Analysis of the high-speed polysilicon photodetector in fully standard CMOS technology

A high-performance lateral polysilicon photodiode was designed in standard 0.18 um CMOS technology. The device has a frequency bandwidth far in the GHz range: the measured bandwidth of the poly photodiode was 6 GHz, which gure was limited by the measurement equipment. The high intrinsic (physical) bandwidth is due to a short excess carrier lifetime. The external (electrical) bandwidth is also high because of a very small parasitic capacitance (<0.1 pF). This is the best bandwidth performance among all reported diodes designed in a standard CMOS. The quantum efficiency of this poly photodiode is 0.2% due to the very small light sensitive diode volume. The diode active area is limited by a narrow depletion region and its depth by the technology

Changes in Polyphenolic Content and Antioxidant Activity of Grapes cv Vranac During Ripening

This study characterised and evaluated the phenolic composition and antioxidant activity of the redwine grape Vranac (Vitis vinifera L.) from the southern Serbian vineyard region during grape ripening.Polyphenol composition at different harvest dates was determined by HPLC-DAD analysis. Antioxidantactivity was estimated by DPPH assay. The study demonstrates that the Vranac variety representsimportant sources of dietary antioxidants. The results show that (+)-catechin, (-)-epicatechin andprocyanidin dimer B2 were the most prevalent in the seeds, and quercetin and malvidin glucosides in thegrape skins. All grape extracts were shown to have high radical-scavenging activity. Strong correlationsbetween radical-scavenging activity and polyphenols suggest that the phenolic composition of the Vranacvariety contributes significantly to the antioxidant capacities of grape extracts. During grape ripeningthere were significant changes in physiological properties and phenolic content, and it is important todetermine optimal harvest time, which will ensure grapes with very good quality parameters (in our studyat the 30th day after véraison)

The Average Structural Density of Barite Crystals of Different Habit Types

Eight different habit types of barite crystals which could be classified into 4 essentially different groups were determined by morphological analysis: Eb group - barite crystals elongated in the [010] direction; Ea group - barite crystals elongated in the [100] direction; Tc group - barite crystals tabular on the basal pinacoid {001}; Ec group - barite crystals elongated in the [001] direction. By determination and comparison of the average structural densities of different habit types of barite crystals, it was possible to establish the spans of their values from 276.1 to 495.8, and overlapping of values for Eb group with Ea group and Tc group with Ec group. The sequence of habit types, with regard to the decreasing average structural density, i.e. the priority sequence of developing of barite crystal types, was determined: Eb group - Ea group - Tc group - Ec group

Cost-effective Ultrasonic Extraction of Bioactive Polyphenols from Vine and Wine Waste in Serbia

By using cost-effective ultrasonic extraction techniques, bioactive phenolic extracts were obtained from Merlot and Vranac (Vitis vinifera L.) vine and wine waste produced in Serbian wineries. These wastes include vine leaves, grape pomace, seeds, skins and stems, which can find further use in the food and pharmacology industries as preservatives against microbes. The extracts showed strong scavenging free radical activity (EC50 from 0.37 to 2.02 mg/L), which was in very good correlation with the total polyphenol content.  Strong antimicrobial activity was found against six Gram-positive and five Gram-negative bacterial strains, and against the yeast Candida albicans. The principal component and agglomerative hierarchical clustering analyses performed were shown to be good for grouping and distinguishing the results from thevine and wine by-products (leaves and seeds) from both investigated grape varieties based on the content of various polyphenolic classes, and antioxidant and antimicrobial activities. The valorisation of the grape by-products is consistent with the concept of a sustainable and environmentally oriented wine industry and provides an important economic advantage

Correlation between Surface Roughness Characteristics in CO2 Laser Cutting of Mild Steel

CO2 laser oxygen cutting of mild steel is widely used industrial application. Cut surface quality is a very important characteristic of laser cutting that ensures an advantage over other contour cutting processes. In this paper mathematical models for estimating characteristics of surface quality such as average surface roughness and ten-point mean roughness in CO2 laser cutting of mild steel based on laser cutting parameters were developed. Empirical models were developed using artificial neural networks and experimental data collected. Taguchi’s orthogonal array was implemented for experimental plan. From the analysis of the developed mathematical models it was observed that functional dependence between laser cutting parameters, their interactions and surface roughness characteristics is complex and non-linear. It was also observed that there exist region of minimal average surface roughness to ten-point mean roughness ratio. The relationship between average surface roughness and ten-point mean roughness was found to be nonlinear and can be expressed with a second degree polynomial

Estimation of photovoltaic power generation potential in Serbia based on irradiance, air temperature, and wind speed data

