BER Performance of IM/DD FSO System with OOK using APD Receiver

In this paper, the performance of intensity-modulated with direct detection (IM/DD) free space optical (FSO) system using the on-off keying (OOK) and avalanche photodiode (APD) receiver is observed. The gamma-gamma model is used to describe the effect of atmospheric turbulence since it provides good agreement in the wide range of atmospheric conditions. In addition, the same FSO system with equal gain combining applied at the reception is analyzed. After theoretical derivation of the expression for the bit error rate (BER), the numerical integration with previously specified relative calculation error is performed. Numerical results are presented and confirmed by Monte Carlo simulations. The effects of the FSO link and receiver parameters on the BER performance are discussed. The results illustrate that the optimal APD gain in the minimum BER sense depends considerably on the link distance, atmospheric turbulence strength and receiver temperature. In addition, the value of this optimal gain is slightly different in the case of spatial diversity application compared with single channel reception

Anaesthesia in Oral Surgery

U oralnoj se kirurgiji većina zahvata radi u lokalnoj anesteziji, samo 5-10% zahtijeva opću anesteziju. Svrha našega istraživanja bile su indikacije i komplikacije anestezije. U retrospektivnoj studiji, tijekom 2002., analizirali smo anestezirane bolesnike s oralno kirurškim zahvatima u KB ”Dubrava”. 528 bolesnika promatrali smo u vezi sa zahvatom i vrstom anestezije. Zahvati u anesteziji bili su: vađenje zuba 306, popravka zuba 65, alveotomija 121, incizija u usnoj šupljini 36. Većinom djeca i odrasle osobe s duševnom retardacijom. Inhalacijskoj anesteziji podvrgli smo 298 bolesnika, u balansiranoj anesteziji bilo ih je 197 i u potpunoj intravenoznoj (TIVA) 33. Osnovne indikacije za anesteziju u našoj bolnici su osobe s duševnom retardacijom 231, djeca mlađa od 5 godina 140, odrasli 121, upala u usnoj šupljini s komplikacijama 36. Kod anestezije su se pojavile ove komplikacije: bronhospazam u dva bolesnika, aritmije u tri bolesnika, povraćanje u dvojice i izgubljeni zub u jednoga bolesnika (koji je nađen u jednjaku). Od svih zahvata u oralnoj kirurgiji 5,8% ih je učinjeno u općoj anesteziji i komplikacije su se pojavile u 1,6% anesteziranih bolesnika.The majority of procedures in oral surgery are performed in the local anaesthesia. Only 5-10% are performed in general anaesthesia. Indications and complications of anaesthesia were examined in our study. In a retrospective study, during 2002, we analysed patients with procedures in oral surgery in the University Hospital Dubrava. 528 patients were divided according to anaesthesia and procedure. We performed these procedures in anaesthesia: dental extractions 306, dental treatment 65, alveotomy 121, incision in the oral cavity 36. Most of them were children and persons with mental retardation. Inhalation anaesthesia was performed in 298 patients, balanced anaesthesia in 197 pts and TIVA in 33. The basic indications for anaesthesia in our hospital were: persons with mental retardation 231, children under 5 years of age 140, adult 121, inflammation of the oral cavity with complications 36. We had the following complications: bronchospasm in two cases, arrhythmia three cases, vomiting two cases and in one case lost tooth (it was found in oesophagi). Our results show that 5,8% of all procedures in oral surgery were in general anaesthesia and complications occured in 1.6 %

Stylistics of figurative expressions in primary school Стилистика фигуральных выражений в начальной школе

