bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of ‘7.23’ hydrogen cylinder explosion accidents of three quartz products companys
Authors: Kong Xiangzhi , Yang Chengcheng , Zhang Lijing , Tao Gang 
Published: March 2021

Abstract
On July 23, 2004, three quartz manufacturing companies’ hydrogen cylinders exploded during operation in the same county of China. Six people were killed and several buildings collapsed. In this paper, the cause of hydrogen cylinder explosions is analyzed by introducing the production and operation process of hydrogen. The energy and the overpressure generated by the explosion are estimated through quantitative analysis. In order to safely release hydrogen, corresponding methods are designed. The lessons learned from chemical process safety are also presented to prevent similar accidents from occurring, which is helpful to prevent personal injury and loss of property.
Experimental validation of the Finite Element-Multibody model of a cryomodule during road transportation
Authors: Bucchi F , Neri P , Passarelli D 
Published: March 2021

Abstract
The present activity aims to test the Transportation Tooling (TT) designed for the Cryomodule SSR1 at Fermilab facilities. The tests consisted of road transportation trials of a cryomodule sub-assembly, suspended on a truck using the designed TT. The truck drove along a path inside Fermilab facilities. The trial was performed at an approximate speed of about 25 km/h, which is close to the transportation conditions of the complete Cryomodule. Several accelerometers were mounted on the Transportation Tooling frame and the cryomodule sub-assembly. This allowed comparing the vibration behavior of the inner frame of the TT with the solicitation coming from the truck loading bed, to assess the filtering capabilities of the tooling. Also, the acceleration of the main components could be monitored during the whole transportation, to obtain a validation of the developed numerical model.
Development of Android Based Application for Monitoring Engine Lubricant Condition in Four Wheeled Vehicle and Driving Behaviour Effects on Engine Lubricant Condition
Authors: Nugroho H S , Dewantoro M A , Atmaja D E 
Published: March 2021

Abstract
Engine lubricant is a liquid chemical that is given between two moving objects to reduce the frictional force that occurs. Engine lubricant needs to be replaced periodically to maintain the durability of four-wheeled vehicles. Manufacturers of four-wheeled vehicle manufacturers have given the lubricant replacement period to consumers, but this time period is only a reference. The purpose of this research is to study the calculation method to find the right time to replace the lubricant along with its parameters, study the relationship and characteristics between engine lubricant temperature with coolant temperature, and study the relationship of driving behaviour to decrease engine lubricant conditions. This research was carried out by taking data on engine lubricant temperature and coolant using ANCEL and then analysed it to get the formula for determining engine oil temperature and found the mean absolute error of 0 to 3.60. This research is done by testing the driving behaviour of eco, normal, and sport as far as 300 km for each driving behaviour. In this study, engine speed and coolant temperature data are taken through OBD II and then processed using Raspberry Pi into RPS and engine lubricant temperature then further processed by the backend then the data is sent to Android. On the Android application, the output of the data processing results is displayed as a percentage of engine lubricant conditions, engine lubricant remaining distance, and engine lubricant remaining time. The test results show that in sports driving behaviour, the condition of engine lubricants decreased the most at 3.9% followed by normal at 3.18% and the lowest decreased was eco with 2.39%.
The Effect of Gain and Frequency on Eddy Current Testing for Copper Material Defect Inspection
Authors: Mohd W.Syahidah W. , Attan Farraniza , Rifai Damhuji , Ali Kharudin , Sulaiman M.Aizat M. , Mamat Nor Hana 
Published: March 2021

