Studies on bud dormancy of woody species

The role of endogenous inhibitors and growth substances in the regulation of bud dormancy of wood plants was investigated using mature trees, seedlings, isolated shoots, and aseptically cultured buds and shoots. The photoperiodic induction of dormancy was not mediated through changes in inhibitor β activity, or ABA levels of buds and leaves of Alnus viridis seedlings. Changes in the activity of the inhibitor β fraction of buds and leaves of field grown Alnus glutinosa occurred during autumn but were not correlated with the onset of dormancy. Exogenous applications of 10-4M ABA, 10-3M CCC, ABA + CCC, 10-3M C5, 10-3M C9 and 10-3M C10 to actively growing Alnus viridis seedlings did not result in the formation of dormant buds. Dormancy was not induced by pruning the root system of actively growing alder seedlings or by the treatment of isolated growing shoots with 10-4M ABA. ABA prolonged the dormancy of apparently dormant buds after their transfer to an environment favouring growth, but this effect was modified by species, time of year, presence and absence of leaves, and position of the bud on the stem. C8 and C9 prolonged the dormancy of Populus nigra Italica while C10 promoted bud burst in Salix alba/babylonica. CCC was ineffective in most species tested (Alnus, Populus and Salix) except when in combination with ABA. The use of aseptic shoots of Populus yunnanensis cultured in vitro as a bioassay for dormancy-inducing substances was found to be limited by the variable growth responses elicited. No dormancy-inducing substances were detected in extracts, including the inhibitor β fraction, of dormant buds or leaves or shoots. The presence of various concentrations of ABA, C5, C10, AMO 1618 and ABA + AMO 1618 in the medium did not cause the formation of dormant shoot morphology, although growth was inhibited by certain treatments. Results are discussed in relation to the inhibitor hypothesis of dormancy regulation

Aromatic network for power distribution system

Electricity is an essential part of our existence in present days but inconsistent supply of electricity during tropical cyclones and natural disasters or fault in grid can create a dilemma over our life style, especially for remote area or island and even for the entire nation. These problems can be addressed at the distribution level by using smart, self-controlled and resilient micro electric grid that can operate on its own as microgrid or with grid connected mode as distribution network and energized by Renewable Energy Sources (RES). Three different designs of distribution network are commonly used and modified as microgrid structure which are: radial network, ring/loop network and mesh network architecture. Each of them has serious drawbacks to work during the disaster situations especially during the tropical cyclone or even snowstorm. To overcome these situation; a novel distribution network with better control and management techniques is designed here which is intrinsically potential for the future power systems to achieve reliability, efficiency and quality power supply even during the disaster. This design is essentially inspired by natural structure of an aromatic molecule which could be applied in the grid structure that would be strong enough to withstand any unexpected situations or faults. The novel network structure is represented as an aromatic molecule, like dichlorodiphenyltrichloroethane (DDT) where hexagonal benzene is the basic element for the network. This aromatic structure and the properties of the compound are used as the concept of the proposed design for the distribution network to ensure better stability and resiliency. Moreover, self-healing mechanism is embedded in the distribution system to minimize system interruptions during common faults. Finally, to maximize energy efficiency and reduce human effort, smart wireless communication system, effective control technology and switching of distributed generations (DG’s) with respect to demand and consumption have been included in this network design

Design of an optimum MPPT controller for solar energy system

Solar energy is compared to be the best potential source of renewable energy in Pacific region. For this reason a photovoltaic cell is needed to harvest this kind of energy, gathering the most of it and the PV having a good efficiency. The maximum efficiency is achieved when the PV works at its Maximum Power Point which entirely depends on the irradiation and temperature. This paper proposes a new design of hybrid Maximum Power Point Tracking and a comparative study is made with various existing MPPT techniques which include Perturb and Observe method, Incremental Conductance and Fuzzy Logic. From the comprehensive comparison study between existing MPPT technique and the proposed MPPT technique/theory, a hardware setup was demonstrated to verify the proposed design by charge controller in photovoltaic systems to which maximize the output power under various lighting conditions. The design is based on the computed results using the buck-boost DC-DC conveter. From the simulation, the proposed method tends to show better performance with almost no oscillations around the MPP

Impact of Wind Generators in Power System Stability

Wind electricity is one of the quickest developing renewable resources of power. This rapid development is expected considering the environmental factors, but in terms of power system stability, it comes with a number of concerns. Generators play a vital role on stability for a particular capacity and design of a network. This paper investigated the overall performance of 3 foremost types of wind turbines via small signal stability analysis on IEEE 9 bus system. Simulations have been done and established that the generators dynamic model have significant impact on power system stability at different capacity of the generators

Assessment of drug utilization pattern and impact of infographics in patients with chronic liver disease

