Sharp Loss Research Articles

SU‐F‐18C‐03: Loss of Image Sharpness in CT Bone Imaging Due to Positioning Within the Scan Field of View – Possible Solutions

Purpose:To demonstrate how both the positioning of an object in the scan field of view (SFOV) and the size of the reconstructed field of view (RFOV) can both significantly affect and degrade the image sharpness.Methods:Clinical CT scans of the shoulders and elbows were inspected for image sharpness. GE scanners were used for the imaging with a “Bone Plus” reconstruction algorithm. In all scans the anatomy of interest was significantly displaced from the center of the SFOV (away from the scanner iso‐center). Radial and azimuthal image sharpness measurements using the Modulation Transfer Function (MTF) were made using the same RFOV at the center of the SFOV and at varying distances from the center. These MTF measurements were also made with varying values of the RFOV.Results:Clinical images with the bone anatomy of interest positioned farther from the center of the SFOV showed increasing image softness occasionally to the point of being non‐diagnostic. The MTF measurements showed that the resolution degraded significantly, by more than a factor of 2, moving from the center toward the periphery of the SFOV: from 12 cycles/cm to less than 6 cycles/cm at distances of 15 cm or more from the center of the SFOV. Increasing the RFOV beyond 20 cm also degraded the resolution, though less significantly.Conclusion:When preservation of bone detail is important one must not only use the proper bone reconstruction algorithm, but also must keep the body part as close to the center of the SFOV as possible. Though this may be difficult with some imaging tasks, such as imaging of the shoulder and elbow, every effort should be made to this end. For the best resolution, the RFOV should also be kept small, ideally to 20 cm or less.Partial research funding from GE HealthCare.

Calcium-looping for post-combustion CO2 capture. On the adverse effect of sorbent regeneration under CO2

The multicyclic carbonation/calcination (c/c) of CaO solid particles at high temperature is at the basis of the recently emerged Calcium-looping (CaL) technology, which has been shown to be potentially suitable for achieving high and sustainable post-combustion CO2 capture efficiency. Despite the success of pilot plant projects at the MWth scale, a matter of concern for scaling-up the CaL technology to a commercial level (to the GWth scale) is that the CaO carbonation reactivity can be recovered only partially when the sorbent is regenerated by calcination at high temperatures (around 950°C) as required by the CO2 high concentration in the calciner. In order to reactivate the sorbent, a novel CaL concept has been proposed wherein a recarbonator reactor operated at high temperature/high CO2 concentration leads to further carbonation of the solids before entering into the calciner for regeneration. Multicyclic thermogravimetric analysis (TGA) tests demonstrate the feasibility of recarbonation to reactivate the sorbent regenerated at high calcination temperatures yet at unrealistically low CO2 partial pressure mainly because of technical limitations concerning low heating/cooling rates. We report results from multicyclic c/c and carbonation/recarbonation/calcination (c/r/c) TGA tests at high heating/coling rates and in which the sorbent is regenerated in a dry atmosphere at high CO2 partial pressure. It is shown that at these conditions there is a drastic drop of CaO conversion to a very small residual value in just a few cycles. Moreover, the introduction of a recarbonation stage has actually an adverse effect. Arguably, CaCO3 decomposition in a CO2 rich atmosphere is ruled by CO2 dynamic adsorption/desorption in reactive CaO (111) surfaces as suggested by theoretical studies, which would preclude the growth of the regenerated CaO crystal structure along these reactive surfaces, and this effect would be intensified by recarbonation. Nevertheless, the presence of H2O in the calciner, which is also adsorbed/desorbed dynamically in CaO reactive planes, would shield CO2 adsorption/desorption thus mitigating the deeply detrimental effect of CO2 on the carbonation reactivity of the regenerated CaO structure. Oxy-combustion, which produces a significant amount of H2O, is currently used in pilot-scale plants to raise the temperature in the calciner. Auxiliary techniques are being explored to help heating the partially carbonated solids since oxyxombustion represents an important penalty to the CaL technology. Our study suggests that steam injection would be necessary in a dry calciner environment to avoid a sharp loss of CaO conversion if the sorbent is regenerated at high CO2 partial pressure.

