Empty Columns Research Articles

Legal Re-Construction; The Impact of Empty Column Victory Over Single Candidates in Simultaneous Direct Elections of Regional Heads as A New Phenomenon of Legal Politics in Indonesia

This study examines the legal re-construction of the victory impact of an empty column over a single candidate as a new phenomenon of legal politics in Makassar City, South Sulawesi, Indonesia. This is a doctrinal normative legal research, which uses the analytical, explorative, explanatory, and qualitative analysis techniques. The result showed that legal reconstruction needs to be carried out on disputes, policies of single candidate pairs and empty columns, nomination requirements and political party support for candidates. The legal construction also needs to be conducted on the phrase "next election," the emptiness of definitive city government leaders, postponement and legal uncertainty, establishment of Provisional Acts (Pjs), as well as the loss of the constitutional rights of communities and regions.. Legal reconstruction also needs to be carried out through the political management of post-conflict local elections with changes in legal policies Law No.10 of 2016, PKPU No.13 of 2018, Minister of Home Affairs Regulation (Permendagri) No. 1 of 2018.

Hydrodynamic performance and structural optimization of a slurry bubble column with vertical tube internals

The slurry bubble column, as a multiphase reactor, is widely used in chemical, biological, petroleum refining, environmental, and other fields. However, most published studies of the hydrodynamic performance of slurry bubble columns have been carried out on empty columns without internal components, and recent studies on columns with vertical heat exchange tubes have been limited. In this study, the hydrodynamic performance of a laboratory-scale slurry bubble column with vertical tube bundles was studied, and a new vertical tube structure with fins was proposed. The effect of the new structure on the hydrodynamic performance of the laboratory-scale slurry bubble column was studied via a combination of experimental and numerical simulations. The results of these simulations showed that the vertical heat exchange tube structure with fins was helpful for improving fluid flow, exerted a certain fragmentation effect on large bubbles, and could strengthen mass transfer between gas and liquid, thereby improving the hydrodynamic performance.

Four Kinds of Polymer Microspheres Prepared by the Seed Swelling Method Used to Purify the Industrial Production of Phytol.

Four monodisperse porous polymer microspheres were successfully prepared by seed emulsion polymerization and used as stationary phases for HPLC and preparative high-performance liquid chromatography (Prep-HPLC). All four polymer microspheres(polystyrene-polystyrene (PS-PS), polystyrene-poly(glycidyl methylate) (PS-PGMA), polystyrene-poly(methyl methylate) and poly(glycidyl methylate)-poly(glycidyl methylate) were used for filling HPLC empty columns. According to the analysis results of the HPLC column, PS-PS and PS-PGMA microspheres were screened out as the stationary phase of Prep-HPLC. The industrial-grade phytol was successfully separated and purified, and the purity of the final phytol was as high as 99%. The two types of polymer microspheres have been applied to industrial-grade phytol purification and have been used in factories.

Comparison between the use of polyether ether ketone and stainless steel columns for ultrasonic-assisted extraction under various ultrasonic conditions

The ultrasound-assisted extraction (UAE) was conducted using the stainless steel (SS) and polyether ether ketone (PEEK) columns and analyzed with high-performance liquid chromatography (HPLC) to understand the mechanism of ultrasound-assisted chromatography (UAC). Empty SS and PEEK columns were used to extract dyes from a fabric under identical conditions with several parameters including the initial ultrasonic bath temperatures (30 °C and 40 °C), ultrasound power intensities (0, 20, 40, 60, 80, and 100 %), ultrasound operation modes (normal and sweep), and ultrasound frequencies (25 kHz, 40 kHz, and 132 kHz) to compare their extraction capabilities. After 30 min of extraction, the amount of extract was determined by HPLC. The PEEK material was significantly affected by ultrasonic radiation compared to the SS material, especially at a higher temperature (40 °C), power intensity (100 %), and frequency (132 kHz) with sweep mode. At a maximum power density of 45 W/L, the extraction effectiveness ratio of PEEK to SS was in the range of 1.8 - 3.9 depending on the specific frequency, initial temperature, and with or without temperature control. The most optimal ultrasound frequencies, in terms of enhancing extraction effectiveness, are in the order of 132 kHz, 40 kHz, and 25 kHz. Unlike the SS material, the PEEK material was more affected by temperature and acoustic effects under identical conditions, especially at 132 kHz ultrasound frequency. In contrast, at lower frequencies of 40 kHz and 25 kHz, no significant differences in the acoustic effects were observed between the PEEK and SS materials. The findings of this study contribute to elucidating the roles of column materials in UAE and UAC.

