Miracle-dz/UniFAR-FTUs huggingface dataset:
Simulation of ionization-wave discharges: a direct comparison between the fluid model and E-FISH measurements

For a long period, there was a resolution gap between numerical modeling and experimental measurements, making it hard to conduct a direct comparison between them, but they are now developing in parallel. In this work, we numerically study diffusive ionization wave and fast ionization wave discharge experiments using recently published electric-field-induced second-harmonic (E-FISH) data together with a classical fluid model. We propose a pressure-E/N range for the drift diffusion approximation and a pressure-grid range for the local field/mean energy approximation of the fluid model. The three-term Helmholtz photoionization model is generalized using parameters given for N2, O2, CO2, and air. The capabilities of the classical fluid method for modeling the inception, propagation, and channel breakdown stages are studied. The calculated electric field evolution of the ionization is compared with E-FISH measurements in the discharge development and gap-closing stages. The influence of electrode shape and predefined electron density on the streamer morphology and the long-standing inception problem of the ionization waves are discussed in detail. Within the application range of the classical fluid model, good agreement can be achieved between calculation and measurement.
On the periphery of university physics: trainee physics teachers’ experiences of learning undergraduate physics

High school physics teachers have a difficult job to do. On the one hand, they are charged with contributing to the creation of a scientifically literate society, while on the other they play a pivotal role in the recruitment of future physicists. Given the importance of this dual role, one might expect that the training of future physics teachers would be a priority for any physics department. However, research suggests that this is often not the case. While concerns have been raised about future physics teachers’ understanding of physics content, less work has focussed on the sociocultural experiences of the learning environments trainees meet when learning undergraduate physics. This case study examines how a sample of trainee physics teachers perceive learning undergraduate physics content together with engineering and physics bachelor students in a large, high-status, research-oriented physics department. The findings aim to be of interest to physics lecturers when examining their own practice. We interviewed 17 trainee physics teachers about their experiences of learning undergraduate physics, how they perceived the relevance of their physics courses for their future role as teachers, and how this affected their physics learning. Here, we identified four central themes of the students’ experiences: (1) teacher programme invisibility, (2) passive classroom culture, (3) perceived relevance of physics courses, and (4) no incentive to do well in physics. We discuss how this study illustrates the potential struggles trainee physics teachers may encounter when learning undergraduate physics. We also suggest how our findings may be used to inform the practice of university physics lecturers who come in contact with trainee physics teachers, and comment on the structure and organization of physics teacher education as a whole.
Nonheating ozone suppression in pulsed air discharges: role of pulse duration and repetition rate

Facilitating the separate production of ozone (O3) and nitrogen oxides (NO x ) in air discharges without a thermal process is of most merit in diversifying plasma technology; in particular, it is a primary requirement in certain cold, heat-sensitive plasma applications. Here, we propose a new method of nonheating ozone suppression in air discharges. The present work demonstrates that controlling the plasma chemical kinetics by adjusting the duration (width) and/or repetition frequency of the high-voltage DC pulse is effective in suppressing ozone formation in a surface dielectric barrier discharge in static ambient air. The temporal development of each oxygen- and nitrogen-related species in air discharge is complicated and shows different trends in the time range <10 µs; relatively long-lived O3 and NO x are strongly governed by the temporal behavior of short-lived reactive species, such as excited N2(A) and N2(v). To quantify time-varying O3 and NO x , an in situ UV absorption spectroscopy is applied to our gas-tight plasma reactor, which is operated in air at 21 °C. With a fixed frequency at 10 kHz and decreasing pulse duration from 10 μs to 0.18 μs, ozone is quenched faster in the plasma reactor, resulting in an irreversible chemical mode transition from an O3- to NO-rich environment. From a different set of experiment (with a 200 ns pulse duration and a frequency range of 1–10 kHz), we can conclude that the off-pulse period also plays a crucial role in the temporal evolution of O3 and NO x ; the larger the applied driving frequency is, the earlier the ozone-free phenomenon appears over the discharge time. Our findings represent a breakthrough in expanding the usage of air discharges and their application in various fields of interest.
Low band-gap polymers incorporating benzotriazole and 5,6-dialkoxy-benzothiadiazole as solution processable electrochromic materials

