuba. Dužina usatka određena je u skladu s navedenom radiološkom raščlambom tako da je usadak na poziciji 35 kraći od usadaka 34 i 37 zbog anatomske pozicije foramena mentale. Pri kirurškome pozicioniranju usatka osim pozicije koja je određena šablonom usadci su u okomitome smjeru pozicionirani u skladu s biološkom širinom sluznice i u konačnici parodontološko estetskim zahtjevima. Rezultati prikazuju uspješnost terapije nakon dobra planiranja i pripreme. Prikazana je prednost slojevite tomografije u planiranju i određivanju anatomsko-morfoloških karakteristika donje čeljusti koja nam daje sigurnost u izboru dužine, a osobito širine usatka. Predkirurško planiranje je postupak kojime možemo predvidjeti položaj usatka i estetiku budućega protetskog rada te tako olakšati kirurški zahvat.One of the fundamental pre-conditions for successful therapy by osseo-integrating implants is good pre-surgical planning. The aim of this work is to present the possibilities of radiographic and prosthetic evaluation prior to surgical treatment in the case of partial edentulousness.in the distal part of the mandibula. Diagnostic wax-up is done on a model of the jaw. After which a pattern is made of vacuum thermoplastic foil. Metal pellets of known diameter are placed in the positions of the waxed-up teeth to enable radiographic evaluation of the possibility of implantation in the planned positions. Classical orthopantomography is performed on the basis of which a multi-layer tomogram is done with exact cross-sections of the mandibula in the positions of future implants. On the basis of radiographic findings the position and length of the implants are determined. The classical two-phase surgical protocol is described and surgical technique with intraoral pre-prosthetic patterns. Astratech microthread implants of conical profile are used to ensure that the implant diameter is as close as possible to the diameter of the future tooth. The length of an implant is determined in accordance with the cited radiographic analysis, so that the implant in position 35 is shorter in relation to implants 34 and 37, due to the anatomic position of the foramen mentale.
During surgical positioning of implants, apart from the position which is defined by the pattern, in the vertical direction the implants are positioned in accordance with the biological width of the mucous membrane and finally with periodontal aesthetic requirements. The results show the success of the therapy following good planning and preparation. The advantage is shown of multi-layer tomography in planning and determining the anatomical-morphological characteristics of the lower jaw, which provides assurance in the choice of length and particularly the width of the implant. Pre-surgical planning is a procedure by which it is possible to foresee the position of an implant and aesthetics of future prosthetic work, and thus to facilitate the surgical intervention
Therapy of Advanced Periimplantitis - Case Presentation Clinical and Microbial Results after 10 Months
Sve više bude postavljenih usadaka neizbježno je da će biti više komplikacija u vezi s takvim terapijskim postupkom. Jedna od komplikacija koju je najteže izliječiti i koja posljedično može dovesti do gubitka usatka jest bakterijski uzrokovan periimplantitis. U ovome prikazu slučaja opisat će se uspješna terapija uznapredovala periimplantitisa. Pacijent u dobi od 58 godina poslan je parodontologu zbog smetnji u usnoj šupljini u obliku neugodna zadaha te gnojenja oko zuba i usadaka. Prigodom parodontološkoga pregleda opaženo je da su oba usatka na mjestima 22 i 25 zahvaćena periimplantatnim mukozitisom te da postoji krvarenje i gnojenje pri sondiranju. Kod usatka u području 25 postojao je i problem potpunoga nedostatka keratinizirane gingive. Na temelju kliničkog i rtg nalaza te pozitivnog mikrobiološog nalaza na parodontopatogene dijagnosticiran je periimplatitis oko oba usatka. Inicijalna parodontološka terapija završena je u četiri posjeta. Pacijent je dobio upute kako da održava oralnu higijenu te je uključena antiseptička terapija, ispiranje klorheksidinom i uporaba klorheksidinskoga gela izravno u džepove oko usadaka. Kako i nakon takve terapije gnojenje nije prestalo, uključena je i antibiotska terapija te ispiranje džepova jodom. Nakon što je infektivni proces uspješno stavljen pod nadzor, u daljnjem terapijskom postupku proveden je parodontološki kirurški zahvat kako bi se oko usatka 25 pokušao ispraviti nedostatak keratinizirane gingive i dobiti nov pričvrstak. Pošto je režanj odignut, površina usatka očišćena je sterilnom vatom natopljenom u klorheksidin, a s nepca je uzet vezivni presadak te je postavljen na kosti i na izložene navoje usatka. Preko presatka postavljen je Gengigel (hijaluronska kiselina) radi boljeg cijeljenja rane. Pet mjeseci nakon operacije ponovljena je mikrobiološka raščlamba te više nije bilo parodontnih patogena, a klinička mjerenja su pokazala da je smanjena dubina sondiranja, da ne postoji krvarenje ili gnojenje i da je nastala zona keratinizirane gingive od 2 mm oko usatka 25.With the ever increasing number of placed implants it is inevitable that the