Bunching Technique Research Articles

Peritoneal Flap Following Lymph Node Dissection in Robotic Radical Prostatectomy: A Novel "Bunching" Technique.

Pelvic lymph node dissection (PLND) is recommended while performing robot-assisted radical prostatectomy (RARP) for patients with localized intermediate or high-risk prostate cancer. However, symptomatic lymphoceles can occur after surgery, adding significant morbidity to patients. Our objective is to describe a novel Peritoneal Bladder Flap Bunching technique (PBFB) to reduce the risk of clinically significant lymphoceles in patients undergoing RARP and PLND. We evaluated 2267 patients who underwent RARP with PLND, dividing them into two groups: Group 1, comprising 567 patients who had the peritoneal flap (PBFB), and Group 2, comprising 1700 patients without the flap; propensity score matching carried out at a 1:3 ratio. Variables analyzed included estimated blood loss (EBL), operative time, postoperative complications, lymphocele formation, and the development of symptomatic lymphocele. The two groups exhibited similar preoperative characteristics after matching. There was no statistically significant difference in the occurrence of lymphoceles between the flap group and the non-flap group, with rates of 24% and 20.9%, respectively (p = 0.14). However, none of the patients in the flap group (0%) developed symptomatic lymphoceles, whereas 2.2% of patients in the non-flap group experienced symptomatic lymphoceles (p = 0.01). We have demonstrated a modified technique for a peritoneal flap (PBFB) with the initial elimination of postoperative symptomatic lymphoceles and promising short-term outcomes.

Step-by-step Peritoneal Bladder Flap Bunching (PBFB) technique: an innovative approach following lymph node dissection in robotic radical prostatectomy.

Robot-assisted radical prostatectomy (RARP) has become a popular surgical approach for localized prostate cancer due to its favorable oncological and functional outcomes, as well as lower morbidity. In cases of intermediate- and high-risk prostate cancer, bilateral pelvic lymphadenectomy (PLND) is recommended as an adjunct to RARP (1-3). Despite its benefits, PLND can lead to surgical complications, with postoperative lymphocele formation being the most common. Most postoperative lymphoceles are clinically insignificant with variable incidence, reaching up to 60% of cases 4. However, a small percentage of patients 2-8% may experience symptomatic lymphoceles (SL), which can cause significant morbidity (4, 5). We perform our RARP technique with our standard approach in all patients (6). After vesicourethral anastomosis a modified PF created to prevent symptomatic lymphocele. We start by suturing the peritoneal fold on the right side, medially to the vas deferens, followed by a similar stitch on the left side to approximate the edges in the midline. A running suture bunches the bladder peritoneum from both sides, passing through the pubic bone periosteum to secure it in place (7). This approach keeps the lateral pelvic gutters open for lymphatic drainage, while allowing fluid drainage from the true pelvis into the abdomen. A pelvic ultrasound was done for all patients at 6 weeks post operative, and additional clinical follow-up was carried out at 3 months following surgery. We have demonstrated a modified technique of peritoneal flap (PBFB) with an initial decrease in postoperative symptomatic lymphoceles, the technique is feasible, safe, does not add significant morbidity, and does not require a learning curve.

Beam dynamics optimization for high gradient beam driven plasma wakefield acceleration at SPARC-LAB

The SPARC_LAB test facility at the LNF (Laboratori Nazionali di Frascati, Rome) holds a high brightness photo-injector used to investigate advanced beam manipulation techniques. High brightness electron bunch trains (so-called comb beams) can be generated striking on the photo-cathode of a Radio Frequency (RF) photo-injector with a ultra-short UV laser pulse train in tandem with the velocity bunching technique. Beam dynamics studies have been performed with the aim of optimizing the dynamics of the double beam (driver and witness) used to perform particle driven plasma wake field acceleration (PWFA). In this scenario different scans on beam parameters were carried on adopting the ASTRA simulation code, in order to optimize the witness beam quality and improve the plasma booster stage performances. A benchmark of the simulations has been then performed, reproducing the experimental data obtained from the optimization of machine performances, and a good agreement was found.

