Independent Reflections Research Articles

Reflectivity enhancement of full color tri-layer electrowetting display with polymer cholesteric liquid crystal films

Electronic paper display has received increasing attention due to its outstanding properties of wide viewing angle, bistable state and lower energy consumption. Among various electronic paper display technologies, electrowetting e-paper (EWD) is the most promising as it can achieve full-color display by using stacked layers or RGB color filter. However, the EWD is faced with several challenges, including poor color brightness, low contrast ratio and small color gamut. To improve the performance of the EWD, we proposed a new configuration of EWD consisting of three independent PCLC reflection films based on the cholesteric liquid crystal materials. We designed and experimentally fabricated three types of reflection films, and then added the PCLC films to the tri-layered EWD device. We experimentally characterized the reflectivity and color gamut of the sample in the dark room. It is found that the experimental results and simulation results match with each other. It is demonstrated that with the PCLC films, the reflectivity is improved by 20%, while the color gamut is improved by 80%, which is sufficient for the daily display demand of E-paper. The proposed EWD device containing PCLC reflection films provide a new strategy to improve the brightness and color gamut of current EWD device, and is promising for realizing the full-color E-paper display.

Analisis Pengaruh Belanja Daerah, DBH dan DAU terhadap Pendapatan Asli Daerah di Provinsi Jawa Tengah

Regional autonomy is a policy in which the government system shifts from a centralized system to a decentralized one. The increase in the Balancing Fund is expected to be followed by an increase in regional fiscal independence in the form of a significant increase in Local Revenue (PAD) as a reflection of regional independence. The purpose of this study was to determine the effect of Regional Expenditure, Revenue Sharing Funds (DBH), General Allocation Funds (DAU) on Regional Original Revenues in Central Java Province. This research uses a quantitative approach with a regression test. The results showed that the allocation of Regional Expenditures and Revenue Sharing Funds have a positive effect on Regional Original Revenues, while the General Allocation Funds have a negative effect on Regional Original Revenues.

Refinements for Bragg coherent X-ray diffraction imaging: electron backscatter diffraction alignment and strain field computation.

Bragg coherent X-ray diffraction imaging (BCDI) allows the 3D measurement of lattice strain along the scattering vector for specific microcrystals. If at least three linearly independent reflections are measured, the 3D variation of the full lattice strain tensor within the microcrystal can be recovered. However, this requires knowledge of the crystal orientation, which is typically attained via estimates based on crystal geometry or synchrotron microbeam Laue diffraction measurements. Presented here is an alternative method to determine the crystal orientation for BCDI measurements using electron backscatter diffraction (EBSD) to align Fe-Ni and Co-Fe alloy microcrystals on three different substrates. The orientation matrix is calculated from EBSD Euler angles and compared with the orientation determined using microbeam Laue diffraction. The average angular mismatch between the orientation matrices is less than ∼6°, which is reasonable for the search for Bragg reflections. The use of an orientation matrix derived from EBSD is demonstrated to align and measure five reflections for a single Fe-Ni microcrystal via multi-reflection BCDI. Using this data set, a refined strain field computation based on the gradient of the complex exponential of the phase is developed. This approach is shown to increase accuracy, especially in the presence of dislocations. The results demonstrate the feasibility of using EBSD to pre-align BCDI samples and the application of more efficient approaches to determine the full lattice strain tensor with greater accuracy.