Bubble size distribution in a bubble column with vertical tube internals: Experiments and CFD‐PBM simulations

AbstractKnowledge of bubble size distribution (BSD) is critical for controlling mass transfer and reaction in bubble column reactors. Installation of internals further complicates this issue. The effects of internals on BSD were systematically investigated through experiments and computational fluid dynamics‐population balance model simulations. The experiments show a bimodal distribution of the volume‐based BSD except at low superficial gas velocity of 0.01 m/s. Addition of 20% internals increases the small‐bubbles fraction, making the first BSD peak more evident. Correspondingly, the simulation reveals a prominent decrease of turbulent dissipation rate and turbulent kinetic energy. Moreover, while the unresolved turbulent kinetic energy dominates in the empty columns, the resolved portion becomes the major component in the presence of internals. This suggests that internals may redistribute turbulent kinetic energy in each scale, which provides more insights into the complex flow characteristics in the presence of internals and process intensification.

Urgensi Re-Desain Penyelenggaraan Pilkada dengan Satu Pasangan Calon Berdasarkan Dinamika Implementasi di Jawa Tengah dalam Perspektif Pengawasan

This research tries to unravel the patterns that emerge from implementing single-pair candidate elections from electoral supervisors' perspective in Central Java. The aim is to identify the problems of the election, particularly from the electoral supervisory’s point of view. This descriptive qualitative research using the online interview as a primary data collecting method added with a questionnaire and supervisory report as secondary data finds some regulatory gaps regarding the “subject” and “activity” of empty columns. The gap has been the main factor in the issues of the electoral supervisory elections with the single-pair candidate. Moreover, if these gaps are not addressed promptly, it will become an ongoing problem that will re-emerge and even escalate into widespread horizontal conflict. Therefore, it is necessary to redesign the electoral institution of single-pair candidates comprehensively to suppress various potential problems.

Load bearing capacity of thin-walled rectangular and I-shaped steel sections of short both empty and concrete-filled columns

In this experimental work, strength results obtained on short columns subjected to concentric loads are presented. The specimens used in the tests have made of cold-rolled, thin-walled steel. Twenty short columns of the same cross-section area and wall thickness have been tested as follows: 8 empty and 12 filled with ordinary concrete. In the aim to determine the column section geometry with the highest resistance, three different types of cross-sections have been compared: rectangular, I-shaped unreinforced and, reinforced with 100 mm spaced transversal links. The parameters studied are the specimen height and the cross-sectional steel geometry. The registered experimental results have been compared to the ultimate loads intended by Eurocode 3 for empty columns and by Eurocode 4 for compound columns. These results showed that a concrete-filled composite column had improved strength compared to the empty case. Among the three cross-section types, it has been found that I-section reinforced is the most resistant than the other two sections. Moreover, the load capacity and mode of failure have been influenced by the height of the column. Also, it had noted that the experimental strengths of the tested columns don’t agree well with the EC3 and EC4 results.

Sole Candidate in the Local Leader Election and Its Implications on the Supervision of the Democratic Process in Indonesia

The sole candidate in the local leader election has become a phenomenon in the world of democracy in Indonesia. The sole candidate in the local leader election in Indonesia, is considered a solution to the impasse of democracy since 2015. This phenomenon has become a solution as well as a polemic in the community, because it is full of monopoly power. This study examines the implementation of a sole candidate in the local leader election in Bone Regency and its implications on the democratic process. This research is classified as field research with qualitative methods, while the approach used is descriptive analytic. The data sources of this research are based on primary data and secondary data. Primary data were taken from the results of interviews and observations. The results of this study indicate that the practice of selecting a sole candidate (choosing an empty column) in Bone Regency is not in the same breath as democracy and reduces the interests of the people's sovereignty in electing a leader. Some of the implications that arise include: a monopoly on political parties, injuring the interests of local communities, sole candidate competition which results in harassment and complications of pressure on voters who campaign for empty columns. As a result, people feel that their rights are not taken into account in the local leader election. The implication of this finding is that in responding to the practice of selecting sole candidates as in Bone Regency, there are many problems, so the sole candidate competition must be ended immediately because it is not in tune with the philosophical meaning of democracy.

