Spinel LiMn2O4 Nanorods via Template–Engaged Method and as Cathode Materials for Li-Ion Batteries

Spinel LiMn2O4 nanorods were prepared by a hydrothermal method followed by solid-state lithiation. The produce β-MnO2 nanowire as template, and LiOH·H2O was used as lithium source. The spinel LiMn2O4 nanorods samples were characterized by SEM, XRD, (HR)TEM, and galvanostatic charge/discharge profile measurement. Compared with the LiMn2O4 nanoparticles, the LiMn2O4 nanorods showed superior cycling stability, better rate capability, good high temperature performance, and delivered a discharge capacity of 122 mAh/g (at 1 C, 100 cycles).

Two-telescope-based solar seeing profile measurement simulation

Measurements of the daytime seeing profile of the atmospheric turbulence are crucial for evaluating a solar astronomical site so that research on the profile of the atmospheric turbulence as a function of altitude C n 2 ( h n ) becomes more and more critical for performance estimation and optimization of future adaptive optics (AO) including the multi-conjugate adaptive optics (MCAO) systems. Recently, the S-DIMM+ method has been successfully used to measure daytime turbulence profiles above the New Solar Telescope (NST) on Big Bear Lake. However, such techniques are limited by the requirement of using a large solar telescope which is not realistic for a new potential astronomical site. Meanwhile, the A-MASP (advanced multiple-aperture seeing profiler) method is more portable and has been proved that can reliably retrieve the seeing profile up to 16 km with the Dunn Solar Telescope (DST) on the National Solar Observatory (Townson, Kellerer et al.). But the turbulence of the ground layer is calculated by combining A-MASP and S-DIMM+ (Solar Differential Image Motion Monitor+) due to the limitation of the two-individual-telescopes structure. To solve these problems, we introduce the two-telescope seeing profiler (TTSP) which consists of two portable individual telescopes. Numerical simulations have been conducted to evaluate the performance of TTSP. We find our TTSP can effectively retrieve seeing profiles of four turbulence layers with a relative error of less than 4% and is dependable for actual seeing measurement.

Single-shot measurement of longitudinal phase space beam profile in an electron storage ring

A novel scheme to measure the longitudinal emittance and phase space profile in an electron storage ring by using correlations between time and the vertical coordinate, and between energy and the horizontal coordinate, is proposed. This longitudinal profile measurement scheme will help to demonstrate recent results of advanced studies for manipulating the longitudinal beam profile and for investigating beam instability in an electron storage ring.

Compilation of ozonesonde observation over Schirmacher oasis east Antarctic from 1999-2007

