Acoustic analysis of the drainage cycle in a washing machine

Washing machine manufacturers are working towards producing quieter appliances as many people consider noise emission a key factor when buying. Although the spinning cycle is the noisiest, the amount of noise the pump makes is the cause for many users’ complaints. In an attempt to reduce the noise emitted when a washing machine is pumping out, an experimental study was performed. First, the measurement of the sound pressure allowed us to identify the main sources of noise as the electric motor and the vibration of the cabinet. Next, a detailed analysis based on the measurement of the vibration of the cabinet provided information about the predominant radiating panels. It was also inferred that the electromagnetic noise is drowned out by the structure-borne noise. Finally, several proposals to diminish the sound power were analyzed, and a reduction of 3 dBA was achieved by decreasing the contact zone of the pump with the kick plate

Actores que influyen en la toma de decisiones en la gestión escolar en la Universidad Autónoma de Tamaulipas

El presente trabajo tiene como objetivo determinar el nivel de influencia que tienen los académicos en la toma de decisiones en la gestión escolar en los siguientes aspectos: designación de funcionarios, selección de nuevos académicos, promoción, presupuesto, carga docente, evaluación del estudiante, evaluación de profesor, criterios de ingreso para nuevos estudiantes, programas académicos, líneas de investigación, entre otras, en las facultades y unidades académicas de la Universidad Autónoma de Tamaulipas (UAT). Los resultados aquí presentados fueron obtenidos del Proyecto de investigación la Reconfiguración de la Profesión Académica en México. (PRAM), que se llevó a cabo a nivel nacional. El objetivo del proyecto esta encaminado a conocer los cambios que ha sufrido la profesión académica en los últimos años, y dentro de este proyecto se aborda un espacio importante para la labor del profesor académico en cuanto a la gestión escolar y determinar el nivel de influencia que éstos tienen en las decisiones de la institución

Washing machine dynamic model to prevent tub collision during transient state

In horizontal-axis washing machines, the front gasket as well as the damping system are crucial owing to the possible collision of the tub with the housing during the transient period. However, most dynamic models for predicting tub motion focus on the steady state and consider only the suspension system without including the gasket. We conducted an experimental study to analyze the effect of the gasket on the transient motion of the tub. The results obtained indicate the necessity of implementing the gasket in the multibody model of a washing machine to accurately predict the tub behavior during this period. The gasket model is formed by a combination of Voigt elements. Stiffness parameters are determined using a load cell, and damping factors are estimated using a process that integrates Adams/View, Matlab optimization algorithms, and displacement measurements that are taken using accelerometers. A D-optimal design used to predict the effect of the gasket parameters reveals that the tub displacement is most sensitive to the changes in linear stiffness in the transversal direction. Finally, the model of the gasket provides a better approach for predicting the tub movement during resonance that can be used in the design phase to avoid tub collision

Ocean acidification promotes otolith growth and calcite deposition in gilthead sea bream (Sparus aurata) larvae

This work received funding from the Marine Alliance for Science and Technology for Scotland (MASTS) Small Grant initiative (SG330 and SG407). MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. PBW would like to thank the Royal Society for the award of an Industry Fellowship. Financial support to CRB and JG were through the BIOACID (Biological Impacts of Ocean Acidification; Phase II) research programme.The effects of ocean acidification on otolith crystallization and growth rates were investigated in gilthead sea bream (Sparus aurata) larvae. Larvae were exposed to three different pH levels: pH8.2, pH7.7 and pH7.3 for a period of 18 days post-fertilization. For the first time, we demonstrate that pH has a significant impact on the carbonate polymorph composition, showing calcite in a significant percentage of individuals at low pH. Around 21% of the larvae exposed to pH7.3 showed irregular calcitic otoliths rather than commonly found round aragonitic otoliths. Calcitic otoliths showed a moderate level of heritability suggesting an important role of genetic factors. We also observed significantly larger otoliths in larvae reared at pH7.7 and pH7.3 compared to pH8.2 in both sagittae and lapilli. Our results demonstrate that otolith growth rates in gilthead sea bream larvae increase at low pH while a significant proportion of larvae are prone to the formation of calcitic otoliths at pH7.3.Publisher PDFPeer reviewe

Directional quantum dot emission by soft-stamping on silicon Mie resonators

We present a soft-stamping method to selectively print a homogenous layer of CdSeTe/ZnS core–shell quantum dots (QDs) on top of an array of Si nanocylinders with Mie-type resonant modes. Using this new method, we gain accurate control of the quantum dot's angular emission through engineered coupling of the QDs to these resonant modes. Using numerical simulations we show that the emission into or away from the Si substrate can be precisely controlled by the QD position on the nanocylinder. QDs centered on a 400 nm diameter nanocylinder surface show 98% emission directionality into the Si substrate. Alternatively, for homogenous ensembles placed over the nanocylinder top-surface, the upward emission is enhanced 10-fold for 150 nm diameter cylinders. Experimental PL intensity measurements corroborate the simulated trends with cylinder diameter. PL lifetime measurements reflect well the variations of the local density of states at the QD position due to coupling to the resonant cylinders. These results demonstrate that the soft imprint technique provides a unique manner to directly integrate optical emitters with a wide range of nanophotonic geometries, with potential applications in LEDs, luminescent solar concentrators, and up- and down-conversion schemes for improved photovoltaics

Removal of a migrated biliary stent using new digital cholangioscopy retrieval devices in a transplant patient

