Non-wetting drops at liquid interfaces: From liquid marbles to Leidenfrost drops

We consider the flotation of deformable, non-wetting drops on a liquid interface. We consider the deflection of both the liquid interface and the droplet itself in response to the buoyancy forces, density difference and the various surface tensions within the system. Our results suggest new insight into a range of phenomena in which such drops occur, including Leidenfrost droplets and floating liquid marbles. In particular, we show that the floating state of liquid marbles is very sensitive to the tension of the particle-covered interface and suggest that this sensitivity may make such experiments a useful assay of the properties of these complex interfaces.Comment: 21 pages, 9 figures. Minor typos correcte

Pengaruh Pelatihan terhadap Kompetensi (Penelitian Tentang Pelatihan pada Calon Tenaga Kerja Indonesia di PT Tritama Bina Karya Malang)

The aim of this research is to know the influence of the variables of Training Method (X1), Training Material (X2), Training Instructor (X3) on Labor Competence (Y) simultaneously and partially. This type of training is explanatory research (explanation) with quantitative approach and conducted by questionnaire method. This research is done by giving a written question to all employees of PT Tritama Bina Karya Malang distribution of labor services which amounted to 106 people and located Ki Ageng Gribig street Kedungkandang, Malang City. Data analysis technique used is descriptive analysis and multiple linear regression analysis with F (simultaneous) and t test (partial). Based on F test, it can be seen that F arithmetic> F table is 46,439> 2,694 or sig value. F (0,000) <α = 0.05 then the regression analysis model is significant because H0 is rejected and H1 is accepted. So it can be concluded that the dependent variable (Labor Competence) can be significantly affected by the independent variables of Training Methods, Training Materials, and Training Instructors simultaneously. Based on t test results it can be seen that each independent variable (Training Method, Training Material, and Training Instructor) has a partially significant influence on the dependent variable (Labor Competency). Kеywords: Training Methods, Training Materials, Training Instructors and Labor Competencies АBSTRАK Jenis pelatihan ini adalah explanatory research (penjelasan) dengan pendekatan kuantitatif dan dilakukan dengan metode kuesioner. Penelitian ini dilakukan dengan memberikan seperangkat pertanyaan tertulis kepada seluruh tenaga kerja PT Tritama Bina Karya Malang penyaluran jasa tenaga kerja yang berjumlah 106 orang dan berlokasi jalan Ki Ageng Gribig Kedungkandang, Kota Malang. Teknik analisis data yang digunakan adalah analisis deskriptif dan analisis regresi linier berganda dengan uji F (simultan) dan uji t (parsial). Berdasarkan uji F yang dilakukan dapat diketahui bahwa F hitung>F tabel yaitu 46,439 > 2,694 atau nilai sig. F (0,000) < α = 0.05 maka model analisis regresi adalah signifikan karena H0 ditolak dan H1 diterima. Jadi dapat disimpulkan bahwa variabel terikat (Kompetensi Tenaga Kerja) dapat dipengaruhi secara signifikan oleh variabel bebas Metode Pelatihan, Materi Pelatihan, dan Instruktur Pelatihan secara simultan. Berdasarkan hasil uji t dapat diketahui bahwa masing-masing variabel bebas (Metode Pelatihan, Materi Pelatihan, dan Instruktur Pelatihan) mempunyai pengaruh yang signifikan secara parsial terhadap variabel terikat (Kompetensi Tenaga Kerja). Kаtа Kunci: Metode Pelatihan, Materi Pelatihan, Instruktur Pelatihan dan Kompetensi Tenaga Kerj

An improved moth flame optimization algorithm based on rough sets for tomato diseases detection

Plant diseases is one of the major bottlenecks in agricultural production that have bad effects on the economic of any country. Automatic detection of such disease could minimize these effects. Features selection is a usual pre-processing step used for automatic disease detection systems. It is an important process for detecting and eliminating noisy, irrelevant, and redundant data. Thus, it could lead to improve the detection performance. In this paper, an improved moth-flame approach to automatically detect tomato diseases was proposed. The moth-flame fitness function depends on the rough sets dependency degree and it takes into a consideration the number of selected features. The proposed algorithm used both of the power of exploration of the moth flame and the high performance of rough sets for the feature selection task to find the set of features maximizing the classification accuracy which was evaluated using the support vector machine (SVM). The performance of the MFORSFS algorithm was evaluated using many benchmark datasets taken from UCI machine learning data repository and then compared with feature selection approaches based on Particle Swarm Optimization (PSO) and Genetic Algorithms (GA) with rough sets. The proposed algorithm was then used in a real-life problem, detecting tomato diseases (Powdery mildew and early blight) where a real dataset of tomato disease were manually built and a tomato disease detection approach was proposed and evaluated using this dataset. The experimental results showed that the proposed algorithm was efficient in terms of Recall, Precision, Accuracy and F-Score, as long as feature size reduction and execution time

Role of phosphoric acid on the corrosion performance of Pb-1.7%Sb gridof lead-acid batteries

The corrosion behavior of a commercial Pb-1.7% Sb gridof lead-acid batteries under open circuit conditions in 5M H 2SO4 in the presence of phosphoric acid is studiedby electrochemical impedance spectroscopy and cyclicvoltammetry. Dependence of corrodibility of the alloy onH 3PO4 concentration is weak up to 0.7M. After days ofcorrosion, the corrosion rate in the presence of H 3PO4 isslightly higher than in its absence, due to retardation of the growth of an insulating PbSO 4 layer that acts as an effective diffusion barrier of the corrosive species. The electronic and diffusion properties of the passive layer formed in the presence of H 3PO4 are substantially inferior. Cyclic voltammetry indicates a decrease in amounts of PbSO 4 and Sb 2O3 formed in the presence of H3PO4 and with increasing its concentration. Also, the amount of PbO formed beneath the PbSO 4 layer increases with increasing H3PO4 concentration on the expense of the amount of PbSO 4

Exploring AdS Waves Via Nonminimal Coupling

We consider nonminimally coupled scalar fields to explore the Siklos spacetimes in three dimensions. Their interpretation as exact gravitational waves propagating on AdS restrict the source to behave as a pure radiation field. We show that the related pure radiation constraints single out a unique self-interaction potential depending on one coupling constant. For a vanishing coupling constant, this potential reduces to a mass term with a mass fixed in terms of the nonminimal coupling parameter. This mass dependence allows the existence of several free cases including massless and tachyonic sources. There even exists a particular value of the nonminimal coupling parameter for which the corresponding mass exactly compensates the contribution generated by the negative scalar curvature, producing a genuinely massless field in this curved background. The self-interacting case is studied in detail for the conformal coupling. The resulting gravitational wave is formed by the superposition of the free and the self-interaction contributions, except for a critical value of the coupling constant where a non-perturbative effect relating the strong and weak regimes of the source appears. We establish a correspondence between the scalar source supporting an AdS wave and a pp wave by showing that their respective pure radiation constraints are conformally related, while their involved backgrounds are not. Finally, we consider the AdS waves for topologically massive gravity and its limit to conformal gravity.Comment: 26 pages, 1 figure. Minor change