507 research outputs found
A preliminary study for determination of the possibility of simultaneous selection for oil content and grain yield in maize
We investigated the genetic potential of six maize families for simultaneous selection of oil content and grain yield. Six generations of six families were generated in 2011 and 2012. These genotypes were tested in a field experi- ment, conducted in Dardanos Research and Application Center, Çanakkale, Turkey, in 2013. Data were collected on oil content and grain yield per plant and then analyzed by using Generation Mean Analysis method to determine the appropriate families for simultanous selection studies. We also calculated genetic effect estimations for these traits in the investigated genotypes.
Results showed that there were significant differences among the families and generations for oil content and grain yield. The variation in oil content in the families was mainly controlled by additive gene actions. Simultaneous selection did not seem feasible in the tested families, though there was a good chance for considerable enhance- ment in some genotypes if the investigated traits were taken into account singlehandedly. Three families (A680x- IHO, IHOxB73 and IHOxHYA) showed potential for selection to enhance oil content, while two others (IHOxMo17 and Mo17xIHO) were promising for grain yield. Estimated genetic gains were in the range of 0.4% to 4.1% per cycle for oil content, and 17.7 g to 60.7 g per cycle for grain yield
The Effect of the Co-Planar Structure on HPBW and the Directional Gain at the Square Patch Antenna around ISM 2450 MHz
In this study, ISM-band microstrip square patch antenna with 2450 MHz operating frequency was designed, the S11 reflection coefficient of the antenna and the maximum antenna gain at φ and θ angles was determined, and the values of HPBW were calculated. The simulations were performed in Ansoft HFSS and the accuracy of the gain value enhancement in the results was confirmed by CST Studio Suit. Then, by placing the co-planar structure around this patch, the values for different co-planar thicknesses were obtained again. The maximum antenna gain of the co-planar structure in φ and θ angles and its effect on HPBW values were compared. According to this, the maximum gain value of 113 × 118 mm microstrip square patch antenna with no co-planar structure was obtained as 0,308 dB and HPBW value was obtained as 55,05°. When these values were obtained again by adding co-planar structure without changing the antenna dimensions, it was observed that the maximum gain value was 0,748 dB and HPBW value was 49,46°. As can be understood from these values, the addition of co-planar structure was observed to have a positive effect on the antenna parameters by causing the increase in Maximum Gain. HPBW values decreased contrast to the gain. Here, it was observed that adding co-planar structure increased the directionality and max gain of the antenna on the radiation pattern, and the θ angle, in which the max gain occurred, shifted from 90 to 85. It was also observed that a similar effect occurred at different antenna sizes. Traditionally, antenna gain is achieved by increasing antenna dimensions. In this study, it was investigated to increase the antenna gain without increasing the antenna size marginally
Site index conversion equations for mixed stands of scots pine (Pinus sylvestris L.) and oriental beech (Fagus orientalis Lipsky) in the Black Sea Region, Turkey
The site index conversion equations are important for estimating the site index of one tree species from the site index of another tree species in mixed stands. In this study, data were obtained from 162 sample plots in mixed stands of Scots pine (Pinus sylvestris L.) and Oriental beech (Fagus orientalis Lipsky) from the Black Sea Region in the north of Turkey. The breast height ages and height of the site trees were measured and the site index was estimated by these data. Geometric linear regression was used to estimate the parameters of a linear model relating to site indices of Scots pine and Oriental beech species. The correlation between the site indices of Scots pine and Oriental beech was 0.818, indicating a good fit to the linear model. Validation procedure showed that conversion equations were suitable for the studied mixed stands. The conversion equations can be applied to mixed species stands with inconsistent stratification or in stand conversion situations for an accurate and reliable evaluation of forest quality
Determination of stand structure in even-aged Oriental Beech Forests in Turkey
The data for this study were obtained from Altun et al. (2012) project. The authors thank all who provided data. This work was supported by the TUBITAK - TOVAG (The Scientific and Technological Research Council of Turkey - Research Committee of Agriculture, Forestry and Veterinary), Project Number: 107O752.This study aimed at developing a stand yield model for even-aged and pure Oriental beech (Fagus orientalis) stands in Sinop Province, located in the north of Turkey. The data used in this study were obtained from 238 sample plots. The sample plots are 24-131 years of stand age range, 19.0-35.9 m of site index range, and 2.2-10.8 of stand density range (relative density index). With the generated equation systems, stand age, site index and density of the three main factors in Oriental beech stands, including the effects of individual, dual and triple factor interactions on the stands were numerically determined. As for even-aged Oriental beech stands, the main stand volume values increase depending on age, site index and density. The number of stems per hectare decreases as the stand grows older, and site index rises; the number, however, increases in parallel with stand density. The current annual volume increment reaches a peak at 3035 years at all site index groups and density levels, and begins to fall afterwards. Mean annual volume increment peaks up at 65-75 years at all site index classes and density levels, before beginning to decline. The results were in arrangement with the acknowledged growth rules. Stand yield models were assessed as Density-Variable Yield Table used for estimation of the remaining, removal and total stands