Higher spins from exotic dualisations

At the free level, a given massless field can be described by an infinite number of different potentials related to each other by dualities. In terms of Young tableaux, dualities replace any number of columns of height hi by columns of height D − 2 − hi, where D is the spacetime dimension: in particular, applying this operation to empty columns gives rise to potentials containing an arbitrary number of groups of D − 2 extra antisymmetric indices. Using the method of parent actions, action principles including these potentials, but also extra fields, can be derived from the usual ones. In this paper, we revisit this off-shell duality and clarify the counting of degrees of freedom and the role of the extra fields. Among others, we consider the examples of the double dual graviton in D = 5 and two cases, one topological and one dynamical, of exotic dualities leading to spin three fields in D = 3.

Dinamika Proses Penyelenggaraan Pemilihan Walikota di Kota Makassar Tahun 2018

This research aims to assess and analyze the dynamics that occurred in the process of electoral mayor in Makassar City in 2018. The type of research used in this study is qualitative, which will provide a factual representation of the purpose of research. The results of this study show that: there are problems and dynamics that occur in several phases. As at the stage of verification of individual candidate support that there is a chairman of PPS who commits violations and unneutrality ASN. In the stage of setting the candidate is also quite dynamic where the dispute occurs between the elections of the mayor and organizers. At the campaign stage, the APPI-CICU pair is not intense reporting its campaign activities. Then, in the stage of voting and counting, there is a form of the disintegration of the organizers of the district PPK Tamalate that manipulates the data of sound results. As for the stage of determination of candidates elected, KPU Kota Makassar announced it will conduct the election of the mayor back in 2020 because the couple APPI-CICU was defeated by the acquisition of empty columns

Sparse prefix sums: Constant-time range sum queries over sparse multidimensional data cubes

Prefix sums are a powerful technique to answer range-sum queries over multi-dimensional arrays in O(1) time by looking up a constant number of values in an array of size O(N), where N is the number of cells in the multi-dimensional array. However, the technique suffers from O(N) update and storage costs. Relative prefix sums address the high update costs by partitioning the array into blocks, thereby breaking the dependency between cells.In this paper, we present sparse prefix sums that exploit data sparsity to reduce the high storage costs of relative prefix sums. By building upon relative prefix sums, sparse prefix sums achieve the same update complexity as relative prefix sums. The authors of relative prefix sums erroneously claimed that the update complexity is O(N) for any number of dimensions. We show that this claim holds only for two dimensions, whereas the correct complexity for an arbitrary number of d dimensions is O(Nd−1d). To reduce the storage costs, the sparse prefix sums technique exploits sparsity in the data and avoids to materialize prefix sums for empty rows and columns in the data grid; instead, look-up tables are used to preserve constant query time. Sparse prefix sums are the first approach to achieve O(1) query time with sub-linear storage costs for range-sum queries over sparse low-dimensional arrays. A thorough experimental evaluation shows that the approach works very well in practice. On the tested real-world data sets the storage costs are reduced by an order of magnitude with only a small overhead in query time, thus preserving microsecond-fast query answering.

Tests of self-compacting concrete filled elliptical steel tube columns

This paper presents an experimental study into the axial compressive behaviour of self-compacting concrete filled elliptical steel tube columns. In total, ten specimens, including two empty columns, with various lengths, section sizes and concrete strengths were tested to failure. The experimental results indicated that the failure modes of the self-compacting concrete filled elliptical steel tube columns with large slenderness ratio were dominated by global buckling. Furthermore, the composite columns possessed higher critical axial compressive capacities compared with their hollow section companions due to the composite interaction. However, due to the large slenderness ratio of the test specimens, the change of compressive strength of concrete core did not show significant effect on the critical axial compressive capacity of concrete filled columns although the axial compressive capacity increased with the concrete grade increase. The comparison between the axial compressive load capacities obtained from experimental study and prediction using simple methods provided in Eurocode 4 for concrete-filled steel circular tube columns showed a reasonable agreement. The experimental results, analysis and comparison presented in this paper clearly support the application of self-compacting concrete filled elliptical steel tube columns in construction engineering practice.