Abstract
Copper and the copper alloys are some of the most versatile materials available and used for applications in every type of industry with world consumption of exceeding 14 million tonnes per annum. In eddy current testing inspection (ECT), several forms of device calibration must be done before the assessment can be performed. The electronics equipment must be calibrated to ensure the accuracy of measurement. This paper is focused on investigate the optimum frequency and gain for copper material block. The material used to produce the sample test in this project was copper. They are many methods that involved in this project such as producing sample test and artificial defect, conductivity measure and perform calibration for copper material block. Two thickness of copper block were selected 8mm and 16 mm. Artificial defect with depth of defect 0.5 mm, 1mm and 2.0 mm are fabricate on the sample. Different frequency and gain of eddy current testing was used in order to identify the best setting for both parameters in ECT for copper material defect inspection. Experimental result showed that the thickness is directly proportional with the applied gain. From here the negative scanning will giving the good result of different slot of defect comparing the negative scanning. Besides the percentage of increment of signal amplitude being identify with increment 40% signal between 0.5mm and 1.0mm slot of defect. Lastly the depth of the slot is inversely proportional with applied gain.
Thermal Characterization of Polyvinyl Alcohol Nanocomposites
Authors: Faiz M.Alif , Yahya Nor Aisyah Mat , Yusoff N.N.A.N. , Hashim Norazlina , Shakirah Lili , Abdullah Nabihah 
Published: March 2021

Abstract
Nanocomposite films of PVA (polyvinyl alcohol) with GF(graphene flakes), GO (graphene oxide) and G(Graphite) as nanofillers have been synthesized. Nanocomposites were prepared to contain various weight amounts of nanofiller (0.3, 1, 1.5, 2 and 3%) within PVA matrix. The film is cast on a clean glass plate through the solution casting method and dried in the oven. Here a report of a simple and practical approach to synthesizing graphene-reinforced poly (vinyl alcohol) (PVA) composite films by incorporating other filler into PVA aqueous solution. Further, the investigation of thermal properties was used using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal stability shows the best stability with the nanofillers content of 1% for G, GO and GF. Nanocomposites with an additional of 1% GF gives the highest thermal stability compared to 1% of G and GO.
Organic-inorganic composition for stone masonry walls of ancient tower and necropolis buildings in the North Caucasus
Authors: Bataev D K-S , Murtazaevi S-A J , Mazhiev Kh N , Maloroev M M , Bataev G K-S , Goitemirov R U , Gaziev M A , Bataeva P D 
Published: March 2021

Abstract
Search works were performed based on archival and bibliographic research, which allowed us to get an idea of the monuments of archeology, history, and culture. For laboratory physical and physicomechanical studies, samples collection of the masonry wall solution was taken. Based on the conducted laboratory studies, a conclusion was made about the necessary grade strength of the masonry mortar of 25-75 kg/cm2 with the following physical and mechanical properties of the solution are as follows: average compressive strength-8.3 MPa; water absorption-11.7%; porosity-18.3%; volume weight-1.56 g / cm3.stress-related properties: average compression strength – 8.3 MPa; water absorption – 11.7%; porosity – 18.3%; volume weight – 1.56 g/cm3. The testing of new experimental compositions was performed in places accessible for observation and documented. Local inert, reinforcing, and binding materials were used to select the composition of the stone masonry solution for the walls of ancient tower and necropolis buildings. The research was carried out using existing methods, adjusted to take into account the peculiarities of the historical and cultural monuments under consideration. Based on the study results were developed organic-inorganic compositions of solutions of stone masonry walls of ancient tower and necropolis buildings in the North Caucasus.
Behavior of asphalt concrete mixture during relaxation
Authors: Shishkin E A , Ivanchenko S N , Shemyakin S A 
Published: March 2021

Abstract
The article discusses the asphalt concrete mixture compaction process with a road roller. The rheological model of a smooth drum and material interaction is adopted. The relaxation process that occur in the asphalt concrete mixture during compaction has been studied. During dynamic modeling, the physical and mechanical characteristics of the compacted material influence on the behavior of the latter during relaxation was established. The article reveals the relaxation process physical essence, which plays an important role in the material compaction. The law of asphalt concrete mixture behavior during relaxation was determined. The obtained dependencies make it possible to evaluate the effectiveness of the force effect of a smooth drum on each pass of the roller.
Study of the tension of a heterogeneous hydroelastic system
Authors: Zaretskaya M V 
Published: March 2021

