Peculiar Change Research Articles

Dual dome-like superconductivity in CuIr2Te3.85S0.15-xSex chalcogenides

In this paper, we report the superconductivity (SC) evolution on Se-substitution CuIr2Te3.85S0.15 telluride chalcogenide. The results of powder X ray-diffraction (PXRD) show that CuIr2Te3.85S0.15Se0.15-x (0≤x ≤ 0.15) series maintain a layered triangular structure and the space group are P3-m1 (No.164). Both the lattice constants a and c increase with increasing Se content. To systematically characterize the superconductivity properties, the electrical, magnetic, and thermal properties of the CuIr2Te3.85S0.15Se0.15-x (0≤x ≤ 0.15) series were tested. The resistivity and magnetic susceptibility measurements reveal that when Se gradually replaces S, CuIr2Te3.85S0.15Se0.15-x remains superconducting at low temperatures and does not disappear or transform into other electron ground states. In addition, With the increase of Se doping, the superconducting critical temperature (Tc) Rises and then falls twice, so the Tc value has two peaks in CuIr2Te3.85S0.15Se0.15-x (0≤x ≤ 0.15) series. Finally, we plot a phase plot of the superconducting transition temperature (Tc) versus the x content, which shows a "double dome" shape. CuIr2Te3.85S0.15Se0.15-x retains the inhibitory effect on CDW as the host CuIr2Te3.85S0.15. This peculiar change in superconducting transition temperature may be due to the change in the density of states at the Fermi surface caused by Se doping.

Defects induced changes in conduction bands of HfS2

We report on a comprehensive study of the electronic structures of the layered semiconductor 1T-HfS2 by employing angle-resolved photoemission spectroscopy (ARPES). With in-situ potassium doping, the band structures of HfS2 could be tuned, and both of the valence band and the conduction band could be observed. S vacancy defects could be induced by post-annealing of HfS2 and a certain amount of S vacancies would result in a peculiar change of the conduction band at M¯ point— the fracture of the conduction band bottom. Our results could provide key information for the defect studies and the application of HfS2.

Dynamic Shape Change of Liquid Crystal Polymer Based on An Order‐Order Phase Transition

AbstractLiquid crystal actuators conventionally undergo shape changes across an order‐disorder phase transition between liquid crystal (LC) and isotropic phases. In this study, we introduce an innovative Liquid Crystal Polymer (LCP) actuator harnessing an order‐order LC phase transition mechanism. The LCP film is easily stretchable within the LC phase, facilitated by the π–π stacking of phenyl groups serving as robust physical crosslinking points, and thereby transforms to a stable monodomain structure. The resultant monodomain LCP actuator shows a distinctive reversible dynamic shape change, exhibiting extension followed by contraction along the LC director on cooling. The extension is propelled by the reversible smectic C to smectic A phase transition, and the contraction is attributed to the re‐entry to the smectic C phase from smectic A phase. Thermal annealing temperature determines this peculiar dynamic shape change, which occurs during both heating and cooling processes. This pivotal attribute finds manifestation in gripper and flower‐shaped actuators, adeptly executing grabbing and releasing as well as blooming and closure motions within a single thermal stimulation. In essence, our study introduces an innovative approach to the realm of LCP actuators, ushering in a new avenue for the design and fabrication of versatile and dynamically responsive LCP actuators.

Dynamic Shape Change of Liquid Crystal Polymer Based on An Order-Order Phase Transition.

Liquid crystal actuators conventionally undergo shape changes across an order-disorder phase transition between liquid crystal (LC) and isotropic phases. In this study, we introduce an innovative Liquid Crystal Polymer (LCP) actuator harnessing an order-order LC phase transition mechanism. The LCP film is easily stretchable within the LC phase, facilitated by the π-π stacking of phenyl groups serving as robust physical crosslinking points, and thereby transforms to a stable monodomain structure. The resultant monodomain LCP actuator shows a distinctive reversible dynamic shape change, exhibiting extension followed by contraction along the LC director on cooling. The extension is propelled by the reversible smectic C to smectic A phase transition, and the contraction is attributed to the re-entry to the smectic C phase from smectic A phase. Thermal annealing temperature determines this peculiar dynamic shape change, which occurs during both heating and cooling processes. This pivotal attribute finds manifestation in gripper and flower-shaped actuators, adeptly executing grabbing and releasing as well as blooming and closure motions within a single thermal stimulation. In essence, our study introduces an innovative approach to the realm of LCP actuators, ushering in a new avenue for the design and fabrication of versatile and dynamically responsive LCP actuators.

