Thermal Box Research Articles

Research on Aging and Burning Performance of AC 380V ZR-YJV Cable Insulation sheat

Carrying out research on the aging and burning performance of cable insulation sheath is an important means to prevent cable fires. The thermal aging test box, cone calorimeter and synchronous thermal analyzer were used to study the effect of thermal aging on the combustion performance of AC 380V ZR-YJV cable insulation sheath. The results show that in the early stage of thermal aging of the cable, the ignition time of the YJV cable insulation sheath material gradually increases; compared with unaged cables, the ignition time of cables being aged for 15 days has increased from 8 seconds to 57 seconds while the initial peak value of the heat release rate of the cable decreased from 123 kW/m2 to 22 kW/m2. A large amount of easily decomposable additives in the early stage of thermal volatilized from aging cable sheath may be responsible for the reduction trend of the ignition and fire occurrence of the cable insulation sheath. And for the condition of the aging time increasing, the ignition time decreases from 57s to 32s, and the heat release rate will increase from 22 kW/m2 to 85 kW/m2 in which the ignition and fire trend of the cable insulation sheath increase.

Thermal Characterization of Building Walls Under Random Boundary Conditions

Abstract This work aims to improve the knowledge on dynamic thermophysical characterization of building envelopes by comparing three numerical methods applied on an experimental wall made of masonry brick. The thermal conductivity λ and the thermal capacity ρCp are determined by performing a data fitting optimization between the experimental measurements of the heat flux and the heat flux resulting from these numerical models. The experimental device consists of a thermal box with a controlled ambiance through a radiator linked to a thermostatic bath and placed inside the thermal box, on the opposite side facing the wall. Three different methods were examined: the heat transfer matrix (HTM) analytical method using the HTM, the finite element method (FEM) using comsol multiphysics® software, and the building simulation model (BSM) method using trnsys® Type 56 coupled with Genopt® optimization tool. The reproducibility of the methods was also validated through two other datasets (one random and one harmonic). The obtained results were satisfactory for both λ and for ρCp and for the three studied methods with deviations less than 5% between the results of the different methods. The data logging duration for random boundary conditions was found to be around five days while in harmonic boundary conditions two days were sufficient for the solution to converge.

WATER POTABILITY OF CACIMBAS: CASE STUDY IN A DISTRICT OF THE CITY OF BARRO, CEARÁ

Nesse sentido, o presente trabalho buscou analisar a qualidade físico-química e microbiológica da água proveniente de cacimbas na zona rural do distrito de Iara, cidade de Barro, Ceará. As amostras de água foram coletadas diretamente nas cacimbas em fracos esterilizados, depois foram armazenadas em caixas térmicas com gelo para conservação e transportadas para análises em laboratório. Foram realizadas análises físico-químicas para determinação da turbidez, condutividade elétrica, dureza total, cloretos, nitrogênio amoniacal, nitrato, nitrito, pH, alumínio, ferro total, sólidos totais dissolvidos e manganês, e análises microbiológicas para determinação de coliformes totais e Escherichia coli. Os resultados mostraram que a maioria das amostras de água proveniente das cacimbas apresentaram qualidade em relação aos parâmetros físico-químicos, mas algumas mostraram alterações em relação a dureza, e aos teores de nitrato e ferro. Todas as amostras apresentaram contaminação microbiológica por coliformes totais e somente uma não teve contaminação por E. coli. Os dados reforçam a questão da susceptibilidade das cacimbas a vários fatores de contaminação e a necessidade de maiores medidas para se rever hábitos da população que provocam a contaminação de cacimbas.

