Increasing the Sustainability of the Hybrid Mold Technique through Combined Insert Polymeric Material and Additive Manufacturing Method Design

To reduce plastic waste generation from failed product batches during industrial injection molding, the sustainable production of representative prototypes is essential. Interesting is the more recent hybrid injection molding (HM) technique, in which a polymeric mold core and cavity are produced via additive manufacturing (AM) and are both placed in an overall metal housing for the final polymeric part production. HM requires less material waste and energy compared to conventional subtractive injection molding, at least if its process parameters are properly tuned. In the present work, several options of AM insert production are compared with full metal/steel mold inserts, selecting isotactic polypropylene as the injected polymer. These options are defined by both the AM method and the material considered and are evaluated with respect to the insert mechanical and conductive properties, also considering Moldex3D simulations. These simulations are conducted with inputted measured temperature-dependent AM material properties to identify in silico indicators for wear and to perform cooling cycle time minimization. It is shown that PolyJetted Digital acrylonitrile-butadiene-styrene (ABS) polymer and Multi jet fusioned (MJF) polyamide 11 (PA11) are the most promising. The former option has the best durability for thinner injection molded parts, and the latter option the best cooling cycle times at any thickness, highlighting the need to further develop AM options.

Ecomorphic Structure Transformation of Soil Macrofauna Amid Recreational Impact

The level of reacreation load on the components of urban green areas is increasing, so identifying the effective management tools in these ecosystems is becoming crucial for ensuring the maintenance of soil biota habitats. The purpose of this study is to reveal a pattern of structuring community of soil macrofauna under a recreational impact based on an ecomorphic approach. The article assesses the level of recreational transformation of the soil macrofauna of public green spaces in the city of Melitopol on the territory of Novooleksandrivskyi Park. For research purposes, a testing site was allocated in an area with a high level of recreational load, with samples taken within this site. To collect soil macrofauna and assess soil properties at each point of the testing site, soil and zoological tests were carried out and the following soil indicators were measured: temperature, electrical conductivity, humidity and soil penetration resistance, litter depth and grass stand height. The community ordination was performed using two approaches: OMI and RLQ analysis. The study found that the ecological niches of soil macrofauna in recreational conditions are spatially structured. The main factors for structuring the ecological niche of soil macrofauna within the study area are soil penetration resistance in the range of the entire measured layer, soil moisture, and distance to trees. As for the number of species, the basis of the coenomorphic structure of soil macrofauna are silvants (45.5%) and pratants (24.2%). As for the species abundance, the basis of the coenomorphic structure of macrofauna comprises pratants (64.5%), slightly less stepants (19.1%) and silvants (16.1%), and sporadic occurrence of paludants (0.2%). Such coenomorphic structure can be considered as ecologically labile. Zoophages, hemiaerophobes, and megatrophs are tolerant to a high level of recreational load. The area corresponding to the highest level of recreational load is vacant. This indicates factual absence of soil macrofauna species that could exist amid intense recreational exposure

Biotherapic T. cruzi 17DH when continuously used clinically improves mice infected with T. cruzi.

Introduction: In Trypanosoma cruzi infection, the pathogenesis is the result of a rupture in the host - parasite relationship [1]. This rupture is related to the imbalance of the vital force of the host, expressed through signs and symptoms, defined by Hahnemann (1995)[2] as being the source of the disease. There is no research in the literature about the clinical evolution of mice experimentally infected with T. cruzi and treated in different ways using biotherapic. Therefore, this is an area to be studied in the future. Aim: To evaluate the effect of different ways of treatment using biotherapic T. cruzi 17 DH on clinical evolution of mice experimentally infected with T. cruzi. Materials and methods: A blind randomized controlled trial was performed, using 30 swiss male mice, aged 28 days, divided into groups according to the treatment: CONTROL - animals treated with 7% water-alcohol solution diluted in water given ad libitum in an amber bottle; GAVAGE – animals treated with medication highly diluted T. cruzi 17 DH from 4th to 9th day of infection by gavage; WATER -animals treated with highly diluted T. cruzi 17 DH in water ad libitum offered in an amber bottle until the end of the study period. The groups were infected with the Y strain of T. cruzi, intraperitoneal, 1400 blood trypomastigotes. The medicine was handled according to the Brazilian Homeopathic Pharmacopoeia [3] with microbiological test according to RDC n° 67 and in vivo biological risk. Parasitemic curve was determined by daily counting of the parasites [4]. Were measured temperature, weight, intake of water and feed, the ruffle fur and survival of mice. Statistical analysis was performed using the tests Fisher Exact and Log-Rank, with a significance of 5%. The experiment was approved under the protocol n° 030/2008 - Ethics in Animal Experimentation of the Universidade Estadual de Maringá. Results: The mice under different treatment ways using biotherapic T. cruzi 17DH showed differences in the clinical evolution. The treatment using biotherapic diluted in water initially shows hypothermia, with subsequent recovery of normal temperature (p=0.05) (Fig1). The weight curve shows a better evolution in mice treated with water compared to control groups (p=0.055) and the groups treated by gavage (p=0.0064). Feed and water intake did not differ among the groups. While the mice that were treated with biotherapic diluted in water showed a slight level of ruffled fur, the mice in control groups and the ones treated by gavage showed a more intense level of ruffled fur (p=0.00001). The difference in the evolution of mortality among the groups was significant (p=0.034), while in the group treated with biotherapic diluted with water, the mortality rate started later, reaching the maximum of 90%. This group showed a better clinical result, expressed by the smaller extent of ruffled fur, a better evolution of the temperature curve and higher gain of weight. This is an important result because the Y strain of T. cruzi has a mortality rate of 100% in mice, showing once again the good performance of biotherapic in this model of infection. Conclusion: The use of biotherapic T. cruzi 17DH for a long period causes clinical improvement of the infected mice with Trypanosoma cruzi. The clinical use of these results in human beings should consider the allometric medicine dosage which takes into account the metabolic rate of each organism.

