Evaluation of heating efficiency and thermal comfort in special purpose vehicle cabins

The paper presents the integrated application of two methods during testing HVAC system efficiency in the cabins of HUMMER.1151A1 and OAR 1RL-128D offroad vehicles. Spatial measurements of change in air temperature per time have been performed at three vertical levels (head, knees, and feet) of the driver and passengers, which totals to 15 measuring points per vehicle. The main goal of testing was to evaluate accurately the efficiency of heating and cooling in relation time interval required to attain a designed temperature of comfort in the vehicle cabin, on condition that the difference in ambient temperature levels does not exceed 10 degrees C. With a view to more efficient evaluation of thermal comfort in vehicle cabins, the testing was performed also of predicted mean vote and predicted percentage of dissatisfied indices. Standard thermal comfort surveys ask subjects about their thermal sensation on a seven-point scale from cold (-3) to hot (+3). This research is carried out according to the methods based on ISO 7730, ASHRAE 55, and SORS 8419 standards

Evaluation of heating efficiency and thermal comfort in special purpose vehicle cabins

The paper presents the integrated application of two methods during testing HVAC system efficiency in the cabins of HUMMER.1151A1 and OAR 1RL-128D offroad vehicles. Spatial measurements of change in air temperature per time have been performed at three vertical levels (head, knees, and feet) of the driver and passengers, which totals to 15 measuring points per vehicle. The main goal of testing was to evaluate accurately the efficiency of heating and cooling in relation time interval required to attain a designed temperature of comfort in the vehicle cabin, on condition that the difference in ambient temperature levels does not exceed 10 degrees C. With a view to more efficient evaluation of thermal comfort in vehicle cabins, the testing was performed also of predicted mean vote and predicted percentage of dissatisfied indices. Standard thermal comfort surveys ask subjects about their thermal sensation on a seven-point scale from cold (-3) to hot (+3). This research is carried out according to the methods based on ISO 7730, ASHRAE 55, and SORS 8419 standards

Enhanced photocatalytic degradation of RO16 dye using Ag modified ZnO nanopowders prepared by the solvothermal method

In this work, Zn(CH3 COO)(2) 2 H-2 O with AgNO3 content from 0 to 6 mol% was solvothermally treated at 120 C for 18 h in the presence of poly(vinyl pyrrolidone), ethylene glycol and sodium hydroxide. The structural , microstructural and photocatalytic properties of the unmodified and Ag modified ZnO powders have been investigated by the XRPD, FESEM, TEM, UV-vis, Raman and BET techniques. The Ag modified samples consist of ZnO nanocrystals and metallic Ag on the surface. The average crystallite size of all samples was about 20 nm. The FESEM revealed the uniformity in size and approximately spherical shape of ZnO nanopar-ticles. The BET data suggest that all prepared samples are mesoporous. All prepared samples showed higher photocatalytic efficiency in the degradation of the Reactive Orange 16 (RO16) azo dye than the commercial ZnO. In addition, Ag modified ZnO powders, especially those with 1.5 and 0.75 mol% of Ag, were more efficient than the unmodified one

Hydrothermal Synthesis of CeO2 and Ce0.9Fe0.1O2 Nanocrystals

Pure and 10 mol% Fe3+ doped CeO2 nanocrystals were synthesized by hydrothermal method using two different basic solutions (NH4OH and NaOH). All the samples were calcinated at 140 degrees C and 200 degrees C. The characterization of crystalline structure, vibrational and optical properties was performed using X-ray diffraction, Raman spectroscopy and spectroscopic ellipsometry. The obtained results showed that the Fe-doped samples are solid solutions with different size of nanocrystals, very dependent on the synthesis temperature and type of basic solution. The Raman measurements demonstrated electron molecular vibrational coupling and increase of oxygen vacancy concentration whereas doping provokes a small decrease of optical absorption edge in comparison with pure ceria.International School and Conference on Photonics (PHOTONICA09), Aug 24-28, 2009, Belgrade, Serbi

Development of new smart metal nanomaterials based on titanium-dioxide for photocatalytic and antimicrobial activities / Разработка новых умных металлических наноматериалов на основе диоксида титана для фотокаталитической и антимикробной активностей / Razvoj novih pametnih metalnih nanomaterijala na bazi titanijum-dioksida za fotokatalitičku i antimikrobnu aktivnost

