scholarly journals Design of an Acoustic-Based Nondestructive Test (NDT) Instrument to Predict the Modulus of Elasticity of Wood

2020 ◽  
Vol 24 (6) ◽  
pp. 109-116
Author(s):  
Sentagi Sesotya Utami ◽  
Abdurrahman Mappuji ◽  
Balza Achmad ◽  
Ali Awaluddin ◽  
Ayutyastuti Ayutyastuti ◽  
...  
Keyword(s):  
Impulse Response ◽  
Modulus Of Elasticity ◽  
Wood Sample ◽  
Mechanical Characteristics ◽  
Raspberry Pi ◽  
Longitudinal Stress ◽  
Telecommunication System ◽  
Band Pass ◽  
R Value

Modulus of elasticity (E) can predict the mechanical characteristics, as well as grade the quality of wood. The Destructive Test (DT) method is the more commonly used, where the wood sample is split up when being tested. This research used the NDT method based on the longitudinal stress wave method (LSWM) whilst utilizing handheld instruments. The calculated E-dynamic (Ed) from the NDT method was compared with the E-static (Es) from the DT method to validate the technique. Six different wood types were tested with ten samples of each kind. An average R-value of 0.898 was obtained, indicating a high correlation between the Ed values and Es values. The LSWM method requires reliable hardware and software to record the impulse response. It starts by hitting the wood with a hammer to create an impulse, finding the resonance frequency (f0), and later calculating the Ed. A more practical and easy-to-use handheld mobile instrument was developed using a Raspberry Pi-2 microcomputer as the signal processor, an LCD touchscreen, a USB soundcard, and a dynamic microphone that covers 0.1-5kHz and -64 ± 3dB. An internal telecommunication system is provided to support measurements conducted at lumber mills. The software includes band-pass filtering of the recorded spectrum where the f0 is depicted. A time-domain envelope fitting is then applied to the filtered spectrum to obtain the R2envelope. A low R2envelope value indicates an inadequate impulse response, and therefore, the test should be redone.

scholarly journals The Effect of Twisted Polymer Fiber on Physical and Mechanical Characteristics of Concrete C35

2018 ◽  
Vol 14 (1) ◽  
pp. 126-135
Author(s):  
Reza Mirzaei ◽  
Naser Zarifmoghaddam
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Modulus Of Elasticity ◽  
Mechanical Characteristics ◽  
Fiber Reinforced Concrete ◽  
Polymer Fiber ◽  
New Materials ◽  
Concrete Mix ◽  
Physical And Mechanical Characteristics

 Concrete as the most used material, is known as an integral part of construction. So far, many studies have been done in the field of improving the quality of concrete that most of them have examined change in concrete mix which is called concrete mix plan. However, the use of additives and also replacing commonly used materials in concrete with new materials always has been noteworthy. In this study, description of tests that have been done on fiber reinforced concrete will be discussed. Also, the condition of concrete mix plan will be discussed. Comparison between results of the tests showed that Forta reinforced concretes have more compressive, flexural and tensile strength and modulus of elasticity than normal and ordinary concretes.Journal of the Institute of Engineering, 2018, 14(1): 126-135 

scholarly journals Implementation of RF Band-Pass Filter on UMTS Systems to Improve Quality of Service

2019 ◽  
Vol 7 (2) ◽  
pp. 31-49
Author(s):  
Nyoman Gunantara ◽  
Made Adi Surya Antara ◽  
NMAE Dewi Wirastuti
Keyword(s):  
Quality Of Service ◽  
Communication Networks ◽  
Band Pass Filter ◽  
Interference Effects ◽  
Mobile Telecommunication ◽  
Telecommunication System ◽  
Pass Filter ◽  
Access Rate ◽  
Band Pass

A large number of cellular operators in an area causes high interference effects. One indicator is the problem with received total wideband power (RTWP) found in a universal mobile telecommunication system (UMTS). High RTWP is one of the causes of a decrease in the quality of service (QoS) in cellular communication networks. To solve this problem, an RF band-pass filter device can be implemented on a UMTS system, where RF band-pass filters have been designed and tested in previous studies. In this research, the RF band-pass filter was installed between the BTS node and bottom jumper. After implementing it, QoS measurements with the Huawei M2000 application and Drive Test were carried out. The QoS analysis included RTWP, Circuit-Switched access rate, Packet-Switched access rate, and Received Signal Code Power (RSCP) value. The results show that the RTWP value decreases, while the CS access rate, PS access rate, and RSCP value increase. These results indicate that QoS on the UMTS increases.