Предмет рада Стилистика фигуративних израза у основној школи јесте попис и опис само оних стилских фигуративних јединица које се обрађују у уџбеницима књижевности и језика (како читанкама и граматикама, тако и у радним свескама и/или наставним листовима) у основним школама у Србији. У анализу је био укључен већи број уџбеника и теми се приступало и са дијахронијске и са синхронијске стране (посматрани су и старији и савремени уџбеници) како би се показале разноврсности у слободи обраде програмом предвиђених садржаја о фигуративним изразима. Праћена је поступност увођења појединих типова фигуративних израза у одређене разреде с обзиром на сложеност њихове језичке и семантичке структуре. Такође, анализиран је и начин упознавања ученика са одређеним фигуративним изразом, посебно кад је реч о стилским фигурама, тако да је праћено на ком је ученичком узрасту описно упућивано на значење дате фигуре, а на ком су ученици упознавани са самим термином, и његовим местом у терминосистему сродних фигуративних израза. Разматран је редослед појављивања стилских фигура, извршена оцена његове „утемељености” и анализиран међуоднос наставних програма и уџбеника. Анализа фигуративних израза вршена је с обзиром на двопланску вредност сваке стилеме, па је тако и свака од стилских фигура анализирана с обзиром на своју стилематичност и своју стилогеност. Врло битан аспект анализе била је и дисциплинарна припадност уведеног фигуративног израза: да ли је он обрађиван унутар садржаја књижевности, језика или садржаја културе изражавања. У анализи је посебна пажња посвећена разматрању типова књижевних текстова за основну школу с циљем да се утврди колико они представљају репрезентативне примере за упознавање ученика са стилогеним и стилематичним аспектима фигуративних израза.The subject of the work Stylistics of figurative expressions in primary school represents a list and a description of only those stylistic figurative units that are processed in textbooks of literature and language (both textbooks and grammars, and in workbooks and/or worksheets) in primary schools in Serbia. A large number of textbooks were included in the analysis, and the topic was approached from both the diachronic and synchronic sides (both older and modern textbooks were observed) in order to show the diversity in the freedom of processing the content of figurative expressions planned by the curriculum. There was monitored the gradual introduction of certain types of figurative expressions into the certain grades considering the complexity of their linguistic and semantic structure. Also, the way of introducing a certain figurative expression to the students was analysed, especially when we talk about stylistic figures, so it was monitored at which student’s age the meaning of a given figure was descriptively referred to, and at which age the students were introduced to the term itself and its place in the system of terms of related figurative expressions. The order of appearance of stylistic figures was also considered, the assessment of its ”foundation” was conducted, as well as the analysis of the interrelation of curriculum and the textbooks. The analysis of figurative expressions was performed considering the two-dimensional value of each stylistics, so each of the stylistic figures was analyzed with regard to its stylematicity and stylogenity. A very important aspect of the analysis was the disciplinary affiliation of the introduced figurative expression: whether it was processed within the contents of literature, language or the content of the culture of expression. In the analysis, special attention is paid to considering the types of literary texts for primary school with a goal to determine how well they represent the good examples of introducing students to the stylogenic and stylematic aspects of figurative expressions

A 3 tesla magnetic resonance imaging volumetric analysis of the hippocampal formation: dependence on handedness and age

Background: The hippocampal formation (HF) is one of the most important parts of the brain in the magnetic resonance imaging (MRI) volumetric analysis in various domains, but not completely from all aspects, including the handedness. The aim of our study was to evaluate the possible differences in the volume of the right and left HF among the healthy right-handed and left-handed subjects, and to determine whether the volume differences are age related. Materials and methods: The MRI of this prospective study was performed using T1 fast field echo (FFE) sequence. The 124 subsequent coronal slices (thickness 1.5 mm) were performed in each participant. The obtained HF volumes were normalised and statistically compared. Volunteers comprised 30 persons aged 22.0 years, 12 of whom were the left-handed, and 30 persons aged 75.2 years on average, 9 of whom were the left-handed. Results: The right and left HF volumes averaged 2.986 cm3 and 2.858 cm3 in the right-handed, and 2.879 cm3 and 3.020 cm3 in the left-handed young volunteers, as well as 2.728 cm3 and 2.650 cm3 in the right-handed, and 2.617 cm3 and 2.780 cm3 in the left-handed elderly persons. The HF volume ratios in the young left-handed participants showed a significant left-greater-than-right asymmetry. A significant difference was also noticed within the right-to-left volume ratios of the right- and left-handed young and elderly participants. The latter reduction in the HF volume within the aged group can be interpreted as a slight atrophy of the HF. Conclusions: There is a significant difference in the volumes of the left and right HF of the left-handed young participants. The age related HF volume differences were proven between the groups of the young and elderly volunteers. The obtained data should be included into the future MRI studies of the HF volumes in various clinical domains.

Kovalentne modifikacije proteina biološki aktivnim hinonima

The avarone/avarol quinone/hydroquinone couple shows considerable antitumor activity. In this work, covalent modification of beta-lactoglobulin by avarone and its derivatives as well as by the synthetic steroidal quinone 2,5(10)-estradiene-1,4,17-trione and its derivatives were studied. The techniques for studying chemical modification of beta-lactoglobulin by quinones were: UV/Vis spectrophotometry, SDS PAGE and isoelectrofocusing. SDS PAGE results suggest that polymerization of the protein Occurs. It Could be seen that the protein of 18 kD gives the bands of 20 kD, 36 kD, 40 kD, 45 kD, 64 kD and 128 kD depending on modification agent. The shift of the pl of the protein (5.4) upon modification toward lower values (from pl 5.0 to 5.3) indicated that lysine amino groups are the principal site of the reaction of beta-lactoglobulin with the quinones.Hinonsko/hidrohinonski par avaron/avarol pokazuje značajnu antitumorsku aktivnost. U ovom radu proučavane su kovalentne modifikacije β-laktoglobulina avaronom, sintetičkim steroidnim hinonom 2,5(10)-estradien-1,4,17-trionom i njihovim derivatima. Tehnike za praćenje hemijske modifikacije bile su: UV/Vis spektrofotometrija, SDS PAGE i izoelektrofokusiranje. Rezultati SDS PAGE ukazuju da se dešava polimerizacija proteina.Može se videti da protein od 18 kD daje trake od 20 kD, 36 kD, 40 kD, 45 kD, 64 kD i 128 kD u zavisnosti od agensa za modifikaciju. Pomeranje pI vrednosti proteina (5,4) nakon modifikacije ka nižim vrednostima (od pI 5,0 do 5,3) pokazuje da su amino-grupe lizina glavna mesta reakcije β-laktoglobulina sa hinonima

