A stationary diesel engine is tested using HHO produced on board by a commercial electrolytic cell as additive. The cell uses KOH as electrolytic and is connected to the engine battery. Experiments ...show the cell efficiency is better when current is 6–10 A. Engine was tested in several load regimes, measuring fuel consumption and others parameters, including vibration. Results shows that BSFC and thermal efficiency with HHO improves an average of 3,81% and 2,79% respectively, depending on engine regime and load. Vibration is evaluated using RMS and peak-to-peak values of vibration acceleration, measured in two points on top and one side of the engine. The addition of HHO reduces vibration in most of the experimental points, ought to a better combustion process of gasoil in presence of hydrogen.
•Brown gas contains water vapor.•Power increases in 3,81%, torque in 2,79%, BSFC reduces in 2,66% and 9,29%.•At full load BSFC increases in 2%.•Exhaust gas temperature raises in 15–20 °C, representing a variation of 3–10%.•The engine run with less vibrations level when uses HHO.
Hepatocellular carcinoma (HCC), the fourth leading cause of cancer mortality worldwide, develops almost exclusively in patients with chronic liver disease and advanced fibrosis
. Here we interrogated ...functions of hepatic stellate cells (HSCs), the main source of liver fibroblasts
, during hepatocarcinogenesis. Genetic depletion, activation or inhibition of HSCs in mouse models of HCC revealed their overall tumour-promoting role. HSCs were enriched in the preneoplastic environment, where they closely interacted with hepatocytes and modulated hepatocarcinogenesis by regulating hepatocyte proliferation and death. Analyses of mouse and human HSC subpopulations by single-cell RNA sequencing together with genetic ablation of subpopulation-enriched mediators revealed dual functions of HSCs in hepatocarcinogenesis. Hepatocyte growth factor, enriched in quiescent and cytokine-producing HSCs, protected against hepatocyte death and HCC development. By contrast, type I collagen, enriched in activated myofibroblastic HSCs, promoted proliferation and tumour development through increased stiffness and TAZ activation in pretumoural hepatocytes and through activation of discoidin domain receptor 1 in established tumours. An increased HSC imbalance between cytokine-producing HSCs and myofibroblastic HSCs during liver disease progression was associated with increased HCC risk in patients. In summary, the dynamic shift in HSC subpopulations and their mediators during chronic liver disease is associated with a switch from HCC protection to HCC promotion.
Coastal ecosystems influenced by river discharges are subjected to important environmental changes. Understanding how marine biota cope with its environment is relevant in predicting the responses to ...future conditions imposed by climate change. To date, a large number of studies have addressed the role of pH on shell and biomineralization properties on multiple calcifying species; however the role of salinity in combination with other stressors has been poorly studied. In particular, the edible mussel Mytilus chilensis, an important marine resource of the Chilean coasts, inhabits estuarine areas which show high natural variability in terms of pH and salinity. Here, we studied how M. chilensis shell periostracum, shell organic matrix and crystal orientation are affected by different pH (8.1 and 7.7) and salinity conditions (30, 25 and 20 psu), isolated and in combination, at different time intervals. Our results show differences in the plasticity of the different biomineralogical properties studied during the experiment under the different pH and salinity treatments. While the periostracum thickness and the total shell organic matter were not affected by pH and salinity, the periostracum organic composition did. Higher amounts of polysaccharides were observed under low pH conditions after 20 days of experiment, while after 60 days, low salinity was responsible for the decrease of the polysaccharides and proteins in the periostracum. Low salinity also produced a major disorder in crystal organization at the outer shell surface. Finally, total shell weight was only affected by low pH conditions under lower salinity conditions (20 psu). From the results, in the majority of the shell properties observed we did not observe any combined effect of pH and salinity. Also, we detected that the magnitude of the impacts of salinity and pH are variable and time-dependent. This would be suggesting some level of acclimatization of M. chilensis to lower pH and salinity conditions.
Display omitted
•Coastal habitats such as estuaries show high environmental variability.•pH and salinity impact on the periostracum organic composition.•pH and salinity impact on the shell mineral organization.•Salinity modulates the impact of pH on shell weight.•The level of plasticity in shell properties differs with time exposure.