The subject of this study was the synthesis, characterization and testing of titanium (IV) oxide nanoparticles (TiO2-NPs) and their lanthanum (La3+), iron (Fe3+) and vanadium (V3+) dopants for the photocatalytic and microbiological activity, as well as their comparison with the catalytic activity of the tested commercial TiO2 (Degussa P-25® and anatase nanoparticles, 99.9 %, Alfa Aesar Lancaster). The TiO2-NPs photocatalysts were synthetized and doped with different metal dopants concentrations for different calcination durations, such as: TiO2-NPs (anatase-NPs, calcination duration of 5 and 7 h), La3+ (0.65, 1, 2, 3, 4, 5 and 6 wt. %, calcination duration of 7 h), Fe3+ (1, 2.5, 3.0 and 5 wt. %, calcination duration of 7 and 24 h), and V3+ (10 wt. %, calcination duration of 7 and 24 h). The Pseudomonas aeruginosa strains DV 2739 and ATCC 9023 were used as model microorganisms in the microbiological experiments performed in a microbiological cabinet. The photocatalytic and coupled photocatalytic-microbiological processes were performed in a slurry-catalyst bath circulation photoreactor in the presence of direct UV radiation simulated with a sodium lamp SONT UV400 in lab conditions. The study has demonstrated that the catalyst sample S28, an La-dopant with a concentration of 1wt. %, displays the best photocatalytic properties among all La-dopants, while the best photocatalytic activity among all catalysts was achieved in S111 sample, an Fe-dopant of titania (5 wt. %, calcination duration of 7 h). Our results also show different degradation rates for TiO2 doped with V3+ of 10.0 wt. %, samples S93 and S96, synthetized with different duration times (7h and 24h, respectively) and calcination heating rates (66.7 and 135 ᵒC/h, respectively), which can be explained by anomalies in their behavior. Finally, the best antimicrobial activity is obtained in S24 sample, an Fe-dopant for which it was shown that 0.25 mg/L could be toxic for microorganisms. In accordance with our results of superior Fe-dopant characteristics and theoretical knowledge for TiO2 nanoparticles doped with Ag, Au and Fe, we get directions for further studies of their photocatalytic and antimicrobial activities, as well as for the development of TiO2-nanoparticles and nanotubes for enhancing antibiotics and their use in cancer treatment. / Предметом данного исследования являются синтез, классификация и испытания наночастиц титана (IV) оксида (TiO2- НЧ-а) и легирования лантана (La3+), железа (Fe3+) и ванадия (V3+) для фотокаталитической и микробиологической активностей, а также сравнение с каталитическим активностима испытанными в коммерческих целях TiO2 (P25, Degussa® и наночастиц анатаза, чистоты 99,9%, компанией Alfa Aesar из Ланкастера). Наночастицы диоксида титана были синтезированы и легированы с различной концентрацией металлических допантов, при различной продолжительности процесса прокаливания: TiO2-НЧ (анатаз-НЧ, время процесса прокаливания 5 и 7 часов), La3+ (0.65, 1, 2, 3, 4, 5 и 6 вес. %, продолжительность прокаливания 7 часов), Fe3+ (1, 2,5, 3,0 и 5 вес. %, продолжительность прокаливания 7 и 24 часа) и V3+ (10 вес. %, продолжительность прокаливания 7 и 24 часа). Штамм „Pseudomonas aeruginosa DV 2739“ использован в качестве модели микроорганизмов в микробиологических экспериментах, проведенных в микробиологической лаборатории. Совместный процесс фотокаталических и микробиологических испытаний эксперимента проводился в катализаторной ванне при прямом концентрированном ультрафиолетовом излучении от натриевой лампы SONT UV 400, симулирующей солнечное излучение. Исследование показало, что образец катализатора С28, La-легирующей примеси с концентрацией 1 вес. %, обладает лучшими фотокаталитическими свойствами по сравнению с другими La-допантами, в то время, как лучшая фотокаталитическая активность была достигнута в образце S111, Fe-легирующей примеси диоксида титана (5 вес.%, продолжительность прокаливания составляет 7 часов). Результаты нашего исследования также показали различную степень деградации при применении V-допанта TiO2 с концентрацией 10 вес.% образцы С93 и С96 были синтезированы при различной продолжительности прокаливания (67.5 и 135 ᵒC/ч, поочередно), что можно считать аномалией в их поведении. И наконец лучшая антимикробная активность получена в образце СS24, Fe-легирующей примеси, которая показала, что 0,25 мг/л является токсичным для микроорганизмов. Результаты нашего исследования о преимущественных характеристиках Fe- легирующей примеси и теоретические знания о наночастицах TiO2, легированных Ag, Au и Fe, безусловно облегчат исследователям дальнейшую работу в изучении фотокаталитической и антимикробной активностей, а также развития наночастиц TiO2 и нанотрубок, с целью усиления действия антибиотиков и их применения при лечении онкологических заболеваний. / Predmet ove studije bila je sinteza, karakterizacija i testiranje nanočestica titanijum (IV) oksida (TiO2-NČ-a) i njihovih dopanata lantana (La3+), gvožđa (Fe3+) i vanadijuma (V3+) za fotokatalitičku i mikrobiološku aktivnost, kao i njihovo poređenje sa katalitičkim aktivnostima testiranih komercijalnih TiO2 (Degusa P-25® i nanočestica anatasa, čistoće 99,9%, Alfa Aesar iz Lankestera). Titanijum-dioksid nanočestice su sintetizovane i dopirane različitim koncentracijama metalnih dopanata, tokom različitog trajanja kalcinacije, kao što su: TiO2-NPs (anatas-NPs, vreme trajanja kalcinacije od 5 i 7 h), La3+ (0.65, 1, 2, 3, 4, 5 i 6 težinskih %, sa trajanjem kalcinacije od 7 h), Fe3+ (1, 2,5, 3,0 i 5 težinskih %, sa trajanjem kalcinacije od 7 i 24 h) i V3+ (10 težinskih %, sa trajanjem kalcinacije od 7 i 24 h). Sojevi 'Pseudomonas aeruginosa DV 2739 i ATCC 9023' korišćeni su kao model mikroorganizama u mikrobiološkom delu eksperimenata koji su izvedeni u mikrobiološkom kabinetu. Zajednički fotokatalitički i mikrobiološki procesi izvedeni su u cirkularnom fotoreaktoru sa emulgovanim katalizatorom u prisustvu direktnog UV zračenja simuliranog natrijumovom lampom 'SONT UV400'. Studija je pokazala da uzorak katalizatora S28, La-dopanta sa koncentracijom od jednog težinskog %, pokazuje najbolje fotokatalitičke osobine od svih La-dopanata, ali najbolju fotokatalitičku aktivnost od svih katalizatora postignut je kod S111 uzorka, Fe-dopanta (5 težinskih %, trajanje kalcinacije od 7 h). Naši rezultati takođe pokazuju različiti stepen degradacije kada je korišćen V-dopant TiO2, u koncentraciji od 10 težinskih %, uzorci S93 i S96, sintetisani sa različitim trajanjem kalcinacije (7 i 24 h) i brzinom zagrevanja tokom kalcinacije (67,5 i 135 ᵒC/h, redom), što se može objasniti anomalijom u njihovom ponašanju. Konačno, najbolja antimikrobna aktivnost dobijena je korišćenjem uzorka S24, Fe-dopanta, koji je pokazao da koncentracija od 0,25 mg/L može biti toksična za mikroorganizme. U skladu sa našim rezultatima superiornih karakteristika Fe-dopanta i teorijskih znanja za nanočestice TiO2 dopiranih Ag, Au i Fe, došlo se do smernica za dalja istraživanja njihove fotokatalitičke i antimikrobne aktivnosti, kao i za razvoj titanijum-dioksid nanočestica i nanotuba za unapređenje antibiotika i njihovu upotrebu u lečenju raka

