Linear stability of a rotating liquid column revisited

We revisit the somewhat classical problem of the linear stability of a rigidly rotating liquid column in this article. Although the literature pertaining to this problem dates back to 1959, the relation between inviscid and viscous stability criteria has not yet been clarified. While the viscous criterion for stability, given by $We < n^2 + k^2 -1$ , is both necessary and sufficient, this relation has only been shown to be sufficient in the inviscid case. Here, $We = \rho \varOmega ^2 a^3 / \gamma$ is the Weber number and measures the relative magnitudes of the centrifugal and surface tension forces, with $\varOmega$ being the angular velocity of the rigidly rotating column, $a$ the column radius, $\rho$ the density of the fluid and $\gamma$ the surface tension coefficient; $k$ and $n$ denote the axial and azimuthal wavenumbers of the imposed perturbation. We show that the subtle difference between the inviscid and viscous criteria arises from the surprisingly complicated picture of inviscid stability in the $We$ – $k$ plane. For all $n > 1$ , the viscously unstable region, corresponding to $We > n^2 + k^2-1$ , contains an infinite hierarchy of inviscidly stable islands ending in cusps, with a dominant leading island. Only the dominant island, now infinite in extent along the $We$ axis, persists for $n=1$ . This picture may be understood, based on the underlying eigenspectrum, as arising from the cascade of coalescences between a retrograde mode, that is the continuation of the cograde surface-tension-driven mode across the zero Doppler frequency point, and successive retrograde Coriolis modes constituting an infinite hierarchy.

Role of Disulfide Bonds and Sulfhydryl Blocked by N-Ethylmaleimide on the Properties of Different Protein-Stabilized Emulsions

To investigate the role of sulfhydryl groups and disulfide bonds in different protein-stabilized emulsions, N-ethylmaleimide (NEM) was used as a sulfhydryl-blocking agent added in the emulsion. The addition of NEM to block the sulfhydryl groups resulted in a reduction in disulfide bond formation, which enabled the internal structure of the protein molecule to be destroyed, and then decreased the restriction of protein membrane on the oil droplets. Furthermore, with the NEM content increasing in the emulsion, a reduction in the protein emulsifying activity and emulsion stability also occurred. At the same time, the intermolecular interaction of the protein on the oil droplet interface membrane was destroyed, and the emulsion droplet size increased with the NEM content in the emulsion. Although NEM blocking sulfhydryl groups from forming disulfide bonds has similar effects on three types of protein emulsion, the degree of myofibrillar protein (MP), egg-white protein isolate (EPI), and soybean protein isolate (SPI) used as emulsifiers had a subtle difference.

Electronic Sensing Platform (ESP) Based on Open-Gate Junction Field-Effect Transistor (OG-JFET) for Life Science Applications: Design, Modeling and Experimental Results

This paper presents a new field-effect sensor called open-gate junction gate field-effect transistor (OG-JFET) for biosensing applications. The OG-JFET consists of a p-type channel on top of an n-type layer in which the p-type serves as the sensing conductive layer between two ohmic contacted sources and drain electrodes. The structure is novel as it is based on a junction field-effect transistor with a subtle difference in that the top gate (n-type contact) has been removed to open the space for introducing the biomaterial and solution. The channel can be controlled through a back gate, enabling the sensor’s operation without a bulky electrode inside the solution. In this research, in order to demonstrate the sensor’s functionality for chemical and biosensing, we tested OG-JFET with varying pH solutions, cell adhesion (human oral neutrophils), human exhalation, and DNA molecules. Moreover, the sensor was simulated with COMSOL Multiphysics to gain insight into the sensor operation and its ion-sensitive capability. The complete simulation procedures and the physics of pH modeling is presented here, being numerically solved in COMSOL Multiphysics software. The outcome of the current study puts forward OG-JFET as a new platform for biosensing applications.

Classification of steel balls by resonant eddy current sensor

The quality and work-life of ball bearings depending on the material properties of the steel ball, hence it is necessary to carefully classify their properties for bearings and related applications. Classification of steel balls based on the subtle difference in their electromagnetic properties is presented in this paper. The conductivity and magnetic susceptibility for the steel balls of the same kind are measured to investigate the correlation with eddy-current signals. The developed eddy-current sensor works at the resonant frequency of 117 kHz with an optimal readout resistance of 15 kΩ, which helps to boost the signal level without a high-gain preamplifier. To detect the eddy-current signal, the steel ball under test moves through the pickup coil, and the recorded data are used to build the voltage probability map for the classification of the steel ball properties. Experimental results show that the steel balls with and without the hardening process can be identified by the change in the amplitude and phase of the eddy current signal, which is consistent with the observed change in the electromagnetic properties of steel balls. The built system can be applied to the related industries to check the quality of steel balls before use.

Role of Disulfide Bonds and Sulfhydryl Blocked by N-Ethylmaleimide on the Properties of Different Protein-Stabilized Emulsions

To investigate the role of sulfhydryl groups and disulfide bonds in different protein-stabilized emulsions, N-ethylmaleimide (NEM) was used as sulfhydryl-blocking agent to be added in the emulsion. The addition of NEM to block the sulfhydryl groups resulted in a reduction of the content of disulfide bonds formation, which enabled destruction of the internal structure of the protein molecule, and then decreased the restriction of protein membrane on the oil droplets. Furthermore, with NEM content increasing in the emulsion, a reduction of protein emulsifying activity and emulsion stability also occurred. At the same time, the intermolecular interaction of the protein on the oil droplet interface membrane was destroyed, and the emulsion droplet size increased with the NEM content in the emulsion. Although NEM blocking sulfhydryl groups not to form disulfide bonds has similar effects on three types of protein emulsion, the degree of myofibrillar protein (MP), egg-white protein isolate (EPI), and soybean protein isolate (SPI) as emulsifier had a subtle difference.

