Thermophysical Phenomena Associated With Nano-Droplet Impingement on a Solid Surface

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Geoffrey M. Haas ◽  
Aaron P. Wemhoff
Keyword(s):  
Kinetic Energy ◽  
Solid Surface ◽  
Collision Energy ◽  
Temperature Jump ◽  
Md Simulations ◽  
Entire Group ◽  
Small Droplet ◽  
Droplet Impingement ◽  
Significant Difference ◽  
Bulk Speed

The thermophysical properties pertaining to the impingement of a nano-droplet onto a solid surface were investigated using molecular dynamics (MD) simulations. The MD simulations used data collection for an entire group of molecules to investigate the propagation of energy in the system. Simulations of a moving nano-droplet colliding with a stationary solid were performed to determine the heat transfer between the droplet and the surface. It was discovered that the droplet-substrate collision caused the droplet temperature to rise significantly upon impact. The substrate also experiences a temperature jump with a slower response time. A theoretical relation for the substrate temperature jump is also developed that shows reasonable agreement with the MD simulations for small droplet diameters. Increasing the diameter of the droplet from 2.0 nm to 4.5 nm showed a gain in the total added substrate kinetic energy. Varying the initial speed of the droplet from 10 m/s to 40 m/s showed no significant difference in the applied kinetic energy onto the substrate, suggesting that the acceleration of the droplet toward the surface due to intermolecular interactions produces an impact speed relatively independent of the initial droplet bulk speed. These trends were also reflected in a thermodynamically based simple theoretical prediction of collision energy, which was shown to be accurate for droplet diameters up to 3.5 nm. The collision energy was estimated to be on the order of 1–10 eV, and the applied heat flux is on the order of GW/m2.

Nano-Droplet Impingement Heat Transfer on a Solid Surface

2010 ◽  
Author(s):  
Geoffrey Haas ◽  
Aaron P. Wemhoff
Keyword(s):  
Solid Surface ◽  
Md Simulations ◽  
Maximum Efficiency ◽  
Attractive Alternative ◽  
Droplet Impingement ◽  
Nano Scale ◽  
Simulation Techniques ◽  
Impingement Heat Transfer ◽  
Alternative Approach ◽  
Cooling Methods

The reduction of electronic components towards the nano-scale drives the development of novel cooling methods to keep up with the increasing thermal demands of the electronics industry. Since transistor dimensions are shrinking to the order of 1–10 nm, pinpointed cooling may be required for maximum efficiency. Many nano-scale cooling methods are difficult to observe in direct experimentation, so simulation techniques present an attractive alternative approach. In this respect, molecular dynamics (MD) simulations of nano-droplet impingement on a solid surface is being investigated as a potential means for pinpointed cooling. Various observations of thermophysical phenomena associated with the impingement are discussed, including the temperature rise at the collision point, the acceleration of the droplet prior to impact, and and the ordering of molecules in the liquid due to the influence of the solid.

scholarly journals Radiooncological View on Therapy Outcome after Multidisciplinary Treatment of Sinonasal Tumors

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2364
Author(s):  
Olena Klymenko ◽  
Anna Maria Stefanie Buchberger ◽  
Barbara Wollenberg ◽  
Klaus-Dietrich Wolff ◽  
Victoria Kehl ◽  
...  
Keyword(s):  
Tumor Volume ◽  
Multidisciplinary Treatment ◽  
Treatment Strategies ◽  
Entire Group ◽  
Sinonasal Carcinoma ◽  
Volume Delineation ◽  
Sequential Boost ◽  
Significant Difference ◽  
Integrated Boost ◽  
Primary Focus