number of complications connected with such therapeutic procedure will also increase. One of the complications which is hardest to treat and which consequently can lead to loss of the implant, is bacterial caused periimplantitis. This case presentation describes the successful therapy of advanced periimplantitis. The male patient, aged 58 years, was referred to the periodontist because of problems in the oral cavity in the form of unpleasant breath and suppuration around the tooth and implant. During the periodontal examination it was observed that both implants on places 22 and 25 were affected by periimplantic mucositis and bleeding and suppuration occurred during probing. With regard to the implant in area 25 the problem of complete loss of keratinised gingiva was also present. On the basis of the clinical and X-ray findings, and positive microbial test for periodontopathogens, periimplantitis was diagnosed around both implants. Initial periodontological therapy was carried out in four visits. The patient received instructions on the maintenance of oral hygiene and antiseptic therapy was included, rinsing with chlorhexidine and application of chlorhexidine gel directly into the pockets around the implants. As after this therapy the suppuration did not stop antibiotic therapy was included, with rinsing of the pockets with iodine. After successful control of the infective process, further therapy involved a periodontological surgical operation in order to correct the loss of keratinised gingiva around implant 25 and to obtain new attachment. After lifting the flap the surface of the implant was cleaned with sterile cotton wool soaked in chlorhexidine, and from the palate a connective transplant was taken and placed on the bone and the exposed thread of the implant. Gengigel (hyaluronic acid) was placed over the transplant for better healing of the wound. Five months after the operation microbial analysis was repeated. Periodontal pathogens were no longer present and clinical measurements showed reduced probing depth, absence of bleeding and suppuration, and the occurrence of zones of keratinised gingiva of 2 mm around implant 25
Heavy metals pollution profiles in streams serving the Owabi reservoir
Water samples from five sampling points on four rivers, Owabi, Akyeampomene, Pumpunase and Sukobri, representing the main streams serving the Owabi reservoir were analysed for some pollution indicators using standard methods. Heavy metals (Zn, Cu, Mn, Cu, Pb and As) concentrations and some physical parameters of the water samples were determined. Electrical conductivity and pH of waters from all the streams were found to be within the acceptable limits of the World Health Organization (WHO). All the streams showed high turbidity values above WHO limits. Of the heavy metals determined in the water samples, Fe, Mn, Zn and Cu concentrations in all the streams were within the acceptable WHO limits, whiles Pb and As appeared to be higher than the acceptable limits in all the streams. The highest concentrations of most of the heavy metals were recorded at the Kronum site on Owabi stream. There was a statistically significant positive correlation between pH and some metals at all the sample points (p = 0.05). The results showed that all the streams were polluted and must be treated before consumption. It was also recommended that, human activities within the catchments should be monitored closely to minimise their polluting impacts on the water quality.Key words: Heavy metals, Owabi, pollution, water quality, WHO
Water Quality Assessment of the Southwestern and Coastal River Systems of Ghana
Investigation into physico-chemical water quality and dissolved heavy metal contents of major rivers from the Southwestern and Coastal River Systems of Ghana from 19 stations was undertaken from 2007 to 2010. The waters are used in their raw states for domestic purposes including drinking in most communities in the study area. The concentrations of the various parameters were assessed in relation to the Ghana Raw Water Quality Criteria and Guidelines for raw water, and in few instances, are compared with the WHO guidelines where the waters are known to be sources of drinking water. Turbidity, Total Suspended Solids (TSS) and Total Hardness were the physical parameters selected for the quality assessment of the waters in relation to domestic use. An Adapted Water Quality Index (WQI) was used to characterize the overall water quality status of the waters. Turbidity and TSS were found to be above their respective Target Water Quality Range (TWQR) values for raw water, while Total Hardness concentration were within guideline values. The levels of the trace metals investigated in the waters, Fe, Mn, Zn, Pb, Cr, Ni, Cu, As, Cd, and Hg, were found to be generally low, and do not yet pose health risks in the dissolved form. However, Fe and Mn levels were moderately high, exceeding their respective TWQR values stipulated for Ghanaian freshwaters. An assessment of non-cancerous health risk from exposure to Fe, Mn, and Zn was performed with the Risk Integrated Software for cleanup (RISC 4.02) developed by the USEPA. Results of the risk assessment, however, revealed a hazard quotient greater than 1 in some locations, indicating that the risk of adverse health effects associated with exposure to zinc, manganese and iron is high in those locations. Efforts should therefore be made to prevent metal pollutants, mainly from mining activities, from entering our water bodies to keep them suitable for their intended uses. Keywords: Risk assessment, Southwestern Rivers Systems, Coastal Rivers Systems, Water Quality, Water Quality Index