Hkkjr ekSle foKku foHkkx }kjk Hkkjrh; bysDVªks&dsfedy vkstksulkSans dh enn ls ,aVkdZfVdk ij Hkkjr ds nwljs LVs'ku eS=h ¼70-7 fMxzh n-] 11-7 fMxzh iw-½ ls vkstksu fLFkfr ¼izksQkby½ dk fu;fer eki fd;k tk jgk gSA ok;qeaMy ds mnxz LraHk esa vkstksu ds ?kuRo dh x.kuk iwjs o"kZ esa fy, x, lkIrkfgd vkstksu lkmfUMax ls dh tkrh gSA ok;qeaMyh; vkstksu dh mnxz fLFkfr ¼izksQkby vkSj vkstksu fNnz ¼gksy½ dh fo'ks"krkvksa dk v/;;u djus ds fy, flracj&vDVwcj ekg ds nkSjku cgqr ckj ifjKfIr;k¡ ¼lkmfUMax½ yh xbZ gSaA bl 'kks/k i= esa lrg ls 10 gsDVk ik- ds chp vkstksu vkSj rkieku ds ekfld ,oa okf"kZd vkSlr esa fofo/krk dh x.kuk ,oa fo'ys"k.k o"kZ 1999 ls 2007 dh vof/k esa fy, vkstksulkSans vkjksg.kksa ls fd;k x;k gSA bl v/;;u ls irk pyk gS fd vkstksu fNnz ds laca/k esa xgu vo{k; vDrwcj esa vkSj vYi ijUrq egRoiw.kZ vo{k; flracj ekg esa gqvk gSA vDrwcj esa yxHkx 250 ,oa 20 gs-ik- ds chp lcls lqLi"V vo{k; gqvk gS ftlesa vf/kdre LFkkuh; vkstksu ds Lrj esa 70 gs-ik- vkSj 10 gs- ik- ds Lrjksa ij vkSj flrEcj esa 70 gs- ik- ij fxjkoV ns[kh xbZA fHkUu&fHkUu nkc Lrjksa ds fy, vkstksu dk rkieku ds lkFk lglaca/k ls ubZ tkudkfj;ksa vkSj vkstksu ifjorZu esa foLrkj dk irk pyk gSA iwjs o"kZ esa 300 ls 50 gs- ik- ds chp U;wure okf"kZd vkSlr rkieku -55 fMxzh ls -63 fMxzh lsaVhxzsM rd cnyrk gSA vxLr vkSj flrEcj ds eghuksa esa 70 gs- ik- rFkk 100 gs- ik- Lrjksa ij rkieku dk -80 fMxzh lsaVhxzsM ls de gksuk ,oa vDrwcj ekg esa 70 gs- ik- rFkk 100 gs- ik- Lrjksa ij yxHkx -70 fMxzh lsaVhxzsM ls de gksus dh fLFkfr dks vDrwcj ekg esa vkst+ksu vo{k; ds ladsrd ds :i esa ekuk tk ldrk gSA Regular ozone profile measurement over Antarctica has been made by India Meteorological Department over Indian second station Maitri (70.7° S, 11.7° E) with the help of Indian electro-chemical ozonesonde. Ozone density in the vertical column of the atmosphere is computed with weekly ozone soundings taken throughout the year. During the month of September- October more frequent soundings were taken to study vertical profile of atmospheric ozone and features of ozone hole. The mean monthly and yearly variation of ozone and temperature from surface to 10 hPa has been computed and analyzed from the ozonesonde ascents for the period 1999 to 2007. The study has shown profound depletion in October and lesser but substantial depletion in September, in association with the ozone hole. Depletion is most pronounced between about 250 and 20 hPa in October, with maximum local ozone losses near 70 hPa & 100 hPa levels and in September at 70 hPa. Ozone correlations with temperature for several pressure levels have revealed new insights into the causes and extent of ozone change. Lowest annual mean temperature varies from -55 to -63 °C between 300 to 50 hPa in all the year. The temperature less than -80 °C in months of August & September at 70 hPa & 100 hPa levels and about -70 °C in month of October at 70 hPa & 100 hPa levels can be attributed as an indicator of ozone depletion in months of October

Step Surface Profile Measurement Based on Fringe Projection Phase-Shifting Using Selective Sampling

Fringe projection is a non-contact optical method that is widely used in the optical precision measurement of complex stepped surfaces. However, the accuracy of the fringe phase extraction employed has a direct impact on the measurement precision of the surface shape. Where phase-shifting measurement is used, the classical equal step phase extraction algorithm can only be used to measure simple and smooth surfaces, and leads to measurement errors on complex stepped surfaces, which affects the accuracy of the phase extraction. In addition, the iterative process lasts for a long time, resulting in a low efficiency. This paper proposes a step-by-step phase-shifting extraction algorithm based on selective sampling to measure the contour of the stepped surface. Firstly, the fringe pattern is sampled at equal intervals to reduce the iterative calculation time. Finally, the accurate measurement phase is calculated by the alternating iteration method. The phase extraction accuracy and iteration times are compared in experimental measurements between classical iterative algorithms such as four-step phase-shifting algorithms and the variable phase shift phase interpolation algorithm based on selective sampling. It is shown that the variable frequency phase-shifting extraction algorithm based on selective sampling has a shorter operation time, smaller error, and higher accuracy than the traditional iterative algorithm in fringe projection measuring complex stepped surfaces.

