Pengukuran Waktu Tunda (Time Delay) pada Dua Sinyal dengan Cross Correlation Function (CCF)

Intisari: Pengukuran waktu tunda pada sinyal pengukuran sering menjadi hal yang penting dalam keakuratan suatupengukuran. Selama ini masih banyak digunakan pengukuran secara manual (langsung pada grafik sinyal) untuk mendapatkanwaktu tunda. Dengan menggunakan cross correlation function (CCF), diharapkan hasil pengukuran menjadilebih akurat. Penelitian ini dilaksanakan menggunakan beberapa data uji untuk menguji kemampuan program. Selanjutnya,data dari pengukuran langsung dengan CCF menghasilkan nilai waktu tunda kedua sinyal. Hasil pengukuranyang diperoleh mempunyai simpangan 1,68%.Kata kunci: waktu tunda, cross corelation function(CCF)Abstract: The measurement of the delay time of measurement signal has become an important aspect on measurementaccuracy. Manual measurement has been commonly used to obtain the delay time (directly on signal graphic). By usingthe cross-correlation function (CCF), it is hoped that the measurement result becomes more accurate. This researchused several test data to observe the program performance. Finally, from direct measurement by using CCF will producethe time delay of both signals. The result will have error value for about 1,68%.Keywords: time delay, cross correlation function (CCF

Sistem Kontrol On/Off Menggunakan SMS (Short Message Service) Berbasis Mikrokontroler AT89C52

Modul sistem kontrol berbasis mikrokontroler AT89C52 ini dirancang untuk melakukan pengiriman SMS (Short Message Service) agar dapat mengktifkan atau menonaktifkan beberapa alat listrik. Dalam mikrokontroler ini, dibuat dalam mode teks formal PDU (Protocol Data Unit), PDU terdiri dari sistem penyanfian pasangan-pasangan bilangan heksa desimal agar dapat dimengerti oleh mikrokontroler Modul Sistem dirancang menggunakan mikrokontroler AT89C52, Telephone Seluller Receiver kemudian melakukan aksi mengaktifkan atau menonaktifkan led sesuai perintah dalam isi SMS. Dari hasil perancangan dan simulasi, alat ini dapat melakukan responnya dengan baik sesuai dengan perintah isi SMS dalam simulasi ini dilakukan pengujian dengan beberapa aspek yaitu pengujian perintah-perintah dalam SMS, waktu pengiriman SMS hingga aksi yang dilakukan dengan varisi beberapa jenis kartu seluller

Synthesis of Fe(III)-IIPs (Ion Imprinted Polymers): Comparing Different Concentrations of HCl and HNO3 Solutions in the Fe(III) Polymer Extraction Process for Obtaining the Largest Cavities in Fe(III)-IIPs

This study was conducted to synthesize Fe (III)-IIPs by free radical polymerization using the cooling-heating method. Cooling processat -5◦C for 1 hour, as well as heating at 75◦C, 80◦C, and 85◦C maintained for 3 hours, 2 hours and 1 hour, respectively. The Fe (III)-IIPs synthesis process involved Fe(NO3)3 with an average diameter of 18.23 nm, methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), benzoyl peroxide (BPO) and ethanol, each of which plays a role as an analyte, functional monomer, cross-linker, initiator, and porogen. The result of the polymerization process was a polymer containing ions namely Fe(III) polymer. The ions need to be removed by the extraction process to produce Fe(III)-IIPs, which act as absorbents. Furthermore, the extraction process is very influential in the process of losing ions and the formation of cavities or templates in the polymer body. The number of cavities formed tends to affect the ability of Fe(III)-IIPs to identify the target ion which has similar physical and chemical properties to the shape of the Fe(III)-IIPs cavity. The extraction process was carried out on Fe(III) polymer samples using HCl and HNO3 solutions with varying concentrations of 3 M and 6 M, respectively. The transmission percentage of FTIR analysis showed that for samples of Fe(III)-IIPs HCl 3 M and 6 M were 94.258% and 95.666%, while for Fe(III)-IIPs HNO3 3 M and 6 M were 92.735%, respectively. The largest percentage was shown in the 6 M HCl IIPs sample, which indicated that there were several ions lost from the polymer body after the extraction process. This is also reinforced by the results of the SEM analysis processed with Matlab, which showed 498 cavities with a distribution of voids on a scale of <100 nm, totaling 470

Dynamics of Peatland Fires in South Sumatra in 2019: Role of Groundwater Levels

During the dry season, extensive peatland fires in South Sumatra and another peatland in Indonesia result in environmental damage and pose health risks to humans. The Indonesian Government has implemented several measures to prevent the recurrence of these fires. One such measure involves the establishment of observation stations to monitor hydrometeorological parameters in different peatlands across Indonesia, including those in South Sumatra. To effectively control fires in South Sumatra’s peatland and minimize hotspot occurrences, it is essential to determine hydrometeorological parameters that can serve as fire control indicators. Therefore, this study aimed to investigate the relationship between groundwater levels and hotspot occurrences by analyzing groundwater level data collected from six Peat Restoration Agency stations in South Sumatra’s peatland, along with hotspot data obtained from Moderate Resolution Imaging Spectroradiometer satellite measurements. The findings reveal a significant correlation between groundwater levels and hotspots at the six stations. As the GWL increased, the number of hotspots tended to decrease, and vice versa. This means that GWL can be used as a controlling variable for hotspot emergence. To effectively minimize hotspot occurrences, it is recommended to maintain a minimum groundwater level of −0.45 ± 0.09 m in the peatland of South Sumatra