Two series of donor-acceptor type conjugated polymers bearing benzotriazole or 5,6-dialkoxy-benzothiadiazole as acceptors unit are synthesized via Stille coupling. The optical, electrochemical, spectroelectrochemical characterizations and theoretical calculations are carried out. The polymers display excellent solubility in common organic solvents upon the introduction of long aliphatic side chains. The electrochromic performances of the polymers are also studied. Upon oxida- tion, the polymers switch from magenta or blue to a transmissive light blue state. In particular, respectable optical contrasts of about 44 and 40% are obtained in the visible and near infrared (NIR) region respectively for P2. The polymers also reveal fast switching of about from one second to a few seconds. In addition, P2 exhibits a high coloration efficiency of 518 and 561 cm 2 /C in the visible and NIR region respectively. The promising electrochromic behaviour of these polymers, together with the enhanced solubility will allow large-scale processing and advancement towards real applications.
Catalyst-free III-nitride Nanowires by Plasma-assisted Molecular Beam Epitaxy: Growth, Characterization, and Applications

ii Dedication . iii Acknowledgments . iv Vita . vii List of Figures . xii Chapter 1 . 1 1.1 Background on III-nitrides . 1 1.2 Benefits of Nanowires Compared to Thin Films . 2 Chapter 2 . 11 2.1 Basics of GaN Growth by PAMBE . 12 2.2 Growth Phase Diagrams of GaN NWs on Si(111) . 18 2.3 Two-step growth procedure . 26 2.4 Increased lateral growth of GaN nanowires . 31 2.5 Vertical and Coaxial GaN/AlN Nanowire Superlattices . 36 Chapter 3 . 46 3.1 Motivation for non-polar, AlN/GaN Resonant Tunneling Diodes . 47 x 3.2 Growth and Structural Characterization . 52 3.3 Electrical Characterization . 55 Chapter 4 . 62 4.1 Polarization in III-nitrides . 62 4.2 Motivation for nanowire-based polarization doped devices . 74 4.3 Polarization-induced Nanowire Light Emitting Diodes (PINLEDs) . 77 4.4 Growth of Graded Nanowires . 80 4.5 Structural Characterization . 85 4.6 Device Characterization of Dopant-reinforced PINLEDs . 91 4.7 Device Characterization of Dopant-free PINLEDs . 103 Chapter 5 . 113 5.1 The Importance of Material Polarity in Polarization-doped Devices . 114 5.2 Characterization by Selective Etching and Electron Microscopy . 117 5.3 Characterization by Conductive Atomic Force Microscopy . 122 5.4 Electroluminescence and Mixed Polarity . 129 Chapter 6 . 135 6.1 Optimizing p-down PINLEDs on p-Si . 136 6.2 Metal Substrates as an Alternative to Si . 144 6.3 Further Optimization of PINLED Design . 151 xi Chapter 7 . 157 References . 160 Appendix A: MBE Growth Details . 172 Appendix B: Processing Details . 176 Appendix C: Miscellaneous Nanowire Growth Results . 179 C.1 Two-step samples with short nucleation times . 179 C.2 Nanowires on Mo coated Sapphire substrates . 186
MINERAL STORAGE OF CO2

Carbon dioxide (CO2) levels in the atmosphere are higher and rising faster than at any time in human history, largely because of the use of fossil fuels such as coal, oil, and natural gas. Continued fossil fuel burning will increase CO2 concentrations in the atmosphere at previously unseen rates, raising global temperatures, sea level and ocean acidity with potentially devastating impacts on the availability of food and water, human shelter and coastlines, and energy. Solutions are needed to address this growing threat while continuing to address our energy needs. Limiting this rise in temperature requires a substantial and sustained reduction in the net flow of CO2 into the atmosphere.
An Investigation of Thai Learners’ Needs of English Language Use for Intensive English Course Development

