Sequential Spot Research Articles

Modelling and Optimization of Continual Laser Joining Processes for Silicon Aluminum Alloy in Microwave Devices

Due to its higher energy and smaller heating area, laser joining technology is widely used in aluminum alloy welding and other industrial fields, which meets the solder sealing requirements for electronic packaging. According to experiments, cracks were prone to occur at the corners and spot-welding positions near the weld. In this paper, the depth and width of the melt pool were measured experimentally, and the results were used to calibrate and validate the heat source model. An empirical relationship between heat source parameters and melt pool morphology is presented. The heat source model of laser deep penetration welding was established under the same experimental conditions. And the results were in agreement with the experimental results. The finite element method was used to numerically simulate the welding process of a 50%SiAl shell and a 27%SiAl cover plate. The effects of different spot-welding sequences and numbers on the residual stress and cracking possibility of laser welded samples were analyzed. The results show that under sequential spot-welding, when the amount of spot-welding is increased, the stress peak value decreases. Compared with sequential spot welding and side-by-side spot welding, the spot-welding sequence of diagonal points first, and then side-by-side spot welding, can effectively reduce the residual stress. This research enables us to provide some guidelines in terms of studying the reliability issues of microwave devices.

Managing combined power and heat portfolios in sequential spot power markets under uncertainty

The integrated provision of energy among various energy sectors plays an important role in the process of decarbonisation of large energy systems. An important pillar is thereby the decarbonisation of the heat sector, where nowadays still a large percentage of heat supply originates from high-emission fossil fuels like coal or oil. In Central Europe, combined heat and power (CHP) plant applications, e.g. in local district heating networks, represent established methods to provide both electricity and heat at the same time, lowering overall fuel demands and lowering concomitant emissions. Heat pumps, converting electricity into heat, are also increasingly adopted by commercial (and household) customers. However, the optimal marketing and production scheduling of the heat and power- providing portfolios under price uncertainty is a challenging and often complex task. The importance of proper uncertainty handling is underscored even more if the optimal dispatch of flexible technologies like storages needs to be considered. In this paper, we propose an enhanced multi-stage stochastic programming model for coordinated bidding in two sequential markets, namely the one-hour and the fifteen-minute electricity products in the German (day-ahead) spot market. Our study develops and applies a stochastic mixed-integer linear programming model for a virtual power plant, acting as a price taker in the mentioned electricity markets. The model determines the optimal bidding strategies for a heterogeneous portfolio of small gas-fired motor- CHP units, heat pumps, electric storage heaters and battery storage systems. Thereby, we introduce a novel approach to construct piece-wise linear bidding curves for these markets, choosing their supporting points based on the simulated price paths. For the evaluation of the benefits of decision-making by help of stochastic modelling and optimization with different scenario numbers, we develop a new concept, the Benefit of Stochastic Optimization (BSO) and reflect and contrast our results with the computational burden of stochastic simulation, using the example of a real-world portfolio. We find that stochastic optimisation is a valuable optimisation method that may inform and improve individual marketer’s decision-making processes. However, the observable additional benefits, i.e. compared to deterministic point forecasts, are limited in the investigated cases, while computational expensiveness increases significantly when adding further scenarios.