Exergy analysis and the energy saving mechanism for coal to synthetic/substitute natural gas and power cogeneration system without and with CO2 capture

The energy saving mechanism and the potential of efficiency improvement for coal to synthetic/substitute natural gas and power plant with different schemes and CO2 capture is disclosed through exergy analysis, and the effects of key parameters on exergy losses and system performance are investigated. Scheme A represents the system without CO2 capture but with a full syngas component adjustment and partial recycle of the chemical unconverted gas, Scheme B represents the system without CO2 capture and syngas component adjustment but with partial recycle of the chemical unconverted gas, and Scheme C represents the SNG and power cogeneration with CO2 capture and partial recycle of the chemical unconverted gas but without syngas component adjustment. Results show that the exergy efficiencies of Scheme A, B and C range from 56% to 62%, 57% to 67%, 52% to 62%, respectively. Coal gasification, water–gas-shift process, SNG methanation, and fuel combustion in combined cycle are identified as the main sources of exergy losses. Compared with Scheme A, the exergy efficiency of Scheme B is higher due to the avoidance of exergy losses from syngas adjustment. Scheme C is less energy efficient than Scheme B because of the CO2 capture. Compared with single product systems, the total exergy input of Scheme A, B and C can be reduced by 7.0–11.0%, 14.0–19.0%, 15.0–21.0%, respectively assuming the same product output. The chemical to power output ratio (CPOR) will impact the exergy losses of the whole plant greatly. For all schemes, with the increasing CPOR, the exergy losses for chemical synthesis island will increase whereas the exergy losses for power island will decrease. Especially high CPOR will cause sharp exergy losses of chemical synthesis island. The coupling between exergy losses for chemical synthesis and power islands leads to an optimal CPOR making the total exergy losses of the plant minimal and the system efficiency maximized. The results presented in this paper can help to confirm the potential of system integration and can be a guide for system integration.

Labor Union Political Strategy in an Era of Decline and Revitalization

U.S. labor unions faced sharp membership losses over the last few decades, and some responded by ushering in a new, revitalized model of organizing. Yet we know little about how these forces may be shaping the political activities of the labor movement. Has crisis prompted unions to take aim at public policies inhibiting union vitality, or have unions turned outward to embrace broader social causes? This paper uses an original dataset of union appearances in congressional hearings to analyze unions’ legislative advocacy activities. Findings suggest substantial differences between those unions that are likely to appear in hearings on core labor‐related topics and those that appear in hearings on broad social issues: AFL‐CIO unions are more likely to participate in hearings on core labor issues, while unions commonly cited as “revitalized” and public sector unions are more likely to appear in hearings on broad social issues.

Autoimmune pancreatitis: Multimodality non-invasive imaging diagnosis.

Autoimmune pancreatitis (AIP) is characterized by obstructive jaundice, a dramatic clinical response to steroids and pathologically by a lymphoplasmacytic infiltrate, with or without a pancreatic mass. Type 1 AIP is the pancreatic manifestation of an IgG4-related systemic disease and is characterized by elevated IgG4 serum levels, infiltration of IgG4-positive plasma cells and extrapancreatic lesions. Type 2 AIP usually has none or very few IgG4-positive plasma cells, no serum IgG4 elevation and appears to be a pancreas-specific disorder without extrapancreatic involvement. AIP is diagnosed in approximately 2%-6% of patients that undergo pancreatic resection for suspected pancreatic cancer. There are three patterns of autoimmune pancreatitis: diffuse disease is the most common type, with a diffuse, "sausage-like" pancreatic enlargement with sharp margins and loss of the lobular contours; focal disease is less common and manifests as a focal mass, often within the pancreatic head, mimicking a pancreatic malignancy. Multifocal involvement can also occur. In this paper we describe the features of AIP at ultrasonography, computed tomography, magnetic resonance and positron emission tomography/computed tomography imaging, focusing on diagnosis and differential diagnosis with pancreatic ductal adenocarcinoma. It is of utmost importance to make an early correct differential diagnosis between these two diseases in order to identify the optimal therapeutic strategy and to avoid unnecessary laparotomy or pancreatic resection in AIP patients. Non-invasive imaging plays also an important role in therapy monitoring, in follow-up and in early identification of disease recurrence.

Local smoothing for the Schrödinger equation with a prescribed loss

We consider a family of surfaces of revolution, each with a single periodic geodesic which is degenerately unstable. We prove a local smoothing estimate for solutions to the linear Schrödinger equation with a loss that depends on the degeneracy, and we construct explicit examples to show our estimate is saturated on a weak semiclassical time scale. As a byproduct of our proof, we obtain a cutoff resolvent estimate with a sharp polynomial loss.