Electron beam analysis and sensitivity studies for the EuPRAXIA@SPARC_LAB RF injector

The interest in plasma-based accelerators as drivers of user facilities is growing worldwide thanks to their compactness and reduced costs. The EuPRAXIA@SPARC_LAB collaboration is preparing a technical design report for a multi-GeV plasma-based accelerator with outstanding electron beam quality to pilot an X-ray FEL, the most demanding in terms of beam brightness. The beam dynamics has been studied aiming to a reliable operation of the RF injector to generate a so-called comb-beam with 500 MeV energy suitable as driver of the Beam-driven Plasma Wakefield Accelerator. A case of interest is the generation of a trailing bunch with 1 GeV energy, less than 1 mm-mrad transverse emittance and up to 2 kA peak current at the undulator entrance. The comb-beam is generated through the velocity bunching technique, an RF compression tool that enables high brightness beams within relatively compact machine. Since it is based on a rotation of the beam phase space inside the external RF fields, it could be particularly sensitive to amplitude and phase jitters in the RF injector. The electron beam dynamics and the machine sensitivity to the possible jitters are presented in terms of effect on the beam quality so to provide the basis for the jitter tolerances.

Exploratory Study on High-Efficiency High-Power W-Band Klystron Based on Kladistron Technology

To achieve tens of kilowatt (kW) output power, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}$ </tex-math></inline-formula> -band klystron usually employs a large beam tunnel to accommodate high current. The deteriorated effective impedance of the cavity could be reenhanced by adopting extended interaction (EI) cavities. In this article, a new approach utilizing simple fundamental modes in cascaded single-gap cavities for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}$ </tex-math></inline-formula> -band klystron is proposed and discussed. Although the effective impedance of each cavity is far lower than its EI klystron (EIK) counterpart, this disadvantage could be efficiently compensated by densely populating those single-gap cavities using the kladistron technology previously conceived for the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${C}$ </tex-math></inline-formula> - or <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${X}$ </tex-math></inline-formula> -band high-efficiency (HE) klystrons. However, kladistron is rarely reported and normally regarded as less a promising HE bunching technique overwhelmed by the self-excitation issues caused by adjacent mode coupling. Fortunately, such instability could be naturally suppressed in a higher frequency regime, so further exploration of kladistron technology is intriguing. In this article, an exemplary 30-kW <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}$ </tex-math></inline-formula> -band klystron equipped with big circular beam tunnel is designed using the kladistron technology, which finally shows no instability issues in 3-D particle-in-cell (PIC) simulation. This novel device delivers up to 37% electronic efficiency and 24% RF efficiency, validating that the kladistron concept is well suited for this millimeter-wave amplifier, which indicates possible HE substitutes for existing EIK technology.

Saving Lives by Tying Hands: The Unexpected Effects of Constraining Health Care Providers

Abstract We study how emergency department (ED) doctors respond to incentives to reduce wait times. We use bunching techniques to study an English policy that imposed strong incentives to treat patients within four hours. The policy reduced time spent in the ED by 21 minutes for affected patients yet caused doctors to increase treatment intensity and admit more patients. We find a striking 14% reduction in mortality. Analysis of patient severity and hospital crowding strongly suggests it is the wait time reduction that saves lives. We conclude that, despite distorting medical decisions, constraining ED doctors can induce cost-effective reductions in mortality.

Effect of the Sound Source Position Error on Distribution Characteristics of Underwater Shock Wave Bunching Sound Field

Curved reflection bunching technique of underwater plasma sound source (UPSS) uses the geometric characteristics of the curved reflector to reflect and bunching intense sound shock wave, so the center position error of the sound source is one of the important factors affecting the bunching performance of the shock wave. In this paper, the cause of the sound source position error is analyzed in detail, and nonlinear finite element software ANSYS/LS-DYNA (dynamic analysis software developed by LSTC) is used to establish the model of the shock wave bunching sound field. Through numerical simulations, the shock wave bunching sound field distribution characteristics under the influence of different position errors are comprehensively simulated, and the bunching performance of the shock wave and its influence law are deeply analyzed according to the simulation results. It provides guidance for reasonably controlling the machining error and installation error of the reflector and discharge electrode, estimating the effective discharge times of the discharge electrode, and formulating the design process.

