Volume 10, Issue 1, January 2019


Current Scenario of Healthcare 

Ashutosh Tiwari

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 1-1
DOI: 10.5185/amlett.2019.1001

We are delighted to publish the 10th volume,1st issue, 2019 of the Advanced Materials Letters with the editorial on the ‘Current Scenario of Healthcare’. Medical errors pertaining to health care has been growing over the last decade and some studies depict that they are quite difficult to manage. Numerous investigations center around patients encountering damage and give a significant understanding of the extent of mischief coming about because of blunders. The Different investigations, more constrained in number, center around the event of mistakes, both those that outcome in mischief and those that don't (now and then called ''close misses"). It is found to get more faults the doctor’s facilities than in other medicinal services conveyance settings. Blending and translating the discoveries in the writing related to mistakes in human services is convoluted because of the nonappearance of institutionalized terminology. For reasons, in this report, the terms mistake and antagonistic occasion are characterized as pursues: A blunder is characterized as the disappointment of an arranged activity to be finished as expected or the utilization of a wrong intend to accomplish a point. An unfriendly occasion is a damage caused by medicinal administration as opposed to the basic state of the patient. 

Dry cutting with high-pressure liquid CO2 jets

Eckart Uhlmann; Patrick John

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 2-8
DOI: 10.5185/amlett.2019.2231

The main advantages of cutting with liquid jets are the flexibility and consistently sharpness of the tool, which allows the machining of a variety of materials and complex shapes. Unfortunately, the humidification of the components can be a problem for certain applications and inhibits the spread of jet technology. Besides, the dry and residue-free cutting of materials is an important topic of today’s research in manufacturing engineering. Due to these advantages, high-pressure liquid CO2 jet cutting has the potential to open new fields of applications in which water jet cutting is not suitable. The liquid CO2 jet with a pressure of up to 300 MPa can be used to machine various materials and functional surfaces before it expands to gas and atmospheric pressure. However, the transition from liquid to gaseous phase implicates density differences which change the cutting performance. As a result, the knowledge about waterjets cannot be adapted to CO2 jets and further investigations are necessary. A new test stand was put into operation and a feed line with abrasives was added. Technological investigations concerning the formation of kerfs with high-pressure liquid CO2 and water jets were performed with and without abrasives as well as subsequently analyzed. The cutting tests were carried out on parts of various metals and technical plastics. The influence of the fluid on the attained cutting surfaces and kerfs produced by the jet was investigated. The experiments indicate that the performance of the CO2 jet as well as of the waterjet depends mainly on pressure and nozzle diameter but show different separation behavior. Especially the impact of the working distance will be discussed. The investigations reveal that high-pressure liquid CO2 jet cutting has a high potential in the field of dry and residue-free cutting of metals, technical plastics and CFRP. Furthermore, no temperature influence was observed and the potential for jet cutting in 3D-applications and for hollow profiles was proven.

Removal of dyes from wastewater by nanomaterials : A review

Wenqian Ruan; Jiwei Hu; Jimei Qi; Yu Hou; Chao Zhou; Xionghui Wei

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 9-20
DOI: 10.5185/amlett.2019.2148

Dyes are widely used to colour products in textile, leather tanning, cosmetics, pigment and many other industries. Effluents discharged from these industries cause potential hazards to environment and human health. Hence, the removal of dyes from water/wastewater has gained a huge attention in recent years. So far, biological, chemical and physical methods are the traditional techniques, of which adsorption is found to be a more effective and cheap method for removing dyes. Nanotechnology has applied successfully to the water/wastewater treatment and emerged as a fast-developing promising field. Application of nanomaterials (NMs) in dyes removal seems to be an efficient way. In this review, extensive literature information was presented with regard to dyes, its classification and toxicity, different methods for dyes removal including the removal of dyes by NMs. It is evident from the literature survey that NMs have shown good capability for the removal of dyes. 

