Miracle-dz/UniFAR-FTUs huggingface dataset:
Improving the Electrical Parameters of a Photovoltaic Panel by Means of an Induced or Forced Air Stream

The main priority in photovoltaic (PV) panels is the production of electricity. The transformation of solar energy into electricity depends on the operating temperature in such a way that the performance increases with the decreasing temperatures. In the existing literature, different cooling techniques can be found. The purpose of most of them is to use air or water as thermal energy carriers. This work is focused on the use of air as a working fluid whose movement is either induced by natural convection or forced by means of a fan. The aim of this study is to characterise the electrical behaviour of the solar panels in order to improve the design of photovoltaic installations placed in roof applications ensuring low operating temperatures which will correct and reverse the effects produced on efficiency by high temperature. To do this, a test installation has been constructed at the Universidad Politecnica de Cartagena in Spain. In this paper, the results of the tests carried out on two identical solar panels are included. One of them has been modified and mounted on different channels through which air flows. The different studies conducted show the effects of the air channel cross-section, the air velocity, and the panel temperature on the electrical parameters of the solar panels, such as the voltage, current, power, and performance. The results conclude that the air space between the photovoltaic panels and a steel roof must be high enough to allow the panel to be cooled and consequently to achieve higher efficiency.
Advanced UV Examination of Wastewater

UV examination is a simple technique for the quality control of wastewater, which is complementary to classical parameters (TOC, BOD5, COD, TSS, …). A discussion of the significance of UV absorption shows some limitations for its use. However, it is probably one of the most relevant methods for the study of wastewater quality as it can be illustrated with the results of a new deconvolution method, based on the deterministic choice of UV reference spectra. The deterministic deconvolution of UV spectra of wastewater yields qualitative and quantitative results. Probably the most interesting results are the estimations of the classical non-specific parameters or the determination of specific ions such as nitrate. The method can easily be used for the control of wastewater treatment plants or for monitoring the quality of surface water.
Study of complexes of poly(vinyl pyrrolidone) with copper and cobalt on solid state

A polymer–metal complex is a metal complex containing a polymer ligand, showing a remarkably specific structure in which central metal ions are surrounded by a colossal polymer chain. Based on this polymeric ligand, the polymer–metal complex has interesting and important characteristics, especially catalytic activities. This activity is different from that of the corresponding ordinary metal complex of low molecular weight. In this work we studied the synthesis and characterization, in the solid state, of different poly(vinyl pyrrolidone)–cobalt (PVP/Co) and –copper (PVP/Cu) complexes. We used differential thermal analysis and FTIR as the experimental techniques. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1512–1518, 2004
The Effects of Different Substrates on Ammonium Removal in Constructed Wetlands: A Comparison of Their Physicochemical Characteristics and Ammonium‐Oxidizing Prokaryotic Communities

A vertical flow constructed wetland (VFCW) filled with natural zeolite had higher ammonium removal (82.4–94.0%) than another VFCW filled with volcanic rock (51.3–69.4%) treating piggery wastewater under any of three recirculation ratios. To reveal the underling reasons, physicochemical characteristics and ammonium-oxidizing prokaryotes (AOPs) of two substrates were determined. The calculated maximum ammonium adsorption of zeolite (11.6 mg g−1) was remarkably higher than that of volcanic rock (0.21 mg g−1), mainly because the former contains two cationic binding crystalline species, and montmorillonite. Quantitative analyses indicated that ammonium-oxidizing archaea (AOA) are the dominant AOP of zeolite and ammonium-oxidizing bacteria (AOB) are the dominant AOP of volcanic rock respectively. Diversity and phylogenetic analysis further showed that both AOB and AOA communities were significantly different between two substrates. Nitrosospira-like AOB (92.6%) and sediment/soil clade AOA (71.4%) were the main components of AOB and AOA in natural zeolite, whereas Nitrosomonas-like AOB (76.1%) and water/sediment clade AOA (77.1%) dominated the AOB and AOA in volcanic rock. These results suggest that the substrates show high selectivity to AOP community. Thus, in addition to physicochemical characteristics, the AOP of substrates is very likely to affect ammonium removal in VFCWs.
Liquid chromatography–high-resolution mass spectrometry for identifying aqueous chlordecone hydrate dechlorinated transformation products formed by reaction with zero-valent iron