‘Spider-like’ POSS in NIPU webs: enhanced thermal stability and unique swelling behavior

PEO-based non-isocyanate polyhydroxyurethane (NIPU, PHU) networks physically modified with octa(3-hydroxy-3-methylbutyldimethylsiloxy)POSS (8OHPOSS) were synthesized via one-pot one-step approach. POSS was introduced into the polymer matrix in the amount of 1–10 wt%. Polar hydroxyls on the vertex groups of POSS allowed for uniform dispersion even up to high loadings (10 wt%). Composites exhibit enhanced thermal stability in comparison to the pristine matrix. FTIR analysis confirmed that POSS strengthens the hydrogen bonding in the material. Upon POSS introduction, plasticization was observed with a peculiar trend change at POSS loadings over 5 wt%. Glass transition temperature of highly crystalline 8OHPOSS was measured and reported to be at around 3 °C. NIPUs at hand exhibit high water absorption (around 200 wt%) typical for hydrogels. Swelling studies show that 8OHPOSS enhances PHUs hydrogels absorption capacity in phosphate-buffered saline (PBS). Higher absorption capacity in PBS solution in comparison to distilled water is an uncommon phenomenon in hydrogels.

RF-wave induced CBRAM characteristic modulation specific to sheet-like conductive filaments

The shape of conductive filaments in CBRAM is important for resistance switching and conductance modulation, especially in applications like neuromorphic and reservoir computing that use conductance as weight. We report on RF-induced modulation of CBRAM using Ge2Sb3.4Te6.2 with sheet-like filaments and compared it to those with dendritic filaments. RF input below 100 MHz reduced SET and RESET voltages, similar to CBRAM with dendritic filaments, but showed significantly different resistance changes. Repeated RF on/off input gradually increased the resistance of low-resistance state, unlike the dendritic filament CBRAM, where the resistance decreased. The increased resistance suggests RF-induced denser sheet-like filaments. Furthermore, the resistance of the high-resistance state showed a peculiar RF-induced resistance change not observed in dendritic filaments. The resistance decreased during RF input and increased to nine times the initial value when RF was switched off. The results show that the conductance modulation by RF input strongly depends on the filament type.

Quantum Linear Magnetoresistance and Nontrivial Berry Phase in High‐Mobility Elemental Tellurium

AbstractElemental Tellurium (Te) is an important p‐type semiconductor with wide practical applications. It is currently of great interest as a chiral crystal with broken inversion and mirror symmetries, and its topological nature is under active discussion. Here the Shubnikov–de Haas (SdH) oscillations with a nontrivial π Berry phase and the quantum linear magnetoresistance (MR) in as‐synthesized high‐mobility Te single crystals are reported. The vapor transport grown Te shows a hollow hexagonal prism structure with tunable carrier density and high mobility of about 1000 cm2 V−1 s−1 at low temperature. For concentration p > 1017 cm−3, the conspicuous SdH oscillations map out the dumbbell‐shaped Fermi surface and the long‐standing peculiar amplitude change with varying magnetic field orientation is explained by careful quantitative analyses. Pulsed magnetic field measurements up to 57 T disclose a quantum linear MR beyond the quantum limit and the Landau fan diagram clearly reveals a topologically nontrivial π Berry phase. This work paves way for the synthesis of high‐mobility Te structures and sheds light onto the intrinsic nontrivial topology of the attractive elemental substance.

Sedimentary aspects of the onset of Middle Triassic continental rifting in the western end of Neotethys; inferences from the Silica and Torna Nappes, NE Hungary: a review