Purpose: We report the outcome of a mono-institutional retrospective study of sinonasal carcinoma with the primary focus on GTV (gross tumor volume) and the effect of radiotherapy. Methods: 53 patients with sinonasal carcinoma and that of the nasal cavity, paranasal sinus or both except lymphoma were included. All patients were treated between 1999 and 2017. For tumor volume delineation, all pre-therapeutic images were fused to the planning CT (computed tomography). Results: The median follow-up was 17 months [0.3–60], the median age 60 years, 35 males and 18 females were included. Squamous cell carcinoma (SCC) (60.4%) was the predominant histology, followed by adenocarcinoma (15.1%). The mean composite OS (overall survival) time was 33.3 ± 3.5 months. There was no significant difference in the 5 y composite OS between tumor localization or radiotherapy setting. The simultaneous integrated boost concept showed a trend towards improving five-year composite OS compared to the sequential boost concept. The only factor with a significant impact on the 5 y composite OS rate was the pre-therapeutic GTV (cutoff 75 cm3; p = 0.033). The GTV ≥ 100 cm3 has no effect on the 5 y composite OS rate for SCC. Conclusions: The pre-therapeutic GTV is a prognostic factor for five-year composite OS for the entire group of patients with sinonasal tumors, influencing the outcome after completion of all treatment strategies. The GTV seems to not influence five-year composite OS in SCC. For this rare tumor entity, an intensive, multidisciplinary discussion is essential to finding the best treatment option for the patient.

Fragmentation of alkoxide ions following collisional activation. An energy-resolved study

1988 ◽  
Vol 66 (11) ◽  
pp. 2947-2953 ◽  
Author(s):  
Roger S. Mercer ◽  
Alex G. Harrison
Keyword(s):  
Kinetic Energy ◽  
Collisional Activation ◽  
Collision Energy ◽  
Relative Importance ◽  
Elimination Reaction ◽  
Proton Abstraction ◽  
Relative Stabilities ◽  
Collisionally Activated Dissociation ◽  
Reaction Channels ◽  
Alkane Elimination

The collisionally activated dissociation reactions of the C2 to C5 alkoxide ions have been studied for collisons occurring at 8 keV kinetic energy and also over the range 5 to 100 eV kinetic energy. The alkoxide ions fragment by 1,2-elimination of H2 and/or an alkane. Thus, primary alkoxide ions fragment by elimination of H2 only, secondary alkoxide ions show elimination of H2 and alkane molecules, while tertiary alkoxide ions show elimination of alkanes only. In alkane elimination, loss of CH4 is much more facilie than loss of larger alkanes. For secondary alkoxide ions, where more than one elimination reaction occurs, the energy dependence of fragmentation has been explored over the collision energy range 5 to 100 eV. The results are interpreted in terms of a step-wise mechanism involving formation of an anion-carbonyl compound ion-dipole complex, followed by proton abstraction by the H− or alkyl anion leading to the final products. The relative importance of the reaction channels is determined by the relative stabilities of these ion-dipole complexes.

Effect of Hydroxychloroquine on the Lipid Profile of Patients with Sjögren Syndrome

2014 ◽  
Vol 41 (5) ◽  
pp. 902-908 ◽  
Author(s):  
Michail P. Migkos ◽  
Theodora E. Markatseli ◽  
Chrisoula Iliou ◽  
Paraskevi V. Voulgari ◽  
Alexandros A. Drosos
Keyword(s):  
Lipid Profile ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Sjögren Syndrome ◽  
Lipoprotein Cholesterol ◽  
Atherogenic Index ◽  
Entire Group ◽  
Sjogren Syndrome ◽  
Significant Difference ◽  
Changes Over Time