BIFURCATION CONTROL OF A PREDATOR–PREY MODEL BASED ON NUTRITION KINETICS

The existence conditions of Hopf bifurcation for a predator–prey model based on nutrition kinetics are given. The two results may appear as follows: one is that the model has a stable periodic trajectory from Hopf bifurcation, which shows the system is in an ecological balance; the other is that periodic trajectory from Hopf bifurcation is unstable, which indicates the system is in a sharp or catastrophic loss of stability. For the latter, a bifurcation controller is designed to make the periodic trajectory stable. Finally, some simulations are carried out to prove the results.

Improvement of microwave absorption for PAni/HA/TiO2 /Fe3 O4 nanocomposite after chemical treatment

In order to obtain efficient microwave absorbers that possess high conductivity, dielectric and magnetic properties, hexanoic acid doped polyaniline (PAni) nanocomposites which contain different ratios of ferum (II) oxide (Fe3O4) and titanium dioxide (TiO2) nanoparticles were successfully prepared by in situ chemical polymerization through template free method. Chemical structure, conductivity, morphology, thermal stability, magnetic properties, and amorphous/ crystalline behavior of PAni nanocomposites were characterized by Fourier transform infrared spectrometer (FTIR), four point probe, field emission scanning electron microscope (FESEM), thermal gravimetric analysis (TGA), vibrating samples magnetometer (VSM), and X-ray diffractometer (XRD), respectively. From this study, conductivity was significantly improved from 8.48 3 10 24 21.23 3 10 22 S/cm for PAni nanocomposites without any chemical treatment (during addition of Fe3O4) to 3.58 3 10 22 24.77 3 10 22 S/ cm for those with chemical treatment. PAni nanocomposites with chemical treatment show a narrow sharp reflection loss (RL) peak with high absorption (248.9 dB) at lower frequency due to the limited individual Fe3O4 nanoparticles outside the nanorods/nanotubes as proved by the new proposed mechanism (Fig. 5), while it shows a broad RL peak with poor absorption (213 dB) at higher frequency for those without chemical treatment. The novelty of this research has been focused on PAni with chemical treatment which yield better microwave absorption property (99.999% absorption), combination of high conductivity (3.58 3 10 22 24.77 3 10 22 S/cm), high heterogeneity and moderate magnetization (Ms 58.87–28.49 emu/g) compare to the PAni without chemical treatment. POLYM. COMPOS., 34:1186–1194, 2013. V C 2013 Society of Plastics Engineers

SP0026 Ultrasound Assessment of the Cartilage

Musculoskeletal ultrasound (US) is a valuable imaging modality for detecting and quantifying a range of joint pathologies occurring in rheumatic diseases (1-2). In inflammatory arthritis and in osteoarthritis (OA) it...

탈휘발화 과정에서 혼탄의 반응률과 열적 거동에 관한 연구

본 연구 목적은 탈휘발화 과정에서의 역청탄과 아역청탄의 혼탄 열중량 곡선을 예측 하는 것이다. TSL (Thermal Shock Large) TGA를 통하여 실험을 수행 하였으며, 반응속도상수 분석은 Coats-redfern 방법을 이용하였다. 도출된 반응속도상수를 기반으로 단일탄의 Sum Method에 대한 일차적 검증을 하였으며, 혼탄시의 TG curve를 WSM(Weight Sum Method)와 저자가 제시한 MWSM (Modified Weight Sum Method)를 사용하여 예측 및 비교하였다. WSM 및 MWSM를 통한 예측결과와 TG curve 실험결과의 정량적인 비교를 위해 Linear least square method를 사용하였다. TG curve 상에서 서로 다른 기울기를 가지는 경우와 많은 휘발분의 방출로 인한 급격한 질량감소가 나타나는 구간의 경우 MWSM이 WSM 보다 실험결과에 더 정확한 결과를 예측함을 확인하였다. 탈휘발 과정에서의 혼탄의 열적 거동은 단일탄의 특성에서부터 예측할 수 있음을 확인할 수 있었다. The objective of this research is to predict the TG curve of blends of bituminous coal and sub-bituminous coal during devolatilization. TSL (Thermal Shock Large) TGA was used for Experiments, and Coats-redfern method was used for reaction order calculation. Based on reaction order, sum method was verified to be suitable for a single coal, then, prediction and comparison of TG curve of coal blends was conducted using both of WSM (Weight Sum Method) and MWSM (Modified Weight Sum Method), where the latter was developed in this research. The presented experiment results and WSM & MWSM were showed to be reasonable using linear least square method. MWSM performed more accurately than WSM for the case that TG curve had different slopes and the case that sharp weight loss happened due to release of volatile matter. The results showed that it's possible to predict the thermal behavior of coal blends during devolatilization based on the thermal behavior of single coals.

