Varijabilnost i koeficijent heritabilnosti prosečnog sadržaja suve materije u lukovicama crnog luka (Allium cepa L.)

In order to research the variability of average dry matter content in onion bulbs, the trial has been set up on the experimental plot in the Centre for Vegetable Crops in Smederevska Palanka during 2000. and 2001. The trial has been performed by applying the method of random block design with five replicas. Ten cultivars of different geographical origin have been used. Examined characteristics were determined by applying the variance analysis of two-factorial trial - model 2. Hadzivukovic, 1991. The components of phenotype variance, genotype and phenotype coefficient of variance and heritability in broader sense have been calculated according to SINGH and CHAUDHARY (1976). The significant variability has been found for dry matter content in bulbs during both years of research. The researched trait had a greater genotype variance than out door conditions factor variance and the coefficient of phenotype variation greater than genetic variance coefficient. High percentage of genetic variability in total phenotype variability has been confirmed by high heritability. .U cilju ispitivanja varijabilnosti prosečnog sadržaja suve materije u lukovicama crnog luka, postavljen je ogled na oglednom polju Centra za povrtarstvo u Smederevskoj Palanci u toku 2000. i 2001. godine. Ogled je izveden po slučajnom blok sistemu u pet ponavljanja. Za istraživački materijal korišćeno je deset sorata, različitog geografskog porekla. Utvrđene vrednosti ispitivanih svojstava su obrađene analizom varijanse dvofaktorijalnog ogleda-model 2. (Hadživuković, 1991). Komponente fenotipske varijanse, genotipski i fenotipski koeficijent varijacije i heritabilnost u širem smislu izračunate su prema Singh i Chaudhary (1976). Značajna varijabilnost je dobijena za prosečni sadržaj suve materije u lukovicama tokom obe godine istraživanja. Ispitivana osobina imala je varijansu genotipa veću od varijanse faktora spoljašnje sredine i koeficijent fenotipske varijacije veći od koeficijenta genetičke varijacije. Veći udeo genetičke u ukupnoj fenotipskoj varijabilnosti potvrđuje visoka heritabilnost.

Characterization and utilization of the permeate and retentate obtained after “dead-end” ultrafiltration

In the recent years, with the increase in bioethanol production, the increasing amounts of distillery wastewater are generated. Such wastewater (stillage) is one of the most polluted waste product of the food and beverage industries. The present study evaluates the treatment of distillery wastewater by ultrafiltration (UF), in order to reduce its pollution and evaluate the composition of the permeate and retentate. Polyethersulfone ultrafiltration membrane with molecular weight cut-off (MWCO) 30000 Da, was used for the experiments. The UF was carried out in dead-end mode. The results of the analyses of the permeate and retentate obtained after ultrafiltration were considered as well as different ways for their further utilization. The pollutant level in the permeate was decreased significantly in comparison to the raw stillage, and suspended solids were completely removed from the stillage. [Projekat Ministarstva nauke Republike Srbije, br. TR 31002

Microfiltration of distillery stillage: Influence of membrane pore size

Stillage is one of the most polluted waste products of the food industry. Beside large volume, the stillage contains high amount of suspended solids, high values of chemical oxygen demand and biological oxygen demand, so it should not be discharged in the nature before previous purification. In this work, three ceramic membranes for microfiltration with different pore sizes were tested for stillage purification in order to find the most suitable membrane for the filtration process. Ceramic membranes with a nominal pore size of 200 nm, 450 nm and 800 nm were used for filtration. The influence of pore size on permeate flux and removal efficiency was investigated. A membrane with the pore size of 200 nm showed the best filtration performance so it was chosen for the microfiltration process