Kalman filter tracking of sequence spot centroid ablated by femtosecond laser

AbstractIn the process of processing monocrystalline silicon by femtosecond laser, there is a phenomenon of derived plasma luminescence, which formed the time series spot. The laser spot image contains some effective information related to process parameters, such as ablation power of femtosecond laser, processing speed and so on. Through the comprehensive analysis of the geometric features of the sequential spot image, it can be used in the closed‐loop feedback system of micromachining based on the features of the plasma spot image. Because the spot centroid can be used to locate the spot position accurately, the sequential spot centroid obtained by gray centroid method was used as the sampling data, which was tracked by Kalman filter, and then the movement law of the spot was observed and analyzed. In this paper, the discrete linear Kalman filter algorithm is used to establish motion model of the spot centroid, and the next movement state of spot is predicted, and then the trajectory of the spot is obtained. Generally, the traditional Kalman filter has some shortcomings, such as inaccurate model, too much noise, and it is difficult to achieve the optimal estimation, therefore, the application of Kalman filter in spot centroid tracking is optimized. Firstly, the process noise is updated in real time to correct the direction of acceleration accurately and reduce the uncontrollability of process noise by introducing the factor l; Secondly, combined with Wiener filter, the observation value is optimized to minimize the influence of observation noise; Thirdly, starting from the Kalman filter equation, the actual value of the previous moment is connected with the optimal estimated value by weighted addition based on the “Identity of A‐OE” operator, so as to improve the prediction accuracy of the current time. Finally, the EF‐BP neural network is introduced on the basis of the “Identity of A‐OE” operator, and a stable training system is used to optimize the weight repeatedly, so that the error can reach the expected value. The results show that the error of the observation value is reduced by 8.2503%, the error of the optimal filter estimation value is reduced to 0.3490, and the error reduction range is 6.7662. The centroid tracking accuracy of the ablated spot image is improved obviously.

Limited Reliability of the Spot Urine Protein/Creatinine Ratio in the Longitudinal Evaluation of Patients With Lupus Nephritis

IntroductionCross-sectional studies document that the spot protein/creatinine ratio (PCR) is often an inaccurate estimate of proteinuria magnitude compared with the 24-hour PCR, which is the gold standard. However, the extent to which the inaccuracy of the spot PCR varies over time and between individuals has not previously been reported. We address these crucial questions using a unique database, an National Institutes of Health trial in which lupus nephritis (LN) patients (N = 103) provided spot PCR testing each month and 24-hour PCR testing every 3 months for up to 15 months after induction therapy.MethodsA gold standard proteinuria trend line was constructed for each patient by joining the points that represented the serial 24-hour PCR values of the patient. The spot PCR values of the patient were then plotted in relationship to the 24-hour PCR trend line. Using our previous work, which estimated the 95% confidence intervals for the 24-hour PCR at specific levels, we determined in each patient whether the spot PCR values were “reliable,” “problematic,” or “unreliable.” The sequential spot PCR of the patients deviated widely and often from the 24-hour PCR trend line, to the extent that, if the spot PCR results were used in real time for clinical decision-making, it was likely management errors would occur.ResultsSpot PCRs were reliable in 41%, problematic in 24%, and unreliable in 35% of patients. Those with unreliable spot PCRs could not be predicted and were more likely to respond poorly to treatment.ConclusionThe spot PCR should not be used for management of LN, and perhaps, other glomerulopathies.

OP.LB.02.01] STRATEGY TO OPTIMIZE SODIUM INTAKE FOR INDIVIDUAL PATIENTS

Objective: Most Americans (90%) have dietary sodium intakes between 2.5 and 5.0 g/d. These limits are coterminous with optimal Cardiovascular (CVD) outcomes and, outcomes do not vary within this range. Beyond those limits, CVD risk increases. The health consequences of raising low, or lowering high intakes, is unknown. Thus, for persons at the extremes of sodium intake, we propose a strategy for their identification, dietary remediation, and ongoing health assessment may benefit as much as10% of the nation's population. Design and method: Epidemiological studies linking sodium intake with subsequent CVD were reviewed. History, physical exam, urine and blood tests can identify patients with sodium intakes < 2.5, and > 5.0 g/d. Dietary modification and/or supplementation can alter sodium intake. Although the strategy proposed is experimental, because its components are safe, and its effects readily assessed, it can be safely applied in clinical settings pending feasible rigorous scientific testing. Results: Persons with sodium intake < 2.5 or > 5. g/d can be identified and treated. Restricted diets and elevated Plasma Renin Activity (PRA), or signs of volume depletion, are associated with low sodium intakes < 2.5. Increased CVD risk is also present at sodium intakes >5.0 g/, but only when associated with hypertension. These patients have suppressed PRA. Sequential spot and, finally, 24-hour urine-analyses, can identify those most likely to benefit from optimtimizing sodium intake through a 1.0 g/d dietary change. Urinary sodium, PRA and blood pressure response should be monitored. Randomized trials – ultimately with hard clinical endpoints - must validate these interventions. Conclusions: The sodium intake of most Americans is optimal, yet 10% with intakes <2.5 or >5.0 g/d are at increased CVD risk. Since health consequences of altering dietary sodium are unknown, any intervention to modify intake is experimental and can and should be evaluated through clinical trials. Nevertheless, concerned and informed patients and physicians may seek to improve health outcomes by increasing or decreasing their sodium intakes. We have described a feasible strategy to identify individual patients for whom proven intervention to optimize sodium intake may be beneficial.