Lesions of the sheep reproductive system found in a slaughterhouse in the state of Bahia, Brazil

ABSTRACT: The present study aimed to evaluate and diagnose pathologies of the reproductive system of slaughtered sheep in slaughterhouses in the state of Bahia since there are few data on the subject as well as it is important to note the diagnosis of these diseases to apply appropriate control and prophylaxis measures. The research was carried out in slaughterhouses in the state of Bahia according to the “Serviço de Inspeção Federal” and “Serviço de Inspeção Estadual” for sheep slaughter. From July 2018 to February 2019, visits and monitoring of 1,072 slaughtered sheep were carried out. The animals came from 22 municipalities in the state of Bahia, aged from six to 18 months. During slaughter, the sheep reproductive systems were sectioned for evisceration and lesion collection. Additionally, epidemiological surveys related to origin, age, and race were obtained. For bacteriological examination, collections were performed with sterile scalpel slides and swabs in Stuart medium sterile tubes and refrigerated in a thermal box. For histopathological analysis, fragments were fixed in 10% formaldehyde and routinely processed for histology, stained with Hematoxylin and Eosin (HE). A study of the sheep’s main pathological changes in slaughterhouses in the state of Bahia was carried out, in which 1.072 genital systems were evaluated, and 211 alterations were identified. The most affected reproductive organs were the ovaries (65.3%), followed by the uterus (29.4%) and uterine tubes (5.3%). In the ovaries, the most frequent lesion was a follicular cyst (34.1%); in the fallopian tubes, the cysts represented 3.3% of the lesions, and in the womb, endometritis was observed in 9% of the animals. Other pathologies identified in the ovaries were: luteinized cyst (2.3%); cystic granulosa cell tumor (0.5%); benign lesion (0.5%); agenesis unilateral (0.5%), in addition to other changes of little clinical significance, such as corpus luteum cysts (11.8%) and paraovarian cysts (15.6%). In the fallopian tubes, hydrosalpinx was observed (1%), as well as adenoma (0.5%), agenesis (0.5%), and cysts (3.3%). Uterine lesions included hydrometra (2.3%); Cystic Endometrial Hyperplasia (CEH), abscess, and pyometra (1.4% each); adenomyosis, womb sera petechiae, and total segmental aplasia (1% each); two pregnant uterus, in early pregnancy, presented pyometra (0.9%), however, no change was observed in the fetuses; and uterine polyp (0.5%). Ectopic pregnancy with fetal maceration (0.5%) was observed; vaginitis occurred in 0.5% of the animals, and endometrial melanosis in 8.5%. The high incidence of follicular cysts and endometritis are characterized as diseases that reduce the reproductive efficiency in herds, causing infertility and economic losses in production.

Physicochemical, microbiological and bioactive evaluations of ‘Araçá-Boi’ (Eugenia stipitata Mc Vaugh) pulp exposed to Gamma Irradiation

The aim of this research was to evaluate the physicochemical, microbiological and bioactive quality of ‘Araçá-Boi’ pulps exposed to Gamma Irradiation. Manual harvesting was done in the morning, using good agricultural practices, and fruits were packed in thermal boxes and transported to the ‘Laboratório de Armazenamento e Processamento de Produtos Agrícolas’ of the ‘Universidade Federal de Campina Grande’, to obtain the pulp. The ‘Araçá-Boi’ pulp was irradiated in the ‘Laboratório de Irradiação Gama do Centro de Desenvolvimento de Tecnologia Nuclear’ (CDTN), located at UFPE - Recife, PE, where three doses of Gamma Irradiation (2, 3, 4 kGy) were applied for later comparison with the non-irradiated sample (control). After irradiation, the microbiological, physicochemical parameters and the quantification of vitamin C and flavonoids were evaluated it can be observed that dose 6 is grouped in a set with differential characteristics of the other treatments, as it provided higher AA, pH, luminosity and water activity (Aw). It was observed that there was no microorganism development after irradiation in all analyzed treatments. It can be concluded that the different doses of Gamma Irradiation guaranteed the microbiological quality of the ‘Araçá-Boi’ pulp, remaining fit for consumption and in compliance with the Brazilian legislation.