A 51-year-old man who had undergone liver transplantation developed a symptomatic anastomotic biliary stricture 23 months after surgery. Endoscopic biliary therapy via endoscopic retrograde cholangiopancreatography (ERCP) was planned. Progressive biliary balloon dilation of the stenosis was performed, with placement of three coaxial plastic stents (8.5-Fr × 12 cm, 8.5-Fr × 9 cm, and 10-Fr × 12 cm; Advanix, Boston Scientific, Natick, Massachusetts, USA). During an endoscopy to replace the stents, fluoroscopy revealed proximal migration of an 8.5-Fr plastic stent at the level of the cystic insertion ([Fig. 1]). Several failed extraction attempts were made using the standard ERCP techniques (i. e. extractor balloon, Lasso technique, and others) [1] [2]. Single-operator peroral intraductal cholangioscopy (SpyGlass DS direct visualization system, Boston Scientific) confirmed impaction of the distal end of the proximally migrated stent, located 3 cm proximally to the duodenal papilla. An attempt to mobilize the migrated stent was made using biopsy forceps (SpyBite, Boston Scientific), without success

Fast-growing growth hormone transgenic coho salmon (Oncorhynchus kisutch) show a lower incidence of vaterite deposition and malformations in sagittal otoliths

DGS is a Serra Húnter Tenure-Track lecturer, and this work has been partially funded by the Ministerio de Ciencia y Tecnología grant number RTI2018-100757-B-100. RHD acknowledges support from the Canadian Regulatory System for Biotechnology (grant number 61740).In fish otoliths, CaCO3 normally precipitates as aragonite, and more rarely as vaterite or calcite. A higher incidence of vaterite deposition in otoliths from aquaculture-reared fish has been reported and it is thought that high growth rates under farming conditions might promote its deposition. To test this hypothesis, otoliths from growth hormone (GH) transgenic coho salmon (TF) and non-transgenic (NT) fish of matching size were compared. Once morphometric parameters were normalized by animal length, we found that TF fish otoliths were smaller (-24%, -19%, -20% and -30%; P<0.001 for length, width, perimeter and area, respectively) and rounder (-12%, +13.5%, +15% and -15.5% in circularity, form factor, roundness and ellipticity; P<0.001) than otoliths from non-transgenic fish of matching size. Interestingly, transgenic fish had smaller eyes (-30% eye diameter) and showed a strong correlation between eye and otolith size. We also found that the percentage of otoliths showing vaterite deposition was significantly smaller in transgenic fish (21-28%) compared to non-transgenic (69%; P&lt;0.001). Likewise, the area affected with vaterite deposition within individual otoliths was reduced in transgenic fish (21-26%) compared to non-transgenic (42.5%; P<0.001). Our results suggest that high growth rates per se are not sufficient to cause vaterite deposition in all cases, and that GH overexpression might have a protective role against vaterite deposition, an hypothesis that needs further investigation.Publisher PDFPeer reviewe

Pilot study to investigate the effect of long-term exposure to high pCO2 on adult cod (Gadus morhua) otolith morphology and calcium carbonate deposition

Funding was provided by the Bonus Baltic Sea research and development programme (Art 185) BIO-C3 project, funded jointly by the EU and the BMBF (Grant No. 03F0682A), BIOACID project (Biological Impacts of Ocean Acidification: Grant No. 03F0655K) funded by the German Ministry for Education and Research (BMBF), and the EU AQUAEXCEL transnational access grant for aquaculture infrastructures. Part of the work was supported by the FINEAQUA-project (Grant Number 12212001) funded by the Program for the Future Economy (financed by the European Regional Development Fund, the Federal Republic of Germany and the state of Schleswig–Holstein), the Centre for Marine Aquaculture, Tromsø, and the Marine Alliance for Science and Technology for Scotland (MASTS) Small Grant initiative (SG330 and SG407), and their support especially by the staff of the centre for Marine Aquaculture is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. PBW would like to thank the Royal Society for the award of an Industry Fellowship. DGS is a Serra Húnter Tenure-Track lecturer.To date the study of ocean acidification on fish otolith formation has been mainly focused on larval and juvenile stages. In the present pilot study, wild-captured adult Atlantic cod (Gadus morhua) were exposed to two different levels of pCO2, 422µatm (ambient, low pCO2) or 1091µatm (high pCO2), for a period of 30 weeks (from mid-October to early April 2014–2015) in order to study the effects on otolith size, shape and CaCO3 crystallization amongst other biological parameters. We found that otoliths from cod exposed to high pCO2 were slightly smaller (− 3.4% in length; − 3.3% in perimeter), rounder (− 2.9% circularity and + 4% roundness) but heavier (+ 5%) than the low pCO2 group. Interestingly, there were different effects in males and females; for instance, male cods exposed to high pCO2 exhibited significant changes in circularity (− 3%) and roundness (+ 4%) compared to the low pCO2 males, but without significant changes on otolith dimensions, while females exposed to high pCO2 had smaller otoliths as shown for length (− 5.6%), width (− 2%), perimeter (− 3.5%) and area (− 4.8%). Furthermore, while the majority of the otoliths analysed showed normal aragonite deposition, 10% of fish exposed to 1091µatm of pCO2 had an abnormal accretion of calcite, suggesting a shift on calcium carbonate polymorph crystallization in some individuals under high pCO2 conditions. Our preliminary results indicate that high levels of pCO2 in adult Atlantic cod might affect otolith growth in a gender-specific way. Our findings reveal that otoliths from adult cod are affected by ocean acidification, and we believe that the present study will prompt further research into this currently under-explored areaPublisher PDFPeer reviewe