Implementasi Voip Server Berbasis IPV6 Dengan Raspberry PI

2019 ◽  
Vol 9 (01) ◽  
pp. 47-54
Author(s):  
Rabbai San Arif ◽  
Yuli Fitrisia ◽  
Agus Urip Ari Wibowo
Keyword(s):  
Internet Protocol ◽  
Wireless Transmission ◽  
Raspberry Pi ◽  
Test Results ◽  
Average Delay ◽  
Ipv6 Network ◽  
Ip Network ◽  
Selection Of ◽  
Better Than

Voice over Internet Protocol (VoIP) is a telecommunications technology that is able to pass the communication service in Internet Protocol networks so as to allow communicating between users in an IP network. However VoIP technology still has weakness in the Quality of Service (QoS). VOPI weaknesses is affected by the selection of the physical servers used. In this research, VoIP is configured on Linux operating system with Asterisk as VoIP application server and integrated on a Raspberry Pi by using wired and wireless network as the transmission medium. Because of depletion of IPv4 capacity that can be used on the network, it needs to be applied to VoIP system using the IPv6 network protocol with supports devices. The test results by using a wired transmission medium that has obtained are the average delay is 117.851 ms, jitter is 5.796 ms, packet loss is 0.38%, throughput is 962.861 kbps, 8.33% of CPU usage and 59.33% of memory usage. The analysis shows that the wired transmission media is better than the wireless transmission media and wireless-wired.

Pengaruh Tekanan dan Penggunaan Conplast terhadap Sifat Mekanik Eternit dari Abu Cangkang Sawit

2016 ◽  
Vol 8 (15) ◽  
pp. 47-54
Author(s):  
Haspiadi Haspiadi
Keyword(s):  
Mechanical Properties ◽  
Oil Palm ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Density Values ◽  
Test Result

The purpose of this research is to know the influence of pressure and use of conplast against mechanical properties which are a Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) of plasterboard. The study is done because still low quality of plasterboard made from a mixture of ashes of oil-palm shell especially of the mechanical properties compared to the controls. The method of this reserach used variation of printed pressure and the addition of conplast. Test result is obtained that the highest value of Modulus of Elasticity (MOE) 90875.94 Kg/cm2, Modulus of Rupture (MOR) 61.16 Kg/cm2 and density values in generally good printed at the pressure 60 g/cm3 and the addition of conplast 25% as well as the composition of the ash of palm shell oil 40%: limestone 40%: cement 15%: fiber 5% and 300 mL of water. ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh tekanan dan penggunaan conplast terhadap sifat mekanik yaitu kuat lentur dan keteguhan patah eternit berbahan dasar abu cangkang sawit. Penelitian ini dilakukan karena masi rendahnya mutu eternit berbahan campuran abu cangkang sawit dari bolier khususnya sifat mekanik dibandingkan dengan kontrol. Metode penelitian yang digunakan adalah dengan variasi tekanan cetak dan penambahan conplast. Hasil uji diperoleh bahwa kuat lentur tertinggi sebesar 90875,94 Kg/cm2 dan keteguhan patah sebesar 61,16 Kg/cm2, yang dicetak pada tekanan 60 g/cm3 dan penambahan conplast 25% dengan komposisi  abu cangkang sawit 40 %: kapur 40 % : semen 15 %: serat 5 % dan air 300 mL.Kata Kunci :  Abu cangkang sawit, conplast, kuat lentur, keteguhan patah.

ANALYSIS OF SOUND SPEED IN LONGITUDINAL DIRECTION AT REFERENCE MOISTURE CONTENT (w = 12 %) IN SAWMILL ASSORTMENTS (FAGUS SYLVATICA, L.)

