27 research outputs found
Simulation and Optimization of Independent Renewable Energy Hybrid System
In this paper the majority of research refers to the optimal
configuration of hybrid system that uses renewable energy
and wind energy and solar radiation in association with diesel
aggregate and batteries. These independent energy systems
(hybrid systems) are becoming popular due to increasing energy
costs and decreasing prices of turbines and Photo-Voltaic (PV)
panels. But the only drawback is that their outputs depend upon
the climatic conditions. The main goal to optimization a hybrid
system is necessary to obtain the configuration of the system as
well as the control strategy that minimizes the total cost through
the useful life of the installation to meet the desired consumption
and/or the pollutant emissions. The HOGA (Hybrid Optimizations
by Genetic Algorithms) program was used to simulate the system
operation and calculate technical economic parameters for each
configuration. The system configuration of the hybrid is derived
based on the data of wind and solar radiation which are related
to the southern Croatian coast, as on a theoretical annual load
at an observed location. Also, technical data for components
are taken from the manufacturer’s specifications (datasheet).
In this paper the advantages and disadvantages of commonly
used types of generators (synchronous and asynchronous
generators) are presented. Results show that the hybrid systems
have considerable reductions in carbon emission and cost of the
system
Optimal Design of Ship’s Hybrid Power System for Efficient Energy
The International Maritime Organization regulations on the reduction of greenhouse gas emissions (GHGs) from ships require efficient dealing with this complex techno-economic and highly political problem through joint efforts of all major stakeholders from the shipbuilding industry and ship operations. The key problems of any research in the field of renewable energy, including power generation, storage, transformation and distribution, and the issues associated with limited power generation for specific loads, are the same issues that are experienced in the implementation of electric distribution technologies onboard ships. This paper analyses the effects of efficient shipping using the solar panel system and batteries to ensure continuous power supply, regardless of the weather conditions. The logistics chain of this control architecture is modelled by Colored Petri Nets. The economic analysis examines the annual costs of fuel consumption, the initial capital cost, total net cost and CO2 emissions
A Review and Comparison of Ship Power Simulation Methods
Safe, secure and efficient clean sea shipping proposed by the IMO requires the development of the appropriate design, operating knowledge and tools for assessing energy efficient design and operation of ships. A brief overview of the methods and models of ship power management simulation shows the advantages and disadvantages of representative models. This review includes a comparison of different simulation methods, which implies different models, with the aim of optimizing the production of electricity on board, emission reductions and improved energy efficiency. In addition, the recommended technical solution for contributing to energy efficiency on board is given
A formal model for planning and controlling search and rescue actions at sea
Recently, during search and rescue actions at sea, Unmanned Aerial Vehicles (UAVs) have been used. Onboard decision capabilities allow an UAV vehicle to reach the entity that is in dis­tress at sea. UAVs are launched within a few minutes to begin search actions. When the exact location of the irtjured entity is detected, a rescue action should begin. According to the collected information about the vessel's position, manoeuvrability, and velocity, the control centre deter­mines which vessel is to be engaged in the rescue action.
