Vibrational Tools Research Articles

Multivariate Imaging for Fast Evaluation of In Situ Dark Field Microscopy Hyperspectral Data.

Dark field scattering microscopy can create large hyperspectral data sets that contain a wealth of information on the properties and the molecular environment of noble metal nanoparticles. For a quick screening of samples of microscopic dimensions that contain many different types of plasmonic nanostructures, we propose a multivariate analysis of data sets of thousands to several hundreds of thousands of scattering spectra. By using non-negative matrix factorization for decomposing the spectra, components are identified that represent individual plasmon resonances and relative contributions of these resonances to particular microscopic focal volumes in the mapping data sets. Using data from silver and gold nanoparticles in the presence of different molecules, including gold nanoparticle-protein agglomerates or silver nanoparticles forming aggregates in the presence of acrylamide, plasmonic properties are observed that differ from those of the original nanoparticles. For the case of acrylamide, we show that the plasmon resonances of the silver nanoparticles are ideally suited to support surface enhanced Raman scattering (SERS) and the two-photon excited process of surface enhanced hyper Raman scattering (SEHRS). Both vibrational tools give complementary information on the in situ formed polyacrylamide and the molecular composition at the nanoparticle surface.

The Prevalence, Causes and Prevention of Occupational Musculoskeletal Disorders

Musculoskeletal disorders (MSDs) are collectively referring to an array of conditions affecting the human locomotor system, such as muscles, nerves, joints, tendons and spinal discs. MSDs related to work are called occupational MSDs and are typically caused by physical factors consisting of repetitive tasks, forceful exertions, awkward positions, vibration due to use of vibrational tools and prolonged staying in the same positions. These physical factors are often complicated by psychosocial factors comprising job demand, job control, social support, job satisfaction, job security, work arrangement, etc. which can aggravate the biomechanical loading imposed by physical factors, thus resulting in more severe outcomes. Besides, individual factors such as health conditions, age, education level and medical history could lead to highly variable physiological responses and internal tolerances, hence outcomes. As the physical and psychosocial risk factors vary widely in different workplaces, the prevalence of MSDs tends to vary with sectors, occupations and even regions. Generally, healthcare sector has been reported to have relatively high occupational MSDs cases in multiple nations. To prevent occupational MSDs, priority should be given to elimination of the associated risks through job and workplace designs and management. Where elimination is not practical, the risks could be reduced through modification of workplace layout, work environment, work systems and tools as well as the use of mechanical aids. Provision of information, instruction and training, and other administrative controls such as job rotation which do not target at reducing the risks would have lower priority and should be used together with other control measures of higher priority.

Vibrational Data Communication Tools and Methods for Mining and Oil and Gas Extraction

Summary For the purpose of exploration and extraction, the drilling process in the mining and oil and gas industries is very complicated because of the obvious invisibility of the operation of the drill bit. Acoustic/vibrational telemetry has been of keen interest because it is so far the only method that allows a high data transfer rate as well as less data loss, over other methods. The method certainly depends on the use of the right communication tools and efficient communication schemes to achieve the highest data transfer rate. Although the acoustic method provides a very high data transmission rate, it also has its limitations. However, limitations can be overcome through certain approaches and the use of technologies. The proper use of a communication device with the steel pipe is the most important factor to consider so that the transducer works as the right actuator for the pipeline. The type of sensor that is used to pick up the data also plays a major role because signals are most likely to attenuate, and a sensitive sensor is necessary to collect these attenuated signals. This research demonstrates the use of a transducer as a communication device and oil and gas pipe as the medium of data transmission. The transducer can be used both as an actuator driver and as a receiver sensor. A new piezoelectric transducer was manufactured for this research, which was used with a test setup of a total 184 ft length of six oil and gas pipes. The test setup performed well and data were sent through this setup successfully. A communication scheme is developed using novel theories to achieve the highest data transfer rate. The scheme is tested with the transfer function data obtained from the experimental system. The communication scheme developed outputs a signal, which is a type of binary phase-shift keying signal data along with an equalizer filter. Then the signals developed from the scheme are used in the actual experimental setup to test the speed of the transmission and bit error rate (BER). For the six oil and gas pipes setup, the scheme provides a data transmission of 153 bits/sec (bps) with zero error percentage, which is high enough to use in any oil and gas industry.