Abstract
The purpose of the article is to analyze seismic-acoustic wave fields and stress-strain state in a complex heterogeneous seismogenic structure of the contact area of the continental and oceanic crust, taking into account two types of impact: technogenic and pressure of the oceanic water column. The study uses the theory of block structures and the block element method, developed on the basis of a topological approach. It is shown that the contact stress can be considered as a superposition of stress waves occurring at the interface between the liquid and elastic media. The number of waves, their amplitude and frequency are determined by the physical and geometric characteristics of the volume of the liquid, the elastic semi-bounded layer, the elastic foundation, as well as the oscillation frequency of the external harmonic load. The model can be useful in the design of a transport network, production facilities on the coastal territory, since it allows one to assess seismic risks before the start of the process, as well as the risks of associated hazardous exogenous phenomena - landslides, tsunamis, and volcanism activation.
Losing the shock wave front profile due to interaction with turbulence
Authors: Fukushima Gaku , Wei Jiaxi , Ogawa Shingo , Hagiwara Jun , Nakamura Yusuke , Sasoh Akihiro 
Published: March 2021

Abstract
In this study, losing the shock wave profiles under interactions with grid turbulence was investigated experimentally and theoretically. We demonstrated that the shock wave contrast on side-view schlieren images gradually decreased to an undetectable level in the experiment. This shock wave ‘vanishment’ occurred at a low shock Mach number with a high turbulent Mach number. With a relatively strong shock wave, the contrast of the shock wave remained detectable although the shock wave profile region was expanded. To understand the shock wave vanishment phenomenon during interaction with turbulence, we established a shock wave vanishment model based on the solution of a one-dimensional interaction between a shock wave and forward induced flow. The criterion of the occurrence of local vanishment of the shock wave was derived as

M

t

⩾
(

M

s

2

−
1
)

/

M

s

, where

M

t

is the turbulent Mach number and

M

s

is the shock Mach number. The proposed shock vanishment model involves the effect of the interaction length and the shock wave recovery characteristics. The derived model explains the vanishment of weak shock wave profile during turbulence with an interaction length of ten times the order of the integral scale of the turbulence, as observed in the experiment.
Geometry of spiral beams: 3D curved structured vortex beams and optical currents
Authors: Volyar A V , Abramochkin E G , Razueva E V , Bretsko M V , Akimova Ya E 
Published: March 2021

Abstract
Our research concerns the problem of constructing multiple-twisted spiral beams and the geometry of their fine structure. We analyzed the distribution of energy flows in triangular spiral beams and critical points’ positions responsible for their structural stability. It was shown experimentally that a three-spot beam propagates without breaking the internal structure, while the intricate framing of a multiple-twisted triangular beam is distorted beyond the Rayleigh length. We associate such a structural violation with the imperfection of the holographic grating in the spatial light modulator.
Synthesis of photocatalytic CdO-imbedded ZnO nanopebbles for enhanced biocidal activity
Authors: Karunakaran C , Vijayabalan A 
Published: March 2021

Abstract
CdO-imbedded ZnO nanopebbles have been synthesised by a two-step process. The scanning and transmission electron microscopic images display the morphology and size (62–98 nm). The selected area electron diffractogram reveals the presence cubic CdO and hexagonal ZnO, the latter is confirmed by X-ray diffractogram. Implantation of CdO in ZnO lattice increases the charge transfer resistance. However, the absorption and emission are unaffected by the implanted CdO. The nanopebbles are powerful bactericidal material; the antibacterial activity of nanocrystalline CdO/ZnO is larger than those of CdO and ZnO nanoparticles. Further, CdO-implantation in ZnO nanopebbles does not suppress the photocatalytic activity. Thus, the title material is a powerful bactericide with unsuppressed photocatalytic activity.
Preparation of magnetic manganese ferrite/graphene oxide nanocomposites as efficient adsorbents towards ibuprofen
Authors: Thy Lu Thi Mong , Dang Nguyen Minh , My Nguyen Huong Tra , Tai Le Tan , Tu Tran Hoang , Oanh Doan Thi Yen , Viet Thieu Quang Quoc , Nam Hoang Minh , Hieu Nguyen Huu , Phong Mai Thanh 
Published: March 2021

