Steady State and Transient Computational Study of Multiple Hydrokinetic Turbines

Computational fluid dynamics (CFD) simulations have been conducted for different configurations of pre-designed multiple hydrokinetic turbines. The turbines are modeled physically within the fluid domain instead of low fidelity actuator lines or actuator disk modeling approaches. The turbulence model, k-ω Shear Stress Transport (SST) was employed to resolve turbulent flow field. The primary focus of this study is to investigate transient behavior of multiple turbines and providing solutions to enhance downstream turbine performance in close proximity to the upstream turbine wake. The wake interaction behind the upstream turbine reduces downstream turbine performance with inline configurations being the most severe cases. One of the many suggested solutions is staggering downstream units beyond the wake region. Other solutions for an inline array: increasing the longitudinal distance between units and modifying downstream turbine rotation speed to move turbine operation point to the best efficiency point.The CFD simulations revealed that the upstream turbine power generation is nearly the same with the single unit power generation for each multiple turbine arrangement. The downstream turbine relative power obtained was 0.18 for the unit placed inline and 0.98 when it was placed outside the wake region. For inline configurations, increasing the stream-wise spacing between the units from 6Dt to 10Dt improved relative power from 0.16 to 0.60, while reducing the rotation speed from 150 rpm to 100 rpm resulted relative power increment from 0.24 to 0.55

Large eddy simulations of ventilated micro-hydrokinetic turbine and pump-turbines

Large eddy simulations of ventilated hydrokinetic turbine and pump-turbine are conducted. The mathematical modeling of oxygen dissolution and the flow model employed were validated by comparing predicted dissolved oxygen concentration against reported experimental measurements. A parametric study is performed to investigate the influence of interfacial forces, surface tension and bubble breakage and coalescence terms. It is demonstrated that aeration via hydrokinetic turbines can be used to improve the dissolved oxygen level in rivers for better water quality. It is also shown that aeration can effectively be achieved via the pump-turbine system to provide the desired dissolved oxygen level for the microorganisms’ growth during the wastewater treatment process. Air injection is applied to the wake region of each unit. The influence of aeration on the turbine performance, flow induced vibration and oxygen dissolution characteristics are investigated. The numerical predictions reveal that the aeration can be utilized in both hydro systems without experiencing a significant penalty in power generations. Aeration significantly reduces the flow induced vibration in the pump turbine system. The pressure pulsation on the draft tube surface of the pump-turbine is reduced significantly with both central and peripheral aeration. In hydrokinetic turbine, the variation in the standard deviation of power, which is related to the vibration of the turbine unit, is strongly dependent on the turbine operating conditions. Draft tube aeration provided 30% greater amount of dissolved oxygen and 3.2 times higher dissolution efficiency inside the draft tube as compared to the central aeration. The mathematical approaches and the numerical methods employed here can be used to design and optimize the aeration process in these systems

The effect of doxorubicin on rats that received toxic and carcinogenic benzo(a)pyrene.

Benzo(a)pyrene (B(a)P) is a polycyclic aromatic hydrocarbon with carcinogenic and toxic effects. Doxorubicin is a DNA-interacting drug widely used in chemotherapy. In the present study we investigated the effects of doxorubicin on rats that received benzo(a)pyrene. Sprague-Dawley male rats, 3-4 months old, were divided into 5 groups (n=9 per group). Group 1 (controls) received normal saline intraperitoneally (i.p.) and intragastrically (i.g.), Group 2 (controls) similarly received corn oil i.p. and i.g., Group 3 received corn oil soluble benzo(a)pyrene (10mg/kg b.wt every 10 days for 40 days), Group 4 received doxorubicin (4 mg i.p. on 3 consecutive days), Group 5 received doxorubicin for 3 days (as in group 4) followed by benzo(a)pyrene as in group 3. After twenty-four hours urine samples were collected, heart blood, liver and kidney tissue samples were obtained. Biochemical data were evaluated on urine and blood; liver and kidney tissue samples were investigated histologically. Uric acid, urine creatinine, creatine clearance, urea nitrogen, serum creatinine values, serum glutamic oxaloacetic transaminase (SGOT, AST), serum glutamic pyruvic transaminase (SGPT, ALT), alkaline phosphatase (ALP, AP), superoxide dismutase (SOD), catalase (CAT) activities and malondialdehyde (MDA) levels were significantly different in the 3rd group compared with control groups. Most of the parameters group 5 were statistically similar to control values. Histological appearance of the liver and the kidney tissue samples supported the improvement in the 5th group. The result of our study indicated that liver and kidney functions impaired with benzo(a)pyrene may be partially restored by doxorubicin

