Half Parts Research Articles

Load Mismatch Compensation of Doherty Power Amplifier Using Dual-Input and Mode Reconfiguration Techniques

Doherty power amplifier (DPA) has shown great potentials in wireless communication systems. However, the output power and efficiency of a DPA are very susceptible to load mismatch. This paper presents the load mismatch analysis and compensation of coupler-based DPAs leveraging on dual-input and mode reconfiguration techniques. A comprehensive analysis, which takes voltage clipping into consideration, is conducted on a coupler-based dual-input DPA (CBDI-DPA) under load mismatch condition. It is illustrated that the parallel Doherty mode could recover the saturation and back-off drain efficiencies (DEs) for the load mismatch in the left and right half parts of the Smith chart, respectively. And the serial Doherty mode could recover the back-off and saturation DEs for the load mismatch in the left and right half parts of the Smith chart, respectively. As a validation, a CBDI-DPA operating at 2.4 GHz is fabricated and measured in this paper. Under the optimal load impedance condition, the fabricated CBDI-DPA delivers a saturation power of more than 43.5 dBm, a saturation DE of more than 70% and a 6 dB back-off DE of more than 60% in both the parallel and the serial Doherty modes. Meanwhile, the simulation and experimental results demonstrate the proposed method can recover the output power and efficiency of a DPA when the load mismatch is inside the 2:1 VSWR circle.

An Investigation on the Relationship Between Mineral Nutrition of Lemon and Rumple

This study investigated the relationship between Rumple and tree crown parts regarding direction, fruit development stages and fruit rind nutrient content. A Lemon orchard on which Rumple disorders have shown severely were chosen among Erdemli and Silifke region where the majority of grown lemon cultivar is Kütdiken. In this orchard, from healthy and contaminated trees samples were taken from the South and West half parts of crown and the North and East parts of the crown separately. Also, fruit samples were taken at four fruit development stages which were hazelnut-sized fruit, end of fruit enlargement, the beginning of maturation and fully mature fruit stages. The rind of samples fruit was analyzed, and their content of N, P, K, Ca, Mg, S, Mn, Fe, Zn, B, Cl and Na was determined. PCA was used to analyze these data. Biplot scheme of the 2nd Sampling from the part one-half of the trees which includes the South and West directions, that is, from the Healthy (G2S) and Rumple signed trees (G2B) taken were examined. The increase in K, Zn, Fe, Ca, and Mg is associated with Na, P and Cl concentration reduction. Besides this, in this period, it was observed that fruit rind has higher N, S, Mn and B content which were taken from part one, that is, the South and West sides, of healthy plants. The relationship identified here is important because Rumple’s symptoms become visible after this stage.

Influence of asymmetric pre-whirl stator spacing on unsteady characteristics of pump-jet propulsor

This work studies the effect of the asymmetric pre-whirl stator spacing on the hydrodynamic performance of a pump-jet propulsor (PJP). The PJP contains a 13-stator and 7-rotor. The stator count is altered in the upper and lower half, and the total count is held constant. Results show that the steady performance is independent of the stator non-uniformity at design conditions. While the unsteady fluctuation of the rotor force and flow field is deeply affected by this adjustment. The cause is that the different incident angles of each rotor resulted from various stator spacing. The larger the stator count on one side, the great the incident angle in the corresponding location. Eventually, the stator root vortices in the lower half, where stator count is relatively larger, are weakened, whereas the tip vortex shape and intensity are not affected by the stator non-uniformity. Most notably, the PJP with a slight change of stator arrangement, in which the difference between two half parts is one, does not cause a significant change in flow, and the thrust amplitude at specific frequency decreases by 40% compared to the uniform stator case.

Establishing essentially symmetrical combustion plus apparent improvement in burnout and NOx emissions within a down-fired furnace by rearranging its W-shaped flame into a sidewall-dominated pattern