On Numerical Evaluation of Packet-Error Rate for Binary Phase-Modulated Signals Reception over Generalized-K Fading Channels

We present a numerical evaluation of packet error rate (PER) for digital binary phase modulations over wireless communication channels. The analysis is valid for a quasistatic fading communication channel, where multipath fading and shadowing appear simultaneously. The approach is based on numerical evaluation of signal-to-noise ratio threshold that is further used in PER computation. We analyze the threshold and PER dependence on signal power, multipath fading and shadowing severity, as well as packet length

AVERAGE BER PERFORMANCE OF SIM-DPSK FSO SYSTEM WITH APD RECEIVER

In this paper, average bit error rate (BER) analysis of the free-space optical (FSO) system employing subcarrier intensity modulation (SIM) with differential phase-shift keying (DPSK) and avalanche photodiode (APD) receiver is presented. The atmospheric turbulence is described by the Gamma-Gamma statistical model taking the pointing errors into account. Numerical results are presented and confirmed by Monte Carlo simulations. The effects of atmospheric turbulence, pointing errors and receiver parameters on the average BER performance are observed and discussed. Based on the presented results, it is concluded that the minimum of the average BER exists for an optimal value of APD gain, which is heavily dependent on receiver noise temperature, bit rate and atmospheric conditions

Photoactivity of Immobilized Titanium Dioxide (TiO2 ) in Lindane Degradation

Introduction and study objectives: Lindane is a generic name for γ-hexachlorocyclohexane, one of the isomers from the group of Hexachlorocyclohexanes (HCH) [1]. Due to its neurotoxic activity, it had a very wide application, from agricultural to non-agricultural purposes. As a result of its lipophility, lindane can easily pass through the blood-brain barrier. The reason of his neurotoxicity is that it can interact with GABAA receptors and obstruct GABA neurotransmitter signaling in nervous system. People who have been exposed to lindane for a long time can experience serious health problems, such as: poor liver function, cardiac arrhythmias, and irregular menstruation. Due to its adverse health effect, lindane is classified as a “pregnancy category C” chemical [2]. It is also one of the Persistent Organic Pollutants (POPs) that were listed under the Annex A (elimination) of the Stockholm Convention with a specific exemption for use as a human health pharmaceutical [3]. The aim of this paper was the assessment of the immobilized titanium dioxide photocalytic properties in lindane degradation. Methodology: Spray pyrolysis method was used for a synthesis of thin titanium oxide films on the foils of the stainless steel [4]. The lindane solution was incubated with TiO2 and exposed to UV/VIS light. Aliquots were taken from the reaction mixture after 0, 2, 4, 6, 8, 10 and 12 hours. Lindane was extracted according to the EPA method 505 [5], and analyzed using an Agilent 7890A gas chromatograph (GC) connected to an electron capture detector (ECD). The GC was equipped with a Thermo Scientific™ TraceGOLD™ TG-5MT capillary column (60 m × 0.25 mm ID × 0.25 μm). The temperature program used for gas chromatography was: Initial heating temperature: 50 °C for 3 minutes, then heating at a rate of 30 °C/min to 210 °C for 20 minutes. Hydrogen with a flow rate of 60 mL/min was used as the carrier gas. Results and conclusions: Photoactivity of immobilized titanium dioxide in the degradation of lindane was measured as a percentage of lindane’s degradation compared to its initial concentration. The obtained results demonstrated that after two hours 45.32 % of lindane was degraded, while after twelve hours the percentage of degradation increased to 98.20 %. In this study we proved that the immobilized titanium dioxide can be used as a productive and fast photocatalyst for lindane photodegradation

Risk management of unexploded ordnance in the Republic of Serbia for environmental protection - Borovac case study

