Abstract
In the competition of the lighting market, LED technology has stood out for excellent characteristics, one of which is the possibility of dimming, compared to other technologies. The dimming ...capacity allows to find the comfort zone with respect to two parameters, illuminance and correlated colour temperature (CCT). The present work provides a methodology to find comfort with respect to two variables, the level of illumination and the CCT. A controller with a simple structure, supported by Arduino, is proposed to control the above-mentioned variables of LEDs. The LEDs are located on a tape attached to a heat sink. In addition, the use of a light box as an environment for analysis is proposed. The design of this cubicle is based on literature. The controller has the possibility to regulate 12 different channels and the linearity between the PWM output and the illuminance was verified. The cubicle has an area for the observer whose dimensions are 60 cm × 60 cm. In this area, the illuminance measurement was carried out over time and the almost null variation of the illuminance 347± 1 lx was confirmed while the CCT varied in a controlled way from 3000 K to 6500 K.
Different models of development have a different impact on sustainability. In this paper, we contrast the development model as growth of the Gross Domestic Product (GDP), dominant in economic ...theories, with the model of human development or capabilities. The objective is to show the development of capabilities as a theoretical-practical perspective to guide education towards sustainability, a goal assigned by UNESCO. The method used is hermeneutic. The conclusions are: the capabilities approach defends the values required for sustainability and this approach convincingly argues for the political principles and good practices that should govern education.
Laplacian-based models for the exchange energy Cancio, A. C.; Wagner, Chris E.; Wood, Shaun A.
International journal of quantum chemistry,
15 December 2012, Letnik:
112, Številka:
24
Journal Article
The quantification of terrestrial carbon pools is important for the modeling of carbon fluxes in forest ecosystems. As a contribution to the understanding of the factors that influence the carbon ...sequestration capacity of Mediterranean forest soils, the present study focuses on the quantification of the superficial soil carbon stocks in evergreen oak stands (
Quercus ilex
L.) representative of its distribution area in Mainland Spain and to analyze the influence of site factors (climate and topography) and the soil chemical properties in the topsoil carbon storage capacity. For that purpose, 103
Quercus ilex
stands were studied grouped in four main formations: 40 wooded grassland ecosystems with scattered oak trees (
dehesas
), 14
open Holm oak stands
, 28
mixed Holm oak forests
and 21
dense Holm oak forests
. The soil organic carbon stocks (SOCS) in the upper organo-mineral soil layer ranged between 1.4–15.6 kg m
−2
and total soil carbon stocks (TSCS) between 1.4–17.9 kg m
−2
. Tree density was a significant factor for SOC storage in the soil. The wooded grassland
dehesas
presented the minimum superficial SOC stocks (3.6 kg m
−2
), while
dense Holm oak forests
reached the maximum average values (7.6 kg m
−2
). Maximum SOCS (>10 kg m
−2
) were measured in the
mixed
and
dense Holm oak forests
over soils with calcareous substrates. Summer mean temperature (
R
= −0.46;
P
< 0.001) was the climatic variable that most influenced the SOCS. Soil properties had stronger positive correlations with SOCS than site factors: nitrogen concentrations (
R
= 0.70;
P
< 0.001), clay content (
R
= 0.62;
P
< 0.001), soluble calcium (
R
= 0.60;
P
< 0.001) and magnesium (
R
= 0.42;
P
< 0.001). Climatic and topographic variables together explained 30 % of the SOCS variability. An increase up to 63 % was obtained by including soil variables. Under Mediterranean climate conditions, the soil properties that enhance the organic matter protection achieve a notable relevance. The soil carbon storage is favored by large organic matter inputs, high soil clay contents, a calcium-saturated soil matrix and reduced summer aridity.
We explore a model of armchair graphene nanoribbons tuned by functionalizing the edge states. Edge modifications are modeled by changing the electronic energy of the edge states in specific periodic ...patterns. The model can be considered to mimic a controlled doping process with different elements. The band structure, density of states, conductance, and local density of states are calculated, using the tight binding approach, Green’s function methodology, and the Landauer formula. The results show interesting behaviors, which are considerably different from the properties of the perfect nanoribbons. The hybridization of conducting bands with non-conducting bands, which appear perfectly flat in the perfect ribbon, opens up and modifies gaps in conductance near the Fermi level. One particular pattern of edge functionalization causes a strong, symmetric, and systematic band gap change about the Fermi level, modifying the electronic characteristics in the energy dispersion, density of states, local density of states, and conductance.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Over a decade ago, Wilson (1980) argued that race was declining in significance as a determinant of economic rewards. In response to his critics, he asserted that young Blacks in the 1970s were ...closing the earnings gap with their White counterparts; he gave no indication that he thought the trend toward racial parity in earnings would reverse. We tested Wilson's assertion by comparing the net effect of race on hourly wages for two cohorts of young workers. We also decomposed the racial gap in hourly wages into a discrimination component and a nondiscrimination component. Our samples were taken from the Panel Study of Income Dynamics in 1976 and 1985. Contrary to Wilson's proposition, we show that: (1) The effect of race, net of controls, increased during this time, and (2) the proportion of the racial gap in hourly wages due to discrimination (i.e., not explained by racial differences in measured qualifications) increased between 1976 and 1985. We contend that the government's retreat from anti-discrimination initiatives in the 1980s resulted in organizational discrimination against Blacks and contributed to a reversal in the postwar trend toward racial parity in earnings.