Hybrid Reinforcement Learning for STAR-RISs: A Coupled Phase-Shift Model Based Beamformer

A simultaneous transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) assisted multi-user downlink multiple-input single-output (MISO) communication system is investigated. In contrast to the existing ideal STAR-RIS model assuming an independent transmission and reflection phase-shift control, a practical coupled phase-shift model is considered. Then, a joint active and passive beamforming optimization problem is formulated for minimizing the long-term transmission power consumption, subject to the coupled phase-shift constraint and the minimum data rate constraint. Despite the coupled nature of the phase-shift model, the formulated problem is solved by invoking a hybrid continuous and discrete phase-shift control policy. Inspired by this observation, a pair of hybrid reinforcement learning (RL) algorithms, namely the hybrid deep deterministic policy gradient (hybrid DDPG) algorithm and the joint DDPG & deep-Q network (DDPG-DQN) based algorithm are proposed. The hybrid DDPG algorithm controls the associated high-dimensional continuous and discrete actions by relying on the hybrid action mapping. By contrast, the joint DDPG-DQN algorithm constructs two Markov decision processes (MDPs) relying on an inner and an outer environment, thereby amalgamating the two agents to accomplish a joint hybrid control. Simulation results demonstrate that the STAR-RIS has superiority over other conventional RISs in terms of its energy consumption. Furthermore, both the proposed algorithms outperform the baseline DDPG algorithm, and the joint DDPG-DQN algorithm achieves a superior performance, albeit at an increased computational complexity.

Кристаллохимические особенности обогащенного стронцием аквалитоподобного минерала из Кондерского массива

A hydrated Sr-rich member of the eudialyte-group mineral from Konder (Southern Yakutia) alkaline complex has been investigated by the methods of electron probe microanalysis and X-ray diffraction. The crystal structure was refined to R = 3.9 % in the anisotropic approximation of atomic displacements using 2188 independent reflections with F > 3(F). The unit-cell parameters are: a = 14.1039(2), c = 31.0743(4) Å, V = 5353.1 Å3; the space group R3. The chemical composition of the studied mineral (Z = 3): 
 Na3.87K0.06Sr1.01Ba0.16Ca4.65REE0.47Y0.3Fe0.38Mn1.27Zr2.92Hf0.3Ti0.09Nb0.12Mg0.07Si25.83O72Cl0.17. 
 The crystal chemistry features of the mineral and its place among hydrated eudialytes are discussed.

Crystallographic phase retrieval method for liquid crystal bicontinuous phases: indicator-based method.

An indicator-based crystallographic phase retrieval method has been developed for diffraction data of bicontinuous cubic phases of lyotropic liquid crystals. Such liquid crystals have large structural disorder; the number of independent Bragg reflections that can be observed is limited. This paper proposes two indicators to identify plausible combination(s) of crystallographic phases, i.e. electron-density distribution. The indicators are based on the characteristics of the liquid crystals: amphiphilic molecules diffuse mainly in the direction parallel to polar-nonpolar interfaces and the electron density in the direction parallel to the interfaces is averaged. One indicator is the difference between the maximum and minimum electron density, and the other is calculated from the Hessian matrix of the electron density. Using test data, the electron densities were calculated for all possible phase combinations and indicators were obtained. The results indicated that the electron densities with the minimum indicators were close to the true electron density. Therefore, this method is effective for phase retrieval. The accuracy of the phase retrieval decreased when the volume fraction of the region including the triply periodic minimal surface increased.

A Narrative Study of Professional Growth of Outstanding Elementary School Music Teachers

Outstanding elementary school music teachers are outstanding representatives of the elementary school music teacher community, and they are the objects of study and emulation for general elementary school music teachers. Their professional growth experiences can provide inspiration for teacher education institutions to train elementary school music teachers and for general elementary school music teachers to grow professionally on their own. The narrative study of the outstanding elementary school music teachers revealed that the factors affecting their professional growth were from four aspects: personal, family, school and society, and the basic ways of their professional growth were professional learning, teaching and research activities and reflective summaries. It is pointed out that social opinion and encouragement are the key prerequisites for the professional growth of elementary school music teachers, government support and guidance are the important conditions for the professional growth of elementary school music teachers, and school service and management are the basic guarantees for the professional growth of elementary school music teachers, and independent learning and reflection are the inexhaustible motivation for the professional growth of elementary school music teachers.

Discovery of the Li-Sr-La-Zr-O Compound and the Investigation of Its Lithium-Ion Conductivity.

