266 research outputs found
Edificio para CristalerÃa Española
In the course of a series of lectures on the subject of curtain walls, held at the Higher Technical College of Architecture, in Madrid, the author described his own experience whilst constructing a building (designed by him and by Mr. Manuel Barbero) for the firm CristalerÃa Española, at San Andrés del Palomar, Barcelona.
Mr. De la Joya summarised the advantages that foreign experts attribute to curtain walls. These advantages are: less weight of the materials of the enclosing walls; maximum use of the available building surface; cheaper foundations; better building time control; superior quality and accuracy; and greater maintenance facility.
The lecturer then explained why, and in what aspects, he was in disagreement with the above supposed advantages. He dealt with these as follows: 1. In terms of present day construction, with concrete blocks and lightweight flooring structures, it is not easy to save much weight, owing to the number of special fittings that are necessary to support and keep the curtain wall in place.—2. Although in theory a. curtain wall may be only 4 or 5 cm thick, the truth is that unless heating or air conditioning is provided on a much larger scale, a special internal protection layer is necessary.—3. It is difficult to reduce the cost of the foundations by fitting curtain walls, and any calculated saving in cost in this aspect is more theoretical than real.—4. Building time estimates usually fail to work out in practice, and in addition to this, workmanship quality is not yet very satisfactory.—5. Curtain walls require periodic overhauls, so that they do not age too rapidly, and in this sense they are no better than traditional walls.
The lecturer also made a number of additional points, one of them being that he did not advise the use of curtain walls in Spain (because of the cheapness of brickwalls, the climate, the high cost of air conditioning, etc. He also emphasized how important it is to make a very full and careful study of cost when preparing a project involving curtain walls, in order to evaluate correctly their advantages.<br><br>Dio a conocer—dentro del ciclo de conferencias sobre muros-cortina, celebrado en la Escuela Técnica Superior de Arquitectura, de Madrid—sus experiencias personales en la construcción de un edificio, proyectado por él y por Manuel Barbero, para CristalerÃa Española, en San Andrés del Palomar, de Barcelona.
Enumeró las ventajas que exponen los técnicos de otros paÃses sobre el muro-cortina: menor peso de los materiales que componen la fachada; máximo aprovechamiento de la superficie habitable; abaratamiento de la cimentación; mejor control del tiempo; calidad y precisión; y facilidad de conservación.
A continuación, y en el mismo orden, explicó por qué y en qué puntos no estaba de acuerdo con dichas ventajas:
1.° Partiendo de la construcción actual, con elementos de hormigón y forjados de tipo aligerado, no es fácil obtener una gran economÃa debido a la serie de elementos que hay que emplear para colocar y mantener en su sitio el muro-cortina.
2.° Que aunque teóricamente el muro-cortina puede tener 4 ó 5 m de espesor, la realidad es que si no es a costa de un enorme aumento de la calefacción, o del acondicionamiento, precisan, además, un revestimiento interior.
3.° Es muy difÃcil que los cimientos puedan abaratarse por el empleo de este tipo de fachada, ya que dicho abaratamiento es más teórico que real.
4.° Que aparte de que el factor tiempo suele fallar, la calidad en la ejecución no está todavÃa muy lograda.
5.° Se necesita un entretenimiento periódico para que la vejez no se acentúe, al igual que en las fachadas de tipo tradicional.
Se extendió en una serie de consideraciones, además de las puramente técnicas, que no aconsejan el empleo del muro-cortina en España (economÃa en la mano de obra de albañilerÃa, factor clima, carestÃa de las instalaciones de acondicionamiento, etc.). A continuación, haciendo un estudio de precios del nuevo sistema, resaltó la importancia que para la perfección y economÃa del mismo tiene un adecuado y completo estudio del proyecto
Hypercalcitoninemia is not Pathognomonic of Medullary Thyroid Carcinoma
Hypercalcitoninemia has frequently been reported as a marker for medullary thyroid carcinoma. Currently, calcitonin measurements are mostly useful in the evaluation of tumor size and progression, and as an index of biochemical improvement of medullary thyroid carcinomas. Although measurement of calcitonin is a highly sensitive method for the detection of medullary thyroid carcinoma, it presents a low specificity for this tumor. Several physiologic and pathologic conditions other than medullary thyroid carcinoma have been associated with increased levels of calcitonin. Several cases of thyroid nodules associated with increased values of calcitonin are not medullary thyroid carcinomas, but rather are related to other conditions, such as hypercalcemias, hypergastrinemias, neuroendocrine tumors, renal insufficiency, papillary and follicular thyroid carcinomas, and goiter. Furthermore, prolonged treatment with omeprazole (> 2–4 months), beta-blockers, glucocorticoids and potential secretagogues, have been associated with hypercalcitoninemia. An association between calcitonin levels and chronic auto-immune thyroiditis remains controversial. Patients with calcitonin levels >100 pg/mL have a high risk for medullary thyroid carcinoma (~90%–100%), whereas patients with values from 10 to 100 pg/mL (normal values: <8.5 pg/mL for men, < 5.0 pg/mL for women; immunochemiluminometric assay) have a <25% risk for medullary thyroid carcinoma
Sporadic Medullary Thyroid Carcinoma: Clinical Data From A University Hospital
