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The seroreaction of Ehrlichia chaffeensis through the indirect immunofluorescence test (IFI) was determined in owners of dogs with a history of ehrlichiosis. In addition, the association with gender, age, exposure to ticks and level of contact with dogs was evaluated. The study was conducted between January and December 2009, where 95 people from Lima Metropolitan Region (Peru) were evaluated, regardless of gender, age or socioeconomic status, and whose dogs had a history of ehrlichiosis of less than one year. The results showed that 31.6% (30/95) of dog owners presented antibodies against E. chaffeensis. Besides, 38.7% (24/62) of the individuals younger than 40 years and 18.2% (6/33) of individuals older than 40 years were seropositive to E. chaffeensis (p<0.05), 29.4% of males and 32.7% of females were seropositive to E. chaffeensis (p<0.05), and 40.0 and 8.0% of those exposed an...

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Se determinó la seropositividad contra Ehrlichia chaffeensis en propietarios de perros con antecedentes de ehrlichiosis mediante la prueba de inmunofluorescencia indirecta (IFI) y su asociación con el género, edad, exposición a garrapatas y nivel de contacto con los perros. El estudio se realizó entre enero de 2009 y diciembre de 2009, donde se evaluaron 95 personas de Lima Metropolitana (Perú), sin distinción de género, edad o condición socioeconómica y cuyos perros tenían historia de ehrlichiosis menor de un año. El 31.6% (30/95) presentaron anticuerpos contra E. chaffeensis. El 38.7% (24/62) de los individuos menores a 40 años y el 18.2% (6/33) de los individuos mayores a 40 años resultó ser seropositivo a E. chaffeensis (p<0.05). El 29.4% de varones y el 32.7% de mujeres resultaron seropositivos a E. chaffeensis (p<0.05). Además, el 40.0 y 8.0% de las personas e...

Nanocrystalline solar cells were made by incorporation of cis-dithiocyanato-bis(2,2'-bipyridyl- 4,4'-dicarboxylate) ruthenium (I1) into sputter deposited titanium oxide films. After a pyridine treatment, it was possible 10 achieve a photoelectric conversion efficiency as high as 7% for a solar intensity of100W/m almost the same as for conventional nanocrystalline cells with colloidally prepared titanium oxide. Transmission electron microscopy indicated a parallel penniform microstructure, and secondary ion mass spectroscopy showed that the dye incorporation was uniform except in the bottom parts of the sputtered films where a decreased porosity seems to limit the penetration of the dye.

This work has been financially supported by the International Program for Physical Science of Uppsala University (IPPS), the Instituto de Investigacion of Universidad Nacional de Ingenieria, and CONCYTEC (Peruvian Research Council).

The objective of the present study is to select appropriate wall materials for houses in high Andean regions based on the measurements of the thermal behavior of construction materials using a "Test Cell" under real environmental conditions. It will be the first "Test Cell" to be installed in Peru, in Imata-Arequipa, at 4500 masl. The design and thermal analysis of the "Test Cell" are presented using dynamic simulations with the EnergyPlus program. Initially, the thermal performance of adobe, a traditional construction material in rural regions of Peru, is simulated using real meteorological data recorded in Imata between August 18 and 24, 2018, a period with low temperatures (-12.6 °C). © Published under licence by IOP Publishing Ltd.

This study includes the evaluation and validation of two experimental housing modules built in Imata, Arequipa, Peru, at 4500 meters above sea level (masl) and with a very cold climate. The modules are similar, differing only in that one of them has a greenhouse attached to the north wall. The design and materials used in the module envelopes are similar to what is mostly used locally. For the simulation work and the validation of the energetic behavior, both modules were equipped for the acquisition of the temperatures in the interior, and for the simulation, the EnergyPlus software was used. The exchange of air between the module with the greenhouse and its greenhouse was controlled by means of opening and closing the door and window that connected them, using different configurations. When the door and the window are open during daytime, the temperature inside the module can increase ...