Estimating diameter at breast height (DBH) from diameter at stump height (DST) in triple mixed stands in the region of Artvin in Turkey
This study was supported by the Scientific Research Projects Unit of Karadeniz Technical University under Project KTU 2009.113.001.6.Diameter at breast height is used as an independent variable in the calculation of most tree or stand parameters because it can be measured easily and has high correlation with tree variables. But, it is necessary to
estimate the size of the DBH of the tree concerned to have knowledge of the tree which has been separated
from the area. In this study, DST-DBH relationships were investigated on stands where Oriental Spruce (So),
Scots Pine (Ps) and Eastern Black sea Fir (Fb) were mixed. For this purpose, 206 trees (69 So, 69 Ps and 68 Fb)
were used which were cut from 23 different sample areas taken in fully closed SoPsFb and PsSoFb stands in
Artvin. According to the statistics analysis; models that best explain the variability of the DBH are power for
spruce, quadratic for pine and linear models for fir. These models can explain the variance of DBH in triple
mixed stands by 95.2% for spruce, 96.5% for pine and 96.4% for fir, and standard errors of models are 1.850,
1.598 and 1.643 respectively. As a result, these models, which at a certain height of success in predicting DBH,
can be used by practitioners at fully closed triple mixed stands in Artvin.Göğüs çapı, kolay ölçülebilir olması ve diğer ağaç değişkenleriyle yüksek korelasyona sahip olmasından
dolayı, tek ağaç veya meşcere parametrelerinin birçoğunun hesaplanmasında bağımsız bir değişken olarak
kullanılmaktadır. Ancak ormanlık alandan ayrılmış olan ağaç hakkında bilgi sahibi olabilmek için göğüs çapı
büyüklüğünü tahmin etmek gerekmektedir. Bu çalışmada, Doğu Ladini (L), Sarıçam (Çs) ve Doğu Karadeniz
Göknarı (G) karışık meşcerelerinde göğüs çapı-kütük çapı ilişkisi araştırılmıştır. Bu amaçla Artvin’de tam kapalı
olan LÇsG ve ÇsLG meşcerelerinden alınan 23 farklı örnek alandan kesilmiş olan 206 ağaç (69 adet L, 69 adet Çs
ve 68 adet G) verisi kullanılmıştır. Yapılan istatistiksel analizlere göre, göğüs çapındaki değişkenliği açıklayan en
iyi modeller Ladin’de power, Sarıçamda kuadratik ve Göknarda ise doğrusal modeller olmuştur. Bu modellerin
üçlü karışık meşcerlerde göğüs çapı değişkenliğini açıklama oranları Ladin için %95,2, Sarıçam için %96,5 ve
Göknar için de %96,4 ve bu modellerin hataları da sırasıyla 1.850, 1.598 ve 1.643 şeklinde bulunmuştur. Sonuç
olarak, göğüs çapını tahmin etmede belli başarı seviyesinde olan bu modeller, Artvin’deki tam kapalı üçlü
karışık meşcerelerde uygulayıcılar tarafından kullanılabilir olarak bulunmuştur
Design of an efficiency-enhanced Greinacher rectifier operating in the GSM 1800 band by using rat-race coupler for RF energy harvesting applications
Radio frequency energy harvesting (RFEH) circuits can convert the power of communication signals from radio frequencies (RF) in the environment into direct current and voltage (DC power). In this study, the Greinacher full-wave rectifier
circuit topology was combined with a 180 hybrid ring (rat-race) coupler which
was a passive RF/microwave circuit. Thus, higher RF-DC conversion efficiency
was obtained. First, using the Greinacher rectifier topology, RFEH circuit operating
at the center frequency of 1850 MHz was designed. Then, at this frequency,
designing of the rat-race coupler having 1000 MHz bandwidth was made. The
S-parameter measurements and simulation data of the designed coupler circuit were
compared. Finally, the high efficiency rectifier circuit where these two circuits
were used together was designed. The proposed rectifier circuit was constructed on
70 × 70 × 1.6 mm3 FR4 substrate material with a permittivity of 4.3 (εr = 4.3).
The power conversion efficiency (PCE) of the rectifier circuit, which had
125 MHz bandwidth at the center frequency of 1850 MHz and was developed with
rat-race coupler, was calculated as 71% at 4.7 dBm input power. In addition, with
this study, at −15 dBm input power, which was a relatively low power level, 40%
PCE value was obtained
Dynamic base-age invariant site index models based on generalized algebraic difference approach for mixed Scots pine (Pinus sylvestris L.) and Oriental beech (Fagus orientalis Lipsky) stands
Data from stem analysis of 397 dominant trees (198 Scots pine and 199 Oriental beech) were used to evaluate dynamic base-age invariant site index models derived from Bertalanffy–Richards, Hossfeld, and Lundqvist–Korf functions with the generalized algebraic difference approach (GADA) for mixed Scots pine (Pinus sylvestris L.) and Oriental beech (Fagus orientalis Lipsky) stands.
