Nutritive values, Mineral and Antioxidant properties of Pistia stratiotes (Water lettuce)

Proximate, mineral and antioxidant composition of the leaf and root samples of Pistia stratiotes were estimated using standard methods. The samples show appreciable levels of moisture (4.50±0.50%and 4.50±0.10%), crude fibre (17.50±0.87% and 20.50±1.80%), crude lipid (2.17±0.29% and 1.83±0.29%), crude protein (6.96±0.13% and 3.18±0.14%), ash (35.20±1.56% and 44.50±0.50%) and carbohydrate (38.20±2.08% and 30.00±1.46%) respectively. The minerals determined were sodium (373.00±0.50mg/100g and 113.00±0.06mg100/g), potassium (3283.00±0.76mg100/g and 1750.00±0.50mg100/g), phosphorus (336.00±0.10mg/100g and 313.00±0.03mg/100g), calcium (230.00±0.01mg/100g and 230.00±0.03mg/100g) and magnesium (370.00±0.03mg/100g and 230.00±0.03mg/100g) respectively. The antioxidant estimated are vitamin A (480.0±1.50mg/100g and1050.00±1.50mg/100g), vitamin C (560.00±0.20mg/100g and 3130.00±0.31mg/100g) and vitamin E (8260.00±3.00mg/100g and 3060±1.83mg100/g) respectively. The results show that the leaf and root portions of P.stratiotes have potential nutritional uses and the leaf parts have significant (P<0.05) high values of mineral element and antioxidant than that of the root samples.Keywords: Pistia stratiotes, mineral elements, proximate analysis, antioxidant

Electronic and optical properties of Bi2Se3 topological insulator: a promising absorbing layer for broadband photodetector

Bismuth selenide (Bi2Se3) is a van der Waals compound which has been excellently reported as thermoelectric material. Linear dispersion near Fermi energy level is an exciting feature to consider, a promising candidate for photonic device within broadband wavelengths. For this application, detailed knowledge of its structural, electronic and optical properties is very essential. The electronic properties were determined by density functional theory (DFT) calculations implemented in Quantum-Espresso simulation package which uses plane wave basis and pseudopotential for the core electrons. Optical properties are computed by solving Bethe-Salpeter equation of many-body perturbation theory (MBPT) as implemented in Yambo code. The band structure results show the semiconducting behaviour of Bi2Se3. Taken into account the effects of electron-hole interaction by solving Bethe-Salpeter equation, the calculated optical properties are in better agreement with available experimental results. The exciton energy shows that the title material can absorb light within infrared region

Mn(II), Co(II), Ni(II), and Cu(II) complexes of amino acid derived Schiff base ligand: Synthesis, characterization and in-vitro antibacterial investigations

Four complexes of Mn(II), Co(II), Ni(II) and Cu(II) with Schiff base ligand (H3L) derived from 2-amino-3-methylbutanoic acid and acetylacetonate were synthesized. All complexes were characterized by elemental analysis, Fourier-transform infrared spectroscopy and electronic spectroscopy. The results confirmed the coordination of the ligand to metals in tridentate fashion via the hydroxyl oxygen, the azomethine nitrogen and the enolic acetylacetonate oxygen. Antimicrobial activities were established for all complexes, free ligand and ciprofloxacin for comparison. Both the ligand and its metal complexes were active against Gram-positive and negative bacterial strains. The Cu(II) complex, showed highest antibacterial activity among the complexes screened. Other complexes displayed considerable antibacterial activity. Octahedral geometry was proposed for the metal(II) complexes with the Schiff base.                     KEY WORDS: Schiff base, Amino acid, Metal Complexes, Antibacterial agents   Bull. Chem. Soc. Ethiop. 2021, 35(1), 97-106. DOI: https://dx.doi.org/10.4314/bcse.v35i1.