Akustika ◽  
2020 ◽  
pp. 45-50
Author(s):  
Alena Rohanová
Keyword(s):  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Sound Speed ◽  
Longitudinal Direction ◽  
Structural Timber ◽  
Sound Speeds ◽  
Dynamic Modulus Of Elasticity ◽  
Round Timber

This paper explores the analysis of sound speeds in the longitudinal direction and their reduction to the reference moisture content w = 12 %. The sound speed cw was determined with Sylvatest Duo device. Moisture content of beech sawmill assortments (round timber: N = 16, logs: N = 2 × 16, structural boards: N = 54) in the range of 12 – 72 % was measured. For the analysis purposes, the sound speed was converted to reference conditions (c12, uref = 12%). A second-degree polynomial (parabola) with a regression equation of the form: c// = 5649 - 27,371 × w + 0.0735 × w2 was used to convert cw to c12, and correction of measured and calculated values was used as well. The sound speeds c12 in sawmill assortments (c12,round, c12,log, c12,board) were evaluated by linear dependences. Dependence was not confirmed for c12,round and c12,board1 (r = 0.168), in contrast for c12,round and c12,log2 the dependence is statistically very significant (r = 0.634). The results of testing showed that the most suitable procedure for predicting quality of structural timber is the first step round timber – log2, the second step: log2 - board2. More exact results of the construction boards were obtained from log2 than from log1. The sound speed is used in the calculation of dynamic modulus of elasticity (Edyn). EN 408 mentions the possibility of using dynamic modulus of elasticity as an alternative method in predicting the quality of structural timber.

scholarly journals Prediction of Maritime Pine Boards Modulus of Elasticity by Means of Sonic Testing on Green Timber

2021 ◽  
Vol 11 (4) ◽  
pp. 1748
Author(s):  
Giovanna Concu
Keyword(s):  
Modulus Of Elasticity ◽  
Structural Timber ◽  
Maritime Pine ◽  
Manufacturing Costs ◽  
Sonic Waves ◽  
Wet Condition ◽  
Structural Grade ◽  
The Relationship ◽  
Grade Yield

Timber buildings are experiencing a rapid diffusion due to their good performance and their sustainability; however, some steps of structural timber production process, such as drying, are energy-intensive and environmentally impactful, and many wood species are also affected by low yield. Therefore, it would be important to determine the quality of the green material, that is, in wet condition, before undergoing the most impactful and expensive production steps. This paper describes a research aimed at quantifying the variation of the dynamic modulus of elasticity MoEdyn, which is commonly used for structural timber mechanical grading, from wet to dry condition in Sardinian maritime pine boards to be used for the production of laminated timber, and to examine the relationship between wet and dry MoEdyn. The MoEdyn was determined from measurements of the velocity of sonic waves propagating through the boards. The results show that the dry MoEdyn can be estimated starting from boards sonic testing in the wet condition, so providing a basis for implementing Sardinian maritime pine pre-grading in order to obtain the reduction of manufacturing costs, the abatement of environmental impact, and the increase of structural grade yield.

Self Compacting Concrete Structures: A Techno-Economic Analysis

2017 ◽  
Vol 21 ◽  
pp. 624-631 ◽  
Author(s):  
Nicolae Cazacu ◽  
Aurelia Bradu ◽  
Nicolae Florea
Keyword(s):  
Mechanical Characteristics ◽  
Concrete Surface ◽  
Mix Design ◽  
Building Industry ◽  
Skilled Workers ◽  
Self Compacting Concrete ◽  
Construction Time ◽  
Placement Method ◽  
Global Cost

The concept of self-compacting concrete (SCC) was performed in late 1980 by Japanese researchers as a solution for the lack of skilled workers and decreasing quality in building industry. The high fluidity of SCC allows flowing under its own weight, filling completely the formwork without any vibration or material segregation, providing a higher quality of the concrete surface. Since its discovery, a large number of researcher studied its rheological properties, adjusted mix design methods and analysed mechanical characteristics. The placement method for conventionally concrete is no more valid for SCC, as mixture behaviour changed substantially. This aspect was less examined and the published material is inconsistent, even though it plays an essential role in the assessment of the global cost of a building. The aim of this study is to investigate materials cost, the labour requirements, formwork demands, methods of placement and construction time for building a structure using SCC and vibrated concrete and compare the results.

scholarly journals Rancang Bangun Voice Over Internet Protocol dan GSM Gateway Berbasis Raspberry Pi