Single crystals of Li3.957Sr1.957La0.043ZrO6, having a new crystal structure, were successfully grown in air using the floating zone crystallization method. The obtained crystals were colorless and had a rectangular shape with a maximum dimension of 8(φ) × 50 mm. The elemental composition of the crystal was determined via energy-dispersive X-ray spectroscopy. Single-crystal X-ray structure analysis revealed that the crystal was monoclinic, in space group P21/n, with lattice parameters of a = 5.7506 (2) Å, b = 6.2968 (3) Å, c = 8.4906 (3) Å, and β = 97.066 (1) deg. Crystal structure refinement using 652 independent reflections resulted in a confidence factor (R) of 1.78% and a wR factor of 2.57%. The AC-impedance measurement revealed that the lithium-ion conductivity of the Li3.957Sr1.957La0.043ZrO6 single crystal at 298 K was 6.8 × 10-4 S/cm, and the activation energy calculated from the Arrhenius plot was 0.24 eV. The proposed single crystals exhibit significant potential for application as solid electrolytes for lithium-ion batteries at low temperatures.

BIOS: An Omni RIS for Independent Reflection and Refraction Beamforming

As an important member of reconfigurable intelligent surfaces (RISs), intelligent omni-surface (IOS) has attracted increasing attention recently due to its ability of simultaneously serving user equipments (UEs) on both sides of the metasurface. However, in practical implementation, the phase shifts of the IOS must be shared for both reflection and refraction signals, which inevitably leads to coupled reflection and refraction beams. To address this issue, in this letter, we propose an innovative bilayer-IOS (BIOS) structure to achieve flexible reflection and refraction beamforming. Thanks to the deployment of two neighboring IOSs, the BIOS can almost independently control the reflection and refraction beams for UEs on both sides of it. We apply the proposed BIOS in a multi-user multi-input single-output system, formulate the joint base station precoding and BIOS passive beamforming optimization problem aiming at maximizing the system spectral efficiency, and solve it via a weighted mean square error minimization design approach. Simulation results validate the superiority of BIOS over the conventional RISs.

Debate: International Company Tax Developments And Some Reflections On Ways Forward For The African Continent

The article comments on the contribution in this edition entitled ‘Unilateral Digital Services Tax in Africa; Legislative Challenges and Opportunities’. The current paper also serves as an independent reflection on contemporary developments in company taxation and potential ways forward in this regard for the African continent. With a view to submitting suggestions that could cater to the needs and revenue mobilization interests of African countries and – building on the observations of the commented paper’s author – the current paper proposes some suggestions for potential tax policy approaches for Africa. These are based on securing two objectives: (1) maintain and/or attract investment while (2) devising ways and means to further securing sustainable revenue mobilization policies. The first objective could be pursued by prudently continuing to compete for investment to the extent possible considering the available scope for such under the envisaged Pillar Two approach and on a regionally coordinated basis. Meeting the second objective could occur by furthering the market-based tax base division agenda that has emerged in recent years along with the spread of digital services taxes and in the context of developments towards the construction of the Amount A concept in Pillar One. Such a policy direction could also be pursued if the envisaged Pillars collapse. Corporate Income Tax, base erosion and profit shifting (BEPS), Pillar One, Pillar Two, tax competition, special tax zones, tax incentive regimes, developing countries, developing world, Africa, capacity building, human resource development, fairness.

The Role of the Bi3+ Lone Pair Effect in Bi(H3O)(SO4)2, Bi(HSO4)3, and Bi2(SO4)3.

