scholarly journals Effect of Sulfate Crystallization on Sandstone in the Yungang Grottoes

2021 ◽  
Author(s):  
De-an Sun ◽  
Qi-ting Zhou ◽  
WenJing SUN ◽  
JiZhong Huang
Keyword(s):  
Ultrasonic Velocity ◽  
Optical Microscope ◽  
Test Results ◽  
Action Mechanism ◽  
Internal Solution ◽  
Slowing Down ◽  
Soft State ◽  
Long Time ◽  
Yungang Grottoes ◽  
Evaporation Stage

Abstract Subjected to various weathering in nature over long time, sandstone has been deteriorated in the Yungang Grottoes. The repeated dissolution and crystallization of soluble salts are important factors that cause the deterioration of the grotto sandstone. In order to study the action mechanism of sulfate crystallization in the Yungang Grottoes sandstone, deterioration tests were carried out by the “soaking-evaporation” cycle of saturated magnesium sulfate (MgSO4) and saturated sodium sulfate (Na2SO4) solutions in laboratory. The test results show that the participation of sulfate greatly accelerated the weathering speed of sandstone. The ultrasonic velocity of the specimens circulated in both Na2SO4 and MgSO4 solutions show a trend of first increasing and then decreasing, and changes more obviously in Na2SO4 solution. In the evaporation stage of the circulation, the peeling mass of the specimens circulated in Na2SO4 solution is significantly greater than that in MgSO4 solution. From the evaporation tests on saturated Na2SO4 and MgSO4 solutions and observation with optical microscope and scanning electron microscope, it is found that a dense crystal layer was formed on the surface during the evaporation of saturated MgSO4 solution, and it gradually seals the internal solution, slowing down the further evaporation. During the solution evaporation, Na2SO4 crystallizes into powdery crystals in a flocculent and soft state, and there are pores between the crystal grains. The change in the ultrasonic velocity of specimens in the "soaking-evaporation" cycle tests can be explained by the evaporation test results.

Rancang Bangun Sistem Komunikasi Data Antara Mikrokontroller Atmega8 Dengan Arduino Pada Mesin Roaster Coffe Digital

2020 ◽  
Vol 3 (2) ◽  
pp. 103-113
Author(s):  
Rachmad Ikhsan ◽  
Effendi Effendi
Keyword(s):  
Temperature Sensor ◽  
Data Communication ◽  
Test Results ◽  
Industry Standards ◽  
Long Time ◽  
Roasting Time

Roasting coffee manually is widely applied by coffee producers. This process takes a very long time and is less efficient in terms of productivity for industry standards. This machine  is equipped with a thermocouple sensor as a temperature sensor that will measure the temperature in the roasting cylinder, then equipped with a timer as a reminder of roasting time that ranges from 15 minutes at a temperature of 200 degrees Celsius, this machine  is also equipped with android as a timer controller on the coffee roaster machine. This machine is also equipped with a microcontroller and Bluetooth as a media transmitter and data receiver. From the test results obtained data that Bluetooth can be used for data communication between the microcontroller and Android with a distance of 30 meters in the room, and 12 meters outside the room. If it exceeds that distance, then Bluetooth will not respond back

scholarly journals Evaluation of the Feasibility of NaCaPO4-Blended Zirconia as a New CAD/CAM Material for Dental Restoration

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3819
Author(s):  
Ting-Hsun Lan ◽  
Yu-Feng Chen ◽  
Yen-Yun Wang ◽  
Mitch M. C. Chou
Keyword(s):  
Computer Aided Design ◽  
Optical Microscope ◽  
Dental Restoration ◽  
Numerical Control ◽  
Test Results ◽  
Cnc Machine ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design ◽  
Better Than

The computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication technique has become one of the hottest topics in the dental field. This technology can be applied to fixed partial dentures, removable dentures, and implant prostheses. This study aimed to evaluate the feasibility of NaCaPO4-blended zirconia as a new CAD/CAM material. Eleven different proportional samples of zirconia and NaCaPO4 (xZyN) were prepared and characterized by X-ray diffractometry (XRD) and Vickers microhardness, and the milling property of these new samples was tested via a digital optical microscope. After calcination at 950 °C for 4 h, XRD results showed that the intensity of tetragonal ZrO2 gradually decreased with an increase in the content of NaCaPO4. Furthermore, with the increase in NaCaPO4 content, the sintering became more obvious, which improved the densification of the sintered body and reduced its porosity. Specimens went through milling by a computer numerical control (CNC) machine, and the marginal integrity revealed that being sintered at 1350 °C was better than being sintered at 950 °C. Moreover, 7Z3N showed better marginal fit than that of 6Z4N among thirty-six samples when sintered at 1350 °C (p < 0.05). The milling test results revealed that 7Z3N could be a new CAD/CAM material for dental restoration use in the future.

Creep Tests of Rotating Disks at Elevated Temperature and Comparison With Theory

1954 ◽  
Vol 21 (3) ◽  
pp. 225-235
Author(s):  
A. M. Wahl ◽  
G. O. Sankey ◽  
M. J. Manjoine ◽  
E. Shoemaker
Keyword(s):  
Elevated Temperatures ◽  
Experimental Program ◽  
Test Results ◽  
Rotating Disks ◽  
Creep Tests ◽  
Shear Theory ◽  
Heat Treated ◽  
Long Time ◽  
Average Tension ◽  
Creep Deformations

Abstract A theoretical and experimental program involving methods of calculating creep in rotating disks at elevated temperatures is described. This program consisted primarily of the following: (a) Obtaining forged disks from the same ingot of 12 per cent chrome steel, all disks being forged and heat-treated in the same manner; (b) making spin tests at 1000 F on three of these disks for periods up to about 1000 hr; ( ) making long-time tension-creep tests at 1000 F on many specimens cut out circumferentially from several of the other disks at stresses approximating those of the spin tests; (d) investigating theoretical methods of calculation of creep deformation in such disks; and (e) comparison of spin-test results with those calculated theoretically using average tension-creep data. It was found that available methods of calculating rotating disks based on the Mises criterion gave creep deformations too low compared to the test values, i.e., on the unsafe side for design. Considerably better agreement between test and theoretical results is obtained if the latter is based on the maximum-shear theory. Some discussion is given of the reasons for the better agreement obtained using the latter theory; these are believed to be related in part to the anisotropy of the forged material tested. Further tests on other materials are necessary before general conclusions can be drawn; however, in the absence of test data it is suggested that a conservative course in design for such disks is to apply the maximum-shear theory.

scholarly journals Detecting hotspots of atmosphere–vegetation interaction via slowing down – Part 1: A stochastic approach

2013 ◽  
Vol 4 (1) ◽  
pp. 63-78 ◽  
Author(s):  
S. Bathiany ◽  
M. Claussen ◽  
K. Fraedrich
Keyword(s):  
Climate Models ◽  
Stochastic Approach ◽  
General Context ◽  
Grid Cells ◽  
Climate System Model ◽  
Local Loss ◽  
Slowing Down ◽  
Current State ◽  
Long Time ◽  
Sudden Transition

Abstract. An analysis of so-called early warning signals (EWS) is proposed to identify the spatial origin of a sudden transition that results from a loss in stability of a current state. EWS, such as rising variance and autocorrelation, can be indicators of an increased relaxation time (slowing down). One particular problem of EWS-based predictions is the requirement of sufficiently long time series. Spatial EWS have been suggested to alleviate this problem by combining different observations from the same time. However, the benefit of EWS has only been shown in idealised systems of predefined spatial extent. In a more general context like a complex climate system model, the critical subsystem that exhibits a loss in stability (hotspot) and the critical mode of the transition may be unknown. In this study we document this problem with a simple stochastic model of atmosphere–vegetation interaction where EWS at individual grid cells are not always detectable before a vegetation collapse as the local loss in stability can be small. However, we suggest that EWS can be applied as a diagnostic tool to find the hotspot of a sudden transition and to distinguish this hotspot from regions experiencing an induced tipping. For this purpose we present a scheme which identifies a hotspot as a certain combination of grid cells which maximise an EWS. The method can provide information on the causality of sudden transitions and may help to improve the knowledge on the susceptibility of climate models and other systems.