Evaluation of the Sequential Spot Sampler (S3) for time-resolved measurement of PM&amp;lt;sub&amp;gt;2.5&amp;lt;/sub&amp;gt; sulfate and nitrate through lab and field measurements

Abstract. The Sequential Spot Sampler (S3), a newly developed instrument to collect aerosols for time-resolved chemical composition measurements, was evaluated in the laboratory and field for the measurement of particulate sulfate and nitrate. The S3 uses a multi-temperature condensation growth tube to grow individual aerosols to droplets which are then deposited as a ∼ 1 mm diameter dry spot at the end of the growth tube in a 100 µL well of a multi-well plate. The well plate advances automatically to provide a sequence of time-resolved samples. The collected aerosols are subsequently analyzed in the laboratory. The sample is concentrated during the collection process, and the laboratory extraction and analysis steps can be automated. The well plate, as received from the field, is placed onto a needle-based autosampler that adds liquid for sample extraction and injects sample extract from each well onto an ion chromatograph for analysis. Laboratory evaluation for sulfate and nitrate ions showed that poly ether ether ketone (PEEK) used as well plate material does not contribute any artifacts; a 60 min extraction procedure leads to the recovery of sulfate and nitrate from the dry spots at above 95 % extraction efficiency; and samples stored frozen and analyzed up to 23 months later show less than a 10 % change in sulfate and nitrate concentrations. The limit of detection was 0.5 µg m−3 for sulfate and 0.2 µg m−3 for nitrate for a 1 h sampling period. In a month-long field study conducted in southern California, two S3s were deployed alongside a URG denuder–filter-pack and a Particle-Into-Liquid Sampler combined with an Ion Chromatograph (PILS-IC). Collocated S3 sampler concentrations compared by linear regression show good agreement, with r2 = 0.99 and slope = 0.99 (±0.004) µg m−3 for sulfate and r2 = 0.99 and slope = 1.0 (±0.006) µg m−3 for nitrate. When compared to the URG denuder–filter-pack and the PILS-IC, the S3 sulfate and nitrate concentrations yielded correlations above 0.84 for the square of the correlation coefficient and regression slopes close to 1.

Time-resolved characterization of particle associated polycyclic aromatic hydrocarbons using a newly-developed sequential spot sampler with automated extraction and analysis

A versatile and compact sampling system, the Sequential Spot Sampler (S3) has been developed for pre-concentrated, time-resolved, dry collection of fine and ultrafine particles. Using a temperature-moderated laminar flow water condensation method, ambient particles as small as 6 nm are deposited within a dry, 1-mm diameter spot. Sequential samples are collected on a multiwell plate. Chemical analyses are laboratory-based, but automated. The sample preparation, extraction and chemical analysis steps are all handled through a commercially-available, needle-based autosampler coupled to a liquid chromatography system. This automation is enabled by the small deposition area of the collection. The entire sample is extracted into 50–100 μL volume of solvent, providing quantifiable samples with small collected air volumes. A pair of S3 units was deployed in Stockton (CA) from November 2011 to February 2012. PM2.5 samples were collected every 12 h, and analyzed for polycyclic aromatic hydrocarbons (PAHs). In parallel, conventional filter samples were collected for 48 h and used to assess the new system's performance. An automated sample preparation and extraction was developed for samples collected using the S3. Collocated data from the two sequential spot samplers were highly correlated for all measured compounds, with a regression slope of 1.1 and r2 = 0.9 for all measured concentrations. S3/filter ratios for the mean concentration of each individual PAH vary between 0.82 and 1.33, with the larger variability observed for the semivolatile components. Ratio for total PAH concentrations was 1.08. Total PAH concentrations showed similar temporal trend as ambient PM2.5 concentrations. Source apportionment analysis estimated a significant contribution of biomass burning to ambient PAH concentrations during winter.

