Permasalahan sampah menjadi problema klasik yang selalu dihadapi oleh penduduk terutama di wilayah Srengseng Sawah Jagakarsa. Karena kuantitas maupun tingkat bahayanya, sampah terutama sampah plastik yang tersusun dari bahan kimia sukar diuraikan sehingga berbahaya bagi lingkungan, untuk itu perlu dilakukan pengolahan sampah untuk mengubah sampah plastik menjadi kerajinan yang memiliki nilai jual dan estetika. Metode yang digunakan dalam program pemanfaatan limbah plastik sebagai kerajian adalah survey analisis situasi dan pelaksanaan penyuluhan dan pelatihan. Implemetasi hasil proses pengolahan sampah yang berasal dari kemasan plastik menjadi kerajinan tangan di Kelurahan Srengseng Sawah dilakukan untuk meningkatkan kreatifitas serta keterampilan warga terutama ibu-ibu rumah tangga, pemuda pengangguran dan anak-anak yang putus sekolah. Selain itu juga dapat meminimalisir pencemaran lingkungan sehingga warga Kelurahan Srengseng Sawah dapat lebih peduli terhadap kebersihan lingkungan. Melalui pelatihan dan pendampingan pembuatan kreasi pemanfaatan sampah yang berasal dari kemasan plastik warga lebih punya pengetahuan mengenai peluang usaha yang dapat tercipta melalui kreatifitas dan keterampilan tersebut agar tingkat ekonomi warga Kelurahan Srengseng Sawah menjadi lebih tinggi.

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Pump as Turbine (PAT) is one of a hydropower plant that applies a pump with a reversed flow, working as a turbine to generate electrical power. It has the advantages of low-cost, widely available in the market and user-friendly. However, like other hydropower plants, PAT technology has low performance in term of power output. The impeller surface roughness is one of critical aspect, which influences PAT performance because poor surface roughness causes losses and cavitation. The objective of the research is to increase the PAT performance by improving the quality of the surface roughness and validate by the experimental tests. A low-cost and customize hand grinding process was applied to produce five impellers with three different levels of surface roughness (average surface roughness of 0.16 mm, 0.24 mm, and 0.40 mm), an edge rounded impeller, and a varnish lacquer coated impeller. All of the impellers undergo performance testing. The performance of the original impeller (without modification) used as a comparison. The experiment result shows that an impeller with a lower surface roughness (lower Ra number) has a higher performance. An impeller with an average surface roughness of 0.16 mm improved 10.9% of its initial performance. Additional edge rounding for a 0.16 mm surface roughness impeller would improve its performance by 13.1%.  The optimum turbine efficiency of 15.45% was achieve-able by implementing an impeller with the lowest surface roughness.

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Paraffin is well known thermal energy storage with the high latent heat of fusion. Unfortunately, low thermal conductivity and low melting temperature inhibit large-scale applications for lower temperature applications like solar water heaters and desalination. The addition of high thermal conductivity material can increase the thermal conductivity of paraffin and increase the melting temperature of paraffin. In this study, a new approach is taken by using volcanic sand as thermal conductivity enhancement material. The properties of the sand are examined. The chemical composition of the sand is dominated by Fe (51.23 %), Fe2O3 (23.24 %) and SiO2 (11 %), which are known as good thermal conductivity materials. Six different compositions of paraffin/sand (weight ration) are tested to observe the melting and vapor temperature of the composite. Adding sand (with granule size of 44 µm) by 30 wt % can accelerate the charging rate by 25 % compared to pure paraffin, where the discharging rate is increased significantly by 17.8 %. The supercooling degree of the composite is only 1 °C, where pure paraffin has a supercooling degree by 8 °C. The charging and discharging characteristics for each sample are discussed in detail within the article. Overall, the addition of volcanic sand improves paraffin's charging and discharging rate, reducing the supercooling degree and can be considered a convenient method to improve the paraffin performance as latent heat storage