Structure and properties of Ln6MoO12 (Ln = Nd, Sm, Gd, Dy) optoelectronic nanoceramics

Auto-igniting combustion technique is used for preparing Ln6MoO12 (Ln = Nd, Sm, Gd, Dy) nanoceramics. Crystallographic phase is ascertained by comparing the XRD patterns of prepared samples with ICDD data. X-ray diffraction line broadening is used to decide the average crystal size. Vibrational tools like Raman and FTIR spectroscopy are used to evaluate the metal oxide stretching frequencies. TEM analysis is used to investigate the particulate properties and SEM analysis is used to study the surface morphology of the sintered material. The ultraviolet–visible absorption spectra and photoluminescence spectra of the samples are noted and examined. The examination of ultraviolet absorption spectra discloses intense broad absorption in the UV-to-visible region with peaking at near UV region. Electrical properties of Nd6MoO12 are investigated using Impedance spectroscopy. The contributions of bulk and grain boundary to the overall electric response of the material are inferred by studying the electrical properties as a function of frequency (50 – 5 MHz) at various temperatures (400 – 850 °C).

Synthesis and characterization of AZrTi2O7 (A = mg, ca, Sr and Ba) functional nanoceramics

Nanocrystalline AZrTi2O7 (A = Mg, Ca, Sr and Ba) system has been synthesized by an auto-ignited combustion technique. The structure of the system is analyzed by powder X-ray diffraction and vibrational spectroscopic tools. The cation deficient zirconolite (CaZrTi2O7) is found to be a monoclinic structure with the space group C2/c. A narrow size distribution of the nanoparticles is observed by transmission electron microscopy with a peak at 11 nm. The optical band gap of the ceramics obtained by using Tauc’s plot is in between 3.10 eV and 3.30 eV. The photoluminescence emission spectra of the samples are investigated and the probable transitions producing the emissions are identified. The microstructure of the sintered pellets are examined by scanning electron microscopy and the elemental compositions are confirmed by energy-dispersive spectrometry. Impedance spectroscopic analysis of the sample showed that ions are the main source of conduction. Ionic conduction and grain boundary conduction stimulate high conductivity to the material. Electrical property measurements in the temperature range 500–850 °C indicate that CaZrTi2O7 is stable and can be utilized over a wide range of temperatures and frequencies. These materials are found suitable for optical and solid oxide fuel cell applications.

The Study of Acoustic Cavitation and Cavitation Erosion of Materials and Coatings

The article describes a study of cavitation in the border areas of the vibrational tools and static solid of ultrasonic field. A high-speed camera Fastcam SA-X2 version 1000K which is able to shoot up to 1 million frames per second with electronic shutter 283 ns was used for a more practical covering of the processes occurring in the cavitation bubble at collapse near a solid surface, as well as on the possibility of fixing the cumulative impact of a collapsed bubble to the surface. The studies of cavitation resistance materials peening methods, failure of which could be due to the cumulative effect or cavitation bubbles collapse in the immediate vicinity of the sample can be used to optimize the choice of emitter material operating in corrosive liquid environments.

Estimation of Total Phenols, Flavanols and Extractability of Phenolic Compounds in Grape Seeds Using Vibrational Spectroscopy and Chemometric Tools.