This study is devoted to the research of spatial-temporal variation of electricity generation from the kilowatt-peak photovoltaic system made of crystalline silicon solar cells. The research was conducted in the territory of Serbia using the model for estimation photovoltaic performances as a function of incident irradiance and module temperature. Preparation of input data and calculation of the final results was done within the geographical information system. Some of the required raster data, like solar irradiance and wind speed, were already available, while air temperature raster was created from discrete set of observed data using the regression-kriging model. Obtained results were presented in the form of raster maps that enabled further analysis and discussion about new findings. The analysis of seasonal variations reveals that during spring and summer months photovoltaic systems are producing up to 70% of total annual electricity yield. In terms of the spatial distribution, the most promising areas for electricity generation are located in the south part of Serbia and along main river valleys. In addition, discussion part addresses the issue of data imperfection caused by the accuracy of the selected model, as well as quality and availability of data series

EKOLOŠKA POLJOPRIVREDA - MOGUĆNOSTI ZA MALOG PROIZVOĐAČA NA POPOVOM POLJU

Present activities have been implemented under the scope of the “Agricultural Development of Rural Communities in Eastern Herzegovina” project whose main objective is to create appropriate conditions for the integrated reactivation of the agriculture in the Popovo polje valley. Within this framework, two integrated pilot projects for the introduction of organic agriculture have been carried out complemented with a specific research on market possibilities for organic production, in order to contribute to the correct management of the natural resources of the area, as well as to give impulse to productive and commercial capacities of the farmers. One pilot project was production of potato and onion, while the other one was plantation of medicinal and aromatic plants (MAP). Within both pilot projects activities were oriented to provide assistance and technical training for farmers as well as assistance on organic certification procedure and assistance on marketing the production. Results of both pilot projects proved that organic production was possible from agro-technical and agro-ecological aspects in Popovo polje. Analysis of essential oils of the cultivated MAP showed that quality was good to very good and production was easily marketed with a comparative profitability as against initial investment needs. Among cultivated MAP, dill production came out to be the most attractive taking into consideration money and work invested for production. In case of vegetables, figures related to profitability, if compared with those related to conventional production; confirm the potential of organic farming vegetables to provide a slightly higher margin of profitability especially once the initial investment of land conversion is mortgaged. As regards the results of the market research, the analysis of the demand showed the limitations: organic products have higher prices than those conventionally produced, and distrust of the organic products label and the conditions in which these products are actually grown. In any case, they also showed consumers low level of awareness of the importance of organic farming, and he existence of an official certification body. Considering all the prof and contras, in the present situation of development of agriculture market in Bosnia and Herzegovina, and looking for better opportunities for the Popovo Polje valley small producers who compete in conventional agriculture with bigger farmers and companies, it has been proved that organic agriculture can be a profitable alternative for small producers as well as better long-term choice.Glavna zadaća projekta “Poljoprivredni razvoj ruralnog stanovništva istočne Hercegovine” je stvaranje odgovarajućih uvjeta za integraciju poljoprivrede u dolinu Popovog polja. U tu svrhu provedena su dva integrirana projekta za uvođenje ekološke poljoprivrede, praćena istraživanjima mogućnosti trgovine ekološkim proizvodima, s ciljem ispravnog korištenja prirodnih izvora područja i poticanja proizvodnih i trgovačkih mogućnosti farmera. Jedan pilot project odnosio se na krumpir i luk, a drugi na ljekovito i aromatsko bilje. U okviru oba projekta planirana je pomoć i tehnička obuka farmera, kao i pomoć u organizaciji postupaka certificiranja i marketinga proizvoda. Rezultati provedbe oba projekta pokazali su da je ekološka proizvodnja na Popovom polju agrotehnički i agroekološki moguća. Analiza ulja dobivenog iz aromatskog i ljekovitog bilja pokazala je da je kakvoća proizvoda dobra do vrlo dobra, a proizvod se lako prodaje s dohodovnošću potrebnom kod početnih ulaganja. Od aromatskog bilja, proizvodnja kopra pokazala se najatraktivnija glede uloženih sredstava i zarade. U slučaju povrća, dohodovnost uspoređena s onom u konvencionalnoj proizvodnji potvrdila je mogućnosti ekoloških farmi da osiguraju nešto bolji dohodak, posebno nakon što prođu početne investicije u konverziju oranica. Istraživanja tržišta ukazala su na ograničavajući učinak viših cijena ekoloških proizvoda, kao i nepovjerenje u markicu koja garantira ekološki proizvod. Ovo također ukazuje i na nizak stupanj razumijevanja značaja ekološke poljoprivrede i službenog tijela za certifikaciju proizvoda. Uzevši u razmatranje sve argumente za i protiv, u trenutnoj situaciji razvoja poljoprivrednog tržišta u Bosni i Hercegovini, te mogućnostima Popovog polja, pokazalo se da ekološka poljoprivreda može biti dobar dugoročni izbor i dohodovna alternativa za malog farmera u takmičenju s velikim farmerima konvencionalnog pristupa poljoprivrednoj proizvodnji

A study of novel cobalt(II) octaazamacrocyclic complexes with aminocarboxylates or their derivativ