Varijabilnost biohemijskih parametara krvnog seruma karakačanske ovce

Karakachan sheep represents an endangered, indigenous sheep breed from Balkan Peninsula. There is relatively little information about the characteristics of this sheep breed in the veterinary scientific literature. The aim of this research was an examination of certain metabolic profile parameters of the Karakachan sheep blood serum, and variability of their concentrations in comparison to age and some other indigenous sheep breeds from Balkans. Examination was conducted on 14 clinically healthy sheep divided in two age groups. Blood samples were collected by puncture of v. jugularis and blood serum was separated after spontaneous coagulation. The concentrations of total protein, albumin, calcium, inorganic phosphorus, aspartate amino transferase (AST) and γ- glutamyl transferase (GGT) were determined. In relation to age of Karakachan sheep, statistically significant difference between the calculated mean values of examined parameters was not observed. A statistically significant difference was found between the mean concentrations of the studied parameters in Karakachan sheep and other breeds in total protein (Tsigai, Dubrovnik and Dalmatian sheep), albumin (Dalmatian), calcium and inorganic phosphorus (Tsigai, Dubrovnik) and AST's (Dalmatian, Karakachan sheep from Bulgaria).Karakačanska ovca je ugrožena autohtona rasa ovaca sa Balkanskog poluostrva, o čijim rasnim karakteristikama postoji relativno malo podataka. Cilj ovog rada je bio da se u uzorcima krvnog seruma ispitaju određeni biohemijski parametri karakačanske ovce i ustanove odstupanja njihovih vrednosti u odnosu na starost karakačanske ovce, kao i u odnosu na vrednosti istih parametara kod drugih autohtonih rasa ovaca Balkana. Ispitivanjem je obuhvaćeno 14 klinički zdravih ovaca podeljenih u dve starosne grupe. Uzorci krvi uzimani su punkcijom v. jugularis iz kojih je, nakon spontane koagulacije i centrifugovanja, izdvojen krvni serum. Određivane su koncentracije ukupnih proteina, albumina, kalcijuma, neorganskog fosfora, aspartat amino transferaze (AST) i γ-glutamil transferaze (GGT). U odnosu na starost karakačanske ovce, nije ustanovljena statistički značajna razlika između izračunatih srednjih vrednosti ispitivanih parametara. Statistički značajna razlika je ustanovljena između srednjih vrednosti koncentracija ispitivanih parametara karakačanske ovce i drugih rasa za: ukupne proteine (cigaja, dubrovačka i dalmatinska ovca), albumin (dalmatinska), kalcijum i neorganski P (cigaja i dubrovačka) i aktivnosti AST-a (dalmatinska, karakačanska ovca iz Bugarske)

Procena energetskog statusa krava na osnovu telesne kondicije i parametara metaboličkog profila

The aim of this study was to assess the significance of body condition scoring and metabolic profile test for estimation of energy status of healthy high-yielding dairy cows. Twenty one healthy cows (primiparous and secundiparous) were divided into three groups: dry cows, early puerperal cows and early lactating cows. Cow's energy status was estimated by the analysis of blood samples for beta-hydroxybutirate (BHBA) and glucose. Additionally, urea, total bilirubine and total protein were measured in blood serum samples. According to body condition scores (BCS) results dry cows were overweight (4.03±0.29 points). Immediately after calving, cows lost their weight significantly, since BCS was 2.85±0.46 points at puerperal period and 3.12±0.33 points at day 60 of lactation (p lt 0.001 compared to dry period, respectively). Glucose concentration did not change significantly between dry and puerperal period, while BHBA increased significantly (0.46±0.14 mmol/l at dry period to 1.08±0.21 mmol/l at puerperal period; p lt 0.001). Urea concentration did not change significantly during examined period. Total bilirubin concentration significantly increased from dry (6.31±0.37 mmol/l) to puerperal period (7.63±2.52 mmol/l; p lt 0.001 compared to dry period) and remained high until day 60 of lactation (7.62±0.13 mmol/l; p lt 0.001 compared to dry period). Total protein concentration decreased from dry to puerperal period (69.59±6.14 g/l to 58.87±3.29 g/l; p lt 0.001). According to obtained results it can be concluded that cows were not in adequate energy status during transition period. Our results also indicate that, body condition scoring, BHBA and total bilirubin concentrations can be used as reliable indicators of cow's energy status even when there are not clinically visible health disorders.Cilj istraživanja bio je da se ukaže na značaj metaboličkog profila i telesne kondicije u oceni energetskog statusa visoko-mlečnih krava holštajn rase. Za ispitivanje su odabrane tri grupe po sedam krava. Uzorci krvi uzimani su u zasušenju (15 dana pre očekivanog teljenja), ranom puerperijumu (7 dana nakon teljenja) i 60. dana laktacije. U uzorcima sveže krvi određivana je koncentracija glukoze i beta hidroksi-buterne kiseline (BHBA), a u uzorcima krvnog seruma koncentracija ukupnih proteina, ureje i ukupnog bilirubina. Rezultati ocene telesne kondicije pokazuju da su krave u periodu zasušenja preuhranjene (X=4,03±0,29 poena), dok su u puerperijumu (X=2,85±0,46 poena) i 60. dana laktacije (X=3,12±0,33 poena) u značajno slabijoj telesnoj kondiciji (p lt 0,001 u odnosu na zasušenje). Rezultati ispitivanja parametara metaboličkog profila ukazuju da je koncentracija proteina jedino u periodu ranog puerperijuma bila niža od fiziološke vrednosti (X=56,87±3,29 g/l). Koncentracija glukoze nije se statistički značajno menjala tokom ispitivanih perioda, dok je neposredno posle teljenja došlo do značajnog povećanja koncentracije BHBA (p lt 0,001 u odnosu na zasušenje). Uremija u periodu zasušenja (X=7,73±2,34 mmol/l), ranom puerperijumu (X=8,07±3,09 mmol/l) i 60. dana laktacije (X=7,41±2,03 mmol/l) bila je veća od gornje fiziološke granice. Koncentracija ukupnog bilirubina u periodu zasušenja je bila značajno niža (p lt 0,001) u odnosu na oba ispitivana perioda nakon teljenja. Na osnovu dobijenih rezultata može se zaključiti da krave nisu adekvatno pripremljene za nastupajuću laktaciju, zbog čega je kod njih došlo do značajnog odstupanja u telesnoj kondiciji i vrednostima parametara metaboličkog profila. Ova odstupanja ukazuju na nedovoljnu sposobnost životinja da se prilagode u uslovima negativnog bilansa energije na početku laktacije