Photocatalytic degradation of wastewater polluted by methyl-tertiary-butyl-ether using titanium-dioxide and doped titanium-dioxide

The subject of this research was utilization of concentrated solar radiation simulated with a sodium lamp SONT UV100, in lab condition, on removal of wastewater polluted by methyl-tertiary-butyl-ether (MTBE). The effects of titanium dioxide catalyst (commercial: Degussa P-25 (R) and 100% anatase, as well as sol-gel obtained titanium) on degradation of MTBE have been investigated. The processes were performed in slurry-catalyst batch circulating reactor. The photocatalytic degradation with different concentrations of TiO2 Degussa P-250 (R) catalyst: 2.5 g/L, 1 g/L and 0.50 g/L was studied. Our results showed that the MTBE degradation reached 50.80% in only 60 minutes, when 2.5 g/L of that catalyst was used. Also, the concentrated irradiation in combination with TiO2 (100% anatase) and FeCl3 caused high total degradation degree of 58.22%, for only 30 minutes. We synthesized titanium-dioxide, nanopowders doped with LaCl3 center dot 7H(2)O and FeCl3 center dot 6H(2)O, by sol-gel procedure. The highest degradation rate showed La-TiO2, for only 30 minutes and 48.60% of total degradation.Mathematics and Computers in Science and Engineering, 4th IASME/WSEAS International Conference on Water Resources, Hydraulics and Hydrology, Feb 24-26, 2009, Cambridge, Englan

Photocatalytic degradation of wastewater polluted by methyl-tertiary-butyl-ether using titanium-dioxide and doped titanium-dioxide