Asymmetric combustion, which is mainly incurred by the guiding effect of the short and asymmetric upper furnace, appears universally in down-fired furnaces equipped with a conventional front/rear wall-dominated W-shaped flame pattern (labeled as the FRW-flame pattern). It generally favors the occurrence of heat deviation, poor burnout, and high NOx emissions. Aiming at eliminating asymmetric combustion and solving these incidental problems from the mentioned fountainhead, a sidewall-dominated W-shaped flame solution (labeled as the SW-flame pattern) was proposed and then trialed in a 600 WMe supercritical down-fired furnace to replace the original FRW-flame pattern. Industrial-size measurements were performed at normal full load for not only uncovering the asymmetric combustion characteristics and furnace performance with the FRW-flame pattern but also validating the subsequent numerical simulations. Numerical simulations before and after the SW-flame application were carried out for achieving two functions: (i) deepening the understanding about asymmetric combustion and explaining the poor furnace performance incurred by the original FRW-flame pattern; and (ii) confirming the SW-flame solution in establishing essentially symmetrical combustion and improving comprehensively the furnace performance. For the FRW-flame pattern, asymmetric combustion (clearly higher gas temperatures in the rear-half side) plus a severely deflected flow field developed in the furnace, where the downward coal/air flow in the front-half side penetrated much further while proceeded mainly in the low-temperature near-wall zone. A combination of (i) the much poorer combustion status in the front-half part, (ii) great differences of the downward coal/air penetration and the fuel-lean coal/air flow trajectories in the front/rear half parts, and (iii) the sufficient oxygen levels in the local high-temperature zones strengthened by asymmetric combustion, finally developed the poor furnace performance with carbon in fly ash of 8.5 % and NOx emissions of 1467 mg/m3 at 6 % O2. As the FRW-flame pattern was replaced by the SW-flame pattern, an essentially symmetrical combustion form with a symmetrical flow field was established in the furnace. The symmetrical downward coal/air flows penetrated sufficiently in the lower furnace. The fuel-lean coal/air trajectories were symmetrically redirected in the high-temperature furnace central part. The local high-temperature zones below arches and in the furnace central part were homogenized by the symmetrical combustion and were filled with low O2 levels. Consequently, the furnace performance was greatly improved, with the calculated carbon in fly ash reduced from 7.74 % to 5.17 % and NOx emissions dropped from 1355 to 745 mg/m3 at 6 % O2 (i.e., reducing NOx emissions by 45 %).

Investigation of relative abundance of radioelement concentration over a portion along Birnin Yauri, Northwestern Nigeria

The radiometric method involves the measurement of naturally occurring radioactive materials emitting the ionization radiation (α, β, from rocks). In the field, the gamma rays and their adequate energies are detected by a spectrometer coupled with the scintillation detector. Three (3) high resolution airborne radiometric data obtained from the Nigerian geological survey agency (NGSA) were used to obtain the concentration of Potassium (K), Uranium (U) and Thorium (Th) respectively in the study area. The gridded data were fed into Oasis montaj software for appropriate filtering, in other to produce solutions for radioelement concentration across the area under study, thereafter producing shaded count maps as well as ternary maps. The result of the analysis revealed that potassium concentration is between 0.090 to 2.455% with an average of 2.365%. The thorium concentration values ranged from -0.539 to 15.221 ppm with an average of 7.341 ppm. The uranium concentration revealed values from -0.402ppm to 3.902ppm with an average of 1.75ppm. The ternary map of the radiometric data showed a red/cyan colour grid depicting potassium which is more pronounced across the area, followed by the uranium content(blue) covering an appreciable portion across with only but a few (green) coloured shaded regions depicting thorium. The results obtained have shown that the area has substantial amount of radioelement concentration, with potassium being the most abundant covering the central and western half of the area while the uranium content is more abundant towards the mid-western half and eastern parts of the area. The thorium content is minimal across the region.

Experimental study on control of flame inclination in a thermal flow reversal reactor with extra lean premixed methane/air intake

Combustion instability is a basic obstacle to the wide application of porous media combustion devices in industry. However, the investigation about it with extremely dilute gas fuel issorelylacking due to the limitation of laboratory test conditions. In this study, inclinational instability of extra lean-premixed flame (with volume fraction below 1%) in a thermal flow-reversal reactor with honeycomb ceramic packings is investigated experimentally. The effects of inlet methane concentration on the flame inclination are studied. Then the flame inclination is restrained through electronically controlled adjustment on the valve opening and switch time. The experimental results show that the intake methane concentration has a remarkable effect on the flame inclination angle variation in each semi cycle. When the intake concentration decreases from 0.6 vol% to 0.2 vol% and the flow direction is downward, the growth of the flame inclination angle in each semi cycle gets lower. The adjustment on the scale of the high temperature zones in two half parts of the packed bed through the valve opening has a great influence on the flame front position and flame inclination angle. The setting of asymmetric switch time for the reverse flow also has obvious effect on the evolution of the flame inclination. Finally, the flame inclination angle drops firmly for approach of the two high temperature zones in size and height. The synchronous adjustment of valve opening and switch time fastens the convergence of the two high temperature zones in two half parts of the packed bed. This work is beneficial to the development of thermal flow-reversal reactor technique for better dealing with ventilation air methane and other lean gaseous fuel streams.

