Keeping Theology and Religious Studies Together

In this article, I offer some personal reflections on the developments NTT Journal for Theology and the Study of Religion has gone through in recent years. Moreover, I argue that the continuing existence of journals like NTT JTSR is important for three reasons. (1) This type of general journals counterbalances the overspecialization that characterizes today’s universities. (2) Their rootedness in particular geographical areas and political entities makes that this type of journal makes a distinctive contribution to theology and religious studies. (3) It is important that this journal keeps theology and religious studies together in one journal, for in spite of centrifugal forces at work, they belong together.

Axial rotation as a cause of loss of interference in a shrink fitted split disc assembly

На примере составного диска, созданного посредством операции горячей посадки, изучается прочность такого соединения на отрыв. Отрывные усилия создаются в качестве центробежных инерционных сил при вращении диска относительное его центральной оси. Показывается, что созданный натяг в сборке имеет выраженную тенденцию к уменьшению. Однако для его обнуления необходимы достаточно значительные угловые скорости вращения. Приведен пример расчета придельной угловой скорости в зависимости от первоначального нагрева охватывающей детали сборки, термомеханических свойств материала сборки и геометрических параметров итоговой конструкции. Подобные расчеты в снижающемся натяге совершенно необходимы, когда эксплуатационные условия требуют принять вращение составного диска в качестве части его функциональных обязанностей. On the example of a composite disk, created by means of a hot-fit operation, the pulloff strength of such a disk is studied. separation forces as centrifugal forces with relative rotation of its central axis. It is shown that the created interference fit in the assembly has a pronounced tendency to decrease. However, for vanishing, sufficiently significant angular velocities of rotation are required. An example of calculating the near-limit angular velocity, depending on the original covered part of the assembly, of the thermomechanical properties of the material and the geometric characteristics of the final structure is given. Such computations in decreasing interference are essential when operating conditions require the rotation of the composite disc to be accepted as part of its functionality.

Editorial for Special Issue “Gravity Concentration”

Gravity concentration is the process by which particles of different densities, sizes, and shapes separate from each other when under the action of gravity or centrifugal forces [...]

Centrifugal force assessment in ram sperm: identifying species-specific impact

Background Centrifugation is routinely employed in handling the ejaculates of some species, but it is not part of the commonly used protocols in ram. However, the development and implementation of new assisted reproductive technologies, alternative preservation models based on washing sperm from a cellular ageing-accelerating substance such as the seminal plasma, and basic studies in spermatology is associated with the use of centrifugation. This requires a specific evaluation of the centrifugation protocols considering the species-specific relationship with the potential damage produced by this procedure. No previous studies have determined the effect of different centrifugation forces on ram sperm. Therefore, we aimed to assess the performance of three centrifugal forces (600×g, 3000×g, and 6000×g for 10 min at room temperature) and their effects on ram sperm motility and functionality. Results Sperm motility and functionality parameters were assessed at 0 h and after 2 h of incubation at 37 °C. As expected, a higher cell packaging degree was obtained at high centrifugation forces (P ≤ 0.0001). Cell packaging was unstable at all centrifugal forces. Thus, there was a high cell resuspension rate after less than 2 min. Regarding sperm quality, there was a change in movement pattern of 3000×g and 6000×g centrifuged sperm after 2 h of incubation at 37 °C, characterized by an increase in rapid progressive motility, linearity, straightness, and beat frequency, and a decrease in medium progressive motility, curvilinear velocity, path velocity, and head lateral amplitude. Non-significant differences were obtained among the different treatments concerning the total viability. However, we observed a significant increase (P ≤ 0.05) in the percentage of viable apoptotic sperm in the samples centrifuged at 6000×g at 0 h. Conclusions Centrifugal forces equal to or greater than 3000×g induced some deleterious effects in ram sperm quality, and lower forces did not provide a successful cell packaging degree.