Abstract
This study aims to prepare in manganese ferrite/graphene oxide (MnFe2O4/GO) nanocomposites for the removal of ibuprofen drug residue from water. The synthesised nanocomposites with various MnFe2O4 content from 30–60 wt.% were characterised by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, vibrating sample magnetometer, Brunauer - Emmett - Teller specific surface area, and energy dispersive X-ray. It was found that the suitable mass ratio of MnFe2O4 in nanocomposite for ibuprofen removal was 50 wt.%. The adsorption process followed the pseudo-second-order kinetic and Langmuir isotherm model. The maximum capacity of MnFe2O4/GO was found to be 156.25 mg g−1. Accordingly, the MnFe2O4/GO could be used as an efficient adsorbent for the removal of ibuprofen from water.
Effect of porous corncob on the removal of HCN in cigarette mainstream smoke
Authors: Wang Yipeng , Jia Yunzhen , Sun Xuehui , Sun Peijian , Yang Song , Yan Quanping , Peng Bin , Guo Jizhao , Zhang Xiaobing , Nie Cong 
Published: March 2021

Abstract
In order to reduce the hydrogen cyanide (HCN) release in cigarette mainstream smoke, a new type of porous corncob (PCC) material which was different from traditional corncob-based activated carbon was prepared by a two-step chemical reaction of carboxymethylation and cupric ion complexation. Fourier Transformation Infrared Spectroscopy (FTIR) showed that the carboxymethyl group had been introduced onto the corncob, the carboxymethyl content and the cupric ion loading amount were measured. The x-ray photoelectron spectrometer (XPS) results showed that the Cu content on the surface of PCC was much higher than that of the whole material. The scanning electron microscope (SEM) and nitrogen adsorption-desorption results suggested that PCC had a porous structure. With the increase of the amounts of chloroacetic acid and sodium hydroxide in carboxymethylation reaction and the concentration of cupric ion aqueous solution in complexing reaction, the BET surface areas and pore volumes increased, while the most probable pore sizes of PCCs were close to each other. Compared with the control cigarette, the addition of PCC could effectively remove the HCN release in cigarette mainstream smoke, and the highest reduction rates of HCN per total particulate matter (TPM) was 72.4 %.
Antibacterial, antioxidant and physicochemical investigations of tin dioxide nanoparticles synthesized via microemulsion method
Authors: Haq Sirajul , Ahmad Pervaiz , Khandaker Mayeen Uddin , Faruque M R I , Rehman Wajid , Waseem Muhammad , Din Salah Ud 
Published: March 2021

Abstract
The Tin dioxide nanoparticles (SnO2 NPs) were synthesized by modified microemulsion method and were screened for antibacterial and antioxidant applications. The crystalline nature was explored by using x-ray diffraction (XRD) analysis and the calculated crystallite size is 24.68 nm. The morphology was examined by scanning and transmission electron microscopies (SEM and TEM) and particles based on TEM image is 79.10 nm. The elemental analysis was performed by energy dispersive x-ray (EDX) and only desired elements was detected. The optical activity was investigated using diffuse reflectance spectroscopy (DRS) and band gap derived via Tauc plot is 2.82 eV. The surface functional moiety was detected by Fourier transform infrared spectroscopy (FTIR). The agar well diffusion technique was manipulated to screen the SnO2 NPs against selected bacteria whereas DPPH free radical scavenging activity was also performed. The activity of both samples was noticed to increase with increasing the amount of samples in the experiment. The SnO2 NPs with IC50 value of 1.50 g was found more active than the ascorbic acid with IC50 of 2.42 g.
Experimental study on fast electron generation during internal crash
Authors: MAI Chaowei , HU Liqun , XU Liqing , LUO Zhengping , LIN Shiyao , CHEN Yiping 
Published: March 2021