Designing a Rear Wing for Binghamton\u27s Formula Race Car: From Small-Scale Simulations and Experiments to Full-Scale Manufacturing

Binghamton\u27s Formula Society of Automotive Engineers (FSAE) designed an aerodynamically efficient rear wing with three airfoils for their new electric vehicle (EV) to improve lap time. They used an integral model, JavaFoil, to determine the size and configuration of each airfoil. Over 4,000 simulations were conducted to determine the optimal spacing and angle of attack for each airfoil to achieve the best downforce. The results were confirmed through computational fluid dynamics (CFD) simulations and experiments at the AEROLAB Wind Tunnel. The final configuration was manufactured using a manual wet layup technique for epoxy resin and carbon fiber. The rear wing assembly will be installed on the 2023 FSAE EV vehicle, which will compete in June 2023 at the Michigan International Speedway. The findings and insights gained from this project will not only assist future aerodynamics teams at Binghamton Motorsports but will also benefit other FSAE teams.https://orb.binghamton.edu/research_days_posters_2023/1033/thumbnail.jp

Reproductive Outcome After Surgical Treatment of Endometriosis – Retrospective Analytical Study

Objective: The aim of the study was to investigate the reproductive outcomes of patients after surgical treatment of endometriosis. Material and Methods: The study included 100 infertile women, aged 21 to 41 years, who underwent surgical treatment of endometriosis. From January 2007 to January 2012, excision of endometriosis was performed by operative laparoscopy or laparotomy. Demographic, clinical, surgical and reproductive outcomes of 52 patients were retrospectively analyzed. Result: Twenty-three pregnancies (44%) were obtained in 52 patients, resulting in 16 term pregnancies, 4 spontaneous abortions under 16 weeks gestation, 2 spontaneous abortions at 20 gestational weeks and 1 ectopic pregnancy. Twenty nine patients did not achieve pregnancy and 68.9% (20/29) of them were treated with IVFICSI. Spontaneous pregnancies were obtained within 7 months after the surgery, whereas IVF-ICSI pregnancies were obtained within the period of 11 months. Seven patients were stage I, 14 patients stage II, 19 patients stage III, and 12 patients stage IV according to the American Fertility Society (AFS) Classification of Endometriosis. The pregnancy rate was 57% in stages I-II, 47% in stage III, 16% in stage IV endometriosis; and the rate of term pregnancies was 83%, 66%, and 0%, respectively. Seven pregnancies (7/14) were obtained in patients with bilateral endometriosis and 5 of them resulted in term pregnancy. Sixteen pregnancies (16/38) were obtained in patients with unilateral endometriosis and 11 of them resulted in term pregnancy. Conclusion: After surgical treatment of endometriosis, the pregnancy and live birth rates seem to be improved. Reproductive outcome is closely associated with the AFS score. Bilaterality of endometriosis does not affect pregnancy outcome

Wpływ hormonalnej terapii zastępczej oraz tamoxifenu na depresję u szczurów poddanych usunięciu jajników