Development and utilization of hexacopter unmanned aerial vehicle platform to characterize vertical distribution of boundary layer ozone in wintertime

Vertical observations of ozone play vital roles in understanding various atmospheric chemical processes in the boundary layer, particularly in winter. In this study, we attempted to measure vertical profiles of boundary layer ozone in the winter of 2018 over the Yangtze River Delta region of China, using a hexacopter unmanned aerial vehicle (UAV) platform. A commercial portable ozone monitor mounted in a thermal insulation box was attached to the UAV platform to conduct vertical ozone measurements. The results showed that the UAV platform could effectively capture the vertical variations of boundary layer ozone in wintertime. During the field campaign, surface ozone was in relatively low levels due to weak photochemical production. In the daytime, the ozone was well mixed within the boundary layer. At nighttime, uniform vertical distribution patterns and stratified distribution patterns were frequently obtained in ozone profiles below 500 m. Backward trajectories and wind profiles were used to investigate the horizontal and vertical transport of ozone. The stratified distribution patterns of ozone were closely associated with strong contemporary advection transport of ozone that was accompanied by enhanced winds aloft. Besides, strong wind shear enhanced the downward transport of ozone from the free troposphere into the boundary layer, leading to uniform vertical distribution patterns of boundary layer ozone and the elevated nocturnal surface ozone levels. The results of this study could provide insights into the understanding of the spatial variations and evolution patterns of boundary layer ozone in wintertime and constructing suitable boundary layer schemes in atmospheric chemical models.

Evaluation of Hydrogen Peroxide and Cetylpyridinium Chloride as Bacterial Decontaminants of Dental Unit Water Lines at a Private Peruvian Dental School.

ABSTRACTAim:The aim of this study was to evaluate the hydrogen peroxide and cetylpyridinium chloride as bacterial decontaminants of dental unit water lines at a private Peruvian dental school.Materials and Methods:Water samples were obtained from 66 dental units of a University Dental Clinic before decontamination treatment and at days 3 and 7 thereafter. The biofilm treatments were applied equitably among the two treatment groups (n = 22) and one negative control (distilled water). The samples obtained on each collection day were taken to the biochemical laboratory in thermal boxes and then diluted, seeded, and incubated at 37°C for 24h to count colony forming units per milliliter (CFU/mL).Results:The samples to which hydrogen peroxide were applied had a mean of 1.53 × 105 CFU/mL before application, 0.04 × 105 CFU/mL at day 3, and 0.03 × 105 CFU/mL at day 7, whereas the samples undergoing cetylpyridinium chloride treatment had a mean of 1.74 × 105 CFU/mL before application, 615.38 CFU/mL on day 3, and 307.69 CFU/mL on day 7. Distilled water treatment showed a mean of 1.72 × 105 ± 0.39 × 105 CFU/mL at baseline, 1.51 × 105 ± 1.40 × 105 CFU/mL at day 3, and a mean of 1.74 × 105 ± 0.47 × 105 CFU/mL at day 7. Statistically significant differences were found among the three treatment groups at days 3 (P ≤ 0.001) and 7 (P ≤ 0.001) but not at baseline (P = 0.306).Conclusions:The antibacterial effect of cetylpyridinium chloride was significantly greater than that of hydrogen peroxide and distilled water, and can, therefore, be used for bacterial control in the water lines of dental units.

Antioxidant effect on viability of boar semen cooled to 15°C

ABSTRACT This study aimed to evaluate the addition of Vitamin C, reduced Glutathione and trolox on sperm characteristics of pork refrigerated semen. Six pigs were collected through the technique of gloved hand (10 ejaculates/animals). The semen was diluted in MR-A®. After the previous evaluations, the treatments were added: Control group: diluent only; Vitamin C Group: 200μM/mL Vitamin C; Trolox Group: 200μM/mL Trolox; Glutathione group: 2.5mM/ml Reduced glutathione. The semen was stored in thermal boxes and placed inside the refrigerator at 15oC and evaluated at D0, 12, 48, 72 hours. After 30 hours of incubation, each treatment was divided into two equal fractions and the same concentration of antioxidants was added in one of the parts. The results show that reduced glutathione supplementation preserves sperm motility after 24 hours but also has a higher percentage of acrosome intact in the presence of this antioxidant. There was no effect of adding a second dose of the antioxidants. In conclusion, the addition of reduced Glutathione to the swine semen diluent is a promising alternative for better preservation of sperm characteristics and the addition of the second dose of antioxidants during storage is detrimental to semen.