Background: The current study was conducted to ensure that the drugs were effectively utilised and also to create awareness and knowledge by providing counselling with the help of infographics among study population.Methods: A prospective interventional study was conducted in the gastroenterology department of a tertiary care hospital in Kerala. A total of 100 patients diagnosed with chronic liver disease (CLD) were enrolled for the study and data were recorded in a predesigned pro forma. Statistical analysis (paired t test) was performed to assess whether the drug has been effectively utilized in patients. The study population was counselled with the help of infographics and its impact was assessed from the questionnaire, which was set based on 5- point Likert’s scale.Results: Among 100 patients, males are more prevalent between the age groups 60-70. Diabetes mellitus (DM) (66%) and alcohol (37%) are the most common risk factors. Most of the study subjects belong to Child A (50%) category and model for end-stage liver disease (MELD) score of 51% of the patients were ≤9 with estimated 3-month mortality rate of 1.9%. Liver function tests (LFT) had shown that there was a significant difference between prior to and after treatment with the level of significance p<0.05, indicating that the drugs had been properly utilized in patients and found to be effective. The distributed infographics had a great impact among the study population.Conclusions: The study concluded that the drugs had been properly utilized and found to be effective in patients. The Infographics showed a positive impact among the study population

Knowledge, attitude and practice of foot care in diabetes patients with foot at risk attending diabetology department of a tertiary care hospital

Background: The current study was undertaken to assess the knowledge, attitude and practice (KAP) of foot care among diabetes patients with foot at risk, to evaluate the impact of counselling in terms of KAP score, VPT (vibration perception threshold) value, foot examination status and other clinical parameter, to assess the severity of peripheral neuropathy in diabetes patients based on VPT value and to assess the prevalence of peripheral neuropathy among men and women.Methods: A prospective cross-sectional and interventional study was conducted in the diabetology department of a tertiary care hospital in South India. A total of 100 diabetes patients with foot at risk were selected for the study. A questionnaire was used to assess the knowledge, attitude and practice of foot care among diabetes patients with foot at risk. The questionnaire consists of total 24 questions. Their knowledge, attitude and practice were classified as good, satisfactory and poor depending upon the score. For the KAP, if score is ≥70% it was regarded as good, 50-69% as satisfactory and <50% as poor.Results: The study assessed that among 100 patients, 6% of the participants had good knowledge before counselling and after counselling, 46% had satisfactory level of knowledge and 43% had good knowledge. Most of the patients had a good attitude towards foot care before and after counselling. Only 1% of patients were in good practice before counselling and after counselling 62% of the patients had satisfactory practice and 25% had good practice. The study revealed that about 53% had a VPT value of 26-50 V before providing counselling and after counselling about 43% of the participants VPT became 26-50 V. The study also showed that the prevalence of peripheral neuropathy according to VPT value is more in males than females.Conclusions: Poor knowledge and poor practice were observed among the diabetes patients with foot at risk who had attended the diabetology department. Poor knowledge and practice are the major reason for the amputation of limb as the people are unaware of their foot care. Thus, by providing proper education regarding foot care, the foot complications can be improved and there by the amputation rate can be reduced to an extent

Power quality improvement of distribution network using optimum combination of battery energy storage system and capacitor banks

This paper proposes static and dynamic Volt Amp Reactive (VAR) planning based on the active and reactive power profile enhancing for dynamic voltage stability of distribution networks with Battery Energy Storage System (BESS) and capacitor bank using VAR planning scheme on distribution networks. Firstly, the impact of dynamic high impedance and resistive non-linear loads in the static voltage stability of the system has been studied and the effects of complex load behaviour on system dynamical performance is presented through a system stability analysis for three network structures. A VAR planning method is proposed where active and reactive loadability (P-Q) is considered to analyse the vulnerability of the network to voltage collapse and system inefficiency. Compensating devices are placed considering P-Q loadability to improve system voltage profile and stability limit. Finally, a cost-effective combination of BESS and capacitor bank is determined through static and dynamic analysis to ensure voltage stability of the network. The results show that the proposed approach can reduce the required sizes of compensating devices which reduces costs, enhances the voltage regulation of the system and minimizes power losses

Power quality improvement of distribution network using BESS and capacitor bank

The power demand around the world is increasing rapidly. The aging distribution network architectures are used by the existing utility companies to deliver power to the consumers, which significantly affects the reliability, stability and quality of the delivered power. Different techniques such as compensation devices have been used by power system engineers and researchers to maintain the quality of power transmitted to end users. In this paper, wattage and volt-amp reactive (VAR) planning scheme has been proposed by using the combination of battery energy storage systems and compensators to deal with the vulnerability of networks to voltage drop and system inefficiency. The cost-effective combination of battery energy storage system (BESS) and shunt capacitor bank will then be analyzed to indicate the benefit of the proposed scheme

Reliability of power distribution networks with renewable energy sources

To improve economical, technological and social growth of a community, stable and reliable power supply is essential. The electric power companies around the world are working to meet the customer satisfaction with major concern of reducing power failure rates in distribution networks. Appropriate information on systems performance is required to measure and improve the reliability of the system. In this paper, IEEE 13 bus radial distribution network has been converted in to ring and mesh networks to identify their reliability based on reliability indices and factors. Finally, renewable energy sources have been integrated into the ring and mesh networks to determine the networks performance with comparison to the fossil fuel based distributed generation