This highly autonomous system can be described as a discrete event system. Certain states of such systems, such as collisions, are undesirable. This paper presents implementation of information flow to supervise, control, and monitor the behaviour of the UAVs during the search, to avoid collisions and to communicate with computational onboard sub-systems. Planning algorithms and coloured Petri nets are used to specify different phases of the mission execution. When a certain UAV detects an injured entity, alternative encoded reactions are triggered and a control centre starts implementing the rescue plan
CARDIOTOCOGRAPHY: FROM THE FIRST DETECTION OF FETAL HEART RATE TO FIGO GUIDELINES
Gotovo punih 150 godina bilo je potrebno da bi se od otkrića kucaja čedinjeg srca stvorili tehnički preduvjeti za razvitak kardiotokografije – kontinuiranog i istodobnog bilježenja fetalne srčane frekvencije i trudova. Daljnje sazrijevanje znanstvene misli i razumijevanje CTG zapisa rezultiralo je nastankom različitih shema, indeksa i zbrojeva za ¬procjenu nalaza. FIGO smjernice objavljene koncem 80-ih godina prošlog stoljeća, omogućuju objektivnu procjenu CTG zapisa, uporabu jedinstvenih definicija, smanjenje razlika u »inter- i intraobserver« tumačenjima nalaza, te upućuju na daljnje dijagnostičke i terapeutske postupke. Ove smjernice u redovitoj su primjeni i u svim našim klinikama i bolnicama, ali nažalost o tome nije zadnjih 15 godina objavljivano. Smatramo da rastuća prava pacijenata, kao i povećana pravna ¬odgovornost liječnika prioritetnom nameću i Hrvatskom društvu za perinatologiju izradu jedinstvenih pismenih smjernica za ante- i intrapartalnu kardiotokografiju.It has taken almost 150 years from the first detection of fetal heart rate to the creation of technical prerequisites for the development of cardiotocography – continuous and simultaneous registration of fetal heart rate and uterine contractions. Further reopening of scientific idea and understanding of cardiotocography has resulted in the development of different schemes and scores to assess the fetal heart rate recording patterns. FIGO guidelines, which were reported at the end of 1980, enable the objective assessment of fetal heart rate recording patterns. It also enables the use of uniformed definitions, decrease in different »inter- and intraobserver« interpretations during CTG analysis and gives directions ¬towards further diagnostic and therapeutic procedures. These guidelines are being regularly applied throughout our ¬hospitals and clinics, but unfortunately nothing has been published about them in the past fifteen years. Therefore we strongly believe that the growing rights of the patients as well as the doctors’ growing legal responsibilities are requiring from the Croatian Society for Perinatology as its priority the establishment of the unique written guidelines for the ante- and intrapartum cardiotocography
Miastenična kriza kao nuspojava liječenja metimazolom: Prikaz slučaja
Myasthenia gravis and Graves’ disease are two autoimmune diseases with a similar mechanism, both having circulating organ autoantibodies and cell specific autoantibodies. It is not unusual for these diseases to occur together. There is a large body of data proving that antithyroid drugs such as methimazole and propylthiouracil have an immunomodulatory effect in addition to their thyrosuppressant action. This case report describes a 34-year-old woman hospitalized for just diagnosed myasthenic crisis (Osserman IV). She had a prior history of hyperthyroidism and treatment with methimazole was initiated. However, improvement in thyroid disease led to the burst of myasthenia. The phenomenon described as worsening of one disease while improving the other, the so-called ‘see-saw’ relationship, occurred in this case. The question is whether antithyroid drugs improve hyperthyroidism while unveiling or worsening myasthenia. Is the ‘see-saw’ relationship actually a therapeutic side effect of antithyroid drug? The proposed mechanism of methimazole action is intracellular: it lowers the level of proliferating cell nuclear antigen (PCNA). PCNA pro¬motes selective apoptosis in some T lymphocyte clones. In this way, CD4+CD25+ regulatory T cells might ‘skip’ immune self-tolerance and autoantibodies against acetylcholine receptor may occur. Do antithyroid drugs actually create an immune ‘thymic surrounding’?Miastenija gravis i Gravesova bolest su dvije autoimune bolestI sa sličnim mehanizmom nastanka, u objema se nalaze cirkulirajuća antitijela te stanično specifična autoantitijela. Pojava navedenih bolesti zajedno nije neuobičajena. Postoji mnogo podataka koji pokazuju da antitireoidni lijekovi kao što su metimazol i propiltiouracil uz tireosupresivno djelovanje imaju i imunomodulacijski