Impact of increasing dietary oil concentrations with a constant energy level on the tolerance of broiler chickens to a high ambient temperature

Broiler males (n= 140) were used in a straight-run experimental design and distributed randomly among four treatment groups with seven replicates per treatment and five broilers per replicate. During 21–42 d old, the chickens were fed iso-caloric and iso-nitrogenous diets containing four levels of dietary vegetable oils (DVO), of 2.7, 4, 6 and 8%. During d 25–27, 31–33, and 38–40 of age, broilers were exposed to heat stress for 4 h a day (1000–1400 h) at 34 ºC, 70–75 % relative humidity. Feeding an 8% DVO diet significantly increased body weight gain compared to the other DVO levels. The feed conversion ratio, protein conversion ratio, metabolizable energy conversion ratio and European production index were significantly enhanced due to feeding an 8% DVO diet compared to a diet containing 6% DVO. Feeding 8% DVO significantly increased the meat protein and lipid percentages, compared to the control group (2.7 % DVO), but decreased the plasma low-density lipoprotein, very-low-density lipoprotein and lymphocytes. Feeding 8% DVO significantly increased the mean cell volume and mean cell hemoglobin, and bursa weight and percentage compared to the control. In addition, 6 and 8% DVO significantly increased the plasma total antioxidant capacity compared to the control group, but decreased the malondialdehyde. Thus, broilers fed a diet containing 8% DVO have an increased tolerance to heat stress, as evidenced by increasing the productive performance, meat quality, blood hematological and biochemical traits, antioxidants and immunity

Synthesis, structural characterization and nematicidal studies of some new N2O2 Schiff base metal complexes

ABSTRACT. Cobalt(II), copper(II), yttrium(III), zirconium(IV), lanthanum(III) and uranium(VI) complexes of 1,4-di(2-hydroxybenzylidene)thiosemicarbazide (H2L) were prepared and characterized. The proposed structures were determined from their elemental analyses, molar conductivities, magnetic moment, IR, Proton NMR, UV-Vis., mass spectra, X-ray diffraction and thermal analyses measurements. The high conductance data supply evidence for the electrolytic nature of the complexes. The changes in the selected bands in IR of Schiff base ligand upon coordination showed that Schiff base exhibits as a neutral tetradentate manner with oxygen and nitrogen donor sites. The complexes are thermally steady at room temperature and break up to two or three steps. The kinetic and thermodynamic parameters of complexes have been determined by using Coats-Redfern and Horowitz-Metzeger methods at n=1 and n≠1 and values suggest more ordered activated complex formation. The calculated bond length and force constant, F(U=O), in the uranyl complex are 1.744 Å and 664.886 Nm-1. The nematicidal activity of free Schiff base and all complexes were investigated and showed a low inhibition percentage (%I) of complexes compared with H2L.                     KEY WORDS: Schiff base, IR, Thermal, XRD, Nematicidal activity   Bull. Chem. Soc. Ethiop. 2021, 35(2), 315-335. DOI: https://dx.doi.org/10.4314/bcse.v35i2.

Design of Serial-Fed Bend-Array and Measured Results

For the next generation mobile system (5G), a cylindrical lens antenna is developed for mobile base station application. As for the feed radiator for this lens antenna, bendarray configuration that produces a bifurcated beam is also developed. The bend-array configuration consisting of four rectangular patch array elements with serial feed network. In previous work, achievement of the bifurcated beam by bendarray configuration was shown by electromagnetic simulations. In this paper, a practical bend-array composed of four numbers of patch elements is fabricated. To verify the radiation characteristics, measured results of antenna input characteristic and radiation pattern are compared with the designed results. Through good agreement of measured and designed results, achievement of practical antenna is ensured

Spectroscopic, thermal analyses, XRD spectra and nematicidal activity study of some new N2O2 tetradentate Schiff base metal ions complexes