Objective.Many studies have highlighted the hypolipidemic action of hydroxychloroquine (HCQ). We investigated the effect of HCQ on the lipid profile of patients with Sjögren syndrome (SS).Methods.The present retrospective observational study included 71 female patients with SS treated with HCQ. The levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol, triglycerides (TG), and atherogenic index (TC/HDL) were measured at baseline, after 6 months, and 1, 3, and 5 years after initiation of HCQ treatment. Analysis to investigate changes over time was performed in the entire patient group and in the separate subgroups: those receiving (21 patients) and those not receiving (50 patients) hypolipidemic treatment.Results.For the entire group of patients a statistically significant decrease in TC was noted (levels before treatment 220 ± 41 mg/dl, and at 5 yrs 206 ± 32 mg/dl, p = 0.006). A statistically significant difference was observed in the levels of HDL (57 ± 14 mg/dl vs 67 ± 17 mg/dl, p < 0.001) and in atherogenic index (4.0 ± 1.3 vs 3.3 ± 0.9, p < 0.001). Patients not receiving a hypolipidemic agent during the same period demonstrated a decrease in TC (214 ± 40 mg/dl vs 208 ± 34 mg/dl, p = 0.049), an increase in HDL levels (55 ± 15 mg/dl vs 67 ± 18 mg/dl, p < 0.001), and a decrease in atherogenic index (4.0 ± 1.4 vs 3.3 ± 0.9, p < 0.001). In the subgroup of patients receiving hypolipidemic treatment, the respective changes in their lipid profile were not significant in the first years but became significant in the long term.Conclusion.Use of HCQ in patients with SS was related to a statistically significant decrease in TC, an increase in HDL, and improvement in the atherogenic index.

Clinical Differentiation with the Spiral Aftereffect Technique

1970 ◽  
Vol 31 (3) ◽  
pp. 995-999 ◽  
Author(s):  
John E. Obrzut ◽  
Roger C. Thweatt
Keyword(s):  
Brain Damage ◽  
Exposure Time ◽  
False Positive ◽  
Light Adaptation ◽  
False Negative ◽  
Entire Group ◽  
Significant Difference ◽  
Lighting Intensity ◽  
Organic Brain ◽  
Time Variables

The spiral aftereffect (SAE) apparatus was administered to 100 Ss, 50 independently medically diagnosed organic patients and 50 normals matched in sex and age to the first group. Each S was given standard instructions for six trials of 30-sec. exposure time. Variables, such as rate and direction of rotation, lighting intensity, light adaptation, etc., were controlled for all Ss. Scores and percentage computations of Ss in the various diagnostic groups indicate that the spiral aftereffect test has significantly differentiated between cases of organic brain damage and those who are normal ( χ2 = 42.2, p < .01, df = 1). No differences were shown between infectious vs noninfectious organics and convulsive vs nonconvulsive organics. However, there was a significant difference between prenatal organics and postnatal organics (χ2 = 21.4, P < .01, df = 1). For the entire group there were 32% false negative classifications and 8% false positive classifications.

scholarly journals Molecular Dynamics Study on Deformation Mechanism of Grain Boundaries in Magnesium Crystal: Based on Coincidence Site Lattice Theory

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ken-ichi Saitoh ◽  
Kohei Kuramitsu ◽  
Tomohiro Sato ◽  
Masanori Takuma ◽  
Yoshimasa Takahashi
Keyword(s):  
Molecular Dynamics ◽  
Deformation Mechanism ◽  
Coincidence Site Lattice ◽  
Md Simulations ◽  
Uniaxial Tensile ◽  
High Angle ◽  
Site Lattice ◽  
Embedded Atom ◽  
Significant Difference ◽  
Eam Potential

As for magnesium (Mg) alloys, it has been noted that they are inferior to plastic deformation, but improvement in the mechanical properties by further refinement of grain size has been recently suggested. It means the importance of atomistic view of polycrystalline interface of Mg crystal. In this study, to discuss the deformation mechanism of polycrystalline Mg, atomistic grain boundary (GB) models by using coincidence site lattice (CSL) theory are constructed and are simulated for their relaxed and deformatted structures. First, GB structures in which the axis of rotation is in [11¯00] direction are relaxed at 10 Kelvin, and the GB energies are evaluated. Then, the deformation mechanism of each GB model under uniaxial tensile loading is observed by using the molecular dynamics (MD) method. The present MD simulations are based on embedded atom method (EAM) potential for Mg crystal. As a result, we were able to observe atomistically a variety of GB structures and to recognize significant difference in deformation mechanism between low-angle GBs and high-angle GBs. A close scrutiny is made on phenomena of dislocation emission processes peculiar to each atomistic local structure in high-angle GBs.