Chlordecone (CLD) is a persistent toxic chlorinated pesticide which contaminates different ecosystems in French West Indies. A soil remediation process including zero-valent iron (ZVI) has produced promising results but failed to completely degrade CLD, and the analytical procedures used yielded little information on the transformation products. To fill these gaps, dechlorination of aqueous CLD by micrometric particles of ZVI has been investigated. Aliquots of water with 25% (v/v) of acetone spiked with 100 ppm CLD were taken at different times during a 30-day ZVI treatment and directly analysed by ultra-high-performance liquid chromatography in negative electrospray ionisation mode. CLD has been totally transformed after 14 days into 14 dechlorinated degradation products, including 9 isomeric compounds. The maximum chloride concentrations appearing in the medium represent 44% of that which would result from total dechlorination of CLD. The CLD transformation products identified by accurate mass measurements on an ultra-high-resolution Q-TOF mass spectrometer (Q-TOF-MS) were C10H3Cl9O2, C10H4Cl8O2, C10H5Cl7O2, C10H6Cl6O2 and C10H7Cl5O2. The results show the interest of LC-Q-TOF-MS for identifying transformation products of organic contaminants, and the effectiveness of micrometric ZVI particles to totally transform CLD into less chlorinated products.
A critical account on π–π stacking in metal complexes with aromatic nitrogen-containing ligands

A geometrical analysis has been performed on π–π stacking in metal complexes with aromatic nitrogen-containing ligands based on a Cambridge Structural Database search and on X-ray data of examples in the recent literature. It is evident that a face-to-face π–π alignment where most of the ring-plane area overlaps is a rare phenomenon. The usual π interaction is an offset or slipped stacking, i.e. the rings are parallel displaced. The ring normal and the vector between the ring centroids form an angle of about 20° up to centroid–centroid distances of 3.8 A. Such a parallel-displaced structure also has a contribution from π–σ attraction, the more so with increasing offset. Only a limited number of structures with a near to perfect facial alignment exists. The term π–π stacking is occasionally used even when there is no substantial overlap of the π-ring planes. There is a number of metal–ligand complexes where only the edges of the rings interact in what would be better described a C–H⋯π attraction.
The development of bone char-based filters for the removal of flouride from drinking water

Millions of people rely on drinking water that contains excess fluoride. Only few fluoride removal techniques have been implemented on a wider scale in low and middle income countries. One of these methods, bone char filtration, is highly efficient. However, its lifespan is rather limited. This paper presents first laboratory results and field testing of a new fluoride removal technology, based on a combination of bone char and calcium-phosphate pellets. These chemicals are slowly released to the water for fluoride precipitation. Although this method, commonly referred to as contact precipitation is known, the development of such pellets is new. Fixed-bed laboratory experiments show that this mixture of materials can increase filter uptake capacity by a factor of 3 and more. However, to reduce the phosphate concentration in the treated water, the design of full-scale community filters for field testing has to be slightly modified.
Effects of vitamin E and vitamin A supplementation on performance, thyroid status and serum concentrations of some metabolites and minerals in broilers reared under heat stress (32 deg C)