We present a deorbitalization of the recent simplified, regularized Tao-Mo exchange functional ( J. Chem. Phys. 2023, 159, 214102) that is faithful to the parent functional. That is a major gain ...relative to our earlier deorbitalization which did poorly on molecular heats of formation ( J. Chem. Phys. 2023, 159, 214103). The improvement arises from augmentation of the Mejía-Rodríguez and Trickey deorbitalization strategy ( Phys. Rev. A 2017, 96, 052512) to use a smoothed replacement for the reduced density Laplacian (conventionally denoted q) obtained from that Laplacian itself. The augmentation also rationalizes the improvement obtained from the cutoff of q < 0 that was poorly understood at the time of the previous paper. The new scheme yields deorbitalized chemical region indicators that are much closer to those from the parent, orbital-dependent functional than were obtainable from the previous deorbitalization. It also replicates the good 3d elemental magnetization of the parent functional reasonably well.We present a deorbitalization of the recent simplified, regularized Tao-Mo exchange functional ( J. Chem. Phys. 2023, 159, 214102) that is faithful to the parent functional. That is a major gain relative to our earlier deorbitalization which did poorly on molecular heats of formation ( J. Chem. Phys. 2023, 159, 214103). The improvement arises from augmentation of the Mejía-Rodríguez and Trickey deorbitalization strategy ( Phys. Rev. A 2017, 96, 052512) to use a smoothed replacement for the reduced density Laplacian (conventionally denoted q) obtained from that Laplacian itself. The augmentation also rationalizes the improvement obtained from the cutoff of q < 0 that was poorly understood at the time of the previous paper. The new scheme yields deorbitalized chemical region indicators that are much closer to those from the parent, orbital-dependent functional than were obtainable from the previous deorbitalization. It also replicates the good 3d elemental magnetization of the parent functional reasonably well.
Exacerbation of pulmonary dysfunction has been reported in patients receiving a pleural drain inserted through the intercostal space in comparison to patients with an intact pleura undergoing ...coronary artery bypass grafting (CABG). Evidence suggests that shifting the site of pleural drain insertion to the subxyphoid position minimizes chest wall trauma and preserves respiratory function in the early postoperative period. The aim of this study was to compare the pulmonary function parameters, clinical outcomes, and pain score between patients undergoing pleurotomy with pleural drain placed in the subxyphoid position and patients with intact pleural cavity after off-pump CABG (OPCAB) using left internal thoracic artery (LITA).
Seventy-one patients were allocated into two groups: I (n = 38 open left pleural cavity and pleural drain inserted in the subxyphoid position); II (n = 33 intact pleural cavity). Pulmonary function tests and clinical parameters were recorded preoperatively and on postoperative days (POD) 1, 3 and 5. Arterial blood gas analysis and shunt fraction were evaluated preoperatively and in POD1. Pain score was assessed on POD1. To monitor pleural effusion and atelectasis chest radiography was performed routinely 1 day before operation and until POD5.
In both groups a significant impairment was found in lung function parameters until on POD5. However, no significant difference in forced vital capacity and forced expiratory volume in 1 second were seen between groups. A significant decrease in partial pressure of arterial oxygen and an increase in shunt fraction values were observed on POD1 in both groups, but no statistical difference was found when the groups were compared. Pleural effusion and atelectasis until on POD5 were similar in both groups. There were no statistical differences in pain score, duration of mechanical ventilation and postoperative hospital stay between groups.
Subxyphoid insertion of pleural drain provides similar effects to preserved pleural integrity in pulmonary function, clinical outcomes, and thoracic pain after OPCAB. Therefore, our results support the hypothesis that once pleural cavities are incidentally or purposely opened during LITA dissection, subxyphoid placement of the pleural drain is recommended.
Overactive bladder (OAB) is the most common voiding dysfunction in children; however, nonneurogenic or idiopathic OAB remains poorly studied. First-line treatment includes conservative measures; ...however, as many patients are refractory, have adverse effects, or are contraindicated for anticholinergics, new options must be explored. This review covers the use of intravesical botulinum toxin (BoNT) for idiopathic OAB treatment in children, emphasizing its efficacy, safety, differences between toxins, doses, and injection techniques. Clinical results were promising, with all 8 studies reporting good results. All authors used BoNT type A (BoNT-A), either onabotulinum or abobotulinum toxin A. Response rates were variable, with full-response percentages of 32%-60%. As proven by the full-response rates of 50%, repeated injections are as safe and effective as first injections. Only a few cases of urinary tract infection, transient urinary retention, and hematuria have been reported, with no major local or systemic adverse effects. Despite these limitations, evidence encourages and supports BoNT-A use as a safe and effective treatment modality for refractory idiopathic OAB in pediatric settings, regardless of dosage and target toxin. To the best of our knowledge, this is the first systematic review of the use of intravesical BoNT-A for idiopathic OAB treatment in children.
The size distribution of 14 polycyclic aromatic hydrocarbons (PAHs) present in particulate aerosol in two different areas of the city of Las Palmas de Gran Canaria was investigated in May 2002. One ...of the study areas (Bravo Murillo) was under the influence of heavy traffic and the other (Pedro Lezcano) under that of small-scale industries of various nature. The average concentration of total suspended particulates (TSP) at Bravo Murillo (35.2 μg m^sup -3^) was roughly one-half that at Pedro Lezcano (73.6 μg m^sup -3^); the former, however, exhibited a higher PAH content (sum of PAHs: 6.6 ± 1.8 versus 5.1 ± 3.9 ng m^sup -3^). The aerosol size partition of total PAHs at Bravo Murillo, with a unimodal peaking at 0.08--0.3 μm, was completely different from that at Pedro Lezcano, where accumulation observed in the 3.8--7.4 μm range suggests the ageing of particles occurred, with PAHs have redistributed according to surface extension of particles.PUBLICATION ABSTRACT
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