Atomistic Mechanism of Ion Beam Deposition Induced Curvature Formation in Thin-Films

2007 ◽  
Author(s):  
Sachin S. Terdalkar ◽  
Sulin Zhang ◽  
Joseph J. Rencis
Keyword(s):  
Kinetic Energy ◽  
Incident Energy ◽  
Ion Beam ◽  
Md Simulations ◽  
Stress Generation ◽  
Intrinsic Stress ◽  
Graphene Sheets ◽  
High Incident Energy ◽  
Upward Deflection ◽  
Generation Mechanisms

Molecular dynamics (MD) simulations are performed to study the stress generation mechanisms in cantilever graphene sheets impacted by energetic carbon neutrals. The carbon-carbon interactions are described by the Tersoff-Brenner potential [1]. The MD simulations show that the free-end deflection of the graphene sheets is strongly dependent on the kinetic energy of the incident ions. At low incident energy (<<10eV), the free end bends towards to the side on which ions are deposited (upward deflection); at high incident energy, the free end bends away from the side on which the ions are deposited (downward deflection). The downward deflection reaches its maximum at around 50 eV, beyond which the downward deflection decreases with increasing incident energies. In addition, the evolution of the free-end deflection in terms of the number of deposited atoms is also dependent on the kinetic energy of the incident ions. These numerical observations suggest that intrinsic stress of different levels in the graphene sheets is generated. A close examination of the microstructures of the grown films indicates that the generated stress can be attributed to a competing mechanism of the production and annihilation of vacancy-like and interstitial-like defects in the films.

Stem Cell Transplantation from Mismatched Related Donors for Paediatric Haematological Disorders : The Hospital for Sick Children, Toronto, Experience.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 5168-5168
Author(s):  
Gary Nicolin ◽  
Prabodh Das ◽  
Elizabeth McDougall ◽  
Adam Gassas ◽  
Lillian Sung ◽  
...  
Keyword(s):  
Stem Cell ◽  
Chronic Gvhd ◽  
Hla Typing ◽  
Entire Group ◽  
Molecular Technique ◽  
Cell Transplant ◽  
Significant Difference ◽  
Haematological Disorders ◽  
Sick Children ◽  
Cd34 Selection

Abstract Between June 1994 and December 2003, 31 patients with haematological disorders presenting at the Hospital for Sick Children, Toronto, Canada, received a stem cell transplant (SCT) from a mismatched related donor. Diagnoses included ALL (15), AML (10), CML (1), JMML (1), SAA (2), de novo MDS (1) and Fanconi anaemia (1). Patients were aged between 0.9 to 17.8 years (mean 8.5 years). There were 20 males and 11 females. HLA typing included A, B and DRB1 on all patients (Class 1 alleles by low resolution molecular technique and Class 2 by high resolution technique). 22 patients had 1 major mismatch and 9 had 2–3 major mismatches. The source of stem cells was bone marrow in 15 patients (mean total nucleated cell dose 4.44 x 108/kg, range 1.89–6.63), peripheral blood (PBSC) in 15 patients (mean CD34 dose 11.80 x 106/kg, range 3.19–42.18) and one patient received both BM and PBSC. Of those who received PBSC, 9 had CD34 selection, 3 had CD34 selection and T-cell depletion, and 3 received an unmodified product. Conditioning regimens included cyclophosphamide and total body irradiation (TBI) (15), etoposide and TBI (6), busulfan and cyclophosphamide (6), etoposide and cyclophosphamide (1), fludarabine, cyclophosphamide and TBI (1), fludarabine and cyclophosphamide (1) and fludarabine, melphalan and thiotepa (1). Graft versus host disease (GvHD) prophylaxis included combinations of cyclosporine A, methotrexate, anti-thymocyte globulin and methylprednisolone. There was one primary graft failure and 3 secondary graft failures. Mean time to neutrophil engraftment was 17 days (range 9–36). The incidence of acute and chronic GvHD was 48% and 51% respectively. Of the 31 patients, 15 are alive (12 in complete remission (one of these with a secondary brain tumour) and 3 with relapsed disease) and 16 are dead (3 of relapsed progressive disease, 12 from transplant related mortality (TRM - 9 of these were in CR) and in one the cause is not known). Three year actuarial OS and EFS for the entire group were 50±9% and 45±9%, OS and EFS for those matched at 5/6 loci were 56±11% and 44±11% and OS and EFS for 3/6 and 4/6 matched were 38±16% and 36±16%. The mean follow-up time for survivors is 5.6 years (range 11.6 months to 9.7 years). In this series, there was no significant difference in survival when comparing BM vs. PBSC harvests; in one vs. 2–3 mismatch donors; and in the presence vs. absence of acute or chronic GvHD. These results confirm the feasibility and efficacy of using mismatched related donors for paediatric haematological disorders. Steps should be taken to decrease the TRM to achieve a better survival rate.

