scholarly journals Application of explosive metal cladding in the manufacture of new, advanced layered materials exemplified by titanium Ti6Al4V – aluminium AA2519 bonding

2020 ◽  
pp. 184-191
Author(s):  
Aleksander Gałka
Keyword(s):  
Alternative Methods ◽  
Metal Cladding ◽  
Ballistic Resistance ◽  
Bonding Parameters ◽  
Space Industry ◽  
Wide Range ◽  
New Material ◽  
Bonding Technology ◽  
Non Destructive ◽  
Titanium Aluminium

Explosive metal cladding technology has been extensively developed since the mid-20th century. It is an area with the largest use of explosives for civil purposes, apart from mining. The global production of these materials runs at tens of thousands of square metres annually. Explosive bonding enables the production of a wide range of intermetallic compositions where, in many cases, no alternative methods are available. As an example, layered products include clad plates made of light metals, e.g. titanium, aluminium, magnesium showing different melting points, densities and hardness. Each new material combination requires an adaptation of the technology used by selecting suitable bonding parameters and new modified explosives. Several variants of Ti6Al4V/AA2519 explosive alloy bonding technology were created. The clad plates were tested using destructive and non-destructive techniques to determine bond strength and integrity. The study aimed to create new materials with improved ballistic resistance for structures used in the aviation and space industry.

Luminescence from individual dislocations in II-VI and III-V semiconductors

1991 ◽  
Vol 49 ◽  
pp. 834-835
Author(s):  
J W Steeds
Keyword(s):  
Group Iv ◽  
Luminescence Properties ◽  
Carrier Recombination ◽  
Transmission Electron ◽  
Wide Range ◽  
Basic Physics ◽  
Semiconducting Compounds ◽  
Diamond Group ◽  
Non Destructive ◽  
Technological Significance

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.

Classical and modern drug extraction techniques: facts and figures

2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Bharti Umrethia ◽  
Bharat Kalsariya ◽  
Prof. P. U. Vaishnav
Keyword(s):  
Solvent Extraction ◽  
Dosage Forms ◽  
Herbal Extract ◽  
Alternative Methods ◽  
Extraction Techniques ◽  
Modern Drug ◽  
Novel Drugs ◽  
Wide Range ◽  
In The Mists ◽  
Heating Pattern

In present era, herbal extract succeeds inimitable place in pharmaceutical science. In view back the earliest extraction techniques are lost in the mists of history. As time went the plants have been processed by grinding, boiling or immersing. The systemic presentation of Ayurvedic extraction system has been first time familiarized by Acharya Charaka as Panchavidha Kashaya Kalpana (five basic primary dosage forms) and based upon these primary dosage forms, secondary dosage forms are developed by using different heating pattern for extraction of pharmacological active ingredients. The administration of these dosage forms is mainly dependent on the Bala (strength) of Vyadhi (disease) and Atura (patient). Due to increased demand of Ayurvedic medicines and industrialization, the transformation of classical dosage forms takes place by implanting a wide range of technologies with different methods of extraction include conventional techniques such as maceration, percolation, infusion, decoction, hot continuous extraction etc. and recently, alternative methods like ultrasound assisted solvent extraction (UASE), microwave assisted solvent extraction (MASE) and supercritical fluid extractions (SFE). The extract obtained by these procedure uses as a large source of therapeutic phyto-chemicals that may lead to the development of novel drugs. Essentially, the purpose behind this changing face in both the extraction systems are different but can say that it is a new insight from ancient essence.

Control of properties and structure of steel vessels by cooling in various media at the outlet of rolling and pressing lines

2021 ◽  
pp. 34-38
Author(s):  
R. L. Shatalov ◽  
V. A. Medvedev
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Metal Structure ◽  
Machine Building ◽  
Regression Equations ◽  
Wide Range ◽  
Industrial Mineral ◽  
Cooling Media ◽  
Technological Limitations ◽  
Non Destructive

