Analysis and optimal design of micro-energy harvesting systems for wireless sensor nodes

Presently, wireless sensor nodes are widely used and the lifetime of the system is becoming the biggest problem with using this technology. As more and more low power products have been used in WSN, energy harvesting technologies, based on their own characteristics, attract more and more attention in this area. But in order to design high energy efficiency, low cost and nearly perpetual lifetime micro energy harvesting system is still challenging. This thesis proposes a new way, by applying three factors of the system, which are the energy generation, the energy consumption and the power management strategy, into a theoretical model, to optimally design a highly efficient micro energy harvesting system in a real environment. In order to achieve this goal, three aspects of contributions, which are theoretically analysis an energy harvesting system, practically enhancing the system efficiency, and real system implementation, have been made. For the theoretically analysis, the generic architecture and the system design procedure have been proposed to guide system design. Based on the proposed system architecture, the theoretical analytical models of solar and thermal energy harvesting systems have been developed to evaluate the performance of the system before it being designed and implemented. Based on the model’s findings, two approaches (MPPT based power conversion circuit and the power management subsystem) have been considered to practically increase the system efficiency. As this research has been funded by the two public projects, two energy harvesting systems (solar and thermal) powered wireless sensor nodes have been developed and implemented in the real environments based on the proposed work, although other energy sources are given passing treatment. The experimental results show that the two systems have been efficiently designed with the optimization of the system parameters by using the simulation model. The further experimental results, tested in the real environments, show that both systems can have nearly perpetual lifetime with high energy efficiency

A ZigBee-based home automation system

In recent years, the home environment has seen a rapid introduction of network enabled digital technology. This technology offers new and exciting opportunities to increase the connectivity of devices within the home for the purpose of home automation. Moreover, with the rapid expansion of the Internet, there is the added potential for the remote control and monitoring of such network enabled devices. However, the adoption of home automation systems has been slow. This paper identifies the reasons for this slow adoption and evaluates the potential of ZigBee for addressing these problems through the design and implementation of a flexible home automation architecture. A ZigBee based home automation system and Wi-Fi network are integrated through a common home gateway. The home gateway provides network interoperability, a simple and flexible user interface, and remote access to the system. A dedicated virtual home is implemented to cater for the system’s security and safety needs. To demonstrate the feasibility and effectiveness of the proposed system, four devices, a light switch, radiator valve, safety sensor and ZigBee remote control have been developed and evaluated with the home automation system

WEIGHT LOSS EXERCISE PRESCRIPTION EFFECTS ON OBESE FEMALE COLLEGE STUDENTS PHYSICAL HEALTH

ABSTRACT Introduction The discussion about the impact on the physical and mental health of obese college students is a current issue. The implementation of “weight loss exercise prescription” seeks to discuss weight loss techniques and their effects, problems most faced by obese girls. Objective Explore the effect of sports intervention on the physical and mental health of obese female students. Methods 20 female college students with simple obesity were selected for an 18-week intervention experiment of fitness exercise associated with long-distance running. The physical and mental health of the volunteers was measured before and after the experiment for statistical analysis. Results After 18 weeks of exercise, it was observed that interpersonal sensitivity, depression, anxiety, and SCL-90 scores decreased significantly, indicating that the implementation of the exercise prescription had a positive impact on the mental health of obese girls. Across the study, compared to a single exercise method, associated aerobic exercise had a significant effect on improving BMI indicators, body weight, and body fat rate in obese adolescent girls. Conclusion By prescribing exercise for weight loss, one can significantly improve the cardiopulmonary function of obese college students and promote physical health, manifesting in the indices of vital capacity and cardiopulmonary function. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.</div

Can the Nitroso Ene Reaction Proceed Concertedly?

All nitroso ene reactions so far reported follow exclusively stepwise reaction paths. Herein, we report the first concerted nitroso ene reaction that occurs between o-isotoluene (or its naphthalenic analogues) and nitroso compounds (e.g., nitrosomethane and 4-nitronitrosobenzene)

Dimetalloendofullerene U₂@C₆₀ Has a U−U Multiple Bond Consisting of Sixfold One-Electron-Two-Center Bonds

Endohedral metallofullerenes (EMFs) have been extensively studied since their discovery in 1985. Metal−metal bonds, nevertheless, have never been explicitly observed in EMFs synthesized so far. In this contribution, we show by means of all-electron relativistic density functional computations that the dimetalloendofullerene, U2@C60, has an unprecedented U−U multiple bond consisting solely of sixfold ferromagnetically coupled one-electron-two-center bonds with the electronic configuration (5fπu)2(5fσg)1(5fδg)2(5fφu)1, which are dominated by the uranium 5f atomic orbitals. This bonding scheme is completely distinct from the metal−metal bonds discovered thus far in the d- and f-block polynuclear metal complexes. This finding initiates a connection of the metal−metal multiple bonding chemistry and the fullerene chemistry

