Review Article: Health Care Environment: A War-zone

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Optimization of insulated HfO2 dielectrics of GaN/InN/GaN/ In0.1Ga0.9N enhancement mode of MIS-HEMT heterostructure for high frequency power amplifier applications

In this paper, the enhancement-mode operation of the hetestructure of GaN/InN/GaN/In0.1Ga0.9N of the Metal Insulator Semiconductor High Electron Mobility Transistor (MIS-HEMTs) device having lnN-channel was investigated. The effect of scaling the device dimensions of Metal Insulator, such as the dielectric thickness of HfO2 and the channel lengths, on the electrical performances was analyzed and compared to the currently used heterostructure. The numerical simulation of synopsis TCAD used showed a significant improvement in the electrical properties of the device that achieved a threshold voltage (VT) = 0.828 maximum drain current of 1.77 A/mm V, transconductance (gm) of 2.29 S.mm−1, lowest ON-state resistance (RON) of 0.21 Ω.mm, and along with high-frequency performance achieving fT/ fmax of 98 GHz/129 GHz and 200 GHz/ 360 GHz respectively. The simulations also showed that this scaled GaN/ InN/ GaN/ In0.9Al0.1N heterostructure MIS-HEMT is an excellent substitute to the currently used MIS-HEMTs for delivering high power density and frequency at RF/power amplifier applications.Keywords: Enhancement mode, Hydrodynamic simulation, InN channel, MIS-HEMT, In0.9Al0.1N barrier/buffer, HfO2, TCH, Transconductanc

Security challenges and solutions for e-business

The advantages of economic growth and increasing ease of operation afforded by e-business and e-commerce developments are unfortunately matched by growth in cyber attacks. This paper outlines the common attacks faced by e-business and describes the defenses that can be used against them. It also reviews the development of newer security defense methods. These are: (1) biometrics for authentication; parallel processing to increase power and speed of defenses; (2) data mining and machine learning to identify attacks; (3) peer-to-peer security using blockchains; 4) enterprise security modelling and security as a service; and (5) user education and engagement. The review finds overall that one of the most prevalent dangers is social engineering in the form of phishing attacks. Recommended counteractions include education and training, and the development of new machine learning and data sharing approaches so that attacks can be quickly discovered and mitigated

Screening for Total Carotenoids and &#946-Carotene in Some Widely Consumed Vegetables in Nigeria

Ten different locally grown and widely consumed vegetables were selected for the screening of total carotenoids and â-carotene contents. The pigments were extracted by solvent extraction and the concentrations determined using UV-visible spectrophotometer. Carrot (Daucus carota) has the highest values of both the total carotenoids (397.8 ± 2.0 ìg/g) and â-carotene (203.0 ìg/g). Squash (C. moschata) has the lowest concentrations of total carotenoids (20.3 ± 2.0 ìg/g) while cabbage has the lowest â-carotene (24.41 ± 9.8 ìg/g). These vegetables, if properly processed, may serve as good sources of provitamin A in addition to other nutritional roles. The potentials of these vegetables as candidates for biofortification with â -carotene for the eradication of vitamin A deficiency were discussed.Keywords: Vegetables, Carotenoids, â-carotene, Vitamin A deficienc

Phytoremediation of cadmium-polluted soils with Ipomoea asarifolia (Desr.) Roem. & Schult

Phytoremediation is an alternative method for restoring soils polluted with heavy metals which is cost-effective and environment-friendly. The present study evaluated the potential of Ipomoea asarifolia to remediate  soils experimentally-amended with Cadmium. The plant was grown on soils amended with 0, 1500, 2000, and 2500 mg CdCl2 salt. The salt was mixed with small portions of the soils and made upto 3kg salt/soil mixtures each. These were applied into 4 separate polythene-pots labelled; A, B, C and D respectively. Sample A containing 3kg non-amended soil (without Cd) served as the control. The concentrations of Cd applied to the soils were therefore; 0, 306.61, 408.82 and 511.02 mg//kg soils in the samples A-D respectively. Atomic absorption spectrophotometry (AAS) was used to analyse the bioaccumulation of Cd in the plant’s parts, over three harvesting phases of the study period. The results revealed that I. asarifolia is a good phytoaccumulator as it accumulated a total biomass of 0.23 ± 0.63, 272.85 ± 1.99, 377.40 ± 0.63 and 459.48 ± 0.60 mg/kg Cd from the amended soils A-D respectively. The Transportation Indices; RTI and STI for translocation of Cd to the plant’s stems and leaves were both greater than 1 (TI >1), indicating that the plant has a phytoextraction potential for Cadmium. These results therefore, suggest that I. asarifolia could be effective in phytoremediation of Cadmium-polluted environments.Keywords: Heavy metals, cadmium, pollution, phytoremediation, Ipomoea asarifoli

