El-nino effect on reservoir volumetric (A case study of the Batujai Dam on the island of Lombok)

El-Nino has been occurred from 1952 to 2016 with the types of weak, medium, strong and very strong. The event of El-Nino has significant impact on all aspects of economy, social, industry and agriculture. There is a decrease in the quantity of water resources such as in the reservoir where the reservoir inflow becomes very small and the water outflow becomes high. At the event of very strong El-Nino is occurred some of the reservoirs will dry. The aim of the research is to investigate the deficit capacity of the reservoir in the event of El-Nino. The data analyzed in this article were the volume of the half-month reservoir, especially in the event of El-Nino events. The analysis of frequency deficit probability was using Weibull probability and Log Pearson Type III distribution. The results show significant decrease in reservoir water volume over a very long-time period. The reservoir volume never reached maximum water level and persists for almost one year. The deficit of reservoir volumes reached was 16,01x106 m3, 18.64x106 m3, and 21,07x103 m3 for weak, moderate, and very strong El-Nino, respectively

Pengembangan Model Indek Kekeringan Hidrologi Berdasarkan Volumetrik waduk

Phenomena perubahan iklim global hampir terjadi diseluruh belahan dunia dan berdampak pada berbagai sektor kehidupan di bumi. El-Nino merupakan salah satu bencana alam akibat dari terjadinya perubahan iklim global. Peristiwa El-Nino ditandai dengan meningkatnya suhu permukaan air laut dan berkurangnya curah hujan yang terjadi. Pada saat peristiwa El-Nino, terjadi suatu kondisi berkurangnya pasokan dan ketersediaan air yang dibutuhkan untuk memenuhi kebutuhan air multi sektor. Badan air berupa sungai, danau, waduk dan air bawah permukaan menjadi defisit. Pada saat tersebut juga terjadi peningkatan kebutuhan air sehingga terjadi ketidak seimbangan antara ketersediaan dan kebutuhan

Sustainable ground improvement method using encapsulated polypropylene (PP) column reinforcement

This study investigates the effectiveness of encapsulated polypropylene (PP) column in enhancing the undrained shear strength of kaolin (soft clay). The usage of PP in treating problematic soil is a more sustainable and cost-effective alternative compared to other materials. The installation of granular column can be done by using vibro-replacement method. Several geotechnical tests to determine the properties of materials were conducted. The shear strength of treated kaolin sample was examined by using Unconfined Compression Test (UCT). There are seven (7) batches of soil sample in total which included a control sample, three (3) batches of 14 mm and three (3) batches of 20 mm diameter PP column. Different diameters of PP column were examined with 60 mm, 80 mm and 100 mm height, respectively with soil sample of 50 mm in diameter and 100 mm in height. The shear strength improvement of kaolin is 33.82%, 46.51%, and 49.88% when implanted with a PP column with a 7.84 area replacement ratio and 0.6, 0.8 and 1.0 penetration ratio. The soft soil treated using 16.00 area replacement ratio with 0.6, 0.8 and 1.0 penetration ratio has a shear strength increment of 25.22%, 33.39% and 37.59% respectively. In short, the shear strength improvement of the kaolin clay depends on the parameter of the PP column used to reinforce the sample

Stabilization of kaolin clay soil reinforced with single encapsulated 20mm diameter bottom ash column

Ground improvement methods are used to reduce the weakness of soft clay, which is low strength and high compressibility. The stone column technique involves replacing any of the soil with crushed stone such as broken rocks or sand which is an efficient method of improving the strength parameters of soil. Bottom ash usage in materials of building will effectively decrease the buildup of the waste and hence protect the environment. This study is to determine the shear strength of kaolin soft clay reinforced with a 20 mm diameter single encapsulated bottom ash column with various lengths. The research will look into the physicomechanical qualities of the materials used, including subsoil and bottom ash. Three (3) batches of samples with each batch consists of five (5) samples were prepared by using compaction method. All kaolin samples with a diameter of 50mm and height of 100mm with single encapsulated bottom ash columns with various lengths which are 60mm, 80mm, and 100mm were tested under Unconfined Compression Test (UCT). The result illustrated that the strength of samples increases as the height and volume of encapsulated bottom ash column increases