These functions were compared with respect to residuals of these models; specifically, the evaluation criteria were bias (– root mean
square error (RMSE), absolute mean error (AME), adjusted coefficient of determination (R2
), and Akaike information criterion.
The best results were obtained with generalized algebraic difference equations derived from the base models of Bertalanffy–Richards for Oriental beech and Hossfeld for Scots pine. These selected models accounted for 95%–96% of the total variance in height–age relationships in dominant trees with bias of 0.049841 and 0.00171, RMSE of 1.55624 and 1.353736, AME of 0.940128 and 0.884034, and AIC of 723.55 and 1250.78 for Scots pine and Oriental beech, respectively. These dynamic base-age invariant site index models for the 2 tree species presented more effective and accurate polymorphic site index curves with multiple asymptotes than earlier site index models for Oriental beech and Scots pine. The important differences of height growth trend between developed base-age invariant site index models in this study and earlier site curves were determined by graphical comparisons for site index predictions. Therefore, the new dynamic base-age invariant site index models developed based on GADA methodology can be recommended for dominant height prediction and forest site quality evaluations in the mixed stands of these 2 species
Modeli rasta prirodnih sastojina kalabrijskog bora u središnjem mediteranskom području Turske
Stand growth models are needed for a variety of forestry practices, primarily management plans and silvicultural studies. The goal of this study was to create stand-level models for natural, pure even-aged stands of Calabrian pine in the central Mediterranean region of Turkey. The study area consists of pure and natural Calabrian pine stands located within the boundaries of the Antalya and Mersin Regional Forestry Directorates in the central Mediterranean region of Turkey. Data was collected from 486 temporary plots scattered throughout the region. Two trees (the dominant tree and the tree representing the quadratic mean diameter of the stand) were measured in each plot, yielding 972 trees. The data showed that the age varied from 6 to 135 years, the site index (SI) from 8.5 to 33.5 m, and the density from 0.3 to 12.4. The density-dependent yield tables were generated using regression equations based on stand age, SI, and stand density with individual, two-factor, and three-factor interaction effects. For SI classes I, II, and III, the optimal rotation period that would result in the highest yields for pure Calabrian pine stands is 60, 65, and 75 years, respectively. The stand growth models developed (i.e., density-dependent yield tables) agreed with the fundamental growth principles and data provided in the literature.Modeli rasta sastojina potrebni su za različite prakse u šumarstvu, ponajprije planove gospodarenja i studije uzgoja šuma. Cilj ove studije bio je stvoriti modele na razini sastojina za jednodobne, čiste i prirodne sastojine kalabrijskog bora u središnjem mediteranskom području Turske. Područje istraživanja sastoji se od čistih i prirodnih sastojina kalabrijskog bora, smještenih unutar granica regionalnih uprava za šumarstvo Antalije i Mersina u središnjoj mediteranskoj regiji Turske. Podaci su prikupljeni s 486 privremenih ploha razasutih diljem regije. Dva stabla (dominantno stablo i stablo koje predstavlja kvadratni srednji promjer sastojine) izmjerena su na svakoj plohi, dajući 972 stabla. Podaci su pokazali da je starost varirala od 6 do 135 godina, indeks staništa (SI) od 8,5 do 33,5 m, a gustoća od 0,3 do 12,4. Prirasno-prihodne tablice ovisne o gustoći generirane su korištenjem regresijskih jednadžbi na temelju starosti sastojine, SI i gustoće sastojine s pojedinačnim, dvofaktorskim i trofaktorskim interakcijskim učincima. Optimalno razdoblje ophodnje koje bi rezultiralo najvećim prinosima za čiste sastojine kalabrijskog bora može se odabrati kao 60, 65 i 75 godina za SI klase I, II, odnosno III. Razvijeni modeli rasta sastojine (tj. Prirasno-prihodne tablice ovisne o gustoći) slagali su se s temeljnim zakonima rasta i podacima prikazanim u literaturi
Oblikovanje baze podataka za praćenje zaliha u skladištu sustavom PostgreSQL
Cilj izrade ovog rada je prikaz izrade i primjene sustava za praćenje zaliha u skladištu nekog poduzeća. U radu je ukratko opisana povijest SQL-a koji je najkorišteniji jezik za rad bazama podataka te je detaljno opisan PostgreSQL sustav koji je korišten za izradu programskog rješenja. U radu se takoĊer detaljno opisuju koraci u izgradnji baze podataka koja sluţi kao potpora radu aplikacije za praćenje zaliha u skladištu kreirane u alatu Microsoft Visual Studio. TakoĊer je prikazan rad aplikacije te su opisane njezine mogućnosti. Na temelju opisanih koraka oblikovanja baze podataka i aplikacije kreiran je odgovarajući sadrţaj i napisan tekst završnog rada
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