scholarly journals THE FIRST INVESTIGATION OF AAC(6’)-Ib ENZYME IN CARBAPENEM-RESISTANT ENTEROBACTERIACEAE ISOLATED FROM INDONESIAN PATIENTS

2019 ◽  
Vol 2 (1) ◽  
pp. 8-14
Author(s):  
Beauty Novianty ◽  
Ella Amalia ◽  
Ziske Maritska ◽  
Yuwono Yuwono ◽  
Lusia Hayati
Keyword(s):  
Resistance Mechanism ◽  
Test Results ◽  
Gram Negative ◽  
Therapy Options ◽  
The Past ◽  
Carbapenem Resistant ◽  
Long Time ◽  
Pcr Method ◽  
Vitek 2 ◽  
Carbapenem Resistant Enterobacteriaceae

Background: Over the past decade, numbers of Carbapenemase Producing-Carbapenem Resistant Enterobacteriaceae (CP-CRE) has been increasing worldwide and it has been becoming a threat because of its resistance against carbapenem which is considered as the “last resort” antibiotic. Therapy options for its infection are still limited. Aminoglycoside serves as one of the most commonly used antibiotics, but the resistance against it has already been presented for a long time. Aminoglycoside Modifying Enzyme (AME) is the most important resistance mechanism against aminoglycoside. AAC(6’)-Ib enzyme is one of the most common AME produced by the gram-negative bacteria.Objectives: This study wished to identify the gene of this enzyme among CRE isolated from infected Indonesian patients in Dr. Mohammad Hoesin Hospital Palembang.Methods: Twenty-eight isolates collected from CRE-infected patients identified by Vitek 2 Compact (bioMerieux, USA) in dr. Mohammad Hoesin Hospital Palembang during September—November 2017. AAC(6’)-Ib gene was identified using PCR method, then visualize by electrophoresis. The result is then analyzed by comparing it with a susceptibility test.  Results: Out of 28 samples, AAC(6’)-Ib is identified in 22 (78.57%) samples. Samples with AAC(6’)-Ib showed to be less resistant to various antibiotics, significantly to amikacin (p=0.023).Conclusion: AAC(6’)-Ib gene is found in most of samples implying its frequent occurrence in Indonesian patients.

scholarly journals HUBUNGAN PIJAT BAYI DENGAN PERKEMBANGAN MOTORIK BAYI USIA 1 – 12 BULAN DI DESA PUNDUNGSARI BULU SUKOHARJO

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Rahayu Setyaningsih ◽  
Kristiani Eka Prasetyo Wat ◽  
Asri Utami
Keyword(s):  
Rapid Growth ◽  
Experimental Studies ◽  
Sampling Technique ◽  
Test Results ◽  
Infant Massage ◽  
Chi Square ◽  
The Public ◽  
Touch Therapy ◽  
Mother And Child ◽  
Long Time

AbstractIntroduction: Infant massage is a touch therapy oldest known to the public. Infant massage is one of the communication between mother and child is communication through touch. Infant massage has been known to man for a long time and reduced down - generations. Age 1-12 months is a period of rapid growth that is traversed by the child, including motoric development. Infant massage can provide a stimulus to promote weight and to increase motoric development.The purpose: Of this study was to correlate of infant massage and motoric development in infants aged 1-12 months in District Pundungsari Bulu Sukoharjo.The subjects: Were mother with infants aged 1-12 months, in the District Pundungsari. Sampling is done with total sampling technique. They are 33 sample in this research.Methods: This study was a non-experimental studies, correlation approach. Data obtained by the method of questionare, which is mother has filled the questionare about baby massage in infants aged 1-12 months and motoric development. The data have been collected and analyzed by chi square with p= 0.05. The research found that respondents do baby massage with continue and not continue and motoric development found delayed, normal and advance. After the test results obtained chi square p 0.000 to p <0.05, which means Ha accepted and Ho rejected.The conclusion: Of this study is infant massage correlate with motoric development in infants aged 1-12 months in District Pundungsari Bulu Sukoharjo.Keywords: Infant massage, motoric development

scholarly journals Sistem Komunikasi Suara Bawah Air dengan Metoda Simplex menggunakan Visible Light Communication (VLC)

