Transport on flexible Rydberg aggregates using circular states

Assemblies of interacting Rydberg atoms show promise for the quantum simulation of transport phenomena, quantum chemistry and condensed matter systems. Such schemes are typically limited by the finite lifetime of Rydberg states. Circular Rydberg states have the longest lifetimes among Rydberg states but lack the energetic isolation in the spectrum characteristic of low angular momentum states. The latter is required to obtain simple transport models with few electronic states per atom. Simple models can however even be realized with circular states, by exploiting dipole-dipole selection rules or external fields. We show here that this approach can be particularly fruitful for scenarios where quantum transport is coupled to atomic motion, in adiabatic excitation transport or quantum simulations of electron-phonon coupling in light harvesting. Additionally, we explore practical limitations of flexible Rydberg aggregates with circular states and to which extent interactions among circular Rydberg atoms can be described using classical models.Comment: 9 Pages, 5 Figure

Development of a Voice Controlled Electric Wheelchair to Aid the Movement of the Physically Challenged

Nigeria is said to have the highest number of physically challenged in Africa and second only to India in the world. Traditional Electrical Wheel Chair has some limitations. In order to assist the physically handicapped, this paper presents the development of a voice controlled wheelchair. The user can control the wheelchair by voice commands, such as “jagaba (go forward)” in Hausa. A grammar-based recognition parser was used in the system. The system comprises of a wheelchair motorize by a DC motor, works on inputs such as voice commands via an android phone and navigates according to the command and battery powered. Voice command input was taken from android mobile and converted into text which is transmitted to microcontroller via Bluetooth module to control the operation of DC motors. Also an IR detection system was used to detect the obstacle in the path of wheelchair to avoid its collision. The chair enables the handicapped person to independently move around. A running experiment with three (3) persons was carried out on speech recognition. 95.4% and 94.0% of the movement command and the verification command were obtained respectively. Keywords: Control, Home Navigation System, Microcontroller, Physically Challenged, Voice Command, Voice Recognition and Wheelchair

Association of Dietary Acid Load with Insulin Sensitivity Index among Apparently Healthy Nigerians

The possible role of regular consumption of diets with high acid forming potential in decreasing cellular sensitivity to insulin and its associated complications has been investigated. However, findings across different study groups are conflicting. It is likely that the association is affected by genetic and environmental factors that differ among different populations. We investigated the impact of diet-induced acidosis on the degree of insulin sensitivity among apparently healthy adult Nigerians. Assessment of dietary intake was done using a semi-quantitative food frequency questionnaire and the Nigerian Food Composition Table. Acid forming potential of our local diets were estimated as Potential Renal Acid Load (PRAL) scores. Fasting plasma glucose and insulin were measured. Degree of insulin sensitivity was calculated as Quantitative Insulin Sensitivity Check Index (QUICKI). About 35 (16.2%) of the study subjects were observed to have insulin resistance. Across the study groups, there was a statistically significant trend with higher intake of dietary acid associated with decreased insulin sensitivity (p for trend < 0.05). We conclude that among apparently healthy adult subjects in this study, regular consumption of diets with high acid forming potential might be linked with worsening of insulin sensitivity.&nbsp

THE POTENTIAL OF MAIZE AS PHYTOREMEDIATION TOOL OF HEAVY METALS

This paper shows result obtained from analysis done on some selected heavy metals accumulated in maize planted in contaminated soil for forty two days. The soil (3kg) each was contaminated with 2g of the metals (as FeSO4, CdCO3 and Zn, Mn, Pb, and Cr powder), adapting experimental method of Abd-El Naby 2002 . The results show that essential heavy metals (Fe, Zn and Mn) at day 14 were high with values of 28.275±0.05, 18.210±0.03 and 4.815±0.11 in the experimental and Fe and Zn were high at 28 days with values of 30.21±0.02 and 16.52± 0.01, while at 42 days Fe and Mn were high with values of 33.01±0.00 and 16.88±0.01 respectively. The result for the control soil indicates that Fe, Pb and Zn reduced considerably with values of 3.650± 0.06, 2.006±0.00 and 1.113±0.00 respectively while at day 28 and 42 the same trend was observed to be as day 14. Generally, it was observed that the heavy metals accumulation by the plant in soil for both experimental and control is high in maize. The results show that maize can be used to phytoremediate these metals

