The paper proposes the problem solution of optimal location determining of several power stations in some region. These stations receive primary energy from renewable sources, such as solar panels and wind turbines. At the same time, the condition of the problem includes the availability of information on several perspective areas in this region for the placement of such power stations, as well as information of values and distribution of loads. The developed algorithm for solving of the optimal location selection problem of power stations consists of several stages. The content of the first stage of the algorithm is ranking of possible areas for the location of power stations using local criteria, which are proposed as the specific estimated cost of station arrangement, the remoteness of the proposed location of the power station from loads and settlements. The second stage of the algorithm consists in a set formation of possible areas for the location of stations. And at the final stage of the algorithm, they are ranked using system criteria that evaluate these sets of areas for the location of power stations as a power supply system. The estimated cost of a power supply system arrangement based on power stations, located on areas of the rated set, the specific estimated cost of power stations arrangement, applied to the set of power stations with power lines as an autonomous power supply system, as well as the average rating of areas are proposed as system criteria. In this case, the decision maker, after familiarizing with values of system criteria, sets critical boundaries for each of them. The result of the algorithm is a certain totality of prospective sets for the location of several power stations in a given region, estimates of which according to system criteria are the best correspond to preferences of the decision maker. A feature of the proposed approach is the participation of the decision maker at all stages of design.
Background : Particles in exhaled air (PEx) are formed from the lining fluid in small airways, and is suggested a new method to monitor respiratory disease affecting small airways. To interpret PEx results it is important to know effects of potential influential factors like bronchoconstriction. Aim : To examine the effect of bronchomotor tone and pollen season on PEx. Method : 13 subjects with pollen-asthma and 12 healthy non-atopic subjects were examined before and after bronchodilation during and after pollen season. The subjects performed spirometry and sampling of PEx in 60 L of exhaled air, by an in-house developed instrument, using a breathing maneuvers allowing for airway closure and re-opening Results : The subjects with asthma had mild symptoms and low reversibility also during pollen-season (ΔFEV 1 = 6.1 % predicted normal). They had lower PEx concentrations during pollen season compared to out of pollen season (3.46 v s 4.32, p=0.01). Controls showed non-significant differences between seasons, and exhaled significanly higher contentration of particles than subjects with asthma, but only during pollenseason. PEx concentrations increased after bronchodilatation in subjects with asthma (median 4.05*10 3 to 4.92*10 3 , p=0.02), but not in controls. The change in PEx concentration (%) was associated with the change in FVC (%) (r p = 0.51, p=0.001) and FEV 1 (r p = 0.46, p=0.003) among subjects with asthma whereas there were no significant correlations among controls. Conclusion : During pollen season airway opening is reduced despite unaffected spirometry among pollen sensitized subjects with asthma. Bronchodilatation presumably increases airway opening resulting in an increased number of exhaled particles.
The paper presents the structural scheme and design of a multi-fuel autonomous power generating unit based on a low-boiling coolant and a rotary vane expansion machine. The developed power generating unit works with any type of fuel as well as with low-potential sources of thermal energy. Studies of operating modes of an autonomous power generating unit using a simulation model, developed in the Matlab/Simulink, showed the possibility of obtaining a stable output voltage without using an inverter when the load and parameters of the thermal part were changing. Calculations were carried out to determine the power generation efficiency of the proposed unit. They showed that the cost of generated electricity with using the developed unit is much lower compared to using a diesel generator.
Nocturnal gastroesophageal reflux (nGER) is associated with respiratory symptoms and sleep-disordered breathing (SDB), but the pathogenesis is unclear. We aimed to investigate the association between nGER and respiratory symptoms, exacerbations of respiratory symptoms, SDB and airway inflammation. Participants in the European Community Respiratory Health Survey III in Iceland with nGER symptoms (n = 48) and age and gender matched controls (n = 42) were studied by questionnaires, exhaled breath condensate (EBC), particles in exhaled air (PEx) measurements, and a home polygraphic study. An exacerbation of respiratory symptoms was defined as an episode of markedly worse respiratory symptoms in the previous 12 months. Asthma and bronchitis symptoms were more common among nGER subjects than controls (54 % vs 29 %, p = 0.01; and 60 % vs 26 %, p < 0.01, respectively), as were exacerbations of respiratory symptoms (19 % vs 5 %, p = 0.04). Objectively measured snoring was more common among subjects with nGER than controls (snores per hour of sleep, median (IQR): 177 (79–281) vs 67 (32–182), p = 0.004). Pepsin (2.5 ng/ml (0.8–5.8) vs 0.8 ng/ml (0.8–3.6), p = 0.03), substance P (741 pg/ml (626–821) vs 623 pg/ml (562–676), p < 0.001) and 8-isoprostane (3.0 pg/ml (2.7–3.9) vs 2.6 pg/ml (2.2–2.9), p = 0.002) in EBC were higher among nGER subjects than controls. Albumin and surfactant protein A in PEx were lower among nGER subjects. These findings were independent of BMI. In a general population sample, nGER is associated with symptoms of asthma and bronchitis, as well as exacerbations of respiratory symptoms. Also, nGER is associated with increased respiratory effort during sleep. Biomarker measurements in EBC, PEx and serum indicate that micro-aspiration and neurogenic inflammation are plausible mechanisms.