Numerical Analysis of the Impact of the Location of a Commercial Broiler House on Its Energy Management and Heat Exchange with the Ground

This paper addresses the impact of location on energy management and ground heat transfer in a commercial large-scale broiler house. Four locations in Europe were selected for analysis: Krakow (Poland), Vienna (Austria), Modena (Italy), and Oslo (Norway). An analysis of the impact of location on energy management was performed using the numerical method of computing elemental balances (MEB). WUFIplus® computer software was used to assist in the calculation process. Computer simulations of the effects of location on selected technical factors were performed after validating the computational model. The complex area of building and land was divided into cuboidal balance–difference elements using model discretization. Energy and temperature balance calculations were performed for each balance–difference element assuming a time step every 60 min. Validation of the computational model was performed based on the measured temperature inside and outside the broiler house. The variation in outdoor climate significantly affected the energy flow through the building envelope and ventilation system. Providing that the same material and construction solutions are adopted, a building located in the south of Europe requires 43% less energy for heating compared to a building located in the northern part of the continent. Due to it having the highest solar radiation, the highest energy gains were obtained for the building located in Modena. The buildings located in Krakow and Vienna had a 50% lower yield of thermal energy from the external environment. The percentage of land in the energy balance of the studied building ranged from 8.00 to 8.56%, depending on location. The highest energy gains were obtained for the building located in Modena (4112.8 kWh/a). The buildings located in Krakow and Vienna were characterized by a heat energy yield from the external environment that was two times lower. For the site located in Oslo, it was found that the largest thermal energy gain came from the ground medium located under and surrounding the broiler house (1137 kWh/a). The location of the broiler house significantly affects year-round heating needs. The building located in Oslo required 677,207.2 kWh/a of energy for heating purposes.

Frequency and Consequences of Routine Temperature Measurement at Well-Child Visits

OBJECTIVES: To determine the (1) frequency and visit characteristics of routine temperature measurement and (2) rates of interventions by temperature measurement practice and the probability of incidental fever detection. METHODS: In this retrospective cohort study, we analyzed well-child visits between 2014–2019. We performed multivariable regression to characterize visits associated with routine temperature measurement and conducted generalized estimating equations regression to determine adjusted rates of interventions (antibiotic prescription, and diagnostic testing) and vaccine deferral by temperature measurement and fever status, clustered by clinic and patient. Through dual independent chart review, fever (≥100.4°F) was categorized as probable, possible, or unlikely to be incidentally detected. RESULTS: Temperature measurement occurred at 155 527 of 274 351 (58.9%) well-child visits. Of 24 clinics, 16 measured temperature at >90% of visits (“routine measurement clinics”) and 8 at <20% of visits (“occasional measurement clinics”). After adjusting for age, ethnicity, race, and insurance, antibiotic prescription was more common (adjusted odds ratio: 1.21; 95% CI 1.13–1.29), whereas diagnostic testing was less common (adjusted odds ratio: 0.76; 95% CI 0.71–0.82) at routine measurement clinics. Fever was detected at 270 of 155 527 (0.2%) routine measurement clinic visits, 47 (17.4%) of which were classified as probable incidental fever. Antibiotic prescription and diagnostic testing were more common at visits with probable incidental fever than without fever (7.4% vs 1.7%; 14.8% vs 1.2%; P < .001), and vaccines were deferred at 50% such visits. CONCLUSIONS: Temperature measurement occurs at more than one-half of well-child visits and is a clinic-driven practice. Given the impact on subsequent interventions and vaccine deferral, the harm–benefit profile of this practice warrants consideration.

Engine Oil- Crankshaft Interaction Fem Modelling of an Air-Cooled Diesel Engine under Dynamic Severe Functioning Conditions

Taking into account the interaction between the engine oil and the crankshaft to model crankshaft thermomechanical behavior under dynamic loading is very important. In particular, when the crankshaft is working in severe conditions. This paper deal with an air cooled direct injection-type engine crankshaft thermomechanical FEM modelling account for engine oil-cranks half interaction in severe working conditions. As case of application we consider the diesel engine Deutz F8L413. The model takes into account 2 forced convectives heat flux: engine oil and crankcase air. The severe mechanical and thermal characteristics of engine are experimentally measured on a bench test equipped with a hydraulic brake. The temperature distribution inside the crankshaft was computed using the measured temperature as boundary conditions. The most thermo-mechanical stressed zones of the crankshaft have been determined. The fatigue resistance of the crankshaft under thermo-mechanical conditions was examined using Dang-Van multi-axial fatigue criteria. To prove our model efficiency, we have compared crankshaft damage in service to the numerical simulation results. It was found the breakage occurred in an area where the numerical simulations give the highest stresses.