An ultra-compact x-ray free-electron laser

In the field of beam physics, two frontier topics have taken center stage due to their potential to enable new approaches to discovery in a wide swath of science. These areas are: advanced, high gradient acceleration techniques, and x-ray free electron lasers (XFELs). Further, there is intense interest in the marriage of these two fields, with the goal of producing a very compact XFEL. In this context, recent advances in high gradient radio-frequency cryogenic copper structure research have opened the door to the use of surface electric fields between 250 and 500 MV m−1. Such an approach is foreseen to enable a new generation of photoinjectors with six-dimensional beam brightness beyond the current state-of-the-art by well over an order of magnitude. This advance is an essential ingredient enabling an ultra-compact XFEL (UC-XFEL). In addition, one may accelerate these bright beams to GeV scale in less than 10 m. Such an injector, when combined with inverse free electron laser-based bunching techniques can produce multi-kA beams with unprecedented beam quality, quantified by 50 nm-rad normalized emittances. The emittance, we note, is the effective area in transverse phase space (x, p x /m e c) or (y, p y /m e c) occupied by the beam distribution, and it is relevant to achievable beam sizes as well as setting a limit on FEL wavelength. These beams, when injected into innovative, short-period (1–10 mm) undulators uniquely enable UC-XFELs having footprints consistent with university-scale laboratories. We describe the architecture and predicted performance of this novel light source, which promises photon production per pulse of a few percent of existing XFEL sources. We review implementation issues including collective beam effects, compact x-ray optics systems, and other relevant technical challenges. To illustrate the potential of such a light source to fundamentally change the current paradigm of XFELs with their limited access, we examine possible applications in biology, chemistry, materials, atomic physics, industry, and medicine—including the imaging of virus particles—which may profit from this new model of performing XFEL science.

Bunch technique for semionline with two groups of items

Bunch technique for semionline with two groups of items is proposed in this paper. Algorithm to solve this problem is to distribute items from the first group bunch approach and after that apply LS-algorithm to assign items from the se cond group. In order to prove the estimation of our algorithm is introduced different types of bunches to distribute all items from the first group such a way that only one of the entered types of bunches are obtained. During the second stage we use LS with worst case performance is at most 17/9.

Best practice for deltoid intramuscular injections in older adults: Study in cadavers

Most injectable vaccines are administered via deltoid intramuscular injection (IMI). Nursing students are taught to perform deltoid IMI in their entry-to-practice education program. However, best practice evidence is lacking regarding specific techniques of deltoid IMI, and students are often taught what their instructor was taught in his/her own entry-to-practice (ETP) program. Nursing textbooks provide instructions and diagrams for how to perform deltoid IMI, but rarely cite underpinning empirical evidence. This study tested the injection techniques of bunching (squeezing) or flattening (stretching) the deltoid muscle before administering IMI using medical school donated cadavers. Flattening technique resulted in over-penetration of deltoid injections more than 85% of the time in these older adults, whereas nearly 80% of deltoid IMI are successful using bunching technique. Body mass index (BMI) and needle length are also crucial considerations when administering deltoid IMI. Nurses, and other health professionals who use deltoid IMI to administer vaccines to older adults, should determine the client’s body mass index to select the appropriate needle length. Based on these results, bunching technique is recommended. Flattening technique is not recommended for older adults with a BMI &lt; 30.

Under Pressure? Performance Evaluation of Police Officers as an Incentive to Cheat: Evidence from Drug Crimes in Russia

This paper provides an empirical analysis of possible manipulations of amounts of seized drugs, based on a unique dataset that contains full information on drug crimes in Russia reported during 2013-2014. First, using a standard bunching estimator, I investigate the incentives for police officers to manipulate and find that the motivation most likely arises from the officers’ performance evaluation system. Second, applying a novel bunching technique, I determine that police officers are more likely to manipulate the drug amounts seized from repeat offenders. The overall effect of manipulation is an additional year of incarceration, and this is not dependent on a guilty plea.