Acute Leukemia in Patients Sixty Years of Age and Older: A Retrospective Review.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4605-4605
Author(s):  
Chantal S. Leger ◽  
Ann Lee ◽  
Heather A. Leitch ◽  
Paul F. Galbraith ◽  
Charles H. Li ◽  
...  
Keyword(s):  
Acute Leukemia ◽  
Treatment Outcomes ◽  
Induction Chemotherapy ◽  
De Novo ◽  
Disease Free Survival ◽  
Retrospective Chart Review ◽  
Prolonged Survival ◽  
Entire Group ◽  
Secondary Leukemia ◽  
Significant Difference

Abstract Acute leukemia, especially acute myeloid leukemia (AML), occurs more frequently in the elderly population. Treatment outcomes for this condition have traditionally been poor and very few patients survive for prolonged periods following diagnosis. We performed a retrospective chart review of all patients sixty years of age and older diagnosed with acute leukemia at St. Paul’s hospital, Vancouver, Canada, from June 1984 to July 2004. One hundred and three patients were diagnosed with acute leukemia [AML- 81; ALL- 15; ALN (acute leukemia not otherwise specified)- 7]. The median age was 72 (range 60–88) years. Fifty-seven (55%) and 46 (45%) patients had de novo and secondary leukemia, respectively. Sixteen patients (28%) had an unfavourable karyotype. Fifty-three patients (51%) received induction chemotherapy (treated) and 50 (49%) were provided with supportive care only (untreated). Treated patients were younger [67 years (60–79)] than untreated patients [76 years (61–88)], (p<0.0001), and no patients >/= 80 years were treated (n=17). Of the treated patients, 33 (62%) achieved a complete remission (CR), 10 (19%) had resistant disease and 10 (19%) died from complications related to treatment. The median overall survival for the entire group was 103 (1–1229) days, and for treated versus untreated patients was 216 (1–1213) and 38 (2–1229) days, respectively (p=0.0021). The disease free survival in treated patients achieving a CR (n=33) was 262 days (9–722). Less than 5% of patients were alive at 4 years from diagnosis. Univariate variables predictive of prolonged survival included receiving induction chemotherapy (p=0.0027), de novo as opposed to secondary leukemia (p=0.0420), and younger age, with a relative increase in death in older subgroups (60–69, 70–79, 80+), (p=0.0311). Induction chemotherapy was the only independent predictor of prolonged survival in multivariate analysis (p=0.0027). There was no statistically significant difference in the number of treated patients and treatment outcomes between 1984–1993 and 1994–2004. In conclusion, this single-institution series of 103 patients aged sixty years and older with acute leukemia, shows that the prognosis of this disease in older patients is extremely poor. Even though induction chemotherapy seems to prolong survival in patients who are fit to receive treatment, the prognosis remains grim and most patients ultimately die of leukemia, supporting a role for investigational regimens focusing solely on this age group. It is no longer appropriate to follow regimens that have remained largely unsuccessful and unchanged over 20 years.

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