An experiment on Cobb-500 male broilers was conducted to evaluate the effects of vitamin E (α -tocopherol- acetate), vitamin A (retinol), and their combination on broiler performance and serum concentrations of triiodothyronine (T3), thyroxine (T4), adrenocorticotropine hormone (ACTH) and some metabolite and mineral concentrations in broilers reared under heat stress (32°C). One day-old 120 broilers were randomly assigned to 4 treatment groups, 3 replications of 10 birds each. The birds were fed either a control diet or a control diet supplemented with either vitamin A (15 000 IU retinol/kg diet), vitamin E (250 mg α -tocopherol-acetate/kg diet), or a combination of vitamin A and E (15 000 IU retinol plus 250 mg of α -tocopherol- acetate/kg diet). Considered separately or as a combination, supplemental vitamin A and vitamin E increased feed intake (P = 0.01) and live weight gain (P = 0.03). However, feed efficiency remained similar in all treatments (P = 0.18). Serum T3 and T4 concentrations were also higher (P ≤ 0.001) with vitamin A, vitamin E, and vitamin A plus vitamin E groups than those of the control. However, ACTH concentration in serum was lower (P ≤ 0.001) in supplemental dietary vitamin groups compared with control. Serum glucose, uric acid, triglyceride, and cholesterol concentrations decreased (P ≤ 0.001) while protein and albumin concentrations increased (P ≤ 0.001) when both dietary vitamin E and vitamin A were supplemented. Serum activities of serum glutamic oxalate transaminase (SGOT) and serum glutamic pyruvate transaminase (SGPT) were not influenced by dietary vita- min E, vitamin A nor by a combination of vitamin A and vitamin E (P > 0.72). However, serum activity of alkaline phosphatase (AP) increased (P ≤ 0.001) with supplemental dietary vitamin E, vitamin A, or a combination of vitamin A and vitamin E. In addition, supplemental dietary vitamin E and vitamin A resulted in an increase in serum concentrations of both Ca and P (P ≤ 0.001). In general, when a significant effect was found for a parameter, the magnitude of responses to vitamin supplements was greatest with the combination of vitamin A and vitamin E, rather than that of each vitamin supplement separately. The results of the present study show that supplementing a combination of dietary vitamin E and vitamin A offers a good management practice to reduce heat stress-related decreases in broiler performance.
Molecular Encapsulation of Flurbiprophen and/or Ibuprophen by Hydroxypropyl-β-cyclodextrin in Aqueous Solution. Potentiometric and Molecular Modeling Studies

Thermodynamic and structural studies of the binding of the nonsteroidal antiinflammatory drugs, flurbiprophen and ibuprophen, to hydroxypropyl-β-cyclodextrin (HPBCD) have been carried out from pH potentiometric measurements, molecular mechanics, and dynamics calculations. The potentiometric study was performed by measuring the pH of aqueous solutions of the drugs as a function of cyclodextrin concentration, at several temperatures ranging from 15 to 40 °C. The dissociation constants of the drugs, as well as the binding constants of the inclusion complexes formed by HPBCD and the ionized and nonionized drugs, have been simultaneously determined at all the temperatures. The nonionic forms have shown a higher affinity to HPBCD than their ionic counterparts. A van't Hoff analysis of the determined binding constants reveals that the complexes formed by the flurbiprophen species and HPBCD are enthalpy driven, with a favorable enthalpic term and an unfavorable entropic term. Both contributions are found to be te.
Status of Iron, Manganese, Copper, and Zinc of Soils and Plants and Their Requirement for Ruminants in Inner Mongolia Steppes of China

The availability of heavy metal micronutrients and their distribution in soils and plants as well as their requirements for grazing animals are important when assessing the environmental quality and nutritive status for ruminants of a given area. The mean available copper (Cu), zinc (Zn), and manganese (Mn) contents of all soils were respectively 1.20, 1.60, and 3.38 g kg−1 of calcareous soils in the Inner Mongolia steppe of China. The heavy metals content of the chernozem soil were usually greater than those of other soils, whereas their contents in plants, however, were usually smaller than those in plants from other soils. It means that the heavy metal bioavailability in the chernozem soil is relative low. Positive significant correlations between available Cu, Zn, and Mn and organic carbon, total nitrogen and clay contents, and between available Cu and Zn and between available Zn and Mn in soils were observed. On the other hand, negative significant correlations between heavy metals and pH were found. The results of stepwise regression analysis showed that the parameter organic carbon and clay are the most important variables. Available Cu, Zn, and Mn contents increased with increasing organic carbon and clay. Means and ranges of iron (Fe), Mn, Cu, and Zn in plants of the five soils were 14.6–91.5, 3.1–5.4, 0.8–2.3, and 1.5–2.2, respectively. Therefore, all plant samples were considered severely deficient in Fe, Mn, Cu and Zn for all ruminants. The availability of micronutrient heavy metals in soils to plants and to grazing animals in plants deserves further studies in this region. The Fe, Mn, Cu and Zn contents in feces of grazing sheep averaged 125.3, 16.4, 4.8 and 6.2 mg kg−1. In the natural grassland, animal manures, therefore, may be an important heavy metals source.
The determination of the content of phenolic compounds from different Romanian wines using Folin-Ciocîlteu method.

