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Growth, characterization and optical properties of potassium iodide (KI) doped potassium hydrogen phthalate (KHP) single crystals for optoelectronic applications

Abstract

Potassium iodide (KI) doped potassium hydrogen phthalate (KHP) single crystals were grown by slow evaporation technique using millipore water as a solvent. The grown single crystals were analyzed by powder X-ray diffraction and the analysis confirmed that KI-doped KHP crystallizes in orthorhombic system with space group Pca21. The functional groups were identified by FT-IR technique which showed slight shift in vibrational frequencies, indicating inclusion of dopant into the crystal lattice. The UV-Vis spectral studies revealed the optical transparency of the doped crystals in the entire visible region. The optical band gap values were estimated from Tauc plots. Kurtz-Perry powder test was employed for second harmonic generation efficiency studies of the grown crystals.

Open access
Growth, electrical, thermal, mechanical and etching studies on 4-chloroanilinium hydrogen (2R, 3R)-tartrate monohydrate-an organic NLO single crystal

Abstract

An organic single crystal of 4-chloroanilinium hydrogen (2R,3R)-tartrate monohydrate (4CAHT) was grown by slow evaporation solution growth technique at room temperature. Single crystal XRD study confirmed that the crystal belongs to monoclinic system with the space group P21. Powder XRD analysis confirmed the crystalline nature of the compound. The presence of various functional groups in the compound was revealed by FT-IR analysis. UV studies showed the absence of absorption in the entire visible region. To determine the thermal stability of the grown crystals it was subjected to thermogravimetric and differential thermal analyses. Microhardness and etching studies were also carried out for the crystal. The powder second harmonic generation efficiency of 4CAHT was tested by Kurtz and Perry powder technique and the relative SHG efficiency of 4CAHT was found to be 1.44 times greater than that of standard KDP.

Open access
Improving Quality Management - the Way Toward Economic Prosperity and Quality of Life

Abstract

The National Quality Programme of the Slovak Republic for 2017-2021 strongly emphasises the primary objectives and priorities of the Quality Improvement Strategy. This should be one of the main priorities of the Slovak Government in the upcoming period. The Quality Improvement Strategy should, in general, lead to an improvement in the quality of life. The aim of the paper is to point out the opportunities for improvement by applying indicators aimed at defining the excellence of organisations within the national economy of the Slovak Republic.

Open access
The influence of a goal programming approach for safety management practices on the performance of a selected Indian construction organization

Abstract

The construction industry in India is the second most important contributor to its gross domestic product. However, high rate of accidents and fatalities have tarnished the image of industry in India. Although the industry contributes significantly to the Indian economy, safety management is the primary concern alongside with frequent workplace accidents. The role of safety management is vital to improve safety performance of an organization. The functions of safety management include planning, organizing, staffing, directing, controlling and coordinating safety activities with an aim to minimize accidents/injuries. Safety trainings, employee participation, compliance of safety procedures and motivational schemes are part of safety management which influences the overall safety performance. Several metrics were developed to measure the safety performance of an organization but not a single measure will reflect the overall performance. The present study considered parameters pertaining to the safety management which have influence on the safety performance of a construction organization in India. The parameters are analyzed by formulating a goal programming model. The results of the study suggests that much improvement is needed in the area of safety trainings and the revised targets were established.

Open access
Influence of Honeycomb Core Stabilization on Composite Sandwich Structure Geometry

Abstract

Authors showed the influence of stabilization of the honeycomb core on shape of the composite sandwich test panel. Adhesive film laid on core ramps and cured with suitable cure cycle served as core stabilizer. Test panel geometry included different ramp angles (20° and 30°). To verify stabilization process a technology trial was performed. Three test panels were manufactured (3-stage, 1-stage and 1-stage with stabilized core). All test panels were manufactured in OoA process (Out of Autoclave). Panel surfaces were scanned with 3D scanner and compared with the reference CAD model. Both outer skin and inner skin were manufactured in Automated Fiber Placement Laboratory of Warsaw Institute of Aviation.

Open access
Initial Analysis of Helicopter Impact on Hospital Helipads

Abstract

The need to quickly provide assistance to victims of accidents or seriously ill has created the need for the construction of helipads at selected hospitals. Their operation and the conditions of use are governed by regulation of the Ministry of Health on Hospital Emergency Ward (SOR) and rules required by the Civil Aviation Authority.

The direct vicinity of the helipads causes impact of landing and departing helicopters on buildings, people and hospital equipment as well as the construction of the airfield. This article presents vibroacoustic impact of helicopters on helipads’ measurement methods and the results of the preliminary measurements to estimate the impact of Helicopter Air Rescue (LPR) on adjacent buildings and surroundings.

Open access
Investigation, analysis and comparison of current-voltage characteristics for Au/Ni/GaN Schottky structure using I-V-T simulation

Abstract

In this work, we have presented a theoretical study of Au/Ni/GaN Schottky diode based on current-voltage (I-V) measurement for temperature range of 120 K to 400 K. The electrical parameters of Au/Ni/GaN, such as barrier height (Φb), ideality factor and series resistance have been calculated employing the conventional current-voltage (I-V), Cheung and Chattopadhyay method. Also, the variation of Gaussian distribution (P (Φb)) as a function of barrier height (Φb) has been studied. Therefore, the modified ((ln(I0T2)(q2σs022kT2)=ln(AA*)qB0kT)vs.(1kT)) relation has been extracted from (I-V) characteristics, where the values of ΦB0 and ASimul* have been found in different temperature ranges. The obtained results have been compared to the existing experimental data and a good agreement was found.

Open access
Investigation of the structural, optical and photoluminescence properties of electrosynthesized hexagonal nanocrystalline Cd0.3Zn0.7S thin film

Abstract

In this paper, Cd0.3Zn0.7S thin film has been electrodeposited from aqueous bath containing CdSO4, ZnSO4, Na2S2O3 and EDTA, having pH ~ 14. The structural, optical, morphological, surface wettability and photoluminescence properties of the film were investigated. The XRD pattern showed that the film consisted of mixed phases of CdS and ZnS with polycrystalline structure. The bandgap of the film was evaluated as 2.69 eV. The AFM study revealed that the Cd0.3Zn0.7S thin film contained spherical grains with root mean square roughness of 6.09 nm. The water contact angle measurement showed that the thin film was hydrophilic in nature. Moreover, the PL study revealed that the excitation wavelength was 460 nm.

Open access
Mathematical Models and Computer Simulations of Aerial Spraying and Droplets Distribution in a Target Site

Abstract

Mathematical models describing aerial spraying and the distribution of liquid droplets on a target were presented. Relationships based on “free models” with Gaussian distribution of droplet concentrations and “bound models” that account for the impact of disturbances in the velocity field behind agricultural aircraft were expanded, and the hybrid model too. The results of experimental studies were presented and compared with theoretical calculations. The “bound model” was found to be the most effective solution for describing the physical phenomena that accompany the aerial spraying process.

Open access
Operation manager and its role in the enterprise

Abstract

Presented paper concentrate on problems connected with the role of operation manager within industrial company. Operation management concentrate many activities in today’s industrial corporation and because of that the role of it’s manager is very important. He should to have many skills described in this paper. We analysed responsibilities of the operation manager, his basic operational skills and also give some examples of duties and responsibilities of good operation manager on the example of food industry. This example can give some remarks about practical skills needed in operation management in particular enterprise.

Open access