Penerapan Model Pembelajaran Guided Discovery untuk Meningkatkan Keterampilan Berpikir Kritis Siswa Kelas XI SMA N 9 Pekanbaru dalam Pembelajaran Fisika

This research aimed to know enhancement on critical thinking skillssecondary grades students SMA N 9 Pekanbaru through application guideddiscovery learning model in learning physics and to know the difference learningoutcomes between secondary grades students that teached by conventional learningmodel with secondary grades students that teached by guided discovery learningmodel on spring force matter. This research conducted on SMA N 9 Pekanbaru fromJuly to December 2015. This type of research is quasi experimental design withNonequivalent Control Group Design. Sampling technique of this research usedsimple random sampling technic by taking two classes at random from population.The Samples is sciences two as experiment class and sciences four as control class.The number of students on experiment class is 29 childrens which consist of 10 boysand 19 girls.While the number of students on the control class of 30 people consist of12 boys and 18 girls.Multiple choices questions used for collect data as techniquetest. Based on analyze of mean percentage posttest show that mean percentageexperiment class with 71,67 % percentages is different than control class with59,52 % percentages. Based on analyze with t-test, show that thitung > ttabel then Horejected and Ha accepted with a significance level 5 %. Its show that there aredifference learning outcomes between experiment class and control class

Pelaksanaan Pemberian Hak Normatif Pekerja Perempuan di PT. Gatra Mapan (Studi Analisis Undang-undang Nomor 13 Tentang Ketenagakerjaan dan Hukum Islam)

Islam menganjurkan manusia agar melaksanakan tugasnya, salah satu tugas manusia adalah bekerja. Bekerja merupakan salah satu sarana bagi manusia (baik laki-laki maupun perempuan) untuk memenuhi kebutuhan hidup, karena bekerja merupakan salah satu bentuk dari jihad. Perempuan juga diperbolehkan bekerja diluar rumah selama ia tidak melupakan kodtratnya. Perempuan memiliki alat reproduksi yang berbeda dengan perempuan, maka perempuan berhak mendapatkan perlindungan ketenagakerjaan yang berbeda dengan laki-laki.Penelitian ini membahas bagaimana pemenuhan hak-hak pekerja perempuan di sebuah Perusahaan jika di tinjau dari UU Ketenagakerjaan dan Hukum Islam.Tujuan dari penelitian ini adalah untuk mengetahui bagaimana pemenuhan hak hak-hak normatif pekerja perempuan ditinjau dari pasal 81, 82 dan 83 Undang-Undang Ketenagakerjaan No.13 Tahun 2003 dan Hukum Islam. Penelitian ini termasuk kedalam penelitian hukum empiris. Pendekatan yang digunakan adalah yuridis sosiologi yaitu pendekatan yang didasarkan pada ketentuan Perundang-undangan yang berlaku dikaitkan dengan teori hukum serta melihat realita yang terjadi dimasyarakat.Hasil penelitian disebuah Perusahaan menunjukkan bahwa berdasarkan Undang-Undang Ketenagakerjaan No. 13 Tahun 2003 ada salah satu hak normatif pekerja perempuan yang tidak dipenuhi oleh Perusahaan, yakni hak untuk menyusui. Menurut hukum Islam semua hak-hak pekerja prempuan wajib dipenuhi sesuai dengan yang telah diatur didalam UU Ketengakerjaan jika suatu Perusahaan tersebut sudah memiliki kemampuan untuk memenuhinya.Kata Kunci: UU Ketenagakerjaan, Pekerja Perempuan, Perusahaa

Karakterisasi Material Kemasan Pulp Cetak tanpa Perekat dari Pulp Batang Jagung

Molded pulp is an alternative packaging which has renewable and biodegradable properties. The use of molded pulp as packaging material still constrained due to the specific data that describes the characteristics of molded pulp has not widely publicized yet. This study was conducted to identify the characteristics of molded pulp as an alternative packaging material. Cornstalk was selected as raw materials which has abundant availabilty. Molded pulp packaging was manufactured by thermoformed methods. The thermoset nature of lignin in cornstalks would give possibilties in manufacture of molded pulp without using adhesive. The results showed the mechanical characteristics of binderless molded pulp from cornstalk pulp which have tensile index from 17.78 to 35.78 Nm/g, tear index from 9,25 to 26,09 mN.m2/g, and burst index from 0.901 to 1.5 kPa.m2/g. The effects of dependent variables on the mechanical properties of molded pulp were studied by statistical modelling using a polynomial second order. The empirical models were deduced to satisfactorily fit experimental data with the values of independent variables and allow to quantifiying the effects of each variables. The most influential factor on tensile and burst index of molded pulp was temperature of processing. Whereas, the processing pressure has greater influence on tear index of molded pulp

Geochemical Investigation of Selected Elements in an Agricultural Soil: Case Study in Sumani Watershed West Sumatera in Indonesia

