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Characterization of Silica Nanoparticles from Pumice as an Aerogel Adsorbent Hidayah, Rahma; Kurniawati, Desy; Alizar, Alizar
Indonesian Journal of Chemical Science and Technology (IJCST) Vol. 7 No. 1 (2024): JANUARY 2024
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ijcst.v7i1.56435

Abstract

Pumice is often found around the banks of rivers, this stone is a type of igneous rock formed from volcanic eruptions. One of the compounds contained in pumice is silica. Therefore, the synthesis of silica nanoparticles from pumice using the sol gel method was used because it is simpler and more efficient in terms of cost and processing time. the initial step was by reacting pumice powder and NaOH at 70°C - 80°C then synthesized by adding 2M HCI to form a gel or white precipitate, soaking in ethanol, teos, hexane solutions was then synthesized to become an aerogel. Silica synthesis results into silica aerogels were characterized by FTIR and XRF. From FTIR silanol and siloxane functional groups were found, and the SiO2 composition increased to 93,299% after synthesis.
Effect Type of Desorption Eluent and Concentration in Desorption of Zn2+ Cation from Sulfonate Modified Silica Gel-GPTMS (Glycydoxypropyltrimethoxysilane) Adsorbent Hafis, Muhamad; Oktavia, Budhi; Alizar, Alizar; Warda Ningsih, Sherly Kasuma
Indonesian Journal of Chemical Science and Technology (IJCST) Vol. 7 No. 2 (2024): JULY 2024
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ijcst.v7i2.62256

Abstract

Silica has silanol groups contained in it which have low binding ability because it has low acidity, resulting in low absorption effectiveness on silica. In order to improve the properties and to expand the field of utilization, a modification process is carried out on silica gel using GPTMS bridging compounds and sulfonate salts as modifiers. The study explains that CaCl2.2H2O with a desorption percent of 97.25% has a greater ability than NaCl which is only 83.93% in the desorption of Zn2+ cations. The study also explains that the optimum concentration of CaCl2.2H2O eluent in the desorption of Zn2+ cations is at 1mmol/L where the desorption yield is 93.74%.
An Analysis of Traffic Congestion Due to Railway Crossings on Prof. Dr. Latumenten Road, Grogol, West Jakarta Wisnu Akbar; Alizar, Alizar
International Journal Multidisciplinary Science Vol. 4 No. 2 (2025): June: International Journal Multidiciplinary Science
Publisher : Asosiasi Dosen Muda Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56127/ijml.v4i2.2231

Abstract

This study aims to analyze the impact of railway crossings on congestion levels, traffic volume, delays on Jalan Prof. Dr. Latumenten Grogol, West Jakarta. The research methods used include collecting traffic data through primary data from direct surveys and analyzing secondary data from related agencies. The parameters analyzed include vehicle volume, queue duration, side barrier performance, delays and frequency of crossing barrier closures. The method used refers to the Indonesian Road Capacity Guidelines (PKJI 2023). The final result of the research writing is to provide recommendations for handling traffic congestion due to railway crossings, such as proposals for the construction of flyovers or underpasses, improving traffic management in affected areas
Operational Speed Analysis of LRT Trains on Curved Track Sections in the Kuningan Line (Long Spans) Yuli Sulistiyohadi; Alizar, Alizar; Norfi Janoko Sakti
International Journal Multidisciplinary Science Vol. 4 No. 2 (2025): June: International Journal Multidiciplinary Science
Publisher : Asosiasi Dosen Muda Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56127/ijml.v4i2.2292

Abstract

Mass transit systems such as Light Rail Transit (LRT) offer an efficient and environmentally friendly solution to urban mobility challenges. The performance of LRT systems is highly influenced by track geometric design, particularly in segments involving curve radii and long-span structures. The analysis is based on technical parameters such as centrifugal force, track elevation (superelevation), and railway geometric standards as stipulated by national regulations. The findings indicate a reduction in operational speed on certain curved sections where the radius does not align with ideal design speeds, primarily due to geometric constraints and safety considerations.
Time Management Analysis on the Terban Market Renovation Project in Yogyakarta Panca setiawan; Alizar, Alizar
International Journal Multidisciplinary Science Vol. 4 No. 3 (2025): October: International Journal Multidisciplinary Science
Publisher : Asosiasi Dosen Muda Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56127/ijml.v4i3.2293

Abstract

The construction of the Terban Market in Yogyakarta requires time management that not only sharpens priorities but also enhances the efficiency and effectiveness of project execution. This study aims to analyze the application of time management in the Terban Market construction project, with a focus on improving prioritization, efficiency, and effectiveness. The research method used is Earned Value Analysis (EVA) to evaluate project performance in terms of time and cost. Data were obtained through field observations and interviews as primary data, and project documents such as the S-Curve and Budget Plan (RAB) from the contractor as secondary data. The analysis results indicate that time management implementation still requires improvement, particularly in on-site execution, with several weaknesses identified during project implementation.