Pesticides Bioconcentration Potential of Aquatic Plants in the Volta Lake
The Volta Lake is known for the proliferation of numerous aquatic plants in its shallow waters. A major cause for the presence of the luxuriant vegetation is the intensive agricultural activities along the banks. These activities are heavily dependent on agrochemicals including fertilizers, which eventually get into the aquatic ecosystem via water ways. In this study, two aquatic plants; Ceratophyllum demersum and Nymphaea lotus were investigated in a pilot study to determine their bioconcentration of pesticides. Levels of organochlorine (OCs) and synthetic pyrethroids (SPs) were analysed using gas chromatograghy equipped with electron capture detector while gas chromatography equipped with pulse flame photometric detector was used for the organophosphorus pesticides (OPs) determination in the plant tissues. The ambient concentrations of these pesticides in the aqueous medium were also determined and the ratios of pesticide concentration in the plant and water samples estimate bioconcentration potential of the plants. Out of 38 detected pesticides, 22 (representing 58%) were bioconcentrated by the aquatic weeds. The Bioconcentration Factor (BCF) range for Ceratophyllum demersum was 1.06 – 4,470 and that for Nymphaea lotus was 1.27 – 800. By the standard of the European Union regulation for registration of chemicals, levels of diazinon and chlorpyrifos in Ceratophyllum demersum fulfilled the ‘bioaccumulation’ criterion (i.e BCF > 2000) while fenitrothion, with BFC of 5500 in the same plant fulfilled ‘very bioaccumulation’ criterion (BCF ≥ 5000). This study shows that aquatic weeds in their natural ecosystem have the remediation potential, though to varying degrees and hence play a role in the improvement of water quality
Underlying indicators for measuring smartness of buildings in the construction industry
Purpose: This study investigates the underlying indicators for measuring the smartness of buildings in the construction industry; where the Smart Building Technology (SBT) concept (which incorporates elements of the Zero Energy Building (NZEB) concept) could ensure efficient energy consumption and high performance of buildings.
Design/methodology/approach: An overarching post-positivist and empirical epistemological design was adopted to analyze primary quantitative data collected via a structured questionnaire survey with 227 respondents. The mean ranking analysis and one-sample t-test were employed to analyse data.
Findings: Research findings revealed that the level of knowledge of smart building indicators is averagely high in the Ghanaian construction industry. Future research is required to evaluate the awareness level of Smart Building Technologies (SBTs) by construction professionals and identify barriers to its adoption.
Originality/value: A blueprint guidance model (consisting of significant indicators for measuring building smartness) was developed to help improve building performance and inform policymakers
IZGUBLJENI SJAJ LJEKARNIŠTVA U DEBELJAČI
In the general trend of nationalization after 1945, many pharmacies in our area were destroyed, relocated or repurposed. During these events, their interiors changed, and the inventory was damaged or destroyed. The aim of this paper is to research the historiography of pharmacy by reconstructing the chronology of the Joanović pharmacy as well as the Public Pharmacy of the town of Debeljača until it moved out of the building where the pharmacy was founded. Descriptive research covers the periods before the First World War, between the two World Wars and after the Second World War. The data presented in this paper are the result of interdisciplinary research related to the study of the historiography of the Joanović pharmacy as well as the Public Pharmacy of the town of Debeljača. This paper is based on unpublished documents (database of the pharmacy Joanović and the Publik Pharmacy of the town of Debeljača), as well as on the statements and written statements of Mrs. Mila Đorđević born Joanović and pharmacist Ivan Šimić as documents from the author’s personal archive. Methods of documentation analysis and desk analysis of secondary data were used. In the Joanović Pharmacy, almost semi-industrial production of cosmetic and perfumery products was developed, as well as the production of flavors for the production of alcoholic and non-alcoholic beverages. After the forced purchase, a biochemical laboratory was formed in the newly established National Pharmacy, which provided a large number of various laboratory services. The results