It is well known that the bioactive compounds could have a benefic or harmful effects on human health. Recent studies point out the role of polyphenolic compounds in ant ioxidant activities. Wine polyphenols are considere the main responsible molecules present in wine to have benef icial effects on cardiac health and atherosclerosis , including neurological and carcinogenic illnesses. For this r eason, in this paper we determined the content of p olyphenolic compounds from different sample of red and white Ro manian wines. It was used the Folin-Cocîlteu method . The obtained results are interpreted according to: grape varieties, agroecological conditions of viney ards (terroir), the vinification process, special winemaking procedures , microbial metabolism related to the fermentative process, climate conditions and other additional procedures like agi ng.
Fast production of β-Ni(OH)2 nanostructures with (001) and (100) plane exposure and their electrochemical properties

Based on theoretical analysis of the crystal structure of β-Ni(OH)2, the (001) and (100) planes have the highest and the second highest Ni2+ cation concentration, respectively. Therefore, F− anions were selected to control the growth behavior of β-Ni(OH)2 through the selective adsorption of F− anions because of their small size, simple effect and ability to coordinate with Ni2+ cations. As a result, a series of β-Ni(OH)2 nanostructures with (001) and (100) planes exposed were successfully synthesized within several tens of minutes under the stimulation of microwave irradiation. The surface area ratio of (100) to (001) planes can be changed by altering the reaction time. The exposure of (100) planes was found to be favorable to the electrochemical activity rather than (001) planes.
Antipseudomonal Ergosteryl Triterpenes from the Paste of Spondias pinnata kruz. Bark, Pre-Treated with Curd-Brew

Two new ergosteryl triterpenes were isolated from ethnopharmacological lead of Indian origin consisting of a paste of Spondias pinnata barks, pre-treated with curd brew. The chemical structures of the newly isolated compounds were established from detailed IR, 1H NMR, 13C NMR, GCMS and HRMS spectroscopic analyses. The triterpenes were evaluated for their antipseudomonal activities against a tetracycline and ampicillin-resistant strain of Pseudomonus aeruginosa by disc diffusion method. One of the compounds exhibited significant protection against the test microbe, comparable to streptomycin.
Evaluating the potential contribution of vegetation as a nutrient source in snowmelt runoff

Elliott, J. 2013. Evaluating the potential contribution of vegetation as a nutrient source in snowmelt runoff. Can. J. Soil Sci. 93: 435-443. On the Canadian prairies, most nutrient transport to surface waters takes place during snowmelt. The potential for a range of 11 residue types to release nitrogen (N), phosphorus (P) and carbon (C) was assessed by snowmelt simulation. Interactions between soils and residues were measured for two contrasting residues. Samples (taken in late fall) were frozen prior to snowmelt simulations that consisted of three diurnal temperature cycles from -5°C to +9°C followed by a final melt at +5°C. Releases of total and total dissolved P (TP and TDP), total dissolved N (TDN), and dissolved organic C (DOC) during simulated snowmelt were greater from actively growing residues than from crop stubble and were significantly related to plant moisture and nutrient contents. Nutrient release from wheat stubble (WS) was statistically similar to that from the underlying surface soil but releases of P and ammonia (NH3) from winter wheat (WW) were at least four times greater than for the corresponding soil. When combined samples of residue and soil were tested, releases of most nutrients were less than when the residue and soil were tested separately. Potential release of nutrients from vegetation is a factor for consideration in the design of practices to reduce nutrient transport.
NOVEL IN SITU SILICA/POLYDIMETHYLSILOXANE NANOCOMPOSITES: FACILE ONE-POT SYNTHESIS AND CHARACTERIZATION

Abstract Synthesis of in situ silica/polydimethylsiloxane (PDMS) nanocomposites by using tetraethylorthosilicate (TEOS) as the precursor for silica and octamethylcyclotetrasiloxane for the polymer in presence of base was undertaken. Simultaneous generation of silica and polymer and dispersion of the nanofiller in the polymer have been reported for the first time. Fourier transform infrared spectroscopy was used as a tool to monitor the reaction conditions. The structure–property relationship of in situ silica/PDMS nanocomposites has been highlighted. Transmission electron microscopic studies reveal finest extent of dispersion of the in situ generated nanosilica, which is found to undergo polymorphic modification determined from wide-angle X-ray diffraction. Nanocomposites exhibit huge improvement in mechanical properties (>150% improvement in tensile strength for just 2 phr TEOS-filled sample) and room temperature storage modulus (>460% improvement in storage modulus for 8 phr TEOS-loaded sample). Polymer.
Influence of morphology on the in vitro bioactivity of hydroxyapatite nanostructures prepared by precipitation method