Design and Development of Two Channel Portable Near Infrared Spectroscopy System for Studies of Cerebral Oxygenation in Prefrontal Cortex of Human Brain

Functional near infrared spectroscopy is a noninvasive, non harmful, low cost and safe optical technique that can be used to study the functional activities in the human brain. This paper describes the development of two channel Near InfraRed Spectroscopy (NIRS) system and the results of the cerebral oxygenation changes during the different cognitive tasks. The objective of the study is to design, develop a portable non-invasive continuous wave NIRS system with dual wave length for determining the hemoglobin content of the blood chromophores during different activities of the prefrontal cortex of the brain. The two channel NIRS system designed and it was tested with 20 healthy, ie.,15 males and 5 females with an average age group of 21±2.25, they were given a 2 different mental tasks such as sequential subtraction (mathematical task) and spot the difference (Visuo-spatial task) and their Oxy &amp; de-Oxy hemoglobin concentration was measured which showed more changes during the task period when compared to relaxation in both left and right part of pre-frontal cortex.

Analysis of Vegetation Cover Changing Trend in Pearl River Basin

The vegetation cover changing trend in Pearl River Basin during 1998-2012 are analyzed based on sequential SPOT VEGETATION data with Maximum Value Composites (MVC) method and linear regression technique. Results show: (1) From 1998 to 2012, the seasonal maximum NDVI changes in Pearl River Basin are obvious, peak appears in September and minimum in February, average is 0.578, the mean maximum NDVI is on the rise during the recent 15 years; the average of maximum NDVI is 0.740, the vegetation cover condition is good, but there is an obvious spatial difference. (2) In recent 15 years, the mean maximum NDVI trend shows that vegetation overall improved, deteriorated partly. Improved area, deteriorated area and invariant area account for 69.80 percent, 2.10 percent and 28.10 percent of the total area respectively.

Design and Laboratory Evaluation of a Sequential Spot Sampler for Time-Resolved Measurement of Airborne Particle Composition.

A new sampling approach has been developed to enable affordable, time-resolved monitoring of particulate chemical compositions, and more generally to provide concentrated samples of airborne particles. Using a newly developed, moderated water-based condensational growth technology, individual particle samples are deposited in a 1-mm diameter dry "spot". The moderated condensation technology enables this collection with minimal temperature rise, providing robust collection for volatile constituents. Measured collection efficiencies are above 95% for particles in the size range from 0.010 μm to 2.5 μm. A set of 20 or more time-resolved samples, plus blanks, may be collected onto a multiwell collection plate. For chemical analysis the plate is returned to the laboratory, and placed directly into a modified autosampler, without extraction or preparation. The autosampler handles the addition of eluent, extraction, and sample injection without user manipulation. This paper presents the design and laboratory evaluation of a 1.5 L/min sampling rate version of this system.

Periodic Wnt1 expression in response to ecdysteroid generates twin-spot markings on caterpillars

Among various pigmentation patterns on caterpillars, sequential spot markings are often observed and used for aposematic colouration. In contrast to adult wings, caterpillar cuticle markings are repeatedly generated at each moult, but little is known about how the patterns are formed and maintained periodically. Here we focus on a silkworm mutant, multi lunar (L), with twin-spot markings on sequential segments. Positional cloning of L and expression analyses reveal that cis-regulatory change in Wnt1 is responsible for the spot patterning. The periodical upregulation of Wnt1 in response to ecdysteroid is detected only in epidermis within spot marking area. We verify by transgenic expression that the ectopic Wnt1 induces the additional pigmentation. Furthermore, the association of Wnt1 expression with spot markings is observed in the wild Bombyx species and swallowtail butterfly Papilio machaon. Taken together, we anticipate that periodic Wnt1 expression may contribute to natural variations of spot patterning on caterpillar cuticle.

Urine biochemistry in the early postoperative period after cardiac surgery: role in acute kidney injury monitoring.