Numerical Modelling of Heat Transport in Freezing Mortars with an External Liquid Reservoir

Several studies indicate that the temperature distribution in concrete may affect the extent of frost scaling. This study presents a numerical model that describes the thermal response of freezing mortars in the presence of an external liquid reservoir, where the external liquid is either pure water or 3% sodium chloride solution. The phase transformation of supercooled external liquid is modelled in two stages: quick freezing, when the supercooled liquid starts to form crystals and slow freezing. The model is developed in two parts. In part I, the focus is the modelling of external liquid, and therefore a non-porous body with an external liquid reservoir is modelled and validated. In part II, the model developed in part I is developed further for a porous body containing different phases, i.e., unfrozen liquid and ice, in the pores. A comparison of simulated and experimentally measured temperature distributions shows a good agreement.

IoT-Based Smart Health Monitoring System for COVID-19 Patients

During the ongoing COVID-19 pandemic, Internet of Things- (IoT-) based health monitoring systems are potentially immensely beneficial for COVID-19 patients. This study presents an IoT-based system that is a real-time health monitoring system utilizing the measured values of body temperature, pulse rate, and oxygen saturation of the patients, which are the most important measurements required for critical care. This system has a liquid crystal display (LCD) that shows the measured temperature, pulse rate, and oxygen saturation level and can be easily synchronized with a mobile application for instant access. The proposed IoT-based method uses an Arduino Uno-based system, and it was tested and verified for five human test subjects. The results obtained from the system were promising: the data acquired from the system are stored very quickly. The results obtained from the system were found to be accurate when compared to other commercially available devices. IoT-based tools may potentially be valuable during the COVID-19 pandemic for saving people’s lives.

The ‘excess gas’ method for laboratory formation of methane hydrate-bearing sand: geotechnical application

Over recent years, there has been a growing interest in producing methane gas from hydrate-bearing sands (MHBS) located below the permafrost in arctic regions and offshore within continental margins. Geotechnical stability of production wellbores is one of the significant challenges during the gas extraction process. The vast majority of geotechnical investigations of MHBS have been conducted on laboratory-formed samples due to the complex procedure of undisturbed sample extraction. One of the most commonly used hydrate laboratory-formation methods is the excess-gas method. This work investigates fundamental aspects in the excess-gas formation of MHBS that are affecting the geotechnical interpretation and modeling. The work finds that (1) the measured temperature in the experimental system may be quite different from the in-sample temperature, and can reach 4 $$^\circ$$ ∘ C difference during thermodynamic processes. This potential difference must be considered in investigation of hydrate formation or dissociation, (2) various calculation approaches may yield different hydrate saturation values of up to tens of percentages difference in high hydrate saturations. The calculation formulas are specified together with the fundamental difference between them, (3) the water mixture method during the sample assembling is critical for homogeneous MHBS laboratory formation, in which a maximum initial water content threshold of 9.1 to 1.3 % are obtained for a minimal fraction size of 0.01 to 0.8 mm, respectively, (4) the hydrate formation duration may influence the MHBS properties, and should be rigorously estimated according to the real-time gas consumption convergence. The outcomes of this work may contribute to the integration of data sets derived from various experiments for the study of MHBS mechanical behavior.

Clinical evaluation of non-contact infrared thermometers

Non-contact infrared thermometers (NCITs) are being widely used during the COVID-19 pandemic as a temperature-measurement tool for screening and isolating patients in healthcare settings, travelers at ports of entry, and the general public. To understand the accuracy of NCITs, a clinical study was conducted with 1113 adult subjects using six different commercially available NCIT models. A total of 60 NCITs were tested with 10 units for each model. The NCIT-measured temperature was compared with the oral temperature obtained using a reference oral thermometer. The mean difference between the reference thermometer and NCIT measurement (clinical bias) was different for each NCIT model. The clinical bias ranged from just under − 0.9 °C (under-reporting) to just over 0.2 °C (over-reporting). The individual differences ranged from − 3 to + 2 °C in extreme cases, with the majority of the differences between − 2 and + 1 °C. Depending upon the NCIT model, 48% to 88% of the individual temperature measurements were outside the labeled accuracy stated by the manufacturers. The sensitivity of the NCIT models for detecting subject’s temperature above 38 °C ranged from 0 to 0.69. Overall, our results indicate that some NCIT devices may not be consistently accurate enough to determine if subject’s temperature exceeds a specific threshold of 38 °C. Model-to-model variability and individual model accuracy in the displayed temperature were found to be outside of acceptable limits. Accuracy and credibility of the NCITs should be thoroughly evaluated before using them as an effective screening tool.