The initiation of continental rifting from the latest Early Triassic was reconstructed by correlation of sedimentary formations deposited in the western end of Neotethys (in the Dinaric–Alpine oceanic branch). The shallow-marine and basinal strata of the Silica Nappes and the Bódvarákó Series from the Torna Nappe (located in the southern part of the Inner Western Carpathians) were studied and compared to sedimentary successions described from the Alps, the Carpathians and the Dinarides. The depositional zonation, developed on the shelf during the Late Permian‒Early Triassic transgression, was dissected and rearranged from the latest Early Triassic. The facies pattern and the differential sedimentary evolution of the shelf domains suggest that the accelerated subsidence began in the latest Early Triassic, and was connected to the onset of continental rifting. Three stages are reconstructed in the studied time-frame. (1) Dark grey carbonates, very poor in fossils, were deposited in restricted and hypersaline intraplatform basins in many shelf domains. In the external domains, shallow-marine carbonates, depositional gaps and terrestrial deposits are typical (formations in the Southern Alps, the External Dinarides and the Serbian–Macedonian Massif). From the latest Early Triassic, this latter shelf segment formed a threshold that restricted water circulation from the intraplatform basins. (2) Shallowing-up carbonate successions mark the next stage that implies a period of tectonic quiescence on the shelf from the late Early Anisian to late Middle Anisian. A peculiar change in biota occurring in previously restricted domains was coeval in shallow-marine and deep-marine settings. The biotic change is revealed by observations that dark grey carbonates, which are very poor in fossils, are overlain by carbonate successions rich in fossils typical for normal-marine water. The biota and environmental changes indicate the opening of a passage which allowed the circulation of well-oxygenated and normal-salinity marine water towards the previously restricted depositional areas. The geodynamic setting switching from continental rifting to spreading in the southern sector of the Dinaric–Alpine oceanic branch (Hellenides and Albanides), triggered the opening of the gateway between the future continental margins, i.e., between the External Dinaridic domain (Adria) and Serbian–Macedonian Massif (Eurasia). (3) Following the biotic event in the northern sector of the shelf, subsidence accelerated and additional intraplatform basins opened from the latest Pelsonian.

Unusual Lattice Parameters Behavior for La1.9Ca0.1NiO4+δ at the Temperatures below Oxygen Loss

In this work, we studied the structural features of La1.9Ca0.1NiO4.11, which is considered a promising cathode material for intermediate temperature solid-oxide fuel cells (IT-SOFC). The effect of different pretreatments on the structural characteristics of the sample was studied using X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) in order to elucidate the origin of a peculiar change of lattice parameters observed earlier during in situ XRD studies. The XRD studies have shown that anisotropic broadening for reflections with a high Miller index l appears after tempering of a quenched (from 1100 °C) sample at 250 °C. This temperature is too low for the release/incorporation of oxygen into the structure but is sufficient for oxygen migration inside the structure. The HRTEM assisted us in revealing differences in the defect structure after different pretreatments. Based on obtained results, the following possible explanation was proposed. Observed additional microstrains and non-oriented planar defects as well as a decrease in the coherent scattering region size in the [00l] direction are caused by the non-homogeneous redistribution of interstitial oxygen in the structure during tempering.

A case of common spontaneous oleogranuloma

Oleogranuloma, a peculiar change in the subcutaneous fatty tissue, was quite often observed in our typhoid epidemics of 1918-22. At the end of this period, this suffering, as a complication after typhus, was sufficiently studied. At the same time, similar changes in adipose tissue were found in cases not related to typhus. The latter group includes our case, which is distinguished by the universality of the distribution of oleogranulomas.

Not your typical rate structure change: Heterogeneous water demand responses

This paper investigates behavioral responses to a complicated and peculiar change in a municipality's water rate structure. In 2006, the City of Norman, Oklahoma Water Utility added a four-dollar fixed fee, reduced the number of block-rate tiers, and changed the rate structure from one that decreased and then increased across higher consumption block groups, to a strictly increasing rate structure. The changes in the volumetric rates were not uniform across the block rates. Customers at ultra-low volumes of consumption faced a one-penny reduction in their volumetric rate but experienced a large increase in total and average cost of water due to the addition of the relatively large fixed fee. In contrast, higher-volume users faced a less severe increase in the total and average charge per gallon consumed. To address the co-determination of average water charge and consumption choice, we estimate separate regressions for households grouped by pre-price change demand and the block group of last gallon consumed. Using detailed, monthly panel data for 23,408 residential water customers from 2002 to 2010 and a variety of model specifications, our results highlight heterogeneous responses across consumption groups. Ultra-low users responded to the price-regime change by increasing consumption whereas higher-volume users reduced consumption. Behavioral responses were found to be greater in the longer-run than shorter-run as expected.