Needs analysis plays an important role in course and curriculum development. Not only is it a necessary step for mandatory courses offered at schools and universities, but it is also crucial for language schools and institutes that offer intensive courses to learners. Assessing the purposes and needs as well as the activities for which the language is needed for the learners can help direct the curriculum as well as lead to successful teaching and learning. The objectives of the study were to study the needs of the learners and the English skills needed by the learners who enrolled in intensive English courses at Chulalongkorn University Language Institute (CULI), and also to investigate the content, teaching methods and length of the courses appropriate for them. The participants were 321 learners who voluntarily took part in the study. The learners were divided into 3 groups based on their occupations and CULI’s course management as follows: students, government officials and employees of private organizations. The data were collected from a needs analysis questionnaire and interviews with selected participants. Both quantitative and qualitative methods were used to analyze the data. The results showed that the learners were interested in improving their English in all four language skills. They needed basic language skills such as reading for the main idea, giving information and general conversational skills in order to communicate effectively in everyday life. There were also demands for English for Specific Purposes courses targeting skills related to their occupations. In addition, interesting information useful for course and curriculum development and management was also identified.
Nitric Dioxide and Acetone Sensors Based on Iron Oxide Nanoparticles

The Fe2O3 and CoFe2O4 nanoparticle-based Langmuir–Blodgett films for sensing of nitric dioxide (NO2) and acetone vapours have been explored. Both the sensitivity of the chemiresistors and dynamic properties, such as the response/recovery time, have been probed in dependence of the number of nanoparticle monolayers and working temperatures. The response of 23 at the NO2 concentration of 1 ppm, i.e., approaching the canine detection limit, has been monitored implying the appropriateness for the detection of nitrate-based explosives.
A clinicopathological study of primary localised cutaneous amyloidosis

Background: Amyloidosis is defined as extracellular deposits of heterogenic, misfolded proteins, amyloid fibrils, in various tissues. The term primary cutaneous amyloidosis (PLCA) usually includes macular amyloidosis (MA), lichen amyloidosis (LA) and nodular amyloidosis. Primary cutaneous amyloidosis is very common in Kerala probably due to socio-cultural practices. There has been no published data on PLCA from Kerala thus we undertook this study. The objectives of the study were to correlate clinical features of primary localized cutaneous amyloidosis with histopathologic findings; to evaluate the sensitivity of Congo red staining with polarized light in histopathologically proven primary localized cutaneous amyloidosis) Methods: We undertook an observational analysis for a period of 2 years from May 2012 to April 2014 in the Department of Dermatology, Amrita Institute, Cochin. All cases clinically diagnosed as cutaneous amylodosis were included in the study. After informed consent, skin biopsy was taken. The histopathologic sections were stained with Congo red and seen under polarized microscopy for apple green birefrengance. Results: A total of 70 patients were included in the study. Of the 70 cases, there were 20 males and 50 females. The most common clinical type was lichen amylodosis observed in 32 patients followed by macular amylodosis (28) and biphasic amyloidosis (10) cases. Histopathological compatibility was seen in 71% of MA and 89% cases of LA. Congored positivity was seen in 53.8%. Congored stain under immunofluorescence microscopy was done for 30 patients which gave a positivity of 85% which indicates that it is more sensitive that polarizing microscopy. Conclusions: Our study showed that the most common type is lichen amylodosis. Histopathology and congo red staining with polarized light is a valuable aid in diagnosis. Congo red stain under immunofluorescence microscopy has greater sensitivity and improves the diagnostic yield.
Magnetic Effect on Thermal Instability of Forced Convection Flow over a Horizontal Plate Heated Form below

This paper presents numerical study of magnetic effect on thermal instability in forced convection flow over a horizontal plate heated from below. The criterion on the position marking on the onset of longitudinal vortices is defined in the present paper. The results show that the onset position characterized by the Grashof number depends on the Prandtl number, the Reynolds number, the wave number, and the Hartmann number. The flow is becomes more stable as the applied magnetic field increases. The results of the present numerical prediction show reasonable agreement with the experimental data with Ha^2/Re =0 in the literature.
PREPARATION AND CHARACTERIZATION OF