Experimental Investigations on the Folding Process of Polyurethane Foam-Filled Aluminium Columns with Circular Discontinuities

This article performs an experimental study on empty and polyurethane foam-filled thin-walled aluminium columns with quadrangular cross section in two different conditions: with or without centrally circular discontinuities on the longitudinal or latitudinal sides of column cross section during the folding process (local buckling). In each sample, two circular cut-outs were perforated into the opposite sides of specimens and the samples were axially compressed between two rigid platens under the quasi-static loading. The samples were prepared with different initial lengths, filling conditions and cut-out diameters. Effects of mentioned characteristics are investigated on total absorbed energy, specific absorbed energy, crush force efficiency, peak load and folding wavelength. Experimental observations show that by increasing the cut-out diameter and also by filling the column with the foam, folding wavelength decreases. Also, experiments show that there is an optimum diameter for the longitudinal side cut-outs which total absorbed energy by the filled rectangular specimen with the optimum cut-out is the highest. Furthermore, results illustrate that total absorbed energy increases due to increment of column length, but specific absorbed energy and crush force efficiency are independent of column length.

Development opportunities for storing and displaying of spatial data in long-term experiments

Long-term experiments are required to evaluate the impact of irrigation, nutrient utilization, and year factor as well as to assess the potential consequences of climate change. However, in the long-term experiment, it may be necessary to display spatial data for each parcel, either for investigation of soil heterogeneity or presentation. This article aims to provide help for researchers working in long-term experiments for storing and displaying spatial data.
 After the outlines of each experimental site were measured with GPS, a spatial database has been created in Quantum GIS. Then, a filter script in R statistical environment using RStudio graphical interface was written. The script helps avoid the QGIS data input interface so that large data can be attached to each parcel directly and as a result there is no need for a separate data entry, only the basic statistical database.
 The created GIS database can be used in many ways; it can be exported to KML file format that can be displayed using Google Earth. It is possible to view exported KML files in Google Drive with importing them to Google My Maps application, and with that a browser can display the map. With the Google Drive the maps can be shared within the research group, additionally the outlines can be edited and it is possible to upload the measurement data to the attributes table to existing empty table columns. The map created in Quantum GIS can be used for presentation purposes.

Ballistic limit velocity of empty rectangular metal columns under a blunt projectile penetration

This paper studies the ballistic limit velocity of empty rectangular columns under a blunt projectile penetration, theoretically and numerically. The deformation mechanism of the empty column is considered as plugging. The projectile is assumed to be a flat-ended cylinder without deformation. A new theoretical model of deformation is introduced, and based on the energy method, a theoretical formula is derived to estimate the ballistic limit velocity of the process. Numerical simulations of the penetration process of a blunt solid cylinder into the empty metal columns are performed using the LS-DYNA explicit solver. Different empty columns are used as the targets, and these columns are made from Weldox 460E steel and have different wall thicknesses (6, 7, 8 and 9 mm) and internal column edge lengths (60, 70, 80 and 90 mm). To validate the derived relation for the ballistic limit velocity, the results of the numerical simulations are compared with the corresponding theoretical predictions. Finally, the effects of some geometrical characteristics such as projectile diameter and mass on the perforation process and the ballistic limit velocity are discussed.

Irreversible and reversible reactive chromatography: Analytical solutions and moment analysis for rectangular pulse injections

This work is concerned with the analysis of models for linear reactive chromatography describing irreversible A→B and reversible A↔B reactions. In contrast to previously published results rectangular reactant pulses are injected into initially empty or pre-equilibrated columns assuming both Dirichlet and Danckwerts boundary conditions. The models consist of two partial differential equations, accounting for convection, longitudinal dispersion and first order chemical reactions. Due to the effect of involved mechanisms on solute transport, analytical and numerical solutions of the models could be helpful to understand, design and optimize chromatographic reactors. The Laplace transformation is applied to solve the model equations analytically for linear adsorption isotherms. Statistical temporal moments are derived from solutions in the Laplace domain. Analytical results are compared with numerical predictions generated using a high-resolution finite volume scheme for two sets of boundary conditions. Several case studies are carried out to analyze reactive liquid chromatographic processes for a wide range of mass transfer and reaction kinetics. Good agreements in the results validate the correctness of the analytical solutions and accuracy of the proposed numerical algorithm.