Influence factors on the comminution process of wood for the production of precursors and basic chemicals for the chemical industry

Moritz Eisenlauer; Ulrich Teipel

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 21-28
DOI: 10.5185/amlett.2019.2150

The upstream process of comminution is a key element in the use of renewable raw materials, which impacts the consecutive disintegration of the materials. Energy efficiency of the comminuition process is therefore of utmost importance. The key factors to increase energy efficiency are, beside the mill type and the mill operation factors, the species of the renewable resource, in terms of water contend and the mechanical properties which are the dominant factors in biomass size reduction. In this study the influence of different factors on the effective specific comminution energy (ESCE) is elucidated. For theses purpose, three types of raw wood chips as well as recycled wood of two different qualities, were comminuted with a cutting mill and a swing hammer mill. The materials were comminuted at several levels of moister contend, under varied opening sizes of the internal screen of the mills. Particle size distributions of the comminuted materials were examined with sieve analyses and dynamic image analysis. Especially, the moister content directly influences the ESCE and the particle size distribution. Moreover the type of material, due to its different mechanical properties, is of significant influence on the particle size distribution and the ESCE. 

Possibilities of filling polymeric anchors with secondary raw materials with effect on price and final parameters

Rostislav Drochytka; Jakub Hodul; Tomáš Žlebek

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 29-34
DOI: 10.5185/amlett.2019.2138

Within this work different types and amounts of the suitable secondary raw materials as filler to polymer anchor were tested as possible substitution of currently used primary fillers. Physical and mechanical properties of the fast curing anchoring material based on epoxy resin were determined. The aim of this research was to achieve the anchor containing high amount of the secondary raw materials with the same or better final properties than reference anchors. As the suitable secondary raw materials, waste transparent packaging glass (TPG), high temperature filter fly ash (HTF) and circulating fluidized bed combustion filter fly ash (FCA) contaminated by the selective non-catalytic reduction (SNCR) denitrification technology were chosen. To use as much as possible suitable secondary raw materials to limit its landfilling and save the price for the expensive epoxy resin was verified. It was found out that the developed polymer anchors containing up to 45% contaminated filter fly ash shows better physical and mechanical properties than the reference anchors utilizing only primary materials. This ascertainment should make the production of polymer anchor both environmentally and financially less demanding. Furthermore, the microstructure of the developed anchors was investigated by the CT tomography, and it was found out that even after the pull-out force of 120 kN there was no deterioration of the polymer anchor, and a filler in the form of fly ash (HTF, FCA) and waste packaging glass (TPG) was evenly distributed in the polymer mass (EPB1). 

Hybrid EEG-EMG based brain computer interface (BCI) system for real-time robotic arm control

Saad Abdullah; Muhammad A. Khan; Mauro Serpelloni; Emilio Sardini

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 35-40
DOI: 10.5185/amlett.2019.2171

Nowadays, bio-signal based BCI systems are widely being used in healthcare systems and hence proven to be an effective tool in rehabilitation engineering to assist disabled people in improving their quality of life [1]. In this research work, handicapped people with above hand amputee have been targeted and hence non-invasive EEG and EMG biosensors are used to design wireless hybrid BCI system. The presented hybrid system is able to control real-time movement of robotic arm via combined effect of brain waves (attention and meditation mind states) and wrist muscles movements of healthy arm as command signal. The system operates the robotic arm within 3 degree of freedom (DOF) motion which corresponds to movement of shoulder (internal and external rotation), elbow (flexion and extension) and wrist (Gripper open and close) joint. It has been experimentally tested on 4 subjects with upper limb amputee (having one healthy arm) after training period of one day. On receiving the input signals from EEG and EMG sensors, subjects have successfully controlled the movements of the robotic arm with accuracy of 70% to 90%. In order to validate the obtained results, a potentiometer has been fixed on robotic arm and angular motion of shoulder and elbow joint is recorded (actual motion) and compared with results of the BCI system (required motion). The comparison shows high resemblance between actual and required motion which reflects the reliability of the system. In addition, apart from robotic prototype, its 2D modelled is also designed on visual studio. The presented preliminary experimental results show that the motorized prosthetic prototype movement due to mind and muscle control is in accordance with the 2D modelled virtual arm permitting to improve its real-time adoption for rehabilitation. 