Membranes of PEEKlWC containing carbonate derivative ~-cyclodextrin (~-CD) have been prepared and their catalytic behaviour for the p-nitrophenylacetate (PNPA) hydrolysis has been investigated. The effect of different average degree of ~-CD carbonate substitution (DS), the amount of immobilized ~-CD carbonate and operating stirring speeds have been examined under a constant substrate concentration and constant permeation rate. The performance and productivity of the ~-CD membrane reactor indicate an improvement of CD stability.
Perceptions of female narcissism in intimate partner violence: A thematic analysis

This study sought to explicitly investigate manifestations of female narcissism and their attempts at self-regulation in the context of intimate partner violence (IPV). This novel phenomenon was explored through the lens of ex-partners’ perceptions of female narcissists. A qualitative approach using individual interviews was adopted to gain an in-depth insight of the subtleties and nuances of gender differences in narcissistic personality. Semi-structured interviews were carried out with ten male participants who reported having experienced an abusive relationship with a female narcissist. These interviews were transcribed and analysed using thematic analysis. Three overarching themes emerged from the data analysis: (i) dualistic personas of narcissism; (ii) the mask of femininity; and (iii) the hidden paradox of gender roles. Findings illustrated that perceived expressions of female narcissists depicted presentations of narcissistic vulnerability. Analysis also demonstrated that gender-related norms further shaped motives and self-regulatory strategies for females to obtain positions of power and control. These were established through adopting a ‘victim status’, playing the ‘mother card’ and using legal and societal benefits to their advantage. Female narcissists were perceived to employ strategic attempts at self-construction in sinister and abusive ways, governed by what society allows them to express. It is concluded that narcissism describes a phenomenon in females that moves beyond the overt grandiose stereotype. Limitations and suggestions for future research are discussed.
Symmetry change of majorite solid-solution in the system Mg3Al2Si3O12-MgSiO3

Abstract Six single crystals of Mg3(MgxSixAl2-2x)Si3O12 with x = 0.05, 0.13, 0.24, 0.38, 0.52, and 0.64 (the majorite solid-solution) were synthesized at 20 GPa and 2000 °C with a “6-8” type uniaxial splitsphere apparatus. Single-crystal X-ray diffraction studies revealed discontinuities in compositional dependence of the molar volume, equivalent isotropic temperature factors (Beq), and mean bond lengths between x = 0.24 and 0.38. Single crystals in the compositional range 0 ≤ x ≤ 0.24 show no birefringence, whereas those of x = 0.64 have a slight optical anisotropy. Moreover, the cell symmetry for x = 0.64 obtained using synchrotron X-ray radiation is tetragonal with a slight deviation from cubic. On the basis of site splitting expected from compositional dependence of Beq obtained by cubic refinement, the most probable space group in the range 0.38 ≤ x ≤ 0.64 is I41/acd (tetragonal), which is the maximal subgroup of the space group Ia3̅d (cubic). Given that the previous reports that crystals with 0.8 ≤ x ≤ 1.0 have the tetragonal space group I41/a, the majorite solid-solution in this system undergoes the series of symmetry changes, Ia3̅d →I41/acd→I41/a, with increasing MgSiO3 component. The symmetry changes from Ia3̅d to I41/acd cannot be explained by the cation ordering on the octahedral site. Strong electrostatic interaction between the dodecahedral (Mg2+) and tetrahedral (Si4+) cations was observed from atomic thermal motion and electron density distribution. Because one of the site symmetries of the two nonequivalent tetrahedral sites in I41/acd structure loses the center of symmetry with the symmetry reduction from Ia3̅d to I41/acd, the symmetry reduction may be caused by the electronic polarization of the cations due to the neighboring cation-cation interaction.
RETROSPECTIVE AND PROSPECTIVE STUDY OF STAGE PRESENTATION OF CARCINOMA BREAST IN TERTIARY HEALTH CARE CENTRE, INDORE

