Solar photovoltaic (PV) system has become the greatest attraction in the clean, renewable electricity generation. However, the performance is varying due to various parameters and environmental conditions. Hence, a remote and real-time monitoring system is needed to assess its performance. Implementation of the Internet of Things (IoT) in the monitoring of the solar PV system was proposed and its performance was studied. The system consists of data acquisition, data gateway, and smartphone application display. The data acquisition was successfully collect the data with 98.49% accuracy and was uploaded to the data gateway. The data gateway was able to send the graphical representation of the data to the smartphone application with a mean transmission time of 52.34 seconds. The results demonstrate that the proposed monitoring system can be a promising solution for intelligent remote and real-time monitoring of a solar PV system.

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Abstract. Al Mukarramah Boarding School is located in Bandung Regency, West Java Province. The total land area owned by this boarding school is 3000 m2 (three thousand square meters) consisting of several spaces and buildings. PLN is the main electricity source for lighting in this schools with a total power of 4400 VA and costs an average of Rp. 3,000,000.00 per month. This cost is certainly quite burdensome since not all santri are well-off to pay education coaching contributions (SPP) as a source of monthly operational costs. Therefore, efforts to reduce the costs borne by this school through alternative electricity sources need to be done. This was carried out in Community Service (PKM) through the installation of a simple Solar Power Plant. Counseling on how the PLTS works and the maintenance technique of PLTS is also provided so that PLTS can work well and can last a long time.Abstrak. Pesantren Al Mukarramah terletak di Kabupaten Bandung, Provinsi Jawa Barat. Luas tanah yang dimiliki pesantren ini sekitar 3000 m2 (tiga ribu meter persegi) yang terdiri dari beberapa ruang dan bangunan. Sumber listrik utama bagi penerangan di pesantren saat ini berasal dari PLN dengan total daya 4400 VA dan menghabiskan biaya rata-rata Rp 3.000.000,00 per bulan. Biaya sebesar ini tentunya cukup memberatkan sebab tidak semua santri berkecukupan untuk membayar sumbangan pembinaan pendidikan (SPP) sebagai sumber biaya operasional bulanan. Oleh karena itu, upaya untuk meringankan biaya yang ditanggung pesantren melalui sumber energi listrik alternatif perlu dilakukan. Hal ini dilaksanakan dalam Pengabdian Kepada Masyarakat (PKM) melalui pemasangan Pembangkit Listrik Tenaga Surya sederhana. Penyuluhan tentang cara kerja dan teknik pemeliharaan PLTS ini juga diberikan agar PLTS dapat bekerja dengan baik dan bertahan lama.

The activity concentration of 226 Ra, 232 Th and 40 K were determined by gamma spectrometry in twenty-six different brands of powdered milk available in Malaysia. The measured activity concentration was then used to estimate the radiation hazard indices in term of ingestion dose and cancer risk. The total ingestion dose was found to range between 35.19 and 461.72 lSv y -1 and the estimated cancer risk for adult is 1.23 9 10 -4 . These results were found to be below the internationally recommended level. This indicates that the powdered milk in Malaysia would not pose any significant radiological impact to the population.

The Hp(10) of an ideal TLD is independent of photon energy. This is to say that at any photon energy, the ratio R of the measured dose Hp(10)meas to the delivered dose Hp(10)del is always 1. In practice however the Hp(10) is dependent on the energy and R is not equal to 1. For this reason, ICRP has set the lower limit LL and upper limit UL for R as 0.55≤R≤1.63 for detection limit of 0.1 mSv and Hp(10)del=1 mSv. As R is the quantity arises from the measurement processes, the existence of uncertainty of R, i.e. ΔR is inevitable. In the boundary cases, such as when R is slightly lower than LL or slightly larger than UL, ΔR would serve a useful quantity in decision making either to accept or to reject the value of R. The purpose of the present work is to estimate ΔR for the TLD–100H for photon energy of 24–1250 keV. The estimation of ΔR is based on the error propagation method. For the eleven photon energies, this work obtained (a) R in the range of 0.77 to 1.16, (b) ΔR in the range of ± 0.02 to ± 0.04. The values of R were satisfactory as they complied the ICRP limit. The determined ΔR is considered very small as it is in the order of 3% in comparison of R.