Pengembangan Bahan Ajar dalam Bentuk Modul Fisika Kontekstual pada Materi Fluida dalam Pembelajaran Fisika di Sma/ma

Physics is the case of lessons learned which are difficult to assume in many of the formulas that must be described in the sense of abstracts for students. To improve the performance skills of students, it is necessary to develop appropriate teaching materials with the curriculum and characteristic of the inadvertants. In the KTSP it is suggested that there be close learning in the contextual contextual approach. One of the ways to Peruse a philosophy is to create teaching materials in a contextual form. The objective of the research is to produce teaching materials (module) contextualfisikapadaterifluida. Type of research is research and development (r & d). Ujicobapenggunaanmoduldilakukan in class XI IA Granada MA Islamic College Arrisalah.Instrumen used is sheet of expert validation and student questionnaire. The data obtained were analyzed using descriptive and graphical descriptive method. The module validation result has an average value of 3.75, meaning that the module has a good validity. Results of student questionnaire analysis obtained an average value of 74.19, which means modul have good practicality. Abstrak Fisika adalah salah satu mata pelajaran yang dianggap sulit karena banyaknya rumus yang harus dihapal atau fisika masih abstrak bagi siswa. Untuk meningkatkan keterampilan serta pemahaman siswa, diperlukan pengembangan bahan ajar yang sesuai dengan kurikulum dan karakteristik peserta didik. Dalam KTSP disarankan suatu pendekatan dalam pembelajaran, yaitu pendekatan kontekstual. Salah satu cara membantu siswa memahami fisika adalah dengan membuat bahan ajar dalam bentuk modul kontekstual. Tujuan penelitian adalah menghasilkan bahan ajar (modul) kontekstual fisika pada materi fluida. Jenis penelitian adalah penelitian dan pengembangan (research and development/ r&d). Uji coba penggunaan modul dilakukan di kelas XI IA Granada MA Perguruan Islam Arrisalah. Instrumen yang digunakan adalah lembaran validasi pakar dan angket siswa. Data yang diperoleh dianalisis menggunakan metoda grafik dan statistik deskriptif. Hasil validasi modul memiliki nilai rata-rata 3,75, artinya modul kontekstual memiliki validitas baik. Hasil analisis angket siswa didapatkan nilai rata-rata 74,19, artinya modul kontekstual memiliki kepraktisan yang baik

Study of Photocatalytic Behavior of Photochemical Doped TiO2 Nanoparticles with In-V Synthesized by Sol-Gel and Hydrothermal Methods

Indium- vanadium doped with different molar percent (0.05-1%) was prepared by photochemical reduction method on pure TiO2 nanoparticles synthesized by sol –gel and hydrothermal process. XRD, FT-IR, TEM, SEM and EDX analysis were done for characterized nanoparticles and methyl orange (MO) was used as an environmental pollutant to verify photocatalytic effect of synthesized particles under visible and UV lamps. Result of tests was showed that In-V doping restrain from crystal growth, that only hydrothermal TiO2 particles with binary doped 0.2% molar of In-V can improve photocatalytic activity compared to solgel nanoparticles. Pure TiO2 prepared by hydrothermal and sol-gel processes were calcined at 300,400,450,550 ºC for 3h and 500º C for 2h, respectively. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3528

Numerical Modeling of a Wave Turbine and Estimation of Shaft Work

Wave rotors are periodic-flow devices that provide dynamic pressure exchange and efficient energy transfer through internal pressure waves generated due to fast opening and closing of ports. Wave turbines are wave rotors with curved channels that can produce shaft work through change of angular momentum from inlet to exit. In the present work, conservation equations with averaging in the transverse directions are derived for wave turbines, and quasi-one-dimensional model for axial-channel non-steady flow is extended to account for blade curvature effects. The importance of inlet incidence is explained and the duct angle is optimized to minimize incidence loss for a particular boundary condition. Two different techniques are presented for estimating the work transfer between the gas and rotor due to flow turning, based on conservation of angular momentum and of energy. The use of two different methods to estimate the shaft work provides confidence in reporting of work output and confirms internal consistency of the model while it awaits experimental data for validation. The extended wave turbine model is used to simulate the flow in a three-port wave rotor. The work output is calculated for blades with varying curvature, including the straight axial channel as a reference case. The dimensional shaft work is reported for the idealized situation where all loss-generating mechanisms except flow incidence are absent, thus excluding leakage, heat transfer, friction, port opening time, and windage losses. The model developed in the current work can be used to determine the optimal wave turbine designs for experimental investment