učinak. Opisuje se slučaj 34-godišnje bolesnice koja je hospitalizirana zbog prvi puta dijagnosticirane miastenije sa slikom miastenične krize (Osserman IV.). U njenoj ranijoj povijesti bolesti navodila se hipertireoza, zbog čega je započeto liječenje metimazolom. Međutim, uz poboljšanje bolesti štitnjače došlo je do pojave miastenije. Fenomen “klackalice”, tj. see-saw relationship, je pojava opisana kao poboljšanje jedne bolesti za vrijeme pogoršanja druge. Pitanje je poboljšavaju li antitireoidni lijekovi hipertireozu, u isto vrijeme razotkrivajući ili pogoršavajući miasteniju?. Jeli fenomen “klackalice” zapravo nuspojava tireostatika? Pretpostavljeni učinak metimazola je unutarstanični: on snižava razinu nuklearnog antigena stanične proliferacije (PCNA). PCNA potiče selektivnu apoptozu u nekim klonovima T limfocita. Na taj bi način CD4+CD25+ regulatorni T limfociti mogli ‘zaobići’ imunu toleranciju prema vlastitom tkivu te dovesti do pojave autoantitijela protiv acetilkolinskog receptora. Stvaraju li zapravo doista antitireoidni lijekovi okruženje slično onome u timusu
CONTRACEPTIVE IMPLANT First experiencies
Cilj ispitivanja. Određivanje kontraceptivne učinkovitosti, raščlamba učestalosti i vrste nuspojava te utjecaja na obrazac menstruacijskih krvarenja i dismenoreju. Materijal i metode. Tijekom četiri godine je postavljeno 30 kontraceptivnih implantata s etonogestrelom. Po završetku praćenja je izvršeno ispitivanje pacijentica u pismenoj formi, a ¬podatci statistički obrađeni. Rezultati. Ukupno je ostvareno 673 mjeseci kontraceptivne zaštite i zabilježena jedna trudnoća. Kod polovice pacijentica je registrirano smanjenje duljine i obilnosti menstruacijskih krvarenja. Učestalost amenoreje iznosi 22,7%. Simptomi dismenoreje se poboljšavaju kod svih pacijentica. Najčešće neželjene pojave su nepravilno krvarenje, akne, dobitak na težini i glavobolja. Implantat je u osam slučajeva odstranjen prije vremena. Zaključak. ¬Kontraceptivni implantat je veoma pouzdano kontraceptivno sredstvo. Nuspojave koje zahtijevaju prekid metode se ¬javljaju u trećine korisnica. Naša preporuka je prije odluke o primjeni kontraceptivnog implantata ordinirati mini-pilule s dezogestrelom, a potom u slučaju dobre podnošljivosti samo gestagenske kontracepcije razmotriti prijelaz na kontraceptivni implantat s etonogestrelom.Aims of the study were to determine the contraceptive effectiveness and the analysis of the pattern of ¬frequency and types of common adverse effects, the influence on menstrual bleeding and dysmenorrhoea as well as the acceptability of the idea of new contraceptive method. Material and methods. During four years of our study we ¬implanted 30 contraceptive implants with etonogestrel. After the following time the patients were asked to complete questionnairy.The data were statistically evaluated. Results. Throughout our study we followed 673 contraceptive months and registered one pregnancy. The length and the abundance of menstrual bleeding decreasead in about half of the participants. The frequency of amenorrhoea was 22.7%, whereas symptoms of dysmenorrhoea improved in all patients. As regards the most common adverse effects were vaginal bleeding disturbances, acne, weight gain and headache. ¬Implant had to be removed earlier in eight cases. Conclusion. Contraceptive implant is very effective contraceptive method. Common adverse effects, which require discontinuation of the contraception, are present in about 1/3 of users. Our recommendation however is the prescription of progestogen-only-pills with desogestrel, before the decision for ¬contraceptive implant with etonogestrel
Alergijske bolesti i atopija među školskom djecom u istočnoj Hrvatskoj
A cross-sectional study was carried out in Brod-Posavina County, Croatia, to assess the prevalence of allergic diseases and atopy, as well as to investigate the possible etiologic factors for asthma, allergic rhinitis and eczema in childhood. The study included 1687 schoolchildren aged 10-11 years. Data were collected using standardized International Study of Asthma and Allergies in Childhood (ISAAC) Phase II written questionnaire. Skin prick tests were performed to provide an objective measure of atopy, defined as skin reactivity to one or more allergens. Lifetime prevalence of wheezing was 22.7%, rhinitis symptoms 22.5%, and eczema symptoms 17.9%. Period prevalence in the past 12 months was 7.9% for attacks of wheezing, 9.9% for rhinoconjunctivitis symptoms, and 10.1% for eczema symptoms. Of the children in which skin prick test was performed, 20.2% were positive for at least one of the allergens used, with house dust mite sensitization being the most frequent one. Risk factors for allergic disease include allergic disease in family, atopy, sensitization to indoor and