The construction and characterization of MgO transmission dynodes

In this work we demonstrate that ultra-thin (5 and 15 nm) MgO transmission dynodes (tynodes) with sufficient high transmission electron yield (TEY) can be constructed. These tynodes act as electron amplification stages in a novel vacuum electron multiplier: the Timed Photon Counter (TiPC). The ultra-thin membranes with a diameter of 30 {\mu}m are arranged in a square 64-by-64-array. The TEY was determined with a scanning electron microscope (SEM) using primary electrons with primary energies of 0.75 - 5 keV. The method allow us to make a TEY map of the surface while simultaneously imaging the surface. The TEY of individual membranes can be extracted from the TEY map. An averaged maximum TEY of 4.6 +/- 0.2 was achieved by using 1.35 keV primary electrons on a TiN/MgO bi-layer membrane with a layer thickness of 2 and 5 nm, respectively. The TiN/MgO membrane with a layer thickness of 2 and 15 nm, respectively, has a maximum TEY of 3.3 +/- 0.1 (2.35 keV). Furthermore, the effect of the electric field strength on transmission (secondary) electron emission was investigated by placing the emission surface of a tynode in close proximity to a planar collector. By increasing the electric potential between the tynode and the collector, from -50 V to -100 V, the averaged maximum TEY improved from 4.6 +/- 0.2 to 5.0 +/- 0.3 at a primary energy of 1.35 keV with an upper limit of 5.5 on one of the membranes

Material characterization of the main steam gate valve made of X20CrMoV 12.1 steel after long term service

Martensitic steel X20CrMo12.1 has been extensively used within the last few decades as a material for tubing systems and pipelines in thermal power plants (TPP). Long term behavior of this steel is very well known and understood and because of that was found to be reliable material for prolonged service at elevated temperatures. It is well known that during operation TPP components are subject to microstructural changes that inevitably reflect decrease in their mechanical properties that lead to the loss of structural integrity and serviceability of component. This paper deals with the comprehensive investigation carried out on the main steam gate valve parent material of welded joint, as a part of main steam pipeline, after 170.000 h of service (545 degrees C and 19MPa). The obtained results showed that the microstructural degradation caused by long term operation had little effects on the hardness and strength of material, while the changes in impact toughness were observed. Comprehensive microstructural analysis included the examination of the microstructure on the surface and trough the wall thickness

Material characterization of the main steam gate valve made of X20CrMoV 12.1 steel after long term service

Martensitic steel X20CrMo12.1 has been extensively used within the last few decades as a material for tubing systems and pipelines in thermal power plants (TPP). Long term behavior of this steel is very well known and understood and because of that was found to be reliable material for prolonged service at elevated temperatures. It is well known that during operation TPP components are subject to microstructural changes that inevitably reflect decrease in their mechanical properties that lead to the loss of structural integrity and serviceability of component. This paper deals with the comprehensive investigation carried out on the main steam gate valve parent material of welded joint, as a part of main steam pipeline, after 170.000 h of service (545 degrees C and 19MPa). The obtained results showed that the microstructural degradation caused by long term operation had little effects on the hardness and strength of material, while the changes in impact toughness were observed. Comprehensive microstructural analysis included the examination of the microstructure on the surface and trough the wall thickness

Ultra-thin corrugated metamaterial film as large-area transmission dynode

Large-area transmission dynodes were fabricated by depositing an ultra-thin continuous film on a silicon wafer with a 3-dimensional pattern. After removing the silicon, a corrugated membrane with enhanced mechanical properties was formed. Mechanical materials, such as this corrugated membrane, are engineered to improve its strength and robustness, which allows it to span a larger surface in comparison to flat membranes while the film thickness remains constant. The ultra-thin film consists of three layers (Al$_2$O$_3$ /TiN/Al$_2$O$_3$) and is deposited by atomic layer deposition (ALD). The encapsulated TiN layer provides in-plane conductivity, which is needed to sustain secondary electron emission. Two types of corrugated membranes were fabricated: a hexagonal honeycomb and an octagonal pattern. The latter was designed to match the square pitch of a CMOS pixel chip. The transmission secondary electron yield was determined with a collector-based method using a scanning electron microscope. The highest transmission electron yield was measured on a membrane with an octagonal pattern. A yield of 2.15 was achieved for 3.15 keV incident electrons for an Al$_2$O$_3$ /TiN/Al$_2$O$_3$ tri-layer film with layer thicknesses of 10/5/15 nm. The variation in yield across the surface of the corrugated membrane was determined by constructing a yield map. The active surface for transmission secondary electron emission is near 100%, i.e. a primary electron generates transmission secondary electrons regardless of the point of impact on the corrugated membrane