Mechanism and Regioselectivity for the Reactions of Propylene Oxide with X(100)-2×1 Surfaces (X = C, Si, Ge): A Density Functional Cluster Model Investigation

We have performed density functional cluster model calculations to explore the mechanism and regioselectivity for the reactions of propylene oxide with X(100)-2×1 surfaces (X = C, Si, and Ge). The computations reveal the following:  (i) the reactions on Si(100) and Ge(100) are barrierless and highly exothermic; (ii) the reactions on X(100) (X = Si and Ge) are initiated by the formation of a dative-bonded precursor state followed by regioselective cleavage of the C2−O bond (C2 directly connected to the methyl-substituent) in propylene oxide, giving rise to a five-membered ring surface species; and (iii) the reaction on C(100), although highly exothermic, requires a large activation energy and would be kinetically forbidden at room temperature

Additional file 1: of Low molecular weight heparin versus other anti-thrombotic agents for prevention of venous thromboembolic events after total hip or total knee replacement surgery: a systematic review and meta-analysis

Figure S1. Sensitivity analysis using the leave-one-out approach of the influence of each study on the pooled estimate for comparing total VTE rate between LMWH vs. control (A) placebo, (B) inhibitor of factor Xa, and (C) direct thrombin inhibitor for THR and TKR patients. Abbreviations: CI, confidence interval; Lower limit, lower bound of the 95% CI; Upper limit, upper bound of the 95% CI. Figure S2. Sensitivity analysis using the leave-one-out approach of the influence of each study on the pooled estimate for comparing total DVT rate between LMWH vs. control (A) placebo, (B) inhibitor of factor Xa, and (C) direct thrombin inhibitor for THR and TKR patients. Abbreviations: CI, confidence interval; Lower limit, lower bound of the 95% CI; Upper limit, upper bound of the 95% CI. Figure S3. Sensitivity analysis using the leave-one-out approach of the influence of each study on the pooled estimate for comparing PE rate between LMWH vs. control (A) inhibitor of factor Xa, and (B) direct thrombin inhibitor for THR and TKR patients. Abbreviations: CI, confidence interval; Lower limit, lower bound of the 95% CI; Upper limit, upper bound of the 95% CI. Figure S4. Sensitivity analysis using the leave-one-out approach of the influence of each study on the pooled estimate for comparing major bleeding rate (A) inhibitor of factor Xa, and (B) direct thrombin inhibitor for THR and TKR patients. Abbreviations: CI, confidence interval; Lower limit, lower bound of the 95% CI; Upper limit, upper bound of the 95% CI. Figure S5. The results of quality assessment for (A) individual studies, and (B) the summary of bias for all included studies. Figure S6. Forest graph showing the incidence of major bleeding events. Figure S7. Forest graph showing reoperation rate in this population. Figure S8. Forest graph showing the immortality rate in this population. Figure S9. Forest graph showing the percentage of patients who discontinued treatment due to adverse reaction. Figure S10. Forest graph showing the incidence of cardiovascular events. Figure S11. Forest graph showing the incidence of stroke. Table S1. Summary of meta-analysis results. Table S2. Published systematic review and meta-analysis relating to thromboprophylasis after THR and TKR (DOCX 734 kb

Electronic Structure and Redox Properties of the Open-Shell Metal−Carbide Endofullerene Sc₃C₂@C₈₀: A Density Functional Theory Investigation

Density functional theory calculations have shown that the open-shell metal−carbide endofullerene Sc3C2@C80 has the valence state (Sc3+)3(C2)3-@C806-. A lot of low-lying isomers differing in geometries and locations of the endohedral [(Sc3+)3(C2)3-] cluster have been located, indicating unusual dual intramolecular dynamic behaviors of this endofullerene at room temperature. The electrochemical redox properties of this endofullerene have been elucidated in terms of electronic structure theory. Its redox states are found to follow the general charge−state formula (Sc3+)3C2(3-q)-@C806- (q is the charge of the whole molecule ranging from +1 to −3), demonstrating the high charge flexibility of the endohedral metal−carbide cluster. The structure of the endohedral [(Sc3+)3C2(3-q)-] cluster varies with the redox processes, shifting from a planar structure (for q = 0 and −1) to a trifoliate structure (for q = +1, −2, −3)

bodyparametersofpairedbirdsusedinthisstudy.xls

body parameters of paired birds used in this study. We collected them in the field

Genotype dataset of ground tit for Dryad

The dataset includes genotype information of all the ground tit individuals used in this paper