We have recently suggested that sequential urine electrolyte measurement in critically ill patients may be useful in monitoring kidney function. Cardiac surgery is one of the leading causes of acute kidney injury (AKI) in the intensive care unit (ICU). In this paper, we describe the sequential behavior of urine electrolytes in three patients in the early (first 60 hours) postoperative period after cardiac surgery according to AKI status: no AKI, transient AKI, and persistent AKI. We have found that the patient with no AKI had stable and high concentrations of sodium (NaU) and chloride (ClU) in sequential spot samples of urine. AKI development was characterized in the other two patients by decreases in NaU and ClU, which have started early after ICU admission. Transient AKI was marked by also transient and less severe decreases in NaU and ClU. Persistent AKI was marked by the less favorable clinical course with abrupt and prolonged declines in NaU and ClU values. These electrolytes in urine had a behavior like a “mirror image” in comparison with that of serum creatinine. We suggest that sequential urine electrolytes are useful in monitoring acute kidney injury development in the early postoperative period after cardiac surgery.

Identification of Peripherin as a Akt Substrate in Neurons

Activation of Akt-mediated signaling pathways is crucial for survival and regeneration of injured neurons. In this study, we attempted to identify novel Akt substrates by using an antibody that recognized a consensus motif phosphorylated by Akt. PC12 cells that overexpressed constitutively active Akt were used. Using two-dimensional PAGE, we identified protein spots that exhibited increased immunostaining of the antibody. Mass spectrometry revealed several major spots as the neuronal intermediate filament protein, peripherin. Using several peripherin fragments, the phosphorylation site was determined as Ser(66) in its head domain in vitro. Furthermore, a co-immunoprecipitation experiment revealed that Akt interacted with the head domain of peripherin in HEK 293T cells. An antibody against phosphorylated peripherin was raised, and induction of phosphorylated peripherin was observed not only in Akt-activated cultured cells but also in nerve-injured hypoglossal motor neurons. These results suggest that peripherin is a novel substrate for Akt in vivo and that its phosphorylation may play a role in motor nerve regeneration.

A spatial statistical operator applied to multidate satellite imagery for identification of coral reef stress

We examine the potential for a spatial operator to highlight the change in the spatial homogeneity of a coral reef over time from satellite imagery. The Getis statistic may be used to quantify the degree of spatial homogeneity or heterogeneity of a spatial data set. We test the application for sequential SPOT imagery that includes a coral reef in the Savusavu region of Fiji that underwent extensive damage due to an industrial accident between the image dates. The ability of the statistic to capture this damage is evaluated through comparison against a null case of open water with no change. A decadal time sequence of SPOT imagery for the Bunaken region of North Sulawesi is also examined to determine whether the statistic may be useful for image understanding where there is a lack of independent knowledge of the degree of coral stress in the area. For the time series of data analyzed for the Bunaken region, we believe that a change in the spatial statistic applied to SPOT data represents a change in reef heterogeneity. Our premise is that heterogeneity is, at this scale, a surrogate for changes in ‘reef health’ with the assumption that a healthy reef illustrates heterogeneity at the scale of the statistical operator. With additional data, this change detection procedure can be used to identify potential ‘hot spots’ that warrant field examination for potential reef damage. This alternative to per-pixel-based approaches has the advantage that it is relatively insensitive to changes in depth, water constituents and atmospheric variability within the area of the spatial operator.

Long-term work contracts versus sequential spot markets: experimental evidence on firm-specific investment

The length of work contracts may be irrelevant for firm-specific investment if rational behavior generates endogenous job security. In an experiment, we implement such a situation and study actual investment behavior. In contrast to the game-theoretic prediction, we find reduced investment in case of short-term contracting compared to long-term contracting. This is due to nonequilibrium behavior that generates a substantial risk of unemployment if contracts are short-term. Since the effect of nonequilibrium behavior differs between institutions, the length of contract is in fact relevant for firm-specific investment.

Analysis of urban landuse change using sequential aerial photographs and spot data: An example of north Bhubaneswar, Orissa

As urban area undergoes a rapid change it will be necessary to review development and the urban plans once in five years in relation to important public and other decisions taken from time to time. In order to know the trend of development and landuse patterns, analysis of sequential aerial photographs and satellite imagery of different years can be a useful tool for interpretation of various landuses and their comparison, In the present study an attempt has been made to understand the change detection using sequential aerial photographs of 1974 and 1989, and comparison with SPOT data of I988 with the help of ‘USEMAP’ GIS software package.

