922 research outputs found

    Annual Biomass Production, Chemical Composition and In- sacco Degradability of Different Cultivars of Moringa oleifera

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    Types of plant cultivars and seasons often affect production and productivity of fodder biomass and nutritional quality to animals. Selection of suitable cultivars and better understanding of year round biomass production are indispensable for improving quality feed supply to animals. Black Seed Moringa (BSM-L) and White Seed Moringa (WSM), the two local cultivars and Black Seed Moringa (BSM-T) cultivar of Thailand origin of Moringa oleifera were cultivated in the fodder research field of the Bangladesh Livestock Research Institute (BLRI) during the period of 19 August 2014 to 23 December 2015. An agronomical trial was conducted to determine the biomass yield of the three cultivars in different seasons of a year under common agronomical practices. The effect of the cultivars on the daily relative growth rate (RGR), chemical composition and in-sacco dry matter (DM) degradability were also evaluated. The cultivar response to biomass production performances, chemical composition and nutritional values were analyzed in an ANOVA of a Randomized Block Design (RBD), while the differences in the rate and extent of the DM degradability in-sacco determined using three rumen cannulated bulls were analyzed in an ANOVA of 3x3 Latin Square Design. The annual biomass yield of BSM-L tops (114.5 t/ha fresh; 22.7 t/ha DM) was significantly higher than that of WSM (29.0 t/ha fresh; 5.80 t/ha DM) or BSM-T (83.5 t/ha fresh; 16.0 t/ha DM). No significant difference in chemical composition (224.9, 222.4 & 223.8 g.kg-1 DM of crude protein (CP), respectively, and 450.9, 455.3 & 435.4 g.kg-1 DM of neutral detergent fiber, respectively) or nutritional value (47.4, 46.7 & 45.3% of potential, and 62.8, 64.2 and 63.6% of effective degradability of dry matter) was found for the cultivars. BSM-L had a significantly higher survivability (97.2%), prune number per plant (3.50) and RGR (15.6 mg DM/day) than WSM (25.0%, 2.30 & 4.20 mg DM/day) or BSM-T (55.6%, 3.10 & 10.8 mg DM/day) respectively. The hot and dry, and hot and humid climate having a Heat Index (HI) range of 25o to 35o F and monthly total rainfall of 130 mm to 332 mm were suitable for cultivation of all the Moringa cultivars. It was concluded that considering biomass production and its quality in terms of chemical composition and nutritional values, Black Seed Moringa (Moringa oleifera) may be cultivated as a plant fodder crop for the production of feed for ruminant animals

    Successful Use of Microporous Polytetrafluoroethylene Flexible Thin Sheets in NASA's OSIRIS-REx Mission

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    Microporous black polytetrafluoroethylene (PTFE) flexible thin sheets are successfully flown as solar diffusers on NASA's Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft. They serve as multilayer insulation (MLI) blanket outer covers for the arm of the Touch And Go Sample Acquisition Mechanism (TAGSAM), the sunshade of the OSIRIS-REx Camera Suite (OCAMS) PolyCam imager, and the motor riser of the OCAMS SamCam imager. Additionally, microporous white PTFE flexible thin sheets are successfully flown as a MLI blanket outer cover with a low ratio of absorptance to emittance for the Regolith X-ray Imaging Spectrometer (REXIS). For ground testing, microporous black and white PTFE flexible thin sheets were successfully used as optical targets of the Touch And Go Camera System (TAGCAMS) NavCam imagers in the flight system thermal vacuum test

    Substrate integrated waveguide cavity backed frequency reconfigurable antenna for cognitive radio applies to internet of things applications