Mass balance and morphological evolution of the Dokriani Glacier, central Himalaya, India during 1999–2014

Glaciological mass balance (MB) is considered the most direct, undelayed and unfiltered response of the glaciers to climatic perturbations. However, it may inherit errors associated with stake under-representation, averaging over the entire glacier and human bias. Therefore, proper validation of glaciological MB with geodetic MB is highly recommended by the World Glacier Monitoring Service (WGMS). The present study focuses on the Dokriani Glacier, central Himalaya which is one of the bench-mark glaciers in the region and has glaciological MB records from 1993 to 2013 with intermittent gaps. In the present study, firstly the glaciological MB series is extended to 2014 i.e., field-based MB for one more year is computed and, to compare with it, the geodetic MB is computed for the 1999–2014 period using high resolution Cartosat-1 digital elevation model (DEM) and SRTM DEM. Finally, the study assesses the regional representation of the Dokriani Glacier in terms of MB and evaluates the influence of the MB regime on its morphological evolution. Results show that the average glaciological MB (−0.34 ± 0.2 m water equivalent (w.e.) y−1) is more negative than the geodetic MB (−0.23 ± 0.1 m w.e. y−1) for the 1999–2014 period. This is likely because of the partial representation of glacier margins in the glaciological MB, where melting is strikingly low owing to thick debris cover (>30 cm). In contrast, geodetic MB considers all marginal pixels leading to a comparatively low MB. A comparative assessment shows that the MB of Dokriani Glacier is less negative (possibly due to its huge accumulation area) than most other glacier-specific and regional MBs, restricting it to be a representative glacier in the region. Moreover, continuous negative MB has brought a peculiar change in the epiglacial morphology in the lower tongue of the glacier as differential debris thickness-induced differential melting has turned the glacier surface into a concave one. This concavity has led to development of a large (10–20 m deep) supraglacial channel which is expanding incessantly. The supraglacial channel is also connected with the snout wall and accelerates terminus disintegration. Given the total thickness of about 30–50 m in the lower glacier tongue, downwasting at its current pace, deepening/widening of supraglacial channel coupled with rapid terminus retreat may lead to the complete vanishing of the lower one km glacier tongue.

Topological magnons for thermal Hall transport in frustrated magnets with bond-dependent interactions

Thermal transport in topologically-ordered phases of matter provides valuable insights as it can detect the charge-neutral quasiparticles that would not directly couple to electromagnetic probes. An important example is the edge heat transport of the Majorana fermions in a chiral spin liquid, which leads to a half-quantized thermal Hall conductivity. This signature is precisely what has recently been measured in $\ensuremath{\alpha}\text{\ensuremath{-}}{\mathrm{RuCl}}_{3}$ under external magnetic fields. The plateau-like behavior of the half-quantized thermal Hall conductivity as a function of external magnetic field, and the peculiar sign change depending on the magnetic field orientations, have been proposed to be strong evidence for the non-Abelian Kitaev spin liquid. On the other hand, for in-plane magnetic fields, it has been theoretically shown that such a sign structure can also arise from topological magnons in the field-polarized state. In this paper, we investigate the full implications of topological magnons as heat carriers on thermal transport measurements. We first prove analytically that for any commensurate order with a finite magnetic unit cell, reversing the field direction leads to a sign change in the magnon thermal Hall conductivity in two-dimensional systems. We corroborate this proof numerically with nontrivial magnetic orders as well as the field-polarized state in Kitaev magnets subjected to an in-plane field. In the case of the tilted magnetic field, in which there exists both finite in-plane and out-of-plane field components, we find that the plateau-like behavior of the thermal Hall conductivity and the sign change upon the reversal of the in-plane component of the magnetic field arises in the partially polarized state, as long as the in-plane field contribution to the Zeeman energy is significant. While these results are consistent with the experimental observations, we comment on other aspects that require further investigation in future studies.

