Resumen En este trabajo se estudiaron las microfibras de un textil (camiseta) de la cultura Chimú. Esta cultura se desarrolló en la costa norte del Perú. Para determinar la materia prima y calidad estructural de las microfibras, los resultados del textil Chimú fueron comparados con los correspondientes para las microfibras del algodón de la costa norte del Perú (algodón nativo). Las imágenes de microscopia electrónica de barrido revelaron que los hilos del textil Chimú están compuestos por un conjunto de microfibras entrelazadas. Las técnicas de espectroscopia de rayos X por energía dispersiva y de plasmas inducidos por laser permitieron identificar átomos característicos de la celulosa en las microfibras del textil Chimú y del algodón nativo. Únicamente para el textil Chimú, estas técnicas espectroscópicas permitieron identificar átomos que corresponderían a tintes naturales y a residuos de polvo. La espectroscopia de infrarrojo con transformada de Fourier por reflexión total permitió identificar los mismos enlaces moleculares para las microfibras del textil Chimú y del algodón nativo. Para las microfibras del textil Chimú y del algodón nativo, los difractogramas de rayos X mostraron picos característicos del polimorfismo de la celulosa Iß de estructura monoclínica P21. La materia prima del textil Chimú es el algodón y las microfibras del mismo presentan una significativa estabilidad estructural.

Abstract In this work, we studied the microfibers of a textile (T-shirt) of the Chimú culture. This culture developed on the northern coast of Peru. To determine the raw material and structural quality of the microfibers, the results of the Chimú textile were compared with the corresponding results for the microfibers of cotton from the northern coast of Peru (native cotton). Scanning electron microscopy images revealed that the Chimú textile yarns are composed of a set of interwoven microfibers. Energy-dispersive X-ray spectroscopy and pulsed laser-induced plasma spectroscopy techniques allowed the identification of characteristic cellulose atoms in the microfibers of Chimú textile and native cotton. Only for the Chimú textile, these spectroscopic techniques allowed the identification of atoms corresponding to natural dyes and powder residues. Attenuated total reflection Fourier transform infrared spectroscopy identified the same molecular bonds for the microfibers of Chimú textile and native cotton. For the microfibers of Chimú textile and native cotton, the X-ray diffractograms showed peaks characteristic of the cellulose Ig polymorphism of monoclinic P21 structure. The raw material of the Chimú textile is cotton and the microfibers of this material show significant structural stability.

Abstract This paper presents a method to cancel the constant phase loading and transmission line that are added to the S-parameters of coupled resonant networks. Thus, the phase-corrected S-parameters may be used to obtain a rational model together with its representative coupling matrix. This method is applicable to lossy and lossless coupled resonator networks with two ports, such as microwave filters. In addition, it has the advantage of not requiring S-parameters with wide frequency ranges, and offers less computational effort than other approaches. Examples including simulations of microwaves passband filters are provided in order to demonstrate the effectiveness of this new technique.

Resumo A reciclagem tem sido apontada como alternativa ao descarte de resíduos em aterros industriais. No presente trabalho é mostrada a transformação de resíduos (areia descartada de fundição - ADF, grits e lama de cal) em materiais vitrocerâmicos. Os vidros foram obtidos pelo método de fusão/resfriamento. Os materiais precursores, compostos vítreos e vitrocerâmicos foram caracterizados pelas técnicas de difração de raios X (DRX), fluorescência de raios X (FRX) e calorimetria exploratória diferencial/análise termogravimétrica (CED/ATG). Os materiais vítreos foram moídos, pastilhados e tratados termicamente nas temperaturas de cristalização obtidas por CED para preparar os materiais vitrocerâmicos (885, 961 e 1090 ºC). As fases obtidas foram cristobalita, α-wolastonita (parawolastonita) e β-wolastonita (pseudowolastonita). As vitrocerâmicas apresentaram baixa absorção de água e porosidade aparente (0,26 até 0,88 wt% e 0,66 até 1,77 vol%, respectivamente). Os resultados confirmaram que os resíduos estudados podem ser utilizados como matéria-prima na fabricação de materiais vítreos e vitrocerâmicos.

Abstract Recycling has been pointed out as an alternative to the disposal of waste materials in industrial landfills. In the present study, the transformation of residues (discarded foundry sand - DFS, grits, and lime mud) in glass-ceramic materials is shown. The glasses were obtained by the melting/cooling method. The precursor materials, glasses, and glass-ceramics were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), and differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA). The glassy materials were milled, pelleted, and thermally treated at the crystallization temperatures given by DSC data to obtain the glass-ceramics (885, 961, and 1090 ºC). The main formed phases were cristobalite, α-wollastonite (parawollastonite), and β-wollastonite (pseudowollastonite). The glass-ceramics showed very low water absorption and apparent porosity (0.26 to 0.88 wt% and 0.66 to 1.77 vol%, respectively). The results confirmed that the studied residues can be used as raw materials for the manufacture of vitreous and glass-ceramic materials.

Resumo Um biocompósito cerâmico/polimérico com alto potencial para aplicações práticas multifuncionais em engenharia de tecidos ósseos foi sintetizado usando o conhecido polímero piezoelétrico, fluoreto de polivinilideno (PVDF), e a cerâmica altamente bioativa, fosfato de cálcio bifásica (BCP), obtida a partir de ossos de peixes reciclados. Uma alta bioatividade foi observada no compósito PVDF-BCP quando este foi submetido a condições que simulam um corpo animal. De fato, uma camada de apatita muito espessa (9 μm) cresceu em sua superfície no experimento de imersão (7 dias) em fluido corpóreo simulado (SBF). As características estruturais do compósito PVDF-BCP mostraram semelhanças com ossos de animais jovens, altamente bioativos, sobrepostos com fases polimórficas de PVDF. Ensaios mecânicos revelaram propriedades muito semelhantes às do tecido ósseo humano, com uma resistência à compressão atingindo 80 MPa. Juntos, todos esses fatores indicaram um material muito promissor para aplicação em implantes e/ou substituições ósseas com recuperação pós-operatória controlada/acelerada por estímulos externos.