ABSTRACT. A series of metal complexes [Co(HL)2(H2O)2]Cl2.5H2O (A), [Cu(HL)2](CH3COO)2.2H2O (B), [Y(HL)2]Cl3.2H2O (C), [ZrO(HL)2H2O]Cl2.H2O (D), [La(HL)2(H2O)2]Cl3.5H2O (E) and [UO2(HL)2](CH3COO)2 (F) were prepared. The structures of the compounds in solid state were detected by micro analytical, Fourier transform IR, 1H NMR, UV-Vis, mass, X-ray diffraction spectra, molar conductivity, magnetic susceptibility measurements and TG/DTG analysis. The IR spectral data point out that the ligand behaves as tridentate in nature with Cu(II), Y(III), U(VI) and bidentate with Co(II), Zr(IV) and La(III) metal ions. The conductivity values showed that the complexes found as electrolytes and the XRD models of the complexes indicated crystalline nature. The thermodynamic parameters of compounds have been detected using Coats-Redfern and Horowitz-Metzeger methods at n = 1 and n ≠ 1 and values point out more ordered activated complex formation. The nematicidal efficacy of compounds was assessed.                     KEY WORDS: Schiff base, Spectroscopic analysis, Thermal analysis, XRD, Nematicidal   Bull. Chem. Soc. Ethiop. 2021, 35(2), 381-397. DOI: https://dx.doi.org/10.4314/bcse.v35i2.1

Academicians' Acceptance of Online Learning Environments: A Review of Information System Theories and Models

Aim of this paper is to review technology IS acceptance theories and models recognizing empirical evidence available to support the suitability of each theoretical model in explaining academicians acceptance of online learning technology Understanding the factors influencing system usage is crucial for decision-makers to recognize potential user needs and concerns which could be addressed during the development phase of a system Thus for decades researchers have been trying to understand why people accept new technologies As a result a wide variety of theories and models explaining the concept of technology acceptance Some prominent theoretical models explaining technology acceptance are Theory of Reasoned Action Diffusion of Innovation theory Theory of Planned Behavior Social Cognitive Theory Technology Acceptance Model Model of PC Utilization Motivational Model Unified Theory of Acceptance and Use of Technology UTAUT 2 UTAUT 3 The concept of academic s acceptance of online learning technology can be explained through several determinants that are operationalized through above information systems model

SRI LANKAN SENIOR SECONDARY STUDENTS’ CONCEPTIONS OF LEARNING AND APPROACHES TO LEARNING SCIENCE: IS THERE ANY RELATIONSHIP?

There has been a growing research during recent years on student related cognitive factors that associated with learning process such as conceptions of and approaches to learning. Students’ conceptions as well as their learning approaches are considered as predictors of student performance. It is reported that the performance of Sri Lankan senior secondary students in the subject science is not satisfactory as expected. In this context, the analysis of their conceptions of learning and approaches to learning science provides important evidence in order to improve the performance level in students. This study was aimed to ascertain the relationship between Sri Lankan senior secondary students’ conceptions and approaches to learning science. The Conceptions of Learning Science (COLS) questionnaire and Approaches to Learning Science (ALS) questionnaire were used to assess students’ conceptions and approaches to learning respectively. The data was analysed using partial least square structural equation modelling (PLS-SEM). It was revealed that constructive conceptions of these students showed a positive relationship with deep learning approach. Conversely, a negative relationship was found between constructivist conceptions and surface approaches. The reproductive conception ‘preparing for tests’ showed a positive relationship with surface approaches to learning science. The results indicate that the learning approaches of these students can be predicted by their conceptions of learning. It provides an evidence that the meaningful learning approaches in these students can be promoted by developing constructivist conceptions in order to improve their performance in science. The findings provide important implications for curriculum developers, teacher trainers, teachers and students with respect to the improvement of science learning.  Article visualizations

A contribution of in situ UV/Vis/NIR spectroscopy to characterize molybdenum oxide catalysts