Characteristics of complex interaction between two oppositely-moving laminar buoyant-plumes within slender vertical-channels

The article presents laminar plumes, cellular structures and spatial-waviness in free convective flow within a vertical channel under anti-symmetric heating, and the subtle flow-features during the transition to anti-asymmetry. We perform numerical simulations for a wide range of cross-sectional Grashof numbers (262.4≤ Grb ≤33025), channel aspect ratio (0.0375≤ψ ≤0.1255) and isothermal boundary conditions (anti-asymmetric heating to anti-symmetric heating). The chosen working fluid is air; hence the Prandtl number (Pr) is fixed at 0.715. Certain modified parameters are defined for the present study, such as the channel Grashof number (Gr) and symmetry ratio (εC), to govern the working condition of the channel. The physics of the interaction between oppositely moving wall plumes is studied thoroughly, and the highly sensitive, spatially-oscillatory nature of the flow near the plume interface is shown with the help of velocity and temperature contours. Analytical expressions for the primary velocity and temperature have been derived for the wall plumes for the developed region. Also, the crucial role of the secondary velocity field on the heat and mass transfer across the plume interface and convection cell formation is highlighted, which fails to find much attention in the available literature. Motivated by the flow-features, a novel vorticity-mapping is performed, and the entire flow domain is divided into two regimes, viz. a highly rotational core region and a unidirectional near-wall region, which are separated and illustrated using limiting streamlines. The rotational, stagnant core region seems to expand as Gr increases, resulting in a drop in pumping performance. The Gr is varied by changing both the ψ as well as the hot wall temperature ΘH. The relative effects of these methods on the channel pumping, and thermal performance are studied and an optimum method of Gr variation is proposed for the channel. Finally, the effect of the degree of opposing buoyancy forces is studied by varying the cold wall temperature to attain thermal boundary conditions ranging from anti-asymmetry to anti-symmetry. As the opposing buoyancy increases, the heat transfer becomes more convection dominant near the colder wall and less convection dominant near the hotter wall. Also, the pumping performance seems to be affected adversely, as εC is increased. A peculiar change in the channel performance is also highlighted during the transition to anti-symmetric heating conditions near εC=0.9.

High-pressure Raman scattering and x-ray diffraction studies of the supercritical fluid of hydrogen

The high-pressure properties of the supercritical fluid H2 have been investigated in the Raman scattering and synchrotron radiation x-ray diffraction experiments at room temperature. The pressure dependence of four vibrational modes, i.e., Q1(0), Q1(1), Q1(2), and Q1(3), and four rotational modes, i.e., S0(0), S0(1), S0(2), and S0(3), were precisely obtained, and three rotational constants under pressure, i.e., B0, D0, and H0, were estimated from theoretical formulas. A peculiar change in the pressure dependence of the Raman spectra was observed at 1–2 GPa. Through x-ray experiments, halo patterns were collected within a wide pressure range of 0.1–5 GPa, and the molar volume at each pressure was estimated from the d-value of the halo peak. The obtained pressure–volume relation suggested that the fluid H2 showed a change in compressibility at around 1 GPa and became incompressible above this pressure because the repulsive term of the intermolecular potential became dominant. The dependence followed the relational expression of P ∼ Vm−3.11 above 1 GPa, whereas fluid O2 and N2 of the same homonuclear diatomic molecule followed the relational expression of P ∼ Vm−4.32 above 0.2 GPa. It was found that the fluid H2 behaves differently from fluid O2 and N2 and is more easily compressed than those. The behavior of Vm was significantly correlated with the pressure dependence of the Raman spectra, and the peculiar change of the Raman spectra has been attributed to the enhancement of the intermolecular interaction due to the transfer to the solid-like pressure–volume relation.

Aberration of Serum and Tissue N-Glycans in Mouse β1,4-GalT1 Y286L Mutant Variants.

β1,4-GalT1 is a type II membrane glycosyltransferase. It catalyzes the production of lactose in the lactating mammary gland and is supposedly also involved in the galactosylation of terminal GlcNAc of complex-type N-glycans. In-vitro studies of the bovine β4Gal-T1 homolog showed that replacing a single residue of tyrosine with leucine at position 289 alters the donor substrate specificity from UDP-Gal to UDP-N-acetyl-galactosamine (UDP-GalNAc). The effect of this peculiar change in β1,4GalT1 specificity was investigated in-vivo, by generating biallelic Tyr286Leu β1,4GalT1 mice using CRISPR/Cas9 and crossbreeding. Mice bearing this mutation showed no appreciable defects when compared to wild-type mice, with the exception of biallelic female B4GALT1 mutant mice, which were unable to produce milk. The detailed comparison of wild-type and mutant mice derived from liver, kidney, spleen, and intestinal tissues showed only small differences in their N-glycan pattern. Comparable N-glycosylation was also observed in HEK 293 wild-type and knock-out B4GALT1 cells. Remarkably and in contrast to the other analyzed tissue samples, sialylation and galactosylation of serum N-glycans of biallelic Tyr286Leu GalT1 mice almost disappeared completely. These results suggest that β1,4GalT1 plays a special role in the synthesis of serum N-glycans. The herein described Tyr286Leu β1,4GalT1 mutant mouse model may, therefore, prove useful in the investigation of the mechanism which regulates tissue-dependent galactosylation.