Regional diversity in the murine cortical vascular network is revealed by synchrotron X-ray tomography and is amplified with age

Cortical bone is permeated by a system of pores, occupied by the blood supply and osteocytes. With ageing, bone mass reduction and disruption of the microstructure are associated with reduced vascular supply. Insight into the regulation of the blood supply to the bone could enhance the understanding of bone strength determinants and fracture healing. Using synchrotron radiation-based computed tomography, the distribution of vascular canals and osteocyte lacunae was assessed in murine cortical bone and the influence of age on these parameters was investigated. The tibiofibular junction from 15-week- and 10-month-old female C57BL/6J mice were imaged post-mortem. Vascular canals and three-dimensional spatial relationships between osteocyte lacunae and bone surfaces were computed for both age groups. At 15 weeks, the posterior region of the tibiofibular junction had a higher vascular canal volume density than the anterior, lateral and medial regions. Intracortical vascular networks in anterior and posterior regions were also different, with connectedness in the posterior higher than the anterior at 15 weeks. By 10 months, cortices were thinner, with cortical area fraction and vascular density reduced, but only in the posterior cortex. This provided the first evidence of age-related effects on murine bone porosity due to the location of the intracortical vasculature. Targeting the vasculature to modulate bone porosity could provide an effective way to treat degenerative bone diseases, such as osteoporosis

Spectral dynamic causal modelling in healthy women reveals brain connectivity changes along the menstrual cycle

Longitudinal menstrual cycle studies allow to investigate the effects of ovarian hormones on brain organization. Here, we use spectral dynamic causal modelling (spDCM) in a triple network model to assess effective connectivity changes along the menstrual cycle within and between the default mode, salience and executive control networks (DMN, SN, and ECN). Sixty healthy young women were scanned three times along their menstrual cycle, during early follicular, pre-ovulatory and mid-luteal phase. Related to estradiol, right before ovulation the left insula recruits the ECN, while the right middle frontal gyrus decreases its connectivity to the precuneus and the DMN decouples into anterior/posterior parts. Related to progesterone during the mid-luteal phase, the insulae (SN) engage to each other, while decreasing their connectivity to parietal ECN, which in turn engages the posterior DMN. When including the most confident connections in a leave-one out cross-validation, we find an above-chance prediction of the left-out subjects’ cycle phase. These findings corroborate the plasticity of the female brain in response to acute hormone fluctuations and may help to further understand the neuroendocrine interactions underlying cognitive changes along the menstrual cycle

Stabilizing ultrathin Silver (Ag) films on different substrates

This paper reports an effective method of stabilizing ultrathin Silver (Ag) films on substrates using a filler metal (Zn). Ag films with a thickness < 15 nm were deposited by DC magnetron sputtering above a Zn filler metal on glass, quartz, silicon and PET (polyethylene terephthalate) substrates. Zinc is expected to partially or fully fill the roughness associated with the substrates. The Zn filler material and ultrathin Ag film form a 3-D augmented atomically chemically graded interface. 3-D interfaces have smoothly varying chemistry. The ability of Zn to partially or fully fill the substrate roughness improves the adhesion of Zn along with the Ag to the substrate. Also, Zn acts as a barrier layer against the diffusion of Ag into the substrate. This technique leads to ultrathin Ag films with low sheet resistance (~ 3 {\Omega}/Sq.), low mean absolute surface roughness (~1 nm), good optical transparency (~ 65 %), better stability and compatibility with the environment. The results indicate significant potential for applying stable ultrathin Ag film/electrode as a practical and economically feasible design solution for optoelectronic (transparent and conductive electrodes for solar cells and LEDs) and plasmonic devices. This film shows good conductivity, transparency, stability, and flexibility.Comment: 16 pages,8 figures, 3 table

Hierarchical dynamic causal modeling of resting-state fMRI reveals longitudinal changes in effective connectivity in the motor system after thalamotomy for essential tremor