Measurement of Ozone at Maitri, Antarctica

Regular ozone profile measurement over Antarctica has been made by India Meteorological Department since 1987 at Dakshin Gangotri and later at Maitri (70.7°S, 11.7°E) since 1990 with the help of Indian electro-chemical ozone sonde. Surface ozone measurement was also started at Dakshin Gangotri since 1989 and later at Maitri. Ozone sonde data at Dakshin Gangotri and Maitri have been analysed and ozone hole structure has been studied in detail. The drastic decrease in ozone amount is clearly seen between 100 hPa to 30 hPa layer reaching near zero value. Incidently this is the layer where highest ozone concentration occurs during other months except September-October. The ozone hole has been quite severe during 1994-95 with increase in area and depth. During 1996 the Antarctic ozone hole was also similar to previous years. An interesting feature of the 1995 event was the persistence of ozone hole through November & December. Stratospheric temperature changes during 1995 also support that the cold core vortex during 1995 was very cold and persisted up to November.

A weighted fusion method with multi-system for improving measurement accuracy of structured light 3D profilometry

It is a challenge to improve the accuracy of 3D profile measurement based on binary coded structured light for complex surfaces. A new method of weighted fusion with multi-system is presented to reduce the measurement errors due to the stripe grayscale asymmetry, which is based on the analysis of stripe center deviation related to surface normal and the directions of incident and reflected rays. First, the stripe center deviation model is established according to the geometric relationship between the stripe center deviation, the incident and reflected angles at any measured point. The influence of each variable on stripe center deviation is analyzed, and three subsystems are formed by a binocular structured light framework to achieve multiple measurements based on the influence regularity. Then in order to improve the measurement accuracy, different weights are assigned to the measured point in different subsystems according to the stripe center deviation model and its relationship with measurement error, and the weighted data from different subsystems are fused. Experiments are carried out to validate the presented method, and the experimental results demonstrate that it effectively improves the measurement accuracy of complex surfaces and measurement accuracy is improved by about 27% compared with the conventional method.

Temperature profile measurement applications of moving webs and roll structures with intelligent roll embedded sensor technology

An intelligent roll for sheet and roll cover temperature profiles is a mechatronic system consisting of a roll in a web handling machine that is also used as a transducer for sensing cross-machine direction (CD) profiles. The embedded temperature sensor strips are mounted under or inside the roll cover, covering the full width of the roll’s cross-dimensional length. The sensor system offers new opportunities for online temperature measurement through exceptional sensitivity and resolution, without adding external measurement devices. The measurement is contacting, making it free from various disturbances affecting non-contacting temperature measurements, and it can show the roll cover’s internal temperatures. This helps create applications that have been impossible with traditional technology, with opportunities for process control and condition monitoring. An application used for process analysis services without adding a roll cover is made with “iRoll Portable Temperature” by mounting the sensor on the shell in a helical arrangement with special taping. The iRoll Temperature sensors are used for various purposes, depending on the application. The two main targets are the online temperature profile measurement of the moving web and the monitoring of the roll covers’ internal temperatures. The online sheet temperature profile has its main utilization in optimizing moisture profiles and drying processes. This enables the removal of speed and runnability bottlenecks by detecting inadequate drying capacity across the sheet CD width, the monitoring condition of the drying equipment, the optimization of drying energy consumption, the prevention of unnecessary over-drying, the optimization of the float drying of coating colors, and the detection of reasons for moisture profile errors. This paper describes this novel technology and its use cases in the paper, board, and tissue industry, but the application can be extended to pulp drying and industries outside pulp and paper, such as the converting and manufacture of plastic films.