Three new members in the Bi2O3-SO3-H2O system are identified by single crystal X-ray diffraction and Rietveld refinement after a fundamental examination of this phase space. Bi(H3O)(SO4)2 crystallizes in space group P21/c (no. 14, a = 1203.5(4), b = 682.9(2), c = 821.2(2) pm, β = 102.99(1)°, 861 independent reflections, 88 refined parameters, wR2 = 0.14) homeotypic with Nd(H3O)(SO4)2 featuring edge-sharing BiO9 polyhedra. Bi(HSO4)3 crystallizes in a new structure type in space group P1 (no. 2, a = 492.04(7), b = 910.8(1), c = 1040.8(2) pm, α = 85.443(5)°, β = 86.897(5)°, γ = 74.542(4)°, 3227 independent reflections, 154 refined parameters, wR2 = 0.05) comprising dimers of edge-sharing BiO8 polyhedra. For Bi2(SO4)3, a new modification crystallizing in space group P21/n (no. 14, a = 1308.03(7), b = 473.25(3), c = 1452.61(8) pm, β = 100.886(2)°, 3189 independent reflections, 155 refined parameters, wR2 = 0.03) isotypic to Sb2(SO4)3 with noncondensed BiO7 polyhedra is presented. The role of the Bi3+ lone pair effect as elucidated by density functional theory (DFT) calculations is discussed for all three compounds with respect to their structural and optical properties. Additionally, the Bi3+ lone pair activity is compared to the recently reported borosulfates Bi(H3O)[B(SO4)2]4 and Bi2[B2(SO4)6]. Geometrical calculations based on structural data are correlated with electron localization function (ELF) calculations to establish the origin of the direction and strength of the lone pair stereoactivity of Bi3+ in oxidic compounds. Finally, the thermal properties of the three compounds are reported.

Diagram Ishikawy w dydaktyce akademickiej na specjalnościach nauczycielskich

The article shows a new perspective on teaching students to diagnose the causes of complex problems using dedicated tools, such as the Ishikawa diagram. The theoretical part discusses why complex diagnosis of problems is an essential element of a teacher’s work. The author describes the heterogeneity of the school environment and its dependence on the network of relationships with the family and social environment as well as the mental and physical condition of individual students. This part of the article also describes the changes in the structure of the Ishikawa diagram, and examples of how it has been modified in various fields of knowledge. The empirical part is a report on constructing a students’ exemplary diagram. This part discusses using the Ishikawa diagram in the humanities to illustrate the causes of the reading problem among children and adolescents. An analysis was conducted of building expert knowledge by people actively involved in the learning process. The article’s author argues that the Ishikawa diagram is a valuable element in academic teaching, because reflection on any complex problem using visualization methods prepares students to diagnose potential issues in future professional work. The conclusions emphasize the importance of students’ independent reflection on complex problems. Accordingly, the author asks about the primary goal of university education.

Growth, crystal structure, Hirshfeld surface and vibrational properties of a new supramolecular hybrid material: (C4H7N2)2TeBr6

A novel tellurium (IV) hybrid compound with 2-methylimidazole was prepared. The crystal was grown by slow evaporation method from aqueous solutions at room temperature giving birth to a new compound with formula (C4H7N2)2TeBr6. The structure was determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic system, space group C 2/c, with the following parameters: a = 18.577(2)Å, b = 9.1497(10)Å, c = 13.5355(17)Å, α = 90°, β = 123.835(5)°, γ = 90° and Z = 8. The structure was solved with a final R = 0.044 for 2783 independent reflections. The crystal arrangement consists of [TeBr6]2− anions surrounded by [C4H7N2]2+ cations. The stability of the structure was ensured by hydrogen bonding contacts (N–H…Br) lengths that are in the range of 3.490–3.682 Å. The infrared spectra (FTIR) were recorded in the 4000–550 cm−1, confirming the existence of vibrational modes that correspond to the organic and inorganic groups. The crystal packing was stabilized mainly by Br…H (73.6%) interactions. Hirshfeld surface calculations were conducted to further investigate intermolecular interactions, associated 2D fingerprint plots and enrichment ratio, revealing the quantitatively relative contribution of these interactions in the crystal packing.