Design with Comfort: Expanding the psychrometric chart with radiation and convection dimensions

We present an expansion of the psychrometric chart for thermal comfort analysis using a new contour shading method that demonstrates a wider range of potential comfort conditions through the incorporation of additional comfort parameters. These extra dimensions include mean radiant temperature, air movement, metabolic rate, skin wettedness and the transitional behavior of occupants. The representations allow us to think outside the thermal comfort box with the use of innovative thermal design and comfort feedback for occupants. Building on the Olgyay bioclimatic chart, allowing architects to “Design with Climate”, the new chart vizualizes a wide range of conditions that illustrate a physical basis for expanding comfort zones. It uses basic spatially invariant metrics employed in adaptive and other comfort models to allow "design with comfort" across all thermal comfort variables. The development of these methods has resulted in an open-source repository and web app available for designers and researchers to reproduce the charts and color-shading for their own projects.

Experimental validation of a steady periodic analytical model for Breathing Walls

The Breathing Wall behaviour under variable boundary conditions is described by an analytical model based on a one-dimensional porous domain crossed by air and subject to third type steady periodic boundary conditions. To the best of the authors’ knowledge, its experimental validation is not provided in literature.In this work, a new model is derived considering Dirichlet steady periodic boundary conditions. The model is experimentally validated testing a 1 m2 no-fines concrete sample in the Dual Air Vented Thermal Box apparatus, specially improved to replicate dynamic thermal conditions. The experiments show that increasing the air flow velocity across the Breathing Wall from 0 to 12 mm/s enhances thermal coupling between the two environments, namely reduces the wall thermal capacity, with a decrease in the penetration time from 4.3 h to 3 h.The model shows a very good agreement with experimental data when predicting temperature distribution across the domain, with error averages and standard deviations within the thermocouple accuracy after calibration, assumed to be 0.15 ∘C. The lesser yet good agreement concerning conduction heat flux density is explained in terms of accuracy in the measurement of the boundary conditions and critical issues in the heat flow measure itself (i.e. probe thermal resistance, thermal contact, emissivity mismatch).

The nursing team’s role in vaccine care: a scoping review

Vaccines or immunobiologicals have antigenic properties and, in public health, are considered an important strategy in the prevention and control of immuno-preventable diseases. The objective of this study was to carry out review of the nursing staff's role in vaccine care. This is a scoping review, conducted in first semester of 2017, with data collected in 17 national and international databases. To guide the evaluation of the selected materials, an instrument composed of some collection indicators was used. The final sample consisted of eight publications. The data was inserted into the Microsoft Excel 2010 Program, and analyzed in a descriptive way. The identification of a variety of actions of the nursing team in the care with vaccines was verified and grouped in: vaccine room; behavior in the vaccine room; refrigerator care; organization of vaccines inside the refrigerator; monitoring and register of changes in temperature; measures adopted with vaccines under suspect; behaviors regarding vaccines in thermal boxes; professional knowledge in the vaccine room and other important behaviors. Given this evidence, it is essential to detect factors that may compromise the quality and conservation of vaccines. For this, it is understood the need for training aimed at the professionals involved in the immunization and the importance of supervision activities in the vaccine room by the nurse.