Device and method for the biomechanical analysis of articular amplitude using micro-sensors for the measurement of movement

Mauro Callejas-Cuervo; Juan C. Alvarez; Diego Alvarez

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 41-44
DOI: 10.5185/amlett.2019.1909

The present article describes the creation and operation of a device for biomechanical analysis, which is portable, precise, non-invasive, and which allows us to autonomously obtain the position, orientation and measurement of the articular amplitude of two body segments connected by a joint. The above is carried out with data obtained from a number of inertial and magnetic microsensors. The device, through the application of a series of methods, allows the recording of the movements made by a person while they go about their daily activities without the need of including a computing system that operates it. This can be done in real time or delayed-mode, and for long periods of time, depending on the battery charge of the device. 

Spectroscopic characterization and laser test of a 10at.% Yb:Y3Sc1.5Al3.5O12 ceramic sample  

Angela Pirri; Guido Toci; Jiang Li; Yagang Feng; Tengfei Xie; Zhaoxiang Yang; Barbara Patrizi; Matteo Vannini

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 45-48
DOI: 10.5185/amlett.2019.2145

We present the spectroscopic characterization and the laser measurements obtained with a 10 at.% Yb:Y3Sc1.5Al3.5O12 (=YSAG) ceramic sample. Longitudinally pumped in quasi-Continuous Wave (QCW) and in Continuous Wave (CW) at 936 nm, the ceramic has shown good laser performance. In the former pumping regime it delivers 6.7 W with a slope efficiency of ηs=67.8% and a laser threshold below 0.5 W. In the latter, the maximum output power was 5 W with ηs=52.7%.  Finally, the tunable laser action has been obtained in the range between 991.5 nm and 1073 nm, i.e. 81.5 nm, by using a ZnSe prism. 

Impact of carbon black aggregates on the optical properties of black rubber samples in the terahertz frequency range

Shinichi Watanabe; Misako Fujii; Makoto Okano

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 49-52
DOI: 10.5185/amlett.2019.2157

We report on the optical responses of black rubber samples in the terahertz regime as a function of the carbon black (CB) concentration. We prepared samples with different CB concentrations and investigated their absorbance, birefringence, and the angle of the slow optic axis in the terahertz frequency range. A monotonic increase of the terahertz absorbance is observed with increasing CB concentration, which indicates that the density of the CB aggregates inside the black rubber plays a crucial role for controlling the absorbance. In addition, a systematic increase of the birefringence is observed with increasing draw ratio, while the spatial fluctuation of the angle of the slow optic axis systematically decreases. This simultaneous behavior indicates that the mechanical stretching of the black rubber sample induces an alignment of the CB aggregates along the stretching direction. These results provide the fundamentals to understand the correlation between the terahertz response and the condition of the CB aggregates inside the samples. The thorough understanding of this correlation is important for future applications.

T-x-y-z phase diagrams assembling: Na2MoO4-Na2CrO4-Na2WO4-Na2SO4, Fe-Ni-Co-Cu, Pb-Cd-Bi-Sn, Fe-Ni-Co-FeS-NiS-CoS  

Vasily I Lutsyk; Vera P Vorob’eva; Anna E Zelenaya

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 53-57
DOI: 10.5185/amlett.2019.2172

The T-x-y-z diagrams of quaternary Na2MoO4-Na2CrO4-Na2WO4-Na2SO4, Fe-Ni-Co-Cu, Pb-Cd-Bi-Sn systems and their four-dimension (4D) computer models are considered. Geometric constructions of these diagrams are described by special di-, uni- and invariant states schemes. Assumed liquidus of the Fe-Ni-CoFeS-NiS-CoS subsystem T-x-y-z diagram on the basis of the data about the structure of the border systems is predicted and the 4D computer model is designed. The possibilities of calculating of three- (3D) and two-dimensional (2D) iso- and polythermal sections are shown. 