Pozzolanic and mechanical properties of Date Palm Seed Ash (Dpsa) concrete

This paper presents the findings of a research work conducted on how to improve the mechanical properties of concrete using Date Palm Seed Ash (DPSA) as partial replacement of cement. The DPSA used was obtained by controlled burning of date palm seed in a kiln at a maximum temperature of 630oC for eight hours and air cooled afterwards. The ash obtained was sieved through 75μm sieve and its oxide composition analysed using X-ray fluorescence (XRF) procedures. DoE method of mix design was used to produce concrete ingredients for grade 30N/mm2 giving a water-cement ratio of 0.53. The effect of partial replacement of cement with DPSA on cement paste and concrete using 0, 2.5, 5, 7.5, 10, 15 and 20% DPSA was investigated through consistency and setting times tests, workability test, compressive strength test (at 7, 21, 28 and 56 days curing duration), pozzolanic activity index evaluation and water absorption test. Results show that DPSA has high silicon dioxide (45.50%), aluminum oxide (20.75%) and Iron oxide (7.25%). Findings indicate that the consistency and setting times of cement-DPSA paste increased with increase in the replacement of cement with DPSA. The workability of DPSA concrete decreased with increase in cement replacement. Compressive strength test results show that cement can be replaced with DPSA up to 10% as the compressive strength at 10% replacement is 31.5N/mm2 as against the 31N/mm2 of the normal concrete, at 56 days. The pozzolanic activity index result also show that DPSA concrete meets up the minimum requirement of 75% specified by ASTM C618-15. Also, the water absorption capacity of DPSA concrete at the highest replacement (20%) is 11% less than that at 0%. Keywords: Cement, Compressive strength, Concrete, Date palm seed ash, Partial replacement, Pozzolan

Performance evaluation of 200W solar photovoltaic panel considering Bauchi microclimatic conditions

Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. This paper focuses on optimizing the performance of 200W solar module taking into consideration the local climatic conditions of Bauchi locality. The uncertainty in life cycle savings for solar thermal and photovoltaic (PV) systems as linearly correlated with uncertainty in solar resource data. These uncertainties paved way for the need to conduct a critical assessment of the resource. Assessment of the solar resource for these technologies rely upon measured data, where available. In this paper, we present the development of mathematical model of photovoltaic solar cells based on their detailed single diode equivalent circuit representation. Pertinent simulation models for PV solar module both for an ideal weather situation and for taking into consideration the effects of microclimatic conditions that prevail in Bauchi as evaluated and compared with benchmarks available. The complete model of the PV system was implemented using MATLAB/Simulink platform. The standard characteristic curves for the 200W solar panel are as presented. The simulation of the ideal PV system made use of standard test conditions (STC) to facilitate comparison with the existing benchmark results in the literature. The analysis of the characteristics performance curves returned an average VOC = 42.9v and ISC = 4.21A. The simulation results further revealed that the power delivered by the 200W monocrystalline solar module of 144.3W @620W/m2, 35ºC as recorded for Bauchi under all climatic conditions as evaluated. The benchmark values obtained in the laboratory are VOC = 45.5V, ISC = 5.92A and 200-W under the Standard test condition (STC) conditions of cell temperature 25ºC, solar irradiance of 1000W/m2 and air mass (AM) of 1.5. The average conversion efficiency and fill factor as evaluated are 0.77 and 16% respectively. This result agrees with the benchmark of module efficiency of >15.66% recorded at STC. The results conclusively reveal that the microclimate of a locality essentially affects the performances of solar PV systems deployed to each location on the globe. Therefore, utilization of these parameters is essential for consideration in the design of solar systems in all localities

Preliminary Phytochemical Screening, Elemental and Proximate Composition of Two Varieties of Cyperus esculentus (Tiger Nut)