Few-femtosecond electron beam with terahertz-frequency wakefield-driven compression

We propose and demonstrate a novel method to produce few-femtosecond electron beam with relatively low timing jitter. In this method a relativistic electron beam is compressed from about 150 fs (rms) to about 7 fs (rms, upper limit) with the wakefield at THz frequency produced by a leading drive beam in a dielectric tube. By imprinting the energy chirp in a passive way, we demonstrate through laser-driven THz streaking technique that no additional timing jitter with respect to an external laser is introduced in this bunch compression process, a prominent advantage over the conventional method using radio-frequency bunchers. We expect that this passive bunching technique may enable new opportunities in many ultrashort-beam based advanced applications such as ultrafast electron diffraction and plasma wakefield acceleration.

How do taxpayers respond to a large kink? Evidence on earnings and deduction behavior from Austria

This paper contributes to recent literature examining the importance of the different channels through which taxable income responses occur. Using bunching techniques and exploiting a large kink point where marginal tax rates increase by as much as 38 percentage points, I first recover modest gross earnings responses of Austrian employees. Next, I demonstrate that when accounting for deduction behavior, the additional mass of wage earners at the kink increases by around 50%. I show direct evidence of wage earners targeting the kink with their deduction claiming. Finally, I contrast the responses of wage earners with those of self-employed taxpayers, and find that access to different tax adjustment channels corresponds with different adjustment behavior. In sum, my results suggest that distinguishing between earnings and deduction responses matters even for taxpayers with only limited possibilities to shelter taxable income.

Experimental progress in positronium laser physics

The field of experimental positronium physics has advanced significantly in the last few decades, with new areas of research driven by the development of techniques for trapping and manipulating positrons using Surko-type buffer gas traps. Large numbers of positrons (typically ≥106) accumulated in such a device may be ejected all at once, so as to generate an intense pulse. Standard bunching techniques can produce pulses with ns (mm) temporal (spatial) beam profiles. These pulses can be converted into a dilute Ps gas in vacuum with densities on the order of 107 cm−3 which can be probed by standard ns pulsed laser systems. This allows for the efficient production of excited Ps states, including long-lived Rydberg states, which in turn facilitates numerous experimental programs, such as precision optical and microwave spectroscopy of Ps, the application of Stark deceleration methods to guide, decelerate and focus Rydberg Ps beams, and studies of the interactions of such beams with other atomic and molecular species. These methods are also applicable to antihydrogen production and spectroscopic studies of energy levels and resonances in positronium ions and molecules. A summary of recent progress in this area will be given, with the objective of providing an overview of the field as it currently exists, and a brief discussion of some future directions.Graphical abstract

Tax Bunching by Owners of Small Corporations

We study the options for income shifting by owners of small corporations in the Netherlands using bunching techniques on individual tax records over the period 2007–2011. We find that the distribution of gross labour income strongly peaks at the minimum level of the reference wage, specified in the tax code. Next, taxable labour income bunches at the cut-offs of the tax brackets. The elasticity of taxable income at the top tax cut-off ranges from 0.06 to 0.11. Distributed profits strongly responded to the temporary tax cut from 25 to 22% in 2007, which doubled tax revenues on dividends. We reconfirm the importance of intertemporal income shifting for business owners.

Generation of high brightness electron beam by brake-applied velocity bunching with a relatively low energy chirp

Velocity bunching technique is a tool for compressing electron beams in modern high brightness photoinjector sources, which utilizes the velocity difference introduced by a traveling rf wave at a relatively low energy. It presents peculiar challenges when applied to obtain a beam with a very high current and a low transverse emittance in photoinjectors. The main difficulty is to control the emittance oscillations of the beam during high compression, which can be naturally considered as an extension of the emittance compensation process. In this paper, a brake-applied velocity bunching scheme is proposed, in which the electron bunch is injected into the accelerator with a low gradient at a deceleration phase, like “a brake is applied”, afterward slips to an acceleration phase. During the entire compression process, the energy chirp induced by the rf field is mostly linear, which retains a symmetric electron beam in the temporal distribution. The key point of the new scheme is a smaller energy chirp at a lower beam energy compared with the normal velocity bunching. Besides, the beam energy chirp before compression is dominated by the linear correlation due to a relatively short laser pulse. With a symmetric bunch compression, the transverse emittance could be compensated even if the compression factor is extremely high. As to our simulation results, the peak current of the compressed beam can be above 1.8 kA for the charge of 800 pC with a good emittance compensation.