INTRODUCTION: Medullary thyroid carcinoma may occur in a sporadic (s-medullary thyroid carcinoma, 75%) or in a multiple endocrine neoplasia type 2 form (MEN2, 25%). These clinical forms differ in many ways, as s-medullary thyroid carcinoma cases are RET-negative in the germline and are typically diagnosed later than medullary thyroid carcinoma in MEN2 patients. In this study, a set of cases with s-medullary thyroid carcinoma are documented and explored. PURPOSE: To document the phenotypes observed in s-medullary thyroid carcinoma cases from a university group and to attempt to improve earlier diagnosis of s-medullary thyroid carcinoma. Some procedures for diagnostics are also recommended. METHOD: Patients (n=26) with apparent s-medullary thyroid carcinoma were studied. Their clinical data were reviewed and peripheral blood was collected and screened for RET germline mutations. RESULTS: The average age at diagnosis was 43.9 years (± 10.82 SD) and did not differ between males and females. Calcitonin levels were increased in all cases. Three patients presented values that were 100-fold greater than the normal upper limit. Most (61.54%) had values that were 20-fold below this limit. Carcinoembryonic antigen levels were high in 70.6% of cases. There was no significant association between age at diagnosis, basal calcitonin levels or time of disease onset with thyroid tumor size (0.6-15 cm). Routine thyroid cytology yielded disappointing diagnostic accuracy (46.7%) in this set of cases. After total thyroidectomy associated with extensive cervical lymph node resection, calcitonin values remained lower than 5 pg/mL for at least 12 months in eight of the cases (30.8%). Immunocyto- and histochemistry for calcitonin were positive in all analyzed cases. None of the 26 cases presented germline mutations in the classical hotspots of the RET proto-oncogene. CONCLUSION: Our cases were identified late. The basal calcitonin measurements and immunostaining for calcitonin were highly useful for diagnosing s-medullary thyroid carcinoma. The rate of complete patient recovery was low, and none of the parameters analyzed were useful predictors of the thyroid tumor size. Our findings support previous recommendations for routine serum calcitonin evaluation and immunostaining analysis involving single thyroid nodules
School-Based Intervention Impacts Availability of Vegetables and Beverages in Participants’ Homes
As rates of metabolic syndrome rise, children consume too few vegetables and too much added sugar. Because children tend to eat what is available at home, the home environment plays a key role in shaping dietary habits. This secondary analysis evaluated the effects of a school-based gardening, cooking, and nutrition education intervention (TX Sprouts) compared to control on the availability of vegetables, fruit juice, and sugar-sweetened beverages (SSBs) at home. In the TX Sprouts cluster-randomized trial, 16 schools were randomized to TX Sprouts
Enhancing Co3O4 nanoparticles: Investigating the impact of nickel doping and high-temperature annealing on NiCo2O4/CoO heterostructures.
Abstract: In this study, we investigated the phase transition of cobalt spinel (Co3O4) nanoparticles into Co3−xNixO4/CoO heterostructures by introducing varying amounts of nickel (x = 0.0–0.16) and subjecting the particles to high annealing temperatures of 1000 ℃. X-ray diffraction (XRD) analysis confirmed the Co3−xNixO4CoO structure for all samples. Transmission electron microscopy (TEM) provided further insights into the phase or heterostructure of the samples after annealing, revealing the arrangement of the two phases. Fourier-transform infrared spectroscopy measurements demonstrated a band shift around 537 cm−1 with increasing Ni content, while ultraviolet-visible (UV-Vis) measurements indicated the energy band (Eg). Significant morphological changes were observed in scanning electron microscope (SEM) measurements at 0.16 Ni, displaying irregular agglomerates. Our findings suggest that introducing Ni into the Co3O4 structure and increasing the annealing temperature to 1000 ℃ can lead to the formation of a heterostructured system. Furthermore, our study’s significance is highlighted by the streamlined synthesis of NiCo2O4/CoO using the sol-gel method followed by calcination. This departure from complex techniques provides an efficient route to acquiring the NiCo2O4/CoO system, a promissory material for advancing supercapacitor research
Recommended from our members
Glass ceilings and stone floors: an intersectional approach to challenges UK geographers face across the career lifecycle
While there has been a steady growth of women working in geography in UK universities since the mid-Twentieth Century, there are continuing challenges in gendered career progression and professional interactions within the contemporary discipline. These range from problems associated with employment precarity and inflexible work practices, life choices and obligations in the domestic arena, discrimination and bullying, to less tangible gendered norms and cultures in the workplace. This paper discusses these challenges and inequalities in the light of a brief overview of sector-wide statistical data on appointments by gender and career-stage and with the analysis of some 250 in-depth responses to a nationwide qualitative survey of gender and career experience in UK universities (Maddrell et al 2016). While the term ‘glass ceiling’ still has significant relevance, findings show a more complicated picture which also includes ‘stone floors’ and stumbling blocks. It also shows how career experience varies by institution and individual: challenges in career progression can be compounded by institutional protocols and intersectional factors, and vary with career stage. The intersection of early-career job precarity, reproductive decisions and associated family responsibilities were particularly highlighted in this study. These ‘pinch points’ in career development disproportionately affect, but are not limited to, female early career scholars. Early career progress may be stalled in mid-career in multi-staged promotional systems such as that in UK universities; some from minorities face compound barriers; men with caring responsibilities may face prejudice. The paper concludes with suggested strategies for change, highlighting the importance of individual university and department protocols and practices; line manager and other senior colleagues’ attitudes and leadership in creating workplaces with an equality-driven ethos and structures that allow individuals to flourish
Preparation and application of Nb2O5 nanofibers in CO2 photoconversion.