Site splitting at M3 in allanite-(Ce)

AbstractWe report the crystal structure of allanite-(Ce), with composition (Ca1.0REE0.9□0.1)Σ2.0(Al1.46Fe3+0.52Fe2+0.76Mg0.12Ti0.15)Σ3.01Si3O12(OH) from the Xinfeng rare earth element (REE)-bearing granite in Guangdong Province, China. It has the unit cell a = 8.9550(4) Å, b = 5.77875(16) Å, c = 10.2053(4) Å, β = 114.929(5)° and Z = 2 in space group P21/m and is characterised by site splitting at M3 into M3a and M3b, at a distance of 0.38(3) Å, which are occupied partially by Fe0.764Mg0.12 and Ti0.15, respectively. The structure was determined by single-crystal X-ray diffraction and refined with anisotropic full-matrix least-squares refinement on F2 to R1 = 2.82%, wR2 = 7.77% for 1856 independent reflections (8772 collected reflections). However, M3 splitting is not present in either ferriallanite-(Ce) or epidote, in which M3 is almost fully occupied either by Fe2+ or by Fe3+. Comparisons of bond lengths and volumes in cation polyhedra among allanite-(Ce), ferriallanite-(Ce) and epidote tend to indicate that the essential factor that facilitates site splitting of M3 in allanite-(Ce) is heterovalent substitution and occupation of a crystallographic site between Fe2+(Mg2+/Mn2+)–Al3+(Ti4+), a common phenomenon in minerals, such as the plagioclase series. Fine structure analysis of the M3 split model revealed that deformation of A2 is related closely to distorted M3, which is consistent with Fe2+ incorporation following REE substitution.

66 An Evaluation of ‘Remote Consultations’: A Simulation-Based Education Intervention

The COVID-19 pandemic necessitated an increase in virtual consultations with a disruption to the management of long-term conditions. Ongoing virtual consultations are required to assist with demand, patient experience and environmental impact. In both primary and secondary care, there has been no formal education provided to the workforce on how to conduct virtual consultations. Anecdotally this is affecting staff experience and well-being, patient experience and, could impact on the effectiveness of the consultation in aiding self-management. There is also an inherent risk of missed or incorrect diagnosis in virtual consultations, which could be mitigated with adequate training of the workforce.The training aimed to promote the development of clinical practitioners in a safe environment and to expose these participants to the key aspects of remote consultations. Additionally, the course aimed to encourage independent reflection of participant knowledge, skills, behaviour, attitudes and service quality provision in relation to simulated remote consultation scenarios.We provided a combination of didactic and simulation-based education (SBE) on virtual consultations. We provided educational recordings of virtual model consultations for reference. Trainees were provided with the videos to complete a self-paced didactic educational session. Subsequently, a group session was held virtually in groups of six involving simulated clinical scenarios with a faculty-led debrief. Avatars were used to simulate patients and patient medical records were simulated in the ‘chat’ function. These simulation sessions allowed the transfer of knowledge into practice whilst using SBE methods to debrief on human factors skills, specifically focussing on human factors in a virtual world.The purposely developed ‘Remote Consultation Self-Assessment Tool’ was completed immediately prior to and after the training. This tool provided Likert responses to 10 statements relating to the course content and consequent quantitative analysis was based on the percentage change in participant self-assessment. The General Self Efficacy Scale (GSE) was also used to gather information from participants prior to and after the training. The GSE measures participant self-efficacy via a 5-point Likert scale.A total of 29 participants attended the course. There was a high failure to attend rate of 40%, with covering the COVID-19 vaccine clinics a commonly stated reason for failure to attend. Primary care workers made up 60% (n = 18) of participants, 26% (n = 9) worked in secondary care and 6% (n = 2) worked in other settings. Most participants (85%) were naive to SBE. There was a significant improvement in both the remote consultation self-assessment tool (mean difference 12.08 [95% CI 5.31 to 18.83] p = 0.001) and the GSE (mean difference 3.54 [95% CI 1.81 to 5.27] p < 0.0001). This model of delivering SBE has improved access for staff working in primary care and other areas who have not been able to access SBE previously. The use of avatars is a feasible method of delivering SBE. Consideration to improving attendance rates at courses should be a priority for those delivering SBE.