Introduction/purpose: Decades of dealing with unexploded ordnance (UXO) in some areas of the Republic of Serbia have confirmed that it presents a substantial hazard to the security of people, property, and the environment. Even though the terrain has been cleaned, various threats from difficult-tofind UXO components remain serious. Inadequate systemic solutions for UXO management can have significant harmful consequences. Methods: Based on the spatial distribution analysis and different UXO types and quantities, this article studies the effects of dangerous components of unexploded ordnance on human lives and the environment. Two different geospatial analyses were performed including the guidelines for risk management through risk elimination based on multiple criteria, the GIS, and the Remote Sensing analysis. Results: Two different geospatial analyses resulted in the areas at high risk of remaining UXO. Conclusion: The article significantly contributes to creating an environmental risk management strategy for UXO-contaminated regions. It presents an effective technique for addressing risk assessment challenges in such sites. The analysis considers both risk analysis and environmental protection options. Using the multi-criteria analysis and the GIS, it estimates the exposure of built structures, people, soil types, and plant species to UXO dangers in key locations. This paper serves as a guideline for environmental risk assessment

Internal Quality Control as an Important Part of Radiological Analysis of Environmental Samples Using Semiconductor HPGe Spectrometry

Ugalj kao fosilno gorivo sadrži brojne prirodne radioaktivne izotope koji pripadaju uranovom i torijumovom nizu, kao i 40K. Najviše se koristi u industriji, kao i u proizvodnji energije. Problem u vezi sa proizvodnjom energije iz uglja je takozvani „energetski otpad“, kao što su pepeo i šljaka, koji predstavljaju nesagorivi i nesagoreli ostatak pri sagorevanja uglja. Ako se pepeo i šljaka odlažu u životnu sredinu, može doći do povećanja i/ili preraspodele prirodnog sadržaja radionuklida. Da bi se utvrdio potencijalni uticaj „energetskog otpada“ na životnu sredinu, uzorci uglja, pepela i šljake iz termoelektrana „Nikola Tesla“ i „Kolubara“ mereni su poluprovodničkim HPGe spektrometrom u Laboratoriji za nuklearnu i plazmu fiziku Instituta „Vinča“. Kao rezultat ovih merenja, dobijene su koncentracije prirodnih radionuklida i veštačkog radionuklida 137Cs kao, što je prikazano u ranije objavljenim radovima. Prikazani rezultati su u saglasnosti sa istraživanjima sprovedenim širom sveta. Da bi se obezbedila tačnost i preciznost (pouzdanost) dobijenih rezultata merenja, u okviru Laboratorije uspostavljen je program kontrole kvaliteta (QC) i osiguranja kvaliteta (QA). Interna kontrola obuhvata proveru karakteristika poluprovodničkog HPGe spektrometra koji se koristi za merenje svih analiziranih uzoraka. Tačkasti izvori 60Co i 137Cs se koriste kao kontrolni izvori za proveru položaja pika, ukupne površine ispod pika, FWHM (puna širina na polovini maksimuma pika), FWTM (puna širina na desetini maksimuma pika) i odnos FWHM/FWTM. Pored navedenih karakteristika, redovno se kontroliše i ukupni odbroj prirodnog fona. Svaka od navedenih karakteristika može ukazati na neku nepravilnost u radu detektorskog sistema. Cilj ovograda je da se prikažu kontrolne karte ispitivanih karakteristika poluprovodničkog HPGe spektrometra korišćenog za merenje uzoraka uglja, pepela i šljake. Dobijene kontrolne karte predstavljaju važan alat na osnovu kojeg se analizira dugoročna stabilnost spektrometraeir daughter products, as well as 40K. It is widely used in industry as well as in energy pro-duction. The problems associated with the production of energy from coal is the so-called “energy waste”, such as ash and slag, which are incombustible and unburnt residue from combustion of coal. If ash and slag are released into the environment an increase and/or redistribution of natural radio-nuclide content can occur. To determine the potential impact of “energy waste” on the environment, samples of coal, ash, and slag from thermal power plant "Nikola Tesla" and "Kolubara" were meas-ured with a semiconductor HPGe spectrometer. Results of activity concentration of natural radionu-clides and artificial 137Cs in coal, slag and ash are presented in few previously published papers and obtained values are in accordance with similar worldwide investigations. o ensure the accuracy and precision (reliability) ofthe obtained measurement results, quality control (QC) and quality assurance (QA) program were established. Internal control includes check-ing of the characteristics of HPGe spectrometer used for measurement of all analysed samples. Point sources of 60Co and 137Cs are used as control sources for checking following characteristics: peak positions, net peak area, FWHMs (Full Width at Half Maximum), FWTMs (Full Width at Tenth Max-imum) and FWHM/FWTM ratios. In addition to the mentioned characteristics, the counting of back-ground is also regularly controlled. Each of the mentioned characteristics may indicate some irreg-ularity in the operation of the detector system and thus could influence reliability of performed activ-ity concentration measurements.The paper presents the control charts of the examined characteristics of the HPGe spectrometer used for measurements of coal, ash and slag samples. The obtained control charts indicate the long-term stability of the spectrometer and hence confirm accuracy and precision of measurement results.36. Međunarodni kongres o procesnoj industriji - PROCESING ′23 : zbornik radova ; 1-2. jun, Šaba