Negative Interresonator Coupling Structure Enclosed in Waveguide Resonator Filter

This work presents a new negative interresonator coupling structure that can be applied to circular waveguide resonators, such as substrate-integrated waveguide (SIW) resonators and metallic cavity resonators utilizing the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">011</sub> mode. The negative coupling is obtained by using the fact that the magnetic field in the resonator circulates in the opposite directions in the upper and lower half parts. As it can be entirely enclosed within a filter structure, it does not produce radiation loss. For verifying the proposed negative coupling structure, we have designed and fabricated a fourth-order bandpsss filter having a pair of transmission zeros using SIW resonators. In addition, the proposed negative coupling structure can be applied to the metallic waveguide cavity resonator filters. Hence, we also have designed, fabricated, and measured a fourth-order metallic cavity bandpass filter having a pair of transmission zeros by adopting the proposed negative coupling structure.

Resistance Status of Anopheles maculipennis and Anopheles superpictus to the Conventional Insecticides in Northeastern Caspian Littoral, Iran.

Background:Malaria resurgence has occurred in the northern half parts of Iran. The resurgence of malaria in the prone area could arise from various factors, e.g. wide use of pesticides in the agriculture sector and factors such as habitual patterns of movement of local people from problematic southeastern foci in Iran toward the Caspian Littoral. There are no new data on the resistance status of main malaria vectors in the Caspian Littoral, and this study was aimed at renewal data on conventional insecticides.Methods:The field strain of adult Anopheles superpictus and Anopheles maculipennis were collected using the hand catch method and transferred to the laboratory. The susceptibility tests were carried out against DDT 4%, Malathion 5%, Permethrin 0.75%, Deltamethrin 0.05%, and Lambda-cyhalothrin 0.05%, followed by the WHO’s procedure.Results:The primary malaria vector in Caspian Littoral is An. maculipennis, revealed to be still resistant to DDT and mortality rate, LT50 and LT90 of female mosquitoes were 75.0%, 54.2, minutes and 111.3 minutes. The under ‘verification required’ status of An. maculipennis was also revealed to Lambda-cyhalothrin based on recent WHO’s criteria. The malaria vector An. superpictus is also considered the second malaria vectors in the west parts of the studied area, which showed to be susceptible to all insecticides tested.Conclusion:DDT resistance is persisted in An. maculipennis despite stopping residual spraying with DDT since 1978 in the Caspian Littoral, but the occurrence of pyrethroid under ‘verification required’ status is a progressive threat to the possible development of cross-resistance in the future.

Mechanical properties and microstructure of additively manufactured stainless steel with laser welded joints

Powder bed fusion (PBF) is a commonly employed metal additive manufacturing (AM) process in which components are built, layer-by-layer, using metallic powder. The component size is limited by the internal build volume of the employed PBF AM equipment; the fabrication of components larger than this volume therefore requires mechanical joining methods, such as laser welding. There are, however, very limited test data on the mechanical performance of PBF metal with laser welded joints. In this study, the mechanical properties of PBF built 316L stainless steel parts, joined together using laser welding to form larger components, have been investigated; the microstructure of the components has also been examined. 33 PBF 316L stainless steel tensile coupons, with central laser welds, welded using a range of welding parameters, and with coupon half parts built in two different orientations, were tested. The porosity, microhardness and microstructure of the welded coupons, along with the widths of the weld and heat-affected zone (HAZ), were characterised. The PBF base metal exhibited a typical cellular microstructure, while the weld consisted of equiaxed, columnar and cellular dendrite microstructures. Narrow weld regions and HAZs were observed. The PBF base metal was found to have higher proof and ultimate strengths, but a similar fracture strain and a lower Young’s modulus, compared with conventionally manufactured 316L stainless steel. The strengths were dependent on the build direction – the vertically built specimens showed lower proof strengths than the horizontal specimens. The laser welds generally exhibited lower microhardness, proof strengths and fracture strains than the PBF base metal which correlated with the observed structure. This work has demonstrated that PBF built parts can be joined by laser welding to form larger components and provided insight into the resulting strength and ductility.