Geotechnical properties of bauxite: A case study in Bukit Goh, Kuantan, Malaysia

The research focuses on the basic and morphological characteristics to ensure bauxite ore reached the International Maritime Solid Bulk Cargoes Code (IMSBC Code) standard before being exported to other countries. The testing procedure, referred to as Geo-spec 3: Model Specification for Soil Testing, was performed to discover the basic parameters of the soil, including pore size distribution, water content, particle density, and morphology qualities. At Bukit Goh, Kuantan, about four (4) samples were chosen, whereas two (2) samples were from the stockpile and two (2) samples were from the Bukit Goh mine. The results illustrated that the mean water content of the soil is 20.64% which is above 10% of the recommended value. The value of Bulk Density is not in the range of 1190 kg/m3 to 1389 kg/m3, which is 2836.25 kg/m3 and the particle size distribution for fine material is greater than 30%, and coarse material is less than 70%. The SEM examination revealed a high concentration of tiny particles in bauxite samples. Bukit Goh bauxite cannot be classified as group C under the IMSBC Code. As a result, the bauxite does not meet the criteria and cannot be shipped

Wskaźnik suszy hydrologicznej obliczany na podstawie pojemności zbiornika – przypadek zapory Batujai na wyspie Lombok, West Nusa Tenggara w Indonezji

Hydrological drought index analysis has been widely developed and applied for the development of water resources. The island of Lombok, which is largely a dry land, requires a significant hydrological drought index to be sourced from measurable data analysis. This research focused aims to obtain hydrological drought index in Lombok Island using the capacity change of reservoir. The analysis includes reservoir data especially in the event of El-Nino. The main parameters analysed in this work are data homogeneity, decrease line of reservoir volume, increase in the line of reservoir volume, reservoir volume deficit, and hydrological drought index (RDI). The basic equation uses the water balance in the reservoir, which is the inflow–outflow and change of reservoir. The results of the analysis show that in the event of El-Nino, the drought hydrological index indicates different levels depending upon the water level of the reservoir. The criteria for the drought level are as follows: weak RDI = from −0.46 to −0.01 at an reservoir elevation of 90.88 to 92.33 m a.s.l, moderate RDI: from −0.59 to −0.46 at water level of reservoir from 90.27 to 90.88 m a.s.l, sever RDI: from −0.80 to −0.59 at water level of reservoir from 88.83 to 90.27 m a.s.l. and very severe RDI: from −0.89 to −0.80 at water level of water reservoir 87.78–88.83 m a.s.l. The duration of drought was 9 months, i.e., from February to November.Analiza wskaźnika suszy hydrologicznej ma szerokie zastosowanie w zarządzaniu zasobami wodnymi. Na ubogiej w wodę wyspie Lombok wskaźnik suszy powinien być określany na podstawie analizy mierzalnych danych. Przedstawione w niniejszej pracy badania miały na celu ustalenie wskaźnika dla wyspy z wykorzystaniem zmian pojemności zbiornika. Podstawą analiz były dane o zbiorniku, szczególnie podczas wystąpień El-Niño. Głównymi parametrami analizowanymi w tej pracy były: homogeniczność danych, linia spadku objętości zbiornika, linia wzrostu objętości zbiornika, deficyt objętości zbiornika i wskaźnik suszy hydrologicznej (RDI). Podstawowe równanie ujmuje bilans wody w zbiorniku, tzn. dopływ, odpływ i zmiany objętości. Wyniki analiz wskazują, że w trakcie trwania El-Niño wskaźnik suszy hydrologicznej przyjmował różne wartości w zależności od poziomu wody w zbiorniku. Kryteria natężenia suszy były następujące: słaba susza – RDI od –0,46 do –0,01, gdy poziom wody w zbiorniku wynosił od 90,88 do 92,33 m n.p.m., umiarkowana susza – RDI od –0,59 do –0,46, gdy poziom wody od 90,27 do 90,88 m n.p.m., silna susza – RDI od –0,80 do –0,59, gdy poziom wody od 88,83 do 90,27 m n.p.m. i bardzo silna susza – RDI od –0,89 do –0.80, gdy poziom wody od 87,78 do 88,83 m n.p.m. Susza w trakcie bardzo silnego El-Niño trwała 9 miesięcy od lutego do listopada