Adsorption isotope effects for carbon dioxide from illite- and quartz-packed column experiments

The transport of gas through porous media can be affected by diffusion and advection, reaction with solid and liquid phases, and adsorption onto solid substrates. Stable isotope substitution within a gas affects its adsorption affinity, solubility and diffusion coefficients and therefore isotope fractionation occurs with these processes. Adsorption of CO2 onto dry solid substrates has been shown to have an apparent inverse isotope effect whereby 12CO2 is preferentially retained during chromatography compared to 13CO2. Here, carbon isotope compositions are reported for CO2 eluted from 1-dimensional flow-through column experiments on dry geologic substrate including quartz sand and crushed illite. An analytical solution to a coupled advection–diffusion–adsorption equation is developed to fit the carbon isotope data and interpret the results from each experiment and a Rayleigh fractionation model is used to interpret adsorption results. Adsorption results from the illite-packed column are shown to closely follow a Rayleigh fractionation model with an alpha value (αadsorbed-gas) of 0.9909 whereas only diffusion and advection are required to describe the empty and quartz-packed columns with a diffusivity (D) ratio of 0.9991 between 13CO2 and 12CO2. These results demonstrate that adsorption isotope effects may significantly change the δ13C value of CO2 that is transported across dry geologic media and these effects should be considered in carbon capture and storage (CCS) leakage detection studies and studies attempting to accurately source CO2 respired in soils under transient state conditions. Isotope effects associated with CO2 adsorption in partially or fully water-saturated geologic media should be investigated in the future.

Experimental and theoretical study of the lateral compression process on the empty and foam-filled hexagonal columns

In this article, a new analytical model of plastic deformation during the flattening process on hexagonal metal columns under the lateral loading in the quasi-static condition is presented. Based on the introduced model, some theoretical relations are derived to forecast the average and instantaneous lateral load of the hexagonal column in two different conditions: empty and polyurethane foam-filled. Then, some lateral compression tests were carried out on the empty and foam-filled metal columns and the experimental results were compared with the theoretical predictions by the present formulas that showed an admissible correlation. The theoretical relations estimate variations of the lateral load in terms of lateral displacement. The theoretical analysis shows that the lateral load on the hexagonal column during the flattening process is dependent on the column wall thickness, column length, and material properties of the column and polyurethane foam-filler. Finally, the effects of geometrical characteristics of the hexagonal columns and material properties of the columns and foams on the lateral load are investigated, experimentally.

New and Highly Efficient Column Chromatographic Extraction and Simple Purification of Camptothecin from Camptotheca acuminata and Nothapodytes pittosporoides

Camptothecin, a widely used natural anti-cancer drug, is difficult to extract and purify effectively from plants. To develop new and highly efficient extraction and purification methods for analysis and production of camptothecin from leaves and fruits of Camptotheca acuminata and Nothapodytes pittosporoides roots. Dried materials were loaded in empty columns with fivefold 60% ethanol for leaves or 70% ethanol for fruits of C. acumnata, and sixfold 70% ethanol for N. pittosporoides roots. The columns were eluted with the same solvents at room temperature. Eluent was collected as extraction solution. Extraction solution from leaves and fruits of C. acuminata was vacuum-evaporated to remove ethanol, precipitated at pH 8.0 to remove alkaline insolubles and fractionated with chloroform at pH 3.0, which yields a crude product with 70% purity. Extraction solution from N. pittosporoides roots was concentrated to 1/10 volume and precipitated at pH 3.0, which yields a crude product with 60% purity. All crude products were purified by crystallisation. All steps were monitored by HPLC. Camptothecin was extracted from the three plant materials at a 98% rate with 15- or 18-fold solvent for content analysis, or at a 97% rate with five- or sixfold solvent for production. All crude products were purified to 98%. The overall recovery rates of camptothecin from plant materials to purified products reached 92% or higher. The new procedures are simple and highly efficient, and have multiple advantages for quantitative analysis and large production of camptothecin from plants.

Influence of ultra-high strength infill in slender concrete-filled steel tubular columns

This paper describes 24 tests conducted on slender circular tubular columns filled with normal, high, and ultra-high strength concrete for plain, bar reinforced and steel fiber reinforced columns. These were reinforced and subjected to both concentric and eccentric axial load. It is a continuation of a previous research paper (Portoles et al., 2011 [1]), which presented test results on eccentrically loaded plain concrete columns. The test parameters are nominal strength of concrete (30, 90 and 130MPa), eccentricity e (0, 20 and 50mm) and type of reinforcement. A comparison with the corresponding empty tubular columns is performed, as the aim of the paper is to analyze the influence of each type of infill and establish the best option for practical application. For the limited cases analyzed the results show that the addition of high or ultra-high strength infill is more useful for concentric loaded cases than for eccentric loaded ones, where it seems that the best design option is the utilization of bar reinforced concrete filling rather than steel fiber to reinforce CFST columns. The experimental ultimate load of each test was compared with the design loads from Eurocode 4, accurate for the eccentrically loaded tests.