Импульсный индукционный CO-=SUB=-2-=/SUB=--лазер с энергией излучения 1 J и высоким КПД с ВЧ возбуждением

An efficient pulsed gas-discharge inductive CO2-laser with a radiation energy of 1.05 J has been developed for the first time. In this case, the pulse duration of the laser radiation was about 10 msec. The maximum efficiency of 21.1% was obtained at a radiation energy of 340 mJ. RF current pulses propagated along the inductor conductor and, thus, an inductive discharge was formed to create an inverse population at the infrared (IR) transitions of CO2* molecules. The temporal and energy characteristics of the radiation of the inductive CO2-laser depending on the duration of the pump pulse are investigated. The spatial characteristics and spectrum of the radiation of the developed laser are estimated. The divergence of the laser radiation was 0.52 mrad. The cross-sectional dimension of the laser output beam was about 35 mm in diameter.

Pressure Change for Single- and Two-Phase Non-Newtonian Flows through Sudden Contraction in Rectangular Microchannel

The flow characteristics of the single-phase liquid and the gas–liquid two-phase flows including the Newtonian and non-Newtonian liquids were experimentally investigated in a horizontal rectangular micro-channel with a sudden contraction—specifically the pressure change across the contraction. The rectangular cross-sectional dimension has Wu × Hu (width × height) = 0.99 × 0.50 mm2 on the upstream side of the contraction and Wd × Hd = 0.49 × 0.50 mm2 on the downstream side. The resulting contraction ratio, σA (=Wd/Wu), was 0.5. Air was used as the test gas (in the case of the gas–liquid two-phase flow experiment), distilled water and three kinds of aqueous solution, i.e., glycerin 25 wt%, xanthangum 0.1 wt% and polyacrylamide 0.11 wt% were used as the test liquid. The pressure distribution in the flow direction upstream and downstream of the channel was measured. The pressure change and loss at the sudden contraction were determined from the pressure distribution. In addition, the pressure change data were compared with the calculation by several correlations proposed by various researchers as well as a newly developed correlation in this study. From the comparisons, it was found that calculations by the newly developed correlations agreed well with the measured values within the error of 30%.

IBOA-Based Optimization of Cross-Sectional Dimension of Rods for a 3-RRR PPM to Minimize Energy Consumption

For obtaining optimal cross-sectional dimensions of rods for a 3-RRR planar parallel manipulator (PPM) to minimize energy consumption, the inverse dynamics of the manipulator is modeled based on the Newton–Euler method, after which the coefficient matrix of the inverse dynamics equation is decomposed based on matrix theory. Hence, the objective function, that is, the logical relationship between the energy consumption of the manipulator and the cross-sectional dimension of each rod, is established. However, in solving the multidimensional constrained single-object optimization problem, there are difficulties such as the penalty function’s sensitivity to the penalty factors if the problem is transformed into the one of unconstrained multiobjective optimization. Therefore, to properly handle the constraints, an improved butterfly optimization algorithm (IBOA) is presented to ensure that the new iterated point always falls into the feasible region according to the butterfly optimization algorithm (BOA). Finally, the comparisons among the IBOA, particle swarm optimization (PSO), and BOA and further experiments of the physical prototype are implemented to validate the effectiveness of the proposed theoretical model and numerical algorithm. Results indicate that the proposed IBOA is more suitable for solving the constrained single-object optimization problem with better convergence speed and accuracy.

Meningkatkan Daya Dukung Tiang Pondasi Minipile Persegi Pada Gedung Kantor Ngasem Kabupaten Kediri Menggunakan Metode Mayerhoff

The foundation is one part under the building that has a very important role. The choice of the type of foundation is something that needs to be considered. One type of foundation that is widely used is the minipile foundation. Minipile foundation itself is a type of foundation that is used if the load received from the superstructure is not too heavy and the hard soil type is at a depth of between 5-10m. The purpose of this study was to plan the bearing capacity of the minipile foundation pile in the PT. BPJE in Ngasem, Kediri Regency. The building is planned to be used as an office building. The planned sub-building includes foundation planning with a mini-square building with a cross-sectional dimension of 20x20. The calculations carried out include the calculation of the bearing capacity of the foundation using the Mayerhoff method, the calculation of the flexural factor and the calculation of reinforcement. The calculation results (sigma Vertical Ultimate) Vu = 114.78 tons. With bending factor tk = 286.95 kg /. The reinforcement in the pile cap for the x direction of tensile reinforcement = D16–170 and compression reinforcement = D16–250 while for tensile reinforcement in the y direction = D16 - 170 and compressive reinforcement = D10 - 250. Thus, the results of the planning can be used as a reference for the implementation of building construction. office of PT. BPJE in Ngasem, Kediri Regency.

Periaortic venous necklace and renal right double arteries; Case report

The case was found on an organic sample consisting of the two kidneys with the renal pedicles and the corresponding segments of the abdominal aorta and inferior vena cava. From the inferior face of the left renal vein, on the lower side of the aorta, a venous branch with an upward path of 8.02 mm was detached, passing on the anterior face of the aorta, passing before its right side, in order to end on the left side of the inferior vena cava, 13.9 mm above the end of the left renal vein in the inferior vena cava, this branch thus describing a periaortic ring (necklace), in which on the left side of the aorta the inferior adrenal vein ends. The periaortic ring (necklace) had a cross-sectional dimension of 3.2 mm and a vertical one of 1.7 cm. On the right side of the aorta, a 2.9 mm venous branch came out of the renal vein, ending on the left side of the inferior vena cava, 1.2 mm above the end of the left renal vein. At the level of the right kidney there were two renal arteries, superior and inferior. Between the two arteries there was an interval of 5.1 cm.

