The Three Tier-Test untuk Mengungkap Kuantitas Siswa yang Miskonsepsi pada Konsep Gaya Pegas

Sebelum memasuki ruang pembelajaran para siswa telah memiliki konsep masing-masing mengenai fisika. Konsep tersebut berasal dari interaksi siswa dengan lingkungan. Konsep awal yang dimiliki siswa tersebut sering kali mengalami miskonsepsi atau tidak cocok dengan konsep yang dimiliki oleh fisikawan.Faktor lain yang menyebabkan siswa mengalami miskonsepsi adalah proses pembelajaran yang dilakukan masih berfokus pada hafalan dan rumus sehingga pada saat siswa diberikan bentuk soal mengenai penguasaan konsep, siswa mengalami kesulitan. Berhasil atau tidaknya siswa dalam mempelajari fisika sangat ditentukan oleh penguasaan konsep yang dimiliki. Penguasaan konsep yang kurang dapat menyebabkan siswa mengalami miskonsepsi. Miskonsepsi adalah suatu konsep yang tidak sesuai atau konsep yang salah dengan pengertian ilmiah dengan para ahli. Konsep yang salah atau tidak sesuai yaitu konsep yang bertentangan dengan konsepsi para fisikawan.Penelitian ini bertujuan untuk mendapatkan gambaran mengenai kuantitas siswa yang miskonsepsi pada konsep gaya pegas. Penelitian ini adalah deskriptif kuantitatif dengan teknik purposive sampling. Siswa diwajibkan untuk menjawab soal (dalam bentuk three tier-test) tentang konsep gaya pegas pada lembar jawaban, kemudian lembar jawaban siswa dianalisis. Terdapat dua sub konsep distribusi miskonsepsi pada materi Gaya Pegas yaitu; 1. Pada susunan pegas seri gaya terbesar terjadi pada pegas yang dekat dengan beban; 2. Gaya yang bekerja pada masing-masing pegas paralel sama dengan gaya yang diberikan dimana . Hasilnya menunjukkan bahwa persentase kuantitas siswa yang miskonsepsi yang terjadi pada kedua konsep adalah sama. Dengan adanya penelitian ini diharapkan pada penelitian selanjutnya dapat memberikan solusi untuk mereduksi kuantitas siswa yang miskonsepsi pada materi gaya pegas

Marketing Information System of VCO (Virgin Coconut Oil) Using Operational Database

The virgin coconut oil (VCO) marketing information system uses an operational database with JavaScript Object Notation (JSON) as its database and its function in providing information. Improvement in making the design of VCO products on trade in the information system to enlarge the marketing of VCO trade. Utilization of information technology in open competition through mastery of skills, especially information technology, the internet in the form of a marketing information system based on operational databases. The research data uses the JSON object type marked with curly brackets ({}) and arrays as square brackets ([]), in this research object uses 3 objects consisting of 10 fields, namely: Product Name in string data, Price for string data type, product image type string model, object name string data type, category string data type, location string data type, address string data type, contact name string data type and availability of string data type in building a VCO marketing pricing information system that allows admin user can change data create, insert, update or delete data in operational database

Co-composting: An Opportunity to Produce Compost with Designated Tailor-Made Properties

AbstractCo-composting is a technique that allows the aerobic degradation of organic waste mixtures, primarily aiming at obtaining compost that can be used as fertiliser or soil amendment. As compared to the typical composting activity, the main difference is not merely the use of more than one feedstock to start and sustain the biodegradation process, but also the possibility of combining various kinds of waste to obtain 'tailored' products with designed properties, or to reclaim and valorise natural resources, such as degraded soils or polluted soils and sediments. Set up of appropriate co-composting protocols can be a way to optimise the management of waste produced by different sectors of agriculture and industry and also from human settlements. Different formulations can not only optimise the biodegradation process through the adjustment of nutrient ratios, but also lead to the formation of products with innovative properties. Moreover, co-composting can be a technique of choice for the reclamation of soils degraded by intensive agriculture or contaminated soils and sediments. In fact, an appropriate mix of organic waste and soils can restore the soil structure and induce fertility in nutrient-depleted soils, and also remediate polluted soils and sediments through degradation of organic pollutants and stabilisation of heavy metals. While the selection of different mixes of organic waste may lead to the design of composts with specific properties and the potential valorisation of selected waste materials, there are still several factors that hamper the development of co-composting platforms, mainly insufficient knowledge of some chemical and microbiological processes, but also some legislative aspects. This chapter illustrates the progress achieved in co-composting technology worldwide, some key legislative aspects related to the co-composting process, the main scientific and technical aspects that deserve research attention to further develop co-composting technology, and successful applications of co-composting for the reclamation of soils and sediments, allowing their use for cultivation or as growing media in plant nurseries. A specific case study of the production of fertile plant-growing media from sediment co-composting with green waste is also illustrated

Rate equations analysis of external-cavity quantum cascade lasers

We present a comprehensive analysis of an external-cavity (EC) quantum cascade (QC) laser system, which is based on a coupled-mode system with the length of the EC set equal to that of the laser chip and accommodating the large difference in physical cavity length by introducing an effective speed of light for light propagating in the EC. By analyzing the rate equations and discussing the cross sections and losses of the EC QC lasers, numerical results as well as suggestions for a further optimization of the spectral tuning range of the EC system are presented. Besides, the delayed onset of the EC modes with respect to that of the internal Fabry–Perot modes in pulsed operation has been simulated using the rate equations, yielding a good agreement with the experimental data

High-performance continuous-wave room temperature 4.0-μm quantum cascade lasers with single-facet optical emission exceeding 2 W

A strain-balanced, AlInAs/InGaAs/InP quantum cascade laser structure, designed for light emission at 4.0 μm using nonresonant extraction design approach, was grown by molecular beam epitaxy. Laser devices were processed in buried heterostructure geometry. An air-cooled laser system incorporating a 10-mm × 11.5-μm laser with antireflection-coated front facet and high-reflection-coated back facet delivered over 2 W of single-ended optical power in a collimated beam. Maximum continuous-wave room temperature wall plug efficiency of 5.0% was demonstrated for a high-reflection-coated 3.65-mm × 8.7-μm laser mounted on an aluminum nitride submount