Thalamotomy at the ventralis intermedius nucleus for essential tremor is known to cause changes in motor circuitry, but how a focal lesion leads to progressive changes in connectivity is not clear. To understand the mechanisms by which thalamotomy exerts enduring effects on motor circuitry, a quantitative analysis of directed or effective connectivity among motor-related areas is required. We characterized changes in effective connectivity of the motor system following thalamotomy using (spectral) dynamic causal modeling (spDCM) for resting-state fMRI. To differentiate long-lasting treatment effects from transient effects, and to identify symptom-related changes in effective connectivity, we subject longitudinal resting-state fMRI data to spDCM, acquired 1 day prior to, and 1 day, 7 days, and 3 months after thalamotomy using a non-cranium-opening MRI-guided focused ultrasound ablation technique. For the group-level (between subject) analysis of longitudinal (between-session) effects, we introduce a multilevel parametric empirical Bayes (PEB) analysis for spDCM. We found remarkably selective and consistent changes in effective connectivity from the ventrolateral nuclei and the supplementary motor area to the contralateral dentate nucleus after thalamotomy, which may be mediated via a polysynaptic thalamic-cortical-cerebellar motor loop. Crucially, changes in effective connectivity predicted changes in clinical motor-symptom scores after thalamotomy. This study speaks to the efficacy of thalamotomy in regulating the dentate nucleus in the context of treating essential tremor. Furthermore, it illustrates the utility of PEB for group-level analysis of dynamic causal modeling in quantifying longitudinal changes in effective connectivity; i.e., measuring long-term plasticity in human subjects non-invasively

Lasting organ-level bone mechanoadaptation is unrelated to local strain

Bones adapt to mechanical forces according to strict principles predicting straight shape. Most bones are, however, paradoxically curved. To solve this paradox, we used computed tomography–based, four-dimensional imaging methods and computational analysis to monitor acute and chronic whole-bone shape adaptation and remodeling in vivo. We first confirmed that some acute load-induced structural changes are reversible, adhere to the linear strain magnitude regulation of remodeling activities, and are restricted to bone regions in which marked antiresorptive actions are evident. We make the novel observation that loading exerts significant lasting modifications in tibial shape and mass across extensive bone regions, underpinned by (re)modeling independent of local strain magnitude, occurring at sites where the initial response to load is principally osteogenic. This is the first report to demonstrate that bone loading stimulates nonlinear remodeling responses to strain that culminate in greater curvature adjusted for load predictability without sacrificing strength

Volumetric Plasma Discharge in a Coaxial Electrode Configuration Using Repetitively Pulsed Nanosecond Discharges

Transient plasma discharges can be created in di erent electrode geometries and the use of a coaxial electrodes can assist in initiating ignition at multiple points at the same time to create volumetric ignition. The current study investigates discharge formation in a coaxial electrode in quiescent, atmoshpheric and non-reacting conditions. This is the rst systematic study to understand the behavior of such a discharge as a function of di erent pulse parameters like pulse width (40-110 ns), repetition frequency (1-50 kHz) and input voltage (14-20 kV). Additionally, the polarity of the central electrode was changed between positive and negative. An intensi ed ccd camera was used to visualize the discharge for- mation. The exposure of the camera is set to capture 500 discharges in a single frame. The discharges were found to behave di erently for positive and negative polarity discharges. The positive polarity discharge tends to form a strong arc and spins around the outer cylinder which is con rmed using a high speed camera. The negative polarity discharges form a uniform streamer discharge for most of the pulse parameters. The current study has provided an initial understanding of the dynamics of plasma discharges in a coaxial electrode

Shape-preserving erosion controlled by the graded microarchitecture of shark tooth enameloid

The teeth of all vertebrates predominantly comprise the same materials, but their lifespans vary widely: in stark contrast to mammals, shark teeth are functional only for weeks, rather than decades, making lifelong durability largely irrelevant. However, their diets are diverse and often mechanically demanding, and as such, their teeth should maintain a functional morphology, even in the face of extremely high and potentially damaging contact stresses. Here, we reconcile the dilemma between the need for an operative tooth geometry and the unavoidable damage inherent to feeding on hard foods, demonstrating that the tooth cusps of Port Jackson sharks, hard-shelled prey specialists, possess unusual microarchitecture that controls tooth erosion in a way that maintains functional cusp shape. The graded architecture in the enameloid provokes a location-specific damage response, combining chipping of outer enameloid and smooth wear of inner enameloid to preserve an efficient shape for grasping hard prey. Our discovery provides experimental support for the dominant theory that multi-layered tooth enameloid facilitated evolutionary diversification of shark ecologies