Breast cancer is most common cause of death in middle aged women today in most of developed cities of India, and up to some extent in rural areas. Significant change is observed during last two decades in distribution of ca breast in India. In this paper, our proposed work focuses on identifying stage of ca breast along with age at which patient is diagnosed as ca breast. This paper also analyzes ca breast ratio for rural and urban population. Then we also tried to find out menstrual status of patients and chief complaints associated with ca breast patients at that particular stage. AIMS OF THE STUDY: The aim of this paper is to document the patient characteristics, stage at presentation of breast carcinoma. To identify specific age group and distribution of ca breast in females. To estimate the disease load on the community. SETTINGS & DESIGN: This was retrospective and prospective study n=400 cases of carcinoma breast. METHODS & MATERIALS: Only FNAC or biopsy proven cases was included in the study. Patients were evaluated in reference to the risk factors i.e. age, menstrual history, breast feeding, OCP/HRT, H/O other malignancy and stage of presentation at the time of diagnosis. For proper staging triple assessment was done, triple assessment included clinical examination, imaging and histopathological examination. Metastatic work done by using LFTs, USG abdomen & chest, X-ray chest & spine and bone scan/CT brain if needed. RESULTS & CONCLUSION: There is significant difference in age at the time of diagnosis and stage distribution of the patients. Mean age of presentation is 40 years, which is ten years earlier as compared to other studies. Bulk of the patients around 55% fell between 30-50 years age group. In stage presentation, maximum patients came under stage II which was 45%,while there were 38% of patients in stage III, 16% patients were fell in stage IV, only 1% patients were found in stage I and none of pt were diagnosed under stage 0. Lymph node metastasis was found in 63% of patients. In view of menstruation 67% of pts were postmenopausal, 18% perimenopausal and 15% were menstruating. According to location 66.5% patients were from rural and 33.5% belong to urban area. There is significant difference in age of distribution and stage of presentation of carcinoma breast, which indicates impact of risk factors and awareness towards the carcinoma breast in our developing country.
NUMERICAL SIMULATION AND PARAMETRIC STUDY OF FORCED CONVECTIVE CONDENSATION IN VERTICAL CHANNEL

Forced convective condensation in vertical channel is investigated numerically. The condensation boundary layers that occur due to temperature difference between the walls and saturation temperature of steam is simulated by the volume of fluid (VOF) method. The effect of variations in the hydraulic diameter, steam velocity, Re number and temperature difference between the wall and saturation temperature of inlet steam on heat transfer coefficients are investigated. Simulation results showed that the condensation length and heat transfer coefficient increase by the increase in the amount of inlet velocity and Reynolds number of inlet steam. Also, it was seen a reduction in temperature difference between the wall and saturated steam.
Laboratory Experiments on Gregariousness During Setting in Balanus Balanoides and other Barnacles

Laboratory experiments showed that cyprids of Balanus balanoides settled readily only when offered surfaces which bore settled barnacles of their own species, or the cemented bases left on surfaces from which these barnacles had been removed. Without such surfaces they proved to be capable of postponing setting for at least 2 weeks, and they chose such surfaces in preference to similar surfaces which bore related species. Cyprids of B. crenatus and Elminius modestus were also capable of making this choice. Setting usually occurred in the immediate vicinity of barnacles or bases, but some cyprids crawled short distances away during their final reconnaissances. When they encountered barnacles attached to glass, they were stimulated to proceed with setting, but they swam away from this unfavourably smooth surface and settled on bare stones nearby. Fragments from various parts of the body, placed upon surfaces which had never borne barnacles, made these somewhat more favourable for setting. Since attached bases alone produced a strong reaction, the cyprids probably respond to contact between their groping antennules and some substance in the cuticle. They did not settle readily when prevented from making contact with adults by a barrier of bolting silk, or with bases by a thin film of nitrocellulose; chemosensory perception of a water-soluble substance, emanating from settled barnacles, is therefore unlikely to be involved. The power of the bases to induce setting was retained after heating to over 200° C, but not after heating to 275° C, when charring occurred. It withstood prolonged washing in water, heating with fat solvents and dilute acids, and treatment in the cold with caustic alkalis, concentrated acids, pepsin, formaldehyde, benzoquinone, sodium sulphide, phenol, urea, and diazonium solution. It was destroyed in the cold by sodium hypochlorite, which was observed to dissolve the bases, and also by hot concentrated acids and alkalis. The chemical properties of the active substance are thus entirely consistent with those of quinone-tanned proteins, which are known to form the epicuticle and attachment cement. A field experiment showed that similar behaviour occurs under natural conditions. It leads cyprids to suitable habitats and it facilitates breeding.