Penerapan model pembelajaran Collaborative Creativity (CC) untuk meningkatkan keterampilan berpikir kreatif peserta didik pada materi usaha dan energi

Keterampilan berpikir kreatif menjadi salah satu keterampilan yang dituntut harus dilatihkan kepada peserta didik di Abab 21. Namun yang terjadi di lapangan menunjukkan bahwa keterampilan berpikir kreatif peserta didik masih rendah. Salah satu upaya yang dapat meningkatkan keterampilan berpikir kreatif peserta didik yaitu dengan menerapkan model pembelajaran Collaborative Creativity (CC). Tujuan dari penelitian ini untuk mengetahui keterlaksanaan setiap tahapan model pembelajaran Collaborative Creativity dan peningkatan keterampilan berpikir kreatif peserta didik setelah diterapkannya model pembelajaran Collaborative Creativity pada materi Usaha dan Energi. Metode penelitian yang digunakan adalah metode pre-eksperimental dengan desain one-group pretest-posttest. Sampel dalam penelitian ini adalah peserta didik kelas X MIPA 2 SMAN 1 Rancaekek Kabupaten Bandung dengan jumlah 30 peserta didik. Hasil penelitian menunjukkan bahwa keterlaksanaan model pembelajaran Collaborative Creativity berlangsung sangat baik dengan persentase rata-rata aktivitas guru sebesar 95% dan peserta didik sebesar 89%. Berdasarkan hasil pengujian hipotesis dengan menggunakan uji t diperoleh nilai thitung sebesar 47,27 dan nilai ttabel sebesar 2,042 (thitung > ttabel) dengan taraf signifikansi 0,05. Sehingga dapat disimpulkan bahwa terdapat peningkatan keterampilan berpikir kreatif peserta didik setelah diterapkannya model pembelajaran Collaborative Creativity dengan nilai N-gain sebesar 0,78 pada kategori tinggi

Selective detection of bacterial layers with terahertz plasmonic antennas

Current detection and identification of micro-organisms is based on either rather unspecific rapid microscopy or on more accurate complex, time-consuming procedures. In a medical context, the determination of the bacteria Gram type is of significant interest. The diagnostic of microbial infection often requires the identification of the microbiological agent responsible for the infection, or at least the identification of its family (Gram type), in a matter of minutes. In this work, we propose to use terahertz frequency range antennas for the enhanced selective detection of bacteria types. Several microorganisms are investigated by terahertz time-domain spectroscopy: a fast, contactless and damage-free investigation method to gain information on the presence and the nature of the microorganisms. We demonstrate that plasmonic antennas enhance the detection sensitivity for bacterial layers and allow the selective recognition of the Gram type of the bacteria

Robots with Lights: Overcoming Obstructed Visibility Without Colliding

Robots with lights is a model of autonomous mobile computational entities operating in the plane in Look-Compute-Move cycles: each agent has an externally visible light which can assume colors from a fixed set; the lights are persistent (i.e., the color is not erased at the end of a cycle), but otherwise the agents are oblivious. The investigation of computability in this model, initially suggested by Peleg, is under way, and several results have been recently established. In these investigations, however, an agent is assumed to be capable to see through another agent. In this paper we start the study of computing when visibility is obstructable, and investigate the most basic problem for this setting, Complete Visibility: The agents must reach within finite time a configuration where they can all see each other and terminate. We do not make any assumption on a-priori knowledge of the number of agents, on rigidity of movements nor on chirality. The local coordinate system of an agent may change at each activation. Also, by definition of lights, an agent can communicate and remember only a constant number of bits in each cycle. In spite of these weak conditions, we prove that Complete Visibility is always solvable, even in the asynchronous setting, without collisions and using a small constant number of colors. The proof is constructive. We also show how to extend our protocol for Complete Visibility so that, with the same number of colors, the agents solve the (non-uniform) Circle Formation problem with obstructed visibility

Electromagnetic effects in the surface enhanced Raman scattering from a molecule at a liquid Hg surface

In a previous publication the image enhancement effect and the enhanced radiation due to near field excitation of surface roughness were calculated for a finite-size molecule above a metal described by a nonlocal dielectric relation [Phys. Rev. Letters 44 (1980) 1774]. When applied to a roughened Ag surface these calculations led to a predicted Surface Enhanced Raman Scattering (SERS) gain of [approximate]103 due to each effect, yielding an overall gain [approximate]106, in agreement with experiment. Here these calculations are extended to the case of a liquid Hg surface, the roughness corresponding to thermally excited ripplons. The SERS gain due to image enhancement is reduced to [approximate]10, due primarily to the [approximate]24 times greater electron scattering rate in Hg over that in Ag. The roughness gain is reduced to [approximate]2 at room temperature, due to the difference between the ripplon spectrum and that of the boss-like surface structures assumed for the solid surface. The predicted overall SERS gain for Hg is [approximate]20, far less than reported in recent observations [R. Naanan et al., J. Phys. Chem. 84 (1980) 2692]. The discrepancy raises serious questions about the electromagnetic explanations of SERS.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24261/1/0000524.pd

Interrogating the Transient Selectivity of Bacterial Chemotaxis-Driven Affinity and Accumulation of Carbonaceous Substances via Raman Microspectroscopy

Carbonaceous substances are fundamental organic nutrients for microbial metabolism and catabolism in natural habitats. Microbial abilities to sense, accumulate, and utilize organic carbonaceous substances in the complex nutrient environment are important for their growth and ecological functions. Bacterial chemotaxis is an effective mechanism for microbial utilization of carbonaceous substances under nutrient depletion conditions. Although bacterial accumulation and utilization to individual carbonaceous substance in long-term cultivation has been well studied, their selective affinity of mixed carbonaceous substances remains to be investigated, primarily because of technical limitations of conventional methods. Herein, we applied Raman microspectroscopy to identify chemotaxis-driven affinity and accumulation of four organic carbonaceous substances (glucose, succinate, acetate, and salicylate) by three bacterial strains (Acinetobacter baylyi, Pseudomonas fluorescence, and Escherichia coli). A. baylyi exhibited strong binding affinity toward glucose and succinate, whereas P. fluorescence and E. coli were preferentially responsive to glucose and acetate. For the first time, bacterial transient selectivity of carbonaceous substances was studied via interrogating Raman spectral alterations. Post-exposure to carbonaceous-substance mixtures, the three bacterial strains showed distinct selective behaviors. Stronger selective affinity enhanced the chemotaxis-related signal transduction in A. baylyi cells, whereas the carbonaceous substance signal transduction in E. coli was decreased by higher selective affinity. In P. fluorescence, there was no specific effect of selective affinity on signal transduction. Our study suggests that Raman microspectroscopy can successfully investigate and distinguish different scenarios of bacterial competitive and transient unitization of organic carbonaceous substances