CFD investigation of internal elbow pipe flows in laminar regime

Elbow pipes are crucial parts of many fluid transport systems in the oil and gas industry. The curved shape of such pipes induces centrifugal forces on the internal flow, ultimately affecting the flow velocity and creating pressure differences within the elbow. The present study aims to investigate the effects of the curvature ratio of an elbow pipe on the internal pipe flow using three-dimensional numerical simulations. For laminar flows, the simulations are based on four Reynolds numbers ranging from 200 to 2000 and three curvature ratios of Ro=5.6, 11.2 and 22.4. A mesh convergence study is carried out for 3 meshes with increasing resolution. The results based on the optimal mesh is then compared with the published experimental and numerical results for validation. Once the validation is confirmed, further simulation and analysis are performed for each combination of curvature ratio and Reynolds number. The results reveal that there is flow separation due to the centrifugal forces induced by the curved shape. It is also shown that secondary flows consisting of symmetrical helical vortices called Dean vortices are generated. The intensity of this secondary flow is shown to increase with the increasing Dean number.

Preparation and in vivo toxicity study of allantoin incorporated hyaluronic acid-L-cysteine oral solution: A future treatment for mucositis

Background: Thiolated hyaluronic acid (HA) with interesting properties, such as muco-adhesiveness, enzyme inhibitory, permeation enhancing, and release controlling properties can be applied for drug delivery in various diseases like mucositis. The purpose of this study was to evaluate the stability and toxicity of thiol modified HA by the aid of L-cysteine ethyl ester hydrochloride (Cys) named (HA-Cys) and allantoin (Alla) incorporated HA-Cys (HA-Cys-Alla) to reveal their potential for the future treatment of mucositis. Methods: The HA modification and drug incorporation were investigated using FTIR spectroscopy. The evaluation of in vitro cytotoxicity on Caco-2 cell line by means of MTT assay and in vivo toxicity by measuring the hematological and biochemical parameters in rats were performed. The appearance stability of HA-Cys and HA-Cys-Alla was evaluated at room and refrigerator temperatures over time. In addition, the stability of HA-Cys and HA-Cys-Alla subjected to heating and cooling, freeze-thaw, centrifugal forces, as well as the pH stability under the above-mentioned conditions were also investigated. Results: The results indicated that the synthesized HA-Cys and HA-Cys-Alla with pseudo-plastic rheological behavior demonstrated excellent stability at refrigerator temperature. Although HA-Cys showed good stability, the HA-Cys-Alla revealed color change at room temperature. Moreover, despite no much resistance of HA-Cys and HA-Cys-Alla against the heating-cooling test, the samples exhibited good resistance against freeze-thaw and centrifugal forces. Also, convenient pH stability and high in vitro and in vivo biocompatibility were observed. Conclusions: The low in vitro and in vivo toxicity and convenient stability of HA-Cys-Alla has introduced it as a proper candidate for future clinical applications.

Opera against the Odds

Until 1864, provincial opera operated within a Napoleonic system designed to ensure hierarchically ordered provision for large and smaller towns nationwide and in the colonies. Discussion of how the system worked, how it was funded, how it served indirectly to erase regional difference, and how raw material from Paris (Grand Opera and the voice types it required) became too expensive, helps explain why the system was already at a breaking point by the 1830s, catalyzing heated local and local–national debates. The significance of provincial opera’s travails, its competitors in the entertainment sector from café-concert to radio, and the importance of two regional triumphs—Wagner and open-air opera—become clear in the light of this Paris-generated organizational history. Considerations of decentralization shift at this point to those of the tensions between genre of “national opera” and the centrifugal forces of cultural regionalism (with its attendant identitarian concerns), using the nature and significance of operatic “local color” as a test bed.

Faraday–Fresnel rotation and splitting of orbital angular momentum carrying waves in a rotating plasma

Rotational Fresnel drag – or orbital Faraday rotation – in a rotating magnetised plasma is uncovered and studied analytically for Trivelpiece–Gould and whistler–helicon waves carrying orbital angular momentum (OAM). Plasma rotation is shown to introduce a non-zero phase shift between OAM-carrying eigenmodes with opposite helicities, similarly to the phase shift between spin angular momentum eigenmodes associated with the classical Faraday effect in a magnetised plasma at rest. By examining the dispersion relation for these two low-frequency modes in a Brillouin rotating plasma, this Faraday–Fresnel rotation effect is traced back to the combined effects of Doppler shift, centrifugal forces and Coriolis forces. In addition, the longitudinal group velocity in the presence of rotation is shown to depend both on rotation and azimuthal mode, therefore predicting the Faraday–Fresnel splitting of the envelope of a wave packet containing a superposition of OAM-carrying eigenmodes with opposite helicities.