Parametric optimization of wall-mounted cuboid rows installed in interdigitated flow channel of HT-PEM fuel cells

High temperature proton exchange membrane (HT-PEM) fuel cells reduce water management problems and tolerates CO better in a polybenzimidazole (PBI) membrane because they work at temperatures higher than 120 °C. This paper examines the effect of setting wall-mounted cuboid rows in the interdigitated flow channel on the performance of HT-PEM fuel cells through experiments and simulations. The results of numerically analyzing the four flow channels show that setting the wall-mounted cuboid rows in top half parts of the channel can improve the cell performance. The best net electric power occurs at the arrangement of Case I increasing net electric power by 7.82% compared to the smooth interdigitated flow channel.The Case I design is then used to conduct the experiment with L27 orthogonal array of the Taguchi method to determine different optimal combined factors. The best combined factor level raises 191.09% electrical power than that for the minimum pressure loss, but it decreases the pressure drop than that for maximum power up to 17.00%. Applying Nyquist plots compares the internal impedance between various optimal parameters combinations of Case I and the smooth interdigitated flow channel to confirm the polarization performance results.

Piecewise wet and dry spell duration-number relationship and possible climate change impact identification in Turkey

Wet (dry) spells correspond to successive surplus (deficit) in hydro-meteorology daily, weekly, monthly, or annual records according to above (below) of a given any threshold parameter value such as arithmetic average, median, mod, or quantile precipitation. Researchers generally consider wet (dry) spell durations and their numbers, but this paper also focuses on the climate change impacts. For this purpose, available hydro-meteorological records, obtained from different climatic and geographic regions of Turkey, are divided into two half parts, and the wet and dry spell (month) durations are plotted versus their numbers, where the scatter points appear as decreasing straight lines on semi-logarithmic paper, and their mathematical expressions are in the form of exponential functions. The slopes of these straight lines provide useful information about the climate change impacts on each meteorology station. The physical interpretations and explanations are provided through relevant tables and figures. The application of this procedure is presented for a set of meteorology station monthly rainfall records from different climate regions of Turkey.

Drinfeld double of deformed quantum algebras

We provide a deformation, fβ, of Lusztig algebra f. Various quantum algebras in literatures, including half parts of two-parameter quantum algebras, quantum superalgebras, and multi-parameter quantum algebras/superalgebras, are all specializations of fβ. Moreover, fβ is isomorphic to Lusztig algebra f up to a twist. As a consequence, half parts of those quantum algebras are isomorphic to Lusztig algebra f over a big enough ground field up to certain twists. We further construct the entire algebra Uβ,ξ by Drinfeld double construction. As special cases, above quantum algebras all admit a Drinfeld double construction under certain assumptions.

Proof of principle of an optical Stokes absolute roll-angle sensor with ultra-large measuring range

We present a novel optical roll-angle sensor called Stokes roll-angle sensor. The measurement principle relies on modulating the roll angular displacement into the change of state of polarization (SoP) of polarized probe light by a quarter-wave plate (QWP). The SoP of the emerging elliptically polarized light from QWP is then detected by a Stokes polarimeter. Based on the detected Stokes vector, the roll angle can be extracted. Experimental results have shown that the proposed Stokes roll-angle sensor can realize absolute angle measurement in an unprecedented range of 180° with 0.02° resolution. Further expanding the measuring range to 360° is realizable by making a marker on the QWP to distinguish its two half parts divided by the fast-axis in the rotation. Other benefits of the proposed Stokes roll-angle sensor include simplicity, compactness, high speed, and low cost.

Global urban climate governance in three and a half parts: Experimentation, coordination, integration (and contestation)

Cities are increasingly central to the global governance of climate change, and much of their activity takes place within city‐networks operating at national, regional, and global scales. As the scope and ambition of city activities have been augmented over the past decade, so the scholarship has evolved as well. I set out in this review article to trace this evolution by focusing on four lines of inquiry organized around the conceptual foundations of governance experimentation, horizontal coordination, vertical integration, and political contestation. As we stand at the cusp of a vital moment in the global response, I suggest the need for a concerted effort to direct more, and more sustained, attention to the last of these. I argue that careful, critical, and creative thinking with respect to the power relations shaping the role of cities as global climate governors offers a means through which scholars can best contribute to augmenting the capacity for a just and effective urban contribution to the global effort.This article is categorized under: Policy and Governance &gt; Governing Climate Change in Communities, Cities, and Regions