Microstructure and mechanical properties of metal powder treated AISI- 430 FSS welds

Abstract: An innovative yet simple technique for the inoculation of the weld pool of commercial AISI 430 Ferritic Stainless Steel (FSS) with metal powders for grain refinement is discussed. Aluminum or titanium powder in varying amounts introduced into the weld pool via powder preplacement technique was melted under a tungsten inert gas (TIG) torch. This strategy of inoculating the welds offers dual benefits of grain refinement and constriction in the weld geometry. The addition of the metal powders constricts the HAZ by as much as 50% of the conventional weld providing a grain refinement index (GRI) of about 0.8 in titanium powder treated welds. It equally emerged that weld property is not influenced by the grain size alone but equally by the amount of delta ferrite in the microstructure

Piece-wise linear analog to digital (PLADC) converter process

Transducers are devices that transform energy from one form to another. Such transformation process may be applicable in the measurement of physical quantities, transfer of information and also in performing a certain control action. Transducers used as measuring devices are generally termed as sensors. Such transducers detect the changes in characteristics of a physical quantity and convert the change into a corresponding electrical signal. This is a common phenomenon when transducers are used to detect temperature, speed, force, liquid level or viscosity. On the other hand transducers, used to carry out control actions, are termed as actuators. These transducers usually convert an electrical signal into some form of physical control action such as heating or movement and are carried by the control devices. Various types of transducers exist meant for sensing and controlling different physical quantities. For example, a light dependent resistor (LOR) or a photodiode can be used to sense light intensity of an environment while lamps and LED displays can be used to control it. Likewise, a thermistor can be used to measure the temperature of an environment while a heater/fan can be used to control it and a tachometer can be used to measure the speed of a device while a stepper motor can be used to control it [1-3]. The focus of this chapter is on the problems and issues related to the interfacing of transducers when used as measuring devices or sensors in smart applications. Smart applications are also termed as tuned control for detecting changes in the parameter of interest which used to be ignorable in the traditional measurement and control system

Design of multi-valued quaternary based analog-to-digital converter

Problem statement: The design of multi-valued quaternary based Analog-to-Digital Converter (ADC) circuit was presented. The ADC generates multi-valued logic outputs rather than the conventional binary output system to overall reduction in circuit complexity and size. Approach: Design was implemented using pipeline ADC architecture and was simulated using model parameters based on standard 0.13 µm CMOS process. Results: Performance analysis of the design showed desirable performance parameters in terms of response, low power consumption, and a sampling rate of 10 MHz at a supply voltage of 1.3V was achieved. Conclusion/Recommendations: The ADC design was suitable for the needs of mixed-signal integrated circuit design and can be implemented as a conversion circuit for systems based on multiple-valued logic design

Process simulation and analysis of carbon capture with an aqueous mixture of ionic liquid and monoethanolamine solvent

This study investigated the prospect of using aqueous mixture of 1-butylpyridinium tetrafluoroborate ([Bpy][BF4]) ionic liquid (IL) and monoethanolamine (MEA) as solvent in post-combustion CO2 capture (PCC) process. This is done by analysis of the process through modelling and simulation. In literature, reported PCC models with a mixture of IL and MEA solvent were developed using equilibrium-based mass transfer approach. In contrast, the model in this study is developed using rate-based mass transfer approach in Aspen Plus®. From the results, the mixed aqueous solvent with 5–30 wt% IL and 30 wt% MEA showed 7%–9% and 12%–27% less specific regeneration energy and solvent circulation rate respectively compared to commonly used 30 wt% MEA solvent. It is concluded that the IL concentration (wt%) in the solvent blend have significant impact on specific regeneration energy and solvent circulation rate. This study is a starting point for further research on technical and economic analysis of PCC process with aqueous blend of IL and MEA as solvent

Sonographic diagnosis of pregnancy and study of gestational changes in rabbit-does