Tuberculosis of the genitourinary system-Urinary tract tuberculosis: Renal tuberculosis-Part I

Tuberculosis (TB) remains a worldwide scourge and its incidence appears to be increasing due to various factors, such as the spread of human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS). The insidious onset and non-specific constitutional symptoms of genitourinary tuberculosis (GUTB) often lead to delayed diagnosis and rapid progression to a non-functioning kidney. Due to hematogenous dissemination of TB, there is a potential risk of involvement of the contralateral kidney too. Imaging plays an important role in the making of a timely diagnosis and in the planning of treatment, and thus helps to avoid complications such as renal failure. Imaging of GUTB still remains a challenge, mainly on account of the dearth of literature, especially related to the use of the newer modalities such as magnetic resonance imaging (MRI). This two-part article is a comprehensive review of the epidemiology, pathophysiology, and imaging findings in renal TB. Various imaging features of GUTB are outlined, from the pathognomonic lobar calcification on plain film, to finer early changes such as loss of calyceal sharpness and papillary necrosis on intravenous urography (IVU); to uneven caliectasis and urothelial thickening, in the absence of renal pelvic dilatation, as well as the hitherto unreported ‘lobar caseation’ on ultrasonography (USG). Well-known complications of GUTB such as sinus tracts, fistulae and amyloidosis are described, along with the relatively less well-known complications such as tuberculous interstitial nephritis (TIN), which may remain hidden because of its ‘culture negative’ nature and thus lead to renal failure. The second part of the article reviews the computed tomography (CT) and MRI features of GUTB and touches upon future imaging techniques along with imaging of TB in transplant recipients and in immunocompromised patients.

Controlled synthesis of Au-loaded Fe3O4@C composite microspheres with superior SERS detection and catalytic degradation abilities for organic dyes

Bifunctional Au-loaded Fe3O4@C composite microspheres were controllably synthesized by coating of Au nanoparticles (NPs) on the surface of the poly(diallyldimethylammonium chloride) (PDDA) functionalized Fe3O4@C microspheres. The amount of Au loading can be effectively tuned by altering the feeding amounts of solution Au NPs or further growth. The obtained Au-loaded Fe3O4@C composite microspheres exhibit both superior surface-enhanced Raman scattering (SERS) sensitivity and catalytic degradation activity for organic dyes. The SERS signal intensity of methylene blue (MB) distinctly enhances with the increase of Au loading, which endows increased Raman 'hot spots' and provides a significant enhancement of the Raman signal through electromagnetic (EM) field enhancements. Furthermore, the catalytic experiments of the Fe3O4@C@Au composite microspheres with the highest Au loading demonstrate that the model organic dye of MB molecules could be degraded within 10 min and the catalytic activity could be recovered without sharp activity loss in six runs, which indicates their superior catalytic degradation activity. The reason could be mainly ascribed to the synergistic effects of small size of Au NPs, the good adsorption behavior of carbon layers and the excellent dispersivity of the composite microspheres induced by the sandwiched carbon layers. The results indicate that the bifunctional Au-loaded Fe3O4@C composite microspheres could be served as promising materials in wastewater treatment.

Plasmin‐dependent proteolysis of tissue factor pathway inhibitor in a mouse model of endotoxemia

The development of a procoagulant state in sepsis, owing to aberrant expression of tissue factor (TF) and a sharp decrease in the level of its major inhibitor, TF pathway inhibitor (TFPI), could lead to microthrombotic organ failure. The mechanism for the decline in TFPI activity in the lung could involve plasmin-mediated cleavage of the inhibitor. To investigate the effect of plasmin generation on lung-associated TFPI activity, in normal conditions and during infusion of endotoxin (lipopolysaccharide [LPS]) in mice. Plasmin generation and TFPI activity were assayed in the lungs of mice deficient in tissue-type plasminogen (Plg) activator (t-PA) or Plg, at 2 h after LPS or saline injection. The sharp loss of lung-associated TFPI activity at 2 h after LPS challenge paralleled the abrupt increase in plasmin generation. TFPI activity was significantly retained in both t-PA(-/-) and Plg(-/-) mice, which are unable to generate plasmin. The increased plasmin generation during the early stages of sepsis could cleave/inactivate TFPI and thus lead to thrombotic complications.