Objectives: To determine the effects of tamoxifen and hormone replacement therapy in order to assess their role in depressive behavior. Material and Methods: Different protocols of hormone replacement therapies were administered to surgically ovariectomized rats. Intact rats were used for tamoxifen experiments. Properly assigned control groups were used and cognitive processes were studied on animal models of surgical menopause using the Porsolt Forced Swim Test and locomotor activity experiments. Results: In the tamoxifen experiments, an interaction between treatment and days did not reach statistical significance, but indicated a trend in this direction [F(1,26)=3.557, p=0.071]. The number of repeated movements significantly decreased after the Porsolt test (F(1,44) = 8.483, PCel: Określenie wpływu tamoxifenu oraz hormonalnej terapii zastępczej celem oceny ich roli w zachowaniach depresyjnych. Materiał i metody: Różne protokoły hormonalnej terapii zastępczej zastosowano u szczurów poddanych chirurgicznemu usunięciu jajników. Tamoxifen podawano szczurom, których nie operowano. Wykorzystano odpowiednio dobraną grupę kontrolną. Zbadano procesy poznawcze na modelach zwierzęcych z chirurgiczną menopauzą przy pomocy testu Porsolt Forced Swim oraz doświadczeń aktywności ruchowej. Wyniki: W doświadczeniach z tamoxifenem, związek pomiędzy terapią a dniami nie osiągnął statystycznej istotności, ale wykazał trend w tym kierunku [F(1,26)=3,557,p=0,071]. Liczba powtórzeń ruchów istotnie zmniejszyła się po teście Porsolta [F(1,44)=8,483,

Genomic alterations in low-grade, anaplastic astrocytomas and glioblastomas.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.To extend our understanding of potential stepwise genetic alterations that may underlie tumor progression from low-grade astrocytomas to glioblastomas, histopathologic and comparative genomic hybridization analyses were performed on tumor specimens from 68 primary lesions, including 40 glioblastomas, 10 anaplastic and 18 low-grade astrocytomas. The number of aberrations per case increased towards the higher grade tumors (grade II: 1.66+/-1.49; grade III: 2.80+/-1.68; grade IV: 3.02+/-1.07; F=6.955, p=0.002). A gain of 7/7q was common and the most frequently seen aberration in low-grade astrocytomas, whereas loss of 10q was the most frequently seen anomaly in anaplastic astrocytomas and glioblastomas. Chromosome 7p amplification was only detected in glioblastomas. Chromosome 10/10q deletion and combination of 1p, 19q and 17p deletions were specific to high-grade astrocytic tumors. Sequences of chromosome 7 and 10 seem to have pivotal roles in the biology of human gliomas. The genomic copy deletions of chromosomes 1p and 19q might provide an alternative mechanism in the genesis of astrocytomas

New surgical approach for late complications from spinal cord injury

BACKGROUND: The most frequent late complications in spinal cord injury result from arachnoiditis and consequent alterations in dynamics of cerebrospinal fluid flow. A surgical procedure carried out on patients with these alterations, resolved the various pathologies more efficiently in all cases. METHODS: From October 2000 to March 2006, 23 patients were selected for surgery: three showed signs of syringomyelia, three presented with microcystic lesions, three presented with arachnoid cysts in different locations but always confluent to the scar area, and 14 showed evidence of tethered cords. The surgery consisted of laminectomy at four levels, followed by dural opening in order to remove all the arachnoiditis at the level of the scar and to remove the altered arachnoid and its cysts, at least at two levels above and below the lesion. The dentate ligaments were cut at all exposed levels. RESULTS: The patients had no postoperative problems and not only retained all neurological functions but also showed neurological recovery. According to the motor and sensory scale of the American Spinal Injury Association, the recoveries were motor 20.6% (P < 0.001), touch 15.6% ((P < 0.001) and pinprick 14.4% (P < 0.001). These patients showed no signs of relapse at 4–66 month follow-up. CONCLUSION: This alternative surgery resolved the pathologies provoking neurological deterioration by releasing the complete spinal cord at the level of the scar and the levels above and below it. It thus avoids myelotomies and the use of shunts and stents, which have a high long-term failure rate and consequent relapses. Nevertheless, this surgical procedure allows patients the chance to opt for any further treatment that may evolve in the future