Molybdenum oxide based catalysts are suitable candidates for many selective oxidation reactions [1]. Such catalysts containing only Mo and O have been successfully prepared by controlled adjustment of precursor concentration, temperature or nature of counter cation. The obtained materials, namely orthorhombic and hexagonal MoO3, a supramolecular Mo36 and a trimolybdate compound were thoroughly analysed by XRD, TEM, TG, TPRS and Raman spectroscopy [2]. As such materials undergo electronic changes during catalytic reactions we will present an in situ UV/Vis/NIR study on the different families of molybdenum oxide (MoOx) catalysts. Experimental A commercial UV/Vis/NIR spectrometer (Lambda 9, Perkin Elmer) equipped with a BaSO4 coated integrating sphere was supplemented with a new construction (specially formed light conductor in vertical position) to measure in situ diffuse reflectance spectra of different MoOx from room temperature (RT) to 673 K [3]. The spectra were recorded both from 250 to 2500 nm (scan speed of 240 nmmin-1, slit 1 nm) and 250 to 800 nm (scan speed 60 nmmin-1, slit 0.2 nm) with Spectralon (Labsphere) as a white standard in the reference position. Powder samples (ca. 0.6 g) were charged in the home-made microreactor and fed with a flow of air, pure He or 21 % oxygen in helium. The MoOx samples were prepared using precipitation method (0.28 up to 2 mol/L AHM, Na2MoO4, K2MoO4, Li2MoO4 dissolved in bi-distilled water and 1 mol/L up to 5 mol/L HNO3) from 30oC to 70oC. Results and discussion MoOx spectra show NIR bands with different intensities, distinguishable LMCT bands and band gap energies (Eg) at RT. Based on the exact determination of such spectroscopic characteristics the following LMCT bands (nm) (I) and Eg’s (eV) (II) are attributed to the above mentioned MoOx families: (I) 322 (NH4+), 314 (K+); (II) 3.48 (NH4+), 3.44 (K+) to supramolecular Mo36; (I) 313 (NH4+), 319 (K+), 327 (Na+); (II) 3.35 (NH4+); 3.30 (K+), 3.27 (Na+) to hexagonal MoO3; (I) 296 (Li+); (II) 3.44 (Li+) to orthorhombic MoO3 and (I) 284 (K+); (II) 3.77 (K+) to trimolybdate MoOx. From a blue shift of the LMCT band in the series supramolecular/hexagonal orthorhombic trimolybdate and a decreasing broadening of this band it may be concluded that the cluster size decreases. All MoOx samples evolved NIR bands at 1435, 1940, and 2040 nm. They are assignable to an overtone mode of the OH stretching vibration and a combination mode of the OH stretching and bending vibration, respectively. Other NIR bands, e.g., those detected in MoOx samples prepared from AHM at 1570 and 2150 are caused by ammonia. Initial experiments in dependence on temperature show that the bands at 1440, 1940 and 2030 nm initially decrease at higher temperature and then disappear. In addition, by increasing the temperature the band at 2150 nm begins to disappear at 553 K and the band at 1570 nm dimi- nished around 633 K (not shown). In Vis range a new band at 660/670 nm develops at 553 K which decreases in presence of He and increases in presence of O2 in He with increasing temperature (Fig. 1). This band is assigned to a d-d transition. In He this band suffers a blue shift to about 570 nm at 673 K. The appearance of the new Vis band can be correlate with TG/DSC data. At 553 K ammonia as counter ion de- composes to NOx and reduces the Mo matrix; ammonia is completely removed from the sample at around 693 K

Investigation of concrete floor vibration using heel-drop, test

In recent years, there is an increased in floor vibration problems of structures like residential and commercial building. Vibration is defined as a serviceability issue related to the comfort of the occupant or damage equipment. Human activities are the main source of vibration in the building and it could affect the human comfort and annoyance of residents in the building when the vibration exceed the recommend level. A new building, Madrasah Tahfiz located at Yong Peng have vibration problem when load subjected on the first floor of the building. However, the limitation of vibration occurs on building is unknown. Therefore, testing is needed to determine the vibration behaviour (frequency, damping ratio and mode shape) of the building. Heel-drop with pace 2Hz was used in field measurement to obtain the vibration response. Since, the heel-drop test results would vary in light of person performance, test are carried out three time to reduce uncertainty. Natural frequency from Frequency Response Function analysis (FRF) is 17.4Hz, 16.8, 17.4Hz respectively for each test

Disparity Map Algorithm Based on Edge Preserving Filter for Stereo Video Processing

This paper proposes a new local-based stereo matching algorithm for stereo video processing. Fundamentally, the Sum of Absolute Differences (SAD) algorithm produces an accurate results on the stereo video processing for the textured regions. However, this algorithm sensitives to low texture and radiometric distortions (i.e., contrast or brightness). To overcome these problems, the proposed algorithm utilizes edgepreserving filter which is known as Bilateral Filter (BF). The BF algorithm reduces noise and sharpen the images. Additionally, BF works fine on the low or plain texture areas. The proposed algorithm produces an accurate results and performs much better compared to some established algorithms on the standard benchmarking results of the Middlebury and KITTI dataset