The DC link for the single-phase four-level voltage inverter is considered. This DC link includes reversible impulse converters, which used for alternatively forming of levels of the curve of the output voltage. Due to this, the scheme of the DC link does not depend on the number of levels of the output curve. The mathematical model is developed and modelling is performed.
Results of the analysis of electromagnetic processes in a three-port DC-DC converter are presented. It is shown that a constant component of the magnetizing current of the output transformer occurs during the practical realization of the converter due to the scatter of inductance values of storage reactors. It was proposed to replace two of these reactors by one with two magnetically coupled windings in order to eliminate this effect. Using of an additional inductor, connected the converter power source to a common point of magnetically coupled windings, reduces the ripple of the input current. The results represented can be used to design local electricity grids with renewable energy sources.
The airway opening generates particles in the distal airways. At high exhalation flows, particles can be formed due to dynamic compression in more central airways. The aim with the present study was to compare particle number and size distributions as well as concentrations of SpA in PEx formed during tidal breathing, airway opening and dynamic compression using forced exhalations. Ten healthy volunteers performed three different types of breathing maneuvers in randomized order; Reference maneuver (R): no airway closure and no dynamic compression (slow expiration), Dynamic compression (DC): maximal exhalation and no preceding airway closure, Airway opening (AO): slow expiration preceded by an inspiration from tidal lung volume. PEx were counted, sampled and analyzed for surfactant protein A (SpA) content using ELISA. Compared to the R maneuver; the DC maneuver doubled the particle concentration and the AO maneuver gave a ten times increase in the amount of particles per liter exhaled. Flow volume curves indicated that dynamic compression was limited by the back pressure in the instrumentation. The mass ratio of Sp-A in the PEx were highest in PEx using the R maneuvre; 13% v.s 5%DC (p Conclusion In conclusion, fast exhalation flows generates more particles than slow exhalation flows, but probably not by the dynamic compression mechanism.
Alzheimer's disease (AD) is the most common dementia and a steadily growing health concern in the aging world population. Early detection and diagnosis of AD is pivotal in the development and monitoring of new disease modifying treatments. CSF biomarkers have proven a viable way of allowing this, and there is great need of additional biomarkers providing earlier diagnosis, further diagnostic accuracy or clues to pathologic processes. The current paradigm of proteomic data analysis is identification-driven, i.e. data from the mass spectrometry run is first searched against a protein sequence database. A limitation of this approach for biomarker discovery is that only spectra that result in peptide identification are further evaluated. This results in major data loss as 70–80% of all data is discarded due to identification failure when running endogenous peptides. We propose a new quantification-driven approach using a clustering algorithm to mathematically search for similar spectra across samples and compare their abundances across patient groups. We prove this concept by employing the approach on a patient cohort consisting of 40 AD patients, 40 healthy controls (HC) and 40 mild cognitive impairment (MCI) patients. Using our novel approach a new potential biomarker of AD, a peptide from the protein pleiotrophin, was identified. The AD group had significantly (p < .05) higher concentrations (222% increase) of this peptide as compared to the HC group. The MCI patients had intermediate levels. We also validated this finding and found a similar pattern of increased concentrations of the pleiotrophin peptide in AD in an independent patient material consisting of 15 AD, 15 Parkinson disease (PD), 15 progressive supranuclear palsy (PSP) and 15 HC subjects. The increased concentrations in AD vs HC were significant (p < .05) but less prominent here (38%). There were also significantly increased concentrations in AD vs PD (37%, p < .05) and AD vs PSP (20%, p < .05). Pleiotrophin is a potential new biomarker for AD, and the results of this study indicate that it might be an early and specific biomarker of AD pathology. The results of this study are proof-of-concept for our proposed new strategy of quantification-driven clinical mass spectrometry data analysis.
Exhaled breath contains nonvolatile substances that are part of aerosol particles of submicrometer size. These particles are formed and exhaled as a result of normal breathing and contain material from distal airways of the respiratory system. Exhaled breath can be used to monitor biomarkers of both endogenous and exogenous origin and constitutes an attractive specimen for medical investigations.This review summarizes the present status regarding potential biomarkers of nonvolatile compounds in exhaled breath. The field of exhaled breath condensate is briefly reviewed, together with more recent work on more selective collection procedures for exhaled particles. The relation of these particles to the surfactant in the terminal parts of the respiratory system is described. The literature on potential endogenous low molecular weight compounds as well as protein biomarkers is reviewed. The possibility to measure exposure to therapeutic and abused drugs is demonstrated. Finally, the potential future role and importance of mass spectrometry is discussed.Nonvolatile compounds exit the lung as aerosol particles that can be sampled easily and selectively. The clinical applications of potential biomarkers in exhaled breath comprise diagnosis of disease, monitoring of disease progress, monitoring of drug therapy, and toxicological investigations.