Hierarchical BoW with segmental sparse coding for large scale image classification and retrieval

The bag-of-words (BoW) has been widely regarded as the most successful algorithms for content-based image related tasks, such as large scale image retrieval, classification, and object categorization. Large visual words acquired by BoW quantization through large vocabulary or codebooks have been receiving much attention in the past years. However, not only construction of large vocabulary but also the quantization process impose a heavy burden in terms of time and memory complexities. In order to tackle this issue, we propose an efficient hierarchical BoW (HBoW) to achieve large visual words through quantization by a compact vocabulary instead of large vocabulary. Our vocabulary is very compact since it is only composed of two small dictionaries which is learned through segmental sparse decomposition of local features. To generate the BoW with large size, we first divide the local features into two half parts, and use the two small dictionaries to compute their sparse codes. Then, we map the two indices of the maximum elements of the two sparse codes to a large set of visual words based upon the fact that data with similar properties will share the same base weighted with the largest sparse coefficient. To further make similar patches have higher probability of select the same dictionary base to get similar BoW vectors, we propose a novel collaborative dictionary learning method by imposing the similarity regularization factor together with the row sparsity regularization across data instances during group sparse coding. Additionally, based on index combination of top-2 large sparse codes of local descriptors, we propose a soft BoW assignment method so that our proposed HBoW can tolerate different word selection for similar patches. By employing the inverted file structure built through our HBoW, K-nearest neighbors (KNN) can be efficiently retrieved. After incorporation of our fast KNN search into the SVM-KNN classification method, our HBoW can be used for efficient image classification and logo recognition. Experiments on serval well-known datasets show that our approach is effective for large scale image classification and retrieval.

A rapid virtual assembly approach for 3D models of production line equipment based on the smart recognition of assembly features

Because of the large quantity of three-dimensional (3D) models and the manual operation process used for their virtual assembly, production line assembly design is time consuming and cannot readily meet the requirements of normalization. To address these problems, we propose a rapid virtual assembly approach based on the smart recognition of assembly features and present a system based on this concept. A 3D-two-dimensional (2D)-3D assembly feature recognition mode is proposed. The 3D models are first standardized using a standardization algorithm. The standardized 3D models are subsequently divided into six half parts, and each half part is projected into the coordinate plane to obtain its 2D projection drawing. The contours of the 2D projection drawings are obtained via a contour-recognition algorithm, and segments in contours are classified into different groups according to collinearity. A lightweight 3D model of the original 3D model is created through a series of Boolean operations. Assembly features can be obtained by matching the lightweight 3D model with the original 3D model. The recognized assembly features are used in the rapid assembly system to perform the assembly, and the constraints among these features are automatically added when two models are in proximity. Three comparison tests are conducted, and the results show that the system simplifies the assembly process, greatly increases the assembly design efficiency of the production line, and simultaneously reduces the workload and operational complexity.

On Transient EHL of a Skew Roller Subjected to a Load Impact in Rolling Bearings

Based on the non-steady state operating condition in machine elements, numerical analysis of a transient elastohydrodynamic lubrication (EHL) finite line contact between a skewed roller and an outer race in cylindrical roller bearings was carried out, and a complete numerical solution of skewed roller pairs EHL under the transient condition was obtained. The effects of the load impact, together with the skewing angle impulses on the lubricating performance of skew roller pairs were discussed. Results show that, different from the steady state, the transient effect of the skew roller lubrication is mainly governed by the skew angle impulse, and the load impact. The film dimple is generated during the load impact, or the skewing angle impulse due to the normal approach velocity of the film. Compared to that of the ideal roller, the minimum film thickness decreases due to the roller skew when the transient load happens. Variation in the skewing angle leads to contrary distribution of the film thickness at the two half parts of the roller. Meanwhile, it can decrease the minimum film thickness and be harmful to the lubrication compared to the steady state. Consequently, the transient effect in the process of lubrication of skew roller pairs should not be neglected.