When controlling the mechanical properties and structure of vessels made of carbon structural steels manufactured by hot deformation on rolling and pressing lines (PPL) of machine-building enterprises of Russia, such cooling media as water, I20 industrial mineral oil, air are used. The applied cooling media are able to provide the workpieces with a given structure with a wide range of mechanical properties. However, the cooling media have a number of technological limitations and conditions of the use, non-compliance with which leads to reject. When cooled in oil, the probability of ignition is high; when cooled in water, hardening cracks may form, and air is not always able to provide the required rate and uniformity of heat transfer to the environment. The efficiency of control of physical and mechanical properties and structure of deformed vessels made of 50 steel by cooling in TERMAT polymer aqueous solutions in different concentrations on PPL of the plant of JSC NPO Pribor was studied. The effect of varying the concentration from 2 to 9% of TERMAT polymer on the formation of metal structure, as well as physical and mechanical properties of hot-deformed vessels was studied. The results of testing the strength and plastic characteristics of vessels by destructive and non-destructive control methods are presented. According to the results of physical and mechanical properties, regression equations were obtained with at least 95% reliability of R2, which establish the relationship between the controlled plastic and strength parameters of the vessel metal`s properties. The conducted researches allowed to compare the indicators of the main physical and mechanical properties of steel vessels at the PPL outlet and to propose methods of inhomogeneity control that reduce time and material costs by 5–10% during the tests.

scholarly journals Family and childcare support public expenditures and short-term fertility dynamics

2013 ◽  
Vol 60 (3) ◽  
pp. 347-364 ◽  
Author(s):  
Cosmin Enache
Keyword(s):  
Birth Rate ◽  
Crude Birth Rate ◽  
Low Fertility ◽  
Alternative Methods ◽  
Public Expenditures ◽  
Short Term ◽  
Wide Range ◽  
Policy Measures ◽  
Support Policy ◽  
Cash Benefits

In a period of very low fertility, effective family and childcare support policy measures are needed. From a wide range of instruments available to government intervention, we focus on public expenditures effects on short-term fertility. Using a sample of 28 European countries in a panel framework, we found that there is a small positive elasticity of crude birth rate to cash benefits related to childbirth and childrearing provided through social security system. Different public services provided to ease the burden of parents and all other benefits in kind, means or non-means tested, are found to be insignificant. These results are robust to alternative methods of estimation. Controlling for country heterogeneity by religion and by culture, some particularly interesting differences in birth rate determinants were highlighted as well.

scholarly journals A framework for corrosion assessment in metallic structures, from data analysis to risk based inspection

2021 ◽  
Vol 23 (1) ◽  
pp. 11-20
Author(s):  
Xiaofei Cui ◽  
Xiaoxia Liang ◽  
Ujjwal Bharadwaj
Keyword(s):  
Corrosion Damage ◽  
Quantitative Information ◽  
Assessment Process ◽  
Steel Bridge ◽  
Destructive Testing ◽  
Metallic Structures ◽  
Wide Range ◽  
Corrosion Assessment ◽  
Metallic Corrosion ◽  
Non Destructive

Metallic corrosion is a big challenge affecting many sectors in a nation’s economy. Necessary corrosion prevention actions have to be taken in order to maintain the integrity of engineering assets susceptible to corrosion. This paper proposes a holistic framework to support the management of corrosion in metallic structures. It is a fully automation corrosion assessment process, with risk updated by Bayesian theory. Through analyzing the thickness data measured by non-destructive testing (NDT) techniques, the influence of corrosion on the component can be estimated using statistical methods, which will enable users to make decisions on maintenance based on quantitative information. A case study using corrosion data from a steel bridge is included to demonstrate the proposed framework. It improved the conventional corrosion analysis method by the proposed statistical approach using representative thickness data, which aims to take full use of the remaining life. This model can be adapted to a wide range of metallic structure suffering from corrosion damage.

scholarly journals CubeSat Communications: Recent Advances and Future Challenges

2020 ◽  
Author(s):  
Nasir Saeed ◽  
Ahmed Elzanaty ◽  
Heba Almorad ◽  
Hayssam Dahrouj ◽  
Tareq Y. Al-Naffouri ◽  
...  
Keyword(s):  
Channel Modeling ◽  
Future Research ◽  
New Paradigm ◽  
Earth Remote Sensing ◽  
Research Directions ◽  
Space Industry ◽  
Recent Advances ◽  
Wide Range ◽  
Future Challenges ◽  
Future Research Directions

