Energy-saving estimation model for hypermarket HVAC systems applications

Energy saving estimation model (ESEM) use normal distribution (Gaussian) probability theory to predict potential savings for previously determined system improvements. Those improvements are low/high cost investments based on data gathered during one year monitoring of typical hypermarket facility HVAC system. The consumption of electrical energy and natural gas has been monitored and system segments with largest amount of energy consumption have been marked. Gathered data pointed out to fan units as the biggest energy consumers and suggested that system energy-saving improvement must be focused on fans energy consumption control. This paper deals with ESEM inputs and outputs in order to provide correct financial estimation of specific investment.     

The preparation and properties of zinc coordination complexes of poly(4-vinylpyridine-co-n-butyl methacrylate) copolymers

Two poly(4-vinylpyridine-co-n-butyl methacrylate) copolymers containing 14.2 and 30.0 mol% of 4-vinylpyridine residues were prepared by free radical copolymerization reactions. Insoluble complexes were obtained for each copolymer by reaction with zinc chloride. The coordination complexes obtained had a molar ratio of 4-vinylpyridine residues to zinc atoms close to 2 in both cases. The rheological behavior of each of these complexes has been compared to that of the corresponding metal-free copolymers, which were recovered by decomplexation. The metal complexed polymers exhibited much higher glass transition temperatures and much longer high temperature relaxation times than the corresponding uncomplexed copolymers.     

Gold Medal Award for Life Achievement in Psychological Science: Donald Benjamin Lindsley.

On August 12, 1989, at the annual meeting of the American Psychological Association (APA) in New Orleans, Louisiana, the American Psychological Foundation (APF) announced the recipients of the Gold Medal Award for Life Achievement in Psychological Science, Donald Benjamin Lindsley. This article provides a citation and biography about Mr. Lindsley and his life accomplishments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A psychometric study of the McMaster Family Assessment Device in psychiatric, medical, and nonclinical samples.

Investigated the psychometric properties of the McMaster Family Assessment Device (FAD [N. Epstein et al; see PA, Vol 71:2891]), a multidimensional measure of family functioning, using data from psychiatric (n?=?1,138), nonclinical (n?=?627), and medical (n?=?298) samples. Internal scale reliabilities and factorial validity were assessed for each group, and results were compared across groups. In general, scale reliabilities were favorable and the hypothesized factor structure of the FAD was supported. Results also support the use of the 60-item version over the original 53-item version. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pulsed neutron source measurements in the subcritical ADS experiment YALINA-Booster

A subcritical zero-power source-driven coupled core, the YALINA-Booster, has been constructed for experimental investigations of neutron kinetics of source-driven systems. In this study, the reactivity of two subcritical configurations has been determined by the area ratio method. The prompt neutron decay constants have been evaluated through slope fitting of the prompt neutron decay as well as through the pulsed Rossi-α method. It is shown that the slope fitting method and the pulsed Rossi-α method give stable results whereas the area ratio method results show spatial dependence. The reasons for the spatial spread are addressed.     

Influence of electrostatic field on the interaction of AB5-type alloy LaNi4.4Al0.3Fe0.3 with hydrogen

The effect of the electrostatic field on hydrogen absorption is experimentally studied for the case of AB₅-type intermetallic compound LaNi_4.4Al_0.3Fe_0.3 with low equilibrium pressure. Experimental facility contained control and measurement system for PCT-isotherms and a non-conductive polymer vessel immersed in a bath of a thermostat with transformer oil. The test sample with 100 g of the activated alloy powder was used. Electrostatic field was created between a copper tube, which simultaneously served as a hydrogen inlet, connected to a high voltage source and a grounded nickel plate rolled in the form of a cylinder around the outer wall of the vessel. The electrodes were arranged coaxially, the maximum voltage on the internal electrode was 15 kV. The high voltage source also allowed changing the polarity on the internal electrode.It was found that the electrostatic field had no effect on the already established equilibrium in the hydrogen-alloy system at a voltage at the electrode up to 15 kV, regardless of the polarity. However, the process of hydrogen absorption is noticeably slowed down when a voltage of up to 15 kV with negative polarity is applied to the internal electrode, and the effect increases with increasing voltage. At a voltage of 15 kV and the positive polarity of the internal electrode, there was no noticeable effect on the hydrogen absorption process.     