On-chip RT-LAMP and colorimetric detection of the prostate cancer 3 biomarker with an integrated thermal and imaging box

To achieve low-cost, compact, and portable nucleic acid testing, an integrated device containing a three-dimensional printing fabricated reverse transcription loop-mediated isothermal amplification (RT-LAMP) chip, a thermal module, and an imaging module was developed. Samples and RT-LAMP reagents were loaded on a sponge-like polyvinyl alcohol pad on a chip, whereas the colorimetric detection zone was a dry paper pre-loaded with Calcine. The sealed chip was incubated on the integrated thermal module, and the RT-LAMP products were pressed into the Calcine pre-loaded dry paper by a stick. Colorimetric changes could be visually observed by the naked eye or imaged with a smartphone camera through the imaging module. For detection of the prostate cancer antigen 3 (PCA3) biomarker, LAMP primers were designed and verified. The specificity of Calcine pre-loaded dry paper based on colorimetric detection of positive LAMP products was investigated. The reaction conditions for on-chip RT-LAMP such as amplification time, temperature, and volume were optimized. Finally, a detection limit of 0.34 fg/μL RNA was achieved with the proposed on-chip RT-LAMP and colorimetric detection method for PCA3. Since the thermal plate is powered by a 12-V battery and the color change can be imaged with a smartphone, the integrated platform can be operated on-site, highlighting its potential in point-of-care testing applications.

Use of the ACP® and BTS extenders for cooling at 15°C white-lipped peccary (Tayassu pecari) semen

ABSTRACT: Knowledge about reproduction of white-lipped peccary is of great importance to assist with the conservation of this species and enable its rational use in captivity. This study aimed to evaluate the effect of ACP-103®, ACP-116® and BTS semen extenders on sperm viability during cooling of Tayassu pecari semen. Five ejaculates from four adult males were chilled. The animals were submitted to the protocols of sedation and anesthesia for semen collection by the electroejaculation method. After collection, the semen was macro- and microscopically assessed and diluted to reach 35x106 spermatozoa/mL in each of the three different extenders tested. The fresh-extended semen was packed in a BotuFLEX® thermal box to keep samples at 15°C for 24 hours. After cooling, the following semen parameters were analyzed: sperm motility, functional and structural integrity of sperm membranes, mitochondrial activity, chromatin condensation, and the thermoresistance test was performed. The parameters sperm motility, structural and functional integrity of sperm membranes, mitochondrial activity, and chromatin condensation were preserved after use of the extenders tested, and were similar to those of in natura semen (p>0.05). Curvilinear velocity (VCL) (p<0.05) was the only parameter with reduced values after cooling regardless of the extender used. The percentage of sperm with normal morphology was greater in samples cooled using the BTS extender (p<0.05). The ACP-103®, ACP-116® and BTS extenders can be used for the cooling and preservation of white-lipped peccary semen at 15°C for 24 hours.

Measuring a Breathing Wall's effectiveness and dynamic behaviour

Breathing Walls are building structures based on porous materials crossed by an airflow, which act both as building envelopes and ventilation system components. In climates where both heating and cooling are needed, a pro-flux configuration (heat and air mass both flowing in the same direction) might be alternated with a contra-flux configuration (heat and air mass flowing in opposite directions) during the year or even on a day. Understanding and modelling the Breathing Walls' stationary and dynamic behaviour is thus fundamental, in order to optimize their design and to fully exploit their energy-saving potential. In this experimental study, a small-scale no-fines concrete Breathing Wall was investigated. The steady-state contra-flux tests performed in a Dual Air-Vented Thermal Box laboratory apparatus were used to derive the heat recovery efficiency of the sample as a function of the cross airflow velocity. The effectiveness of this technology was then evaluated in a virtual case study. An optimal airflow velocity across the Breathing Wall was found, leading to energy savings between 9% and 14%. Dynamic tests were performed assuming a sinusoidal variation of the operative temperature on one side of the sample. They showed how airflow velocity affected the Breathing Wall inertia and dynamic behaviour.