On the incorporation of strontium into the crystal structure of bredigite: structural effects and phase transition

Sr-substitution in the crystal structure of bredigite has been studied in detail. Samples of a hypothetical solid-solution series with nominal composition Ca7-xSrxMg[SiO4]4 (x = 0, 2, …,7) have been prepared from sinter reactions in the temperature range between 1275 and 1325 °C and characterized using powder and single-crystal X-ray diffraction. Synthesis runs between x = 1 and x = 4 resulted in compounds with increasing Sr contents, for which single-crystal diffraction studies revealed the following Sr/(Sr + Ca) atomic ratios: 0.133,0.268, 0.409 and 0.559. They are isostructural to the pure calcium end-member (x = 0) and adopt the orthorhombic space group Pnnm. Evolution of the unit-cell parameters and cell volumes of the solid-solution series are defined by linear or nearly linear trends when plotted against the Sr/(Sr + Ca) atomic ratio. Replacement of calcium with strontium atoms on the different sites shows clear preferences for specific positions. For the experiment with x = 5, formation of bredigite-related single-crystals with Sr/(Sr + Ca) = 0.675 was observed. These samples, however, exhibited a halved c lattice parameter when compared with the corresponding value in the Pnnm structure, pointing to a compositionally induced phase transition somewhere in region between Sr/(Sr + Ca) = 0.559 and 0.675. The crystal structure of this new phase with composition Ca2.32Sr4.82Mg0.86[SiO4]4 was successfully determined in space group Pbam. Basic crystallographic data are as follows: a = 18.869(2) Å, b = 6.9445(8) Å, c = 5.5426(6) Å, V = 726.28(14) Å3, Z = 2. Structure determination was accomplished using charge flipping. Subsequent least-squares refinements resulted in a residual of R(|F|) = 2.70% for 822 independent reflections and 87 parameters. The Pbam- and the Pnnm-structures are in a group-subgroup relationship and topologically related. Both are based on so-called pinwheel-like MSi6O24 clusters consisting of a central magnesium-dominated [MO6]-octahedron as well as six attached [SiO4]-tetrahedra. The clusters are linked into chain-like elements running along [001]. Linkage between the chains is provided by mixed Sr/Ca positions with 6 to 10 oxygen ligands. Differences between the two phases result from changes in Sr-Ca site occupancies in combination with displacements of the atoms and tilts of the tetrahedra. The distortion pattern has been studied using group-theoretical methods including mode analysis. Notably, for the samples with x = 6 and x = 7—the latter corresponding to the hypothetical pure strontium end-member composition—no bredigite-type phases could be identified, indicating that there is an upper limit for the Sr-uptake.

Declined Offers for Deceased Donor Kidneys Are Not an Independent Reflection of Organ Quality.

Deceased donor kidney offers are frequently declined multiple times before acceptance for transplantation, despite significant organ shortage and long waiting times. Whether the number of times a kidney has been declined, reflecting cumulative judgments of clinicians, is associated with long-term transplant outcomes remains unclear. In this national, retrospective cohort study of deceased donor kidney transplants in the United States from 2008 to 2015 (n=78,940), we compared donor and recipient characteristics and short- and long-term graft and patient survival outcomes grouping by the sequence number at which the kidney was accepted for transplantation. We compared outcomes for kidneys accepted within the first seven offers in the match-run, after 8-100 offers, and for hard-to-place kidneys distinguishing those requiring >100 and >1000 offers before acceptance. Harder-to-place kidneys had lower donor quality and higher rates of delayed graft function (46% among kidneys requiring >1000 offers before acceptance versus 23% among kidneys with ≤7 offers). In unadjusted models, later sequence groups had higher hazard of all-cause graft failure, death-censored graft failure, and patient mortality; however, these associations were attenuated after adjusting for Kidney Donor Risk Index (KDRI). After adjusting for donor factors already taken into consideration during allocation, and recipient factors associated with long-term outcomes, graft, and patient survival outcomes were not significantly different for the hardest-to-place kidneys compared with the easiest-to-place kidneys, with the exception of death-censored graft failure (adjusted hazard ratio, 1.16, 95% CI, 1.05 to 1.28). Late sequence offers may represent missed opportunities for earlier successful transplant for the higher-priority waitlisted candidates for whom the offers were declined.