It seems that the available studies about the effect of morphology on the bioactivity of pure hydroxyapatite (Ca10(PO4)6(OH)2, HAP) are yet insufficient. For this purpose, a novel morphology-controlled synthesis method to fabricate HAP nanostructures is employed by using different Schiff bases as chelating ligands. The formation mechanism of zero-dimensional (0-D) and one-dimensional (1-D) nanostructures of HAP is also considered. Based on the morphological studies of the final products, it is found that the formation of tetradentate and bidentate ligands leads to the preparation of 0-D and 1-D HAP nanocrystals, respectively. The in vitro bioactivity of the as-produced HAP nanostructures is evaluated by soaking the products in simulated body fluid (SBF). The analytical measurements indicate that the changes in the Ca and P concentrations of the 1-D HAP nanostructures are more than those of the 0-D HAP nanostructures, indicating good bioactivity of the nanorods and nanobundles. The formation of new apatite crystals on the surfaces of the HAP nanostructures soaked in the SBF solutions is proved by field emission scanning electron microscopy (FESEM) and diffuse reflectance Fourier transform infrared spectrometry (ATR-FTIR).
Respiratory Effects Among Cotton Workers in Relation to Dust and Endotoxin Exposure

Cotton dusts contain agents, namely endotoxins, which can cause chronic inflammatory responses in the airways and the lung. We have hypothesized that the adverse effects of cotton dusts result from airborne endotoxin levels. The population studied comprised two groups: those who worked in the carding departments (opening, blowing, carding, drawing and roving) (n = 231) and those who worked in the weaving departments (n = 186). Cotton dust levels were monitored gravimetrically using Millipore polyvinylchloride filters and vertical elutriators with a 15 µm mass median aerodynamic diameter cut-off size. The amount of airbone endotoxin was determined using the Limulus amoebocyte lysate technique. Questionnaire administration and pulmonary function testing were carried out on each worker before entering the workshop after a 36 h rest period. Function tests were repeated at the end of the shift. In the carding department, workers were measured for airway reactivity. A test of bronchial reactivity was performed with graded doses of inhaled methacoline according the method described by Cockcroft et al. Time-weighted averages of cotton dust levels were highest in the carding departments (0.19–1.3 mg/m3) than in the weaving departments (0.11–0.58 mg/m3). The endotoxin levels in the carding departments varied between 2.5 and 58 ng/m3; endotoxin was not found in the weaving departments. The workers in the carding areas presented a higher frequency of respiratory symptoms (28.3%) than those in the weaving areas (12.7%). A relationship was found between decreases in FEV 1 and airborne endotoxin levels, but not for dusts. The average reaction to methacoline was related to the amount of airborne endotoxin. The results support the hypothesis of a dose–response relationship between endotoxin levels in cotton dust and chronic lung impairment in cotton workers and the presence of increased bronchial reactivity in workers in the cotton industry.
The Swelling Behaviors and Network Parameters of Cationic Starch-g-Acrylic Acid/Poly(dimethyldiallylammonium chloride) Semi-Interpenetrating Polymer Networks Hydrogels

Amphiphilic semi-interpenetrating polymer networks (semi-IPN) hydrogels were prepared by a sequential-IPN method by acrylic acid graft copolymerization into cationic starch in mild aqueous media of poly(dimethyldiallylammonium chloride). Some main factors were investigated to evaluate the swelling of hydrogels, and the network parameters Mc were given accordingly to elaborate the interaction between polymers. The chemical structure of the resulting hydrogel was confirmed using Fourier transform infrared spectroscopy. The cationic starch-based semi-IPN hydrogels achieved a high swelling capacity of 1070 g/g in deionized water and 94 g/g in 0.9 wt % NaCl solution, respectively) and high compressive stress in a high water content. Besides, a different pH-dependent behavior was found for this semi-IPN hydrogel. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008