Some population parameters of Mnemiopsis leidyi A. Agassiz, 1865 (Ctenophora: Lobata) in Sinop coasts of the Black Sea

Some population parameters of gelatinous macrozooplankton species, Mnemiopsis leidyi, were studied in the present study carried out from January 2008 to December 2008 along the coasts of Sinop in the Black Sea. A total of 980 M. leidyi specimens were measured and weighed. The estimated average length and weight of the species were 3.2±0.060 cm and 7.3±0.250 g, respectively. The observed maximum and minimum lengths were 10.8 cm and 0.2 cm. The maximum and minimum weights measured were 63 g and 0.1 g. The length-weight relationship equation for M. leidyi was determined to be W = 0.7905L1.6406.

Coupling numerical model of hydraulic fracturing seepage in soft coal based on elastoplastic damage

In order to guide the field application of hydraulic fracturing of soft coal in coal mine, based on the elastic-plastic damage theory, the coupling numerical model of soft coal hydraulic fracturing seepage was studied. The porosity strain relationship equation, permeability strain relationship equation, the relationship between permeability and volume plastic tensile strain and volume plastic shear strain of coal and rock mass are derived, and the plastic correction equation and softening parameters are defined. The stress coupling equation and yield criterion are programmed and embedded into the finite difference software FLAC3D for numerical solution. The numerical simulation shows that the numerical calculation model of soft coal hydraulic fracturing conforms to the actual law, and the field fracturing radius investigation experiment is consistent with the numerical simulation results.

ANALISIS PENAMPANG KOLOM BETON BERTULANG PERSEGI PANJANG BERLUBANG

Installation of pipes (conduit) in the building columns often found in reinforced concrete structures. The installation of pipes inside the columns is utilized as sanitary and mechanical electrical pipes. The case research in this study is to analyze the rectangular column with the applied research type (applied/pratical research). This research aims to analyze the impact of the holes on square rectangular columns. This calculation consists of 675 samples with differentconcrete compression strength (f'c), reinforcement area, holes area, and the dimensions of the column. Analysis of the calculation of hollow rectangular columns using the stress-strain relationship equation developed by Hognestaad. The results of the analysis on hollow rectangular columns resulted in a decrease column capacity. The largest decrease of the rectangular column capacity occurred on holes area of 7%, with concrete compression strength 30 MPa, and dimensions of the column 450 x 1800 mm which is 16.97%.

Predicting the skin-permeating components of externally-applied medicinal herbs: application of a newly constructed linear free-energy relationship equation for human skin permeation

The LFER equation may be used to predict skin-permeating components of externally applied herbs, with log Kp≥ −7.0 considered as a screening criterion.

Study on Linear Relationship between Refractive Index Difference and Band Gap Width of the 1-D PCs

Set the Refractive Indexes of the One-Dimensional Photonic Crystals (1-D Pcs) were n2 and n3, Keeping n2=1.5 Unchanged and Adjusting n3 in the Range of 2.5--3.5, the Dispersion Curves were Obtained through Characteristic Matrix Method (CMM). The Results Show that when n3 Increased from 2.5 to 3.5, the Band Gap Width Also Increased from about 0.086 to 0.140 Correspondingly. Furthermore, the Results Show that it’s a Linear Growth Process between the Refractive Index Difference and the Band Gap Width of the 1-D Pcs, for the First Propose Quantitatively, there is a Relationship Equation Δω=0.0537(Δn)+0.0336(Δn=n3-n2) Approximately.

Analysis Temperature Characteristics of Atmosphere Pressure Sensor Caused by Residual Gas

In this paper, temperature characteristic of a previous developed nickel-chromium (Ni-Cr) thin film atmosphere pressure sensor is analyzed caused by residual gas. As expected, the output signal of the previous fabricated sensor increases with atmosphere pressures. But when pressure load is fixed, the voltage-temperature characteristic is nonlinear. One factor of this effect is residual gas. Based on the pressure-displacement equation of membrane, the gas balance equation and Provided that the deformation of membrane is spherical crown, the relationship equation of relative change of piezoresistor is defined. Studying the First order derivative and second order derivative of relationship equation of relative change of piezoresistor, it is proved that the residual gas will affect the temperature characteristic of previous designed sensor.

Experimental and Theoretical Study on Influence of Different Charging Structures on Blasting Vibration Energy

As an important parameter in blasting design, charging structure directly influences blasting effect. Due to complex conditions of this blasting and excavating engineering in Jiangsu, China, the authors carried out comparative researches with coupling structure, air-decoupling structure, and water-decoupling structure. After collecting, comparing, and analyzing produced signals on blasting vibration, the authors summarized that when proportional distances are the same, water-decoupling structure can reduce instantaneous energy of blasting vibration more effectively with more average rock fragmentation and less harm of dust. From the perspective of impedance matching, the present paper analyzed influence of charging structure on blasting vibration energy, demonstrating that impedance matching relationship between explosive and rock changes because of different charging structures. Through deducing relationship equation that meets the impedance matching of explosive and rock under different charging structures, the research concludes that when blasting rocks with high impedance, explosive with high impedance can better transmits blasting energy. Besides, when employing decoupling charging, there exists a reasonable decoupling coefficient helping realize impedance matching of explosive and rock.