A sour cherry orchard. An excursion through Chekhovian green spaces

The cherry orchard marks the end of Anton Chekhov’s life, consecrating him as the author who defined the threshold of the new epoch. In this article, I construe the garden as the motif linking Chekhov’s sensitivity to the general spirit of his era, revealing his poetics to the global stage as the distinctive mark of a historical and socioeconomic shift. On this path, I will clarify how the subtle difference between sour cherries and sweet cherries becomes a symbol of Chekhov’s dramatic construction, and how his poetics are built on nuances and subtle shifts in meanings, representing the irrevocable fading of a culture. A philological reflection combined with an attentive reading of Chekhov’s letters, Stanislavsky’s memoirs and scenic sketches reveal the author’s interest in the relationship between man and nature as well as the need to read his work from a more spatial-oriented standpoint. Chekhov clearly anticipates the so-called ‘spatial turn’, approaching space not through the description of a specific landscape or dramaturgical setting, but from a phenomenological point of view, leading him to profound reflections on the relationship between physical planning and socio-political development, as later conceptualised by key social thinkers such as Henry Lefebvre and Edward Soja. Chekhov’s dramaturgical construction and symbology are the result of this awareness and endless passion for nature in all its forms.

Thor dicaprio sp. nov., a new, conspicuously coloured shrimp from the tropical western Atlantic, with taxonomic remarks on the T. amboinensis (De Man, 1888) complex (Decapoda: Caridea: Thoridae)

Thor amboinensis (De Man, 1888), known as “sexy shrimp” or “anemone squat shrimp” and popular among divers and aquarists, was previously believed to have a worldwide distribution, with populations throughout the tropical parts of the Indo-Pacific and Atlantic Ocean. However, consistent differences in some details of the colour pattern strongly suggest that T. amboinensis does not represent a single species, but a pantropical species complex. A recent phylogeographic analysis of T. amboinensis based on molecular data confirmed that this taxon is composed of at least five putative cryptic or pseudocryptic species. In the present study, a new cryptic species, Thor dicaprio sp. nov., is established for the western Atlantic populations previously referred to as T. amboinensis. The new species can be distinguished from all other members of the T. amboinensis complex by two differences in the colour pattern and a subtle difference in the size and setation of the appendix masculina, the latter yet to be confirmed. The conspicuous red-white banding of the antennal flagella appears to be the most diagnostic feature of the new species. In addition, T. dicaprio sp. nov. forms a genetically distinctive, homogeneous, tropical western Atlantic (TWA) clade, with the COI pairwise genetic distances from other clades ranging from 8.8% to 19.2%. The distribution of T. dicaprio sp. nov. includes the entire Caribbean Sea, parts of the Gulf of Mexico, Florida, Bahamas, Bermuda, as well as some offshore localities off northern and eastern Brazil. The main aspects and biology and ecological variability of T. dicaprio sp. nov. are discussed in the light of phylogeographic data presently available for the T. amboinensis complex.

Virali and Artistic Background Change

Humans carried the ideas that came to their minds to the people through the arts. Artists are those who have the power to express the arts to others through their culture. The role of such artists in the Sangam era was of great importance. Ninga had a place in the kingdom and in the battlefields. In Sangam songs, the words for the artist were Panar, Porunar, Kuiluvar, Vayiriyar, Viraliyar, Kuttar, Kannular and Patiniyar. Although all of these are generic, there is a subtle difference between the names in terms of musical instruments' playing, dancing, and singing skills. Of these, Viraliyar is a feminist and singer. Virali is a performer who leads a nomadic life. Virali, who excelled in receiving gifts, exemplified the success of kings through their arts. The literature shows that they received valuables gifts like mountain, country, gold, jewelers when they sang songs in praise of the kings. In perumpanatrupadaiviralis beauty was lauded from head to toe. The detailed description is present inkesathipatha. From these descriptions we can get to understand their significance. Such a beautiful and elegantviralis transferred intoparaththiyarover a period of time.

Surface Design Technique through Tradition Technique

This aim of this study is to examine the application of tritik technique in creating exquisite batik pattern design. Essentially, tritik is a technique in batik pattern making that is almost similar to the “tie-and-dip” (ikat-dan- celup) technique; however, the subtle difference between the two techniques lies in the aspect of fabric treading, with the former being able to produce elegant and appealing patterns. This study used a qualitative approach using an observation method in which the researchers observed the creation of such art through studio practice. Essentially, the examination of the practice of such a technique was carried out based on direct observation and unstructured interviews, and the collection of textile products. The research findings showed the experimentation of the tritik technique in the textile pattern designs was highly effective, as evidenced by the exquisite aesthetical effects on the surface of the fabrics, such as the formation of elegant lines consisting of dots and of dashed lines and 3-dimensional texture. In addition, the research findings revealed that the quality of fabrics, the type of colors, and sewing polarity heavily influenced such exquisite tritik pattern design. Collectively, all the above elements were intertwined that helped create appealing, beautiful tritik pattern design infused with high aesthetical values.