Pseudolipomatosis Cutis: A Retrospective Case Series of Skin Biopsies Showing a Distinctive Vacuolar Artifactual Change.

Pseudolipomatosis cutis is a distinctive artifact characterized by the presence of adipocyte-like vacuoles in the biopsy specimens. We describe this change in a series of skin biopsies clustered over 2 periods, November 2017-December 2017 and February 2019. Hematoxylin and eosin-stained sections from 21 skin biopsies were examined by 2 dermatopathologists. Variable-sized vacuoles were noted in the epidermis, dermis, and/or subcutaneous fat in all biopsies. Vacuoles were seen in the stratum corneum in 2 biopsies, epidermis in 15 biopsies, papillary dermis in 19 biopsies, reticular dermis in 20 biopsies, and subcutis in 9 biopsies. The vacuoles resembled a true histological change in many biopsies: vacuolated keratinocytes (n = 6), basal cell vacuolization (n = 6), foamy histiocytes (n = 12), and adipocytes (n = 20). Other changes included dermal collagen sclerosis and empty ectatic vascular channels. The clustering of this peculiar change in biopsies from patients with unrelated skin diseases that stopped on changing the formalin solution in both instances suggests that it is an artifactual change due to improper tissue fixation.

Tension dynamics of graphene oxide and peculiar change of yield strain

Tension dynamics is key to graphene oxide (GO) when composited in flexible materials, and there is still lack of some dynamic pictures to show how it is affected by oxidation level. In this paper, uniaxial tension of GO with different oxygen-containing functional groups densities (R) are simulated by molecular dynamics. It is indicated that the elastic modulus and ultimate stress both decrease with increasing R, especially when R < 30%. The yield strain along AC-orientation falls after rises because of the R-depended fractural mechanisms: when R is small, cracks initiate from the distorted carbon bonds connecting to oxygen-containing groups and propagate along the ZZ-orientation, or else, cracks start from the point defects and expands by consolidating point defects; when loaded along the ZZ-orientation, however, fractures are edge dominated. Our research suggests that introducing oxygen-containing groups would be a feasible strategy to improve the deformability of graphene oxide.

6. Qui bénéficie de la croissance mondiale ?

Depuis les années 1980, la distribution globale des revenus a connu une transformation très particulière. La croissance mondiale a eu un effet ambigu sur les inégalités, ayant principalement profité à la fois à une élite mondiale et aux individus pauvres dans certains pays émergents. La hausse des inégalités à l’intérieur des pays a été compensée par une baisse des inégalités entre les pays depuis les années 2000, mais cette dernière tendance égalisatrice a de plus en plus de mal à contrecarrer la hausse des inégalités au sein des pays.

Analysis of the polarized IR reflectance spectra of the monoclinic α-oxalic acid dihydrate.

In contrast to the extensive molecular and crystal structure investigations on oxalic acid dihydrate (C2H2O4·2H2O, α-POX) and its deuterated analogues (α-DOX), stands the absence of a complete vibrational spectra analysis. Such analysis is desirable in view of the proton dynamics in α-POX crystals. In this communication we report the room temperature polarized IR reflectance spectra of a single crystal of α-POX recorded from the ac crystal plane, and from the plane containing the b-crystallographic axis, with polarization along the axis. Dispersion analysis of the reflectance spectra of both Bu and Au symmetry type modes, using model dielectric and reflectance function valid for the monoclinic case, have been performed and the results are discussed. Some aspects of the obtained fit results for some of the spectral regions and the peculiar change of the reflectance function with polarization angle are also discussed in this work. A correlation between the crystal structure and measured spectra, together with the results of the performed dispersion analysis, gave answers to some of the problems concerned with the orientation of the transition dipole moments of the IR active modes. The assignment of modes is assisted by DFT calculations. Another aspect covered in this work is the model reflectance functions using different averaging theories that have been applied in obtaining the reflectance spectrum of a polycrystalline sample. The results of the comparison between these spectra and the recorded reflectance spectra from a polycrystalline sample were further discussed.