2019 ◽  
Vol 7 (2) ◽  
pp. 253
Author(s):  
LUCIA JAMBOLA ◽  
ARSYAD RAMADHAN DARLIS ◽  
LITA LIDYAWATI ◽  
DZIKRI FACHRI HUSAENI
Keyword(s):  
Visible Light ◽  
Communication Systems ◽  
Light Transmission ◽  
Visible Light Communication ◽  
Color Filter ◽  
Underwater Communication ◽  
Test Results ◽  
Voice Communication ◽  
Yellow Color ◽  
Long Time

ABSTRAKSistem komunikasi suara bawah air telah dikenal sejak lama, diantaranya sonar dan akustik. Seiring perkembangan zaman dan kemajuan teknologi, kini hadir komunikasi dengan media transmisi cahaya tampak yaitu Visible Light Communication (VLC) yang dapat diterapkan pada komunikasi bawah air. Pada penelitian ini telah dilakukan komunikasi suara bawah air (simplex) menggunakan VLC, dengan media akuarium berisi air dan beberapa pengujian diantaranya menggunakan color filter, didapat hasil pengujian terbaik yaitu tegangan 4,4 Vpp dan frekuensi 3,003 kHz untuk color filter yellow, pengujian menggunakan lensa didapat hasil pengujian terbaik yaitu tegangan 4,4 Vp-p dan frekuensi 3,051 kHz untuk lensa (+50), dan pengujian terakhir menggunakan lampu UV didapat hasil pengujian terbaik dengan tegangan 4,4 Vp-p dan frekuensi 3,010 kHz. Implementasi sistem VLC ini menunjukkan hasil yang baik dan layak untuk diterapkan pada komunikasi suara bawah air (simplex).Kata kunci: VLC, Komunikasi Suara Bawah Air, Simplex. ABSTRACTUnderwater voice communication systems have been known for a long time, including sonar and acoustics. Along with the development and advancement of technology, now there is communication with visible light transmission media, namely Visible Light Communication (VLC) which can be applied to underwater communication. Under this study underwater voice communication (simplex) has been carried out using VLC, with aquarium media containing water and several tests including using a color filter, the best test results obtained are voltage 4.4 Vp-p and frequency 3.003 kHz for yellow color filter, testing using the lens obtained the best test results namely voltage 4.4 Vp-p and frequency 3.051 kHz for lenses (+50), and the last test using UV lights obtained the best test results with a voltage of 4.4 Vp-p and a frequency of 3.010 kHz. The implementation of the VLC system shows good and feasible results to be applied to underwater voice communication (simplex).Keywords: VLC, Underwater Voice Communication, Simplex.

scholarly journals Design of multilayer microfluidic paper chip and its visual detection of pesticide residues

2020 ◽  
Vol 11 ◽  
pp. 170-182
Author(s):  
Li zhi Li ◽  
Han Ping Mao
Keyword(s):  
Pesticide Residues ◽  
Visual Detection ◽  
Channel Structure ◽  
Test Results ◽  
Mixed Effect ◽  
Detection Range ◽  
Long Time ◽  
Paper Chip ◽  
Channel Structures ◽  
High Repeatability

