Natural Frequency of Vibrating Foundations on Layered Soil System-An Experimental Investigation

This paper presents model block vibration tests results on two and three layered soil system underlain by rigid layer. Using sand and sawdust in different positions (either at top or at middle or at bottom) and thickness (es) inside a tank, different layered soil bed are prepared and vibration tests are conducted on each prepared bed using Lazan Type oscillator. A large number of response curves (frequency vs. amplitude) are obtained on different layered system. Maximum amplitudes (resonant amplitude) and corresponding frequencies (resonant frequency) are tabulated to study the effect of layering on resonant frequencies. Effects of position and thickness (es) of the layer/layers on natural frequencies are found to be significant, Natural frequency increases significantly due to presence of thin stiff layer at top compared to natural frequency of bottom layer treating it to be half space whereas it decreases significantly due presence of thin soft layer at top. Several other significant observations are made and presented in the paper. Natural frequencies of the soil foundation on different layered soil systems used for the experimental investigations are predicted using static equivalent stiffness of the system and compared with experimental results. Predicted results are found to be in good agreement with the experimental results

Colocalization of intranuclear lamin foci with RNA splicing factors

The lamins form a fibrous network underlying the inner nuclear membrane termed the nuclear lamina. In order to gain insights into the role of lamins in nuclear organization, we have characterized a monoclonal antibody (LA-2H10) raised against recombinant rat lamin A that labels nuclei in a speckled pattern in all cells of unsynchronized populations of HeLa and rat F-111 fibroblast cells, unlike the typical nuclear periphery staining by another monoclonal antibody to lamin A, LA-2B3. In immunolocalization studies the lamin A speckles or foci were found to colocalize with the RNA splicing factors SC-35 and U5-116 kD, but not with p80 coilin found in coiled bodies. Lamin B1 was also associated with these foci. These foci dispersed when cells entered mitosis and reformed during anaphase. The differential reactivity of LA-2H10 and LA-2B3 was retained after nuclei were extracted with detergents, nucleases and salt to disrupt interactions of lamins with chromatin and other nuclear proteins. Using deletion fragments of recombinant lamin A, the epitope recognized by LA-2H10 was located between amino acids 171 and 246. Our findings are consistent with a structural role for lamins in supporting nuclear compartments containing proteins involved in RNA splicing

Novel multicomponent B2-ordered aluminides: Compositional design, synthesis, characterization, and thermal stability

For the first time, multicomponent alloys belonging to a B2-ordered single phase were designed and fabricated by melting route. The design concept of high entropy alloys is applied to engineering the transition metal sublattice of binary B2 aluminide. The equiatomic substitution of transition metal elements in the Ni sublattice of binary AlNi followed to produce Al(CoNi), Al(FeNi), Al(CoFe), Al(CoFeNi), Al(CoFeMnNi), and Al(CoCuFeMnNi) multicomponent alloys. CALculation of PHAse Diagrams (CALPHAD) approach was used to predict the phases in these alloys. X-ray diffraction and transmission electron microscopy were used to confirm the B2 ordering in the alloys. Thermal stability of the B2 phase in these alloys was demonstrated by prolonged heat treatments at 1373 K and 1073 K up to 200 h. © 2020 by the author. Licensee MDPI, Basel, Switzerland

A rocket-borne Langmuir probe response to continuous and pulsed sweep modes

Nightime ionospheric electron density and temperature are measured using a rocket-borne Langmuir probe (LP) launched on board a SONDA III rocket from the Brazilian equatorial rocket launching station in Alcantara-MA, at 23:51 hrs (LT) on May 31, 1992. A sweep voltage varying between -IV and +2.5V is applied to the spherical LP sensor alternately in continuous and pulsed modes. In the continuous mode the effect of contamination of the sensor surface on the current collected by the sensor is clearly seen in the current-voltage characteristics and thereby on the electron temperature estimated, while this effect is practically absent in the pulsed mode operation. An electron temperature profile estimated from the LP data is compared with the IRI90 model profile.Material digitalizado en SEDICI gracias a la colaboración de la Facultad de Ciencias Astronómicas y Geofísicas (UNLP).Asociación Argentina de Geofísicos y Geodesta