Historic processes are expected to influence present diversity patterns in combination with contemporary environmental factors. We hypothesise that the joint use of beta diversity partitioning ...methods and a threshold-based approach may help reveal the effect of large-scale historic processes on present biodiversity. We partitioned intra-regional beta diversity into its turnover (differences in composition caused by species replacements) and nestedness-resultant (differences in species composition caused by species losses) components. We used piecewise regressions to show that, for amphibian beta diversity, two different world regions can be distinguished. Below parallel 37, beta diversity is dominated by turnover, while above parallel 37, beta diversity is dominated by nestedness. Notably, these regions are revealed when the piecewise regression method is applied to the relationship between latitude and the difference between the Last Glacial Maximum (LGM) and the present temperature but not when present energy-water factors are analysed. When this threshold effect of historic climatic change is partialled out, current energy-water variables become more relevant to the nestedness-resultant dissimilarity patterns, while mountainous areas are associated with higher spatial turnover. This result suggests that nested patterns are caused by species losses that are determined by physiological constraints, whereas turnover is associated with speciation and/or Pleistocene refugia. Thus, the new threshold-based view may help reveal the role of historic factors in shaping present amphibian beta diversity patterns.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Osteoarthrosis is a main cause of knee pain in the elderly. Pain associated with this condition is often refractory to conservative treatment. Total knee replacement may be the best option for severe ...pathologies; however, the occurrence of a chronic pain state after knee replacement has been well documented in the literature. The previous descriptions of the genicular nerves have been considered somewhat inaccurate. This innervation is complex and exhibits significant interindividual variability. A precise description of these nerves will increase our knowledge on different patterns and targets, to guide treatment and improve outcomes. The objective of this study was to determine sensory innervation patterns of the knee joint and correlate them with dynamic visualization via ultrasound imaging.
Systematic cadaveric dissections were performed to determine different patterns of sensory innervation of the knee followed by ultrasonographic correlation. A short-axis ultrasound view of the nerves was used to inject India ink at several points along their course to facilitate the anatomic dissection and confirm their location among adjacent structures.
The visualized structures were the following: infrapatellar branch of the saphenous nerve, the branches to vastus medialis, intermedius, and lateralis muscles; obturator nerve; and lateral retinacular and recurrent peroneal nerves.
We conclude that reproducible correlations showing the sensory innervations for the knee are linked to muscular structures. However, high variability among individuals makes it difficult to predict their paths. Our systematic approach, using direct visualization via ultrasound, allows a more accurate placement of the needle for therapeutic purposes.
Containers have emerged as a more portable and efficient solution than virtual machines for cloud infrastructure providing both a flexible way to build and deploy applications. The quality of ...service, security, performance, energy consumption, among others, are essential aspects of their deployment, management, and orchestration. Inappropriate resource allocation can lead to resource contention, entailing reduced performance, poor energy efficiency, and other potentially damaging effects. In this paper, we present a set of online job allocation strategies to optimize quality of service, energy savings, and completion time, considering contention for shared on-chip resources. We consider the job allocation as the multilevel dynamic bin-packing problem that provides a lightweight runtime solution that minimizes contention and energy consumption while maximizing utilization. The proposed strategies are based on two and three levels of scheduling policies with container selection, capacity distribution, and contention-aware allocation. The energy model considers joint execution of applications of different types on shared resources generalized by the job concentration paradigm. We provide an experimental analysis of eighty-six scheduling heuristics with scientific workloads of memory and CPU-intensive jobs. The proposed techniques outperform classical solutions in terms of quality of service, energy savings, and completion time by 21.73-43.44%, 44.06-92.11%, and 16.38-24.17%, respectively, leading to a cost-efficient resource allocation for cloud infrastructures.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•To protect the lives of people exposed to lightning currents in open fields and backcountry places, special attention should be given to ground current mechanism.•Tests were conducted with ...high-currents on an A-frame survival lightning shelter prototype constructed using an electrically conductive textile in a high-voltage laboratory.•An instrumented dummy with posing capability was developed and used to measure the voltages that appear on some contact points inside the shelter.•Two positions inside the shelter were considered in this study: lying down and crawling position.•The conductive fabric used to make the tested shelter acts as an equipotential surface reducing the risk of lightning ground currents.