Utility of respiratory‐navigator‐rejected k‐space lines for improved signal‐to‐noise ratio in three‐dimensional cardiac MR

To develop and evaluate a technique that uses the k-space lines rejected by prospective respiratory navigator (NAV) to improve the signal-to-noise ratio (SNR) without increasing the scan time. In conventional image reconstruction, the motion-corrupted k-space lines rejected by the NAV are not used. In this study, a set of translational motion parameters for the NAV-rejected lines and a phase-corrected average for the k-space line are estimated jointly using a maximum-likelihood approach and the information from the corresponding accepted k-space lines. Left coronary artery images were acquired in 10 healthy adult subjects, and the proposed approach incorporating the NAV-rejected lines was compared with the conventional dataset with NAV-accepted lines only, as well as a simple average of all k-space lines, in terms of SNR, normalized vessel sharpness and qualitative image scores on a four-point scale (1 = poor, 4 = excellent). Late gadolinium enhancement images of the left atrium were also acquired in 21 patients with atrial fibrillation pre- or post-pulmonary vein isolation. Images reconstructed with the proposed, conventional, and simple averaging methods were compared in terms of SNR, and subjective image quality on a four-point scale. For coronary MRI, there was a significant improvement in SNR with the proposed technique, but no significant difference in normalized vessel sharpness or qualitative image scores were observed with respect to the conventional method. Simple averaging resulted in an SNR gain, but significant loss in vessel sharpness and image quality. For late gadolinium enhancement, there was a significant increase in SNR, but no significant differences were observed in subjective image quality scores between the proposed and conventional methods. There was an SNR gain, but image quality loss for simple averaging, when compared with the conventional technique. In both coronary MRI and late gadolinium enhancement, the SNR gain of the proposed method was not significantly different than the maximum theoretical SNR gain. The proposed technique improves SNR using the additional information from NAV-rejected k-space lines, while providing similar image quality to standard reconstruction using motion-free k-space data only, with no increase in scan time.

Mapping of Electron-Hole Excitations in the Charge-Density-Wave System1T−TiSe2Using Resonant Inelastic X-Ray Scattering

In high-resolution resonant inelastic x-ray scattering at the Ti L edge of the charge-density-wave system 1T-TiSe(2), we observe sharp low energy loss peaks from electron-hole pair excitations developing at low temperature. These excitations are strongly dispersing as a function of the transferred momentum of light. We show that the unoccupied bands close to the Fermi level can effectively be probed in this broadband material. Furthermore, we extract the order parameter of the charge-density-wave phase from temperature-dependent measurements.

The reliability of musculoskeletal ultrasound in the detection of cartilage abnormalities at the metacarpo-phalangeal joints

To assess the reliability of ultrasound (US) in detecting cartilage abnormalities at the metacarpo-phalangeal (MCP) joints in people with cartilage pathology. Nine expert ultrasonographers initially achieved consensus on definitions and scanning protocols. They then examined the second to fifth MCP joints of the dominant hand of eight people with hand osteoarthritis (OA). US examinations were conducted in two rounds, with independent blinded evaluations of cartilage lesions. Global cartilage abnormalities were assessed by applying a dichotomous (presence/absence) score; in addition, the following lesions were evaluated using the same scoring system: loss of anechoic structure and/or thinning of the cartilage layer, and irregularities and/or loss of sharpness of at least one cartilage margin. Reliability was assessed using kappa (k) coefficients. Thirty-two joints were examined. Intra-observer k values ranged from 0.52 to 1 for global cartilage abnormalities; k values ranged from 0.54 to 0.94 for loss of anechoic structure and/or thinning of cartilage layer and from 0.59 to 1 for irregularities and/or loss of sharpness of at least one cartilage margin. Values of k for inter-observer reliability were 0.80 for global cartilage abnormalities, 0.62 for loss of anechoic structure and/or thinning of cartilage layer, and 0.39 for irregularities and/or loss of sharpness of at least one cartilage margin. US is a reliable imaging modality for the detection of cartilage abnormalities in patients with cartilage pathology in the MCP joints. The analysis of specific cartilage measures showed more variable results that may be improved by modifying definitions and further standardization of US techniques.