outdoor allergens, and environmental tobacco smoke exposure at home. International comparison with the results of other ISAAC Phase II studies showed the Brod-Posavina County to be an area with moderate prevalence of atopy and current asthma symptoms.Cilj je bio istražiti učestalost alergijskih bolesti i atopije u dječjoj dobi na području Brodsko-posavske županije, moguće etiološke činitelje alergijskih bolesti te usporediti dobivene rezultate s rezultatima istraživača koji su rabili iste metode u Hrvatskoj i u svijetu. Istraživanje je obuhvatilo 1687 školske djece u dobi od 10-11 godina. Primijenjen je standardizirani upitnik Međunarodnog istraživanja o astmi i alergijama u dječjoj dobi za procjenu učestalosti alergijskih bolesti. Ispitanicima za koje smo dobili pismenu suglasnost roditelja učinjen je kožni ubodni test na inhalacijske i nutritivne alergene. Tijekom djetinjstva bronhoopstrukcije je prijavilo 22,7%, simptome rinitisa 22,5%, a simptome atopijskog dermatitisa 17,8% ispitanika. Učestalost alergijskih bolesti u posljednjih 12 mjeseci iznosila je 7,9% za bronhoopstrukciju, 9,9% za simptome rinokonjunktivitisa i 10,1% za simptome atopijskog dermatitisa. Kožni test učinjen je u skupini od 1070 (63.5%) djece, od kojih je 20,2% imalo pozitivan kožni test na najmanje jedan od primijenjenih alergena, s najčešćom senzibilizacijom na alergene grinje. Istraživanjem rizičnih činitelja uočeno je kako alergijske bolesti u obitelji, alergijska senzibilizacija i izloženost duhanskom dimu povećavaju rizik za alergijske bolesti u dječjoj dobi. Usporedbom s drugim međunarodnim centrima Brodsko-posavska županija se svrstava u područja s umjerenom učestalošću alergijskih bolesti i atopije u dječjoj dobi
Association of systemic lupus erythematosus associates with decreased immunosuppressive potential of the IgG glycome
Objective: Glycans attached to the Fc portion of IgG are important modulators of IgG effector functions. Interindividual differences in IgG glycome composition are large and they associate strongly with different inflammatory and autoimmune diseases. IKZF1, HLA–DQ2A/B, and BACH2 genetic loci that affect IgG glycome composition show pleiotropy with systemic lupus erythematosus (SLE), indicating a potentially causative role of aberrant IgG glycosylation in SLE. We undertook this large multicenter case–control study to determine whether SLE is associated with altered IgG glycosylation. Methods: Using ultra-performance liquid chromatography analysis of released glycans, we analyzed the composition of the IgG glycome in 261 SLE patients and 247 matched controls of Latin American Mestizo origin (the discovery cohort) and in 2 independent replication cohorts of different ethnicity (108 SLE patients and 193 controls from Trinidad, and 106 SLE patients and 105 controls from China). Results: Multiple statistically significant differences in IgG glycome composition were observed between patients and controls. The most significant changes included decreased galactosylation and sialylation of IgG (which regulate proinflammatory and antiinflammatory actions of IgG) as well as decreased core fucose and increased bisecting N-acetylglucosamine (which affect antibody-dependent cell-mediated cytotoxicity). Conclusion: The IgG glycome in SLE patients is significantly altered in a way that decreases immunosuppressive action of circulating immunoglobulins. The magnitude of observed changes is associated with the intensity of the disease, indicating that aberrant IgG glycome composition or changes in IgG glycosylation may be an important molecular mechanism in SLE
Glycosylation of immunoglobulin G is regulated by a large network of genes pleiotropic with inflammatory diseases
Effector functions of immunoglobulin G (IgG) are regulated by the composition of a glycan moiety, thus affecting activity of the immune system. Aberrant glycosylation of IgG has been observed in many diseases, but little is understood about the underlying mechanisms. We performed a genome-wide association study of IgG N-glycosylation (N = 8090) and, using a data-driven network approach, suggested how associated loci form a functional network. We confirmed in vitro that knockdown of IKZF1 decreases the expression of fucosyltransferase FUT8, resulting in increased levels of fucosylated glycans, and suggest that RUNX1 and RUNX3, together with SMARCB1, regulate expression of glycosyltransferase MGAT3. We also show that variants affecting the expression of genes involved in the regulation of glycoenzymes colocalize with variants affecting risk for inflammatory diseases. This study provides new evidence that variation in key transcription factors coupled with regulatory variation in glycogenes modifies IgG glycosylation and has influence on inflammatory diseases