Evaluation results of the thermal performance of an experimental housing module (EHM) are presented with considerations for the level of insulation and the installation of two active heaters powered by solar energy. The EHM is located in a high Andean rural area in southern Peru (latitude: 13° 45'40" S, longitude: 73° 51'26" W, and elevation: 3700 masl), where in situ measurements were made. The design and implementation of the EHM was based on the application of bioclimatic strategies and techniques. For the thermal evaluation of the EHM, 43 temperature sensors connected to dataloggers were used. The results show that the temperature inside the EHM increased more than 12 °C with respect to the outside temperature in the critical hours of extreme cold and frost when the isolation and the proposed radiative systems are used. Finally, the thermal behavior of the EHM was simulated using ...

A millenary building material that has been used in many cultures is "adobe". In the Peruvian Andean regions during the winter, the temperature decreases drastically (+5 to -15°C), affecting the health of people of vulnerable age, agriculture and bovine livestock. Bioclimatic techniques must be considered to provide a comfortable thermal environment in the interior of housing. Furthermore, knowing the thermal conductivity of the elements that compose the houses allows us to perform thermal exchange simulations before construction is developed. Specifically, in this investigation, the thermal conductivity of adobe with and without Stipa ichu was measured as 0.371 W/m K and 0.349 W/m K, respectively, considering the norm ASTM C177 for that purpose. The mechanical behavior is as important as the thermal properties, and a value of 2.41 N/mm2 was obtained for unit compression. Additionally, ...

Carbon-based perovskite solar cells were manufactured by the screen-printing method using a triple mesoscopic layer of TiO2, ZrO2 and carbon. The perovskite solution was infiltrated at the TiO2/ZrO2 porous interface through the printed carbon layer on top of the ZrO2. Using a simple preheating of the substrates and the perovskite solution, a film deposited in air can be obtained. Using this method, an air-processed CPSC made under a humid atmosphere with 55% RH achieved a PCE of 10.35%. © Published under licence by IOP Publishing Ltd.

Nanoestructured TiO2 solar cells modified with MgO (TiO2-MgO) were assembled and characterized; they were sensitized with N791 dye. The MgO modification of the TiO2 films was performed using suspensions with different concentrations of Mg(OH)2 prepared from magnesium nitrate in aqueous solution. One drop of the suspension was placed on top of the film and then was sintered at 530 °C during 30 min. Unsealed cells and sealed cells were obtained, the latter achieved an efficiency of 4.4%, representing an increase of 69% compared to the unmodified sealed cells, which showed an efficiency of 2.6%. Solar efficiency measurements were also performed in darkness and under illumination. It was found that the efficiency diminished 19% in darkness after 22 days, but under illumination diminished 76 % in two days. 

The aim of this study was to determine antibodies against the bovine viral diarrhea virus (BVDv) in serum samples of adult goats, females and males, of intensive, semi-extensive and transhumant production systems, from 89 farmers of four provinces of the department of Lima: Huaura (n=196), Huaral (n=233), Canta (n=153) and Lima (n=172). The detection of neutralizing antibodies against the BVDv in serum samples (n=754) was done by the viral neutralization test. The results showed that 1.2% (9/754) of the samples had antibodies against the virus. Seroreactive samples were from transhumant goats from the provinces of Canta and Huaura.

El objetivo del presente estudio fue determinar anticuerpos contra el virus de la diarrea viral bovina (VDVB) en muestras de suero de caprinos adultos, hembras y machos, de crianza estabulada, semi-extensiva y trashumante, pertenecientes a 89 criadores de cuatro provincias del departamento de Lima: Huaura (n=196), Huaral (n=233), Canta (n=153) y Lima (n=172). La detección de los anticuerpos neutralizantes contra el VDVB en muestras de suero (n=754) se hizo mediante la prueba de neutralización viral. El 1.2% (9/754) de las muestras presentaron anticuerpos contra el VDVB. Las muestras serorreactoras fueron de cabras de crianza trashumante de las provincias de Canta y Huaura.