Four new air-stable mixed-ligand Co(II) complexes having the general formula [Co2(Y)tpmc]Z3×q(H2O/CH3CN) (HY = N-methylglycine/N,N-dimethylglycine, Z = BF4-, qH2O = 4 or 3; HY = S-norvaline/S-valine Z = ClO4- , qCH3CN = 0.5; qH2O = 0.5; tpmc = N,N’,N’’,N’’’-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane) were prepared. The composition, some physical and chemical properties and their tentative geometries were evaluated based on elemental analysis (C, H, N), conductometric and magnetic measurements, spectroscopic data (UV/Vis, IR) and cyclic voltammetry. The data were compared with earlier described analogous complexes containing the macrocyclic ligand and aliphatic aminocarboxylates. It is assumed that all complexes are binuclear with an exo coordination mode of the octaazamacrocyclic pendant ligand in the boat conformation. In addition, two –N–(CH2)2–N– portions of the cyclam ring within the tpmc ligand and Co(II) ions in the high-spin state are most probably bridged via oxygen atoms from the anion of the amino-carboxylate/derivatives, whereas nitrogen atoms rest uncoordinated. In all cases, a combined chelate-bridged coordination is proposed as the most probable. The complexes were electrochemically stable in the potential range –1.0 to 1.0 V. They were also preliminary assayed toward some microorganisms together with the ligands, starting simple salts and solvents as test substances. In some cases, certain antimicrobial activity of the complexes was detected

Korelativni odnosi za definisanje deformabilnosti stene

In the framework of geotechnical investigations of the rock mass at the partition site MHE Bočac 2 (BiH), Jelašnica dams on the same river in southern Serbia and nine partition sites of hydroelectric power plants on the river Ibar, detailed geotechnical investigations of the rock mass were carried out. They included exploration drilling with the definition of quasihomogenic zones within the drilled core, determination of RQD for each separated quasi-chemical zone, dilatometric tests in each well, seismic ventilation between exploratory wells or seismic carotid, core testing by the Point Load method and laboratory tests of the single-axial strength of the samples. By connecting the results of the one-axial strength, the velocity of the elastic waves and the quality of the rockl mass (RMR), i.e. these indirect data for defining the deformability of the rock masses with the obtained results of in situation deformability testing, with the results of dilatometric tests, the analysis of correlation bonds is carried out which is applied in engineering geological or geotechnical practice. As is known, in engineering practice, the following correlations are used to define the deformation module: D = f(RMR); D= f(RMR,σci); D= f(Vp) i D = f(Vp, σci). After the analysis, a correlation was applied which included all three indirect data and it gave the closest data for defining the deformability of the rock mass.U okviru geotehničkih istraživanja stenske mase na pregradnom mestu MHE 'Bočac 2‟ (BiH), brane 'Jelašnica' na istoimenoj reci u južnoj Srbiji i na devet pregradnih mesta hidroelektrana na Ibru (Srbija) izvršena su detaljna geotehnička ispitivanja stenske mase. Ona su obuhvatila: istražno bušenje sa definisanjem kvazihomogenih zona u okviru izbušenog jezgra, određivanje RQD-a za svaku izdvojenu kvazihomogenu zonu, dilatometarska ispitivanja u svakoj bušotini, seizmičko prozračivanje između istražnih bušotina ili seizmički karotaž, ispitivanje jezgra metodom PointLoad i laboratorijska ispi-tivanja jednoaksijalne čvrstoće uzoraka. Na navedenim istražnim lokacijama teren grade različite ste-nske mase. Teren pregradnog mesta MHE 'Bočac 2' je izgrađen od krednih krečnjaka, teren brane 'Jelašnica' od paleozojskih gnajseva, a teren hidroelektrana na Ibru od mezozojskih peridotita i serpentinita. Povezivanjem rezultata jednoaksijalne čvrstoće, brzine elastičnih talasa i kvaliteta stenske mase (RMR), odnosno ovih posrednih podataka za definisanje deformabilnosti stenskih masa sa do-bijenim rezultatima ispitivanja deformabilsnosti in situ, tj. Sa rezultatima dilatometarskih ispitivanja, urađena je analiza korelacionih veza koja se primenjuje u inženjeresko-geološkoj odnosno geotehničkoj praksi. Kao što je poznato, u inženjerskoj praksi primenjuju se sledeće korelacije za definisanje modula deformacije: D=f(RMR); D=f(RMR,); D=f(Vp) i D=f(Vp, ). Nakon analize, primenjena je korelacija, koja je obuhvatila sva tri posredna podatka i ona je dala najbliže podatke za definisanje deformabilnosti stenske mase. Sva navedena ispitivanja deformabilnosti metodom dilatometra, geofizička ispitivanja i inženjersko-geološko kartiranje jezgra i okolne stenske mase izvršena su od strane Instituta za vodoprivredu 'Jaroslav Černi' iz Beograda