Effects of biochar amendments on rice growth and metabolic response to salinity stress in salt-affected soils

Exploring cheaper and sustainable strategies for managing salt-affected soils remains crucial in irrigated areas. Many researchers recommended using gypsum as material for reclamation salt-affected soils, which are costly and unavailable for most farmers. In this study, we used biochar derived from the common materials found in the irrigated areas that are locally available and less utilized as a substitute for gypsum for sustainable reclamation of salt-affected soils. Salt-affected soils (saline, saline-sodic and sodic) and unaffected were collected from the Watari Irrigation project, Kano State Nigeria using farmers' perceptions about the salinity situations of the irrigation scheme and existing legacy map data. The biochar used for this study were made using the Typha grass, rice straw, and rice bran samples collected from the same area. Thirty-six (36) containers (plastic pots) with a diameter of 27.5cm and height of 45cm each were filled with eight-kilogram dried soils, including non-saline, saline, and saline-sodic. We measured plant height, and normalized difference vegetation index (NDVI) at interval of 14 days. Number of tillers per plant were also measured during tillering stage at interval of 14 days. Stover dry weight, grain dry weight, electrolytic leakage and proline contents were measured after the end of the experiment. The results revealed a high significant effect (p<0.01) of biochar amendments in remediating different forms of salt affected soils. Saline sodic soil was effectively managed when using Typha biochar with a mean value very close to non-saline soil. Rice straw and rice bran reduces the salinity levels particularly in sodic soil. Therefore, biochar from different source could be used in addressing salt-specific problems rather than using a uniform treatment

Students’ Psychosocial Perception of Automobile Technology Learning Environment and Attitudinal Outcomes in North-eastern Nigeria Tertiary Institutions

AbstractStudents’ perception of their learning environment is a crucial factor in improving quality of learning. Several researches revealed that students’ perception of the learning environment has a significant impact on the students’ academic performance and attitude. This study investigated relationships between students’ perception of automobile technology learning environments and their attitude towards automobile technology in north-eastern tertiary institutions of Nigeria. The research design of the study was a correlational survey design and the sample comprised 474 students offering automobile technology as a course in the institutions. The data were collected using ATLEI and ATAQ and these were analyzed using descriptive statistics, simple correlation, and multiple correlation analysis. The findings revealed that the automobile technology learning environments remain traditional and students anxiety-dominated the learning environment in the north-eastern tertiary institutions of Nigeria. It was recommended that lecturers in the institutions of learning should be sensitized on the importance of students’ perception of learning environment and enhanced student-student and student-lecturer relationships in their institutions

Convergence of Path and Approximation of Common Element of Null Spaces of Countably Infinite Family of m

We prove path convergence theorems and introduce a new iterative sequence for a countably infinite family of m-accretive mappings and prove strong convergence of the sequence to a common zero of these operators in uniformly convex real Banach space. Consequently, we obtain strong convergence theorems for a countably infinite family of pseudocontractive mappings. Our theorems extend and improve some important results which are announced recently by various authors

Surface Phonon Polariton Modes in Suspended Monolayer Hexagonal Boron Nitrides

Dispersion properties and characteristics of transverse magnetic (TM) and transverse electric (TE) surface phonon polaritons (SPhP) in suspended monolayer hexagonal boron nitrides (hBN) was studied extensively. The analytical results show that the hBN based TM (TE) phonon polaritons exist in restsrahlen bands when imaginary surface conductivity is positive. The effective mode index of TM phonon polaritons is much higher than that of TE phonon polaritons with respective values of ~3000 and ~1.0002 which makes TM SPhP more promising in the practical realization. In addition, the propagation length of TE SPhP is less lossy and surpass that of TM SPhP by factor of 104. This study compares these important properties and sheds more insight into their applications in optical communications, photonics and optoelectronics devices