Transient Behavior Analysis for Solar Energy Storage in PCM-CFM Material Using Equivalent Heat Capacity Method as Storage Model

A paraffin wax and copper foam matrix were used as a thermal energy storage material in the double passes air solar chimney (SC) collector to get ventilation effect through daytime and after sunset. Air SC collector was installed in the south wall of an insulated test room and tested with different working angles (30o, 45o and 60o). Different SC types were used; single pass, double passes flat plate collector and double pass thermal energy storage box collector (TESB). A computational model based on the finite volume method for transient tw dimensional domains was carried out to describe the heat transfer and storage in the thermal energy storage material of collector. Also, equivalent specific heat method was employed to describe the heat storage and release in the mushy zone. Experimental results referred to an increase in thermal conductivity of paraffin wax that supported by copper foam matrix more than ten times. While the ventilation effect was still active for hours after the sun set, depending on the heat storage amount. Maximum ventilation mass flow rate with TESB collector was recorded with value equals to 36.651 kg/hr., when the overall discharge coefficient that was calculated for the system equals to 0.371. Experimental results showed that the best working angle range was 45~60o, and the highest air to the collector approaching temperature appeared to the double passes flat plate collector. Results gave greater heat storage efficiency of (47)% when the maximum solar radiation was 780 W/m2 at 12.00pm, while the energy summation through duration charge time was 18460 kJ. Computational results, depending on the equivalent heat capacity method for heat storage or release from phase change material that supported by copper foam matrix, showed the behavior of paraffin wax melting and solidification situation through periodic for charge and released heat from the solar collector. Also, these results gave agreement approaching the experimental results for the heat storage in the combined heat storage material, with standard error of 16.8%.

Numerical study on the energy performance of building zones with transparent water storage envelopes

Researches on water wall passive solar technologies, especially the numerical study on the energy performance of building zones with Transparent Water Storage Envelopes (TWSEs), are reported in this paper. TWSE is a climatic adaptive building envelope consisting of visually transparent modular water containers, exterior shading devices, water supply and return pipes. It is an upgraded water wall that can serve both as an energy efficient facade and an auxiliary water cistern in a building. Currently the energy simulation involving transparent water walls cannot be explicitly done in all energy simulation programs because transparent envelopes are always predefined as the surfaces without thermal mass due to the embedded algorithms complied with ISO15099 standard. A numerical approach based on the integrated energy and computational fluid dynamics (IE&CFD) simulation was developed for solving the energy simulation problem related with TWSEs. A simplified optical model of TWSE was proposed and validated through light transmission testing. Meanwhile, cooling and heating loads of a zone with TWSEs and conventional glazing in summer and winter months were studied. The thermal performance of a TWSE relative to the conventional glazing was also investigated via the comparative thermal box testing. Based on the simulation and testing results, it reveals that TWSEs can exceed most high performance coated glazing with regard to solar radiation control, and they are also exceptional energy efficient transparent envelopes that can outperform the ASHRAE standard window and conventional glazing in terms of cooling and heating load reduction as long as being configured and operated properly according to their physical characteristics and outdoor climatic condition. Furthermore, the innovative technical paradigm of TWSEs, along with the numerical approach developed for their energy simulation, demonstrates a wide range of versatility to be implemented in research and practice for ultra low energy buildings.

Numerical and experimental studies on the energy performance of thermal mass windows

Thermal mass window is a transparent water storage envelope for improving energy efficiency of building. Currently, the embedded algorithms in all energy simulation programs disable the explicit energy simulation of building zones with thermal mass windows. The energy simulation methodology for building zones with thermal mass windows, as well as the comparative experiment for testing their energy performance, is presented in the article. For solving the inherent energy simulation problem, the integrated numerical approach based on the simplified one-dimensional nodal thermal model and the optical model was proposed. In a case study, the numerical approach was applied to an office-building zone with a typical thermal mass window to investigate its energy performance. Meanwhile, a comparative experiment on two thermal boxes with and without thermal mass windows under the identical outdoor conditions was also performed for the verification of energy performance of thermal mass windows. Both the simulation and the experimental results reveal that thermal mass windows can outperform conventional glazing in terms of thermal performance and energy efficiency. Shaded thermal mass windows in summer can produce cooling load reduction, while exposed ones in sunny winter days contribute to heating load reduction, which is beneficial for building energy saving.