Abstract A ceramic/polymer biocomposite with high potential for multifunctional practical applications in bone tissue engineering was synthesized by using a well-known piezoelectric polymer, polyvinylidene fluoride (PVDF), and a high bioactive biphasic calcium phosphate (BCP) ceramic obtained from recycled fish bones. High-bioactivity was observed for the PVDF-BCP composite when it was subjected to conditions that simulate the animal body once a very thick apatite layer (9 μm) was grown on its surface in an immersion experiment (7 days) in simulated body fluid. The structural characteristics of the PVDF-BCP composite showed similarities with highly bioactive young animal bones, overlapped with PVDF polymorphic phases. Mechanical tests revealed properties very similar to those of the human bone tissue with a resistance strength reaching 80 MPa. Together, all these factors indicated a very promising material for application in osseous implants/replacement with postoperative recovery controlled/accelerated by external stimuli.

BACKGROUND: On 11 November 1994, 26 preadolescent girls, 2 adult supervisors and 7 dogs were sleeping in a tent in rural South Africa when the tent was struck by lightning. Four of the girls and 4 of the dogs were killed. The 2 adults were unharmed, but all but 3 of the children suffered significant injuries. An article in 2002 detailed the event and examined the medical and psychological changes in the surviving girls. OBJECTIVE: To understand the medical and psychological changes secondary to lightning strike years after injury. METHODS: An online questionnaire was prepared that included a checklist of physical and psychological symptoms. Participants were asked to report on both initial and current symptoms. Eleven of the 22 survivors were contacted, and 10 completed the survey. RESULTS: Participants reported that initial physical symptoms generally resolved over time, with ~10 - 20% continuing to experience physical symptoms. Vision problems persisted in 50% of respondents. Psychological symptoms, overall, had a later onset and were more likely to be chronic or currently experienced. Depression and anxiety, specifically, were higher among the survivors than the reported incidence in South Africa. CONCLUSIONS: Initial and current/chronic physical and psychological symptoms following lightning strike are reported, adding to the body of literature on the long-term after-effects of lightning strike on survivors. A brief discussion on post-traumatic stress disorder symptomatology and post-lightning shock syndrome is provided.

Resumo: Com a finalidade de avaliar a incidência de manifestações patológicas em fachadas de edifícios, correlacionando com as direções geográficas, neste trabalho foram analisados 52 edifícios de uso residencial e comercial distribuídos em diversas regiões da cidade de Curitiba - Brasil. Foi observado que todos os edifícios vistoriados apresentaram algum tipo de manifestação patológica, sendo que 25 apresentaram problemas nas fachadas. Verificou-se que as manifestações patológicas nas fachadas aparecem em quantidades diferentes nas diferentes direções, tendo sido identificada uma relação com a variação de temperatura e com a direção dos ventos, conforme a direção geográfica.

Abstract: In order to evaluate the incidence of pathological manifestations on the facades of buildings, correlated with the geographical location, 52 buildings for residential and commercial use were analyzed in this study; these were distributed in different parts of the city of Curitiba, Brazil. It was observed that all the buildings evaluated had some type of pathological manifestation, and 25 of these were present on the facades of the buildings. It was found that the pathological manifestations on the facades show up in different amounts and locations, having identified a relation with the variation of temperature and the direction of the wind in terms of geographical orientation.

Resumen: Con el propósito de evaluar la incidencia de manifestaciones patológicas en fachadas de edificios, correlacionadas con la dirección geográfica, se analizaron en este estudio 52 edificios de uso residencial y comercial distribuidos en varias partes de la ciudad de Curitiba - Brasil. Se observó que todos los edificios evaluados tuvieron algún tipo de manifestación patológica, y 25 de éstas en las fachadas. Se encontró que las manifestaciones patológicas en fachadas aparecen en diferentes cantidades y direcciones, habiéndose identificado una relación con la variación de la temperatura y la dirección del viento en función de la orientación geográfica.

This paper aimed to determine the excretion period of B19 vaccine strain during a complete reproductive cycle (from estrus synchronization, artificial insemination, pregnancy and until 30 days after parturition) of dairy cows from 3 to 9 years old that were previously vaccinated from 3 to 8 months. Three groups were monitored with monthly milk and urine collection during 12 months: G1 with seven cows from 3 to 4 years old; G2 with three cows from 5 to 6 years old; and G3 with four cows from 7 to 9 years old. Urine and milk samples were submitted to bacteriological culture and urine and PCR reactions for detection of Brucella spp. and PCR-multiplex for B19 strain identification. Ring test (RT) was also performed in the milk samples, and serum samples were tested by buffered acidified plate antigen test (BAPA). All animals were serologically negative at BAPA and Brucella spp. was not isolated from both urine and milk samples. RT revealed 13/210 (6.2%) positive milk samples. PCR reactions detected DNA of Brucella spp. in 86/420 (20.5%) samples. In urine it was found a significantly higher frequency (35.2%; 74/210) than in milk (5.7%; 12/210), more frequently from the estrus to 150 days of pregnancy and after parturition (6.7%; 10/150), and from 150 days of pregnancy to parturition (3.4%; 2/60), and they were all identified as B19 strain. In three groups, intermittent excretion of B19 strain was detected mainly in urine samples, which confirmed its multiplication and persistence in cows for until 9 years.