Energy efficient Nordic greenhouse:case:University of Oulu botanical gardens

Abstract. The human population has grown sevenfold over the past two century, proportionately the food demand increased and the land for cultivation is shrinking. According to the United Nations (UN), the present size of the world population is more than 7.6 billion, and it estimates that this number will exceed 13 billion during the current century, which is a considerable challenge for tackling the future food security for all. In the scarcity of land, to meet the food demand of this enormous population, a contemporary agricultural arrangement is needed. By contrast, to conserve the environment, the use of land and fossil fuel should be limited. In continuation of this, to meet the future food demands, ‘greenhouse farming’ can be a suitable alternative, notably, in the region where the environmental conditions are not entirely favourable for year-round production. Greenhouses are widely used to provide a suitable environment in cultivation around the world. Generally, a high amount of energy input is needed to make a favourable condition for the plants’ growth. Moreover, the energy consumption profile is much complex when the site location is in a cold climate. For this reason, an energy-efficient greenhouse is not as simple as anyone guess, whereas various factors, including ventilation, covering material, orientation, lighting system and also energy input are considered as the key elements to ensure energy-efficient environment. In order to overcome the crisis, photovoltaic (PV) solar energy conversion systems could be considered as the most promising systems to aggregate electricity in a carbon-free environment. However, the PV generation blended with Economic, environmental and sustainability aspects. This study aims to evaluate all the aspects that can hinder greenhouse efficiency in the Nordic region. For this purpose, a grid-connected solar PV system chosen for two different scenarios. It has observed that every scenario have an adequate individual reason for their feasibility. For the first scenario, it was found that it can produce 10459.00 kWh electricity with a power rating 127.80 kWp, while second can generates 109771.50 kWh with a power rating 141.30 kWp. It also observed that the PV array could meet 25.25% to 26.51% of annual demand of the University of Oulu Botanical Gardens. Moreover, payback time found equal for both scenario, while in their lifetime they can can reduce 846.85 tonnes to 889.15 tonnes of carbon emission to the atmosphere

Shelf life of dried products from small indigenous fish species under various packing and storage conditions

The overall quality of five SIS products was found in good condition up to 2 months storage on the basis of organoleptic, biochemical and bacteriological characteristics and all the products was excellent in sealed packed condition up to 45 days of storage. However, quality of the products stored in open air atmospheric temperature was found excellent for first 15 days. In an average the initial moisture content was in the range of 13.5 to 15.0% with highest moisture content in puti and lowest in chapila. At the end of the 60 days the moisture content reached to the range of 18.5 to 19.0% which was more or less near the recommended limit of 16% for dried fishery products. The moisture content beyond the recommended limit as the storage period increased further and at the end of 90 days the moisture content increased to the range of 22.9 to 24% when organoleptically the product quality became very poor. The changes in the value of total volatile base nitrogen (TVB-N), peroxide value (PO), moisture and aerobic plate count (APC) of solar tunnel dried products in sealed polythene packages were investigated during 60 days of storage. There was little or no differences in TVB-N, PO and bacterial load of each species packed under various polythene density. The initial TVB-N values were in the range of 10.30 to 12.40 mg/100g of the samples. TVB-N value increased slowly up to the end of the storage period and was to in the range of 46.20 to 57.00 mg/1 00 g of sample. Initially the peroxide values (P.O.) were in the range of 6.54 to 8.40 m.eq./kg oil of the samples. During 60 days of storage, P.O. values increased slowly and at the end of the storage period these values reached to the range of 22.00 to 25.30meq./kg of sample. The initial APC was in the range 5.3xl04-7.3x104 CFU/g. The bacterial load increased slowly and at the end of the 60 days storage period reached to the range 6.6x106 - 8.6x107 CFT/g

A single LC tank based active voltage balancing circuit for battery management system

Nowadays, battery operated vehicles and machine power tools are becoming popular due to their simple and compact structure, low operating and maintenance costs, moreover renewable energy utilization facility etc. In order to obtain the necessary operating voltage and current of these devices, many electric cells are combined together in series and parallel combination. A series battery balancing circuit can be used to improve the efficiency of each cell charging and discharging process and consequently increase the lifespan of it. A battery management system (BMS) needs an efficient balancing circuit. This paper presents a high-speed single LC-tank DC to DC converter based electric cell balancing schemes. Since the supercapacitors are equivalent of rechargeable battery; in this research two supercapacitors have been used instead of rechargeable batteries. The voltage balance has been maintained by charging and discharging the supercapacitors through a single LC-tank circuit. As a result, the overall voltage balancing time has been reduced and improved the circuit performance. Experimental result shows that the proposed balancing circuit can reduce the voltage difference between the two supercapacitors from 350 mV to 0 V in 284 seconds, which is less time than the existing system. Satu pengubah resonan sesiri telah direka bagi mengimbangi aras voltan pada kenderaan beroperasikan bateri dan pada mesin jana kuasa yang menjadi semakin popular.Ini kerana strukturnya yang mudah dan kompak, kos operasi dan penyelenggaraan yang rendah, termasuk kemudahan penggunaan tenaga kitar semula dan sebagainya. Bagi mendapatkan voltan dan arus operasi yang sesuai, banyak sel elektrik telah digabungkan bersama dalam gabungan sesiri dan selari. Litar pengimbang bateri sesiri boleh digunakan bagi meningkatkan kecekapan setiap proses pengecasan dan penyahcas sel dan sekaligus meningkatkan jangka hayat sel. Sistem pengurusan bateri (BMS) memerlukan litar pengimbang yang cekap. Kertas ini membentangkan tentang satu pengubah DC-DC tangki-LC berkelajuan tinggi berdasarkan skim pengimbang sel elektrik. Oleh kerana supercapacitors bertindak seperti bateri boleh cas semula; penyelidikan ini telah mengguna pakai dua super-kapasitor dan bukan bateri boleh cas semula. Baki voltan telah dikekalkan dengan mengecas dan menyahcas super-kapasitor menggunakan satu litar tangki-LC. Dengan ini, masa pengimbang keseluruhan voltan dapat dikurangkan dan kecekapan litar dapat ditingkatkan. Hasil eksperimen menunjukkan litar pengimbang yang dicadangkan dapat mengurangkan perbezaan voltan antara dua super-kapasitor dari 350 mV kepada 0 V dalam tempoh 284 saat, kurang daripada masa sistem sedia ada