Protecting people from the effects of lightning with portable shelters made of lightweight and easily transportable materials is a challenge that seeks to reduce the risk posed by lightning currents and improve the safety of people exposed to them. We describe laboratory tests conducted on an A-frame survival lightning shelter prototype constructed using an electrically conductive textile. To estimate the injected energy that a human body inside the shelter would withstand when lightning currents flow through the ground, it was developed and used a dummy. Voltages were measured and recorded on the dummy between both hands, hands to knee, and head to feet for two basic positions: in crawling position and lying down. The estimated energy on the dummy inside the shelter was less than 1 joule, when lightning currents up to 10 kA, related to non-direct strikes, circulating through the ground were simulated. Since ground currents are the cause of most lightning fatalities, our findings suggest that the proposed shelter strategy can help protect people's lives when they are inside, thereby significantly mitigating the overall risk of injury from lightning strikes.
Display omitted
TiO2 and ZnO, two semiconductors with promising optical properties, are considered as potential candidates for solar and photocatalytic applications. Although chemical methods have been primarily ...used to enhance the optical properties of these oxides, the current authors recently reported enhanced photocatalytic performance of pure TiO2 and ZnO by plastic straining due to the generation of high-pressure phases and oxygen vacancies. In this study, to improve the optical properties further, large fractions of ZnO/TiO2 interphase boundaries are also introduced by application of high-pressure torsion (HPT) straining to a mixture of anatase-TiO2 and wurtzite-ZnO powders. It was found that the amounts of oxygen vacancies and nanograined high-pressure TiO2-II and rocksalt-ZnO phases increase with increasing plastic strain. Moreover, due to the plastic strain effect, the rutile-TiO2 phase is formed at room temperature, which is at least 600 K below the reported anatase-to-rutile transition temperature. These structural features, together with the formation of large fraction of interphase boundaries, lead to electron spin resonance, optical bandgap narrowing, diminishing of the band-to-band photoluminescence and thus, improvement of photocatalytic hydrogen generation. Despite improvements in the photocatalytic activity of TiO2-ZnO composites after large straining, photocatalytic activity becomes poor by processing at ultra-large strains due to the significant reduction in crystallinity.
Display omitted
•TiO2 and ZnO mixture is plastically stained by high-pressure torsion.•Fractions of high-pressure phases and oxygen vacancies increase with straining.•Large fractions of ZnO/TiO2 interphases are formed by increasing plastic strain.•Optical bandgap increases and band-to-band photoluminescence decreases by straining.•Photocatalytic hydrogen production improves for samples with reasonable crystallinity.
Telemedicine provided older adults the ability to safely seek care during the coronavirus disease (COVID-19) pandemic. This study aimed to evaluate the potential impact of acculturation factors in ...telemedicine uptake between ethnic groups. As part of the National Health and Aging Trends Study 2018 survey, 303 participants (≥65 years) were interviewed. We assessed the impact of acculturation on telemedicine readiness by race and ethnicity. Compared to the white non-Hispanic immigrant population, Hispanic and Asian/Pacific Islander (API) populations had significantly lower telemedicine readiness and uptake. Limited English proficiency or older age at the time of migration was associated with telemedicine unreadiness and uptake in the Hispanic and API populations. Our findings suggested that acculturation factors play a substantial role in telemedicine uptake among older adult immigrants in the United States. Therefore, acculturation factors should be considered when promoting and adopting telemedicine technologies in older adults.
The extractive distillation of ethanol using glycerol as entrainer is studied in order to find its optimal design and operating conditions. The optimization is formulated as a mixed integer nonlinear ...programming (MINLP) problem. The discrete variables determine the number of stages of the columns and their feed stage locations. The continuous variables include the variables of the equilibrium model and operating variables. The solution of the optimization problem is achieved through a two-level strategy that combines stochastic and deterministic algorithms. The result obtained establishes the process that maximizes an economic criterion for the industrial production of bioethanol satisfying the problem constraints.
PDF