Abstract
Hard x-ray (HXR) burst is found during internal crash in the flat top current stage of experimental advanced superconducting tokamak (EAST) discharges and it is caused by fast electrons. The generated electrons during internal crashes may be an operational safety issue in advanced tokamaks. During an internal crash, locations of fast electron generation from HXR evolution agree with areas of magnetic reconnection from soft x-ray (SXR) tomographic reconstruction. Further statistical analyses show a 27 μs time difference between SXR crashes and HXR bursts, and the agreement between time broadening of HXR bursts and estimated characteristic time of magnetic reconnection in EAST. The magnetic reconnections during internal crash are proved to generate fast electrons, by both spatial and temporal agreements.
Changes in psychological distress before and during the COVID-19 pandemic among older adults: the contribution of frailty transitions and multimorbidity
Authors: Wang Yi , Fu Peipei , Li Jie , Jing Zhengyue , Wang Qiong , Zhao Dan , Zhou Chengchao 
Published: March 2021

Abstract

Aim
To investigate changes in psychological distress in community-dwelling older adults before and during the coronavirus disease 2019 (COVID-19) pandemic and the contribution of frailty transitions and multimorbidity in predicting the psychological distress.

Methods
Prospective repeated-measures cohort study on a sample of participants aged 60 and over. A total of 2, 785 respondents at the baseline (May 2019) were followed during the COVID-19 (August 2020). The changes in psychological distress before and during the COVID-19 were assessed using generalised estimation equations with adjusting for sex, age, education, economic status, marital status, tea drinking status, smoking status, alcohol drinking status, sedentary time, sleep quality and activities of daily living.

Results
The psychological distress of older people has significantly increased in August 2020 compared with May 2019. Both older adults who remained frail and transitioned into frail state reported more psychological distress during the COVID-19. Similarly, both pre-existing multimorbidity and emerging multimorbidity groups were associated with more psychological distress. The group of frailty progression who reported new emerging multimorbidity showed more increase in psychological distress in comparison with those who remained in the non-frail state who reported no multimorbidity.

Conclusion
Psychological distress has increased among the community-dwelling older adults during the COVID-19 pandemic, and sustained and progressive frail states as well as multimorbidity were all associated with a greater increase of psychological distress. These findings suggest that future public health measures should take into account the increased psychological distress among older people during the COVID-19 pandemic, and the assessment of frailty and multimorbidity might help in warning of psychological distress.
Sheltering in Place and the Likelihood of Nonnatural Death
Authors: Catalano Ralph , Glymour M Maria , Chen Yea-Hung , Bibbins-Domingo Kirsten 
Published: March 2021

AbstractIncreasing hospitalizations for COVID-19 in the United States and elsewhere have ignited debate over whether to reinstate shelter-in-place policies adopted early in the pandemic to slow the spread of infection. The debate includes claims that sheltering in place influences deaths unrelated to infection or other natural causes. Testing this claim should improve the benefit/cost accounting that informs choice on reimposing sheltering in place. We used time-series methods to compare weekly nonnatural deaths in California with those in Florida. California was the first state to begin, and among the last to end, sheltering in place, while sheltering began later and ended earlier in Florida. During weeks when California had shelter-in-place orders in effect, but Florida did not, the odds that a nonnatural death occurred in California rather than Florida were 14.4% below expected levels. Sheltering-in-place policies likely reduce mortality from mechanisms unrelated to infection or other natural causes of death.