of this study could be used in further study of the historiography of pharmacy research of the goods that pharmacies offered to consumers.U općem trendu nacionalizacije nakon 1945. mnoge su ljekarne na našim prostorima unište-ne, premještene ili prenamijenjene. Tijekom tih događanja promijenili su se njihovi enterijeri, a inventar je oštećen ili uništen. Cilj je ovog rada istraživanje historiografije ljekarništva re-konstruirajući kronologiju Apoteke Joanović, kao i Narodne apoteke Debeljača do iseljenja iz zgrade u kojoj je ljekarna osnovana. Istraživanje obuhvaća razdoblje prije Prvoga svjetskog rata, između dvaju svjetskih ratova i nakon Drugoga svjetskog rata. Podaci predstavljeni u ovom radu rezultat su interdisciplinarnog istraživanja povezanog s proučavanjem historio-grafije Apoteke Joanović i Narodne apoteke u Debeljači. Rad je zasnovan na neobjavljenim dokumentima (baza podataka Apoteke Joanović i Narodne apoteke u Debeljači), kazivanju i pismenim izjavama gospođe Mile Đorđević rođene Joanović i ljekarnika Ivana Šimića te na dokumentima iz osobne autorove arhive. Korištene su metode analize dokumentacije i desk-analize sekundarnih podataka. U Apoteci Joanović bila je razvijena gotovo poluindu-strijska proizvodnja kozmetičkih i parfumerijskih proizvoda te proizvodnja esencija i aroma za proizvodnju alkoholnih i bezalkoholnih pića. Nakon prinudnog otkupa, u novoosnovanoj Narodnoj apoteci osnovan je biokemijski laboratorij koji je pružao velik broj najrazličitijih laboratorijskih usluga. Rezultati ove studije mogli bi poslužiti u daljem proučavanju histori-ografije ljekarništva i u istraživanju asortimana koje su ljekarne nudile potrošačima
Dimethylglyoxime based ion-imprinted polymer for the determination of Ni(II) ions from aqueous samples
A Ni(II)-dimethylglyoxime ion-imprinted polymer {Ni(II)-DMG IIP} was synthesised by the bulk polymerisation method. The morphology of the Ni(II)-DMG IIP and non-imprinted polymer were observed by scanning electron microscopy and the chemical structures were evaluated by infrared spectroscopy. Selectivity of the Ni(II)-DMG IIP was studied by analysing, using an inductively coupled plasma-optical emission spectrometer, for Ni(II) ions that were spiked with varying concentrations of Co(II), Cu(II), Zn(II), Pd(II), Fe(II), Ca(II), Mg(II), Na(I) and K(I) in aqueous samples. The studies revealed Ni(II) recoveries ranging from 93 to 100% in aqueous solutions with minimal interference from competing ions. Enrichment factors ranged from 2 to 18 with a binding capacity of 120 μg∙g−1. Co(II) was the only ion found to slightly interfere with the determination of Ni(II). Selectivity studies confirmed that the Ni(II)-DMG IIP had very good selectivity, characterised by %RSD of less than 5%. The limits of detection and quantification were 3x10-4 μg∙mℓ−1 and 9x10-4 μg∙mℓ−1, respectively. The accuracy of the method was validated by analysing a custom solution of certified reference material (SEP-3) and the concentration of Ni(II) obtained was in close agreement with the certified one. The Ni(II)-DMG IIP was successfully employed to trap Ni(II) ions from a matrix of sea, river and sewage water. It is believed that the Ni(II)-DMG IIP has potential to be used as sorbent material for pre-concentration of Ni(II) ions from aqueous solutions by solid-phase extraction
Adverse drug reaction reporting by doctors in a developing country: A case study from Ghana
Background: Spontaneous adverse drug reaction reporting is the most widely used and cost effective method of monitoring the safety of drugs. This method is heavily afflicted by underreporting by healthcare professionals. The study aims at assessing adverse drug reaction (ADR) reporting rate by doctors, knowledge of the reporting system and attitudes to SADR in the Greater Accra region.Methods: This was a cross sectional survey of 259 doctors randomly selected from 23 hospitals classified as government 199 (76.8%), quasi-governmental 43(16.6%) and private 17 (6.6%) hospitals in the Greater Accra Region of Ghana. Data collection was by self-administered questionnaire from May 5, 2012- July 6, 2012. Descriptive statistics was used to describe the background characteristics of the doctors and the outcome measures like training and reasons for ADR reporting were summarized as frequencies and percentages.Results: One-third (27.4%) of doctors surveyed had received previous training on drug safety monitoring and ADR reporting; training and knowledge of the reporting system was found to improve reporting. Morethan half 154 (59.5%) of the doctors had seen a patient with suspected ADR in the past one year although only 31 (20%) had reported it by completing the SADR reporting form. Doctors working in government hospitals were about 5 times more likely to report than those in private hospitals [OR=4.94, 95%CI (1.55-15.69)].Conclusion: Training and knowledge of the ADR reporting system were found to be associated with the likelihood of reporting an ADR. Most of the doctors had not previously received training on ADR reporting.Keywords: Spontaneous reporting, adverse drug reaction, underreporting, doctors, Ghan
- …