Novel Multicomponent B2-Ordered Aluminides: Compositional Design, Synthesis, Characterization, and Thermal Stability

For the first time, multicomponent alloys belonging to a B2-ordered single phase were designed and fabricated by melting route. The design concept of high entropy alloys is applied to engineering the transition metal sublattice of binary B2 aluminide. The equiatomic substitution of transition metal elements in the Ni sublattice of binary AlNi followed to produce Al(CoNi), Al(FeNi), Al(CoFe), Al(CoFeNi), Al(CoFeMnNi), and Al(CoCuFeMnNi) multicomponent alloys. CALculation of PHAse Diagrams (CALPHAD) approach was used to predict the phases in these alloys. X-ray diffraction and transmission electron microscopy were used to confirm the B2 ordering in the alloys. Thermal stability of the B2 phase in these alloys was demonstrated by prolonged heat treatments at 1373 K and 1073 K up to 200 h. © 2020 by the author. Licensee MDPI, Basel, Switzerland

Impact of calcium on salivary α-amylase activity, starch paste apparent viscosity and thickness perception

Thickness perception of starch-thickened products during eating has been linked to starch viscosity and salivary amylase activity. Calcium is an essential cofactor for α-amylase and there is anecdotal evidence that adding extra calcium affects amylase activity in processes like mashing of beer. The aims of this paper were to (1) investigate the role of salivary calcium on α-amylase activity and (2) to measure the effect of calcium concentration on apparent viscosity and thickness perception when interacting with salivary α-amylase in starch-based samples. α-Amylase activity in saliva samples from 28 people was assessed using a typical starch pasting cycle (up to 95 °C). The activity of the enzyme (as measured by the change in starch apparent viscosity) was maintained by the presence of calcium, probably by protecting the enzyme from heat denaturation. Enhancement of α-amylase activity by calcium at 37 °C was also observed although to a smaller extent. Sensory analysis showed a general trend of decreased thickness perception in the presence of calcium, but the result was only significant for one pair of samples, suggesting a limited impact of calcium enhanced enzyme activity on perceived thickness

Visualisation of stabilising particles at the gas solid interface of metal foams

In this article, we demonstrate a technique to visualise the stabilising particles at the gas solid interface of metal foams by employing metallographic etching. This technique is easy to perform and can be applied on a relatively large sample size. The particles present at the gas solid interface of five different types of foams were investigated. Information on the type of particles and the particle coverage could be obtained from this stud

The Maltase Involved in Starch Metabolism in Barley Endosperm Is Encoded by a Single Gene

During germination and early seedling growth of barley (Hordeum vulgare), maltase is responsible for the conversion of maltose produced by starch degradation in the endosperm to glucose for seedling growth. Despite the potential relevance of this enzyme for malting and the production of alcoholic beverages, neither the nature nor the role of maltase is fully understood. Although only one gene encoding maltase has been identified with certainty, there is evidence for the existence of other genes and for multiple forms of the enzyme. It has been proposed that maltase may be involved directly in starch granule degradation as well as in maltose hydrolysis. The aim of our work was to discover the nature of maltase in barley endosperm. We used ion exchange chromatography to fractionate maltase activity from endosperm of young seedlings, and we partially purified activity for protein identification. We compared maltase activity in wild-type barley and transgenic lines with reduced expression of the previously-characterised maltase gene Agl97, and we used genomic and transcriptomic information to search for further maltase genes. We show that all of the maltase activity in the barley endosperm can be accounted for by a single gene, Agl97. Multiple forms of the enzyme most likely arise from proteolysis and other post-translational modifications