Onion juice assisted green reduction of graphene oxide with tunable structural and optical properties: Effect of onion juice concentration and reaction temperature

Sumeet Kumar; Dipjyoti Bhorolua; Animesh K. Ojha; Ashok Kumar

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 58-66
DOI: 10.5185/amlett.2019.2124

In most of the studies, toxic and harmful reducing agents were used for the chemical reduction of graphene oxide (GO) and into reduced graphene oxide (rGO). Here, onion juice is used as a natural and green reducing agent for the reduction of GO into rGO. The effect of onion juice concentration and reaction temperature on the reduction ability of onion juice have been studied. The present synthesis approach avoids the use of toxic and harmful chemicals for reduction of GO. The mechanism of reduction of GO at various concentrations of onion juice is explained in terms of presence of cysteine in the onion juice as one of the chemical constituents. The X-ray diffraction (XRD) results revealed the high degree of reduction with superior quality. Transmission electron microscopy (TEM) images provide clear evidence for the formation of transparent and thin layers of graphene. We have extended our analysis to reveal the quality of rGO produced by onion juice assisted reduction of GO using D, G and 2D bands present in the Raman spectra. Moreover, we have discussed the role of onion juice concentration and reaction temperature on evolution of D and G bands and ID/IG ratio, which in turn tell the overall growth of graphene sheet.  Fourier transforms infrared spectroscopy (FTIR) measurements also show significant degree of reduction of GO. The UV-Vis. absorption spectrum further confirms the ability of onion juice to reduce GO into rGO. The synthesized product shows good dispersibility in aqueous solvent. Thus, the present report provides a green and facile approach for the synthesis of graphene derivatives with enormous potential. 

Production and characterization of silica nanoparticles from rice husk  

Daniel F. Hincapié Rojas; Posidia Pineda Gómez; Andrés Rosales Rivera

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 67-73
DOI: 10.5185/amlett.2019.2142

The rice process generates a large amount of husk, which can become an environmental contaminant if it does not receive an adequate management. Because rice husk is a natural source of silica, in this work silica nanoparticles were obtained as an alternative use for this residue. The synthesis was carried out with the incineration, acid leaching process, and particle size reduction through high-energy mechanical ball milling. For its characterization, thermal, chemical, morphological, structural and superficial area analyses were performed with thermogravimetric analysis, X-ray fluorescence method, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Nitrogen adsorption/desorption isotherm techniques. The results indicated that between 150-450°C the organic material of the rice husk was released, and above 550°C was obtained ash rich in silica. The silica purity was effectively increased to 98.48%, through acid leaching with acid nitric. The reduction of particle size by mechanical milling at 600 rpm for 3 h was achieved up to nanometer size. Most of the nanoparticles were spherical with a diameter between 14 and 28 nm. Silicon oxide was the principal structural phase of the nanoparticles corroborated by the broad peak corresponding to the (101) plane shown by XRD pattern. A substantial increase of two magnitude orders of the specific surface area of nanoparticles was reached in comparison with particles without milling. The nanosilica particles obtained from rice husk can be used for the production of high-performance silicon or they can be also used as supplementary cementitious materials. 

Electronic scale properties of pristine stanene and tin forms using ab-initio methods 

T Chaitanya Sagar; Viswanath R Chinthapenta

Advanced Materials Letters, 2019, Volume 10, Issue 1, Pages 74-78
DOI: 10.5185/amlett.2019.2154

In the current study, elastic properties of stanene, a hexagonal honeycomb allotrope of tin is investigated using tools in computational material science. The simulations are performed using Quantum Espresso, an open-source package suit used for conducting ab-initio density functional theory simulations. The lattice structure of stanene analogous to the other group-IV elements 2D structures like graphene, silicene, and germanene. The relaxed structure of stanene in hexagonal honeycomb structure is found to have a lattice parameter .  Unlike pristine graphene which has no buckling, stanene structure shows a buckling . All the calculations are carried out using generalized gradient approximation (GGA), and the exchange-correlation is treated using Perdew-Burke-Ernzerhof (PBE) functional. The cohesive energy of the structure is found to be . The calculations are conducted at groundstate without the inclusion of spin orbit coupling. The band structure, total and partial density of states at the ground state reveal the conducting nature of stanene. In addition, the second order elastic constants evaluated are reported and compared with the -tin and -tin counterparts.