Diseño y estudio de la distribución eléctrica de una plaza universitaria. Caso Universidad Técnica de Manabí, Ecuador.

La Universidad Técnica de Manabí no cuenta con una plaza de actividades múltiples, por lo cual se ha planteado y analizado la creación de una plaza universitaria, para esto se han planteado estudios y diseños tanto arquitectónicos, civiles y eléctricos. La presente investigación se enfoca en el diseño y estudio de la distribución eléctrica de la plaza universitaria en la Universidad Técnica de Manabí. Se realizó el estudio de carga de cada uno de los locales incorporados a la plaza universitaria, determinando el calibre del conductor, y consecuentemente se utilizó como acometida para cada uno de los circuitos derivados dentro de la plaza. Se debe de tomar en cuenta que los diseños de la plaza universitaria potencian la actividad universitaria tanto desde lo estético como desde el apartado técnico. Una vez colocadas las tuberías se ubicaron las cajas rectangulares como octagonales, de allí se procedió a realizar el respectivo cableado de luz y de fuerza, los cuales salen de una caja de protección térmica. También se colocó mobiliario metálico en el área de estudio para definir las instalaciones eléctricas de forma adecuada para que los estudiantes puedan desarrollar sin ningún problema sus actividades estudiantiles. Se concluye que los estudiantes tendrán un lugar en el que pueden combinar sus actividades, al mismo tiempo tendrán a disposición un lugar confortable en el que podrán desarrollar cómodamente sus diversas actividades tanto educativas como sociables. Palabras clave: diseño, planos eléctricos, demanda eléctrica, carga eléctrica.

Detection of Listeria monocytogenes in frescal cheese traded in the northwestern region of the state of Paraná

ABSTRACT Listeria monocytogenes is responsible for listeriosis, a food-borne zoonosis causing food poisoning episodes throughout the world. It lives in the soil, vegetation, silage, nasal discharge and also in the intestinal flora of many animals. Its transmission takes place through material contaminated with feces, urine, aborted fetuses, uterine discharge, milk and its derivatives, mainly frescal cheese, since they are manufactured with non-pasteurized milk, are not cured, present a low percentage of salt and a high humidity, factors that are favorable for the quick microbial growth and consequent food poisoning to its consumers. Frescal cheese is widely consumed due to its low cost, palatability and in-natura state, meeting the growing demand for minimally processed food. This paper had the purpose of detecting the presence of Listeria monocytogenes in frescal cheese traded in the northwestern region of the state of Parana. A total of 21 samples of frescal cheese traded in different establishments were purchased. The samples were stored in thermal boxes and duly identified. They were then forwarded to the Laboratory of Food and Water Quality Control and Inspection (LACOMA) at Universidade Federal do Parana (UFPR), Palotina campus, where the analyses were performed. All of the 21 samples analyzed were absent for Listeria monocytogenes in a 25-gram sample, in compliance with the microbiological standard for high-humidity cheese (55%) as defined by the Brazilian National Health Surveillance Agency (Agencia Nacional de Vigilância Sanitaria - ANVISA).

Analytical modelling of Breathing Walls: experimental verification by means of the Dual Air Vented Thermal Box lab facility

Breathing Walls are air permeable envelope components based on porous materials. In contra-flux operation air flows opposite to conductive flux, while in pro-flux they have the same direction. The Breathing Wall behaves either as a ventilation heat exchanger or as an active insulation.In literature an analytical model describing steady state heat transfer across a Breathing Wall can be found. Since it lacks an exhaustive experimental validation, a facility developed at the Energy Department of Politecnico of Milano was used to investigate the thermo-physical behavior of a no-fines concrete based Breathing Wall in steady state Dirichlet conditions and contra-flux operation.