Near infrared hyperspectral data were collected for 200 Syrah and Tempranillo grape seed samples. Next, a sample selection was carried out and the phenolic content of these samples was determined. Then, quantitative (modified partial least square regressions) and qualitative (K-means and lineal discriminant analyses) chemometric tools were applied to obtain the best models for predicting the reference parameters. Quantitative models developed for the prediction of total phenolic and flavanolic contents have been successfully developed with standard errors of prediction (SEP) in external validation similar to those previously reported. For these parameters, SEPs were respectively, 11.23 mg g−1 of grape seed, expressed as gallic acid equivalents and 4.85 mg g−1 of grape seed, expressed as catechin equivalents. The application of these models to the whole sample set (selected and non-selected samples) has allowed knowing the distributions of total phenolic and flavanolic contents in this set. Moreover, a discriminant function has been calculated and applied to know the phenolic extractability level of the samples. On average, this discrimination function has allowed a 76.92% of samples correctly classified according their extractability level. In this way, the bases for the control of grape seeds phenolic state from their near infrared spectra have been stablished.

Experimental research on vibrational digging-up of sugar beet

The technological process of vibrational digging-up of sugar beet has spread in many sugar beet-sowing coun- tries. The experience of using this process demonstrated its advantages compared against other ways of dig- ging-up, but there have been scarce experimental researches of the vibrational digging-up of sugar beet from soil which makes this topic urgent for sugar beet production. Aim. The experimental determination of rational parameters and modes of the vibrational digging-up working tool to ensure the required quality of conducting the technological process of digging sugar beet from soil. Methods. The methods of planning a multifactor ex- periment, fi eld studies, statistical processing, regression analysis of the experimental data with building graphic curves were applied. Results. A new model of a tool for vibrational digging-up of sugar beet from soil has been elaborated. The accepted program and method were used to conduct experimental research on the impact of the main construction and technological parameters of the vibrational digging-up working tool of the beet harvester on the quality indices of performing the technological process of harvesting sugar beet. The energy parameters of new vibrational digging-up working tools were studied in fi eld conditions via registering the values of tenzometric sensors in different modes of the device and different parameters and working modes of the vibrational digging-up tools. Conclusions. It was established that there is a value of the vibration frequency and running depth in soil of the vibrational digging-up working tool for each value of the translational veloc- ity of the vibrational digging-up machine which corresponds to minimal losses and damage to crop roots. It was also found that the degree of crop root damage depends on the conditions of performing the technological process of vibrational digging-up (soil solidity and humidity), and the weight of damaged crop roots increases with the increase in solidity and the decrease in humidity of soil.

Electrical and optical properties of pure and zirconium added dysprosium titanates

Nanoparticles of Dy2Ti2O7 and Dy2Ti1.5Zr0.5O7 (abbreviated as DTO and DTZO, respectively) have been prepared through an auto-igniting combustion technique. The structure of the system is analyzed by powder X-ray diffraction and vibrational spectroscopic tools. The samples are crystallized with cubic pyrochlore structure with the space group $$Fd\bar {3}m$$. The particle size obtained from XRD and TEM analysis shows that the samples are nanocrystalline. The Fourier-transform infrared and Raman spectra of the samples are investigated in detail. The ultraviolet–visible absorption spectra of the samples are also recorded and their optical bandgap energy values are calculated. The photoluminescence spectra of the samples are recorded and the transitions causing emissions are identified. The surface morphology of the sintered pellets were studied by scanning electron microscopy which indicates minimum porosity, and the elemental composition was confirmed by energy-dispersive spectrometry. Impedance spectroscopic studies of the samples are carried out at different temperatures. The conductivity of the samples increased with temperature, and the highest conductivity of 1.93 × 10−1 S/m at 850 °C is obtained for DTO. The materials are suitable candidates for optoelectronic applications and the fabrication of electrolytes in solid oxide fuel cells at moderate temperatures.

