The present study evaluated the main factors that influence the photocatalytic activity of titanium dioxide (TiO2) films grown by metalorganic chemical vapor deposition (MOCVD) at 400 and 500 °C, in ...different growth times. The photocatalytic behavior was analyzed by measuring the methyl orange dye degradation at different pH values. Structural and morphological characteristics, and the recyclability of the catalysts for several cycles were also investigated. Anatase phase was identified in all films. The higher photodegradation performances were obtained at acidic pH. The results demonstrated that the photocatalyst thickness is an important parameter in heterogenous photocatalysis. The best photocatalytic result occurred for the 395 nm-thick TiO2 film grown at 400 °C, which presented 65.3% of the dye degradation under UV light. The recyclability experiments demonstrated that the TiO2 films grown by MOCVD present a great stability after several photocatalytic cycles, which allows their practical application for water treatment with high efficiency.
Limbic encephalitis is a subacute syndrome characterized by memory impairment, confusion, seizures, hypothalamic dysfunction and psychiatric symptoms. It has been associated to tumors located outside ...of the central nervous system. In 2007, anti-N-methyl-D-aspartate receptors (NMDAr) antibodies were found in serum and CSF of patients with this particular type of encephalitis. We report a 25-year-old female who, following upper respiratory tract symptoms, developed serious behavioral and consciousness impairment that progressed to coma. Cerebrospinal fluid (CSF) analysis showed a lymphocyte pleocytosis, the electroencephalogram was altered with a slow encephalopathic rhythm and a brain magnetic resonance imaging was normal. Infectious etiologies were ruled out. CSF and serum anti NMDA receptors antibodies were positive.
The prevalence of Helicobacter pylori infection was assessed in a randomly selected sample of individuals from low-income community in Fortaleza, Northeastern Brazil. Overall, 384 out of 610 ...participants (62.9%) were H. pylori positive. A 47.5% infection rate was found in subjects aged six months to 10 years old, increased to 73.3% in subjects aged 11-20 years and then continued to increase with age reaching up to 87% in those over 60 years old. After this age group, the prevalence decreased slightly. The prevalence of infection increased significantly with age (p<0.0001).
To study bone marrow (BM) stromal damage in a mouse model of infusion-induced BM failure.
Sublethally irradiated CByB6F1 mice were infused with 5 × 10
6 C57BL/6 (B6) lymph node (LN) cells. Recipient ...BM cells were taken at 3, 7, 10, and 14 days following LN infusion and were cultured in vitro in α-modified Eagle media for 2–3 weeks. Peripheral blood and was analyzed by complete blood counts while BM lymphocyte infiltration/expansion was analyzed by flow cytometry. Marrow cells from affected and control mice were mixed and cultured in vitro to test nonspecific stromal damage.
Donor lymphocytes infiltrated host BM within 3–7 days and expanded significantly between 7 and 10 days, concurrent with the development of leukopenia, thrombocytopenia, and marrow hypoplasia. BM cells from mice at 7, 10, and 14 days after B6-LN cell infusion were progressively defective in forming stromal feeder layers. A 1:1 mixture of BM cells from affected CByB6F1 mice and normal B6 mice failed to form an effective stromal feeder layer that could support cobblestone colony formation, indicating that lymphocytes in the BM of affected CByB6F1 mice were able to damage stromal cells in the normal B6 BM.
Activated lymphocytes destroy both hematopoietic and stromal cells as innocent bystanders in the infusion-induced BM failure model.
The very nature of a complex system does not allow that a single person be able to master all required competences for its development or operation. Therefore, specialization, team work and ...coordination are required to achieve the desired goals. In order to assure positive synergy between every participant, system engineering concepts must be taken into account, like development methods, product decomposition, functional classification, design patterns, interface and compatibility assessment, configuration management, technological plans, technical standards, integration policies, system commissioning and validation. These systems engineering concepts are shown in the presented work through the development of a fully functional AUV system and control architecture. The control system and its components are properly described and compared against other state of the art architectures. It is also shown that it was possible to sustain the project development tasks among many successive group or generation of students, demonstrating the benefits of the proposed engineering methods. The proposed system was tested in field tests of the AUV during an oceanographic mission.
•The article presents an approach for developing the AUV embedded system in the university environment.•The control system hardware is based on a network of microntrolled based board integrated by a CAN bus system.•Software is described in terms of functional modules arranged according to abstraction layers, combining deliberative and reactive paradigms.•Validation results were recorded during an oceanographic mission in the South coast of Brazil.
•Parameters extraction method based on drain current measurements is proposed.•Mobility degradation factors influence on series resistance extraction is analyzed.•Flatband voltage and low field ...mobility are also extracted.•Method accuracy is analyzed considering devices of different characteristics.•Method application is demonstrated in experimental devices.
The aim of this work is to propose and qualify a systematic method for parameters extraction of Junctionless Nanowire Transistors (JNTs) based on drain current measurements and compact modeling. As junctionless devices present a different conduction mechanism than inversion-mode transistors, the methods developed for the latter devices either are not compatible or cannot be directly applied to JNTs before a deep analysis on their applicability. The current work analyzes the extraction of the series resistance, including a discussion about the influence of the first and second order mobility degradation factors, flatband voltage and low field mobility in junctionless transistors based only on static drain current curves. An analysis of the method accuracy considering the influence of the channel length, nanowire width and height, gate oxide thickness and doping concentration is also presented for devices with different characteristics through three-dimensional numerical simulations. The inclusion of the second order effects in a drain current model is also shown, considering the extracted values. The method applicability is also successfully demonstrated in experimental devices.