Increasing global warming due to NOx, CO2, and CH4, is significantly harming ecosystems and life worldwide. One promising methodology is converting pollutants into valuable chemicals via photocatalytic processes (by reusable photocatalysts). In this context, the present work aimed to produce a Nb2O5 photocatalyst nanofiber system by electrospinning to convert CO2. Based on the collected data, the calcination at 600 ◦C for 2 h resulted in the best condition to obtain nanofibers with homogeneous surfaces and an average diameter of 84 nm. As a result, the Nb2O5 nanofibers converted CO2 mostly into CO and CH4, reaching values around 8.5 µmol g−1 and 0.55 µmol g−1, respectively
Morphological characteristics of motor neurons do not determine their relative susceptibility to degeneration in a mouse model of severe spinal muscular atrophy
Spinal muscular atrophy (SMA) is a leading genetic cause of infant mortality, resulting primarily from the degeneration and loss of lower motor neurons. Studies using mouse models of SMA have revealed widespread heterogeneity in the susceptibility of individual motor neurons to neurodegeneration, but the underlying reasons remain unclear. Data from related motor neuron diseases, such as amyotrophic lateral sclerosis (ALS), suggest that morphological properties of motor neurons may regulate susceptibility: in ALS larger motor units innervating fast-twitch muscles degenerate first. We therefore set out to determine whether intrinsic morphological characteristics of motor neurons influenced their relative vulnerability to SMA. Motor neuron vulnerability was mapped across 10 muscle groups in SMA mice. Neither the position of the muscle in the body, nor the fibre type of the muscle innervated, influenced susceptibility. Morphological properties of vulnerable and disease-resistant motor neurons were then determined from single motor units reconstructed in Thy.1-YFP-H mice. None of the parameters we investigated in healthy young adult mice - including motor unit size, motor unit arbor length, branching patterns, motor endplate size, developmental pruning and numbers of terminal Schwann cells at neuromuscular junctions - correlated with vulnerability. We conclude that morphological characteristics of motor neurons are not a major determinant of disease-susceptibility in SMA, in stark contrast to related forms of motor neuron disease such as ALS. This suggests that subtle molecular differences between motor neurons, or extrinsic factors arising from other cell types, are more likely to determine relative susceptibility in SMA
Regulamento da Millenium - Journal of Education, Technologies, and Health
PbMoO(4) micro-octahedrons were prepared by the coprecipitation method at room temperature without the presence of surfactants and processed in a conventional hydrothermal at different temperatures (from 60 to 120 degrees C) for 10 min. These micro-octahedrons were structurally characterized by X-ray diffraction (XRD) and micro-Raman (MR) spectroscopy, and its morphology was investigated by field-emission gun scanning electron microscopy (FEG-SEM). The optical properties were analyzed by ultraviolet-visible (UV-vis) absorption spectroscopy and photoluminescence (PL) measurements. XRD patterns and MR spectra confirmed that the PbMoO(4) micro-octahedrons are characterized by a scheelite-type tetragonal structure. FEG-SEM micrographs points, out that these structures present a polydisperse particle size distribution in consequence of a predominant growth mechanism via aggregation of particles. In addition, it was observed that the hydrothermal conditions favored a spontaneous formation of micro-octahedrons interconnected along a common crystallographic orientation (oriented-attachment), resulting in self-organized structures. An intense blue PL emission at room temperature was observed in these micro-octahedrons when they were excited with a 350 nm wavelength. The origin of the PL emissions as well as its intensity variations are explained by means of a model based on both distorted [MoO(4)] and [PbO(8)] clusters into the lattice.CAPESCoordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)CNPqFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPES
- …