Spherical cooper oxide (CuO) nanoparticles were synthetized by wet route using cooperacetate and sodium hydroxide. The CuO nanoparticles were characterized by dynamiclight scattering (DLS) and small angle X-ray scattering (SAXS). Furthermore to completestructural and morphological studies of the nanoparticles were performed X-ray diffractionand electron microscopy analysis. The results displayed that the CuO nanoparticles showedhigh dispersion; however, has a narrow size distribution for particles with size less than100 nm. Besides, the correlation between dispersion analysis, light and X-ray, and X-raydiffraction and electron microscopy was very good.

The project CIMO North-South-South‘‘PROENV2’’, theAdMAtU–project (AKVA Program) financed by the Academy ofFinland, and HYMEPRO financed by the Finnish FundingAgency for Innovation (Tekes) are acknowledged for the financial support. The National University of Tumbes (ProyectoCanon – Resoluci ?on N80722-2014/UNT-R) and the PeruvianNational Council for Science and Technology (CONCYTEC)(Proyecto. No. 002/PE/2012) are gratefully recognized for theirsupport. The authors also want to thank their home universities for their support.

The characterization of the thermal insulation properties of construction materials represents a fundamental step on building insulation assessment. The present work aims to design and build a portable apparatus, namely, Portable LAMBDA UNI, capable of measuring the thermal conductivity of insulation materials. This portable apparatus is based on the standard ASTM C 518, which is a secondary method for measuring thermal conductivity. The apparatus also measures the effective thermal conductivity of square prism thermal insulation materials of 60 mm per side and a maximum thickness of 14 mm. The thermal conductivity of the drywall and adobe with Stipa ichu was measured with the Portable LAMBDA UNI, with the values being 0.265 W m-1 K-1and 0.357 W m-1 K-1, respectively. © 2021 Published under licence by IOP Publishing Ltd.

In Colombia, the departments of Cundinamarca, Huila and Tolima, among others, represent 19.16% of the total domestic production of pig farms. Gastrointestinal parasites (PGI) limit the productive potential of infected animals, affecting parameters such as average daily gain and food conversion ratio. The aim of the study was to determinate the prevalence of PGI with a zoonotic potential in backyard farms and semi-technical production. Farmyard pigs were sampled in three semi-technified farms with full production cycle (breeding, fattening and lift) in the municipalities of Vega, Chia, Tibirita and in four backyard pig farms (fattening) in the towns of Chía and Santandersito. The farms were chosen for convenience. Three samplings were performed serially at intervals of 15 days and analyzed with a total of 119 samples, 94 farms and 25 semi-technified backyard farms. Stool samples in "pool...

Composite material (AC-ZnO) was prepared by growing ZnO nanoparticles during the production of biomass based-activated carbon (AC) via the incorporation of zinc acetate in the process. Comprehensive analyses confirmed the presence of ZnO nanoparticles over the AC surface and described the particular nature of the composite adsorbent. Methylene blue (MB) equilibrium data fitted the Dubinin-Radushkevich model. The MB adsorption capacity was higher for the bare activated carbons (197.9–188.7 mg/g) than the activated carbons with ZnO nanoparticles (137.6–149.7 mg/g). The adsorption of the MB on the adsorbents is physical because the mean adsorption energy (E) is between 1.76 and 2.00 kJ/mol. Experiments that combine adsorption and photocatalysis were carried out with different loads of adsorbents and with and without UV-light exposure. Photocatalytic activity was identified mostly at the...

ZnCl2-activated carbon was prepared using coffee husk for phosphate adsorption in aqueous solutions. Textural, morphological and structural analyses were carried out to characterize the produced materials. XRD detected the presence of ZnO in the activated carbon structure, and the measured nitrogen isotherm showed a micro-macroporous structure with 989 m2/g of specific surface area for this material. Phosphate equilibrium and kinetic experiments were conducted. Equilibrium data fit best to the Dubinin-Radushkevich model (r2≥0.96), with maximum adsorption capacities of 59.38 – 63.87 mg P/g in the pH range between 5 and 9. Intraparticle diffusion was the rate-limiting mechanism of the adsorption.