Synthesis, crystal structure, IR spectroscopy, and DFT computation of the new variety of 2-carboxyanilinium dihydrogen phosphate (C7H8NO2+. H2PO4−)

The crystals of 2-carboxyanilinium dihydrogen phosphate (C7H8NO2+. H2PO4−) were prepared by slow evaporation technique at room temperature. Single crystal X-Ray diffraction analysis shows that the new synthetized compound crystallizes in the monoclinic system with P21/n (Z = 4) space group, and the following unit cell parameters a =10.6538(8) Å, b = 4.8249(4) Å, c = 19.0605(15) Å, β= 99.317 (3)°, V = 966.85(13) Å3. The structure refinement is made by the least-squares method with full matrix at R = 0.032 and wR = 0.092 for 2948 independent reflections. In the title structure, [H2PO4]− anions and [C7H8NO2]+ cations are linked together by medium to strong hydrogen bonds, forming a three-dimensional complex network, which ensures the structure cohesion. The new structure variety is compared to the allotropic triclinic form determined elswhere. The infrared spectrum of this compound is reported and discussed based on theoretical group and computational analyses. For this, the optimal molecular geometry, harmonic vibrational frequencies, and infrared intensities were calculated using the density function theory (DFT) method using the B3LYP functional with the 6–311 G (d,p) basis set. The theoretical Infrared and the HOMO-LUMO properties have been determinated and discussed for this compound. The computational structural parameters results are generally found in agreement with the experimental investigations.

Uszkolnienie marksizmu. Edukacja a zmiana społeczna

One of the constitutive assumptions for Marx and Engels’ thought was to criticise the Enlightenment’s ideaof revolution in school education. This education, which was an elite right in their time, did not become anobject of independent reflection. The workers’ movement identified it with self-education. Intelligence withschooling. The development of schooling pushed towards the transfer of political struggle to the school.Educational policy in countries ruled by authoritarian parties appealing to Marxism and in countries wheremovements appealing to Marxism had an impact on education became a new problem. The current profoundcrisis of these phenomena makes us ask questions about the logic of their development and the reasons forthe current breakdown.

Synthesis, Crystal Structure, Vibrational Study and DFT Computation of Barium Dihydrogenomonophosphate Ba(H2PO4)2

The single crystal of barium dihydrogenomonophosphate, Ba(H2PO4)2 was prepared by the direct method. This compound exists in two forms: one orthorhombic, the other triclinic. In this work, we are interested in the triclinic form from the vibrational and crystalline side too. X-ray crystallography showed that this compound crystallizes in the triclinic centrosymmetric with space group P-1 (Z=2) with a = 6.9917(5)Å,b = 7.1929(5)Å,c = 7.9667(9)Å,α = 104.517(8)°,β = 95.918(7)° and γ = 109.459(6). The structure was solved from 3444 independent reflections with R = 0.0198 with wR= 0.0633.The bands observed in the infrared and Raman spectra of Ba(H2PO4)2 are assigned based on the literature results and the theoretical group analyses carried out in the group of factors Ci. The optimal molecular geometry, harmonic vibrational frequencies, infrared intensities, and Raman scattering activities were calculated using density functional theory (DFT/B3LYP) methods with the LanL2DZ basis set. The HOMO-LUMO properties and geometries of this compound have been determined and discussed. The computational structural parameters are generally in agreement with the experimental investigations. The theoretical infrared and Raman spectra for the title compound have been constructed.