Urban land use change detection using sequential aerial photographs and spot image case study: Chiangmai, Thailand

In most of the developing countries, cities are expanding due to urbanization. To cope-up with problem, planners/decision makers need up-to-date physical data base for proper planning and management of the cities. Such data base can be generated quickly through aerial/satellite remote sensing techniques. In this ‘Case Study’ of Chiangmai, Thailand, sequential aerial photographs and SPOT image were used for urban landuse change studies. A comparison was also made for the growth studies of SPOT and aerial photographs. The analysis of study revealed that maximum agriculture land was converted to urban landuse. Urban growth of the city found to be 3.5 times less in case of SPOT results compared to aerial photographs. Urban landuse change was observed all around the city.

「内部請負制」は一九世紀イギリスの工場における作業組織を、有効に説明するか?

To mention subcontract has been an answer to the question how the factories were operated in nineteenth century Britain. First, this article examines whether or to what extent this system was prevalent, and second, whether it played the same managerial functions in various industry branches. Finally, in place of subcontract, a different framework in interpretating the nineteenth century employment is proposed. Whether the subcontract system was prevalent or not can be measured by investigating the forms of wages paid to the foremen or skilled workers who were in charge of a group of workers. Some were paid by piece, but they were mostly paid by time. In the latter case, these workers were not subcontractors. More important still was the attitude of skilled workers to subcontract or 'piece-masters', and further to the forms of payment, which differed from industry to industry. These indicate that the subcontact did not carry out the same managerial function throughout all the industries. Further, in spite of these seemingly different attitudes to wages and employment, they have one motive in common, i.e., to maintain the autonomy of skilled workers. Various facts can be interpretated more successfully by using a different framework rather than by subcontract. That is to use the idea of internalisation of production function and the transaction of labour to the manufacturing firms. In these respects, autonomy of skilled workers lies in the intermediate areas between the systematically organised workshops since the end of the nineteenth century and the sequential spot contracts of labour before the Industrial Revolution.

Earth-to-space laser beam transmission for spacecraft attitude measurement

A method for attitude determination of spacecraft by means of an optical technique is presented in which a laser beam is transmitted from a ground station and detected by a TV camera on a satellite. The principle of determining three attitude parameters using the sequential multiple spot images of the laser beam transmitter appearing in the TV camera’s image plane is discussed briefly. Experiments of attitude determination by this method have been conducted, where a TV camera onboard the Japanese Engineering Test Satellite-3 (ETS-3) and a ground-based optical station were used. In the experiments, argon laser transmission from the earth to space and satellite observation by the optical system were done simultaneously. The attitude of this satellite, i.e., a set of pitch, roll, and yaw angles, was determined with high accuracy for some orbits, which permitted us to evaluate the three-axes attitude control system and some attitude control experiments of the satellite.

An Optical, Noncontacting Surface Sensor (Optical Probe)

An optical, noncontacting surface sensor (optical probe) breadboard with a tungsten light source and silicon detectors has detected a change of about 0.1 microm in the axial position of a small surface area from a distance of 4 cm. The optical probe utilizes two diametrically opposed, converging beams from one lens to form temporarily sequential images of a small illuminated spot on the surface whose axial location is to be determined. With the surface at the external probe focus, the sequential spot images are precisely coincident, but they separate in opposite directions as the surface approaches or departs from the probe. Two detectors are arranged to detect the extremely small imbalance in reflected light resulting from image separation, the difference in their outputs providing the distance error signal. The sum of their outputs provides a measure of the probe's departure from normal to the surface. The calculated distance error detectivity (DED) of the probe on a diffuse surface is about 10 nm with a tungsten source, on the order of 0.1 nm with a xenon arc, and even better with a laser. A specular surface provides increased gain and improved DED. Possible applications of the probe are discussed, and the restrictions imposed by the normality adjustment mechanism required on nonflat surfaces are considered.