Estuarine Macrophytes at Bakkhali, Cox’s Bazar, Bangladesh with Reference to Mangrove Diversity

The diversity and ecosystem significance of macrophyte communities was studied, with emphasis on the mangrove species in the Bakkhali estuary of Cox’s Bazar, Bangladesh. Macrophytes of the Bakkhali river estuary were mainly mangroves (Avicennia marina Forssk Vierh and A. alba Blume and Acanthus ilicifolius Linnaeus) of inundation Class-IV; i.e., the mangroves are inundated 2-20 times per month (Watson, 1928), a wild rice variety of salt marsh (Porteresia coarctata Tateoka), Congon grass (Imperata cylindrica P. Beauv.), seagrass (Halophila beccarii Ascherson), macro-algae (Ulva intestinalis Linnaeus, Catenella nipae Zanardini and Hypnea sp.) and mangrove associates Suaeda maritima Only two individual plants of mangrove, Sonneratia apetala and Aegialitis rotundifolia, were found growing in the inter-tidal area of this estuary. On the eastern side of the estuary, almost 100% of the intertidal area is covered by the salt marsh plant P. coarctata, with patches of seagrass Halophila beccarii. The western portion of the estuary is covered by mangroves, mixed with patchy salt marsh and seagrass in and sheltered by a sand bar. Salt marsh and seagrass grow in mangrove dominated sites as 2nd pioneer species in the newly accreted land at the mouth of Bakkhali estuary. These estuarine macrophytes are of both economic and ecological significance and the macrophyte community plays a principal role directly or indirectly in supporting the local communities as source of food, cash and energy

Clinical presentations among adult patients with tuberculous meningitis

Background: Bangladesh is a country with a high burden of pulmonary as well as extrapulmonary tuberculosis. TBM is a particularly important public health issue in our country. Identifying prognostic predictors would improve the quality of management and ultimately will prevent long-term mortality and morbidity. The aim of the study was to observe and identify the most common clinical presentations among patients with tuberculous meningitis. Methods: This hospital-based prospective cohort study was carried out at the in-patient Department of Clinical Neurology at the National Institute of Neurosciences and Hospital (NINS and H), Dhaka, Bangladesh from October 2016 to September 2017, 1 year. A total of 54 patients admitted to the hospital with features of tuberculous meningitis (TBM) were selected for the study following inclusion and exclusion criteria. Results: Over 70% of patients were adolescents or young adults with a mean age of 28.2±12.3 years. The majority (48.2%) of the participants were from TBM stage II, while 37% were from stage III of TBM. Fever, headache, and systematic symptoms were the most frequent clinical presentations. The median delay in treatment was 30 days. Interruption in anti-TB treatment was reported in 3 (9.3%) cases. Conclusions: The study found that among possible TBM cases, the most frequent clinical features were fever, headache, and systematic symptoms. Focal neurological deficit and cerebral nerve palsy also had a high prevalence among the participants. The majority of the participants were young adults and female prevalence was high in the present study. The majority were from stage II TB among the study participants

A series regeneration converter technique for voltage balancing of energy storage devices

A single series resonant converter has been designed to balance the voltage level of a storage battery for electric vehicles. The proposed design has been simulated and verified by using two 100F supercapacitors instate of the conventional rechargeable battery. A voltage monitoring circuit detects the voltage condition of the individual capacitor and sends the voltage status to the control circuit for action. A technique has been developed to control a set of switches to transfer the current between the capacitor to balance the voltage level. The MATLAB simulated result shows the balancing circuit decreases the voltage difference between the two supercapacitors from 200 mV to 0V in 140 seconds, which is less than the existing methods. This fast voltage balancing technique can be used in the battery management system or electric vehicles for long lasting the battery life

Genomic Sequencing of Ranaviruses Isolated from Edible Frogs (Pelophylax esculentus)

Ranaviruses were isolated from wild edible frogs (Pelophylax esculentus)during epizootics in Denmark and Italy. Phylogenomic analyses revealed that these isolates are closely related and belong to a clade of ranaviruses that includes the Andrias davidianus ranavirus (ADRV), common midwife toad ranavirus (CMTV), Testudo hermanni ranavirus (THRV), and pike-perch iridovirus (PPIV)

Active voltage balancing circuit using single switched-capacitor and series LC resonant energy carrier

Single switched-capacitor and series LC resonant converter-based active voltage balancing circuit are presented in this Letter. This converter is proposed to balance the cell voltage in series-connected electrochemical energy storage devices namely battery or supercapacitor. This balancing circuit directly transfers the energy from higher capacitive energy storage cells to lower energy storage cells in the string. It realises the maximum energy recovery and zero voltage gap between the cells and overcomes the drawback of switching loss, conduction loss, balancing time duration, and the voltage difference between the cells of conventional switched-capacitor as well as single LC converter. The details of the balancing circuit operation, theoretical, and mathematical analysis are presented. The experimental result demonstrated that the balancing circuit result where the voltage difference is 451–0 mV in 124 min for two 12 V, 4.5 Ah lead-acid batteries