State ownership and bank equity in the Asia-Pacific region

Our study examines the effectiveness of worldwide banking regulations and government involvement in providing a balanced risk–reward trade-off to bank shareholders during both normal time periods and the periods of financial crisis. Ownership structure varies across world regions with government holding bigger stakes in the Asia-Pacific region and Latin America than in North America. Partial state ownership of banks, particularly in the Asia-Pacific region, helped avoid sharp losses during financial crises without sacrificing returns in normal periods. The restrictions on the types of activities reduce bank riskiness and wealth losses during the crisis period but they also stifle innovations and returns during normal time periods.

CURRENT OPPORTUNITIES OF SONOGRAPHIC DIAGNOSTICS TIBIAL OSTEOCHONDROMAS

Osteochondroma is the most common tumor of the skeleton. Its frequency is more than 40% of benign and at least 20% of all human bone tumors. The objective of this study was to improve methods of diagnostics of shin bone osteochondromas with using of modern imaging techniques. There were treated 81 patients with primary tibia osteochondroma and one with a secondary chondrosarcoma during the period from 2000 to 2011 in the Clinic of Traumatology and Orthopedics of the Astrakhan Medical Academy Diagnostics was based on the data of anamnesis, physical examination, standard X-rays and computed tomography. We applied ultrasound studies of shin bones in 11 patients. The ultrasonography has allowed revealing two main forms of osteochondromas: “globular-shaped” and “hill-shaped”. The tumor goes into the third “cauliflower-shaped” form in the case of malignant transformation. The distribution of the cartilage on the osteochondroma surface is irregular and depends on the tumor shape. The indirectly malignant signs are the loss of sharpness and smoothness of the contour, hyperechoic inclusions in the cartilage cap.

Attempted immunotherapy for Mycobacterium tuberculosis with viral and protein vaccines based on Ag85B-ESAT6 in a mouse model

The increasing threat of drug-resistant strains of Mycobacterium tuberculosis (M. tb) and co-infection with human immunodeficiency virus (HIV) has worsened the international public health crisis and challenged conventional chemotherapy. Therapeutic vaccines, which possess the capacity to stimulate the immune system and affect the disease progression, deserve reconsideration to aid chemotherapy. Vaccines based on Ag85B-ESAT6 fusion protein were tested as potential immunotherapeutic vaccines against ongoing intravenous infection in a mouse model. Therapeutic efficacy was evaluated by enumeration of bacilli in infected tissues and by histological examination of the lungs. Ag85B-ESAT6 with the adjuvant dimethyl dioctadecylammonium bromide (DDA) - monophosphoryl lipid A (MPL) did not reduce bacterial load, however induced a sharp weight loss and worsened pathology. Recombinant virus-based vaccines failed to protect mice against tuberculosis either. More efforts should be taken to search for protective candidates and elucidate the mechanism for immunotherapy.

Three Dimensional Simulation of Transfer Process

A three-dimensional calculation of a first transfer subsystem in an electrophotograpy is carried out and toner scatterings on a transfer belt are simulated. This simulation consists of an electric field calculation and a toner movement calculation. In order to estimate electric field precisely, Boundary Fitted Coordinate (BFC) is used for the finite deference method to consider shapes of a photoconductor drum and rollers. To calculate force on a toner in detail, force from electric field, discharge phenomenon, resistivity of materials and toner adhesion force are considered. A toner detaches from the photoconductor and begins to move downward to the belt when the force on the toner is greater than adhesion force between the toner and the photoconductor. Toner movement is calculated according to Newton's law of motion and the dot image on the belt is simulated. Toner scatterings, which result in a loss of sharpness and resolution, are recognized around the peripheral of the dot. The simulation shows that toner scattering formation arises from the toner jumping across the transfer gap before the photoconductor contacts the belt. The effects of transfer parameters on toner scatterings are investigated with the simulation. To suppress toner scattering, the position of the roller, transfer bias, and the resistivity of the belt should be optimized to create an appropriate electric field distribution and to realize that the toner transfer happens in a small gap or in a contact nip with the photoconductor and the belt.