Principally, renewable energy technology produces energy by converting natural resources into useful forms of energy. Bio-battery is an alternative natural energy source that utilizes nanoparticles from plants to generate electricity. In this study, coffee grounds were used as an electrolyte paste to produce bio-battery. This study aims to determine the potential use of spent coffee grounds as an electrolyte paste. Furthermore, the analysis of the composition of the best coffee grounds to produce the optimum current and the level of effectiveness of the bio-battery in terms of the current value. To determine whether there is an effect of coffee grounds concentration on the resulting current, a series of experiments were carried out to determine the best composition between the type and concentration of coffee grounds. Characterization of the device produces a maximum voltage of 1.11 ± 0.09 V and a power of 0.25 mW. The combination of series and parallel needs to be developed to achieve higher circuit voltages and power.

Pergeseran tanah merupakan salah satu faktor terjadinya tanah longsor (landslide). Untuk itu, diperlukan suatu prototype alat yang dapat  membantu memberikan informasi dini dan peringatan akan terjadinya longsor. Telah dilakukan penelitian tentang simulasi pergeseran tanah dengan menggunakan sensor LVDT (Linear Variable Differential Transformer). Sensor LVDT dihubungkan dengan Arduino uno yang kemudian ditampilkan pada LCD dan juga monitoring pada komputer. Pengamatan pergeseran tanah  dilakukan selama 5 jam dengan melakukan variasi terhadap sudut kemiringan tanah. Tujuan dari penelitian ini yaitu untuk menguji kerja dari sensor LVDT yang merupakan hasil dari penelitian sebelumnya. Dari hasil pengamatan, terlihat bahwa sensor LVDT ini mampu membaca pergeseran tanah dengan ketlitian 0.01 mm. Adapun jangkauan pergeseran alat ini yaitu hany sampai 14 cm, untuk penelitian selanjutnya akan dikembankan sensor LVDT dengan jangkaun pengukuran yang lebih panjang.

No abstract

Many researcher said that emotion or mood can be detected from physiological changes like the heartbeat. In order to measure human heart activity, we were using tools like Electrocardiograph. The changes on human emotion or mood affect physiology. This paper is part of our research that talked about Analysis of Mood State from Heart Signal during Playing Flappy Bird. In this paper, we will explain how we design ECG tools that could measure or detect the human heartbeat especially that affect by mood changes. E-Health Sensor Platform v2.0 and Arduino Uno were used to build this system. E-Health Sensor Platform v2.0 contains several sensors that can measure the biological state of humans such as heart rate, breathing, skin conductance and many others. This device can operate when connected with Arduino Uno as a microcontroller. Arduino uno role as a liaison between the Platform and the PC via a serial port. We were using C programming languange on Arduino Uno. 100 Hz were sett in programming code so we can read all data from ECG sensor clearly. To visualize the heartbeat signals we were using KSTPlot. This system has successfully read the heart signals of 20 participants. Although there is signal noise but it does not affect the data. The noise can also be removed with a filter.In our next study, the raw data will be analyzed using the HRV method, but this will be discussed in another paper.

Recent studies have revealed the relationship between human Emotion and health. Researchers are trying to find the best features to distinguish human Emotion through its psychophysiology signals in the Affective Computing study. Humans have six basic emotions, such as Anger, Sadness, Happy, Surprise, Fear, and Disgust. Emotions affect human ANS (Autonomous Nervous System). The heart is one of the human inner organs affected by the ANS (working under ANS). Heart rate is one of the Psychophysiological signals that changed depends on human Emotion. This study tried to analyze the difference between human heart rate during Anger and Normal Emotion Stimulation. Video Stimuli were used to Evoke Emotion. 15 Participant’s heartbeats were recorded using an ECG sensor from E-Health Sensor Platform v2.0. We used HRV (Heart Rate Variability) MeanRR feature as a comparison. Some studies said that experiencing long-term Anger Emotions can cause serious illness to the human body. There are some differences in the MeanRR feature between ANGER State and NORMAL State. The findings of this investigation complement those of earlier studies about HRVi. This research supports the idea that HRV can be used as a feature to detect human affect state.