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    In this article, a new multiband frequency reconfigurable substrate integrated waveguide cavity slot antenna was designed using Computer Simulation Technology software tool for addressing the specific design challenges posed by the internet of things (IoT) based cognitive radio networks. Reconfiguration of frequency bands is achieved using PIN diodes. The antenna resonated at 2.624, 2.664, 2.720, 2.752, 4.304, 4.532, 4.556, 5.236, 5.304, 5.368, 5.332, and 5.392 GHz. The resonant frequency capability and radiation performance are demonstrated by both simulations and measurements. The simulated and measured results were in agreement. The higher efficiency, gain and average bandwidth obtained are 90%, 8.2 dBi and 65 MHz, respectively. The compactness, integrity, reliability, and performance at various operating frequencies make the proposed antenna a good candidate for IoT applications

    Reconfigurable metamaterial structure for 5G beam tilting antenna applications

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    In this paper, we propose a metamaterial (MTM) structure with a reconfigurable property designed to operate at the millimetre-wave (mm-wave) spectrum. Four switches are used to achieve the reconfigurable property of the MTM with two configurations. These two configurations exhibit different refractive indices, which used to guide the radiation beam of the antenna to the desired direction. The proposed planar dipole antenna operates at the 5th generation (5G) band of 28 GHz. The electromagnetic (EM) rays of the proposed antenna pass through different MTM configurations with different phases, subsequently results in the tilting of the radiation beam toward MTM configuration of high refractive index. Simulated and measured results of the proposed antenna loaded by MTM demonstrate that the radiation beam is tilted by angles of +34° and −31° in the E-plane depending on the arrangement of two MTM configurations onto the antenna substrate. Furthermore, the gain is improved by 1.7 and 1.5 dB for positive and negative tilting angles, respectively. The reflection coefficients of the antenna with MTM are kept below −10 dB at 28 GHz

    Psychometric Properties of an Instrument Developed to Assess Students’ Evaluation of Teaching in Higher Education

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    Student evaluation of teaching is a global predominant practice in higher education institutions. Therefore, a major university in Jordan developed a questionnaire for students’ use in evaluating their instructors’ teaching effectiveness.  Since student evaluation of teaching is an important process, the present study tried to examine the psychometric properties of the instrument. Item-total correlations showed acceptable internal consistency. In addition, a two-factor structure of the scale (teaching effectiveness and course attributes) was supported by exploratory factor analysis and confirmatory factor analysis from two independent samples. Convergent validity was supported by a moderate correlation coefficient between course averages of students’ ratings on the first factor and course averages of students’ final grades in each course. Finally, students’ responses on the factor that captures teaching effectiveness were found to have very high internal consistency (Cronbach’s alpha of 0.96). However, this instrument lacks evidences of content validity and convergent validity. Therefore, it is important to be cautious in evaluating faculty members and making promotion decisions that is based solely on the scores obtained using this instrument.

    Monitoring spindle orientation: Spindle position checkpoint in charge

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    Every cell division in budding yeast is inherently asymmetric and counts on the correct positioning of the mitotic spindle along the mother-daughter polarity axis for faithful chromosome segregation. A surveillance mechanism named the spindle position checkpoint (SPOC), monitors the orientation of the mitotic spindle and prevents cells from exiting mitosis when the spindle fails to align along the mother-daughter axis. SPOC is essential for maintenance of ploidy in budding yeast and similar mechanisms might exist in higher eukaryotes to ensure faithful asymmetric cell division. Here, we review the current model of SPOC activation and highlight the importance of protein localization and phosphorylation for SPOC function

    A stochastic Model for Predicting Irrigation Water Requirements (IWR)

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    The main objective of this paper is to develop a stochastic time series model with trend, periodic and irregular components using a ten years IWR decade data for three different types of cotton crops cultivated in Gezira Scheme, SUDAN. The model was applied to cotton Brackat and then used to Shmbat & Akala cotton. In the analysis of IWR time series the correlogram technique was used to detect the periodicity which then smoothed by Fourier series method. The series is then tested for stationary and the dependent part of irregular component is found to be well expressed by the first order autoregressive model for all the crops. The developed model superimposes a periodic-deterministic process and an irregular componen
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