A Time-of-Flight detector in CDF-II Acosta, D.; Ahn, M.; Anikeev, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2004, Letnik:
518, Številka:
1
Journal Article
Recenzirano
A Time-of-Flight (TOF) detector, based on plastic scintillators and fine-mesh photomultipliers, has been added to the Collider Detector at Fermilab (CDF)-II experiment at the Tevatron
p
p
̄
collider. ...The primary physics motivation is to provide charged kaon identification to improve neutral B meson flavor determination. Besides that, the TOF detector found application in the CDF trigger system in implementation of highly ionizing particle, high multiplicity and cosmic rays triggers.
The Abrolhos Bank is the largest reef complex in the South Atlantic, harboring unique pinnacle formations (“chapeirões”) and the world's most extensive rhodolith bed. Building organisms (e.g., ...bryozoans, crustose coralline algae, and corals) interplay with bioeroding groups (e.g., sponges, fishes, echinoderms, and polychaetes) in the carbonate production and erosion processes controlling the reef structure. Many physical, chemical, and biological erosion processes break down these calcareous organisms in several sediment grain sizes. The present study aims to characterize the superficial sediments of three Abrolhos Bank carbonate reefs with increasing depth (6–33 m) and distance from the coast (14–75 km). Surface sediments (∼5 cm surface layer) were analyzed to determine their biological source, mineralogical compositions, and grain size distribution. In the site closer to the coast (Pedra de Leste), values of organic matter and finer terrigenous sediments were higher, while offshore sites (Parcel dos Abrolhos and California Reef) were composed mainly of carbonate bioclastics. The analyzed fragments were composed of 11 large groups, comprising eight invertebrates: Annelida, Ascidiacea, Bryozoa, Cnidaria, Crustacea, Echinodermata, Mollusca, and Porifera, plus Foraminifera, Osteichthyes, and one macroalgae(Rhodophyta). Within these large groups, a total of 61 taxa were identified, including five new records for the Abrolhos Bank (two Bryozoa and three Mollusca). In shallower reefs (Pedra de Leste and Parcel dos Abrolhos), the main bioclastic component was crustose coralline algae, CCA (45 and 49%, respectively), while in the mesophotic reef (California Reef) it was Bryozoa (42%). The sponge chips' contribution to the sediment composition varied from 0.3% to 3% in Pedra de Leste and Parcel dos Abrolhos, respectively. However, it could be underestimated due to the formation of peloids or fine sediment aggregates, which mask the visualization of some fine-grained particles. The main results from sediment analyses highlight the importance of calcifying organisms (CCA and Bryozoa) and bioeroding ones (sponges) to sediment formation on different cross-shelf reefs on the Abrolhos Bank.
•Sediment composition varies between shallow and mesophotic reefs in Abrolhos.•Bryozoa is the major sediment component in a mesophotic reef in the Abrolhos Bank.•CCA is the major sediment component in shallower and closer-to-coast reefs.•Five taxa (three Mollusca and two Bryozoa) were first recorded in Abrolhos.•Boring sponge's microchips corresponded up to 3% of the finer sediment.
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•Elevated CO2 led to higher transpiration rates under full irrigation, and lower transpiration under drought.•Varying transpiration patterns were unrelated to maximum stomatal ...conductance or foliar ABA levels.•Transpiration rates in irrigated plants were linked to varying stomatal closure rate.•Aquaporins may have played key roles in altering stomatal function and hydraulic conductance.•Elevated CO2 improved plant water status and growth under drought.
Rising air CO2 concentration (CO2) is believed to mitigate the negative impacts of global climate changes such as increased air temperatures and drought events on plant growth and survival. Nonetheless, how elevated CO2 affects the way coffee (Coffea arabica L.) plants sense and respond to drought remains a critical unknown. In this study, potted coffee plants were cultivated under two air CO2 (ca. 400 ppm or 700 ppm) in open top chambers under greenhouse conditions. After a 5-month exposure to CO2 treatments, plants were submitted to a progressive, controlled soil water deficit down to 20 % soil field capacity. Under well-watered (100 % field capacity) conditions, 700-plants displayed lower whole-plant transpiration rates (T) than their 400-counterparts. Changes in T were unrelated to stomatal conductances at the leaf scale (as well as stomatal morphology) or foliar ABA levels, but they were rather associated with faster stomata closure rates upon rapid increases in vapor pressure deficit in the 700-plants. During drought, 700-plants were able to maintain higher water potentials and plant hydraulic conductances for longer in parallel to higher T than their 400-counterparts. Under elevated CO2, the faster stomatal closure rates (irrigated conditions) or the maintenance of plant hydraulic conductances (drought conditions) were associated with higher (3 to 40-fold) transcript abundance of most aquaporin genes. Altogether, our results suggest that elevated CO2 has marked implications on how coffee plants respond to soil water deficit, ultimately permitting 700-plants to have improved fitness under drought when compared to 400-plants.
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