The study aimed at phytochemical screening, elemental and proximate composition of two varieties of Cyperus esculentus (tiger nut) big yellow and small brown nuts using standard methods. The phytochemicals tested for were alkaloid, saponin, tannin, glycoside, flavonoid, steroid and resin. All the aforementioned phytochemicals with the exception of resin were present in the two varieties. The elements tested for were Na, Ca, Mg, Mn, Zn, K and Fe. The result shows big yellow variety had higher Na, K, and Ca with mean values 70.8 mg/Kg, 3694.43 mg/Kg and 372.2 mg/Kg respectively. Both samples had equal Fe, Zn and Mn contents of 21.0 mg/Kg, 8.3 mg/Kg and 1.67 mg/Kg respectively. Small brown variety had higher Mg content (308.3 mg/Kg). The proximate analysis show brown yellow variety had higher ash, crude protein and crude fiber contents with values of 1.85%, 2.75% and 9.25% respectively. While small brown variety had higher moisture and fatty acid contents of 4.25 % and 15.2% respectively. Considering the potential nutritive and health benefits of the underutilized tiger nuts, it is suggested that utilization of tiger nut products (such as biscuits, flour and milk etc.) should be encouraged so as to ameliorate the problem of protein-calorie malnutrition in children, since it is rich in nutritional contents.Keywords: Cyperus esculentus, elemental, phytochemical, proximate, tiger nu

Comparative Application of Differential Evolution and Particle Swarm Techniques to Reactive Power and Voltage Control

This paper presents the comparative application of two metaheuristic approaches: Differential Evolution (DE) and Particle Swarm Optimization (PSO) to the solution of the reactive power and voltage control problem. Efficient distribution of reactive power in an electric network leads to minimization of the system losses and improvement of the system voltage profile. It can be achieved by varying the excitation of generators or the on-load tap changer positions of transformers as well as by switching of discrete portions of inductors or capacitors etc. This constitutes a typical mixed integer non-linear optimization problem for the solution of which metaheuristic techniques have proven well suited in principle. The feasibility, effectiveness and generic nature of both DE and PSO approaches investigated are exemplarily demonstrated on the Nigerian grid system and the New England power system. Comparisons were made between the two approaches in terms of the solution quality and convergence characteristics. The simulation results revealed that both approaches were able to remove the voltage limit violations, but PSO procured in some instances slightly higher power loss reduction as compared with DE; on the other hand DE required a lower number of function evaluations as compared with PSO. Consideration of computational effort is relevant for potential real time on line application

Computational Enhancement of Genetic Algorithm Via Control Device Pre-Selection Mechanism for Power System Reactive Power/Voltage Control

In this paper, the application of a novel and computationally enhances genetic algorithm (GA) for solving the reactive power dispatch problem is presented. In order to attain a significant reduction in the computational time of GA, a systematic procedure of reactive power control device pre-selection mechanism is herein proposed to choose a-priori subsets of the available control devices, which maximally influence buses experiencing voltage limit violations. The GA reactive power dispatch module then accesses such judiciously pre-selected control device candidates to determine their optimal settings. A pragmatic scheme aimed at further curtailing the number of the final control actions entertained is also set forth. The far-reaching simulation results obtained for two case study scenarios using the proposed algorithmic procedures on a German utility network of Duisburg, replicated on an operator-training simulator, are presented and fully discussed in depth

Reactive Power and Voltage Control of the Nigerian Grid System using Micro-Genetic Algorithm

In this paper, a micro-genetic based approach to the optimization of reactive power and voltage profiles improvement and real power loss minimization is presented. The reactive power control devices such as generators, tap positions of on-load tap changer of transformers, shunt reactors are used to correct voltage limits violations while simultaneously reducing the system real power losses. Genetic algorithms (GAs) are well-known global search techniques anchored on the mechanisms of natural selection and genetics. Because of the time intensive nature of the conventional GA, the micro-GA is proposed as a more time efficient alternative. The feasibility and effectiveness of the developed algorithm is tested and verified on the Nigerian grid power system for three case studies scenarios preset in the power world simulator. The far-reaching simulation results that validate the effectiveness of the developed tool are presented and discussed in depth