PPy doped PEG conducting polymer films synthesized on LiFePO4 particles

In this work, polyethyleneglycole (PEG) is introduced into polypyrrole (PPy) film coated on LiFePO₄ powder particles to promote the properties of cathode material for lithium-ion batteries. The enhancement of the electrochemical activity by the substitution of a carbon with electrochemically active polymer is investigated. Films of the PPy doped with the PEG were prepared by the chemical oxidative polymerization of pyrrole (Py) monomer. PEG has been added as an additive during polymerization process to improve mechanical and structural properties of the PPy in final PPy/PEG-LiFePO₄ cathode material. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge measurements were employed to characterize the electrochemical properties of PPy/PEG-LiFePO₄ material. The electrochemical performance of PPy-LiFePO₄ electrodes was greatly improved by introduction of PEG into the PPy films. Charge/discharge measurements confirmed the increase in capacity when applying PEG in PPy. The morphology and particle sizes of the prepared cathode powder material were investigated by scanning electron microscopy (SEM) and particle size analysis (PSA). Distribution of PPy and PPy/PEG films onto the LiFePO₄ particles surface was studied by time of flight secondary ion mass spectrometry (TOF-SIMS). In addition to polymeric coating layer on the surface of PPy-LiFePO₄ composite particles, some PPy unequally distributed between the particles was found. The median diameter value is 4.92 μm for PPy-LiFePO₄ sample. TOF-SIMS measurements and SEM images confirmed that thickness of polypyrrole coating on LiFePO₄ particles is about 100 nm.     

Titanium-containing amorphous hydrogenated silicon carbon films (a-Si:C:H/Ti) for durable solar absorber coatings

By the incorporation of silicon into titanium-containing amorphous hydrogenated carbon films (a-C:H/Ti), the lifetime stability at 250°C in air can be strongly enhanced. A combined PVD/PECVD process for the vacuum deposition of these titanium-containing amorphous hydrogenated silicon carbon films (a-Si:C:H/Ti) is described. Elemental compositions of the deposited films have been determined by in situ core-level photoelectron spectroscopy (XPS). Optical constants for these films have been determined in the wavelength range from 400 to 2500 nm by means of spectrophotometry. Single layers of a-Si:C:H/Ti and a-C:H/Ti deposited on aluminum and copper substrates have been subjected to comparative aging tests. At 250°C in air, the stability of the a-Si:C:H/Ti films is significantly higher than that of the a-C:H/Ti films. If the silicon content is not too high, the aging properties under humid conditions do not suffer a lot from the incorporation of silicon. However, if the silicon content is clearly higher than the carbon content, the humidity resistance will decrease. For an absorber coating for flat plate solar collectors, the optimized silicon content is expected to be in the range where the high-temperature stability in air is already improved, and where the humidity resistance is still good. For vacuum collectors, a higher silicon content might be advantageous.     

Selection of metal hydrides-based thermal energy storage: Energy storage efficiency and density targets

Thermo-chemical energy storage based on metal hydrides has gained tremendous interest in solar heat storage applications such as concentrated solar power systems (CSP) and parabolic troughs. In such systems, two metal hydride beds are connected and operating in an alternative way as energy storage or hydrogen storage. However, the selection of metal hydrides is essential for a smooth operation of these CSP systems in terms of energy storage efficiency and density. In this study, thermal energy storage systems using metal hydrides are modeled and analyzed in detail using first law of thermodynamics. For these purpose, four conventional metal hydrides are selected namely LaNi₅, Mg, Mg₂Ni and Mg₂FeH₆. The comparison of performance is made in terms of volumetric energy storage and energy storage efficiency. The effects of operating conditions (temperature, hydrogen pressure and heat transfer fluid mass flow rates) and reactor design on the aforementioned performance metrics are studied and discussed in detail. The preliminary results showed that Mg-based hydrides store energy ranging from 1.3 to 2.4 GJ m^?3 while the energy storage can be as low as 30% due to their slow intrinsic kinetics. On the other hand, coupling Mg-based hydrides with LaNi₅ allow us to recover heat at a useful temperature above 330 K with low energy density ca.500 MJ m^?3 provided suitable operating conditions are selected. The results of this study will be helpful to screen out all potentially viable hydrides materials for heat storage applications.     

Pyrolysis-field ionization mass spectrometry of modified bagasse fractions

The fractions obtained from bagasse after activation with 17.5% NaOH, alternative alkylation with quarternary ammonium groups and extraction with 80% ethanol, water and 5% NaOH, were analyzed using pyrolysis-field ionization mass spectrometry (Py-FIMS). The proposed degradation products from lignin were mostly symmetric fragments containing two aromatic rings while the compounds formed from polysaccharides were the result of dehydration reactions. From the temperature-resolved Py-FIMS it could be seen that ethanol-lignin starts to degrade at temperatures lower than 180°C before the degradation of the hemicellulose fraction. The lignin markers are eliminated from hemicellulose fractions before the polysaccharide gasification starts. The quarternary ammonium groups are cleaved from the fractions at temperatures lower than 200°C.