<pre><pre>Given the increasing number of space-related applications, research in the emerging space industry is becoming more and more attractive. One compelling area of current space research is the design of miniaturized satellites, known as CubeSats, which are enticing because of their numerous applications and low design-and-deployment cost. </pre><pre>The new paradigm of connected space through CubeSats makes possible a wide range of applications, such as Earth remote sensing, space exploration, and rural connectivity.</pre><pre>CubeSats further provide a complementary connectivity solution to the pervasive Internet of Things (IoT) networks, leading to a globally connected cyber-physical system.</pre><pre>This paper presents a holistic overview of various aspects of CubeSat missions and provides a thorough review of the topic from both academic and industrial perspectives.</pre><pre>We further present recent advances in the area of CubeSat communications, with an emphasis on constellation-and-coverage issues, channel modeling, modulation and coding, and networking.</pre><pre>Finally, we identify several future research directions for CubeSat communications, including Internet of space things, low-power long-range networks, and machine learning for CubeSat resource allocation.</pre></pre>

scholarly journals New material-saving technologies of pipe rolling on pilgrim units

2021 ◽  
Vol 6 (131) ◽  
pp. 149-162
Author(s):  
Valery Balakin ◽  
Stanislav Stasevsky ◽  
Yuri Ugryumov
Keyword(s):  
Continuous Casting Machine ◽  
Cast Billet ◽  
Continuous Cast ◽  
Centrifugally Cast ◽  
Continuous Cast Billet ◽  
Wide Range ◽  
New Material ◽  
Thin Walled ◽  
Pilger Rolling ◽  
Material Saving

In this work, based on the analysis of the process of hot pilger rolling of pipes of a wide range of sizes and grades from a round continuous cast billet, new and improved existing metal-saving technologies have been developed to reduce metal losses in the pilger head.Using scientific and patent sources of information in the field of pilger rolling and its mathematical modeling with the calculation of tables for rolling pipes of a wide range of sizes from a round continuous-cast billet with a diameter of 385-470 mm, metal losses into technological scrap on a pilgerstan are determined: a seed and a pilger head.On the basis of the results of the theoretical determination of metal losses in the process scrap on the pilgerstan: the seed and the pilger head, a forecast was made to reduce the weight of the pilger head, which was used to develop new material-saving technologies for pilger rolling of pipes, both thick-walled with D / S = 6 - 12.5, and thin-walled with D / S = 12.5 - 40. Metal losses in the pilger head are the main factor of increased metal consumption coefficients on pilger units, which reduces their competitiveness in comparison with other units when using round continuously cast billets as a starting material.The forecast for the reduction of metal losses in the pilger head made for the first time makes it possible to estimate the reserves for reducing the mass of the pilger head both by eliminating the underflow of the liner and trimming of the pipe end adjacent to the pilger head, and by means of individual parts of its profile part and predicting its decrease to the minimum possible size, ensuring the removal of the pipe from the mandrel using a gate device.To reduce the weight of the pilger head when rolling thick-walled pipes, it is recom-?ended to use improved technologies for butt-end rolling and rolling of the pilger head on the free section of the mandrel.The results of the studies and the proposed new material-saving technologies can be used on pilgrim units when rolling thick-walled (D / S = 6 - 12.5) and thin-walled (D / S = 12.5 - 40) pipes of a wide range of brands (carbon, alloyed, highly alloyed and special) from both continuous casting machine and forged and centrifugally cast billets, as well as ingots.

scholarly journals Estimating upper-extremity function from kinematics in stroke patients following goal-oriented computer-based training

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Belén Rubio Ballester ◽  
Fabrizio Antenucci ◽  
Martina Maier ◽  
Anthony C. C. Coolen ◽  
Paul F. M. J. Verschure
Keyword(s):  
Data Science ◽  
Objective Assessment ◽  
Noise Model ◽  
Alternative Methods ◽  
Reaching Movements ◽  
Stroke Patients ◽  
Kinematic Data ◽  
Work Area ◽  
Wide Range ◽  
Computer Based