2019 ◽  
Vol 5 (1) ◽  
pp. 55-64
Author(s):  
Ardi Windiarto ◽  
Kholilatul Wardani
Keyword(s):  
Packet Loss ◽  
Internet Protocol ◽  
Quality Of Services ◽  
Line Of Sight ◽  
Raspberry Pi ◽  
Voice Over Internet Protocol ◽  
Non Line Of Sight

Makalah ini membahas desain layanan jaringan komunikasi VoIP Server menggunakan Raspberry Pi sebagai alat komunikasi wireless. VoIP server berbasis Raspberry Pi menggunakan sistem operasi RasPBX. Di dalam sistem operasi RasPBX sudah ada software asterisk yang berfungsi sebagai softswicth. Client VoIP menggunakan zoiper sebagai softphone. Alat ini dilengkapi dengan fitur GSM gateway yaitu fitur yang dapat menghubungkan jaringan VoIP ke jaringan GSM. Fitur GSM gateway ini menggunakan modem GSM sebagai jembatan yang menghubungkan jaringan VoIP dengan jaringan GSM. Persentase keberhasilan panggilan VoIP ke VoIP, VoIP ke GSM, dan GSM ke VoIP mencapai 100%. Berdasarkan hasil pengujian Quality of services (QoS) pada panggilan VoIP ke GSM, dihasilkan rata-rata delay sebesar 12,11 ms yang termasuk dalam kategori kualitas baik, Troughput sebesar 0,151, jitter sebesar 0,052 ms yang termasuk dalam kategori kualitas baik, dan packet loss sebesar 0% yang termasuk dalam kategori kualitas sangat baik. Jangkauan maksimal antara client VoIP ke server agar komunikasi berjalan dengan baik adalah 100 meter dalam kondisi Line Of Sight (LOS). Pengujian dengan jarak 25 m dalam kondisi Non Line Of Sight (NLOS), masih menghasilkan komunikasi yang baik. Berdasarkan hasil pengujian kuisioner dari 30 pengguna, dihasilkan nilai MOS 3,88 yang termasuk dalam kategori kualitas cukup baik.

scholarly journals Methodology for the Formation of Assessment Values of Expert Performance Indicators for Perspective Automated Digital Telecommunication Systems

2021 ◽  
Vol 27 (3) ◽  
pp. 368-379
Author(s):  
D. M. Nenadovich ◽  
I. V. Markin
Keyword(s):  
Performance Indicators ◽  
Quantitative Assessment ◽  
Telecommunication Networks ◽  
Expert Performance ◽  
Telecommunication System ◽  
Performance Quality ◽  
Telecommunication Systems

One of the main goals of modernization of telecommunication networks is to increase its performance. For a quantitative assessment of the success of improving the system, methods were developed for assessing the expert indicators of the performance quality of the designed digital telecommunication system, synthesized on the basis of previously developed decomposition and reduction algorithms. The main expert indicators of the performance quality of the designed system are considered, the dependences for calculating these indicators are presented.

scholarly journals Investigation of Effective Mechanical Characteristics of Nanomodified Carbon-Epoxide Composite by Numerical and Analytical Methods

2021 ◽  
Vol 12 (5) ◽  
pp. 535-541
Author(s):  
M.O. Kaptakov
Keyword(s):  
Mechanical Properties ◽  
Numerical Modeling ◽  
Fracture Surface ◽  
Mechanical Characteristics ◽  
Modeling Methods ◽  
Fullerene Soot ◽  
The Matrix ◽  
Numerical And Analytical Methods ◽  
Composite Samples

In this work, the mechanical properties of composite samples prepared using a conventional and nanomodified matrix were studied. The thickness of the monolayers in the samples was 0,2 μm. It was found in experiments, that the addition of fullerene soot as a nanomodifierled to an increase in the mechanical properties of the samples along the direction of reinforcement. At the same time, an improvement in the quality of the contact of the matrix with the fibers in the samples with the nanomodifier was observed: on the fracture surface, the nanomodified matrix envelops the fibers, while the usual matrix completely exfoliates. The obtained effects of changing the strength of composites can be associated, among other things, with a change in the level of residual stresses arising in composites during nanomodification. Analytical and numerical modeling methods are used to explain these effects.

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