An experimental validation of Feynman-Alpha Method’s Bunching Technique in the IPEN/MB-01 Nuclear Reator

In this paper we perform an experimental verification of the Bunching Technique proposed by Misawa et al. (1962) to deal with limited time in reactor experiments. This method, widely used in nuclear experiments when the Feynman-Alpha Method is present, permits a significant economy on the measuring time, but lacks broader experimental validation. This issue is addressed in this work. As this work is aimed to those who are already familiar with the Feynman-Alpha Method and its Bunching Technique, only a brief explanation of this method is provided, as the paper focuses on the comparison of experimental and theoretical results. It is also important to stress that the data used was acquired in the IPEN/MB-01 reactor.

A hybrid approach for generating ultra-short bunches for advanced accelerator applications

Generation of electron beams with high phase-space density, short bunch length and high peak current is an essential requirement for future linear colliders and bright electron beam sources. Unfortunately, such bunches cannot be produced directly from the source since forces from the mutual repulsion of electrons would destroy the brilliance of the beam within a short distance. Here, we detail a beam dynamics study of a two-stage compression scheme that can generate ultra-short bunches without degrading the beam quality. In the first stage, a magnetized beam is compressed with a velocity bunching technique in which the longitudinal phase space is rotated so that electrons on the bunch tail become faster than electrons in the bunch head. In the second stage, the beam is further compressed with a magnetic chicane. With the aid of numerical simulations we show that our two-staged scheme is capable to increase the current of a 50pC bunch by a notable factor of 100 (from 15A to 1.5kA) while the emittance growth can be suppressed to 1% with appropriate tailoring of the initial beam distribution.

An improved Feynman-α analysis with a moving–bunching technique

ABSTRACTThe bunching technique has been widely utilized in Feynman-α neutron correlation analysis to synthesize neutron counts within longer gate widths by bunching time-sequence neutron counts stored in multichannel scaler channels. An alternative technique referred to as “moving–bunching technique” was proposed to reduce a statistical scatter of variance-to-mean ratio of neutron counts. The conventional bunching technique has no overlap of adjacent bunches, while the present technique makes adjacent bunches overlap as long as possible similarly to the moving average technique. A Feynman-α experiment was performed in the UTR-KINKI, to confirm the advantage of the proposed bunching technique. When a neutron detector was placed far from the core, a Feynman-α analysis with the conventional bunching technique led to a scattered variance-to-mean ratio from which the prompt-neutron decay constant was never determinable. However, another analysis with the proposed technique remarkably reduced the above scatter and enabled the determination of the decay constant. For a neutron detector close to the core, the proposed technique also reduced statistical error of the decay constant.

Chunking and Storing of Sensitive Data in Public Cloud for Hospital Management

Big data refers to the dynamic, bombastic and different bulk of data being produced by individuals and machines. It requires new, innovative and scalable technology to gather, emcee and analytically proctitis the huge amount of data gathered in order to derive real-time business insights that associate to consumers, risk, profit, execution, productivity management and enhanced shareholder value. If the data is shown to the other side people means, it violates the privacy of the information. So it is need to provide the privacy over the micro data. Here we consider the dataset as electronic health care records, which contain the personal sensitive information's. Most of the existing systems are failed because of scalability, utilization of data and security of data on the public cloud. In proposed system it is need to store the data in an secure format. For that an effective system or infrastructure is used. If the information is transfer from one place to another means how to securely transfer the data and also how to provide the privacy over the sensitive information's. For adminicle, they do not need to build their own up infrastructure. It can reduce the cost of consumption. All the data's are stored on the cloud in the encrypted form by using an efficient encryption algorithm. Hybrid bunching technique is introduced for overcome the problem of existing system. To gain high scalability of data Map Reduce algorithm is used. For keeping both data confidentiality and patient's identity on public cloud a organization novel authorized accessible privacy model is used, which can provide the specific access of data on public cloud by setting an access tree.