This paper presents the geochemical study of agricultural soil and river sediments along Sumani watershed, West Sumatra in Indonesia. We examined the distribution and abundances of 16 elements (Pb, Zn, Cu, Ni, Cr,V, Sr, Rb, Ce, Th, Zr, Si, Ti, Fe Ca, and P) in vegetable soil, sawah soil =and river sediment sample, to evaluate the factors controlling their abundances, possible sources, and environmental implications. Average concentrations of Pb, Zn, Cu, Ni, Cr,V, Sr, Rb, Ce, Th, Zr at vegetable (1) soil were 38, 88.3, 38.7, 3, 8, 101, 96, 98, 87, 31 and 218 mg kg-1 , 26, 39.05, 8.8, 13.5, 31, 231.5, 37, 19, 78, 16 and 303.5 mg kg-1 at sawah soil (3, 4) and 30, 61.6, 35.7, 9, 22, 294, 65, 12, 78, 14 and 232 mg kg-1 at river sediment (2), respectively. The concentration of Pb, Rb, Th and Zr at upland vegetables, V and Zr at sawah soil and river sediment were mostly two time Sumatra BCSCST or BCC in several samples. Enrichment factor values showed low to moderate enrichment of Pb, Zn, Cu, Rb, Ce and Zr, whereas Th showed significant contamination at vegetables soil, suggesting contributions from anthropogenic sources. Anthropogenic contributions of most metals mainly originate from natural processes. However, Pb, Ce, Th and Zr ranges of 527–108, 41-89, 66-117 and 35-100%, respectively, at Vegetable and sawah soil and river sediment confirm their anthropogenic contribution. Factor analysis and correlation matrices suggested that elevated metal concentrations at agricultural soil in Sumaniwatershed might be controlled by pH, CEC, Fe-oxy-hydroxides. Deposition of metals at vegetable and sawah soil and river sediment might be controlled by non-ferrous metal (i.e., aluminosilicates), sediment grain size, or source rock composition (andesite, alluvial fan, undifferentiated volcanic material, granite and gneiss).Keyword: Agricultural soil, anthropogenic activities, enrichment factor, metals source, river sediment, watershed trace [How to Cite: Aflizar, Muzakkir, R Afrizal and MA Rahman. 2016. Geochemical Investigation of Selected Elements in an Agricultural Soil: Case Study in Sumani Watershed West Sumatera in Indonesia. J Trop Soils 21: 49-66. Doi: 10.5400/jts.2016.21.1.49][Permalink/DOI: www.dx.doi.org/10.5400/jts.2016.21.1.49

Characterization of flow rate and Heat Loss in Heating, Ventilation and Air Conditioning (HVAC) Duct System for Office Building

A building is an assemblage that is firmly attached to the ground and provides the performance of human activities and need to be considered in the daily operation in that building. The improvements in building performance are focused on improving the energy efficiency of buildings. This is approach by designing heating, ventilation and air conditioning (HVAC) duct system due to one of the most utilized energy in maintaining building performance and environment. The objectives of this research is to calculate the air (CFM) supply in office building, to characterize the velocity and head loss in a round and rectangular HVAC ducting system at various duct thickness and to optimize the thickness of the duct in HVAC system according to ASHRAE Standard. The increasing of velocity in duct system shows the increasing of head loss. The round duct design gives the lowest velocity and head loss in HVAC system approximately around 9.35% as compared to rectangular duct at 0.06 inches thickness. Hence, the trends of the head loss and duct thickness has influenced in reducing noise in HVAC duct system in order to select the best design concepts which is round shape design

An approach to enhance the durability and mechanical properties of Class G cement using nano materials

Maintaining the integrity of the cement used to seal off the injection intervals of sequestrations sites is crucial to confine CO2 for thousands of years. There have been many studies to resolve the issue of cement degradation induced in the presence of CO2, but a very limited success has been reported to the application of the approaches proposed so far. Nano materials have gained the attention of many researchers in the past decade and might be able to resolve the issue of cement degradation given their outstanding performance and proven applications in the civil and polymer industries. In this paper, attempts are made to improve the physical and mechanical characteristics of class G cement using nano glass flakes (NGFs) and multiple-walled carbon nanotubes (MWCNTs). To do this, different cement-nanocomposites were prepared using two mixing techniques and their physical and mechanical changes were evaluated under different curing conditions. Samples with cylindrical shape of were prepared and cured under the temperature of 50°C and atmospheric pressure for 1 days. The results obtained indicated both nanoparticles are neutrally stable and may have a very slight effect on the cement rheology but may significantly increase the strength of the cement. It was concluded that the cement with 0.05 wt.% MWCNTs can provide the best results in terms of rheology, compositional changes and compressive strength

Thin Film Rupture from the Atomic Scale

The retraction of thin films, as described by the Taylor-Culick (TC) theory, is subject to widespread debate, particularly for films at the nanoscale. We use non-equilibrium molecular dynamics simulations to explore the validity of the assumptions used in continuum models, by tracking the evolution of holes in a film. By deriving a new mathematical form for the surface shape and considering a locally varying surface tension at the front of the retracting film, we reconcile the original theory with our simulation data to recover a corrected TC speed valid at the nanoscale