The subject of this research was utilization of concentrated solar radiation simulated with a sodium lamp SONT UV100, in lab condition, on removal of wastewater polluted by methyl-tertiary-butyl-ether (MTBE). The effects of titanium dioxide catalyst (commercial: Degussa P-25 (R) and 100% anatase, as well as sol-gel obtained titanium) on degradation of MTBE have been investigated. The processes were performed in slurry-catalyst batch circulating reactor. The photocatalytic degradation with different concentrations of TiO2 Degussa P-250 (R) catalyst: 2.5 g/L, 1 g/L and 0.50 g/L was studied. Our results showed that the MTBE degradation reached 50.80% in only 60 minutes, when 2.5 g/L of that catalyst was used. Also, the concentrated irradiation in combination with TiO2 (100% anatase) and FeCl3 caused high total degradation degree of 58.22%, for only 30 minutes. We synthesized titanium-dioxide, nanopowders doped with LaCl3 center dot 7H(2)O and FeCl3 center dot 6H(2)O, by sol-gel procedure. The highest degradation rate showed La-TiO2, for only 30 minutes and 48.60% of total degradation.Mathematics and Computers in Science and Engineering, 4th IASME/WSEAS International Conference on Water Resources, Hydraulics and Hydrology, Feb 24-26, 2009, Cambridge, Englan

Raman Study of Vanadium-Doped Titania Nanopowders Synthesized By Sol-Gel Method

Pure titania (TiO(2)) nanopowders and TiO(2) doped with 10 mol % of vanadium ions (V(3+)) are synthesized by sol-gel method. The dependence of structural characteristics of nanopowders on synthesis conditions is investigated by X-ray diffraction and Raman spectroscopy. Very intensive modes observed in Raman spectra of all nanopowders are assigned to anatase phase of TiO(2). Additional Raman modes of extremely low intensity which can be related to the presence of small11th Annual YUCOMAT Conference 2009, Aug 31-Sep 04, 2009, Herceg Novi, Montenegr

Investigation of surface defect states in CeO2-y nanocrystals by Scanning-tunneling microscopy/spectroscopy and ellipsometry

Synthesis process strongly influences the nanocrystalline CeO2-y defective structure. The presence of surface defects, in the form of oxygen vacancies in different charge states (F centers), can change the electronic properties of ceria nanocrystals. Nanocrystalline CeO2-y samples were synthesized using three different methods (precipitation, self-propagating room temperature, and hydrothermal synthesis). Raman spectroscopy was used to identify the presence of oxygen vacancies which presumably were formed at the nanoparticle surface. The defect concentration depended on the crystallite size of differently prepared CeO2-y samples. Scanning tunneling microscopy/spectroscopy and ellipsometry were employed to investigate the electronic band structure of defective CeO2-y nanocrystals. Scanning tunneling spectroscopy measurements demonstrated that inside the band gap of CeO2-y nanocrystals, besides the filled 4 f states, appeared additional states which were related to occupied and empty F center defect states. From the ellipsometric measurements, using the critical points model, the energy positions of different F centers states and the values of the reduced band gap energies were determined. The analysis of obtained data pointed out that depending on the synthesis method, different types of F centers (F+ and F-0) can be formed in the CeO2-y nanocrystals. The formation of different F center defect states inside the ceria gap have a strong impact on the electrical, optical, and magnetic properties of ceria nanocrystals. (C) 2014 AIP Publishing LLC

Photocatalytic degradation of metoprolol in water suspension of TiO2 nanopowders prepared using sol-gel route

Nanocrystalline titanium dioxide (TiO2) powders have been synthesized by sol-gel method using titanium tetrachloride (TiCl4) or tetrabutyl titanate (Ti(OC4H9)(4) as precursors, different alcohols and calcination temperatures in the range from 400 to 650 A degrees C. The photocatalytic activity of as-prepared powders has been tested for the degradation of metoprolol tartrate salt, a selective beta-blocker used to treat a variety of cardiovascular diseases, and compared to photocatalytic activity obtained from Degussa P25. Nanosized TiO2 powders prepared from TiCl4 and amyl-alcohol, calcined at 550 A degrees C, displayed an activity comparable to Degussa P25, whereas the sample from the same series, calcined at 650 A degrees C, showed higher photocatalytic activity in the whole range of the catalyst loading. Structural, morphological and surface properties of synthesized TiO2 nanopowders have been investigated by XRD, SEM, EDS and BET measurements, as well as FTIR and Raman spectroscopy, in order to find out the material properties which enable rapid an efficient decomposition of metoprolol under UV radiation