El-Nino effect on reservoir capacity reliability: Case study of Sumi dam, Sumbawa Island, Indonesia

Reservoirs have a very important function in providing multi-sector water requirements. In the future, reservoirs not only serve to store and available water can also be used as disaster mitigation instruments. The completeness of hydrological measurements in reservoirs can be expanded more widely for climate change mitigation. The reliability of the reservoir capacity varies greatly depending on the El-Nino character that occurs among them El-Nino is weak, moderate, strong and very strong. The El-Nino characteristic is very influential on the period of water availability, the increase of evaporation capacity and decrease of reservoir capacity. Analysis of the reliability of the reservoir volume due to El-Nino using the Weibull equation. The deficit reservoir was calculated using the concept of water balance in the reservoir that is the relationship between inflow, outflow, and change of storage at the same time. Based on the results of the analysis showed that the evaporation increase and the decrease of reservoir capacity had a different pattern that is when the evaporation capacity started to increase at the same time the reservoir capacity decreased significantly. The correlation coefficient between evaporation capacity increase and decrease of reservoir water capacity are consecutively –0.828, –0.636, and –0.777 for El-Nino weak, moderate and very strong respectively. At the reservoir capacity reliability of 50% reservoir has a significant deficit. When weak El-Nino the deficit is 2.30∙106 m3, moderate: 6.58∙106 m3, and very strong 8.85∙106 m3

Pengaruh Penambahan Tepung Rebon Pada Pakan Buatan Terhadap Nilai Chroma Ikan Mas Koki (Carassius Auratus)

Penelitian ini bertujuan untuk mengetahui konsentrasi penambahan tepung udang rebon dalam pakan buatan yang tepat sehingga akan meningkatkan warna pada ikan mas koki (Carassius auratus). Penelitian dilaksanakan pada tanggal 10 Juni 2012 sampai dengan 20 Juli 2012 di Balai Pengembangan dan Penelitian Budidaya Ikan Hias (BP2BIH), Depok, Jawa Barat. Metode penelitian yang digunakan adalah metode eksperimen dengan Rancangan Acak Lengkap (RAL) yang terdiri atas 5 perlakuan dan 3 kali ulangan. Kelima perlakuan tersebut adalah pemberian tepung udang rebon sebanyak 0, 5, 10, 15, 20 %. Parameter yang diamati adalah nilai chroma sebagai data utama sedangkan pertambahan bobot dan kelangsungan hidup sebagai data penunjang. Hasil penelitian menunjukkan bahwa penambahan tepung udang rebon memberikan pengaruh terhadap peningkatan warna dan pertumbuhan ikan mas koki, tetapi tidak berpengaruh terhadap tingkat kelangsungan hidup. Penambahan tepung udang rebon 10 % dari total pakan buatan memberikan peningkatan kualitas warna benih ikan mas koki terbaik dengan nilai rata-rata chroma sebesar 25,97

Virtual reality learning environments for vocational education: a comparative study with conventional instructional media on two-stroke engine

Virtual reality technology has been adopted as a modern learning media in vocational education. Nowadays, the practical learning needs complete equipment and tools to achieve the goal study. However, the conventional media requirement is a challenge for academician for learning process, specifically in automotive and machine areas. Virtual reality provides a solution for this problem, but still needs proper analysis on the impact of usability between conventional and VR media to which each learning objective is achieved. The case study used in this research is a two-stroke engine, which is currently a rare item in the real world. We replicated this two-stroke engine in the developed VR system using Unity game engine and Oculus quest. A comparison on the usability effectiveness on conventional and virtual reality methods was conducted using cognitive walkthrough, which follows the four steps of learning objective training. The result shows that three out of four learning objectives are similar with conventional objective training. One of the process on preparation for disassembly machine has slight difference with conventional training; faulty engine due from environment elements (liquid, rusty iron) was not included