This study was carried out to evaluate early pregnancy diagnosis using ultrasound and baseline information on the sonographic features of the reproductive cycle of  rabbit-doe. Eight adult does, that had kittened at least once and an Ultrasound machine (Medison S600V®) with a 6.5 MHz transcutaneous curve-linear probe, were used for the study. Rabbit-does were mated naturally by the introduction of a doe to a buck. Abdominal regions were shaved liberally from the level of xyphoid cartilage to the pelvic area and aquasonic gel applied. The uterus was scanned on day 5 post-coitus and  thereafter on days 7, 12, 15, 20, 25, 27 and 29, using the bladder as a land mark. Embryonic vesicles, visualized as small anechoic (darkened) structures were first seen on day 7 of gestation. Hypoechoic structures within vesicles corresponding to embryo and placenta were seen on day 12 with an increase in size at day 15 of gestation. Bony formation, bi-parietal diameter, vertebrae column, fetal heart and fetal heart rate were visible with progressive gestational age. This study demonstrated that ultrasound can be used effectively to diagnose pregnancy in rabbit-doe as early as day 7 of gestation. Also there is a correlation between the sonographic observable changes with gestational age.Key words: Ultrasonography, Rabbit, Pregnancy Diagnosis, Gestation

Modeling the impacts of hot drought on forests in Texas

IntroductionUnder climate change, drought is increasingly affecting forest ecosystems, with subsequent consequences for ecosystem services. An historically exceptional drought in Texas during 2011 caused substantial tree mortality. We used 2004–2019 Forest Inventory and Analysis (FIA) data and state-wide weather data to examine the climatic conditions associated with this elevated tree mortality.MethodsWe measured moisture extremes (wet to dry) using the Standardized Precipitation Evapotranspiration Index (SPEI) at two timescales (12- and 36-month). We quantified heat wave severity using the Heat Wave Magnitude Index daily (HWMId) over the same period. We performed statistical modeling of the relationship between tree mortality and these indices across four Texas regions (Southeast, Northeast, North Central, and South) and for prominent tree genera (Pinus, Juniperus, Quercus, Liquidambar, Prosopis, and Ulmus) as well as selected species: Quercus stellata, Q. virginiana, and Q. nigra.ResultsThe highest tree mortality was observed between 2011 and 2013. We found similarity in the trends of the 12- and 36-month SPEI, both of which exhibited more extreme negative intensities (i.e., drought) in 2011 than other years. Likewise, we found that the extreme heat experienced in 2011 was much greater than what was experienced in other years. The heat waves and drought were more intense in East (i.e., Southeast and Northeast) Texas than Central (i.e., North Central and South) Texas. In gradient boosted regression models, the 36-month SPEI had a stronger empirical relationship with tree mortality than the 12-month SPEI in all regions except South Texas, where HWMId had more influence than SPEI at either timescale. The correlations between moisture extremes, extreme heat, and tree mortality were high; typically, mortality peaked after periods of extreme moisture deficit rather than surplus, suggesting that the mortality was associated with hot drought conditions. The effects of extreme heat outweighed those of SPEI for all tree genera except oaks (Quercus). This was also true for oak species other than water oak (Q. nigra). In generalized additive models, the median trend showed tree mortality of Prosopis was higher during conditions of moderate drought (SPEI36 ∼ –1) or worse, but for Pinus and Quercus, mortality started to become apparent under mild drought conditions (SPEI36 ∼ –0.5). The impacts of extreme heat on the mortality of Juniperus occurred when heat wave magnitude reached the ultra extreme category (HWMId > 80) but occurred at lower magnitude for Liquidambar.DiscussionIn summary, we identified risks to Texas forest ecosystems from exposure to climate extremes. Similar exposure can be expected to occur more frequently under a changing climate

Design and implementation of an optimal fuzzy logic controller using egentic algorithm

Most control systems suITer from problems related to undesirable overshoot, longer settling times aoo vibrations while going from one state 10 an(){her state. Works so far reponed techniques which are on how to oveTCQme or reduce the effects of these issues for ensuring smoother and finely tuned eolltrolling proceM. The devised solution is softwllrebased which employs an algorithmic approach for programming II PICI6F877A microcontroller, thus eliminating allogether the parametric dependence issues while adding the benefits of easier modification to suit a given control system for varying operational conditions_ The approach is first simulated using MATLAB/and the simulated results are verified by programming {he PICI6I'g77A mierocontrolter with {he algorithm and using it on a temperature control system where a fan is regulated in response to variations in the ambient system temperature. The results justify the effectiveness of the approach implemented in this study and they lUnher prove toot the optimized Fuzzy Logic Controller is functioning better than the conventional PID Controlle