Links, fit or sacrifice: job embeddedness and intention to quit among Generation Y

PurposeThe study aims to determine how the relationship among links, fit and sacrifice (dimensions of job embeddedness) influence employees' intention to quit in the case of professionals belonging to Generation Y.Design/methodology/approachA quantitative correlational study was conducted with a cross-sectional dimension of time. The survey technique was applied through a certified online panel. The sample consisted of 211 members of Generation Y.FindingsIt has been verified that the only significant dimension for Generation Y is sacrifice.Research limitations/implicationsIt is necessary to extend the study of the dimensions of job embeddedness and their influence on employees' intention to quit in different demographic groups. It would be advisable to conduct longitudinal studies to observe the dynamics of job embeddedness throughout the years.Practical implicationsOrganizations concerned with retaining the talent of young professionals can focus on the development of policies and benefits that encourage sacrifice.Social implicationsThe finding that the sacrifice dimension is the one that would reduce the intention to leave for Generation Y will help to ensure that organizations retain the workforce that they value.Originality/valueThe study is important to gain a better understanding of Generation Y behavior. In addition, in response to the demand from the literature, the sample considered only Generation Y with work experience.

Soft-bodied adaptive multimodal locomotion strategies in fluid-filled confined spaces

Soft-bodied locomotion in fluid-filled confined spaces is critical for future wireless medical robots operating inside vessels, tubes, channels, and cavities of the human body, which are filled with stagnant or flowing biological fluids. However, the active soft-bodied locomotion is challenging to achieve when the robot size is comparable with the cross-sectional dimension of these confined spaces. Here, we propose various control and performance enhancement strategies to let the sheet-shaped soft millirobots achieve multimodal locomotion, including rolling, undulatory crawling, undulatory swimming, and helical surface crawling depending on different fluid-filled confined environments. With these locomotion modes, the sheet-shaped soft robot can navigate through straight or bent gaps with varying sizes, tortuous channels, and tubes with a flowing fluid inside. Such soft robot design along with its control and performance enhancement strategies are promising to be applied in future wireless soft medical robots inside various fluid-filled tight regions of the human body.

Dynamic Response of an Inhomogeneous Elastic Pile in a Multilayered Saturated Soil to Transient Torsional Load

In this paper, we solve the dynamic response of an inhomogeneous elastic pile embedded in a multilayered saturated soil and subjected to a transient torsional load via a semianalytical method. To portray the inhomogeneity of the pile and the stratification of surrounding soil, the pile-soil system is subdivided into Nth layers along the depth direction in view of the variation of shear modulus or cross-sectional dimension of the pile or differences in soil properties. Then, the vibration displacement solution with undermined constants for any saturated soil layer subjected to the time-harmonic torsional load is obtained by virtue of the separation of variables scheme. To establish the connection of adjacent longitudinal soil layers, the circumferential contact traction at the interface of the adjacent layers is treated as the distributed Winkler subgrade model independent of the radial distance. Then, by utilizing the continuity conditions of the pile-soil system and the method of recursion typically used in the transfer function technique, the torsional impedance of the pile top can be derived in the frequency domain. By virtue of inverse Fourier transform and convolution theorem, the velocity response of an inhomogeneous pile subjected to a transient half-sine exciting torque and embedded in a layered saturated soil is gained in the time domain. Finally, selected numerical results are gained to investigate the influence of typical defects in pile and soil layering on the velocity response of the pile top in the time domain.

Testing for slope heterogeneity in Stata

In this article, we introduce a new community-contributed command, xthst, to test for slope heterogeneity in panels with many observations over cross-sectional units and time periods. The command implements such a test, the delta test (Pesaran and Yamagata, 2008, Journal of Econometrics 142: 50–93). Under its null, slope coefficients are homogeneous across cross-sectional units. Under the alternative, slope coefficients are heterogeneous in the cross-sectional dimension. xthst also includes two extensions. The first is a heteroskedasticity- and autocorrelation-consistent robust test along the lines of Blomquist and Westerlund (2013, Economics Letters 121: 374–378). The second extension is a cross-sectional-dependence robust version. We discuss all tests and present examples using an economic growth model. A Monte Carlo simulation shows that the size and the power behave as expected.

Modeling Uniaxial Bond Stress–Slip Behavior of Reinforcing Bars Embedded in Concrete with Different Strengths

This paper aims to study the uniaxial bond stress–slip characteristics of reinforcing bars embedded in concrete with different strengths. Tests were conducted on tension–pull specimens that had a cross-sectional dimension with a reinforcing bar embedded in the center section. The experimental variable was the concrete compressive strength (20, 40, and 60 MPa). The test results show that in the specimen subjected to any fixed load, the maximum value of the concrete strain occurred around the central position, and its value increased as the compressive strength of the concrete increased. Depending on the embedded position of the steel bars, the bond stress–slip relationship was also different. In addition, the analytical results indicate that the proposed bond stress–slip constitutive relationship is very accurate in describing the true bond stress–slip relationship.