Aurivillius oxides ferroelectric layered materials are formed by bismuth oxide and pseu-do-perovskite layers. They have a good ionic conductivity, which is beneficial for various photo-catalyzed ...reactions. Here, we synthesized ultra-thin nanosheets of two different Aurivillius oxides, Bi
WO
(BWO) and Bi
MoO
(BMO), by using a hard-template process. All materials were characterized through XRD, TEM, FTIR, TGA/DSC, DLS/ELS, DRS, UV-Vis. Band gap material (E
) and potential of the valence band (E
) were calculated for BWO and BMO. In contrast to previous reports on the use of multi composite materials, a new procedure for photocatalytic efficient BMO nanosheets was developed. The procedure, with an additional step only, avoids the use of composite materials, improves crystal structure, and strongly reduces impurities. BWO and BMO were used as photocatalysts for the degradation of the water pollutant dye malachite green (MG). MG removal kinetics was fitted with Langmuir-Hinshelwood model obtaining a kinetic constant k = 7.81 × 10
min
for BWO and k = 9.27 × 10
min
for BMO. Photocatalytic dye degradation was highly effective, reaching 89% and 91% MG removal for BWO and BMO, respectively. A control experiment, carried out in the absence of light, allowed to quantify the contribution of adsorption to MG removal process. Adsorption contributed to MG removal by a 51% for BWO and only by a 19% for BMO, suggesting a different degradation mechanism for the two photocatalysts. The advanced MG degradation process due to BMO is likely caused by the high crystallinity of the material synthetized with the new procedure. Reuse tests demonstrated that both photocatalysts are highly active and stable reaching a MG removal up to 95% at the 10th reaction cycle. These results demonstrate that BMO nanosheets, synthesized with an easy additional step, achieved the best degradation performance, and can be successfully used for environmental remediation applications.
Active Pixel Sensors used in High Energy Particle Physics require low power consumption to reduce the detector material budget, low integration time to reduce the possibilities of pile-up and fast ...readout to improve the detector data capability. To satisfy these requirements, a novel Address-Encoder and Reset-Decoder (AERD) asynchronous circuit for a fast readout of a pixel matrix has been developed. The AERD data-driven readout architecture operates the address encoding and reset decoding based on an arbitration tree, and allows us to readout only the hit pixels. Compared to the traditional readout structure of the rolling shutter scheme in Monolithic Active Pixel Sensors (MAPS), AERD can achieve a low readout time and a low power consumption especially for low hit occupancies. The readout is controlled at the chip periphery with a signal synchronous with the clock, allows a good digital and analogue signal separation in the matrix and a reduction of the power consumption. The AERD circuit has been implemented in the TowerJazz 180nm CMOS Imaging Sensor (CIS) process with full complementary CMOS logic in the pixel. It works at 10MHz with a matrix height of 15mm. The energy consumed to read out one pixel is around 72pJ. A scheme to boost the readout speed to 40MHz is also discussed. The sensor chip equipped with AERD has been produced and characterised. Test results including electrical beam measurement are presented.
The features of the 180nm TowerJazz 1 CMOS technology allow for the first time the use of CMOS Monolithic Active Pixel Sensors (MAPS) under the harsh operational conditions of the LHC experiments. ...The stringent requirements of the ALICE Inner Tracking System (ITS) in terms of material budget, radiation hardness, readout speed and a low power consumption have thus lead to the choice of MAPS as baseline technology option for the recently approved upgrade of the ITS and are the key drivers for R&D efforts on basic transistor and Explorer and MIMOSA pixel sensor prototypes produced in TowerJazz technology. Though the radiation loads expected for the ITS are below those of ATLAS and CMS, it is however necessary to assess the radiation hardness for ITS MAPS prototypes. Total Ionizing Dose (TID) radiation hardness has been established for basic transistor structures using a 60keV X-ray machine. The main operational characteristics and detection properties such as noise, charge collection efficiency and signal over noise ratio of Explorer-0 and MIMOSA32 and MIMOSA34 pixel sensor prototypes have been studied using X-rays ( 55 Fe) and test beams at CERN and DESY before and after Non Ionizing Energy Loss (NIEL) and TID irradiation. In this paper the results of these R&D activities will be presented and discussed.
We have investigated the role of TGIF, a TALE-class homeodomain transcription factor, in Drosophila development. In vertebrates, TGIF has been implicated, by in vitro analysis, in several pathways, ...most notably as a repressor modulating the response to TGFbeta signalling. Human TGIF has been associated with the developmental disorder holoprosencephaly. Drosophila TGIF is represented by the products of two tandemly repeated highly similar genes, achintya and vismay. We have generated mutations that delete both genes. Homozygous mutant flies are viable and appear morphologically normal, but the males are completely sterile. The defect lies at the primary spermatocyte stage and differentiation is blocked prior to the onset of the meiotic divisions. We show that mutants lacking TGIF function fail to activate transcription of many genes required for sperm manufacture and of some genes required for entry into the meiotic divisions. This groups TGIF together with two other genes producing similar phenotypes, always early and cookie monster, as components of the machinery required for the activation of the spermatogenic programme of transcription. TGIF is the first sequence-specific transcription factor identified in this pathway. By immunolabelling in mouse testes we show that TGIF is expressed in the early stages of spermatogenesis consistent with a conserved role in the activation of the spermatogenesis transcription programme.
The authors describe their series of seven cases of complications and failures of shoulder hemiarthroplasty that were submitted to revision surgery involving an inverse prosthesis. This prosthesis ...has for some time now been indicated in elderly patients with arthropathy caused by rupture of the cuff. In our cases this prosthesis was implanted in patients who had undergone shoulder hemiarthroplasty for fracture and for arthrosis. The Constant score was used for pre- and postoperative evaluation. Results at mid-term, from 2 to 4 years, indicate evident improvement in Constant score that rose from a mean of 23.14 preoperatively to a mean of 49.14 postoperatively. Despite the limited follow-up the authors suggest the use of the inverse prosthesis as an effective alternative solution in shoulder arthroplasty revision surgery.
The notion of affect has generated much confusion in anthropology given its focus on that which seems to escape our language. The evanescent features of affects have irritated many anthropologists ...who consider affect theory as an empirically weak or esoteric hermeneutics. In this article, I respond to these critiques by developing an anthropology of therapy that foregrounds the role of affects. My intent is to explore the possible contribution of affect theory to medical and psychological anthropology. I draw from my ethnography on couple’s therapy in Argentina to suggest that we cannot understand therapeutic efficacy if we focus only on language and discourse. I ask what it means to regard affects as late modern spirits and take psychotherapy as a modern ritual of “affect dispossession.” I propose to ask how affects, like spirits, can haunt our present rendering our lives barely livable. Focusing on a session of therapy in Buenos Aires, I describe how a therapist channels the spirit of impasse that colonizes the lives of her patients. Developing an
enchanted hermeneutics
, I engage with Eve Sedgwick’s call for an other-than-paranoid social theory by engaging the imagination as an important organ of perception in the medical anthropology of affects.
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