Abstract Introduction After a stroke, a wide range of deficits can occur with varying onset latencies. As a result, assessing impairment and recovery are enormous challenges in neurorehabilitation. Although several clinical scales are generally accepted, they are time-consuming, show high inter-rater variability, have low ecological validity, and are vulnerable to biases introduced by compensatory movements and action modifications. Alternative methods need to be developed for efficient and objective assessment. In this study, we explore the potential of computer-based body tracking systems and classification tools to estimate the motor impairment of the more affected arm in stroke patients. Methods We present a method for estimating clinical scores from movement parameters that are extracted from kinematic data recorded during unsupervised computer-based rehabilitation sessions. We identify a number of kinematic descriptors that characterise the patients’ hemiparesis (e.g., movement smoothness, work area), we implement a double-noise model and perform a multivariate regression using clinical data from 98 stroke patients who completed a total of 191 sessions with RGS. Results Our results reveal a new digital biomarker of arm function, the Total Goal-Directed Movement (TGDM), which relates to the patients work area during the execution of goal-oriented reaching movements. The model’s performance to estimate FM-UE scores reaches an accuracy of $$R^2$$ R 2 : 0.38 with an error ($$\sigma$$ σ : 12.8). Next, we evaluate its reliability ($$r=0.89$$ r = 0.89 for test-retest), longitudinal external validity ($$95\%$$ 95 % true positive rate), sensitivity, and generalisation to other tasks that involve planar reaching movements ($$R^2$$ R 2 : 0.39). The model achieves comparable accuracy also for the Chedoke Arm and Hand Activity Inventory ($$R^2$$ R 2 : 0.40) and Barthel Index ($$R^2$$ R 2 : 0.35). Conclusions Our results highlight the clinical value of kinematic data collected during unsupervised goal-oriented motor training with the RGS combined with data science techniques, and provide new insight into factors underlying recovery and its biomarkers.

scholarly journals Elements Identification in Golden Strawberries (Physalis Peruviana L.) using Wavelength Dispersive X-Ray Fluorescence

2019 ◽  
Vol 7 (6) ◽  
pp. 851
Author(s):  
Uğur Akbaba
Keyword(s):  
Weight Loss ◽  
Functional Food ◽  
Medical Field ◽  
X Ray ◽  
Physalis Peruviana ◽  
Food Properties ◽  
Wide Range ◽  
Important Health ◽  
Fluorescence Spectrometer ◽  
Non Destructive

Physalis peruviana (PP) is a popular exotic fruit due to its functional food properties. This product has a wide range of uses in the medical field, including treatments for cancer, malaria, hepatitis, dermatitis, rheumatism, weight loss, and diabetes. In this study, the PP element concentrations were investigated using a Wave Dispersive X-ray Fluorescence Spectrometer (WDXRF). Al, Ca, Fe, Mn, P, S, Zn, Cl, K, Mg, Na, F, Si, and B were detected, and the Ca, Fe, Zn, P, Na, Mg elements were found in significant amounts. Therefore, PP has some important health elements. For example, Mg and Mn may be associated with diabetes control. WDXRF is a cheap, quick, and non-destructive technique used in the elemental analysis of plant samples.

scholarly journals Micro-Raman Spectroscopy Assessment of Chemical Compounds of Mantle Clinopyroxenes

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1084
Author(s):  
Anastasiya D. Kalugina ◽  
Dmitry A. Zedgenizov
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Composition ◽  
Chemical Compounds ◽  
Peak Position ◽  
Mantle Xenoliths ◽  
Wide Range ◽  
Stretching Vibration ◽  
Raman Modes ◽  
Non Destructive ◽  
Heterovalent Isomorphism

The composition of clinopyroxenes is indicative for chemical and physical properties of mantle substrates. In this study, we present the results of Raman spectroscopy examination of clinopyroxene inclusions in natural diamonds (n = 51) and clinopyroxenes from mantle xenoliths of peridotites and eclogites from kimberlites (n = 28). The chemical composition of studied clinopyroxenes shows wide variations indicating their origin in different mantle lithologies. All clinopyroxenes have intense Raman modes corresponding to metal-oxygen translation (~300–500 cm−1), stretching vibrations of bridging O-Si-Obr (ν11~670 cm−1), and nonbridging atoms O-Si-Onbr (ν16~1000 cm−1). The peak position of the stretching vibration mode (ν11) for the studied clinopyroxenes varies in a wide range (23 cm−1) and generally correlates with their chemical composition and reflects the diopside-jadeite heterovalent isomorphism. These correlations may be used for rough estimation of these compounds using the non-destructive Raman spectroscopy technique.

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