With the increase of China's grain production, the use of pesticides is gradually increasing. Traditional pesticide detection takes a long time and requires expensive experimental instruments, which is not conducive to the rapid and accurate detection of pesticide residues in the field. To solve this problem, this paper proposes a visual detection method of pesticide residues based on multi-layer microfluidic paper chips. The internal channel structure of paper chip is designed from the perspective of efficient mixing. Through the simulation of the mixed effect of three kinds of staggered channel structures, which are arc type, triangle type, and ladder type, the "ladder-type h-0.3, s-2.6" is selected as the best-staggered structure, and the mixing strength is 0.91534. The best simulation structure was tested by a colored reagent, and the image processing of 15 test results was carried out with MATLAB. The average mixing strength was 0.84, and the and the standard deviation was 0.022. The visual detection experiment of acetamiprid and profenofos in cabbage samples was carried out by using the device，The detection range of acetamiprid was 4~72 μg/kg, and the detection range of profenofos was 3~54 μg/kg . The recovery of acetamiprid was 75%~85%, and the recovery of profenofos was 80%~90%. The detection range and recovery rate indicate that the device has high repeatability and accuracy in the actual sample detection

scholarly journals Effect of Chemical Aggressive Media on the Flexural Properties of Cured-In-Place Pipes Supported by Microstructure Observation and Acoustic Emission

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3051
Author(s):  
Jakub Hodul ◽  
Jana Majerová ◽  
Rostislav Drochytka ◽  
Richard Dvořák ◽  
Libor Topolář ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Vinyl Ester ◽  
Optical Microscope ◽  
Flexural Properties ◽  
Cumulative Number ◽  
Test Results ◽  
Short Term ◽  
Microstructure Observation ◽  
Inorganic Acids ◽  
Sample Structure

The cured-in-place pipe (CIPP) method is currently the most frequently used approach for the renovation of piping without digging; this technology is suitable for pipes made from all types of material. The authors of this paper examined how chemical substances and increased temperature change samples of CIPP with vinyl-ester resin taken from a simulated installation. Changes were observed at several levels: visually via a digital optical microscope, through changes of short-term bending properties and by observation of the activity of the sample structure by means of acoustic emission (AE). Interdependencies among the observed parameters were examined, specifically, the cumulative number of hits (cnt)/deflection and flexural properties/mechanic wave velocity. The test results prove that after three weeks of immersion in a simulated aggressive environment that mirrors what may happen to CIPP in real conditions, short-term mechanical properties change. This is also proven by the results of the AE measurements. For clarity, the results include images from a digital optical microscope. In addition, this paper proves that CIPP samples have good resistance to the action of organic and inorganic acids and to increased temperatures. After three weeks of exposure to a temperature of 100 °C the CIPP flexural properties of the samples had even improved.

scholarly journals A Study on the Thermal Properties of High-Strength Concrete Containing CBA Fine Aggregates

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1493 ◽  
Author(s):  
In-Hwan Yang ◽  
Jihun Park
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Ultrasonic Velocity ◽  
High Strength Concrete ◽  
High Strength ◽  
Unit Weight ◽  
Test Results ◽  
Strength Concrete ◽  
Fine Aggregates

The thermal conductivity of concrete is a key factor for efficient energy consumption in concrete buildings because thermal conductivity plays a significant role in heat transfer through concrete walls. This study investigated the effects of replacing fine aggregates with coal bottom ash (CBA) and the influence of curing age on the thermal properties of high-strength concrete with a compressive strength exceeding 60 MPa. The different CBA aggregate contents included 25%, 50%, 75%, and 100%, and different curing ages included 28 and 56 days. For concrete containing CBA fine aggregate, the thermal and mechanical properties, including the unit weight, thermal conductivity, compressive strength, and ultrasonic velocity, were measured. The experimental results reveal that the unit weight and thermal conductivity of the CBA concrete were highly dependent on the CBA content. The unit weight, thermal conductivity, and compressive strength of the concrete decreased as the CBA content increased. Relationships between the thermal conductivity and the unit weight, thermal conductivity and compressive strength of the CBA concrete were proposed in the form of exponential functions. The equations proposed in this study provided predictions that were in good agreement with the test results. In addition, the test results show that there was an approximately linear relationship between the thermal conductivity and ultrasonic velocity of the CBA concrete.

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