Spectroscopic and computational investigation of the structure and pharmacological activity of 1-benzylimidazole

The chemical and pharmacological activity of the compound 1-benzylimidazole was analysed using vibrational, NMR and UV-Visible spectroscopic tools. The necessary data were obtained by recording FT-IR, FT-Raman, NMR and UV-Visible spectra. 1H and 13C NMR spectral chemical shifts were observed and investigated to understand the basis of the antiparasitic, antifungal and antimicrobial activities. The elaborate electronic excitational absorptions in which bathochromic shifts in the UV-Visible spectrum are linked to strong cardiotonic activity are noteworthy. The pharmacodynamic activity was related to the molecular polarization as analysed according to different analytical parameters. The molecular reactivity was studied according to the dislocation of charge levels in frontier molecular orbitals. NBO analysis was carried out to delineate the asymmetric charge interaction transitions among orbitals, which were correlated with the pharmacological behaviour of the compound. The enantiomer errors in the electronic structure have been analysed by simulating ECD and VCD spectra.

Theoretical Research of the Impact of the Digging-Out Working Tool on the Beetroot During the Vibrational Digging up from the Soil

Aim. The elaboration of the theory of the impact of the vibrational digging-out working tool on the body of the beetroot, attached to the soil, and the substantiation of the rational kinematic and constructive parameters of the advanced vibrational digging-out working tool on the basis of the results obtained. Methods. The main provisions of advanced mathematics and theoretical mechanics were used, in particular, the general theory of mechanical impact and the oscillation theory. The equation systems obtained were solved using PC and the elaborated programme. Results. The main provisions of the theory of the impact of the digging-out working tool on the beetroot while extracting the latter from the soil were elaborated. The mathematical model of the impact interaction of the digging-out working tool and the body of the beetroot, attached to the soil, during the vibrational digging-out of sugar beets was created. The equations, describing the mentioned process, were used as a basis for the impact impulse and the impact force; the conditions of not damaging the beetroot during the impact were established. The analytic expression for the determination of the allowed frequency of vibra- tions of the working vibrational digging-out tool with the consideration of its constructive parameters and the translational motion was obtained. The estimates, obtained using PC calculations, allow designing advanced working vibrational digging-out tools to harvest sugar beets, taking the condition of avoiding damage to the root into account. Conclusions. The analytic expression for the determination of the allowed frequency of vibrations of the vibrational digging-out working tool, taking into account its constructive parameters and the translational motion, was obtained taking the condition of avoiding damage to the root into consideration. The algorithm and the PC analysis programme for the allowed frequency of oscillations of the vibrational digging- out working tool with the consideration of no damage to the beetroot during the impact interaction were elabo- rated. Numerous PC estimates demonstrated that on condition of the mentioned weight of the working tool of m = 1.0 kg the allowed frequency, at which there is no damage to the beetroot, should not exceed v = 10.0 hertz (with the oscillation amplitude of a = 0.015 m and the maximum depth of the digging-out working tool in the soil of h = 0.1 m). Here the translational motion should be in the range of 1.3 ... 2.2 m/s. The obtained results of the theoretical research allow designing advanced vibrational digging-out working tools to harvest sugar beets without damaging them.

More effective noise reduction of vibroabrasive machine tools

An integrated approach to reducing the noise level of pulsed vibrational machine tools at the design stage is proposed.

Daily exposure to hand arm vibration by different electric olive beaters

The electric hand held olive harvesters have a low weight (about 2 kg) and cause the fruit pick up by means of impacts produced by their vibrational tools: for this reason they transmit elevated vibration doses to the operator’s hand arm system during the work. In this paper electric beaters of different manufacturers and different models were considered, to analyse their vibrational behaviour in field, during the olive harvesting campaign in a site located in Northern Italy. One operator did the tests, to avoid the operator’s uncertainty on the obtained results. All the five examined beaters gave high acceleration values (in a range from 10 to 26 ms<sup>–2</sup>), but the most restricting data were the daily vibration exposures, calculated considering the real working duration time acquired in field, almost ranged between 10 and 18 ms<sup>–2</sup>. Also the operator posture during the work (with the arms over the shoulders) may set health problems, related to upper limb disorders, other than the already known musculoskeletal, nervous and vascular pathologies.