Nanocrystal growth and morphology of PbTeSe-ZnSe composite thin films prepared by one-step synthesis method

The microstructure of polycrystalline PbTe1−xSex-ZnSe composite thin films has been studied by scanning transmission electron microscopy and electron diffraction. The films were prepared by the one-step synthesis method using simultaneous evaporation of PbTe and ZnSe. The nanocrystals of PbTe1−xSex are formed in a ZnSe matrix. Tellurium concentration can be tuned by controlling the PbTe evaporation source temperatures between 753 K and 793 K. Binary PbSe nanocrystals were formed at 753 K, while ternary PbTe1−xSex nanocrystals were formed at 793 K. The nanocrystals grow in a granular shape at the initial stage of film growth, and the morphology changes to nanowire-shape as the film grows, irrespective of the Te concentration. The ternary PbTe1−xSex nanocrystals were composed of two phases with different Te concentration; Te-rich (Se-poor) granular crystals were formed near the bottom half parts of the film and Te-poor (Se-rich) nanowires were formed at the upper half parts of the film. Columnar ZnSe crystals contain high-density {111} stacking faults due to the low stacking fault energy of ZnSe. A balance of deposition and re-evaporation on the substrate during the film growth will be responsible for the resultant nanocrystal morphology.

KARAKTERISTIK MORFOLOGI ESOFAGUS DAN LAMBUNG BANDIKUT (Echymipera kalubu) (Esophagus and Stomach Morphological Characteristic of Bandicoot Echymipera kalubu (Marsupialia: Peroryctidae))

The morphological characteristics of the stomach and esophagus of five adults bandicoot (Echymipera kalubu) with average 1.16±0.29 kg in body weight and 38.2±4.76 cm in body length were studied macroscopically, microscopically and histochemically. The bandicoot esophagus were found relatively long about one third of body length. The esophageal glands were identified along the esophagus and the number decreased gradually from cranial to caudal region. In addition of smooth muscle, skeletal muscles were also examined in the external muscle layer of esophagus up to the esophageal junction. The stomach of the E. Kalubu had short lesser curvature and three glandular regions of cardiac, fundic and pyloric glands were observed, respectively. The cardiac glands area was small and concentrated in the cranial part of the stomach. The fundic glands area occupied about half parts of the stomach. Mucous surface epithelial cells, mucous neck cells, parietal cells and chief cells were found in the entire fundic gland. The parietal cells were the most abundant cells in the major curvature distributed from the basal to neck area of the glands, but few in the minor curvature. Chief cells were mostly distributed in the basal gland. The pyloric glands region was observed in caudal part of the stomach. Staining with alcian blue-periodic acid Schift (AB-PAS) showed various distribution and intensity of neutral and acid mucopolysaccharides in the esophageal and stomach mucosa. High concentration of neutral and acid mucopolysaccharides were detected in esophageal and stomach glands with various concentration. Morphological characteristics of the esophagus and stomach were assumed to be related to the digestive processes in the gastrointestinal tract of bandicoot.

Effects of dietary lysine and methionine supplementation on Ross 708 male broilers from 21 to 42 d of age (III): serum metabolites, hormones, and their relationship with growth performance

SUMMARY A previous study has shown that a limited increase of lysine (Lys) and methionine (Met) in broiler diets may improve feed conversion ratio (FCR), BW, carcass yield, and breast meat yield. This study was conducted to determine the effects of dietary Lys and Met supplementation on various blood serum metabolites and hormones, and their relationship with growth performance and the meat yield of male Ross × Ross 708 broilers. Experimental diets, including 2 Lys levels (100 and 120% of recommended levels) and 4 Met levels (80, 100, 120, and 140% of recommended levels), were fed from 21 to 42 d of age. Blood serum metabolites were not affected by any of the dietary treatments. Uric acid concentration was negatively correlated with absolute weights of the whole body, carcass, pectoralis minor, wing, leg quarter, and front half parts. Cholesterol was negatively correlated with pectoralis major, wing, pectoralis major+minor, and front half. Insulin-like growth factor I (IGF1) and testosterone concentrations were found to be positively related to BW. In addition, positive correlations occurred between concentrations of total protein and high-density lipoprotein cholesterol; uric acid and total cholesterol; and IGF1 and testosterone. In conclusion, dietary amino acid supplementation did not affect the blood serum metabolites investigated, which may be due to the fact that these metabolites are highly regulated in the blood. However, because the expression of genes for these metabolites may be unique to individual birds, growth and the deposition of specific muscles among birds can be quite variable. Even though Lys and Met supplementation improved growth performance, and BW was positively related to circulating IGF1 and testosterone concentrations, these 2 hormones were not affected by dietary Met supplementation. The increase in growth rate caused by dietary Lys or Met supplementation may be due to changes in various integral metabolic pathways as a result of polygenic and pleiotropic relationships, rather than by the isolated effects of individual hormones and metabolites.